Population and particle decay of isobaric analog states in medium heavy nuclei

International Nuclear Information System (INIS)

Gales, S.

1980-05-01

The systematic features of proton stripping and neutron pick-up reactions to Isobaric Analog States in medium heavy nuclei are presented. The ( 3 He,d) reaction investigated at high incident energy is shown to selectively excite high-spin particle-analog states. Similarly the ( 3 He,α) reaction populates hole-analog states. The recent results related to such highly excited states in a wide range of nuclei ( 48 Ca to 208 Pb) are discussed in the framework of the DWBA theory of direct reactions with special emphasis on the treatment of unbound proton states or deeply-bound neutron hole states. The particle decay of Isobaric Analog States are investigated using the ( 3 He,d p) and ( 3 He, α p) sequential processes. The experimental method developed at Orsay (0 0 detection) for particle-particle angular correlations is presented. The advantage and the limits of such approach are illustrated by typical examples of particle decays: core-excited states, neutron particle-hole multiplets and the first observation of the proton emission of hole-analog levels. In conclusion new experimental approaches such as asymmetry measurements for analog states observed in transfer reactions or possible population of double analog states in heavy nuclei are discussed

Space-time description of particle creation in gravitational and electromagnetic fields

International Nuclear Information System (INIS)

Mamaev, S.G.; Trunov, N.N.

1983-01-01

The dynamics of the creation of pairs of particles from the vacuum in strong time-dependent external fields is studied. The space-time correlation function of the pair is determined. An analysis of the behavior of this function allows one, in particular, to study the pair-creation process, to distinguish between real and virtual particles, etc

Entropy generation in cosmological particle creation

International Nuclear Information System (INIS)

Castagnino, M.A.; Gaioli, F.H.; Sforza, D.M.

1996-01-01

A very simplified model of the Universe is considered in order to propose an alternative approach to the irreversible evolution of the Universe at very early times. The entropy generation at the quantum stage can be thought of as a consequence of an instability of the system. Then particle creation arises from this instability

On particle creation by a time-dependent scalar field

International Nuclear Information System (INIS)

Dolgov, A.D.; Kirilova, D.P.

1989-01-01

The probability of particles creation by a homogeneous scalar field Χ (t) is calculated. Explicit analytical expressions are obtained in two limiting cases in the quasiclassical approximation and in the framework of perturbation theory. In the case when the mass of the created particles is defined by the time-dependent field Χ (t) according to the expression g Χ (t) Ψ-barΨ, where Χ (t) =Χ 0 cos (ωt), it is shown that the creation probability is suppresed not exponentially, but as ω 1/2 . Some cosmological consequences of the results are discussed. 13 refs

Particle creation and reheating in a braneworld inflationary scenario

Science.gov (United States)

Bilić, Neven; Domazet, Silvije; Djordjevic, Goran S.

2017-10-01

We study the cosmological particle creation in the tachyon inflation based on the D-brane dynamics in the Randall-Sundrum (RSII) model extended to include matter in the bulk. The presence of matter modifies the warp factor which results in two effects: a modification of the RSII cosmology and a modification of the tachyon potential. Besides, a string theory D-brane supports among other fields a U(1) gauge field reflecting open strings attached to the brane. We demonstrate how the interaction of the tachyon with the U(1) gauge field drives cosmological creation of massless particles and estimate the resulting reheating at the end of inflation.

Erratum: Erratum to: Thermodynamic implications of the gravitationally induced particle creation scenario

Science.gov (United States)

Saha, Subhajit; Mondal, Anindita

2018-04-01

We would like to rectify an error regarding the validity of the first law of thermodynamics (FLT) on the apparent horizon of a spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) universe for the gravitationally induced particle creation scenario with constant specific entropy and an arbitrary particle creation rate (see Sect. 3.1 of original article)

Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' Particle Creation

Science.gov (United States)

Amoroso, Richard L.

Modeling the `creation/emergence' of matter from spacetime is as old as modern cosmology itself and not without controversy within each model such as Static, Steady-state, Big Bang or Multiverse Continuous-State. In this paper we present only a brief primitive introduction to a new form of `Exciplex-Zitterbewegung' dual space-antispace vacuum Particle Creation applicable especially to Big Bang alternatives which are well-known but ignored; Hubble discovered `Redshift' not a Doppler expansion of the universe which remains the currently popular interpretation. Holographic Anthropic Multiverse cosmology provides viable alternatives to all seemingly sacrosanct pillars of the Big Bang. A model for Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' particle creation has only become possible by incorporating the additional degrees of freedom provided by the capacity complex dimensional extended Yang-Mills Kaluza-Klein correspondence provides.

Particle creation by a black hole as a consequence of the Casimir effect

International Nuclear Information System (INIS)

Nugayev, R.M.

1987-01-01

Particle creation by a blackhole is investigated in terms of temperature corrections to the Casimir effect. The reduction of the Hawking effect to more familiar effects observed in the laboratory enables us to reveal the mechanism of particle creation. The blackbody nature of the Hawking radiation is due to the interaction of virtual particles with the surface of a ''cavity'' formed by the Schwarzschild gravitational field potential barrier. These particles are ''squeezed out'' by the contraction of the potential barrier and appear to an observer at J + as the real blackbody ones. (orig.)

Particle Creation in Oscillating Cavities with Cubic and Cylindrical Geometry

Science.gov (United States)

Setare, M. R.; Dinani, H. T.

2008-04-01

In the present paper we study the creation of massless scalar particles from the quantum vacuum due to the dynamical Casimir effect by oscillating cavities with cubic and cylindrical geometry. To the first order of the amplitude we derive the expressions for the number of the created particles.

On the creation of scalar particles in some anisotropic universe

International Nuclear Information System (INIS)

Nariai, Hidekazu.

1978-01-01

Because of an importance of the particle creation (especially, its possible fulfilment of the black-body law with a definite temperature) in an early universe to various other cosmological problems we study how the creation of scalar particles occurs in the Bianchi-type I anisotropic universe adopted in our previous works on the quantized scalar field. It is shown that, as in a special isotropic case dealt with in recent papers, the creation may occur at the sacrifice of the requirement that the quantization procedure should reproduce the usual theory for a free field in the limit when the anisotropic universe changes into the Minkowski space-time. It is further shown that the creation occurs in accordance with the black-body law only in a 2-dimensional hyper-surface relating to the anisotropic cosmic expansion, provided that we fix two arbitrary constants appearing in a general expression for the Feynman propagator in terms of a procedure similar to that in the isotropic case. A speculation on the isotropization of our model-universe is also made from the standpoint of seeking for how the thermal equilibrium in the whole universe is attained. (auth.)

On the creation of scalar particles in some anisotropic universe

International Nuclear Information System (INIS)

Nariai, Hidekazu

1978-01-01

Because of an importance of the particle creation (especially, its possible fulfilment of the black-body law with a definite temperature) in an early universe to various other cosmological problems, we study how the creation of scalar particles occurs in the Bianchi-type I anisotropic universe adopted in our previous works on the quantized scalar field. It is shown that, as in a special isotropic case dealt with in recent papers, the creation may occur at the sacrifice of the requirement that the quantization procedure should reproduce the usual theory for a free field in the limit when the anisotropic universe changes into the Minkowski space-time. It is further shown that the creation occurs in accordance with the black-body law only in a 2-dimensional hyper-surface relating to the anisotropic cosmic expansion, provided that we fix two arbitrary constants appearing in a general expression for the Feynman propagator in terms of a procedure similar to that in the isotropic case. A speculation on the isotropization of our model-universe is also made from the standpoint of seeking the attainment of the thermal equilibrium in the whole universe. (author)

Particle swarm optimization for automatic creation of complex graphic characters

International Nuclear Information System (INIS)

Fister, Iztok; Perc, Matjaž; Ljubič, Karin; Kamal, Salahuddin M.; Iglesias, Andres; Fister, Iztok

2015-01-01

Nature-inspired algorithms are a very promising tool for solving the hardest problems in computer sciences and mathematics. These algorithms are typically inspired by the fascinating behavior at display in biological systems, such as bee swarms or fish schools. So far, these algorithms have been applied in many practical applications. In this paper, we present a simple particle swarm optimization, which allows automatic creation of complex two-dimensional graphic characters. The method involves constructing the base characters, optimizing the modifications of the base characters with the particle swarm optimization algorithm, and finally generating the graphic characters from the solution. We demonstrate the effectiveness of our approach with the creation of simple snowman, but we also outline in detail how more complex characters can be created

On particle creation by black holes. [Quantum mechanical state vector, gravitational collapse, Hermition scalar field, density matrix

Energy Technology Data Exchange (ETDEWEB)

Wald, R M [Chicago Univ., Ill. (USA). Lab. for Astrophysics and Space Research

1975-11-01

Hawking's analysis of particle creation by black holes is extended by explicity obtaining the expression for the quantum mechanical state vector PSI which results from particle creation starting from the vacuum during gravitational collapse. We first discuss the quantum field theory of a Hermitian scalar field in an external potential or in a curved but asymptotically flat spacetime with no horizon present. Making the necessary modification for the case when a horizon is present, we apply this theory for a massless Hermitian scalar field to get the state vector describing the steady state emission at late times for particle creation during gravitational collapse to a Schwarzschild black hole. We find that the state vector describing particle creation from the vacuum decomposes into a simple product of state vectors for each individual mode. The density matrix describing emission of particles to infinity by this particle creation process is found to be identical to that of black body emission. Thus, black hole emission agrees in complete detail with black body emission (orig./BJ).

Some remarks on spinor particle pair creation in alternating homogeneous external field

International Nuclear Information System (INIS)

Perelomov, A.M.

1975-01-01

It is shown that the dynamical symmetry group of the problem of spinor particle pair creation in alternating homogeneous external fields is the SO(5) group. The probability of pair creation is given by the modulus square of the matrix element of spinor representation of this group. (Auth.)

Particle creation rate for dynamical black holes

Energy Technology Data Exchange (ETDEWEB)

Firouzjaee, Javad T. [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of); University of Oxford, Department of Physics (Astrophysics), Oxford (United Kingdom); Ellis, George F.R. [University of Cape Town, Mathematics and Applied Mathematics Department, Rondebosch (South Africa)

2016-11-15

We present the particle creation probability rate around a general black hole as an outcome of quantum fluctuations. Using the uncertainty principle for these fluctuation, we derive a new ultraviolet frequency cutoff for the radiation spectrum of a dynamical black hole. Using this frequency cutoff, we define the probability creation rate function for such black holes. We consider a dynamical Vaidya model and calculate the probability creation rate for this case when its horizon is in a slowly evolving phase. Our results show that one can expect the usual Hawking radiation emission process in the case of a dynamical black hole when it has a slowly evolving horizon. Moreover, calculating the probability rate for a dynamical black hole gives a measure of when Hawking radiation can be killed off by an incoming flux of matter or radiation. Our result strictly suggests that we have to revise the Hawking radiation expectation for primordial black holes that have grown substantially since they were created in the early universe. We also infer that this frequency cut off can be a parameter that shows the primordial black hole growth at the emission moment. (orig.)

Radiation from moving mirrors: The creation and absorption of particles

International Nuclear Information System (INIS)

Castagnino, M.; Ferraro, R.

1984-01-01

A massless scalar quantized field is studied in a region bounded by two mirrors, one of which has an in-out motion. The space time is bidimensional and flat. A simple criterion is found to build motion with and without particle creation. The spectrum of the created particles is computed in some cases and conjectures on their origin are made

Particle creation and particle number in an expanding universe

International Nuclear Information System (INIS)

Parker, Leonard

2012-01-01

I describe the logical basis of the method that I developed in 1962 and 1963 to define a quantum operator corresponding to the observable particle number of a quantized free scalar field in a spatially-flat isotropically expanding (and/or contracting) universe. This work also showed for the first time that particles were created from the vacuum by the curved spacetime of an expanding spatially-flat Friedmann–Lemaître–Robertson–Walker (FLRW) universe. The same process is responsible for creating the nearly scale-invariant spectrum of quantized perturbations of the inflaton scalar field during the inflationary stage of the expansion of the universe. I explain how the method that I used to obtain the observable particle number operator involved adiabatic invariance of the particle number (hence, the name adiabatic regularization) and the quantum theory of measurement of particle number in an expanding universe. I also show how I was led in a surprising way, to the discovery in 1964 that there would be no particle creation by these spatially-flat FLRW universes for free fields of any integer or half-integer spin satisfying field equations that are invariant under conformal transformations of the metric. The methods I used to define adiabatic regularization for particle number were based on generally-covariant concepts like adiabatic invariance and measurement that were fundamental and determined results that were unique to each given adiabatic order. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker's 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’. (paper)

Effect of electromagnetic fields on the creation of scalar particles in a flat Robertson-Walker space-time

International Nuclear Information System (INIS)

Haouat, S.; Chekireb, R.

2012-01-01

The influence of electromagnetic fields on the creation of scalar particles from vacuum in a flat Robertson-Walker space-time is studied. The Klein-Gordon equation with varying electric field and constant magnetic one is solved. The Bogoliubov transformation method is applied to calculate the pair creation probability and the number density of created particles. It is shown that the electric field amplifies the creation of scalar particles while the magnetic field minimizes it. (orig.)

Will There Be Future Deceleration? A Study of Particle Creation Mechanism in Nonequilibrium Thermodynamics

Directory of Open Access Journals (Sweden)

Supriya Pan

2015-01-01

Full Text Available The paper deals with nonequilibrium thermodynamics based on adiabatic particle creation mechanism with the motivation of considering it as an alternative choice to explain the recent observed accelerating phase of the universe. Using Friedmann’s equations, it is shown that the deceleration parameter (q can be obtained from the knowledge of the particle production rate (Γ. Motivated by thermodynamical point of view, cosmological solutions are evaluated for the particle creation rates in three cosmic phases, namely, inflation, matter dominated era, and present late time acceleration. The deceleration parameter (q is expressed as a function of the redshift parameter (z, and its variation is presented graphically. Also, statefinder analysis has been presented graphically in three different phases of the universe. Finally, two noninteracting fluids with different particle creation rates are considered as cosmic substratum, and deceleration parameter (q is evaluated. Whether more than one transition of q is possible or not is examined by graphical representations.

Particle-hole calculation of the isobaric analog and isovector monopole resonances

International Nuclear Information System (INIS)

Auerbach, N.; Nguyen Van Giai

1977-06-01

The correlated proton particle-neutron hole spectrum is calculated for N>Z nuclei using a Skyrme type interaction and the response function method. The basis of the calculation is a complete one particle-one hole space with the continuum included. As a result the distribution of the isovector monopole strength in the analog nucleus is obtained. This distribution has a narrow peak which corresponds to the isobaric analog resonance and at higher energies a broad peak which is the isovector monopole resonance. The coupling between these two states is inherent in the calculation

Thermodynamics of gravitationally induced particle creation scenario in DGP braneworld

Energy Technology Data Exchange (ETDEWEB)

Jawad, Abdul; Rani, Shamaila; Rafique, Salman [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan)

2018-01-15

In this paper, we discuss the thermodynamical analysis for gravitationally induced particle creation scenario in the framework of DGP braneworld model. For this purpose, we consider apparent horizon as the boundary of the universe. We take three types of entropy such as Bakenstein entropy, logarithmic corrected entropy and power law corrected entropy with ordinary creation rate Γ. We analyze the first law and generalized second law of thermodynamics analytically for these entropies which hold under some constraints. The behavior of total entropy in each case is also discussed which implies the validity of generalized second law of thermodynamics. Also, we check the thermodynamical equilibrium condition for two phases of creation rate, that is constant and variable Γ and found its vitality in all cases of entropy. (orig.)

Thermodynamics of gravitationally induced particle creation scenario in DGP braneworld

International Nuclear Information System (INIS)

Jawad, Abdul; Rani, Shamaila; Rafique, Salman

2018-01-01

In this paper, we discuss the thermodynamical analysis for gravitationally induced particle creation scenario in the framework of DGP braneworld model. For this purpose, we consider apparent horizon as the boundary of the universe. We take three types of entropy such as Bakenstein entropy, logarithmic corrected entropy and power law corrected entropy with ordinary creation rate Γ. We analyze the first law and generalized second law of thermodynamics analytically for these entropies which hold under some constraints. The behavior of total entropy in each case is also discussed which implies the validity of generalized second law of thermodynamics. Also, we check the thermodynamical equilibrium condition for two phases of creation rate, that is constant and variable Γ and found its vitality in all cases of entropy. (orig.)

Particle creation from the vacuum by an exponentially decreasing electric field

International Nuclear Information System (INIS)

Adorno, T C; Gavrilov, S P; Gitman, D M

2015-01-01

We analyze in detail the creation of fermions and bosons from a vacuum by an electric field that exponentialy decreases in time. In our calculations, we use quantum electrodynamics (QED) and mainly consider the particle creation effect in a homogeneous electric field. To this end, we find complete sets of exact solutions of the d-dimensional Dirac equation in the exponentially decreasing electric field, and we use them to calculate all the characteristics of the effect, and specifically the total number of created particles and the probability that a vacuum will remain a vacuum. Note that the latter quantities were derived in the case under consideration for the first time. All possible asymptotic regimes are discussed in detail. In addition, switching on and switching off effects are studied. (paper)

On the creation of scalar particles in an early stage of the Friedmann closed-universe II

International Nuclear Information System (INIS)

Ishihara, Hideki; Nariai, Hidekazu.

1982-09-01

As a sequel to the previous work, the creation of scalar particles in an expanding closed-universe is studied in terms of our Feynman propagator and of fixing a pair of particle states. It is shown that the obtained spectral law for the creation of particles is identical with the previous one derived in terms of the vacuum expectation value at an initial time eta = eta sub(i) of the number operator at late time eta = eta sub(f). (author)

Particle creation in a universe filled with radiation and dust-like matter

International Nuclear Information System (INIS)

Villalba, V.M.

1993-01-01

In this article the particle creation process of scalar and spin 1/2 particles in a spatially open cosmological model associated with a universe filled with radiation and dustlike matter is analyzed. The Klein-Gordon and the Dirac equations are solved via separation of variables. After comparing the in and out vacua, we obtain that the number of created particles corresponds to Planckian and Fermi-Dirac distributions for the scalar and Dirac cases respectively. (author)

Particle creation and Dirac's large number hypothesis; and Reply

International Nuclear Information System (INIS)

Canuto, V.; Adams, P.J.; Hsieh, S.H.; Tsiang, E.; Steigman, G.

1976-01-01

The claim made by Steigman (Nature; 261:479 (1976)), that the creation of matter as postulated by Dirac (Proc. R. Soc.; A338:439 (1974)) is unnecessary, is here shown to be incorrect. It is stated that Steigman's claim that Dirac's large Number Hypothesis (LNH) does not require particle creation is wrong because he has assumed that which he was seeking to prove, that is that rho does not contain matter creation. Steigman's claim that Dirac's LNH leads to nonsensical results in the very early Universe is superficially correct, but this only supports Dirac's contention that the LNH may not be valid in the very early Universe. In a reply Steigman points out that in Dirac's original cosmology R approximately tsup(1/3) and using this model the results and conclusions of the present author's paper do apply but using a variation chosen by Canuto et al (T approximately t) Dirac's LNH cannot apply. Additionally it is observed that a cosmological theory which only predicts the present epoch is of questionable value. (U.K.)

Incorporation particle creation and annihilation into Bohm's Pilot Wave model

Energy Technology Data Exchange (ETDEWEB)

Sverdlov, Roman [Raman Research Institute, C.V. Raman Avenue, Sadashiva Nagar, Bangalore, Karnataka, 560080 (India)

2011-07-08

The purpose of this paper is to come up with a Pilot Wave model of quantum field theory that incorporates particle creation and annihilation without sacrificing determinism; this theory is subsequently coupled with gravity.

Non-minimal Particle Creation from Asymptotic-de Sitter Inflation

Science.gov (United States)

Yusofi, E.; Mohsenzadeh, M.

2018-06-01

A general form of quasi-de Sitter(dS) modes is used to study the creation of particle during the inflation. Actually, by considering the general form of inflaton field equation as a function of the Hankel function index and by using the Planck 2015 constraint on spectral index, we obtain the possible new constraints for the values of coupling constant in the era with asymptotic-dS space-time. Then, we explicitly calculate the general form of expectation value of the created particles in terms of the Hankel function index and the conformal time. The correction terms in the number of created particles are very tiny in the early time but can have the significant effects in the later universe. Our result is general and at the early time limit confirm the conventional special results for the Minkowski and dS background.

Particle creation phenomenology, Dirac sea and the induced Weyl and Einstein-dilaton gravity

Energy Technology Data Exchange (ETDEWEB)

Berezin, V.A.; Dokuchaev, V.I.; Eroshenko, Yu.N., E-mail: berezin@inr.ac.ru, E-mail: dokuchaev@inr.ac.ru, E-mail: eroshenko@inr.ac.ru [Institute for Nuclear Research, Russian Academy of Sciences, 60th October Anniversary Prospect 7a, 117312 Moscow (Russian Federation)

2017-01-01

We constructed the conformally invariant model for scalar particle creation induced by strong gravitational fields. Starting from the 'usual' hydrodynamical description of the particle motion written in the Eulerian coordinates we substituted the particle number conservation law (which enters the formalism) by 'the particle creation law', proportional to the square of the Weyl tensor (following the famous result by Ya.B. Zel'dovich and A.A. Starobinsky). Then, demanding the conformal invariance of the whole dynamical system, we have got both the (Weyl)-conformal gravity and the Einstein-Hilbert gravity action integral with dilaton field. Thus, we obtained something like the induced gravity suggested first by A.D. Sakharov. It is shown that the resulting system is self-consistent. We considered also the vacuum equations. It is shown that, beside the 'empty vacuum', there may exist the 'dynamical vacuum', which is nothing more but the Dirac sea. The latter is described by the unexpectedly elegant equation which includes both the Bach and Einstein tensors and the cosmological terms.

Creation of particles in the gravitational field and the boundary conditions for quantized fields

International Nuclear Information System (INIS)

Khrustalev, O.A.; Silaev, P.K.

1995-01-01

We prove, that if one impose the linear constraints on the quantized fields that satisfy different boundary conditions, it can leads to such a transformation between creation-annihilation operators, that corresponds to particle creation. We also prove, that the correspondence between field, quantized in Minkowski space and the field, quantized in Rindler space has Rindler space can't be observed. 7 refs

Number of particle creation and decoherence in the nonideal dynamical Casimir effect at finite temperature

International Nuclear Information System (INIS)

Celeri, L.C.; Pascoal, F.; Ponte, M.A. de; Moussa, M.H.Y.

2009-01-01

In this work we investigate the dynamical Casimir effect in a nonideal cavity by deriving an effective Hamiltonian. We first compute a general expression for the average number of particle creation, applicable for any law of motion of the cavity boundary, under the only restriction of small velocities. We also compute a general expression for the linear entropy of an arbitrary state prepared in a selected mode, also applicable for any law of motion of a slow moving boundary. As an application of our results we have analyzed both the average number of particle creation and linear entropy within a particular oscillatory motion of the cavity boundary. On the basis of these expressions we develop a comprehensive analysis of the resonances in the number of particle creation in the nonideal dynamical Casimir effect. We also demonstrate the occurrence of resonances in the loss of purity of the initial state and estimate the decoherence times associated with these resonances. Since our results were obtained in the framework of the perturbation theory, they are restricted, under resonant conditions, to a short-time approximation.

Annihilation or Creation of Particles: An Autonomous Reaction-Diffusion Process

International Nuclear Information System (INIS)

Roshani, Farinaz

2010-12-01

Annihilation or creation of particles on a D-dimensional region with boundaries is considered. Particles can be injected or extracted at the boundary as well. Two general behaviours of this system are investigated. The stationary behaviour of this system, and the dominant way of the relaxation of the system towards its stationary state. Based on the first behaviour, static phase transitions (discontinuous changes in the stationary profiles of the system) are investigated. Based on the second behaviour, dynamical phase transitions (discontinuous changes in the relaxation-times of the system) are studied. The investigation is specialized to systems in which the evolution equation of one-point functions are closed (the autonomous system). (author)

Analog and hybrid computing

CERN Document Server

Hyndman, D E

2013-01-01

Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

Thermodynamic implications of the gravitationally induced particle creation scenario

Energy Technology Data Exchange (ETDEWEB)

Saha, Subhajit [Indian Institute of Science Education and Research Kolkata, Department of Physical Sciences, Mohanpur, West Bengal (India); Mondal, Anindita [S N Bose National Centre for Basic Sciences, Department of Astrophysics and Cosmology, Kolkata, West Bengal (India)

2017-03-15

A rigorous thermodynamic analysis has been done as regards the apparent horizon of a spatially flat Friedmann-Lemaitre-Robertson-Walker universe for the gravitationally induced particle creation scenario with constant specific entropy and an arbitrary particle creation rate Γ. Assuming a perfect fluid equation of state p = (γ - 1)ρ with (2)/(3) ≤ γ ≤ 2, the first law, the generalized second law (GSL), and thermodynamic equilibrium have been studied, and an expression for the total entropy (i.e., horizon entropy plus fluid entropy) has been obtained which does not contain Γ explicitly. Moreover, a lower bound for the fluid temperature T{sub f} has also been found which is given by T{sub f} ≥ 8 (((3γ)/(2)-1)/((2)/(γ)-1)) H{sup 2}. It has been shown that the GSL is satisfied for (Γ)/(3H) ≤ 1. Further, when Γ is constant, thermodynamic equilibrium is always possible for (1)/(2) < (Γ)/(3H) < 1, while for (Γ)/(3H) ≤ min {(1)/(2), (2γ-2)/(3γ-2)} and (Γ)/(3H) ≥ 1, equilibrium can never be attained. Thermodynamic arguments also lead us to believe that during the radiation phase, Γ ≤ H. When Γ is not a constant, thermodynamic equilibrium holds if H ≥ (27)/(4) γ{sup 2}H{sup 3} (1-(Γ)/(3H)){sup 2}, however, such a condition is by no means necessary for the attainment of equilibrium. (orig.)

Thermodynamic implications of the gravitationally induced particle creation scenario

International Nuclear Information System (INIS)

Saha, Subhajit; Mondal, Anindita

2017-01-01

A rigorous thermodynamic analysis has been done as regards the apparent horizon of a spatially flat Friedmann-Lemaitre-Robertson-Walker universe for the gravitationally induced particle creation scenario with constant specific entropy and an arbitrary particle creation rate Γ. Assuming a perfect fluid equation of state p = (γ - 1)ρ with (2)/(3) ≤ γ ≤ 2, the first law, the generalized second law (GSL), and thermodynamic equilibrium have been studied, and an expression for the total entropy (i.e., horizon entropy plus fluid entropy) has been obtained which does not contain Γ explicitly. Moreover, a lower bound for the fluid temperature T f has also been found which is given by T f ≥ 8 (((3γ)/(2)-1)/((2)/(γ)-1)) H 2 . It has been shown that the GSL is satisfied for (Γ)/(3H) ≤ 1. Further, when Γ is constant, thermodynamic equilibrium is always possible for (1)/(2) < (Γ)/(3H) < 1, while for (Γ)/(3H) ≤ min {(1)/(2), (2γ-2)/(3γ-2)} and (Γ)/(3H) ≥ 1, equilibrium can never be attained. Thermodynamic arguments also lead us to believe that during the radiation phase, Γ ≤ H. When Γ is not a constant, thermodynamic equilibrium holds if H ≥ (27)/(4) γ 2 H 3 (1-(Γ)/(3H)) 2 , however, such a condition is by no means necessary for the attainment of equilibrium. (orig.)

A cosmological model with particle creation

International Nuclear Information System (INIS)

Chatterjee, Sujit

2001-01-01

A higher dimensional cosmological model is proposed where an expanding universe evolves from the vacuum fluctuation and matter creation takes place out of the gravitational energy. Choosing a particular form of the matter creation function N(t) as an initial conditions it can be shown that starting from an inflationary era the cosmos enters the higher dimensional Friedmann-like phase after a time scale when the matter creation stops

The apparent irreversibility of particle creation: A study of time scales and of the mechanisms responsible for entropy production in quantum field theory

International Nuclear Information System (INIS)

Rau, J.

1993-01-01

In the presence of strong gravitational, electromagnetic or other gauge fields, particle-antiparticle pairs are created out of the vacuum. Creation processes of this type are responsible for, e.g., hadron production in heavy ion collisions or the radiation of black holes. They lead to an increase in entropy, thus contributing to the thermalization of the system under consideration. This suggests that particle creation in strong fields is an irreversible process. Key issues to be addressed are: (1) under which conditions particle creation is indeed irreversible, and how this can be reconciled with the time-reversal invariance of the underlying microscopic dynamics: (ii) if-and if so, how-particle creation can be described within the framework of a theory of nonequilibrium processes: (iii) how the associated entropy is defined; and (iv) how particle creation can be incorporated into a kinetic equation that also accounts for subsequent acceleration and collisions. These issues are studied by means of the projection method. After a comprehensive introduction to that method, it is applied to a simple model from quantum electrodynamics which incorporates acceleration, collisions, and pair creation due to the Schwinger mechanism. For this model, the author obtains: (1) the complete set of time scales, which furnishes a precise mathematical criterion for the irreversibility of particle creation; (2) the associated relevant entropy to which the H-theorem applies; and (3) a generalization of the quantum Boltzmann equation which includes a source term derived from first principles

Inflationary Quasiparticle Creation and Thermalization Dynamics in Coupled Bose-Einstein Condensates.

Science.gov (United States)

Posazhennikova, Anna; Trujillo-Martinez, Mauricio; Kroha, Johann

2016-06-03

A Bose gas in a double-well potential, exhibiting a true Bose-Einstein condensate (BEC) amplitude and initially performing Josephson oscillations, is a prototype of an isolated, nonequilibrium many-body system. We investigate the quasiparticle (QP) creation and thermalization dynamics of this system by solving the time-dependent Keldysh-Bogoliubov equations. We find avalanchelike QP creation due to a parametric resonance between BEC and QP oscillations, followed by slow, exponential relaxation to a thermal state at an elevated temperature, controlled by the initial excitation energy of the oscillating BEC above its ground state. The crossover between the two regimes occurs because of an effective decoupling of the QP and BEC oscillations. This dynamics is analogous to elementary particle creation in models of the early universe. The thermalization in our setup occurs because the BEC acts as a grand canonical reservoir for the quasiparticle system.

Inflationary Quasiparticle Creation and Thermalization Dynamics in Coupled Bose-Einstein Condensates

Science.gov (United States)

Posazhennikova, Anna; Trujillo-Martinez, Mauricio; Kroha, Johann

2016-06-01

A Bose gas in a double-well potential, exhibiting a true Bose-Einstein condensate (BEC) amplitude and initially performing Josephson oscillations, is a prototype of an isolated, nonequilibrium many-body system. We investigate the quasiparticle (QP) creation and thermalization dynamics of this system by solving the time-dependent Keldysh-Bogoliubov equations. We find avalanchelike QP creation due to a parametric resonance between BEC and QP oscillations, followed by slow, exponential relaxation to a thermal state at an elevated temperature, controlled by the initial excitation energy of the oscillating BEC above its ground state. The crossover between the two regimes occurs because of an effective decoupling of the QP and BEC oscillations. This dynamics is analogous to elementary particle creation in models of the early universe. The thermalization in our setup occurs because the BEC acts as a grand canonical reservoir for the quasiparticle system.

Cosmological event horizons, thermodynamics, and particle creation

International Nuclear Information System (INIS)

Gibbons, G.W.; Hawking, S.W.

1977-01-01

It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological constant. An observer in these models will have an event horizon whose area can be interpreted as the entropy or lack of information of the observer about the regions which he cannot see. Associated with the event horizon is a surface gravity kappa which enters a classical ''first law of event horizons'' in a manner similar to that in which temperature occurs in the first law of thermodynamics. It is shown that this similarity is more than an analogy: An observer with a particle detector will indeed observe a background of thermal radiation coming apparently from the cosmological event horizon. If the observer absorbs some of this radiation, he will gain energy and entropy at the expense of the region beyond his ken and the event horizon will shrink. The derivation of these results involves abandoning the idea that particles should be defined in an observer-independent manner. They also suggest that one has to use something like the Everett-Wheeler interpretation of quantum mechanics because the back reaction and hence the spacetime metric itself appear to be observer-dependent, if one assumes, as seems reasonable, that the detection of a particle is accompanied by a change in the gravitational field

Analog model of a Friedmann-Robertson-Walker universe in Bose-Einstein condensates: Application of the classical field method

International Nuclear Information System (INIS)

Jain, Piyush; Weinfurtner, Silke; Visser, Matt; Gardiner, C. W.

2007-01-01

Analog models of gravity have been motivated by the possibility of investigating phenomena not readily accessible in their cosmological counterparts. In this paper, we investigate the analog of cosmological particle creation in a Friedmann-Robertson-Walker universe by numerically simulating a Bose-Einstein condensate with a time-dependent scattering length. In particular, we focus on a two-dimensional homogeneous condensate using the classical field method via the truncated Wigner approximation. We show that for various forms of the scaling function the particle production is consistent with the underlying theory in the long wavelength limit. In this context, we further discuss the implications of modified dispersion relations that arise from the microscopic theory of a weakly interacting Bose gas

Particle in a box in PT-symmetric quantum mechanics and an electromagnetic analog

Science.gov (United States)

Dasarathy, Anirudh; Isaacson, Joshua P.; Jones-Smith, Katherine; Tabachnik, Jason; Mathur, Harsh

2013-06-01

In PT-symmetric quantum mechanics a fundamental principle of quantum mechanics, that the Hamiltonian must be Hermitian, is replaced by another set of requirements, including notably symmetry under PT, where P denotes parity and T denotes time reversal. Here we study the role of boundary conditions in PT-symmetric quantum mechanics by constructing a simple model that is the PT-symmetric analog of a particle in a box. The model has the usual particle-in-a-box Hamiltonian but boundary conditions that respect PT symmetry rather than Hermiticity. We find that for a broad class of PT-symmetric boundary conditions the model respects the condition of unbroken PT symmetry, namely, that the Hamiltonian and the symmetry operator PT have simultaneous eigenfunctions, implying that the energy eigenvalues are real. We also find that the Hamiltonian is self-adjoint under the PT-symmetric inner product. Thus we obtain a simple soluble model that fulfills all the requirements of PT-symmetric quantum mechanics. In the second part of this paper we formulate a variational principle for PT-symmetric quantum mechanics that is the analog of the textbook Rayleigh-Ritz principle. Finally we consider electromagnetic analogs of the PT-symmetric particle in a box. We show that the isolated particle in a box may be realized as a Fabry-Perot cavity between an absorbing medium and its conjugate gain medium. Coupling the cavity to an external continuum of incoming and outgoing states turns the energy levels of the box into sharp resonances. Remarkably we find that the resonances have a Breit-Wigner line shape in transmission and a Fano line shape in reflection; by contrast, in the corresponding Hermitian case the line shapes always have a Breit-Wigner form in both transmission and reflection.

Particles and energy fluxes from a conformal field theory perspective

International Nuclear Information System (INIS)

Fabbri, A.; Navarro-Salas, J.; Olmo, G.J.

2004-01-01

We analyze the creation of particles in two dimensions under the action of conformal transformations. We focus our attention on Mobius transformations and compare the usual approach, based on the Bogoliubov coefficients, with an alternative but equivalent viewpoint based on correlation functions. In the latter approach the absence of particle production under full Mobius transformations is manifest. Moreover, we give examples, using the moving-mirror analogy, to illustrate the close relation between the production of quanta and energy

Pair creation of neutral particles in a vacuum by external electromagnetic fields in 2 + 1 dimensions

International Nuclear Information System (INIS)

Qiong-gui Lin; Department of Physics, Zhongshan University, Guangzhou 510275

1999-01-01

Neutral fermions of spin-1/2 with magnetic moment can interact with electromagnetic fields through nonminimal coupling. In 2 + 1 dimensions the electromagnetic field strength plays the same role to the magnetic moment as the vector potential to the electric charge. This duality enables one to obtain physical results for neutral particles from known ones for charged particles. We give the probability of neutral particle-antiparticle pair creation in a vacuum by non-uniform electromagnetic fields produced by constant uniform charge and current densities. (author)

Estimation of coincidence and correlation in non-analogous Monte Carlo particle transport - 159

International Nuclear Information System (INIS)

Szieberth, M.; Leen Kloosterman, J.

2010-01-01

The conventional non-analogous Monte Carlo methods are optimized to preserve the mean value of the distributions and therefore they are not suited for non-Boltzmann problems like the estimation of coincidences or correlations. This paper presents a general method called history splitting for the non-analogous estimation of such quantities. The basic principle of the method is that a non-analogous particle history can be interpreted as a collection of analogous histories with different weights according to the probability of their realization. Calculations with a simple Monte Carlo program for a pulse-height-type estimator prove that the method is feasible and provides unbiased estimation. Different variance reduction techniques have been tried with the method and Russian roulette turned out to be ineffective in high multiplicity systems. An alternative history control method is applied instead. Simulation results of a Feynman-α measurement shows that even the reconstruction of the higher moments is possible with the history splitting method, which makes the simulation of neutron noise measurements feasible. (authors)

On the creation of scalar particles in an early stage of the Friedmann closed-universe

International Nuclear Information System (INIS)

Ishihara, Hideki; Nariai, Hidekazu.

1982-03-01

Under impetus of the two experimental studies on neutrinos by Reines-group and Lyubimov's, it has been shown by Zel'dovich et al. that the cosmological universe is closed, provided that the neutrino masses m sub(#betta#sub(i)) (i = e, μ, tau) satisfy the inequality μ/i m sub(#betta#sub(i))c 2 >= 20 ev. In a previous paper, the senior author dealt with the creation of scalar particles in an expanding universe with non-flat 3-space, but the case of a closed universe was practically ignored owing to the situation that the positive frequency part (in the sense of the author) of a quantized scalar field is not well-defined in that universe. In view of these circumstances, the creation of scalar particles in an early stage of the Friedmann closed-universe is searched for, on the supposition that the Fulling condition is preferable to define the positive frequency part in question near the early stage (as well as the later one). (author)

Quantum creation of fermions in a hot universe

International Nuclear Information System (INIS)

Gyunter, U.; Zhuk, A.I.

1987-01-01

The creation of spinor particles in an arbitrary external field from states described by quadratic density matrices is considered. Expressions are obtained for the spectra of the created particles. It is shown that in the case of the creation of fermions (spin 1/2) in the Friedmann universe from states described by a thermal density matrix statistical effects significantly suppress the particle creation process

Particle creation by a black hole as a consequence of quantum-field effects in flat space-time

International Nuclear Information System (INIS)

Nugayev, R.M.

1985-01-01

The application of quantum-field flat-space-time results to a black hole reveals the domain and the mechanism of particle creation. The Hawking radiation is ''squeezed out'' by the tail of gravitational-field potential barrier in the [1.5 Rg, infinity] region. Its black-body spectrum is due to the interaction of virtual particles with the ''cavity'' formed by the potential barrier

Particle creation effect on M4 X S7 Kaluza-Klein cosmologies

International Nuclear Information System (INIS)

Koikawa, T.; Maeda, K.

1984-01-01

The particle creation effect on the higher-dimensional Kaluza-Klein cosmologies with M 4 xS 7 topology is studied. This quantum effect is found to change the classical behavior of the internal and external scale factors drastically in the early stage of the expansion, so that the dimensional reduction seems to fail. However, at the later stage two scale factors get separated from each other and the internal scale factor approaches the final singularity just like the vacuum case. (orig.)

Momentum, heat, and mass transfer analogy for vertical hydraulic transport of inert particles

Directory of Open Access Journals (Sweden)

Jaćimovski Darko R.

2014-01-01

Full Text Available Wall-to-bed momentum, heat and mass transfer in vertical liquid-solids flow, as well as in single phase flow, were studied. The aim of this investigation was to establish the analogy among those phenomena. Also, effect of particles concentration on momentum, heat and mass transfer was studied. The experiments in hydraulic transport were performed in a 25.4 mm I.D. cooper tube equipped with a steam jacket, using spherical glass particles of 1.94 mm in diameter and water as a transport fluid. The segment of the transport tube used for mass transfer measurements was inside coated with benzoic acid. In the hydraulic transport two characteristic flow regimes were observed: turbulent and parallel particle flow regime. The transition between two characteristic regimes (γ*=0, occurs at a critical voidage ε≈0.85. The vertical two-phase flow was considered as the pseudofluid, and modified mixture-wall friction coefficient (fw and modified mixture Reynolds number (Rem were introduced for explanation of this system. Experimental data show that the wall-to-bed momentum, heat and mass transfer coefficients, in vertical flow of pseudofluid, for the turbulent regime are significantly higher than in parallel regime. Wall-to-bed, mass and heat transfer coefficients in hydraulic transport of particles were much higher then in single-phase flow for lower Reynolds numbers (Re15000, there was not significant difference. The experimental data for wall-to-bed momentum, heat and mass transfer in vertical flow of pseudofluid in parallel particle flow regime, show existing analogy among these three phenomena. [Projekat Ministarstva nauke Republike Srbije, br. 172022

Evidence for cosmological particle creation?

Energy Technology Data Exchange (ETDEWEB)

Pigozzo, C. [Imperial Centre for Inference and Cosmology, Imperial College, Prince Consort Road, London, SW7 2AZ (United Kingdom); Carneiro, S.; Borges, H.A. [Instituto de Física, Universidade Federal da Bahia, Rua Barão de Geremoabo, Salvador, 40210-340, BA (Brazil); Alcaniz, J.S. [Departamento de Astronomia, Observatório Nacional, Rua General José Cristino 77, Rio de Janeiro, 20921-400, RJ (Brazil); Fabris, J.C., E-mail: cpigozzo@ufba.br, E-mail: saulo.carneiro@pq.cnpq.br, E-mail: alcaniz@on.br, E-mail: humberto@ufba.br, E-mail: fabris@pq.cnpq.br [Departamento de Física, Universidade Federal do Espírito Santo, Av. Fernando Ferrari 514, Vitória, 29075-910, ES (Brazil)

2016-05-01

A joint analysis of the linear matter power spectrum, distance measurements from type Ia supernovae and the position of the first peak in the anisotropy spectrum of the cosmic microwave background indicates a cosmological, late-time dark matter creation at 95% confidence level.

Alignment creation by elastic electron scattering. A quantum treatment

International Nuclear Information System (INIS)

Csanak, G.; Kilcrease, D.P.; Fursa, D.V.; Bray, I.

2004-01-01

Alignment creation by elastic heavy particle scattering has been studied by many authors. A formula for the alignment creation cross section by elastic scattering is obtained by quantum-mechanical methods. The formula obtained differs from the analogous formula relevant for inelastic electron scattering. In the case of a J=1 to J=1 transition according to the inelastic formula, the alignment created is proportional to the quantity σ (1) - σ (0) where σ (M) is the excitation cross section of the M magnetic sublevel and thus σ (1) = (σ 1-1 + σ 10 + σ 11 )/3 and σ (0) = (σ 0-1 +σ 00 + σ 01 )/3 where σ MM' refers to the cross section of the electron impact induced M' to M transition. In the elastic scattering alignment creation formula obtained in the case of a J=1 to J=1 elastic scattering, the alignment created is proportional to the quantity q(1) - q(0) where q(1) σ (1) - σ 11 /3 and q(0) = σ 00 /3. Thus in obtaining q(M), the elastic scattering cross section by the M magnetic sublevel, σ MM' , is subtracted. This derivation considered only direct scattering, i.e. the incident electron was considered distinguishable from the target electrons. (Y.Kazumata)

DockoMatic: automated peptide analog creation for high throughput virtual screening.

Science.gov (United States)

Jacob, Reed B; Bullock, Casey W; Andersen, Tim; McDougal, Owen M

2011-10-01

The purpose of this manuscript is threefold: (1) to describe an update to DockoMatic that allows the user to generate cyclic peptide analog structure files based on protein database (pdb) files, (2) to test the accuracy of the peptide analog structure generation utility, and (3) to evaluate the high throughput capacity of DockoMatic. The DockoMatic graphical user interface interfaces with the software program Treepack to create user defined peptide analogs. To validate this approach, DockoMatic produced cyclic peptide analogs were tested for three-dimensional structure consistency and binding affinity against four experimentally determined peptide structure files available in the Research Collaboratory for Structural Bioinformatics database. The peptides used to evaluate this new functionality were alpha-conotoxins ImI, PnIA, and their published analogs. Peptide analogs were generated by DockoMatic and tested for their ability to bind to X-ray crystal structure models of the acetylcholine binding protein originating from Aplysia californica. The results, consisting of more than 300 simulations, demonstrate that DockoMatic predicts the binding energy of peptide structures to within 3.5 kcal mol(-1), and the orientation of bound ligand compares to within 1.8 Å root mean square deviation for ligand structures as compared to experimental data. Evaluation of high throughput virtual screening capacity demonstrated that Dockomatic can collect, evaluate, and summarize the output of 10,000 AutoDock jobs in less than 2 hours of computational time, while 100,000 jobs requires approximately 15 hours and 1,000,000 jobs is estimated to take up to a week. Copyright © 2011 Wiley Periodicals, Inc.

Creation of vector bosons by an electric field in curved spacetime

International Nuclear Information System (INIS)

Kangal, E. Ersin; Yanar, Hilmi; Havare, Ali; Sogut, Kenan

2014-01-01

We investigate the creation rate of massive spin-1 bosons in the de Sitter universe by a time-dependent electric field via the Duffin–Kemmer–Petiau (DKP) equation. Complete solutions are given by the Whittaker functions and particle creation rate is computed by using the Bogoliubov transformation technique. We analyze the influence of the electric field on the particle creation rate for the strong and vanishing electric fields. We show that the electric field amplifies the creation rate of charged, massive spin-1 particles. This effect is analyzed by considering similar calculations performed for scalar and spin-1/2 particles. -- Highlights: •Duffin–Kemmer–Petiau equation is solved exactly in the presence of an electrical field. •Solutions were made in (1+1)-dimensional curved spacetime. •Particle creation rate for the de Sitter model is calculated. •Pure gravitational or pure electrical field effect on the creation rate is analyzed

Assets and liabilities are the momentum of particles and antiparticles displayed in Feynman-graphs

Science.gov (United States)

Braun, Dieter

2001-02-01

An analogy between assets and liabilities and the momentum of particles and antiparticles (called actons and passons) is proposed. It allows physicists to use physical methods in economy for the analysis of monetary systems and for the analysis of double entry bookkeeping. Economists can use it to subdivide and discuss complicated balance transactions in terms of Feynman-graphs which introduce the time dimension to bookkeeping. Within the analogy, assets and liabilities come into existence by pair creation. Conservation of momentum is fulfilled whereas the conservation of energy corresponds to the regulation of a constant amount of money. Interest rates accelerate the particles by imposing a negative friction. The statistical description of an ideal money gas is derived and the transcription to semiconductor physics is given. The analogy is hoped to open a new field for physics and to reveal new insights on monetary systems.

Quantum creation of an inflationary Universe

International Nuclear Information System (INIS)

Linde, A.D.

1984-01-01

The problem of quantum creation of the Universe is discussed. It is shown that the process of quantum creation of the Universe in a wide class on elementary particle theories leads with a high probability to the creation of an exponentially expanding (inflationary) Universe. Universe size after expansion should exceed l approximately 10 28 cm

Neural network based cluster creation in the ATLAS silicon pixel detector

CERN Document Server

Selbach, K E; The ATLAS collaboration

2012-01-01

The read-out from individual pixels on planar semi-conductor sensors are grouped into clusters to reconstruct the location where a charged particle passed through the sensor. The resolution given by individual pixel sizes is significantly improved by using the information from the charge sharing between pixels. Such analog cluster creation techniques have been used by the ATLAS experiment for many years to obtain an excellent performance. However, in dense environments, such as those inside high-energy jets, clusters have an increased probability of merging the charge deposited by multiple particles. Recently, a neural network based algorithm which estimates both the cluster position and whether a cluster should be split has been developed for the ATLAS pixel detector. The algorithm significantly reduces ambiguities in the assignment of pixel detector measurement to tracks within jets and improves the position accuracy with respect to standard interpolation techniques by taking into account the 2-dimensional ...

Neural network based cluster creation in the ATLAS silicon Pixel Detector

CERN Document Server

Andreazza, A; The ATLAS collaboration

2013-01-01

The read-out from individual pixels on planar semi-conductor sensors are grouped into clusters to reconstruct the location where a charged particle passed through the sensor. The resolution given by individual pixel sizes is significantly improved by using the information from the charge sharing between pixels. Such analog cluster creation techniques have been used by the ATLAS experiment for many years to obtain an excellent performance. However, in dense environments, such as those inside high-energy jets, clusters have an increased probability of merging the charge deposited by multiple particles. Recently, a neural network based algorithm which estimates both the cluster position and whether a cluster should be split has been developed for the ATLAS Pixel Detector. The algorithm significantly reduces ambiguities in the assignment of pixel detector measurement to tracks within jets and improves the position accuracy with respect to standard interpolation techniques by taking into account the 2-dimensional ...

Unbiased estimators of coincidence and correlation in non-analogous Monte Carlo particle transport

International Nuclear Information System (INIS)

Szieberth, M.; Kloosterman, J.L.

2014-01-01

Highlights: • The history splitting method was developed for non-Boltzmann Monte Carlo estimators. • The method allows variance reduction for pulse-height and higher moment estimators. • It works in highly multiplicative problems but Russian roulette has to be replaced. • Estimation of higher moments allows the simulation of neutron noise measurements. • Biased sampling of fission helps the effective simulation of neutron noise methods. - Abstract: The conventional non-analogous Monte Carlo methods are optimized to preserve the mean value of the distributions. Therefore, they are not suited to non-Boltzmann problems such as the estimation of coincidences or correlations. This paper presents a general method called history splitting for the non-analogous estimation of such quantities. The basic principle of the method is that a non-analogous particle history can be interpreted as a collection of analogous histories with different weights according to the probability of their realization. Calculations with a simple Monte Carlo program for a pulse-height-type estimator prove that the method is feasible and provides unbiased estimation. Different variance reduction techniques have been tried with the method and Russian roulette turned out to be ineffective in high multiplicity systems. An alternative history control method is applied instead. Simulation results of an auto-correlation (Rossi-α) measurement show that even the reconstruction of the higher moments is possible with the history splitting method, which makes the simulation of neutron noise measurements feasible

Progress in the optoelectronic analog signal transfer for high energy particle detectors

International Nuclear Information System (INIS)

Tsang, T.; Radeka, V.

1992-05-01

We report the progress in the development of a radiation hard Optoelectronic analog system to transfer particle detector signals with high accuracy. We will present the motivation of this study, the operating principle of the optoelectronic system, the system noise study, the recent R ampersand D efforts on radiation effect, temperature stability, and the realization of an integrated l x l6 optical modulator. The issue of photon source for driving such a large-scale optoelectronic modulators is a major concern. We will address this problem by examining different possible photon sources and comment on other possible alternative for signal transfer

Pair creation by an external non-Abelian field

International Nuclear Information System (INIS)

Hamil, B; Chetouani, L

2014-01-01

The problem of the creation of particle pairs of spin 0 and 1/2 from the vacuum by an external field of a non-Abelian type plane wave on the light cone is considered following the approach of Schwinger. Using simple shifts and only by an algebraic calculation, it is shown that with this form of interaction, there is no creation of particles. (paper)

Study on the creation and destruction of transport barriers via the effective safety factors for energetic particles

Science.gov (United States)

Ogawa, Shun; Leoncini, Xavier; Dif-Pradalier, Guilhem; Garbet, Xavier

2016-12-01

Charged particles with low kinetic energy move along the magnetic field lines, but so do not the energetic particles. We investigate the topological structure changes in the phase space of energetic particles with respect to the magnetic one. For this study, cylindrical magnetic fields with non-monotonic safety factors that induce the magnetic internal transport barrier are considered. We show that the topological structure of the magnetic field line and of the particle trajectories can be quite different. We explain this difference using the concept of an effective particle q-profile. Using this notion, we can investigate the location and existence of resonances for particle orbits that are different from the magnetic ones. These are examined both numerically by integrating an equation of motion and theoretically by the use of Alfvén's guiding center theory and by the use of an effective reduced Hamiltonian for the integrable unperturbed system. It is clarified that, for the energetic particles, the grad B drift effect shifts the resonances and the drift induced by curvature of the magnetic field line leads to the vanishing of the resonances. As a result, we give two different mechanisms that lead to the creation of transport barriers for energetic particles in the region where the magnetic field line is chaotic.

A versatile analog device for identifying charged particles by their energies and ionizing powers

International Nuclear Information System (INIS)

Harmanci, Ali Emre

1971-06-01

The various methods of identification previously used are discussed; particular attention is given to an ΔE-E telescope. The usual approximations of the equation of Beth-Livingstone are examined and a more universal formula is given. It is shown that when this formula is applied to the case of light particles (p, d, t, H e 3 , α) identification over a wide energy range is possible. The equipment operates logarithmically using analog operators. The identifier possesses certain number of special features, especially concerning the logarithmic converters and the base line restorers. High accuracy, speed, and a good performance at high counting rates have been achieved. Experimental results confirm the performance of the equipment and the validity of the formulas used. A large number of particles corresponding to Z = 8, were identified. (author) [fr

Creation of quantized particles, gravitons, and scalar perturbations by the expanding universe

International Nuclear Information System (INIS)

Parker, Leonard

2015-01-01

Quantum creation processes during the very rapid early expansion of the universe are believed to give rise to temperature anisotropies and polarization patterns in the CMB radiation. These have been observed by satellites such as COBE, WMAP, and PLANCK, and by bolometric instruments placed near the South Pole by the BICEP collaborations. The expected temperature anisotropies are well-confirmed. The B-mode polarization patterns in the CMB are currently under measurement jointly by the PLANCK and BICEP groups to determine the extent to which the B-modes can be attributed to gravitational waves from the creation of gravitons in the earliest universe.As the original discoverer of the quantum phenomenon of particle creation from vacuum by the expansion of the universe, I will explain how the discovery came about and how it relates to the current observations. The first system that I considered when I started my Ph.D. thesis in 1962 was the quantized minimally-coupled scalar field in an expanding FLRW (Friedmann, Lemaitré, Robertson, Walker) universe having a general continuous scale factor a(t) with continuous time derivatives. I also considered quantized fermion fields of spin-1/2 and the spin-1 massless photon field, as well as the quantized conformally-invariant field equations of arbitrary integer and half-integer spins that had been written down in the classical context for general gravitational metrics by Penrose.It was during 1962 that I proved that quanta of the minimally-coupled scalar field were created by the general expanding FLRW universe. This was relevant also to the creation of quantized perturbations of the gravitational field, since these perturbations satisfied linear field equations that could be quantized in the same way as the minimally-coupled scalar field equation. In fact, in 1946, E.M. Lifshitz had considered the classical Einstein gravitational field in FLRW expanding universes and had shown that the classical linearized Einstein field

Particle creation and non-equilibrium thermodynamical prescription of dark fluids for universe bounded by an event horizon

OpenAIRE

Saha, Subhajit; Biswas, Atreyee; Chakraborty, Subenoy

2015-01-01

In the present work, flat FRW model of the universe is considered to be an isolated open thermodynamical system where non-equilibrium prescription has been studied using the mechanism of particle creation. In the perspective of recent observational evidences, the matter distribution in the universe is assumed to be dominated by dark matter and dark energy. The dark matter is chosen as dust while for dark energy, the following choices are considered: (i) Perfect fluid with constant equation of...

Analog electronics for radiation detection

CERN Document Server

2016-01-01

Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

Few-photon electron-positron pair creation in the collision of a relativistic nucleus and an intense x-ray laser beam

International Nuclear Information System (INIS)

Mueller, C.; Gruen, N.; Voitkiv, A.B.

2004-01-01

We study the nonlinear process of e - e + pair creation by a nucleus which moves at a relativistic energy in the laboratory frame and collides with an intense x-ray laser beam. The collision system under consideration is chosen in such a way that the simultaneous absorption of at least two photons from the laser wave is required in order to exceed the energy threshold of the reaction. We calculate total and differential rates for both free-free and bound-free pair production. In the case of free-free pair creation we demonstrate the effect of the laser polarization on the spectra of the produced particles, and we show that at very high intensities the total rate exhibits features analogous to those well known from above-threshold ionization rates for atoms. In the case of bound-free pair creation a singularity is found in the laboratory frame angular distribution of the produced positron. This singularity represents a distinct characteristic of the bound-free pair production and allows one to separate this process from free-free pair creation even without detecting a bound state of the captured electron. For both types of pair creation we consider the dependences of the total rates on the collision parameters, give the corresponding scaling laws, and discuss the possibility to observe these nonlinear processes in a future experiment

Multi-pair states in electron–positron pair creation

Directory of Open Access Journals (Sweden)

Anton Wöllert

2016-09-01

Full Text Available Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

Multi-pair states in electron–positron pair creation

Energy Technology Data Exchange (ETDEWEB)

Wöllert, Anton, E-mail: woellert@mpi-hd.mpg.de; Bauke, Heiko, E-mail: heiko.bauke@mpi-hd.mpg.de; Keitel, Christoph H.

2016-09-10

Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

Multi-pair states in electron–positron pair creation

International Nuclear Information System (INIS)

Wöllert, Anton; Bauke, Heiko; Keitel, Christoph H.

2016-01-01

Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

Inhomogeneous and anisotropic particles in optical traps: Physical behaviour and applications

Science.gov (United States)

Simpson, S. H.

2014-10-01

Beyond the ubiquitous colloidal sphere, optical tweezers are capable of trapping myriad exotic particles with wildly varying geometries and compositions. This simple fact opens up numerous opportunities for micro-manipulation, directed assembly and characterization of novel nanostructures. Furthermore, the mechanical properties of optical tweezers are transformed by their contents. For example, traps capable of measuring, or applying, femto-Newton scale forces with nanometric spatial resolution can be designed. Analogous, if not superior, angular sensitivity can be achieved, enabling the creation of exquisitely sensitive torque wrenches. These capacities, and others, lead to a multitude of novel applications in the meso- and nanosciences. In this article we review experimental and theoretical work on the relationship between particle geometry, composition and trap properties. A range of associated metrological techniques are discussed.

Is the continuous matter creation cosmology an alternative to ΛCDM?

International Nuclear Information System (INIS)

Fabris, J.C.; Pacheco, J.A. de Freitas; Piattella, O.F.

2014-01-01

The matter creation cosmology is revisited, including the evolution of baryons and dark matter particles. The creation process affects only dark matter and not baryons. The dynamics of the ΛCDM model can be reproduced only if two conditions are satisfied: 1) the entropy density production rate and the particle density variation rate are equal and 2) the (negative) pressure associated to the creation process is constant. However, the matter creation model predicts a present dark matter-to-baryon ratio much larger than that observed in massive X-ray clusters of galaxies, representing a potential difficulty for the model. In the linear regime, a fully relativistic treatment indicates that baryons are not affected by the creation process but this is not the case for dark matter. Both components evolve together at early phases but lately the dark matter density contrast decreases since the background tends to a constant value. This behaviour produces a negative growth factor, in disagreement with observations, being a further problem for this cosmology

Classical-quantum correspondence in electron-positron pair creation

International Nuclear Information System (INIS)

Chott, N. I.; Su, Q.; Grobe, R.

2007-01-01

We examine the creation of electron-positron pairs in a very strong force field. Using numerical solutions to quantum field theory we calculate the spatial and momentum probability distributions for the created particles. A comparison with classical mechanical phase space calculations suggests that despite the fully relativistic and quantum mechanical nature of the matter creation process, most aspects can be reproduced accurately in terms of classical mechanics

Analogical reasoning and the content of creation stories : Quantitative comparisons of preindustrial societies

NARCIS (Netherlands)

Moor, N.; Ultee, W.; Need, A.

2009-01-01

A long-standing question in sociology concerns preindustrial societies and the relationship between their subsistence technology and ideas about god. This article proposes a shift from questions regarding gods who now and then create to questions about creations that sometimes involve a god. For

Particle creation by black holes

International Nuclear Information System (INIS)

Hawking, S.W.

1975-01-01

In the classical theory black holes can only absorb and not emit particles. However it is shown that quantum mechanical effects cause black holes to create and emit particles. This thermal emission leads to a slow decrease in the mass of the black hole and to its eventual disappearance: any primordial black hole of mass less than about 10 15 g would have evaporated by now. Although these quantum effects violate the classical law that the area of the event horizon of a black hole cannot decrease, there remains a Generalized Second Law: S + 1/4 A never decreases where S is the entropy of matter outside black holes and A is the sum of the surface areas of the event horizons. This shows that gravitational collapse converts the baryons and leptons in the collapsing body into entropy. It is tempting to speculate that this might be the reason why the Universe contains so much entropy per baryon. (orig.) [de

The Feynman fluid analogy in e+e- annihilation

International Nuclear Information System (INIS)

Hegyi, S.; Krasznovszky, S.

1990-07-01

An analysis of the charged particle multiplicity distributions observed in e + e - annihilation is given using the generalized Feynman fluid analogy of multiparticle production. Only the two-and three-particle integrated correlation functions are included into the scheme. It is shown that the model correctly describes the available experimental data from the TASSO and HRS collaborations. Some properties of the fluid of the analogy are computed and a prediction is made for the multiplicity distribution at √s = 91 GeV. (author) 19 refs.; 5 figs.; 1 tab

Pair creation and plasma oscillations

International Nuclear Information System (INIS)

Prozorkevich, A. V.; Vinnik, D. V.; Schmidt, S. M.; Hecht, M. B.; Roberts, C. D.

2000-01-01

We describe aspects of particle creation in strong fields using a quantum kinetic equation with a relaxation-time approximation to the collision term. The strong electric background field is determined by solving Maxwell's equation in tandem with the Vlasov equation. Plasma oscillations appear as a result of feedback between the background field and the field generated by the particles produced. The plasma frequency depends on the strength of the initial background fields and the collision frequency, and is sensitive to the necessary momentum-dependence of dressed-parton masses

Statefinder diagnostic for modified Chaplygin gas cosmology in f(R,T) gravity with particle creation

Science.gov (United States)

Singh, J. K.; Nagpal, Ritika; Pacif, S. K. J.

In this paper, we have studied flat Friedmann-Lemaître-Robertson-Walker (FLRW) model with modified Chaplygin gas (MCG) having equation of state pm = Aρ ‑ B ργ, where 0 ≤ A ≤ 1, 0 ≤ γ ≤ 1 and B is any positive constant in f(R,T) gravity with particle creation. We have considered a simple parametrization of the Hubble parameter H in order to solve the field equations and discussed the time evolution of different cosmological parameters for some obtained models showing unique behavior of scale factor. We have also discussed the statefinder diagnostic pair {r,s} that characterizes the evolution of obtained models and explore their stability. The physical consequences of the models and their kinematic behaviors have also been scrutinized here in some detail.

Bound states for a neutral particle analogous to a quantum dot induced by the non-inertial effects of the Fermi-Walker reference frame

International Nuclear Information System (INIS)

Bakke, Knut

2010-01-01

We study the appearance of bound states analogous to a quantum dot, proposed by Tan and Inkson (1996) , in the non-relativistic quantum dynamics of a neutral particle with permanent magnetic dipole moment induced by the non-inertial effects of the Fermi-Walker reference frame.

Iconicity can ground the creation of vocal symbols.

Science.gov (United States)

Perlman, Marcus; Dale, Rick; Lupyan, Gary

2015-08-01

Studies of gestural communication systems find that they originate from spontaneously created iconic gestures. Yet, we know little about how people create vocal communication systems, and many have suggested that vocalizations do not afford iconicity beyond trivial instances of onomatopoeia. It is unknown whether people can generate vocal communication systems through a process of iconic creation similar to gestural systems. Here, we examine the creation and development of a rudimentary vocal symbol system in a laboratory setting. Pairs of participants generated novel vocalizations for 18 different meanings in an iterative 'vocal' charades communication game. The communicators quickly converged on stable vocalizations, and naive listeners could correctly infer their meanings in subsequent playback experiments. People's ability to guess the meanings of these novel vocalizations was predicted by how close the vocalization was to an iconic 'meaning template' we derived from the production data. These results strongly suggest that the meaningfulness of these vocalizations derived from iconicity. Our findings illuminate a mechanism by which iconicity can ground the creation of vocal symbols, analogous to the function of iconicity in gestural communication systems.

Explaining money creation by commercial banks

DEFF Research Database (Denmark)

Ravn, Ib

2015-01-01

Educators and economists concerned with monetary reform face the extraordinary challenge of explaining to the public and its elected representatives not only what a reformed system would look like, but also how the current system works. Centrally, the point that in a modern economy money is largely...... created by commercial banks, as explained by the Bank of England recently (McLeay, Radia & Thomas, 2014b), is often met with incredulity: “What do you mean, created?” This paper introduces five easy-to-grasp analogies that educators and reformers may use to convey key money-creation concepts to a lay...... audience. The analogies offered include (1) money as patches in an expandable patchwork quilt that covers a nation’s real assets, (2) the money supply as water in a bathtub with a faucet and a drain, (3) money understood as debt in a model economy run by schoolchildren, (4) the misleading concept of a bank...

Pair creation at large inherent angles

International Nuclear Information System (INIS)

Chen, P.; Tauchi, T.; Schroeder, D.V.

1992-01-01

In the next-generation linear colliders, the low-energy e + e - pairs created during the collision of high-energy e + e - beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al. At energies where the beamstrahlung parameter Υ lies approximately in the range 0.6 approx-lt Υ approx-lt 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. Since the central issue is the transverse momentum for particles with large angles, the authors notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. In this paper they reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer

Flocking from a quantum analogy: spin-orbit coupling in an active fluid

Science.gov (United States)

Loewe, Benjamin; Souslov, Anton; Goldbart, Paul M.

2018-01-01

Systems composed of strongly interacting self-propelled particles can form a spontaneously flowing polar active fluid. The study of the connection between the microscopic dynamics of a single such particle and the macroscopic dynamics of the fluid can yield insights into experimentally realizable active flows, but this connection is well understood in only a few select cases. We introduce a model of self-propelled particles based on an analogy with the motion of electrons that have strong spin-orbit coupling. We find that, within our model, self-propelled particles are subject to an analog of the Heisenberg uncertainty principle that relates translational and rotational noise. Furthermore, by coarse-graining this microscopic model, we establish expressions for the coefficients of the Toner-Tu equations—the hydrodynamic equations that describe an active fluid composed of these ‘active spins.’ The connection between stochastic self-propelled particles and quantum particles with spin may help realize exotic phases of matter using active fluids via analogies with systems composed of strongly correlated electrons.

Single-event effects in analog and mixed-signal integrated circuits

International Nuclear Information System (INIS)

Turflinger, T.L.

1996-01-01

Analog and mixed-signal integrated circuits are also susceptible to single-event effects, but they have rarely been tested. Analog circuit single-particle transients require modified test techniques and data analysis. Existing work is reviewed and future concerns are outlined

Non-analog Monte Carlo estimators for radiation momentum deposition

International Nuclear Information System (INIS)

Hykes, Joshua M.; Densmore, Jeffery D.

2009-01-01

The standard method for calculating radiation momentum deposition in Monte Carlo simulations is the analog estimator, which tallies the change in a particle's momentum at each interaction with the matter. Unfortunately, the analog estimator can suffer from large amounts of statistical error. In this paper, we present three new non-analog techniques for estimating momentum deposition. Specifically, we use absorption, collision, and track-length estimators to evaluate a simple integral expression for momentum deposition that does not contain terms that can cause large amounts of statistical error in the analog scheme. We compare our new non-analog estimators to the analog estimator with a set of test problems that encompass a wide range of material properties and both isotropic and anisotropic scattering. In nearly all cases, the new non-analog estimators outperform the analog estimator. The track-length estimator consistently yields the highest performance gains, improving upon the analog-estimator figure of merit by factors of up to two orders of magnitude.

Electron-positron pair creation in heavy ion collisions

International Nuclear Information System (INIS)

Kienle, P.

1987-08-01

We review here the status of experiments to study the electron positron pair creation in heavy ion atom collisions at bombarding energies close to the Coulomb barrier. The disentanglement and characterisation of various sources of positrons observed in such collisions are described with a focus on the monoenergetic electron positron pairs observed. They seem to originate from the two-body decay of a family of neutral particles with masses of about 3 m e and life times in the range of 6x10 -14 s -10 s, produced by high Coulomb fields. First attempts were made to create these particles by resonant Bhabha scattering. First we present some experimental methods for high efficiency positron spectroscopy in heavy ion collisions. Then we describe the discovery of positron creation induced by strong time changing Coulomb fields. (orig./HSI)

Creation Stories: Myths about the Origin of Money

OpenAIRE

Desan, Christine

2013-01-01

A myth about the origins of money has long organized modern approaches to the medium. According to that creation story, money is the natural product of human exchange. It can be analogized to a commodity like silver that comes to hand out of the decentralized activity of trading or a convention like language that arises out of a consensus about the value of an item. But if we consider clues about money’s origins and extrapolate from its continuing practice, another story comes into focus. It ...

Creation through Polychronization

Directory of Open Access Journals (Sweden)

John Matthias

2017-11-01

Full Text Available I have recently suggested that some of the processes involved in the collaborative composition of new music could be analogous to several ideas introduced by Izhikevich in his theory of cortical spiking neurons and simple memory, a process which he calls Polychronization. In the Izhikevich model, the evocation of simple memories is achieved by the sequential re-firing of the same Polychronous group of neurons which was initially created in the cerebral cortex by the sensual stimulus. Each firing event within the group is contingent upon the previous firing event and, in particular, contingent upon the timing of the firings, due to a phenomenon known as “Spike Timing Dependent Plasticity.” I argue in this article that the collaborative creation of new music involves contingencies which form a Polychronous group across space and time which helps to create a temporary shared memorial space between the collaborators.

FRW-type cosmologies with adiabatic matter creation

International Nuclear Information System (INIS)

Lima, J.A.; Germano, A.S.; Abramo, L.R.

1996-01-01

Some properties of cosmological models with matter creation are investigated in the framework of the Friedmann-Robertson-Walker line element. For adiabatic matter creation, as developed by Prigogine and co-workers, we derive a simple expression relating the particle number density n and energy density ρ which holds regardless of the matter creation rate. The conditions to generate inflation are discussed and by considering the natural phenomenological matter creation rate ψ=3βnH, where β is a pure number of the order of unity and H is the Hubble parameter, a minimally modified hot big-bang model is proposed. The dynamic properties of such models can be deduced from the standard ones simply by replacing the adiabatic index γ of the equation of state by an effective parameter γ * =γ(1-β). The thermodynamic behavior is determined and it is also shown that ages large enough to agree with observations are obtained even given the high values of H suggested by recent measurements. copyright 1996 The American Physical Society

Bosonic analog of the Klein paradox

International Nuclear Information System (INIS)

Wagner, R. E.; Ware, M. R.; Su, Q.; Grobe, R.

2010-01-01

The standard Klein paradox describes how an incoming electron scatters off a supercritical electrostatic barrier that is so strong that it can generate electron-positron pairs. This fermionic system has been widely discussed in textbooks to illustrate some of the discrepancies between quantum mechanical and quantum field theoretical descriptions for the pair creation process. We compare the fermionic dynamics with that of the corresponding bosonic system. We point out that the direct counterpart of the Pauli exclusion principle (the central mechanism to resolve the fermionic Klein paradox) is stimulated emission, which leads to the resolution of the analogous bosonic paradox.

Dynamics of an exclusion process with creation and annihilation

International Nuclear Information System (INIS)

Juhasz, Robert; Santen, Ludger

2004-01-01

We examine the dynamical properties of an exclusion process with creation and annihilation of particles in the framework of a phenomenological domain-wall theory, by scaling arguments and by numerical simulation. We find that the length and the time scales are finite in the maximum current phase for finite creation and annihilation rates as opposed to the algebraically decaying correlations of the totally asymmetric simple exclusion process (TASEP). Critical exponents of the transition to the TASEP are determined. The case where bulk creation and annihilation rates vanish faster than the inverse of the system size N is also analysed. We point out that shock localization is possible even for rates proportional to N -a , 1 < a < 2

Recoil effects in multiphoton electron-positron pair creation

International Nuclear Information System (INIS)

Krajewska, K.; Kaminski, J. Z.

2010-01-01

Triply differential probability rates for electron-positron pair creation in laser-nucleus collisions, calculated within the S-matrix approach, are investigated as functions of the nuclear recoil. Pronounced enhancements of differential probability rates of multiphoton pair production are found for a nonzero momentum transfer from the colliding nucleus. The corresponding rates show a very dramatic dependence on the polarization of the laser field impinging on the nucleus; only for a linearly polarized light are the multiphoton rates for electron-positron pair production considerably large. We focus therefore on this case. Our numerical results for different geometries of the reaction particles demonstrate that, for the linearly polarized laser field of an infinite extent (which is a good approximation for femtosecond laser pulses), the pair creation is far more efficient if the nucleus is detected in the direction of the laser-field propagation. The corresponding angular distributions of the created particles show that the high-energy pairs are predominantly produced in the plane spanned by the polarization vector and the laser-field propagation direction, while the low-energy pairs are rather spread around the latter of the two directions. The enhancement of differential probability rates at each energy sector, defined by the four-momentum conservation relation, is observed with varying the energy of the produced particles. The total probability rates of pair production are also evaluated and compared with the corresponding results for the case when one disregards the recoil effect. A tremendous enhancement of the total probability rates of the electron-positron pair creation is observed if one takes into account the nuclear recoil.

Real time event selection and flash analog-to-digital converters

International Nuclear Information System (INIS)

Imori, Masatosi

1983-01-01

In high-energy particle experiments, high-speed analog logic is employed to select events on a real-time basis. Flash analog-to-digital converters replace the high-speed analog logic with digital logic. The digital logic gives great flexibility to the scheme for real-time event selection. This paper proposes the use of flash A/D converters for the logic used to obtain the total sum of the energy deposited in individual counters in a shower detector. (author)

Frequency distributions from birth, death, and creation processes.

Science.gov (United States)

Bartley, David L; Ogden, Trevor; Song, Ruiguang

2002-01-01

The time-dependent frequency distribution of groups of individuals versus group size was investigated within a continuum approximation, assuming a simplified individual growth, death and creation model. The analogy of the system to a physical fluid exhibiting both convection and diffusion was exploited in obtaining various solutions to the distribution equation. A general solution was approximated through the application of a Green's function. More specific exact solutions were also found to be useful. The solutions were continually checked against the continuum approximation through extensive simulation of the discrete system. Over limited ranges of group size, the frequency distributions were shown to closely exhibit a power-law dependence on group size, as found in many realizations of this type of system, ranging from colonies of mutated bacteria to the distribution of surnames in a given population. As an example, the modeled distributions were successfully fit to the distribution of surnames in several countries by adjusting the parameters specifying growth, death and creation rates.

Temperature dependence of radiation induced defect creation in a-SiO2

International Nuclear Information System (INIS)

Devine, R.A.B.; Grouillet, A.; Berlivet, J.Y.

1988-01-01

The efficiency of oxygen vacancy defect creation in samples of amorphous SiO 2 subjected to ultraviolet laser or ionizing particle radiation (energetic H + ions) has been measured as a function of sample temperature during irradiation. For the case of laser radiation (E photon ≅ 5 eV) we find that vacancy centers are only created when the irradiation temperature is above 150 K. The efficiency of peroxy radical defect creation observed after post irradiation annealing is consistent with the behaviour of the oxygen vacancy creation efficiency. In samples with energetic protons, the opposite behaviour is observed and one finds that defect creation is enhanced as the implantation temperature is lowered. Possible physical mechanisms controlling the defect creation efficiency as a function of sample temperature and radiation are discussed. (orig.)

Experimental study of single-vertex $(e^{-}-e^{+})$ pair creation in a crystal

CERN Multimedia

2002-01-01

This experiment will study the newly predicted process of $e^{-}-e^{+}$ pair production by high energy photons incident along major axial direction of a single crystal. This process is based upon the well-known channeling properties of negatively charged particles along atomic rows of a crystal. The $e^{-}-e^{+}$ pair creation may proceed in a one-step process, without violating energy and momentum conversation laws, due to the lowering of the total energy of the channeled electron (Fig. 1). \\\\ \\\\ The pair creation rate should increase with increasing photon energies (above a threshold of a few GeV) and largely exceed the Bethe-Heitler process rate for photon energies of a few tens of GeV. It is also expected that the created particles share the photon energy nearly equally, in contrast with the rather flat energy distribution associated with the Bethe-Heitler process. \\\\ \\\\ The experimental set-up (Fig. 2) is designed for the study of those two features: photon energy dependence of the pair creation rate, an...

Bethe-Heitler pair creation in a bichromatic laser field

International Nuclear Information System (INIS)

Augustin, Sven

2014-01-01

Within this thesis, the non-linear creation of electron-positron pairs in the superposition of a nuclear Coulomb field and a two-colour laser field of high intensity is studied. Primarily, two complementary scenarios are investigated: On the one hand, if the two laser frequencies are commensurable, quantum interference may occur. This interference manifests in the total pair-creation rate and the angular distribution of the created particles, which are studied in the nuclear rest frame and the laboratory frame. Furthermore, the relative phase between the two laser modes allows to tune the strength of the terms arising from interference. Therefore, this parameter may be used to optimize the pair-creation yield. On the other hand, for incommensurable frequencies, a set-up of largely differing frequencies is considered. This way, a strong laser field in the non-perturbative regime assisted by a single highly-energetic γ-photon is described. Due to the assistance of the latter, a strong enhancement of the total pair-creation rate can be found depending on the laser intensity. Additionally, the influence of the γ-photon on the angular and energetic distribution of the created particles is investigated, again in the nuclear rest frame and the laboratory frame. Furthermore, the differences arising in the two former cases are directly compared by means of a continuous variation of the laser frequency ratio. This illustrates the strong modifications due to the interference in the commensurable case. Finally, for the special case of two modes with identical frequency, the total pair-creation rate is studied as a function of the ellipticity of the combined laser field. Here, the cases of a constant total field intensity and a constant maximum field intensity are compared.

Analytic analysis of auxetic metamaterials through analogy with rigid link systems

OpenAIRE

Rayneau-Kirkhope, Daniel; Zhang, Chengzhao; Theran, Louis; Dias, Marcelo A.

2017-01-01

Recent progress in advanced additive manufacturing techniques has stimulated the growth of the field of mechanical metamaterials. One area particular interest in this subject is the creation of auxetic material properties through elastic instability. This paper focuses on a novel methodology in the analysis of auxetic metamaterials through analogy with rigid link lattice systems. Our analytic methodology gives extremely good agreement with finite element simulations for both the onset of elas...

Generalized quantum operators of creation and annihilation

International Nuclear Information System (INIS)

Kuryshkin, Vassili

1980-01-01

Generalized permutation relation determined by a set of coefficients μ=(μ 1 ,...,μsub(k)) are under consideration for a pair of operators a and a + conjugated to each other. The totality of operator functions of a and a + (the μ-algebra) is investigated. It is shown that a and a + can be interpreted as the annihilation and creation operators of some 'particles'. Unlike the well known types of the quantization of Bose-Einstein and Fermi-Dirac the μ-quantization generally violates the proportionality between the energy of a state and its number of 'particles', a fact which is treated as a certain interaction between the 'particles'. All the particular cases of μ-quantization free from interaction are determined [fr

Integral simulation of the creation and expansion of a transonic argon plasma

International Nuclear Information System (INIS)

Peerenboom, K S C; Goedheer, W J; Van Dijk, J; Van der Mullen, J J A M

2010-01-01

A transonic argon plasma is studied in an integral simulation where both the plasma creation and expansion are incorporated in the same model. This integral approach allows for simulation of expanding plasmas where the Mach number is not known a priori. Results of this integral simulation are validated with semi-analytical models. Inside the creation region the results for the electron temperature, the heavy particle temperature and the electron density are compared with a global model of the creation region. In the expansion region, the simulation results of the compressible flow field are compared with predictions for the shock position. Both the results inside the creation region as well as in the expansion region are in good agreement with the semi-analytical models.

Initial behavior of a quantized scalar field the associated pair-creation in several anisotropic universes

International Nuclear Information System (INIS)

Nariai, Hidekazu

1981-01-01

As a sequel to previous works on the definition of a positive frequency part of a quantized scalar field near an initial stage of several Robertson-Walker universes with flat, open or closed 3-space and the associated pair-creation of those particles, an attempt is made to seek for the same concept in several Bianchi-type I anisotropic universes. It is shown that, if the positive frequency part is introduced, the pair-creation of scalar particles and their spectral law are uniquely determined, as in the case of isotropic universes. (author)

Co-Creation

DEFF Research Database (Denmark)

Degnegaard, Rex

2012-01-01

Co-creation as a concept has won terrain over the past 10 years. In practice as well as in literature, co-creation is climbing the agenda in relation to contemporary opportunities and challenges within management, organization development, and change initiatives. However, there Is very little...... research-based literature on the development of co-creation. This paper aims to build an overview of the literature on co-creation to explore what the existing literature relate to and indeed to pinpoint if any pattern or streams can be identified. A main finding from the analysis is how co-creation tends...

Microscopic description and excitation of unitary analog states

Energy Technology Data Exchange (ETDEWEB)

Kisslinger, L S [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA); Van Giai, N [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

1977-12-05

A microscopic investigation in a self-consistent particle-hole model reveals approximate unitary analog states in spite of large symmetry breaking. The K-nucleus elastic scattering and (K/sup -/, ..pi../sup -/) excitation of these states are studied, showing strong surface effects.

Analog data transmission via fiber optics

International Nuclear Information System (INIS)

Cisneros, E.L.; Burgueno, G.F.

1987-01-01

In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particularly susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

Analog data transmission via fiber optics

International Nuclear Information System (INIS)

Cisneros, E.L.; Burgueno, G.F.

1986-10-01

In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particulary susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

Non-relativistic spinning particle in a Newton-Cartan background

Science.gov (United States)

Barducci, Andrea; Casalbuoni, Roberto; Gomis, Joaquim

2018-01-01

We construct the action of a non-relativistic spinning particle moving in a general torsionless Newton-Cartan background. The particle does not follow the geodesic equations, instead the motion is governed by the non-relativistic analog of Papapetrou equation. The spinning particle is described in terms of Grassmann variables. In the flat case the action is invariant under the non-relativistic analog of space-time vector supersymmetry.

Particle creation and non-equilibrium thermodynamical prescription of dark fluids for universe bounded by an event horizon

Science.gov (United States)

Saha, Subhajit; Biswas, Atreyee; Chakraborty, Subenoy

2015-03-01

In the present work, flat FRW model of the universe is considered to be an isolated open thermodynamical system where non-equilibrium prescription has been studied using the mechanism of particle creation. In the perspective of recent observational evidences, the matter distribution in the universe is assumed to be dominated by dark matter and dark energy. The dark matter is chosen as dust while for dark energy, the following choices are considered: (i) Perfect fluid with constant equation of state and (ii) Holographic dark energy. In both the cases, the validity of generalized second law of thermodynamics (GSLT) which states that the total entropy of the fluid as well as that of the horizon should not decrease with the evolution of the universe, has been examined graphically for universe bounded by the event horizon. It is found that GSLT holds in both the cases with some restrictions on the interacting coupling parameter.

Numerical study of active particles creation and evolution in a nitrogen point-to-plane afterglow discharge at low pressure

International Nuclear Information System (INIS)

Potamianou, S; Spyrou, N; Held, B; Loiseau, J-F

2006-01-01

The last part of a numerical study of low-pressure nitrogen cold plasma created by a pulsed discharge in a point-to-plane geometry at 4 Torr is presented. The present work deals with the discharge and plasma behaviour during the falling part of a rectangular shaped applied voltage pulse and completes our investigation of the discharge under the stress of this voltage shape. The relative model is based on fluid description of the cold plasma, on Poisson's equation for the electric field and on balance equations for the excited population taking into account only the most important generation and decay mechanisms of the radiative B 3 Π g , C 3 Π u and the metastables A 3 Σ μ + states of nitrogen, according to the conclusions of our recent work (Potamianou et al 2003 Eur. Phys. J. Appl. Phys. 22 179-88). Results for space and time evolution of the charged particles densities, electric field, potential and electron current density are reported. According to these results, a non-neutral channel is formed that evolves slowly and ends in the formation of a double layer. Excited particle distributions are presented and the influence of the electron current density discussed. It seems that, in this kind of discharge, creation of active particles is not only due to electron current density but also physicochemical mechanisms. The obtained results will help to determine optimal conditions for polymer surface treatment

Electron-positron pair creation in heavy ion collisions

International Nuclear Information System (INIS)

Kienle, P.

1987-01-01

The authors review the status of experiments to study the electron positron pair creation in heavy ion atom collisions at bombarding energies close to the Coulomb barrier. The disentanglement and characterization of various sources of positrons observed in such collisions are described with a focus on the monoenergetic electron positron pairs observed. They seem to originate from the two-body decay of a family of neutral particles with masses of about 3m and lifetimes in the range of 6 x 10 - 14 s, produced by high Coulomb fields. First attempts were made to create these particles by resonant Bhabha scattering

Formal analogy between Compton scattering and Doppler effect

DEFF Research Database (Denmark)

Nielsen, A.; Olsen, Jørgen Seir

1966-01-01

Viewed from the scatterer, the energy of the incoming photon or particle is equal to that of the outgoing, and the angle of incidence is equal to the angle of reflection, when the direction of the velocity of the scatterer after the collision is taken as reference. This paper sets out to prove...... this statement in a more simple and direct way. The authors only consider the Compton scatting process as it is quite analogous to the particle case....

Dynamical creation of complex vector solitons in spinor Bose-Einstein condensates

International Nuclear Information System (INIS)

Xiong Bo; Gong Jiangbin

2010-01-01

By numerical simulations of the Gross-Pitaevskii mean-field equations, we show that the dynamical creation of stable complex vector solitons in a homogeneous spin-1 Bose-Einstein condensate can be achieved by applying a localized magnetic field for a certain duration, with the initial uniform density prepared differently for the formation of different vector solitons. In particular, it is shown that stable dark-bright-dark vector solitons, dark-bright-bright vector solitons, and other analogous solutions can be dynamically created. It is also found that the peak intensity and the group velocity of the vector solitons thus generated can be tuned by adjusting the applied magnetic field. Extensions of our approach also allow for the creation of vector-soliton chains or the pumping of many vector solitons. The results can be useful for possible vector-soliton-based applications of dilute Bose-Einstein condensates.

Analog Circuit Design Optimization Based on Evolutionary Algorithms

Directory of Open Access Journals (Sweden)

Mansour Barari

2014-01-01

Full Text Available This paper investigates an evolutionary-based designing system for automated sizing of analog integrated circuits (ICs. Two evolutionary algorithms, genetic algorithm and PSO (Parswal particle swarm optimization algorithm, are proposed to design analog ICs with practical user-defined specifications. On the basis of the combination of HSPICE and MATLAB, the system links circuit performances, evaluated through specific electrical simulation, to the optimization system in the MATLAB environment, for the selected topology. The system has been tested by typical and hard-to-design cases, such as complex analog blocks with stringent design requirements. The results show that the design specifications are closely met. Comparisons with available methods like genetic algorithms show that the proposed algorithm offers important advantages in terms of optimization quality and robustness. Moreover, the algorithm is shown to be efficient.

Creation, Phase Change and Evolution of the Universe Based on the "Convection Bang Hypothesis"

Science.gov (United States)

Gholibeigian, Hassan; Amirshahkarami, Abdolazim; Gholibeigian, Kazem

2016-04-01

In our vision, it is believed that creation and phase change of universe and their coupling began by the gigantic Large Scale Forced Convection System (LSFCS) in very high temperature including a swirling wild wind and energetic particles like gravitons. That wind as the creator of the inflation process was carrying many Quantum Convection Loops (QCLs). Those QCLs have been transformed to black holes as the cores of galaxies. Convection Bang (CB) Model for creation, phase change and evolution of the Universe is constituted based on three assumptions as follows: The first is: "Gravity Hypothesis" that describes the gravity fields generation by the LSFCSs of the heat and mass inside the planets, stars, galaxies and clusters. The LSFCS changes the material properties of the domain and produces coupling of the matched electromagnetic and gravity fields. Gravity hypothesis is a new way to understand gravitation phenomenon which is different from the both Newton's law of gravity and Einstein's theory of general relativity approaches [Gholibeigian et. al, AGU Fall Meeting 2015, P11A-2056 ]. The second is: "Substantial Motion" theory of Iranian philosopher, Mulla Sadra (1571/2-1640), which describes space-time, time's relativity for all atoms (bodies) which are different from each other [Gholibeigian, APS April Meeting 2015, abstract #L1.027], atom's (body) volume squeezing, black hole's mass lightening while increases the velocities of its involved masses inward (a paradox with general relativity), and changes of material properties and geometries in speed of near light speed [Gholibeigian, APS March Meeting 2016, abstract #]. The third is: "Animated Sub-particles" model. These sub-particles (sub-strings) are origin of life and creator of the momentums of the fundamental particles and forces, and basic link of the information transfer to them, [Gholibeigian, APS April Meeting 2015, abstract #L1.027]. In this model, there are four proposed animated sub-particles of mater

The creation and development of new physics of acceleration

International Nuclear Information System (INIS)

Bonch-Osmolovskij, A.G.

1992-01-01

The creation and stages of development of the new field of physics - the physics of the dense charge-particle ensembles and connected with it new principles of acceleration are considered. In brief form the explanation of the essence of the physics of new acceleration methods was given, their state and perspectives of their development were pictures. 13 refs

A half-century of terrestrial analog studies: From craters on the Moon to searching for life on Mars

Science.gov (United States)

Léveillé, Richard

2010-03-01

Terrestrial analogs to the Moon and Mars have been used to advance knowledge in planetary science for over a half-century. They are useful in studies of comparative geology of the terrestrial planets and rocky moons, in astronaut training and testing of exploration technologies, and in developing hypotheses and exploration strategies in astrobiology. In fact, the use of terrestrial analogs can be traced back to the origins of comparative geology and astrobiology, and to the early phases of the Apollo astronaut program. Terrestrial analog studies feature prominently throughout the history of both NASA and the USGS' Astrogeology Research Program. In light of current international plans for a return missions to the Moon, and eventually to send sample return and manned missions to Mars, as well as the recent creation of various analog research and development programs, this historical perspective is timely.

Analogy of QCD hadronization and Hawking-Unruh radiation at NICA

Energy Technology Data Exchange (ETDEWEB)

Nasser Tawfik, Abdel [Modern University for Technology and Information (MTI), Egyptian Center for Theoretical Physics (ECTP), Cairo (Egypt); World Laboratory for Cosmology And Particle Physics (WLCAPP), Cairo (Egypt); Academy for Scientific Research and Technology (ASRT), Network for Nuclear Sciences (NNS), Cairo (Egypt)

2016-08-15

The proposed analogy of particle production from high-energy collisions and Hawking-Unruh radiation from black holes is extended to finite density (collisions) and finite electric charge (black holes). Assuming that the electric charge is directly proportional to the density (or the chemical potential), it becomes clear that for at least two freezeout conditions; constant s/T{sup 3} and E/N, the proposed analogy works very well. Dependence of radiation (freezeout) temperature on finite electric charge leads to an excellent estimation for kaon-to-pion ratio, for instance, especially in the energy range covered by NICA. The precise and complete measurements for various light-flavored particle yields and ratios are essential in characterizing Hawking-Unruh radiation from charged black holes and the QCD hadronization at finite density, as well. (orig.)

Creation-field cosmology: A possible solution to singularity, horizon, and flatness problems

International Nuclear Information System (INIS)

Narlikar, J.V.; Padmanabhan, T.

1985-01-01

A solution of Einstein's equations which admits radiation and a negative-energy massless scalar creation field as a source is presented. It is shown that the cosmological model based on this solution satisfies all the observational tests and thus is a viable alternative to the standard big-bang model. The present model is free from singularity and particle horizon and provides a natural explanation for the flatness problem. We argue that these features make the creation-field cosmological model theoretically superior to the big-bang model

Detecting analogical resemblance without retrieving the source analogy.

Science.gov (United States)

Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

2010-06-01

We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

Creationism in Europe

DEFF Research Database (Denmark)

For decades, the creationist movement was primarily situated in the United States. Then, in the 1970s, American creationists found their ideas welcomed abroad, first in Australia and New Zealand, then in Korea, India, South Africa, Brazil, and elsewhere—including Europe, where creationism plays...... an expanding role in public debates about science policy and school curricula. In this, the first comprehensive history of creationism in Europe, leading historians, philosophers, and scientists narrate the rise of—and response to—scientific creationism, creation science, intelligent design, and organized...... antievolutionism in countries and religions throughout Europe. Providing a unique map of creationism in Europe, the authors chart the surprising history of creationist activities and strategies there. Over the past forty years, creationism has spread swiftly among European Catholics, Protestants, Jews, Hindus...

Comparison of iron and tungsten absorber structures for an analog hadron calorimeter

International Nuclear Information System (INIS)

Guenter, Clemens

2015-05-01

Future electron-positron-collider experiments will require unprecedented jet-energy resolution to complete their physics programs. This can only be achieved with novel approaches to calorimetry. One of these novel approaches is the Particle Flow Algorithm, which uses the best suited sub-detector to measure the energy of the particles produced by the electronpositron collision. The CALICE Collaboration evaluates different read-out technologies for Particle Flow Calorimeters. This thesis describes the comparison of two different absorber materials, iron and tungsten, for the CALICE Analog Hadron Calorimeter. It is described how test-beam data, that have been recorded in the range from 2 GeV to 10 GeV with the Analog Hadron Calorimeter are calibrated, and how samples are selected containing showers from just one particle type. The data are then compared to simulations, and the remaining disagreement between data and simulation is discussed. The validated simulations are then used to decompose the showers into different fractions. These fractions are compared for the two absorber materials to understand the impact of the absorber material choice on the calorimeter performance.

Four different animated sub-particles as the origins of the life and creator of different angular momentums of elementary particles

Science.gov (United States)

Gholibeigian, Hassan; Gholibeigian, Zeinab

2015-04-01

Understanding the internal structure of the proton is crucial challenge for QCD, and one important aspect of this is to understand how the spin of the nucleon is build-up from the angular momentum of its quarks and gluons. In this way, what's the origin of differences between angular momentums of fundamental particles? It may be from their substructures. It seems there are four sub-particles of mater, plant, animal and human in substructure of each fundamental particle (string) as the origins of life and cause of differences between spins of those elementary particles. Material's sub-particle always is on and active. When the environmental conditions became ready for creation of each field of the plant, animal and human, sub-particles of their elementary particles became on and active and then, those elementary particles participated in processes of creation in their own field. God, as the main source of information, has been communicated with their sub-particles and transfers a package (bit) of information and laws (plus standard ethics for human sub-particles) to each of them for process and selection (mutation) of the next step of motion and interaction of their fundamental particles with each other in each Plank's time. This is causality for particles' motion in quantum area.

Analogical scaffolding: Making meaning in physics through representation and analogy

Science.gov (United States)

Podolefsky, Noah Solomon

This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

Evaluation of using digital gravity field models for zoning map creation

Science.gov (United States)

Loginov, Dmitry

2018-05-01

At the present time the digital cartographic models of geophysical fields are taking a special significance into geo-physical mapping. One of the important directions to their application is the creation of zoning maps, which allow taking into account the morphology of geophysical field in the implementation automated choice of contour intervals. The purpose of this work is the comparative evaluation of various digital models in the creation of integrated gravity field zoning map. For comparison were chosen the digital model of gravity field of Russia, created by the analog map with scale of 1 : 2 500 000, and the open global model of gravity field of the Earth - WGM2012. As a result of experimental works the four integrated gravity field zoning maps were obtained with using raw and processed data on each gravity field model. The study demonstrates the possibility of open data use to create integrated zoning maps with the condition to eliminate noise component of model by processing in specialized software systems. In this case, for solving problem of contour intervals automated choice the open digital models aren't inferior to regional models of gravity field, created for individual countries. This fact allows asserting about universality and independence of integrated zoning maps creation regardless of detail of a digital cartographic model of geo-physical fields.

Application of digital sampling techniques to particle identification in scintillation detectors

International Nuclear Information System (INIS)

Bardelli, L.; Bini, M.; Poggi, G.; Taccetti, N.

2002-01-01

In this paper, the use of a fast digitizing system for identification of fast charged particles with scintillation detectors is discussed. The three-layer phoswich detectors developed in the framework of the FIASCO experiment for the detection of light charged particles (LCP) and intermediate mass fragments (IMF) emitted in heavy-ion collisions at Fermi energies are briefly discussed. The standard analog electronics treatment of the signals for particle identification is illustrated. After a description of the digitizer designed to perform a fast digital sampling of the phoswich signals, the feasibility of particle identification on the sampled data is demonstrated. The results obtained with two different pulse shape discrimination analyses based on the digitally sampled data are compared with the standard analog signal treatment. The obtained results suggest, for the present application, the replacement of the analog methods with the digital sampling technique

SSERVI Analog Regolith Simulant Testbed Facility

Science.gov (United States)

Minafra, Joseph; Schmidt, Gregory; Bailey, Brad; Gibbs, Kristina

2016-10-01

The Solar System Exploration Research Virtual Institute (SSERVI) at NASA's Ames Research Center in California's Silicon Valley was founded in 2013 to act as a virtual institute that provides interdisciplinary research centered on the goals of its supporting directorates: NASA Science Mission Directorate (SMD) and the Human Exploration & Operations Mission Directorate (HEOMD).Primary research goals of the Institute revolve around the integration of science and exploration to gain knowledge required for the future of human space exploration beyond low Earth orbit. SSERVI intends to leverage existing JSC1A regolith simulant resources into the creation of a regolith simulant testbed facility. The purpose of this testbed concept is to provide the planetary exploration community with a readily available capability to test hardware and conduct research in a large simulant environment.SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers.SSERVI provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment.The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area, including dust mitigation and safety oversight.Facility hardware and environment testing scenarios could include, Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, Surface features (i.e. grades and rocks)Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and

Classical relativistic constituent particles and composite-particle scattering

International Nuclear Information System (INIS)

King, M.J.

1984-01-01

A nonlocal Lagrangian formalism is developed to describe a classical many-particle system. The nonstandard Lagrangian is a function of a single parameter s which is not, in general, associated with the physical clock. The particles are constrained to be constituents of composite systems, which in turn can decompose into asymptotic composite states representing free observable particles. To demonstrate this, explicit models of composite-composite particle scattering are constructed. Space-time conservation laws are not imposed separately on the system, but follow upon requiring the constituents to ''pair up'' into free composites at s = +infinity,-infinity. One model is characterized by the appearance of an ''external'' zero-mass composite particle which participates in the scattering process without affecting the space-time conservation laws of the two-composite system. Initial conditions on the two incoming composite particles and the zero-mass participant determine the scattering angle and the final states of the two outgoing composite particles. Although the formalism is classical, the model displays some features usually associated with quantum field theory, such as particle scattering by means of constituent exchange, creation and annihilation of particles, and restriction of values of angular momentum

Collisionless analogs of Riemann S ellipsoids with halo

International Nuclear Information System (INIS)

Abramyan, M.G.

1987-01-01

A spheroidal halo ensures equilibrium of the collisionless analogs of the Riemann S ellipsoids with oscillations of the particles along the direction of their rotation. Sequences of collisionless triaxial ellipsoids begin and end with dynamically stable members of collisionless embedded spheroids. Both liquid and collisionless Riemann S ellipsoids with weak halo have properties that resemble those of bars of SB galaxies

Matter and Interactions: a particle physics perspective

OpenAIRE

Organtini, Giovanni

2011-01-01

In classical mechanics matter and fields are completely separated. Matter interacts with fields. For particle physicists this is not the case. Both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this paper we explain why particle physicists believe in such a picture, introducing the technique of Feynman diagrams starting from very basic and popular analogies with classical mechanics, making the physics ...

Creation of a European network dedicated to technology transfer

CERN Multimedia

2008-01-01

The CERN Council recently approved the creation of a technology transfer network, whose aim will be to improve European industry’s access to the technologies developed by the particle physics community in the Member States. The gas detectors for the TOTEM experiment (GEM) offer potential for fruitful collaboration within the framework of the TT network. Many other technologies are going down the same road.The desire to set up a technology transfer network follows on from the European Strategy for Particle Physics, approved by the CERN Council on 14 July 2006 in Lisbon. In this context, special emphasis was laid on European industry’s participation in the implementation of particle physics programmes and, in particular, its access to the new technologies developed by the scientific community. It was recognised that effort needs to be put into improving the efficiency of technology transfer...

Zinc-phosphate nanoparticles with reversibly attached TNF-α analogs: an interesting concept for potential use in active immunotherapy

International Nuclear Information System (INIS)

Hribar, Gorazd; Žnidaršič, Andrej; Bele, Marjan; Maver, Uroš; Caserman, Simon; Gaberšček, Miran; Gaberc-Porekar, Vladka

2011-01-01

The authors’ intention was to prepare nanometer-sized zinc-phosphate nanoparticles that would be capable of binding histidine-rich TNF-α analogs onto their surface via a coordinative bond. Zinc-phosphate nanoparticles with a size of around 60 nm were prepared by a wet precipitation method and characterized using SEM, EDX, XRD, and DLS. First, BSA was bound as a testing protein, afterward two TNF-α analogs with decreased activity were bound to the described nanoparticles. The efficiency of binding and the existence of coordinative bond were confirmed with SDS-PAGE analysis. During binding, particle storage, and release experiments, the prepared TNF-α analogs retained their biological activity—hence the epitopes necessary for formation of antibodies stayed intact. The particle size did not change within a period of 2 weeks. No significant agglomeration was observed, the particles could be quickly dispersed in ultrasound. The present nanoparticles and the general approach of coordinative binding are widely applicable for natural and engineered histidine-rich proteins. The nanoparticles bearing appropriate TNF-α analogs could also be potentially used for active immunotherapy to tackle the chronic inflammatory diseases associated with pathogenically elevated levels of TNF-α.

Detecting analogies unconsciously

Directory of Open Access Journals (Sweden)

Thomas Peter Reber

2014-01-01

Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

Coherent pair creation from beam-beam interaction

International Nuclear Information System (INIS)

Chen, Pisin.

1989-09-01

It has recently been recognized that in future linear colliders, there is a finite probability that the beamstrahlung photons will turn into e + e - pairs induced by the same beam-beam field, and this would potentially cause background problems. In this paper, we first review the probability of such a coherent pair creation process. It is seen that the constraint on the beamstrahlung parameter, Υ, is tight of these coherent pairs to be totally suppressed. We then point out that there exists a minimum energy for the pair-created particles, which scales as ∼1/5Υ. When combining this condition with the deflection angle for the low-energy particles, the constraint on the allowable Υ value is much relaxed. Finally, we calculate the effective cross section for producing the weak bosons by the low-energy e + e - pairs. It is shown that these cross sections are substantial for Υ > 1. We suggest that this effect can help to autoscan the particle spectrum in the high energy frontier. 10 refs., 2 figs

Micro-particles in ITER: A comprehensive review

International Nuclear Information System (INIS)

Grisolia, C.; Rosanvallon, S.; Sharpe, Ph.; Winter, J.

2009-01-01

In a fusion reactor like ITER, in-vessel materials are subjected to interactions with the plasma. One of the main consequences of these plasma-material interactions is the creation of co-deposited layers. Due to internal stresses, part of these layers can crack leading to micro particle creation. The purpose of the following paper is to review the Tokamak operation processes which lead to erosion and layer creation. Then, the proportion of these layers that is converted into micro-particles will be evaluated in the case of Tore Supra experiments and extrapolated for ITER. It is major importance to measure the ITER mobilizable dusts present in the Vacuum Vessel and compare the measured quantity with the safety limits. When approaching these limits, removal systems must be used in order to control the in-vessel dust inventory. In the second part of the paper, diagnostics and removal system under development will be presented.

Theories of opportunity creation and effective entrepreneurial actions in opportunity creation context

Directory of Open Access Journals (Sweden)

Behrooz Jamali

2018-09-01

Full Text Available Created opportunities are refered as the opportunities in which none of the supply and demand parties exists clearly and obviously one or both of them must be created. Therefore, several economic inventions should take place in marketing, franchising, etc. so that opportunity can be created. This perception of opportunity deals with the creation of new markets. In the meantime, identifying some entrepreneurial actions influencing on the creation of entrepreneurial opportunities can provide backgrounds for the formation and empowering the opportunity creation. In this paper, some basic ideas about the creation of entrepreneurial opportunities and the evolution of opportunity creation theories are examined. Then effective actions on the opportunity creation are identified. Finally, the structure of the investigated actions is examined using the DEMATLE Method. The results which were according to the opinions of 15 experts of entrepreneurship showed that leadership, decision making, and strategy actions influence other entrepreneurial actions.

Theory of analogous force on number sets

Energy Technology Data Exchange (ETDEWEB)

Canessa, Enrique [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)

2003-08-01

A general statistical thermodynamic theory that considers given sequences of x-integers to play the role of particles of known type in an isolated elastic system is proposed. By also considering some explicit discrete probability distributions p{sub x} for natural numbers, we claim that they lead to a better understanding of probabilistic laws associated with number theory. Sequences of numbers are treated as the size measure of finite sets. By considering p{sub x} to describe complex phenomena, the theory leads to derive a distinct analogous force f{sub x} on number sets proportional to ({partial_derivative}p{sub x}/{partial_derivative}x){sub T} at an analogous system temperature T. In particular, this yields to an understanding of the uneven distribution of integers of random sets in terms of analogous scale invariance and a screened inverse square force acting on the significant digits. The theory also allows to establish recursion relations to predict sequences of Fibonacci numbers and to give an answer to the interesting theoretical question of the appearance of the Benford's law in Fibonacci numbers. A possible relevance to prime numbers is also analyzed. (author)

Higher-dimensional string theory in Lyra geometry

Indian Academy of Sciences (India)

Cosmic strings as source of gravitational field in general relativity was discussed by ... tensor theory of gravitation and constructed an analog of Einstein field ... As string concept is useful before the particle creation and can explain galaxy for-.

Unified time analysis of photon and particle tunnelling

International Nuclear Information System (INIS)

Olkhovsky, Vladislav S.; Recami, Erasmo; Jakiel, Jacek

2001-07-01

A unified approach to the time analysis of tunnelling of nonrelativistic particles is presented, in which Time is regarded as a quantum-mechanical observable, canonically conjugated to Energy. The validity of the Hartman effect (independence of the Tunnelling Time of the opaque barrier width, with superluminal group velocities as a consequence) is verified for all the known expressions of the mean tunnelling time. Moreover, the analogy between particle and photon tunnelling is suitably exploited. On the basic of such an analogy, an explanation of some recent microwave and optics experimental results on tunnelling time is proposed. Attention is devoted to some aspects of the causality problem for particle and photon tunnelling. (author)

Particle based 3D modeling of positive streamer inception

NARCIS (Netherlands)

H.J. Teunissen (Jannis)

2012-01-01

htmlabstractIn this report we present a particle based 3D model for the study of streamer inception near positive electrodes in air. The particle code is of the PIC-MCC type and an electrode is included using the charge simulation method. An algorithm for the adaptive creation of super-particles is

Automatic activation of categorical and abstract analogical relations in analogical reasoning.

Science.gov (United States)

Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

2006-10-01

We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy.

Sources for charged particles

International Nuclear Information System (INIS)

Arianer, J.

1997-01-01

This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)

Smooth and sharp creation of a Dirichlet wall in 1+1 quantum field theory: how singular is the sharp creation limit?

International Nuclear Information System (INIS)

Brown, Eric G.; Louko, Jorma

2015-01-01

We present and utilize a simple formalism for the smooth creation of boundary conditions within relativistic quantum field theory. We consider a massless scalar field in (1+1)-dimensional flat spacetime and imagine smoothly transitioning from there being no boundary condition to there being a two-sided Dirichlet mirror. The act of doing this, expectantly, generates a flux of real quanta that emanates from the mirror as it is being created. We show that the local stress-energy tensor of the flux is finite only if an infrared cutoff is introduced, no matter how slowly the mirror is created, in agreement with the perturbative results of Obadia and Parentani. In the limit of instaneous mirror creation the total energy injected into the field becomes ultraviolet divergent, but the response of an Unruh-DeWitt particle detector passing through the infinite burst of energy nevertheless remains finite. Implications for vacuum entanglement extraction and for black hole firewalls are discussed.

Survey < > Creation

DEFF Research Database (Denmark)

2017-01-01

The project, Survey Creation suggests that point cloud models from 3D scans of an existing space can be the source for explorative drawings. By probing into the procedure of 3D laser scanning, it became possible to make use of the available point clouds to both access geometric representation......) and the creation drawing (of the anticipated)....

Polarization effects for pair creation by photon in oriented crystals at high energy

International Nuclear Information System (INIS)

Baier, V.N.; Katkov, V.M.

2006-01-01

Pair creation by a photon in an oriented crystal is considered in the frame of the quasiclassical operator method, which includes processes with polarized particles. Under some quite generic assumptions the general expression is derived for the probability of pair creation of longitudinally polarized electron (positron) by circularly polarized photon in oriented crystal. In the particular cases θ > V /m (θ is the angle of incidence, angle between the momentum of the initial photon and axis (plane) of crystal, V is the scale of a potential of axis or a plane relative to which the angle θ is defined) one has the constant field approximation and the coherent pair production theory correspondingly. Side by side with coherent process the probability of incoherent pair creation is calculated, which differs essentially from amorphous one. At high energy the pair creation in oriented crystal is strongly enhanced comparing with the amorphous medium. In the corresponding appendixes the integral polarization of positron is found in an external field and for the coherent and incoherent mechanisms

Analog computing

CERN Document Server

Ulmann, Bernd

2013-01-01

This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

Quantum walks based on an interferometric analogy

International Nuclear Information System (INIS)

Hillery, Mark; Bergou, Janos; Feldman, Edgar

2003-01-01

There are presently two models for quantum walks on graphs. The ''coined'' walk uses discrete-time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the particle will move. The continuous walk operates with continuous time. Here a third model for quantum walks is proposed, which is based on an analogy to optical interferometers. It is a discrete-time model, and the unitary operator that advances the walk one step depends only on the local structure of the graph on which the walk is taking place. This type of walk also allows us to introduce elements, such as phase shifters, that have no counterpart in classical random walks. Several examples are discussed

Analogies between optical and quantum mechanical angular momentum.

Science.gov (United States)

Nienhuis, Gerard

2017-02-28

The insight that a beam of light can carry orbital angular momentum (AM) in its propagation direction came up in 1992 as a surprise. Nevertheless, the existence of momentum and AM of an electromagnetic field has been well known since the days of Maxwell. We compare the expressions for densities of AM in general three-dimensional modes and in paraxial modes. Despite their classical nature, these expressions have a suggestive quantum mechanical appearance, in terms of linear operators acting on mode functions. In addition, paraxial wave optics has several analogies with real quantum mechanics, both with the wave function of a free quantum particle and with a quantum harmonic oscillator. We discuss how these analogies can be applied.This article is part of the themed issue 'Optical orbital angular momentum'. © 2017 The Author(s).

Balancing Venturi and Laissez-Faire Management Styles: Insights from Fluid Mechanical Analogs

Directory of Open Access Journals (Sweden)

Ruud Weijermars

2007-12-01

Full Text Available Mobilizing distributed Organizational Intelligence involves managerial efforts whereby the generation of new tacit knowledge requires dissemination of newly codified externalized knowledge. The managerial role in the early stage of knowledge creation is to support and stimulate the process of knowledge generation and to aid the diffusion of knowledge across organizational boundaries. In contrast, the subsequent 'harvesting' and goal-oriented application of knowledge requires convergence of human actors (H as carriers of distributed intelligence (DI. Optimization of the organizational performance and improved workflow efficiency is best effectuated by applying insights from fluid mechanical analogs. Several such analogs are introduced here and these provide insight that helps to funnel tacit and explicit knowledge into tangible asset value. Three sets of managerial lessons are inferred from the analogs: (1 Social bonding between professionals needs to be stimulated because professionals with strong social bonds (S can sustain effective workflows under relatively high pressures, while weak social bonds lead to turbulence and disruption; (2 Effective vision sharing is essential for goal-oriented and accelerated knowledge development in DI systems, and; (3 Managerial pressure may not overheat the critical limit that can be handled by resilient and strongly bonded DI networks, as this would result in disruptive turbulence even in experienced neural networks.

Creation of a bovine herpes virus 1 (BoHV-1) quantitative particle standard by transmission electron microscopy and comparison with established standards for use in real-time PCR.

Science.gov (United States)

Hoferer, Marc; Braun, Anne; Sting, Reinhard

2017-07-01

Standards are pivotal for pathogen quantification by real-time PCR (qPCR); however, the creation of a complete and universally applicable virus particle standard is challenging. In the present study a procedure based on purification of bovine herpes virus type 1 (BoHV-1) and subsequent quantification by transmission electron microscopy (TEM) is described. Accompanying quantitative quality controls of the TEM preparation procedure using qPCR yielded recovery rates of more than 95% of the BoHV-1 virus particles on the grid used for virus counting, which was attributed to pre-treatment of the grid with 5% bovine albumin. To compare the value of the new virus particle standard for use in qPCR, virus counter based quantification and established pure DNA standards represented by a plasmid and an oligonucleotide were included. It could be shown that the numbers of virus particles, plasmid and oligonucleotide equivalents were within one log10 range determined on the basis of standard curves indicating that different approaches provide comparable quantitative values. However, only virus particles represent a complete, universally applicable quantitative virus standard that meets the high requirements of an RNA and DNA virus gold standard. In contrast, standards based on pure DNA have to be considered as sub-standard due to limited applications. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Science Teachers' Analogical Reasoning

Science.gov (United States)

Mozzer, Nilmara Braga; Justi, Rosária

2013-08-01

Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

Analogies between Kruskal space and de Sitter space

International Nuclear Information System (INIS)

Rindler, W.

1986-01-01

Kruskal space is the analytical completion of Schwarzschild space and it consists of two outside and two inside Schwarzchild regions. Under suppression of the two angular coordinates, this space is usually diagrammed in terms of the Kruskal coordinates, μ,upsilon, much like Minkowski space is in terms of x, y. In particular, radial light paths correspond to +- 45 0 lines, the hyperbolas of μ/sup 2/ - upsilon/sup 2/ = a/sup 2/ represent uniformly accelerated particles (these being at rest in outer Schwarzschild space), and Lorentz transformations in μ, upsilon map the space into itself. Hermann Weyl first gave the analytic completion of de Sitter space as a hyper-hyperboloid μ/sub 1//sup 2/ + μ/sub 2//sup 2/ + μ/sub 3//sup 2/ + μ/sub 4//sup 2/ - upsilon/sup 2/ = a/sup 2/ in five-dimensional Minkowski space, which also contains two outside inside de Sitter regions. In a Weyl diagram, μ/sub 3/ and μ/sub 4/ are suppressed. There are many analogies: Lorentz transformations in μ/sub i/, upsilon map Weyl space into itself, the +- 45 0 generators are light paths, timelike plane hyperbolic sections are uniformly accelerated particles, and the horizon structure relative to each free worldline is analogous to the absolute horizon structure in Kruskal space

Path Creation

DEFF Research Database (Denmark)

Karnøe, Peter; Garud, Raghu

2012-01-01

This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts. Competenc......This paper employs path creation as a lens to follow the emergence of the Danish wind turbine cluster. Supplier competencies, regulations, user preferences and a market for wind power did not pre-exist; all had to emerge in a tranformative manner involving multiple actors and artefacts....... Competencies emerged through processes and mechanisms such as co-creation that implicated multiple learning processes. The process was not an orderly linear one as emergent contingencies influenced the learning processes. An implication is that public policy to catalyse clusters cannot be based...

Creationism in Europe

DEFF Research Database (Denmark)

For decades, the creationist movement was primarily situated in the United States. Then, in the 1970s, American creationists found their ideas welcomed abroad, first in Australia and New Zealand, then in Korea, India, South Africa, Brazil, and elsewhere—including Europe, where creationism plays...... the teaching of creationism as a scientific discipline on an equal footing with the theory of evolution." Creationism in Europe offers a discerning introduction to the cultural history of modern Europe, the variety of worldviews in Europe, and the interplay of science and religion in a global context...

Analog synthetic biology.

Science.gov (United States)

Sarpeshkar, R

2014-03-28

We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

A proposed physical analog for a quantum probability amplitude

Science.gov (United States)

Boyd, Jeffrey

What is the physical analog of a probability amplitude? All quantum mathematics, including quantum information, is built on amplitudes. Every other science uses probabilities; QM alone uses their square root. Why? This question has been asked for a century, but no one previously has proposed an answer. We will present cylindrical helices moving toward a particle source, which particles follow backwards. Consider Feynman's book QED. He speaks of amplitudes moving through space like the hand of a spinning clock. His hand is a complex vector. It traces a cylindrical helix in Cartesian space. The Theory of Elementary Waves changes direction so Feynman's clock faces move toward the particle source. Particles follow amplitudes (quantum waves) backwards. This contradicts wave particle duality. We will present empirical evidence that wave particle duality is wrong about the direction of particles versus waves. This involves a paradigm shift; which are always controversial. We believe that our model is the ONLY proposal ever made for the physical foundations of probability amplitudes. We will show that our ``probability amplitudes'' in physical nature form a Hilbert vector space with adjoints, an inner product and support both linear algebra and Dirac notation.

Creation of Two-Particle Entanglement in Open Macroscopic Quantum Systems

Directory of Open Access Journals (Sweden)

M. Merkli

2012-01-01

Full Text Available We consider an open quantum system of N not directly interacting spins (qubits in contact with both local and collective thermal environments. The qubit-environment interactions are energy conserving. We trace out the variables of the thermal environments and N−2 qubits to obtain the time-dependent reduced density matrix for two arbitrary qubits. We numerically simulate the reduced dynamics and the creation of entanglement (concurrence as a function of the parameters of the thermal environments and the number of qubits, N. Our results demonstrate that the two-qubit entanglement generally decreases as N increases. We show analytically that, in the limit N→∞, no entanglement can be created. This indicates that collective thermal environments cannot create two-qubit entanglement when many qubits are located within a region of the size of the environment coherence length. We discuss possible relevance of our consideration to recent quantum information devices and biosystems.

r-particle irreducible kernels, asymptotic completeness and analyticity properties of several particle collision amplitudes

International Nuclear Information System (INIS)

Bros, J.

1984-01-01

An account is given of the present status of many-particle structure analysis in the general framework of massive quantum field theory. Two main questions are discussed, namely: i) the equivalence between the asymptotic completeness of a field and the r-particle irreducibility of associated Bether-Salpeter type kernels; ii) the derivation of extended analyticity properties of the Green functions and multiparticle collision amplitudes around the corresponding physical regions. Substantial results concerning the 3→3 particle processes are described. An analogous multiparticle version of these results yields a partial understanding of the general case

Scattering and structures essentials and analogies in quantum physics

CERN Document Server

Povh, Bogdan

2017-01-01

Quantum physics may appear complicated, especially if one forgets the "big picture" and gets lost in the details. However, it can become clearer and less tangled if one applies a few fundamental concepts so that simplified approaches can emerge and estimated orders of magnitude become clear. Povh and Rosina’s Scattering and Structures presents the properties of quantum systems (elementary particles, nucleons, atoms, molecules, quantum gases, quantum liquids, stars, and early universe) with the help of elementary concepts and analogies between these seemingly different systems. In this new edition, sections on quantum gases and an up to date overview of elementary particles have been added.

Uses of solid state analogies in elementary particle theory

International Nuclear Information System (INIS)

Anderson, P.W.

1976-01-01

The solid state background of some of the modern ideas of field theory is reviewed, and additional examples of model situations in solid state or many-body theory which may have relevance to fundamental theories of elementary particles are adduced

Rhetoric and analogies

OpenAIRE

Aragonès, Enriqueta; Gilboa, Itzhak; Postlewaite, Andrew; Schmeidler, David; Universitat Autònoma de Barcelona. Unitat de Fonaments de l'Anàlisi Econòmica; Universitat Autònoma de Barcelona. Institut d'Anàlisi Econòmica

2013-01-01

The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One tech- nique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain reg- ularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a com- p...

Plutonium Particle Migration in the Shallow Vadose Zone: The Nevada Test Site as an Analog Site

Science.gov (United States)

Hunt, J. R.; Smith, D. K.

2004-12-01

The upper meter of the vadose zone in desert environments is the horizon where wastes have been released and human exposure is determined through dermal, inhalation, and food uptake pathways. This region is also characterized by numerous coupled processes that determine contaminant transport, including precipitation infiltration, evapotranspiration, daily and annual temperature cycling, dust resuspension, animal burrowing, and geochemical weathering reactions. While there is considerable interest in colloidal transport of minerals, pathogenic organisms, and contaminants in the vadose zone, there are limited field sites where the actual occurrence of contaminant migration can be quantified over the appropriate spatial and temporal scales of interest. At the US Department of Energy Nevada Test Site, there have been numerous releases of radionuclides since the 1950's that have become field-scale tracer tests. One series of tests was the four safety shots conducted in an alluvial valley of Area 11 in the 1950's. These experiments tested the ability of nuclear materials to survive chemical explosions without initiating fission reactions. Four above-ground tests were conducted and they released plutonium and uranium on the desert valley floor with only one of the tests undergoing some fission. Shortly after the tests, the sites were surveyed for radionuclide distribution on the land surface using aerial surveys and with depth. Additional studies were conducted in the 1970's to better understand the fate of plutonium in the desert that included studies of depth distribution and dust resuspension. More recently, plutonium particle distribution in the soil profile was detected using autoradiography. The results to date demonstrate the vertical migration of plutonium particles to depths in excess of 30 cm in this arid vadose zone. While plutonium migration at the Nevada Test Site has been and continues to be a concern, these field experiments have become analog sites for the

Web Archives for the Analog Archivist: Using Webpages Archived by the Internet Archive to Improve Processing and Description

OpenAIRE

Gelfand, Aleksandr

2018-01-01

Twenty years ago the Internet Archive was founded with the wide-ranging mission of providing universal access to all knowledge. In the two decades since, that organization has captured and made accessible over 150 billion websites. By incorporating the use of Internet Archive's Wayback Machine into their workflows, archivists working primarily with analog records may enhance their ability in such tasks as the construction of a processing plan, the creation of more accurate historical descript...

Intuitive analog circuit design

CERN Document Server

Thompson, Marc

2013-01-01

Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

Value Creation in Digital Service Platforms

DEFF Research Database (Denmark)

Ghazawneh, Ahmad; Mansour, Osama

2017-01-01

Value creation is increasingly relevant for owners of digital service platforms (DSPs). These owners have two vital goals: increase their service base and sustain their service offerers. A key element in continuously accommodating these goals is value creation. While the literature on DSPs is gro...... of service offerers. As such, our study proposes and contributes a value creation framework for DSPs that identifies 8 value sources and highlights resource combination and exchange in the process of value creation.......Value creation is increasingly relevant for owners of digital service platforms (DSPs). These owners have two vital goals: increase their service base and sustain their service offerers. A key element in continuously accommodating these goals is value creation. While the literature on DSPs...... is growing, there is a paucity of knowledge on the value creation process in these platforms. Drawing on a qualitative study of Uber drivers in Denmark and Sweden, we synthesize Schumpeter’s theory of value creation to develop an understanding of the value creation process in DSPs from the perspective...

Internal frame dragging and a global analog of the Aharonov-Bohm effect

International Nuclear Information System (INIS)

March-Russell, J.; Preskill, J.; Wilczek, F.

1992-01-01

It is shown that the breakdown of a global symmetry group to a discrete subgroup can lead to analogs of the Aharonov-Bohm effect. At sufficiently low momentum transfer, the cross section for scattering of a particle with nontrivial Z 2 charge off a global vortex is almost equal to (but definitely different from) maximal Aharonov-Bohm scattering; the effect goes away at large momentum transfer. The scattering of a spin-1/2 particle off a magnetic vortex provides an amusing experimentally realizable example

Gravitationally induced adiabatic particle production: from big bang to de Sitter

Science.gov (United States)

de Haro, Jaume; Pan, Supriya

2016-08-01

In the background of a flat homogeneous and isotropic space-time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology.

Gravitationally induced adiabatic particle production: from big bang to de Sitter

International Nuclear Information System (INIS)

Haro, Jaume de; Pan, Supriya

2016-01-01

In the background of a flat homogeneous and isotropic space–time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology. (paper)

The Future of Co-Creation

DEFF Research Database (Denmark)

Seppa, Marko; Tanev, Stoyan

2011-01-01

The objective of this article is to provide a brief summary of the key directions in value co-creation research that have emerged in the last 10 years. It points to several emerging streams in value co-creation research including: i) general management perspective; ii) new product development...... on business co-creation. The development of business co-creation frameworks integrating the participatory role of both universities and vibrantly emerging business ecosystems represents a valuable alternative to traditional technology transfer and business administration approaches....

The Higgs Particle: A Useful Analogy for Physics Classrooms

Science.gov (United States)

Cid, Xabier; Cid, Ramon

2010-01-01

In November 2009, the largest experiment in history was restarted. Its prime target is the Higgs particle--the last remaining undiscovered piece of our current theory of matter. We present a very simple way to introduce this topic to senior secondary school students, using a comparison with the refractive index of light.

'Ethos' Enabling Organisational Knowledge Creation

Science.gov (United States)

Matsudaira, Yoshito

This paper examines knowledge creation in relation to improvements on the production line in the manufacturing department of Nissan Motor Company and aims to clarify embodied knowledge observed in the actions of organisational members who enable knowledge creation will be clarified. For that purpose, this study adopts an approach that adds a first, second, and third-person's viewpoint to the theory of knowledge creation. Embodied knowledge, observed in the actions of organisational members who enable knowledge creation, is the continued practice of 'ethos' (in Greek) founded in Nissan Production Way as an ethical basis. Ethos is knowledge (intangible) assets for knowledge creating companies. Substantiated analysis classifies ethos into three categories: the individual, team and organisation. This indicates the precise actions of the organisational members in each category during the knowledge creation process. This research will be successful in its role of showing the indispensability of ethos - the new concept of knowledge assets, which enables knowledge creation -for future knowledge-based management in the knowledge society.

Bound states of 'dressed' particles

International Nuclear Information System (INIS)

Shirokov, M.I.

1994-01-01

A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)

Value Creation in International Business

DEFF Research Database (Denmark)

The edited collection brings into focus the meanings, interpretations and the process of value creation in international business. Exploring value creation in the context of emerging and developed economies, Volume 2 takes the perspective of small and medium sized enterprises and examines various...... approaches to value creation in the process of firm internationalization. Providing theoretical and practical insights, the authors open an intellectual debate into what value is, and how it is created through the internationalization activities of firms. Value Creation in International Business...... is a pioneering two volume work intended to provoke theoretical and empirical development in International Business research. Moreover, it is intended as a bridge between concepts derived from general business firm-level research agendas such as value creation and business model, and internationalization...

High-speed and high-resolution analog-to-digital and digital-to-analog converters

NARCIS (Netherlands)

van de Plassche, R.J.

1989-01-01

Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog

Particle physics data system at IHEP

International Nuclear Information System (INIS)

Alekhin, S.I.; Grudtsin, S.N.; Demidov, N.G.; Ezhela, V.V.

1981-01-01

This note presents the description of information search and retrieval facilities supplied by the Berkeley Database Management System - BDMS V2.2 implemented for ICL-1906A computers at IHEP. The system is used for creation and maintenance of archieve Particle Physics Data Bases [ru

Density matrix of a quantum field in a particle-creating background

International Nuclear Information System (INIS)

Gavrilov, S.P.; Gitman, D.M.; Tomazelli, J.L.

2008-01-01

We examine the time evolution of a quantized field in external backgrounds that violate the stability of vacuum (particle-creating backgrounds). Our purpose is to study the exact form of the final quantum state (the density operator at the final instant of time) that has emerged from a given arbitrary initial state (from a given arbitrary density operator at the initial time instant) in the course of evolution. We find a generating functional that allows one to obtain density operators for an arbitrary initial state. Averaging over states of the subsystem of antiparticles (particles), we obtain explicit forms of reduced density operators for the subsystem of particles (antiparticles). Analyzing one-particle correlation functions, we establish a one-to-one correspondence between these functions and the reduced density operators. It is shown that in the general case a presence of bosons (e.g., gluons) in the initial state increases the creation rate of the same type of bosons. We discuss the question (and its relation to the initial stage of quark-gluon plasma formation) whether a thermal form of one-particle distribution can appear even if the final state of the complete system is not in thermal equilibrium. In this respect, we discuss some cases when pair-creation by an electric-like field can mimic the one-particle thermal distribution. We apply our technics to some QFT problems in slowly varying electric-like backgrounds: electric, SU(3) chromoelectric, and metric. In particular, we analyze the time and temperature behavior of the mean numbers of created particles, provided that the effects of switching the external field on and off are negligible. It is demonstrated that at high temperatures and in slowly varying electric fields the rate of particle-creation is essentially time-dependent

Density matrix of a quantum field in a particle-creating background

Energy Technology Data Exchange (ETDEWEB)

Gavrilov, S.P. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05315-970 Sao Paulo, SP (Brazil)], E-mail: gavrilovsergeyp@yahoo.com; Gitman, D.M. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05315-970 Sao Paulo, SP (Brazil)], E-mail: gitman@dfn.if.usp.br; Tomazelli, J.L. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05315-970 Sao Paulo, SP (Brazil)], E-mail: tomazelli@fsc.ufsc.br

2008-06-01

We examine the time evolution of a quantized field in external backgrounds that violate the stability of vacuum (particle-creating backgrounds). Our purpose is to study the exact form of the final quantum state (the density operator at the final instant of time) that has emerged from a given arbitrary initial state (from a given arbitrary density operator at the initial time instant) in the course of evolution. We find a generating functional that allows one to obtain density operators for an arbitrary initial state. Averaging over states of the subsystem of antiparticles (particles), we obtain explicit forms of reduced density operators for the subsystem of particles (antiparticles). Analyzing one-particle correlation functions, we establish a one-to-one correspondence between these functions and the reduced density operators. It is shown that in the general case a presence of bosons (e.g., gluons) in the initial state increases the creation rate of the same type of bosons. We discuss the question (and its relation to the initial stage of quark-gluon plasma formation) whether a thermal form of one-particle distribution can appear even if the final state of the complete system is not in thermal equilibrium. In this respect, we discuss some cases when pair-creation by an electric-like field can mimic the one-particle thermal distribution. We apply our technics to some QFT problems in slowly varying electric-like backgrounds: electric, SU(3) chromoelectric, and metric. In particular, we analyze the time and temperature behavior of the mean numbers of created particles, provided that the effects of switching the external field on and off are negligible. It is demonstrated that at high temperatures and in slowly varying electric fields the rate of particle-creation is essentially time-dependent.

Del „yo creo” al „nosotros creamos”: analogías y contextualizaciones en la asunción de la creatividad social - From the „I create” to the „we create”: analogies and contextualization in the assumption of the social creativity

Directory of Open Access Journals (Sweden)

SANTACRUZ GUERRERO, Pablo

2014-06-01

Full Text Available Exploration of some conditions and features, from different views, has been associated with favoring creativity in expressive and productive processes of individual imprint, which is contextualized in possible dynamics of social creativity, not from categorical reductionism but based on analog links that propitiate the exam of some required specificities from a comprehensive perspective of cultural creation and policy underwritten by a collective or community subject. Those factors which intervene vitally in the origin of creation dynamics until the conditions that work in cooperative ventures are considered, passing through those characteristics that tend to define the functionality of a creative thought since the referred social perspective. In order to establish connections between theory and practice, it is referred a significant experience that integrates some of the main points that animate this exposure.

Structured Analog CMOS Design

CERN Document Server

Stefanovic, Danica

2008-01-01

Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

Water Uptake By Mars Salt Analogs: An Investigation Of Stable Aqueous Solutions On Mars Using Raman Microscopy

Science.gov (United States)

Nuding, D.; Gough, R. V.; Jorgensen, S. K.; Tolbert, M. A.

2013-12-01

To understand the formation of briny aqueous solutions on Mars, a salt analog was developed to closely match the individual cation and anion concentrations as reported by the Wet Chemistry Laboratory aboard the Phoenix Lander. ';Instant Mars' is a salt analog developed to fully encompass the correct concentrations of magnesium, calcium, potassium, sodium, perchlorate, chloride, and sulfate ions. Using environmental Raman microscopy, we have studied the water uptake by the Instant Mars analog as a function of temperature and relative humidity. Water uptake was monitored using Raman spectroscopy in combination with optical microscopy. A MicroJet droplet generator was used to generate 30 μm diameter particles that were deposited onto a quartz disc. The particles undergo visual transformations as the relative humidity (RH) is increased and the presence of water uptake is confirmed by Raman spectroscopy. At -30° C, water uptake begins at ~ 35% RH as humidity is increased. The water uptake is marked by the growth of a sulfate peak at 990 cm-1, an indicator that sulfate has undergone a phase transition into an aqueous state. As the RH continues to increase, the peak in the O-H region (~3500 cm-1) broadens as more liquid water accumulates in the particles. The Instant Mars particles achieve complete deliquescence at 68% RH, indicated both visually and with Raman spectroscopy. The gradual water uptake observed suggests that deliquescence of the Instant Mars particles is not an immediate process, but that it occurs in steps marked by the deliquescence of the individual salts. Perhaps of even more significance is the tendency for the Instant Mars particles to remain aqueous at low humidity as RH is decreased. Raman spectra indicate that liquid water is present as low as 2% RH at -30° C. Ongoing work will examine the phase of Instant Mars particles under simulated Martian surface and subsurface conditions to gain insight into the possibility for aqueous solutions on Mars

Creation of hydrophobic surfaces using a paint containing functionalized oxide particles

Science.gov (United States)

Sino, Paul Albert L.; Herrera, Marvin U.; Balela, Mary Donnabelle L.

2017-05-01

Hydrophobic surfaces were created by coating various substrates (aluminum sheet, soda-lime glass, silicon carbide polishing paper, glass with double-sided adhesive) with paint containing functionalized oxide particles. The paint was created by functionalizing oxide particles (ground ZnO, TiO2 nanoparticles, or TiO2 microparticles) with fluorosilane molecules in absolute ethanol. Water contact angle of samples shows that the coated substrate becomes hydrophobic (water contact angle ≥ 90°). Among the oxides that were used, ground ZnO yielded contact angle exemplifying superhydrophobicity (water contact angle ≥ 150°). Scanning electron micrograph of paint-containing TiO2 nanoparticles shows rough functionalized oxides structures which probably increase the hydrophobicity of the surface.

Particle creation amplification in curved space due to thermal effects

International Nuclear Information System (INIS)

Laciana, C. E.

1997-01-01

A physical system composed by a scalar field minimally coupled to gravity and a thermal reservoir as in thermo field dynamics, all of them in curved space-time, is considered. When the formalism of thermo field dynamics is generalized to the above case, an amplification in the number of created particles is predicted

Analog-to-digital conversion

CERN Document Server

Pelgrom, Marcel J M

2010-01-01

The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

The Connection and Distinction between the Design Argument with the Teleological Argument and the Best Creational System

Directory of Open Access Journals (Sweden)

Farah Ramin

2011-09-01

Full Text Available The design argument faced with big different writings in its Western background so that these writings have essential difference with each others. The design argument is posteriori demonstration for the existence of God which by analogy or induction and partial or general instances of the order in nature tries to affirm the intelligent designer.  Since the concepts of design and end have firm connection with each other in the Western writings of this design but the concepts of purposiveness of divine acts, purposiveness of nature and its best system is assumed the same with each other and obvious confusion has been made between the design argument with the teleological argument and the best creational system. The aim of the article is to consider order in the world based upon the united components of a system (design argument, final cause (teleological argument and best system (best creational system argument and also to manifest the connection and distinction of these three reasoning. 

The Co-creation Continuum

DEFF Research Database (Denmark)

Ind, Nicholas; Iglesias, Oriol; Markovic, Stefan

2017-01-01

-creation - from tactical market research tool to strategic collaborative innovation method, and shows that brands can be positioned along a continuum between these two polarities. This article also presents the implications for those that want to seize the potential of co-creation....

Technical Knowledge Creation: Enabling Tacit Knowledge Use

DEFF Research Database (Denmark)

Søberg, Peder Veng; Chaudhuri, Atanu

2018-01-01

The paper investigates knowledge creation in nascent technical industries, a somewhat neglected empirical setting concerning knowledge creation. Frameworks on organizational learning and knowledge creation assume that knowledge creation depends on language creation and neglect the benefits involved...... by allowing elements of new product and process ideas to mature in a tacit form, whereas cognitive neuroscience data suggests that technical knowledge creation is largely nonlinguistic. The four case studies point to excessive reliance on group discussion, a need for more trial and error and that field tests...... and prototypes generate new learnings that save time and lowers subsequent risks. Technical knowledge creation in nascent high tech industries requires opportunities to work with and further develop knowledge in its tacit form. The paper refines frameworks on organizational learning and knowledge creation...

Job Creation and Job Types

DEFF Research Database (Denmark)

Kuhn, Johan M.; Malchow-Møller, Nikolaj; Sørensen, Anders

We extend earlier analyses of the job creation of start-ups vs. established firms by taking into consideration the educational content of the jobs created and destroyed. We define educationspecific measures of job creation and job destruction at the firm level, and we use these to construct...... a measure of “surplus job creation” defined as jobs created on top of any simultaneous destruction of similar jobs in incumbent firms in the same region and industry. Using Danish employer-employee data from 2002-7, which identify the start-ups and which cover almost the entire private sector......, these measures allow us to provide a more nuanced assessment of the role of entrepreneurial firms in the job-creation process than previous studies. Our findings show that while start-ups are responsible for the entire overall net job creation, incumbents account for more than a third of net job creation within...

Discursive interactions and the use of analogies in physics teaching

Directory of Open Access Journals (Sweden)

Fernanda Cátia Bozelli

2012-03-01

Full Text Available In the last few years, Science Education researchers have shown new ways do conceive the processes of teaching and learning, demanding the displacement from the individual understanding of specific phenomena to a new context, which means, to a bias of meanings construction in a social context. However, still there are few researches concerned with how teachers give support to the process throughout the students build meanings in science classrooms, about how these interactions are produced, developed and, in what level they indeed interfere in students’ learning. This research tries to move forward in this line of research, investigating the interactive discursive processes related to the figures of speech (in this case, analogies, particularly about the context of its creation, working out and exploration in physics classrooms. One of the questions which allowed that reflection was that to explain scientific concepts in classroom involves, even to understand contents, as to be able to communicate this content in a more effective way. Does the posture assumed by teachers in the conversational aspect, during the discursive interaction, has contributed or influenced the rise and exploration of analogies in classrooms? To answer these questions we adopted a qualitative and interpretative approach, trough which we analyzed a sample of 23 futures high school physics teachers, during a semester, when the development of supervised practicum activities, carried out in the two last semesters of their undergraduate program, done in a public state university in São Paulo, Brazil. Data collected show that it is necessary more discussion about the use of analogies in teachers initial training programs; taking account its function, benefit or disadvantage, how to explore analogies in a more effective way. Besides that, how the discursive interactive context among teacher and students can interfere in the teaching and learning processes in classroom. We

Asymmetric active nano-particles for directive near-field radiation

DEFF Research Database (Denmark)

Arslanagic, Samel; Thorsen, Rasmus O.

2016-01-01

In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

Unified time analysis of photon and particle tunnelling

International Nuclear Information System (INIS)

Olkhovsky, V.S.; Recami, Erasmo; Jakiel, Jacek

2004-01-01

A unified time analysis of photon and nonrelativistic particle tunnellings is presented, in which time is regarded as a quantum observable, canonically conjugated to energy. Within this approach, one can introduce self-consistent definitions of the tunnelling times, on the basis of conventional quantum mechanics (or one-dimensional quantum electrodynamics) only. The validity of the Hartman effect [which states the tunnelling duration to be independent of the (opaque) barrier width, with superluminal group velocities of the tunnelling packet as a consequence] is verified for all the known expressions of the mean tunnelling time. However, some noticeable generalizations of (and deviations from) the Hartman effect are, as well, briefly investigated. Moreover, the analogy between particle and photon tunnelling is suitably exploited; on the basis of such an analogy, an explanation of some recent interesting microwave and optical experimental results on tunnelling times is proposed. Attention is devoted, at last, to some aspects of the causality problem for particle and photon tunnelling

Analog earthquakes

International Nuclear Information System (INIS)

Hofmann, R.B.

1995-01-01

Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository

Scattering and structures. Essentials and analogies in quantum physics. 2. ed.

Energy Technology Data Exchange (ETDEWEB)

Povh, Bogdan [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Rosina, Mitja [Ljubljana Univ. (Slovenia). Dept. of Physics

2017-07-01

Quantum physics may appear complicated, especially if one forgets the ''big picture'' and gets lost in the details. However, it can become clearer and less tangled if one applies a few fundamental concepts so that simplified approaches can emerge and estimated orders of magnitude become clear. Povh and Rosina's Scattering and Structures presents the properties of quantum systems (elementary particles, nucleons, atoms, molecules, quantum gases, quantum liquids, stars, and early universe) with the help of elementary concepts and analogies between these seemingly different systems. In this new edition, sections on quantum gases and an up to date overview of elementary particles have been added.

Teaching Einsteinian Physics at Schools: Part 2, Models and Analogies for Quantum Physics

Science.gov (United States)

Kaur, Tejinder; Blair, David; Moschilla, John; Zadnik, Marjan

2017-01-01

The Einstein-First project approaches the teaching of Einsteinian physics through the use of physical models and analogies. This paper presents an approach to the teaching of quantum physics which begins by emphasising the particle-nature of light through the use of toy projectiles to represent photons. This allows key concepts including the…

Eternal and evanescent black holes and accelerating mirror analogs

Science.gov (United States)

Good, Michael R. R.; Linder, Eric V.

2018-03-01

The analogy between black hole radiation and accelerating mirror radiation (the dynamical Casimir effect) is particularly strong for mirror trajectories giving rise to a constant thermal flux of particles. We present new ways to achieve such thermal plateaus, and customize their finite, semi-infinite, and eternal presence, corresponding to forming/collapsing, complete-evaporation/remnants, and eternal black holes. We find simple expressions for the energy flux in terms of the mirror rapidity as a function of proper time and null time.

Creationism in Europe

DEFF Research Database (Denmark)

Blancke, Stefaan; Hjermitslev, Hans Henrik; Braeckman, Johan

2013-01-01

which material is missing from the literature (the “gaps”) and signal which gaps we think should first be filled. Third, on the basis of a forthcoming international historical study, we outline the possible factors that affect the popularity of creationism in Europe (the “prospects”). We also sketch how...... a sustained study of European creationism can contribute to other research domains such as the study of cultural evolution and the relation between science and religion....

Analog circuit design

CERN Document Server

Dobkin, Bob

2012-01-01

Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

A study on the application of two different acoustic analogies to experimental PIV data

NARCIS (Netherlands)

Koschatzky, V.; Westerweel, J.; Boersma, B.J.

2011-01-01

The aim of the present study is to compare two different acoustic analogies applied to time-resolved particle image velocimetry (PIV) data for the prediction of the acoustic far-field generated by the flow over a rectangular cavity. We consider the model problem of sound radiating from an open,

Optical analogy. Synthesis report

International Nuclear Information System (INIS)

1965-01-01

The authors report the study of conditions under which light attenuation (reflection, diffusion, absorption) and the attenuation of some radiations (notably thermal neutrons) can be described with analogical calculations. The analogy between light physical properties and neutron properties is not searched for, but the analogy between their attenuation characteristics. After having discussed this possible analogy, they propose a mathematical formulation of neutron and optical phenomena which could theoretically justify the optical analogy. The second part reports a more practical study of optics problems such as the study of simple optics materials and illumination measurements, or more precisely the study of angular distributions of optical reflections, a determination of such angular distributions, and an experimental determination of the albedo

Recirculator "SALO" - A basis for creation of a model of sub-critical reactor controlled by the accelerator

NARCIS (Netherlands)

Gann, V.V.; Guk, I.S.; Dovbnya, A.N.; Kononenko, S.G.; Kostromin, A.S.; Peev, F.A.; Prochorets, I.M.; Soldatov, C.A.; Tarasenko, A.S.; Wiel, van der M.J.; Botman, J.I.M.

2006-01-01

Recently opportunities of creation test facility with sub-crit. reactors controlled by accelerators of particles are actively discussed. At an initial stage of these researches it is the most expedient to use electron accelerators as cost of such facility will be much less, than at use of proton

The creation of economic policy after the entrance to EU

Directory of Open Access Journals (Sweden)

Vodzinská Vladimíra

2004-06-01

Full Text Available The Slovac republic, analogous to other countries which came in the Europe Union this year, is standing before solving the problem of real integration to the economic and monetary system.Submitted article shows, that preliminary transformation process of national economy, specially the privatization process of national property was remarked by influencies, which has led to the creation of social excessively high losts and very negative affected also for the creation and realization the economis policy of the state.In this signification remarked also bargaining position of Slovac republic in so called before entrance negotiations with the representants from Europe union as well the character of risks related to urgency subserve the main liability in conection with the entrance to the EU, i.e. the convergency criterias specified by maastrichts agreement.In this continuity becomes the cardinal problem of the economic policy of the state alternative modeling of exercitation its fiscal and monetary tools, which permits of such time and general harmonising of real and nominal processes convergency, which will have tenable social character.Videlicet, the entrance fixation of the Slovac republic to the ERM2 for the year 2006 and to the eurozone for the year 2008, or 2009 involves to assert the tools of economic policy as, that the economic increase couched in expected long tenable development of GDP, balance of payments, inflation and unemployment was social effective.In this signification are intraducing some risks and factors, which can work against these development.

Rapid creation of distant entanglement by multi-photon resonant fluorescence

Science.gov (United States)

Cohen, Guy Z.; Sham, L. J.

2014-03-01

We study a simple, effective and robust method for entangling two separate stationary quantum dot spin qubits with high fidelity using multi-photon Gaussian state. The fluorescence signals from the two dots interfere at a beam splitter. The bosonic nature of photons leads, in analogy with the Hong-Ou-Mandel (HOM) effect, to selective pairing of photon holes (photon absences in the fluorescent signals). By the HOM effect, two photon holes with the same polarization end up at the same beam splitter output. As a result, two odd photon number detections at the outgoing beams, which must correspond to two photon holes with different polarizations, herald entanglement creation. The robustness of the Gaussian states is evidenced by the ability to compensate for photon absorption and noise by a moderate increase in the number of photons at the input. We calculate the entanglement generation rate in the ideal, non-ideal and near-ideal detector regimes and find substantial improvement over single-photon schemes in all three regimes. Fast and efficient spin-spin entanglement creation can form the basis for a scalable quantum dot quantum computing network. Our predictions can be tested using current experimental capabilities. This research was supported by the U.S. Army Research Office MURI award W911NF0910406, by NSF grant PHY-1104446 and by ARO (IARPA, W911NF-08-1-0487). The authors thank D. G. Steel for useful discussions.

Molasses or Crowds: Making Sense of the Higgs Boson with Two Popular Analogies

Science.gov (United States)

Alsop, S.; Beale, S.

2013-01-01

The recent discovery of the Higgs boson at the Large Hadron Collider (LHC) has contributed to a surge of interest in particle physics and science education in general. Given the conceptual difficulty of the phenomenon in question, it is inevitable that teachers and science communicators rely on analogies to explain the Higgs physics and its…

Twistor theory a particle-physicist attitude

International Nuclear Information System (INIS)

Perjes, Z.

1979-07-01

Particle models in twistor theory are reviewed, starting with an introduction into the kinematical-twistor formalism which describes massive particles in Minkowski space-time. The internal transformations of constituent twistors are then discussed. The quantization rules available from a study of twistor scattering situations are used to construct quantum models of fundamental particles. The theory allows the introduction of an internal space with a Kaehlerian metric where hadron structure is described by ''spherical'' states of bound constituents. It is conjectured that the spectrum of successive families of hadrons might approach an accumulation point in energy. Above this threshold energy, the Kaehlerian analog of ionization could occur wherein the zero-mass constituents (twistors) of the particle break free. (author)

Are all analogies created equal? Prefrontal cortical functioning may predict types of analogical reasoning.

Science.gov (United States)

Chrysikou, Evangelia G; Thompson-Schill, Sharon L

2010-06-01

Abstract The proposed theory can account for analogies based on learned relationships between elements in the source and target domains. However, its explanatory power regarding the discovery of new relationships during analogical reasoning is limited. We offer an alternative perspective for the role of PFC in analogical thought that may better address different types of analogical mappings.

Creationism in Europe

DEFF Research Database (Denmark)

For decades, the creationist movement was primarily situated in the United States. Then, in the 1970s, American creationists found their ideas welcomed abroad, first in Australia and New Zealand, then in Korea, India, South Africa, Brazil, and elsewhere—including Europe, where creationism plays....... It will be of interest to students and scholars in the history and philosophy of science, religious studies, and evolutionary theory, as well as policy makers and educators concerned about the spread of creationism in our time....

Possible applications of the sigma delta digitizer in particle physics

International Nuclear Information System (INIS)

Hallgren, B.

1991-01-01

The sigma delta (ΣΔ) principle is an analog-to-digital conversion technique based on high-frequency sampling and low-pass filtering of the quantization noise. Resolution in time is exchanged for that in amplitude so as to avoid the difficulty of implementing complex precision analog circuits, in favour of digital circuits. The approach is attractive because it will make it possible to integrate complete channels of high resolution analog-to-digital converters and time digitizers in submicron digital VLSI technologies. Advantage is taken of the fact that the state-of-the-art VLSI is better suited for providing fast digital circuits than for providing precise analog circuits. This article describes the principle and the performance of the ideal ΣΔ digitizer. The design and measurements of a new 10 MHz prototype circuit of a second-order ΣΔ is presented to show the high speed operation of such a circuit. The expected performance of a CMOS test design using the same principles is discussed. Digital filters, useful for particle physics, are introduced. A comparison to other digitizing techniques is made and the potential applications of the ΣΔ digitizer in particle physics are outlined. (orig.)

Troubleshooting analog circuits

CERN Document Server

Pease, Robert A

1991-01-01

Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

Analogical Reasoning in Geometry Education

Science.gov (United States)

Magdas, Ioana

2015-01-01

The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

A Generalized Boltzmann Fokker-Planck Method for Coupled Charged Particle Transport

Energy Technology Data Exchange (ETDEWEB)

Prinja, Anil K

2012-01-09

The goal of this project was to develop and investigate the performance of reduced-physics formulations of high energy charged particle (electrons, protons and heavier ions) transport that are computationally more efficient than not only analog Monte Carlo methods but also the established condensed history Monte Carlo technique. Charged particles interact with matter by Coulomb collisions with target nuclei and electrons, by bremsstrahlung radiation loss and by nuclear reactions such as spallation and fission. Of these, inelastic electronic collisions and elastic nuclear collisions are the dominant cause of energy-loss straggling and angular deflection or range straggling of a primary particle. These collisions are characterized by extremely short mean free paths (sub-microns) and highly peaked, near-singular differential cross sections about forward directions and zero energy loss, with the situation for protons and heavier ions more extreme than for electrons. For this reason, analog or truephysics single-event Monte Carlo simulation, while possible in principle, is computationally prohibitive for routine calculation of charged particle interaction phenomena.

Analogy Between Particle in a Box and Jahn–Teller Effect

Indian Academy of Sciences (India)

IAS Admin

Solving the SchrÄodinger equation, the allowed energy levels of the particle are given .... to slight distortion of the cube. Using (3), the new energy of ... ARTICLE. The Jahn–Teller theorem states that in a nonlinear molecule, if degenerate orbitals are asymmetrically occupied a distortion will occur to remove the degeneracy.

A theory approach for creation of the matter of universe

International Nuclear Information System (INIS)

Duong Van Phi; Duong Anh Duc

1993-08-01

We shall represent an approach for the creation of the matter of Universe in the framework of a Quantum Theory, established in an 8-dimensional space. The primitive matter was being created from the Primary Vacuum and it consisted of the deuterons atoms, neutrinos and photons. From these neutral elements the attractive centres were formed and in the final stage an extremely high mass density Universe was built, and successively, the Big-Bang occurred. The problems of particle dominance, of excess of the deuterons and of magnitude of the numbers of neutrinos, etc. are discussed. (author). 19 refs, 2 tabs

Value Creation in International Business

DEFF Research Database (Denmark)

is a pioneering two volume work intended to provoke theoretical and empirical development in International Business research. Moreover, it is intended as a bridge between concepts derived from general business firm-level research agendas such as value creation and business model, and internationalization......The edited collection brings into focus the meanings, interpretations and the process of value creation in international business. Exploring value creation in the context of emerging and developed economies, Volume 2 takes the perspective of small and medium sized enterprises and examines various...

Current flow and pair creation at low altitude in rotation-powered pulsars' force-free magnetospheres: space charge limited flow

Science.gov (United States)

Timokhin, A. N.; Arons, J.

2013-02-01

We report the results of an investigation of particle acceleration and electron-positron plasma generation at low altitude in the polar magnetic flux tubes of rotation-powered pulsars, when the stellar surface is free to emit whatever charges and currents are demanded by the force-free magnetosphere. We apply a new 1D hybrid plasma simulation code to the dynamical problem, using Particle-in-Cell methods for the dynamics of the charged particles, including a determination of the collective electrostatic fluctuations in the plasma, combined with a Monte Carlo treatment of the high-energy gamma-rays that mediate the formation of the electron-positron pairs. We assume the electric current flowing through the pair creation zone is fixed by the much higher inductance magnetosphere, and adopt the results of force-free magnetosphere models to provide the currents which must be carried by the accelerator. The models are spatially one dimensional, and designed to explore the physics, although of practical relevance to young, high-voltage pulsars. We observe novel behaviour (a) When the current density j is less than the Goldreich-Julian value (0 electrically trapped particles with the same sign of charge as the beam. The voltage drops are of the order of mc2/e, and pair creation is absent. (b) When the current density exceeds the Goldreich-Julian value (j/jGJ > 1), the system develops high voltage drops (TV or greater), causing emission of curvature gamma-rays and intense bursts of pair creation. The bursts exhibit limit cycle behaviour, with characteristic time-scales somewhat longer than the relativistic fly-by time over distances comparable to the polar cap diameter (microseconds). (c) In return current regions, where j/jGJ generated pairs allow the system to simultaneously carry the magnetospherically prescribed currents and adjust the charge density and average electric field to force-free conditions. We also elucidate the conditions for pair creating beam flow to be

Skyrmion creation and annihilation by spin waves

International Nuclear Information System (INIS)

Liu, Yizhou; Yin, Gen; Lake, Roger K.; Zang, Jiadong; Shi, Jing

2015-01-01

Single skyrmion creation and annihilation by spin waves in a crossbar geometry are theoretically analyzed. A critical spin-wave frequency is required both for the creation and the annihilation of a skyrmion. The minimum frequencies for creation and annihilation are similar, but the optimum frequency for creation is below the critical frequency for skyrmion annihilation. If a skyrmion already exists in the cross bar region, a spin wave below the critical frequency causes the skyrmion to circulate within the central region. A heat assisted creation process reduces the spin-wave frequency and amplitude required for creating a skyrmion. The effective field resulting from the Dzyaloshinskii-Moriya interaction and the emergent field of the skyrmion acting on the spin wave drive the creation and annihilation processes

Value Co-creation Behaviour

DEFF Research Database (Denmark)

Laud, Gaurangi; Karpen, Ingo Oswald

2017-01-01

Purpose:The purpose of this paper is to identify antecedents and consequences ofcustomers’ value co-creation behaviour (VCB). VCB as a means to facilitatevalue realisation processes is gaining importance in service research andpractice. Encouraging such enactments can be challenging, but can also...... offercompetitive advantages. Design/methodology/approach:We empirically investigate a conceptual model by converging threecontemporary concepts of co-creation research – embeddedness, VCB and value-in-context– and examining the interdependencies between them. Data were collected in anonline forum of a leading......, the studyhighlights the significance of the nature of customer’s social constellationsto develop contexts where value outcomes are actualised. Understanding thefactors that shape VCB offers insights for firms to recognise how and wherevalue propositions can be deployed that drives on-going co-creation processes...

Designing Learning for Co-Creation

DEFF Research Database (Denmark)

Gnaur, Dorina; Larsen-Nielsen, Marie

2017-01-01

Designing learning for co-creation - conceptual and practical considerations, Dorina Gnaur and Inger Marie Larsen-Nielsen explore the practical educational point of view. The question they are posing themselves is: how can higher and further education (HE) educate for co-creation, that is, provide...... educational frameworks that respond to the societal demand for co-creation, particularly within the public welfare sector? First, they focus on which organisational and individual requirements an HE learning design should take into account in order to support the diffusion of co-creation competences....... Then they argue for the need to integrate these considerations in the learning design and demonstrate a practical application in the form of a didactical design. They call this a hybrid learning design, in that it takes advantage of technological developments to mediate co-creative learning in multiple learning...

Analog and mixed-signal electronics

CERN Document Server

Stephan, Karl

2015-01-01

A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

Meat analog: a review.

Science.gov (United States)

Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

2015-01-01

The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers.

Modelling of non-metallic particles motion process in foundry alloys

Directory of Open Access Journals (Sweden)

P. L. Żak

2015-04-01

Full Text Available The behaviour of non-metallic particles in the selected composites was analysed, in the current study. The calculations of particles floating in liquids differing in viscosity were performed. Simulations based on the Stokes equation were made for spherical SiC particles and additionally the particle size influence on Reynolds number was analysed.The movement of the particles in the liquid metal matrix is strictly connected with the agglomerate formation problem.Some of collisions between non-metallic particles lead to a permanent connection between them. Creation of the two spherical particles and a metallic phase system generates the adhesion force. It was found that the adhesion force mainly depends on the surface tension of the liquid alloy and radius of non-metallic particles.

Digital and analog communication systems

Science.gov (United States)

Shanmugam, K. S.

1979-01-01

The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

Antiproton annihilation physics annihilation physics in the Monte Carlo particle transport code particle transport code SHIELD-HIT12A

DEFF Research Database (Denmark)

Taasti, Vicki Trier; Knudsen, Helge; Holzscheiter, Michael

2015-01-01

The Monte Carlo particle transport code SHIELD-HIT12A is designed to simulate therapeutic beams for cancer radiotherapy with fast ions. SHIELD-HIT12A allows creation of antiproton beam kernels for the treatment planning system TRiP98, but first it must be benchmarked against experimental data. An...

Children's Development of Analogical Reasoning: Insights from Scene Analogy Problems

Science.gov (United States)

Richland, Lindsey E.; Morrison, Robert G.; Holyoak, Keith J.

2006-01-01

We explored how relational complexity and featural distraction, as varied in scene analogy problems, affect children's analogical reasoning performance. Results with 3- and 4-year-olds, 6- and 7-year-olds, 9- to 11-year-olds, and 13- and 14-year-olds indicate that when children can identify the critical structural relations in a scene analogy…

Facilitating Value Co-Creation

DEFF Research Database (Denmark)

Veith, Anne; Assaf, Albert; Josiassen, Alexander

2013-01-01

will also lead to a high rewards. According to postmodern consumerism theory, consumers are intrinsically motivated to participate (Arnould et al., 2006; Borghini & Caru, 2008; Etgar, 2008; Fisher & Smith, 2011), but may also be extrinsic motivated by, for instance, appraisal and 'autonomy' (Etgar, 2008......). Therefore, for instance, being part of the process is a key incentive for consumers. Postmodern consumers' search for unique experiences calls for individualization, personalization, etc. Although Prahalad & Ramaswamy (2004), Karpen et al. (2008), and Karpen et al. (2011) have presented S-D Logic...... as a middle range theory it is still difficult for organizations to operationalize their co-creation efforts. This paper argues that postmodern consumerism can be used to guide the operationalization of the co-creation process by identifying the key facilitators of co-creation for the postmodern consumer...

Ludic Educational Game Creation Tool

DEFF Research Database (Denmark)

Vidakis, Nikolaos; Syntychakis, Efthimios; Kalafatis, Konstantinos

2015-01-01

This paper presents initial findings and ongoing work of the game creation tool, a core component of the IOLAOS(IOLAOS in ancient Greece was a divine hero famed for helping with some of Heracles’s labors.) platform, a general open authorable framework for educational and training games. The game...... creation tool features a web editor, where the game narrative can be manipulated, according to specific needs. Moreover, this tool is applied for creating an educational game according to a reference scenario namely teaching schoolers road safety. A ludic approach is used both in game creation and play....... Helping children staying safe and preventing serious injury on the roads is crucial. In this context, this work presents an augmented version of the IOLAOS architecture including an enhanced game creation tool and a new multimodality module. In addition presents a case study for creating educational games...

ESD analog circuits and design

CERN Document Server

Voldman, Steven H

2014-01-01

A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

Creation of radiation defects in KCl crystals

International Nuclear Information System (INIS)

Lushchik, A.Ch.; Pung, L.A.; Khaldre, Yu.Yu.; Kolk, Yu.V.

1981-01-01

Optical and EPR methods were used to study the creation of anion and cation Frenkel defects in KCl crystals irradiated by X-ray and VUV-radiation. The decay of excitons with the creation of charged Frenkel defects (α and I centres) was detected and investigated at 4.2 K. The decay of excitons as well as the recombination of electrons with self-trapped holes leads to the creation of neutral Frenkel defects (F and H centres). The creation of Cl 3 - and Vsub(F) centres (cation vacancy is a component of these centres) by X-irradiation at 80 K proves the possibility of cation defects creation in KCl [ru

Software compensation in Particle Flow reconstruction

CERN Document Server

Lan Tran, Huong; Sefkow, Felix; Green, Steven; Marshall, John; Thomson, Mark; Simon, Frank

2017-01-01

The Particle Flow approach to calorimetry requires highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analog energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the calorimeter system. This improvement in the single particle energy resolution also results in a better overall jet energy resolution by improving the energy measurement of identified neutral hadrons and improvements in the pattern recognition stage by a more accurate matching of calorimeter energies to tracker measurements. This paper describes the software compensation technique and its implementation in Particle Flow reconstruct...

Hydraulic Capacitor Analogy

Science.gov (United States)

Baser, Mustafa

2007-01-01

Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

Analog fourier transform channelizer and OFDM receiver

OpenAIRE

2007-01-01

An OFDM receiver having an analog multiplier based I-Q channelizing filter, samples and holds consecutive analog I-Q samples of an I-Q baseband, the I-Q basebands having OFDM sub-channels. A lattice of analog I-Q multipliers and analog I-Q summers concurrently receives the held analog I-Q samples, performs analog I-Q multiplications and analog I-Q additions to concurrently generate a plurality of analog I-Q output signals, representing an N-point discrete Fourier transform of the held analog ...

Black holes, magnetic fields and particle creation. [Quantum field theory

Energy Technology Data Exchange (ETDEWEB)

Gibbons, G W [Cambridge Univ. (UK). Dept. of Applied Mathematics and Theoretical Physics

1976-10-01

Wald has given a classical argument suggesting that a rotating black hole immersed in a uniform magnetic field B will acquire a charge Q = 2JB where J is the angular momentum of the hole. The note contains a quantum field theoretic treatment of this process. For fields B greater than B/sub 0/ = 4 x 10/sup 13/ G the black hole will rapidly emit charged particles to achieve the equilibrium value. If B is less than the critical value the charge will remain zero.

Analog quantum simulation of gravitational waves in a Bose-Einstein condensate

International Nuclear Information System (INIS)

Bravo, Tupac; Sabin, Carlos; Fuentes, Ivette

2015-01-01

We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by a real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms. (orig.)

Analog quantum simulation of gravitational waves in a Bose-Einstein condensate

Energy Technology Data Exchange (ETDEWEB)

Bravo, Tupac; Sabin, Carlos; Fuentes, Ivette [University of Nottingham, School of Mathematical Sciences, Nottingham (United Kingdom)

2015-01-04

We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by a real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms. (orig.)

Job Creation and Job Types

DEFF Research Database (Denmark)

Kuhn, Johan Moritz; Malchow-Møller, Nikolaj; Sørensen, Anders

2016-01-01

We extend earlier analyses of the job creation of start-ups versus established firms by considering the educational content of the jobs created and destroyed. We define education-specific measures of job creation and job destruction at the firm level, and we use these measures to construct a meas...

Job Creation and Job Types

DEFF Research Database (Denmark)

Kuhn, Johan M.; Malchow-Møller, Nikolaj; Sørensen, Anders

We extend earlier analyses of the job creation of start-ups vs. established firms by taking into consideration the educational content of the jobs created and destroyed. We define educationspecific measures of job creation and job destruction at the firm level, and we use these to construct a mea...

Money Creation in a Random Matching Model

OpenAIRE

Alexei Deviatov

2006-01-01

I study money creation in versions of the Trejos-Wright (1995) and Shi (1995) models with indivisible money and individual holdings bounded at two units. I work with the same class of policies as in Deviatov and Wallace (2001), who study money creation in that model. However, I consider an alternative notion of implementability–the ex ante pairwise core. I compute a set of numerical examples to determine whether money creation is beneficial. I find beneficial e?ects of money creation if indiv...

Inductive, Analogical, and Communicative Generalization

Directory of Open Access Journals (Sweden)

Adri Smaling

2003-03-01

Full Text Available Three forms of inductive generalization - statistical generalization, variation-based generalization and theory-carried generalization - are insufficient concerning case-to-case generalization, which is a form of analogical generalization. The quality of case-to-case generalization needs to be reinforced by setting up explicit analogical argumentation. To evaluate analogical argumentation six criteria are discussed. Good analogical reasoning is an indispensable support to forms of communicative generalization - receptive and responsive (participative generalization — as well as exemplary generalization.

If there is dissipation the particle can gain energy

International Nuclear Information System (INIS)

De Carvalho, R Egydio

2015-01-01

In this work, we summarize two different mechanisms to gain energy from the presence of dissipation in a time-dependent non-linear system. The particles can gain energy, in the average, from two different scenarios: i) for very week dissipation with the creation of an attractor with high velocity, and ii) in the opposite limit, for very strong dissipation, the particles can also gain energy from a boundary crisis. From the thermodynamic viewpoint both results are totally acceptable. (paper)

Components of Co-creation

DEFF Research Database (Denmark)

Tanev, Stoyan

2009-01-01

, such an approach misses the advantages of an empirically driven quantitative approach that benefits from larger size samples and is more appropriate for theory building through the development and testing of hypotheses. It is important, therefore, to seek the development of a research methodology that combines...... the benefits of both qualitative and quantitative research approaches for studying the nature of value co-creation. The article provides a first attempt to identify the main research steps of such a methodology. It provides some preliminary results on the key components of value co-creation between firms...... the inner logic of the value co-creation phenomenon as well as the nature of the results reported in this article. The specific nature of the results was found to be suitable for the application of small-N techniques such as the Qualitative Comparative Analysis (QCA) technique which combines the advantages...

Relativistic local quantum field theory for m=0 particles

International Nuclear Information System (INIS)

Morales Villasevil, A.

1965-01-01

A method is introduced ta deal with relativistic quantum field theory for particles with m=0. Two mappings I and J, giving rise respectively to particle and anti particle states, are defined between a test space and the physical Hilbert space. The intrinsic field operator is then defined as the minimal causal linear combinations of operators belonging to the annihilation-creation algebra associated to the germ and antigerm parts of the element. Local elements are introduced as improper test elements and local field operators are constructed in the same way as the intrinsic ones. Commutation rules are given. (Author) 17 refs

Sources for charged particles; Les sources de particules chargees

Energy Technology Data Exchange (ETDEWEB)

Arianer, J.

1997-09-01

This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.).

Exploring value creation from corporate-foresight activities

DEFF Research Database (Denmark)

Rohrbeck, René

2012-01-01

This paper looks at value creation from corporate futures research. Through a literature review, potential value creation is identified. This serves as guidance for an empirical investigation in which value creation is observed and linked to methods and practices. Using data from 20 case studies......, three examples of value creation are discussed in detail. In addition, cross-case analysis allowed me to identify four success criteria for corporate foresight activities: (1) foresighters committed to creating value, (2) participation of internal stakeholders, (3) analysis that follows a systemic logic...

Analogical Reasoning and Computer Programming.

Science.gov (United States)

Clement, Catherine A.; And Others

1986-01-01

A study of correlations between analogical reasoning and Logo programming mastery among female high school students related the results of pretests of analogical reasoning to posttests of programming mastery. A significant correlation was found between analogical reasoning and the ability to write subprocedures for use in several different…

Creation and evolution of excited states in α particle tracks in anthracene crystals

International Nuclear Information System (INIS)

Klein, G.

1977-01-01

The kinematics of excited states in anthracene crystals bombarded by 5MeV α particles is studied. The elementary processes which account for the transitions from the primary excited states to the lowest singlet S 1 and triplet T 1 excited states is described. The equation governing the evolution of the S 1 and T 1 excitons in the α particle track are then solved, and the scintillation decay curve is calculated. This calculated result is in good agreement with all available experimental results. The experimental part of this work are scintillation decay curves measurements. The scintillation decay was measured between 0.5nsec and 40μsec. The influence of the initial very fast singlet excitons quenching by triplet excitons can be seen in the beginning of scintillation. The delayed component is described by the triplet excitons kinematics. The magnetic field effect on the scintillation was investigated. This effect is attributed to an effect on the T 1 -T 1 annihilation and an effect on the triplet excitons quenching by radicals which are formed in the α particle track

Separable orthogonal coordinates and particle creation for an accelarating observer

International Nuclear Information System (INIS)

Costa, Isaias.

1986-01-01

An exactly solvable example of a non-stationary system, which has an inertial and an uniform accelerated asymptotic region is presented. A set of solutions that are quasi-classical in these two regions is constructed and the two sets are compared. The Bogolinbov-coefficients have the thermal character and show a temperature of a ∞ / 2Π, where a ∞ is the asymptotic acceleration in the out-region. This result is much what one would expect on the grounds of the Hawking-effect. It implies that the natural particle number is not conserved in free Minkowski - space. (Author) [pt

Particles in a magnetic field and plasma analogies: doubly periodic boundary conditions

International Nuclear Information System (INIS)

Forrester, P J

2006-01-01

The N-particle free fermion state for quantum particles in the plane subject to a perpendicular magnetic field, and with doubly periodic boundary conditions, is written in a product form. The absolute value of this is used to formulate an exactly solvable one-component plasma model and further motivates the formulation of an exactly solvable two-species Coulomb gas. The large N expansion of the free energy of both these models exhibits the same O(1) term. On the basis of a relationship to the Gaussian free field, this term is predicted to be universal for conductive Coulomb systems in doubly periodic boundary conditions

Fault diagnosis for analog circuits utilizing time-frequency features and improved VVRKFA

Science.gov (United States)

He, Wei; He, Yigang; Luo, Qiwu; Zhang, Chaolong

2018-04-01

This paper proposes a novel scheme for analog circuit fault diagnosis utilizing features extracted from the time-frequency representations of signals and an improved vector-valued regularized kernel function approximation (VVRKFA). First, the cross-wavelet transform is employed to yield the energy-phase distribution of the fault signals over the time and frequency domain. Since the distribution is high-dimensional, a supervised dimensionality reduction technique—the bilateral 2D linear discriminant analysis—is applied to build a concise feature set from the distributions. Finally, VVRKFA is utilized to locate the fault. In order to improve the classification performance, the quantum-behaved particle swarm optimization technique is employed to gradually tune the learning parameter of the VVRKFA classifier. The experimental results for the analog circuit faults classification have demonstrated that the proposed diagnosis scheme has an advantage over other approaches.

Money Creation and Destruction

OpenAIRE

Faure, Salomon; Gersbach, Hans

2017-01-01

We study money creation and destruction in today’s monetary architecture and examine the impact of monetary policy and capital regulation in a general equilibrium setting. There are two types of money created and destructed: bank deposits, when banks grant loans to firms or to other banks and central bank money, when the central bank grants loans to private banks. We show that equilibria yield the first-best level of money creation and lending when prices are flexible, regardless of the monet...

Analogical reasoning in children with specific language impairment: Evidence from a scene analogy task.

Science.gov (United States)

Krzemien, Magali; Jemel, Boutheina; Maillart, Christelle

2017-01-01

Analogical reasoning is a human ability that maps systems of relations. It develops along with relational knowledge, working memory and executive functions such as inhibition. It also maintains a mutual influence on language development. Some authors have taken a greater interest in the analogical reasoning ability of children with language disorders, specifically those with specific language impairment (SLI). These children apparently have weaker analogical reasoning abilities than their aged-matched peers without language disorders. Following cognitive theories of language acquisition, this deficit could be one of the causes of language disorders in SLI, especially those concerning productivity. To confirm this deficit and its link to language disorders, we use a scene analogy task to evaluate the analogical performance of SLI children and compare them to controls of the same age and linguistic abilities. Results show that children with SLI perform worse than age-matched peers, but similar to language-matched peers. They are more influenced by increased task difficulty. The association between language disorders and analogical reasoning in SLI can be confirmed. The hypothesis of limited processing capacity in SLI is also being considered.

Eksplorasi Desain Dasar (Nirmana melalui Kombinasi Media Grafis Analog dan Digital: Suatu Penelitian Kelas/Studio

Directory of Open Access Journals (Sweden)

Anita Rahardja

2013-10-01

Full Text Available This article is based on a research aiming to contextualize the fundamental principles of art and design to current setting in which analog media are no longer chosen as the ultimate hardware/tools. It is important considering digital hardware becomes more and more prevalent even preferred by students, whereas analog tools are getting harder to obtain, expensive and less ecological friendly. The goal of this research is to produce method analysis and the creation of two-dimensional basic design through digital media (Camera followed by conventional drawing tools, documented and conducted by the lecturers and the students. So far, almost 100% of the studies concerning basic design could only be found in foreign publications, with visual work examples that cannot be used freely in Indonesian local education due to copyright issue. Therefore, a literature study is conducted to examine the formal objects of this research which are the elements and fundamental principles in design, followed by ideation and visualization processes carried by the students in basic design classes through the semester. The visualization itself will integrate analog and digital media to generate the material objects of the research, which is a series of two dimensional design compositions. These compositions are then analyzed and classified to taxonomic category of fundamental principles of two-dimensional design as an integral part of teaching-learning process (self-evaluation class for future improvement. 

Motivating quantum field theory: the boosted particle in a box

International Nuclear Information System (INIS)

Vutha, Amar C

2013-01-01

It is a maxim often stated, yet rarely illustrated, that the combination of special relativity and quantum mechanics necessarily leads to quantum field theory. An elementary illustration is provided using the familiar particle in a box, boosted to relativistic speeds. It is shown that quantum fluctuations of momentum lead to energy fluctuations, which are inexplicable without a framework that endows the vacuum with dynamical degrees of freedom and allows particle creation/annihilation. (letters and comments)

Creation of electron-positron plasma with superstrong laser field

International Nuclear Information System (INIS)

Narozhny, N.B.; Fedotov, A.M.

2014-01-01

We present a short review of recent progress in studying QED effects within the interaction of ultra-relativistic laser pulses with vacuum and e - e + plasma. Current development in laser technologies promises very rapid growth of laser intensities in the near future. Two exa-watt class facilities (ELI and XCELS, Russia) in Europe are already in the planning stage. Realization of these projects will make available a laser intensity of 10 26 W/cm 2 or even higher. Therefore, discussion of nonlinear optical effects in vacuum are becoming compelling for experimentalists and are currently gaining much attention. We show that, in spite of the fact that the expected field strength is still essentially less than E S = m 2 c 3 /eℎ = 1.32*10 16 V/cm, the nonlinear vacuum effects will be accessible for observation at the ELI and XCELS facilities. The most promising effect for observation is pair creation by a laser pulse in vacuum. It is shown, that at intensities of about 5*10 25 W/cm 2 , creation even of a single pair is accompanied by the development of an avalanche QED cascade. There exists a distinctive feature of the laser-induced cascades, as compared with the air showers arising due primarily to cosmic rays entering the atmosphere. In our case the laser field plays not only the role of a target (similar to a nucleus in the case of air showers) but is also responsible for the acceleration of slow particles. It is shown that the effect of pair creation imposes a natural limit for the attainable laser intensity and, apparently, the field strength E ≅ E S is not accessible for a pair-creating electromagnetic field at all. (authors)

PEMETAAN ANALOGI PADA KONSEP ABSTRAK FISIKA

Directory of Open Access Journals (Sweden)

Nyoto Suseno

2014-11-01

Full Text Available The research of any where founded majority students have common difficulties in abstract physics concept. The result of observation, lecturers have problem  in teaching implementation of abstract concepts on physics learning. The objective of this research is to find out the ways how to overcome this problem. The research place of  physics education programs and senior high school. The data are colected by quetionere, observation and interview. The lecturer behavior to making out this case is use of analogy to make concrete a abstract concept. This action is true, because the analogies are dynamic tools that facilitate understanding, rather than representations of the correct and static explanations. Using analogies not only promoted profound understanding of abstract concept, but also helped students overcome their misconceptions. However used analogy in teaching not yet planed with seriousness, analogy used spontanously with the result that less optimal. By planing and selecting right analogy, the role of analogy can be achieved the optimal result. Therefore, it is important to maping analogies of abstract consepts on physics learning.

Science Teachers' Analogical Reasoning

Science.gov (United States)

Mozzer, Nilmara Braga; Justi, Rosária

2013-01-01

Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to…

IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

Energy Technology Data Exchange (ETDEWEB)

Hoerst, S. M.; Tolbert, M. A, E-mail: sarah.horst@colorado.edu [Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO (United States)

2013-06-10

The organic haze produced from complex CH{sub 4}/N{sub 2} chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH{sub 4} concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

International Nuclear Information System (INIS)

Hörst, S. M.; Tolbert, M. A

2013-01-01

The organic haze produced from complex CH 4 /N 2 chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH 4 concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

Value co-creation in healthcare through positive deviance.

Science.gov (United States)

Zanetti, Cole Anthony; Taylor, Natalie

2016-12-01

To explore how converging fields of co-creation and positive deviance may increase value in healthcare. Informed by research in positive deviance, patient engagement, value co-creation, and quality improvement, we propose a positive deviance approach to co-creation of health. Co-creation has shown to improve health outcomes with regard to multiple health conditions. Positive deviance has also shown to improve outcomes in multiple healthcare and patient community environments. A positive deviance co-creation framework may aid in achieving improved outcomes for patients, care teams and their respective healthcare organizations. Copyright © 2016 Elsevier Inc. All rights reserved.

Analytic analysis of auxetic metamaterials through analogy with rigid link systems

Science.gov (United States)

Rayneau-Kirkhope, Daniel; Zhang, Chengzhao; Theran, Louis; Dias, Marcelo A.

2018-02-01

In recent years, many structural motifs have been designed with the aim of creating auxetic metamaterials. One area of particular interest in this subject is the creation of auxetic material properties through elastic instability. Such metamaterials switch from conventional behaviour to an auxetic response for loads greater than some threshold value. This paper develops a novel methodology in the analysis of auxetic metamaterials which exhibit elastic instability through analogy with rigid link lattice systems. The results of our analytic approach are confirmed by finite-element simulations for both the onset of elastic instability and post-buckling behaviour including Poisson's ratio. The method gives insight into the relationships between mechanisms within lattices and their mechanical behaviour; as such, it has the potential to allow existing knowledge of rigid link lattices with auxetic paths to be used in the design of future buckling-induced auxetic metamaterials.

Analog circuits cookbook

CERN Document Server

Hickman, Ian

2013-01-01

Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

MOF@MOF core–shell vs. Janus particles and the effect of strain: potential for guest sorption, separation and sequestration

NARCIS (Netherlands)

Szilagyi, P.A.; Lutz, M.; Gascon, J.; Juan-Alcañiz, J.; van Esch, J.; Kapteijn, F.; Geerlings, H.; Dam, B.; van der Krol, R.

2013-01-01

The effect of strain on core–shell MOFcore@MOFshell particles is discussed and compared with that observed for analogous Janus particles. Whereas Janus particles do not display any effect of strain, the core of fully coated core–shell particles collapsed upon the formation of the outer shell,

Soliton pair creation at finite temperatures

International Nuclear Information System (INIS)

Grigoriev, D.Yu.; Rubakov, V.A.

1988-01-01

Creation of soliton-antisoliton pairs at finite temperature is considered within a (1+1)-dimensional model of a real scalar field. It is argued that at certain temperatures, the soliton pair creation in quantum theory can be investigated by studying classical field evolution in real time. The classical field equations are solved numerically, and the pair creation rate and average number of solitons are evaluated. No peculiar suppression of the rate is observed. Some results on the sphaleron transitions in (1+1)-dimensional abelian Higgs model are also presented. (orig.)

Path integral for relativistic particle theory

International Nuclear Information System (INIS)

Fradkin, E.S.; Gitman, D.M.; Shvartsman, Sh.M.

1990-06-01

An action for a relativistic spinning particle interacting with external electromagnetic field is considered in reparametrization and local supergauge invariant form. It is shown that various path integral representations derived for the causal Green function correspond to the different forms of the relativistic particle action. The analogy of the path integral derived with the Lagrangian path integral of the field theory is discussed. It is shown that to obtain the causal propagator, the integration over the null mode of the Lagrangian multiplier corresponding to the reparametrization invariance, has to be performed in the (0,+infinity) limits. (author). 23 refs

Advances in Analog Circuit Design 2015

CERN Document Server

Baschirotto, Andrea; Harpe, Pieter

2016-01-01

This book is based on the 18 tutorials presented during the 24th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of efficient sensor interfaces and low-power RF systems. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development. ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing.

Dissociation of carbon dioxide and creation of carbon particles and films at room temperature

Science.gov (United States)

Fukuda, Takahiro; Maekawa, Toru; Hasumura, Takashi; Rantonen, Nyrki; Ishii, Koji; Nakajima, Yoshikata; Hanajiri, Tatsuro; Yoshida, Yoshikazu; Whitby, Raymond; Mikhalovsky, Sergey

2007-09-01

As fluids approach their gas-liquid critical points, the physical properties such as the specific heat and compressibility diverge due to the formation of large molecular clusters. Incident light cannot penetrate near-critical fluids because of the large clusters, a phenomenon known as critical opalescence. In this paper, we irradiate near-critical carbon dioxide (ncCO2), the critical temperature and pressure of which are 31.0°C and 7.38 MPa, with a laser beam of 213, 266, 355 and 532 nm wavelength and show that CO2 is dissociated and particles are produced when the system is set so close to the critical point that critical opalescence occurs in the case of 213 and 266 nm wavelength, whereas no particles are produced when the temperature is made to deviate from the critical value. We also apply a dc electric field to ncCO2 during irradiation with a laser beam of 213 and 266 nm wavelength and find that particles are formed on both anode and cathode. As the intensity of the electric field increases, films are formed on the electrodes. Electron diffraction patterns and energy-dispersive x-ray, Auger electron, x-ray photoelectron and Raman spectroscopic analyses show that the particles and films are composed of amorphous carbon.

Dissociation of carbon dioxide and creation of carbon particles and films at room temperature

International Nuclear Information System (INIS)

Fukuda, Takahiro; Maekawa, Toru; Hasumura, Takashi; Rantonen, Nyrki; Ishii, Koji; Nakajima, Yoshikata; Hanajiri, Tatsuro; Yoshida, Yoshikazu; Whitby, Raymond; Mikhalovsky, Sergey

2007-01-01

As fluids approach their gas-liquid critical points, the physical properties such as the specific heat and compressibility diverge due to the formation of large molecular clusters. Incident light cannot penetrate near-critical fluids because of the large clusters, a phenomenon known as critical opalescence. In this paper, we irradiate near-critical carbon dioxide (ncCO 2 ), the critical temperature and pressure of which are 31.0 0 C and 7.38 MPa, with a laser beam of 213, 266, 355 and 532 nm wavelength and show that CO 2 is dissociated and particles are produced when the system is set so close to the critical point that critical opalescence occurs in the case of 213 and 266 nm wavelength, whereas no particles are produced when the temperature is made to deviate from the critical value. We also apply a dc electric field to ncCO 2 during irradiation with a laser beam of 213 and 266 nm wavelength and find that particles are formed on both anode and cathode. As the intensity of the electric field increases, films are formed on the electrodes. Electron diffraction patterns and energy-dispersive x-ray, Auger electron, x-ray photoelectron and Raman spectroscopic analyses show that the particles and films are composed of amorphous carbon

Duality invariance of black hole creation rates

International Nuclear Information System (INIS)

Brown, J.D.

1997-01-01

Pair creation of electrically charged black holes and its dual process, pair creation of magnetically charged black holes, are considered. It is shown that the creation rates are equal provided the boundary conditions for the two processes are dual to one another. This conclusion follows from a careful analysis of boundary terms and boundary conditions for the Maxwell action. copyright 1997 The American Physical Society

Students' Pre- and Post-Teaching Analogical Reasoning when They Draw Their Analogies

Science.gov (United States)

Mozzer, Nilmara Braga; Justi, Rosaria

2012-01-01

Analogies are parts of human thought. From them, we can acquire new knowledge or change that which already exists in our cognitive structure. In this sense, understanding the analogical reasoning process becomes an essential condition to understand how we learn. Despite the importance of such an understanding, there is no general agreement in…

Service creation: a model-based approach

NARCIS (Netherlands)

Quartel, Dick; van Sinderen, Marten J.; Ferreira Pires, Luis

1999-01-01

This paper presents a model-based approach to support service creation. In this approach, services are assumed to be created from (available) software components. The creation process may involve multiple design steps in which the requested service is repeatedly decomposed into more detailed

Analogical proportions: another logical view

Science.gov (United States)

Prade, Henri; Richard, Gilles

This paper investigates the logical formalization of a restricted form of analogical reasoning based on analogical proportions, i.e. statements of the form a is to b as c is to d. Starting from a naive set theoretic interpretation, we highlight the existence of two noticeable companion proportions: one states that a is to b the converse of what c is to d (reverse analogy), while the other called paralogical proportion expresses that what a and b have in common, c and d have it also. We identify the characteristic postulates of the three types of proportions and examine their consequences from an abstract viewpoint. We further study the properties of the set theoretic interpretation and of the Boolean logic interpretation, and we provide another light on the understanding of the role of permutations in the modeling of the three types of proportions. Finally, we address the use of these proportions as a basis for inference in a propositional setting, and relate it to more general schemes of analogical reasoning. The differences between analogy, reverse-analogy, and paralogy is still emphasized in a three-valued setting, which is also briefly presented.

General particle transport equation. Final report

International Nuclear Information System (INIS)

Lafi, A.Y.; Reyes, J.N. Jr.

1994-12-01

The general objectives of this research are as follows: (1) To develop fundamental models for fluid particle coalescence and breakage rates for incorporation into statistically based (Population Balance Approach or Monte Carlo Approach) two-phase thermal hydraulics codes. (2) To develop fundamental models for flow structure transitions based on stability theory and fluid particle interaction rates. This report details the derivation of the mass, momentum and energy conservation equations for a distribution of spherical, chemically non-reacting fluid particles of variable size and velocity. To study the effects of fluid particle interactions on interfacial transfer and flow structure requires detailed particulate flow conservation equations. The equations are derived using a particle continuity equation analogous to Boltzmann's transport equation. When coupled with the appropriate closure equations, the conservation equations can be used to model nonequilibrium, two-phase, dispersed, fluid flow behavior. Unlike the Eulerian volume and time averaged conservation equations, the statistically averaged conservation equations contain additional terms that take into account the change due to fluid particle interfacial acceleration and fluid particle dynamics. Two types of particle dynamics are considered; coalescence and breakage. Therefore, the rate of change due to particle dynamics will consider the gain and loss involved in these processes and implement phenomenological models for fluid particle breakage and coalescence

The analogy in the formation of hardness salts and gallstones according to the EPR study

Science.gov (United States)

Pichugina, Alina; Tsyro, Larisa; Unger, Felix

2017-11-01

The article shows that the hardness salts contain the same crystalline phases as the bile stone pigment. The identity of EPR spectra of hardness salts and pigment of gallstones containing calcium carbonate was established. An analogy between the processes of formation of hardness salts and gallstones is played, in which particles with open spin-orbitals (fermions) play a decisive role.

Dissociation of carbon dioxide and creation of carbon particles and films at room temperature

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Takahiro [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Maekawa, Toru [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Hasumura, Takashi [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Rantonen, Nyrki [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Ishii, Koji [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Nakajima, Yoshikata [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Hanajiri, Tatsuro [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Yoshida, Yoshikazu [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Whitby, Raymond [School of Pharmacy and Biomolecular Sciences, University of Brighton, Cockroft Building, Lewes Road, Brighton BN2 4GJ (United Kingdom); Mikhalovsky, Sergey [School of Pharmacy and Biomolecular Sciences, University of Brighton, Cockroft Building, Lewes Road, Brighton BN2 4GJ (United Kingdom)

2007-09-15

As fluids approach their gas-liquid critical points, the physical properties such as the specific heat and compressibility diverge due to the formation of large molecular clusters. Incident light cannot penetrate near-critical fluids because of the large clusters, a phenomenon known as critical opalescence. In this paper, we irradiate near-critical carbon dioxide (ncCO{sub 2}), the critical temperature and pressure of which are 31.0{sup 0}C and 7.38 MPa, with a laser beam of 213, 266, 355 and 532 nm wavelength and show that CO{sub 2} is dissociated and particles are produced when the system is set so close to the critical point that critical opalescence occurs in the case of 213 and 266 nm wavelength, whereas no particles are produced when the temperature is made to deviate from the critical value. We also apply a dc electric field to ncCO{sub 2} during irradiation with a laser beam of 213 and 266 nm wavelength and find that particles are formed on both anode and cathode. As the intensity of the electric field increases, films are formed on the electrodes. Electron diffraction patterns and energy-dispersive x-ray, Auger electron, x-ray photoelectron and Raman spectroscopic analyses show that the particles and films are composed of amorphous carbon.

Analog circuit design art, science and personalities

CERN Document Server

Williams, Jim

1991-01-01

This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

Resistive RAMs as analog trimming elements

Science.gov (United States)

Aziza, H.; Perez, A.; Portal, J. M.

2018-04-01

This work investigates the use of Resistive Random Access Memory (RRAM) as an analog trimming device. The analog storage feature of the RRAM cell is evaluated and the ability of the RRAM to hold several resistance states is exploited to propose analog trim elements. To modulate the memory cell resistance, a series of short programming pulses are applied across the RRAM cell allowing a fine calibration of the RRAM resistance. The RRAM non volatility feature makes the analog device powers up already calibrated for the system in which the analog trimmed structure is embedded. To validate the concept, a test structure consisting of a voltage reference is evaluated.

Kinematics of a relativistic particle with de Sitter momentum space

International Nuclear Information System (INIS)

Arzano, Michele; Kowalski-Glikman, Jerzy

2011-01-01

We discuss kinematical properties of a free relativistic particle with deformed phase space in which momentum space is given by (a submanifold of) de Sitter space. We provide a detailed derivation of the action, Hamiltonian structure and equations of motion for such a free particle. We study the action of deformed relativistic symmetries on the phase space and derive explicit formulae for the action of the deformed Poincare group. Finally we provide a discussion on parametrization of the particle worldlines stressing analogies and differences with ordinary relativistic kinematics.

Co-creation theory.

Science.gov (United States)

Lynch, Elizabeth

The Design Council is working with healthcare staff and users to reconfigure services for the 21st century. This 'co-creation approach' has focused on diabetes and motivating older people to stay healthy.

Duality and 'particle' democracy

Science.gov (United States)

Castellani, Elena

2017-08-01

Weak/strong duality is usually accompanied by what seems a puzzling ontological feature: the fact that under this kind of duality what is viewed as 'elementary' in one description gets mapped to what is viewed as 'composite' in the dual description. This paper investigates the meaning of this apparent 'particle democracy', as it has been called, by adopting an historical approach. The aim is to clarify the nature of the correspondence between 'dual particles' in the light of a historical analysis of the developments of the idea of weak/strong duality, starting with Dirac's electric-magnetic duality and its successive generalizations in the context of (Abelian and non-Abelian) field theory, to arrive at its first extension to string theory. This analysis is then used as evidential basis for discussing the 'elementary/composite' divide and, after taking another historical detour by analyzing an instructive analogy case (DHS duality and related nuclear democracy), drawing some conclusions on the particle-democracy issue.

Fast multichannel analog storage system

International Nuclear Information System (INIS)

Freytag, D.R.

1982-11-01

A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. = 11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

Banks’ Capital and Liquidity Creation

OpenAIRE

Horváth, Roman; Seidler, Jakub; Weill, Laurent

2012-01-01

This paper examines the relation between banks’ capital and liquidity creation. This issue is of interest to determine the potential impact of higher capital requirements for banks on their liquidity creation, which may have particular importance with new Basel III reform demanding from banks higher capital. We perform Granger-causality tests in a dynamic GMM panel estimator framework on an exhaustive dataset of Czech banks from 2000 to 2010.

A map for heavy inertial particles in fluid flows

Science.gov (United States)

Vilela, Rafael D.; de Oliveira, Vitor M.

2017-06-01

We introduce a map which reproduces qualitatively many fundamental properties of the dynamics of heavy particles in fluid flows. These include a uniform rate of decrease of volume in phase space, a slow-manifold effective dynamics when the single parameter s (analogous of the Stokes number) approaches zero, the possibility of fold caustics in the "velocity field", and a minimum, as a function of s, of the Lyapunov (Kaplan-Yorke) dimension of the attractor where particles accumulate.

Study of high-spin analog resonances near the N=50 neutron shell

International Nuclear Information System (INIS)

Gales, S.; El Hage, Y.; Schapira, J.P.; Fortier, S.; Laurent, H.; Maison, J.M.

1979-01-01

The 96 Zr( 3 He,d) 97 Nb and the 92 Mo( 3 He,d) 93 Tc reactions, investigated at, respectively 39.0 and 28.5 MeV incident energies, were used to selectively populate high-spin analog resonances in the 97 Nb and 93 Tc nuclei. Angular distributions were measured for the dsub(3/2), gsub(7/2) and hsub(11/2) analog states of the low-lying levels in 97 Zr. A DWBA analysis of the data for these unbound levels (using Gamov functions as form factors) was carried out and spectroscopic strengths extracted. The 96 Zr( 3 He,dp) and 92 Mo( 3 He,dp) reactions were performed, respectively, at 37.5 and 30 MeV incident energies. The angular distributions of the emitted protons were measured in coincidence using method II of Litherland and Ferguson with 0 0 detection of deuteron groups. Spins, population parameters and proton branching ratios to the ground state and excited states of the targets were determined from the analysis of the angular correlation data. The position of the neutron threshold as compared with the excitation energies of the analog states in 97 Nb and 93 Tc is found to be an important parameter in the extraction of the structure informations on core-excited components in the parent levels wave functions. Neutron particle-hole multiplets are observed for the first time in 96 Zr through the decay of the gsub(7 /2) and hsub(11/2) analog resonances. The limitation of the present method due to the neutron threshold or to the energy resolution in the proton channel is discussed and compared with the results of inelastic resonant scattering through isobaric analog resonances

Crowdsourcing Content Creation in the Classroom

Science.gov (United States)

Hills, Thomas T.

2015-01-01

The recent growth in crowdsourcing technologies offers a new way of envisioning student involvement in the classroom. This article describes a participatory action research approach to combining crowdsourced content creation with the student as producer model, whereby students' interests are used to drive the identification and creation of…

Ecological ethics and creation faith

Directory of Open Access Journals (Sweden)

Ulrich Körtner

2016-08-01

Full Text Available Over past decades a concept of ecological ethics has taken root, which is often equated with environmental ethics. Church and theology have also responded to the environmental crisis. In the last third of the past century an intense discourse about the concerns and extent of a so called creation ethics was conducted. In connection with the question of a creation ethics, and the global responsibility of humans for the biosphere of our planet, the topic of creation has also gained new attention in dogmatics. In this way, ecology has also become a topic of systematic theology. The article focuses on the debate in the German speaking context. Occasionally, a quasi-religious elevation of ecology to the status of a doctrine of salvation is observable. Because theology always also has a function of critique of religion, it must also critically engage the sometimes open and sometimes hidden religious contents and claims of eco-ethical concepts. For this purpose, the first step of the present contribution is to more precisely determine the concepts of creation and nature. Thereafter, the problem of anthropocentrism is analysed. In a further step, the concept of sustainability is analysed. In conclusion, the main features of a responsibility-ethics model of ecological ethics are outlined.

Electrical Circuits and Water Analogies

Science.gov (United States)

Smith, Frederick A.; Wilson, Jerry D.

1974-01-01

Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

Producing and Recognizing Analogical Relations

Science.gov (United States)

Lipkens, Regina; Hayes, Steven C

2009-01-01

Analogical reasoning is an important component of intelligent behavior, and a key test of any approach to human language and cognition. Only a limited amount of empirical work has been conducted from a behavior analytic point of view, most of that within Relational Frame Theory (RFT), which views analogy as a matter of deriving relations among relations. The present series of four studies expands previous work by exploring the applicability of this model of analogy to topography-based rather than merely selection-based responses and by extending the work into additional relations, including nonsymmetrical ones. In each of the four studies participants pretrained in contextual control over nonarbitrary stimulus relations of sameness and opposition, or of sameness, smaller than, and larger than, learned arbitrary stimulus relations in the presence of these relational cues and derived analogies involving directly trained relations and derived relations of mutual and combinatorial entailment, measured using a variety of productive and selection-based measures. In Experiment 1 participants successfully recognized analogies among stimulus networks containing same and opposite relations; in Experiment 2 analogy was successfully used to extend derived relations to pairs of novel stimuli; in Experiment 3 the procedure used in Experiment 1 was extended to nonsymmetrical comparative relations; in Experiment 4 the procedure used in Experiment 2 was extended to nonsymmetrical comparative relations. Although not every participant showed the effects predicted, overall the procedures occasioned relational responses consistent with an RFT account that have not yet been demonstrated in a behavior-analytic laboratory setting, including productive responding on the basis of analogies. PMID:19230515

Capacity factors and solar job creation

International Nuclear Information System (INIS)

Croucher, Matt

2011-01-01

We discuss two main job creation statistics often used by solar advocates to support increased solar deployment. Whilst overall solar technologies have a tendency to be labor-intensive, we find that the jobs per gigawatt hour statistic is relatively mis-leading as it has a tendency to reward technologies that have a low capacity factor. Ultimately the lower the capacity factor the more amplified the solar job creation number. - Highlights: → Solar generation is labor intensive. → Jobs per gigawatt hour statistics are often mis-leading. → The lower the capacity factor the higher the jobs per gigawatt. → Reliance on job creation statistics may lead to inefficient deployment.

Capacity factors and solar job creation

Energy Technology Data Exchange (ETDEWEB)

Croucher, Matt, E-mail: matthew.croucher@asu.edu [Department of Economics, L. William Seidman Research Institute, W.P. Carey School of Business, Arizona State University, P.O. Box 873806, Tempe, AZ 85287 (United States)

2011-11-15

We discuss two main job creation statistics often used by solar advocates to support increased solar deployment. Whilst overall solar technologies have a tendency to be labor-intensive, we find that the jobs per gigawatt hour statistic is relatively mis-leading as it has a tendency to reward technologies that have a low capacity factor. Ultimately the lower the capacity factor the more amplified the solar job creation number. - Highlights: > Solar generation is labor intensive. > Jobs per gigawatt hour statistics are often mis-leading. > The lower the capacity factor the higher the jobs per gigawatt. > Reliance on job creation statistics may lead to inefficient deployment.

Negative numbers and antimatter particles

International Nuclear Information System (INIS)

Tsan, Ung Chan

2012-01-01

. Experimental observation of CP violation aroused a great hope for explaining why our universe is not exactly matter antimatter symmetric. Sakharov stated that without the violation of baryonic number, it is not possible to obtain from pure energy a universe made of only matter. The fact that our universe is asymmetric (in number) but perfectly neutral, points toward the existence of a hypothetic interaction violating A and L but conserving all charges. This Matter Creation (MC) interaction creating either a pair of matter particles or antimatter particles (instead of a pair of particle antiparticle) would have a charge BAL = (A-L) and a neutral messenger Z*. Even if CP is conserved, MC would allow the creation of a number of matter particles not exactly equal to the number of antimatter particles. Our universe would then correspond to the remaining excess when all matter antimatter pairs have disappeared. Observation of matter nonconservation processes would be of great interest to falsify this speculation. In a plan with A and L as axes, pure energy is represented by the origin (A = 0, L = 0). A symmetric universe is also represented by (A = 0, L = 0) meaning that there are exactly the same number of baryons and antibaryons, and the same number of leptons and antileptons. Our present matter universe is instead represented by a point of the diagonal with A = L = present A value. This value is tiny relative to the number of gammas resulting from the annihilation of matter–antimatter particles. (author)

Motion of spinning particles. Post-Newtonian approximation in the Einstein-Cartan theory

Energy Technology Data Exchange (ETDEWEB)

Boccaletti, D; Agostini, W; Festa, P [Rome Univ. (Italy). Ist. di Matematica

1979-01-11

The equations of motion of spinning particles are obtained in the post-Newtonian approximation of the Einstein-Cartan theory. The starting point of the calculation is the Hehl combined equation and a semi-classical model is assumed for the system of spinning particles. Comparison is made with an analogous quantum result obtained in the context of Gupta quantization of the linearized Einstein theory.

Challenges in Using Analogies

Science.gov (United States)

Lin, Shih-Yin; Singh, Chandralekha

2011-01-01

Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same…

Man creation had began since the creation of the first biological ...

African Journals Online (AJOL)

Keywords – Man creation, Early life evolution, Montmorillonite clay, RNA oligomerization ... appearance of specific conditions when liquid hydrocarbons and water could meet each ..... Journal of Physical Chemistry B. 112, 3597–3604. Nahvi ...

The Micro-Category Account of Analogy

Science.gov (United States)

Green, Adam E.; Fugelsang, Jonathan A.; Kraemer, David J. M.; Dunbar, Kevin N.

2008-01-01

Here, we investigate how activation of mental representations of categories during analogical reasoning influences subsequent cognitive processing. Specifically, we present and test the central predictions of the "Micro-Category" account of analogy. This account emphasizes the role of categories in aligning terms for analogical mapping. In a…

Contextual-Based Knowledge Creation for Agroindustrial Innovation

Directory of Open Access Journals (Sweden)

Elisa Anggraeni

2017-08-01

Full Text Available This paper discusses the knowledge creation process in one department, in a higher educational context, and the possible actions to take to improve the efficiency and effectiveness of the knowledge creation system in it. We conducted a case study at one department of a university that strives to improve its innovations, in terms of their quantity and quality.We used a soft system methodology to investigate the knowledge creation system in the chosen department. From the study, we conclude that the department can be considered as a learning organization, within which its staff continually create, acquire and transfer knowledge. This department has a learning environment which is conducive, concrete learning processes, and leadership that reinforces learning. In the context of producing agroindustry innovations, the knowledge creation system in this department is considered to be less effective since it frequently happens more at individual or small group levels. To improve its effectiveness, the management may facilitate the institutionalization of knowledge creation processes at every phase of the interactions between tacit and explicit knowledge.

A Comprehensive Comparison of Relativistic Particle Integrators

Science.gov (United States)

Ripperda, B.; Bacchini, F.; Teunissen, J.; Xia, C.; Porth, O.; Sironi, L.; Lapenta, G.; Keppens, R.

2018-03-01

We compare relativistic particle integrators commonly used in plasma physics, showing several test cases relevant for astrophysics. Three explicit particle pushers are considered, namely, the Boris, Vay, and Higuera–Cary schemes. We also present a new relativistic fully implicit particle integrator that is energy conserving. Furthermore, a method based on the relativistic guiding center approximation is included. The algorithms are described such that they can be readily implemented in magnetohydrodynamics codes or Particle-in-Cell codes. Our comparison focuses on the strengths and key features of the particle integrators. We test the conservation of invariants of motion and the accuracy of particle drift dynamics in highly relativistic, mildly relativistic, and non-relativistic settings. The methods are compared in idealized test cases, i.e., without considering feedback onto the electrodynamic fields, collisions, pair creation, or radiation. The test cases include uniform electric and magnetic fields, {\\boldsymbol{E}}× {\\boldsymbol{B}} fields, force-free fields, and setups relevant for high-energy astrophysics, e.g., a magnetic mirror, a magnetic dipole, and a magnetic null. These tests have direct relevance for particle acceleration in shocks and in magnetic reconnection.

Priming analogical reasoning with false memories.

Science.gov (United States)

Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

2015-08-01

Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

An emergent approach to analogical inference

Science.gov (United States)

Thibodeau, Paul H.; Flusberg, Stephen J.; Glick, Jeremy J.; Sternberg, Daniel A.

2013-03-01

In recent years, a growing number of researchers have proposed that analogy is a core component of human cognition. According to the dominant theoretical viewpoint, analogical reasoning requires a specific suite of cognitive machinery, including explicitly coded symbolic representations and a mapping or binding mechanism that operates over these representations. Here we offer an alternative approach: we find that analogical inference can emerge naturally and spontaneously from a relatively simple, error-driven learning mechanism without the need to posit any additional analogy-specific machinery. The results also parallel findings from the developmental literature on analogy, demonstrating a shift from an initial reliance on surface feature similarity to the use of relational similarity later in training. Variants of the model allow us to consider and rule out alternative accounts of its performance. We conclude by discussing how these findings can potentially refine our understanding of the processes that are required to perform analogical inference.

Children's analogical reasoning about natural phenomena.

Science.gov (United States)

Pauen, S; Wilkening, F

1997-10-01

This report investigates children's analogical reasoning in a physics task, using an analogy generated by the children rather than by the experimenter. A total of 127 elementary school children took part in three related studies. Children learned to predict the behavior of a balance scale. Later, they were asked to solve a force interaction problem. Two versions of the balance scale training were devised: version A suggested an incorrect solution to the target problem (negative analogy), and version B suggested a correct solution to the target problem (positive analogy). In Study 1, 9- to 10-year-olds showed spontaneous transfer in both training conditions. In Study 2, 7-year-olds did not show any transfer in the positive analogy condition. Study 3 revealed that the lack of transfer in younger children was not due to a failure either to notice the analogy or to perform the mapping. Instead, 7-year-olds transferred only selected aspects of the correct solution. Copyright 1997 Academic Press.

Working memory predicts children's analogical reasoning.

Science.gov (United States)

Simms, Nina K; Frausel, Rebecca R; Richland, Lindsey E

2018-02-01

Analogical reasoning is the cognitive skill of drawing relationships between representations, often between prior knowledge and new representations, that allows for bootstrapping cognitive and language development. Analogical reasoning proficiency develops substantially during childhood, although the mechanisms underlying this development have been debated, with developing cognitive resources as one proposed mechanism. We explored the role of executive function (EF) in supporting children's analogical reasoning development, with the goal of determining whether predicted aspects of EF were related to analogical development at the level of individual differences. We assessed 5- to 11-year-old children's working memory, inhibitory control, and cognitive flexibility using measures from the National Institutes of Health Toolbox Cognition battery. Individual differences in children's working memory best predicted performance on an analogical mapping task, even when controlling for age, suggesting a fundamental interrelationship between analogical reasoning and working memory development. These findings underscore the need to consider cognitive capacities in comprehensive theories of children's reasoning development. Copyright © 2017 Elsevier Inc. All rights reserved.

Process and circuiting arrangement for the conversion of analog signals to digital signals and digital signals to analog signals

International Nuclear Information System (INIS)

Wintzer, K.

1977-01-01

Process for analog-to-digital and digital-to-analog conversion in telecommunication systems whose outstations each have an analog transmitter and an analog receiver. The invention illustrates a method of reducing the power demand of the converters at times when no conversion processes take place. (RW) [de

Non-commutative gauge Gravity: Second- order Correction and Scalar Particles Creation

International Nuclear Information System (INIS)

Zaim, S.

2009-01-01

A noncommutative gauge theory for a charged scalar field is constructed. The invariance of this model under local Poincare and general coordinate transformations is verified. Using the general modified field equation, a general Klein-Gordon equation up to the second order of the noncommu- tativity parameter is derived. As an application, we choose the Bianchi I universe. Using the Seiberg-Witten maps, the deformed noncommutative metric is obtained and a particle production process is studied. It is shown that the noncommutativity plays the same role as an electric field, gravity and chemical potential.

Cosmology in the laboratory: An analogy between hyperbolic metamaterials and the Milne universe

Science.gov (United States)

Figueiredo, David; Moraes, Fernando; Fumeron, Sébastien; Berche, Bertrand

2017-11-01

This article shows that the compactified Milne universe geometry, a toy model for the big crunch/big bang transition, can be realized in hyperbolic metamaterials, a new class of nanoengineered systems which have recently found its way as an experimental playground for cosmological ideas. On one side, Klein-Gordon particles, as well as tachyons, are used as probes of the Milne geometry. On the other side, the propagation of light in two versions of a liquid crystal-based metamaterial provides the analogy. It is shown that ray and wave optics in the metamaterial mimic, respectively, the classical trajectories and wave function propagation, of the Milne probes, leading to the exciting perspective of realizing experimental tests of particle tunneling through the cosmic singularity, for instance.

Analogies and the 5E Model

Science.gov (United States)

Orgill, Mary Kay; Thomas, Megan

2007-01-01

Science classes are full of abstract or challenging concepts that are easier to understand if an analogy is used to illustrate the points. Effective analogies motivate students, clarify students' thinking, help students overcome misconceptions, and give students ways to visualize abstract concepts. When they are used appropriately, analogies can…

How Analogy Drives Physics

International Nuclear Information System (INIS)

Hofstadter, Doug

2004-01-01

Many new ideas in theoretical physics come from analogies to older ideas in physics. For instance, the abstract notion of 'isospin' (or isotopic spin) originated in the prior concept of 'spin' (quantized angular momentum); likewise, the concept of 'phonon' (quantum of sound, or quantized collective excitation of a crystal) was based on the prior concept of 'photon' (quantum of light, or quantized element of the electromagnetic field). But these two examples, far from being exceptions, in fact represent the bread and butter of inventive thinking in physics. In a nutshell, intraphysics analogy-making -- borrowing by analogy with something already known in another area of physics -- is central to the progress of physics. The aim of this talk is to reveal the pervasiveness -- indeed, the indispensability -- of this kind of semi-irrational, wholly intuitive type of thinking (as opposed to more deductive mathematical inference) in the mental activity known as 'doing physics'. Speculations as to why wild analogical leaps are so crucial to the act of discovery in physics (as opposed to other disciplines) will be offered.

Edward Burne-Jones’ The Days of Creation: A Celestial Utopia

Directory of Open Access Journals (Sweden)

Liana De Girolami Cheney

2014-09-01

Full Text Available Edward Burne-Jones’ cycle of The Days of Creation of 1870-66(Fogg Art Museum, Harvard University Museums, Cambridge, MA was highly praised and elegantly described by Oscar Wilde: “The picture is divided into six compartments, each representing a day in the Creation of the World, under the symbol of an angel holding a crystal globe, within which is shown the work of a day.” This essay examines how Burne-Jones visualized an unusual celestial creation where angels holding magical spheres unveil the divine manifestation for the creation of a terrestrial realm. His The Days of Creation is an aesthetic culmination of the artistic power of invention, imitation and creation of beauty. Burne-Jones borrows the divine concept of world creation to formulate his own artist creation. Selecting God’s week of creation, he empowers a daily angel to manifest the beauty and power of divine creation. Ultimately, Burne-Jones creates a cosmic utopia, a mythical heavenly and natural realm, where angels design a world of beauty to be emulated not only by the artist, but also by most of all by the viewer.

On analog simulation of ionization cooling of muons

International Nuclear Information System (INIS)

Xie, Ming

2001-01-01

Analog simulation, proposed here as an alternative approach for the study of ionization cooling of muons, is a scaled cooling experiment, using protons instead of muons as simulation particles. It is intended to be an effective and flexible, quick and inexpensive experiment for the understanding and validation of unprecedentedly complicated cooling physics, for the demonstration and optimization of various elaborated techniques for beam manipulation in 6D phase space. It can be done and perhaps should be done before the costly and time-consuming development of extremely challenging, muon-specific cooling technology. In a nutshell, the idea here is to build a toy machine in a playground of ideas, before staking the Imperial Guard of Napoleon into the bloody battlefield of Waterloo

Component Processes in Analogical Reasoning

Science.gov (United States)

Sternberg, Robert J.

1977-01-01

Describes alternative theoretical positions regarding (a) the component information processes used in analogical reasoning and (b) strategies for combining these processes. Also presents results from three experiments on analogical reasoning. (Author/RK)

Classical analog for electronic degrees of freedom in nonadiabatic collision processes

International Nuclear Information System (INIS)

Meyer, H.; Miller, W.H.

1979-01-01

It is shown how a formally exact classical analog can be defined for a finite dimensional (in Hilbert space) quantum mechanical system. This approach is then used to obtain a classical model for the electronic degrees of freedom in a molecular collision system, and the combination of this with the usual classical description of the heavy particle (i.e., nuclear) motion provides a completely classical model for the electronic and heavy particle degrees of freedom. The resulting equations of motion are shown to be equivalent to describing the electronic degrees of freedom by the time-dependent Schroedinger equation, the time dependence arising from the classical motion of the nuclei, the trajectory of which is determined by the quantum mechanical average (i.e., Ehrenfest) force on the nuclei. Quantizing the system via classical S-matrix theory is shown to provide a dynamically consistent description of nonadiabatic collision processes; i.e., different electronic transitions have different heavy particle trajectories and, for example, the total energy of the electronic and heavy particle degrees of freedom is conserved. Application of this classical model for the electronic degrees of freedom (plus classical S-matrix theory) to the two-state model problem shows that the approach provides a good description of the electronic dynamics

Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

Directory of Open Access Journals (Sweden)

J Elizabeth Richey

Full Text Available Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

Science.gov (United States)

Richey, J Elizabeth; Phillips, Jeffrey S; Schunn, Christian D; Schneider, Walter

2014-01-01

Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

Science.gov (United States)

Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

2014-01-01

Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants’ performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks [3], [4]. Participants’ improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning. PMID:25188356

Semiclassical description of soliton-antisoliton pair production in particle collisions

Energy Technology Data Exchange (ETDEWEB)

Demidov, S.V.; Levkov, D.G. [Institute for Nuclear Research of the Russian Academy of Sciences,60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation)

2015-11-10

We develop a consistent semiclassical method to calculate the probability of topological soliton-antisoliton pair production in collisions of elementary particles. In our method one adds an auxiliary external field pulling the soliton and antisoliton in the opposite directions. This transforms the original scattering process into a Schwinger pair creation of the solitons induced by the particle collision. One describes the Schwinger process semiclassically and recovers the original scattering probability in the limit of vanishing external field. We illustrate the method in (1+1)-dimensional scalar field model where the suppression exponents of soliton-antisoliton production in the multiparticle and two-particle collisions are computed numerically.

Beginning analog electronics through projects

CERN Document Server

Singmin, Andrew

2001-01-01

Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

Is the creation of admixed embryos "an offense against human dignity"?

Science.gov (United States)

Jones, David Albert

2010-01-01

The controversy over the creation of admixed human-nonhuman embryos, and specifically of what have been termed "cybrids," involves a range of ethical and political issues. It is not reducible to a single question. This paper focuses on one question raised by that controversy, whether creating admixed human-nonhuman entities is "an offense against human dignity. "In the last decade there has been sustained criticism of the use of the concept of human dignity within bioethics. The concept has been criticized as "vague" and "useless." Nevertheless, the concept continues to be invoked in bioethical discussion and in international instruments. This paper defends a concept of human dignity that is coherent but that is wider than contemporary post-Kantian approaches. "Human dignity" is best regarded as having a set of analogically related meanings, more than one of which is relevant to the field of bioethics. A more subtle understanding of the concept of human dignity can help identify what is ethically problematic in human-nonhuman combinations and so shed light on one aspect of the admixed embryo debate.

Multiple particle production processes in the ''light'' of quantum optics

International Nuclear Information System (INIS)

Friedlander, E.M.

1990-09-01

Ever since the observation that high-energy ''nuclear active'' cosmic-ray particles create bunches of penetrating particles upon hitting targets, a controversy has raged about whether these secondaries are created in a ''single act'' or whether many hadrons are just the result of an intra-nuclear cascade, yielding one meson in every step. I cannot escape the impression that: the latter kind of model appeals naturally as a consequence of an innate bio-morphism in our way of thinking and that in one guise or another it has tenaciously survived to this day, also for hadron-hadron collisions, via multi-peripheral models to the modern parton shower approach. Indeed, from the very beginning of theoretical consideration of multiparticle production, the possibility of many particles arising from a single ''hot'' system has been explored, with many fruitful results, not the least of which are the s 1/4 dependence of the mean produced particle multiplicity and the ''thermal'' shape of the P T spectra. An important consequence of the thermodynamical-hydrodynamical models is that particle emission is treated in analogy to black-body radiation, implying for the secondaries a set of specific Quantum-Statistical properties, very similar to those observed in quantum optics. From here on I shall try to review a number of implications and applications of this QS analogy in the study of multiplicity distributions of the produced secondaries. I will touch only in passing another very important topic of this class, the Bose-Einstein two-particle correlations

Neutral particle kinetics in fusion devices

International Nuclear Information System (INIS)

Tendler, M.; Heifetz, D.

1986-05-01

The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub α/ emission rates, plenum pressures, and charge-exchange emission spectra

Neutral particle kinetics in fusion devices

Energy Technology Data Exchange (ETDEWEB)

Tendler, M.; Heifetz, D.

1986-05-01

The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub ..cap alpha../ emission rates, plenum pressures, and charge-exchange emission spectra.

Kinetic Modeling of the Lif:Mg,Ti TL System including Defect Creation: Implications to, and Development of Track Structure Theory Calculations of Heavy Charged Particle Radiation Effects

International Nuclear Information System (INIS)

Eliyahu, Ian

2015-01-01

differ somewhat from the vacancies originally present in un-irradiated samples due to differences in their immediate environment. The kinetic model accurately simulates the experimentally observed F center dose response over the entire investigated dose range of 10 Gy -105 Gy under the following conditions: (i) The concentration of vacancies initially present is unexpectedly high at ~ 1023 m-3, possibly due to the highly doped, noncrystalline and hot-pressed nature of the LiF:Mg,Ti samples. (ii) The transition probability, An4o, for electron capture into the initially-present vacancies is ~ 40 times greater than An4, the transition probability for the viii radiation-created vacancies. These two factors marginalize the effect of the created vacancies at low dose resulting in a linear dose response. 3. Track structure theory: The third focus of investigation concerned the ability of TST to accurately calculate HCP induced OA Relative HCP OA efficiencies. Values of ηTST based on LID dose response, were compared with experimentally measured relative efficiencies, ηm, at no-track-overlap fluence levels of 1010-1011 cm-2 for protons and He particles. The F band values of ηm/ηTST are 2.0 and 2.6 for the He ions and protons respectively. The deviation from unity is explained as due to the neglect of enhanced vacancy/F center creation in the conventional TST calculations which ignore defect creation. It is demonstrated that kinetic analysis simulating LID dose response with enhanced vacancy creation, and incorporated into the TST calculation, can lead to values of ηm=ηTST for the F band. At the other extreme, for the 4.0 eV band, the values of ηm/ηTST are much less than unity, equal to 0.18 for the protons and < 0.12 for the He ions. These very low values suggest that the 4.0 eV trapping structure is being either destroyed or de-populated (perhaps by local heating/thermal spike/Coulomb explosion) during the HCP slowing down. Processes which do not occur (or are greatly

Digital remote control system for power supplies of particle channel magnetooptical elements

International Nuclear Information System (INIS)

Vetrov, P.B.; Ermolina, G.P.; Kuznetsov, V.S.; Mojbenko, A.N.

1986-01-01

Current control of magnetooptical elements of accelerator particle channels is based on control of reference voltage of current stabilizers. Advent of industrial multidigit (12 bits) integral analog-to-digital converters permitted to develop simple digital sources of reference voltage. A digital control system of 30 spatially remoted power supplies of magnetooptical elements of particle channels on the basis of the ''Elektronika-60'' microcomputer is described. The microcomputer is connected by the standard communication line (20 mA) with the SM-4 computer. The ''Summa'' crate is connected with the microcomputer through the branch driver. Digit data are transmitted by the multibranch trunk of sequential communication (Manchester-2 code) at the rate of 0.5 Mband. Feedback was realized by connection of analog signals through the distributed commutator to the measuring line with a digital voltmeter

Spectral distribution of scalar particles created by a moving boundary with Robin boundary condition

International Nuclear Information System (INIS)

Mintz, B.; Farina, C; Maia Neto, P.A.; Rodrigues, R.B.

2006-01-01

We consider a massless scalar field in 1+1 dimensions satisfying a Robin boundary condition (BC) at a non-relativistic boundary. By deriving a Bogoliubov transformation between the input and output bosonic field operators, we calculate the spectral distribution of created particles. The particular cases of Dirichlet and Neumann BC may be obtained from our result as limiting cases, yielding equal spectra (this result is valid only in this space-time dimensionality). The creation effect for the field under Dirichlet BC turns out to be an upper bound for the spectra derived for Robin BC. Also, we show that the particle creation phenomenon with Robin conditions can be considerably reduced (with respect to the Dirichlet or Neumann cases) by selecting a particular mechanical oscillation frequency of the moving boundary. (author)

Analog circuit design art, science, and personalities

CERN Document Server

Williams, Jim

1991-01-01

Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

Particle trapping induced by the interplay between coherence and decoherence

International Nuclear Information System (INIS)

Yi Sangyong; Choi, Mahn-Soo; Kim, Sang Wook

2009-01-01

We propose a novel scheme to trap a particle based on a delicate interplay between coherence and decoherence. If the decoherence occurs as a particle is located in the scattering region and subsequently the appropriate destructive interference takes place, the particle can be trapped in the scattering area. We consider two possible experimental realizations of such trapping: a ring attached to a single lead and a ring attached to two leads. Our scheme has nothing to do with a quasi-bound state of the system, but has a close analogy with the weak localization phenomena in disordered conductors.

Synthetic Analogs of Phospholipid Metabolites as Antimalarials.

Science.gov (United States)

1979-07-01

phosphatidic acid analogs containing ether and phosphonate groups; completely non- hydrolyzable lecithin analogs containing phosphinate and ether groups...substance is a completely non- hydrolyzable analog of lecithin containing ether and phosphonate moieties instead of the normally labile carboxylic and...and also ant-i-phospholipase C (clostridial enzyme) activity. This substance Is a completely non- hydrolyzable analog of lecithin containing ether

FGF growth factor analogs

Science.gov (United States)

Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

2012-07-24

The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

Structure problems in the analog computation

International Nuclear Information System (INIS)

Braffort, P.L.

1957-01-01

The recent mathematical development showed the importance of elementary structures (algebraic, topological, etc.) in abeyance under the great domains of classical analysis. Such structures in analog computation are put in evidence and possible development of applied mathematics are discussed. It also studied the topological structures of the standard representation of analog schemes such as additional triangles, integrators, phase inverters and functions generators. The analog method gives only the function of the variable: time, as results of its computations. But the course of computation, for systems including reactive circuits, introduces order structures which are called 'chronological'. Finally, it showed that the approximation methods of ordinary numerical and digital computation present the same structure as these analog computation. The structure analysis permits fruitful comparisons between the several domains of applied mathematics and suggests new important domains of application for analog method. (M.P.)

Molecular modeling of fentanyl analogs

Directory of Open Access Journals (Sweden)

LJILJANA DOSEN-MICOVIC

2004-11-01

Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

Creative participation: collective sentiment in online co-creation communities

NARCIS (Netherlands)

Lee, H.H.M.; van Dolen, W.

2015-01-01

Co-creation communities allow companies to utilize consumers’ creative thinking in the innovation process. This paper seeks to understand the role of sentiment in user co-creation. The results suggest that management style can affect the success of co-creation communities. Specific employees’

Analog front-end cell designed in a commercial 025 mu m process for the ATLAS pixel detector at LHC

CERN Document Server

Blanquart, L; Comes, G; Denes, P; Einsweiler, Kevin F; Fischer, P; Mandelli, E; Meddeler, G; Peric, I; Richardson, J

2002-01-01

A new analog pixel front-end cell has been developed for the ATLAS detector at the future Large Hadron Collider (LHC) at the European Laboratory for Particle Physics (CERN). This analog cell has been submitted in two commercial 0.25 mu m CMOS processes (in an analog test chip format), using special layout techniques for radiation hardness purposes. It is composed of two cascaded amplifiers followed by a fast discriminator featuring a detection threshold within the range of 1000 to 10000 electrons. The first preamplifier has the principal role of providing a large bandwidth, low input impedance, and fast rise time in order to enhance the time-walk and crosstalk performance, whereas the second fully differential amplifier is aimed at delivering a sufficiently high-voltage gain for optimum comparison. A new do feedback concept renders the cell tolerant of sensor leakage current up to 300 nA and provides monitoring of this current. Two 5-bit digital-to-analog converters tolerant to single- event upset have been i...

Initial behavior of a quantized scalar field and the associated pair-creation in several isotropic closed and open universes

International Nuclear Information System (INIS)

Nariai, Hidekazu.

1981-01-01

The concept of a positive frequency part near the initial epoch in a big-bang universe or its counterpart in other (say, de Sitter) one for a canonically quantized scalar field is important in discussing the associated pair-creation of those particles. Therefore, an attempt is made to define the positive frequency part in such isotropic closed and open universes that the scalar wave equation can be exactly solved. Except for some closed universe, the parts in question and, therefore, the Feynman propagators in the remaining universes are uniquely settled. Then it is shown that (1) the pair-creation in the Friedmann open universe (which is very interesting not only from observational, but also from theoretical viewpoints) is essentially equivalent to that in the Chitre-Hartle universe with flat 3-space and (2) the respective pair-creations in expanding metrics with open and flat 3-spaces of the de Sitter universe are different from each other, as insisted upon by Gibbons and Hawking basing on the original static metric. (author)

Initial behavior of a quantized scalar field and the associated pair-creation in several isotropic closed and open universes

International Nuclear Information System (INIS)

Nariai, Hidekazu

1982-01-01

The concept of a positive frequency part near the initial epoch in a big-bang universe or its counterpart in other (say, de Sitter) one for a canonically quantized scalar field is important in discussing the associated pair-creation of those particles. Therefore, an attempt is made to define the positive frequency part in such isotropic closed and open universes that the scalar wave equation can be exactly solved. Except for some closed universe, the parts in question and, therefore, the Feynman propagators in the remaining universes are uniquely settled. Then it is shown that (1) the pair-creation in the Friedmann open universe (which is very interesting not only from observational, but also from theoretical viewpoints) is essentially equivalent to that in the Chitre-Hartle universe with flat 3-space and (2) the respective pair-creations in expanding metrics with open and flat 3-spaces of the de Sitter universe are different from each other, as insisted upon by Gibbons and Hawking basing on the original static metric. (author)

Terrestrial Analogs to Mars

Science.gov (United States)

Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

2002-08-01

It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

Particle acceleration by pulsars

International Nuclear Information System (INIS)

Arons, Jonathan.

1980-06-01

The evidence that pulsars accelerate relativistic particles is reviewed, with emphasis on the γ-ray observations. The current state of knowledge of acceleration in strong waves is summarized, with emphasis on the inability of consistent theories to accelerate very high energy particles without converting too much energy into high energy photons. The state of viable models for pair creation by pulsars is summarized, with the conclusion that pulsars very likely lose rotational energy in winds instead of in superluminous strong waves. The relation of the pair creation models to γ-ray observations and to soft X-ray observations of pulsars is outlined, with the conclusion that energetically viable models may exist, but none have yet yielded useful agreement with the extant data. Some paths for overcoming present problems are discussed. The relation of the favored models to cosmic rays is discussed. It is pointed out that the pairs made by the models may have observable consequences for observation of positrons in the local cosmic ray flux and for observations of the 511 keV line from the interstellar medium. Another new point is that asymmetry of plasma supply from at least one of the models may qualitatively explain the gross asymmetry of the X-ray emission from the Crab nebula. It is also argued that acceleration of cosmic ray nuclei by pulsars, while energetically possible, can occur only at the boundary of the bubbles blown by the pulsars, if the cosmic ray composition is to be anything like that of the known source spectrum

Expert analogy use in a naturalistic setting

Science.gov (United States)

Kretz, Donald R.; Krawczyk, Daniel C.

2014-01-01

The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker's goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption) of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance. PMID:25505437

Expert Analogy Use in a Naturalistic Setting

Directory of Open Access Journals (Sweden)

Donald R Kretz

2014-11-01

Full Text Available The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker’s goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance.

A bilateral frontoparietal network underlies visuospatial analogical reasoning.

Science.gov (United States)

Watson, Christine E; Chatterjee, Anjan

2012-02-01

Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.

Analogy between electromagnetic potentials and wave-like dynamic variables with connections to quantum theory

Science.gov (United States)

Yang, Chen

2018-05-01

The transitions from classical theories to quantum theories have attracted many interests. This paper demonstrates the analogy between the electromagnetic potentials and wave-like dynamic variables with their connections to quantum theory for audiences at advanced undergraduate level and above. In the first part, the counterpart relations in the classical electrodynamics (e.g. gauge transform and Lorenz condition) and classical mechanics (e.g. Legendre transform and free particle condition) are presented. These relations lead to similar governing equations of the field variables and dynamic variables. The Lorenz gauge, scalar potential and vector potential manifest a one-to-one similarity to the action, Hamiltonian and momentum, respectively. In the second part, the connections between the classical pictures of electromagnetic field and particle to quantum picture are presented. By characterising the states of electromagnetic field and particle via their (corresponding) variables, their evolution pictures manifest the same algebraic structure (isomorphic). Subsequently, pictures of the electromagnetic field and particle are compared to the quantum picture and their interconnections are given. A brief summary of the obtained results are presented at the end of the paper.

Neural correlates of creativity in analogical reasoning.

Science.gov (United States)

Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

2012-03-01

Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key determinant of the creativity of analogical mapping (i.e., more distant analogies are generally more creative). Here, we used functional magnetic resonance imaging to assess brain activity during an analogy generation task in which we varied the semantic distance of analogical mapping (as derived quantitatively from a latent semantic analysis). Data indicated that activity within an a priori region of interest in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. Results implicate increased recruitment of frontopolar cortex as a mechanism for integrating semantically distant information to generate solutions in creative analogical reasoning. 2012 APA, all rights reserved

Defect creation rates in CdTe irradiated by electrons

International Nuclear Information System (INIS)

Caillot, M.

1978-01-01

Up to now, the defect creation rates in CdTe irradiated by electrons were unknown. They have been calculated for different electron kinetic energies. As the samples studied are thick, the energy loss when the electrons penetrate the material has been taken into account. The cross-sections of Cd and Te displacements vs the depth of electron penetration were determined for different electron kinetic energies, and the defect creation rates obtained for each sublattice. These creation rates have been compared with those deduced from experiments and it was found that the experimental creation rates were lower than the calculated ones. This discrepancy can be explained in terms of creation of neutral Frenkel pairs. (Auth.)

Using Visual Analogies To Teach Introductory Statistical Concepts

Directory of Open Access Journals (Sweden)

Jessica S. Ancker

2017-07-01

Full Text Available Introductory statistical concepts are some of the most challenging to convey in quantitative literacy courses. Analogies supplemented by visual illustrations can be highly effective teaching tools. This literature review shows that to exploit the power of analogies, teachers must select analogies familiar to the audience, explicitly link the analog with the target concept, and avert misconceptions by explaining where the analogy fails. We provide guidance for instructors and a series of visual analogies for use in teaching medical and health statistics.

Energy creation in electrical sparks and discharges

International Nuclear Information System (INIS)

Pappas, P.T.

1991-01-01

In this paper deficiencies of Lorentz force law, of Maxwell';s displacement current, of poynting vector, and of other explicit or implicit assumptions in E/D are analyzed. The infallible Cardinal law of E/D of Ampere is suggested as the most dominating candidate for the future E/D. Apparent difficulties of the Cardinal law are removed by resuming the ideal inertial frame concept to pragmatical cases. Energy creation is considered as not binding, but as possible, according to the Cardinal law as an alternative principle to the continuous creation hypothesis of Astronomy. Various inherent arc oscillations are presented as direct experimental evidence of energy creation. Several unexplained and exciting phenomena in E/D are readily explained by the Cardinal law. Finally, the unique constructive property of the Cardinal law is presented, suggested to be responsible for the Cosmos' creation and constructive evolution to higher forms of organization

The potential of shared value creation: a theoretical analysis

Directory of Open Access Journals (Sweden)

Victor Danciu

2016-06-01

Full Text Available The urgent issues economy, environment and society are facing need new approaches which allow a well-balanced sharing of value created by the economy. A step forward is the concept of shared value creation. This paper aims to analyze the main features, the content of strategy of shared value creation and to propose the social innovation as main strategic way of shared value creation. At the beginning, the drivers and challenges of shared value creation are investigated in a systematized manner, in order to better understand why this new way of doing business is needed. Then, the concept and the three levels of shared value creation are investigated as sources of economic, environmental and social benefits that a business creates. These benefits depend on how efficient and diligent the company works. We are advancing the social innovation as main strategy having the greatest potential to create value with economic, environmental and social benefits. Finally, a framework for measurement of shared value creation is included. This framework is aiming at giving a tool for checking up the potential the shared value creation has for solving environmental and social issues.

Quantum creation of the universe in N = 8 supergravity

International Nuclear Information System (INIS)

Goncharov, Yu.P.; Bytsenko, A.A.

1988-01-01

We discuss the possibility of quantum creation of an inflationary universe filled with the fields of maximal extended N = 8 supergravity. If the created universe has spatial topology (S 1 ) 3 and after the creation Starobinskii's inflationary scenario through the topological Casimir effect in N = 8 supergravity is realized, the probability of creation of such a universe can be estimated in the semiclassical approximation. The estimate shows that the creation of a universe with a more isotropic topology is more probable

Co-creation, Prevailing Streams and a Future Design Trajectory

DEFF Research Database (Denmark)

Degnegaard, Rex

2014-01-01

of the literature on co-creation to explore what the existing literature relates to and indeed to pinpoint if any patterns or streams can be identified. The paper illustrates how the use of the concept of co-creation suggests a necessity for focusing further on specific co-creation-related issues and challenges...... of significance to business and society. The paper highlights new co-creation-related issues and challenges. Further, the paper crystallises an emerging design trajectory in theory and practice....

Money creation process in a random redistribution model

Science.gov (United States)

Chen, Siyan; Wang, Yougui; Li, Keqiang; Wu, Jinshan

2014-01-01

In this paper, the dynamical process of money creation in a random exchange model with debt is investigated. The money creation kinetics are analyzed by both the money-transfer matrix method and the diffusion method. From both approaches, we attain the same conclusion: the source of money creation in the case of random exchange is the agents with neither money nor debt. These analytical results are demonstrated by computer simulations.

CMOS analog circuit design

CERN Document Server

Allen, Phillip E

1987-01-01

This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.

Towards new analog read-out electronics for the HADES drift chamber system

Energy Technology Data Exchange (ETDEWEB)

Wiebusch, Michael [Goethe-Universitaet, Frankfurt (Germany); Collaboration: HADES-Collaboration

2016-07-01

Track reconstruction in HADES is realized with 24 planar, low-mass drift chambers (MDC). About 27000 drift cells provide precise spatial information of track hit points together with energy loss information, serving for particle ID. In order to handle high rates and track densities required at the future SIS100 accelerator at FAIR, an upgrade of the MDC system is necessary, i.e. by receiving additional redundant layers of drift cells in front of the magnet. This involves new front-end electronics, as the original analog read-out ASIC (ASD8) is no longer in stock and cannot be produced due to its legacy silicon process. Employing new FEE would allow to further increase the sensitivity, e.g. providing additional valuable information for the analysis. This contribution presents a market analysis of alternative state-of-the-art technologies for the analog read-out of drift chambers. Test procedures to evaluate the suitability for the HADES MDCs are discussed and preliminary results are shown. Emphasis is put on the benefits and possible implementations of using two separate analog channels for reading out a sense wire, i.e. a fast amplifier with a discriminator for recording the arrival time of the signal pulse and a slow integrating amplifier with a time-over-threshold discriminator to measure the total charge of the pulse.

Frontopolar cortex mediates abstract integration in analogy.

Science.gov (United States)

Green, Adam E; Fugelsang, Jonathan A; Kraemer, David J M; Shamosh, Noah A; Dunbar, Kevin N

2006-06-22

Integration of abstractly similar relations during analogical reasoning was investigated using functional magnetic resonance imaging. Activation elicited by an analogical reasoning task that required both complex working memory and integration of abstractly similar relations was compared to activation elicited by a non-analogical task that required complex working memory in the absence of abstract relational integration. A left-sided region of the frontal pole of the brain (BA 9/10) was selectively active for the abstract relational integration component of analogical reasoning. Analogical reasoning also engaged a left-sided network of parieto-frontal regions. Activity in this network during analogical reasoning is hypothesized to reflect categorical alignment of individual component terms that make up analogies. This parieto-frontal network was also engaged by the complex control task, which involved explicit categorization, but not by a simpler control task, which did not involve categorization. We hypothesize that frontopolar cortex mediates abstract relational integration in complex reasoning while parieto-frontal regions mediate working memory processes, including manipulation of terms for the purpose of categorical alignment, that facilitate this integration.

The force of dissimilar analogies in bioethics.

Science.gov (United States)

Mertes, Heidi; Pennings, Guido

2011-04-01

Although analogical reasoning has long been a popular method of reasoning in bioethics, current literature does not sufficiently grasp its variety. We assert that the main shortcoming is the fact that an analogy's value is often judged on the extent of similarity between the source situation and the target situation, while in (bio)ethics, analogies are often used because of certain dissimilarities rather than in spite of them. We make a clear distinction between dissimilarities that aim to reinforce a similar approach in the source situation and the target situation and dissimilarities that aim to undermine or denounce a similar approach. The former kind of dissimilarity offers the analogy more normative force than if there were no dissimilarities present; this is often overlooked by authors who regard all relevant dissimilarities as detrimental to the analogy's strength. Another observation is that an evaluation of the normative force of an analogy cannot be made independently of moral principles or theories. Without these, one cannot select which elements in an analogy are morally relevant nor determine how they should be interpreted.

Interactivity, Game Creation, Design, Learning, and Innovation

DEFF Research Database (Denmark)

This book constitutes the proceedings of two conferences: The 5th International Conference on ArtsIT, Interactivity and Game Creation (ArtsIT 2016) and the First International Conference on Design, Learning and Innovation (DLI 2016). ArtsIT is reflecting trends in the expanding field of digital art......, interactive art, and how game creation is considered an art form. The decision was made to augment the title of ArtsIT to be in future known as “The International Conference on Interactivity, Game Creation, Design, Learning, and Innovation”. The event was hosted in Esbjerg, Denmark in May 2016 and attracted...

Anti-Plasmodium activity of ceramide analogs

Directory of Open Access Journals (Sweden)

Gatt Shimon

2004-12-01

Full Text Available Abstract Background Sphingolipids are key molecules regulating many essential functions in eukaryotic cells and ceramide plays a central role in sphingolipid metabolism. A sphingolipid metabolism occurs in the intraerythrocytic stages of Plasmodium falciparum and is associated with essential biological processes. It constitutes an attractive and potential target for the development of new antimalarial drugs. Methods The anti-Plasmodium activity of a series of ceramide analogs containing different linkages (amide, methylene or thiourea linkages between the fatty acid part of ceramide and the sphingoid core was investigated in culture and compared to the sphingolipid analog PPMP (d,1-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. This analog is known to inhibit the parasite sphingomyelin synthase activity and block parasite development by preventing the formation of the tubovesicular network that extends from the parasitophorous vacuole to the red cell membrane and delivers essential extracellular nutrients to the parasite. Results Analogs containing methylene linkage showed a considerably higher anti-Plasmodium activity (IC50 in the low nanomolar range than PPMP and their counterparts with a natural amide linkage (IC50 in the micromolar range. The methylene analogs blocked irreversibly P. falciparum development leading to parasite eradication in contrast to PPMP whose effect is cytostatic. A high sensitivity of action towards the parasite was observed when compared to their effect on the human MRC-5 cell growth. The toxicity towards parasites did not correlate with the inhibition by methylene analogs of the parasite sphingomyelin synthase activity and the tubovesicular network formation, indicating that this enzyme is not their primary target. Conclusions It has been shown that ceramide analogs were potent inhibitors of P. falciparum growth in culture. Interestingly, the nature of the linkage between the fatty acid part and the

The future of vitamin D analogs

Directory of Open Access Journals (Sweden)

Carlien eLeyssens

2014-04-01

Full Text Available The active form of vitamin D3, 1,25-dihydroxyvitamin D3, is a major regulator of bone and calcium homeostasis. In addition, this hormone also inhibits the proliferation and stimulates the differentiation of normal as well as malignant cells. Supraphysiological doses of 1,25-dihydroxyvitamin D3 are required to reduce cancer cell proliferation. However, these doses will lead in vivo to calcemic side effects such as hypercalcemia and hypercalciuria. During the last 25 years, many structural analogs of 1,25-dihydroxyvitamin D3 have been synthesized by the introduction of chemical modifications in the A-ring, central CD-ring region or side chain of 1,25-dihydroxyvitamin D3 in the hope to find molecules with a clear dissociation between the beneficial antiproliferative effects and adverse calcemic side effects. One example of such an analog with a good dissociation ratio is calcipotriol (DaivonexR, which is clinically used to treat the hyperproliferative skin disease psoriasis. Other vitamin D analogs were clinically approved for the treatment of osteoporosis or secondary hyperparathyroidism. No vitamin D analog is currently used in the clinic for the treatment of cancer although several analogs have been shown to be potent drugs in animal models of cancer. Omics studies as well as in vitro cell biological experiments unraveled basic mechanisms involved in the antineoplastic effects of vitamin D and its analogs. 1,25-dihydroxyvitamin D3 and analogs act in a cell type- and tissue-specific manner. Moreover, a blockade in the transition of the G0/1 towards S phase of the cell cycle, induction of apoptosis, inhibition of migration and invasion of tumor cells together with effects on angiogenesis and inflammation have been implicated in the pleiotropic effects of 1,25-dihydroxyvitamin D3 and its analogs. In this review we will give an overview of the action of vitamin D analogs in tumor cells and look forward how these compounds could be introduced in the

Creation / accumulation city

NARCIS (Netherlands)

Doevendans, C.H.; Schram, A.L.

2005-01-01

A distinction between basic archetypes of urban form was made by Bruno Fortier: the accumulation city as opposed to the creation city. These archetypes derive from archaeology - being based on the Roman and the Egyptian city - but are interpreted as morphological paradigms, as a set of assumptions

Fano factor evaluation of diamond detectors for alpha particles

Energy Technology Data Exchange (ETDEWEB)

Shimaoka, Takehiro; Kaneko, Junichi H.; Tsubota, Masakatsu; Shimmyo, Hiroaki [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-8628 (Japan); Sato, Yuki [Naraha Remote Technology Development Center, Japan Atomic Energy Agency, Naraha-machi, Futaba-gun, Fukushima, 979-0513 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Mokuno, Yoshiaki [Advanced Power Electronics Research Center, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577 (Japan); Watanabe, Hideyuki [Research Institute for Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, 305-8565 (Japan)

2016-10-15

This report is the first describing experimental evaluation of Fano factor for diamond detectors. High-quality self-standing chemical vapor deposited diamond samples were produced using lift-off method. Alpha-particle induced charge measurements were taken for three samples. A 13.1 ±0.07 eV of the average electron-hole pair creation energy and excellent energy resolution of approximately 0.3% were found for 5.486 MeV alpha particles from an {sup 241}Am radioactive source. The best Fano factor for 5.486 MeV alpha particles, calculated from experimentally obtained epsilon values and the detector intrinsic energy resolution, was 0.382 ± 0.007. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Enhancing programming logic thinking using analogy mapping

Science.gov (United States)

Sukamto, R. A.; Megasari, R.

2018-05-01

Programming logic thinking is the most important competence for computer science students. However, programming is one of the difficult subject in computer science program. This paper reports our work about enhancing students' programming logic thinking using Analogy Mapping for basic programming subject. Analogy Mapping is a computer application which converts source code into analogies images. This research used time series evaluation and the result showed that Analogy Mapping can enhance students' programming logic thinking.

Gemini analogs of vitamin D.

Science.gov (United States)

Pazos, Gonzalo; Rivadulla, Marcos L; Pérez-García, Xenxo; Gandara, Zoila; Pérez, Manuel

2014-01-01

The Gemini analogs are the last significant contribution to the family of vitamin D derivatives in medicine, for the treatment of cancer. The first Gemini analog was characterized by two symmetric side chains at C-20. Following numerous modifications, the most active analog bears a C-23-triple bond, C-26, 27- hexafluoro substituents on one side chain and a terminal trideuteromethylhydroxy group on the other side chain. This progression was possible due to improvements in the synthetic methods for the preparation of these derivatives, which allowed for increasing molecular complexity and complete diastereoselective control at C-20 and the substituted sidechains.

A fast multichannel analog storage system

International Nuclear Information System (INIS)

Freytag, D.R.

1983-01-01

A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. =11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

Atheism and Analogy: Aquinas Against the Atheists

OpenAIRE

Linford, Daniel J.

2014-01-01

In the 13th century, Thomas Aquinas developed two models for how humans may speak of God - either by the analogy of proportion or by the analogy of proportionality. Aquinas's doctrines initiated a theological debate concerning analogy that spanned several centuries. In the 18th century, there appeared two closely related arguments for atheism which both utilized analogy for their own purposes. In this thesis, I show that one argument, articulated by the French materialist Paul-Henri Thiry Bar...

Analog filters in nanometer CMOS

CERN Document Server

Uhrmann, Heimo; Zimmermann, Horst

2014-01-01

Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

The Mayo Clinic Value Creation System.

Science.gov (United States)

Swensen, Stephen J; Dilling, James A; Harper, C Michel; Noseworthy, John H

2012-01-01

The authors present Mayo Clinic's Value Creation System, a coherent systems engineering approach to delivering a single high-value practice. There are 4 tightly linked, interdependent phases of the system: alignment, discovery, managed diffusion, and measurement. The methodology is described and examples of the results to date are presented. The Value Creation System has been demonstrated to improve the quality of patient care while reducing costs and increasing productivity.

Scientific Analogies and Their Use in Teaching Science

Science.gov (United States)

Kipnis, Nahum

Analogy in science knew its successes and failures, as illustrated by examples from the eighteenth-century physics. At times, some scientists abstained from using a certain analogy on the ground that it had not yet been demonstrated. Several false discoveries in the 18th and early 19th centuries appeared to support their caution. It is now clear that such a position reflected a methodological confusion that resulted from a failure to distinguish between particular and general analogies. Considering analogy as a hierarchical structure provides a new insight into "testing an analogy". While warning science teachers of dangers associated with use of analogy, historical cases and their analysis provided here may encourage them to use analogy more extensively while avoiding misconceptions. An argument is made that the history of science may be a better guide than philosophy of science and cognitive psychology when it concerns the role of analogy in science and in teaching science for understanding.

Coupled Particle Transport and Pattern Formation in a Nonlinear Leaky-Box Model

Science.gov (United States)

Barghouty, A. F.; El-Nemr, K. W.; Baird, J. K.

2009-01-01

Effects of particle-particle coupling on particle characteristics in nonlinear leaky-box type descriptions of the acceleration and transport of energetic particles in space plasmas are examined in the framework of a simple two-particle model based on the Fokker-Planck equation in momentum space. In this model, the two particles are assumed coupled via a common nonlinear source term. In analogy with a prototypical mathematical system of diffusion-driven instability, this work demonstrates that steady-state patterns with strong dependence on the magnetic turbulence but a rather weak one on the coupled particles attributes can emerge in solutions of a nonlinearly coupled leaky-box model. The insight gained from this simple model may be of wider use and significance to nonlinearly coupled leaky-box type descriptions in general.

Innovation and Entrepreneurship: The Necessary Conditions of Value Creation

Directory of Open Access Journals (Sweden)

Brian Barnard

2017-10-01

Full Text Available The necessary conditions of value creation are considered from the vantage point of innovation and entrepreneurship. Both demand side (basic needs, customer perceived value, and customer satisfaction and supply side (science, technology, and knowledge considerations of value creation are examined. The relationships between value creation and basic needs, customer perceived value, and knowledge are further examined. Although a number of factors are identified that impact value, only four are seen as primary factors of value: price, benefit, satisfaction, and experience. The innovator and entrepreneur can create value, and quantify the uniqueness of their value offerings, through these four primary factors. The study concludes that, on the demand side, basic needs may be an indirect driver of value creation, and customer perceived value as concept may be useful in the context of value creation. At the same time, it is believed that the four factors – price, benefit, satisfaction, and experience – can significantly explain value creation. On the supply side, innovation as the driver of value creation, is not necessarily confined to science and technology – business knowledge and acumen is an important avenue. In addition to existing knowledge and experience, factors like orientation (interests, passion, drive and involvement also explain opportunity recognition.

What does existing research say about value co-creation?

DEFF Research Database (Denmark)

Thomsen, Merethe Stjerne; Tanev, Stoyan; Pedrosa, Alex

2010-01-01

The paper presents a literature review on co-creation, which is summarized into emerging research areas and insights as a basis for a future research agenda for value co-creation. The search methodology is based on a keywords search on ISI Web of Knowledge, leading to 82 articles with a summary...... of four emerging subject areas within marketing science, service management, new product development & innovation and general business and management. The four subject areas lead to new key driving forces of value co-creation by involving the customers in experience networks, where both creating......-customer interaction events, which are extremely personal with unique products, services and experiences. In general the paper is starting up a conceptual refinement on value co-creation by addressing the key characteristics of current literature and driving forces of co-creation....

Adiabatic pair creation in heavy-ion and laser fields

International Nuclear Information System (INIS)

Pickl, P.; Durr, D.

2008-01-01

The planned generation of lasers and heavy-ion colliders renews the hope to see electron-positron pair creation in strong classical fields. This old prediction is usually referred to as spontaneous pair creation. We observe that both heavy-ion collisions and pair creation in strong laser fields, are instances of the theory of adiabatic pair creation. We shall present the theory, thereby correcting earlier results. We give the momentum distribution of created pairs in overcritical fields. We discuss carefully the proposed experimental verifications and conclude that pure laser-based experiments are highly questionable. We propose a new experiment, joining laser fields and heavy ions, which may be feasible with present-day technology and which may indeed verify the theoretical prediction of adiabatic pair creation. Our presentation relies on recent rigorous works in mathematical physics. (authors)

Drawing Analogies in Environmental Education

Science.gov (United States)

Affifi, Ramsey

2014-01-01

Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

Trapped charged particles a graduate textbook with problems and solutions

CERN Document Server

Madsen, Niels; Thompson, Richard C

2016-01-01

At Les Houches in January 2015, experts in the field of particle trapping came together to discuss the fundamental physics of traps and the different types of applications. This textbook collates the lectures delivered there; the Second Winter School on Physics with Trapped Charged Particles. Taken as a whole, the book gives an overview of why traps for charged particles are important, how they work, their special features and limitations, and their application in areas such as precision measurements, mass spectrometry, optical clocks, plasma physics, antihydrogen creation, quantum simulation and quantum information processing. Chapters from various world experts include those on the basic properties of Penning traps, RF traps and particle accelerators, as well as those covering important practical aspects such as vacuum systems, detection techniques, and different types of particle cooling including laser cooling. Finally, individual chapters deal with the different areas of application listed above. Each ...

Anisotropic cosmological models with bulk viscosity and particle ...

Indian Academy of Sciences (India)

4.1.3 Ideal gas. In the case of an ideal gas. = 0 and pc = 0. Then eq. (2) becomes. ˙η + 3ηH = 0. (69). Equation (69), on integration gives η = η1t. −3/n,. (70) where η1 is an integrating constant. Equation (69) is the expression for particle creation density. This model has only bulk viscosity and bulk viscous stress is obtained as.

Facilitating value co-creation in networks

DEFF Research Database (Denmark)

Rasmussen, Mette Apollo

participants in varied ways come to grasp the meaning of networking. The dissertation draws on insights from the Service-Dominant (S-D) Logic to explain how networks can be seen as spheres for value co-creation. Co-creation as a theoretical construct has evolved from varied streams of service marketing...... of networking. The concept of “imaginative value” (Beckert, 2011) is used to explain the oscillating behaviors observed in the two networks. Imaginative value can be defined as symbolic value that actors ascribe to an object, in this case the network. I argue that the group practices in the networks led......The dissertation investigates through two ethnographic case studies how value co-creation takes place in inter-organizational networks that have been facilitated by a municipality. The contribution of the study to business network research is the emphasis on development phases of networks...

Conjecturing via Reconceived Classical Analogy

Science.gov (United States)

Lee, Kyeong-Hwa; Sriraman, Bharath

2011-01-01

Analogical reasoning is believed to be an efficient means of problem solving and construction of knowledge during the search for and the analysis of new mathematical objects. However, there is growing concern that despite everyday usage, learners are unable to transfer analogical reasoning to learning situations. This study aims at facilitating…

Science, evolution, and creationism

National Research Council Canada - National Science Library

Committee on Revising Science and Creationism

... are more comfortable. In the book Science, Evolution, and Creationism, a group of experts assembled by the National Academy of Sciences and the Institute of Medicine explain the fundamental methods of science, document...

Particle physics after the Higgs discovery: Philosophical perspectives

Science.gov (United States)

Friederich, Simon; Lehmkuhl, Dennis

2015-08-01

The recent discovery at the LHC of a particle with properties matching those expected of the Higgs boson is a decisive event in the history of particle physics. The present special section combines three contributions that approach conceptual and methodological challenges related to this event and the current situation in particle physics from different angles. One contribution studies the experimental practices of contemporary particle physics by investigating the role of computer simulations in these practices; in particular, it focuses on the status of simulations as compared to experiments that in some circumstances have analogous functions. One contribution investigates the status of the controversial naturalness problem that many physicists see as the most severe shortcoming of the Standard Model of elementary particle physics. Finally, a third contribution critically assesses the impact of suggested no-go theorems concerning the interpretability of rigorous algebraic quantum field theory in terms of particles at the phenomenological level. In what follows we present a short overview of these contributions, highlighting some of their central ideas and arguments and putting them into context.

Perturbative neutrino pair creation by an external source

International Nuclear Information System (INIS)

Koers, Hylke B.J.

2005-01-01

We consider the rate of fermion-antifermion pair creation by an external field. We derive a rate formula that is valid for a coupling with arbitrary vector and axial vector components to first order in perturbation theory. This is then applied to study the creation of neutrinos by nuclear matter, a problem with astrophysical relevance. We present an estimate for the creation rate per unit volume, compare this to previous results and comment on the role of the neutrino mass

Edge termination of MoS2 and CoMoS catalyst particles

DEFF Research Database (Denmark)

Byskov, Line Sjolte; Nørskov, Jens Kehlet; Clausen, B. S.

2000-01-01

The edge termination of MoS2 and CoMoS catalyst particles is studied by density functional calculations. We show that for structures without vacancies Mo-terminated edges have the lowest edge energies. Creation of vacancies, which are believed to be active sites in these catalyst systems, leads...

Is co-creation really a booster for brand equity? The role of co-creation in observer-based equity (OBBE)

NARCIS (Netherlands)

Kristal, Samuel; Baumgarth, Carsten; Behnke, Carolin; Henseler, Jörg

2016-01-01

Purpose This paper aims to analyse the general effect of co-created products on the brand equity of observers (OBBE). The influence of different implementations of the co-creation approach on the OBBE is tested. It is also discussed whether co-creation can be a strategic method for companies to

Electrical Evolution of a Dust Plume from a Low Energy Lunar Impact: A Model Analog to LCROSS

Science.gov (United States)

Farrell, W. M.; Stubbs, T. J.; Jackson, T. L.; Colaprete, A.; Heldmann, J. L.; Schultz, P. H.; Killen, R. M.; Delory, G. T.; Halekas, J. S.; Marshall, J. R.;

Spectrometric analog-to-digital converter

International Nuclear Information System (INIS)

Ormandzhiev, S.I.; Jordanov, V.T.

1988-01-01

Converter of digit-by-digit counterbalancing with slipping dial with number of channels equal to total number of states of the main digital-to-analog converter of digit-by-digit counterbalancing systems is presented. Algorithm for selection of digital-to-analog converters, which must be used by means of computer is suggested

Astronomy and Creationism.

Science.gov (United States)

Morrison, David

1982-01-01

Discusses the effects on astronomy courses/curriculum if equal time were given to the concept that the universe was created in its present form about ten thousand years ago. Includes the full text on a resolution concerning creationism passed by the Board of Directors of the Astronomical Society of the Pacific. (Author/JN)

Relations as transformations: implications for analogical reasoning.

Science.gov (United States)

Leech, Robert; Mareschal, Denis; Cooper, Richard P

2007-07-01

We present two experiments assessing whether the size of a transformation instantiating a relation between two states of the world (e.g., shrinks) is a performance factor affecting analogical reasoning. The first experiment finds evidence of transformation size as a significant factor in adolescent analogical problem solving while the second experiment finds a similar effect on adult analogical reasoning using a markedly different analogical completion paradigm. The results are interpreted as providing evidence for the more general framework that cognitive representations of relations are best understood as mental transformations.

Fermilab accelerator control system: Analog monitoring facilities

International Nuclear Information System (INIS)

Seino, K.; Anderson, L.; Smedinghoff, J.

1987-10-01

Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system

Value Creation by Process-Oriented Project Management

NARCIS (Netherlands)

Geijtenbeek, W.; Eekelen, van A.L.M.; Kleine, A.J.; Favie, R.; Maas, G.J.; Milford, R.

2007-01-01

The start of a design process based on value creation requires a different approach and new models. The aim of this study is to provide insight into how a design process based on value creation can be initiated. The intended result of the study is the design of the of a collaboration model that can

NEW VENTURE CREATION: HOW START-UPS GROW?

Directory of Open Access Journals (Sweden)

AIDIN SALAMZADEH

Full Text Available ABSTRACT Start-ups, often seen as sources of innovation and change, are prone to failure and accordingly they are attracting considerable attention not least from policy makers and Government officials. However, the various new venture creation studies that have emerged since the early 1980s lack cohesiveness, and the domain remains controversial. This article not only exposes the limitations of the existing body of understanding on the topic but attempts to develop a more comprehensive and comprehendible framework for start up (new venture creation. To do so it uses the frameworks proposed by Whetten, and March and Smith to develop 11 propositions. The resultant model suggests that the creation of a start up involves the identification of an idea or opportunity by an entrepreneur who subsequently organizes a series of activities, mobilizes resources and creates competence using his/her networks in an environment in order to create value. It sheds light on the start-up (new venture creation process and has relevance for entrepreneurs, policy makers and researchers.

Form factors and related quantities in clothed-particle representation

Directory of Open Access Journals (Sweden)

Shebeko Alexander

2017-01-01

Full Text Available We show new applications of the notion of clothed particles in quantum field theory. Its realization by means of the clothing procedure put forward by Greenberg and Schweber allows one to express the total Hamiltonian H and other generators of the Poincaré group for a given system of interacting fields through the creation (annihilation operators for the so-called clothed particles with physical (observed properties. Here such a clothed particle representation is used to calculate the matrix elements (shortly, form factors of the corresponding Nöther current operators sandwiched between the H eigenstates. Our calculations are performed with help of an iterative technique suggested by us earlier when constructing the NN → πNN transition operators. As an illustration, we outline some application of our approach in the spinor quantum electrodynamics.

The analogy method for the description of external characteristic of inner combustion engines

Directory of Open Access Journals (Sweden)

A. Stonys

2004-10-01

Full Text Available The original data for the evaluation of vehicle motion dynamics is external characteristic of its engine, which consists of three parameters: torque, power and specific fuel consumption. It is very important to have the dependences of these characteristics on revs for various engine load cases, creating a vehicle model under real motion conditions. Load cases are defined by a load coefficient. Car-makers usually don’t declare full engine external characteristics, which overtake all load coefficient variation interval. The purpose of this article is to research, how to get full description of engine torque function without its full data. The analogy method, which is used in polymers and composites mechanics, was employed for the description of a torque function. The method is based on the creation of summarized characteristic, making horizontal and vertical shifts of torque dependences. From the curve it is possible to get a proper characteristic at a chosen load coefficient.

Mobile, Collaborative Situated Knowledge Creation for Urban Planning

Directory of Open Access Journals (Sweden)

Nelson Baloian

2012-05-01

Full Text Available Geo-collaboration is an emerging research area in computer sciences studying the way spatial, geographically referenced information and communication technologies can support collaborative activities. Scenarios in which information associated to its physical location are of paramount importance are often referred as Situated Knowledge Creation scenarios. To date there are few computer systems supporting knowledge creation that explicitly incorporate physical context as part of the knowledge being managed in mobile face-to-face scenarios. This work presents a collaborative software application supporting visually-geo-referenced knowledge creation in mobile working scenarios while the users are interacting face-to-face. The system allows to manage data information associated to specific physical locations for knowledge creation processes in the field, such as urban planning, identifying specific physical locations, territorial management, etc.; using Tablet-PCs and GPS in order to geo-reference data and information. It presents a model for developing mobile applications supporting situated knowledge creation in the field, introducing the requirements for such an application and the functionalities it should have in order to fulfill them. The paper also presents the results of utility and usability evaluations.

Examine the Role of Brand Experience in Value Co-creation.

OpenAIRE

Khachontantiphop, Phalida

2011-01-01

The previous experience with brand influences the consumer decision and consumer behavior. The brand is significant criteria in the evaluation of brand alternatives, especially co-creation of value. The co-creation offering is able to assess when the consumer participate and consume it. The consumer has the difficulty to make the purchasing decision. Moreover, the co-creation requires the higher involvement from the consumer to participate in the co-creation process with the company. The bran...

Musik som analogi og metafor

DEFF Research Database (Denmark)

Bonde, Lars Ole

2014-01-01

Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser......Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser...

The particle accelerator; L'accelerateur de particules

Energy Technology Data Exchange (ETDEWEB)

Fadel, K. [Palais de la Decouverte, Dept. de Physique, 75 - Paris (France)

2011-01-15

As the Palais de la Decouverte (in Paris) is the sole scientific vulgarization establishment in the world to operate an actual particle accelerator able to provoke different types of nuclear reactions, the author recalls some historical aspects of the concerned department since the creation of the 'Radioactivity - Atom synthesis' department in 1937. He recalls the experiments which were then performed, the installation of the particle accelerator in 1964 and its renewal. He describes what's going on in this accelerator. He gives an overview of the difficulties faced after it has been decided to move it, of the works which had to be performed, and of radiation protection measures

Logistics potentials in business competitive advantage creation

Directory of Open Access Journals (Sweden)

Rafał Matwiejczuk

2013-12-01

Full Text Available Background: Companies constantly search for ways to achieve and sustain long-term competitive advantage. Among the factors influencing the competitive advantage creation there are so called logistics potentials, which constitute a component part of a business strategic potentials. Logistics resources, logistics capabilities and logistics competences are the main components of the logistics potentials structure and hierarchy. Methods: In order to recognize the logistics potentials which determine the competitive advantage creation one may use the assumptions and elements of contemporary management concepts, including strategic management. In particular the article deals with Resource-Based View (RBV, Dynamic Capabilities Concept (DCC and - first of all - Competence-Based Management (CBM. Results and conclusions: Several significant research projects have presented a wide scope and a large number of possibilities of logistics potentials (and logistics competences in particular influence on business competitive advantage creation. The article briefly presents the research results conducted by: (1 Michigan State University (USA, (2 European Logistics Association (ELA in cooperation with A.T. Kearney, (3 Computer Sciences Corporation and (4 Capgemini. The research results have pointed out to differentiated but at the same distinctive symptoms of logistics competences influence on competitive advantage creation. The article also refers to the results of the research carried out by the Chair of Logistics & Marketing at Opole University (Poland in companies operating in Poland. The research has been mainly dealing with the significance of logistics competences in competitive advantage creation.

Comparison between photon annihilation-then-creation and photon creation-then-annihilation thermal states: Non-classical and non-Gaussian properties

Science.gov (United States)

Xu, Xue-Xiang; Yuan, Hong-Chun; Wang, Yan

2014-07-01

We investigate the nonclassical properties of arbitrary number photon annihilation-then-creation operation (AC) and creation-then-annihilation operation (CA) to the thermal state (TS), whose normalization factors are related to the polylogarithm function. Then we compare their quantum characters, such as photon number distribution, average photon number, Mandel Q-parameter, purity and the Wigner function. Because of the noncommutativity between the annihilation operator and the creation operator, the ACTS and the CATS have different nonclassical properties. It is found that nonclassical properties are exhibited more strongly after AC than after CA. In addition we also examine their non-Gaussianity. The result shows that the ACTS can present a slightly bigger non-Gaussianity than the CATS.

Comparison between photon annihilation-then-creation and photon creation-then-annihilation thermal states: Non-classical and non-Gaussian properties

International Nuclear Information System (INIS)

Xu Xue-Xiang; Wang Yan; Yuan Hong-Chun

2014-01-01

We investigate the nonclassical properties of arbitrary number photon annihilation-then-creation operation (AC) and creation-then-annihilation operation (CA) to the thermal state (TS), whose normalization factors are related to the polylogarithm function. Then we compare their quantum characters, such as photon number distribution, average photon number, Mandel Q-parameter, purity and the Wigner function. Because of the noncommutativity between the annihilation operator and the creation operator, the ACTS and the CATS have different nonclassical properties. It is found that nonclassical properties are exhibited more strongly after AC than after CA. In addition we also examine their non-Gaussianity. The result shows that the ACTS can present a slightly bigger non-Gaussianity than the CATS. (general)

An experimentalists view on the analogy between step edges and quantum mechanical particles

NARCIS (Netherlands)

Zandvliet, Henricus J.W.

1995-01-01

Guided by scanning tunnelling microscopy images of regularly stepped surfaces it will be illustrated that there is a striking similarity between the behaviour of monoatomic step edges and quantum mechanical particles (spinless fermions). The direction along the step edge is equivalent to the time,

Analog-to-digital conversion using custom CMOS analog memory for the EOS time projection chamber

International Nuclear Information System (INIS)

Lee, K.L.; Arthur, A.A.; Jones, R.W.; Matis, H.S.; Nakamura, M.; Kleinfelder, S.A.; Ritter, H.G.; Wienman, H.H.

1990-01-01

This paper describes the multiplexing scheme of custom CMOS analog memory integrated circuits, 16 channels x 256 cells, into analog to digital converters (ADC's) to handle 15,360 signal channels of a time projection, chamber detector system. Primary requirements of this system are high density, low power and large dynamic range. The analog memory device multiplexing scheme was designed to digitize the information stored in the memory cells. The digitization time of the ADC's and the settling times for the memory unit were carefully interleaved to optimize the performance and timing during the multiplexing operation. This kept the total number of ADC's, a costly and power dissipative component, to an acceptable minimum

Entrepreneuring as Organisation-Creation

DEFF Research Database (Denmark)

Hjorth, Daniel

2014-01-01

This chapter aims at making a contribution to the study of entrepreneurship and creativity by developing a processual conceptualisation of a form of entrepreneurial creativity called entrepreneuring or organisation-creation. Such a processual conceptualisation of entrepreneuring will answer...

Making Sense of Value and Value Co-Creation in Service Logic

OpenAIRE

Grönroos, Christian; Voima, Päivi

2012-01-01

In order to further develop the logic of service, value creation, value co-creation and value have to be formally and rigorously defined, so that the nature, content and locus of value and the roles of service providers and customers in value creation can be unambiguously assessed. In the present article, following the underpinning logic of value-in-use, it is demonstrated that in order to achieve this, value creation is best defined as the customer’s creation of value-in-use. The analysis sh...

Proton: the particle.

Science.gov (United States)

Suit, Herman

2013-11-01

The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

Proton: The Particle

Energy Technology Data Exchange (ETDEWEB)

Suit, Herman

2013-11-01

The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

Gravitational Particle Production and the Moduli Problem

CERN Document Server

Felder, G; Linde, Andrei D; Felder, Gary; Kofman, Lev; Linde, Andrei

2000-01-01

A theory of gravitational production of light scalar particles during and after inflation is investigated. We show that in the most interesting cases where long-wavelength fluctuations of light scalar fields can be generated during inflation, these fluctuations rather than quantum fluctuations produced after inflation give the dominant contribution to particle production. In such cases a simple analytical theory of particle production can be developed. Application of our results to the theory of quantum creation of moduli fields demonstrates that if the moduli mass is smaller than the Hubble constant then these fields are copiously produced during inflation. This gives rise to the cosmological moduli problem even if there is no homogeneous component of the classical moduli field in the universe. To avoid this version of the moduli problem it is necessary for the Hubble constant H during the last stages of inflation and/or the reheating temperature T_R after inflation to be extremely small.

Distinctive Dynamic Capabilities for New Business Creation

DEFF Research Database (Denmark)

Rosenø, Axel; Enkel, Ellen; Mezger, Florian

2013-01-01

This study examines the distinctive dynamic capabilities for new business creation in established companies. We argue that these are very different from those for managing incremental innovation within a company's core business. We also propose that such capabilities are needed in both slow...... and fast-paced industries, and that similarities exist across industries. Hence, the study contributes to dynamic capabilities literature by: 1) identifying the distinctive dynamic capabilities for new business creation; 2) shifting focus away from dynamic capabilities in environments characterised by high...... clock-speed and uncertainty towards considering dynamic capabilities for the purpose of developing new businesses, which also implies a high degree of uncertainty. Based on interviews with 33 companies, we identify distinctive dynamic capabilities for new business creation, find that dynamic...

Small and Medium Enterprises, Job Creation, and Sustainability ...

International Development Research Centre (IDRC) Digital Library (Canada)

Small and Medium Enterprises, Job Creation, and Sustainability: Maximizing ... job creation, human capital, and green production and technologies will only materialize if ... IWRA/IDRC webinar on climate change and adaptive water management. International Water Resources Association, in close collaboration with IDRC, ...

Higher-order nonclassical effects generated by multiple-photon annihilation-then-creation and creation-then-annihilation coherent states

International Nuclear Information System (INIS)

Yuan Hong-Chun; Xiao Jin; Xiong Chao; Zhu Xi-Fang; Xu Xue-Xiang

2016-01-01

We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilation-then-creation (AC) and creation-then-annihilation (CA) on the coherent state, respectively, such as higher-order sub-Poissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m . By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation. (paper)

Particle and solute migration in porous media. Modeling of simultaneous transport of clay particles and radionuclides in a salinity gradient

International Nuclear Information System (INIS)

Faure, M.H.

1994-03-01

Understanding the mechanisms which control the transient transport of particles and radionuclides in natural and artificial porous media is a key problem for the assessment of safety of radioactive waste disposals. An experimental study has been performed to characterize the clayey particle mobility in porous media: a laboratory- made column, packed with an unconsolidated sand bentonite (5% weight) sample, is flushed with a salt solution. An original method of salinity gradient allowed us to show and to quantify some typical behaviours of this system: threshold effects in the peptization of particles, creation of preferential pathways, formation of immobile water zones induce solute-transfer limitation. The mathematical modelling accounts for a phenomenological law, where the distribution of particles between the stagnant water zone and the porous medium is a function of sodium chloride concentration. This distribution function is associated with a radionuclide adsorption model, and is included in a convective dispersive transport model with stagnant water zones. It allowed us to simulate the particle and solute transport when the salt environment is modified. The complete model has been validated with experiments involving cesium, calcium and neptunium in a sodium chloride gradient. (author). refs., figs., tabs

NASA HRP Immunology Discipline - Use of Terrestrial Analogs

Science.gov (United States)

Crucian, Brian

2014-01-01

Due to the cost and operational constraints, as well as technical implementation limitations, it is desirous to perform relevant space physiology investigations first in terrestrial 'space analogs'. This is particularly true for initial investigations, which may then provide appropriate focus for subsequent flight investigations, or for mechanistic investigations that simply cannot be performed during spaceflight. Appropriate analog choice is extremely important. There are a wide variety of terrestrial space analogs, each relevant to a particular physiological discipline (or disciplines) and each with a particular fidelity (or lack thereof) to spaceflight, and each with unique operational constraints. The HRP Immunology Discipline is tasked with managing the HRP Risk concerning clinical risk for Astronaut crews related to spaceflight-associated immune dysregulation. Such dysregulation has been documented to occur during spaceflight, and found to persist for the duration of a 6-month ISS mission. Studies continue to characterize the onorbit phenomenon, but it generally consists of diminished immunocyte function, dysregulated cytokine profiles, and persistent herpesvirus reactivation. Causes are thought to synergistically include microgravity, psychological or physiological stress, radiation, and/or circadian misalignment. An appropriate terrestrial analog for immune dysregulation would replicate as many of these influences as possible. Such analogs may include clinostat or bioreactor cell culture (microgravity), hindlimb suspension (stress, fluid shifts, hypokinesis), or human deployment to remote or extreme environments (isolation, stress, circadian). Also, the laboratory setting may be used as an analog, or to augment analogs, such as sleep deprivation/misalignment or human centrifugation to replicate gravitational stress. As an appropriate example of a NASA Disciplines use of Terrestrial space analogs, this talk will discuss spaceflight associated immune

Numerical studies of pair creation in counterpropagating laser fields

Energy Technology Data Exchange (ETDEWEB)

Ruf, Matthias

2009-05-27

Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

Numerical studies of pair creation in counterpropagating laser fields

International Nuclear Information System (INIS)

Ruf, Matthias

2009-01-01

Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

The Development of Analogical Reasoning Processes.

Science.gov (United States)

Sternberg, Robert J.; Rifkin, Bathsheva

1979-01-01

Two experiments were conducted to test the generalizability to children of a theory of analogical reasoning processes, originally proposed for adults, and to examine the development of analogical reasoning processes in terms of five proposed sources of cognitive development. (MP)

Computational approaches to analogical reasoning current trends

CERN Document Server

Richard, Gilles

2014-01-01

Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

Changing public service delivery: learning in co-creation

NARCIS (Netherlands)

Voorberg, William; Bekkers, Victor; Timeus, Krista; Tonurist, Piret; Tummers, L.G.

2017-01-01

Co-creation – where citizens and public organizations work together to deal with societal issues – is increasingly considered as a fertile solution for various public service delivery problems. During co-creation, citizens are not mere consumers, but are actively engaged in building resilient

SMEs’ Wealth Creation Model of an Emerging Economy

Directory of Open Access Journals (Sweden)

Olalekan Usiobaifo ASIKHIA

2016-05-01

Full Text Available This article synthesizes the evidence on SMEs’ wealth creation in an emerging economy, paying particular attention to human resource/expertise, technology adoption, innovation and creativity, unit economies, organizational infrastructure and strategy as determinants of SMEs’ wealth creation. A survey of 581 Nigerian SMEs was conducted and the data was analysed and tested using multiple regression and structural equation modelling. The findings revealed Human resource/CEOs expertise as the highest contributory factor to wealth creation within the firm in the industrial and the commercial sectors. The relevant domains were modelled and relevant policy adjustments were suggested.

Supralinearity and particle discrimination in nuclear emulsion

International Nuclear Information System (INIS)

Katz, R.; Larsson, L.; Pinkerton, F.E.; Benton, E.V.

1977-01-01

Nuclear emulsions may be desensitized in manufacture and/or may be so processed as to discriminate against small latent image sites; to yield supralinear sensitometric response after x-irradiation; and to discriminate against lightly ionizing radiations in favor of heavily ionizing particles. In a circumstance where one electron passing through an emulsion grain is unlikely to generate a latent image sufficiently large to yield a visible grain after development, some larger number of electrons is required, resulting in 'many-hit' statistics, supralinearity, and particle discrimination: for lightly ionizing particles are not likely to generate more than one delta-ray (secondary electron) in their passage through or near a grain. Since these properties are analogous to the response of many biological cells to ionizing radiations, such emulsion-developer combinations have the potential to mimic the response of biological systems to particulate radiations of different charge and speed. (author)

Design and Analysis of Reconfigurable Analog System

Science.gov (United States)

2011-02-01

34010010" �" �" �" �" �" �" �±" N3 N2 N± P1 P2 P3 * Current sources $RR = 1; *Ramp Rate (slope of the...2008/12/12/31e83bac-500f-4182- acca -4d360295fd9c.pdf, Analog Devices, Analog Dialogue 39-06, June 2005. [15] D. A. Johns, K. Martin "Analog Integrated

Measurement methods for high energy particle identification in gaseous mixture detectors

International Nuclear Information System (INIS)

Marchand, Patrick.

1981-01-01

In this work, we discuss some methods for high energy particle identification. We study and design a MWPC equipped with a preamplifier gap for increased resolution. In addition, we propose a new mehod of counting primary collisions. The electronic system used for multiplexing analog wire signals is also described [fr

Particle accelerators test cosmological theory

International Nuclear Information System (INIS)

Schramm, D.N.; Steigman, G.

1988-01-01

Over the past decade two subfields of science, cosmology and elementary-particle physics, have become married in a symbiotic relationship that has produced a number of exciting offspring. These offspring are beginning to yield insights on the creation of spacetime and matter at epochs as early as 10 to the minus 43 to 10 to the minus 35 second after the birth of the universe in the primordial explosion known as the big bang. Important clues to the nature of the big bang itself may even come from a theory currently under development, known as the ultimate theory of everything (T.E.O.). A T.E.O. would describe all the interactions among the fundamental particles in a single bold stroke. Now that cosmology ahs begun to make predictions about elementary-particle physics, it has become conceivable that those cosmological predictions could be checked with carefully controlled accelerator experiments. It has taken more than 10 years for accelerators to reach the point where they can do the appropriate experiments, but the experiments are now in fact in progress. The preliminary results confirm the predictions of cosmology. The cosmological prediction the authors have been concerned with pertains to setting limits on the number of fundamental particles of matter. It appears that there are 12 fundamental particles, as well as their corresponding antiparticles. Six of the fundamental particles are quarks. The other six are leptons. The 12 particles are grouped in three families, each family consisting of four members. Cosmology suggests there must be a finite number of families and, further limits the possible range of to small values: only three or at most four families exist. 7 figs

Crows spontaneously exhibit analogical reasoning.

Science.gov (United States)

Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

2015-01-19

Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

Perceptions of Rebuttal Analogy: Politeness and Implications for Persuasion.

Science.gov (United States)

Whaley, Bryan B.

1997-01-01

States that recent theorizing about the role of analogy in persuasion suggests that "rebuttal" analogy addresses two communicative functions by serving as argument and a method of social attack. Examines message receivers' perceptions of rebuttal analogy and rebuttal analogy users. Finds that participants perceived the communicator using…

The Multiverse and Divine Creation

Directory of Open Access Journals (Sweden)

Michael Almeida

2017-11-01

Full Text Available I provide the account of divine creation found in multiverse theorists Donald Turner, Klaas Kraay, and Tim O’Connor. I show that the accounts Kraay and Turner offer are incoherent. God does not survey all possible worlds and necessarily actualize those universes in the (on balance good worlds or the worthy worlds. If God necessarily actualizes the multiverse, we have no idea which universes are parts of that multiverse. I show next that Tim O’Connor’s multiverse account of creation is also incoherent. I argue that a preferable multiverse would include a much greater variety of universes than are included in Turner, Kraay or O’Connor. In the last section I offer some concluding remarks.

Elucidating the neurotoxic effects of MDMA and its analogs.

Science.gov (United States)

Karuppagounder, Senthilkumar S; Bhattacharya, Dwipayan; Ahuja, Manuj; Suppiramaniam, Vishnu; Deruiter, Jack; Clark, Randall; Dhanasekaran, Muralikrishnan

2014-04-17

There is a rapid increase in the use of methylenedioxymethamphetamine (MDMA) and its structural congeners/analogs globally. MDMA and MDMA-analogs have been synthesized illegally in furtive dwellings and are abused due to its addictive potential. Furthermore, MDMA and MDMA-analogs have shown to have induced several adverse effects. Hence, understanding the mechanisms mediating this neurotoxic insult of MDMA-analogs is of immense importance for the public health in the world. We synthesized and investigated the neurotoxic effects of MDMA and its analogs [4-methylenedioxyamphetamine (MDA), 2, 6-methylenedioxyamphetamine (MDMA), and N-ethyl-3, 4-methylenedioxyamphetamine (MDEA)]. The stimulatory or the dopaminergic agonist effects of MDMA and MDMA-analogs were elucidated using the established 6-hydroxydopamine lesioned animal model. Additionally, we also investigated the neurotoxic mechanisms of MDMA and MDMA-analogs on mitochondrial complex-I activity and reactive oxygen species generation. MDMA and MDMA-analogs exhibited stimulatory activity as compared to amphetamines and also induced several behavioral changes in the rodents. MDMA and MDMA-analogs enhanced the reactive oxygen generation and inhibited mitochondrial complex-I activity which can lead to neurodegeneration. Hence the mechanism of neurotoxicity, MDMA and MDMA-analogs can enhance the release of monoamines, alter the monoaminergic neurotransmission, and augment oxidative stress and mitochondrial abnormalities leading to neurotoxicity. Thus, our study will help in developing effective pharmacological and therapeutic approaches for the treatment of MDMA and MDMA-analog abuse. Copyright © 2014 Elsevier Inc. All rights reserved.

Gold micro- and nano-particles for surface enhanced vibrational spectroscopy of pyridostigmine bromide

DEFF Research Database (Denmark)

Dolgov, Leonid; Fesenko, Olena; Kavelin, Vladyslav

2017-01-01

Triangular gold microprisms and spherical silica nanoparticles with attached gold nano-islands were examined as an active nanostructures for the surface enhanced Raman and infrared spectroscopy. These particles were probed for the detection of pyridostigmine bromide as a safe analog of military c...

Progress in strategies for sequence diversity library creation for ...

African Journals Online (AJOL)

As the simplest technique of protein engineering, directed evolution has been ... An experiment of directed evolution comprises mutant libraries creation and ... evolution, sequence diversity creation, novel strategy, computational design, ...

Creation of Auditing Knowledge:

DEFF Research Database (Denmark)

Liempd, Dennis van

  Even though auditing research could play a role in understanding the many challenges that are threatening the profession, and in providing possible solutions, it seems to have failed in adequately doing so. This is for a major part because of a lack of research into auditing's basic assumptions......, and a too one-sided view on the creation of auditing knowledge. The purpose of this paper is to call for more (diverse) research in this area. Earlier calls have been few and far between, and have not resulted in a lot of research. Within the last two decades though, the auditing universe has changed so...... much that high-quality auditing research never has been needed more. By reviewing available literature challenges to the auditing profession are explored, and the creation of knowledge in general and auditing knowledge in particular are discussed with respect to methodological approaches and operative...

Creationism and intelligent design.

Science.gov (United States)

Pennock, Robert T

2003-01-01

Creationism, the rejection of evolution in favor of supernatural design, comes in many varieties besides the common young-earth Genesis version. Creationist attacks on science education have been evolving in the last few years through the alliance of different varieties. Instead of calls to teach "creation science," one now finds lobbying for "intelligent design" (ID). Guided by the Discovery Institute's "Wedge strategy," the ID movement aims to overturn evolution and what it sees as a pernicious materialist worldview and to renew a theistic foundation to Western culture, in which human beings are recognized as being created in the image of God. Common ID arguments involving scientific naturalism, "irreducible complexity," "complex specified information," and "icons of evolution," have been thoroughly examined and refuted. Nevertheless, from Kansas to Ohio to the U.S. Congress, ID continues lobbying to teach the controversy, and scientists need to be ready to defend good evolution education.

Bose-Einstein condensation and long-range phase coherence in the many-particle Schroedinger wave function

International Nuclear Information System (INIS)

Mayers, J.

2001-01-01

The properties of the many-particle Schroedinger wave function Ψ are examined in the presence of Bose-Einstein condensation (BEC). It is shown that it is possible to define, in terms of Ψ, a function ψ(r-vector vertical bar s-vector), which can be regarded as the single-particle wave function of an arbitrary particle for a fixed configuration s-vector of all other particles. It is shown that ψ(r-vector|s-vector) plays an analogous role to the field operator of standard field-theoretical treatments of superfluidity. It is shown that in the presence of a Bose-Einstein condensate fraction f, ψ(r-vector|s-vector) must be nonzero and phase coherent within at least a fraction f of the total volume of the N-particle system for essentially all s-vector. Examination of the form of variational many-particle wave functions shows that in liquid 4 He, ψ(r-vector|s-vector) extends throughout the spaces left between the hard cores of the other atoms at s-vector. By contrast, in the absence of BEC, ψ(r-vector|s-vector) in the ground state must be nonzero only over a localized region of space. It is shown that in order for long-range phase coherence in ψ(r-vector|s-vector) to be maintained in the presence of velocity fields, any circulation must be quantized over macroscopic length scales. Some numerical calculations of the properties and fluctuations of liquid helium are presented. These suggest that the approach outlined in this paper may have significant advantages for the numerical calculations of the properties of Bose-Einstein condensed systems. The properties of ψ(r-vector|s-vector) are used to show that there is no general connection between the static structure factor and the size of the Bose-Einstein condensate fraction in a Bose fluid. It is suggested that the observed connection in liquid 4 He is due to the creation of vacancies in the liquid structure, which are required so that ψ(r-vector vertical bar s-vector) can delocalize, in the presence of hard

Learning Plate Tectonics Using a Pre-Analogy Step

Science.gov (United States)

Glesener, G. B.; Sandoval, W. A.

2011-12-01

Previous research has shown that children tend to demonstrate lower performance on analogical reasoning tasks at a causal relations level compared to most adults (Gentner & Toupin, 1986). This tendency is an obstacle that geoscience educators must overcome because of the high frequency of analogies used in geoscience pedagogy. In particular, analog models are used to convey complex systems of non-everyday/non-observable events found in nature, such as plate tectonics. Key factors in successful analogical reasoning that have been suggested by researchers include knowledge of the causal relations in the base analog (Brown & Kane, 1988; Gentner, 1988; Gentner & Toupin, 1986), and development of learning strategies and metaconceptual competence(Brown & Kane, 1988). External factors, such as guiding cues and hints have been useful cognitive supports that help students reason through analogical problems (Gick & Holyoak, 1980). Cognitive supports have been seen by researchers to decrease processing demands on retrieval and working memory (Richland, Zur, & Holyoak, 2007). We observed third and fourth graders learning about plate tectonics beginning with a pre-analogy step-a cognitive support activity a student can do before working with an analogy to understand the target. This activity was designed to aid students in developing their understanding of object attributes and relations within an analog model so that more focus can be placed on mapping the corresponding higher-order relations between the base and target. Students learned targeted concepts of plate tectonics, as measured by pre to post gains on items adapted from the Geosciences Concept Inventory. Analyses of classroom interaction showed that students used the object attributes and higher-order relations highlighted in the pre-analogy activity as resources to reason about plate boundaries and plate movement during earthquakes.

Natural analogs for Yucca Mountain

International Nuclear Information System (INIS)

Murphy, W.M.

1995-01-01

High-level radioactive waste in the US, spent fuels from commercial reactors and nuclear materials generated by defense activities, will remain potentially hazardous for thousands of years. Demonstrable long-term stability of certain geologic and geochemical systems motivates and sustains the concept that high-level waste can be safely isolated in geologic repositories for requisite periods of time. Each geologic repository is unique in its properties and performance with reguard to isolation of nuclear wastes. Studies of processes analogous to waste-form alteration and radioelement transport in environments analogous to Yucca Mountain are being conducted at two sites, described in this article to illustrate uses of natural analog data: the Nopal I uranium deposit in the Sierra Pena Blanca, Mexico, and the Akrotiri archaeological site on the island of Santorini, Greece

Taking Stock of Project Value Creation

DEFF Research Database (Denmark)

Laursen, Markus; Svejvig, Per

2014-01-01

This paper presents the outcome of a literature review through classifying and analyzing 59 publications in project value creation literature. The analysis led to five distinct categories: Benefit Realization Management (BRM) and techniques, broad value perspective, value time frame, engineering...... requirements and product development. These five categories cover a wide selection of value creation literature in project contexts. The project types reported in empirical studies are mainly IS/IT and construction and a variety of other types such as R&D and strategy implementation. The literature dates back...

Creatio in musica - Creation in Music

DEFF Research Database (Denmark)

Schwab, Heinrich Wilhelm

2007-01-01

Book abstract  The meaning of the noun 'creation', and the verb 'to create', range from the traditional theological idea of God creating ex nihilo to a more recent sense of the process of artistic conception. This collection of thirteen essays, written by scholars of music, literature, the visual...... includes some twentieth-century musicians. Each essay is dedicated to a particular topic concerned with ritual or artistic beginnings, inventions, harmony and disharmony, as well as representations or celebrations of creation. Central themes include the interplay of the ideas of God as creator, of God...

Job Creation and Job Destruction, Worker Reallocation, and Wages.

OpenAIRE

Belzil, Christian

2000-01-01

Using Danish firm (workplace) data on employment reallocation merged with individual records, the effects of job creation/destruction and worker reallocation on wages are estimated using fixed effects techniques. After controlling for business cycle fluctuations, job creation is found to increase male wages. The effect of net job creation seems present at all phases of the business cycle. Entry wages as well as wages of low tenure workers appear much more sensitive to idiosyncratic job creati...

Creation, Identity and Reflection

Directory of Open Access Journals (Sweden)

Alina Beatrice Cheşcă

2015-05-01

Full Text Available The paper “Creation, Identity and Reflection” approaches the identification in the “mirror” of reality with creation, in other words seeking the authors’ identity in the reflected images. Reflection means attempting to find oneself, the mirror being the main principle of creation. Many characters become interesting only when they step into the world beyond the mirror, when their faces are doubled by the other self or when their selves are returned by other characters. The narcissistic concept of the mirror, i.e. the reflection in the mirror and the representation of the mirror itself, is a recurrent one in literature, but the reflection of the self which is not the self (as it is a reflection does not necessarily appear in a mirror or in a photograph or portrait. Sometimes, the not-self is returned to the self by another person or character. As far as Oscar Wilde’s theories are concerned, the main idea is that people are interesting for their masks, not for their inner nature. What Wilde calls “inner nature” is the characters’ un-reflected self and the mask is the reflection, the self in the mirror. Some characters’ relationships develop within a fiction that they dramatically try to preserve and protect with the risk of suffering. They refuse to take off the masks which define them in the others’ minds and hearts; the narcissistic individuals (both artists and characters seek and love their own image which they project upon facts, thus creating a fictive realm.

Heavy ion irradiation of astrophysical ice analogs

International Nuclear Information System (INIS)

Duarte, Eduardo Seperuelo; Domaracka, Alicja; Boduch, Philippe; Rothard, Hermann; Balanzat, Emmanuel; Dartois, Emmanuel; Pilling, Sergio; Farenzena, Lucio; Frota da Silveira, Enio

2009-01-01

Icy grain mantles consist of small molecules containing hydrogen, carbon, oxygen and nitrogen atoms (e.g. H 2 O, GO, CO 2 , NH 3 ). Such ices, present in different astrophysical environments (giant planets satellites, comets, dense clouds, and protoplanetary disks), are subjected to irradiation of different energetic particles: UV radiation, ion bombardment (solar and stellar wind as well as galactic cosmic rays), and secondary electrons due to cosmic ray ionization of H 2 . The interaction of these particles with astrophysical ice analogs has been the object of research over the last decades. However, there is a lack of information on the effects induced by the heavy ion component of cosmic rays in the electronic energy loss regime. The aim of the present work is to simulate of the astrophysical environment where ice mantles are exposed to the heavy ion cosmic ray irradiation. Sample ice films at 13 K were irradiated by nickel ions with energies in the 1-10 MeV/u range and analyzed by means of FTIR spectrometry. Nickel ions were used because their energy deposition is similar to that deposited by iron ions, which are particularly abundant cosmic rays amongst the heaviest ones. In this work the effects caused by nickel ions on condensed gases are studied (destruction and production of molecules as well as associated cross sections, sputtering yields) and compared with respective values for light ions and UV photons. (authors)

Analogy-Enhanced Instruction: Effects on Reasoning Skills in Science

Science.gov (United States)

Remigio, Krisette B.; Yangco, Rosanelia T.; Espinosa, Allen A.

2014-01-01

The study examined the reasoning skills of first year high school students after learning general science concepts through analogies. Two intact heterogeneous sections were randomly assigned to Analogy-Enhanced Instruction (AEI) group and Non Analogy-Enhanced (NAEI) group. Various analogies were incorporated in the lessons of the AEI group for…

Epistemology of analogy: Knowledge, society and expression

Directory of Open Access Journals (Sweden)

Mauricio Beuchot

2017-06-01

Full Text Available In this article we expose the bases of analog epistemology. This theory of knowledge is between an extreme subjectivism and an extreme objectivism. Analog hermeneutics is a realistic hermeneutics. She seeks the truth, but incorporates the meaning and emotion. We have separated the reason from the experience, the praxis theory, the mind or the soul of the body. We have to get them back together, if we do not get lost in the rational (which says little of the human being, or we lose ourselves in the emotional (without logical consistency. The analogical hermeneutic realism is able, thanks to the analogy itself, to mediate in this way of union.

Aspects of governmental job-creation efforts in Western Europe and North America.

OpenAIRE

Hollister RG

1986-01-01

ILO pub-WEP pub. Working paper, comparison of employment policies for employment creation in Western Europe and the USA - covers job creation measures, target groups, financing, and the relationships between job creation and economic policy and social policies (esp. Social security); looks at problems of design implementation and evaluation of employment creation projects; discusses obstacles to employment creation in the context of economic recession in Western Europe, and in a developing co...

Analog elements for transuranic chemistries

International Nuclear Information System (INIS)

Weimer, W.C.

1982-01-01

The analytical technique for measuring trace concentrations of the analog rare earth elements has been refined for optimal detection. The technique has been used to determine the rare earth concentrations in a series of geological and biological materials, including samples harvested from controlled lysimeter investigations. These studies have demonstrated that any of the trivalent rare earth elements may be used as analog elements for the trivalent transuranics, americium and curium

Analogy, explanation, and proof

Science.gov (United States)

Hummel, John E.; Licato, John; Bringsjord, Selmer

2014-01-01

People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence. PMID:25414655

Analogy, Explanation, and Proof

Directory of Open Access Journals (Sweden)

John eHummel

2014-11-01

Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

Laboratory Studies of the Optical Properties and Condensation Processes of Cosmic Dust Particles

Science.gov (United States)

Abbas, Mian M.; Craven, Paul D.; Spann, James F.; Tankosic, Dragana; Six, N. Frank (Technical Monitor)

2002-01-01

A laboratory facility for levitating single isolated dust particles in an electrodynamics balance has been developing at NASA/Marshall Space Flight Center for conducting a variety of experimental, of astrophysical interest. The objective of this research is to employ this innovative experimental technique for studies of the physical and optical properties of the analogs of cosmic grains of 0.2-10 micron size in a chamber with controlled pressure/temperatures simulating astrophysical environments. In particular, we will carry out three classes of experiments to investigate the microphysics of the analogs of interstellar and interplanetary dust grains. (1) Charge characteristics of micron size single dust grains to determine the photoelectric efficiencies, yields, and equilibrium potentials when exposed to UV radiation. These measurements will provide the much-needed photoelectric emission data relating to individual particles as opposed to that for the bulk materials available so far. (2) Infrared optical properties of dust particles obtained by irradiating the particles with radiation from tunable infrared diode lasers and measuring the scattered radiation. Specifically, the complex refractive indices, the extinction coefficients, the scattering phase functions, and the polarization properties of single dust grains of interest in interstellar environments, in the 1-25 micron spectral region will be determined. (3) Condensation experiments to investigate the deposition of volatile gases on colder nucleated particles in dense interstellar clouds and lower planetary atmospheres. The increase in the mass or m/q ratio due to condensation on the particle will be monitored as a function of the dust particle temperature and the partial pressure of the injected volatile gas. The measured data wild permit determination of the sticking efficiencies of volatile gases of astrophysical interest. Preliminary results based on photoelectric emission experiments on 0.2-6.6 micron

Sources of Value Creation in Born Global Companies

Directory of Open Access Journals (Sweden)

Augustyniak Dobrochna

2017-06-01

Full Text Available Research about the phenomenon of rapid internationalization of small and medium size companies has evolved over the last two decades. Nevertheless, questions about business models or value creation in born global enterprises are rarely addressed in the literature. The objective of this article is to develop a theoretical framework for analyzing the sources of value creation in the business models of international new ventures (INV global companies, starting with adapting the model by Amit and Zott [2001, 2010] to early internationalizing venture. Current literature on international entrepreneurship, business models and value creation is also used as a basis for suggesting future empirical research recommendations.

Insulin analogs with improved pharmacokinetic profiles.

Science.gov (United States)

Brange; Vølund

1999-02-01

The aim of insulin replacement therapy is to normalize blood glucose in order to reduce the complications of diabetes. The pharmacokinetics of the traditional insulin preparations, however, do not match the profiles of physiological insulin secretion. The introduction of the rDNA technology 20 years ago opened new ways to create insulin analogs with altered properties. Fast-acting analogs are based on the idea that an insulin with less tendency to self-association than human insulin would be more readily absorbed into the systemic circulation. Protracted-acting analogs have been created to mimic the slow, steady rate of insulin secretion in the fasting state. The present paper provides a historical review of the efforts to change the physicochemical and pharmacological properties of insulin in order to improve insulin therapy. The available clinical studies of the new insulins are surveyed and show, together with modeling results, that new strategies for optimal basal-bolus treatment are required for utilization of the new fast-acting analogs.

Los pasiegos. La analogía salvaje y lo salvaje de la analogía

Directory of Open Access Journals (Sweden)

JAIME DE LA CALLE VALVERDE

2007-01-01

-entendiendo salvaje como un pensamiento humano prístino-: por un lado en sus relaciones con el racionalismo (¿emerge la analogía desde el racionalismo?, ¿qué relación guarda con éste?, ¿su nacimiento es resultado de una función «natural»? y por otro sobre la naturaleza social de lo salvaje a partir de las bases sociales que lo producen. Es decir, se rastrea lo que de salvaje tiene la analogía, si la analogía es o no una función ahistórica y asocial del intelecto humano. No se examina todo el complejo analógico de los pasiegos, únicamente aquél que establece relaciones homólogas entre las vacas y el entorno.

On a possibility of creation of positive space charge cloud in a system with magnetic insulation of electrons

International Nuclear Information System (INIS)

Goncharov, A.A.; Dobrovol'skii, A.M.; Dunets, S.P.; Evsyukov, A.N.; Protsenko, I.M.

2009-01-01

We describe a new approach for creation an effective, low-cost, low-maintenance axially symmetric plasma optical tools for focusing and manipulating high-current beams of negatively charged particles, electrons and negative ions. This approach is based on fundamental plasma optical concept of magnetic insulation of electrons and non-magnetized positive ions providing creation of controlled uncompensated cloud of the space charge. The axially symmetric electrostatic plasma optical lens is well-known and well developed tool where this concept is used successfully. This provides control and focusing high-current positive ion beams in wide range of parameters. Here for the first time we present optimistic experimental results describing the application of an idea of magnetic insulation of electrons for generation of the stable cloud of positive space charge by focusing onto axis the converging stream of heavy ions produced by circular accelerator with closed electron drift. The estimations of a maximal concentration of uncompensated cloud of positive ions are also made

FY 1998 annual report on the researches on creation of inorganic thin films and fine particles of new functions; 1998 nendo shinkino muki usumaku biryushi no sosei kenkyu chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Creation of inorganic thin films and fine particles under a microgravity atmosphere is studied, for which Japan Microgravity Center's drop test facilities are used. The Cu anodic dissolution tests are conducted using a quasi-two-dimensional electrolytic cell, as part of the basic researches on micromachining for controlling high aspect ratio and shape anisotropy. It is difficult to control natural convection on the ground, even when the electrode thickness is decreased to 100 {mu}m or less. Concentration of the electrolytic solution over the anode surface is more supersaturated under a microgravity than on the ground. For production of fine glass particles, the liquid phase is involved between evaporation and solidification of glass. The Pb-X and Pb-Zn-X systems are molten, and dropped and, at the same time, solidified by quenching. The X component (including Zn) is uniformly dispersed under a microgravity in spheres of several to 20 {mu}m in diameter, although it is separated on the ground. The spherical droplets of GaSb can grow into a single crystal even in the absence of the seed, when supercooled and directed at high speed onto silica glass. A SiGe film with fine voids can be prepared and fast adhered to the base by flash lamp annealing, when it is deposited on the base with a SiN film as the buffer and then made into the film. (NEDO)

How the creative use of analogies can shape medical practice.

Science.gov (United States)

Prasad, G V Ramesh

2015-06-01

Analogical reasoning is central to medical progress, and is either creative or conservative. According to Hofmann et al., conservative analogy relates concepts from old technology to new technologies with emphasis on preservation of comprehension and conduct. Creative analogy however brings new understanding to new technology, brings similarities existing in the source domain to a target domain where they previously had no bearing, and imports something entirely different from the content of the analogy itself. I defend the claim that while conservative analogies are useful by virtue of being comfortable to use from familiarity and experience, and are more easily accepted by society, they only lead to incremental advances in medicine. However, creative analogies are more exciting and productive because they generate previously unexpected associations across widely separated domains, emphasize relations over physical similarities, and structure over superficiality. I use kidney transplantation and anti-rejection medication development as an exemplar of analogical reasoning used to improve medical practice. Anti-rejection medication has not helped highly sensitized patients because of their propensity to rejecting most organs. I outline how conservative analogical reasoning led to anti-rejection medication development, but creative analogical reasoning helped highly sensitized and blood type incompatible patients through domino transplants, by which they obtain a kidney to which they are not sensitized. Creative analogical reasoning is more likely than conservative analogical reasoning to lead to revolutionary progress. While these analogies overlap and creative analogies eventually become conservative, progress is best facilitated by combining conservative and creative analogical reasoning. © 2015 John Wiley & Sons, Ltd.

Analogs for transuranic elements

International Nuclear Information System (INIS)

Weimer, W.C.; Laul, J.C.; Kutt, J.C.

1981-01-01

A combined theoretical and experimental approach is being used to estimate the long-term environmental and biogeochemical behaviors of selected transuranic elements. The objective of this research is to estimate the effect that long-term (hundreds of years) environmental weathering has on the behavior of the transuranic elements americium and curium. This is achieved by investigating the actual behavior of naturally occurring rare earth elements, especially neodymium, that serve as transuranic analogs. Determination of the analog element behavior provides data that can be used to estimate the ultimate availability to man of transuranic materials released into the environment

Dockomatic - automated ligand creation and docking.

Science.gov (United States)

Bullock, Casey W; Jacob, Reed B; McDougal, Owen M; Hampikian, Greg; Andersen, Tim

2010-11-08

The application of computational modeling to rationally design drugs and characterize macro biomolecular receptors has proven increasingly useful due to the accessibility of computing clusters and clouds. AutoDock is a well-known and powerful software program used to model ligand to receptor binding interactions. In its current version, AutoDock requires significant amounts of user time to setup and run jobs, and collect results. This paper presents DockoMatic, a user friendly Graphical User Interface (GUI) application that eases and automates the creation and management of AutoDock jobs for high throughput screening of ligand to receptor interactions. DockoMatic allows the user to invoke and manage AutoDock jobs on a single computer or cluster, including jobs for evaluating secondary ligand interactions. It also automates the process of collecting, summarizing, and viewing results. In addition, DockoMatic automates creation of peptide ligand .pdb files from strings of single-letter amino acid abbreviations. DockoMatic significantly reduces the complexity of managing multiple AutoDock jobs by facilitating ligand and AutoDock job creation and management.

Dockomatic - automated ligand creation and docking

Directory of Open Access Journals (Sweden)

Hampikian Greg

2010-11-01

Full Text Available Abstract Background The application of computational modeling to rationally design drugs and characterize macro biomolecular receptors has proven increasingly useful due to the accessibility of computing clusters and clouds. AutoDock is a well-known and powerful software program used to model ligand to receptor binding interactions. In its current version, AutoDock requires significant amounts of user time to setup and run jobs, and collect results. This paper presents DockoMatic, a user friendly Graphical User Interface (GUI application that eases and automates the creation and management of AutoDock jobs for high throughput screening of ligand to receptor interactions. Results DockoMatic allows the user to invoke and manage AutoDock jobs on a single computer or cluster, including jobs for evaluating secondary ligand interactions. It also automates the process of collecting, summarizing, and viewing results. In addition, DockoMatic automates creation of peptide ligand .pdb files from strings of single-letter amino acid abbreviations. Conclusions DockoMatic significantly reduces the complexity of managing multiple AutoDock jobs by facilitating ligand and AutoDock job creation and management.

23rd workshop on Advances in Analog Circuit Design

CERN Document Server

Baschirotto, Andrea; Makinwa, Kofi

2015-01-01

This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    • Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing; • Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; • Presents material in a tutorial-based format.

Bayesian analogy with relational transformations.

Science.gov (United States)

Lu, Hongjing; Chen, Dawn; Holyoak, Keith J

2012-07-01

How can humans acquire relational representations that enable analogical inference and other forms of high-level reasoning? Using comparative relations as a model domain, we explore the possibility that bottom-up learning mechanisms applied to objects coded as feature vectors can yield representations of relations sufficient to solve analogy problems. We introduce Bayesian analogy with relational transformations (BART) and apply the model to the task of learning first-order comparative relations (e.g., larger, smaller, fiercer, meeker) from a set of animal pairs. Inputs are coded by vectors of continuous-valued features, based either on human magnitude ratings, normed feature ratings (De Deyne et al., 2008), or outputs of the topics model (Griffiths, Steyvers, & Tenenbaum, 2007). Bootstrapping from empirical priors, the model is able to induce first-order relations represented as probabilistic weight distributions, even when given positive examples only. These learned representations allow classification of novel instantiations of the relations and yield a symbolic distance effect of the sort obtained with both humans and other primates. BART then transforms its learned weight distributions by importance-guided mapping, thereby placing distinct dimensions into correspondence. These transformed representations allow BART to reliably solve 4-term analogies (e.g., larger:smaller::fiercer:meeker), a type of reasoning that is arguably specific to humans. Our results provide a proof-of-concept that structured analogies can be solved with representations induced from unstructured feature vectors by mechanisms that operate in a largely bottom-up fashion. We discuss potential implications for algorithmic and neural models of relational thinking, as well as for the evolution of abstract thought. Copyright 2012 APA, all rights reserved.

Analogical reasoning for reliability analysis based on generic data

Energy Technology Data Exchange (ETDEWEB)

Kozin, Igor O

1996-10-01

The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects.

Analogical reasoning for reliability analysis based on generic data

International Nuclear Information System (INIS)

Kozin, Igor O.

1996-01-01

The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects

17 CFR 201.1100 - Creation of Fair Fund.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Creation of Fair Fund. 201... PRACTICE Fair Fund and Disgorgement Plans § 201.1100 Creation of Fair Fund. In any agency process initiated... requiring the payment of disgorgement by a respondent and also assessing a civil money penalty against that...

Particles with small violations of Fermi or Bose statistics

International Nuclear Information System (INIS)

Greenberg, O.W.

1991-01-01

I discuss the statistics of ''quons'' (pronounced to rhyme with muons), particles whose annihilation and creation operators obey the q-deformed commutation relation (the quon algebra or q-mutator) which interpolates between fermions and bosons. Topics discussed include representations of the quon algebra, proof of the TCP theorem, violation of the usual locality properties, and experimental constraints on violations of the Pauli exclusion principle (i.e., Fermi statistics) and of Bose statistics

Molecular dynamics simulations of the role of electronic losses in damage creation of ion irradiated Tungsten

International Nuclear Information System (INIS)

Maya, P.N.; Deshpande, S.P

2014-01-01

Damage creation due to the irradiation of 14 MeV fusion neutrons and the subsequent mechanical failure and alteration of the fuel retention properties of tungsten plasma-facing materials is one of the major concerns of the fusion reactors. In addition to nuclear reactions and the subsequent transmutations, the energetic neutron impars its kinetic energy either partly or completely to a lattice tungsten atom thereby creating a primary knock-on atom (PKA) which, is considered as the onset of damage creation in the lattice. The PKA continues to undergo collisions with the lattice atoms which eventually leads to a collision cascade. In order to understand the collision process, one often simulates such systems using surrogate ions, such as energetic W ions itself, in particle accelerators and due to the experimental constraints (such as the stability of the beam) one often has to opt for high energetic ion beams (∼ 30 MeV) which surpasses the PKA energies created by neutron (∼100s of KeV) in W. Hence it is important to distinguish how the very high energetic tungsten atoms interact with the lattice atoms in comparison with the low energy PKA created by the neutron. One of the key difference is that at higher energies the electronic losses become important which decides the collision dynamics. In this presentation the effect of electronic losses in the damage creation using molecular dynamics simulations have been discussed

Analogical Matrices in Young Children and Students with Intellectual Disability: Reasoning by Analogy or Reasoning by Association?

Science.gov (United States)

Denaes, Caroline

2012-01-01

Background: Analogical reasoning (AR) is renowned for being a complex activity. Young children tend to reason by association, rather by analogy, and people with intellectual disability present problems of memorization. Both these populations usually show low performances in AR. The present author investigated whether familiar material and external…

Neurotoxic Alkaloids: Saxitoxin and Its Analogs

Directory of Open Access Journals (Sweden)

Troco K. Mihali

2010-07-01

Full Text Available Saxitoxin (STX and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs. PSTs are the causative agents of paralytic shellfish poisoning (PSP and are mostly associated with marine dinoflagellates (eukaryotes and freshwater cyanobacteria (prokaryotes, which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

13 CFR 120.861 - Job creation or retention.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be specified...

McMurdo Dry Valleys, Antarctica - A Mars Phoenix Mission Analog

Science.gov (United States)

Tamppari, L. K.; Anderson, R. M.; Archer, D.; Douglas, S.; Kounaves, S. P.; McKay, C. P.; Ming, Douglas W.; Moore, Q.; Quinn, J. E.; Smith, P. H.;

A hierarchical spatiotemporal analog forecasting model for count data.

Science.gov (United States)

McDermott, Patrick L; Wikle, Christopher K; Millspaugh, Joshua

2018-01-01

Analog forecasting is a mechanism-free nonlinear method that forecasts a system forward in time by examining how past states deemed similar to the current state moved forward. Previous applications of analog forecasting has been successful at producing robust forecasts for a variety of ecological and physical processes, but it has typically been presented in an empirical or heuristic procedure, rather than as a formal statistical model. The methodology presented here extends the model-based analog method of McDermott and Wikle (Environmetrics, 27, 2016, 70) by placing analog forecasting within a fully hierarchical statistical framework that can accommodate count observations. Using a Bayesian approach, the hierarchical analog model is able to quantify rigorously the uncertainty associated with forecasts. Forecasting waterfowl settling patterns in the northwestern United States and Canada is conducted by applying the hierarchical analog model to a breeding population survey dataset. Sea surface temperature (SST) in the Pacific Ocean is used to help identify potential analogs for the waterfowl settling patterns.

A Social Vision for Value Co-creation in Design

Directory of Open Access Journals (Sweden)

George Simons

2009-11-01

Full Text Available The Cluetrain Manifesto was introduced in 1999, calling for a powerful global conversation between companies and the people they serve. Since then, the conversation has started and is finally gaining momentum. Co-creation is the buzzword of the day to describe the various types of conversations that are taking place. But the conversation has multiple perspectives. It can be applied to multiple domains ranging from sales tactics and branding contests to strategic, human-centered means of affecting social transformation. In this article we try to articulate a vision for value co-creation by focusing on its social aspects. It is our hope that such social vision will contribute to existing perspectives so that future conversations can take place in a more productive way. The suggested framework organizes the seemingly disparate applications, comparing the mindset, goals and results of three types of value co-creation: monetary, use/experience and social. Although these three types of value co-creation are all relevant, we believe that the social type of value provides a real opportunity for significant social change. However, the rules of engagement for this type of co-creation are particularly challenging. Participation must be face-to-face to allow for real-time interaction to take place. Empathy for the people who will be affected by change is key. Visualization of the collective assets is essential. And having the appropriate mindset about co-creation is the single most important component for success.

Light-induced defect creation in hydrogenated polymorphous silicon

International Nuclear Information System (INIS)

Morigaki, K.; Takeda, K.; Hikita, H.; Roca i Cabarrocas, P.

2005-01-01

Light-induced defect creation in hydrogenated polymorphous silicon (pm-Si:H) is investigated from electron spin resonance measurements and is compared with that in hydrogenated amorphous silicon (a-Si:H). Light-induced defect creation occurs at room temperature similarly for both types of films prepared at 250 deg. C. Thermal annealing of light-induced defects is also investigated as a function of temperature. Different behaviours of annealing characteristics for pm-Si:H from those for a-Si:H are observed and discussed. In particular, we observed a decrease of the light-induced defect creation efficiency with repeated light-soaking-annealing cycles and discuss it with respect to the hydrogen bonding in pm-Si:H films

The Politics of States', Local Governments' Creation and Nigeria's ...

African Journals Online (AJOL)

Nekky Umera

federal structure; the demands for the creation of additional states and localities to the ... The second part dwelt on local government creations, using the 1991 population ..... While big states can threaten the corporate existence and stability of ...

Molecular interactions between (--epigallocatechin gallate analogs and pancreatic lipase.

Directory of Open Access Journals (Sweden)

Shihui Wang

Full Text Available The molecular interactions between pancreatic lipase (PL and four tea polyphenols (EGCG analogs, like (--epigallocatechin gallate (EGCG, (--gallocatechin gallate (GCG, (--epicatechin gallate (ECG, and (--epigallocatechin (EC, were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent.

WWW scattering matrix database for small mineral particles at 441.6 and 632.8 nm

International Nuclear Information System (INIS)

Volten, H.; Munoz, O.; Hovenier, J.W.; Haan, J.F. de; Vassen, W.; Zande, W.J. van der; Waters, L.B.F.M.

2005-01-01

We present a new extensive database containing experimental scattering matrix elements as functions of the scattering angle measured at 441.6 and 632.8 nm for a large collection of micron-sized mineral particles in random orientation. This unique database is accessible through the World-Wide Web. Size distribution tables of the particles are also provided, as well as other characteristics relevant to light scattering. The database provides the light scattering community with easily accessible information that is useful, for a variety of applications such as testing theoretical methods, and the interpretation of measurements of scattered radiation. To illustrate the use of the database, we consider cometary observations and compare them with (1) cometary analog data from the database, and (2) with results of Mie calculations for homogeneous spheres, having the same refractive index and size distribution as those of the analog data

Functional DNA: Teaching Infinite Series through Genetic Analogy

Science.gov (United States)

Kowalski, R. Travis

2011-01-01

This article presents an extended analogy that connects infinite sequences and series to the science of genetics, by identifying power series as "DNA for a function." This analogy allows standard topics such as convergence tests or Taylor approximations to be recast in a "forensic" light as mathematical analogs of genetic concepts such as DNA…

A feature point identification method for positron emission particle tracking with multiple tracers