Towards an Einstein–Podolsky–Rosen paradox between two macroscopic atomic ensembles at room temperature

International Nuclear Information System (INIS)

He, Q Y; Reid, M D

2013-01-01

Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein–Podolsky–Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our proposal would enable the first definitive confirmation of quantum EPR paradox correlations between two macroscopic objects at room temperature. This is a necessary intermediate step towards a nonlocal experiment with causal measurement separations. As well as having fundamental significance, the realization of an atomic EPR paradox could provide a resource for novel applications in quantum technology. (paper)

Towards an Einstein-Podolsky-Rosen paradox between two macroscopic atomic ensembles at room temperature

Science.gov (United States)

He, Q. Y.; Reid, M. D.

2013-06-01

Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein-Podolsky-Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our proposal would enable the first definitive confirmation of quantum EPR paradox correlations between two macroscopic objects at room temperature. This is a necessary intermediate step towards a nonlocal experiment with causal measurement separations. As well as having fundamental significance, the realization of an atomic EPR paradox could provide a resource for novel applications in quantum technology.

Relativistic Nonlocality and the EPR Paradox

Science.gov (United States)

Chamberlain, Thomas

2014-03-01

The exact violation of Bell's Inequalities is obtained with a local realistic model for spin. The model treats one particle that comprises a quantum ensemble and simulates the EPR data one coincidence at a time as a product state. Such a spin is represented by operators σx , iσy ,σz in its body frame rather than the usual set of σX ,σY ,σZ in the laboratory frame. This model, assumed valid in the absence of a measuring probe, contains both quantum polarizations and coherences. Each carries half the EPR correlation, but only half can be measured using coincidence techniques. The model further predicts the filter angles that maximize the spin correlation in EPR experiments.

Quantum paradoxes and physical reality

Energy Technology Data Exchange (ETDEWEB)

Van der Merwe, Alwyn (Denver Univ., CO (USA). Dept. of Physics) (ed.); Selleri, Franco (Bologna Univ. (Italy). Ist. di Fisica)

1990-01-01

This book is devoted to the most fundamental themes of quantum physics: acausality, wave-particle duality, Einstein-Podolsky-Rosen (EPR) paradox, and so on. These are matters of growing interest for physicists. Several paradoxes have plagued quantum physics since its beginnings, the easiest of which to solve are the paradoxes of completeness (Schroedinger's cat, Wigner's friend, de Broglie's box, etc.). At a deeper level is the paradox of wave-particle duality whose solution probably requires the Einstein-de Broglie picture of atomic systems. The most difficult of them all is the EPR paradox (incompatibility between local realism and quantum theory). The book shows that experimental research can, in principle, solve paradoxes such as EPR and wave-particle duality but that the experiments performed on Bell-type inequalities have instead left the conceptual situation fundamentally unmodified. For a fair understanding of the Einstein-de Broglie and of the Bohr-Heisenberg ideas, an 'internal' lecture of physics is not enough. Such 'external' elements as individual biographies, history of culture, and philosophical preconceptions prove also to be important. (author). refs.; figs.; tabs.

EPR paradox revisited

Energy Technology Data Exchange (ETDEWEB)

Cantrell, C.D.; Scully, M.O.

1978-07-01

Einstein, Podolsky, and Rosen (EPR) argued in 1935 that quantum mechanics fails to give an adequate description of physical reality, and also cannot give a consistent wave-function description of certain phenomena. It is shown that a calculation based upon the reduced density matrix removes the formal inconsistency pointed out by EPR. The spirit of the present paper is that of a pedagogical review.

On the solution of the EPR paradox and the explanation of the violation of Bell's inequality

OpenAIRE

Bene, Gyula

1997-01-01

A new interpretation offers a consistent conceptual basis for nonrelativistic quantum mechanics. The Einstein-Podolsky-Rosen (EPR) paradox is solved and the violation of Bell's inequality is explained by maintaining realism, inductive inference and Einstein separability.

Karl R. Popper, 1992: About the EPR controversy

Science.gov (United States)

Combourieu, Marie-Christine

1992-10-01

Sir K. R. Popper's experimental schemes challenge the Copenhagen interpretation of quantum theory, principally Heisenberg's indeterminacy relations and the EPR paradox. “The so-called Einstein-Podolsky-Rosen paradox is not a paradox. It is a theoretical statement in expectation of an interpretation,” says K. R. Popper in this interview. “My experiment ought to be a classical experiment. It is very simple and free from any additional assumption. It should really be done.”

Teaching the EPR Paradox at High School?

Science.gov (United States)

Pospiech, Gesche

1999-01-01

Argues the importance of students at university and in the final years of high school gaining an appreciation of the principles of quantum mechanics. Presents the EPR gedanken experiment (thought experiment) as a method of teaching the principles of quantum mechanics. (Author/CCM)

One-way EPR steering and genuine multipartite EPR steering

Science.gov (United States)

He, Qiongyi; Reid, Margaret D.

2012-11-01

We propose criteria and experimental strategies to realise the Einstein-Podolsky-Rosen (EPR) steering nonlocality. One-way steering can be obtained where there is asymmetry of thermal noise on each system. We also present EPR steering inequalities that act as signatures and suggest how to optimise EPR correlations in specific schemes so that the genuine multipartite EPR steering nonlocality (EPR paradox) can also possibly be realised. The results presented here also apply to the spatially separated macroscopic atomic ensembles.

Resolution of the EPR Paradox for Fermion Spin Correlations

Science.gov (United States)

Close, Robert

2011-10-01

The EPR paradox addresses the question of whether a physical system can have a definite state independent of its measurement. Bell's Theorem places limits on correlations between local measurements of particles whose properties are established prior to measurement. Experimental violation of Bell's theorem has been regarded as evidence against the existence of a definite state prior to measurement. We model fermions as having a spatial distribution of spin values, so that a Stern-Gerlach device samples the spin distribution differently at different orientations. The computed correlations agree with quantum mechanical predictions and experimental observations. Bell's Theorem is not applicable because for any sampling of angles, different points on the sphere have different density of states.

The EPR paradox revisited

International Nuclear Information System (INIS)

Cantrell, C.D.; Scully, M.O.

1978-01-01

Einstein, Podolsky and Rosen (EPR) argued in 1935 that quantum mechanics fails to give an adequate description of physical reality, and also cannot give a consistent wave-function description of certain phenomena. The authors show that a calculation based upon the reduced density matrix removes the formal inconsistency pointed out by EPR. The spirit of the present paper is that of a pedagogical review. (Auth.)

EPR paradox revisited

Energy Technology Data Exchange (ETDEWEB)

Klippert, R. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

1999-07-01

In a seminal paper from 1935 Einstein, Podolsky and Rosen produced one of the most powerful weapon against the unpredictability of the world ensured by quantum mechanics. The recent production of entangled states, with all its possible future applications in quantum computation, re-open the possibility of testing EPR states on physical grounds. The present intends to present a challenge to the wedding of classical (special) relativity with quantum mechanics, the so called relativistic quantum mechanics. Making use of the same apparatus devised in EPR, it is shown that non local quantum states are incompatible with either their possibility of being measured or else with Lorentz invariance (or even with both). (author)

A Local Realistic Reconciliation of the EPR Paradox

Science.gov (United States)

Sanctuary, Bryan

2014-03-01

The exact violation of Bell's Inequalities is obtained with a local realistic model for spin. The model treats one particle that comprises a quantum ensemble and simulates the EPR data one coincidence at a time as a product state. Such a spin is represented by operators σx , iσy ,σz in its body frame rather than the usual set of σX ,σY ,σZ in the laboratory frame. This model, assumed valid in the absence of a measuring probe, contains both quantum polarizations and coherences. Each carries half the EPR correlation, but only half can be measured using coincidence techniques. The model further predicts the filter angles that maximize the spin correlation in EPR experiments.

Towards an Einstein-Podolsky-Rosen paradox between two macroscopic atomic ensembles at room temperature

OpenAIRE

He, Q Y; Reid, M D

2013-01-01

Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein-Podolsky-Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our pr...

Experimental EPR-steering using Bell-local states

Science.gov (United States)

Saunders, D. J.; Jones, S. J.; Wiseman, H. M.; Pryde, G. J.

2010-11-01

The concept of `steering' was introduced in 1935 by Schrödinger as a generalization of the EPR (Einstein-Podolsky-Rosen) paradox. It has recently been formalized as a quantum-information task with arbitrary bipartite states and measurements, for which the existence of entanglement is necessary but not sufficient. Previous experiments in this area have been restricted to an approach that followed the original EPR argument in considering only two different measurement settings per side. Here we demonstrate experimentally that EPR-steering occurs for mixed entangled states that are Bell local (that is, that cannot possibly demonstrate Bell non-locality). Unlike the case of Bell inequalities, increasing the number of measurement settings beyond two-we use up to six-significantly increases the robustness of the EPR-steering phenomenon to noise.

The principle of relativity, superluminality and EPR experiments. "Riserratevi sotto coverta ..."

Science.gov (United States)

Cocciaro, B.

2015-07-01

The principle of relativity claims the invariance of the results for experiments carried out in inertial reference frames if the system under examination is not in interaction with the outside world. In this paper it is analysed a model suggested by J. S. Bell, and later developed by P. H. Eberhard, D. Bohm and B. Hiley on the basis of which the EPR correlations would be due to superluminal exchanges between the various parts of the entangled system under examination. In the model the existence of a privileged reference frame (PF) for the propagation of superluminal signals is hypothesized so that these superluminal signals may not give rise to causal paradoxes. According to this model, in an EPR experiment, the entangled system interacts with the outer world since the result of the experiment depends on an entity (the reference frame PF) that is not prepared by the experimenter. The existence of this privileged reference frame makes the model non invariant for Lorentz transformations. In this paper, in opposition to what claimed by the authors mentioned above, the perfect compatibility of the model with the theory of relativity is strongly maintained since, as already said, the principle of relativity does not require that the results of experiments carried out on systems interacting with the outside world should be invariant.

Teichmuller Space Resolution of the EPR Paradox

Science.gov (United States)

Winterberg, Friedwardt

2013-04-01

The mystery of Newton's action-at-a-distance law of gravity was resolved by Einstein with Riemann's non-Euclidean geometry, which permitted the explanation of the departure from Newton's law for the motion of Mercury. It is here proposed that the similarly mysterious non-local EPR-type quantum correlations may be explained by a Teichmuller space geometry below the Planck length, for which an experiment for its verification is proposed.

Antiparticle in Light of Einstein-Podolsky-Rosen Paradox and Klein Paradox

OpenAIRE

Ni, Guang-jiong; Guan, Hong; Zhou, Weimin; Yan, Jun

2000-01-01

The original version of Einstein-Podolsky-Rosen (EPR) paradox and the Klein paradox of Klein-Gordon (KG) equation are discussed to show the necessity of existence of antiparticle with its wavefunction being fixed unambiguously. No concept of "hole" is needed.

Einstein-Podolsky-Rosen paradox and quantum steering in pulsed optomechanics

Science.gov (United States)

He, Q. Y.; Reid, M. D.

2013-11-01

We describe how to generate an Einstein-Podolsky-Rosen (EPR) paradox between a mesoscopic mechanical oscillator and an optical pulse. We find two types of paradox, defined by whether it is the oscillator or the pulse that shows the effect Schrödinger called “steering”. Only the oscillator paradox addresses the question of mesoscopic local reality for a massive system. In that case, EPR's “elements of reality” are defined for the oscillator, and it is these elements of reality that are falsified (if quantum mechanics is complete). For this sort of paradox, we show that a thermal barrier exists, meaning that a threshold level of pulse-oscillator interaction is required for a given thermal occupation n0 of the oscillator. We find there is no equivalent thermal barrier for the entanglement of the pulse with the oscillator or for the EPR paradox that addresses the local reality of the optical system. Finally, we examine the possibility of an EPR paradox between two entangled oscillators. Our work highlights the asymmetrical effect of thermal noise on quantum nonlocality.

Two-body problem in general relativity: A heuristic guide for the Einstein-Rosen bridge and EPR paradox

OpenAIRE

Weinstein, Galina

2015-01-01

Between 1935 and 1936, Einstein was occupied with the Schwarzschild solution and the singularity within it while working in Princeton on the unified field theory and with his assistant Nathan Rosen, on the theory of the Einstein-Rosen bridges. He was also occupied with quantum theory. He believed that quantum theory was an incomplete representation of real things. Together with Rosen and Boris Podolsky he invented the EPR paradox. I demonstrate that the two-body problem in general relativity ...

On the correlations between the particles in the EPR-paradoxon

International Nuclear Information System (INIS)

Treder, H.J.

1984-01-01

The Einstein-Podolsky-Rosen 'gedanken-experiment' does not imply non-local interactions or an 'action-at-a-distance'. Contrary, the EPR proves the measurements at one particle does not have influences at canonical variables of the other particles if the quantum-mechanical commutation relations are true. But, the EPR implices correlations between the particles which come in by 'subjective knowledge'. These correlations are a priori informations about the relative motion or, complementarily, about the motion of the center of mass. The impression of an action-at-a-distance is produced by the use of usual particle coordinates in the EPR-arrangements. The discussion of the Einstein-Podolsky-Rosen 'gedanken-experiment' (EPR) has been going on over fifty years. Einstein, Podolsky, and Rosen formulated their famous paradox in 1935, and in the discussion between N. Bohr (1935, 1949) and Einstein (1936, 1948); A. Einstein (1948) made his point that the EPR implied an 'action-at-a-distance' for quantum-mechanical particles (without obvious classical interactions). His argument is the starting point for the recent discussion about EPR and causality (see A. Aspect 1981). (author)

EPR trademark project delivery. The value of experience

International Nuclear Information System (INIS)

Leverenz, Ruediger

2013-01-01

We are building the EPR trademark reactor fleet. Together. With four EPR trademark projects under construction in the world, AREVA has unrivalled experience in the delivery of large-scale nuclear projects, including more than a thousand lessons learned captured from Olkiluoto 3 and Flamanville 3 projects. This book of knowledge as well as the return of experience of AREVA's and EDF's teams are now being fully leveraged on ongoing projects, especially on Flamanville 3 and Taishan, and will be incorporated in all future EPR TM projects.

Verification experiment of EPR paradox by (d, 2He) reaction

International Nuclear Information System (INIS)

Sakai, Hideyuki

2003-01-01

FBR paradox which was brought forward by Einstein, Podolsky and Rosen is expressed by Bell's inequality of spin correlation theoretically. In principle it is possible to verify the inequality by measuring spin correlation between two particles having spin 1/2 from a decay of 1 S 0 experimentally. Most of the past experiments to verify the inequality, however, have been performed by using photons. On the other hand, only one experiment by using hadron system was carried out by Lamehi and Mitting, where the [ 1 S 0 ] state was produced by proton-proton scattering at first, and then the spin orientations after the scattering were measured. Unfortunately, there exit some sources of ambiguity to reach definite conclusion from their result because the experiment was done at rather high energy of 13.5 MeV. In the experiment planned by the present author it is designed to overcome the experimental difficulties, which Lamehi and Mitting encountered, by (1) generating high purity singlet [ 1 S 0 ] state of two protons by (d, 2 He) type nuclear reaction at intermediate energy range, and by (2) developing high performance spin-correlation polarimeter which can analyze spins of two protons simultaneously to minimize the systematic errors. The excitation energy of 2 He corresponding to the proton-proton relative energy can be experimentally controlled. An idea singlet is realized by choosing the state with sufficiently small relative energy. It is planned to measure the spin correlation function by using SMART (Swinger and Magnetic Analyzer with Rotator and Twister) at RIKEN Accelerator Research Facility. Einstein POLarimeter (EPOL) to be installed on the second focal plane of SMART is under development, with which high precision measurements of spin orientations of two high energy protons simultaneously coming into limited space from 2 He decay are made selecting the subject events from very many background events. Monte Carlo simulation predicts the possibility to verify the

Einstein, Podolsky, and Rosen paradox in atomic, nuclear, and particle physics

CERN Document Server

Afriat, Alexander

1999-01-01

This text is the first exhaustive treatise on the Einstein, Podolsky, and Rosen (EPR) Paradox - the incompatibility, at empirical level, between local realism and the existing quantum theory The volume collates all the data and thought on the Paradox, from its original formulation in 1935, to some very recent theoretical developments The authors devote an entire chapter to the EPR Paradox for pairs of neutral kaons In addition, their text provides 6 different proofs of Bell's Theorem, about 150 references to the literature, and 74 illustrations

L'argument Einstein Podolsky Rosen (EPR) paradoxe, alternative et demonstration

CERN Document Server

Roussel, P

2003-01-01

En physique quantique, l'absence d'observation d'etats de superposition ne devrait etre une surprise pour personne, que les objets soient microscopiques ou macroscopiques. Cela n'en etait pas une pour Schroedinger. L'experience de pensee "du chat" parmi bien d'autres arguments le montre clairement. On ne doit pas aujourd'hui lui faire dire le contraire. L'article EPR (A.Einstein, B.Podolsky,N.Rosen, ecrit en 1935), qui est a l'origine de l'intervention de Schroedinger et du developpement d'une problematique qui se prolonge jusqu'a aujourd'hui, est analyse. Avec Schroedinger, Bohr, Wigner et jusqu'a aujourd'hui, la reponse a EPR a ete le recours renouvele a l'observateur finalement caracterise par sa conscience. Deux elements nouveaux sont apparus: d'une part un developpement experimental et theorique impressionnant avec l'optique quantique et les manipulations d'atomes, d'autre part la proposition du concept de decoherence susceptible d'expliquer le passage du microscopique au macroscopique et par la d'apport...

A reformulation and a possible modification of quantum mechanics and the EPR paradox

International Nuclear Information System (INIS)

Ghirardi, G.C.; Rimini, A.; Weber, T.

1976-01-01

A reformulation of quantum mechanics is introduced, which describes the ''states'' of an ensemble of quantum systems by means of positive real functionals on the Hilbert space of the systems. This reformulation allows us to generalize quantum mechanics in such a wau as to induce the transition from second-to first-kind mixtures, which has been suggested to occur by various authors in order to eliminate the EPR paradox. A dynamical equation for the functionals is explicitely build up, which reduces to the Schroedinger equation when the sub-systems of a composite quantum system are close together, and gives rise, altering the quantum-mechanical evolution, to a transition to a first-kind mixture when the component subsystems are far apart. This transition is such that, at any time, the predictions concerning measurements of observables referring to one of the subsystems coincide with those which would follow from the pure Schroedinger evolution. The deviations from the standard theory affect, therefore, only the correlations between the subsystems

Verification experiment of EPR paradox by (d, {sup 2}He) reaction

Energy Technology Data Exchange (ETDEWEB)

Sakai, Hideyuki [Tokyo Univ., Graudate School of Science, Tokyo (Japan)

2003-01-01

FBR paradox which was brought forward by Einstein, Podolsky and Rosen is expressed by Bell's inequality of spin correlation theoretically. In principle it is possible to verify the inequality by measuring spin correlation between two particles having spin 1/2 from a decay of {sup 1}S{sub 0} experimentally. Most of the past experiments to verify the inequality, however, have been performed by using photons. On the other hand, only one experiment by using hadron system was carried out by Lamehi and Mitting, where the [{sup 1}S{sub 0}] state was produced by proton-proton scattering at first, and then the spin orientations after the scattering were measured. Unfortunately, there exit some sources of ambiguity to reach definite conclusion from their result because the experiment was done at rather high energy of 13.5 MeV. In the experiment planned by the present author it is designed to overcome the experimental difficulties, which Lamehi and Mitting encountered, by (1) generating high purity singlet [{sup 1}S{sub 0}] state of two protons by (d, {sup 2}He) type nuclear reaction at intermediate energy range, and by (2) developing high performance spin-correlation polarimeter which can analyze spins of two protons simultaneously to minimize the systematic errors. The excitation energy of {sup 2}He corresponding to the proton-proton relative energy can be experimentally controlled. An idea singlet is realized by choosing the state with sufficiently small relative energy. It is planned to measure the spin correlation function by using SMART (Swinger and Magnetic Analyzer with Rotator and Twister) at RIKEN Accelerator Research Facility. Einstein POLarimeter (EPOL) to be installed on the second focal plane of SMART is under development, with which high precision measurements of spin orientations of two high energy protons simultaneously coming into limited space from {sup 2}He decay are made selecting the subject events from very many background events. Monte Carlo

EPR & Klein Paradoxes in Complex Hamiltonian Dynamics and Krein Space Quantization

Science.gov (United States)

Payandeh, Farrin

2015-07-01

-time) states, the original version of EPR paradox can be discussed and the correct answer can be verified based on the strong rooted complex quantum Hamilton-Jacobi theory [2-27] and as another example we can use the negative energy states, to remove the Klein's paradox without the need of any further explanations or justifications like backwardly moving electrons. Finally, comparing the two approaches, we can point out to the existence of a connection between quantum Hamiltonian dynamics, standard quantum field theory, and Krein space quantization [28-43].

EPR and Klein Paradoxes in Complex Hamiltonian Dynamics and Krein Space Quantization

International Nuclear Information System (INIS)

Payandeh, Farrin

2015-01-01

-time) states, the original version of EPR paradox can be discussed and the correct answer can be verified based on the strong rooted complex quantum Hamilton-Jacobi theory [2-27] and as another example we can use the negative energy states, to remove the Klein's paradox without the need of any further explanations or justifications like backwardly moving electrons. Finally, comparing the two approaches, we can point out to the existence of a connection between quantum Hamiltonian dynamics, standard quantum field theory, and Krein space quantization [28-43]. (paper)

Research on the Einstein-Podolsky-Rosen paradox

International Nuclear Information System (INIS)

Piccioni, O.; Mehlhop, W.; Wright, B.

1989-06-01

This report discusses the following: The analysis of the singlet state of separate fermions proves that the EPR contradicts QM. The violation of special relativity. The Schroedinger equation and the EPR. The conservation of angular momentum. The proposal of collapse. The factorization of the spin states. The superposition principle. No paradox exists within the theory. The original state of Einstein et al is not a valid example of the EPR, and it seems impossible to construct a valid linear momentum example. This is another indication that the EPR contradicts QM. Actions at a distance, the model of Einstein et al for particles with mass, and Bell's inequalities and their physical meaning

Experimental test of the irreducible four-qubit Greenberger-Horne-Zeilinger paradox

Science.gov (United States)

Su, Zu-En; Tang, Wei-Dong; Wu, Dian; Cai, Xin-Dong; Yang, Tao; Li, Li; Liu, Nai-Le; Lu, Chao-Yang; Żukowski, Marek; Pan, Jian-Wei

2017-03-01

The paradox of Greenberger-Horne-Zeilinger (GHZ) disproves directly the concept of EPR elements of reality, based on the EPR correlations, in an all-versus-nothing way. A three-qubit experimental demonstration of the GHZ paradox was achieved nearly 20 years ago, followed by demonstrations for more qubits. Still, the GHZ contradictions underlying the tests can be reduced to a three-qubit one. We show an irreducible four-qubit GHZ paradox, and report its experimental demonstration. The bound of a three-setting-per-party Bell-GHZ inequality is violated by 7 σ . The fidelity of the GHZ state was around 81 % , and an entanglement witness reveals a violation of the separability threshold by 19 σ .

Einstein-Podolsky-Rosen constraints on quantum action at a distance: the Sutherland paradox

International Nuclear Information System (INIS)

Cufaro-Petroni, N.; Dewdney, C.; Holland, P.R.; Kyprianidis, A.; Vigier, J.P.

1987-01-01

Assuming that future experiments confirm Aspect's discovery of nonlocal interactions between quantum pairs of correlated particles, the authors analyze the constraints imposed by the EPR reasoning on the said interactions. It is then shown that the nonlocal relativistic quantum potential approach plainly satisfies the Einstein causality criteria as well as the energy-momentum conservation in individual microprocesses. Furthermore, this approach bypasses a new causal paradox for timelike separated EPR measurements deduced by Sutherland in the frame of an approach by means of space-time zigzags with advanced potentials. It is finally demonstrated that this inherent quantum causal direct interaction established permanent EPR correlations which are always restricted to spacelike separations and are instantaneous only in the center-of-mass rest frame of the two-particle system

Ghost-like action-at-a-distance in quantum mechanics: an elementary introduction to the Einstein, Podolsky, Rosen paradox

International Nuclear Information System (INIS)

Mattuck, R.D.

1982-01-01

The remarkable quantum phenomenon of 'non-locality' discovered by Einstein, Podolsky and Rosen (EPR) is the centre of considerable experimental and theoretical activity these days. Nevertheless, many (perhaps most) physicists do not feel the phenomenon is especially paradoxical, or even worthy of interest. This article attempts to reveal, in a simple way, just where the fascination of the EPR paradox lies, and to answer some of the arguments invoked by critics to 'explain away' the paradox. (author)

On the Correlations between the Particles in the EPR-Paradoxon

Science.gov (United States)

Treder, H.-J.

The Einstein-Podolsky-Rosen gedanken-experiment does not imply non-local interactions or an action-at-a-distance.Contrary, the EPR proves the measurements at one particle does not have influences at canonical variables of the other particles if the quantum-mechanical commutation relations are true.But, the EPR implices correlations between the particles which come in by subjective knowledge. These correlations are a priori informations about the relative motion or, complementarily, about the motion of the center of mass. The impression of an action-at-a-distance is produced by the use of usual particle coordinates in the EPR-arrangements.The discussion of the Einstein-Podolsky-Rosen gedanken-experiment (EPR) has been going on over fifty years. EINSTEIN, PODOLSKY, and ROSEN formulated their famous paradox in 1935, and in the discussion between N. BOHR (1935, 1949) and A. EINSTEIN (1936, 1948); A. EINSTEIN (1948) made his point that the EPR implied an action-at-a-distance for quantum-mechanical particles (without obvious classical interactions). His argument is the starting point for the recent discussion about EPR and causality (see A. Aspect, 1981).Translated AbstractÜber die Korrelationen zwischen den Partikeln beim EPR-ParadoxonDas Gedankenexperiment von EINSTEIN, PODOLSKY und ROSEN über die anscheinend paradoxen Beziehungen zwischen beliebig weit entfernten Partikeln gemäß der quantenmechanischen Theorie der Messungen führt tatsächlich nicht auf nichtlokale Wechselwirkungen.Das Einstein-Podolsky-Rosen-Paradoxon zeigt vielmehr, daß die Messung an einem Teilchen keinerlei Einfluß auf die Meßwerte an anderen Partikeln hat, wenn die quantenmechanischen Vertauschungsregeln erfüllt sind.Dagegen weist das Einstein-Podolsky-Rosensche Gedankenexperiment Korrelationen zwischen den Teilchen auf, die die Folge einer a-priori-Kenntnis über die Werte von Hamilton-Jacobischen Zwei-Partikeln-Koordinaten von nicht-wechselwirkenden Teilchen sind.

Ghost-like action-at-a-distance in quantum mechanics: an elementary introduction to the Einstein, Podolsky, Rosen paradox

Energy Technology Data Exchange (ETDEWEB)

Mattuck, R.D. (Copenhagen Univ. (Denmark). H.C. Oersted Inst.)

1982-01-01

The remarkable quantum phenomenon of 'non-locality' discovered by Einstein, Podolsky and Rosen (EPR) is the centre of considerable experimental and theoretical activity these days. Nevertheless, many (perhaps most) physicists do not feel the phenomenon is especially paradoxical, or even worthy of interest. This article attempts to reveal, in a simple way, just where the fascination of the EPR paradox lies, and to answer some of the arguments invoked by critics to 'explain away' the paradox.

On Popper's new EPR-Experiment

International Nuclear Information System (INIS)

Bedford, D.; Selleri, F.

1985-01-01

It is scientifically reasonable to search for particular statistical ensembles to which the standard quantum rules (like Heisenberg relations) do not apply: these rules would instead be applicable to more general statistical ensembles (which might be called ''standard quantum ensembles''). Along these lines, Popper has recently proposed what he calls ''a new version of the EPR experiment'' in which the Copenhagen and statistical interpretations of quantum mechanics apparently lead to distinguishably different predictions

Einstein-Podolsky-Rosen paradox in single pairs of images.

Science.gov (United States)

Lantz, Eric; Denis, Séverine; Moreau, Paul-Antoine; Devaux, Fabrice

2015-10-05

Spatially entangled twin photons provide a test of the Einstein-Podolsky-Rosen (EPR) paradox in its original form of position (image plane) versus impulsion (Fourier plane). We show that recording a single pair of images in each plane is sufficient to safely demonstrate an EPR paradox. On each pair of images, we have retrieved the fluctuations by subtracting the fitted deterministic intensity shape and then have obtained an intercorrelation peak with a sufficient signal to noise ratio to safely distinguish this peak from random fluctuations. A 95% confidence interval has been determined, confirming a high degree of paradox whatever the considered single pairs. Last, we have verified that the value of the variance of the difference between twin images is always below the quantum (poissonian) limit, in order to ensure the particle character of the demonstration. Our demonstration shows that a single image pattern can reveal the quantum and non-local behavior of light.

The EPR Paradox: Einstein Scrutinises Quantum Mechanics -28 ...

Indian Academy of Sciences (India)

Arvind. Einstein, Podolsky and Rosen (EPR), in their fa- mous paper, argued that the quantum-mechani- cal description of physical reality is incomplete. They showed that one can envisage physical sit- uations whereby 'an element of physical reality' can be located such that it does not have a coun- terpart in quantum ...

ysteries, Puzzles, and Paradoxes in Quantum Mechanics. Proceedings

International Nuclear Information System (INIS)

Rodolfo, B.

1999-01-01

These proceedings represent papers presented at the Mysteries, Puzzles, and Paradoxes in Quantum Mechanics Workshop held in Italy, in August 1998. The Workshop was devoted to recent experimental and theoretical advances such as new interference, effects, the quantum eraser, non-disturbing and Schroedinger-cat-like states, experiments, EPR correlations, teleportation, superluminal effects, quantum information and computing, locality and causality, decoherence and measurement theory. Tachyonic information transfer was also discussed. There were 45 papers presented at the conference,out of which 2 have been abstracted for the Energy, Science and Technology database

On the computer simulation of the EPR-Bohm experiment

International Nuclear Information System (INIS)

McGoveran, D.O.; Noyes, H.P.; Manthey, M.J.

1988-12-01

We argue that supraluminal correlation without supraluminal signaling is a necessary consequence of any finite and discrete model for physics. Every day, the commercial and military practice of using encrypted communication based on correlated, pseudo-random signals illustrates this possibility. All that is needed are two levels of computational complexity which preclude using a smaller system to detect departures from ''randomness'' in the larger system. Hence the experimental realizations of the EPR-Bohm experiment leave open the question of whether the world of experience is ''random'' or pseudo-random. The latter possibility could be demonstrated experimentally if a complexity parameter related to the arm length and switching time in an Aspect-type realization of the EPR-Bohm experiment is sufficiently small compared to the number of reliable total counts which can be obtained in practice. 6 refs

A Computational Model for Observation in Quantum Mechanics.

Science.gov (United States)

1987-03-16

Interferometer experiment ............. 17 2.3 The EPR Paradox experiment ................. 22 3 The Computational Model, an Overview 28 4 Implementation 34...40 4.4 Code for the EPR paradox experiment ............... 46 4.5 Code for the double slit interferometer experiment ..... .. 50 5 Conclusions 59 A...particle run counter to fact. The EPR paradox experiment (see section 2.3) is hard to resolve with this class of models, collectively called hidden

EPR experiment and 2-photon interferometry: Report of a 2-photon interference experiment

International Nuclear Information System (INIS)

Shih, Y.H.; Rubin, M.H.; Sergienko, A.V.

1992-01-01

After a very brief review of the historical Einstein, Podolsky, and Rosen (EPR) experiments, a new two-photon interference type EPR experiment is reported. A two-photon state was generated by optical parametric down conversion. Pairs of light quanta with degenerate frequency but divergent directions of propagation were sent to two independent Michelson interferometers. First and second order interference effectors were studied. Different than other reports, we observed that the second order interference visibility vanished when the optical path difference of the interferometers were much less than the coherence length of the pumping laser beam. However, we also observed that the second order interference behaved differently depending on whether the interferometers were set at equal or different optical path differences

EPR experiment and 2-photon interferometry: Report of a 2-photon interference experiment

Science.gov (United States)

Shih, Y. H.; Rubin, M. H.; Sergienko, A. V.

1992-01-01

After a very brief review of the historical Einstein, Podolsky, and Rosen (EPR) experiments, a new two-photon interference type EPR experiment is reported. A two-photon state was generated by optical parametric down conversion. Pairs of light quanta with degenerate frequency but divergent directions of propagation were sent to two independent Michelson interferometers. First and second order interference effectors were studied. Different than other reports, we observed that the second order interference visibility vanished when the optical path difference of the interferometers were much less than the coherence length of the pumping laser beam. However, we also observed that the second order interference behaved differently depending on whether the interferometers were set at equal or different optical path differences.

CW- and pulsed-EPR of carbonaceous matter in primitive meteorites: Solving a lineshape paradox

Science.gov (United States)

Delpoux, Olivier; Gourier, Didier; Binet, Laurent; Vezin, Hervé; Derenne, Sylvie; Robert, François

2008-05-01

Insoluble organic matter (IOM) of Orgueil and Tagish Lake meteorites are studied by CW-EPR and pulsed-EPR spectroscopies. The EPR line is due to polycyclic paramagnetic moieties concentrated in defect-rich regions of the IOM, with concentrations of the order of 4 × 10 19 spin/g. CW-EPR reveals two types of paramagnetic defects: centres with S = 1/2, and centres with S = 0 ground state and thermally accessible triple state S = 1. In spite of the Lorentzian shape of the EPR and its narrowing upon increasing the spin concentration, the EPR line is not in the exchange narrowing regime as previously deduced from multi-frequency CW-EPR [L. Binet, D. Gourier, Appl. Magn. Reson. 30 (2006) 207-231]. It is inhomogeneously broadened as demonstrated by the presence of nuclear modulations in the spin-echo decay. The line narrowing, similar to an exchange narrowing effect, is the result of an increasing contribution of the narrow line of the triplet state centres in addition to the broader line of doublet states. Hyperfine sublevel correlation spectroscopy (HYSCORE) of hydrogen and 13C nuclei indicates that IOM rad centres are small polycyclic moieties that are moderately branched with aliphatic chains, as shown by the presence of aromatic hydrogen atoms. On the contrary the lack of such aromatic hydrogen in triplet states suggests that these radicals are most probably highly branched. Paramagnetic centres are considerably enriched in deuterium, with D/H ≈ 1.5 ± 0.5 × 10 -2 of the order of values existing in interstellar medium.

CW- and pulsed-EPR of carbonaceous matter in primitive meteorites: solving a lineshape paradox.

Science.gov (United States)

Delpoux, Olivier; Gourier, Didier; Binet, Laurent; Vezin, Hervé; Derenne, Sylvie; Robert, François

2008-05-01

Insoluble organic matter (IOM) of Orgueil and Tagish Lake meteorites are studied by CW-EPR and pulsed-EPR spectroscopies. The EPR line is due to polycyclic paramagnetic moieties concentrated in defect-rich regions of the IOM, with concentrations of the order of 4x10(19) spin/g. CW-EPR reveals two types of paramagnetic defects: centres with S=1/2, and centres with S=0 ground state and thermally accessible triple state S=1. In spite of the Lorentzian shape of the EPR and its narrowing upon increasing the spin concentration, the EPR line is not in the exchange narrowing regime as previously deduced from multi-frequency CW-EPR [L. Binet, D. Gourier, Appl. Magn. Reson. 30 (2006) 207-231]. It is inhomogeneously broadened as demonstrated by the presence of nuclear modulations in the spin-echo decay. The line narrowing, similar to an exchange narrowing effect, is the result of an increasing contribution of the narrow line of the triplet state centres in addition to the broader line of doublet states. Hyperfine sublevel correlation spectroscopy (HYSCORE) of hydrogen and (13)C nuclei indicates that IOM* centres are small polycyclic moieties that are moderately branched with aliphatic chains, as shown by the presence of aromatic hydrogen atoms. On the contrary the lack of such aromatic hydrogen in triplet states suggests that these radicals are most probably highly branched. Paramagnetic centres are considerably enriched in deuterium, with D/H approximately 1.5+/-0.5x10(-2) of the order of values existing in interstellar medium.

Joint probabilities reproducing three EPR experiments on two qubits

NARCIS (Netherlands)

Roy, S. M.; Atkinson, D.; Auberson, G.; Mahoux, G.; Singh, V.

2007-01-01

An eight-parameter family of the most general non-negative quadruple probabilities is constructed for EPR-Bohm-Aharonov experiments when only three pairs of analyser settings are used. It is a simultaneous representation of three different Bohr-incompatible experimental configurations involving

On the relation between the Einstein-Podolsky-Rosen paradox and the problem of nonlocality in quantum mechanics

International Nuclear Information System (INIS)

de Muynck, W.M.

1986-01-01

The EPR problem is studied both from an instrumentalistic and from a realistic point of view. Bohr's reply to the EPR paper is analyzed and demonstrated to be not completely representative of Bohr's general views on the possibility of defining properties of a microscopic object. A more faithful Bohrian answer would not have led Einstein to the conclusion that Bohr's completeness claim of quantum mechanics implies nonlocality. The projection postulate, already denounced in 1936 by Margenau as the source of the EPR paradox, is found to be also at the origin of the nonlocality conundrum. Its unobservability in EPR-like experiments is demonstrated, thus showing the redundancy of the idea of nonlocality in the instrumentalist interpretation of quantum mechanics. It is argued that also from a realist point of view there is no reason to assume nonlocality. The relevance of Bohm's quantum potential and of Bells inequalities with respect to the (non) locality problem is discussed

Source independence and the EPR paradox

International Nuclear Information System (INIS)

Mould, R.A.

1989-01-01

It is shown that the lines of action between the photon pairs resulting from a positronium decay are not necessarily in line with the original positronium atom. It is also shown why this 'source-independent' effect is not normally observed, although it is observable in principle. Moreover our initial concerns and some conclusions as they bear on the theory of measurement in quantum mechanics are discussed. Source-independence is shown to give a satisfactory response to a special form of the Einstein-Podolsky-Rosen paradox involving pairs of position measurements. It also leads to a nonlocal relationship between position measurements that depends on the width of the position detectors

Stern-Gerlach experiment, electron spin and intermediate quantum mechanics

Energy Technology Data Exchange (ETDEWEB)

Mackintosh, A.R. (Copenhagen Univ. (Denmark). H.C. Oersted Inst.)

1983-01-01

The paper deals with the theory of electron spin. The Stern-Gerlach experiment, the anticommutation relations and the properties of spin operators are discussed. The Pauli theory, Dirac transformation theory, the double Stern-Gerlach experiment, the EPR paradox and Bell's inequality are also covered.

Applications of EPR steering in quantum teleportation and NOON states

Science.gov (United States)

Zárate, Laura Rosales

2018-04-01

Einstein-Podolsky-Rosen (EPR) steering refers to the type of correlations described in the EPR paradox, where one observer seems to affect ("steer") the state of other observer by using local measurements. There have been several works regarding characterization and quantification of EPR steering. One characteristic of this non-local correlation is that it can be asymmetric, while entanglement is symmetric. This asymmetric property is relevant for potential applications of EPR steering to quantum information, in particular to quantum cryptography and quantum teleportation. This latter refers to the process where one observer sends an unknown quantum state to Bob, who is in a different location. They communicate by classical means. Here we will show that EPR steering is a necessary resource to obtain secure continuous variable teleportation. We will also consider NOON states, which is an example of an entangled state. For this state, we will present a steering signature. This contribution reviews the work derived in Refs. [1] and [2], which was presented as an invited talk in ELAF 2017.

The Stern-Gerlach experiment, electron spin and intermediate quantum mechanics

International Nuclear Information System (INIS)

Mackintosh, A.R.

1983-01-01

The paper deals with the theory of electron spin. The Stern-Gerlach experiment, the anticommutation relations and the properties of spin operators are discussed. The Pauli theory, Dirac transformation theory, the double Stern-Gerlach experiment, the EPR paradox and Bell's inequality are also covered. (U.K.)

Generalized absorber theory and the Einstein-Podolsky-Rosen paradox

International Nuclear Information System (INIS)

Cramer, J.G.

1980-01-01

A generalized form of Wheeler-Feynman absorber theory is used to explain the quantum-mechanical paradox proposed by Einstein, Podolsky, and Rosen (EPR). The advanced solutions of the electromagnetic wave equation and of relativistic quantum-mechanical wave equations are shown to play the role of ''verifier'' in quantum-mechanical ''transactions,'' providing microscopic communication paths between detectors across spacelike intervals in violation of the EPR locality postulate. The principle of causality is discussed in the context of this approach, and possibilities for experimental tests of the theory are examined

Some comments on the EPR (The reasons why experiments should still be done)

International Nuclear Information System (INIS)

Piccioni, O.; Wright, B.

1993-10-01

The authors believe that much of the contradiction they hear about the Einstein Podoisky Rosen Paradox (EPR), can be framed into the diverse ways of using or misusing the principle of ''collapse,'' (a principle, which according to Wigner, is very attractive, but not very informative). To make their points, they will mainly use the model [Lamehi-Rachti, Mittig, Phys. Rev. D14 (1976)] of two free protons scattering in the well known state of singlet, ud-du = SS, according to the Pauli Principle. (An equivalent description can be done with the polarization of photons.) The authors ask the important question whether, on separation, the two fermions will remain in the state SS, where neither proton has a definite state and the whole two fermion system has exactly zero component in any direction

Some comments on the EPR (The reasons why experiments should still be done)

Energy Technology Data Exchange (ETDEWEB)

Piccioni, O.; Wright, B.

1993-10-01

The authors believe that much of the contradiction they hear about the Einstein Podoisky Rosen Paradox (EPR), can be framed into the diverse ways of using or misusing the principle of ``collapse,`` (a principle, which according to Wigner, is very attractive, but not very informative). To make their points, they will mainly use the model [Lamehi-Rachti, Mittig, Phys. Rev. D14 (1976)] of two free protons scattering in the well known state of singlet, ud-du = SS, according to the Pauli Principle. (An equivalent description can be done with the polarization of photons.) The authors ask the important question whether, on separation, the two fermions will remain in the state SS, where neither proton has a definite state and the whole two fermion system has exactly zero component in any direction.

ER=EPR, GHZ, and the consistency of quantum measurements

International Nuclear Information System (INIS)

Susskind, Leonard

2016-01-01

This paper illustrates various aspects of the ER=EPR conjecture. It begins with a brief heuristic argument, using the Ryu-Takayanagi correspondence, for why entanglement between black holes implies the existence of Einstein-Rosen bridges. The main part of the paper addresses a fundamental question: Is ER=EPR consistent with the standard postulates of quantum mechanics? Naively it seems to lead to an inconsistency between observations made on entangled systems by different observers. The resolution of the paradox lies in the properties of multiple black holes, entangled in the Greenberger-Horne-Zeilinger pattern. The last part of the paper is about entanglement as a resource for quantum communication. ER=EPR provides a way to visualize protocols like quantum teleportation. In some sense teleportation takes place through the wormhole, but as usual, classical communication is necessary to complete the protocol. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

ER=EPR, GHZ, and the consistency of quantum measurements

Energy Technology Data Exchange (ETDEWEB)

Susskind, Leonard [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA (United States)

2016-01-15

This paper illustrates various aspects of the ER=EPR conjecture. It begins with a brief heuristic argument, using the Ryu-Takayanagi correspondence, for why entanglement between black holes implies the existence of Einstein-Rosen bridges. The main part of the paper addresses a fundamental question: Is ER=EPR consistent with the standard postulates of quantum mechanics? Naively it seems to lead to an inconsistency between observations made on entangled systems by different observers. The resolution of the paradox lies in the properties of multiple black holes, entangled in the Greenberger-Horne-Zeilinger pattern. The last part of the paper is about entanglement as a resource for quantum communication. ER=EPR provides a way to visualize protocols like quantum teleportation. In some sense teleportation takes place through the wormhole, but as usual, classical communication is necessary to complete the protocol. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Can EPR non-locality be geometrical?

International Nuclear Information System (INIS)

Ne'eman, Y.

1995-01-01

The presence in Quantum Mechanics of non-local correlations is one of the two fundamentally non-intuitive features of that theory. The non-local correlations themselves fall into two classes: EPR and Geometrical. The non-local characteristics of the geometrical type are well-understood and are not suspected of possibly generating acausal features, such as faster-than-light propagation of information. This has especially become true since the emergence of a geometrical treatment for the relevant gauge theories, i.e. Fiber Bundle geometry, in which the quantum non-localities are seen to correspond to pure homotopy considerations. This aspect is reviewed in section 2. Contrary-wise, from its very conception, the EPR situation was felt to be paradoxical. It has been suggested that the non-local features of EPR might also derive from geometrical considerations, like all other non-local characteristics of QM. In[7], one of the authors was able to point out several plausibility arguments for this thesis, emphasizing in particular similarities between the non-local correlations provided by any gauge field theory and those required by the preservation of the quantum numbers of the original EPR state-vector, throughout its spatially-extended mode. The derivation was, however, somewhat incomplete, especially because of the apparent difference between, on the one hand, the closed spatial loops arising in the analysis of the geometrical non-localities, from Aharonov-Bohm and Berry phases to magnetic monopoles and instantons, and on the other hand, in the EPR case, the open line drawn by the positions of the two moving decay products of the disintegrating particle. In what follows, the authors endeavor to remove this obstacle and show that as in all other QM non-localities, EPR is somehow related to closed loops, almost involving homotopy considerations. They develop this view in section 3

EPR by Areva. EPR the 1600+ MWe reactor

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

This brochure presents the GEN III+ EPR reactor designed by the Areva and Siemens consortium. The EPR reactor is a direct descendent of the well-proven N4 and KONVOI reactors, the most modern reactors in France and Germany. The EPR was designed by teams from KWU/Siemens and Framatome, EDF in France and the major German utilities, working in collaboration with both French and German safety authorities. The EPR integrates the results of decades of R and D programs, in particular those performed by the CEA (French Atomic Energy Commission) and the Karlsruhe Research Center in Germany. The EPR benefits from the experience of several thousand reactor-years of operation of pressurized water reactor technology. This experience has put 87 AREVA PWRs online throughout the world. Innovative Features: - An outer shell covering the reactor building, the spent fuel building and two of the four safeguard buildings provides protection against large commercial or military aircraft crash. - A heavy neutron reflector that surrounds the reactor core lowers uranium consumption. - An axial economizer inside the steam generator allows a high level of steam pressure and therefore high plant efficiency. - A core catcher allows passive collection and retention of the molten core should the reactor vessel fail in the highly unlikely event of a core melt. - A digital technology and a fully computerized control room with an operator friendly man-machine interface improve the reactor protection system.

EPR by Areva. EPR the 1600+ MWe reactor

International Nuclear Information System (INIS)

2008-01-01

This brochure presents the GEN III+ EPR reactor designed by the Areva and Siemens consortium. The EPR reactor is a direct descendent of the well-proven N4 and KONVOI reactors, the most modern reactors in France and Germany. The EPR was designed by teams from KWU/Siemens and Framatome, EDF in France and the major German utilities, working in collaboration with both French and German safety authorities. The EPR integrates the results of decades of R and D programs, in particular those performed by the CEA (French Atomic Energy Commission) and the Karlsruhe Research Center in Germany. The EPR benefits from the experience of several thousand reactor-years of operation of pressurized water reactor technology. This experience has put 87 AREVA PWRs online throughout the world. Innovative Features: - An outer shell covering the reactor building, the spent fuel building and two of the four safeguard buildings provides protection against large commercial or military aircraft crash. - A heavy neutron reflector that surrounds the reactor core lowers uranium consumption. - An axial economizer inside the steam generator allows a high level of steam pressure and therefore high plant efficiency. - A core catcher allows passive collection and retention of the molten core should the reactor vessel fail in the highly unlikely event of a core melt. - A digital technology and a fully computerized control room with an operator friendly man-machine interface improve the reactor protection system

Quantum paradoxes, entanglement and their explanation on the basis of quantization of fields

Science.gov (United States)

Melkikh, A. V.

2017-01-01

Quantum entanglement is discussed as a consequence of the quantization of fields. The inclusion of quantum fields self-consistently explains some quantum paradoxes (EPR and Hardy’s paradox). The definition of entanglement was introduced, which depends on the maximum energy of the interaction of particles. The destruction of entanglement is caused by the creation and annihilation of particles. On this basis, an algorithm for quantum particle evolution was formulated.

Time symmetry and interpretation of quantum mechanics. [Paradoxes

Energy Technology Data Exchange (ETDEWEB)

de Beauregard, O.C.

1976-10-01

A drastic resolution of the quantum paradoxes is proposed, combining (I) von Neumann's postulate that collapse of the state vector is due to the act of observation, and (II) my reinterpretation of von Neumann's quantal irreversibility as an equivalence between wave retardation and entropy increase, both being ''factlike'' rather than ''lawlike'' (Mehlberg). This entails a coupling of the two de jure symmetries between (I) retarded and (II) advanced waves, and between Aristotle's information as (I) learning and (II) willing awareness. Symmetric acceptance of cognizance as a source of retarded waves, and of will as a sink of advanced waves, is submitted as a central ''paradox'' of the Copernican or Einsteinian sort, out of which new light is shed upon previously known paradoxes, such as the EPR paradox, Schroedinger's cat, and Wigner's friend. Parapsychology is thus found to creep into the picture.

Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in spontaneous parametric down conversion

Science.gov (United States)

Penin, A. N.; Reutova, T. A.; Sergienko, A. V.

1992-01-01

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function.

Localization of one-photon state in space and Einstein-Podolsky-Rosen paradox in Spontaneous Parametric Down Conversion

International Nuclear Information System (INIS)

Penin, A.N.; Reutova, T.A.; Sergienko, A.V.

1992-01-01

An experiment on one-photon state localization in space using a correlation technique in Spontaneous Parametric Down Conversion (SPDC) process is discussed. Results of measurements demonstrate an idea of the Einstein-Podolsky-Rosen (EPR) paradox for coordinate and momentum variables of photon states. Results of the experiment can be explained with the help of an advanced wave technique. The experiment is based on the idea that two-photon states of optical electromagnetic fields arising in the nonlinear process of the spontaneous parametric down conversion (spontaneous parametric light scattering) can be explained by quantum mechanical theory with the help of a single wave function

Investigations of the EPR reference concept (KATS experiments); Untersuchungen zum EPR-Referenz-Konzept (KATS-Experimente)

Energy Technology Data Exchange (ETDEWEB)

Fieg, G.; Werle, H.; Huber, F.

1995-08-01

The reference concept of an EPR core catcher envisages the spreading of the melt on a protective layer (150 m{sup 2} area) and water cooling from above. Two variants are considered: Spreading on a dry area and on an area covered by water of condensation (1 cm depth). For the reference concept the KATS experiments are performed with thermite melts. After initial problems had rendered it difficult to interprete the first test, repeated tests have been successful. (orig.)

Single, Complete, Probability Spaces Consistent With EPR-Bohm-Bell Experimental Data

Science.gov (United States)

Avis, David; Fischer, Paul; Hilbert, Astrid; Khrennikov, Andrei

2009-03-01

We show that paradoxical consequences of violations of Bell's inequality are induced by the use of an unsuitable probabilistic description for the EPR-Bohm-Bell experiment. The conventional description (due to Bell) is based on a combination of statistical data collected for different settings of polarization beam splitters (PBSs). In fact, such data consists of some conditional probabilities which only partially define a probability space. Ignoring this conditioning leads to apparent contradictions in the classical probabilistic model (due to Kolmogorov). We show how to make a completely consistent probabilistic model by taking into account the probabilities of selecting the settings of the PBSs. Our model matches both the experimental data and is consistent with classical probability theory.

Analysis of the EPR-experiment by relativistic quantum logic

International Nuclear Information System (INIS)

Mittelstaedt, P.

1984-01-01

The Einstein-Podolsky-Rosen-experiment is analysed in the framework of an abstract language for relativistic quantum physics, which can be founded on the most general possibilities of physical observations and without any recourse to the Hilbert-space formulation of relativistic quantum theory. -Within this approach one obtains nonlocal correlations between the two EPR-systems in accordance with recent experiments and with quantum theory. These correlations can, however, not be used in order to produce superluminal signals and thus to violate Einstein-causality and special relativity. (author)

Investigations of the EPR reference concept (KATS experiments)

International Nuclear Information System (INIS)

Fieg, G.; Werle, H.; Huber, F.

1995-01-01

The reference concept of an EPR core catcher envisages the spreading of the melt on a protective layer (150 m 2 area) and water cooling from above. Two variants are considered: Spreading on a dry area and on an area covered by water of condensation (1 cm depth). For the reference concept the KATS experiments are performed with thermite melts. After initial problems had rendered it difficult to interprete the first test, repeated tests have been successful. (orig.)

EPR Studies of Spin-Spin Exchange Processes: A Physical Chemistry Experiment.

Science.gov (United States)

Eastman, Michael P.

1982-01-01

Theoretical background, experimental procedures, and analysis of experimental results are provided for an undergraduate physical chemistry experiment on electron paramagnetic resonance (EPR) linewidths. Source of line broadening observed in a spin-spin exchange process between radicals formed in aqueous solutions of potassium peroxylamine…

Biomolecular EPR spectroscopy

CERN Document Server

Hagen, Wilfred Raymond

2008-01-01

Comprehensive, Up-to-Date Coverage of Spectroscopy Theory and its Applications to Biological SystemsAlthough a multitude of books have been published about spectroscopy, most of them only occasionally refer to biological systems and the specific problems of biomolecular EPR (bioEPR). Biomolecular EPR Spectroscopy provides a practical introduction to bioEPR and demonstrates how this remarkable tool allows researchers to delve into the structural, functional, and analytical analysis of paramagnetic molecules found in the biochemistry of all species on the planet. A Must-Have Reference in an Intrinsically Multidisciplinary FieldThis authoritative reference seamlessly covers all important bioEPR applications, including low-spin and high-spin metalloproteins, spin traps and spin lables, interaction between active sites, and redox systems. It is loaded with practical tricks as well as do's and don'ts that are based on the author's 30 years of experience in the field. The book also comes with an unprecedented set of...

The paradoxical path towards the memorable guest experience

DEFF Research Database (Denmark)

d'Ambrosio, Luigi; Madsen, Jan Halberg

This paper examines the design of hospitality and tourism experiences staged for international tourists in the emerging Italian destination Campi Flegrei on the Bay of Naples. In particular, this case focuses on the paradox that Campi Flegrei (CF) hospitality providers around the Lake Avernus face...... in the conceptualisation of the guest experience in the context of a non-DMO governed destination....

Quantum paradoxes and the collapse of orthodox materialism basics

Directory of Open Access Journals (Sweden)

Oleg Avchenko

2015-06-01

Full Text Available Three quantum paradoxical experiments — (1 double-slit, (2 delayed choice, and (3 EPR paradox ones are considered. These experiments definitely indicate the inadequacy of the mate- rialist paradigm. The materialist doctrine can not describe, explain and predict phenomena and strangeness of quantum world, and the concept of matter is inconsistent at the quantum level. Doubtless, from the materialistic point of view, two propositions saying about that the physical properties of the system are in themselves, they are objective and independent of measurement (1\tand measurement (observation of one system does not affect the result of the measurement (observation of another system (2 are not verified by the recent experiments confirming so- called quantum non-locality or non-local realism. In relation to this, we have to doubt the truth of materialist ontology which denies the existence of transcendental objects or any extrasensory phenomena with certainty. There should be set boundaries for the materialist paradigm, beyond which it can not be accepted. The poliontichny paradigm that considers reality in potential and actual modes is proposed as an alternative world view embracing both material and quantum world. The unity of the world is not denied but it can be distinguished by two structural levels — two modes of reality evidencing the dual nature of the Universe.

Inductive reasoning and judgment interference: experiments on Simpson's paradox.

Science.gov (United States)

Fiedler, Klaus; Walther, Eva; Freytag, Peter; Nickel, Stefanie

2003-01-01

In a series of experiments on inductive reasoning, participants assessed the relationship between gender, success, and a covariate in a situation akin to Simpson's paradox: Although women were less successful then men according to overall statistics, they actually fared better then men at either of two universities. Understanding trivariate relationships of this kind requires cognitive routines similar to analysis of covariance. Across the first five experiments, however, participants generalized the disadvantage of women at the aggregate level to judgments referring to the different levels of the covariate, even when motivation was high and appropriate mental models were activated. The remaining three experiments demonstrated that Simpson's paradox could be mastered when the salience of the covariate was increased and when the salience of gender was decreased by the inclusion of temporal cues that disambiguate the causal status of the covariate. Copyright 2003 Society for Personality and Social Psychology, Inc.

Realization of the Einstein-Podolsky-Rosen paradox using momentum- and position-entangled photons from spontaneous parametric down conversion.

Science.gov (United States)

Howell, John C; Bennink, Ryan S; Bentley, Sean J; Boyd, R W

2004-05-28

We report on a momentum-position realization of the EPR paradox using direct detection in the near and far fields of the photons emitted by collinear type-II phase-matched parametric down conversion. Using this approach we achieved a measured two-photon momentum-position variance product of 0.01 variant Planck's over 2pi (2), which dramatically violates the bounds for the EPR and separability criteria.

Optimal experience among teachers: new insights into the work paradox.

Science.gov (United States)

Bassi, Marta; Delle Fave, Antonella

2012-01-01

Several studies highlighted that individuals perceive work as an opportunity for flow or optimal experience, but not as desirable and pleasant. This finding was defined as the work paradox. The present study addressed this issue among teachers from the perspective of self-determination theory, investigating work-related intrinsic and extrinsic motivation, as well as autonomous and controlled behavior regulation. In Study 1, 14 teachers were longitudinally monitored with Experience Sampling Method for one work week. In Study 2, 184 teachers were administered Flow Questionnaire and Work Preference Inventory, respectively investigating opportunities for optimal experience, and motivational orientations at work. Results showed that work-related optimal experiences were associated with both autonomous regulation and with controlled regulation. Moreover, teachers reported both intrinsic and extrinsic motivation at work, with a prevailing intrinsic orientation. Findings provide novel insights on the work paradox, and suggestions for teachers' well-being promotion.

Comment on ''a classical model of EPR experiment with quantum mechanical correlations and Bell inequalities''

International Nuclear Information System (INIS)

Aspect, A.

1986-01-01

The author states that ''It is impossible to mimick the quantum mechanical predictions for the EPR correlations, with a reasonable classical-looking model, in the spirit of Einstein's ideas''. The author feels that if he is wrong somebody could make a classical model (i.e. following the laws of classical physics) mimicking all the quantum mechanical predictions for the EPR correlations. He attempts to show that it is not the case for Barut's model for the following reasons: the first version of his model is classical, but doesn't mimick at all an EPR type experiment; and by reinterpretation one can get a model that does mimick the experiment, but this model is no longer ''reasonably classical looking'' since it involves negative probabilities. The claim is put in the form of a challenge. It is shown that the model under discussion can be reinterpreted by adding a chip converting the continuous outputs into two-valved outputs

From Einstein-Podolsky-Rosen paradox to quantum nonlocality: experimental investigation of quantum correlations

Science.gov (United States)

Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can

2016-11-01

In 1935, Einstein, Podolsky and Rosen published their influential paper proposing a now famous paradox (the EPR paradox) that threw doubt on the completeness of quantum mechanics. Two fundamental concepts: entanglement and steering, were given in the response to the EPR paper by Schrodinger, which both reflect the nonlocal nature of quantum mechanics. In 1964, John Bell obtained an experimentally testable inequality, in which its violation contradicts the prediction of local hidden variable models and agrees with that of quantum mechanics. Since then, great efforts have been made to experimentally investigate the nonlocal feature of quantum mechanics and many distinguished quantum properties were observed. In this work, along with the discussion of the development of quantum nonlocality, we would focus on our recent experimental efforts in investigating quantum correlations and their applications with optical systems, including the study of entanglement-assisted entropic uncertainty principle, Einstein-Podolsky-Rosen steering and the dynamics of quantum correlations.

One-Piece Faraday Generator: A Paradoxical Experiment from 1851

Science.gov (United States)

Crooks, M. J.; And Others

1978-01-01

Describes an experiment based on Faraday's one-piece generator, where the rotating disk is replaced by a cylindrical permanent magnet. Explains the apparent paradox that an observer in an inertial frame could measure his absolute velocity. (GA)

A sub-Kelvin cryogen-free EPR system.

Science.gov (United States)

Melhuish, Simon J; Stott, Chloe; Ariciu, Ana-Maria; Martinis, Lorenzo; McCulloch, Mark; Piccirillo, Lucio; Collison, David; Tuna, Floriana; Winpenny, Richard

2017-09-01

We present an EPR instrument built for operation at Q band below 1K. Our cryogen-free Dewar integrates with a commercial electro-magnet and bridge. A description of the cryogenic and RF systems is given, along with the adaptations to the standard EPR experiment for operation at sub-Kelvin temperatures. As a first experiment, the EPR spectra of powdered Cr 12 O 9 (OH) 3 [Formula: see text] were measured. The sub-Kelvin EPR spectra agree well with predictions, and the performance of the sub-Kelvin system at 5K is compared to that of a commercial spectrometer. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

SimLabel: a graphical user interface to simulate continuous wave EPR spectra from site-directed spin labeling experiments.

Science.gov (United States)

Etienne, E; Le Breton, N; Martinho, M; Mileo, E; Belle, V

2017-08-01

Site-directed spin labeling (SDSL) combined with continuous wave electron paramagnetic resonance (cw EPR) spectroscopy is a powerful technique to reveal, at the residue level, structural transitions in proteins. SDSL-EPR is based on the selective grafting of a paramagnetic label on the protein under study, followed by cw EPR analysis. To extract valuable quantitative information from SDSL-EPR spectra and thus give reliable interpretation on biological system dynamics, numerical simulations of the spectra are required. Such spectral simulations can be carried out by coding in MATLAB using functions from the EasySpin toolbox. For non-expert users of MATLAB, this could be a complex task or even impede the use of such simulation tool. We developed a graphical user interface called SimLabel dedicated to run cw EPR spectra simulations particularly coming from SDSL-EPR experiments. Simlabel provides an intuitive way to visualize, simulate, and fit such cw EPR spectra. An example of SDSL-EPR spectra simulation concerning the study of an intrinsically disordered region undergoing a local induced folding is described and discussed. We believe that this new tool will help the users to rapidly obtain reliable simulated spectra and hence facilitate the interpretation of their results. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

EPR by Areva. The path of greatest certainty

International Nuclear Information System (INIS)

2008-01-01

AREVA's Evolutionary Power Reactor (EPR) is the first Generation III+ reactor design currently being built to answer the world's growing demand for clean and reliable electricity generation. Already under construction in Finland, France and China, the EPR is also being considered by America, United Kingdom, South Africa and other countries for the development of their nuclear fleet. The EPR is now clearly destined to become the mainstay of standardized, efficient reactor fleets around the globe. AREVA's EPR incorporates unbeatable know-how provided by an uninterrupted track record of reactor building activities and backed by decades of feedback experience from operating PWRs, including the most recent. The EPR is a Franco-German initiative which benefited from the stringent scrutiny of safety authorities from both countries, at each stage of the project. The EPR has already secured construction licenses from two of the world's most demanding safety authorities in France and Finland and is currently in line for a design certification and a combined construction and operating license (COL) in the USA. It is also taking part in the licensing process recently launched in the United Kingdom. Europe's leading utilities have granted the EPR their approval under the 'European Utilities Requirements' and have further expressed individual interest in the design and performance of the EPR for their businesses. AREVA is the only Gen III+ reactor constructor in the world with ongoing building experience. To date, AREVA is the only vendor who has the necessary field experience that future customers can benefit: - Detailed design completed; - Experience feedback from 87 PWR; - 3 projects going on; - Continuous PWR experience in design and construction. Close to 100% of the EPR primary circuit heavy components are sourced directly from AREVA's integrated plants. Engineering, manufacturing, services and fuel cycle management are totally integrated and mastered by AREVA. From its

Position and Momentum Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices: The Einstein-Podolsky-Rosen Paradox on a Lattice

OpenAIRE

Opatrny, T.; Kolar, M.; Kurizki, G.; Deb, B.

2004-01-01

We study a possible realization of the position- and momentum-correlated atomic pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The Einstein-Podolsky-Rosen (EPR) ``paradox'' [Phys. Rev. 47, 777 (1935)] with translational variables is then modified by lattice-diffraction effects. This ``paradox'' can be verified to a high degree of accuracy in this scheme.

The EPR reactor

International Nuclear Information System (INIS)

Lacoste, A.C.; Dupuy, Ph.; Gupta, O.; Perez, J.R.; Emond, D.; Cererino, G.; Rousseau, J.M.; Jeffroy, F.; Evrard, J.M.; Seiler, J.M.; Azarian, G.; Chaumont, B.; Dubail, A.; Fischer, M.; Tiippana, P.; Hyvarinen, J.; Zaleski, C.P.; Meritet, S.; Iglesias, F.; Vincent, C.; Massart, S.; Graillat, G.; Esteve, B.; Mansillon, Y.; Gatinol, C.; Carre, F.

2005-01-01

This document reviews economical and environmental aspects of the EPR project. The following topics are discussed: role and point of view of the French Nuclear Safety Authority on EPR, control of design and manufacturing of EPR by the French Nuclear Safety Authority, assessment by IRSN of EPR safety, research and development in support of EPR, STUK safety review of EPR design, standpoint on EPR, the place of EPR in the French energy policy, the place of EPR in EDF strategy, EPR spearhead of nuclear rebirth, the public debate, the local stakes concerning the building of EPR in France at Flamanville (Manche) and the research on fourth generation reactors. (A.L.B.)

EPR by Areva. The path of greatest certainty

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

AREVA's Evolutionary Power Reactor (EPR) is the first Generation III+ reactor design currently being built to answer the world's growing demand for clean and reliable electricity generation. Already under construction in Finland, France and China, the EPR is also being considered by America, United Kingdom, South Africa and other countries for the development of their nuclear fleet. The EPR is now clearly destined to become the mainstay of standardized, efficient reactor fleets around the globe. AREVA's EPR incorporates unbeatable know-how provided by an uninterrupted track record of reactor building activities and backed by decades of feedback experience from operating PWRs, including the most recent. The EPR is a Franco-German initiative which benefited from the stringent scrutiny of safety authorities from both countries, at each stage of the project. The EPR has already secured construction licenses from two of the world's most demanding safety authorities in France and Finland and is currently in line for a design certification and a combined construction and operating license (COL) in the USA. It is also taking part in the licensing process recently launched in the United Kingdom. Europe's leading utilities have granted the EPR their approval under the 'European Utilities Requirements' and have further expressed individual interest in the design and performance of the EPR for their businesses. AREVA is the only Gen III+ reactor constructor in the world with ongoing building experience. To date, AREVA is the only vendor who has the necessary field experience that future customers can benefit: - Detailed design completed; - Experience feedback from 87 PWR; - 3 projects going on; - Continuous PWR experience in design and construction. Close to 100% of the EPR primary circuit heavy components are sourced directly from AREVA's integrated plants. Engineering, manufacturing, services and fuel cycle management are totally

Towards EPR (European pressurized reactor)

International Nuclear Information System (INIS)

Anon.

2003-01-01

According to the French industry minister, it is nonsense continuing delaying the construction of an EPR prototype because France needs it in order to renew timely its park of nuclear reactors. The renewing is expected to begin in 2020 and will be assured with third generation reactors like EPR. A quick launching of the EPR prototype is necessary to have it being in service by 2012, the feedback operating experience that will be accumulated over the 8 years that will follow will be necessary to optimize the industrial version and to have it ready by 2020. The EPR reactor has indisputable assets: modern, safer, more competitive and it will produce less wastes than present nuclear reactors. The construction cost of an EPR prototype is estimated to 3 milliard Euros and the nuclear industry operators propose to finance it completely. The EPR prototype does not jeopardize the ambitious French program about renewable energy sources, France is committed to produce 21% of its electricity from renewable energies by 2010 and 10 milliard Euros will be invested over this period on wind energy. Nuclear energy and alternative energies must be considered as 2 aspects of a diversified energy policy. (A.C.)

Experimental criteria for steering and the Einstein-Podolsky-Rosen paradox

Science.gov (United States)

Cavalcanti, E. G.; Jones, S. J.; Wiseman, H. M.; Reid, M. D.

2009-09-01

We formally link the concept of steering (a concept created by Schrödinger but only recently formalized by Wiseman, Jones, and Doherty [Phys. Rev. Lett. 98, 140402 (2007)]) and the criteria for demonstrations of Einstein-Podolsky-Rosen (EPR) paradox introduced by Reid [Phys. Rev. A 40, 913 (1989)]. We develop a general theory of experimental EPR-steering criteria, derive a number of criteria applicable to discrete as well as continuous-variable observables, and study their efficacy in detecting that form of nonlocality in some classes of quantum states. We show that previous versions of EPR-type criteria can be rederived within this formalism, thus unifying these efforts from a modern quantum-information perspective and clarifying their conceptual and formal origin. The theory follows in close analogy with criteria for other forms of quantum nonlocality (Bell nonlocality and entanglement), and because it is a hybrid of those two, it may lead to insights into the relationship between the different forms of nonlocality and the criteria that are able to detect them.

EPR-based material modelling of soils

Science.gov (United States)

Faramarzi, Asaad; Alani, Amir M.

2013-04-01

In the past few decades, as a result of the rapid developments in computational software and hardware, alternative computer aided pattern recognition approaches have been introduced to modelling many engineering problems, including constitutive modelling of materials. The main idea behind pattern recognition systems is that they learn adaptively from experience and extract various discriminants, each appropriate for its purpose. In this work an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR). EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial tests are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well-known conventional material models and it is shown that EPR-based models can provide a better prediction for the behaviour of soils. The main benefits of using EPR-based material models are that it provides a unified approach to constitutive modelling of all materials (i.e., all aspects of material behaviour can be implemented within a unified environment of an EPR model); it does not require any arbitrary choice of constitutive (mathematical) models. In EPR-based material models there are no material parameters to be identified. As the model is trained directly from experimental data therefore, EPR-based material models are the shortest route from experimental research (data) to numerical modelling. Another advantage of EPR-based constitutive model is that as more experimental data become available, the quality of the EPR prediction can be improved by learning from the additional data, and therefore, the EPR model can become more effective and robust. The developed EPR-based material models can be incorporated in finite element (FE) analysis.

Time symmetry and the Einstein paradox

International Nuclear Information System (INIS)

Costa de Beauregard, O.

1977-01-01

The characteristic difference between the paleoquantal calculation (addition of partial probabilities) and the neoquantal one (addition of partial amplitudes) for the correlation of photon polarizations in cascade transitions is derived in terms of elementary trigonometry. This deliberate use of simple formulae aims at a transparent rendering of the change in paradigm required by the so-called EPR paradox (which is truly the 1927 Einstein paradox), namely that 1) the two photons do not possess polarizations of their own when leaving the source C, but borrow one later, when interacting with the analysers L and N; 2) the die is thus not cast at C, but later, at L and N; 3) the correlation between the measurements at L and N is tied through C, in their common past. The tight connection between this ''Einstein nonseparability'' and the nonlocality in Feynman's ''theory of positrons'' is demonstrated through an analysis of the e + e - annihilation into two photons. Thus the Einstein paradox corresponds, in the ''new wavelike probability calculus'', to the Loschmid and Zermelo sort of paradox in the old probability calculus. That is, it contrasts the intrinsic time symmetry existing at the elementary level to the factlike macroscopic time asymmetry. The discussion deliberately by-passes the hidden-variable problem, the model in this being Einstein's by-passing of the mechanical aether when proposing special relativity. It is believed today, like in 1905, the problem is tayloring the wording after the (operationally good) mathematics. Moreover, that the change in paradigm, which is needed, comes through a victory of formalism over modelism. (author)

Analysis of SCRM experience in the area of quality assurance for retrospective EPR dosimetry technique with teeth

International Nuclear Information System (INIS)

Sholom, S. V.; Chumak, V.V.

2003-01-01

EPR dosimetry with tooth enamel is commonly accepted as one of most precise and accurate methods for retrospective dosimetry. At the same time, regularly conducted international Intercomparisons and Inter-calibrations of EPR dosimetry techniques demonstrate the significant scatter of results among laboratories operation in this area. This is mainly caused by the lack of commonly adopted unified technique which would be based on clear and efficient scheme of quality assurance. In the present work we will summarize more than ten-year experience of Scientific Center for Radiation Medicine in the area of EPR dosimetry from the point of view of quality assurance. EPR dosimetry technique with teeth, which was developed and being used in SCRM for routine dosimetry of liquidators is characterized by two-level system of quality assurance. In-house level covers all steps of the technique and allows control and minimizing of uncertainties that arise on separate steps. Extramural level provides the control of reliability and accuracy of technique in whole by means of regular participation in bi- and multi-lateral intercomparisons. Cumulative uncertainty of EPR dosimetry technique determined based on the results of 6 different intercomparisons is 21 mGy for dose below 300 and 11% for dose higher that 300 mGy. (authors)

Krótka (prehistoria argumentu EPR

Directory of Open Access Journals (Sweden)

Tadeusz Pabjan

2010-12-01

Full Text Available The 1935 thought experiment of Einstein, Podolsky and Rosen is one of the most important episodes in the history of the dispute about the correct interpretation of quantum mechanics. The present paper deals with the origin of the EPR paper and discusses some other thought experiments that preceded the formulation of the Einstein-Podolsky-Rosen argument. Special attention is paid to the evolution of a simply photon-box experiment, which was devised by Einstein in 1930 and then modified by him several times before 1935. It is argued that the scheme of the original EPR argument is in fact contained in these few seminal experiments.

Active cancellation - A means to zero dead-time pulse EPR.

Science.gov (United States)

Franck, John M; Barnes, Ryan P; Keller, Timothy J; Kaufmann, Thomas; Han, Songi

2015-12-01

The necessary resonator employed in pulse electron paramagnetic resonance (EPR) rings after the excitation pulse and creates a finite detector dead-time that ultimately prevents the detection of signal from fast relaxing spin systems, hindering the application of pulse EPR to room temperature measurements of interesting chemical or biological systems. We employ a recently available high bandwidth arbitrary waveform generator (AWG) to produce a cancellation pulse that precisely destructively interferes with the resonant cavity ring-down. We find that we can faithfully detect EPR signal at all times immediately after, as well as during, the excitation pulse. This is a proof of concept study showcasing the capability of AWG pulses to precisely cancel out the resonator ring-down, and allow for the detection of EPR signal during the pulse itself, as well as the dead-time of the resonator. However, the applicability of this approach to conventional EPR experiments is not immediate, as it hinges on either (1) the availability of low-noise microwave sources and amplifiers to produce the necessary power for pulse EPR experiment or (2) the availability of very high conversion factor micro coil resonators that allow for pulse EPR experiments at modest microwave power. Copyright © 2015 Elsevier Inc. All rights reserved.

EPR-based distance measurements at ambient temperature.

Science.gov (United States)

Krumkacheva, Olesya; Bagryanskaya, Elena

2017-07-01

Pulsed dipolar (PD) EPR spectroscopy is a powerful technique allowing for distance measurements between spin labels in the range of 2.5-10.0nm. It was proposed more than 30years ago, and nowadays is widely used in biophysics and materials science. Until recently, PD EPR experiments were limited to cryogenic temperatures (TEPR as well as other approaches based on EPR (e.g., relaxation enhancement; RE). In this paper, we review the features of PD EPR and RE at ambient temperatures, in particular, requirements on electron spin phase memory time, ways of immobilization of biomolecules, the influence of a linker between the spin probe and biomolecule, and future opportunities. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigations for the EPR-concept - KAPOOL and KATS experiments

International Nuclear Information System (INIS)

Engel, G.; Eppinger, B.; Fieg, G.; Schmidt-Stiefel, S.

2000-01-01

The objective of the KAPOOL and KATS experiments is to investigate basic phenomena in connection with the EPR melt spreading and cooling concept. High-temperature Al 2 O 3 - and Fe-melts produced by the thermite reaction are used to simulate the oxidic and metallic components of the core melt. Two KAPOOL tests have been performed to study the interaction of the oxidic melt with the release gate which is situated between the cavity and the spreading compartment. These tests have been analyzed with the HEATING-5 code and compared with the experimental results. With test KATS-17 (spreading onto dry concrete for the oxide melt, spreading onto concrete with 1 mm water level for the metallic melt) the series of two-dimensional spreading experiments has been finished. KATS-15 (2-dim spreading on dry ceramics) has been analyzed with the code CORFLOW. (orig.) [de

A Regional PD Strategy for EPR Systems: Evidence-Based IT Development

DEFF Research Database (Denmark)

Simonsen, Jesper; Hertzum, Morten

2006-01-01

One of the five regions in Denmark has initiated a remark-able and alternative strategy for the development of Elec-tronic Patient Record (EPR) systems. This strategy is driven by Participatory Design (PD) experiments and based on evidence of positive effects on the clinical practice when using EPR...... systems. We present this PD strategy and our related research on evidence-based IT development. We report from a newly completed PD experiment with EPR in the region conducted through a close collaboration compris-ing a neurological stroke unit, the region’s EPR unit, the vendor, as well as the authors....

Design performances and chemistry program supporting the FA3/UK-EPR (TM) Activity Management: Experience and Modelling Balance

International Nuclear Information System (INIS)

Tigeras, A.; Bachet, M.; Bremmes, O.; Berger, M.; Clinard, M.H.; Jolivet, P.; Chahma, F.

2012-01-01

Several methodologies have been applied to evaluate the source term in the primary circuit and to define the appropriate chemistry conditioning for the EPR reactor. These methodologies are based on nuclear power plant (NPP) feedback experience, laboratory data and modelling considerations. It is concluded that the activity risks are understood and can be managed with EPR design options. A strategy for the chemical conditioning of the primary coolant has been defined through the specifications for 3 parameters: pH, Zn and H 2 whose target and limit values are based on NPP feedback, international experimental data from laboratory tests, theoretical studies and numerical simulations. The material inventory selected for the primary components will allow low dose rates and low crud formation despite the high power level of the EPR reactor

SPIDYAN, a MATLAB library for simulating pulse EPR experiments with arbitrary waveform excitation.

Science.gov (United States)

Pribitzer, Stephan; Doll, Andrin; Jeschke, Gunnar

2016-02-01

Frequency-swept chirp pulses, created with arbitrary waveform generators (AWGs), can achieve inversion over a range of several hundreds of MHz. Such passage pulses provide defined flip angles and increase sensitivity. The fact that spectra are not excited at once, but single transitions are passed one after another, can cause new effects in established pulse EPR sequences. We developed a MATLAB library for simulation of pulse EPR, which is especially suited for modeling spin dynamics in ultra-wideband (UWB) EPR experiments, but can also be used for other experiments and NMR. At present the command line controlled SPin DYnamics ANalysis (SPIDYAN) package supports one-spin and two-spin systems with arbitrary spin quantum numbers. By providing the program with appropriate spin operators and Hamiltonian matrices any spin system is accessible, with limits set only by available memory and computation time. Any pulse sequence using rectangular and linearly or variable-rate frequency-swept chirp pulses, including phase cycling can be quickly created. To keep track of spin evolution the user can choose from a vast variety of detection operators, including transition selective operators. If relaxation effects can be neglected, the program solves the Liouville-von Neumann equation and propagates spin density matrices. In the other cases SPIDYAN uses the quantum mechanical master equation and Liouvillians for propagation. In order to consider the resonator response function, which on the scale of UWB excitation limits bandwidth, the program includes a simple RLC circuit model. Another subroutine can compute waveforms that, for a given resonator, maintain a constant critical adiabaticity factor over the excitation band. Computational efficiency is enhanced by precomputing propagator lookup tables for the whole set of AWG output levels. The features of the software library are discussed and demonstrated with spin-echo and population transfer simulations. Copyright © 2016

How far do EPR-Bell experiments constrain physical collapse theories?

International Nuclear Information System (INIS)

Leggett, A J

2007-01-01

A class of theories alternative to standard quantum mechanics, including that of Ghirardi et al ('GRWP'), postulates that when a quantum superposition becomes amplified to the point that the superposed states reach some level of 'macroscopic distinctness', then some non-quantum-mechanical principle comes into play and realizes one or other of the two macroscopic outcomes. Without specializing to any particular theory of this class, I ask how far such 'macrorealistic' theories are generically constrained, if one insists that the physical reduction process should respect Einstein locality, by the results of existing EPR-Bell experiments. I conclude that provided one does not demand that the prescription for reduction respects Lorentz invariance, at least some theories of this type, while in principle inevitably making some predictions that conflict with those of standard quantum mechanics, are not refuted by any existing experiment

A contribution to the study of Einstein-Podolsky-Rosen paradox. A calculation with propagators

International Nuclear Information System (INIS)

Payen, R.; Vigoureux, J.-M.

1977-01-01

Although polarizers and detectors take an important part in discussions and experimental tests about E.P.R. paradox, they are not explicitly present in usual calculations. A calculation is presented using propagators of the correlation in linear polarization of two photons emitted in a 0→1→0 atomic cascade, by quantum field theory, for a diagram including two polarized atoms taking place of polarizers and detectors. (author)

Realization of the purely spatial Einstein-Podolsky-Rosen paradox in full-field images of spontaneous parametric down-conversion

Science.gov (United States)

Moreau, Paul-Antoine; Mougin-Sisini, Joé; Devaux, Fabrice; Lantz, Eric

2012-07-01

We demonstrate Einstein-Podolsky-Rosen (EPR) entanglement by detecting purely spatial quantum correlations in the near and far fields of spontaneous parametric down-conversion generated in a type-2 beta barium borate crystal. Full-field imaging is performed in the photon-counting regime with an electron-multiplying CCD camera. The data are used without any postselection, and we obtain a violation of Heisenberg inequalities with inferred quantities taking into account all the biphoton pairs in both the near and far fields by integration on the entire two-dimensional transverse planes. This ensures a rigorous demonstration of the EPR paradox in its original position-momentum form.

Continuous variable polarization entanglement, experiment and analysis

International Nuclear Information System (INIS)

Bowen, Warwick P; Treps, Nicolas; Schnabel, Roman; Ralph, Timothy C; Lam, Ping Koy

2003-01-01

We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein-Podolsky-Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincare sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound √3 times more stringent than for the quadrature entanglement

Continuous variable polarization entanglement, experiment and analysis

Energy Technology Data Exchange (ETDEWEB)

Bowen, Warwick P [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Treps, Nicolas [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Schnabel, Roman [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Ralph, Timothy C [Department of Physics, Centre for Quantum Computer Technology, University of Queensland, St Lucia, QLD 4072 (Australia); Lam, Ping Koy [Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia)

2003-08-01

We generate and characterize continuous variable polarization entanglement between two optical beams. We first produce quadrature entanglement, and by performing local operations we transform it into a polarization basis. We extend two entanglement criteria, the inseparability criteria proposed by Duan et al (2000 Phys. Rev. Lett. 84 2722) and the Einstein-Podolsky-Rosen (EPR) paradox criteria proposed by Reid and Drummond (1988 Phys. Rev. Lett. 60 2731), to Stokes operators; and use them to characterize the entanglement. Our results for the EPR paradox criteria are visualized in terms of uncertainty balls on the Poincare sphere. We demonstrate theoretically that using two quadrature entangled pairs it is possible to entangle three orthogonal Stokes operators between a pair of beams, although with a bound {radical}3 times more stringent than for the quadrature entanglement.

EPR-based distance measurements at ambient temperature

Science.gov (United States)

Krumkacheva, Olesya; Bagryanskaya, Elena

2017-07-01

Pulsed dipolar (PD) EPR spectroscopy is a powerful technique allowing for distance measurements between spin labels in the range of 2.5-10.0 nm. It was proposed more than 30 years ago, and nowadays is widely used in biophysics and materials science. Until recently, PD EPR experiments were limited to cryogenic temperatures (T biomolecules, the influence of a linker between the spin probe and biomolecule, and future opportunities.

Black Holes and Information: A New Take on an Old Paradox

Directory of Open Access Journals (Sweden)

K. L. H. Bryan

2017-01-01

Full Text Available Interest in the black hole information paradox has recently been catalyzed by the newer “firewall” argument. The crux of the updated argument is that previous solutions which relied on observer complementarity are in violation of the quantum condition of monogamy of entanglement, with the prescribed remedy being to discard the equivalence principle in favor of an energy barrier (or firewall at the black hole horizon. Differing points of view have been put forward, including the “ER = EPR” counterargument and the final-state solution, both of which can be viewed as potential resolutions to the apparent conflict between quantum monogamy and Einstein equivalence. After reviewing these recent developments, this paper argues that the ER = EPR and final-state solutions can—thanks to observer complementarity—be seen as the same resolution of the paradox but from two different perspectives: inside and outside the black hole.

Multipartite Einstein-Podolsky-Rosen steering and genuine tripartite entanglement with optical networks

Science.gov (United States)

Armstrong, Seiji; Wang, Meng; Teh, Run Yan; Gong, Qihuang; He, Qiongyi; Janousek, Jiri; Bachor, Hans-Albert; Reid, Margaret D.; Lam, Ping Koy

2015-02-01

Einstein, Podolsky and Rosen (EPR) pointed out in their famous paradox that two quantum-entangled particles can have perfectly correlated positions and momenta. Such correlations give evidence for the nonlocality of quantum mechanics and form the basis for quantum cryptography and teleportation. EPR steering is the nonlocality associated with the EPR paradox and has traditionally been investigated between only two parties. Using optical networks and efficient detection, we present experimental observations of multiparty EPR steering and of the genuine entanglement of three intense optical beams. We entangle the quadrature phase amplitudes of distinct fields, in analogy to the position-momentum entanglement of the original paradox. Our experiments complement tests of quantum mechanics that have entangled small systems or have demonstrated tripartite inseparability. Our methods establish principles for the development of multiparty quantum communication protocols with asymmetric observers, and can be extended to qubits, whether photonic, atomic, superconducting, or otherwise.

Copper ESEEM and HYSCORE through ultra-wideband chirp EPR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Segawa, Takuya F.; Doll, Andrin; Pribitzer, Stephan; Jeschke, Gunnar, E-mail: gjeschke@ethz.ch [ETH Zurich, Laboratory of Physical Chemistry, Vladimir-Prelog-Weg 2, CH-8093 Zurich (Switzerland)

2015-07-28

The main limitation of pulse electron paramagnetic resonance (EPR) spectroscopy is its narrow excitation bandwidth. Ultra-wideband (UWB) excitation with frequency-swept chirp pulses over several hundreds of megahertz overcomes this drawback. This allows to excite electron spin echo envelope modulation (ESEEM) from paramagnetic copper centers in crystals, whereas up to now, only ESEEM of ligand nuclei like protons or nitrogens at lower frequencies could be detected. ESEEM spectra are recorded as two-dimensional correlation experiments, since the full digitization of the electron spin echo provides an additional Fourier transform EPR dimension. Thus, UWB hyperfine-sublevel correlation experiments generate a novel three-dimensional EPR-correlated nuclear modulation spectrum.

New Generation of self-calibrated SS/EPR dosimeters: Alanine/EPR dosimeters

International Nuclear Information System (INIS)

Yordanov, N.D.; Gancheva, V.

1999-01-01

A new type of solid state/EPR dosimeters is described. Principally, it contains radiation sensitive diamagnetic material, some quantity of EPR active, but radiation insensitive, substance (for example Mn 2+ /MgO) and a binding material. In the present case alanine is used as a radiation sensitive substance. With this dosimeter, the EPR spectra of alanine and Mn 2+ are simultaneously recorded and the calibration graph represents the ratio of alanine versus Mn 2+ EPR signal intensity as a function of absorbed dose. In this way the reproducibility of the results is expected to be improved significantly including their intercomparison among different laboratories. Homogeneity of the prepared dosimeters and their behaviour (fading of EPR signals with time, influence of different meteorological conditions) show satisfactory reproducibility and stability with time. Because two different EPR active samples are recorded simultaneously, the influence of some instrument setting parameters (microwave power, modulation amplitude and modulation frequency) on the ratio I alanine /I Mn is also investigated. (author)

EPR and Bell Locality

OpenAIRE

Norsen, Travis

2004-01-01

A new formulation of the EPR argument is presented, one which uses John Bell's mathematically precise local causality condition in place of the looser locality assumption which was used in the original EPR paper and on which Niels Bohr seems to have based his objection to the EPR argument. The new formulation of EPR bears a striking resemblance to Bell's derivation of his famous inequalities. The relation between these two arguments -- in particular, the role of EPR as part one of Bell's two-...

The three-box paradox revisited

International Nuclear Information System (INIS)

Ravon, Tamar; Vaidman, Lev

2007-01-01

The classical three-box paradox of Kirkpatrick (2003 J. Phys. A: Math. Gen. 36 4891) is compared to the original quantum three-box paradox of Aharonov and Vaidman (1991 J. Phys. A: Math. Gen. 24 2315). It is argued that the quantum three-box experiment is a 'quantum paradox' in the sense that it is an example of a classical task which cannot be accomplished using classical means, but can be accomplished using quantum devices. It is shown that Kirkpatrick's card game is analogous to a different game with a particle in three boxes which does not contain paradoxical features

The EPR - technology for the 3rd Millennium

International Nuclear Information System (INIS)

Bernstrauch, O.

2000-01-01

The Basic Design of the European Pressurized Water Reactor (EPR) was completed 1997 , the Basic Design Optimization Phase 1998 and the Detailed Design Phase will start in the near future. With these milestones, a new generation of PWRs is moving forward. Most of all, this is another story of a successful Franco-German cooperation. It is a rundown of the history of the EPR, before a decision is made to launch the lead-unit construction. The EPR project was launched in 1992 by Nuclear Power International (NPI), a joint company of FRAMATOME and Siemens KWU, supported by EDF and nine German electric utilities. Each step of the development of the EPR was harmonized with the Nuclear Safety Authorities both in France and Germany to reach an early approval. The EPR integrates the latest technological advances, especially in safety and operational aspects and comprises more than 30 years operating experience. Thus, the EPR combines the qualities of its predecessors, the French N4 and the German Konvoi. Presently, Siemens KWU and FRAMATOME are preparing the detailed design phase and the following construction and commissioning phase. The decision to build an EPR is not yet made either by the German electric utilities or by EdF, but it will be expected within the next months as a strong statement to follow the nuclear way and to ensure the know-how transfer. (author)

Selfcalibrated alanine/EPR dosimeters. A new generation of solid state/EPR dosimeters

International Nuclear Information System (INIS)

Yordanov, N.D.; Gancheva, V.

1999-01-01

Alanine/EPR dosimeters are well established as secondary, reference dosimeters for high-energy radiation. However, there are various sources of uncertainty in the evaluation of absorbed dose. This arises primarily from the necessity to calibrate each EPR spectrometer and each batch of dosimeters before their use. In order to overcome this disadvantage, a new generation alanine/EPR dosimeter has been developed, and its possibilities as a radiation detector are reported. Principally, it is a mixture of alanine, some quantity of EPR active substance, and a binding material. The EPR active substance, acting as an internal EPR standard, is chosen to have EPR parameters which are independent of the irradiation dose. The simultaneous recording of the spectra of both the sample and the standard under the same experimental conditions and the estimation of the ratio I alanine /I Mn as a function of the absorbed dose strongly reduces the uncertainties. The response of these dosimeters for 60 Co γ-radiation exhibits excellent linearity and reproducibility in the range of absorbed dose, 10 2 - 5 x 10 4 Gy. (author)

Paradoxical embolism: Experiences from a single center

Directory of Open Access Journals (Sweden)

Hong-Liang Zhang

2017-06-01

Full Text Available Objective: To present our treatment experiences and the follow-up data of patients with paradoxical embolism (PDE. Methods: The clinical characteristics, management, and follow-up data of all included patients who were diagnosed with PDE at Fuwai Hospital from January 1994 to October 2015 were recorded. Results: Twelve patients were included; all had a pulmonary embolism, and 8 had deep venous thrombosis. The artery embolisms involved the cerebral artery (7 patients, renal artery (2 patients, mesentery artery (2 patients, popliteal artery (1 patient, descending aorta thrombus (1 patient, and thrombus-straddled patent foramen ovale (PFO (1 patient. PFO was found in 3 cases. One patient underwent thrombectomy and PFO closure; Six patients received thrombolysis; and 3 patients were implanted with a vena cava filter. Long-term anticoagulation with warfarin was recommended for each patient. One patient died from ventricular fibrillation despite cardiopulmonary resuscitation. Eleven patients were discharged with improvements. No late mortality occurred in 8 patients with a complete follow-up of 10.6–17.7 years. One had a recurrent deep venous thrombosis. No patient had a recurrent pulmonary or arterial embolism. Two patients changed their treatment from warfarin to aspirin; others remained on warfarin. Only 1 case had an occasional gum bleeding. Conclusions: PDE treatment including thrombolysis, anticoagulation, and embolectomy should be individualized. We recommend long-term anticoagulation therapy to prevent the recurrence of PDE, especially to those with an intracardiac communication or persistent risk factors for re-thrombosis. Keywords: Paradoxical embolism, Pulmonary embolism, Deep venous thrombosis, Patent foramen ovale

A report on the Einstein-Podolski-Rosen paradox

International Nuclear Information System (INIS)

Vizh'e, Zh.P.

1982-01-01

A question on the essence and the existance as itself of causality in the world of physical phenomene is stated. The classical concepts of Laplace and Einstein determinism, used in classical and stochastic mechanics, are exposed. The Einstein-Podolski-Rosen (EPR) paradox is analysed from two viewpoints: the Bohr theory of measurements in quantum mechanics and the theory of local hidden variables. As a conclusion it is marked that the experimental results will force the physisists to made a choice between the Bohr measurements theory, from which the presens of macroscopic space-like noncausal-nonmaterial interactions follows and between the Dirac ideas about real existance of real physical subquantum level of the matter

Time-resolved EPR study of singlet oxygen in the gas phase.

Science.gov (United States)

Ruzzi, Marco; Sartori, Elena; Moscatelli, Alberto; Khudyakov, Igor V; Turro, Nicholas J

2013-06-27

X-band EPR spectra of singlet O2((1)Δg) and triplet O2((3)Σg(-)) were observed in the gas phase under low molecular-oxygen pressures PO2 = 0.175-0.625 Torr, T = 293-323 K. O2((1)Δg) was produced by quenching of photogenerated triplet sensitizers naphthalene C8H10, perdeuterated naphthalene, and perfluoronaphthalene in the gas phase. The EPR spectrum of O2((1)Δg) was also observed under microwave discharge. Integrated intensities and line widths of individual components of the EPR spectrum of O2((3)Σg(-)) were used as internal standards for estimating the concentration of O2 species and PO2 in the EPR cavity. Time-resolved (TR) EPR experiments of C8H10 were the main focus of this Article. Pulsed irradiation of C8H10 in the presence of O2((3)Σg(-)) allowed us to determine the kinetics of formation and decay for each of the four components of the O2((1)Δg) EPR signal, which lasted for only a few seconds. We found that the kinetics of EPR-component decay fit nicely to a biexponential kinetics law. The TR EPR 2D spectrum of the third component of the O2((1)Δg) EPR spectrum was examined in experiments using C8H10. This spectrum vividly presents the time evolution of an EPR component. The largest EPR signal and the longest lifetime of O2((1)Δg), τ = 0.4 s, were observed at medium pressure PO2 = 0.4 Torr, T = 293 K. The mechanism of O2((1)Δg) decay in the presence of photosensitizers is discussed. EPR spectra of O2((1)Δg) evidence that the spin-rotational states of O2((1)Δg) are populated according to Boltzmann distribution in the studied time range of 10-100 ms. We believe that this is the first report dealing with the dependence of O2((1)Δg) EPR line width on PO2 and T.

Full cycle rapid scan EPR deconvolution algorithm.

Science.gov (United States)

Tseytlin, Mark

2017-08-01

Rapid scan electron paramagnetic resonance (RS EPR) is a continuous-wave (CW) method that combines narrowband excitation and broadband detection. Sinusoidal magnetic field scans that span the entire EPR spectrum cause electron spin excitations twice during the scan period. Periodic transient RS signals are digitized and time-averaged. Deconvolution of absorption spectrum from the measured full-cycle signal is an ill-posed problem that does not have a stable solution because the magnetic field passes the same EPR line twice per sinusoidal scan during up- and down-field passages. As a result, RS signals consist of two contributions that need to be separated and postprocessed individually. Deconvolution of either of the contributions is a well-posed problem that has a stable solution. The current version of the RS EPR algorithm solves the separation problem by cutting the full-scan signal into two half-period pieces. This imposes a constraint on the experiment; the EPR signal must completely decay by the end of each half-scan in order to not be truncated. The constraint limits the maximum scan frequency and, therefore, the RS signal-to-noise gain. Faster scans permit the use of higher excitation powers without saturating the spin system, translating into a higher EPR sensitivity. A stable, full-scan algorithm is described in this paper that does not require truncation of the periodic response. This algorithm utilizes the additive property of linear systems: the response to a sum of two inputs is equal the sum of responses to each of the inputs separately. Based on this property, the mathematical model for CW RS EPR can be replaced by that of a sum of two independent full-cycle pulsed field-modulated experiments. In each of these experiments, the excitation power equals to zero during either up- or down-field scan. The full-cycle algorithm permits approaching the upper theoretical scan frequency limit; the transient spin system response must decay within the scan

Quantum Quasi-Paradoxes and Quantum Sorites Paradoxes

CERN Document Server

Smarandache, F

1997-01-01

There can be generated many paradoxes or quasi-paradoxes that may occur from the combination of quantum and non-quantum worlds in physics. Even the passage from the micro-cosmos to the macro-cosmos, and reciprocally, can generate unsolved questions or counter-intuitive ideas. We define a quasi-paradox as a statement which has a prima facie self-contradictory support or an explicit contradiction, but which is not completely proven as a paradox. We present herein four elementary quantum quasi-paradoxes and their corresponding quantum Sorites paradoxes, which form a class of quantum quasi-paradoxes.

The EPR in a few words: all you need to know about the EPR nuclear reactor

International Nuclear Information System (INIS)

2009-01-01

After a brief presentation of the EPR (European - or Evolutionary - Pressurized Reactor) type nuclear reactor, this paper, proposed by the collective group 'Stop EPR', develops the following points: EPR is as dangerous as other reactors; EPR flouts democracy; France's energy demand do not need the construction of EPRs; the construction of EPRs is not a factor of economical and social development; EPR should not be constructed neither in France nor elsewhere and the present building sites should be cancelled; the EPR will not help France to increase its energy independence and protect itself from oil price increases; choosing the EPR is incompatible with the large investments to be made in energy conservation and renewable energies; the EPR is not a solution to climate change; the VHV line corridor that will starts at Flamanville is not justified and poses risks to the environment and public health

Chirp echo Fourier transform EPR-detected NMR.

Science.gov (United States)

Wili, Nino; Jeschke, Gunnar

2018-04-01

A new ultra-wide band (UWB) pulse EPR method is introduced for observing all nuclear frequencies of a paramagnetic center in a single shot. It is based on burning spectral holes with a high turning angle (HTA) pulse that excites forbidden transitions and subsequent detection of the hole pattern by a chirp echo. We term this method Chirp Echo Epr SpectroscopY (CHEESY)-detected NMR. The approach is a revival of FT EPR-detected NMR. It yields similar spectra and the same type of information as electron-electron double resonance (ELDOR)-detected NMR, but with a multiplex advantage. We apply CHEESY-detected NMR in Q band to nitroxides and correlate the hyperfine spectrum to the EPR spectrum by varying the frequency of the HTA pulse. Furthermore, a selective π pulse before the HTA pulse allows for detecting hyperfine sublevel correlations between transitions of one nucleus and for elucidating the coupling regime, the same information as revealed by the HYSCORE experiment. This is demonstrated on hexaaquamanganese(II). We expect that CHEESY-detected NMR is generally applicable to disordered systems and that our results further motivate the development of EPR spectrometers capable of coherent UWB excitation and detection, especially at higher fields and frequencies. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Chirp echo Fourier transform EPR-detected NMR

Science.gov (United States)

Wili, Nino; Jeschke, Gunnar

2018-04-01

A new ultra-wide band (UWB) pulse EPR method is introduced for observing all nuclear frequencies of a paramagnetic center in a single shot. It is based on burning spectral holes with a high turning angle (HTA) pulse that excites forbidden transitions and subsequent detection of the hole pattern by a chirp echo. We term this method Chirp Echo Epr SpectroscopY (CHEESY)-detected NMR. The approach is a revival of FT EPR-detected NMR. It yields similar spectra and the same type of information as electron-electron double resonance (ELDOR)-detected NMR, but with a multiplex advantage. We apply CHEESY-detected NMR in Q band to nitroxides and correlate the hyperfine spectrum to the EPR spectrum by varying the frequency of the HTA pulse. Furthermore, a selective π pulse before the HTA pulse allows for detecting hyperfine sublevel correlations between transitions of one nucleus and for elucidating the coupling regime, the same information as revealed by the HYSCORE experiment. This is demonstrated on hexaaquamanganese(II). We expect that CHEESY-detected NMR is generally applicable to disordered systems and that our results further motivate the development of EPR spectrometers capable of coherent UWB excitation and detection, especially at higher fields and frequencies.

Quantum Quasi-Paradoxes and Quantum Sorites Paradoxes

Directory of Open Access Journals (Sweden)

Smarandache F.

2005-04-01

Full Text Available There can be generated many paradoxes or quasi-paradoxes that may occur from the combination of quantum and non-quantum worlds in physics. Even the passage from the micro-cosmos to the macro-cosmos, and reciprocally, can generate unsolved questions or counter-intuitive ideas. We define a quasi-paradox as a statement which has a prima facie self-contradictory support or an explicit contradiction, but which is not completely proven as a paradox. We present herein four elementary quantum quasi-paradoxes and their corresponding quantum Sorites paradoxes, which form a class of quantum quasi-paradoxes.

Quantum mechanics, common sense and the black hole information paradox

CERN Document Server

Danielsson, U H; Danielsson, Ulf H.; Schiffer, Marcelo

1993-01-01

The purpose of this paper is to analyse, in the light of information theory and with the arsenal of (elementary) quantum mechanics (EPR correlations, copying machines, teleportation, mixing produced in sub-systems owing to a trace operation, etc.) the scenarios available on the market to resolve the so-called black-hole information paradox. We shall conclude that the only plausible ones are those where either the unitary evolution of quantum mechanics is given up, in which information leaks continuously in the course of black-hole evaporation through non-local processes, or those in which the world is polluted by an infinite number of meta-stable remnants.

Radwaste paradox

International Nuclear Information System (INIS)

Carter, L.J.

1983-01-01

The Paradox Basin is one of the places where the US Department of Energy is looking for a site for a deep-mined repository for high-level radioactive waste. This seems appropriately symbolic because the geologic disposal problem has increasingly taken on the aspect of a political and technical conundrum, replete with real or seeming contradictions and paradoxes. A central paradox is that, while the concept of sequestering long-lived wastes in mined repositories is attractive intuitively, the very efforts made to confirm the suitability of particular rock formations give rise to further uncertainties. The new law contemplates repository construction will start as early as 1989. Experience so far at the several sites suggests that the technical and political questions tend to proliferate rather than diminish as more becomes known about the geology and hydrology. The following sites were discussed: the Hanford basalt; the Nevada tuff; and salt beds and salt domes (Utah, Texas, Mississippi). (DP)

Harmonization of dosimetric information obtained by different EPR methods: Experience of the Techa river study

Energy Technology Data Exchange (ETDEWEB)

Volchkova, A. [Urals Research Center for Radiation Medicine, 68A, Vorovsky Str., 454076 Chelyabinsk (Russian Federation); Shishkina, E.A., E-mail: ElenaA.Shishkina@gmail.com [Urals Research Center for Radiation Medicine, 68A, Vorovsky Str., 454076 Chelyabinsk (Russian Federation); Ivanov, D. [Institute of Metal Physics, Russian Academy of Sciences, 18, S. Kovalevskoy Str., 620041 Yekaterinburg (Russian Federation); Timofeev, Yu. [Urals Research Center for Radiation Medicine, 68A, Vorovsky Str., 454076 Chelyabinsk (Russian Federation); Fattibene, P.; Della Monaca, S. [Istituto Superiore di Sanita and Istituto Nazionale di Fisica Nucleare, Viale Regina Elena 299, 00161 Rome (Italy); Wieser, A. [Helmholtz Zentrum Muenchen, German Research Centre for Environmental Health, D-85764 Neuherberg (Germany); Degteva, M.O. [Urals Research Center for Radiation Medicine, 68A, Vorovsky Str., 454076 Chelyabinsk (Russian Federation)

2011-09-15

Between 1949 and 1956 the Techa River (Southern Urals, Russia) was contaminated as a result of releases of radioactive waste by the Mayak Production Association. EPR dosimetry with tooth enamel has been used to estimate the external exposure of Techa riverside residents over the last 17 years. The database 'Tooth' of the Urals Research Center for Radiation Medicine (URCRM) has accumulated about 1000 EPR measurements of tooth enamel from the rural population of the Urals region. The teeth were investigated by laboratories of Russia, USA, Germany and Italy. Most of the enamel samples were measured several times in different laboratories. Each laboratory used different equipment and its own methods for sample preparation and EPR spectra analysis. Even measurements performed at the same laboratory over 10-15 years may not be assumed as uniform: methods change with time, and equipment is subject to aging. These two factors influenced EPR performance. The purpose of this study is, therefore, the harmonization of EPR data accumulated during long-term dosimetric investigations in the Southern Urals for further pooled analysis. The results will be used for external dose evaluation in the Techa River region.

On Neyman-Pearson Theory: Information Content of an Experiment and a Fancy Paradox

Directory of Open Access Journals (Sweden)

Benito Vittorio Frosini

2007-10-01

Full Text Available Two topics, connected with Neyman-Pearson theory of testing hypotheses, are treated in this article. The first topic is related to the information content of an experiment; after a short outline of ordinal comparability of experiments, the two most popular information measures – by Fisher and by Kullback-Leibler – are considered. As far as we require a comparison of two experiments at a time, the superiority of the couple (a,b of the two error probabilities in the Neyman-Pearson approach is easily established, owing to their clear operational meaning. The second topic deals with the so called Jeffreys – or Lindley – paradox: it can be shown that, if we attach a positive probability to a point null hypothesis, some «paradoxical» posterior probabilities – in a Bayesian approach – result in sharp contrast with the error probabilities in the Neyman-Pearson approach. It is argued that such results are simply the outcomes of absurd assumptions, and it is shown that sensible assumptions about interval – not point – hypotheses can yield posterior probabilities perfectly compatible with the Neyman-Pearson approach (although one must be very careful in making such comparisons, as the two approaches are radically different both in assumptions and in purposes.

Another paradox involving the second law of thermodynamics

International Nuclear Information System (INIS)

Sheehan, D.P.

1996-01-01

Recently a paradox has been posed that appears to challenge the second law of thermodynamics in a plasma blackbody environment [D. P. Sheehan, Phys. Plasmas 2, 1893 (1995)]. In this paper another, related paradox is posed in an unmagnetized Q plasma. Laboratory experiments simulating some necessary conditions for the paradoxical system corroborate theoretical predictions and fail to resolve the paradox in favor of the second law. copyright 1996 American Institute of Physics

EPR: Evidence and fallacy.

Science.gov (United States)

Nichols, Joseph W; Bae, You Han

2014-09-28

The enhanced permeability and retention (EPR) of nanoparticles in tumors has long stood as one of the fundamental principles of cancer drug delivery, holding the promise of safe, simple and effective therapy. By allowing particles preferential access to tumors by virtue of size and longevity in circulation, EPR provided a neat rationale for the trend toward nano-sized drug carriers. Following the discovery of the phenomenon by Maeda in the mid-1980s, this rationale appeared to be well justified by the flood of evidence from preclinical studies and by the clinical success of Doxil. Clinical outcomes from nano-sized drug delivery systems, however, have indicated that EPR is not as reliable as previously thought. Drug carriers generally fail to provide superior efficacy to free drug systems when tested in clinical trials. A closer look reveals that EPR-dependent drug delivery is complicated by high tumor interstitial fluid pressure (IFP), irregular vascular distribution, and poor blood flow inside tumors. Furthermore, the animal tumor models used to study EPR differ from clinical tumors in several key aspects that seem to make EPR more pronounced than in human patients. On the basis of this evidence, we believe that EPR should only be invoked on a case-by-case basis, when clinical evidence suggests the tumor type is susceptible. Copyright © 2014 Elsevier B.V. All rights reserved.

Electron paramagnetic resonance (EPR) biodosimetry

International Nuclear Information System (INIS)

Desrosiers, Marc; Schauer, David A.

2001-01-01

Radiation-induced electron paramagnetic resonance (EPR) signals were first reported by Gordy et al. [Proc. Natl. Acad. Sci. USA 41 (1955) 983]. The application of EPR spectroscopy to ionizing radiation dosimetry was later proposed by Brady et al. [Health Phys. 15 (1968) 43]. Since that time EPR dosimetry has been applied to accident and epidemiologic dose reconstruction, radiation therapy, food irradiation, quality assurance programs and archaeological dating. Materials that have been studied include bone, tooth enamel, alanine and quartz. This review paper presents the fundamentals and applications of EPR biodosimetry. Detailed information regarding sample collection and preparation, EPR measurements, dose reconstruction, and data analysis and interpretation will be reviewed for tooth enamel. Examples of EPR biodosimetry application in accidental overexposures, radiopharmaceutical dose assessment and retrospective epidemiologic studies will also be presented

Optical tweezers and paradoxes in electromagnetism

International Nuclear Information System (INIS)

Pfeifer, Robert N C; Nieminen, Timo A; Heckenberg, Norman R; Rubinsztein-Dunlop, Halina

2011-01-01

The widespread application of optical forces and torques has contributed to renewed interest in the fundamentals of the electromagnetic force and torque, including long-standing paradoxes such as the Abraham–Minkowski controversy and the angular momentum density of a circularly polarized plane wave. We discuss the relationship between these electromagnetic paradoxes and optical tweezers. In particular, consideration of possible optical tweezers experiments to attempt to resolve these paradoxes strongly suggests that they are beyond experimental resolution, yielding identical observable results in all cases

Bertrand's paradox: a physical way out along the lines of Buffon's needle throwing experiment

International Nuclear Information System (INIS)

Porto, P Di; Ciattoni, A; Crosignani, B; Liu, H C

2011-01-01

Bertrand's paradox (Bertrand 1889 Calcul des Probabilites (Paris: Gauthier-Villars)) can be considered as a cautionary memento, to practitioners and students of probability calculus alike, of the possible ambiguous meaning of the term 'at random' when the sample space of events is continuous. It deals with the existence of different possible answers to the following question: what is the probability that a chord, drawn at random in a circle of radius R, is longer than the side R√3 of an inscribed equilateral triangle? Physics can help to remove the ambiguity by identifying an actual experiment, whose outcome is obviously unique and prescribes the physical variables to which the term 'random' can be correctly applied. In this paper, after briefly describing Bertrand's paradox, we associate it with an experiment, which is basically a variation of the famous Buffon's needle experiment (Buffon 1733 Histoire de l'Acad. Roy. des. Sciences pp 43-5; Buffon 1777 Histoire naturelle, generale et particuliere Supplement 4 46) for estimating the value of π. Its outcome is compared with the analytic predictions of probability calculus, that is with the probability distribution of variables whose uniform distribution can be considered a sound implementation of complete randomness.

Bell's theorem based on a generalized EPR criterion of reality

International Nuclear Information System (INIS)

Eberhard, P.H.; Rosselet, P.

1995-01-01

First, the demonstration of Bell's theorem, i.e., of the nonlocal character of quantum theory, is spelled out using the EPR criterion of reality as premises and a gedanken experiment involving two particles. Then, the EPR criterion is extended to include quantities predicted almost with certainty, and Bell's theorem is demonstrated on these new premises. The same experiment is used but in conditions that become possible in real life, without the requirements of ideal efficiencies and zero background. Very high efficiencies and low background are needed, but these requirements may be met in the future

Locations of radical species in black pepper seeds investigated by CW EPR and 9GHz EPR imaging.

Science.gov (United States)

Nakagawa, Kouichi; Epel, Boris

2014-10-15

In this study, noninvasive 9GHz electron paramagnetic resonance (EPR)-imaging and continuous wave (CW) EPR were used to investigate the locations of paramagnetic species in black pepper seeds without further irradiation. First, lithium phthalocyanine (LiPC) phantom was used to examine 9GHz EPR imaging capabilities. The 9GHz EPR-imager easily resolved the LiPC samples at a distance of ∼2mm. Then, commercially available black pepper seeds were measured. We observed signatures from three different radical species, which were assigned to stable organic radicals, Fe(3+), and Mn(2+) complexes. In addition, no EPR spectral change in the seed was observed after it was submerged in distilled H2O for 1h. The EPR and spectral-spatial EPR imaging results suggested that the three paramagnetic species were mostly located at the seed surface. Fewer radicals were found inside the seed. We demonstrated that the CW EPR and 9GHz EPR imaging were useful for the determination of the spatial distribution of paramagnetic species in various seeds. Copyright © 2014 Elsevier B.V. All rights reserved.

Homogeneity and EPR metrics for assessment of regular grids used in CW EPR powder simulations.

Science.gov (United States)

Crăciun, Cora

2014-08-01

CW EPR powder spectra may be approximated numerically using a spherical grid and a Voronoi tessellation-based cubature. For a given spin system, the quality of simulated EPR spectra depends on the grid type, size, and orientation in the molecular frame. In previous work, the grids used in CW EPR powder simulations have been compared mainly from geometric perspective. However, some grids with similar homogeneity degree generate different quality simulated spectra. This paper evaluates the grids from EPR perspective, by defining two metrics depending on the spin system characteristics and the grid Voronoi tessellation. The first metric determines if the grid points are EPR-centred in their Voronoi cells, based on the resonance magnetic field variations inside these cells. The second metric verifies if the adjacent Voronoi cells of the tessellation are EPR-overlapping, by computing the common range of their resonance magnetic field intervals. Beside a series of well known regular grids, the paper investigates a modified ZCW grid and a Fibonacci spherical code, which are new in the context of EPR simulations. For the investigated grids, the EPR metrics bring more information than the homogeneity quantities and are better related to the grids' EPR behaviour, for different spin system symmetries. The metrics' efficiency and limits are finally verified for grids generated from the initial ones, by using the original or magnetic field-constraint variants of the Spherical Centroidal Voronoi Tessellation method. Copyright © 2014 Elsevier Inc. All rights reserved.

Homogeneity and EPR metrics for assessment of regular grids used in CW EPR powder simulations

Science.gov (United States)

Crăciun, Cora

2014-08-01

CW EPR powder spectra may be approximated numerically using a spherical grid and a Voronoi tessellation-based cubature. For a given spin system, the quality of simulated EPR spectra depends on the grid type, size, and orientation in the molecular frame. In previous work, the grids used in CW EPR powder simulations have been compared mainly from geometric perspective. However, some grids with similar homogeneity degree generate different quality simulated spectra. This paper evaluates the grids from EPR perspective, by defining two metrics depending on the spin system characteristics and the grid Voronoi tessellation. The first metric determines if the grid points are EPR-centred in their Voronoi cells, based on the resonance magnetic field variations inside these cells. The second metric verifies if the adjacent Voronoi cells of the tessellation are EPR-overlapping, by computing the common range of their resonance magnetic field intervals. Beside a series of well known regular grids, the paper investigates a modified ZCW grid and a Fibonacci spherical code, which are new in the context of EPR simulations. For the investigated grids, the EPR metrics bring more information than the homogeneity quantities and are better related to the grids’ EPR behaviour, for different spin system symmetries. The metrics’ efficiency and limits are finally verified for grids generated from the initial ones, by using the original or magnetic field-constraint variants of the Spherical Centroidal Voronoi Tessellation method.

Towards the evidence of a purely spatial Einstein-Podolsky-Rosen paradox in images: measurement scheme and first experimental results

Science.gov (United States)

Devaux, F.; Mougin-Sisini, J.; Moreau, P. A.; Lantz, E.

2012-07-01

We propose a scheme to evidence the Einstein-Podolsky-Rosen (EPR) paradox for photons produced by spontaneous down conversion, from measurement of purely spatial correlations of photon positions both in the near- and in the far-field. Experimentally, quantum correlations have been measured in the far-field of parametric fluorescence created in a type II BBO crystal. Imaging is performed in the photon counting regime with an electron-multiplying CCD (EMCCD) camera.

Most advanced HTP fuel assembly design for EPR

International Nuclear Information System (INIS)

Francillon, Eric; Kiehlmann, Horst-Dieter

2006-01-01

End 2003, the Finnish electricity utility Teollisuuden Voima Oy (TVO) signed the contract for building an EPR in Olkiluoto (Finland). Mid 2004, the French electricity utility EDF selected an EPR to be built in France. In 2005, Framatome ANP, an AREVA and Siemens company, announced that they will be pursuing a design certification in the U.S. The EPR development is based on the latest PWR product lines of former Framatome (N4) and Siemens Nuklear (Konvoi). As an introductory part, different aspects of the EPR core characteristics connected to fuel assembly design are presented. It includes means of ensuring reactivity control like hybrid AIC/B4C control rod absorbers and gadolinium as burnable absorber integrated in fuel rods, and specific options for in-core instrumentation, such as Aeroball type instrumentation. Then the design requirements for the EPR fuel assembly are presented in term of very high burnup capacity, rod cladding and fuel assembly reliability. Framatome ANP fuel assembly product characteristics meeting these requirements are then described. EPR fuel assembly design characteristics benefit from the experience feedback of the latest fuel assembly products designed within Framatome ANP, leading to resistance to assembly deformation, high fuel rod restraint and prevention of handling hazards. EPR fuel assembly design features the best components composing the cornerstones of the upgraded family of fuel assemblies that FRAMATOME ANP proposes today. This family is based on a set of common characteristics and associated features, which include the HMP grid as bottom end spacer, the MONOBLOC guide tube and the Robust FUELGUARD as lower tie plate, the use of the M5 Alloy, as cladding and structure material. This fully re-crystallized, ternary Zr-Nb-O alloy produces radically improved in-reactor corrosion, very low hydrogen uptake and growth and an excellent creep behavior, which are described there. EPR fuel assembly description also includes fuel rod

Pulse Double-Resonance EPR Techniques for the Study of Metallobiomolecules.

Science.gov (United States)

Cox, Nicholas; Nalepa, Anna; Pandelia, Maria-Eirini; Lubitz, Wolfgang; Savitsky, Anton

2015-01-01

Electron paramagnetic resonance (EPR) spectroscopy exploits an intrinsic property of matter, namely the electron spin and its related magnetic moment. This can be oriented in a magnetic field and thus, in the classical limit, acts like a little bar magnet. Its moment will align either parallel or antiparallel to the field, giving rise to different energies (termed Zeeman splitting). Transitions between these two quantized states can be driven by incident microwave frequency radiation, analogous to NMR experiments, where radiofrequency radiation is used. However, the electron Zeeman interaction alone provides only limited information. Instead, much of the usefulness of EPR is derived from the fact that the electron spin also interacts with its local magnetic environment and thus can be used to probe structure via detection of nearby spins, e.g., NMR-active magnetic nuclei and/or other electron spin(s). The latter is exploited in spin labeling techniques, an exciting new area in the development of noncrystallographic protein structure determination. Although these interactions are often smaller than the linewidth of the EPR experiment, sophisticated pulse EPR methods allow their detection. A number of such techniques are well established today and can be broadly described as double-resonance methods, in which the electron spin is used as a reporter. Below we give a brief description of pulse EPR methods, particularly their implementation at higher magnetic fields, and how to best exploit them for studying metallobiomolecules. © 2015 Elsevier Inc. All rights reserved.

Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradox

Directory of Open Access Journals (Sweden)

Gunnell David

2008-01-01

Full Text Available Abstract This article discusses three statistical paradoxes that pervade epidemiological research: Simpson's paradox, Lord's paradox, and suppression. These paradoxes have important implications for the interpretation of evidence from observational studies. This article uses hypothetical scenarios to illustrate how the three paradoxes are different manifestations of one phenomenon – the reversal paradox – depending on whether the outcome and explanatory variables are categorical, continuous or a combination of both; this renders the issues and remedies for any one to be similar for all three. Although the three statistical paradoxes occur in different types of variables, they share the same characteristic: the association between two variables can be reversed, diminished, or enhanced when another variable is statistically controlled for. Understanding the concepts and theory behind these paradoxes provides insights into some controversial or contradictory research findings. These paradoxes show that prior knowledge and underlying causal theory play an important role in the statistical modelling of epidemiological data, where incorrect use of statistical models might produce consistent, replicable, yet erroneous results.

Bell's theorem based on a generalized EPR criterion of reality

International Nuclear Information System (INIS)

Eberhard, P.H.; Rosselet, P.

1993-04-01

First, the demonstration of Bell's theorem, i.e. of the non-local character of quantum theory, is spelled out using the EPR criterion of reality as premises and a gedanken experiment involving two particles. Then, the EPR criterion is extended to include quantities predicted almost with certainty, and Bell's theorem is demonstrated on these new premises. The same experiment is used but in conditions that become possible in real life, without the requirements of ideal efficiencies and zero background. Very high efficiencies and low background are needed, but these requirements may be met in the future. (author) 1 fig., 11 refs

Using rapid-scan EPR to improve the detection limit of quantitative EPR by more than one order of magnitude.

Science.gov (United States)

Möser, J; Lips, K; Tseytlin, M; Eaton, G R; Eaton, S S; Schnegg, A

2017-08-01

X-band rapid-scan EPR was implemented on a commercially available Bruker ELEXSYS E580 spectrometer. Room temperature rapid-scan and continuous-wave EPR spectra were recorded for amorphous silicon powder samples. By comparing the resulting signal intensities the feasibility of performing quantitative rapid-scan EPR is demonstrated. For different hydrogenated amorphous silicon samples, rapid-scan EPR results in signal-to-noise improvements by factors between 10 and 50. Rapid-scan EPR is thus capable of improving the detection limit of quantitative EPR by at least one order of magnitude. In addition, we provide a recipe for setting up and calibrating a conventional pulsed and continuous-wave EPR spectrometer for rapid-scan EPR. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigation of radical locations in various sesame seeds by CW EPR and 9-GHz EPR imaging.

Science.gov (United States)

Nakagawa, K; Hara, H

2015-01-01

We investigated the location of radical in various sesame seeds using continuous-wave (CW) electron paramagnetic resonance (EPR) and 9-GHz EPR imaging. CW EPR detected persistent radicals (single line) for various sesame seeds. The EPR linewidth of black sesame seeds was narrower than that of the irradiated white sesame seeds. A very small signal was detected for the white sesame seeds. Two-dimensional (2D) imaging using a 9-GHz EPR imager showed that radical locations vary for various sesame seeds. The paramagnetic species in black sesame seeds were located on the seed coat (skin) and in the hilum region. The signal with the highest intensity was obtained from the hilum part. A very low-intensity image was observed for the white sesame seeds. In addition, the 2D imaging of the irradiated white sesame seeds showed that free radicals were located throughout the entire seed. For the first time, CW EPR and 9-GHz EPR imaging showed the exact location of radical species in various sesame seeds.

Malevolent Governance, Intra-Group Conflict and the Paradox of the Plenty: An Experiment

Directory of Open Access Journals (Sweden)

Klarizze Anne Puzon

2015-12-01

Full Text Available Using a laboratory experiment, we behaviourally study the impact of a sudden increase in the common-pool size on within-group conflict, i.e., the paradox of the plenty. We also consider the potential role of governance in avoiding this paradox. In the first stage, a randomly-chosen leader of the group determines how much of the common-pool resource to protect from second-stage conflict. In the next stage, each group member allocates his private endowment between working or fighting for a share of the unprotected resource. We consider two treatments: anarchy (consisting of the second stage only and with a leader deciding in the first stage. We find that the existence of institutions is not always better than anarchy. This is aggravated when the resource size is higher. Group conflict (income decreases (increases only when leaders chose the strongest resource protection. When leaders are malevolent, i.e., they chose weak resource protection, outcomes are worse than when institutions are absent.

Quantitative EPR A Practitioners Guide

CERN Document Server

Eaton, Gareth R; Barr, David P; Weber, Ralph T

2010-01-01

This is the first comprehensive yet practical guide for people who perform quantitative EPR measurements. No existing book provides this level of practical guidance to ensure the successful use of EPR. There is a growing need in both industrial and academic research to provide meaningful and accurate quantitative EPR results. This text discusses the various sample, instrument and software related aspects required for EPR quantitation. Specific topics include: choosing a reference standard, resonator considerations (Q, B1, Bm), power saturation characteristics, sample positioning, and finally, putting all the factors together to obtain an accurate spin concentration of a sample.

Characterization of KCNE1 inside Lipodisq Nanoparticles for EPR Spectroscopic Studies of Membrane Proteins.

Science.gov (United States)

Sahu, Indra D; Zhang, Rongfu; Dunagan, Megan M; Craig, Andrew F; Lorigan, Gary A

2017-06-01

EPR spectroscopic studies of membrane proteins in a physiologically relevant native membrane-bound state are extremely challenging due to the complexity observed in inhomogeneity sample preparation and dynamic motion of the spin-label. Traditionally, detergent micelles are the most widely used membrane mimetics for membrane proteins due to their smaller size and homogeneity, providing high-resolution structure analysis by solution NMR spectroscopy. However, it is often difficult to examine whether the protein structure in a micelle environment is the same as that of the respective membrane-bound state. Recently, lipodisq nanoparticles have been introduced as a potentially good membrane mimetic system for structural studies of membrane proteins. However, a detailed characterization of a spin-labeled membrane protein incorporated into lipodisq nanoparticles is still lacking. In this work, lipodisq nanoparticles were used as a membrane mimic system for probing the structural and dynamic properties of the integral membrane protein KCNE1 using site-directed spin labeling EPR spectroscopy. The characterization of spin-labeled KCNE1 incorporated into lipodisq nanoparticles was carried out using CW-EPR titration experiments for the EPR spectral line shape analysis and pulsed EPR titration experiment for the phase memory time (T m ) measurements. The CW-EPR titration experiment indicated an increase in spectral line broadening with the addition of the SMA polymer which approaches close to the rigid limit at a lipid to polymer weight ratio of 1:1, providing a clear solubilization of the protein-lipid complex. Similarly, the T m titration experiment indicated an increase in T m values with the addition of SMA polymer and approaches ∼2 μs at a lipid to polymer weight ratio of 1:2. Additionally, CW-EPR spectral line shape analysis was performed on six inside and six outside the membrane spin-label probes of KCNE1 in lipodisq nanoparticles. The results indicated significant

ENDOR-Induced EPR of Disordered Systems: Application to X-Irradiated Alanine.

Science.gov (United States)

Kusakovskij, Jevgenij; Maes, Kwinten; Callens, Freddy; Vrielinck, Henk

2018-02-15

The electron paramagnetic resonance (EPR) spectra of radiation-induced radicals in organic solids are generally composed of multiple components that largely overlap due to their similar weak g anisotropy and a large number of hyperfine (HF) interactions. Such properties make these systems difficult to study using standard cw EPR spectroscopy even in single crystals. Electron-nuclear double-resonance (ENDOR) spectroscopy is a powerful and widely used complementary technique. In particular, ENDOR-induced EPR (EIE) experiments are useful for separating the overlapping contributions. In the present work, these techniques were employed to study the EPR spectrum of stable radicals in X-irradiated alanine, which is widely used in dosimetric applications. The principal values of all major proton HF interactions of the dominant radicals were determined by analyzing the magnetic field dependence of the ENDOR spectrum at 50 K, where the rotation of methyl groups is frozen. Accurate simulations of the EPR spectrum were performed after the major components were separated using an EIE analysis. As a result, new evidence in favor of the model of the second dominant radical was obtained.

Estimation of mean and median pO2 values for a composite EPR spectrum.

Science.gov (United States)

Ahmad, Rizwan; Vikram, Deepti S; Potter, Lee C; Kuppusamy, Periannan

2008-06-01

Electron paramagnetic resonance (EPR)-based oximetry is capable of quantifying oxygen content in samples. However, for a heterogeneous environment with multiple pO2 values, peak-to-peak linewidth of the composite EPR lineshape does not provide a reliable estimate of the overall pO2 in the sample. The estimate, depending on the heterogeneity, can be severely biased towards narrow components. To address this issue, we suggest a postprocessing method to recover the linewidth histogram which can be used in estimating meaningful parameters, such as the mean and median pO2 values. This information, although not as comprehensive as obtained by EPR spectral-spatial imaging, goes beyond what can be generally achieved with conventional EPR spectroscopy. Substantially shorter acquisition times, in comparison to EPR imaging, may prompt its use in clinically relevant models. For validation, simulation and EPR experiment data are presented.

The sensitivity analysis of tooth enamel to the absorbed dose for the application to EPR dosimetry

International Nuclear Information System (INIS)

Hong, Dae Seok; Lee, Kun Jai; Cho, Young Hwan

2002-01-01

Electron Paramagnetic Resonance (EPR) spectroscopy is one of the methods applicable to retrospective dosimetry. The retrospective dosimetry is a process that is a part of dose reconstruction for estimation of exposed dose occurred years before the estimation. Many techniques can be used to the retrospective dosimetry. As a physical method, EPR analysis of biological material measures the quantity of free radicals generated in the material from the interaction of radiation and material. Since the later 80s, in many countries, EPR dosimetry with tooth enamel has been studied and applied for the retrospective dosimetry. In the consideration of the biological materials for EPR dosimetry, human fingernail, hair, bone and tooth are generally considered. The tooth can be separated as enamel, dentine and cementum. Among the three parts, enamel shows the best sensitivity to the absorbed dose and is most widely used. In this study, the characteristics of tooth enamel for EPR dosimetry is examined and experimented. At the experiment, for easy separation, tooth was cut into 4 parts and then each part is treated by ultrasonic vibration in NaOH liquid to reduce mechanically induced noise in the corresponding signal. After the separation of the enamel from dentine, background EPR signal is measured and then radiation-induced EPR spectrum is estimated

The happiness paradox

NARCIS (Netherlands)

Bollen, Johan; Gonçalves, Bruno; Leemput, van de Ingrid; Ruan, Guangchen

2017-01-01

Most individuals in social networks experience a so-called Friendship Paradox: they are less popular than their friends on average. This effect may explain recent findings that widespread social network media use leads to reduced happiness. However the relation between popularity and happiness is

The EPR - technology for the 3rd millennium

International Nuclear Information System (INIS)

Bernstrauch, O.; Dubois, F.

2001-01-01

This paper is a story of a successful Franco-German co-operation: the EPR project. It is a rundown of the history of the EPR, before a decision is made to launch the lead-unit construction. The EPR is expected to progressively replace the existing nuclear power plants when they will reach the end of their service life. It integrates the latest technological advances, especially in safety and operational aspects and comprises more than 30 years operating experience. Thus, the EPR combines the qualities of its predecessors, the French N4 and the German Konvoi. The safety of the EPR was maximized both to prevent hypothetical accidents - even severe ones - and to reduce their consequences (corium spreading area, pre-stressed double containment with local liner, four-train safety systems...). The n+2 strategy (in the event of a problem with one train and even if a second train is undergoing maintenance, the remaining two are sufficient to perform the function) allows to perform maintenance during operation which leads consequently to short outage periods, highest availabilities and economical operation. Moreover, most of the EPR components are the result of mastered evolution. The reactor vessel, as a key element for the reactor service life, is designed to be in service for 60 years, the core is large (241 fuel elements instead of 205 in the N4 or 193 in the Konvoi) and the steam generators have higher efficiency. Along the same line, the core and core barrel design have been modified to allow a reduced uranium enrichment and the increase to 65 Gigawatt-day per metric-ton of the fuel discharge burn-up. Finally, the instrumentation and control systems minimize human error by giving the operators a grace period of at least 30 minutes to make decisions. (authors)

Using rapid scan EPR to improve the detection limit of quantitative EPR by more than one order of magnitude

OpenAIRE

Möser, J.; Lips, K.; Tseytlin, M.; Eaton, G.; Eaton, S.; Schnegg, A

2017-01-01

X band rapid scan EPR was implemented on a commercially available Bruker ELEXSYS E580 spectrometer. Room temperature rapid scan and continuous wave EPR spectra were recorded for amorphous silicon powder samples. By comparing the resulting signal intensities the feasibility of performing quantitative rapid scan EPR is demonstrated. For different hydrogenated amorphous silicon samples, rapid scan EPR results in signal to noise improvements by factors between 10 and 50. Rapid scan EPR is thus ca...

Medical application of EPR

International Nuclear Information System (INIS)

Eichhoff, Uwe; Hoefer, Peter

2015-01-01

Selected applications of continuous-wave EPR in medicine are reviewed. This includes detection of reactive oxygen and nitrogen species, pH measurements and oxymetry. Applications of EPR imaging are demonstrated on selected examples and future developments to faster imaging methods are discussed

EPR compared to international requirements (Mainly EUR)

International Nuclear Information System (INIS)

Broecker, B.

1996-01-01

A number of European Utilities have entered an agreement to write common requirements dedicated to future light water nuclear power plants to be built in Europe. The activities are known under the sign EUR (European Utilities Requirements). EPR, the future European Pressurized water Reactor, is the first installation of this type which will be operational from the year 2000 onwards, must fulfill the European requirements. EPR will serve as a test whether these requirements are realistic and well balanced. At the basic design stage of EPR, this paper concentrates on four main topics: the requirements which are new compared with existing reactors and which put a major challenge to the designer; the requirements today still open and the way they can be met by the EPR or not; the points for which already today the EPR special requirements exceed the EUR; the examples where the design of the EPR has given feedback which has led to a change of the EUR. EPR and EUR are different approaches to the reactor of the future. EUR is a set of requirements which leaves a flexibility to the designer while EPR is a real project which defines the technical solutions. EPR will fulfill the EUR and will at the same time serve as a test whether these requirements are realistic. EPR will also fulfill international requirements with minor changes. (J.S.). 7 figs

Rapid-scan EPR imaging.

Science.gov (United States)

Eaton, Sandra S; Shi, Yilin; Woodcock, Lukas; Buchanan, Laura A; McPeak, Joseph; Quine, Richard W; Rinard, George A; Epel, Boris; Halpern, Howard J; Eaton, Gareth R

2017-07-01

In rapid-scan EPR the magnetic field or frequency is repeatedly scanned through the spectrum at rates that are much faster than in conventional continuous wave EPR. The signal is directly-detected with a mixer at the source frequency. Rapid-scan EPR is particularly advantageous when the scan rate through resonance is fast relative to electron spin relaxation rates. In such scans, there may be oscillations on the trailing edge of the spectrum. These oscillations can be removed by mathematical deconvolution to recover the slow-scan absorption spectrum. In cases of inhomogeneous broadening, the oscillations may interfere destructively to the extent that they are not visible. The deconvolution can be used even when it is not required, so spectra can be obtained in which some portions of the spectrum are in the rapid-scan regime and some are not. The technology developed for rapid-scan EPR can be applied generally so long as spectra are obtained in the linear response region. The detection of the full spectrum in each scan, the ability to use higher microwave power without saturation, and the noise filtering inherent in coherent averaging results in substantial improvement in signal-to-noise relative to conventional continuous wave spectroscopy, which is particularly advantageous for low-frequency EPR imaging. This overview describes the principles of rapid-scan EPR and the hardware used to generate the spectra. Examples are provided of its application to imaging of nitroxide radicals, diradicals, and spin-trapped radicals at a Larmor frequency of ca. 250MHz. Copyright © 2017 Elsevier Inc. All rights reserved.

EPR spectroscopy at DNP conditions

International Nuclear Information System (INIS)

Heckmann, J.; Goertz, St.; Meyer, W.; Radtke, E.; Reicherz, G.

2004-01-01

In terms of dynamic nuclear polarization (DNP) studies and systematic target material research it is crucial to know the EPR lineshape of the DNP relevant paramagnetic centers. Therefore in Bochum an EPR spectrometer has been implemented into the 4 He evaporation DNP facility in order to perform EPR studies at DNP conditions (B=2.5 T, T=1 K). The spectrometer hardware and performance as well as first results are presented

EPR dosimetry of irradiated human teeth

International Nuclear Information System (INIS)

Rodas Duran, J.E.; Panzeri, H.; Mascarenhas, S.

1985-01-01

The determination of the absorbed radiation dose in man may be made by Electron Paramagnetic Resonance (EPR) spectroscopy of dental enamel. We analysed the EPR signals for dental enamel submitted to gamma radiation in doses between 1 Gy and 25 Gy. We conclude that independent of the type of tooth analysed there exists a linear relation between the EPR signals and the absorbed doses. These studies were extended to enamel irradiated with gamma rays and with X rays in doses between 0.1 Gy and 0.6 Gy. The graph of the intensity of the EPR signals as a function of the dose has a slope of 0.22. This calibration may be used to calculate the absorbed dose for humans from a measurement of the EPR signal from small samples of enamel taken from any permanent tooth. Finally we comment on some EPR studies of effects of radiation of milk teeth. (author)

Weinberg's nonlinear quantum mechanics and the Einstein-Podolsky-Rosen paradox

Science.gov (United States)

Polchinski, Joseph

1991-01-01

The constraints imposed on observables by the requirement that transmission not occur in the Einstein-Podolsky-Rosen (EPR) experiment are determined, leading to a different treatment of separated systems from that originally proposed by Weinberg (1989). It is found that forbidding EPR communication in nonlinear quantum mechanics necessarily leads to another sort of unusual communication: that between different branches of the wave function.

MDEP Common Position No EPR-01 - Common positions on the EPR instrumentation and controls design

International Nuclear Information System (INIS)

2010-01-01

The purpose of the EPR Working Group (EPRWG) of the Multinational Design Evaluation Program (MDEP) is to identify common positions among the regulators reviewing the EPR Instrumentation and Controls (I and C) Systems in order to: 1. Promote understanding of each country 's regulatory decisions and basis for the decisions, 2. Enhance communication among the members and with external stakeholders, 3. Identify areas where harmonization and convergence of regulations, standards, and guidance can be achieved or improved, and 4. Supports standardization of new reactor designs. Since January 2008, the EPR I and C Technical Expert Subgroup (TESG) members met five times to exchange information regarding their country 's review of the EPR I and C design. The EPR I and C TESG consists of regulators from China, Canada, Finland, France, the United Kingdom, and the United States. The information exchange includes presentation of each country 's review status and technical issues, sharing of guidance documents, and sharing of regulatory decision documents. The TESG focused on the following four core areas of the EPR I and C design: 1. I and C System Independence (particularly for data communications), 2. Level of Defense and Diversity (back-up systems), 3. Qualification/quality of digital platforms, 4. Categorization/classification of systems and functions. As meetings were conducted, some areas were emphasized more depending on the significance of the issues for each country. During the TESG interactions, it became apparent that there were aspects of the EPR design where the countries had common agreement. On November 2, 2009, three of the subgroup countries, France, Finland and the United Kingdom, issued a joint regulatory position on the EPR I and C design as result of the 'Groupe Permanent' meeting in France. This statement of common positions expands upon that joint regulatory position

Spin states of reduced fullerenes (C60 and C120O) by CW and pulsed EPR

International Nuclear Information System (INIS)

Boas, J.F.; Drew, S.C.; Pilbrow, J.R.; Boyd, P.D.W.; Paul, P.; Reed, C.A.; Sun, D.

2003-01-01

Full text: The ESTN (Electron Spin Transient Nutation) EPR (Electron Paramagnetic Resonance) experiments reported at Wagga 2002 showed that the spin states of the reduced fullerenes C 120 O (2-), C 120 O (3-) and C 120 O (4-) were S = 1, S = 1/2 and S = 1 respectively. Further experiments using CW (Continuous Wave) EPR have confirmed the results of Paul et al. and have now shown that these states are the ground states of these anions. In the case of C 60 (3-), the recent CW and ESTN EPR experiments have shown that the electronic ground state of this anion is S = 1/2. The observation of ground states of low multiplicity for these anions is contrary to expectations based on MO calculations and the application of Hund's rules. A series of CW EPR experiments on C 60 (3-) have shown that some previous results may need to be re-interpreted. This arises from the delineation of the effects of microwave power, modulation amplitude and frequency, sample temperature and freezing rate on the EPR spectrum which is the combination of a broad line, attributed to C 60 (3-), and a 'spike' attributed to C 120 O impurities and other oxygen related species. Our results cast doubt on the existence of Jahn-Teller effects at low temperatures and of a low-lying spin quartet excited state

EPR and TL correlation in some powdered Greek white marbles

International Nuclear Information System (INIS)

Baieetto, Vanessa; Villeneuve, Gerard; Guibert, Pierre; Schvoerer, Max

2000-01-01

Thermoluminescence of white powdered marble samples, chosen to display different EPR spectra, were studied. Two peaks at 280 deg. C and 360 deg. C can be observed among the TL glow curves while the EPR spectra exhibit two signals: the A signal with g perp =2.0038 and g par =2.0024 due to the SO - 3 centre and the B one with g 1 =2.0005; g 2 =2.0001; g 3 =1.9998 due to mechanical powder reduction (drilling). Owing to heating and simultaneous experiments, a correlation have been established: the 280 deg. C TL peak is associated to the A signal and thus to the SO - 3 centre and the 360 deg. C TL peak is caused by mechanical treatment corresponding to the B EPR signal

EPR and TL correlation in some powdered Greek white marbles.

Science.gov (United States)

Baïetto, V; Villeneuve, G; Guibert, P; Schvoerer, M

2000-02-01

Thermoluminescence of white powdered marble samples, chosen to display different EPR spectra, were studied. Two peaks at 280 degrees C and 360 degrees C can be observed among the TL glow curves while the EPR spectra exhibit two signals: the A signal with g perpendicular = 2.0038 and g parallel = 2.0024 due to the SO3- centre and the B one with g1 = 2.0005; g2 = 2.0001; g3 = 1.9998 due to mechanical powder reduction (drilling). Owing to heating and simultaneous experiments, a correlation have been established: the 280 degrees C TL peak is associated to the A signal and thus to the SO3- centre and the 360 degrees C TL peak is caused by mechanical treatment corresponding to the B EPR signal.

EPR Test with Photons and Kaons Analogies

CERN Document Server

Gisin, Nicolas

2001-01-01

We present a unified formalism describing EPR test using spin 1/2 particles, photons and kaons. This facilitates the comparison between existing experiments using photons and kaons. It underlines the similarities between birefringence and polarization dependent losses that affects experiments using optical fibers and mixing and decay that are intrinsic to the kaons. We also discuss the limitation these two characteristics impose on the testing of Bell's inequality.

Use of EPR to Solve Biochemical Problems

Science.gov (United States)

Sahu, Indra D.; McCarrick, Robert M.; Lorigan, Gary A.

2013-01-01

EPR spectroscopy is a very powerful biophysical tool that can provide valuable structural and dynamic information on a wide variety of biological systems. The intent of this review is to provide a general overview for biochemists and biological researchers on the most commonly used EPR methods and how these techniques can be used to answer important biological questions. The topics discussed could easily fill one or more textbooks; thus, we present a brief background on several important biological EPR techniques and an overview of several interesting studies that have successfully used EPR to solve pertinent biological problems. The review consists of the following sections: an introduction to EPR techniques, spin labeling methods, and studies of naturally occurring organic radicals and EPR active transition metal systems which are presented as a series of case studies in which EPR spectroscopy has been used to greatly further our understanding of several important biological systems. PMID:23961941

Krótka (pre)historia argumentu EPR

OpenAIRE

Tadeusz Pabjan

2010-01-01

The 1935 thought experiment of Einstein, Podolsky and Rosen is one of the most important episodes in the history of the dispute about the correct interpretation of quantum mechanics. The present paper deals with the origin of the EPR paper and discusses some other thought experiments that preceded the formulation of the Einstein-Podolsky-Rosen argument. Special attention is paid to the evolution of a simply photon-box experiment, which was devised by Einstein in 1930 and then modified by him ...

Isolation of EPR spectra and estimation of spin-states in two-component mixtures of paramagnets.

Science.gov (United States)

Chabbra, Sonia; Smith, David M; Bode, Bela E

2018-04-26

The presence of multiple paramagnetic species can lead to overlapping electron paramagnetic resonance (EPR) signals. This complication can be a critical obstacle for the use of EPR to unravel mechanisms and aid the understanding of earth abundant metal catalysis. Furthermore, redox or spin-crossover processes can result in the simultaneous presence of metal centres in different oxidation or spin states. In this contribution, pulse EPR experiments on model systems containing discrete mixtures of Cr(i) and Cr(iii) or Cu(ii) and Mn(ii) complexes demonstrate the feasibility of the separation of the EPR spectra of these species by inversion recovery filters and the identification of the relevant spin states by transient nutation experiments. We demonstrate the isolation of component spectra and identification of spin states in a mixture of catalyst precursors. The usefulness of the approach is emphasised by monitoring the fate of the chromium species upon activation of an industrially used precatalyst system.

Skew Projection of Echo-Detected EPR Spectra for Increased Sensitivity and Resolution

Science.gov (United States)

Bowman, Michael K.; Krzyaniak, Matthew D.; Cruce, Alex A.; Weber, Ralph T.

2013-01-01

The measurement of EPR spectra during pulsed EPR experiments is commonly accomplished by recording the integral of the electron spin echo as the applied magnetic field is stepped through the spectrum. This approach to echo-detected EPR spectral measurement (ED-EPR) limits sensitivity and spectral resolution and can cause gross distortions in the resulting spectra because some of the information present in the electron spin echo is discarded in such measurements. However, Fourier Transformation of echo shapes measured at a series of magnetic field values followed by skew projection onto either a magnetic field or resonance frequency axis can increase both spectral resolution and sensitivity without the need to trade one against the other. Examples of skew-projected spectra with single crystals, glasses and powders show resolution improvements as large as a factor of seven with sensitivity increases of as much as a factor of five. PMID:23644351

Meeting the next generation PWR safety requirements: The EPR Reactor

International Nuclear Information System (INIS)

Salhi, Othman

2008-01-01

The development process pursued the harmonization of technical solutions and the integration of all the lessons learned from earlier nuclear plants built by both vendors. As far as safety more specifically is concerned, the basic choice for the EPR was to adopt an evolutionary approach based on experience feedback from the reactors built by Areva, which at the time already amounted to nearly 100. This philosophy makes today's Areva EPR the natural descendant of the most advanced French N4 and German Konvoi power reactors currently in operation. EPR design choices affecting safety were motivated by a continuous quest for higher levels of safety. A two-fold approach was followed: 1. improvement of the measures aimed at further reducing the already very low probability of core melt 2. incorporation of measures aimed at further limiting the consequences of a severe accident, in the knowledge that its probability of occurrence has been considerably reduced. Through its filiations with French N4 and German Konvoi power reactors, the EPR benefits from the uninterrupted, evolutionary innovation process that has supported the development of PWRs since their introduction into the market place. This is especially true for safety where the EPR brings a unique combination of both tried and tested and innovative features that further improve the prevention of severe accidents and their mitigation

EPR and TL correlation in some powdered Greek white marbles

Energy Technology Data Exchange (ETDEWEB)

Baieetto, Vanessa E-mail: crpaa@montaigne.u-bordeaux.fr; Villeneuve, Gerard; Guibert, Pierre; Schvoerer, Max

2000-02-01

Thermoluminescence of white powdered marble samples, chosen to display different EPR spectra, were studied. Two peaks at 280 deg. C and 360 deg. C can be observed among the TL glow curves while the EPR spectra exhibit two signals: the A signal with g{sub perp}=2.0038 and g{sub par} =2.0024 due to the SO{sup -}{sub 3} centre and the B one with g{sub 1}=2.0005; g{sub 2}=2.0001; g{sub 3}=1.9998 due to mechanical powder reduction (drilling). Owing to heating and simultaneous experiments, a correlation have been established: the 280 deg. C TL peak is associated to the A signal and thus to the SO{sup -}{sub 3} centre and the 360 deg. C TL peak is caused by mechanical treatment corresponding to the B EPR signal.

EPR studies of melanin from Cladosporium cladosporioides

International Nuclear Information System (INIS)

Pilawa, B.; Buszman, E.; Latocha, M.; Wilczok, T.

1996-01-01

Free radical properties of Cladosporium cladosporioides mycelium and melanin, and synthetic eumelanin and pheomelanin were studied by electron paramagnetic resonance method. Single EPR line and complex EPR spectrum with hyperfine splitting were measured for model DOPA-melanin and cysteinyldopa-melanin, respectively. EPR spectra of Cladosporium cladosporioides samples and pheomelanin show the same character. The concentration of paramagnetic centers in melanins isolated from Cladosporium cladosporioides is considerably higher than that of crude mycelium, whereas the EPR line widths are lower for mycelium than for melanin samples. For all analyzed samples the increase of EPR signals intensity with the increase of microwave power, and the decrease of intensities after saturation were observed the low values of microwave power sufficient for EPR lines saturation demonstrate that the spin-lattice relaxation times of unpaired electrons in melanins are long. (author)

Middle ground approach to paradox: Within- and between-culture examination of the creative benefits of paradoxical frames.

Science.gov (United States)

Leung, Angela K-Y; Liou, Shyhnan; Miron-Spektor, Ella; Koh, Brandon; Chan, David; Eisenberg, Roni; Schneider, Iris

2018-03-01

Thriving in increasingly complex and ambiguous environments requires creativity and the capability to reconcile conflicting demands. Recent evidence with Western samples has suggested that paradoxical frames, or mental templates that encourage individuals to recognize and embrace contradictions, could produce creative benefits. We extended the timely, but understudied, topic by studying the nuances of for whom and why creative advantages of paradoxical frames emerge. We suggest that people endorsing a middle ground approach are less likely to scrutinize conflict and reconcile with integrative solutions, thus receiving less creative benefits of paradoxical frames. Five studies that examined individual and cultural differences in middle ground endorsement support our theory. Study 1 found that paradoxical frames increased creativity, but failed to replicate that experienced conflict mediated the relationship in a Taiwanese sample. In both within- and between-culture analysis, we showed that the creative advantages of thinking paradoxically and experiencing conflict emerged among individuals who endorse lower (vs. higher) levels of middle ground (Study 2) and among Israelis whose culture predominantly endorses middle ground strategy less, but not among Singaporeans whose culture predominantly endorses middle ground more (Study 3). Study 4 further demonstrated the causal role of middle ground in the paradox-conflict-creativity link. To answer "why," Study 5 situationally induced integrative complex thinking that sets distinctions and forms syntheses among contradictory elements, and found that low endorsers of middle ground performed more creatively when they engaged integrative complex thinking to cope with paradoxes. This program of studies offers important insights on harnessing paradoxical experiences to catalyze creativity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

EPR in B physics and elsewhere

International Nuclear Information System (INIS)

Lipkin, H.J.; Tel Aviv Univ.; Argonne National Lab., IL

1997-01-01

The application of Einstein-Podolsky-Rosen correlations in Υ(4s) → B anti B decays to research in CP violation is the first and probably only use of EPR as a technique for research in new physics. Elsewhere highly sophisticated EPR projects question EPR and test its predictions to look for violations of quantum mechanics, hidden variables, Bell''s inequalities, etc

Navigating Instructional Dialectics: Empirical Exploration of Paradox in Teaching

Science.gov (United States)

Thompson, Blair; Rudick, C. Kyle; Kerssen-Griep, Jeff; Golsan, Kathryn

2018-01-01

Navigating contradiction represents an integral part of the teaching process. While educational literature has discussed the paradoxes that teachers experience in the classroom, minimal empirical research has analyzed the strategies teachers employ to address these paradoxes. Using relational dialectics as a theoretical framework for understanding…

Use of the Frank sequence in pulsed EPR

DEFF Research Database (Denmark)

Tseitlin, Mark; Quine, Richard W.; Eaton, Sandra S.

2011-01-01

The Frank polyphase sequence has been applied to pulsed EPR of triarylmethyl radicals at 256MHz (9.1mT magnetic field), using 256 phase pulses. In EPR, as in NMR, use of a Frank sequence of phase steps permits pulsed FID signal acquisition with very low power microwave/RF pulses (ca. 1.5m......W in the application reported here) relative to standard pulsed EPR. A 0.2mM aqueous solution of a triarylmethyl radical was studied using a 16mm diameter cross-loop resonator to isolate the EPR signal detection system from the incident pulses. Keyword: Correlation spectroscopy,Multi-pulse EPR,Low power pulses,NMR,EPR...

High field high frequency EPR techniques and their application to single molecule magnets

International Nuclear Information System (INIS)

Edwards, R.S.; Hill, S.; Goy, P.; Wylde, R.; Takahashi, S.

2004-01-01

We present details of a new high-field/high-frequency EPR technique, and its application to measurements of single-molecule magnets (SMMs). By using a quasi-optical set-up and microwave sources covering a continuous frequency range from 170 to 600 GHz, in conjunction with a millimetre-wave vector network analyser, we are able to measure EPR to high magnetic fields. For example, a g=2 system will exhibit EPR at about 14 T at a frequency of 400 GHz. We illustrate the technique by presenting details of recent high-frequency experiments on several SMMs which are variations of the well-known SMM Mn 12 -Ac. This material has a spin ground state of S=10 and large uniaxial anisotropy, hence frequencies above 300 GHz are required in order to observe EPR from the ground state

Entanglement indicators for quantum optical fields: three-mode multiport beamsplitters EPR interference experiments

Science.gov (United States)

Ryu, Junghee; Marciniak, Marcin; Wieśniak, Marcin; Żukowski, Marek

2018-04-01

We generalize a new approach to entanglement conditions for light of undefined photons numbers given in Żukowski et al (2017 Phys. Rev. A 95 042113) for polarization correlations to a broader family of interferometric phenomena. Integrated optics allows one to perform experiments based upon multiport beamsplitters. To observe entanglement effects one can use multi-mode parametric down-conversion emissions. When the structure of the Hamiltonian governing the emissions has (infinitely) many equivalent Schmidt decompositions into modes (beams), one can have perfect EPR-like correlations of numbers of photons emitted into ‘conjugate modes’ which can be monitored at spatially separated detection stations. We provide entanglement conditions for experiments involving three modes on each side, and three-input-three-output multiport beamsplitters, and show their violations by bright squeezed vacuum states. We show that a condition expressed in terms of averages of observed rates is a much better entanglement indicator than a related one for the usual intensity variables. Thus, the rates seem to emerge as a powerful concept in quantum optics, especially for fields of undefined intensities.

Digitally generated excitation and near-baseband quadrature detection of rapid scan EPR signals.

Science.gov (United States)

Tseitlin, Mark; Yu, Zhelin; Quine, Richard W; Rinard, George A; Eaton, Sandra S; Eaton, Gareth R

2014-12-01

The use of multiple synchronized outputs from an arbitrary waveform generator (AWG) provides the opportunity to perform EPR experiments differently than by conventional EPR. We report a method for reconstructing the quadrature EPR spectrum from periodic signals that are generated with sinusoidal magnetic field modulation such as continuous wave (CW), multiharmonic, or rapid scan experiments. The signal is down-converted to an intermediate frequency (IF) that is less than the field scan or field modulation frequency and then digitized in a single channel. This method permits use of a high-pass analog filter before digitization to remove the strong non-EPR signal at the IF, that might otherwise overwhelm the digitizer. The IF is the difference between two synchronized X-band outputs from a Tektronix AWG 70002A, one of which is for excitation and the other is the reference for down-conversion. To permit signal averaging, timing was selected to give an exact integer number of full cycles for each frequency. In the experiments reported here the IF was 5kHz and the scan frequency was 40kHz. To produce sinusoidal rapid scans with a scan frequency eight times IF, a third synchronized output generated a square wave that was converted to a sine wave. The timing of the data acquisition with a Bruker SpecJet II was synchronized by an external clock signal from the AWG. The baseband quadrature signal in the frequency domain was reconstructed. This approach has the advantages that (i) the non-EPR response at the carrier frequency is eliminated, (ii) both real and imaginary EPR signals are reconstructed from a single physical channel to produce an ideal quadrature signal, and (iii) signal bandwidth does not increase relative to baseband detection. Spectra were obtained by deconvolution of the reconstructed signals for solid BDPA (1,3-bisdiphenylene-2-phenylallyl) in air, 0.2mM trityl OX63 in water, 15 N perdeuterated tempone, and a nitroxide with a 0.5G partially-resolved proton

Genesis of Karl Popper's EPR-like experiment and its resonance amongst the physics community in the 1980s

Science.gov (United States)

Del Santo, Flavio

2018-05-01

I present the reconstruction of the involvement of Karl Popper in the community of physicists concerned with foundations of quantum mechanics, in the 1980s. At that time Popper gave active contribution to the research in physics, of which the most significant is a new version of the EPR thought experiment, alleged to test different interpretations of quantum mechanics. The genesis of such an experiment is reconstructed in detail, and an unpublished letter by Popper is reproduced in the present paper to show that he formulated his thought experiment already two years before its first publication in 1982. The debate stimulated by the proposed experiment as well as Popper's role in the physics community throughout 1980s is here analysed in detail by means of personal correspondence and publications.

EPR STUDIES OF THERMALLY STERILIZED VASELINUM ALBUM.

Science.gov (United States)

Ramos, Paweł; Pilawa, Barbara

2015-01-01

Electron paramagnetic resonance (EPR) spectroscopy was used for examination of free radicals in thermally treated vaselinum album (VA). Thermal treatment in hot air as sterilization process was tested. Conditions of thermal sterilization were chosen according to the pharmaceutical norms. Vaselinum album was heated at the following conditions (T--temperature, t--time): T = 160°C and t = 120 min, T = 170°C and t = 60 min and T = 180°C and t = 30 min. The aim of this work was to determine concentration and free radical properties of thermally sterilized VA. EPR analysis for VA was done 15 min after sterilization. EPR measurements were done at room temperature. EPR spectra were recorded in the range of microwave power of 2.2-70 mW. g-Factor, amplitudes (A) and line width (ΔBpp) of the spectra were determined. The shape of the EPR spectra was analyzed. Free radical concentration (N) in the heated samples was determined. EPR spectra were not obtained for the non heated VA. EPR spectra were detected for all thermally sterilized samples. The spectra revealed complex character, their asymmetry depends on microwave power. The lowest free radicals concentration was found for the VA sterilized at 180°C during 30 min. EPR spectroscopy is proposed as the method useful for optimization of sterilization process of drugs.

Pharmaceutical applications of in vivo EPR

International Nuclear Information System (INIS)

Maeder, K.

1998-01-01

The aim of this article is to discuss the applications of in vivo EPR in the field of pharmacy. In addition to direct detection of free radical metabolites and measurement of oxygen, EPR can be used to characterize the mechanisms of drug release from biodegradable polymers. Unique information about drug concentration, the microenvironment (viscosity, polarity, pH) and biodistribution (by localized measurement or EPR Imaging) can be obtained. (author)

Experimental test of Bell's inequality with a proton pair and quantum nonlocality

International Nuclear Information System (INIS)

Sakai, Hideyuki; Saito, Takaaki

2009-01-01

One of the most profound feature of quantum mechanics is the non-locality of entangled system. Einstein-Podolsky-Rosen (EPR) criticized this non-locality from the classical view point, realistic local theory. This criticism is known as the EPR paradox which has been thought as a philosophical argument between Copenhagen interpretation and EPR rather than the experimental issue. About 30 years later, John Bell found the inequality which is amenable to experiments. We succeeded to measure the spin correlation of an entangled proton pair in high accuracy which disagrees with Bell's inequality and confirmed the nonlocality of quantum mechanics in the massive Fermion pair. This short article introduces our experiment. The difference between present experiment and photon experiments is briefly mentioned. (author)

Contribution of Harold M. Swartz to In Vivo EPR and EPR Dosimetry

International Nuclear Information System (INIS)

Gallez, Bernard

2016-01-01

In 2015, we are celebrating half a century of research in the application of Electron Paramagnetic Resonance (EPR) as a biodosimetry tool to evaluate the dose received by irradiated people. During the EPR Biodose 2015 meeting, a special session was organized to acknowledge the pioneering contribution of Harold M. (Hal) Swartz in the field. The article summarizes his main contribution in physiology and medicine. Four emerging themes have been pursued continuously along his career since its beginning: (1) radiation biology; (2) oxygen and oxidation; (3) measuring physiology in vivo; and (4) application of these measurements in clinical medicine. The common feature among all these different subjects has been the use of magnetic resonance techniques, especially EPR. In this article, you will find an impressionist portrait of Hal Swartz with the description of the 'making of' this pioneer, a time-line perspective on his career with the creation of three National Institutes of Health-funded EPR centers, a topic-oriented perspective on his career with a description of his major contributions to Science, his role as a mentor and his influence on his academic children, his active role as founder of scientific societies and organizer of scientific meetings, and the well-deserved international recognition received so far. (author)

The inner containment of an EPR trademark pressurized water reactor

Energy Technology Data Exchange (ETDEWEB)

Ostermann, Dirk; Krumb, Christian; Wienand, Burkhard [AREVA GmbH, Offenbach (Germany)

2014-08-15

On February 12, 2014 the containment pressure and subsequent leak tightness tests on the containment of the Finnish Olkiluoto 3 EPR trademark reactor building were completed successfully. The containment of an EPR trademark pressurized water reactor consists of an outer containment to protect the reactor building against external hazards (such as airplane crash) and of an inner containment that is subjected to internal overpressure and high temperature in case of internal accidents. The current paper gives an overview of the containment structure, the design criteria, the validation by analyses and experiments and the containment pressure test.

EPR spectroscopic investigation of psoriatic finger nails.

Science.gov (United States)

Nakagawa, Kouichi; Minakawa, Satoko; Sawamura, Daisuke

2013-11-01

Nail lesions are common features of psoriasis and found in almost half of the patients. However, there is no feasible spectroscopic method evaluating changes and severity of nail psoriasis. EPR (electron paramagnetic resonance) might be feasible for evaluating nail conditions in the patients of psoriasis. Finger nails of five cases with nail psoriasis, (three females and two males) were examined. Nail samples were subjected to the EPR assay. The small piece of the finger nail (1.5 × 5 mm(2)) was incubated in ~50 μM 5-DSA (5-doxylstearic acid) aqueous solutions for about 60 min at 37°C. After rinsing and wiping off the excess 5-DSA solution, the nail samples were measured by EPR. EPR spectra were analyzed using the intensity ratio (Fast/Slow) of the two motions at the peaks of the lower magnetic field. We observed two distinguishable sites on the basis of the EPR results. In addition, the modern EPR calculation was performed to analyze the spectra obtained. The nail psoriasis-related region is 2~3 times higher than that of the control. The present EPR results show that there are two distinguishable sites in the nail. In the case of nail psoriasis, the fragile components are 2~3 times more than those of the control. Thus, the EPR method is thought to be a novel and reliable method of evaluating the nail psoriasis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

EPR dosimetry with tooth enamel: A review

International Nuclear Information System (INIS)

Fattibene, Paola; Callens, Freddy

2010-01-01

When tooth enamel is exposed to ionizing radiation, radicals are formed, which can be detected using electron paramagnetic resonance (EPR) techniques. EPR dosimetry using tooth enamel is based on the (presumed) correlation between the intensity or amplitude of some of the radiation-induced signals with the dose absorbed in the enamel. In the present paper a critical review is given of this widely applied dosimetric method. The first part of the paper is fairly fundamental and deals with the main properties of tooth enamel and some of its model systems (e.g., synthetic apatites). Considerable attention is also paid to the numerous radiation-induced and native EPR signals and the radicals responsible for them. The relevant methods for EPR detection, identification and spectrum analyzing are reviewed from a general point of view. Finally, the needs for solid-state modelling and studies of the linearity of the dose response are investigated. The second part is devoted to the practical implementation of EPR dosimetry using enamel. It concerns specific problems of preparation of samples, their irradiation and spectrum acquisition. It also describes how the dosimetric signal intensity and dose can be retrieved from the EPR spectra. Special attention is paid to the energy dependence of the EPR response and to sources of uncertainties. Results of and problems encountered in international intercomparisons and epidemiological studies are also dealt with. In the final section the future of EPR dosimetry with tooth enamel is analyzed.

Immigration and psychotic experiences in the United States: Another example of the epidemiological paradox?

Science.gov (United States)

Oh, Hans; Abe, Jennifer; Negi, Nalini; DeVylder, Jordan

2015-10-30

In Europe, it is widely established that immigration increases risk for psychotic disorder. However, research has yet to confirm this association in the United States, where immigrants paradoxically report better health status than their native-born counterparts. Further, few studies have examined this topic with respect to sub-threshold psychotic experiences, which are more common than psychotic disorders in the general population. This study analyzes the (1) National Comorbidity Survey-Replication, (2) the National Latino and Asian American Survey, and (3) the National Survey of American Life, in order to determine whether generation status had any impact on risk for lifetime and 12-month PE, and whether these associations vary across racial/ethnic groups, adjusting for demographic variables and socioeconomic status. We found an absence of an immigration effect on PE across various ethnic groups and across various geographic areas, and found that immigration is actually protective among Latinos, supporting the idea that the epidemiological paradox extends to the psychosis phenotype. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Unveiling consumer's privacy paradox behaviour in an economic exchange.

Science.gov (United States)

Motiwalla, Luvai F; Li, Xiao-Bai

2016-01-01

Privacy paradox is of great interest to IS researchers and firms gathering personal information. It has been studied from social, behavioural, and economic perspectives independently. However, prior research has not examined the degrees of influence these perspectives contribute to the privacy paradox problem. We combine both economic and behavioural perspectives in our study of the privacy paradox with a price valuation of personal information through an economic experiment combined with a behavioural study on privacy paradox. Our goal is to reveal more insights on the privacy paradox through economic valuation on personal information. Results indicate that general privacy concerns or individual disclosure concerns do not have a significant influence on the price valuation of personal information. Instead, prior disclosure behaviour in specific scenario, like with healthcare providers or social networks, is a better indicator of consumer price valuations.

Linear optics implementation of weak values in Hardy's paradox

International Nuclear Information System (INIS)

Ahnert, S.E.; Payne, M.C.

2004-01-01

We propose an experimental setup for the implementation of weak measurements in the context of the gedanken experiment known as Hardy's paradox. As Aharonov et al. [Y. Aharonov, A. Botero, S. Popescu, B. Reznik, and J. Tollaksen, Phys. Lett. A301, 130 (2002)] showed, these weak values form a language with which the paradox can be resolved. Our analysis shows that this language is indeed consistent and experimentally testable. It also reveals exactly how a combination of weak values can give rise to an apparently paradoxical result

The experience curve, option value, and the energy paradox

International Nuclear Information System (INIS)

Ansar, Jasmin; Sparks, Roger

2009-01-01

This paper develops a model to explain the 'energy paradox,' the inclination of households and firms to require very high internal rates of return in order to make energy-saving investments. The model abstracts from many features of such investments to focus on their irreversibility, the uncertainty of their future payoff streams, and the investor's anticipation of future technological advance. In this setting, the decision to invest in energy-saving technology can be delayed, providing option value. In addition, delay allows the potential investor to cash in on future experience-curve effects: With the passage of time, firms gain practical knowledge in producing and installing the energy-saving technology, enabling them to reduce the technology's up-front cost per unit of energy saved. We incorporate these fundamentals into a stochastic model where the investment's discounted benefits follow geometric Brownian motion. To demonstrate the model's capabilities, we generate simulation results for photovoltaic systems that highlight the experience-curve effect as a fundamental reason why households and firms delay making energy-saving investments until internal rates of return exceed values of 50% and higher, consistent with observations in the economics literature. We also explore altruistic motivations for energy conservation and the model's implications for both 'additionality' and the design of energy-conservation policy

Validating and analyzing EPR hyperfine coupling constants with density functional theory

DEFF Research Database (Denmark)

Hedegård, Erik D.; Kongsted, Jacob; Sauer, Stephan P. A.

2013-01-01

Electron Paramagnetic Resonance (EPR) is a central spectroscopic technique for compounds with non-zero spin. The effective parameters from the EPR spin-Hamiltonian can today be calculated from rst principles using quantum chemical methods. We focus here on the hyperne coupling tensor, A, which....... Unfortunately both organometallic and traditional coordination complexes show a completely different behavior, where the core contributions to AKiso either are comparable (“class 2”) or far exceed (“class 3”) the contributions from the frontier orbitals. Agreement with experiment can for these complexes only...

Probing Microenvironment in Ionic Liquids by Time-Resolved EPR of Photoexcited Triplets.

Science.gov (United States)

Ivanov, M Yu; Veber, S L; Prikhod'ko, S A; Adonin, N Yu; Bagryanskaya, E G; Fedin, M V

2015-10-22

Unusual physicochemical properties of ionic liquids (ILs) open vistas for a variety of new applications. Herewith, we investigate the influence of microviscosity and nanostructuring of ILs on spin dynamics of the dissolved photoexcited molecules. We use two most common ILs [Bmim]PF6 and [Bmim]BF4 (with its close analogue [C10mim]BF4) as solvents and photoexcited Zn tetraphenylporphyrin (ZnTPP) as a probe. Time-resolved electron paramagnetic resonance (TR EPR) is employed to investigate spectra and kinetics of spin-polarized triplet ZnTPP in the temperature range 100-270 K. TR EPR data clearly indicate the presence of two microenvironments of ZnTPP in frozen ILs at 100-200 K, being manifested in different spectral shapes and different spin relaxation rates. For one of these microenvironments TR EPR data is quite similar to those obtained in common frozen organic solvents (toluene, glycerol, N-methyl-2-pyrrolidone). However, the second one favors the remarkably slow relaxation of spin polarization, being much longer than in the case of common solvents. Additional experiments using continuous wave EPR and stable nitroxide as a probe confirmed the formation of heterogeneities upon freezing of ILs and complemented TR EPR results. Thus, TR EPR of photoexcited triplets can be effectively used for probing heterogeneities and nanostructuring in frozen ILs. In addition, the increase of polarization lifetime in frozen ILs is an interesting finding that might allow investigation of short-lived intermediates inaccessible otherwise.

Contribution of Harold M. Swartz to In Vivo EPR and EPR Dosimetry.

Science.gov (United States)

Gallez, Bernard

2016-12-01

In 2015, we are celebrating half a century of research in the application of Electron Paramagnetic Resonance (EPR) as a biodosimetry tool to evaluate the dose received by irradiated people. During the EPR Biodose 2015 meeting, a special session was organized to acknowledge the pioneering contribution of Harold M. (Hal) Swartz in the field. The article summarizes his main contribution in physiology and medicine. Four emerging themes have been pursued continuously along his career since its beginning: (1) radiation biology; (2) oxygen and oxidation; (3) measuring physiology in vivo; and (4) application of these measurements in clinical medicine. The common feature among all these different subjects has been the use of magnetic resonance techniques, especially EPR. In this article, you will find an impressionist portrait of Hal Swartz with the description of the 'making of' this pioneer, a time-line perspective on his career with the creation of three National Institutes of Health-funded EPR centers, a topic-oriented perspective on his career with a description of his major contributions to Science, his role as a mentor and his influence on his academic children, his active role as founder of scientific societies and organizer of scientific meetings, and the well-deserved international recognition received so far. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Characterization of Melanin Radicals in Paraffin-embedded Malignant Melanoma and Nevus Pigmentosus Using X-band EPR and EPR Imaging.

Science.gov (United States)

Nakagawa, Kouichi; Minakawa, Satoko; Sawamura, Daisuke; Hara, Hideyuki

2017-01-01

Continuous wave electron paramagnetic resonance (CW EPR) and X-band (9 GHz) EPR imaging (EPRI) were used to nondestructively investigate the possible differentiation between malignant melanoma (MM) and nevus pigmentosus (NP) melanin radicals in paraffin-embedded specimens. The EPR spectra of both samples were analyzed using linewidth, spectral pattern, and X-band EPRI. The CW-EPR spectra of the MM showed an additional signal overlap. Eumelanin- and pheomelanin-related radicals were observed in the MM specimens. The EPR results revealed that the peak-to-peak linewidths (ΔH pp ) of paraffin-embedded MM and NP samples were 0.65 ± 0.01 and 0.69 ± 0.01 mT, respectively. The g-value was 2.005 for both samples. Moreover, the two-dimensional (2D) EPRI of the MM showed different signal intensities at the different tumor stages, unlike the NP, which displayed fewer variations in signal intensity. Thus, the present results suggest that EPR and 2D EPRI can be useful for characterization of the two melanin radicals in the MM and for determination of their size and concentration.

EPR meeting international safety standards with margin

International Nuclear Information System (INIS)

Mazurkiewicz, S.M.; Brauns, J.; Blombach, J.

2005-01-01

The EPR provides technology that offers a solution to the market's need for safe, economic power. The EPR was originally developed through a joint effort between Framatome ANP and Siemens by incorporating the best technological features from the French and German nuclear reactor fleets into a cost-competitive product capable of international licensing. As such, the EPR is a global product with commercial units currently being built in Finland at the Olkiluoto site, and planned for France, at the Flamanville site. Framatome ANP has recently proposed four EPR units to China in response to a request for vendor bids. In addition, Framatome ANP has announced their intent to pursue design certification with the United States Nuclear Regulatory Commission (NRC). This paper discusses how EPR's innovative safety philosophy ensures compliance with international safety standards for advanced light-water reactors (ALWRs). (author)

EPR meeting international safety standards with margin

International Nuclear Information System (INIS)

Mazurkiewicz, S.M.; Brauns, J.; Blombach, J.

2005-01-01

The EPR provides technology that offers a solution to the market's need for safe, economic power. The EPR was originally developed through a joint effort between Framatome ANP and Siemens by incorporating the best technological features from the French and German nuclear reactor fleets into a cost-competitive product capable of international licensing. As such, the EPR is a global product with commercial units currently being built in Finland at the Olkiluoto site, and planned for France, at the Flamanville site. Framatome ANP has recently proposed four EPR units to China in response to a request for vendor bids. In addition, Framatome ANP has announced their intent to pursue design certification in with the United States Nuclear Regulatory Commission (NRC). This paper discusses how EPR's innovative safety philosophy ensures compliance with international safety standards for advanced light-water reactors (ALWRs). (author)

Colloquium: The Einstein-Podolsky-Rosen paradox: From concepts to applications

DEFF Research Database (Denmark)

Reid, M.; Drummond, P.; Bowen, W.

2009-01-01

amplifier and optical fiber quantum soliton experiments. Current proposals for extending EPR experiments to massive-particle systems are discussed, including spin squeezing, atomic position entanglement, and quadrature entanglement in ultracold atoms. Finally, applications of this technology to quantum key...

Ion Channel Conformation and Oligomerization Assessment by Site-Directed Spin Labeling and Pulsed-EPR.

Science.gov (United States)

Pliotas, Christos

2017-01-01

Mechanosensitive (MS) ion channels are multimeric integral membrane proteins that respond to increased lipid bilayer tension by opening their nonselective pores to release solutes and relieve increased cytoplasmic pressure. These systems undergo major conformational changes during gating and the elucidation of their mechanism requires a deep understanding of the interplay between lipids and proteins. Lipids are responsible for transmitting lateral tension to MS channels and therefore play a key role in obtaining a molecular-detail model for mechanosensation. Site-directed spin labeling combined with electron paramagnetic resonance (EPR) spectroscopy is a powerful spectroscopic tool in the study of proteins. The main bottleneck for its use relates to challenges associated with successful isolation of the protein of interest, introduction of paramagnetic labels on desired sites, and access to specialized instrumentation and expertise. The design of sophisticated experiments, which combine a variety of existing EPR methodologies to address a diversity of specific questions, require knowledge of the limitations and strengths, characteristic of each particular EPR method. This chapter is using the MS ion channels as paradigms and focuses on the application of different EPR techniques to ion channels, in order to investigate oligomerization, conformation, and the effect of lipids on their regulation. The methodology we followed, from the initial strategic selection of mutants and sample preparation, including protein purification, spin labeling, reconstitution into lipid mimics to the complete set-up of the pulsed-EPR experiments, is described in detail. © 2017 Elsevier Inc. All rights reserved.

Pulsed-High Field/High-Frequency EPR Spectroscopy

Science.gov (United States)

Fuhs, Michael; Moebius, Klaus

Pulsed high-field/high-frequency electron paramagnetic resonance (EPR) spectroscopy is used to disentangle many kinds of different effects often obscured in continuous wave (cw) EPR spectra at lower magnetic fields/microwave frequencies. While the high magnetic field increases the resolution of G tensors and of nuclear Larmor frequencies, the high frequencies allow for higher time resolution for molecular dynamics as well as for transient paramagnetic intermediates studied with time-resolved EPR. Pulsed EPR methods are used for example for relaxation-time studies, and pulsed Electron Nuclear DOuble Resonance (ENDOR) is used to resolve unresolved hyperfine structure hidden in inhomogeneous linewidths. In the present article we introduce the basic concepts and selected applications to structure and mobility studies on electron transfer systems, reaction centers of photosynthesis as well as biomimetic models. The article concludes with an introduction to stochastic EPR which makes use of an other concept for investigating resonance systems in order to increase the excitation bandwidth of pulsed EPR. The limited excitation bandwidth of pulses at high frequency is one of the main limitations which, so far, made Fourier transform methods hardly feasible.

Electron paramagnetic resonance (EPR) in medical dosimetry

International Nuclear Information System (INIS)

Schauer, David A.; Iwasaki, Akinori; Romanyukha, Alexander A.; Swartz, Harold M.; Onori, Sandro

2006-01-01

This paper describes the fundamentals of electron paramagnetic resonance (EPR) and its application to retrospective measurements of clinically significant doses of ionizing radiation. X-band is the most widely used in EPR dosimetry because it represents a good compromise between sensitivity, sample size and water content in the sample. Higher frequency bands (e.g., W and Q) provide higher sensitivity, but they are also greatly influenced by water content. L and S bands can be used for EPR measurements in samples with high water content but they are less sensitive than X-band. Quality control for therapeutic radiation facilities using X-band EPR spectrometry of alanine is also presented

EPR investigation of some gamma-irradiated medicines

International Nuclear Information System (INIS)

Aleksieva, Katerina; Yordanov, Nicola

2016-01-01

The results of EPR studies on three medical tablets – Galanthamine, Cytisine and Tribulus terrestris before and after gamma-irradiation are reported. Before irradiation Galanthamine and Cytisine tablets are EPR silent, whereas Tribulus terrestris show a broad singlet line with g factor 2.2084±0.002. The same spectrum is recorded after irradiation. After gamma-sterilization, however, Galanthamine and Cytisine tablets exhibit a typical EPR spectrum due to gamma induced free radicals in lactose used as an excipient. These stable free radicals can be used for identification of radiation processing for a long time after it. Key words: medical tablets, gamma-irradiation, EPR

Regulatory aspects of Olkiluoto 3 nuclear power plant (EPR-1600) (Draft, 12 Sept. 2005)

International Nuclear Information System (INIS)

Sandberg, J.; Tiippana, P.

2005-01-01

A 1600 MWe European Pressurized Water Reactor (EPR) supplied by the Framatome ANP - Siemens Consortium is under construction at the Olkiluoto site in Finland. Current international safety requirements and especially French and German operating experience have been applied in the design. Finnish requirements and operating experience have also been applied, especially regarding site-specific features. Severe accidentmanagement and protection against a collision of a large passenger airplane are implemented in the plant design. The plant safety features, licensing procedure, Finnish regulatory requirements, changes to the original EPR design, project quality management and regulatory control are discussed. (author)

Active or passive systems? The EPR approach

International Nuclear Information System (INIS)

Bonhomme, N.; Py, J.P.

1996-01-01

In attempting to review how EPR is contemplated to meet requirements applicable to future nuclear power plants, the authors indicate where they see the markets and the corresponding unit sizes for the EPR which is a generic key factor for competitiveness. There are no reason in industrialized countries, other than USA (where the investment and amortizing practices under control by Public Utility Commission are quite particular), not to build future plants in the 1000 to 1500 MWe range. Standardization, which has been actively applied all along the French program and for the Konvoi plants, does not prevent evolution and allows to concentrate large engineering effort in smooth realization of plants and achieve actual construction and commissioning without significant delays. In order to contribute to public trust renewal, a next generation of power reactors should be fundamentally less likely to incur serious accidents. To reach this goal the best of passive and active systems must be considered without forgetting that the most important source of knowledge is construction and operating experience. Criteria to assess passive systems investigated for possible implementation in the EPR, such as simplicity of design, impact on plant operation, safety and cost, are discussed. Examples of the principal passive systems investigated are described and reasons why they have been dropped after screening through the criteria are given. (author). 11 figs

Active or passive systems? The EPR approach

Energy Technology Data Exchange (ETDEWEB)

Bonhomme, N [Nuclear Power International, Cedex (France); Py, J P [FRAMATOME, Cedex (France)

1996-12-01

In attempting to review how EPR is contemplated to meet requirements applicable to future nuclear power plants, the authors indicate where they see the markets and the corresponding unit sizes for the EPR which is a generic key factor for competitiveness. There are no reason in industrialized countries, other than USA (where the investment and amortizing practices under control by Public Utility Commission are quite particular), not to build future plants in the 1000 to 1500 MWe range. Standardization, which has been actively applied all along the French program and for the Konvoi plants, does not prevent evolution and allows to concentrate large engineering effort in smooth realization of plants and achieve actual construction and commissioning without significant delays. In order to contribute to public trust renewal, a next generation of power reactors should be fundamentally less likely to incur serious accidents. To reach this goal the best of passive and active systems must be considered without forgetting that the most important source of knowledge is construction and operating experience. Criteria to assess passive systems investigated for possible implementation in the EPR, such as simplicity of design, impact on plant operation, safety and cost, are discussed. Examples of the principal passive systems investigated are described and reasons why they have been dropped after screening through the criteria are given. (author). 11 figs.

EPR of gamma irradiated solid sucrose and UV spectra of its solution. An attempt for calibration of solid state/EPR dosimetry

International Nuclear Information System (INIS)

Yordanov, N.D.; Karakirova, Y.

2007-01-01

A simple new approach for independent calibration of solid state/EPR (SS/EPR) dosimetry system is reported. It is based on the fact that: (i) gamma-irradiation of solid sucrose (sugar) induces stable EPR detectable free radicals accompanied by UV detectable brown colour stable in the solid state and in solution; (ii) both the EPR intensity of gamma-irradiated solid sucrose and its solution UV absorbance linearly depend on the absorbed dose high energy radiation and may be independently used for dosimetric purpose; (iii) UV spectrometers are calibrated. The correlation between EPR response and absorbed dose radiation of solid sucrose and UV absorption of its solutions is used in the present communication for calibration purpose. The procedure of sucrose extraction from sucrose-paraffin dosimeters is described. The calibration procedure may be applied to any other (alanine, self-calibrated, etc.) SS/EPR dosimeters, simultaneously irradiated with sucrose

Nitrosyl hemoglobins: EPR above 80 K

Energy Technology Data Exchange (ETDEWEB)

Wajnberg, E.; Bemski, G.; El-Jaick, L.J.; Alves, O.C.

1995-03-01

The EPR spectra of nitrosyl hemoglobin and myoglobin in different conditions (native, denatured and lyophilized), as well as of hematin-NO were obtained in the temperature range of 80 K-280 K. There is a substantial and reversible.decrease of the areas of the EPR spectra of all the hemoglobin samples above 150 K. The interpretation of the results implies the existence of two conformational states in thermal equilibrium only one of which is EPR detectable. Thermodynamical parameters are determined for the hexa and penta-coordinated cases. (author). 25 refs, 3 figs.

Nitrosyl hemoglobins: EPR above 80 K

International Nuclear Information System (INIS)

Wajnberg, E.; Bemski, G.; El-Jaick, L.J.; Alves, O.C.

1995-03-01

The EPR spectra of nitrosyl hemoglobin and myoglobin in different conditions (native, denatured and lyophilized), as well as of hematin-NO were obtained in the temperature range of 80 K-280 K. There is a substantial and reversible.decrease of the areas of the EPR spectra of all the hemoglobin samples above 150 K. The interpretation of the results implies the existence of two conformational states in thermal equilibrium only one of which is EPR detectable. Thermodynamical parameters are determined for the hexa and penta-coordinated cases. (author). 25 refs, 3 figs

Tachyons without paradoxes

International Nuclear Information System (INIS)

Barrowes, S.C.

1977-01-01

Tachyon paradoxes, including causality paradoxes, have persisted within tachyon theories and left little hope for the existence of observable tachyons. A way is presented to solve the causality paradoxes, along with two other paradoxes, by the introduction of an absolute frame of reference in which a tachyon effect may never precede its cause. Relativity for ordinary matter is unaffected by this, even if the tachyons couple to ordinary particles. Violations of the principle of relativity due to the absolute frame would appear only in the case of free tachyons

High-field EPR on membrane proteins - crossing the gap to NMR.

Science.gov (United States)

Möbius, Klaus; Lubitz, Wolfgang; Savitsky, Anton

2013-11-01

In this review on advanced EPR spectroscopy, which addresses both the EPR and NMR communities, considerable emphasis is put on delineating the complementarity of NMR and EPR concerning the measurement of molecular interactions in large biomolecules. From these interactions, detailed information can be revealed on structure and dynamics of macromolecules embedded in solution- or solid-state environments. New developments in pulsed microwave and sweepable cryomagnet technology as well as ultrafast electronics for signal data handling and processing have pushed to new horizons the limits of EPR spectroscopy and its multifrequency extensions concerning the sensitivity of detection, the selectivity with respect to interactions, and the resolution in frequency and time domains. One of the most important advances has been the extension of EPR to high magnetic fields and microwave frequencies, very much in analogy to what happens in NMR. This is exemplified by referring to ongoing efforts for signal enhancement in both NMR and EPR double-resonance techniques by exploiting dynamic nuclear or electron spin polarization via unpaired electron spins and their electron-nuclear or electron-electron interactions. Signal and resolution enhancements are particularly spectacular for double-resonance techniques such as ENDOR and PELDOR at high magnetic fields. They provide greatly improved orientational selection for disordered samples that approaches single-crystal resolution at canonical g-tensor orientations - even for molecules with small g-anisotropies. Exchange of experience between the EPR and NMR communities allows for handling polarization and resolution improvement strategies in an optimal manner. Consequently, a dramatic improvement of EPR detection sensitivity could be achieved, even for short-lived paramagnetic reaction intermediates. Unique structural and dynamic information is thus revealed that can hardly be obtained by any other analytical techniques. Micromolar

Retrospective individual dosimetry using EPR of tooth enamel

International Nuclear Information System (INIS)

Skvortzo, V.; Ivannikov, A.; Stepanenko, V.; Wieser, A.; Bougai, A.; Brick, A.; Chumak, V.; Radchuk, V.; Repin, V.; Kirilov, V.

1996-01-01

The results of joint investigations (in the framework of ECP-10 program) aimed on the improvement of the sensitivity and accuracy of the procedure of dose measurement using tooth enamel EPR spectroscopy are presented. It is shown, what the sensitivity of method may be increased using special physical-chemical procedure of the enamel samples treatment, which leads to the reducing of EPR signal of organic components in enamel. Tooth diseases may have an effect on radiation sensitivity of enamel. On the basis of statistical analysis of the results of more then 2000 tooth enamel samples measurements it was shown, what tooth enamel EPR spectroscopy gives opportunity to register contribution into total dose, which is caused by natural environmental radiation and by radioactive contamination. EPR response of enamel to ultraviolet exposure is investigated and possible influences to EPR dosimetry is discussed. The correction factors for EPR dosimetry in real radiation fields are estimated

Properties of the ammonium tartrate/EPR dosimeter

International Nuclear Information System (INIS)

Yordanov, N.D.; Gancheva, V.

2004-01-01

The EPR response of γ-irradiated ammonium tartrate on the absorbed dose of γ-rays up to 22 kGy as well as the changes in the shape of the EPR spectrum upon applied modulation amplitude and microwave power are reported. Also the possibility to use ammonium tartrate together with Mn 2+ magnetically diluted in MgO as an internal reference material is evaluated. The influence of the microwave power and the modulation amplitude on their dose response is investigated. The results show that the radiation-induced EPR spectrum of ammonium tartrate, obtained at a low microwave power is complex consisting several patterns and is more easily saturated than the Mn 2+ EPR spectrum. In this case the following settings of the EPR parameters are recommended: H mod ≤0.05 mT and 10≤P MW ≤13 mW. Using these parameters the dosimeters can be considered for use in intercomparisons

Unveiling consumer’s privacy paradox behaviour in an economic exchange

Science.gov (United States)

Li, Xiao-Bai

2015-01-01

Privacy paradox is of great interest to IS researchers and firms gathering personal information. It has been studied from social, behavioural, and economic perspectives independently. However, prior research has not examined the degrees of influence these perspectives contribute to the privacy paradox problem. We combine both economic and behavioural perspectives in our study of the privacy paradox with a price valuation of personal information through an economic experiment combined with a behavioural study on privacy paradox. Our goal is to reveal more insights on the privacy paradox through economic valuation on personal information. Results indicate that general privacy concerns or individual disclosure concerns do not have a significant influence on the price valuation of personal information. Instead, prior disclosure behaviour in specific scenario, like with healthcare providers or social networks, is a better indicator of consumer price valuations. PMID:27708687

A Hydrostatic Paradox Revisited

Science.gov (United States)

Ganci, Salvatore

2012-01-01

This paper revisits a well-known hydrostatic paradox, observed when turning upside down a glass partially filled with water and covered with a sheet of light material. The phenomenon is studied in its most general form by including the mass of the cover. A historical survey of this experiment shows that a common misunderstanding of the phenomenon…

Identification of gamma-irradiated fruit juices by EPR spectroscopy

International Nuclear Information System (INIS)

Aleksieva, K.I.; Dimov, K.G.; Yordanov, N.D.

2014-01-01

The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to “cellulose-like” EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical “sugar-like“ spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation. - Highlights: • The EPR analysis of juices, nectars and syrups proves that the sample has been irradiated. • Two sample preparation procedures were used. • The stability of the radiation induced EPR signals was studied over 2 months. • Application of European standards can be extended for irradiated juices and syrups

Two-dimensional 220 MHz Fourier transform EPR imaging

International Nuclear Information System (INIS)

Placidi, Giuseppe; Brivati, John A.; Alecci, Marcello; Testa, Luca; Sotgiu, Antonello

1998-01-01

In the last decade radiofrequency continuous-wave EPR spectrometers have been developed to detect and localize free radicals in vivo. Only recently, pulsed radiofrequency EPR spectrometers have been described for imaging applications with small samples. In the present work, we show the first two-dimensional image obtained at 220 MHz on a large phantom (40 ml) that simulates typical conditions of in vivo EPR imaging. This pulsed EPR apparatus has the potential to make the time required for three-dimensional imaging compatible with the biological half-life of normally used paramagnetic probes. (author)

EPR design features to mitigate severe accident challenges

International Nuclear Information System (INIS)

Mazurkiewicz, S.M.; Fischer, M.; Bittermann, D.

2005-01-01

The EPR, an evolutionary pressurized water reactor (PWR), is a 4300-4500 MWth that incorporates proven technology within an optimized configuration to enhance safety. EPR was originally developed through a joint effort between Framatome ANP and Siemens by incorporating the best technological features from the French and German nuclear reactor fleets into a cost-competitive product. Commercial EPR units are currently being built in Finland at the Olkiluoto site, and planned for France at the Flamanville site. In recent months, Framatome ANP announced their intention to market the EPR units to China in response to a request for vendor bids as well as their intent to pursue design certification in the United States under 10CFR52. The EPR safety philosophy is based on a deterministic consideration of defense-in-depth complemented by probabilistic analyses. Not only is the EPR designed to prevent and mitigate design basis accidents (DBAs), it employs an extra level of safety associated with severe accident response. Therefore, as a design objective, features are included to ensure that radiological consequences are limited such that the need for stringent counter measures, such as evacuation and relocation of the nearby population, can be reasonably excluded. This paper discusses some of the innovative features of the EPR to address severe accident challenges. (author)

EPR study on tomatoes before and after gamma-irradiation

International Nuclear Information System (INIS)

Aleksieva, K.; Georgieva, L.; Tzvetkova, E.; Yordanov, N.D.

2009-01-01

The results from the EPR studies on fresh, air-dried and lyophilized tomato samples before and after gamma-irradiation are reported. Before irradiation fresh and air-dried tomatoes exhibit one singlet EPR line characterized with common g-factor of 2.0048±0.0005, whereas freeze-dried tomato does not show any EPR spectrum. After irradiation, a typical 'cellulose-like' triplet EPR spectrum appears in all samples, attributed to cellulose free radicals, generated by gamma-irradiation. It consists of intense central line with g=2.0048±0.0005 and two weak satellite lines separated ca. 3 mT left and right of it. In air-dried and lyophilized tomatoes the 'cellulose-like' EPR spectrum is superimposed by an additional partly resolved carbohydrate spectrum. Fading measurements of the radiation-induced EPR signals indicate that the intensity of the EPR spectra of air-dried and freeze-dried tomato are reduced to about 50% after 50 days, whereas those of fresh irradiated tomatoes kept at 4 o C fade completely in 15 days. The reported results unambiguously show that the presence of two satellite lines in the EPR 'cellulose-like' spectra of tomato samples can be used for identification of radiation processing.

Identification of gamma-irradiated fruit juices by EPR spectroscopy

Science.gov (United States)

Aleksieva, K. I.; Dimov, K. G.; Yordanov, N. D.

2014-10-01

The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to "cellulose-like" EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical "sugar-like" spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation.

Generalized Hardy's Paradox

Science.gov (United States)

Jiang, Shu-Han; Xu, Zhen-Peng; Su, Hong-Yi; Pati, Arun Kumar; Chen, Jing-Ling

2018-01-01

Here, we present the most general framework for n -particle Hardy's paradoxes, which include Hardy's original one and Cereceda's extension as special cases. Remarkably, for any n ≥3 , we demonstrate that there always exist generalized paradoxes (with the success probability as high as 1 /2n -1) that are stronger than the previous ones in showing the conflict of quantum mechanics with local realism. An experimental proposal to observe the stronger paradox is also presented for the case of three qubits. Furthermore, from these paradoxes we can construct the most general Hardy's inequalities, which enable us to detect Bell's nonlocality for more quantum states.

Paradoxes of unstable electron

International Nuclear Information System (INIS)

Okun, L.B.; Zeldovich, Ya.B.

1978-01-01

The hypothesis that electron is unstable - when it is consistent with the vanishing mass of the photon- leads to a number of paradoxical statements. The lifetime of the electron is determined by emission of a huge number of longitudinal photons and exponentially depends on the amount of emitted energy. This suggests to discuss searches for charge nonconservation in experiments with high energy particles

Paradoxes of maternal mourning.

Science.gov (United States)

Brice, C W

1991-02-01

It has been customary to conceptualize mourning as a phasic or stage phenomenon (Lindemann 1944; Parkes 1972; Bowlby 1980; Knapp 1986). Such a conceptualization has proved to be of tremendous didactic value, especially in terms of succinctly organizing and communicating the major affects, behaviors, and reactions of mourning. It is, however, my belief, based upon clinical experience with many forms of bereavement, that the phenomenon of mourning is not comprised of clearly delineated stages and phases. I have come to conceptualize the phenomenon of mourning the death of a loved person as involving the bereaved's struggle with a series of more or less unresolvable paradoxes rather than as a progression through stages that possess relatively distinct and predictable beginning and ending points. The specific paradoxes encountered by a bereaved person differ, of course, in accordance with the relationship that was lost (mother, father, spouse, child, or sibling), the developmental stage of the bereaved (childhood, adolescence, adulthood, or maturity), the type of death (sudden or prolonged), and the cause of death (illness, murder, suicide, or accident). In this paper, I will address those paradoxes that seem specific to maternal mourning - that is, to mothers who are mourning the death of a child.

New methods for data processing and designing the EPR European reactor

International Nuclear Information System (INIS)

Bogoslovskij, A.V.

1999-01-01

The basic parameters of the reactor in the assumption of its capacity, equalling 1500 MW and meeting the requirements of the European consumers, are presented. The experience in operating the nuclear facilities in France and Germany during above 1000 reactor/years is used by designed the EPR. The EPR safety systems are based on the maximum simplicity by application of the stand by principle and provision for the redundancy with separated functions. Application of standardization both for the NPP as a whole and individual equipment makes it possible to decrease the construction costs, as well as the expenditures on electrical energy production and the NPP personnel training [ru

EPR spectral investigation of radiation-induced radicals of gallic acid.

Science.gov (United States)

Tuner, Hasan

2017-11-01

In the present work, spectroscopic features of the radiation-induced radicals of gallic acid compounds were investigated using electron paramagnetic resonance (EPR) spectroscopy. While un-irradiated samples presented no EPR signal, irradiated samples exhibited an EPR spectrum consisting of an intense resonance line at the center and weak lines on both sides. Detailed microwave saturation investigations were carried out to determine the origin of the experimental EPR lines. It is concluded that the two side lines of the triplet satellite originate from forbidden "spin-flip" transitions. The spectroscopic and structural features of the radiation-induced radicals were determined using EPR spectrum fittings. The experimental EPR spectra of the two gallic acid compounds were consistent with the calculated EPR spectroscopic features of the proposed radicals. It is concluded that the most probable radicals are the cyclohexadienyl-type, [Formula: see text] radicals for both compounds.

Study of Einstein-Podolsky-Rosen state for space-time variables in a two photon interference experiment

Science.gov (United States)

Shih, Y. H.; Sergienko, A. V.; Rubin, M. H.

1993-01-01

A pair of correlated photons generated from parametric down conversion was sent to two independent Michelson interferometers. Second order interference was studied by means of a coincidence measurement between the outputs of two interferometers. The reported experiment and analysis studied this second order interference phenomena from the point of view of Einstein-Podolsky-Rosen paradox. The experiment was done in two steps. The first step of the experiment used 50 psec and 3 nsec coincidence time windows simultaneously. The 50 psec window was able to distinguish a 1.5 cm optical path difference in the interferometers. The interference visibility was measured to be 38 percent and 21 percent for the 50 psec time window and 22 percent and 7 percent for the 3 nsec time window, when the optical path difference of the interferometers were 2 cm and 4 cm, respectively. By comparing the visibilities between these two windows, the experiment showed the non-classical effect which resulted from an E.P.R. state. The second step of the experiment used a 20 psec coincidence time window, which was able to distinguish a 6 mm optical path difference in the interferometers. The interference visibilities were measured to be 59 percent for an optical path difference of 7 mm. This is the first observation of visibility greater than 50 percent for a two interferometer E.P.R. experiment which demonstrates nonclassical correlation of space-time variables.

Chronic Illness as a Source of Happiness: Paradox or perfectly normal?

Directory of Open Access Journals (Sweden)

S. Hoppe

2013-11-01

Full Text Available In this paper I analyse the relation between happiness and chronic illness from the perspective of medical anthropology and disability studies. By looking at the disability paradox I deconstruct society’s view of people with a disability. I argue that the disability paradox is problematic as it ignores the views of people with a disability. Moreover, such a paradox reinforces the idea that living with a chronic illness or disability is a devastating experience and that happiness and disability are mutally exclusive realities. Based on empiric examples of people who suffer from Multiple Sclerosis I demonstrate that people with a chronic illness can experience happiness in spite of illness, but also as a consequence of it. 

Authority as paradox: the transformations of Don Quijote.

Science.gov (United States)

Priel, Beatriz

2006-12-01

The author's contention is that the analysand's temporary attribution of authority to the analyst is inherent in the analytic situation; this is seen as a transitional and paradoxical form of authority pertaining neither to internal nor external reality, but dwelling in the analytic third. The author proposes a conceptualization of psychoanalytic authority as a form of aesthetic authority according to Gadamer's definitions. While the scientific and hermeneutic codes for the understanding of authority in psychoanalysis assume that the main issue at stake is the delimitation of the objectivity or the subjectivity of the analyst's knowledge, this aesthetic perspective centres on the analysand's attribution of a claim of truth to analytic interpretations, and on the experience of recognition. The experience of recognition of a possible truth is particular and context-bound, as well as self-transformational. A reading of three episodes from Cervantes's The history of Don Quixote de la Mancha illuminates the transitional and paradoxical character of aesthetic authority within a transformational dialogue. These episodes are read as dramatizations of different positions vis-à-vis the paradoxical authority that characterizes transformational dialogues.

EPR-technical codes - a common basis for the EPR

International Nuclear Information System (INIS)

Zaiss, W.; Appell, B.

1997-01-01

The design and construction of Nuclear Power Plants implies a full set of codes and standards to define the construction rules of components and equipment. Rules are existing and are currently implemented, respectively in France and Germany (mainly RCCs and KTA safety standards). In the frame of the EPR-project, the common objective requires an essential industrial work programme between engineers from both countries to elaborate a common set of codes and regulations. These new industrial rules are called the ETCs (EPR Technical Codes). In the hierarchy the ETCs are - in case of France - on the common level of basic safety rules (RFS), design and construction rules (RCC) and - in Germany - belonging to RSK guidelines and KTA safety standards. A set of six ETCs will be elaborated to cover: safety and process, mechanical components, electrical equipment, instrumentation and control, civil works, fire protection. (orig.)

A novel microfluidic rapid freeze-quench device for trapping reactions intermediates for high field EPR analysis.

Science.gov (United States)

Kaufmann, Royi; Yadid, Itamar; Goldfarb, Daniella

2013-05-01

Rapid freeze quench electron paramagnetic resonance (RFQ)-EPR is a method for trapping short lived intermediates in chemical reactions and subjecting them to EPR spectroscopy investigation for their characterization. Two (or more) reacting components are mixed at room temperature and after some delay the mixture is sprayed into a cold trap and transferred into the EPR tube. A major caveat in using commercial RFQ-EPR for high field EPR applications is the relatively large amount of sample needed for each time point, a major part of which is wasted as the dead volume of the instrument. The small sample volume (∼2μl) needed for high field EPR spectrometers, such as W-band (∼3.5T, 95GHz), that use cavities calls for the development of a microfluidic based RFQ-EPR apparatus. This is particularly important for biological applications because of the difficulties often encountered in producing large amounts of intrinsically paramagnetic proteins and spin labeled nucleic acid and proteins. Here we describe a dedicated microfluidic based RFQ-EPR apparatus suitable for small volume samples in the range of a few μl. The device is based on a previously published microfluidic mixer and features a new ejection mechanism and a novel cold trap that allows collection of a series of different time points in one continuous experiment. The reduction of a nitroxide radical with dithionite, employing the signal of Mn(2+) as an internal standard was used to demonstrate the performance of the microfluidic RFQ apparatus. Copyright © 2013 Elsevier Inc. All rights reserved.

Testing the Transivity Explanation of the Allais Paradox

DEFF Research Database (Denmark)

Groes, Ebbe; Jacobsen, Hans Jørgen; Sloth, Birgitte

1999-01-01

This paper uses a two-dimensional version of a standard common consequence experiment to test the intransitivity explanation of Allais-paradox-type violations of expected utility theory. We compare the common consequence effect of two choice problems differing only with respect to whether...... intransitivity as an explanation of the Allais Paradox. The question whether violations of expected utility are mainly due to intransitivity or to violation of independence is important since it is exactly on this issue the main new decision theories differ...

EPR researches of tree cuts for estimating radio - ecological situation

International Nuclear Information System (INIS)

Bitenbayev, M.I.; Polyakov, A.I.

2007-01-01

Full text: The basic aim of present work is to study a possibility of nature object application, in this case the annual rings of trees, for reveal of the effects of post - radiation action for them by EPR method. The cuts of poplars at the age 70 years and older grown in various regions of Kazakhstan with increased level of radiation background were selected as the research objects. EPR spectra were registered for every annual ring separately at the room temperatures. On the basis of EPR experimental results it was ascertained that the EPR spectra of annual rings may be symbolically divided for two groups every of which is possessed of its own definite kind of the spectrum. The first group are the spectra of the annual rings relating to 1981 - 1999 years (in 1999 the trees were cut), and the second group are these of the rings relating 1934 - 1980 years. At that it has been showed that an additional exposure to γ-ray of Co 60 transforms the first group spectrum to the form typical for the second group, i.e. the radiation effect becomes apparent in these experiments. The analyses of EPR spectra parameters has been performed and a correlation between the dependences of intensity of certain components in the spectrum on gamma - irradiation dose and the age of the annul rings has been showed. One can suppose that the intensity changing of these spectrum components in the second group, concerned with free radical accumulation, was the results of long-term action to the object by ionizing radiations. The studied effects can be used for average estimation of absorbed doses of ionizing radiation by environment objects, in particular, by residents of regions surveyed

A web-based database for EPR centers in semiconductors

International Nuclear Information System (INIS)

Umeda, T.; Hagiwara, S.; Katagiri, M.; Mizuochi, N.; Isoya, J.

2006-01-01

We develop a web-based database system for electron paramagnetic resonance (EPR) centers in semiconductors. This database is available to anyone at http://www.kc.tsukuba.ac.jp/div-media/epr/. It currently has more than 300 records of the spin-Hamiltonian parameters for major known EPR centers. One can upload own new records to the database or can use simulation tools powered by EPR-NMR(C). Here, we describe the features and objectives of this database, and mention some future plans

High-frequency EPR on high-spin transition-metal sites

NARCIS (Netherlands)

Mathies, Guinevere

2012-01-01

The electronic structure of transition-metal sites can be probed by electron-paramagnetic-resonance (EPR) spectroscopy. The study of high-spin transition-metal sites benefits from EPR spectroscopy at frequencies higher than the standard 9.5 GHz. However, high-frequency EPR is a developing field. In

Dirac's aether in relativistic quantum mechanics

International Nuclear Information System (INIS)

Petroni, N.C.; Bari Univ.; Vigier, J.P.

1984-01-01

The paper concerns Dirac's aether model, based on a stochastic covariant distribution of subquantum motions. Stochastic derivation of the relativistic quantum equations; deterministic nonlocal interpretation of the Aspect-Rapisarda experiments on the EPR paradox; and photon interference with itself; are all discussed. (U.K.)

Nano-emulsions of fluorinated trityl radicals as sensors for EPR oximetry

Science.gov (United States)

Charlier, N.; Driesschaert, B.; Wauthoz, N.; Beghein, N.; Préat, V.; Amighi, K.; Marchand-Brynaert, J.; Gallez, B.

2009-04-01

This article reports the development and evaluation of two nano-emulsions (F45T-03/HFB and F15T-03/PFOB) containing fluorinated trityl radicals dissolved in perfluorocarbons. Preparation with a high-pressure homogenizer conferred sub-micronic size to both nano-emulsions. In vitro and in vivo EPR spectroscopy showed that the nano-emulsions had much greater oxygen sensitivity than the hydrophilic trityl, CT-03. In vivo experiments in rodents confirmed the ability of the nano-emulsions to follow the changes in oxygen concentration after induced ischemia. Histological evaluation of the tissue injected with the nano-emulsions revealed some acute toxicity for the F45T-03/HFB nano-emulsion but none for the F15T-03/PFOB nano-emulsion. These new formulations should be considered for further EPR oximetry experiments in pathophysiological situations where subtle changes in tissue oxygenation are expected.

EPR Dosimetry for ageing effect in NPP

International Nuclear Information System (INIS)

Choi, Hoon; Lim, Young Ki; Kim, Jong Seog; Jung, Sun Chul

2005-01-01

As one of the retrospective dosimetry method, EPR spectroscopy has been studied by many research up to theses days. As a dosimeter for EPR spectroscopy, Alanine is already a well known dosimeter in the field of radiation therapy and dose assessment in radiological accident by its characteristics as good linearity in a wide range of energy level and extremely low signal fading on time. Through technical document of IAEA, the EPR dosimetry method using alanine sample was published in 2000 after research by coordinated project on management of ageing of in-containment I and C cables. Although alanine sample is regarded as a good EPR dosimeter like above ageing assessment field, actually the assessment of radiation should be done at least for two fuel cycles, because of its relatively low irradiation environment in almost all spots in power plant. So, for getting more accurate detection value of radiation, another material is tested for being put in simultaneously inside the power plant with alanine. The test result for lithium formate monohydrate (HCO 2 LiH 2 0) was presented below for checking its possibility for being applied as EPR dosimeter for this project

EPR and development of quantum electronics

International Nuclear Information System (INIS)

Manenkov, A A

2011-01-01

A role of electron paramagnetic resonance in development of quantum electronics is discussed. Basic principles and history of masers are briefly described. Spin-levels of paramagnetic ions in crystals as a very suitable object for active media of solid-state masers (called as EPR-masers) and physical processes in EPR-masers (population inversion of energy states) are analyzed. This analysis demonstrates a significant role of relaxation processes in multi-level spin-systems for efficient maser action. In this context peculiarities of spin-lattice and spin-spin cross relaxation processes in multi-level systems are analyzed. Development of EPR-masers and their application in radioastronomy and far-space communication systems are briefly described.

EPR spectral investigation of radiation-induced radicals of gallic acid

Energy Technology Data Exchange (ETDEWEB)

Tuner, Hasan [Balikesir University, Department of Physics, Faculty of Art and Science, Balikesir (Turkey)

2017-11-15

In the present work, spectroscopic features of the radiation-induced radicals of gallic acid compounds were investigated using electron paramagnetic resonance (EPR) spectroscopy. While un-irradiated samples presented no EPR signal, irradiated samples exhibited an EPR spectrum consisting of an intense resonance line at the center and weak lines on both sides. Detailed microwave saturation investigations were carried out to determine the origin of the experimental EPR lines. It is concluded that the two side lines of the triplet satellite originate from forbidden ''spin-flip'' transitions. The spectroscopic and structural features of the radiation-induced radicals were determined using EPR spectrum fittings. The experimental EPR spectra of the two gallic acid compounds were consistent with the calculated EPR spectroscopic features of the proposed radicals. It is concluded that the most probable radicals are the cyclohexadienyl-type, O(OH){sub 2}C{sub 6}H{sub 2}COOH radicals for both compounds. (orig.)

Assessment of performance parameters for EPR dosimetry with tooth enamel

International Nuclear Information System (INIS)

Wieser, A.; Fattibene, P.; Shishkina, E.A.; Ivanov, D.V.; De Coste, V.; Guettler, A.; Onori, S.

2008-01-01

In the framework of a comparison between three laboratories, electron paramagnetic resonance (EPR) signal-to-dose response curves were measured for sets of 30 tooth enamel samples and the variance of EPR measurements in dependence on absorbed dose was evaluated, in nine combinations of laboratory of sample preparation and EPR evaluation, respectively. As a test for benchmarking of EPR evaluation, the parameters 'critical dose' and 'limit of detection' were proposed as performance parameters following definitions from chemical-metrology, and a model function was suggested for analytical formulation of the dependence of the variance of EPR measurement on absorbed dose. First estimates of limits of detection by weighted and unweighted fitting resulted in the range 101-552 and 67-561 mGy, respectively, and were generally larger with weighted than with unweighted fitting. Indication was found for the influence of methodology of sample preparation and applied EPR measurement parameters on performance of EPR dosimetry with tooth enamel

EPR spectral investigation of radiation-induced radicals of gallic acid

International Nuclear Information System (INIS)

Tuner, Hasan

2017-01-01

In the present work, spectroscopic features of the radiation-induced radicals of gallic acid compounds were investigated using electron paramagnetic resonance (EPR) spectroscopy. While un-irradiated samples presented no EPR signal, irradiated samples exhibited an EPR spectrum consisting of an intense resonance line at the center and weak lines on both sides. Detailed microwave saturation investigations were carried out to determine the origin of the experimental EPR lines. It is concluded that the two side lines of the triplet satellite originate from forbidden ''spin-flip'' transitions. The spectroscopic and structural features of the radiation-induced radicals were determined using EPR spectrum fittings. The experimental EPR spectra of the two gallic acid compounds were consistent with the calculated EPR spectroscopic features of the proposed radicals. It is concluded that the most probable radicals are the cyclohexadienyl-type, O(OH) 2 C 6 H 2 COOH radicals for both compounds. (orig.)

Costing the EPR Project Using the Real Options Method

International Nuclear Information System (INIS)

Epaulard, Anne; Gallon, Stephane

2001-01-01

Real options theory makes it possible to cost investments which offer flexibility but whose returns are uncertain, such as the construction in 2000 of an EPR prototype; this prototype will enable the European pressurised-water reactor (EPR) to be used to renew EDF's nuclear power stations in 2020 (flexibility) but its economic worth will then depend on the cost of the competing gas-fired power plants (uncertain return). Options theory shows that investing in EPR technology in 2000 provides sufficient flexibility in 2020 to be considered cost-effective, even though use of EPRs is unlikely by that date. The investment made in 2000 to develop EPR technology therefore actually plays the part of an option or, in other words, insurance (against the risk of high gas prices)

EPR: the nuclear impasse; EPR: l'impasse nucleaire

Energy Technology Data Exchange (ETDEWEB)

Marillier, F [Association Ecologiste Greenpeace (France)

2008-07-01

The questions relative to the climatic change constitute crucial challenges for the next ten years. In this context the author aims to show how the EPR project illustrates the nuclear french ''autism''. He presents and analyzes the international and environmental impacts of this obsolete technology, as a project useless and dangerous. (A.L.B.)

Service Recovery Paradox In Indian Banking Industry: An Empirical Investigation

Directory of Open Access Journals (Sweden)

Arunesh Garg

2013-10-01

Full Text Available The present study examines existence of service recovery paradox in Indian banking industry. The study is taken up in the tri-city of Chandigarh, Panchkula and Mohali. The respondents are catego- rized into failure and no-failure groups on the basis of their service experience. Failure group consti- tutes those respondents who have experienced service recovery, and has been further divided into five sub-groups ranging from service recovery++ (service recovery better than expected to service recovery- - (service recovery worse than expected. Service recovery paradox is examined by com- paring service recovery++ group with no-failure group. The study shows evidence for existence of service recovery paradox in relation to satisfaction. It has been concluded that for service recovery paradox to exist, recovery effort has to be exceptionally good and much better than expectation level of the customer. The study suggests that service managers should take service failure as an opportunity to appease customers by providing a much better than expected recovery experience. However, organizations should not plan to create service failure situations because if they falter on imparting the recovery, customer satisfaction may be influenced negatively.

EPR detection of foods preserved with ionizing radiation

Science.gov (United States)

Stachowicz, W.; Burlinska, G.; Michalik, J.

1998-06-01

The applicability of the epr technique for the detection of dried vegetables, mushrooms, some spices, flavour additives and some condiments preserved with ionizing radiation is discussed. The epr signals recorded after exposure to gamma rays and to beams of 10 MeV electrons from linac are stable, intense and specific enough as compared with those observed with nonirradiated samples and could be used for the detection of irradiation. However, stability of radiation induced epr signals produced in these foods depends on storage condition. No differences in shapes (spectral parameters) and intensities of the epr spectra recorded with samples exposed to the same doses of gamma rays ( 60Co) and 10 MeV electrons were observed

EPR detection of foods preserved with ionizing radiation

International Nuclear Information System (INIS)

Stachowicz, W.; Burlinska, G.; Michalik, J.

1998-01-01

The applicability of the epr technique for the detection of dried vegetables, mushrooms, some spices, flavour additives and some condiments preserved with ionizing radiation is discussed. The epr signals recorded after exposure to gamma rays and to the beams of 10 MeV electrons from linac are stable, intense and specific enough as compared with those observed with nonirradiated samples and could be used for the detection of irradiation. However, stability of radiation induced epr signals produced in these foods depends on storage condition. No differences in shapes (spectral parameters) and intensities of the epr spectra recorded with samples exposed to the same doses of gamma rays ( 60 Co) and 10 MeV electrons were observed

EPR detection of foods preserved with ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Stachowicz, W.; Burlinska, G.; Michalik, J

1998-06-01

The applicability of the epr technique for the detection of dried vegetables, mushrooms, some spices, flavour additives and some condiments preserved with ionizing radiation is discussed. The epr signals recorded after exposure to gamma rays and to the beams of 10 MeV electrons from linac are stable, intense and specific enough as compared with those observed with nonirradiated samples and could be used for the detection of irradiation. However, stability of radiation induced epr signals produced in these foods depends on storage condition. No differences in shapes (spectral parameters) and intensities of the epr spectra recorded with samples exposed to the same doses of gamma rays ({sup 60}Co) and 10 MeV electrons were observed.

Bell's inequality and 'ghost-like action-at-a-distance' in quantum mechanics

International Nuclear Information System (INIS)

Mattuck, R.D.

1982-01-01

The phenomenon of non-locality in quantum mechanics is one of its most fundamental features and is most strikingly exemplified in the discussion of the EPR type of experiment. The generality of Bell's inequality and the results of experiments done up to now show that local hidden-variable theories are ruled out as a means to resolve the famous EPR paradox. What remains for further consideration are the non-local and the Einstein-separable hidden-variable models. Finally, an alternative and possible successful approach in trying to 'explain' non-locality might involve ideas of backward causation. (author)

Bell's inequality and 'ghost-like action-at-a-distance' in quantum mechanics

Energy Technology Data Exchange (ETDEWEB)

Mattuck, R.D. (Copenhagen Univ. (Denmark). H.C. Oersted Inst.)

1982-01-01

The phenomenon of non-locality in quantum mechanics is one of its most fundamental features and is most strikingly exemplified in the discussion of the EPR type of experiment. The generality of Bell's inequality and the results of experiments done up to now show that local hidden-variable theories are ruled out as a means to resolve the famous EPR paradox. What remains for further consideration are the non-local and the Einstein-separable hidden-variable models. Finally, an alternative and possible successful approach in trying to 'explain' non-locality might involve ideas of backward causation.

The quercetin paradox

International Nuclear Information System (INIS)

Boots, Agnes W.; Li, Hui; Schins, Roel P.F.; Duffin, Rodger; Heemskerk, Johan W.M.; Bast, Aalt; Haenen, Guido R.M.M.

2007-01-01

Free radical scavenging antioxidants, such as quercetin, are chemically converted into oxidation products when they protect against free radicals. The main oxidation product of quercetin, however, displays a high reactivity towards thiols, which can lead to the loss of protein function. The quercetin paradox is that in the process of offering protection, quercetin is converted into a potential toxic product. In the present study, this paradox is evaluated using rat lung epithelial (RLE) cells. It was found that quercetin efficiently protects against H 2 O 2 -induced DNA damage in RLE cells, but this damage is swapped for a reduction in GSH level, an increase in LDH leakage as well as an increase of the cytosolic free calcium concentration. To our knowledge, this is the first study that indicates that the quercetin paradox, i.e. the exchange of damage caused by quercetin and its metabolites, also occurs in living lung cells. Following depletion of GSH in the cells by BSO pre-treatment, this quercetin paradox becomes more pronounced, confirming that the formation of thiol reactive quercetin metabolites is involved in the quercetin paradox. The quercetin paradox in living cells implies that the anti-oxidant directs oxidative damage selectively to thiol arylation. Apparently, the potential toxicity of metabolites formed during the actual antioxidant activity of free radical scavengers should be considered in antioxidant supplementation

Nuclear spin-lattice relaxation in nitroxide spin-label EPR.

Science.gov (United States)

Marsh, Derek

2016-11-01

Nuclear relaxation is a sensitive monitor of rotational dynamics in spin-label EPR. It also contributes competing saturation transfer pathways in T 1 -exchange spectroscopy, and the determination of paramagnetic relaxation enhancement in site-directed spin labelling. A survey shows that the definition of nitrogen nuclear relaxation rate W n commonly used in the CW-EPR literature for 14 N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14 N spin-lattice relaxation rate, b=W n /(2W e ), preserves the expressions used for CW-EPR, whilst rendering them consistent with expressions for saturation recovery rates in pulsed EPR. Furthermore, values routinely quoted for nuclear relaxation times that are deduced from EPR spectral diffusion rates in 14 N-nitroxyl spin labels do not accord with conventional analysis of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14 N-relaxation: T 1 n =1/W n . Results are compared and contrasted with those for the two-level 15 N-nitroxide system. Copyright © 2016 Elsevier Inc. All rights reserved.

Orientation-dependent effects of EPR-measurements on β-rhombohedral boron

International Nuclear Information System (INIS)

Siems, C.D.; Geist, D.

1976-01-01

EPR studies on β-rhombohedral boron have been reported by several authors. Two EPR-lines with the same g-value have been found by measurements with and without illumination. The microwave frequency used was 9 GHz, as far as is known. In this paper EPR-measurements at 35 GHz on β-rhombohedral boron single crystals are reported. The investigations concerning the 'dark EPR-line' were made at 300 K. (Auth.)

Selective saturation method for EPR dosimetry with tooth enamel

International Nuclear Information System (INIS)

Ignatiev, E.A.; Romanyukha, A.A.; Koshta, A.A.; Wieser, A.

1996-01-01

The method of selective saturation is based on the difference in the microwave (mw) power dependence of the background and radiation induced EPR components of the tooth enamel spectrum. The subtraction of the EPR spectrum recorded at low mw power from that recorded at higher mw power provides a considerable reduction of the background component in the spectrum. The resolution of the EPR spectrum could be improved 10-fold, however simultaneously the signal-to-noise ratio was found to be reduced twice. A detailed comparative study of reference samples with known absorbed doses was performed to demonstrate the advantage of the method. The application of the selective saturation method for EPR dosimetry with tooth enamel reduced the lower limit of EPR dosimetry to about 100 mGy. (author)

Mechanical Paradox: The Uphill Roller

Science.gov (United States)

Cortes, Emilio; Cortes-Poza, D.

2011-01-01

We analyse in detail the dynamics of a mechanical system which is a rigid body with the geometry of a double cone. This double cone is apparently able to spontaneously roll uphill along inclined rails. The experiment has been known for some centuries, and because of its peculiar behaviour, it has been named "mechanical paradox". Although this…

The Paradox of Painful Art

Science.gov (United States)

Smuts, Aaron

2007-01-01

Many of the most popular genres of narrative art are designed to elicit negative emotions: emotions that are experienced as painful or involving some degree of pain, which people generally avoid in their daily lives. Traditionally, the question of why people seek out such experiences of painful art has been presented as the paradox of tragedy, and…

CW EPR and 9 GHz EPR imaging investigation of stable paramagnetic species and their antioxidant activities in dry shiitake mushroom (Lentinus edodes).

Science.gov (United States)

Nakagawa, Kouichi; Hara, Hideyuki

2016-01-01

We investigated the antioxidant activities and locations of stable paramagnetic species in dry (or drying) shiitake mushroom (Lentinus edodes) using continuous wave (CW) electron paramagnetic resonance (EPR) and 9 GHz EPR imaging. CW 9 GHz EPR detected paramagnetic species (peak-to-peak linewidth (ΔHpp) = 0.57 mT) in the mushroom. Two-dimensional imaging of the sharp line using a 9 GHz EPR imager showed that the species were located in the cap and shortened stem portions of the mushroom. No other location of the species was found in the mushroom. However, radical locations and concentrations varied along the cap of the mushroom. The 9 GHz EPR imaging determined the exact location of stable paramagnetic species in the shiitake mushroom. Distilled water extracts of the pigmented cap surface and the inner cap of the mushroom showed similar antioxidant activities that reduced an aqueous solution of 0.1 mM 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl. The present results suggest that the antioxidant activities of the edible mushroom extracts are much weaker than those of ascorbic acid. Thus, CW EPR and EPR imaging revealed the location and distribution of stable paramagnetic species and the antioxidant activities in the shiitake mushroom for the first time.

Paradoxes in probability theory

CERN Document Server

Eckhardt, William

2013-01-01

Paradoxes provide a vehicle for exposing misinterpretations and misapplications of accepted principles. This book discusses seven paradoxes surrounding probability theory.  Some remain the focus of controversy; others have allegedly been solved, however the accepted solutions are demonstrably incorrect. Each paradox is shown to rest on one or more fallacies.  Instead of the esoteric, idiosyncratic, and untested methods that have been brought to bear on these problems, the book invokes uncontroversial probability principles, acceptable both to frequentists and subjectivists. The philosophical disputation inspired by these paradoxes is shown to be misguided and unnecessary; for instance, startling claims concerning human destiny and the nature of reality are directly related to fallacious reasoning in a betting paradox, and a problem analyzed in philosophy journals is resolved by means of a computer program.

EPR study on non- and gamma-irradiated herbal pills

Energy Technology Data Exchange (ETDEWEB)

Aleksieva, K., E-mail: katerina_bas@abv.b [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Lagunov, O. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Yordanov, N.D. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

2011-06-15

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048{+-}0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

EPR study on non- and gamma-irradiated herbal pills

International Nuclear Information System (INIS)

Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N.D.

2011-01-01

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

EPR study on non- and gamma-irradiated herbal pills

Science.gov (United States)

Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N. D.

2011-06-01

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show "cellulose-like" EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

EPR: Some History and Clarification

Science.gov (United States)

Fine, Arthur

2002-04-01

Locality, separation and entanglement 1930s style. We’ll explore the background to the 1935 paper by Einstein, Podolsky and Rosen, how it was composed, the actual argument of the paper, the principles used, and how the paper was received by Schroedinger, and others.We’ll also look at Bohr’s response: the extent to which Bohr connects with what Einstein was after in EPR and the extent to EPR marks a shift in Bohr’s thinking about the quantum theory.

The house economist and the eating paradox.

Science.gov (United States)

Woods, Stephen C

2002-04-01

An important observation of the experiments of George Collier is that animals normally prefer to maintain their body weight by eating a large number of small meals each day. However, as the effort to obtain access to food increases, the animals adapt by changing to a schedule of eating a small number of large meals each day. A strong implication of this is that there is a hidden cost to eating large meals, and this is the basis of the eating paradox that states that although food is a necessary commodity, the act of ingesting it poses certain metabolic problems for animals. Experiments on cephalic insulin secretion, conditioned insulin secretion and meal feeding are discussed to make the point that the economy demonstrated by rats in Collier's paradigm is dictated in part by predictions of the eating paradox. Copyright 2002 Elsevier Science Ltd.

Investigations in quantum games using EPR-type set-ups

Science.gov (United States)

Iqbal, Azhar

2006-04-01

Research in quantum games has flourished during recent years. However, it seems that opinion remains divided about their true quantum character and content. For example, one argument says that quantum games are nothing but 'disguised' classical games and that to quantize a game is equivalent to replacing the original game by a different classical game. The present thesis contributes towards the ongoing debate about quantum nature of quantum games by developing two approaches addressing the related issues. Both approaches take Einstein-Podolsky-Rosen (EPR)-type experiments as the underlying physical set-ups to play two-player quantum games. In the first approach, the players' strategies are unit vectors in their respective planes, with the knowledge of coordinate axes being shared between them. Players perform measurements in an EPR-type setting and their payoffs are defined as functions of the correlations, i.e. without reference to classical or quantum mechanics. Classical bimatrix games are reproduced if the input states are classical and perfectly anti-correlated, as for a classical correlation game. However, for a quantum correlation game, with an entangled singlet state as input, qualitatively different solutions are obtained. The second approach uses the result that when the predictions of a Local Hidden Variable (LHV) model are made to violate the Bell inequalities the result is that some probability measures assume negative values. With the requirement that classical games result when the predictions of a LHV model do not violate the Bell inequalities, our analysis looks at the impact which the emergence of negative probabilities has on the solutions of two-player games which are physically implemented using the EPR-type experiments.

Explaining seemingly paradoxical consumer experiences: conjoining weekly road rage and church attendance.

Science.gov (United States)

Gau, Li-Shiue; Woodside, Arch G; Martin, Drew

2015-02-01

The purposes of the current study are threefold: Provide evidence that an extreme paradoxical group exists-people frequently attending church and exhibiting road rage, profile this group, and frame possible explanations for the seemingly paradoxical behaviors. This study employs data from a national (USA) lifestyle survey conducted by Market Facts with 3,350 American respondents. The major questions asked about church participation and road-rage behavior ("giving a finger" and "flashing headlights"). Nomologically, relevant activities include 3 items for church goers and 3 items for road-rage givers. Additionally, 14 items profiled the lifestyles of the unique paradoxical behavior segment. Utilizing cross-tabulation tables, property space analyses identify the double extreme (XX) group (18 people) and other 6 groups with a significant chi-square test, confirming the extreme group exists. Analyses of variance test results show that comparing nomologically relevant activities among the seven groups is all statistically significant, indicating the nomological validity is met. Overall, the XX group tends to have more males, be younger, and have a higher proportion of people working in sales. The profile of lifestyle analyses shows the XX group members have both high ambitions and expectations, might be very frustrated individuals, and equip with the adventurous and masculine traits related to aggression. The XX behavior group's demographic and psychographic characteristics portray similar lifestyles that differ from other groups. Case-based analyses provide further contextual information of nuances to XX segment individuals. The limited energy theory, the Eagleman's theory of unconscious mind, and justification theory help to explain why people conjointly go to church and commit road rage. Addressing chronic paradoxical behaviors provides implications for social de-marketing to reduce aggressive anti-social behavior such as road rage. Frequent church attendance may

X-band EPR setup with THz light excitation of Novosibirsk Free Electron Laser: Goals, means, useful extras

Science.gov (United States)

Veber, Sergey L.; Tumanov, Sergey V.; Fursova, Elena Yu.; Shevchenko, Oleg A.; Getmanov, Yaroslav V.; Scheglov, Mikhail A.; Kubarev, Vitaly V.; Shevchenko, Daria A.; Gorbachev, Iaroslav I.; Salikova, Tatiana V.; Kulipanov, Gennady N.; Ovcharenko, Victor I.; Fedin, Matvey V.

2018-03-01

Electron Paramagnetic Resonance (EPR) station at the Novosibirsk Free Electron Laser (NovoFEL) user facility is described. It is based on X-band (∼9 GHz) EPR spectrometer and operates in both Continuous Wave (CW) and Time-Resolved (TR) modes, each allowing detection of either direct or indirect influence of high-power NovoFEL light (THz and mid-IR) on the spin system under study. The optics components including two parabolic mirrors, shutters, optical chopper and multimodal waveguide allow the light of NovoFEL to be directly fed into the EPR resonator. Characteristics of the NovoFEL radiation, the transmission and polarization-retaining properties of the waveguide used in EPR experiments are presented. The types of proposed experiments accessible using this setup are sketched. In most practical cases the high-power radiation applied to the sample induces its rapid temperature increase (T-jump), which is best visible in TR mode. Although such influence is a by-product of THz radiation, this thermal effect is controllable and can deliberately be used to induce and measure transient signals of arbitrary samples. The advantage of tunable THz radiation is the absence of photo-induced processes in the sample and its high penetration ability, allowing fast heating of a large portion of virtually any sample and inducing intense transients. Such T-jump TR EPR spectroscopy with THz pulses has been previewed for the two test samples, being a useful supplement for the main goals of the created setup.

Detection by EPR method of radiation treatment in dried fruits containing crystalline sugar

International Nuclear Information System (INIS)

Lehner, K.; Stachowicz, W.

2006-01-01

The results of EPR (electron paramagnetic resonance) measurements are presented on the detection ability and stability of radiation induced sugar-born radicals in the samples of dried (dehydrated) fruits available in the market and related to doses of 0.5, 1 and 3 kGy, respectively. The experiments have been conducted during 12 months of storage. Measurements were done with an EPR - 10 MINI spectrometer in X band (frequency of microwaves 9.5 GHz), St. Petersburg Instruments Ltd. The aim of the work was to prove the reliability of acceptability of the method in routine control of irradiated food. (author)

Paradoxes and Innovation in Family Firms

DEFF Research Database (Denmark)

Ingram, Amy E.; Lewis, Marianne W.; Barton, Sid

2016-01-01

thinkers are more likely to manage these tensions and fuel innovative behavior. Leveraging family business and organizational paradox literatures, this multi-stage exploratory study develops measures of paradoxical tensions and paradoxical thinking in family firms, and tests these propositions. Findings...... indicate that paradoxical tensions may stymie innovative behavior, but that leaders' paradoxical thinking is positively related to innovative behavior....

EPR study on gamma-irradiated fruits dehydrated via osmosis

International Nuclear Information System (INIS)

Yordanov, N.D.; Aleksieva, K.

2007-01-01

The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples

EPR study on gamma-irradiated fruits dehydrated via osmosis

Science.gov (United States)

Yordanov, N. D.; Aleksieva, K.

2007-06-01

The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit "sugar-like" EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

Identifying Quantum Structures in the Ellsberg Paradox

Science.gov (United States)

Aerts, Diederik; Sozzo, Sandro; Tapia, Jocelyn

2014-10-01

Empirical evidence has confirmed that quantum effects occur frequently also outside the microscopic domain, while quantum structures satisfactorily model various situations in several areas of science, including biological, cognitive and social processes. In this paper, we elaborate a quantum mechanical model which faithfully describes the Ellsberg paradox in economics, showing that the mathematical formalism of quantum mechanics is capable to represent the ambiguity present in this kind of situations, because of the presence of contextuality. Then, we analyze the data collected in a concrete experiment we performed on the Ellsberg paradox and work out a complete representation of them in complex Hilbert space. We prove that the presence of quantum structure is genuine, that is, interference and superposition in a complex Hilbert space are really necessary to describe the conceptual situation presented by Ellsberg. Moreover, our approach sheds light on `ambiguity laden' decision processes in economics and decision theory, and allows to deal with different Ellsberg-type generalizations, e.g., the Machina paradox.

Investigation of EPR signals on tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Pavlenko, A; Mironova-Ulmane, N; Polakov, M; Riekstina, D [Institute of Solid State Physics, University of Latvia, Riga (Latvia)

2007-12-15

Calcified tissues are involved in continues metabolic process in human organism exchanging a number of chemical elements with environment. The rate of biochemical reactions is tissue dependent and the slowest one at the tooth enamel, the most mineralized tissue of human organism. The long time stability and unique chemical composition make tooth enamel suitable for number of application. The assessment of individual radiation dose by Electron Paramagnetic Resonance (EPR) and evaluations of elemental composition by Instrumentation Neutron Activation Analysis (INAA) are the well known procedures where properties of tooth enamel intensively used. The current work is focused on investigation of EPR signals and determination of chemical composition on several teeth samples having different origin. The EPR spectra and INAA element content of milk tooth, caries tooth, and paradantose tooth have been compared to each other. The results showed that the intensity of EPR signal is much higher for the caries tooth than the for paradantose tooth that is in agreement with depleted Ca content.

Software for evaluation of EPR-dosimetry performance

International Nuclear Information System (INIS)

Shishkina, E.A.; Timofeev, Yu.S.; Ivanov, D.V.

2014-01-01

Electron paramagnetic resonance (EPR) with tooth enamel is a method extensively used for retrospective external dosimetry. Different research groups apply different equipment, sample preparation procedures and spectrum processing algorithms for EPR dosimetry. A uniform algorithm for description and comparison of performances was designed and implemented in a new computer code. The aim of the paper is to introduce the new software 'EPR-dosimetry performance'. The computer code is a user-friendly tool for providing a full description of method-specific capabilities of EPR tooth dosimetry, from metrological characteristics to practical limitations in applications. The software designed for scientists and engineers has several applications, including support of method calibration by evaluation of calibration parameters, evaluation of critical value and detection limit for registration of radiation-induced signal amplitude, estimation of critical value and detection limit for dose evaluation, estimation of minimal detectable value for anthropogenic dose assessment and description of method uncertainty. (authors)

EPR Spectroscopy in Environmental Lichen-Indication

Science.gov (United States)

Bondarenko, P. V.; Nguyet, Le Thi Bich; Zhuravleva, S. E.; Trukhan, E. M.

2017-09-01

The paramagnetic properties of lichens were investigated using EPR spectroscopy and Xanthoria parietina (L.) Th. Fr. as a case study. It was found that the concentration of paramagnetic centers in lichen thalli increased as the air-pollution level increased. Possible formation mechanisms of the paramagnetic centers in lichens were discussed. The efficiency of using EPR spectroscopy to study lichens as environmental quality indicators was demonstrated.

Transport de paires EPR dans des structures mesoscopiques

Science.gov (United States)

Dupont, Emilie

supraconducteurs, mais ici, les deux points quantiques seront aussi supraconducteurs. On obtiendra alors l'hamiltonien effectif de la meme maniere que precedemment ainsi que la forme du courant. Dans le cas ou la tension entre les deux fils est nulle, nous ferons une comparaison avec l'experience et nous verrons que les resultats obtenus sont plus en accord avec celle-ci si on fait l'hypothese de la presence d'un bain, qui va modeliser le bruit sur l'un des fils. Enfin, dans le dernier chapitre, nous utiliserons a la fois un qubit de charge et un qubit de spin entoures par deux fils supraconducteurs. Nous pourrons alors mesurer l'influence du supraconducteur et voir s'il est possible de creer ici des paires d'electrons intriques et d'aboutir a un pendule quantique. 1Il existe des systemes qui produisent des paires de particules ejectees simultanement dans des directions opposees et qui permettent de tester le paradoxe d' Einstein, Podolsky, Rosen. Chaque particule de la paire est dans un etat indetermine. Si on mesure les etats respectifs des deux particules, on obtient systematiquement des resultats complementaires, soit de facon aleatoire: 0-1 ou 1-0. La mecanique quantique explique que les deux particules ainsi produites constituent un seul systeme, une paire EPR.

Paradoxes in Practice

DEFF Research Database (Denmark)

Madsen, Charlotte Øland; Schulze, Pernille; Larsen, Mette Vinther

The purpose of this paper is to explore how paradoxes unfold in management practices and how moments of relational dialogic, self-reflexive learning can transform these paradoxes into new understandings of the complexities of organizing and management. We work with paradox, not as a label...... to explore ‘the flux of reality from within’ with the managers. We therefore draw on Bakhtin’s ideas regarding ongoing centripetal (monologic) and centrifugal (dialogic) forces of language and aim to demonstrate how working with language and the awareness of the embodied embedded practices at the same time...

On the annealing of the EPR dislocation signal in silicon

International Nuclear Information System (INIS)

Zolotukhin, M.N.; Kveder, V.V.; Osip'yan, Yu.A.

1981-01-01

The annealing kinetics of the (EPR) dislocation signal (D-centers) in silicon is studied. The disappearance of the dislocation EPR signal as a result of annealing is ascribed to rearrangement of the nuclei of the partial dislocations accompanied by pairwise ''closing'' of the broken bonds in the S=0 state. The height of the energy barrier for the rearrangement process is approximately 2 eV. A residual ''nonannealing'' EPR signal is observed in strongly deformed silicon crystals. It resembles an isotropic line with a width approximately 7.5 Oe and a g-factor approximately 2.006. It is suggested that the respective EPR centers (O-centers) are similar to the EPR centers in amorphic silicon [ru

Magnetic, catalytic, EPR and electrochemical studies on binuclear ...

Indian Academy of Sciences (India)

Magnetic, catalytic, EPR and electrochemical studies on binuclear copper(II) complexes ... to the oxidation of 3,5-di--butylcatechol to the corresponding quinone. ... EPR spectral studies in methanol solvent show welldefined four hyperfine ...

EPR spectroscopy of complex biological iron-sulfur systems.

Science.gov (United States)

Hagen, Wilfred R

2018-02-21

From the very first discovery of biological iron-sulfur clusters with EPR, the spectroscopy has been used to study not only purified proteins but also complex systems such as respiratory complexes, membrane particles and, later, whole cells. In recent times, the emphasis of iron-sulfur biochemistry has moved from characterization of individual proteins to the systems biology of iron-sulfur biosynthesis, regulation, degradation, and implications for human health. Although this move would suggest a blossoming of System-EPR as a specific, non-invasive monitor of Fe/S (dys)homeostasis in whole cells, a review of the literature reveals limited success possibly due to technical difficulties in adherence to EPR spectroscopic and biochemical standards. In an attempt to boost application of System-EPR the required boundary conditions and their practical applications are explicitly and comprehensively formulated.

Thermal induced EPR signals in tooth enamel

International Nuclear Information System (INIS)

Fattibene, P.; Aragno, D.; Onori, S.; Pressello, M.C.

2000-01-01

Electron paramagnetic resonance (EPR) spectroscopy was used to detect the effects of temperature on powdered human tooth enamel, not irradiated in the laboratory. Samples were heated at temperature between 350 and 450, at 600 and at 1000 deg. C, for different heating times, between 6 min and 39 h. Changes in the EPR spectra were detected, with the formation of new signals. Possible correlation between the changes in EPR spectra and modifications in the enamel and in the mineral phase of bone detected with other techniques is discussed. The implications for dosimetric applications of signals induced by overheating due to mechanical friction during sample preparation are underlined

The Oxygen Paradox, the French Paradox, and age-related diseases.

Science.gov (United States)

Davies, Joanna M S; Cillard, Josiane; Friguet, Bertrand; Cadenas, Enrique; Cadet, Jean; Cayce, Rachael; Fishmann, Andrew; Liao, David; Bulteau, Anne-Laure; Derbré, Frédéric; Rébillard, Amélie; Burstein, Steven; Hirsch, Etienne; Kloner, Robert A; Jakowec, Michael; Petzinger, Giselle; Sauce, Delphine; Sennlaub, Florian; Limon, Isabelle; Ursini, Fulvio; Maiorino, Matilde; Economides, Christina; Pike, Christian J; Cohen, Pinchas; Salvayre, Anne Negre; Halliday, Matthew R; Lundquist, Adam J; Jakowec, Nicolaus A; Mechta-Grigoriou, Fatima; Mericskay, Mathias; Mariani, Jean; Li, Zhenlin; Huang, David; Grant, Ellsworth; Forman, Henry J; Finch, Caleb E; Sun, Patrick Y; Pomatto, Laura C D; Agbulut, Onnik; Warburton, David; Neri, Christian; Rouis, Mustapha; Cillard, Pierre; Capeau, Jacqueline; Rosenbaum, Jean; Davies, Kelvin J A

2017-12-01

A paradox is a seemingly absurd or impossible concept, proposition, or theory that is often difficult to understand or explain, sometimes apparently self-contradictory, and yet ultimately correct or true. How is it possible, for example, that oxygen "a toxic environmental poison" could be also indispensable for life (Beckman and Ames Physiol Rev 78(2):547-81, 1998; Stadtman and Berlett Chem Res Toxicol 10(5):485-94, 1997)?: the so-called Oxygen Paradox (Davies and Ursini 1995; Davies Biochem Soc Symp 61:1-31, 1995). How can French people apparently disregard the rule that high dietary intakes of cholesterol and saturated fats (e.g., cheese and paté) will result in an early death from cardiovascular diseases (Renaud and de Lorgeril Lancet 339(8808):1523-6, 1992; Catalgol et al. Front Pharmacol 3:141, 2012; Eisenberg et al. Nat Med 22(12):1428-1438, 2016)?: the so-called, French Paradox. Doubtless, the truth is not a duality and epistemological bias probably generates apparently self-contradictory conclusions. Perhaps nowhere in biology are there so many apparently contradictory views, and even experimental results, affecting human physiology and pathology as in the fields of free radicals and oxidative stress, antioxidants, foods and drinks, and dietary recommendations; this is particularly true when issues such as disease-susceptibility or avoidance, "healthspan," "lifespan," and ageing are involved. Consider, for example, the apparently paradoxical observation that treatment with low doses of a substance that is toxic at high concentrations may actually induce transient adaptations that protect against a subsequent exposure to the same (or similar) toxin. This particular paradox is now mechanistically explained as "Adaptive Homeostasis" (Davies Mol Asp Med 49:1-7, 2016; Pomatto et al. 2017a; Lomeli et al. Clin Sci (Lond) 131(21):2573-2599, 2017; Pomatto and Davies 2017); the non-damaging process by which an apparent toxicant can activate biological signal

Limits in EPR dosimetry for irradiated dried fruits discrimination

International Nuclear Information System (INIS)

Brasoveanu, Mirela M. E-mirela@alpha.infim.ro; Nemtanu, R.; Minea, R.; Grecu, V.V.

2003-01-01

Irradiation of food induces free radical species. EPR dosimetry in irradiated goods puts in evidence if these radicals are stable in environmental condition. Irradiation of dried fruits has been carried out. Their behaviour under irradiation was investigated and correlation between EPR signal and irradiation dose was determined. Electrons of 6 MeV (mean energy) and doses up to 10 kGy were used. EPR spectra were recorded with a Jeol spectrometer, JES-ME-3X tip, with a 100 kHz modulation. The dried fruits can be separated into categories depending on the EPR signal intensity. Strong signals are observed in those fruits in which possible crystalline-like phases exist. As the amount of crystallized sugar decreases, the EPR signals become weaker. Dependencies on irradiation dose give a linear correlation below 10 kGy. The spectra are compared to irradiated sugar and differences and similarities are discussed. (authors)

EDF EPR project: operating principles validation and human factor engineering program

International Nuclear Information System (INIS)

Lefebvre, B.; Berard, E.; Arpino, J.-M.

2005-01-01

This article describes the specificities of the operating principles chosen by EDF for the EPR project as a result of an extensive Human Factor Engineering program successfully implemented in an industrial project context. The design process and its achievements benefit of the EDF experience feedback not only in term of NPP operation - including the fully computerized control room of the N4-serie - but also in term of NPP designer. The elements exposed hereafter correspond to the basic design phase of EPR HMI which has been completed and successfully validated by the end of 2003. The article aims to remind the context of the project which basically consists in designing a modern and efficient HMI taking into account the operating needs while relying on proven and reliable technologies. The Human Factor Engineering program implemented merges these both aspects by : 1) being fully integrated within the project activities and scheduling; 2) efficiently taking into account the users needs as well as the feasibility constraints by relying on a multidisciplinary design team including HF specialists, I and C specialists, Process specialists and experienced operator representatives. The resulting design process makes a wide use of experience feedback and experienced operator knowledge to complete largely the existing standards for providing a fully useable and successful design method in an industrial context. The article underlines the design process highlights that largely contribute to the successful implementation of a Human Factor Engineering program for EPR. (authors)

EPR study on gamma-irradiated fruits dehydrated via osmosis

Energy Technology Data Exchange (ETDEWEB)

Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)]. E-mail: ndyepr@bas.bg; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

2007-06-15

The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and {gamma}-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas {gamma}-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

Political Animals: The Paradox of Ecofeminist Politics.

Science.gov (United States)

Sandilands, Catriona

1994-01-01

Analyzes the paradox between the careful work of rigorous political analysis and philosophy and a desire for mystery and the experience of awe and wildness that demands putting aside careful reasoning and the sensing of nature in an altogether different way. (LZ)

Some ideas on the EPR

International Nuclear Information System (INIS)

2003-01-01

Facing the debate and controversial between partisans and opponents of the European Pressurized Reactor construction, the SFP energy Group aims to offer some reflexions. In this framework the following topics are discussed: the french nuclear park and its replacement, the energy costs, the nuclear reactors profitability, the generation IV reactors. The paper examines then the EPR technology and its cost to conclude on the advantage of an EPR construction, in the case of an energy policy based on the nuclear. This last point seems to be the real challenge of the problem. (A.L.B.)

PropeR: a multi disciplinary EPR system

NARCIS (Netherlands)

van der Linden, Helma; Boers, Gerrit; Tange, Huibert; Talmon, Jan; Hasman, Arie

2003-01-01

This article describes the architecture of an EPR system developed for the PropeR project. This EPR system not only aims at supporting home care of stroke patients, but is also designed in such a way that it can be ported to other medical services without much effort. We will briefly describe the

The Flamanville 3 EPR reactor; Le reacteur EPR Flamanville 3

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

On April 10. 2007, the french government authorized EDF to create on the site of Flamanville ( La Manche) a nuclear base installation containing a pressurized water EPR type reactor. This nuclear reactor, conceived by AREVA NP and EDF, is the first copy of a generation susceptible to replace later, at least partly, the French nuclear reactors at present in operation.Within the framework of its mission of technical support of the Authority of Nuclear Safety ( A.S.N.), the I.R.S.N. widely contributed successively: to define the general objectives of safety assigned to this new generation of pressurized water nuclear reactors; to analyze the options of safety proposed by EDF for the EPR project; To deepen, upstream to the authorization of creation, the evaluation of the step of safety and the measures of conception retained by EDF that have to allow to respect the objectives of safety which were notified to it. (N.C.)

Microphysical reality and quantum formalism

International Nuclear Information System (INIS)

Van der Merwe, A.; Tarozzi, G.

1988-01-01

The many controversies and paradoxes surrounding any interpretation of the quantum microworld are here examined in detail by some of the world's foremost experts. In Volume 1 there are sections on quantum measurements, new developments of quantum theory, the meanings of quantum theory, and the EPR Paradox. Volume 2 discusses whether a causal theory of quantum theory is possible and then progresses to an examination of quantum objects as waves or particles. Finally, the EPR paradox is reinterpreted in the light of recent formulations and possible solutions. refs.; figs.; tabs

New strategy to identify radicals in a time evolving EPR data set by multivariate curve resolution-alternating least squares

Energy Technology Data Exchange (ETDEWEB)

Fadel, Maya Abou [LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d' Ascq Cedex (France); Juan, Anna de [Chemometrics Group, Section of Analytical Chemistry, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Vezin, Hervé [LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d' Ascq Cedex (France); Duponchel, Ludovic, E-mail: ludovic.duponchel@univ-lille1.fr [LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d' Ascq Cedex (France)

2016-12-01

Electron paramagnetic resonance (EPR) spectroscopy is a powerful technique that is able to characterize radicals formed in kinetic reactions. However, spectral characterization of individual chemical species is often limited or even unmanageable due to the severe kinetic and spectral overlap among species in kinetic processes. Therefore, we applied, for the first time, multivariate curve resolution-alternating least squares (MCR-ALS) method to EPR time evolving data sets to model and characterize the different constituents in a kinetic reaction. Here we demonstrate the advantage of multivariate analysis in the investigation of radicals formed along the kinetic process of hydroxycoumarin in alkaline medium. Multiset analysis of several EPR-monitored kinetic experiments performed in different conditions revealed the individual paramagnetic centres as well as their kinetic profiles. The results obtained by MCR-ALS method demonstrate its prominent potential in analysis of EPR time evolved spectra. - Highlights: • A new strategy to identify radicals in a time evolving EPR data set. • Extraction of pure EPR spectral signatures and corresponding kinetic profiles. • The proposed method does not require any prior knowledge of the chemical system. • A multiset analysis in order to decrease rotational ambiguity.

Polymer therapeutics and the EPR effect.

Science.gov (United States)

Maeda, Hiroshi

History of the EPR (enhanced permeability and retention) effect is discussed, which goes back to the analyses of molecular pathology in bacterial infection and edema (extravasation) formation. The first mediator we found for extravasation was bradykinin. Later on, were found nitric oxide and superoxide, then formation of peroxynitrite, that activates procollagenase. In this inflammatory setting many other vascular mediators are involved that are also common to cancer vasculature. Obviously cancer vasculature is defective architechtally, and this makes macromolecular drugs more permeable through the vascular wall. The importance of this pathophysiological event of EPR effect can be applied to macromolecular drug-delivery, or tumor selective delivery, which takes hours to achieve in the primary as well as metastatic tumors, not to mention of the inflamed tissues. The retention of the EPR means that such drugs will be retained in tumor tissues more than days to weeks. This was demonstrated initially, and most dramatically, using SMANCS, a protein-polymer conjugated-drug dissolved in lipid contrast medium (Lipiodol) by administering intraarterially. For disseminating the EPR concept globally, or in the scientific community, Professor Ruth Duncan played a key role at the early stage, as she worked extensively on polymer- therapeutics, and knew its importance.

Water-resistant alanine-EPR dosimeter alanpol

International Nuclear Information System (INIS)

Peimel-Stuglik, Zofia; Bryl-Sandelewska, Teresa; Mirkowski, Krzysztof; Sartowska, Bozena

2009-01-01

Alanpol-water-resistant alanine-electron paramagnetic resonance (EPR) dosimeter consisted of cheap DL-α-alanine (9.8-27%) suspended in polyethylene matrix was presented. The rods (O=2.8 mm) were extruded from a hot mixture of alanine and low-density polyethylene. No grinding or crushing was used for alanine preparation. An orientation of cylindrical crystals, up to 300 μm long in parallel to the rod axis was responsible for some differences in a shape of EPR signal. These differences had no negative consequences for dosimetric applications. Signal-to-dose dependence was linear up to 10 kGy. Standard deviation of dosimetric answer was up to ±1.8% and up to 2.4% for dosimeters with 9.8% and 27% of DL-α-alanine, respectively. Irradiation temperature coefficient for both dosimeters was equal 0.2%/ deg. C. Hydrophobic properties of polyethylene and small number of alanine crystals located on the surface of the rod led to high resistance of dosimeters to water and humidity. The 24 h soaking of irradiated dosimeters in liquid water-reduced EPR signals by 3-4% and by 2-3% for dosimeters with 27% and 9.8% of DL-α-alanine, respectively. Three month storage time of irradiated dosimeters in room conditions decreases EPR signal for ∼3%.

EPR meets the next generation PWR safety requirements

International Nuclear Information System (INIS)

Bouteille, Francois; Czech, Juergen; Sloan, Sandra

2006-01-01

features are implemented to satisfy the following safety objectives required by the Safety Authorities: - achieve a significantly lower core melt probability by appropriate prevention means, - achieve the 'preclusion' of accidents liable to cause early containment failure, such as core melt under high pressure conditions, - achieve a major reduction in the radioactive releases, which could result from low pressure core melt accidents. The EPR is furthermore characterized by a robust containment not only with respect to hypothetical loads resulting from a core melt accident but also from external hazards resulting from extreme situations such as an aircraft crash directly on the Nuclear Island buildings. The evolutionary approach chosen by EPR designers thus corresponds to the optimal mix between largely proven solutions derived from the largest experience and innovative features needed to meet new requirements, particularly in the field of safety. (authors)

Computational and instrumental methods in EPR

CERN Document Server

Bender, Christopher J

2006-01-01

Computational and Instrumental Methods in EPR Prof. Bender, Fordham University Prof. Lawrence J. Berliner, University of Denver Electron magnetic resonance has been greatly facilitated by the introduction of advances in instrumentation and better computational tools, such as the increasingly widespread use of the density matrix formalism. This volume is devoted to both instrumentation and computation aspects of EPR, while addressing applications such as spin relaxation time measurements, the measurement of hyperfine interaction parameters, and the recovery of Mn(II) spin Hamiltonian parameters via spectral simulation. Key features: Microwave Amplitude Modulation Technique to Measure Spin-Lattice (T1) and Spin-Spin (T2) Relaxation Times Improvement in the Measurement of Spin-Lattice Relaxation Time in Electron Paramagnetic Resonance Quantitative Measurement of Magnetic Hyperfine Parameters and the Physical Organic Chemistry of Supramolecular Systems New Methods of Simulation of Mn(II) EPR Spectra: Single Cryst...

Pressurized water reactors: the EPR project

International Nuclear Information System (INIS)

Py, J.P.; Yvon, M.

2007-01-01

EPR (originally 'European pressurized water reactor', and now 'evolutionary power reactor') is a model of reactor initially jointly developed by French and German engineers which fulfills the particular safety specifications of both countries but also the European utility requirements jointly elaborated by the main European power companies under the initiative of Electricite de France (EdF). Today, two EPR-based reactors are under development: one is under construction in Finland and the other, Flamanville 3 (France), received its creation permit decree on April 10, 2007. This article presents, first, the main objectives of the EPR, and then, describes the Flamanville 3 reactor: reactor type and general conditions, core and conditions of operation, primary and secondary circuits with their components, main auxiliary and recovery systems, man-machine interface and instrumentation and control system, confinement and serious accidents, arrangement of buildings. (J.S.)

Multisetting Greenberger-Horne-Zeilinger paradoxes

Science.gov (United States)

Tang, Weidong; Yu, Sixia; Oh, C. H.

2017-01-01

The Greenberger-Horne-Zeilinger (GHZ) paradox provides an all-versus-nothing test for the quantum nonlocality. In most of the GHZ paradoxes known so far each observer is allowed to measure only two alternative observables. Here we present a general construction for GHZ paradoxes in which each observer measures more than two observables given that the system is prepared in the n -qudit GHZ state. By doing so we are able to construct a multisetting GHZ paradox for the n -qubit GHZ state, with n being arbitrary, which is genuine n -partite; i.e., no GHZ paradox exists when restricted to a subset of a number of observers for a given set of Mermin observables. Our result fills up the gap of the absence of a genuine GHZ paradox for the GHZ state of an even number of qubits, especially the four-qubit GHZ state as used in GHZ's original proposal.

EPR design: A combined approach on safety and economic competitiveness

International Nuclear Information System (INIS)

Griedl, R.; Sturm, J.; Degrave, C.; Kappler, F.; Martin-Onraet, M.

2001-01-01

Starting in 1991, the French and German cooperation led to common work based on the experience of the two designers FRAMATOME and SIEMENS KWU with all their know how, the most important utilities in France and Germany operating NPP and the technical supports of the Licensing Authorities GRS and IPSN. The conclusion of that work was the issue in November 1997 and February 1999 respectively of two Basic Design reports for a European Pressurized Reactor (EPR) with a power of 4250 MWth and 4900 MWth. The Basic Design approach was led under two key items: Enhancement of the overall safety level by implementation of design measures to: make the plant less dependant to common cause failures; practically eliminate all high pressure core melt sequences which could lead to important radioactive releases to the environment; implement specific systems to face severe accident situation with low-pressure core melt. Use of the many years of experiences in two different nuclear designs is to reach an overall availability figure over 91%, partly due to design improvements on the safety level. With such an objective, demonstrated by feedback of experience on already operating plants, the EPR project can be proposed as a competitive alternative to the most recent fossil plants. (author)

E-PR technologies in political party activities

OpenAIRE

Tereshchuk Vitaliy Ivanovych

2016-01-01

The article discusses the role of the Internet as an important communicative tool in the field of political PR. The article reviews the characteristics of PR-activities on the Internet and the features of e-PR in the political sphere. Particular attention is paid to the system of political party’s e-PR tools.

EPR: the nuclear impasse; EPR: l'impasse nucleaire

Energy Technology Data Exchange (ETDEWEB)

Marillier, F. [Association Ecologiste Greenpeace (France)

2008-07-01

The questions relative to the climatic change constitute crucial challenges for the next ten years. In this context the author aims to show how the EPR project illustrates the nuclear french ''autism''. He presents and analyzes the international and environmental impacts of this obsolete technology, as a project useless and dangerous. (A.L.B.)

Characterization of the factors having an influence on the evolution of the EPR signal of irradiated alanine

International Nuclear Information System (INIS)

Feaugas-Le-Berre, Valerie

1999-01-01

EPR/alanine dosimetry has been used by the LNHB (Laboratoire National Henri Becquerel) since many years for applied metrology. This technic is based on the measurement of the EPR signal of the free radicals induced in alanine by irradiation. The aim of this work is to characterize the factors having an influence on the evolution of the amplitude of the EPR signal of irradiated alanine to limit the uncertainties on the determination of the absorbed dose. The first step of this work has been the choice of the dosimeter. A bibliographic study completed by experiments on the response of alanine isomers to the dose and on its stability with time has lead us to choose L-α-alanine powder as dosimeter. The influence of the recording parameter of the spectrometer on the characteristics of the EPR spectrum has then been studied. This has enabled us to optimize the recording conditions of EPR spectra. As the angular anisotropy of the EPR signal limits the measurements reproducibility, an experimental protocol has been defined to solve this problem. The repeatability of the measurements has been enhanced by modifying the spectrometer and using an internal standard constituted of single crystals of CuSO 4 .5H 2 O. As the amplitude of the EPR signal is sensitive to the measurement temperature, a method of normalization of the results to 20 C has been determined. We have studied the influence of an irradiation parameter and of environmental parameters. We have shown that the EPR signal amplitude increases with irradiation temperature. The EPR signal amplitude and its evolution vary strongly with storage conditions (temperature and moisture) of the dosimeter before and after irradiation. The presence of moisture in alanine powder leads to a loss of signal amplitude. The dosimeters exposition to light also entails a loss of amplitude. Oxygen does not influence the EPR spectrum of alanine. We have noticed that the EPR signal amplitude of samples stored in absence of moisture

X-band EPR setup with THz light excitation of Novosibirsk Free Electron Laser: Goals, means, useful extras.

Science.gov (United States)

Veber, Sergey L; Tumanov, Sergey V; Fursova, Elena Yu; Shevchenko, Oleg A; Getmanov, Yaroslav V; Scheglov, Mikhail A; Kubarev, Vitaly V; Shevchenko, Daria A; Gorbachev, Iaroslav I; Salikova, Tatiana V; Kulipanov, Gennady N; Ovcharenko, Victor I; Fedin, Matvey V

2018-03-01

Electron Paramagnetic Resonance (EPR) station at the Novosibirsk Free Electron Laser (NovoFEL) user facility is described. It is based on X-band (∼9 GHz) EPR spectrometer and operates in both Continuous Wave (CW) and Time-Resolved (TR) modes, each allowing detection of either direct or indirect influence of high-power NovoFEL light (THz and mid-IR) on the spin system under study. The optics components including two parabolic mirrors, shutters, optical chopper and multimodal waveguide allow the light of NovoFEL to be directly fed into the EPR resonator. Characteristics of the NovoFEL radiation, the transmission and polarization-retaining properties of the waveguide used in EPR experiments are presented. The types of proposed experiments accessible using this setup are sketched. In most practical cases the high-power radiation applied to the sample induces its rapid temperature increase (T-jump), which is best visible in TR mode. Although such influence is a by-product of THz radiation, this thermal effect is controllable and can deliberately be used to induce and measure transient signals of arbitrary samples. The advantage of tunable THz radiation is the absence of photo-induced processes in the sample and its high penetration ability, allowing fast heating of a large portion of virtually any sample and inducing intense transients. Such T-jump TR EPR spectroscopy with THz pulses has been previewed for the two test samples, being a useful supplement for the main goals of the created setup. Copyright © 2018 Elsevier Inc. All rights reserved.

EPR spectra of some irradiated polycrystalline perrhenate

International Nuclear Information System (INIS)

Zaitseva, N.G.; Constantinescu, M.; Georgescu, R.; Constantinescu, O.

1978-10-01

An EPR study of the paramagnetic centers formed by γ, electron and neutron irradiation of the NaReO 4 and KReO 4 was made. In the EPR spectra of the powder samples irradiated γ, with electrons and neutrons, the presence of three types of paramagnetic centers was observed. From the EPR parameters, the centers were attributed to the ReOsub(4)sup(.), ReOsub(3)sup(.) and ReOsub(2)sup(.) radicals respectively. The lower intensity of the spectra observed by KReO 4 samples irradiation showed a higher radioresistance of the KReO 4 than that of NaReO 4 . A radiolitical scheme taking into account the paramagnetic centers formation was proposed. (author)

Use of spin traps to detect superoxide production in living cells by electron paramagnetic resonance (EPR) spectroscopy.

Science.gov (United States)

Abbas, Kahina; Babić, Nikola; Peyrot, Fabienne

2016-10-15

Detection of superoxide produced by living cells has been an on-going challenge in biology for over forty years. Various methods have been proposed to address this issue, among which spin trapping with cyclic nitrones coupled to EPR spectroscopy, the gold standard for detection of radicals. This technique is based on the nucleophilic addition of superoxide to a diamagnetic cyclic nitrone, referred to as the spin trap, and the formation of a spin adduct, i.e. a persistent radical with a characteristic EPR spectrum. The first application of spin trapping to living cells dates back 1979. Since then, considerable improvements of the method have been achieved both in the structures of the spin traps, the EPR methodology, and the design of the experiments including appropriate controls. Here, we will concentrate on technical aspects of the spin trapping/EPR technique, delineating recent breakthroughs, inherent limitations, and potential artifacts. Copyright © 2016 Elsevier Inc. All rights reserved.

Increase of weakly acidic gas esophagopharyngeal reflux (EPR) and swallowing-induced acidic/weakly acidic EPR in patients with chronic cough responding to proton pump inhibitors.

Science.gov (United States)

Kawamura, O; Shimoyama, Y; Hosaka, H; Kuribayashi, S; Maeda, M; Nagoshi, A; Zai, H; Kusano, M

2011-05-01

Gastro-esophageal reflux disease (GERD)-related chronic cough (CC) may have multifactorial causes. To clarify the characteristics of esophagopharyngeal reflux (EPR) events in CC patients whose cough was apparently influenced by gastro-esophageal reflux (GER), we studied patients with CC clearly responding to full-dose proton pump inhibitor (PPI) therapy (CC patients). Ten CC patients, 10 GERD patients, and 10 healthy controls underwent 24-h ambulatory pharyngo-esophageal impedance and pH monitoring. Weakly acidic reflux was defined as a decrease of pH by >1 unit with a nadir pH >4. In six CC patients, monitoring was repeated after 8 weeks of PPI therapy. The number of each EPR event and the symptom association probability (SAP) were calculated. Symptoms were evaluated by a validated GERD symptom questionnaire. Weakly acidic gas EPR and swallowing-induced acidic/weakly acidic EPR only occurred in CC patients, and the numbers of such events was significantly higher in the CC group than in the other two groups (P pump inhibitor therapy abolished swallowing-induced acidic/weakly acidic EPR, reduced weakly acidic gas EPR, and improved symptoms (all P gas EPR and swallowing-induced acidic/weakly acidic EPR. A direct effect of acidic mist or liquid refluxing into the pharynx may contribute to chronic cough, while cough may also arise indirectly from reflux via a vago-vagal reflex in some patients. © 2011 Blackwell Publishing Ltd.

Paradoxical self-esteem and selectivity in the processing of social information.

Science.gov (United States)

Tafarodi, R W

1998-05-01

Paradoxical self-esteem is defined as contrasting levels of self-liking and self-competence. Consideration of the social and motivational implications of this uncommon form of self-esteem suggests that heightened selectivity in the processing of social information may be behind its persistence. Two experiments were conducted to confirm the prediction of heightened selectivity in paradoxicals. As expected, those paradoxically low in self-liking were more negatively biased in their memory for personality feedback (Study 1) and interpretation of valuatively ambiguous phrases (Study 2) than were their counterparts who shared the same low self-liking but were also low in self-competence. Symmetrical with this result, those paradoxically high in self-liking exhibited a heightened positive bias relative to those who were high in both self-liking and self-competence. The findings are discussed in relation to attitudes and motivation.

Investigations on resolution enhancement in EPR by means of electron spin echoes

International Nuclear Information System (INIS)

Merks, R.P.J.

1979-01-01

The electron spin echo technique has been applied in four types of experiments: the measurement of electric field induced shifts of the EPR line; the detection of electron spin echo ENDOR; a relaxation measurement and the measurement of hyperfine interactions via the nuclear modulation effect. (Auth.)

Quantum teleportation. New wave of applications of quantum mechanics based on quantum entanglement: non-trivial transfer of quantum information

International Nuclear Information System (INIS)

Andrej, L.; Bednar, M.; Cernansky, M.

1999-01-01

The phenomenon of quantum teleportation is discussed with emphasis on its physical aspects. A brief introduction into the Einstein-Podolsky-Rosen (EPR) paradox is followed by Bohm's reformulation of the EPR paradox for the case of a physical system of two spins in the singlet state. A description of Bell's entangled spin states of two-particle systems of standard fermions as well as polarized photons is also given. In view of the fact that quantum teleportation has been realized experimentally mainly on photons, the next part of the paper is devoted to problems of generation and detection of two-photon Bell's entangled states. A detailed description of the process of quantum teleportation exploiting quantum entangled states follows. A classical formulation of the EPR paradox is given in the Appendix. (Z.J.)

Perspectives on the quantum Zeno paradox

Science.gov (United States)

Itano, Wayne M.

2009-11-01

As of October 2006, there were approximately 535 citations to the seminal 1977 paper of Misra and Sudarshan that pointed out the quantum Zeno paradox (more often called the quantum Zeno effect). In simple terms, the quantum Zeno effect refers to a slowing down of the evolution of a quantum state in the limit that the state is observed continuously. There has been much disagreement as to how the quantum Zeno effect should be defined and as to whether it is really a paradox, requiring new physics, or merely a consequence of "ordinary" quantum mechanics. The experiment of Itano, Heinzen, Bollinger, and Wineland, published in 1990, has been cited around 347 times and seems to be the one most often called a demonstration of the quantum Zeno effect. Given that there is disagreement as to what the quantum Zeno effect is, there naturally is disagreement as to whether that experiment demonstrated the quantum Zeno effect. Some differing perspectives regarding the quantum Zeno effect and what would constitute an experimental demonstration are discussed.

Perspectives on the quantum Zeno paradox

International Nuclear Information System (INIS)

Itano, Wayne M

2009-01-01

As of October 2006, there were approximately 535 citations to the seminal 1977 paper of Misra and Sudarshan that pointed out the quantum Zeno paradox (more often called the quantum Zeno effect). In simple terms, the quantum Zeno effect refers to a slowing down of the evolution of a quantum state in the limit that the state is observed continuously. There has been much disagreement as to how the quantum Zeno effect should be defined and as to whether it is really a paradox, requiring new physics, or merely a consequence of 'ordinary' quantum mechanics. The experiment of Itano, Heinzen, Bollinger, and Wineland, published in 1990, has been cited around 347 times and seems to be the one most often called a demonstration of the quantum Zeno effect. Given that there is disagreement as to what the quantum Zeno effect is, there naturally is disagreement as to whether that experiment demonstrated the quantum Zeno effect. Some differing perspectives regarding the quantum Zeno effect and what would constitute an experimental demonstration are discussed.

Applications of EPR in radiation research

CERN Document Server

Lund, Anders

2014-01-01

Applications of EPR in Radiation Research is a multi-author contributed volume presented in eight themes: I. Elementary radiation processes (in situ and low temperature radiolysis, quantum solids); II: Solid state radiation chemistry (crystalline, amorphous and heterogeneous systems); III: Biochemistry, biophysics and biology applications (radicals in biomaterials, spin trapping, free-radical-induced DNA damage); IV: Materials science (polymeric and electronic materials, materials for treatment of nuclear waste, irradiated food); V: Radiation metrology (EPR-dosimetry, retrospective and medical

Two copies of the Einstein-Podolsky-Rosen state of light lead to refutation of EPR ideas.

Science.gov (United States)

Rosołek, Krzysztof; Stobińska, Magdalena; Wieśniak, Marcin; Żukowski, Marek

2015-03-13

Bell's theorem applies to the normalizable approximations of original Einstein-Podolsky-Rosen (EPR) state. The constructions of the proof require measurements difficult to perform, and dichotomic observables. By noticing the fact that the four mode squeezed vacuum state produced in type II down-conversion can be seen both as two copies of approximate EPR states, and also as a kind of polarization supersinglet, we show a straightforward way to test violations of the EPR concepts with direct use of their state. The observables involved are simply photon numbers at outputs of polarizing beam splitters. Suitable chained Bell inequalities are based on the geometric concept of distance. For a few settings they are potentially a new tool for quantum information applications, involving observables of a nondichotomic nature, and thus of higher informational capacity. In the limit of infinitely many settings we get a Greenberger-Horne-Zeilinger-type contradiction: EPR reasoning points to a correlation, while quantum prediction is an anticorrelation. Violations of the inequalities are fully resistant to multipair emissions in Bell experiments using parametric down-conversion sources.

EPR and X-ray diffraction investigation of some Greek marbles and limestones

International Nuclear Information System (INIS)

Duliu, Octavian; Grecu, Maria Nicoleta; Cristea, Corina

2009-01-01

Twelve different marble and limestone samples collected from well-known Greek quarries have been investigated by X-ray diffraction and electron paramagnetic resonance (EPR). X-ray diffraction spectra permitted to determine both major (calcite and dolomite) and minor (quartz or magnesite) mineralogical components. EPR has been used to investigate the same samples unirradiated and after 10 kGy gamma-ray irradiation. The unirradiated samples display typical EPR spectra of Mn 2+ in calcite and dolomite as well as a superposition of these while some samples displayed EPR free radicals signals of centers (low field signal) and centers (high field signal). From X-ray diffraction and EPR spectra it was possible to extract numerical values of several numerical parameters such as dolomite to calcite ratio, EPR intensity parameter, and low field to high field EPR signals intensity ratio. These values as well as the correlation coefficients between the digital functions that described the low field Mn 2+ ions EPR line have been used as entry data for cluster analysis to quantify the resemblance and differences between analyzed samples. (authors)

Causal ubiquity in quantum physics a superluminal and local-causal physical ontology

CERN Document Server

Neelamkavil, Raphael

2014-01-01

A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly non-causal processes, something exists processually in extension-motion, between the causal and the non-causal. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That

Tachyons and causal paradoxes

International Nuclear Information System (INIS)

Maund, J.B.

1979-01-01

Although the existence of tachyons is not ruled out by special relativity, it appears that causal paradoxes will arise if there are tachyons. The usual solutions to these paradoxes employ some form of the reinterpretation principle. In this paper it is argued first that, the principle is incoherent, second, that even if it is not, some causal paradoxes remain, and third, the most plausible ''solution,'' which appeals to boundary conditions of the universe, will conflict with special relativity

Quantum correlations, non-locality and the EPR paradox

Energy Technology Data Exchange (ETDEWEB)

Paramananda, V.; Butt, D.K.

1987-04-01

An experiment measuring the relative polarisations of paired 511 keV photons from s-state e/sup +/e/sup -/ annihilation has shown that within the errors of measurement quantum correlations do not fall off with increasing detector-detector separation up to a separation of 24 m. An important aspect of the measurement has been that the resolving time of the electronic equipment could be made as small as 100 ps. This gave the largest spacelike geometry of any such measurement so far. An attempt has been made to explain any possible fall-off of the correlation within the error of the measurement in terms of scattering produced by hypothetical virtual quantum black holes.

Implementing a new EPR lineshape parameter for organic radicals in carbonaceous matter.

Science.gov (United States)

Bourbin, Mathilde; Du, Yann Le; Binet, Laurent; Gourier, Didier

2013-07-17

Electron Paramagnetic Resonance (EPR) is a non-destructive, non-invasive technique useful for the characterization of organic moieties in primitive carbonaceous matter related to the origin of life. The classical EPR parameters are the peak-to-peak amplitude, the linewidth and the g factor; however, such parameters turn out not to suffice to fully determine a single EPR line. In this paper, we give the definition and practical implementation of a new EPR parameter based on the signal shape that we call the R10 factor. This parameter was originally defined in the case of a single symmetric EPR line and used as a new datation method for organic matter in the field of exobiology. Combined to classical EPR parameters, the proposed shape parameter provides a full description of an EPR spectrum and opens the way to novel applications like datation. Such a parameter is a powerful tool for future EPR studies, not only of carbonaceous matter, but also of any substance which spectrum exhibits a single symmetric line. The paper is a literate program-written using Noweb within the Org-mode as provided by the Emacs editor- and it also describes the full data analysis pipeline that computes the R10 on a real EPR spectrum.

Overview of LBB implementation for the EPR

International Nuclear Information System (INIS)

Cauquelin, C.

1997-01-01

This paper presents an overview of the use of leak-before-break (LBB) analysis for EPR reactors. EPR is an evolutionary Nuclear Island of the 4 loop x 1500 Mwe class currently in the design phase. Application of LBB to the main coolant lines and resulting design impacts are summarized. Background information on LBB analysis in France and Germany is also presented

Overview of LBB implementation for the EPR

Energy Technology Data Exchange (ETDEWEB)

Cauquelin, C.

1997-04-01

This paper presents an overview of the use of leak-before-break (LBB) analysis for EPR reactors. EPR is an evolutionary Nuclear Island of the 4 loop x 1500 Mwe class currently in the design phase. Application of LBB to the main coolant lines and resulting design impacts are summarized. Background information on LBB analysis in France and Germany is also presented.

EPR study of free radicals in bread

Science.gov (United States)

Yordanov, Nicola D.; Mladenova, Ralitsa

2004-05-01

The features of the recorded EPR spectra of paramagnetic species formed in bread and rusk are reported. The appearance of free radicals in them is only connected with their thermal treatment since the starting materials (flour and grains) exhibit very weak EPR signal. The obtained EPR spectra are complex and indicate that: (i) the relative number of paramagnetic species depends on the temperature and treating time of the raw product; (ii) the g-values are strongly temperature dependent with a tendency to coincide at t≥220 °C. Because of the relatively low (150-220 °C) temperature of thermal treatment, the studied free radicals can be assumed to appear in the course of the browning (Maillard) reaction and not to the carbonization of the material.

EPR of impurity ions in disordered solids

International Nuclear Information System (INIS)

Kliava, J.

1986-01-01

The state of the art in the EPR spectroscopy of disordered solids is reviewed and theoretical aspects of the EPR shape in disordered systems are discussed. Emphasis is placed on the concept of the joint probability density of the spin Hamiltonian parameters. A survey of experimental data is provided on distributions of spin Hamiltonian parametes obtained using computer simulation techniques. A quantitative information is given on the short-range ordering in disordered materials available from EPR studies. A procedure of extracting such type of data which consists in a transformation from the distribution of the spin Hamiltonian parameters to that of atomic coordinates in the surrounding of a paramagnetic center is outlined. Numerical estimates of the degree of continuous disorder are reviewed

X- and Q-band EPR studies on fine powders of irradiated plants. New approach for detection of their radiation history by using Q-band EPR spectrometry

International Nuclear Information System (INIS)

Yordanov, Nicola D.; Aleksieva, Katerina

2004-01-01

X- and Q-band EPR studies after γ-irradiation of some dry spices and aromatic herbs are reported. Before irradiation all samples show only one singlet line in X-band EPR, whereas the Q-band EPR spectrum of the same samples is a superposition of two individual spectra--one corresponding to the above EPR signal, with an anisotropic spectrum, and a second one consisting of six lines due to the Mn 2+ naturally present in plants. The radiation induced EPR signal due to cellulose free radicals was not detected after γ-irradiation, but only the increase of the natural signal present before the irradiation. The fading kinetic of this EPR signal was monitored in three cases--when samples were kept in plastic bags without any special conditioning after irradiation, when samples were covered with paraffin before irradiation and when samples were dried at 60 deg. C for 1 h before irradiation. The studies show that stability of radiation induced EPR signals decreases in the order of: paraffin covered > heated before irradiation > kept at room conditions. The two EPR spectra in the Q-band--one with radiation dependent intensity and a second due to Mn 2+ , which is radiation independent allow identification of previous radiation treatment based on the fact that Mn 2+ quantity in the sample is constant whereas the quantity of radiation-induced free radicals is temperature dependent. It was found that for irradiated samples the ratio between EPR intensity of the free radicals and that of Mn 2+ before and after heating decreases with 50-60% whereas for non-irradiated samples it is ca. 10-15%

Multifrequency EPR study on freeze-dried fruits before and after X-ray irradiation

Science.gov (United States)

Yordanov, N. D.; Aleksieva, K.; Dimitrova, A.; Georgieva, L.; Tzvetkova, E.

2006-09-01

X-, K- and Q-band EPR studies on lyophilized whole pulp parts of blue plum, apricot, peach, melon as well as achens and pulp separately of strawberry before and after X-ray irradiation are reported. Before irradiation all samples show in X band a weak singlet EPR line with g=2.0030±0.0005, except melon, which is EPR silent. Immediately after irradiation all samples exhibit complex fruit-depending spectra, which decay with time and change to give, in ca. 50 days, an asymmetric singlet EPR line with g=2.0041±0.0005. Only apricot pulp gave a typical "sugar-like" EPR spectrum. Singlet EPR lines recorded after irradiation in X -band are K- and Q-band resolved as typical anisotropic EPR spectra with g=2.0023±0.0003 and g⊥=2.0041±0.0005. In addition, K- and Q-band EPR spectra of all samples show a superposition with the six EPR lines of Mn 2+ naturally present in the fruits. The saturation behavior of the EPR spectra of achens of lyophilized and fresh strawberry is also studied. The differences in g factors of samples before and after X-ray irradiation might be used for the identification of radiation processing of fruits in the case of pulp and the differences in the EPR saturation behavior might be used for the achens of strawberry.

Holographic EPR Pairs, Wormholes and Radiation

OpenAIRE

Chernicoff, Mariano; Güijosa, Alberto; Pedraza, Juan F.

2013-01-01

As evidence for the ER=EPR conjecture, it has recently been observed that the string that is holographically dual to an entangled quark-antiquark pair separating with (asymptotically) uniform acceleration has a wormhole on its worldsheet. We point out that a two-sided horizon and a wormhole actually appear for much more generic quark-antiquark trajectories, which is consistent with the fact that the members of an EPR pair need not be permanently out of causal contact. The feature that determi...

EPR of alanine irradiated by neutrons

International Nuclear Information System (INIS)

Pivovarov, S.P.; Seredavina, T.A.; Zhdanov, S.V.; Mul'gin, S.I.; Zhakparov, R.K.

2001-01-01

In the work the first results of EPR studies of alanine, irradiated with diverse doses at neutron cyclotron generator different conditions and on the critical reactor stand are presented. A dose linearity dependence of EPR signal is observing, the methods of γ-background contribution separation are discussed. Obtain results is giving the basis to recommendation of alanine as an effective detector irradiation. However it is demanded the farther study on clarification of radiation sensitivity value dependence on the neutron energy spectrum form

The effect of thermal treatment on radiation-induced EPR signals in tooth enamel

International Nuclear Information System (INIS)

Vorona, I.P.; Ishchenko, S.S.; Baran, N.P.

2005-01-01

The effect of thermal treatment on the radiation-induced EPR spectrum of tooth enamel was studied. Annealing before sample irradiation was found to increase enamel radiation sensitivity by more than 40%. Depending on the annealing conditions the EPR signals of three supplementary radiation radicals were observed in addition to the main signal caused by CO 2 - radicals. It was found that the presence of these signals in the enamel EPR spectra provides evidence of sample annealing. The possibility of obtaining information about sample history by studying the additional EPR signals is discussed. It can be important to EPR dating and EPR dosimetry

Electromagnetic reaction paradox

International Nuclear Information System (INIS)

Aspden, H.

1984-01-01

Alternative explanations for free-electron diamagnetism appear paradoxical and inconsistent with the reactive induction properties of magnetic materials. It is shown that the paradox can be eliminated by a generalized definition of the magnetic field with interesting spin-off consequences, including a justification for the anomalous doubling of the positron's effective mass in a free-electron environment

ISS protocol for EPR tooth dosimetry

International Nuclear Information System (INIS)

Onori, S.; Aragno, D.; Fattibene, P.; Petetti, E.; Pressello, M.C.

2000-01-01

The accuracy in Electron Paramagnetic Resonance (EPR) dose reconstruction with tooth enamel is affected by sample preparation, dosimetric signal amplitude evaluation and unknown dose estimate. Worldwide efforts in the field of EPR dose reconstruction with tooth enamel are focused on the optimization of the three mentioned steps in dose assessment. In the present work, the protocol implemented at ISS in the framework of the European Community Nuclear Fission Safety project 'Dose Reconstruction' is presented. A combined mechanical-chemical procedure for ground enamel sample preparation is used. The signal intensity evaluation is carried out with powder spectra simulation program. Finally, the unknown dose is evaluated individually for each sample with the additive dose method. The unknown dose is obtained by subtracting a mean native dose from the back-extrapolated dose. As an example of the capability of the ISS protocol in unknown dose evaluation, the results obtained in the framework of the 2nd International Intercomparison on EPR tooth enamel dosimetry are reported

EPR of radiation defects in lithium-oxyfluoride glass ceramics

Energy Technology Data Exchange (ETDEWEB)

Fedotovs, A; Rogulis, U; Sarakovskis, A; Dimitrocenko, L, E-mail: andris-f@navigator.l [Institute of Solid State Physics, University of Latvia, Kengaraga st. 8, LV-1063, Riga (Latvia)

2010-11-01

We studied oxyfluoride composites based on lithium silicate glasses with yttrium fluorides and rare-earth dopants. The electron paramagnetic resonance (EPR) has been used to obtain information about radiation induced defects in these materials. Spectra have been measured before and after X-ray irradiation at room temperature and at liquid nitrogen temperature. Fluoride crystallites within samples were created by means of thermal treatment at specific temperatures. EPR spectra of radiation induced defects in oxyfluoride glass ceramics, in which crystallites have not been yet created, show no explicit hfs interaction of fluorine nuclei. However, in glass ceramics, which already contains fluoride crystallites, the hfs characteristic to fluorine nuclei appears in the EPR spectra. EPR hyperfine structure could be explained within a model of an F-type centre in YF{sub 3} crystalline phase.

EPR of radiation defects in lithium-oxyfluoride glass ceramics

Science.gov (United States)

Fedotovs, A.; Rogulis, U.; Sarakovskis, A.; Dimitrocenko, L.

2010-11-01

We studied oxyfluoride composites based on lithium silicate glasses with yttrium fluorides and rare-earth dopants. The electron paramagnetic resonance (EPR) has been used to obtain information about radiation induced defects in these materials. Spectra have been measured before and after X-ray irradiation at room temperature and at liquid nitrogen temperature. Fluoride crystallites within samples were created by means of thermal treatment at specific temperatures. EPR spectra of radiation induced defects in oxyfluoride glass ceramics, in which crystallites have not been yet created, show no explicit hfs interaction of fluorine nuclei. However, in glass ceramics, which already contains fluoride crystallites, the hfs characteristic to fluorine nuclei appears in the EPR spectra. EPR hyperfine structure could be explained within a model of an F-type centre in YF3 crystalline phase.

Reconstructing Bohr's Reply to EPR in Algebraic Quantum Theory

Science.gov (United States)

Ozawa, Masanao; Kitajima, Yuichiro

2012-04-01

Halvorson and Clifton have given a mathematical reconstruction of Bohr's reply to Einstein, Podolsky and Rosen (EPR), and argued that this reply is dictated by the two requirements of classicality and objectivity for the description of experimental data, by proving consistency between their objectivity requirement and a contextualized version of the EPR reality criterion which had been introduced by Howard in his earlier analysis of Bohr's reply. In the present paper, we generalize the above consistency theorem, with a rather elementary proof, to a general formulation of EPR states applicable to both non-relativistic quantum mechanics and algebraic quantum field theory; and we clarify the elements of reality in EPR states in terms of Bohr's requirements of classicality and objectivity, in a general formulation of algebraic quantum theory.

Superhigh-frequency circuit for the EPR spectrometer with rectifier screening

International Nuclear Information System (INIS)

Zhizhchenko, G.A.; Tsvirko, L.V.

1983-01-01

The hamodyne SHF circuit of a 3-cm EPR spectrometer with a reflecting resonator is described. The optimum operating mode of SHF-rectifier at a constant phase difference is automatically assured in the circuit. The circuit employs a reflecting p-i-n- attenuator and a SHF-rectifier sereen which simplify the spectrometer tuming. The circuit is used in a miniature EPR radiospectrometer Minsk EPR-6-type

Comment on the extinct paradox

International Nuclear Information System (INIS)

Levine, D.M.

1983-11-01

The extinction paradox is a contradiction between geometrical optics results which predict that at high frequencies the scattering cross section of an object should equal its geometrical cross section and rigorous scattering theory which shows that at high frequencies the scattering cross section approaches twice the geometrical cross section of the object. Confusion about the reason for this paradox persists today even though the nature of the paradox was correctly identified many years ago by Brillouin. The resolution of the paradox is restated and illustrated with an example, and then the implications to the interpretation of scattering cross sections are identified

The Simpson's paradox unraveled

DEFF Research Database (Denmark)

Hernán, Miguel A; Clayton, David; Keiding, Niels

2011-01-01

Background In a famous article, Simpson described a hypothetical data example that led to apparently paradoxical results. Methods We make the causal structure of Simpson’s example explicit. Results We show how the paradox disappears when the statistical analysis is appropriately guided by subject......-matter knowledge. We also review previous explanations of Simpson’s paradox that attributed it to two distinct phenomena: confounding and non-collapsibility. Conclusion Analytical errors may occur when the problem is stripped of its causal context and analyzed merely in statistical terms....

Ghost-like action at a distance

International Nuclear Information System (INIS)

Mattuck, D.

1981-01-01

No matter how we try to ''resolve'' the Einstein, Podolsky, Rosen (EPR) paradox, it seems that we come up with another paradox. If we try using hidden-variables, it turns out that they have to be non-local, so B's result depends on the setting of distant apparatus A. Introduction of backwards collapse requires that the future influence the past. Any way you look at it, the EPR paradox remains ''number 1'' on the hit-list of weird quantum effects, '' the most difficult of all to reconcile with our usual picture of the physical world''. (EG)

Multifrequency EPR study on freeze-dried fruits before and after X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)]. E-mail: ndyepr@bas.bg; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimitrova, A. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Georgieva, L. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Tzvetkova, E. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria)

2006-09-15

X-, K- and Q-band EPR studies on lyophilized whole pulp parts of blue plum, apricot, peach, melon as well as achens and pulp separately of strawberry before and after X-ray irradiation are reported. Before irradiation all samples show in X band a weak singlet EPR line with g=2.0030+/-0.0005, except melon, which is EPR silent. Immediately after irradiation all samples exhibit complex fruit-depending spectra, which decay with time and change to give, in ca. 50days, an asymmetric singlet EPR line with g=2.0041+/-0.0005. Only apricot pulp gave a typical ''sugar-like'' EPR spectrum. Singlet EPR lines recorded after irradiation in X -band are K- and Q-band resolved as typical anisotropic EPR spectra with g{sub ||}=2.0023+/-0.0003 and g{sub -}bar =2.0041+/-0.0005. In addition, K- and Q-band EPR spectra of all samples show a superposition with the six EPR lines of Mn{sup 2+} naturally present in the fruits. The saturation behavior of the EPR spectra of achens of lyophilized and fresh strawberry is also studied. The differences in g factors of samples before and after X-ray irradiation might be used for the identification of radiation processing of fruits in the case of pulp and the differences in the EPR saturation behavior might be used for the achens of strawberry.

In vivo EPR extracellular pH-metry in tumors using a triphosphonated trityl radical.

Science.gov (United States)

Marchand, Valérie; Levêque, Philippe; Driesschaert, Benoit; Marchand-Brynaert, Jacqueline; Gallez, Bernard

2017-06-01

The ability to assess the extracellular pH (pHe) is an important issue in oncology, because extracellular acidification is associated with tumor aggressiveness and resistance to cytotoxic therapies. In this study, a stable triphosphonated triarylmethyl (TPTAM) radical was qualified as a pHe electron paramagnetic resonance (EPR) molecular reporter. Calibration of hyperfine splitting as a function of pH was performed using a 1.2-GHz EPR spectrometer. Gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) was used as an extracellular paramagnetic broadening agent to assess the localization of TPTAM when incubated with cells. In vivo EPR pH-metry was performed in MDA, SiHa, and TLT tumor models and in muscle. Bicarbonate therapy was used to modulate the tumor pHe. EPR measurements were compared with microelectrode readouts. The hyperfine splitting of TPTAM was strongly pH-dependent around the pKa of the probe (pKa = 6.99). Experiments with Gd-DTPA demonstrated that TPTAM remained in the extracellular compartment. pHe was found to be more acidic in the MDA, SiHa, and TLT tumor models compared with muscle. Treatment of animals by bicarbonate induced an increase in pHe in tumors: similar variations in pHe were found when using in vivo EPR or invasive microelectrodes measurements. This study demonstrates the potential usefulness of TPTAM for monitoring pHe in tumors. Magn Reson Med 77:2438-2443, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Interpretation of the parameters of the EPR spectra of transition metal complexes

International Nuclear Information System (INIS)

Murav'ev, V.I.

2005-01-01

The calculated parameters of the EPR spectra of complexes of d 1 and d 9 ions, inclusive of MoOX 5 (X = Cl, Br), are reviewed. The covalent bond parameters used in the calculations were determined from EPR and experimental optical data (inverse problem of EPR spectroscopy). Various contributions to the expressions for the EPR parameters were compared. The observed abnormal values of the EPR parameters were discussed. The effects of charge-transfer states and the vibronic coupling on the components of g, A, and A L tensors were considered. Mechanisms of spin density transfer to ligands in paramagnetic complexes were proposed [ru

EPR becomes reality at Finland's Olkiluoto 3

International Nuclear Information System (INIS)

Gueldner, R.; Giese, U.

2005-01-01

The EPR is a third-generation pressurized water reactor (PWR). Its development was started in 1992 by Framatome and Siemens within a Franco-German partnership. Since 2001 this work has been continued by Framatome ANP, which was formed when the two companies merged their nuclear businesses. The French company AREVA, world market leader in nuclear technology, holds a 66% share in Framatome ANP, with Siemens owning 34%. From the very start, development of the EPR was focused on improving plant safety and economics even further. The new reactor development was jointly financed together with the leading power utilities of both countries. The first steps towards realization of an EPR nuclear power plant were taken at Olkiluoto, Finland in 2004, consisting of initial preparation of the construction site. By mid-February 2005 the local municipality - Eurajoki - had issued a construction permit, and the Finnish Government a construction license pursuant to the Finnish Nuclear Energy Act. This had been preceded by a preliminary safety assessment prepared by the Finnish Radiation and Nuclear Safety Authority (STUK) for the Finnish Ministry of Trade and Industry in which STUK verified that it did not see any safety-related issues opposing issuance of the nuclear construction license. STUK emphasized that the evolutionary design of the EPR had been further improved by AREVA compared to the previous product lines. Concreting work began this spring and the unit will start commercial operation in 2009. Construction of an EPR has also been given the political go-ahead in France. According to the utility Electricite de France (EDF) the new reactor will be built as a forerunner of a later series at the site of Flamanville in Normandy. Construction is scheduled to begin in 2007. An EPR nuclear power plant has a rated electric capacity of around 1600 MW, depending on specific site conditions. Being the product of intense bilateral cooperation the EPR combines the technological

EPR and NMR spectroscopy on spin-labeled proteins

NARCIS (Netherlands)

Finiguerra, Michelina Giuseppina

2011-01-01

Spin labeling and electron paramagnetic resonance (EPR) have been employed to study structure and dynamics of proteins. The surface polarity of four single cysteine mutants of the Zn-azurin in frozen solution were studied using 275 GHz EPR (J-band), with the advantage compared to 9 GHz (X-band) and

EPR and UV spectrometry investigation of sucrose irradiated with carbon particles

International Nuclear Information System (INIS)

Karakirova, Yordanka; Yordanov, Nicola D.

2010-01-01

Solid state/EPR (SS/EPR) dosimeters of carbon ions irradiated sucrose are studied with EPR, and their water solutions - with UV spectroscopy. Doses between 20 and 200 Gy are used with linear energy transfer (LET) values for carbon ions of 63, 77, 96 and 230 keV μm -1 . After irradiation all samples show typical for irradiated sucrose EPR and UV spectra. The obtained data are compared with those previously reported for nitrogen particles and gamma rays irradiated sucrose. The identical shape of both the EPR and UV spectra of irradiated with various type radiation samples suggests that generated free radicals are not influenced by the nature of radiation. The lack of difference in the line width of the separate lines or the whole EPR spectrum, obtained for gamma and heavy particles irradiation, suggests negligible spin-spin interaction among the radiation-generated free radicals in the samples. The linear dependence of the EPR response on the absorbed dose radiation is found to be higher when generated by gamma rays, than by the same absorbed dose of heavy particles. In addition, the EPR response for carbon ions is higher than that for nitrogen ions. Water solutions of irradiated sucrose exhibit UV spectrum with absorption maximum at 267 nm, attributed to the recombination products of free radicals. The UV band intensity depends on the absorbed dose radiation. The UV spectra obtained for carbon, nitrogen and gamma rays irradiated sucrose are also compared.

The measurement of oxygen in vivo using EPR techniques

International Nuclear Information System (INIS)

Swartz, Harold M.; Clarkson, Robert B.

1998-01-01

The measurement of pO 2 in vivo using EPR has some features which have already led to very useful applications and this approach is likely to have increasingly wide and effective use. It is based on the effect of oxygen on EPR spectra which provides a sensitive and accurate means to measure pO 2 quantitatively. The development of oxygen-sensitive paramagnetic materials which are very stable, combined with instrumental developments, has been crucial to the in vivo applications of this technique. The physical basis and biological applications of in vivo EPR oximetry are reviewed, with particular emphasis on the use of EPR spectroscopy at 1 GHz using particulate paramagnetic materials for the repetitive and non-invasive measurement of pO 2 in tissues. In vivo EPR has already produced some very useful results which have contributed significantly to solving important biological problems. The characteristics of EPR oximetry which appear to be especially useful are often complementary to existing techniques for measuring oxygen in tissues. These characteristics include the capability of making repeated measurements from the same site, high sensitivity to low levels of oxygen, and non-invasive options. The existing techniques are especially useful for studies in small animals, where the depth of measurements is not an overriding issue. In larger animals and potentially in human subjects, non-invasive techniques seem to be immediately applicable to study phenomena very near the surface (within 10 mm) while invasive techniques have some very promising uses. The clinical uses of EPR oximetry which seem especially promising and likely to be undertaken in the near future are long-term monitoring of the status and response to treatment of peripheral vascular disease and optimizing cancer therapy by enabling it to be modified on the basis of the pO 2 measured in the tumour. (author)

Toward 2D and 3D imaging of magnetic nanoparticles using EPR measurements.

Science.gov (United States)

Coene, A; Crevecoeur, G; Leliaert, J; Dupré, L

2015-09-01

Magnetic nanoparticles (MNPs) are an important asset in many biomedical applications. An effective working of these applications requires an accurate knowledge of the spatial MNP distribution. A promising, noninvasive, and sensitive technique to visualize MNP distributions in vivo is electron paramagnetic resonance (EPR). Currently only 1D MNP distributions can be reconstructed. In this paper, the authors propose extending 1D EPR toward 2D and 3D using computer simulations to allow accurate imaging of MNP distributions. To find the MNP distribution belonging to EPR measurements, an inverse problem needs to be solved. The solution of this inverse problem highly depends on the stability of the inverse problem. The authors adapt 1D EPR imaging to realize the imaging of multidimensional MNP distributions. Furthermore, the authors introduce partial volume excitation in which only parts of the volume are imaged to increase stability of the inverse solution and to speed up the measurements. The authors simulate EPR measurements of different 2D and 3D MNP distributions and solve the inverse problem. The stability is evaluated by calculating the condition measure and by comparing the actual MNP distribution to the reconstructed MNP distribution. Based on these simulations, the authors define requirements for the EPR system to cope with the added dimensions. Moreover, the authors investigate how EPR measurements should be conducted to improve the stability of the associated inverse problem and to increase reconstruction quality. The approach used in 1D EPR can only be employed for the reconstruction of small volumes in 2D and 3D EPRs due to numerical instability of the inverse solution. The authors performed EPR measurements of increasing cylindrical volumes and evaluated the condition measure. This showed that a reduction of the inherent symmetry in the EPR methodology is necessary. By reducing the symmetry of the EPR setup, quantitative images of larger volumes can be

Toward 2D and 3D imaging of magnetic nanoparticles using EPR measurements

International Nuclear Information System (INIS)

Coene, A.; Crevecoeur, G.; Dupré, L.; Leliaert, J.

2015-01-01

Purpose: Magnetic nanoparticles (MNPs) are an important asset in many biomedical applications. An effective working of these applications requires an accurate knowledge of the spatial MNP distribution. A promising, noninvasive, and sensitive technique to visualize MNP distributions in vivo is electron paramagnetic resonance (EPR). Currently only 1D MNP distributions can be reconstructed. In this paper, the authors propose extending 1D EPR toward 2D and 3D using computer simulations to allow accurate imaging of MNP distributions. Methods: To find the MNP distribution belonging to EPR measurements, an inverse problem needs to be solved. The solution of this inverse problem highly depends on the stability of the inverse problem. The authors adapt 1D EPR imaging to realize the imaging of multidimensional MNP distributions. Furthermore, the authors introduce partial volume excitation in which only parts of the volume are imaged to increase stability of the inverse solution and to speed up the measurements. The authors simulate EPR measurements of different 2D and 3D MNP distributions and solve the inverse problem. The stability is evaluated by calculating the condition measure and by comparing the actual MNP distribution to the reconstructed MNP distribution. Based on these simulations, the authors define requirements for the EPR system to cope with the added dimensions. Moreover, the authors investigate how EPR measurements should be conducted to improve the stability of the associated inverse problem and to increase reconstruction quality. Results: The approach used in 1D EPR can only be employed for the reconstruction of small volumes in 2D and 3D EPRs due to numerical instability of the inverse solution. The authors performed EPR measurements of increasing cylindrical volumes and evaluated the condition measure. This showed that a reduction of the inherent symmetry in the EPR methodology is necessary. By reducing the symmetry of the EPR setup, quantitative images of

Low temperature EPR investigation of Co2+ ion doped into rutile TiO2 single crystal: Experiments and simulations

Science.gov (United States)

Zerentürk, A.; Açıkgöz, M.; Kazan, S.; Yıldız, F.; Aktaş, B.

2017-02-01

In this paper, we present the results of X-band EPR spectra of Co2+ ion doped rutile (TiO2) which is one of the most promising memristor material. We obtained the angular variation of spectra in three mutually perpendicular planes at liquid helium (7-13 K) temperatures. Since the impurity ions have ½ effective spin and 7/2 nuclear spin, a relatively simple spin Hamiltonian containing only electronic Zeeman and hyperfine terms was utilized. Two different methods were used in theoretical analysis. Firstly, a linear regression analysis of spectra based on perturbation theory was studied. However, this approach is not sufficient for analyzing Co+2 spectra and leads to complex eigenvectors for G and A tensors due to large anisotropy of eigenvalues. Therefore, all spectra were analyzed again with exact diagonalization of spin Hamiltonian and the high accuracy eigenvalues and eigenvectors of G and A tensors were obtained by taking into account the effect of small sample misalignment from the exact crystallographic planes due to experimental conditions. Our results show that eigen-axes of g and A tensors are parallel to crystallographic directions. Hence, our EPR experiments proves that Co2+ ions substitute for Ti4+ ions in lattice. The obtained principal values of g tensor are gx=2.110(6), gy=5.890(2), gz=3.725(7) and principal values of hyperfine tensor are Ax=42.4, Ay=152.7, Az=26 (in 10-4/cm).

Einstein and the Quantum: The Secret Life of EPR

Science.gov (United States)

Fine, Arthur

2006-05-01

Locality, separation and entanglement -- 1930s style. Starting with Solvay 1927, we'll explore the background to the 1935 paper by Einstein, Podolsky and Rosen: how it was composed, the actual argument and principles used, and how the paper was received by Schroedinger, and others. We'll also look at Bohr's response: the extent to which Bohr connects with what Einstein was after in EPR and the extent to which EPR marks a shift in Bohr's thinking about the quantum theory. Time permitting, we will contrast EPR with Bell's theorem.

Paradoxical embolism: computed tomography demonstration

International Nuclear Information System (INIS)

Kaye, J.; Hayward, M.

2001-01-01

Paradoxical emboli are rare and often presumptively diagnosed. A case of paradoxical embolism, in which both the arterial and venous emboli were documented on CT, is described. While paradoxical emboli are not infrequently diagnosed clinically on a presumptive basis, it is rare to document them with imaging such as CT which, in the present case, confirmed the diagnosis. Copyright (2001) Blackwell Science Pty Ltd

EPR spectroscopy of spices

Directory of Open Access Journals (Sweden)

R. T. Тimakova

2016-01-01

Full Text Available From 01 January 2017 you enter the interstate standard GOST 33271-2015 “Dry Spices, herbs and vegetable seasonings. Manual exposure in order to combat pathogens and other microorganisms” which States that the absorbed dose of radiation to the spices should be from 3 to 30 kGy. The study found that before the introduction of permissive legislative framework in the consumer market of Russia there are irradiated food products (chili, ground chili, ground spicy chili, black pepper. For radiation monitoring of food safety, we used the method of electron paramagnetic resonance (EPR, which allows quickly and with a high degree of reliability to establish the fact of irradiation. It is established that all samples of spices irradiated with dose of 12 kGy (technology radappertization gave typical spectra of the signals established by the method of electron paramagnetic resonance in the domestic EPR spectrometer, the intensity, amplitude and peak width of the EPR signal of samples of spices with the increase of irradiation dose increases. It is proven that repeated exposure no effect accumulation. Integration with 2017 Russia in the global practi ce of using radiation technologies of processing of food products and food raw materials with the purpose of extending shelf life confirms the need for a data Bank on the radiation sensitivity of various food products to determine the optimal doses and the eff ect of radiation doses on the shelf life and quality of products.

Einstein, Podolsky, Rosen, and Shannon

OpenAIRE

Peres, Asher

2003-01-01

The EPR paradox (1935) is reexamined in the light of Shannon's information theory (1948). The EPR argument did not take into account that the observers' information was localized, like any other physical object.

Self-testing through EPR-steering

International Nuclear Information System (INIS)

Šupić, Ivan; Hoban, Matty J

2016-01-01

The verification of quantum devices is an important aspect of quantum information, especially with the emergence of more advanced experimental implementations of quantum computation and secure communication. Within this, the theory of device-independent robust self-testing via Bell tests has reached a level of maturity now that many quantum states and measurements can be verified without direct access to the quantum systems: interaction with the devices is solely classical. However, the requirements for this robust level of verification are daunting and require high levels of experimental accuracy. In this paper we discuss the possibility of self-testing where we only have direct access to one part of the quantum device. This motivates the study of self-testing via EPR-steering, an intermediate form of entanglement verification between full state tomography and Bell tests. Quantum non-locality implies EPR-steering so results in the former can apply in the latter, but we ask what advantages may be gleaned from the latter over the former given that one can do partial state tomography? We show that in the case of self-testing a maximally entangled two-qubit state, or ebit, EPR-steering allows for simpler analysis and better error tolerance than in the case of full device-independence. On the other hand, this improvement is only a constant improvement and (up to constants) is the best one can hope for. Finally, we indicate that the main advantage in self-testing based on EPR-steering could be in the case of self-testing multi-partite quantum states and measurements. For example, it may be easier to establish a tensor product structure for a particular party’s Hilbert space even if we do not have access to their part of the global quantum system. (paper)

An American Paradox

International Nuclear Information System (INIS)

Jamieson, D.

2006-01-01

This paper explores the paradox that while Americans generally identify themselves as environmentalists, they show little willingness to voluntarily restrain their behavior or to support specific fiscal policies that would result in increased levels of environmental protection. I explore the role of values in the explanation of this paradox, and discuss some of the difficulties involved in studying values and their role in human behavior

EPR spectra induced by gamma-irradiation of some dry medical herbs

Science.gov (United States)

Yordanov, N. D.; Lagunov, O.; Dimov, K.

2009-04-01

The radiation-induced EPR spectra in some medical herbs are reported. The samples studied are: (i) leaves of nettle, common balm, peppermint and thyme; (ii) stalks of common balm, thyme, milfoil, yarrow and marigold; (iii) blossoms of yarrow and marigold; (iv) blossoms and leaves of hawthorn and tutsan; and (v) roots of common valerian, nettle, elecampane (black and white), restharrows and carlina. Before irradiation all samples exhibit one weak anisotropic singlet EPR line with effective g-value of 2.0050±0.0002. The radiation-induced spectra fall into three groups. EPR spectra of irradiated blossoms of yarrow and marigold, stalks of common balm, thyme, tutsan and yarrow as well as roots of common valerian, nettle and elecampane (black and white) show "cellulose-like" EPR spectrum typical for irradiated plants. It is characterized by one intense central line with g=2.0050±0.0005 and two weak satellite lines situated ca. 30 G left and right to it. EPR spectra of gamma-irradiated restharrows and carlina are complex. They may be represented by one triplet corresponding to the "cellulose-like" EPR spectrum, one relatively intense singlet, situated in the center of the spectrum, and five weak additional satellite lines left and right to the center. The last spectrum was assigned as "carbohydrate-like" type. Only one intense EPR singlet with g=2.0048±0.0005 was recorded after irradiation of leaves of nettle and common balm. The lifetime of the radiation-induced EPR spectra was followed for a period of 3 months.

EPR spectra induced by gamma-irradiation of some dry medical herbs

International Nuclear Information System (INIS)

Yordanov, N.D.; Lagunov, O.; Dimov, K.

2009-01-01

The radiation-induced EPR spectra in some medical herbs are reported. The samples studied are: (i) leaves of nettle, common balm, peppermint and thyme; (ii) stalks of common balm, thyme, milfoil, yarrow and marigold; (iii) blossoms of yarrow and marigold; (iv) blossoms and leaves of hawthorn and tutsan; and (v) roots of common valerian, nettle, elecampane (black and white), restharrows and carlina. Before irradiation all samples exhibit one weak anisotropic singlet EPR line with effective g-value of 2.0050±0.0002. The radiation-induced spectra fall into three groups. EPR spectra of irradiated blossoms of yarrow and marigold, stalks of common balm, thyme, tutsan and yarrow as well as roots of common valerian, nettle and elecampane (black and white) show 'cellulose-like' EPR spectrum typical for irradiated plants. It is characterized by one intense central line with g=2.0050±0.0005 and two weak satellite lines situated ca. 30 G left and right to it. EPR spectra of gamma-irradiated restharrows and carlina are complex. They may be represented by one triplet corresponding to the 'cellulose-like' EPR spectrum, one relatively intense singlet, situated in the center of the spectrum, and five weak additional satellite lines left and right to the center. The last spectrum was assigned as 'carbohydrate-like' type. Only one intense EPR singlet with g=2.0048±0.0005 was recorded after irradiation of leaves of nettle and common balm. The lifetime of the radiation-induced EPR spectra was followed for a period of 3 months

EPR spectra induced by gamma-irradiation of some dry medical herbs

Energy Technology Data Exchange (ETDEWEB)

Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)], E-mail: ndyepr@bas.bg; Lagunov, O. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food technology, 1162 Sofia (Bulgaria)

2009-04-15

The radiation-induced EPR spectra in some medical herbs are reported. The samples studied are: (i) leaves of nettle, common balm, peppermint and thyme; (ii) stalks of common balm, thyme, milfoil, yarrow and marigold; (iii) blossoms of yarrow and marigold; (iv) blossoms and leaves of hawthorn and tutsan; and (v) roots of common valerian, nettle, elecampane (black and white), restharrows and carlina. Before irradiation all samples exhibit one weak anisotropic singlet EPR line with effective g-value of 2.0050{+-}0.0002. The radiation-induced spectra fall into three groups. EPR spectra of irradiated blossoms of yarrow and marigold, stalks of common balm, thyme, tutsan and yarrow as well as roots of common valerian, nettle and elecampane (black and white) show 'cellulose-like' EPR spectrum typical for irradiated plants. It is characterized by one intense central line with g=2.0050{+-}0.0005 and two weak satellite lines situated ca. 30 G left and right to it. EPR spectra of gamma-irradiated restharrows and carlina are complex. They may be represented by one triplet corresponding to the 'cellulose-like' EPR spectrum, one relatively intense singlet, situated in the center of the spectrum, and five weak additional satellite lines left and right to the center. The last spectrum was assigned as 'carbohydrate-like' type. Only one intense EPR singlet with g=2.0048{+-}0.0005 was recorded after irradiation of leaves of nettle and common balm. The lifetime of the radiation-induced EPR spectra was followed for a period of 3 months.

EPR policies for electronics in developing Asia: an adapted phase-in approach.

Science.gov (United States)

Akenji, Lewis; Hotta, Yasuhiko; Bengtsson, Magnus; Hayashi, Shiko

2011-09-01

The amount of e-waste is growing rapidly in developing countries, and the health and environmental problems resulting from poor management of this waste have become a concern for policy makers. In response to these challenges, a number of Asian developing countries have been inspired by policy developments in OECD countries, and have drafted legislations based on the principle of extended producer responsibility (EPR). However, the experiences from developed countries show that a successful implementation of EPR policies requires adequate institutions and sufficient administrative capacity. Even advanced countries are thus facing difficulties. This paper concludes from existing literature and from the authors' own observations that there seems to be a mismatch between the typical policy responses to e-waste problems in developing Asia and the capacity for successful implementation of such policies. It also notes that the e-waste situation in developing Asian countries is further complicated by a number of additional factors, such as difficulties in identifying producers, import of used electronic products and e-waste (sometimes illegal), and the existence of a strong informal waste sector. Given these challenges, the authors conclude that comprehensive EPR policy schemes of the kind that have been implemented in some advanced countries are not likely to be effective. The paper therefore proposes an alternative phase-in approach whereby developing Asian countries are able to move gradually towards EPR systems. It argues that this approach would be more feasible, and discusses what could be the key building blocks of each implementation stage.

Progressive paradoxical sleep deprivation impairs partial memory following learning tasks in rats

Institute of Scientific and Technical Information of China (English)

Chunmin Zhu; Xiangrong Yao; Weisheng Zhang; Yanfeng Song; Yiping Hou

2008-01-01

BACKGROUND: Complex learning tasks result in a greater number of paradoxical sleep phases, which can improve memory. The effect of paradoxical sleep deprivation, induced by "flower pot" technique, on spatial reference memory and working memory require further research. OBJECTIVE: To observe the effect of progressive paradoxical sleep deprivation in rats, subsequent to learning, on memory using the Morris Water Maze. DESIGN, TIME AND SETTING: Controlled observation experiment. The experiment was performed at the Laboratory of Neurobiology, Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Lanzhou University from December 2006 to October 2007. MATERIALS: Twenty-eight, male, Wistar rats, 3-4 months old, were provided by the Experimental Animal Center of Lanzhou University. The Morris Water Maze and behavioral analyses system was purchased from Genheart Company, Beijing, China. METHODS: All animals, according to a random digits table, were randomly divided into paradoxical sleep deprivation, tank control, and home cage control groups. Paradoxical sleep deprivation was induced by the "flower pot" technique for 72 hours, housing the rats on small platforms over water. Rats in the "tank control" and "home cage control" groups were housed either in a tank with large platforms over the water or in normal cages without paradoxical sleep deprivation. MAIN OUTCOME MEASURES: Morris Water Maze was employed for task learning and spatial memory testing. Rats in all groups were placed at six random starting points each day for four consecutive days. Each placement was repeated for two trials; the first trial represented reference memory and the second working memory. Rats in the first trial were allowed to locate the submerged platform within 120 seconds. Data, including swimming distance, escape latency, swimming velocity, percentage of time in correct quarter, and memory scores were recorded and analyzed automatically by behavioral analyses

Case Studies in e-RPL and e-PR

Science.gov (United States)

Cameron, Roslyn; Miller, Allison

2014-01-01

The use of ePortfolios for recognition of prior learning (e-RPL) and for professional recognition (e-PR) is slowly gaining in popularity in the VET sector however their use is sporadic across educational sectors, disciplines, educational institutions and professions. Added to this is an array of purposes and types of e-RPL and e-PR models and…

Mechanical paradox: the uphill roller

International Nuclear Information System (INIS)

Cortes, Emilio; Cortes-Poza, D

2011-01-01

We analyse in detail the dynamics of a mechanical system which is a rigid body with the geometry of a double cone. This double cone is apparently able to spontaneously roll uphill along inclined rails. The experiment has been known for some centuries, and because of its peculiar behaviour, it has been named 'mechanical paradox'. Although this instrument is well known today, we have not found in the literature a dynamical study like the one we are presenting. A deeper analysis of this mechanical object will allow us to go further than explaining the apparent paradox in the system; it will show interesting features of the dynamics that are not evident or intuitive. In this work, we follow a complete study of the geometry, the kinematic variables and the Lagrangian dynamics of the problem for any set of the angular parameters and initial values, and obtain as a result a full description of the dynamic variables of this mechanical device. In addition to studying the dynamics of the system with the angles that yield the typical paradoxical behaviour, we study carefully what we call the constant potential geometry regime, where the centre of mass maintains its height, and found in this particular case some features of the dynamics which are not common in rolling objects. We believe that this work can offer the student good material to review some fundamental concepts of analytical mechanics.

Merleau-Ponty on Human Motility and Libet's Paradox | Mooney ...

African Journals Online (AJOL)

and-antedating” hypothesis/paradox based on the results of an on-going series of experiments dating back to 1964 that measured the neural adequacy [brain wave activity] of “conscious sensory experience”. What is fascinating about the ...

Black Hole Paradoxes

International Nuclear Information System (INIS)

Joshi, Pankaj S.; Narayan, Ramesh

2016-01-01

We propose here that the well-known black hole paradoxes such as the information loss and teleological nature of the event horizon are restricted to a particular idealized case, which is the homogeneous dust collapse model. In this case, the event horizon, which defines the boundary of the black hole, forms initially, and the singularity in the interior of the black hole at a later time. We show that, in contrast, gravitational collapse from physically more realistic initial conditions typically leads to the scenario in which the event horizon and space-time singularity form simultaneously. We point out that this apparently simple modification can mitigate the causality and teleological paradoxes, and also lends support to two recently suggested solutions to the information paradox, namely, the ‘firewall’ and ‘classical chaos’ proposals. (paper)

Einstein and the twin paradox

International Nuclear Information System (INIS)

Pesic, Peter

2003-01-01

Einstein was the first to discuss and resolve the 'twin paradox', which in 1905 he did not consider paradoxical and treated as a consequence of lack of simultaneity. He maintained this view until at least 1914. However, in 1918 Einstein brought forward arguments about accelerated frames of reference that tended to overshadow his initial resolution. His earlier arguments were gradually rediscovered during the subsequent controversy about this 'paradox'

Can an Evolutionary Analysis Dissolve the Paradox of Horror?

DEFF Research Database (Denmark)

Kjeldgaard-Christiansen, Jens; Clasen, Mathias; Johnson, John

The paradox of horror” is the problem of why so many people are motivated to experience the negative emotions induced by horror media. In this talk, we argue that an evolutionary analysis may dissolve the paradox of horror. From an evolutionary perspective, horror may be analyzed as a simulation...... technology that allows users to attain adaptive experience with perceived threat and negative emotion in a safe environment. The argument is supported by results from a comprehensive MTurk survey of American users of horror media (n=1,071). Results include findings on the personal details (e.g., sex......), supernatural beliefs (e.g., paranormal beliefs), personality traits (e.g., Big Five), horror genre preferences (e.g., supernatural versus natural horror), and horror-induced emotional responses of users of horror media. The strongest individual predictors of horror media enjoyment are sex (male preference...

Free-radical probes for functional in vivo EPR imaging

Science.gov (United States)

Subramanian, S.; Krishna, M. C.

2007-02-01

Electron paramagnetic resonance imaging (EPRI) is one of the recent functional imaging modalities that can provide valuable in vivo physiological information on its own merit and aids as a complimentary imaging technique to MRI and PET of tissues especially with respect to in vivo pO II (oxygen partial pressure), redox status and pharmacology. EPR imaging mainly deals with the measurement of distribution and in vivo dynamics and redox changes using special nontoxic paramagnetic spin probes that can be infused into the object of investigation. These spin probes should be characterized by simple EPR spectra, preferably with narrow EPR lines. The line width should be reversibly sensitive to the concentration of in vivo pO II with a linear dependence. Several non-toxic paramagnetic probes, some particulate and insoluble and others water-soluble and infusible (by intravenous or intramuscular injection) have been developed which can be effectively used to quantitatively assess tissue redox status, and tumor hypoxia. Quantitative assessment of the redox status of tissue in vivo is important in investigating oxidative stress, and that of tissue pO II is very important in radiation oncology. Other areas in which EPR imaging and oxymetry may help are in the investigation of tumorangiogenesis, wound healing, oxygenation of tumor tissue by the ingestion of oxygen-rich gases, etc. The correct choice of the spin probe will depend on the modality of measurement (whether by CW or time-domain EPR imaging) and the particular physiology interrogated. Examples of the available spin probes and some EPR imaging applications employing them are presented.

Confirmation of a second EPR to be built at Penly

International Nuclear Information System (INIS)

Anon.

2009-01-01

The French government has made public its decision to launch the construction of a second EPR in France. This EPR is planned to be built on the Penly site (northern region of France). EDF will manage this project but other investors like GDF-Suez are invited to participate. The construction works are planned to begin in 2012 for a commissioning in 2017. This reactor will be the fifth EPR being built in the world. (A.C.)

Quantum Bayesian networks with application to games displaying Parrondo's paradox

Science.gov (United States)

Pejic, Michael

Bayesian networks and their accompanying graphical models are widely used for prediction and analysis across many disciplines. We will reformulate these in terms of linear maps. This reformulation will suggest a natural extension, which we will show is equivalent to standard textbook quantum mechanics. Therefore, this extension will be termed quantum. However, the term quantum should not be taken to imply this extension is necessarily only of utility in situations traditionally thought of as in the domain of quantum mechanics. In principle, it may be employed in any modelling situation, say forecasting the weather or the stock market---it is up to experiment to determine if this extension is useful in practice. Even restricting to the domain of quantum mechanics, with this new formulation the advantages of Bayesian networks can be maintained for models incorporating quantum and mixed classical-quantum behavior. The use of these will be illustrated by various basic examples. Parrondo's paradox refers to the situation where two, multi-round games with a fixed winning criteria, both with probability greater than one-half for one player to win, are combined. Using a possibly biased coin to determine the rule to employ for each round, paradoxically, the previously losing player now wins the combined game with probabilitygreater than one-half. Using the extended Bayesian networks, we will formulate and analyze classical observed, classical hidden, and quantum versions of a game that displays this paradox, finding bounds for the discrepancy from naive expectations for the occurrence of the paradox. A quantum paradox inspired by Parrondo's paradox will also be analyzed. We will prove a bound for the discrepancy from naive expectations for this paradox as well. Games involving quantum walks that achieve this bound will be presented.

The EPR - a safe and competitive solution for future energy needs

International Nuclear Information System (INIS)

Fischer, U.; Bouteille, F.; Leverenz, R.

1999-01-01

NPI, Siemens and Framatome, in co-operation with EDF and the major German Utilities, started the development of the European Pressurized Water Reactor (EPR) as an evolutionary approach. After a careful evaluation of the potential of passive safety features, this way was concluded to be superior compared to a 'revolutionary' approach. The vast majority of advanced reactor designs being developed today is of the evolutionary type. The advantages to base an advanced design on the feedback of operation experience of the more than 100 nuclear power plants designed and constructed by Siemens and Framatome are outstanding. This view is shared by the German and French safety authorities which defined their preference for an evolutionary design early at the beginning of their co-operation for the definition of a common safety approach for future nuclear power plants to be built in Germany and France. In their first common set of recommendations, they gave a clear guideline regarding their point of view for requirements posed to the next generation of nuclear power plants: (1) Preference for an evolutionary design in order to derive a maximum benefit from experience; (2) Significant safety improvements by reduction of core meltdown probability and improvement of the confinement function of the containment under accident conditions; (3) Improvement of operating conditions regarding radiation protection, maintenance and human errors. Besides the French-German co-operation of vendors, utilities and authorities, the European utilities co-operate on a much broader basis for the establishment of the European Utilities' Requirements (EUR). During the development of the basic design, the EPR was continuously assessed against these EUR and it was concluded that the EPR complies with these requirements. At the end of the basic design phase at the end of 1997, all information necessary to file a preliminary safety analysis report and a reliable bill of quantities was elaborated. With

Nuclear spin-lattice relaxation in nitroxide spin-label EPR

DEFF Research Database (Denmark)

Marsh, Derek

2016-01-01

that the definition of nitrogen nuclear relaxation rate Wn commonly used in the CW-EPR literature for 14N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14N spin-lattice relaxation rate, b = Wn/(2We), preserves...... of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14N-relaxation: T1 n = 1/Wn. Results are compared and contrasted...

The use of deciduous molars in EPR dose reconstruction

International Nuclear Information System (INIS)

El-faramawy, N.A.; Wieser, A.

2005-01-01

The use of deciduous teeth in EPR dose reconstruction has the unique potential to measure individual doses that were accumulated in the early childhood in the age up to 12 years. It was found previously that due to the small size of deciduous incisors, the available amount of enamel is not sufficient for EPR measurements. Therefore, dose assessment with deciduous incisors can only be done by measurement of whole teeth, including enamel and dentine. The measurement of whole teeth instead of enamel alone is possibly less reliable for dose reconstruction because the stability of CO 2 - radicals (that are an indicator for the absorbed dose) in biologically active dentine is not known. In the present study naturally loosed deciduous molars were investigated. The feasibility of separating enamel from small size molars was analysed. EPR spectrum parameters of whole molars and separated enamel only were evaluated before and after laboratory irradiation. The EPR signal amplitudes of the CO 2 - and native signals were determined by spectrum deconvolution, in dependence on radiation dose in the range 0.1 - 10 Gy. The fading at room temperature of native and CO 2 - EPR signals was analysed. The detection threshold for absorbed dose in enamel was determined.

Study on the EPR/dosimetric properties of some substituted alanines

International Nuclear Information System (INIS)

Gancheva, Veselka; Sagstuen, Einar; Yordanov, Nicola D.

2006-01-01

Polycrystalline phenyl-alanine and perdeuterated l-α-alanine (l-α-alanine-d 4 ) were studied as potential high-energy radiation-sensitive materials (RSM) for solid state/EPR dosimetry. It was found that phenyl-alanine exhibits a linear dose response in the dose region 0.1-17kGy. However, phenyl-alanine is about 10 times less sensitive to γ-irradiation than standard l-α-alanine irradiated at the same doses. Moreover, the EPR response from phenyl-alanine is unstable and, independent of the absorbed dose, decreases by about 50% within 20 days after irradiation upon storage at room temperature. γ-irradiated polycrystalline perdeuterated l-α-alanine (CD 3 CD(NH 2 )COOH) has not previously been studied at room temperature by EPR spectroscopy. The first part of the present analysis was with respect to the structure of the EPR spectrum. By spectrum simulations, the presence of at least two radiation induced free radicals, R 1 =CH 3 C*(H)COOH and R 2 =H 3 N + -C*(CH 3 )COO - , was confirmed very clearly. Both these radicals were suggested previously from EPR and ENDOR studies of standard alanine crystals. The further investigations into the potential use of alanine-d 4 as RSM, after choosing optimal EPR spectrometer settings parameters for this purpose, show that it is ca. two times more sensitive than standard l-α-alanine

Emergency EPR and OSL dosimetry with table vitamins and minerals.

Science.gov (United States)

Sholom, S; McKeever, S W S

2016-12-01

Several table vitamins, minerals and L-lysine amino acid have been preliminarily tested as potential emergency dosemeters using electron paramagnetic resonance (EPR) and optically stimulated luminescence (OSL) techniques. Radiation-induced EPR signals were detected in samples of vitamin B2 and L-lysine while samples of multivitamins of different brands as well as mineral Mg demonstrated prominent OSL signals after exposure to ionizing radiation doses. Basic dosimetric properties of the radiation-sensitive substances were studied, namely dose response, fading of the EPR or OSL signals and values of minimum measurable doses (MMDs). For EPR-sensitive samples, the EPR signal is converted into units of dose using a linear dose response and correcting for fading using the measured fading dependence. For OSL-sensitive materials, a multi-aliquot, enhanced-temperature protocol was developed to avoid the problem of sample sensitization and to minimize the influence of signal fading. The sample dose in this case is also evaluated using the dose response and fading curves. MMDs of the EPR-sensitive samples were below 2 Gy while those of the OSL-sensitive materials were below 500 mGy as long as the samples are analyzed within 1 week after exposure. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of continuous wave, spin echo, and rapid scan EPR of irradiated fused quartz

International Nuclear Information System (INIS)

Mitchell, Deborah G.; Quine, Richard W.; Tseitlin, Mark; Meyer, Virginia; Eaton, Sandra S.; Eaton, Gareth R.

2011-01-01

The E' defect in irradiated fused quartz has spin lattice relaxation times (T 1 ) about 100-300 μs and spin-spin relaxation times (T 2 ) up to about 200 μs, depending on the concentration of defects and other species in the sample. These long relaxation times make it difficult to record an unsaturated continuous wave (CW) electron paramagnetic resonance (EPR) signal that is free of passage effects. Signals measured at X-band (∼9.5 GHz) by three EPR methods: conventional slow-scan field-modulated EPR, rapid scan EPR, and pulsed EPR, were compared. To acquire spectra with comparable signal-to-noise, both pulsed and rapid scan EPR require less time than conventional CW EPR. Rapid scan spectroscopy does not require the high power amplifiers that are needed for pulsed EPR. The pulsed spectra, and rapid scan spectra obtained by deconvolution of the experimental data, are free of passage effects.

Assessment of an alanine EPR dosimetry technique with enhanced precision and accuracy

International Nuclear Information System (INIS)

Hayes, Robert B.; Haskell, E.H.; Wieser, Albrecht; Romanyukha, Alexander A.; Hardy, Byron L.; Barrus, Jeffrey K.

2000-01-01

Dose reconstruction in the course of a series of blind tests demonstrated that an accuracy of 10 mGy for low doses and 1% for high doses can be achieved using EPR spectroscopy. This was accomplished using a combination of methodologies including polynomial filtration of the EPR spectrum, dosimeter rotation during scanning, use of an EPR standard fixed into the resonator and subtraction of all nonradiogenic signals. Doses were reconstructed over the range of 0.01-1000 Gy using this compound spectral EPR analysis. This EPR technique, being equally applicable to fractionated doses (such as those delivered during multiple radiotherapy treatments), was verified to exhibit dose reciprocity. Irradiated alanine dosimeters which were stored exhibited compound spectral EPR signal fading of ca 3% over 9 months. All error estimates given in this paper are given at the 1 standard deviation level and unless otherwise specified do not account for uncertainties in source calibration

Assessment of an alanine EPR dosimetry technique with enhanced precision and accuracy

CERN Document Server

Hayes, R B; Wieser, A; Romanyukha, A A; Hardy, B L; Barrus, J K

2000-01-01

Dose reconstruction in the course of a series of blind tests demonstrated that an accuracy of 10 mGy for low doses and 1% for high doses can be achieved using EPR spectroscopy. This was accomplished using a combination of methodologies including polynomial filtration of the EPR spectrum, dosimeter rotation during scanning, use of an EPR standard fixed into the resonator and subtraction of all nonradiogenic signals. Doses were reconstructed over the range of 0.01-1000 Gy using this compound spectral EPR analysis. This EPR technique, being equally applicable to fractionated doses (such as those delivered during multiple radiotherapy treatments), was verified to exhibit dose reciprocity. Irradiated alanine dosimeters which were stored exhibited compound spectral EPR signal fading of ca 3% over 9 months. All error estimates given in this paper are given at the 1 standard deviation level and unless otherwise specified do not account for uncertainties in source calibration.

Measurements of Discrete Symmetries in the Neutral Kaon System with the CPLEAR (PS195) Experiment

CERN Document Server

Ruf, Thomas

2015-01-01

The antiproton storage ring LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of T, CPT and CP symmetries in the neutral kaon system. It measured with high precision the time evolution of initially strangeness-tagged $K^0$ and $\\bar{K}^0$ states to determine the size of violations with respect to these symmetries in the context of a systematic study. In parallel, limits concerning quantum-mechanical predictions (EPR paradox, coherence of the wave function) or the equivalence principle of general relativity have been obtained. This article will first discuss briefly the unique low energy antiproton storage ring LEAR followed by a description of the CPLEAR experiment, including the basic formalism necessary to understand the time evolution of a neutral kaon state and the main results related to measurements of discrete symmetries in the neutral kaon system. An exce...

Antibacterial ethylene propylene rubber impregnated with silver nanopowder: AgNP@EPR

Directory of Open Access Journals (Sweden)

Marzieh Miranzadeh

2016-01-01

Full Text Available Following our interest in reaching for a molded rubber article with possible detergent contact applications, durable silver nanopowder (AgNP is synthesized by arc discharge, then mixed with varying ratios of ethylene propylene rubber (EPR, affording novel AgNP@EPR nanocomposites. X-ray diffraction (XRD patterns of AgNP as well as AgNP@EPR show no trace of impurity, while scanning electron microscopy (SEM indicates an average diameter of 50 nm for the former. Transmission electron microscopy (TEM images while confirm the SEM results, show quite a few 5 nm AgNP particles lying beside some micro crumbs. Our DC arc discharge technique involves explosion of movable silver anode and static cathode by a current pulse between 5 to 10 A cm-2. A solution blending method is employed for preparation of AgNP@EPR nanocomposites. The AgNP is first dispersed in toluene using an ultrasonic homogenizer, and then thoroughly mixed with EPR in the same solvent whose removal gives nanocomposites of 2, 4, 6 and 8 vol% AgNP in EPR,  showing strong antibacterial activity against both Escherichia coli and Staphylococcus aureus.

Alanine EPR dosimetry of therapeutic irradiators

International Nuclear Information System (INIS)

Bugay, O.; Bartchuk, V.; Kolesnik, S.; Mazin, M.; Gaponenko, H.

1999-01-01

The high-dose alanine EPR dosimetry is a very precise method in the dose range 1-100 kGy. The system is used generally as the standard high-dose transfer dosimetry in many laboratories. This is comparatively expensive technique so it is important to use it as a more universal dosimetry system also in the middle and low dose ranges. The problems of the middle-dose alanine dosimetry are discussed and the solution of several problems is proposed. The alanine EPR dosimetry has been applied to the dose measurements of medical irradiators in the Kiev City Oncology Center. (author)

EPR Study of [Cu(Him)4]·2Br Complex

International Nuclear Information System (INIS)

Yıldırım, İ; Karabulut, B

2016-01-01

The single crystal of [Cu(Him) 4 ]·2Br (Him: C 3 H 4 N 2 , imidazole) complex has been investigated at ambient temperature in three mutually perpendicular planes by EPR technique. The magnetic environments of [Cu(Him) 4 ]·2Br complex have been identified by EPR technique. The study reveals the existence of two magnetically inequivalent Cu 2+ sites. The principal values of g tensors were obtained. The EPR parameters show that the paramagnetic centers have rhombic symmetry. (paper)

Pulse EPR distance measurements to study multimers and multimerisation

Science.gov (United States)

Ackermann, Katrin; Bode, Bela E.

2018-06-01

Pulse dipolar electron paramagnetic resonance (PD-EPR) has become a powerful tool for structural biology determining distances on the nanometre scale. Recent advances in hardware, methodology, and data analysis have widened the scope to complex biological systems. PD-EPR can be applied to systems containing lowly populated conformers or displaying large intrinsic flexibility, making them all but intractable for cryo-electron microscopy and crystallography. Membrane protein applications are of particular interest due to the intrinsic difficulties for obtaining high-resolution structures of all relevant conformations. Many drug targets involved in critical cell functions are multimeric channels or transporters. Here, common approaches for introducing spin labels for PD-EPR cause the presence of more than two electron spins per multimeric complex. This requires careful experimental design to overcome detrimental multi-spin effects and to secure sufficient distance resolution in presence of multiple distances. In addition to obtaining mere distances, PD-EPR can also provide information on multimerisation degrees allowing to study binding equilibria and to determine dissociation constants.

Managing operational paradoxes

International Nuclear Information System (INIS)

Olson, J.; Baker, K.; Thurber, J.

1992-01-01

The economic, regulatory, and social environment of commercial nuclear power has changed dramatically in the last 10 yr. In addition to the increased regulatory pressure resulting from the Three Mile Island incident and other factors, nuclear utilities have experienced increasing financial pressure from state public utility commissions and investors. To successfully manage nuclear power plants in today's environment requires different skills and strategies than were required 10 yr ago. External pressures on the utility and plant organization have created a series of operational paradoxes unmatched in the history of commercial nuclear power. This paper is based on a synthesis of findings and observations from a series of studies conducted by the authors over the past 10 yr. The authors identify a series of specific paradoxes facing managers of nuclear power plants and suggest several strategies for managing these paradoxes

EPR Imaging at a Few Megahertz Using SQUID Detectors

Science.gov (United States)

Hahn, Inseob; Day, Peter; Penanen, Konstantin; Eom, Byeong Ho

2010-01-01

An apparatus being developed for electron paramagnetic resonance (EPR) imaging operates in the resonance-frequency range of about 1 to 2 MHz well below the microwave frequencies used in conventional EPR. Until now, in order to obtain sufficient signal-to-noise radios (SNRs) in conventional EPR, it has been necessary to place both detectors and objects to be imaged inside resonant microwave cavities. EPR imaging has much in common with magnetic resonance imaging (MRI), which is described briefly in the immediately preceding article. In EPR imaging as in MRI, one applies a magnetic pulse to make magnetic moments (in this case, of electrons) precess in an applied magnetic field having a known gradient. The magnetic moments precess at a resonance frequency proportional to the strength of the local magnetic field. One detects the decaying resonance-frequency magnetic- field component associated with the precession. Position is encoded by use of the known relationship between the resonance frequency and the position dependence of the magnetic field. EPR imaging has recently been recognized as an important tool for non-invasive, in vivo imaging of free radicals and reduction/oxidization metabolism. However, for in vivo EPR imaging of humans and large animals, the conventional approach is not suitable because (1) it is difficult to design and construct resonant cavities large enough and having the required shapes; (2) motion, including respiration and heartbeat, can alter the resonance frequency; and (3) most microwave energy is absorbed in the first few centimeters of tissue depth, thereby potentially endangering the subject and making it impossible to obtain adequate signal strength for imaging at greater depth. To obtain greater penetration depth, prevent injury to the subject, and avoid the difficulties associated with resonant cavities, it is necessary to use lower resonance frequencies. An additional advantage of using lower resonance frequencies is that one can use

Five paradox on energy system management

International Nuclear Information System (INIS)

Frisch, J.R.

1995-01-01

Five paradox are detailed on energy management: internationalization of energy questions but always regional management is present, short term problems must be solved but without forgetting long term problems in environment, the third paradox is : we have time but we are in a hurry, we have reserves but ten, twenty or thirty years are necessary to adapt our energy system; the fourth paradox is : we cannot manage energy by managing only energy, for example : finances system development and environment importance. The last and fifth paradox is : the market, yes, but state too, as regulative force

Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma (EPR-CAT)

Science.gov (United States)

2015-10-01

Award Number: W81XWH-07-1-0682 TITLE: Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma ( EPR -CAT) PRINCIPAL INVESTIGATOR...thoracotomy and open chest CPR, results in unacceptably low survival rates. Emergency Preservation and Resuscitation ( EPR ) was developed to rapidly preserve...further recommended that the trauma surgeons involved in the study obtain hospital privileges for cannulation for the EPR flush. This has been

Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma (EPR CAT)

Science.gov (United States)

2016-12-01

Award Number: W81XWH-07-1-0682 TITLE: Emergency Preservation and Resuscitation for Cardiac Arrest from Trauma ( EPR -CAT) PRINCIPAL INVESTIGATOR...Preservation and Resuscitation ( EPR ) was developed to rapidly preserve the organism during ischemia, using hypothermia, drugs, and fluids, to “buy time...privileges for cannulation for the EPR flush. This has been accomplished. Given the complexity of our planned intervention for trauma patients in

Optimal registration conditions for tooth EPR dosimetry at low accumulated dose

International Nuclear Information System (INIS)

Galtsev, V.E.; Galtseva, E.V.; Lebedev, Y.S.

1997-01-01

The spectrum registration under rapid passage conditions (the second harmonic phase quadrature of the absorption signal) allows one to enhance substantially the sensitivity of tooth enamel and bone EPR dosimetry at a low accumulated dose. In the present work the dependencies of the radiation and background signals on EPR spectrometer parameters are described and the optimal conditions in RPM for EPR dosimetry are obtained. (Author)

Wormhole and entanglement (non-)detection in the ER=EPR correspondence

Energy Technology Data Exchange (ETDEWEB)

Bao, Ning [Institute for Quantum Information and Matter, California Institute of Technology,Pasadena, CA 91125 (United States); Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States); Pollack, Jason; Remmen, Grant N. [Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States)

2015-11-19

The recently proposed ER=EPR correspondence postulates the existence of wormholes (Einstein-Rosen bridges) between entangled states (such as EPR pairs). Entanglement is famously known to be unobservable in quantum mechanics, in that there exists no observable (or, equivalently, projector) that can accurately pick out whether a generic state is entangled. Many features of the geometry of spacetime, however, are observables, so one might worry that the presence or absence of a wormhole could identify an entangled state in ER=EPR, violating quantum mechanics, specifically, the property of state-independence of observables. In this note, we establish that this cannot occur: there is no measurement in general relativity that unambiguously detects the presence of a generic wormhole geometry. This statement is the ER=EPR dual of the undetectability of entanglement.

Wormhole and entanglement (non-)detection in the ER=EPR correspondence

International Nuclear Information System (INIS)

Bao, Ning; Pollack, Jason; Remmen, Grant N.

2015-01-01

The recently proposed ER=EPR correspondence postulates the existence of wormholes (Einstein-Rosen bridges) between entangled states (such as EPR pairs). Entanglement is famously known to be unobservable in quantum mechanics, in that there exists no observable (or, equivalently, projector) that can accurately pick out whether a generic state is entangled. Many features of the geometry of spacetime, however, are observables, so one might worry that the presence or absence of a wormhole could identify an entangled state in ER=EPR, violating quantum mechanics, specifically, the property of state-independence of observables. In this note, we establish that this cannot occur: there is no measurement in general relativity that unambiguously detects the presence of a generic wormhole geometry. This statement is the ER=EPR dual of the undetectability of entanglement.

Clinical EPR: Unique Opportunities and Some Challenges

Science.gov (United States)

Swartz, Harold M.; Williams, Benjamin B.; Zaki, Bassem I.; Hartford, Alan C.; Jarvis, Lesley A.; Chen, Eunice; Comi, Richard J.; Ernstoff, Marc S.; Hou, Huagang; Khan, Nadeem; Swarts, Steven G.; Flood, Ann B.; Kuppusamy, Periannan

2014-01-01

Electron paramagnetic resonance (EPR) spectroscopy has been well established as a viable technique for measurement of free radicals and oxygen in biological systems, from in vitro cellular systems to in vivo small animal models of disease. However, the use of EPR in human subjects in the clinical setting, although attractive for a variety of important applications such as oxygen measurement, is challenged with several factors including the need for instrumentation customized for human subjects, probe and regulatory constraints. This paper describes the rationale and development of the first clinical EPR systems for two important clinical applications, namely, measurement of tissue oxygen (oximetry), and radiation dose (dosimetry) in humans. The clinical spectrometers operate at 1.2 GHz frequency and use surface loop resonators capable of providing topical measurements up to 1 cm depth in tissues. Tissue pO2 measurements can be carried out noninvasively and repeatedly after placement of an oxygen-sensitive paramagnetic material (currently India ink) at the site of interest. Our EPR dosimetry system is capable of measuring radiation-induced free radicals in the tooth of irradiated human subjects to determine the exposure dose. These developments offer potential opportunities for clinical dosimetry and oximetry, which include guiding therapy for individual patients with tumors or vascular disease, by monitoring of tissue oxygenation. Further work is in progress to translate this unique technology to routine clinical practice. PMID:24439333

Extending Cantor Paradox

OpenAIRE

Leon, Antonio

2008-01-01

The inconsistencies involved in the foundation of set theory were invariably caused by infinity and self-reference; and only with the opportune axiomatic restrictions could them be obviated. Throughout history, both concepts have proved to be an exhaustible source of paradoxes and contradictions. It seems therefore legitimate to pose some questions concerning their formal consistency. This is just the objective of this paper. Starting from an extension of Cantor's paradox that suggests the in...

Low temperature EPR investigation of Co{sup 2+} ion doped into rutile TiO{sub 2} single crystal: Experiments and simulations

Energy Technology Data Exchange (ETDEWEB)

Zerentürk, A. [Department of Physics, Marmara University, 34722 Kadıköy, Istanbul (Turkey); Açıkgöz, M., E-mail: muhammed.acikgoz@eng.bau.edu.tr [Bahcesehir University, Faculty of Engineering and Natural Sciences, Besiktas Campus, 34349 Besiktas, Istanbul (Turkey); Kazan, S.; Yıldız, F.; Aktaş, B. [Department of Physics, Gebze Technical University, 41400 Gebze, Kocaeli (Turkey)

2017-02-01

In this paper, we present the results of X-band EPR spectra of Co{sup 2+} ion doped rutile (TiO{sub 2}) which is one of the most promising memristor material. We obtained the angular variation of spectra in three mutually perpendicular planes at liquid helium (7–13 K) temperatures. Since the impurity ions have ½ effective spin and 7/2 nuclear spin, a relatively simple spin Hamiltonian containing only electronic Zeeman and hyperfine terms was utilized. Two different methods were used in theoretical analysis. Firstly, a linear regression analysis of spectra based on perturbation theory was studied. However, this approach is not sufficient for analyzing Co{sup +2} spectra and leads to complex eigenvectors for G and A tensors due to large anisotropy of eigenvalues. Therefore, all spectra were analyzed again with exact diagonalization of spin Hamiltonian and the high accuracy eigenvalues and eigenvectors of G and A tensors were obtained by taking into account the effect of small sample misalignment from the exact crystallographic planes due to experimental conditions. Our results show that eigen-axes of g and A tensors are parallel to crystallographic directions. Hence, our EPR experiments proves that Co{sup 2+} ions substitute for Ti{sup 4+} ions in lattice. The obtained principal values of g tensor are g{sub x}=2.110(6), g{sub y}=5.890(2), g{sub z}=3.725(7) and principal values of hyperfine tensor are A{sub x}=42.4, A{sub y}=152.7, A{sub z}=26 (in 10{sup −4}/cm). - Highlights: • X-band EPR spectra of Co{sup 2+} ion doped rutile (TiO{sub 2}) investigated at 7–13 K. • Two different methods were used in theoretical analysis. • The presence of two structurally equivalent centers for Co{sup 2+} ions observed. • It is concluded that impurity ions substitute for Ti{sup 4+} ion.

Recent results of EPR and Moessbauer investigations on lattice dynamics in ammonium sulphate

CERN Document Server

Grecu, M N; Grecu, V V

2003-01-01

Recent results of the lattice dynamics investigation on ammonium sulfate are reported based on recent experiments carried out using using the non-destructive experimental technique of EPR and NGR. The main results confirm the presence and the contribution of a soft mode, which accompanied the paraferroelectric phase transition in the investigated crystal. (authors)

Perspectives of shaped pulses for EPR spectroscopy

Science.gov (United States)

Spindler, Philipp E.; Schöps, Philipp; Kallies, Wolfgang; Glaser, Steffen J.; Prisner, Thomas F.

2017-07-01

This article describes current uses of shaped pulses, generated by an arbitrary waveform generator, in the field of EPR spectroscopy. We show applications of sech/tanh and WURST pulses to dipolar spectroscopy, including new pulse schemes and procedures, and discuss the more general concept of optimum-control-based pulses for applications in EPR spectroscopy. The article also describes a procedure to correct for experimental imperfections, mostly introduced by the microwave resonator, and discusses further potential applications and limitations of such pulses.

Paradoxical aortic stenosis: A systematic review.

Science.gov (United States)

Cavaca, Rita; Teixeira, Rogério; Vieira, Maria João; Gonçalves, Lino

2017-04-01

Aortic stenosis (AS) is a complex systemic valvular and vascular disease with a high prevalence in developed countries. The new entity "paradoxical low-flow, low-gradient aortic stenosis" refers to cases in which patients have severe AS based on assessment of aortic valve area (AVA) (≤1 cm 2 ) or indexed AVA (≤0.6 cm 2 /m 2 ), but paradoxically have a low mean transvalvular gradient (<40 mmHg) and a low stroke volume index (≤35 ml/m 2 ), despite preserved left ventricular ejection fraction (≥50%). A search was carried out in the PubMed database on paradoxical AS for the period 2007-2014. A total of 57 articles were included for this review. The prevalence of paradoxical AS ranged from 3% to 35% of the population with severe degenerative AS. It was more frequent in females and in older patients. Paradoxical AS was associated with characteristic left ventricular remodeling as well as an increase in systemic arterial stiffness. It was noted that there may be errors and inaccuracies in the calculation of AVA by the continuity equation, which could erroneously suggest the paradoxical phenotype. There are new diagnostic methods to facilitate the study of AS, such as aortic valve calcium score, valvuloarterial impedance and the longitudinal mechanics of the left ventricle. With regard to its natural history, it is not clear whether paradoxical AS corresponds to an advance stage of the disease or if paradoxical AS patients have a distinct phenotype with specific characteristics. Valve replacement, either surgical or percutaneous, may be indicated in patients with severe and symptomatic paradoxical AS. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Making Games Not Work: Paradoxes Embedded in Game-Based Training and Concepts for Overcoming Them

Science.gov (United States)

Jones, Phillip N.; Cuper, Taryn

2010-01-01

An interest in game-based training solutions is natural. All one has to do is watch someone fully engaged in a modern game to see the potential of harnessing that attention for training. However, the reality of game-based training has not fully satisfied these expectations. This paper explains two paradoxes that must be overcome for games to support training. These paradoxes are a result of the realities of the basic human condition clashing with the requirements of learning theory. 80th paradoxes arise from the concept of "engagement" that is central to games. The first comes from a more robust definition of engagement, which is the condition of Flow or Optimal Experience. Flow is the state game developers want to see in users. One aspect of Flow is loss of sense of self as the individual becomes immersed in the experience. The paradox arises because this loss of self directly contradicts the learning requirement of self-reflection. The second paradox comes from theories of play, which state in part that play requires a level of individual freedom. The contradiction arises when game-based play must be harnessed to an organizational training program or regimen. The paper will discuss these paradoxes in the context of an effort to design a game-based training modality to train combat medics and will close with a review of compensating strategies identified by the designers. The paper will provide information important to anyone interested in conceptualizing and designing game-based training.

Dependencies of the radiation sensitivity of human tooth enamel in EPR dosimetry

International Nuclear Information System (INIS)

Wieser, A.; El-Faramawy, N.; Meckbach, R.

2001-01-01

The EPR dose response of tooth enamel was determined for human molars collected in Egypt. The influence of age, gender and residence of the tooth donors as well as tooth position and sample preparation on EPR sensitivity and its variability over the enamel samples was investigated. The EPR sensitivity and its variability were found to depend only on the sample preparation procedure. The variability in EPR sensitivity of enamel from Egyptian teeth was maximally 10% and the mean sensitivity was in good agreement with that of German teeth

Photochemical reduction of water-soluble C60 derivatives (EPR study)

International Nuclear Information System (INIS)

Brezova, V.; Stasko, A.; Dvoranova, D.; Asmus, K.D.; Guldi, D.M.

1999-01-01

The photochemical reduction of three bis-functionalized C 60 derivatives resulted in the formation of a single radical product, characterized by relatively narrow EPR line (g M = 2.0007, pp < 0.02 mT). In the irradiated aqueous solutions containing L-ascorbic acid, in the addition to the EPR line related to bis-adduct mono-anion, also 6-line EPR spectrum of ascorbyl radical was observed. Consequently, the photoinduced formation of ascorbyl radical was attributed to the intermolecular quenching of fullerenes excited states. (authors)

Qualities and Inequalities in Online Social Networks through the Lens of the Generalized Friendship Paradox.

Science.gov (United States)

Momeni, Naghmeh; Rabbat, Michael

2016-01-01

The friendship paradox is the phenomenon that in social networks, people on average have fewer friends than their friends do. The generalized friendship paradox is an extension to attributes other than the number of friends. The friendship paradox and its generalized version have gathered recent attention due to the information they provide about network structure and local inequalities. In this paper, we propose several measures of nodal qualities which capture different aspects of their activities and influence in online social networks. Using these measures we analyse the prevalence of the generalized friendship paradox over Twitter and we report high levels of prevalence (up to over 90% of nodes). We contend that this prevalence of the friendship paradox and its generalized version arise because of the hierarchical nature of the connections in the network. This hierarchy is nested as opposed to being star-like. We conclude that these paradoxes are collective phenomena not created merely by a minority of well-connected or high-attribute nodes. Moreover, our results show that a large fraction of individuals can experience the generalized friendship paradox even in the absence of a significant correlation between degrees and attributes.

Qualities and Inequalities in Online Social Networks through the Lens of the Generalized Friendship Paradox.

Directory of Open Access Journals (Sweden)

Naghmeh Momeni

Full Text Available The friendship paradox is the phenomenon that in social networks, people on average have fewer friends than their friends do. The generalized friendship paradox is an extension to attributes other than the number of friends. The friendship paradox and its generalized version have gathered recent attention due to the information they provide about network structure and local inequalities. In this paper, we propose several measures of nodal qualities which capture different aspects of their activities and influence in online social networks. Using these measures we analyse the prevalence of the generalized friendship paradox over Twitter and we report high levels of prevalence (up to over 90% of nodes. We contend that this prevalence of the friendship paradox and its generalized version arise because of the hierarchical nature of the connections in the network. This hierarchy is nested as opposed to being star-like. We conclude that these paradoxes are collective phenomena not created merely by a minority of well-connected or high-attribute nodes. Moreover, our results show that a large fraction of individuals can experience the generalized friendship paradox even in the absence of a significant correlation between degrees and attributes.

Saturation transfer EPR (ST-EPR) for dating biocarbonates containing large amount of Mn2+: separation of SO3- and CO2- lines and geochronology of Brazilian fish fossil

International Nuclear Information System (INIS)

Sastry, M.D.; Andrade, M.B.; Watanabe, Shigueo

2003-01-01

A method using saturation transfer EPR (ST-EPR) is shown to be feasible for detecting EPR signal of radiation-induced defects in biocarbonates containing large amount of Mn 2+ . The ST-EPR measurements conducted at room temperature on fish fossil of Brazilian origin, enabled the identification of CO 2 - and SO 3 - radical ions, by partially suppressing the intense signal from Mn 2+ when the signal are detected 90 deg. out of phase with magnetic field modulating signal and at high microwave power (50 mW). Using these signals the age of fish fossil is estimated to be (36±5) Ma

Solid-state EPR strategies for the structural characterization of paramagnetic NO adducts of frustrated Lewis pairs (FLPs)

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Marcos de; Magon, Claudio José [Instituto de Física de São Carlos, Universidade de São Paulo, P.O. Box 369, 13560-970 São Carlos, São Paulo (Brazil); Wiegand, Thomas [Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, 8049 Zürich (Switzerland); Elmer, Lisa-Maria; Sajid, Muhammad; Kehr, Gerald; Erker, Gerhard [Organisch-Chemisches Institut, WWU Münster, Corrensstraße 40, D 48149 Münster (Germany); Eckert, Hellmut, E-mail: eckerth@uni-muenster.de [Instituto de Física de São Carlos, Universidade de São Paulo, P.O. Box 369, 13560-970 São Carlos, São Paulo (Brazil); Institut für Physikalische Chemie, WWU Münster, Corrensstrasse 30, D 48149 Münster (Germany)

2015-03-28

Anisotropic interactions present in three new nitroxide radicals prepared by N,N addition of NO to various borane-phosphane frustrated Lewis pairs (FLPs) have been characterized by continuous-wave (cw) and pulsed X-band EPR spectroscopies in solid FLP-hydroxylamine matrices at 100 K. Anisotropic g-tensor values and {sup 11}B, {sup 14}N, and {sup 31}P hyperfine coupling tensor components have been extracted from continuous-wave lineshape analyses, electron spin echo envelope modulation (ESEEM), and hyperfine sublevel correlation spectroscopy (HYSCORE) experiments with the help of computer simulation techniques. Suitable fitting constraints are developed on the basis of density functional theory (DFT) calculations. These calculations reveal that different from the situation in standard nitroxide radicals (TEMPO), the g-tensors are non-coincident with any of the nuclear hyperfine interaction tensors. The determination of these interaction parameters turns out to be successful, as the cw- and pulse EPR experiments are highly complementary in informational content. While the continuous-wave lineshape is largely influenced by the anisotropic hyperfine coupling to {sup 14}N and {sup 31}P, the ESEEM and HYSCORE spectra contain important information about the {sup 11}B hyperfine coupling and nuclear electric quadrupolar interaction. The set of cw- and pulsed EPR experiments, with fitting constraints developed by DFT calculations, defines an efficient strategy for the structural analysis of paramagnetic FLP adducts.

Investigating Pigment Radicals in Black Rice Using HPLC and Multi-EPR.

Science.gov (United States)

Nakagawa, Kouichi; Maeda, Hayato

2017-01-01

We investigated the location and distribution of paramagnetic species in black and white rice using electron paramagnetic resonance (EPR), X-band (9 GHz) EPR imaging (EPRI), and HPLC. EPR primarily detected two paramagnetic species in black rice, which were identified as a stable radical and Mn 2+ species, based on the g values and hyperfine components of the EPR signals. The signal from the stable radical appeared at g ≈ 2.00 and was relatively strong and stable. Subsequent noninvasive two-dimensional (2D) EPRI revealed that this stable radical was primarily located in the pigmented region of black rice, while very few radicals were observed in the rice interior. Pigments extracted from black rice were analyzed using HPLC; the major compound was found to be cyanidin-3-glucoside. EPR and HPLC results indicate that the stable radical was only found within the pigmented region of the rice, and that it could either be cyanidin-3-glucoside, or one of its oxidative decomposition products.

Use of rapid-scan EPR to improve detection sensitivity for spin-trapped radicals.

Science.gov (United States)

Mitchell, Deborah G; Rosen, Gerald M; Tseitlin, Mark; Symmes, Breanna; Eaton, Sandra S; Eaton, Gareth R

2013-07-16

The short lifetime of superoxide and the low rates of formation expected in vivo make detection by standard continuous wave (CW) electron paramagnetic resonance (EPR) challenging. The new rapid-scan EPR method offers improved sensitivity for these types of samples. In rapid-scan EPR, the magnetic field is scanned through resonance in a time that is short relative to electron spin relaxation times, and data are processed to obtain the absorption spectrum. To validate the application of rapid-scan EPR to spin trapping, superoxide was generated by the reaction of xanthine oxidase and hypoxanthine with rates of 0.1-6.0 μM/min and trapped with 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO). Spin trapping with BMPO to form the BMPO-OOH adduct converts the very short-lived superoxide radical into a more stable spin adduct. There is good agreement between the hyperfine splitting parameters obtained for BMPO-OOH by CW and rapid-scan EPR. For the same signal acquisition time, the signal/noise ratio is >40 times higher for rapid-scan than for CW EPR. Rapid-scan EPR can detect superoxide produced by Enterococcus faecalis at rates that are too low for detection by CW EPR. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Peptide-membrane Interactions by Spin-labeling EPR

Science.gov (United States)

Smirnova, Tatyana I.; Smirnov, Alex I.

2016-01-01

Site-directed spin labeling (SDSL) in combination with Electron Paramagnetic Resonance (EPR) spectroscopy is a well-established method that has recently grown in popularity as an experimental technique, with multiple applications in protein and peptide science. The growth is driven by development of labeling strategies, as well as by considerable technical advances in the field, that are paralleled by an increased availability of EPR instrumentation. While the method requires an introduction of a paramagnetic probe at a well-defined position in a peptide sequence, it has been shown to be minimally destructive to the peptide structure and energetics of the peptide-membrane interactions. In this chapter, we describe basic approaches for using SDSL EPR spectroscopy to study interactions between small peptides and biological membranes or membrane mimetic systems. We focus on experimental approaches to quantify peptide-membrane binding, topology of bound peptides, and characterize peptide aggregation. Sample preparation protocols including spin-labeling methods and preparation of membrane mimetic systems are also described. PMID:26477253

Comparative study of some new EPR dosimeters

International Nuclear Information System (INIS)

Alzimami, K.S.; Maghraby, Ahmed M.; Bradley, D.A.

2014-01-01

Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (W PP ) and peak-to-peak signal height (H PP ). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic. - Highlights: ► Several EPR dosimeters were suggested based on SO 3 − radical. ► Taurine, homotaurine, sulfanilic, and sulfamic acid all possess simple EPR spectra. ► Dosimeters were compared to each other in terms of the dosimetric point of view. ► Energy dependence curves of the selected dosimeters were compared to eachother

Explaining the harmonic sequence paradox.

Science.gov (United States)

Schmidt, Ulrich; Zimper, Alexander

2012-05-01

According to the harmonic sequence paradox, an expected utility decision maker's willingness to pay for a gamble whose expected payoffs evolve according to the harmonic series is finite if and only if his marginal utility of additional income becomes zero for rather low payoff levels. Since the assumption of zero marginal utility is implausible for finite payoff levels, expected utility theory - as well as its standard generalizations such as cumulative prospect theory - are apparently unable to explain a finite willingness to pay. This paper presents first an experimental study of the harmonic sequence paradox. Additionally, it demonstrates that the theoretical argument of the harmonic sequence paradox only applies to time-patient decision makers, whereas the paradox is easily avoided if time-impatience is introduced. ©2011 The British Psychological Society.

The core paradox.

Science.gov (United States)

Kennedy, G. C.; Higgins, G. H.

1973-01-01

Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

Multi-photon transitions and Rabi resonance in continuous wave EPR.

Science.gov (United States)

Saiko, Alexander P; Fedaruk, Ryhor; Markevich, Siarhei A

2015-10-01

The study of microwave-radiofrequency multi-photon transitions in continuous wave (CW) EPR spectroscopy is extended to a Rabi resonance condition, when the radio frequency of the magnetic-field modulation matches the Rabi frequency of a spin system in the microwave field. Using the non-secular perturbation theory based on the Bogoliubov averaging method, the analytical description of the response of the spin system is derived for all modulation frequency harmonics. When the modulation frequency exceeds the EPR linewidth, multi-photon transitions result in sidebands in absorption EPR spectra measured with phase-sensitive detection at any harmonic. The saturation of different-order multi-photon transitions is shown to be significantly different and to be sensitive to the Rabi resonance. The noticeable frequency shifts of sidebands are found to be the signatures of this resonance. The inversion of two-photon lines in some spectral intervals of the out-of-phase first-harmonic signal is predicted under passage through the Rabi resonance. The inversion indicates the transition from absorption to stimulated emission or vice versa, depending on the sideband. The manifestation of the primary and secondary Rabi resonance is also demonstrated in the time evolution of steady-state EPR signals formed by all harmonics of the modulation frequency. Our results provide a theoretical framework for future developments in multi-photon CW EPR spectroscopy, which can be useful for samples with long spin relaxation times and extremely narrow EPR lines. Copyright © 2015 Elsevier Inc. All rights reserved.

Decomposition of spectra in EPR dosimetry using the matrix method

International Nuclear Information System (INIS)

Sholom, S.V.; Chumak, V.V.

2003-01-01

The matrix method of EPR spectra decomposition is developed and adapted for routine application in retrospective EPR dosimetry with teeth. According to this method, the initial EPR spectra are decomposed (using methods of matrix algebra) into several reference components (reference matrices) that are specific for each material. Proposed procedure has been tested on the example of tooth enamel. Reference spectra were a spectrum of an empty sample tube and three standard signals of enamel (two at g=2.0045, both for the native signal and one at g perpendicular =2.0018, g parallel =1.9973 for the dosimetric signal). Values of dosimetric signals obtained using the given method have been compared with data obtained by manual manipulation of spectra, and good coincidence was observed. This allows considering the proposed method as potent for application in routine EPR dosimetry

EPR and IR spectral investigations on some leafy vegetables of Indian origin

Science.gov (United States)

Prasuna, C. P. Lakshmi; Chakradhar, R. P. S.; Rao, J. L.; Gopal, N. O.

2009-09-01

EPR spectral investigations have been carried out on four edible leafy vegetables of India, which are used as dietary component in day to day life. In Rumex vesicarius leaf sample, EPR spectral investigations at different temperatures indicate the presence of anti-ferromagnetically coupled Mn(IV)-Mn(IV) complexes. EPR spectra of Trigonella foenum graecum show the presence of Mn ions in multivalent state and Fe 3+ ions in rhombic symmetry. EPR spectra of Basella rubra indicate the presence of Mn(IV)-O-Mn(IV) type complexes. The EPR spectra of Basella rubra have been studied at different temperatures. It is found that the spin population for the resonance signal at g = 2.06 obeys the Boltzmann distribution law. The EPR spectra of Moringa oliefera leaves show the presence of Mn 2+ ions. Radiation induced changes in free radical of this sample have also been studied. The FT-IR spectra of Basella rubra and Moringa oliefera leaves show the evidences for the protein matrix bands and those corresponding to carboxylic C dbnd O bonds.

Echo detected EPR as a tool for detecting radiation-induced defect signals in pottery

International Nuclear Information System (INIS)

Zoleo, Alfonso; Bortolussi, Claudia; Brustolon, Marina

2011-01-01

Archaeological fragments of pottery have been investigated by using CW-EPR and Echo Detected EPR (EDEPR). EDEPR allows to remove the CW-EPR dominant Fe(III) background spectrum, hiding much weaker signals potentially useful for dating purpose. EDEPR spectra attributed to a methyl radical and to feldspar defects have been recorded at room and low temperature for an Iron Age cooking ware (700 B.C.). A study on the dependence of EDEPR intensity over absorbed dose on a series of γ-irradiated brick samples (estimated age of 562 ± 140 B.C.) has confirmed the potential efficacy of the proposed method for spotting defect signals out of the strong iron background. - Highlights: → Fe(III) CW-EPR signals cover CW-EPR-detectable defects in ceramics. → Echo detected EPR gets rid of Fe(III) signals, disclosing defect signals. → Echo detected EPR detects defect signals even at relatively low doses.

EPR (European Pressurized Reactor)

International Nuclear Information System (INIS)

2015-01-01

This document presents the EPR (European Pressurized Reactor), a modernised version of PWRs which uses nuclear fission. It indicates to which category it belongs (third generation). It briefly describes its operation: recalls on nuclear fission, electricity production in a nuclear reactor. It presents and comments its characteristics: power, thermal efficiency, redundant systems for safety control, double protective enclosure, expected lifetime, use of MOX fuel, modular design. It discusses economic stakes (expected higher nuclear electricity competitiveness, but high construction costs), and safety challenges (design characteristics, critics by nuclear safety authorities about the safety data processing system). It presents the main involved actors (Areva, EDF) and competitors in the field of advanced reactors (Rosatom with its VVER 1200, General Electric with its ABWR and its ESBWR, Mitsubishi with its APWR, Westinghouse with its AP100) while outlining the importance of certifications and delays to obtain them. After having evoked key data on EPR fuel consumption, it indicates reactors under construction, evokes potential markets and perspectives

From the BMI paradox to the obesity paradox: the obesity-mortality association in coronary heart disease.

Science.gov (United States)

Antonopoulos, A S; Oikonomou, E K; Antoniades, C; Tousoulis, D

2016-10-01

Despite a strong association between body weight and mortality in the general population, clinical evidence suggests better clinical outcome of overweight or obese individuals with established coronary heart disease. This finding has been termed the 'obesity paradox', but its existence remains a point of debate, because it is mostly observed when body mass index (BMI) is used to define obesity. Inherent limitations of BMI as an index of adiposity, as well as methodological biases and the presence of confounding factors, may account for the observed findings of clinical studies. In this review, our aim is to present the data that support the presence of a BMI paradox in coronary heart disease and then explore whether next to a BMI paradox a true obesity paradox exists as well. We conclude by attempting to link the obesity paradox notion to available translational research data supporting a 'healthy', protective adipose tissue phenotype. © 2016 World Obesity. © 2016 World Obesity.

Measurements of Discrete Symmetries in the Neutral Kaon System with the CPLEAR (PS195) Experiment

Science.gov (United States)

Ruf, Thomas

2015-07-01

The antiproton storage ring LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of T, \\{CPT} and \\{CP} symmetries in the neutral kaon system. It measured with high precision the time evolution of initially strangeness-tagged K0 and overline K ^0 states to determine the size of violations with respect to these symmetries in the context of a systematic study. In parallel, limits concerning quantum-mechanical predictions (EPR paradox, coherence of the wave function) or the equivalence principle of general relativity have been obtained. This article will first discuss briefly the unique low energy antiproton storage ring LEAR followed by a description of the CPLEAR experiment, including the basic formalism necessary to understand the time evolution of a neutral kaon state and the main results related to measurements of discrete symmetries in the neutral kaon system. An excellent and exhaustive review of the CPLEAR experiment and all its measurements is given in Ref. 1.

Paradoxes in carcinogenesis: New opportunities for research directions

Directory of Open Access Journals (Sweden)

Kramer Barnett S

2007-08-01

Full Text Available Abstract Background The prevailing paradigm in cancer research is the somatic mutation theory that posits that cancer begins with a single mutation in a somatic cell followed by successive mutations. Much cancer research involves refining the somatic mutation theory with an ever increasing catalog of genetic changes. The problem is that such research may miss paradoxical aspects of carcinogenesis for which there is no likely explanation under the somatic mutation theory. These paradoxical aspects offer opportunities for new research directions that should not be ignored. Discussion Various paradoxes related to the somatic mutation theory of carcinogenesis are discussed: (1 the presence of large numbers of spatially distinct precancerous lesions at the onset of promotion, (2 the large number of genetic instabilities found in hyperplastic polyps not considered cancer, (3 spontaneous regression, (4 higher incidence of cancer in patients with xeroderma pigmentosa but not in patients with other comparable defects in DNA repair, (5 lower incidence of many cancers except leukemia and testicular cancer in patients with Down's syndrome, (6 cancer developing after normal tissue is transplanted to other parts of the body or next to stroma previously exposed to carcinogens, (7 the lack of tumors when epithelial cells exposed to a carcinogen were transplanted next to normal stroma, (8 the development of cancers when Millipore filters of various pore sizes were was inserted under the skin of rats, but only if the holes were sufficiently small. For the latter paradox, a microarray experiment is proposed to try to better understand the phenomena. Summary The famous physicist Niels Bohr said "How wonderful that we have met with a paradox. Now we have some hope of making progress." The same viewpoint should apply to cancer research. It is easy to ignore this piece of wisdom about the means to advance knowledge, but we do so at our peril.

Identification of irradiated crab using EPR

Energy Technology Data Exchange (ETDEWEB)

Maghraby, A. [Radiation Dosimetry Department, National Institute for Standards (NIS), Ministry of Scientific Research, Haram, 12211- Giza, P.O. Box: 136 (Egypt)]. E-mail: maghrabism@yahoo.com

2007-02-15

EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response.

Identification of irradiated crab using EPR

International Nuclear Information System (INIS)

Maghraby, A.

2007-01-01

EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response

Mast-sipping in EPR trademark plants

International Nuclear Information System (INIS)

Langenberger, Jan; Schienbein, Marcel; Geier, Roland

2010-01-01

For more than 20 years, AREVA applies and develops different sipping techniques to identify fuel assemblies with leaking fuel rods. For the EPR trademark reactors a Mast Sipping System with newest developments will be implemented considering radiation protection and latest standards requirements. The innovative EPR trademark Sipping System differs from previous systems in many ways. One of the main innovations is that all the necessary processes of the Sipping system have been fully digitized. Second, several ALARA design modifications have been implemented to meet the current radiation protection requirements. An additional implementable multilingual assistance program facilitates the handling of the system and helps to prevent incorrect operation. (orig.)

Paradoxical cerebral air embolism

International Nuclear Information System (INIS)

Lopez-Negrete, L.; Garcia-Lozano, J.; Sanchez, J. L.; Sala, J.

2000-01-01

We present a fatal case of intracranial air embolism produced by the passage of intravenous air to the arteries owing to the existence of a patent foremen ovale associated with pulmonary hypertension, which permitted a right-left shunt (paradoxical embolism). The pathophysiological mechanisms of pneumcephalus and paradoxical embolism are discussed and the pertinent literature is reviewed. (Author) 6 refs

EPR studies of excited state exchange and crystal-field effects in rare earth compounds

International Nuclear Information System (INIS)

Huang, C.Y.; Sugawara, K.; Cooper, B.R.

1976-01-01

EPR in excited crystal-field states of Tm 3+ , Pr 3+ , and Tb 3+ in singlet-ground-state systems and in the excited state of Ce 3+ in CeP are reviewed. Because one is looking at a crystal-field excited state resonance, the exchange, even if isotropic, does not act as a secular perturbation. This means that one obtains different effects and has access to more information about the dynamic effects of exchange than in conventional paramagnetic resonance experiments. The Tm and Pr monopnictides studied are paramagnetic at all temperatures. The most striking feature of the behavior of the GAMMA 5 /sup (2)/ EPR in the Tm compounds is the presence of an anomalous maximum in the temperature dependence of the g-factor. The relationship of this effect to anisotropic exchange is discussed. The results of the EPR of the excited GAMMA 5 /sup (2)/ level of Tb 3 + (g-factor becomes very large at T/sub N/ in antiferromagnetic TbX (X = P, As, Sb) and that of the excited GAMMA 8 level of Ce 3+ in antiferromagnetic CeP will also be reported. For sufficient dilution of the Tb 3+ in the terbium monopnictides, the systems become paramagnetic (Van Vleck paramagnets) down to 0 0 K. The Tb 3+ excited state resonance EPR in Tb/sub 0.1/ La/sub 0.9/P was studied as an example of behavior in such systems. 10 fig

On the problem of completeness of QM: von Neumann against Einstein, Podolsky, and Rosen

OpenAIRE

Khrennikov, Andrei

2008-01-01

We performed a comparative analysis of the arguments of Einstein, Podolsky and Rosen -- EPR, 1935 (against the completeness of QM) and the theoretical formalism of QM (due to von Neumann, 1932). We found that the EPR considerations do not match at all with the von Neumann's theory. Thus EPR did not criticize the real theoretical model of QM. The root of EPR's paradoxical conclusion on incompleteness of QM is the misuse of von Neumann's projection postulate. EPR applied this postulate to obser...

Radicals as EPR probes of magnetization of gadolinium stearate Langmuir-Blodgett film

DEFF Research Database (Denmark)

Koksharov, Y.A.; Bykov, I.V.; Malakho, A.P.

2002-01-01

In the present work we have applied the method of the EPR spin probes which allows performing simultaneously EPR and magnetization measurements to the investigation of magnetism of the Cid stearate Langmuir-Blodgett (LB) films. For this purpose we have prepared and studied by the EPR technique...... the Gd and Y stearate LB films. Placing the small BDPA crystal on the film surface we have found that for the Gd LB sample the effective g-value of the radical's resonance depends on the film orientation in respect to the external magnetic field direction. The relative shift of the EPR signal...

EPR by AREVA. An evolutionary reactor

International Nuclear Information System (INIS)

Horstmann, Marion

2010-01-01

The EPR development goals are as follows: 1. Evolutionary design to fully capitalize on the design, construction and operating experience based on the 86 AREVA's PWR operating worldwide; 2. Enhanced Safety compared to operating PWRs: reduce core damage frequency (CDF), accommodate severe accidents with no long-term population effect, Withstand large airplane crash (APC); 3. High availability; 4. Simplified operation and maintenance; and 5. Generation cost at least 10 % lower than 1500 MWe series in operation.The design builds on the achievements of the N4 and Konvoi reactors. The main plant data are tabulated. The PWR structure is shown as an example of the stepwise improvement. Focus of the presentation is on the construction techniques, supply chain, and project delivery. (P.A.)

Results of the basic design of the European Pressurized Water Reactor (EPR) and further prospective

International Nuclear Information System (INIS)

Fischer, U.

1998-01-01

The EPR is an evolutionary design, with maximum consideration given to the experience accumulated by Framatome and Siemens with the existing designs of plants successfully operating.However, substantial improvements with regard to availability, safety and economy have been included. The main target of the basic design phase was a clear definition of technical features based on common technical codes that comply with economic targets and licensability requirements in France and Germany.The EPR basic design represents a new design for a nuclear power plant that complies with the latest laws and regulations, both in France and Germany as well as in most of the countries utilizing nuclear power. Cost estimates prove the design economically viable

EPR: The reactor generation for the 21st century. SFEN-KTG congress 'The EPR Project'', Strasbourg, 13-14 Nov. 1994

International Nuclear Information System (INIS)

Anon.

1995-01-01

The foundation of the subsidiary in 1989, Nuclear Power International (NPI), brought together as partners the two formerly competing companies Siemens/KWU and Framatome who now are planning the novel reactor type within the framework of the joint EPR project. The project goal is to develop a novel French-German PWR reactor type for power generation, named European Pressurized Water Reactor (EPR). The article summarizes the main results of papers and discussions of the congress. (orig./UA) [de

Sharp Contradiction for Local-Hidden-State Model in Quantum Steering

Science.gov (United States)

Chen, Jing-Ling; Su, Hong-Yi; Xu, Zhen-Peng; Pati, Arun Kumar

2016-08-01

In quantum theory, no-go theorems are important as they rule out the existence of a particular physical model under consideration. For instance, the Greenberger-Horne-Zeilinger (GHZ) theorem serves as a no-go theorem for the nonexistence of local hidden variable models by presenting a full contradiction for the multipartite GHZ states. However, the elegant GHZ argument for Bell’s nonlocality does not go through for bipartite Einstein-Podolsky-Rosen (EPR) state. Recent study on quantum nonlocality has shown that the more precise description of EPR’s original scenario is “steering”, i.e., the nonexistence of local hidden state models. Here, we present a simple GHZ-like contradiction for any bipartite pure entangled state, thus proving a no-go theorem for the nonexistence of local hidden state models in the EPR paradox. This also indicates that the very simple steering paradox presented here is indeed the closest form to the original spirit of the EPR paradox.

Service Recovery Paradox In Indian Banking Industry: An Empirical Investigation

Directory of Open Access Journals (Sweden)

Arunesh Garg

2013-11-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 The present study examines existence of service recovery paradox in Indian banking industry. The study is taken up in the tri-city of Chandigarh, Panchkula and Mohali. The respondents are categorized into failure and no-failure groups on the basis of their service experience. Failure group constitutes those respondents who have experienced service recovery, and has been further divided into five sub-groups ranging from service recovery++ (service recovery better than expected to service recovery- - (service recovery worse than expected. Service recovery paradox is examined by comparing service recovery++ group with no-failure group. The study shows evidence for existence of service recovery paradox in relation to satisfaction. It has been concluded that for service recovery paradox to exist, recovery effort has to be exceptionally good and much better than expectation level of the customer. The study suggests that service managers should take service failure as an opportunity to appease customers by providing a much better than expected recovery experience. However, organizations should not plan to create service failure situations because if they falter on imparting the recovery, customer satisfaction may be influenced negatively. Keywords: Banking, service failure, customer satisfaction, recommendation intention, service recovery, recovery paradox. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso

Which Parts of a Clinical Process EPR Needs Special Configuration

DEFF Research Database (Denmark)

Barlach, Anders; Simonsen, Jesper

2007-01-01

Subject: Which parts of an electronic patient record (EPR) can initially form a stable standard solution to be used by all clinicians? And which parts of an EPR can we predict needs initial as well as on-going re-configuration to meet the needs from diverse medical specialties. Purpose: To analyze...... which screen types in a clinical process that can be standard configured and which are subject to initial as well as on-going re-configuration. Methods and results: A pilot-project implementing a fully functional clinical process EPR was configured and used at a neurological ward, replacing all paper...... records 24/7. The analysis characterizes the different types of screens, a total of 243 included in the EPR solution. All screens have been extracted from the application and analyzed for changes – in total 222 changes. Discussion and conclusion: Most screens (87%) are very stable. Few (13%) are subjected...

Biophysical EPR Studies Applied to Membrane Proteins

Science.gov (United States)

Sahu, Indra D; Lorigan, Gary A

2015-01-01

Membrane proteins are very important in controlling bioenergetics, functional activity, and initializing signal pathways in a wide variety of complicated biological systems. They also represent approximately 50% of the potential drug targets. EPR spectroscopy is a very popular and powerful biophysical tool that is used to study the structural and dynamic properties of membrane proteins. In this article, a basic overview of the most commonly used EPR techniques and examples of recent applications to answer pertinent structural and dynamic related questions on membrane protein systems will be presented. PMID:26855825

75 FR 4882 - Meeting of the ACRS Subcommittee on EPR; Notice of Meeting

Science.gov (United States)

2010-01-29

... NUCLEAR REGULATORY COMMISSION Advisory Committee On Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on EPR; Notice of Meeting The ACRS U.S. Evolutionary Power Reactor (EPR) Subcommittee will hold a... with Open Items concerning the U.S. EPR Design Certification (DCD) Application and the Calvert Cliffs...

Chemistry of artemisinin: an EPR study and nucleobases interaction

International Nuclear Information System (INIS)

Mustafa, Damra Elhaj

2000-10-01

In the present, the radical transformations of artemisinin, a potent antimalarial drug have been examined using EPR and EPR spin trapping techniques. The effect of light on artemisinin has been investigated at 77 K as well as with the use of phenyl butyl nitrone (PBN) spin trapping agent. While no EPR signal was observed at 77 K, intense light irradiation of artemisinin/PBN gave EPR signal characteristic of radical transformation of the PBN. The reactions of artemisinin with iron (II), manganese (II), hemin and ferrocyanide ion have been investigated by spin trapping techniques. Artemisinin/iron (II) formed spin adducts with nitrosobenzene, nitroso-t-butane and PBN. The hypertine splittings of the spin adducts were a N =1.08 mT/a N =1.25 mT/a N =0.09 mT and a N =1.56 mT/a N =0.29 mT respectively. PBN trapping of artemether/iron (II) gave similar result to artemisinin/iron (II). These results are indicative of secondary carbon-centered radical formation. While artemisinin/hemin/PBN gave very weak EPR signal, ferrocyanide under the same condition gave no signal. Incubation of artemisinin with RNA at different reaction conditions, including irradiation with light, heat and mild acidic media, revealed no RNA damage when examined by agarose electrophoresis. However, artemisinin/iron (II) caused RNA damage in pH-dependant manner. In contrast, hemin did not show the same effect when it was used instead of iron (II). (Author)

Theory of g-shift and linewidth in CeP excited state EPR

International Nuclear Information System (INIS)

Yang, D.; Cooper, B.R.; Huang, C.Y.; Sugawara, K.

1979-01-01

The Mori-Zwanzig memory function formalism was used to analyze the observed excited state EPR mode in CeP. The mixing of the Zeeman-split crystal-field excitation by the exchange, particularly among those with degenerate frequencies, yields a normal mode determining the observed low-frequency spectrum. This is illustrated by calculation with Heisenberg exchange which yields a single peak in qualitative agreement with the experiment

Stability of cellulose radicals produced by radiation in spices as studied by the EPR spectroscopy

International Nuclear Information System (INIS)

Lehner, K.; Stachowicz, W.

2003-01-01

The results are presented of EPR measurements on the stability of cellulose radicals produced in 26 popular spices irradiated with a dose of 7 kGy of gamma rays. EPR measurements were done with the use of an EPR spectrometer EPR-10 MINI at X band (microwave radiation of frequency 9.5 GHz), produced by St. Petersburg Instruments Ltd. The aim of the work was to prove the applicability of the EPR method for the control of irradiation in the investigated spices. (author)

EPR study of the reactions of tumour and normal tissues under ionizing radiation

International Nuclear Information System (INIS)

Rikhireva, G.T.; Pulatova, M.K.; Turganov, M.M.; Pal'mina, N.P.; Burlakova, E.B.

1978-01-01

Data on the EPR spectrum characteristics of irradiated tissues of tumour-free animals and animals with tumour are presented. Mice of the Csub(3)Hsub(A) line were used in the experiments. Hepatoma was subcutaneously transplanted with the suspension of tumour tissue reduced to fragments. Animals were killed in 6-8 days after transplantation and in the case of tumour-free animals liver was immediately isolated while in the case of animals with tumour isolated were liver and tumour. Tissues cut with scissors were frozen in liquid nitrogen. Tissue samples were exposed to 60 Co at 1 Mrad dose and -196 deg C. On the base of the data it has been concluded: firstly, there are differences between the EPR spectra of normal and tumour tissue samples irradiated at -196 deg C. Asymmetryc signal with Δ H=Ge and g=2.0005 (''tumour signal'') is typical only for the EPR spectra of tumour and liver tissues of the animal with tumour. Thus, in the -author's opinion, irradiation use turns out to be useful for detecting the difference between the normal and tumour tissues. Secondly, ''tumour signal'' intensity changes after ionol incorporation into animal organism, used as a modificator of tissue sensitivity to the irradiation effect

The Age Prospective Memory Paradox: Young Adults May Not Give Their Best outside of the Lab

Science.gov (United States)

Aberle, Ingo; Rendell, Peter G.; Rose, Nathan S.; McDaniel, Mark A.; Kliegel, Matthias

2010-01-01

Previous research has identified the age prospective memory paradox of age-related declines in laboratory settings in contrast to age benefits in naturalistic settings. Various factors are assumed to account for this paradox, yet empirical evidence on this issue is scarce. In 2 experiments, the present study examined the effect of task setting in…

TL and EPR dating: some applications

Energy Technology Data Exchange (ETDEWEB)

Watanabe, S. [Institute of Physics, University of Sao Paulo, Sao Paulo (Brazil)

2006-07-01

The intensity of thermoluminescence light emitted by a crystal is a function of radiation dose. The number of defects or of radicals in a crystal or organic substances is also a function of radiation dose. Since such defects or radicals present EPR signals, the EPR intensity is also a function of radiation dose. These facts are basis for radiation dosimetry and can be applied in dating of archaeological potteries or other materials, as well as in dating geological substances such as sediments, caves speleothemes, animal teeth and bones. Recent investigation on sensitized quartz based dosimeters and dating calcite covering ancient wall painting to find early settlers in Brazil will be presented. (Author)

Hydrogen Analyses in the EPR

International Nuclear Information System (INIS)

Worapittayaporn, S.; Eyink, J.; Movahed, M.

2008-01-01

In severe accidents with core melting large amounts of hydrogen may be released into the containment. The EPR provides a combustible gas control system to prevent hydrogen combustion modes with the potential to challenge the containment integrity due to excessive pressure and temperature loads. This paper outlines the approach for the verification of the effectiveness and efficiency of this system. Specifically, the justification is a multi-step approach. It involves the deployment of integral codes, lumped parameter containment codes and CFD codes and the use of the sigma criterion, which provides the link to the broad experimental data base for flame acceleration (FA) and deflagration to detonation transition (DDT). The procedure is illustrated with an example. The performed analyses show that hydrogen combustion at any time does not lead to pressure or temperature loads that threaten the containment integrity of the EPR. (authors)

Projects of Iberdrola Engineering and Construction on the Flamanville 3 EPR; Proyectos de Iberdrola Ingenieria y construccion en el EPR de Flamanville 3

Energy Technology Data Exchange (ETDEWEB)

Zornoza, J.; Dumas, H.; Sesma, J. L.; Cubian, B.; Diaz, J. I.

2013-06-01

Iberdrola Engineering and Construction is participating during the last 5 years in 5 projects on the Flamanville 3 EPR, both in the nuclear island and conventional island and the pump house. These projects represent a challenge from the technical point of view due to the high requirements applicable to the project because of the experience feedback of the operator EDF and of compliance with new regulations that have emerged since the completion of the last nuclear power station in France. This paper presents the description of these projects, as well as its current status. (Author)

Analysis of Hydroperoxides in solid Polyethylene by NMR and EPR Spectroscopy

International Nuclear Information System (INIS)

Assink, Roger A.; Celina, Mathias C.; Dunbar, Timothy D.; Alam, Todd M.; Clough, Roger Lee; Gillen, Kenneth T.

2000-01-01

The authors have shown that the hydroperoxide species in γ-irradiated 13 C-polyethylene can be directly observed by 13 C MAS NMR spectroscopy. The experiment was performed without the need for special sample preparation such as chemical derivatization or dissolution. Annealing experiments were employed to study the thermal decomposition of the hydroperoxide species and to measure an activation energy of 98 kJ/mol. EPR spectroscopy suggests that residual polyenyl and alkylperoxy radicals are predominantly trapped in interracial or crystalline regions, while the peroxy radicals observed after UV-photolysis of hydroperoxides are in amorphous regions

Study of growth of polyaniline chain by EPR method

Energy Technology Data Exchange (ETDEWEB)

Kulikov, A V [Inst. of Chemical Physics, Chernogolovka (Russian Federation); Kogan, Ya L [Inst. of Chemical Physics, Chernogolovka (Russian Federation); Fokeeva, L S [Inst. of Chemical Physics, Chernogolovka (Russian Federation)

1993-03-22

Chemical aniline polymerization has been studied by the EPR method. After a long delay a weak EPR signal I is appeared and transformed rapidly into a strong Lorentzian line. Constants of spin exchange of signals I and II with paramagnetic probes Fe(CN)[sub 6][sup 3-], Co[sup 2+] and O[sub 2], freely diffusing in solution, have been determined. Effect of ferricyanide ions and urea, a breaker of hydrogen bonds, has been measured for signals I and II. Data obtained show the formation of an array of positive charges in PANI at early stage of doping. Constants of spin exchange depend on prehistory of samples. Averaging of EPR line widths of different paramagnetic centers in polyaniline was found. (orig.)

EPR studies of the vitamin K 1 semiquinone radical anion. Comparison to the electron acceptor A 1 in green plant photosystem I

Science.gov (United States)

Thurnauer, Marion C.; Brown, James W.; Gast, P.; Feezel, Laura L.

Suggestions that the electron acceptor, A 1, in Photosystem I is a quinone have come from both optical and epr experiments. Vitamin K 1 (phylloquinone) is present in the PSI complex with a stoichiometry of two molecules per reaction center. In order to determine if A 1 can be identified with vitamin K 1, X-band and Q-band epr properties of the vitamin K 1 radical anion in frozen alcohol solutions are examined. The results are compared to the epr properties that have been observed for the reduced A 1 acceptor in vivo. The g-values obtained for the vitamin K 1 radical anion are consistent with identifying A 1 with vitamin K 1.

EPR Flamanville 3, Site Management

International Nuclear Information System (INIS)

Menager, Antoine

2014-01-01

Antoine Menager, the EPR Flamanville 3 Site Manager described the organization and the management of the Flamanville site during the construction phase. He placed emphasis on Health and Safety, Environmental and Social Responsibility and on Nuclear Safety and Quality

EPR structure of the gamma irradiated alanine spectrum

Energy Technology Data Exchange (ETDEWEB)

Cabral P, A; Jimenez D, H; Urena N, F; Galindo, S; Bosch, P

1992-03-15

In this study is shown that the broadened five-line EPR pattern of the gamma irradiated alanine possibly decomposes into a more complex pattern when the recorded spectrum is subject to an operation of deconvolution. The EPR powder spectra of gamma irradiated DL- and L-alanine with and without binders are analysed. In all recorded spectra, each observed line is resolved into an asymmetrical triplet when a Gaussian distribution of 8.2 gauss width is removed, by deconvolution, from the observed spectrum. On the other hand, from a simple fitting analysis carried out on the original data, one encounters that some calculated relations between characteristic parameters, such as intensity ratios, deviate consistently from assumed height ratios. Both, from deconvolution and fitting results, a different structure is suggested for the observed broadened five-line EPR pattern of {gamma}-irradiated powder DL- and L-alanine. (Author)

Free radical EPR in delineating oil bearing zones

International Nuclear Information System (INIS)

Sharma, R.K.; Kumar, V.; Das, T.K.; Gundu Rao, T.K.

1993-01-01

Presence of naturally occurring gamma ray activity has long been detected in oil/gas wells is invariably carried out for formation evaluation. Similarly, presence of free radicals in oil bearing formations has also been known for quite sometime. Present paper deals with a systematic study of detecting these free radicals in oil wells and correlations of these with x-ray and other logs for identification of hydrocarbon bearing zones. Present study attempts to establish EPR as as inexpensive and reliable tool in comparison with gamma ray and neutron density logs recorded in exploratory oil wells. EPR studies have been carried out in an exploratory well between depth intervals 1600 m-1400 m located in south of existing producing field in Bombay Offshore region. Based on these results, an EPR log has been prepared and compared with gamma ray and neutron density logs. (author). 4 refs., 1 fig., 1 tab

EPR structure of the gamma irradiated alanine spectrum

International Nuclear Information System (INIS)

Cabral P, A.; Jimenez D, H.; Urena N, F.; Galindo, S.; Bosch, P.

1992-03-01

In this study is shown that the broadened five-line EPR pattern of the gamma irradiated alanine possibly decomposes into a more complex pattern when the recorded spectrum is subject to an operation of deconvolution. The EPR powder spectra of gamma irradiated DL- and L-alanine with and without binders are analysed. In all recorded spectra, each observed line is resolved into an asymmetrical triplet when a Gaussian distribution of 8.2 gauss width is removed, by deconvolution, from the observed spectrum. On the other hand, from a simple fitting analysis carried out on the original data, one encounters that some calculated relations between characteristic parameters, such as intensity ratios, deviate consistently from assumed height ratios. Both, from deconvolution and fitting results, a different structure is suggested for the observed broadened five-line EPR pattern of γ-irradiated powder DL- and L-alanine. (Author)

EPR of free radicals in solids II trends in methods and applications

CERN Document Server

Lund, Anders; Lund, Anders

2012-01-01

EPR of Free Radicals in Solids: Trends in Methods and Applications, 2nd ed. presents a critical two volume review of the methods and applications of EPR (ESR) for the study of free radical processes in solids. Emphasis is on the progress made in the developments in EPR technology, in the application of sophisticated matrix isolation techniques and in the advancement in quantitative EPR that have occurred since the 1st edition was published. Improvements have been made also at theoretical level, with the development of methods based on first principles and their application to the calculation of magnetic properties as well as in spectral simulations. EPR of Free Radicals in Solids II focuses on the trends in applications of experimental and theoretical methods to extract structural and dynamical properties of radicals and spin probes in solid matrices by continuous wave (CW) and pulsed techniques in nine chapters written by experts in the field. It examines the studies involving radiation- and photo-induced in...

Public debate about the EPR nuclear power plant at Flamanville; Debat public sur la centrale nucleaire EPR a Flamanville

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The project of building of he EPR reactor at Flamanville (Manche, France) has been submitted to the public debate. This document includes a presentation of the project and of the rules of the public debate, a synthesis of the file made by the prime contractor (EDF), a synthesis of the collective book of national actors concerned by the project (a group of associations for environment protection, Areva company, the ministries of economy and ecology, Global Chance, association of pro-nuclear ecologists (AEPN), 'Sortir du Nucleaire' (out-of nuclear) network, group of scientists for the information about nuclear (GSIEN), association for the promotion of the Flamanville site (Proflam), French nuclear energy society (SFEN) in association with 'Sauvons le Climat' (let's save climate), regional collective association 'EPR non merci, ni ailleurs, ni ici' (EPR, no thanks, neither elsewhere, nor here), NegaWatt), and 5 detailed books of actors: ACRO (association for the control of radioactivity in Western France), CFDT and CGT syndicates, the economic and social council of Basse Normandie region, and Proflam. (J.S.)

Public debate about the EPR nuclear power plant at Flamanville; Debat public sur la centrale nucleaire EPR a Flamanville

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The project of building of he EPR reactor at Flamanville (Manche, France) has been submitted to the public debate. This document includes a presentation of the project and of the rules of the public debate, a synthesis of the file made by the prime contractor (EDF), a synthesis of the collective book of national actors concerned by the project (a group of associations for environment protection, Areva company, the ministries of economy and ecology, Global Chance, association of pro-nuclear ecologists (AEPN), 'Sortir du Nucleaire' (out-of nuclear) network, group of scientists for the information about nuclear (GSIEN), association for the promotion of the Flamanville site (Proflam), French nuclear energy society (SFEN) in association with 'Sauvons le Climat' (let's save climate), regional collective association 'EPR non merci, ni ailleurs, ni ici' (EPR, no thanks, neither elsewhere, nor here), NegaWatt), and 5 detailed books of actors: ACRO (association for the control of radioactivity in Western France), CFDT and CGT syndicates, the economic and social council of Basse Normandie region, and Proflam. (J.S.)

Chasing our tails: psychological, institutional and societal paradoxes in natural resource management, sustainability, and climate change in Australia.

Science.gov (United States)

Browne, A L; Bishop, B J

2011-06-01

Natural Resource Management (NRM) and Ecologically Sustainable Development (ESD) have been guiding frameworks in Australia for a number of decades. Recently, NRM and ESD have become central to climate change mitigation. In this paper, we explore the psychological paradoxes that function within climate change settings, with particular attention devoted to the way that research and development reinforces these paradoxes by advocating for participatory forms of inquiry. Paradox emerges in NRM at psychological, institutional, and organisational levels. Paradoxes are also features of different forms of democracy such as neoliberal and participatory democracy. Although NRM, ESD and climate change are often conceptualised as distinct issue domains, these policy areas are fundamentally interconnected in both theory and in practice. This interconnection between these policy and research settings, reflections on paradox, and the experience of incorporating community psychology into the paradoxical settings of NRM and climate change are captured in this paper.

EPR: the nuclear impasse

International Nuclear Information System (INIS)

Marillier, F.

2008-01-01

The questions relative to the climatic change constitute crucial challenges for the next ten years. In this context the author aims to show how the EPR project illustrates the nuclear french ''autism''. He presents and analyzes the international and environmental impacts of this obsolete technology, as a project useless and dangerous. (A.L.B.)

EPR of VHal centres in SrS

International Nuclear Information System (INIS)

Seeman, V.; Danilkin, M.; Must, M.; Ots, A.; Paernoja, E.; Pung, L.; Tarkpea, K.

2006-01-01

V Hal centres were studied by EPR in SrS doped with halogens after X-raying the samples at 77 K. V Hal centre arises when a hole is captured by sulphide-ion next to a cation vacancy with a halogen ion substituting the opposite sulphide-ion. EPR parameters and thermal decay characteristics are measured for V Cl , V Br , and V I centres. The efficiency of different halogens to produce and stabilise cation vacancies is shown to vary for different alkaline earth sulphides. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

EPR in characterization of seeds paramagnetic species

International Nuclear Information System (INIS)

Luiz, A.P.C.; Mauro, M.F.F.L.; Portugal, K.O.; Barbana, V.M.; Guedes, C.L.B.; Mauro, E. di; Carneiro, C.E.A.; Zaia, D.A.M.; Prete, C.E.C.

2011-01-01

Full text. In Brazil, since 1970s, renewable fuel programs has been developed in order to replace petroleum. Today a program that has been discussed is the bio diesel, which intend to replace diesel fuel, fossil oil, to bio diesel, renewal fuel. As seeds are the basis for production of oil and consequently processed into bio diesel, the goal of this work is to characterize and compare paramagnetic species present in the seeds by Electron Paramagnetic Resonance (EPR). Samples used in this study were seeds of sorghum, barley, corn, peanuts, soy beans, cotton, wheat, oats, mustard, rice, sunflower and turnip. Some paramagnetic species present in soil was also investigated as goethite (FeOOH), hematite (Fe 2 O 3 ), magnetite (Fe 3 O 4 ), and ferrihydrite (Fe 5 HO 8 · 4H 2 O), since, these species present in appreciable quantities in the soil can be present in the seeds and analyzed for comparison. The characterization of these species is essential to understand the EPR seeds spectra. Each sample is placed in a thin quartz tube 4 mm in diameter, and it is inserted into the cavity of the spectrometer at room temperature, at low temperature (77 K) and variable temperature using liquid nitrogen flow and hot flow through a compressor air. It was used as standard Mg O:Mn 2+ , which is also inserted into the cavity. Shortly after the potency is regulated, frequency, amplitude and sweep the field. The spectroscopic analysis by EPR X-band (∼ 9:5GHz), were performed at the Fluorescence and Electron Paramagnetic Resonance Laboratory, Exact Sciences Center, State University of Londrina, Parana state, Brazil, through an EPR spectrometer JEOL brand (JES-PE-3X). In the EPR spectra, spectroscopic factor or g factor and line width were determined in paramagnetic species. Studies from several seeds with EPR technique detected in all of them presence of same complex of Fe 3+ present in the goethite at g ∼ 2, and in the seeds exist free radicals at g = 2:004, at room temperature

EPR in characterization of seeds paramagnetic species

Energy Technology Data Exchange (ETDEWEB)

Luiz, A.P.C.; Mauro, M.F.F.L.; Portugal, K.O.; Barbana, V.M.; Guedes, C.L.B.; Mauro, E. di; Carneiro, C.E.A.; Zaia, D.A.M.; Prete, C.E.C. [Universidade Estadual de Londrina (UEL), PR (Brazil)

2011-07-01

Full text. In Brazil, since 1970s, renewable fuel programs has been developed in order to replace petroleum. Today a program that has been discussed is the bio diesel, which intend to replace diesel fuel, fossil oil, to bio diesel, renewal fuel. As seeds are the basis for production of oil and consequently processed into bio diesel, the goal of this work is to characterize and compare paramagnetic species present in the seeds by Electron Paramagnetic Resonance (EPR). Samples used in this study were seeds of sorghum, barley, corn, peanuts, soy beans, cotton, wheat, oats, mustard, rice, sunflower and turnip. Some paramagnetic species present in soil was also investigated as goethite (FeOOH), hematite (Fe{sub 2}O{sub 3}), magnetite (Fe{sub 3}O{sub 4}), and ferrihydrite (Fe{sub 5}HO{sub 8} {center_dot} 4H{sub 2}O), since, these species present in appreciable quantities in the soil can be present in the seeds and analyzed for comparison. The characterization of these species is essential to understand the EPR seeds spectra. Each sample is placed in a thin quartz tube 4 mm in diameter, and it is inserted into the cavity of the spectrometer at room temperature, at low temperature (77 K) and variable temperature using liquid nitrogen flow and hot flow through a compressor air. It was used as standard Mg O:Mn{sup 2+}, which is also inserted into the cavity. Shortly after the potency is regulated, frequency, amplitude and sweep the field. The spectroscopic analysis by EPR X-band ({approx} 9:5GHz), were performed at the Fluorescence and Electron Paramagnetic Resonance Laboratory, Exact Sciences Center, State University of Londrina, Parana state, Brazil, through an EPR spectrometer JEOL brand (JES-PE-3X). In the EPR spectra, spectroscopic factor or g factor and line width were determined in paramagnetic species. Studies from several seeds with EPR technique detected in all of them presence of same complex of Fe{sup 3+} present in the goethite at g {approx} 2, and in the seeds

What Paradox?

DEFF Research Database (Denmark)

Holt, Robin; Zundel, Mike

2017-01-01

This chapter investigates the relationship between paradox and the logical typing of classes and members. Class-based thinking affords efficiency in communication and the progressive, additive development of knowledge, but also creates fissures, shortcuts, truncations, and delimitations that gene......This chapter investigates the relationship between paradox and the logical typing of classes and members. Class-based thinking affords efficiency in communication and the progressive, additive development of knowledge, but also creates fissures, shortcuts, truncations, and delimitations...... that emphasizes interconnectedness and interdependency, which Gregory Bateson calls “grace”: the successful integration of smaller with wider arcs of awareness. This is developed here into a method for studying organizational phenomena using the example of an organizational routine, arguing that this may be one...

Chemistry of artemisinin: an EPR study and nucleobases interaction

Energy Technology Data Exchange (ETDEWEB)

Mustafa, Damra Elhaj [Department of Chemistry, Faculty of Education, University of Khartoum, Khartoum (Sudan)

2000-10-01

In the present, the radical transformations of artemisinin, a potent antimalarial drug have been examined using EPR and EPR spin trapping techniques. The effect of light on artemisinin has been investigated at 77 K as well as with the use of phenyl butyl nitrone (PBN) spin trapping agent. While no EPR signal was observed at 77 K, intense light irradiation of artemisinin/PBN gave EPR signal characteristic of radical transformation of the PBN. The reactions of artemisinin with iron (II), manganese (II), hemin and ferrocyanide ion have been investigated by spin trapping techniques. Artemisinin/iron (II) formed spin adducts with nitrosobenzene, nitroso-t-butane and PBN. The hypertine splittings of the spin adducts were a{sub N}=1.08 mT/a{sub N}=1.25 mT/a{sub N}=0.09 mT and a{sub N}=1.56 mT/a{sub N}=0.29 mT respectively. PBN trapping of artemether/iron (II) gave similar result to artemisinin/iron (II). These results are indicative of secondary carbon-centered radical formation. While artemisinin/hemin/PBN gave very weak EPR signal, ferrocyanide under the same condition gave no signal. Incubation of artemisinin with RNA at different reaction conditions, including irradiation with light, heat and mild acidic media, revealed no RNA damage when examined by agarose electrophoresis. However, artemisinin/iron (II) caused RNA damage in pH-dependant manner. In contrast, hemin did not show the same effect when it was used instead of iron (II). (Author)

Specific public debate on the EPR - Position of 'Sauvons le Climat'

International Nuclear Information System (INIS)

2008-01-01

After having evoked the respective performance of Denmark, Sweden and France in terms of CO 2 emission reduction, electricity consumption per inhabitant, and outlined the unavoidable measures of energy saving and reasonable development of renewable energies while keeping on using nuclear energy, this report more particularly addresses various issues related to the EPR within the perspectives of energy production needs. It also outlines the need to stop the current rate of increase of energy consumption, for resource concerns as well as for CO 2 emission concerns, when renewable energies will remain limited. It discusses the objectives of reduction of greenhouse emissions and states that the EPR could be a determining factor to reach these objectives. Moreover, the EPR technology is an industrial asset for France even in front of the emergence of reactors of fourth generation (high temperature gas reactors, fast breeder reactors). It outlines that the EPR design improves nuclear safety and reduces accident probability. Direct, indirect and external costs of the EPR are discussed. The role of this reactor as a tool for electric power production is finally discussed within the French context and within the European context

Entanglement, nonlocality and multi-particle quantum correlations

Science.gov (United States)

Reid, Margaret D.

2018-04-01

This paper contributes to the proceedings of the Latin-American School of Physics (ELAF-2017) on Quantum Correlations, and is a brief review of quantum entanglement and nonlocality. In such a brief review, only some topics can be covered. The emphasis is on those topics relevant that may be relevant to detecting multi-particle quantum correlations arising in atomic and Bose-Einstein condensate (BEC) experiments. The paper is divided into five sections. In the first section, the historical papers of Einstein-Podolsky-Rosen (EPR), Bell, Schrodinger and Greenberger-Zeilinger-Horne (GHZ) are described in a tutorial fashion. This is followed by an introduction to entanglement and density operators. A discussion of the classes of nonlocality is given in the third section, including the modern interpretation of the correlations of the EPR paradox experiments, known as EPR steering correlations. The fourth section covers the detection and generation of so-called continuous variable entanglement and EPR steering. Various known criteria are derived with the details of the proofs given for tutorial purposes. The final section focuses on the criteria and methods that have been useful to detect quantum correlation in BEC or atomic systems. Recent results relating spin squeezing with quantum correlations, including entanglement and EPR steering, are summarised.

Water accessibility in a membrane-inserting peptide comparing Overhauser DNP and pulse EPR methods

Energy Technology Data Exchange (ETDEWEB)

Segawa, Takuya F., E-mail: takuya.segawa@alumni.ethz.ch; Doppelbauer, Maximilian; Garbuio, Luca; Doll, Andrin; Polyhach, Yevhen O.; Jeschke, Gunnar, E-mail: gjeschke@ethz.ch [Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich (Switzerland)

2016-05-21

Water accessibility is a key parameter for the understanding of the structure of biomolecules, especially membrane proteins. Several experimental techniques based on the combination of electron paramagnetic resonance (EPR) spectroscopy with site-directed spin labeling are currently available. Among those, we compare relaxation time measurements and electron spin echo envelope modulation (ESEEM) experiments using pulse EPR with Overhauser dynamic nuclear polarization (DNP) at X-band frequency and a magnetic field of 0.33 T. Overhauser DNP transfers the electron spin polarization to nuclear spins via cross-relaxation. The change in the intensity of the {sup 1}H NMR spectrum of H{sub 2}O at a Larmor frequency of 14 MHz under a continuous-wave microwave irradiation of the nitroxide spin label contains information on the water accessibility of the labeled site. As a model system for a membrane protein, we use the hydrophobic α-helical peptide WALP23 in unilamellar liposomes of DOPC. Water accessibility measurements with all techniques are conducted for eight peptides with different spin label positions and low radical concentrations (10–20 μM). Consistently in all experiments, the water accessibility appears to be very low, even for labels positioned near the end of the helix. The best profile is obtained by Overhauser DNP, which is the only technique that succeeds in discriminating neighboring positions in WALP23. Since the concentration of the spin-labeled peptides varied, we normalized the DNP parameter ϵ, being the relative change of the NMR intensity, by the electron spin concentration, which was determined from a continuous-wave EPR spectrum.

Enhanced accuracy of the microwave field strength measurement in a CW-EPR by pulsed modulation technique

Science.gov (United States)

Rakvin, B.; Carić, D.; Kveder, M.

2018-02-01

The microwave magnetic field strength, B1, in the cavity of a conventional continuous wave electron paramagnetic resonance, CW-EPR, spectrometer was measured by employing modulation sidebands, MS, in the EPR spectrum. MS spectrum in CW-EPR is produced by applying the modulation frequency, ωrf, which exceeds the linewidth, δB, given in frequency units. An amplitude-modulated CW-EPR, AM-CW-EPR, was selected as detection method. Theoretical description of AM-CW-EPR spectrum was modified by adding Bloch-Siegert-like shift obtained by taking into account the cumulative effect of the non-resonant interactions between the driving fields and the spin system. This approach enables to enhance the precision of B1 measurement. In order to increase the sensitivity of the method when saturation effects, due to higher intensity of B1, decrease the resolution of AM-CW-EPR spectrum, detection at the second harmonic of CW-EPR has been employed.

Enhanced accuracy of the microwave field strength measurement in a CW-EPR by pulsed modulation technique.

Science.gov (United States)

Rakvin, B; Carić, D; Kveder, M

2018-02-01

The microwave magnetic field strength, B 1 , in the cavity of a conventional continuous wave electron paramagnetic resonance, CW-EPR, spectrometer was measured by employing modulation sidebands, MS, in the EPR spectrum. MS spectrum in CW-EPR is produced by applying the modulation frequency, ω rf , which exceeds the linewidth, δB, given in frequency units. An amplitude-modulated CW-EPR, AM-CW-EPR, was selected as detection method. Theoretical description of AM-CW-EPR spectrum was modified by adding Bloch-Siegert-like shift obtained by taking into account the cumulative effect of the non-resonant interactions between the driving fields and the spin system. This approach enables to enhance the precision of B 1 measurement. In order to increase the sensitivity of the method when saturation effects, due to higher intensity of B 1 , decrease the resolution of AM-CW-EPR spectrum, detection at the second harmonic of CW-EPR has been employed. Copyright © 2018 Elsevier Inc. All rights reserved.

EPR investigation of some desiccated Ascomycota and Basidiomycota gamma-irradiated mushrooms

Energy Technology Data Exchange (ETDEWEB)

Bercu, V., E-mail: vbercu@gmail.co [University of Bucharest, Department of Atomic and Nuclear Physics, P.O. Box MG-11, 077125 Magurele (Ilfov) (Romania); Negut, C.D., E-mail: dnegut@nipne.r [University of Bucharest, Department of Atomic and Nuclear Physics, P.O. Box MG-11, 077125 Magurele (Ilfov) (Romania); Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, 077125 Magurele (Ilfov) (Romania); Duliu, O.G., E-mail: duliu@b.astral.r [University of Bucharest, Department of Atomic and Nuclear Physics, P.O. Box MG-11, 077125 Magurele (Ilfov) (Romania)

2010-12-15

The suitability of the EPR spectroscopy for detection of {gamma}-irradiation in five species of dried mushroom, currently used in gastronomy: yellow morel-Morchella esculenta, (L.) Pers. (Phylum Ascomycota), button mushroom-Agaricus bisporus (J.E.Lange), Agaricus haemorrhoidarius Fr., golden chantarelle-Cantharellus cibarius Fr., as well as oyster mushroom-Pleurotus ostreatus (Jacq. ex Fr.) (Phylum Basidiomycota) is presented and discussed. Although after irradiation at doses up to 11 kGy, all specimens presented well defined EPR spectra, only A. bisporus EPR signal was enough stable to make detection possible after 18 months.

EPR investigation of some desiccated Ascomycota and Basidiomycota gamma-irradiated mushrooms

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