bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Operator for Unstable Particle and Complex Mass Description in Local QFT
Authors: Lukierski J. 
Published: July 2007

AbstractWe consider the equations describing the local covariant unstable particle field operator as the functional of stable asymptotic decay products. In such a framework, we present two generalizations of the Yang‐Feldman equation, which can be used for the description of unstable particles. In order to introduce a complex mass parameter, we discuss the generalizations of mass renormalization procedure. Also we consider briefly the description using fields with continuous spectrum of asymptotic masses.
Interaction of Photons with Electrons in Dielectric Media
Authors: Novak Miroslav M. 
Published: July 2007

AbstractThe question of the field energy‐momentum tensor in a medium is not new and many workers, in the past, attempted to find the answer to it. Nevertheless, there was no general agreement about the form of such a tensor, thus resulting in a confusion involving the very fundaments of physics. Although the present work uses well established theories, the underlying philosophy is completely novel. Investigations are mainly centered around the collisionless plasma as, in that state, development of the argument is most transparent.On the basis of a simple theoretical reasoning, it is, first of all, postulated that the momentum of the photon in a plasma is given by the Minkowski expression. This hypothesis becomes more viable as it directly leads to the accepted form for the field energy density. Furthermore, utilizing the concepts of stimulated and spontaneous emission and absorption, it is confirmed that, in the equilibrium (between radiation and plasma), the transferred momentum has the value given by the Minkowski theory. However, as will be seen, this result is valid only in the region of high frequencies. Put otherwise, when conditions are such that the laws of geometrical optics apply, the momentum of the photon is, to a good approximation, given by the Minkowski theory.In order to arrive at a more general result, valid in the domain of wave optics, a similarity between the dispersion relation (describing the wave propagation through a medium) and the relativistic energy‐momentum of a particle moving through vacuum, is explored. Accepting the equivalence of these two relations implies that some of the properties of radiation in a medium, can also be described by a massive particle travelling through empty space. In other words, the task of analysing the behaviour of electromagnetic waves in a medium, can be replaced by the analysis of the free neutral vector meson field. Adoption of this equivalence results in the field energy‐momentum tensor being symmetrical.A thorough study of the field theory then provides the basis for interpreting the Abraham tensor as the sum of the “orbital” and “spin” tensors. The former is directly connected with the energy transport, whereas the latter one is not. Realising that the magnitude of the spin term increases towards the lower end of the frequency spectrum provides the resolution of the Abraham‐Minkowski dilemma: the energy‐momentum tensor, corresponding to the electromagnetic wave in a medium, is that given by Abraham, while the one of Minkowski is only an approximation valid at high frequencies.Although this conclusion stems from studies involving collisionless isotropic plasma, it is in excellent agreement with the experimental data.
Conditional Probability and the Axiomatic Structure of Quantum Mechanics
Authors: Guz W. 
Published: July 2007

AbstractThe paper, summarizing the results of recent papers of the author, is devoted to a detailed analysis of postulates of nonrelativistic quantum theory appearing within two classical axiomatic frameworks the “quantum logic” and the “algebraic approach” respectively, which are presently the two main alternatives for quantum axiomatics.The first part of the paper concerns the structure of two important sets, the set of questions (propositional logic) and the set of pure states. It is shown how the quantum logic axiomatic scheme can be modified and improved in order to overcome the well known troubles connected with the lack of satisfactory physical justification for some postulates of this approach. In particular, an axiom system is developed, related closely to the quantum logic axiomatic scheme, in which the questions of the complete lattice structure, the atomisticity, and the validity of the covering law in the propositional logic do not appear so problematic. The particular attention is directed to the covering law, which is here obtained as a consequence of physically clear properties of the experimental procedures (“filters”) associated with the quantum‐mechanical propositions. In Section 1.5 we formulate an axiom system for quantum mechanics based exclusively on the concepts of pure state, transition probability, and pure filter.In the second part of the paper the axiomatic scheme presented in Part 1 is developed with the aim to analyse the algebraic structure of some subspaces of the set of simple observables. The quantum logic axiomatic framework is here shown closely connected with the Jordan‐Banach algebraic scheme.In the third part of the paper, similarly as it was done in Parts 1 and 2, the correspondence between the propositions and the experimental (measuring) procedures verifying these propositions is put as the basic assumption of the axiomatization of quantum mechanics. As a consequence of this assumption, there is established the structure of a real Jordan‐Banach algebra in the set Ob of the bounded observables associated with a physical system, so that we can apply the GNS representation theorem proved recently for such algebras by Alfsen et al. (1978) to obtain the Hilbert space (or, to be more precise, the C*‐algebraic) representation for Ob.
Multidimensional Unified Theories
Authors: Orzalesi Claudio A. 
Published: July 2007

AbstractAn extended spacetime, M4+N, is a Riemannian (4 + N)‐dimensional manifold which admits an N‐parameter group G of (spacelike) isometries and is such that ordinary spacetime M4 is the space M4+N/G of the equivalence classes under G‐transformations of M4+N. A multidimensional unified theory (MUT) is a dynamical theory of the metric tensor on M4+N, the metric being determined from the Einstein‐Hilbert action principle: in absence of matter, the Lagrangian is (essentially) the total curvature scalar of M4+N. A MUT is an extension of the Cho‐Freund generalization of Jordan's five‐dimensional theory. A MUT can be faithfully translated in four‐dimensional language: as a theory on M4, a MUT is a gauge field theory with gauge group G. A unifying aspect of MUT's is that all fields occur as elements of the metric tensor on M4+N. When the isometry generators are subjected to strongest constraints, a MUT becomes the De Witt‐Trautman generalization of Kaluza's five‐dimensional theory; in four‐dimensional language, this is the theory of Yang‐Mills gauge fields coupled to gravity. With weaker constraints, a MUT appears to be more natural than a Yang‐Mills theory as a physical realization of the gauge principle for an exact symmetry of gauged confined color. Such weakly‐constrained MUT leads to bag‐type models without the need for ad hoc surgery on the basic. Lagrangian. The present paper provides a detailed introduction to the formalism of multidimensional unified gauge field theory.
Outline of a Nonlinear, Relativistic Quantum Mechanics of Extended Particles
Authors: Mielke Eckehard W. 
Published: July 2007

AbstractA quantum theory of intrinsically extended particles similar to de Broglie's Theory of the Double Solution is proposed. A rational notion of the particle's extension is enthroned by realizing its internal structure via soliton‐type solutions of nonlinear, relativistic wave equations. These droplet‐type waves have a quasi‐objective character except for certain boundary conditions which may be subject to stochastic fluctuations. More precisely, this assumption amounts to a probabilistic description of the center of a soliton such that it would follow the conventional quantum‐mechanical formalism in the limit of zero particle radius. At short interaction distances, however, a promising nonlinear and nonlocal theory emerges. This model is not only capable of achieving a conceptually satisfying synthesis of the particle‐wave dualism, but may also lead to a rational resolution of epistemological problems in the quantum‐theoretical measurement process. Within experimental errors the results for, e.g., the hydrogen atom can be reproduced by appropriately specifying the nature of the nonlinear self‐interaction. It is speculated that field theoretical issues raised by such notions as identical particles, field quantization and renormalization are already incorporated or resolved by this nonlocal theory, at least in principle.
Higher Effective Actions for Bose Systems
Authors: Kleinert H. 
Published: July 2007

AbstractWe study the generalization of the usual effective action Γ[ϕ] of Bose systems to an explicit functional Γ[ϕ, G, α2, α4] of field ϕ, Green's function G, and three‐ and four‐point vertex functions α3, α4. The equations of motion following by extremization with respect to ϕ, G, α3, α4 provide for non‐linear integral equations whose solution can account for a wide variety of non‐perturbative effects: Condensation of particles, pairs, and three and four‐particle clusters. There can be spontaneous generation of mass as well as of interaction.
How failure prediction methodology affects electronic equipment design
Authors: Leonard Charles T. , Pecht Michael 
Published: July 2007

AbstractElectronic equipment designs embody measures and techniques to enhance reliability. Often, concepts of designing for failure avoidance are inferred from various failure prediction methodologies (FPM) such as MIL‐HDBK‐217,1 BellCore2 etc. However, these FPM models do not accurately predict actual failures of completed assemblies, for they usually emphasize component parts as the dominant cause of problems, and the models cannot be kept up to date. Furthermore, the true causes of failure are not described, and thus they cannot be accomodated by design. As such, use of FPM as a source of guidance for reliability‐enhancing activities in producing reliable products may have less effectiveness than originally intended. Some FPM encouraged features can impose heavy costs, complexities and other penalties. By adopting solutions to problems that are inaccurately defined, true problems may be unaddressed.
Reliability and degradation of 980 NM InGaAs/GaAs strained quantum well lasers
Authors: Fukuda M. , Okayasu M. , Takeshita T. , Wada M. 
Published: July 2007

AbstractDegradation behaviours of 980 nm InGaAs/GaAs strained quantum well (QW) lasers are clarified and compared with normal AlGaAdGaAs, InGaAsP/InP and GaAs/GaAs QW lasers. Through various ageing tests, it is confirmed that 980 nm InGaAs/GaAs strained QW lasers are applicable to optical fibre transmission systems where the components are required to be highly reliable.
Simple adjustments to improve control limits on attribute charts
Authors: Winterbottom Alan 
Published: July 2007

AbstractMany SPC software packages determine control chart limits for attribute data using normal approximations. For some sample sizes and/or process parameter values these approximations are far from adequate, mainly due to skewness in the exact distribution. Significant improvements can be made to the probabilistic accuracy of control limits by simple adjustments derived from Cornish and Fisher expansions for percentage points. The adjustments are preferable to normalizing transformations in that the original scale of the data is retained and most SPC packages allow self‐determined control limits to be inserted. The overall objective is to bring operational meaning and practice for attribute charts more into line with charts for variables.
Field components reliability analysis for french telecommunications equipment
Authors: Boulaire J. Y. , Bauduin B. , Lelievre A. 
Published: July 2007

AbstractThe reliability of components in the equipment of France Telecom has been observed for many years. The computerized database SADE (field failure analysis system) will be described. Some examples of failure analysis on field returns of integrated circuits and optoelectronic devices will be given. Investigations permit the reliability prediction models for new components to be improved.
Off‐line quality control for V‐process castings
Authors: Kumar Pradeep , Gaindhar J. L. 
Published: July 2007

AbstractIn the present work Taguchi's approach has been applied to the V‐process castings of Al‐11 per cent Si alloy to acertain the most influential control factors which will provide better and consistent surface finish to the castings regardless of the noise factors present.The control factors of the V‐process that may affect the quality of the castings are the molding sand, vibration frequency, vibrating time, degree of vacuum imposed, and pouring temperature.In order to understand how these factors affect the surface roughness of the V‐process castings, response surface methodology has been applied, and to obtain the optimal setting of the control factors Taguchi's method has been used.It is found that the pouring temperature has a significant effect on the surface roughness of Al‐11 per cent Si alloy castings made by a V‐process. Thus the pouring temperature must be kept at the lower level. All other factors are insignificant. Therefore, any setting of the insignificant factors/variables that give the minimum cost can be used.
Application of hazard and operability studies to a wide range of industries and activities
Authors: Robinson Brian W. 
Published: July 2007

AbstractThe origins of Hazard and Operability Studies (HAZOPS) in the chemical industry are well known. This paper describes the principles of Hazard and Operability Studies, illustrates how they have been applied over a wide range of industries and activities, and outlines the most important points in carrying‐out the studies.
Ideology, Ethics, and Philosophical Discourse in Eighteenth Century Iran
Authors: Cole Juan R. I. 
Published: July 2007

Intellectual biography as a discipline assumes that the life and thought of an individual can shed light on an epoch. In some cases such a claim is justified, especially where the epoch is obscure and the thinker genuinely representative of the culture of a profession in a city or region. I shall argue the validity of this principle with regard to eighteenth century west-central Iran and Mohammad Mehdi Niraqi (d. 1794), a prominent Imami Shi˓i religious scholar who wrote prolifically and authored a huge three-volume work on ethics. Most of his voluminous writing remains in manuscript, but enterprising scholars in Najaf published the book on ethics, Jāmi˓ as-sa˓ādat (Compendium of Happiness), and it has recently been reissued in Beirut.The political turmoil of eighteenth century Iran at least partially explains the difficulty modern historians have in understanding its cultural history between the fall of the Safavids in 1722 and the rise of the Qajars around 1785.
PARTIAL GASTRECTOMY AND THE WERNICKE‐KORSAKOFF SYNDROME
Authors: Kerr R.A. , Price J. , Shanley B.C. 
Published: July 2007

AbstractIn alcoholics an association is demonstrated between partial gastrectomy and the Wernicke‐Korsakoff syndrome. Comparing Wernicke‐Korsakoff patients who have undergone partial gastrectomy with those who have not, indicated no general difference in thiamin absorption as determined by 35S‐thiamin absorption testing. Those gastrectomized were more likely to have married, to have the continued support of their families and probably for this reason, ultimately to be discharged from hospital. Mechanisms whereby partial gastrectomy may facilitate the development of alcohol dependency are discussed and the need to avoid this operation in those with a drinking history emphasised.
Immunochemical studies on human, bovine and pig brain regulatory subunits of cAMP‐dependent protein kinase type II
Authors: Sveshnikova E. V. , Alexandrova N. A. , Grozdova I. D. , Sveshnikov P. G. , Severin E. S. 
Published: July 2007

AbstractRegulatory subunits type II (RII) purified from human, pig and bovine brains were compared using 11 monoclonal antibodies (MoAb) against bovine brain RII. Bovine RII has at least 5 antigenic sites located in the N‐terminal 1‐110 residues. Immunochemical difference detected between human and animal RII was more pronounced than between pig and bovine RII. Certain MoAb influenced R‐cAMP binding and holoenzyme formation. RII of the three species responded to MoAb attachment in a similar fashion. The results suggest that anchoring of neural protein kinase via the N‐terminal part of RII may influence the enzyme activity.
Purification and partial characterization of a fatty acidbinding protein from the yeast, Yarrowia lipolytica
Authors: Dell'Angelica Esteban C. , Ermácora Mario R. , Santomé José A. 
Published: July 2007

AbstractA low‐molecular‐mass fatty acid‐binding protein was isolated from the cytosol of the yeast Yarrowia lipolytica. Purification was achieved by a two‐step procedure involving size‐exclusion and cation‐exchange chromatography. The isolated protein exists as a monomer of 15 kDa, is basic and has a blocked N‐terminus. Internal amino acid sequencing suggests that this protein may belong to a novel class of fatty acid‐binding proteins.
Enzymatic synthesis of oleamide (cis‐9,10‐octadecenoamide), an endogenous sleep‐inducing lipid, by rat brain microsomes
Authors: Sugiura Takayuki , Kondo Sachiko , Kodaka Tomoko , Tonegawa Takashi , Nakane Shinji , Yamashita Atsushi , Ishima Yoshio , Waku Keizo 
Published: July 2007

AbstractThe enzymatic synthesis of a novel sleep‐inducing lipid, oleamide (cis‐9,10‐octadecenoamide), was studied using rat brain subcellular fractions as enzyme sources. We found that oleamide was formed from oleic acid and ammonia on incubation with a brain homogenate. The enzyme activity catalyzing the formation of oleamide from oleic acid and ammonia was highest in the microsomal fraction among the subcellular fractions. Boiled microsomes did not exhibit appreciable enzyme activity. These results strongly suggest that oleamide can be synthesized enzymatically in the brains of stimulated animals.
2′3′‐CNPase and actin distribution in oligodendrocytes, relative to their mRNAs
Authors: McEwan Neil R. 
Published: July 2007

AbstractBy using oligodendrocyte cells, which have a very highly defined cell morphology, it is demonstrated that, in general, proteins are found slightly more distal, relative to the cell body, than their mRNA counterparts, but that there is a general trend for proteins and the messages which encode them to be found in similar regions within the cell. This has been demonstrated by use of in situ hybridization and immunocytochemistry together on single cells.
The effect of α‐Tocopherol and β‐tocopherol on proliferation, protein kinase C activity and gene expression in different cell lines.
Authors: Fazzio A. , Marilley D. , Azzi A. 
Published: July 2007

Abstractα‐Tocopherol, but not β‐tocopherol, negatively regulates proliferation of A7r5 vascular smooth muscle cells at physiological concentration. The HeLa cell line was not affected whereas the Chinese hamster ovary cell line (CHO) was slightly inhibited by both α‐tocopherol and β‐tocopherol. In A7r5 cells α‐tocopherol inhibited protein kinase C activity, and this correlated with inhibition of proliferation. β‐Tocopherol did not inhibit either protein kinase C or proliferation. In HeLa cells no inhibition by α‐tocopherol or β‐tocopherol of protein kinase C activity and cell proliferation was observed. In Chinese hamster ovary cells both tocopherols inhibited protein kinase C activity but not proliferation. Thus in the latter cells proliferation was not protein kinase C‐dependent. In A7r5 cells α‐tocopherol but not β‐tocopherol activated AP‐l‐mediated gene expression. In HeLa cells no change in gene expression was observed in agreement with the finding that also protein kinase C was not affected. In CHO cells gene expression was activated by both α‐tocopherol and β‐tocopherol. In this case also a positive correlation was found with similar inhibition of protein kinase C activity. In these cells, however, the changes at the level of protein kinase C activity and gene expression did not result in proliferation changes. The effect of α‐tocopherol and β‐tocopherol on protein kinase C activity and gene expression suggest a cause‐to‐effect relationship. Inhibition of proliferation, however, correlates in the case of A7r5 and HeLa cells but not in the case of CHO suggesting a different proliferation pathway for these cells.
Alterations in eighteen‐carbon saturated, monounsaturated and polyunsaturated fatty acid peroxisomal oxidation in mouse brain during development and aging
Authors: Bourre J. M. , Piciotti M. 
Published: July 2007

AbstractPeroxisomal oxidation was measured in mouse brain homogenate by adding cyanide to the test tube (which inhibits mitochondrial oxidation). Eighteen‐carbon fatty acids (saturated, monounsaturated and polyunsaturated ware oxidized by brain peroxisomes. At nearly all ages, oxidation of oleic acid was higher (about 2 fold) than oxidation of other eighteen‐carbon fatty acids. In contrast to other fatty acids, stearic acid oxidation decreased regularly up to weaning (6 fold) and was stable thereafter. Oleic acid oxidation increased up to weaning, decreased during development up to day 70 and remained subsequently nearly stable. Linoleic acid and alpha‐linolenic acid oxidation increased up to weaning, decreased up to day 105 and was nearly stable thereafter. Alpha‐linolenic acid oxidation about was two fold lower than linoleic acid oxidation. Interestingly, peroxisomal oxidation for all fatty acids examined declined during aging, between day 365 and day 450.
Effect of cardiolipin on functional properties of isolated rat liver mitochondria
Authors: Bobyleva Valentina , Bellei Monica , Pazienza Teresa Loredana , Muscatello Umberto 
Published: July 2007

AbstractThe specific involvement of cardiolipin in modulating and/or controlling the activity of a number of mitochondrial carriers, enzymes and receptors is well documented; however, comparatively less understood is its role for the integrated functions of intact mitochondria.The aim of the present research was to get a better insight into this problem by investigating the effect of in vitro addition of cardiolipin on the properties of isolated liver mitochondria.The results obtained show that cardiolipin induces extensive structural and functional perturbations at the level of the inner mitochondrial membrane. In fact, addition of cardiolipin to intact mitochondria causes a significant increase of proton leak associated with a parallel increase of respiratory rate in State 4. Concomitantly, a slight uncoupling of phosphorylation associated with a moderate increase in ATPase activity is observed. Furthermore, the pore‐mediated membrane permeability to calcium is drastically modified, an effect that can be reversed by addition of cyclosporin.