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Using the solution generating technique.s of Das and Chaudhuri (Pramana J. Phys. 40, 277 (1993); Pramana J. Phys. 58, 449 (2002)), static magnetovac solutions of Einstein-Maxwell equations in general relativity are constructed from the stationary gravitational soliton solutions of Einstein's field equations corresponding to a Kerr object. The techniques followed in the present paper have not been much used in the literature so far although the results are obtained in a straightforward way. The stationary gravitational two-soliton solutions of Einstein's field equations for a Kerr object are generated using the soliton technique of Belinskii and Zakharov (Sov. Phys. JETP 48, 985 (1978); Sov. Phys. JETP 50, 1 (1979)). In the next step, following the procedure of Das and Chaudhuri, mentioned above, static magnetovac solutions of Einstein-Maxwell field equations corresponding to the generated stationary two-soliton solutions of the Kerr object are constructed. The solutions are found to be well behaved at spatial infinity and contain monopole, dipole, and other higher mass multipoles. The mass and the dipole moment of the source are evaluated. It is shown that by redefining some constants appearing in the solutions, Bonnor's (Z. Phys. 190, 444 (1966)) magnetic dipole solutions are faithfully reproduced. Key words: general relativity, exact solutions, magnetostatic solutions, Einstein-Maxwell field, two-soliton solution Utilisant la technique de generation de solution de Das et Chauduri (Pramana J. Phys. 40, 277 (1993); Pramana J. Phys. 58, 449 (2002)), des solutions statiques magnetovac des equations d'Einstein-Maxwell en relativite generale sont construites a partir des solutions solitoniques stationnaires des equations de champ d'Einstein correspondant a un objet de Kerr. Les techniques utilisees ici n'ont pas ete beaucoup utilisees dans la litterature jusqu'a present, bien que les resultats soient obtenus de maniere directe. Les solutions gravitationnelles stationnaires a deux solitons des equations d'Einstein pour un objet de Kerr sont generees en utilisant la technique de Belinski et Zakharov (Sov. Phys. JETP 48, 985 (1978); Sov. Phys. JETP 50, 1 (1979)). Dans l'etape suivante, suivant la procedure de Das et Chauduri mentionnee plus haut, sont obtenues les solutions statiques magnetovac des equations de champ d'Einstein-Maxwell correspondant aux solutions statiques a deux solitons generees pour un objet de Kerr. Nous trouvons que les solutions ont un bon comportement a l'infini spatial et contiennent monopole, dipole et multipoles de masse d'ordre plus eleve. La masse et le moment dipolaire de la source sont evalues. Nous montrons que, en redefinissant certaines constantes apparaissant dans la solution, les solutions dipolaires de Bonnor (Z. Phys. 190, 444 (1966)) sont pleinement reproduites. [Traduit par la Redaction] Mots-cles : relativite generale, solutions exactes, solutions magnetostatiques, champ de Einstein-Maxwell, solution a deux solitons, 1. Introduction In this paper, we construct static magnetic dipole solutions of Einstein-Maxwell (EM) field equations from the stationary gravitational two-soliton solutions of a Kerr object [1]. To generate magnetostatic [...]

We discuss the spontaneous decay in a system of cold identical two-level atoms when, due to the strong dipole-dipole interaction, the collision-induced spontaneous decay plays a leading role in the process. We show that the time profile of the spontaneous transition is essentially non-exponential. Also, we argue that at a low initial temperature of the atomic system the spontaneous decay is accompanied by strong heating caused by the inelastic atom-atom collisions. We show that the spontaneous emission spectrum is asymmetric. In addition, the width of the emission spectrum is a function of time. When atoms decay, the emission spectrum becomes broader. The spectrum's asymmetry and the atomic system's heating have the same physical origin: coming from the peculiarities of the atoms' distribution function. Key words: spontaneous decay, cold atoms, optical collisions, atom heating, collective effects. Nous analysons la desexcitation spontanee dans un systeme d'atomes a deux niveaux identiques et froids lorsque, causee par la forte interaction dipole-dipole, la desexcitation spontanee induite par collision joue le premier role dans le processus. Nous montrons que le profil temporel de la transition spontanee n'est pas exponentiel. Aussi, nous arguons que pour une basse temperature initiale du systeme atomique, la desexcitation spontanee est accompagnee d'un fort rechauffement cause par les collisions inelastiques atome-atome. Nous montrons que le spectre de l'emission spontanee est asymetrique. De plus, la largeur de bande de l'emission est une fonction du temps. Alors que les atomes se desexcitent, la largeur du spectre d'emission augmente. L'asymetrie du spectre et le rechauffement du systeme atomique ont la meme origine physique qui provient de la fonction de distribution des atomes. [Traduit par la Redaction] Mots-cles : desexcitation spontanee, atomes froids, collisions optiques, rechauffement des atomes, effets collectifs., 1. Introduction Impressive progress in atomic gas cooling technologies allowed a new look at the physics of electromagnetic processes in matter. This progress contributed to the revival of interest in [...]

The electric dipole transition probabilities and the oscillator strengths of neutral scandium have been calculated using the quantum defect orbital theory and the Cowan code for the 3d4[s.sup.2]-3d4s4p, 3[d.sup.2]4s-3[d.sup.2]4p, and 3d4[s.sup.2]-4[s.sup.2]4p transitions. In addition, a parametric analysis of the fine structure for the 3d4[s.sup.2] configuration of even parity is performed using Cowan code. The transition probabilities and the oscillator strengths obtained in this work are mostly in agreement with the data obtained from different theoretical works given in the literature. Moreover, transition probabilities for 24 levels of neutral scandium are given for the first time. PACS Nos.: 32.70.Cs, 31.15.A-. Les probability de transition dipolaires electriques et les forces d'oscillateur du scandium neutre sont calculees ici dans le cadre de la theorie des orbitales a defaut quantique, utilisant le code source de Cowan pour les transitions 3d4[s.sup.2]-3d4s4p, 3[d.sup.2]4s-3[d.sup.2]4p et 3d4[s.sup.2]-4[s.sup.2]4p. Le code de Cowan permet aussi une analyse parametrique de la structure fine de la configuration de parite paire 3d4[s.sup.2]. Les probabilites de transition et les forces d'oscillateur obtenues ici sont generalement en bon accord avec les donnees de differentes etudes theoriques trouvees dans la litterature. De plus, nous donnons pour la premiere fois les probabilites de transition de 24 niveaux du scandium neutre. [Traduit par la Redaction], 1. Introduction The atomic transition probability is an important fundamental parameter in the fields of atomic spectroscopy, astronomy, and plasma physics. In particular, accurate oscillator strengths are necessary for the [...]

The exited state ([μ.sub.e]) dipole moment of a molecule is an important parameter, which gives information about electronic and geometrical structure of the molecule in the short-lived state. We have experimentally estimated the exited state ([μ.sub.e]) dipole moment of two novel coumarin derivatives, namely, diethyl 2-acetamido-2-((6-methyl-2-oxo-2H- chromen-4-yl) methyl) malamute (DAM) and 5,6-Benzo-3-[1-(4,5-dicarbomethoxy-1,2,3-triazoloacetyl)] coumarin (5BDTC) by three methods, namely, Lippert's, Bakhshiev's, and Kawski-Chamma-Viallet's. In the Solvatochromic shift method, spectral shift is due to internal excitation of the molecule. We have recorded absorption and emission spectra of the above two novel coumarin derivatives at room temperature using solvents of different polarities. The geometry of the molecules were fully optimized and the ground state dipole moment ([μ.sub.g]) were also calculated theoretically by Gaussian 03 software using [B3LYP/6-31g.sup.*] level of theory. The excited state dipole moment was calculated using [CIS/6-31G.sup.*] level of theory. The [μ.sub.g] and were calculated using the solvatochromic shift method and was also determined in combination with [μ.sub.g]. It was observed that were greater than those of [μ.sub.g], indicating a substantial redistribution of the π-electron densities in a more polar excited state for this coumarin. Further, the changes in dipole moment (Δμ) were calculated both from the solvatochromic shift method and on the basis of microscopic empirical solvent polarity ([E.sup.N.sub.T]) and the values are compared. PACS Nos.: 33.50.-j, 87.64.i, 31.70.Hq, 87.15.kg. Le moment dipolaire ([μ.sub.e]) de l'etat excite d'une molecule est un parametre important qui nous renseigne sur la structure electronique et geometrique de la molecule dans cet etat transitoire de faible duree. Nous estimons experimentalement le moment dipolaire d'un etat excite de deux derives de la coumarine, nommement 2-acetamino-2-((6-methyl-2-oxo-2H- chromene-4-yl) methyl) (DAM) et 5,6-Benzo-3-[1-(4,5-dicarbomethoxy-1,2,3-triazoloacetyl)] (5BDTC) a l'aide des trois methodes de Lippert, de Bashkiev et de Kawski-Chamma-Viallet. En solvatochromie, le deplacement spectral est du a l'excitation interne de la molecule. Nous enregistrons les spectres d'emission et d'absorption de nos deux derives de coumarine a la temperature de la piece et en utilisant des solvants de differentes polarites. La geometrie des molecule est completement optimisee et nous calculons theoriquement le moment dipolaire du fondamental ([μ.sub.g]) a l'aide du logiciel Gaussian 03 au niveau [B3LYP/6-31g.sup.*]. Le moment dipolaire de l'etat excite est calcule au niveau [CIS/6-31g.sup.*]. Les moments [μ.sub.g] et [μ.sub.e] sont calcules par la methode du deplacement solvatochromique et est aussi determine en combinaison avec [μ.sub.g]. Nous observons que les valeurs de [μ.sub.e] sont plus grandes que celles de [μ.sub.g], indiquant une redistribution substantielle des densites d'electrons π dans un etat avec plus d'excitation polaire. De plus, nous calculons les changements du moment dipolaire (Δμ) par la methode du deplacement solvatochromique et sur la base d'un modele empirique de la polarite du solvant et nous comparons les valeurs. [Traduit par la Redaction], 1. Introduction The effect of solvent on the absorption and fluorescence characteristics of organic compounds has been a subject of interesting investigation [1-5]. Excitation of a molecule by photon causes [...]

Electric dipole transition probabilities and oscillator strengths for singly ionized terbium (Tb II) have been calculated with the weakest bound electron potential model (WBEPM) theory using experimental energy levels and theoretical expectation values of orbital radii corresponding to those energy levels under the assumption of the Jj coupling scheme. The transition probabilities and the oscillator strengths calculated have been compared with available data in the literature. A good agreement has been obtained. In this work, the WBEPM theory has been applied to heavy atoms, such as Tb II, for the first time. PACS Nos.: 32.70.Cs, 32.10.-f, 31.15.-p. Nous calculons les probabilites de transition dipolaire electrique et les forces d'oscillateur pour du terbium simplement ionise (Tb II) a l'aide du modele theorique du potentiel de l'electron le plus faiblement lie (WBEPM) qui utilise les niveaux d'energie experimentaux et les valeurs theoriques attendues pour les rayons orbitaux correspondant a ces niveaux d'energie sous l'hypothese du couplage Jj. Nous comparons les probabilites de transition et les forces d'oscillateur calculees avec les donnees disponibles dans la litterature. Nous trouvons un bon accord. Ce travail marque la premiere fois oU WBEPM est utilise pour des atomes lourds comme le Tb II. [Traduit par la Redaction], Introduction Deficiency of atomic data, such as transition probabilities, oscillator strengths, and lifetimes for the rare earth elements, especially for terbium, exist in the literature. Calculations of these parameters are [...]

Dielectric constant of binary mixtures of ethyl methyl ketone (EMK) with some carboxylic acid, namely, acetic acid, propionic acid, and butyric acid, is measured at 303.16 K and 455 kHz. The data are used to compute the mutual correlation factor, gab, excess molar polarization, [DELTA]P, and excess Gibbs free energy, [DELTA]G, of mixing to study the molecular interaction. The study reveals that interaction is maximum in EMK + butyric acid system and microheterogeneous [beta]-clusters with antiparallel orientation of dissimilar molecules predominate in it. PACS No.: 30. Nous mesurons, a 303.16 K et 455 kHz, la constante dielectrique de melanges binaires de methyl ethyl cetone (EMK) avec un acide carboxylique, tels l'acide acetique, l'acide propanoique et l'acide butyrique. Les donnees servent a calculer le facteur de correlation mutuelle, [g.sub.ab], la polarisation molaire en exces [DELTA]P et l'energie libre de Gibbs en exces [DELTA]G, afin d'etudier l'interaction moleculaire. L'etude revele que l'interaction est maximale dans le melange EMK + acide butyrique et que les micro-amas-[beta] heterogenes avec orientation antiparallele entre molecules differentes jouent un role dominant. [Traduit par la Redaction], 1. Introduction We have already studied [1-4] the molecular interaction of ethyl methyl ketone (EMK) and 1,2-dichlorobenzene with various polar and nonpolar liquids with a view to identifying an efficient [...]

We show that 'bichromatic coherent control' (BCC) enables the determination of the amplitudes (= magnitudes + phases) of individual transition-dipole matrix elements (TDMs) and the amplitude of time-evolving wave packets from timeresolved fluorescence data. In the present use of BCC, one induces quantum interferences using two external laser fields to coherently deplete the population of different pairs of excited energy eigenstates. The BCC-induced depletion is supplemented by the computation of the Fourier integral of the time-resolved fluorescence at the beat frequencies of the two states involved. The combination of BCC and Fourier transform enables the determination of both the expansion coefficients of the wave packet in a basis of vibrational energy eigenstates and the amplitudes of the electronic TDMs linking the excited and ground rovibrational states. We illustrate our method by determining the amplitudes of the TDMs linking the vibrational states of the [A.sup.1][∑.sup.+.sub.u] ~ [b.sup.3]Π spin orbit coupled potentials to both the singlet [X.sup.1][∑.sup.+.sub.u] and the triplet [a.sup.3][∑.sup.+.sub.u] electronic ground states in LiRb. The approach, which is found to be quite robust against errors in the BCC procedure and experimental data, can be readily generalized to the imaging of wave packets of polyatomic molecules. Key words: molecular, wave packet, transition-dipole moments, coherent control, time dependent, fluorescence. Nous montrons que le 'controle coherent bichromatique' (CCB) permet de determiner les amplitudes (= grandeurs + phases) des elements de matrice de transition dipolaire (EMTD) individuels et l'amplitude des paquets d'ondes a evolution temporelle au moyen de donnees de fluorescence resolues en temps. La presente utilisation du CCB consiste a induire des interferences quantiques en se servant de deux champs laser externes en vue de reduire de maniere coherente la population de differentes paires d'etats propres excites d'energie. La reduction induite par le CCB est completee par le calcul de l'integrale de Fourier de la fluorescence resolue en temps aux frequences de battement des deux etats concernes. La combinaison du CCB et de la transformee de Fourier permet de determiner les coefficients d'expansion du paquet d'ondes dans une base d'etats propres d'energie de vibration, ainsi que les amplitudes des EMTD electroniques reliant les etats rovibrationnels excites et fondamentaux. Pour illustrer notre methode, nous determinons les amplitudes des EMTD reliant les etats vibrationnels des potentiels avec couplage spin orbite [A.sup.1][∑.sup.+.sub.u] ~ [b.sup.3]Π aux etats electroniques fondamentaux singulet [X.sup.1][∑.sup.+.sub.u] ainsi que triplet [a.sup.3][∑.sup.+.sub.u] dans LiRb. L'approche, qui s'avere assez robuste aux erreurs dans la procedure de CCB et les donnees experimentales, est facilement generalisable a l'imagerie des paquets d'ondes de molecules polyatomiques. [Traduit par la Redaction] Mots-cles: moleculaire, paquet d'ondes, moments de transition dipolaire, controle coherent, dependant du temps, fluorescence., Introduction The well-known 'inverse scattering' problem (1) involves determining the phase of the complex-valued scattering amplitudes (2,3) from (differential) cross-section measurements. In bound-bound molecular spectroscopy the analogous 'phase problem' is [...]

Long-range and spatially anisotropic dipole-dipole interactions permit new approaches for the preparation and exploration of strongly correlated quantum matter that exhibits intriguing phenomena such as quantum magnetism, exotic superfluidity and [...], With the production of polar molecules in the quantum regime (1,2), long-range dipolar interactions are expected to facilitate understanding of strongly interacting many-body quantum systems and to realize lattice spin models (3) for exploring quantum magnetism. In ordinary atomic systems, where contact interactions require wave-function overlap, effective spin interactions on a lattice can be mediated by tunnelling, through a process referred to as super-exchange; however, the coupling is relatively weak and is limited to nearest-neighbour interactions (4,5). In contrast, dipolar interactions exist even in the absence of tunnelling and extend beyond nearest neighbours. This allows coherent spin dynamics to persist even for gases with relatively high entropy and low lattice filling. Measured effects of dipolar interactions in ultracold molecular gases have been limited to the modification of inelastic collisions and chemical reactions (6,7). Here we use dipolar interactions of polar molecules pinned in a three-dimensional optical lattice to realize a lattice spin model. Spin is encoded in rotational states of molecules that are prepared and probed by microwaves. Resonant exchange of rotational angular momentum between two molecules realizes a spin-exchange interaction. The dipolar interactions are apparent in the evolution of the spin coherence, which shows oscillations in addition to an overall decay of the coherence. The frequency of these oscillations, the strong dependence of the spin coherence time on the lattice filling factor and the effect of a multipulse sequence designed to reverse dynamics due to two-body exchange interactions all provide evidence of dipolar interactions. Furthermore, we demonstrate the suppression of loss in weak lattices due to a continuous quantum Zeno mechanism (8). Measurements of these tunnelling-induced losses allow us to determine the lattice filling factor independently. Our work constitutes an initial exploration of the behaviour of many-body spin models with direct, long-range spin interactions and lays the groundwork for future studies of many-body dynamics in spin lattices.

We derive a novel expression for the relativistic energy of electric and magnetic dipoles in an external electromagnetic field and discuss its implications. In particular, we find the relativistic dependence of the energy of a dipole on its velocity, v, and show that in the most convenient presentation of the energy (when the proper electric ([p.sub.0]) and magnetic ([m.sub.0]) dipole moments are involved, whereas the electric (E) and magnetic (B) fields are defined in the laboratory frame), its value essentially depends on the orientation of the velocity, v, with respect to vectors [p.sub.0], E, and [m.sub.0], B. To better understand the relativistic behavior of the energy of electric and magnetic dipoles, we introduce the notion of 'latent' momentum of an electric dipole, in addition to the known concept of 'hidden' momentum of a magnetic dipole. We finally show that the contribution of energy terms related to 'hidden' and 'latent' momenta of an electric or magnetic dipole is important in the relativistic case. PACS Nos.: 41.20.-q. Nous derivons une nouvelle expression pour l'energie relativiste d'un dipole electrique ou magnetique dans un champ electromagnetique externe et discutons ses consequences. En particulier, nous trouvons la dependance relativiste de l'energie du dipole sur sa vitesse v et montrons que dans le cas de la representation la plus appropriee de l'energie (quand les moments propres electrique ([p.sub.0]) et magnetique ([m.sub.0]) sont impliques, alors que les champs electrique (E) et magnetique (B) sont definis dans le referentiel du laboratoire), sa valeur depend essentiellement de l'orientation de la vitesse v par rapport aux vecteurs [p.sub.0], E et [m.sub.0], B. Afin de mieux comprendre le comportement relativiste de l'energie d'un dipole electrique ou magnetique, nous introduisons le concept d'impulsion latente du dipole electrique, en plus du concept mieux connu d'impulsion cachee du dipole magnetique. Nous montrons finalement que la contribution des termes d'energie relies aux impulsions latente et cachee des dipoles electrique ou magnetique est importante dans le cas relativiste. [Traduit par la Redaction], 1. Introduction In a series of recent publications [1-3], we derived novel expressions for the force, F, and torque, T, exerted on a compact electrically neutral bunch of charges, characterized [...]

12.1.1 Two-State Spin System In order to contrast decoupled spin response with dielectric dipole response in Sec. 10.2, we will develop the well-known statistical approach of noninteracting paramagnetism. In a [...]

We extend the results of Bakalov et al. (Phys. Rev. Lett. 84, 2350 (2000)) on one-photon electric dipole transition line shift and broadening to the case of two-photon transitions. As an example, we consider the laser-induced transition in antiprotonic helium produced in a helium gas target. The transition is between antiprotonic helium states (n, l) = (33, 32) and (31, 30). PACS Nos: 32.70.Jz, 34.20.Gj, 36.10.-k Nous etendons les resultats de Bakalov et al. (Phys. Rev. Lett. 84, 2350 (2000)) sur le deplacement et l'elargissement de ligne de la transition dipolaire a un photon au cas des transitions a deux photons. Comme exemple, nous examinons la transition induite par laser dans l'atomcule d'helium antiprotonique produit dans une cible d'helium gazeux. La transition est entre les etats (n, l) = (33, 32) et (31, 30). [Traduit par la Redaction], 1. Introduction In this paper, we propose an approach to the evaluation of the density shift and broadening of a two-photon transition line profile. The foundation of our considerations is [...]

Previous simulations of dipole vortices propagating through rotating, stratified fluid have revealed smallscale inertia-gravity waves that are embedded within the dipole near its leading edge and are approximately stationary relative to the dipole. The mechanism by which these waves are generated is investigated, beginning from the observation that the dipole can be reasonably approximated by a balanced quasigeostrophic (QG) solution. The deviations from the QG solution (including the waves) then satisfy linear equations that come from linearization of the governing equations about the QG dipole and are forced by the residual tendency of the QG dipole (i.e., the difference between the time tendency of the QG solution and that of the full primitive equations initialized with the QG fields). The waves do-not appear to be generated by an instability of the balanced dipole, as homogeneous solutions of the linear equations amplify little over the time scale for which the linear equations are valid. Linear solutions forced by the residual tendency capture the scale, location, and pattern of the inertia-gravity waves, although they overpredict the wave amplitude by a factor of 2. There is thus strong evidence that the waves are generated as a forced linear response to the balanced flow. The relation to and differences from other theories for wave generation by balanced flows, including those of Lighthill and Ford et al., are discussed. DOI: 10.1175/2009JAS3147.1

A new constant of the motion is found for an electric charge acted on by an electric dipole. The relation of the constant of the motion to the energy of the panicle is found. Some properties of the motion are studied and known results are reproduced more simply. We discuss conditions for the appearance of bounded and unbounded trajectories, motion on a sphere, and on a plane. Small angular oscillations around a stable circular trajectory are also studied.

The geometric characteristics of low-frequency magnetic dipole fields and their relative insensitivity to the host media have made low-frequency coils useful for underground geolocation. A robust and succinct method is presented for converting dipole field measurements into estimates of receiver position. A noisy half-space model of the Earth is used to model the receiving environment. A perfectly conducting sphere immersed in a homogeneous conducting background is used to study the localized effects of buried metals. Index Terms--Half-space, loop antennas, magnetic dipoles.

Optical parameters of simulated ambient individual ammonmm sulfate and soot-mixed particles were calculated using the discrete-dipole approximation method with different model geometries. Knowledge of the mixing state and the approximation by a suited idealized geometry reduces the errors of the optical properties by [+ or -] 50% to [+ or -] 10%. The influence of the soot content and the mixing state on the optical properties of the total aerosol was estimated. For the total aerosol population, the size distribution and the absolute soot content had the largest influence. The exact geometry of the ammonium sulfate and soot-mixed particles can be neglected. OCIS codes: 010.1290, 010.1110.

The self-assembled monolayers (SAMs) on the gold surface are analyzed for their structures based on the electrostatic interactions influencing the degree of disorder in carboxyl-terminated SAMs. The findings suggest that the presence of dipole moments influences the structure of the corresponding alkanethiol monolayer.

Nearly all underwater vehicles and surface ships today use sonar and vision for imaging and navigation. However, sonar and vision systems face various limitations, e.g., sonar blind zones, dark or murky environments, etc. Evolved over millions of years, fish use the lateral line, a distributed linear array of flow sensing organs, for underwater hydrodynamic imaging and information extraction. We demonstrate here a proof-of-concept artificial lateral line system. It enables a distant touch hydrodynamic imaging capability to critically augment sonar and vision systems. We show that the artificial lateral line can successfully perform dipole source localization and hydrodynamic wake detection, The development of the artificial lateral line is aimed at fundamentally enhancing human ability to detect, navigate, and survive in the underwater environment. dipole localization | hot wire anemometer | micromachining | wake detection | neuromast

Open-sleeve dipoles are versatile antennas primarily because they have several design parameters that can be varied to achieve a wide range of VSWR performance and operating bandwidth. By properly adjusting their parameters, it is possible to create versions of these antennas that have either a broadband or a dual-band response. In this paper, a new variation of the conventional open-sleeve dipole antenna is introduced, which we call an end-loaded planar open-sleeve dipole (ELPOSD). This configuration provides a degree of miniaturization while retaining a comparable bandwidth in terms of the VSWR response to that of conventional open-sleeve dipoles. Several designs are presented for the conventional and end-loaded configurations that demonstrate the VSWR and miniaturization capabilities of this class of antennas. Measured results have been compared with simulations and found to be in good agreement for an end-loaded planar open-sleeve monopole. Index Terms--Broadband antennas, genetic algorithms (GAs), open-sleeve dipole, printed antennas, small antennas.

We examine that an inductively loaded dipole becomes electrical invisible showing that the influence on a nearby antenna's input impedance and on its radiation pattern (scattering) are minimized. We also verify that the direction of the current reverses on the electrically invisible dipole so that the integral of the dipole current becomes zero. By making an inductive load with a distributed constant line, we fabricate an electrically invisible dipole without using chip devices and evaluate its performance. Furthermore, we propose electrically invisible conductor lines formed by connecting these electrically invisible dipoles in series using open stubs as connectors, and analytically examine their invisible state. Index Terms--Current, dipole, inductive, load, scatter.

In a beamforming system, mutual coupling among the elements can significantly degrade the system performance. However, the mutual coupling effects can be compensated if an accurate model of mutual coupling is available. This paper utilizes a mutual coupling matrix model to compensate mutual coupling in the beamforming of a uniform circular array. In addition, a circular array of dipoles was built and measurements were performed. The predictions are compared with measurements, and verified with results from full-wave simulations. Index Terms--Beamforming, compensation, mutual coupling matrix, uniform circular array.

As spin is a fundamental feature of the universe, preliminary evidence suggests that its study could help in understanding consciousness. Research detailed in this article further develops the author's work in Keen (2005). The findings demonstrate that rotating objects generate fields that are also associated with mindgenerated fields. Numerous quantitative properties of these fields generated by rotation are shown to be very different to fields associated with static objects. Dipole antenna radiation patterns are also discovered. The conclusions suggest that vorticity is not only involved in consciousness, but also has wider implications in understanding our universe, and therefore the subject warrants further research. KEYWORDS: Auras, consciousness, dipoles, dowsing, Information Field, physics, structure of universe, vorticity.

We study the performance of various beamformers for estimating a current dipole source at a known location using electroencephalography (EEG) and magnetoencephalography (MEG). We present our beamformers in the form of the generalized sidelobe canceler (GSC). Under this structure, the beamformer can be solved by finding a filter that achieves the minimum mean-squared error (MMSE) between the mainbeam response and filtered observed signal. We express the MMSE as a function of the filter's rank and use it as a criterion to evaluate the performance of the beamformers. We do not make any assumptions on the rank of the interference-plus-noise covariance matrix. Instead, we treat it as low-rank and derive a general expression for the MMSE. We present numerical examples to compare the MSE performance of beamformers commonly studied in the literature: principal components (PCs), cross-spectral metrics (CSMs), and eigencanceler (EIG) beamformers. Our results show that good estimates of the dipole source signals can be achieved using reduced-rank beamformers even for low signal-to-noise ratio (SNR) values. Index Terms--Beamforming, dipole source signal, electroencephalography, low-rank covariance matrix, magnetoencephalography, sensor array processing.

The molecular dipole moments, their derivatives, and the fundamental IR intensities of the fluoro-, chloro- and fluorochloromethanes are determined from quantum theory of atoms-in-molecules (QTAIM) atomic charges and dipoles and their fluxes at the MP2/6-311++G(3d,3p) level. Results show the charge-charge flux-dipole flux (CCFDF) model quantified with QTAIM parameters at the MP2/6-311++G(3d,3p) level provides accurate estimates of the IR fundamental intensities, of the fluorochloromethane molecules.

The antenna theory model is widely employed to numerically simulate the propagation of current wave along lightning return stroke channels and compute the radiated electromagnetic fields. In this model, the channel is approximated as a vertically straight or a horizontally bent thin-wire antenna above perfectly conducting ground for which the numerical solution of the governing electric field integral equation in frequency domain by the conventional method of moment is prohibitively slow. This paper proposes an efficient algorithm to substantially reduce the computation time of the numerical process for the entire frequency components of the excitation current. In this algorithm, a class of predefined wavelet packet transform is first used to effectively sparsify the resulting moment matrix equations. A proper iterative solver is then utilized to take the full advantages of manipulatory sparse matrices. To accelerate the construction of the original moment matrix, the reciprocal closed-form mutual impedance of sinusoidal electric dipoles and the symmetry of the model are fully exploited. A good agreement is observed with computed data found in technical literature while the overall computational time is reduced remarkably. Index Terms--Antenna theory (AT) model, lightning return stroke, method of moment (MoM), sinusoidal dipoles, thin-wire electric field integral equation (EFIE), wavelet packet transform.

The control of pulselike energy propagation through one-dimensional arrays of dipoles is discussed by exploring three systems. In the first system, a chain of coaxial dipoles is gated by two control dipoles whereas in the other two systems, the chain--branch system and the two-branch system, two chains are used as an input and the propagation of energy is controlled by sending one or two signals towards the junction.

Far field radiation from an arbitrarily oriented Hertzian dipole for two-layered uniaxially anisotropic medium with a tilted optic axis is treated analytically by using the dyadic Green's function of the problem when the dipole is placed over or embedded in a two-layered uniaxially anisotropic medium. The radiation fields are evaluated using the steepest descent method. Parameter studies including anistoropy, layer thickness and dipole location are performed to investigate the effects of changing different variables on the radiation fields. Results of this work can be applied in microstrip circuits and antennas. Index Terms--Anisotropic medium, dyadic Green's function, far field radiation, Hertzian dipole.

The dipole-dipole interaction is significantly responsible for the dielectric behaviour of matter. In the past, several analytic models have been developed to describe these dielectric properties. With increasing performance of personal computers, bigger and bigger systems can be simulated numerically on a microscopic scale by calculating the local electric fields at each dipole site. In doing so and applying the method of image dipoles in order to consider the electrodes we can easily calculate the local fields, polarization and effective susceptibility for a system of nanometric size with dimensions smaller than 100 A which consists of more than one sort of atoms, e. g. binary mixtures, or different lattice constants. With this method all depolarization fields within the sample are regarded inherently. The different phases can be arranged differently so that we can investigate the influence of the granularity of the mixture. Defects and inclusions can also be easily included. We have studied for example the impact of an air-filled sphere in a dielectric on the effective susceptibility and simulated local fields for a pyramidal inclusion. For a given plane in the three-dimensional sample we can determine the local fields at (grain) boundaries. Index Terms--Local field, computational materials science, Lorentz field, dielectric polarization, induced dipoles, dipole-dipole interaction, nanodielectric composites, binary mixture, method of image dipoles, electrode effects.

For transient, time dependent polarization processes stretched exponential functions and power laws referred to as Kohlrausch relaxations are often observed in disordered dielectrics. These relaxations can be distributed in time or frequency over more than 12 decades. Among the various existing models for an interpretation two of them based on similar mathematics but different physical grounds are repeated. In these models charges, either electrons or protons, hop between adjacent sites. The distances between the sites are distributed resulting in a distribution of relaxation times. Then two new models which emerged in the last years are discussed. (I) It is shown that the dipolar interaction between dipoles of the same kind, i.e. without a distribution of any property, can result in Kohlrausch relaxations. (II) In solid electrolytic capacitors charges can be attracted by their images in the electrode. After application of an external voltage this charge attraction leads to an external current with a power law time dependence. Index Terms--Insulators, dielectric polarization, relaxation processes, Monte Carlo methods, distribution function, dipolar interaction, electrodes, Kohlrausch relaxations.

The first example of ferroelectrically switchable fluid columnar liquid crystalline compounds generated by achiral molecules is discussed. It was found that it is important to reduce the intercolumnar dipole-dipole interaction for realization of ferroelectric columnar liquid crystals.

ALICE dipole magnet has a singe arm forward muon detector, which requires a dipole magnet with a very large aperture that would be installed next to the solenoid used in the L3 experiment of LEP. The magnet is currently assembled in the experiment underground carven in a location with convenient access conditions where it would be powered and tested during the last quarter of 2003.

The status of the test activities, showing results obtained on the first pre-series dipoles, including crosschecks of various measurements systems and correlation between measurements at room and cryogenic temperatures is reported.

The problems encountered to shape correctly the cold masses, their effect on interconnection of the dipole cold masses and on the mechanical aperture are described. On one side measures to improve the production process in terms of accuracy and reproducibility are taken, whereas on the other side the assembly tolerances could be relaxed following a through review of the machine requirements.

The results of a comprehensive analysis from the geometric point of view of the pre-series LHC dipoles are described. Data concerning the error on sagitta, extremity positions and sextupolar corrector positions are provided for the pre-series magnets.

The mechanical activity of full-scale prototype and first preseries LHC dipole magnets is assessed and correlations with magnet manufacturing procedures and quench performance are demonstrated. The statistical properties of different features of spike such as the maximal amplitude, the energy, the duration and the time correlation between events are presented.

We provide examples of how a computer algebra system can be used to investigate the motion of an electric charge in an electric or magnetic dipole field. [DOI: 10.1119/1.1579496]

Innovative concepts in transverse field magnet design are described and discussed.

Earth's magnetic field is believed to be generated by dynamo action in a rotating electrically conducting fluid (1-3). The magnetic field of Earth is dipole-dominated and suddenly reverses its polarity [...], Using long-duration, three-dimensional magnetohydrodynamic simulation, we found that the magnetic dipole field generated by a dynamo action in a rotating spherical shell repeatedly reverses its polarity at irregular intervals (that is, punctuated reversal). Although the total convection energy and magnetic energy alternate between a high-energy state and a low-energy state, the dipole polarity can reverse only at high-energy states where the north-south symmetry of the convection pattern is broken and the columnar vortex structure becomes vulnerable. Another attractive finding is that the quadrupole mode grows, exceeding the dipole mode before the reversal; this may help to explain how Earth's magnetic field reverses.

Development of a single-layer common-coil magnet is being finalized at Fermilab. The magnet, which incorporates innovative design and technology features, is meant to be used in a future Very Large Hadron Collider.

A series of magnets, based on the 'Common Coil' configuration,' have been designed, fabricatedand tested. Tests of magnets RD-2 and RT-1 have been successfully completed, and RD-3 has tested to a record dipole field of 14.7 Tesla.

AC loss and dynamic magnetic field distortion in the main LHC dipoles is significant for assessment of the accelerator performance and for understanding the properties of assembled magnets. The loss due to current cycling in some 1-meter-long model dipoles, 15-meter-long dipole prototypes and pre-series magnets are measured, resitance between strands of opposite layers of the cable, R[subscript c], is evaluated for the inner winding of the dipole, and the method to estimate the R[subscript c] value in the outer winding is discussed.

Dynamic processes in a synchrotron bending magnet are investigated at the Heavy Ion Research Center (GSI), in Darmstadt, Germany. A hybrid method, based on an integro-differential approach to eddy currents in laminated structures and a volume integral formulation for the magnetization vector, is applied, and data obtained from the numerical simulation are compared with experimental results.

In this paper, we extend a previous prototype study [1] of frequency-domain (FD) and time-domain (TD) Green's functions for an infinite periodic phased line array of dipoles to account for the effects of truncation, as modeled by a semi-infinite array. These canonical problems are to be used eventually for the systematic analysis and synthesis of actual rectangular TD plane phased arrays. In the presentation, we rely on the analytic results and phenomenologies pertaining to the infinite array, which are reviewed. Major emphasis is then placed on the modifications introduced by the truncation. Finite Poisson summation is used to convert the individual dipole radiations into collective truncated wavefields, the FD and TD Floquet waves (FW). In the TD, exact closed-form solutions are obtained, and are examined asymptotically to extract FD and TD periodicity-matched conical truncated FW fields (both propagating and nonpropagating), corresponding tip-diffracted periodicity-matched spherical waves, and uniform transition functions connecting both across the FD and TD-FW truncation boundaries. These new effects can again be incorporated in a FW-modulated geometrical theory of diffraction. A numerical example of radiation from a [text unreadable in original source] phased TD dipole array with band-limited excitation demonstrates the accuracy and efficiency of the FW-(diffracted field) asymptotic algorithm when compared with an element-by-element summation reference solution. Index Terms--Antenna arrays, antenna transient analysis, arrays, Floquet waves (FW), periodic structures, time-domain analysis, time-domain Green's functions, transient analysis.

Two in one shell-type Nb3Sn dipole models for Very Large Haddron Colliders were designed and analyzed.

The high field dipole at Fermilab is discussed in terms of coil end parts design and fabrication issues.

BSCCO common coil dipoles were studied to determine persistent current effects.

Conductor development goals of the Advanced Technology Development Program are discussed, in terms of long term program strategy and results to date.

The Levitated Dipole Experiment is discussed in the context of the high temperature superconducting levitation coil.

Research describing a superconducting dipole, under construction at the National High Magnetic Field Laboratory, Florida, is presented. The purpose of the magnet is to bend beams of charged particles in nuclear physics experiments.