554 research outputs found
ELECTROSTATIC BODY-MOTION REGISTRATION AND THE HUMAN ANTENNA-RECEIVER EFFECT: A NEW METHOD FOR INVESTIGATING INTERPERSONAL DYNAMICAL ENERGY SYSTEM INTERACTIONS
This paper documents that it is possible to measure electromagnetic fields created by physical movements of the human body-termed electrostatic body-motion effects-using readily available EEG amplifiers, and that it possible to measure the human body's capability to serve as an antenna and/or receiver for these electrostatic movements-termed the human antenna-receiver effect. Following the observation by Green et al (1991)1 that small body-motions could be detected by electrometers attached to copper walls, three experiments were conducted measuring the effects of hand-motions and foot-motions using DC amplifiers (the Synamps System by Neuroscan). Clear hand-motion and foot-motion effects could be recorded using a standard electrode box as an antenna. The electrostatic motion effect was attenuated as a function of distance of the motions from the electrode box, and by placing a wire mesh shield over the electrode box. The human body was discovered to funcrion as a strong antenna and/or receiver for electrostatic body-motions. The findings indicate that electrostatic body-motions and the human antenna-receiver effect are easily measurable, and may serve as a new method for investigating interpersonal dynamic energy system interactions in psychology, medicine and healing
Influence of fluid-mechanical coupling in gas generation in undersaturated petroleum reservoirs
Among the several mechanisms of producing an oil reservoir, the gas expansion
mechanism is an important primary recovery process. During the depletion of the reservoir,
the pore pressure may reach values below the bubble pressure of the oil, allowing the gas
release. From the geomechanical point of view, the change in pore volume, due to production,
changes the dynamics of gas generation, since it is dependent upon the change in pore
pressure. Studies considering the fluid-mechanical coupling show the relationship between
variations of fluid pressure and porous structure of the reservoir. This work aims to study the
influence of the fluid-mechanical partial coupling (one and two-way) in the process of gas
release during recovery of hydrocarbon. It was used the partial coupling methodology
developed by ATHENA/GTEP – PUC-Rio. The model called “A” has only one producing
well, while the model called “B” has four injection wells, besides the producer. Initially, the
oil present in the reservoir is in undersaturated condition. In model “A” was observed that the
pressure drop of fluid is more accentuated, until it reaches the bubble pressure, when
considering the two-way coupling. Consequently, the gas release initiation occurs earlier than
one-way coupling scheme. After starting gas generation, the rates of pressure change in both
partial coupling scenarios tend to equalize. In terms of compaction and subsidence, it was
observed most significant displacements values in two-way coupling, highlighting the
rigorous consideration of the geomechanical effects in the applied methodology. In model
“B”, it was observed that the consideration of the two-way coupling resulted in a recovery
scenario without generation of gas, unlike the results shown by the one-way coupling in
which gas was generated during 40% of total simulation time. In geomechanical terms it was
observed, as presented previously, that the values of vertical displacement were greater in the
two-way coupling. The methodology used in this paper proved to be capable of simulating
coupled process in a blackoil reservoir, as could be observed by the results. Furthermore, the
use of one-way partial coupling scheme, which is widely used in the oil industry, showed
results quite different in terms of gas liberation, when are compared with the two-way partial
coupling scheme, which was developed in a more rigorous way
Properties of the Bose glass phase in irradiated superconductors near the matching field
Structural and transport properties of interacting localized flux lines in
the Bose glass phase of irradiated superconductors are studied by means of
Monte Carlo simulations near the matching field B_Phi, where the densities of
vortices and columnar defects are equal. For a completely random columnar pin
distribution in the xy-plane transverse to the magnetic field, our results show
that the repulsive vortex interactions destroy the Mott insulator phase which
was predicted to occur at B = B_Phi. On the other hand, for ratios of the
penetration depth to average defect distance lambda/d <= 1, characteristic
remnants of the Mott insulator singularities remain visible in experimentally
accessible quantities as the magnetization, the bulk modulus, and the
magnetization relaxation, when B is varied near B_Phi. For spatially more
regular disorder, e.g., a nearly triangular defect distribution, we find that
the Mott insulator phase can survive up to considerably large interaction range
\lambda/d, and may thus be observable in experiments.Comment: RevTex, 17 pages, eps files for 12 figures include
Interactions, Distribution of Pinning Energies, and Transport in the Bose Glass Phase of Vortices in Superconductors
We study the ground state and low energy excitations of vortices pinned to
columnar defects in superconductors, taking into account the long--range
interaction between the fluxons. We consider the ``underfilled'' situation in
the Bose glass phase, where each flux line is attached to one of the defects,
while some pins remain unoccupied. By exploiting an analogy with disordered
semiconductors, we calculate the spatial configurations in the ground state, as
well as the distribution of pinning energies, using a zero--temperature Monte
Carlo algorithm minimizing the total energy with respect to all possible
one--vortex transfers. Intervortex repulsion leads to strong correlations
whenever the London penetration depth exceeds the fluxon spacing. A pronounced
peak appears in the static structure factor for low filling fractions . Interactions lead to a broad Coulomb gap in the distribution of
pinning energies near the chemical potential , separating
the occupied and empty pins. The vanishing of at leads to a
considerable reduction of variable--range hopping vortex transport by
correlated flux line pinning.Comment: 16 pages (twocolumn), revtex, 16 figures not appended, please contact
[email protected]
Petrogenesis and geochronology of the Arkasani Granophyre and felsic Dalma volcanic rocks : implications for the evolution of the Proterozoic North Singhbhum Mobile Belt, east India
The North Singhbhum Mobile Belt (NSMB) is a 200 km long, curved Proterozoic fold–
thrust belt that skirts the northern margin of the Archean Singhbhum Craton of NE India. The
Singhbhum Shear Zone (SSZ) developed between the Dhanjori and Chaibasa formations near the
southern margin of the NSMB and represents an important Cu-U-P metallotect. A SHRIMP U–Pb
zircon date of 1861±6 Ma, obtained for the syn- to post-kinematic Arkasani Granophyre that has
intruded the SSZ, provides a minimum age for the prolonged tectonic activity and mineralization along
the SSZ and for the time of closure of the Chaibasa and Dhanjori sub-basins. The Dalma Volcanic
Belt, a submarine rift-related bimodal mafic-felsic volcanic suite, forms the spine of the NSMB. A
SHRIMP U–Pb zircon igneous crystallization date of 1631±6 Ma was obtained for an unfoliated
felsic volcanic rock from the base of the Dalma volcanic sequence. These new findings suggest that
the different sub-basins in the NSMB evolved diachronously under contrasting tectonic environments
and were juxtaposed during a later orogenic movement.http://journals.cambridge.org/action/displayBackIssues?jid=GEO2015-11-30hb201
Suppression of matching field effects by splay and pinning energy dispersion in YBa_2Cu_3O_7 with columnar defects
We report measurements of the irreversible magnetization M_i of a large
number of YBa_2Cu_3O_7 single crystals with columnar defects (CD). Some of them
exhibit a maximum in M_i when the density of vortices equals the density of
tracks, at temperatures above 40K. We show that the observation of these
matching field effects is constrained to those crystals where the orientational
and pinning energy dispersion of the CD system lies below a certain threshold.
The amount of such dispersion is determined by the mass and energy of the
irradiation ions, and by the crystal thickness. Time relaxation measurements
show that the matching effects are associated with a reduction of the creep
rate, and occur deep into the collective pinning regime.Comment: 7 pages, 5 figures, submitted to Phys. Rev.
The nature of slow dynamics in a minimal model of frustration-limited domains
We present simulation results for the dynamics of a schematic model based on
the frustration-limited domain picture of glass-forming liquids. These results
are compared with approximate theoretical predictions analogous to those
commonly used for supercooled liquid dynamics. Although model relaxation times
increase by several orders of magnitude in a non-Arrhenius manner as a
microphase separation transition is approached, the slow relaxation is in many
ways dissimilar to that of a liquid. In particular, structural relaxation is
nearly exponential in time at each wave vector, indicating that the mode
coupling effects dominating liquid relaxation are comparatively weak within
this model. Relaxation properties of the model are instead well reproduced by
the simplest dynamical extension of a static Hartree approximation. This
approach is qualitatively accurate even for temperatures at which the mode
coupling approximation predicts loss of ergodicity. These results suggest that
the thermodynamically disordered phase of such a minimal model poorly
caricatures the slow dynamics of a liquid near its glass transition
Commensurate and Incommensurate Vortex Lattice Melting in Periodic Pinning Arrays
We examine the melting of commensurate and incommensurate vortex lattices
interacting with square pinning arrays through the use of numerical
simulations. For weak pinning strength in the commensurate case we observe an
order-order transition from a commensurate square vortex lattice to a
triangular floating solid phase as a function of temperature. This floating
solid phase melts into a liquid at still higher temperature. For strong pinning
there is only a single transition from the square pinned lattice to the liquid
state. For strong pinning in the incommensurate case, we observe a multi-stage
melting in which the interstitial vortices become mobile first, followed by the
melting of the entire lattice, consistent with recent imaging experiments. The
initial motion of vortices in the incommensurate phase occurs by an exchange
process of interstitial vortices with vortices located at the pinning sites. We
have also examined the vortex melting behavior for higher matching fields and
find that a coexistence of a commensurate pinned vortex lattice with an
interstitial vortex liquid occurs while at higher temperatures the entire
vortex lattice melts. For triangular arrays at incommensurate fields higher
than the first matching field we observe that the initial vortex motion can
occur through a novel correlated ring excitation where a number of vortices can
rotate around a pinned vortex. We also discuss the relevance of our results to
recent experiments of colloidal particles interacting with periodic trap
arrays.Comment: 8 figure
A-dependence of nuclear transparency in quasielastic A(e,e'p) at high Q^2
The A-dependence of the quasielastic A(e,e'p) reaction has been studied at
SLAC with H-2, C, Fe, and Au nuclei at momentum transfers Q^2 = 1, 3, 5, and
6.8 (GeV/c)^2. We extract the nuclear transparency T(A,Q^2), a measure of the
average probability that the struck proton escapes from the nucleus A without
interaction. Several calculations predict a significant increase in T with
momentum transfer, a phenomenon known as Color Transparency. No significant
rise within errors is seen for any of the nuclei studied.Comment: 5 pages incl. 2 figures, Caltech preprint OAP-73
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