Current Pole Research Articles

Regional seismicity and on‐land deformation in the Ryukyu arc: Implications for the kinematics of opening of the Okinawa Trough

The stress field evolution and the kinematics of opening of the Okinawa Trough are investigated on the basis of earthquake focal mechanisms and structural data in the Ryukyu arc and the Okinawa Trough. Focal mechanisms show that the crust underlying the arc and the trough undergoes extension along two suborthogonal directions: a regional arc‐perpendicular extension and a local arc‐parallel extension. Both extensions are concurrent and related to the same regional stress field characterized by permutating horizontal σ2 and σ3 axes. Earthquake slip vectors reveal a southward motion of the Ryukyu arc with respect to the south China block. The current pole of opening of the Okinawa Trough is located around 16°N and 50°E. Fracture analysis in Okinawa island allows identification of three episodes of extension: a late Miocene N40°W to N20°E extension (episode I), a late Pliocene to early Pleistocene N20°E extension (episode II), and a latest Pleistocene to present‐day N20°W extension (episode III). Episodes II and III are characterized by permutations between the two horizontal σ2 and σ3 axes. By synthesizing regional deformation data and by comparing the geometry of the deformation with analogue models of oblique rifting we reconstruct the kinematics of opening of the Okinawa Trough since the late Miocene. The direction of divergence of the Ryukyu arc has rotated clockwise from ∼N150°E in the late Miocene to nearly N‐S today.

Performance of a shaking vessel with current pole

To improve solid particle suspensions in liquids in a shaking vessel, a pole was installed at the axis of the shaking vessel, which was referred to as the “current pole”. The performance of a shaking vessel with current pole at its central axis was examined experimentally with respect to particle dispersion, power consumption, mixing time and solid–liquid mass transfer coefficient. The current pole improved the particle suspension without an increase in power consumption and reduced the critical circulating frequency for complete suspension. The current pole was very effective in eliminating the stagnation point on the vessel bottom and to decrease the mixing time. The mass transfer coefficient with a current pole had the same value as that without a current pole above the critical circulating frequency for complete suspension. As the diameter of the current pole increased, the mixing time decreased. A pole diameter of 5% of the vessel diameter was effective for suspension.

Solid—liquid mass transfer in a shaking vessel for a bioreactor with “current pole”

AbstractA shaking vessel with “current pole”, which is a center pole installed at the bottom, had shorter mixing time than a shaking vessel with a cone at the bottom. The mass transfer rate on the suspended particles was also measured in the shaking vessel where ion‐exchange resin beads were used as the suspended particles. The dependence of the solid‐liquid mass transfer coefficient on the circulating frequency changed at the critical circulating frequency for complete suspension NJS. For a circulating frequency higher than NJS, the mass transfer coefficient was correlated with the power consumption per unit volume, regardless of presence or not of the current pole.

Performance of a shaking vessel-type bioreactor with a current pole

The performance of a shaking vessel-type bioreactor with a current pole at its central axis was examined experimentally with respect to particle dispersion, power consumption, and solid-liquid mass transfer coefficient. The current pole improved the particle dispersion without an increase in power consumption and reduced the critical circulating frequency for complete suspension. The mass transfer coefficient with a current pole had the same value as that without a current pole above the critical circulating frequency for complete suspension. The shaking vessel-type bioreactor with a current pole was thus very suitable for the mass production of regenerated plantlets from fragmented horseradish hairy roots.

Effects of Position and Geometry of Current Pole on Mixing Characteristics in Shaking Vessel

Effects of Position and Geometry of Current Pole on Mixing Characteristics in Shaking Vessel

Improvement of particle dispersion in a shaking vessel with current pole.

The main aim of the work was the improvement of particle dispersions in shaking vessel for application to bioreactors for plant cells. In a previous paper (Kato et al., 1995), it was observed that the particles gathered in the center of the vessel bottom at low circulating frequency. A corn is usually installed at the vessel bottom to improve particle dispersion in impeller mixing. It is shown in this paper that a center pole installed at the vessel bottom was more effective than the corn for shake mixing. Effects of the pole, which is referred as the current pole, on flow patterns, mixing time, and dispersion were also examined

Current monitoring for environmental pollution studies by acoustic Doppler current profiling

NOAA’s National Ocean Service (NOS) has been measuring and predicting coastal currents for over 100 years. In earlier times, measurements were made with current poles, or propeller-type current meters. In the late 1980’s, acoustic Doppler current profilers (ADCPs) were widely adopted. In Tampa Bay, 10 ADCPs (RD Instruments) were deployed in bottom-mounted platforms; a towed ADCP provided spatial contours of current speed. A real-time system provided 6-min averages of current to mariners and environmental managers. This system, still in place, provides vital information for tracking land cleanup of pollutant spills. Recently, an ADCP was added to a conventional current meter array deployed by NOAA/AOML at a wastewater outfall off Miami, Florida. The ADCP measurements compared well with earlier observations and facilitated assessing the effects of mooring motion and bio-fouling. Analysis of ADCP profile data revealed a near-linear velocity gradient from surface to bottom, enabling interpolation of velocity profiles from earlier measurements. ADCP backscatter intensity provided a rough estimate of suspended material. Future applications include mapping the three-dimensional circulation around point sources of pollution. Such maps provide environmental managers with data for effective effluent disposal management at minimum cost.

Rule based controller for an HVDC transmission system

Abstract Rule based techniques for controlling processes have existed for over a decade, incorporating expert systems in their design. This paper outlines the theory behind a simple rule based controller (RBC) and its application to an HVDC system as a current (pole) controller. HVDC systems having different configurations, namely, a two-terminal HVDC system and a three-terminal star-connected HVDC system, were simulated to study the performance of the RBC, using Manitoba HVDC Research Centre's EMTDC package. This paper also compares the results obtained using the RBC with those obtained with a conventional current controller.

Informed Consent for Colonoscopy

Central to the nature of the physician-patient relationship is how fully patients are informed about their disease and prognosis and how active a role they take in deciding treatment; the "autonomy" and "paternalistic" models represent current poles of physician behavior. While informed consent has become ubiquitous in medical practice, it is not clear to what extent the value of patient autonomy has entered into everyday medical decisions. To evaluate informed consent, we prospectively surveyed 102 outpatients scheduled to undergo a colonoscopy and 16 of their physicians. The colonoscopy examination is straightforward and offers an optimal opportunity for patient participation in decision making. We found that most patients wanted guidance from their physicians and most physicians did not view the patient as autonomous. The more traditional parentalistic model continues to influence the physician-patient relationship, at least for this technical endeavor.

Flattening, pole, and albedo features of 4 vesta from photometric data

A number of large asteroids show irregular lightcurves of relatively small amplitude and/or ambiguous rotational periods. These observations and the fact that their strong gravitational binding probably results in quasi-equilibrium shapes lead to model these bodies as axisymmetric, biaxial ellipsoids covered by albedo markings. We developed a general numerical algorithm for obtaining simulated lightcurves of “spotted” asteroids and varied the most critical geometrical and physical parameters (albedo contrast, size, and position of the spots; polar coordinates, and shape of the asteroid). We then analyzed the case of 4 Vesta by assuming an axisymmetric ellipsoidal shape with a large brighter region on one hemisphere, in agreement with the results of photometric and polarimetric observations. Fitting the numerical simulations to the available data, we obtained the flattening of the ellipsoid (0.79 ± 0.03), the albedo contrast and geometry of the brighter region, and the orientation of the polar axis. If the derived flattenning corresponds to the equilibrium shape of a nearly homogeneous body, a density of 2.4 ± 0.3 g cm −3 can be inferred. These results show satisfactory agreement with values by different techniques. We plan to apply the same method both to other large asteroids and to smaller, irregularly shaped ones; in the latter case, this will allow us to test the uncertainties in current pole determination methods.

THINKING LIKE A FAMILY THERAPIST: A MODEL FOR INTEGRATING THE THEORIES AND METHODS OF FAMILY THERAPY*

We present a classification system which presumes that information about families can be seen from three different perspectives (historical, interactional, and existential) and that treatment proceeds from three approaches (understanding, transformation, and identification). Using this scheme, we discuss how theories from different schools of thought are substantially overlapping, show that families may respond according to principles other than those the therapist had in mind, indicate how traditional links between certain evaluation perspectives and approaches are unnecessarily limiting, and define two current poles or modes in family therapy (the “ingenious” and the “involved”), suggesting indications for the use of each mode. Various teaching benefits of the scheme are outlined.

Optimal Second Best Pricing of CATV Pole Attachments

Due to the local monopoly in ownership or control of poles to which cable system operators, out of necessity or business convenience, must attach their distribution facilities, it is contended that the utilities enjoy a superior bargaining position over CATV systems in negotiating the rates, terms and conditions for pole attachments .... The FCC's Office of Plans and Policy, in a staff report released in August 1977, concluded that, although the reasonableness of current pole attachment rates remains open to question, public utilities by virtue of their size and exclusive control over access to pole lines, are unquestionably in a position to extract monopoly rents from cable TV systems in the form of unreasonably high pole attachment rates.

Resistivity modeling for arbitrarily shaped three‐dimensional structures

A numerical technique has been developed to solve the three‐dimensional (3-D) potential distribution about a point source of current located in or on the surface of a half‐space containing an arbitrary 3-D conductivity distribution. Self‐adjoint difference equations are obtained for Poisson’s equation using finite‐difference approximations in conjunction with an elemental volume discretization of the lower half‐space. Potential distribution at all points in the set defining the subsurface are simultaneously solved for multiple point sources of current. Accurate and stable solutions are obtained using full, banded, Cholesky decomposition of the capacitance matrix as well as the recently developed incomplete Cholesky‐conjugate gradient iterative method. A comparison of the 2-D and 3-D simple block‐shaped models, for the collinear dipole‐dipole array, indicates substantially lower anomaly indices for inhomogeneities of finite strike‐extent. In general, the strike‐extents of inhomogeneities have to be approximately 10 times the dipole lengths before the response becomes 2-D. The saturation effect with increasing conductivity contrasts appears sooner for the 3-D conductive inhomogeneities than for corresponding models with infinite strike‐lengths. A downhole‐to‐surface configuration of electrodes produces diagnostic total field apparent resistivity maps for 3-D buried inhomogeneities. Experiments with various lateral and depth locations of the current pole indicate that mise‐à‐la‐masse surveys give the largest anomaly if a current pole is located asymmetrically and, preferably, near the top surface of the burried conductor.

A causal approximation scheme for the commutator of the axial vector-currents

An approximation scheme which fulfils the causality condition is used to compute the matrix elements of the commutator of two axial-vector currents between one proton state. The commutator sum rule is supposed to be saturated by taking into account the nucleon, theN*(3/2, 3/2) resonance, and the partially disconnected pion-proton intermediate states. For the axial current form factors pion pole formulas are assumed. It is shown that only the subtraction constants are relevant for the equal time limit of the commutator and so the equivalence with similar earlier methods is proven.

ANALYTIC MODELS FOR THE INTERPRETATION OF ELECTRICAL SURVEYS USING BURIED CURRENT ELECTRODES

The IP response and the apparent resistivity resulting from a buried current pole in the presence of a stratigraphic target and a three‐dimensional target have been studied. The targets were modeled using a layered model to simulate the stratigraphic target and a buried sphere model to simulate the three‐dimensional target. The results show that there is a substantial increase in the response of the target measured at the surface for current electrode depths of greater than half the depth to the top of the target. A larger anomalous response is of particular importance when dealing with deeply buried targets from which little or no response is measured using conventional surface electrode methods. Furthermore, the results indicate that a survey around a drill hole containing a current electrode can be used to outline mineralization in the immediate vicinity of the drill hole. Some empirical observations resulting from our study are presented which relate the lateral offset of the target from the drill hole and its depth to characteristics of the anomaly pattern as measured on the surface.

Possible relations between current algebra and meson pole dominance

The suggestion is made there is an overlap among the information obtained from current algebra and from meson pole dominance principles. In simple models it is shown that current algebra results can be rederived from meson pole dominance principles alone, up to an unknown scale of the weak axial current. A non-compact alternative to the usual SU2×SU2 current algebra is shown to be inconsistent with meson pole dominance.

Current algebra, pole dominance, and meson-baryon interactions

Current algebra, pole dominance, and meson-baryon interactions

Current Algebra and Regge Poles

It is shown that the $\mathrm{SU}(2)\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(2)$ current commutation relations and partial conservation of axial-vector current lead us to exchange degeneracy between a number of Regge trajectories\char22{}not only for the leading trajectories but for lower-ranking ones. Comparisons with experiments are consistent with all known $N$ and $\ensuremath{\Delta}$ trajectories as well as meson trajectories.

Current Algebras and Pole Dominance: A Consistent Treatment of theAρπSystem

Current Algebras and Pole Dominance: A Consistent Treatment of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>A</mml:mi><mml:mi>ρ</mml:mi><mml:mi>π</mml:mi></mml:math>System

Yang-Mills theory and current algebra

It is shown that the soft-meson results, obtained from current algebra and meson pole dominance in the matrix elements of the vector current and the axial and tensor current divergences, are equivalent to those obtained from an effective Yang-Mills Lagrangian.