Long‐Lifetime Triboelectric Nanogenerator Operated in Conjunction Modes and Low Crest Factor

The high‐output triboelectric nanogenerator (TENG) is indispensable for its practical applications toward industrial products. However, the electricity loss in simple parallel connection among all units and the typically high crest factor output seriously hamper the practical applications of TENG. Here, a rectified TENG is reported in parallel structure to solve the problem of electricity loss in simple parallel connection. The rotational contact–separation structure with phase difference between rectified TENGs addresses high crest factor output and extends service life of rotational TENG simultaneously. The current crest factor is dramatically decreased to 1.31 in multiple rectifier multiple TENG in parallel (MRM‐TENG), while that of TENG in simple parallel is higher than 6. Meanwhile, the current output can retain up to ≈93% of its initial performance after 7 200 000 rotations under 2.00 r s^?1 of 1000 h. Furthermore, the equivalent current can be in linear growth with low crest factor by making MRM‐TENG in parallel for distributed energy supply without electricity loss. This work may provide a new strategy for TENG in parallel to achieve a low crest factor output and long‐term cycling stability power generation in distributed energy harvesting for large‐scale power application.     

Equivalent Circuit of Frog Atrial Tissue as Determined by Voltage Clamp-Unclamp Experiments

The equivalent circuit that has been used in the analysis of nerve voltage-clamp data is that of the membrane capacity in parallel with the membrane resistance. Voltage-clamp experiments on frog atrial tissue indicate that this circuit will not suffice for this cardiac tissue. The change in membrane current associated with a step change in membrane potential does not show a rapid spike of capacitive current as would be expected for the simple parallel resistance-capacitance network. Rather, there is a step change in current followed by an exponential decay in current with a time constant of about 1 msec. This relatively slow capacitive charging current suggests that there is a resistance in series with the membrane capacity. A possible equivalent circuit is that of a series resistance external to the parallel resistance-capacitance network of the cell membranes. Another possible circuit assumes that the series resistance is an integral part of the cell membrane. The data presented in this paper demonstrate that the equivalent circuit of a bundle of frog atrial muscle is that of an external resistance in series with the cell membranes.     

Geographical information system parallelization for spatial big data processing: a review

With the increasing interest in large-scale, high-resolution and real-time geographic information system (GIS) applications and spatial big data processing, traditional GIS is not efficient enough to handle the required loads due to limited computational capabilities.Various attempts have been made to adopt high performance computation techniques from different applications, such as designs of advanced architectures, strategies of data partition and direct parallelization method of spatial analysis algorithm, to address such challenges. This paper surveys the current state of parallel GIS with respect to parallel GIS architectures, parallel processing strategies, and relevant topics. We present the general evolution of the GIS architecture which includes main two parallel GIS architectures based on high performance computing cluster and Hadoop cluster. Then we summarize the current spatial data partition strategies, key methods to realize parallel GIS in the view of data decomposition and progress of the special parallel GIS algorithms. We use the parallel processing of GRASS as a case study. We also identify key problems and future potential research directions of parallel GIS.     

Polarographic direct determination and homogeneous immunoassay of anti-human serum albumin (HSA) by parallel catalytic hydrogen wave of anti-HSA or HSA

Human serum albumin (HSA) or anti-human serum albumin (anti-HSA) yields a catalytic hydrogen wave at about -1.85V (vs Ag/AgCl) in 0.25M NH(3).H(2)O-NH(4)Cl (pH 8.58) buffer. When 1.0 x 10(-2)M K(2)S(2)O(8) is present, the catalytic hydrogen wave is further catalyzed, producing a parallel catalytic wave of hydrogen as catalyst in nature, termed the parallel catalytic hydrogen wave. The sensitivity of the parallel catalytic hydrogen wave is higher by two orders of magnitude than that of the catalytic hydrogen wave. Using the parallel catalytic hydrogen wave of anti-HSA or HSA in the presence of K(2)S(2)O(8), two sensitive methods for the determination of anti-HSA were developed. One is a direct determination based on the parallel catalytic hydrogen wave of anti-HAS itself, and the other is a homogeneous immunoassay based on measuring the decrease of the peak current of the parallel catalytic hydrogen wave of HSA after homogeneous immunoreaction of HSA with anti-HSA. In the direct determination, the second-order derivative peak current of the parallel catalytic hydrogen wave of anti-HSA itself is rectilinear to its titer in the range from 1:1.0 x 10(7) to 1:8.4 x 10(6). In the homogeneous immunoassay, the decrease in the second-order derivative peak current of the parallel catalytic hydrogen wave of HSA is linearly related to the added anti-HSA in the titer range from 1:3.0 x 10(7) to 1:6.0 x 10(6). These assays are highly sensitive and rapid in operation and can be used to evaluate such antigens and their antibodies as those that could yield the parallel catalytic hydrogen wave.     

Electric field induced desorption of bacteria from a conditioning film covered substratum.

Desorption of three oral bacterial strains from a salivary conditioning film on an indium tin oxide electrode during application of a positive (bacterial adhesion to the anode) or a negative electric current was studied in a parallel plate flow chamber. Bacterial adhesion was from a flowing suspension of high ionic strength, after which the bacterial suspension was replaced by a low ionic strength solution without bacteria and currents ranging from -800 to +800 microA were applied. Streptococcus oralis J22 desorbed during application of a positive and negative electric current with a desorption probability that increased with increasing electric current. Two actinomyces strains, however, could not be stimulated to desorb by the electric currents applied. The desorption forces acting on adhering bacteria are electroosmotic in origin and working parallel to the electrode surface in case of a positive current, whereas they are electrophoretic and electrostatic in origin and working perpendicular to the surface in case of a negative current. By comparison of the effect of positive and negative electric currents, it can be concluded that parallel forces are more effective in stimulating bacterial desorption than perpendicular forces. The results of this study point to a new pathway of cleaning industrial and biomedical surfaces without the use of detergents or biocides.     

The effect of current on the distribution of diatoms settling on submerged glass slides

Glass microscope slides were submerged for two to six week periods at selected sites in a small, spring-fed stream near Lennoxville, Quebec. Slides were oriented parallel and perpendicular to the current. Qualitative and quantitative data from transects across slides show that diatoms are randomly distributed on slides perpendicular to the current but not on slides oriented parallel to the current. In the later case, most individuals first settled near the upstream or downstream edge of the slide. Non-random distribution is most pronounced on slides containing Cocconeis placentula. This species and two others, Achnanthes linearis and A. minutissima, are abundant and determine most distribution patterns found on slides. Preference of diatoms for the edges of slides appears to be affected by current. We propose a model, based upon water flow, to explain the preferential distribution of diatoms on slides oriented parallel to the current. Light appears not to affect settling patterns to a great extent in this study.     

Induced electric field and current density patterns in bone fractures

We have used the low frequency solver of the computer program SEMCAD‐X to model the induced electric field and current density patterns in simple models of a fractured femur embedded off‐center in cylindrical muscle tissue; a 1 cm fracture gap is filled with callus. The model is exposed to a 1 kHz, 1 mT sinusoidal magnetic field. The frequency chosen is typical of the major Fourier components of many waveforms used to stimulate fracture healing using pulsed magnetic fields; the intensity is also a typical level. Models include fractures perpendicular to the bone and at an angle from the perpendicular, each exposed to a field applied parallel to the bone or parallel to either of the two axes perpendicular to it. We find that all directions of applied magnetic fields produce essentially parallel induced electric fields and current densities through the plane of the callus, but that a magnetic field applied parallel to the bone induces considerably higher fields and currents than the same strength field applied in either perpendicular direction. Because investigations of pulsed‐field devices, including modeling of induced fields and currents, peaked more than a decade ago, this is the first application to our knowledge of the current capabilities of computer modeling systems to biological systems at low frequencies. Bioelectromagnetics 33:585–593, 2012. © 2012 Wiley Periodicals, Inc.     

Induced current measurements in whole body exposure condition to radio frequency electric fields.

The current induced in a human exposed to radio frequency electric fields has been studied by the use of a stripline, in which whole body exposure to vertical electric fields (3-27 MHz) can be produced. We have examined two different techniques to measure the induced current; parallel plate meters and current probes. When the subject has good connection to the ground, the choice of measurement technique is not crucial, since there are only minor differences in readings between the instruments. But when the subject is wearing shoes and/or standing on a wooden plate, the difference between the instruments increases considerably. The difference can mainly be explained by the capacitive coupling between the parallel plate meters and the ground; therefore, the current probes are preferred when the subject does not have perfect contact with the ground. Since the International Commission on Non-Ionizing Radiation Protection guidelines demand measurements of induced current in humans exposed to radio frequency fields in the range of 10-110 MHz, the importance of finding an appropriate measurement procedure becomes apparent.     

The AC Impedance of Frog Skin and Its Relation to Active Transport

The AC electrical impedance of frog skin was measured in the range 1 cycle/second to 50 kc/second by injecting current sinusoidally at low current density. The behavior of the skin was found to be linear so the usual concepts of impedance could be validly employed. In the range 1 cycle/second to 5 kc/second, the impedance traces out a circular arc locus with its center off the real axis; thus the skin could be represented by a series resistance and a parallel combination of a conductance and a phase shift element. The phase shift element has an impedance angle of about 80 degrees , current leading voltage, with an equivalent capacitance of about 2 muf/cm(2). The phase shift and the equivalent capacitance were independent of the experimental conditions. The parallel conductance, which was responsible for most of the low frequency impedance, could be subdivided into two approximately equal conductances, one associated with sodium ion current and the other associated with chloride ion current. Both currents were determined mainly by the concentrations of the respective ions bathing the outside of the skin. The response to changes in concentration and the response to CO(2) indicated that the chloride current was passive, but the sodium current appeared to be associated with the active transport mechanism; little sodium could pass through the skin unless associated with active transport.     

Shunting effect on resistance measurements in visceral smooth muscle tissue

An electrical network is presented as a model of the electrical connections between cells in a cross section of visceral smooth muscle. Methods of operational calculus are used to analyze the network and to determine the effect of parallel paths on measured resistances between the nodes. The analysis of the model suggests that actual resistances between two adjacent cells if they are isolated from the other cells in the cross section could be three times the values measured when the cells are interconnected with the parallel fibers. It is felt that the analysis presented makes possible a more accurate interpretation of electrical measurements of intercellular resistance by providing an estimate of the shunting effect of the current paths through parallel cells.     

Biomolecular energy calculations using transputer technology

We report an application of current parallel processing transputer technology which has readily achieved a 25-fold reduction in computational time of peptide-solvent interactions.     

Using nuclear gene data for plant phylogenetics: Progress and prospects

The paper reviews the current state of low and single copy nuclear markers that have been applied successfully in plant phylogenetics to date, and discusses case studies highlighting the potential of massively parallel high throughput or next-generation sequencing (NGS) approaches for molecular phylogenetic and evolutionary investigations. The current state, prospects and challenges of specific single- or low-copy plant nuclear markers as well as phylogenomic case studies are presented and evaluated.     

Protein Production and Crystallization at the Joint Center for Structural Genomics

By definition, structural genomics centers must be able to address a large number of diverse protein targets. The methods developed should permit parallel and cost-effective processing while allowing for the diverse nature of proteins. Our approach to this problem is a multi-tiered effort where targets are characterized and categorized by behavior and processed in parallel by appropriate methods. The Joint Center for Structural Genomics (JCSG) has applied this tactic to create a fully integrated and scaleable structure determination pipeline. Highlights of the development of the current pipeline for protein production and crystallization are presented here.     

Reprint of: Using nuclear gene data for plant phylogenetics: Progress and prospects

The paper reviews the current state of low and single copy nuclear markers that have been applied successfully in plant phylogenetics to date, and discusses case studies highlighting the potential of massively parallel high throughput or next-generation sequencing (NGS) approaches for molecular phylogenetic and evolutionary investigations. The current state, prospects and challenges of specific single- or low-copy plant nuclear markers as well as phylogenomic case studies are presented and evaluated.     

The correlation between the increase in slow outward current and in contraction induced by caffeine, ryanodine, and rapid cooling in voltage-clamped frog muscle fibers.

The effects of caffeine, ryanodine, and rapid cooling were tested on the depolarization-induced contraction and the apamin-insensitive slow outward current (Iso) of voltage-clamped (double mannitol gap) single frog muscle fibers. Subthreshold caffeine concentrations (0.5-2 mM) induced a monotonic increase in contractile and Iso amplitude. Whatever the concentration, the increase in contraction was roughly twice the one in current. Similar results were obtained upon rapid cooling (20-4 degrees C) in the presence of 0.5 mM caffeine. In the absence of external Na+ (choline-substituted) 10(-5) M ryanodine induced a delayed increase (approximately 30 min) in contraction and in current, shortly before the development of a drastic and irreversible contracture. Here again, the increase in contraction was twice that in current. In the presence of 5 mM tetraethylammonium (TEA) and (or) 25 nM charybdotoxin, 2 mM caffeine still induced a strong facilitating effect on contraction but the parallel increase in current was strongly reduced. The linear relationship between the increase in current and contractile amplitude has a slope approximately 0.5 (whatever the drug used to increase contractility); it is approximately 0.1 in the presence of TEA and (or) charybdotoxin. In conclusion, provided the changes in contractile amplitude are caused by parallel changes in depolarization-induced sarcoplasmic reticulum Ca2+ release, about 50% of the apamin-insensitive Iso is controlled by internal Ca2+ release. The main part of this current corresponds to the TEA- and charybdotoxin-sensitive component of Iso.     

Theory of the near-wall conductivity

A model describing the phenomenon of the electron current in a plane plasma slab bounded by parallel dielectric walls in the presence of a homogeneous magnetic field perpendicular to the walls and an electric field oriented along the walls is presented. The current flows along the electric field because of the electron collisions with diffusely scattering walls. The model takes into account the presence of Debye layers and the non-Maxwellian character of the electron distribution function. Collisions in the plasma volume are ignored.     

Phagokinetic tracks of 3T3 cells: parallels between the orientation of track segments and of cellular structures which contain actin or tubulin.

Phagokinetic tracks were used to determine the current direction of migration in 3T3 cells. Comparing this direction with the orientation of actin or tubulin-containing cellular structures by indirect immunofluorescence, the following results were obtained. First, the main actin-containing bundles were located at the bottom and tail end of 3T3 cells and ran parallel to the current or preceding direction of migration. Second, the 3 micrometer long rod-like structure (primary cilium), which contains tubulin and which has been observed by other investigators in transmission electron microscopy (Barnes, 1961; Sorokin, 1962; Wheatley, 1969) and in indirect immunofluorescence (Osborn and Weber, 1976), was oriented predominantly parallel to the substrate and to the current movement direction. It seems possible that the primary cilium has a role in the directional control of a migrating 3T3 cell, and that the main actin containing bundles act as substrate-attached rails along which the nucleus and bulk cytoplasm slide during displacement of the cells.     

Gating currents in th intact crayfish giant axon.

Both single-sweep and signal-averaged asymmetry current are measured from intact crayfish axons after ionic currents are blocked with tetrodotoxin and 4-aminopyridine. The ON asymmetry charge saturates at about 0 mV and no ON charge movement is detectable at voltages negative to -140 mV. The areas of ON and OFF asymmetry charge are equal for short depolarizations but the ratio QOFF/QON decreases for longer depolarizing pulses. Sodium and asymmetry current magnitudes can be changed in parallel by lowering the hold potential or by imposing conditioning prepulses. Our results are consistent with the concept that asymmetry current in generated by movement of trapped charge in association with Na channel gating.     

Estimation of synaptic currents by recordings from extracellular electrodes

A method for estimating the synaptic current distribution is described, which is based on solving the inverse problem for a system of homogeneously distributed parallel cylinders as a model of dendrites of the pyramidal neurons. The estimates are compared with the data known from literature and those obtained in an independent model.     

Combined action of static and alternating magnetic fields on ionic current in aqueous glutamic acid solution

Combined parallel static and alternating magnetic fields cause a rapid change in the ionic current flowing through an aqueous glutamic acid solution when the alternating field frequency is equal to the cyclotron frequency. The current peak is 20-30% of the background direct current. The peak is observed with slow sweep in the alternating magnetic field frequency from 1 Hz-10 Hz. Only one resonance peak in the current is observed in this frequency range. The frequency corresponding to the peak is directly proportional to the static magnetic field. The above effect only arises at very small alternating field amplitude in the range from 0.02 μT-0.08 μT. Bioelectromagnetics 19:41–45, 1998. © 1998 Wiley-Liss, Inc.