External Electrical Source Research Articles

A time-varying hyperchaotic system and its realization in circuit

A hyperchaotic system is often used to generate secure keys or carrier wave for secure communication and the realistic hyperchaotic circuit often is made of capacitor, nonlinear resistor unit and induction coil. Parameters are often fixed in these hyperchaotic circuits and the hyperchaotic property of the system can be estimated by using a scheme of synchronization and time series analysis. In this paper, a time-varying hyperchaotic system is proposed by introducing changeable electric power source into the circuit; the changeable electric power source is combined with induction coil or capacitor in series to generate changeable output signals to excite the system. The diagrams of improved circuit are illustrated and critical parameters in experimental circuits are presented; the Lyapunov exponent spectrum vs. external applied electric power source is calculated. It is confirmed that the improved circuit always holds two positive Lyapunov exponents when the external electric power source works, and the chaotic attractors are much too different from the original one; thus, a more changeable hyperchaotic system is constructed in experiment.

A Comparative Study of Sterility Levels in Continuous Ambulatory Peritoneal Dialysis System

Peritonitis remains a serious risk associated with continuous ambulatory peritoneal dialysis (CAPD), although better patient education programs and such technological advances as improved automated connecting devices have greatly decreased its incidence over the past 20 years. The automated devices have a good resistance to contamination, but they rely on an external electrical power source and are not easily portable. There has, therefore, been a need for a highly sterile nonelectric manual connecting device to complement the automated devices already in use. Such a manual device has recently been developed. We compared the level of sterility after touch contamination in this new device with levels in 2 other connecting devices: a conventional device with a manual cap (JMS Co. Ltd., Hiroshima, Japan), and a powered total containment device (JMS Co. Ltd.). Five bacteria frequently causing CAPD-related peritonitis (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans) were separately applied to the tip of each connecting device, and peritoneal washing fluid was injected as in a routine exchange. We used a membrane filter method to determine whether the route had been contaminated by the washing fluid. In the conventional device with a manual cap, 3 to 4 colony-forming units (CFUs) of S. aureus were detected in 2 of 10 drainage samples, 8 CFUs of E. coli in 1 of 10 drainage samples, and 1 CFU of E. coli in the injection fluid. In contrast, no contamination was detected in the automated connecting device or the new manual cap device. This study confirmed that the new device has a risk of touch contamination lower than that of the conventional manual cap device and equal to that of the automated device. Being easily portable and not reliant on an external power source, the new device should be useful in various situations.

Safety, efficacy, and quality control of a photoelectric dye-based retinal prosthesis (Okayama University-type retinal prosthesis) as a medical device

Patients with retinitis pigmentosa lose photoreceptor cells as a result of genetic abnormalities and hence become blind. Neurons such as bipolar cells and ganglion cells remain alive even in the retina of these patients, and ganglion cells send axons to the brain as the optic nerve. The basic concept of retinal prostheses is to replace dead photoreceptor cells with artificial devices to stimulate the remaining neurons with electric currents or potentials. Photodiode arrays and digital camera-type electrode arrays are the two main approaches for retinal prostheses to stimulate retinal neurons, but these arrays have the problems of poor biocompatibility, low sensitivity, and low output of electric currents, and hence have a requirement for external electric sources (batteries). To overcome these problems, we are developing photoelectric dye-based retinal prostheses that absorb light and convert photon energy to generate electric potentials. The prototype, using a photoelectric dye-coupled polyethylene film, could induce intracellular calcium elevation in photoreceptor-lacking embryonic retinal tissues and cultured retinal neurons. The subretinal implantation of the prototype in the eyes of Royal College of Surgeons (RCS) rats led to vision recovery as proved by a behavior test. The photoelectric dye that was chosen for the prototype did not exhibit any cytotoxicity. The surface potentials of the photoelectric dye-coupled film showed a rapid on-and-off response to illumination with a threshold for light intensity as measured by a Kelvin probe system. Photoelectric dye-based retinal prostheses are thin and soft, and therefore, a sheet of the film of large size, corresponding to a large visual field, could be inserted into the vitreous and then to the subretinal space through a small opening by rolling up the film. Clinical studies of photoelectric dye-based retinal prostheses in patients with retinitis pigmentosa who lose sight will be planned after the manufacturing control and the quality control had been established for the medical device.

Continuous Disreefing Method for Parachute Opening

Although round parachutes have been used for airdrop for over 60 years, damage to canopy fabric and suspension lines still occurs during parachute opening due to the rapid canopy opening and the associated high opening force. Continuous disreefing of round parachutes to slow down the opening and decrease the peak opening force has been discussed in the literature, but no viable continuous disreefing method has ever been developed. In this paper, we present a practical, effective, and low-cost continuous disreefing method that does not use any external electrical or power source, only the opening force and the weight of the payload. The method was successfully demonstrated in a full-scale test from an aircraft using a 10.7-m (35-ft) diameter round parachute. The kinetic energy of the payload at parachute deployment of that test was 11 times higher than that of the standard deployment that the parachute is designed for. In spite of the severe deployment condition, no damage to the parachute was observed after ground impact.

Manifest spin 2 duality with electric and magnetic sources

We extend the formulation of spin 2 fields on Minkowski space which makes the action manifestly invariant under duality rotations to the case of interactions with external electric and magnetic sources by adding suitable potentials for the longitudinal and trace parts. In this framework, the string singularity of the linearized Taub-NUT solution is resolved into a Coulomb-like solution. Suitable surface charges to measure energy-momentum and angular momentum of both electric and magnetic type are constructed.

A system of two piezoelectric transducers and a storage circuit for wireless energy transmission through a thin metal wall

A system to wirelessly convey electric energy through a thin metal wall is proposed in the paper, where 2 piezoelectric transducers are used to realize energy transformation between electric and mechanical, and a rechargeable battery is employed to store the transmitted energy. To integrate them as a whole, an interface of a modulating circuit is applied between the transducer system and the storage battery. In addition, a synchronized switch harvesting on inductor in parallel with the transducer system is introduced to artificially extend the closed interval of the modulating circuit. The process of transmitting energy is computed, and the performance of the transducer system is optimized in detail for a prescribed external electric source. The results obtained are useful for understanding and designing wireless energy supply systems.

Constructal view of electrokinetic transfer through porous media

This paper proposes to apply constructal theory to the optimization of ionic transfer by electrokinetics through porous media. By using an external electrical source (potential difference, or current), the ions from the pore solution of a saturated porous medium can be transferred (channelled) in an accelerated fashion, while the direction of their transport can be controlled by the electrodes position and polarity. The constructal law of maximization of flow access is used to optimize the electrokinetic process in two ways: (i) in time and (ii) in space. In (i), the ionic transport is shown to be driven by a diffusive mechanism before convection due to electrical effects which dominate the transfer. Constructal theory explains how the combination of the two mechanisms corresponds to an optimization of transport in time. In an application to ionic decontamination, the optimal location of the electrodes is determined from the constructal law by setting the diffusive ionic flow rate equal to the ionic flow rate due to electrical effects.

Parametric Power Spectral Density Analysis of Noise from Instrumentation in MALDI TOF Mass Spectrometry

Noise in mass spectrometry can interfere with identification of the biochemical substances in the sample. For example, the electric motors and circuits inside the mass spectrometer or in nearby equipment generate random noise that may distort the true shape of mass spectra. This paper presents a stochastic signal processing approach to analyzing noise from electrical noise sources (i.e., noise from instrumentation) in MALDI TOF mass spectrometry. Noise from instrumentation was hypothesized to be a mixture of thermal noise, 1/f noise, and electric or magnetic interference in the instrument. Parametric power spectral density estimation was conducted to derive the power distribution of noise from instrumentation with respect to frequencies. As expected, the experimental results show that noise from instrumentation contains 1/f noise and prominent periodic components in addition to thermal noise. These periodic components imply that the mass spectrometers used in this study may not be completely shielded from the internal or external electrical noise sources. However, according to a simulation study of human plasma mass spectra, noise from instrumentation does not seem to affect mass spectra significantly. In conclusion, analysis of noise from instrumentation using stochastic signal processing here provides an intuitive perspective on how to quantify noise in mass spectrometry through spectral modeling.

A PARAMETRIC STUDY AND PERFORMANCE EVALUATION OF DC ELECTROMAGNETIC PUMPS WITH BEMC-1 CODE

Electromagnetic pumps are used to control liquid metal fluid flow in cooling loops. The principle of operation of an electromagnetic pump is based on Lorentz’s force. This is obtained by interaction of the magnetic field and the electrical current, imposed and adjusted by independent external electric power sources. In this work are presented the continuous current electromagnetic pumps, their basic equations and the BEMC-1 code, developed for design and performance evaluation of a DC electromagnetic pump. The main objective of this paper is a parametric study for magnetic induction, static pressure, fluid flow and performance evaluation of the pump. The theoretical results are compared with the experimental data to get adjust factors to be used in the BEMC-1 code. In this way the BEMC-1 code can be validated and used in the evaluations and projects of DC electromagnetic pumps.

On source radiation in an isotropic chiral medium

Radiation of external electric and magnetic sources in an isotropic chiral medium is studied by means of decomposition of the electromagnetic field into wave fields of circular polarization and introduction of the corresponding combined sources. The elementary-source fields are calculated using the Green’s function. The wave-field energy flux is discussed.

A Feasibility Study of an Auxiliary Power Unit Based on a PEM Fuel Cell for On-Board Applications

Proton exchange membrane (PEM) fuel cells show characteristics of high power density, low operating temperature, and fast start-up capability, which make them potentially suitable to replace conventional power sources (e.g., internal combustion engines) as auxiliary power units (APU) for on-board applications. This paper presents a methodology for a preliminary investigation on either sizing and operating management of the main components of an on-board power system composed by: (i) PEM fuel cell, (ii) hydrogen storage subsystem, (iii) battery, (iv) grid interface for the connection to an external electrical power source when available, and (v) electrical appliances and auxiliaries installed on the vehicle. A model able to reproduce the typical profiles of electric power requests of on-board appliances and auxiliaries has been implemented in a computer program. The proposed methodology helps also to define the sizing of the various system components and to identify the fuel cell operating sequence, on the basis of the above mentioned load profiles.

Modeling electrostatic-photochemistry seismoionospheric coupling in the presence of external currents

In this paper we propose a new 3D model for the generation of electrostatic field in the lithosphere–atmosphere–ionosphere (LAI) system by two external electric sources; namely lithospheric electric field or external current placed near the ground and (simultaneously) in the mesosphere/lower ionosphere. Then we present the results of numerical calculations. We discuss an influence of the generated electric field on the photochemical and ionospheric characteristics in the altitude range of the lower ionosphere. Appearance of strong electric field and strong change of the ionospheric characteristics (such as electron temperature and concentration) in the lower ionosphere is predicted in the presence of external electric sources in the lower atmosphere and mesosphere. An influence of the excited electric field on the losses of VLF electromagnetic waves propagating in the “Earth–ionosphere” waveguide is considered qualitatively, and rough estimation of this phenomenon is carried out. We prove a possibility of “blooming” of the ionosphere for VLF waves, if in the presence of mesospheric external current, an additional external (seismogenic) electric source appears in the lower atmosphere.

Blackout of 2003: Public Health Effects and Emergency Response

We examined the public health effects of the Northeast blackout of August 2003 and the emergency response to the blackout by the New York City Department of Health and Mental Hygiene (DOHMH). We reviewed departmental documents from the DOHMH Emergency Operations Center and surveyed DOHMH employees to identify deficiencies in the response and elicit suggestions for improvement. DOHMH deployed its all-hazards, scalable public health Incident Management System to respond to several impacts: (1) failure of multiple hospital emergency generators; (2) patients dependent on electrically powered equipment; (3) loss of electronic data input to the DOHMH syndromic surveillance system from hospital emergency departments; (4) potential for vaccine spoilage due to loss of refrigeration; (5) beach contamination with untreated sewage; (6) heat-related health effects and increase of foodborne disease; and (7) potential for an increased rodent population as a result of increased amounts of discarded perishables. Areas identified for improvement included communications during the event, DOHMH dependence on an external source of electricity, facility management during the response, and lack of readily available and appropriate emergency supplies.

Thin film NiTi microthermostat array

An autonomous flow restricting microthermostat array was successfully designed and fabricated using thin film nickel–titanium (NiTi) shape memory alloy (SMA). The device relies on changes in the environmental fluid temperature for closing without external electric sources. The array of 88 microthermostats was tested at pressures ranging from 6.9 to 34.5 kPa and water temperatures of room temperature and 80 °C. At 34.5 kPa and room temperature, the flow rate was 722.8 ml/min. As the temperature of the water increased to 80 °C, the flow rate was reduced by 90% depending on the pressure. Finite element predictions are in relatively good agreement with the measured flow rates.

Bi4Cu0.2V1.8 O11–δ based membrane electrochemical reactors for propane oxidation at moderate temperaturesbased membrane electrochemical reactors for propane oxidation at moderate temperatures

Bi4Cu0.2V1.8O11–δ membrane material was synthesized by following the solid-state method. The oxygen permeation flux at 673 K was found to be 0.5 ml/cm2 by the use of an external electric power source. The oxidation of propane was selected as the probe reaction using the Bi4Cu0.2V1.8O11–δ electrochemical membrane reactor. It was found that such electrochemical membrane reactors could have potential application in the area of alkanes selective oxidation at moderate temperatures.

Non-Abelian color dielectric - towards the effective model of the low energy QCD

Lattice motivated triplet color scalar field theory is analyzed. We consider non-minimal as well as covariant derivative coupling with SU(2) gauge fields. Field configurations generated by external electric sources are presented. Moreover non-Abelian magnetic monopoles are found. Dependence on the spatial coordinates in the obtained solutions is identical as in the usual Abelian case. We show also that after a decomposition of the fields a modified Faddeev-Niemi action can be obtained. It contains explicit O(3) symmetry breaking term parameterized by the condensate of an isoscalar field. Due to that Goldstone bosons observed in the original Faddeev-Niemi model are removed.

Hybrid Nanotransport System by Biomolecular Linear Motors

We have demonstrated a novel micro/nanotransport system using biomolecular motors driven by adenosine triphosphate (ATP). For the driving mechanism, microtubule-kinesin system, which is one of the linear biomolecular motor systems was investigated. ATP dissolved in an aqueous condition is hydrolyzed to adenosine diphosphate (ADP) to energize the bionanoactuators in this mechanism. This means the system does not require an external electrical or mechanical energy source. Therefore, a purely chemical system which is similar to the in vivo transport will be realized. This paper reports some fundamental studies to integrate biomaterials and MEMS. The microtubules, or rail molecules, were patterned on a glass substrate with poly(dimethyl siloxane) (PDMS) using a regular soft lithography technique. Microbeads (320 nm in diameter) and a micromachined structure (2/spl times/3 /spl mu/m, 2 /spl mu/m in thickness) coated with kinesin molecules were transported along the microtubules at an average speed of 476/spl plusmn/56 and 308 nm/s, respectively. While ATP injection activated the transport system we have also managed to provide repetitive on/off control using hexokinase as an inhibitor. For the minimum response time in the repetitive control, the optimized concentration for ATP was 10/sup 2/ /spl mu/M and 10/sup 3/ U/L for hexokinase.

On the Equivalence of Sources of Electromagnetic Fields Excited in an Isotropic Chiral Medium

The possibilities of exciting equal electromagnetic fields in an isotropic chiral medium by external monochromatic electric and magnetic sources are discussed. The possibility of exciting fields that differ in a specified way is also considered. The equivalence relationships for currents and charges are determined.

Electrically induced concentration fluctuations in Escherichia coli suspensions

Biological cells are permanently exposed to electric fields by self generated or external electrical sources. It is important to understand whether and how very weak electric fields influence the electric properties of biological cells. In the present study, we demonstrate by the electro-optic method the induced concentration fluctuations in suspensions of Escherichia coli cells subjected to alternating electric fields of low intensity (20–240 V cm−1) and low frequency (0.2–100 Hz). A frequency window is formed where concentration fluctuations are already significant, but the sample is still stable enough under the action of the field and permits the application of longer pulses. Our assumption is that, in this range, conditions are created for the accumulation of considerable induced local density variations and the latter could be responsible for the appearance of instability and electroporation of E. coli cells at similar conditions.

Life cycle analysis of hydrogen fuel: a methodology for a strategic approach of decision making

Two examples are considered in this work in order to show possible settings for decision making in the strategic field of energy: transport vehicles and wastewater treatment plant that are powered by a fuel cell. The environmental impact, measured by evaluating hydrogen life cycle as fuel, varies depending on the source of hydrogen, the process, and the complexity of the productive chain. Nowadays, starting from this point of view, it is possible to get a lot more benefits when hydrogen is directly produced in situ from renewable sources of energy and it is used to make a fuel cell work, as an alternative to an external electric energy source. Future work must be focalized to decrease technological development gap between fuel cells and clean hydrogen extraction, before use of fuel cell would be massive.