Exponential Pulse Research Articles

Long-lived entanglement with pulsed-driven initially entangled qubit pair

The entanglement of different classes of initially entangled qubit pair is investigated in the presence of short laser pulses of rectangular and exponential shapes with either one or both qubits are excited. For the rectangular pulse, the detuning parameter protects the entanglement from degradation and controls its upper and lower bounds. We show that the upper bounds of entanglement decrease if both particles are excited, but the lower bounds are much better if only one particle is excited. The phenomena of entanglement degradation, sudden-death and -birth are shown for small initial time. Long-lived entanglement behavior, but with a variable degree, appears in the presence of rectangular pulse. However, in the case of the exponential pulse one obtains an invariably long-lived entanglement. For the combined case (rectangular + exponential), we show that one can generate a long-lived entanglement with small variable by increasing the strength of the rectangular pulse area and decreasing the Rabi-frequency of the exponential pulse.

Brief Behavioral Response Threshold Level of a Harbor Porpoise (Phocoena phocoena) to an Impulsive Sound

Underwater impulsive sounds may affect the behavior of harbor porpoises within a certain distance from the sound source. To determine the 50% threshold received sound exposure level (SEL) of an impulsive sound that causes a brief behavioral response (a sudden change in swimming speed and/ or direction, similar to a startle response) in harbor porpoises, a male harbor porpoise was exposed once every 3 min to a single impulsive sound: a synthetic exponential pulse with a 5 ms time constant, reproduced by an underwater loudspeaker in a pool (resulting in a signal duration of 10 ms). The sound was transmitted at seven source levels, which were expected to cause brief responses in 10 to 90% of exposures. During each transmission, the harbor porpoise’s behavior was observed, and the presence or absence of a brief response was recorded. A 50% brief response rate was observed at a received SEL of 92 dB re 1 µPa2 s, and a zeroto-peak sound pressure level of 122 dB re 1 µPa. The present study suggests that a single impulsive sound as used in this study does not cause a brief response in harbor porpoises at SELs below around 65 dB re 1 µPa2 s. The duration and spectrum of impulsive sounds change with distance to the sound source, and such changes may affect the responses of wild harbor porpoises.

Pulsed Line Source Response of a Thin Sheet With High-Contrast Dielectric and Conductive Properties—A Time-Domain Analysis

A methodology is presented for analytically modeling the reflection and transmission of line-source excited pulsed electromagnetic fields at a thin, planar layer with high-contrast dielectric and conductive properties. Closed-form analytic time-domain expressions are derived for the field components in a 2-D setting via an extension of the Cagniard-DeHoop method. The response to the power exponential source and the power exponential monocycle pulse were studied using the newly proposed method.

Impact of exponential modulated pulses on stimulation of eye muscles

The use of electric pulses for oculomotor muscles stimulation allows restoring the weakened contractility of muscles and achieving positive therapeutic effect. For myostimulation purposes the paper proposes to use exponential pulses with ascending and descending edges and adjustable basic frequency. The use of a microcontroller in the circuit of portable electrostimulator is relevant. It allows automating the process of affecting the muscle by impulsive complex-modulated current, not exceeding the pain threshold. The microcontroller determines the pain threshold, generates the code of stimulation pulses, not exceeding the threshold, has the function of pulse control and setting by personal computer, transfers the data on electrostimulation parameters to PC for further documentation, analysis and consultations over the Internet. The circuit of the generator of exponential-modulated pulses was developed based on the programmed microcontroller. It provides information about the pulse in the form of numeric codes and transfers it to digital-analog converter. The obtained pulse parameters correspond to the modes of electrostimulation of oculomotor muscles according to standard procedures.

Metal release from stainless steel electrodes of a PEF treatment chamber: Effects of electrical parameters and food composition

Abstract The effects of electrical parameters (field strength E, total specific energy input W T and pulse frequency) and product composition on the release of the main metallic elements (Fe, Cr, Ni and Mn) of stainless steel (type 316L) electrodes of a continuous flow parallel plate PEF chamber into the treatment medium were investigated. Experiments were carried out by subjecting two different buffer solutions (McIlvaine and Trizma-HCl) with the same values of pH (7) and electrical conductivity (σ = 2 mS/cm) to PEF treatments (mono-polar exponential decay pulses, lasting 3.1 μs) at different intensities (E = 12–21–31 kV/cm, W T = 20–60–100 J/mL) and flow rates (2–3–4 L/h). The results showed that, for each field strength applied, the concentration of metallic elements increased upon increasing the total specific energy input. At constant total energy input, it was noticed that the metal concentration decreased upon increasing the field strength applied. These results were mainly attributed to the key role played by the pulse frequency in the charging process of the double layer capacitors at the electrode–solution interface. Moreover, it was shown that the amount of metal released from the electrodes markedly depended on the presence of halides in the composition of the processed product. Industrial relevance Electrochemical reactions at the electrode solution interfaces are unavoidable when typical conditions for PEF processing are applied. For the acceptability of PEF processing as a non-thermal method for liquid food pasteurization, the occurrence of these reactions should be avoided or minimized since they may determine undesired phenomenon of contamination of the food product, electrode-fouling and electrode corrosion. In this paper, electrode corrosion was studied, for the first time, in a continuous flow parallel plate PEF treatment chamber. The present investigation contributes to clarifying the effects of some electrical parameters and food composition on electrode corrosion or release of electrode materials under real PEF treatment conditions.

Electrostatic Discharge Generator Circuit Model and its Simulation

According to the international electrotechnical commission issued IEC61000-4-2 testing standards, through the electrostatic discharge current waveform characteristics analysis and numerical experiment method, using exponential pulse signal and the damped sinusoidal signal to construct a new the ESD current expression. Using Laplace transform, established the ESD system mathematical model. According to the mathematical model, construct four-order circuit model of the ESD system, and the simulation is carried out. The simulation results meet the IEC61000-4-2 standard, and verify the consistency of the ESD current expression, the mathematical model and the circuit model.

Double Second-Order ESD Circuit Model and its Simulation

According to the International Electrotechnical Commission issued IEC61000-4-2 testing standards, through the electrostatic discharge current waveform characteristics analysis and numerical experiment method, using exponential pulse signal and the damped sinusoidal signal to construct a new the ESD current expression. Using Laplace transform, established the ESD system mathematical model. According to the mathematical model, construct double second-order circuit model of the ESD system, and the simulation is carried out. The simulation results meet the IEC61000-4-2 standard, and verify the consistency of the ESD current expression, the mathematical model and the circuit model.

The Analysis of Transient Grounding Resistance of Portable Horizontal Grid Earth Electrodes

Based on current situation of mobile equipments earth devices, a new type of portable horizontal grid earth electrode has been designed. With the impulse ground measurement system, different number of earth electrodes responses to double exponential pulse current have been tested on cement grounds. Impulse waves of voltage and current have been gotten by experiments, and the curve of Transient Grounding Resistance (TGR) can be calculated. The analysis of discharging capacity of horizontal grid earth electrodes in time domain has great significance in the design of mobile equipments earth devices.

Three-dimensional elasticity solution for vibration analysis of composite rectangular parallelepipeds

Abstract A three-dimensional elasticity solution is proposed for determining the free and transient vibrations of composite rectangular parallelepipeds with arbitrary combinations of boundary constraints. The theoretical model is formulated by means of a modified variational principle in conjunction with a multi-segment partitioning procedure based on the three-dimensional linear elasticity theory. The displacement components of each parallelepiped segment are expanded by a triplicate series of orthogonally polynomial functions i.e., the Chebyshev orthogonal polynomials of first and second kind and the Legendre orthogonal polynomials of first kind. To demonstrate the reliability and accuracy of the present methodology, a considerable number of free vibration solutions are given for isotropic and composite rectangular parallelepipeds (including beams, plates, and solids) with different combinations of free, simply-supported, clamped and elastic-supported boundary conditions. The present results are compared with existing experimental and analytical results published in the literature as well as those solutions obtained from finite element analyses. New benchmark solutions are also obtained for composite parallelepipeds. With regard to the transient vibration analyses, composite rectangular parallelepipeds subjected to several time-dependent impulsive loads, including a rectangular pulse, a triangular pulse, a half-sine pulse and an exponential pulse, are investigated. The effects of the fiber orientation, boundary condition as well as the type of impulsive load on the transient responses of composite parallelepipeds are also discussed in detail.

Determination of Threshold Energy Level of Monopolar Defibrillation Pulses Using the Luo–Rudy Cardiomyocyte Model

The effect of defibrillation pulses of different waveforms on the Luo–Rudy cardiomyocyte model in the Cell Electrophysiology Simulation Environment (CESE) was comparatively tested. It was established that a half-sine pulse has the minimum threshold of cell excitation energy, while an exponential pulse exhibits the maximum threshold (22% increase in comparison with the half-sine pulse). The threshold energy of the trapezoidal pulse with sloped rising and falling (waveform of the first phase of bipolar pulse in imPulse AND-P automated external defibrillators at energy levels of 150 and 180 J) was only slightly (4%) higher than the threshold energy of the half-sine pulse. The threshold energy of truncated exponential pulses, which are widely used in modern defibrillators, exceeded the threshold energy of the half-sine pulse by 10-14% (depending on the decline value). These results obtained with the Luo–Rudy model differ significantly from the results obtained using the characteristic energy method with the Blair model.

Nonthermal Pasteurization of Takju using Batch High Voltage Pulsed Electric Fields with Exponential Decay Pulse

Makgeolli, a traditional Korean turbid rice wine, was treated with pulsed electric fields (PEF) for the purpose of a development of a new cold pasteurization processes. Inactivation of yeast in the makgeolli increased with increase in intensity of the electric field strength and treatment time. The initial yeast count of the makgeolli was 2×10 cfu/ ml. A reduction of 2D was obtained at 30 kV/cm and 256 exponential decay pulses at room temperature. The combination of PEF and conventional thermal treatment inactivated the yeast more effectively. Reductions of up to 8D were observed when the makgeolli was treated with PEF of 20 kV/cm and 256 pulses at 50C. The inactivation of the yeast in makgeolli increased with an increase in alcohol content. When the alcohol content of the makgeolli increased to 12%, PEF treatment with 30 kV/cm and 256 pulses resulted in a 4.8D reduction of yeast. No changes in pH, acidity, or the growth of yeast were observed in the PEF treated makgeolli during storage at 4C for 4 weeks.

Study of non-ideal effects in a CT ΣΔ modulator with decaying exponential feedback waveforms

In this article, a detailed theoretical analysis of the impact of finite gain-bandwidth product (GBW) in amplifiers, excess loop delay, and a hysteretic quantiser on a second order, 3-bit, continuous-time sigma-delta (CT ) modulator with decaying exponential feedback pulses has been accomplished. A “short” exponential pulse – namely, an exponential pulse whose time constant is lower than the pulse width – was used in order to improve jitter rejection. An overall noise transfer function (NTF) that includes the effect of the three non-ideal effects was analytically calculated using the modified Z-transform method. The evolution of the NTF poles and zeroes locus in the z-plane is obtained when these effects are taken into account separately or combined. System-level simulations have been also carried out in order to validate the proposed theoretical study. The stability of a modulator with “short” exponential feedback pulses is higher than that of a modulator with rectangular ones when finite GBW or excess loop delay are included. Finally “short” exponential pulses and “narrow” rectangular ones are proved to be equivalent from the stability viewpoint.

Application of TEM horn antenna in radiating NEMP simulator

In order to design a small radiating nuclear electromagnetic pulse simulator with fast rise time, we have investigated the application of TEM horn antenna in this kind of simulator. The TEM horn antenna is excitated by the integral double exponential pulse. Farfield response in time domain is analyzed based on the step response formula which is derived from the equivalent transmission line model of TEM horn antenna. Principle of antenna parameters selection is determined. The results of numerical calculation give a show of the radiation waveform and some problems. Then experiments are implemented and results are compared with the radiation waveforms generated by double exponential pulse excitation. It suggests that the TEM horn antenna can be used as radiating antenna in the NEMP simulator, which can radiate double-exponent-like pulse with the integral double exponential pulse as excitation. Meanwhile, impedance loading can improve farfield waveforms and enhance the low-frequency radiating ability of antenna.

Effect of probe contact pressure on the photoplethysmographic assessment of conduit artery stiffness

Currently, photoplethysmography (PPG) is a frequently studied optical blood pulsation detection technique among biophotonic and biomedical researchers due to the fact that it shows high potential for estimating the arterial stiffness (AS). The extraction of diagnostically useful information requires standardized measurement procedure with good repeatability. However, the effects of a crucially important factor-the optimal contact pressure (CP) of the probe-are often ignored. Also, CP values are not reported to evaluate those effects. It is hypothesized that AS estimated from PPG pulse wave 2nd derivative parameter b/a is strongly inconsistent when recorded at nonoptimal probe CP. Our pilot study confirmed this during in vivo PPG recordings from conduit artery sites on five healthy subjects at variable probe CP (0 to 15 kPa) by using 880 nm reflectance type sensor, force transducer, and PPG alternating current (AC) signal pulse area derived optimal CP criterion. The b/a values, calculated from PPG with variable CP, showed variation >300 percent. In contrast, at the optimal CP, the b/a showed high repeatability (coefficient of variability <5 percent). The effect has been explained with exponential pulse pressure-volume relationship model which indicates the optimal CP range.

椭圆弧型过渡段有界波模拟器

A bounded-wave simulator with ellipse-arc transitional section structure is proposed and designed. The electric field waveform in the simulator is simulated and compared with the tapered transitional section simulator by using the electromagnetic-field simulating software CST. The double exponential pulse with rise time 2 ns, full-width at half-maximum (FWHM) amplitude 25 ns and the step pulse with rise time 2 ns, duration about 80 ns are obtained in the experiment. And a comparison is carried out between the two simulators. The results of simulation and experiment both indicate that the bounded-wave simulator eliminates the interference effectively coming from the discontinuity at the junction of the transitional section and parallel-plate section.

Causal Pulses With Rectangular Spectral Content: A Tool for TD Analysis of UWB Antenna Performance

A class of causal model pulses is constructed by applying a causal modulation to a noncausal function with a rectangular spectral diagram. A particularly suitable modulation is the power exponential pulse, the resulting model pulse having a spectral behavior that is practically flat over a controllable bandwidth, with a steep falloff outside the band. Some of the devised pulses are opportune excitations in ultrawideband antenna models, thus representing effective instruments in their performance analysis, and are appropriate as inputs in electromagnetic time-domain simulation packages.

Kinetics of pulse-induced photoluminescence from a semiconductor quantum dot

Optical methods, which allow the determination of the dominant channels of energy and phase relaxation, are the most universal techniques for the investigation of semiconductor quantum dots. In this paper, we employ the kinetic Pauli equation to develop the first generalized model of the pulse-induced photoluminescence from the lowest-energy eigenstates of a semiconductor quantum dot. Without specifying the shape of the excitation pulse and by assuming that the energy and phase relaxation in the quantum dot may be characterized by a set of phenomenological rates, we derive an expression for the observable photoluminescence cross section, valid for an arbitrary number of the quantum dot's states decaying with the emission of secondary photons. Our treatment allows for thermal transitions occurring with both decrease and increase in energy between all the relevant eigenstates at room or higher temperature. We show that in the general case of N states coupled to each other through a bath, the photoluminescence kinetics from any of them is determined by the sum of N exponential functions, whose exponents are proportional to the respective decay rates. We illustrate the application of the developed model by considering the processes of resonant luminescence and thermalized luminescence from the quantum dot with two radiating eigenstates, and by assuming that the secondary emission is excited with either a Gaussian or exponential pulse. Analytic expressions describing the signals of secondary emission are analyzed, in order to elucidate experimental situations in which the relaxation constants may be reliably extracted from the photoluminescence spectra.

Synergistic combination of physical treatments and carvacrol for Escherichia coli O157:H7 inactivation in apple, mango, orange, and tomato juices

This work has evaluated the bactericidal effect of carvacrol in combination with mild heat or pulsed electric fields (PEF) treatments to describe the treatment conditions needed to inactivate 5 log10 cycles of Escherichia coli O157:H7 cells suspended in apple, mango, orange, and tomato juices. Strong synergistic lethal effects were shown using mild heat (54 °C and 60 °C) or PEF (30 kV/cm) treatments combined with 1.3 mM of carvacrol. In relation to combinations of heat and carvacrol, the time to inactivate 5 log10 cycles of E. coli O157:H7 decreased, on average, by a 75% in apple, mango and tomato juice, and by a 84% in orange juice, or alternatively treatment temperature might be decreased up to 5 °C. With regards to PEF, while 50 exponential decay pulses at 30 kV/cm caused less than 1 log10 cell cycle reduction, the combination with carvacrol caused the inactivation of 5 log10 cell cycles by the application of 20–50 pulses as a function of the juice. The reduction of microbial contamination to 2 × 104 cells/ml allowed us to diminish the addition of carvacrol from 1.3 to the range of 0.21–0.58 mM while maintaining the synergistic effect in combination with heat or PEF. The synergism observed offers a great potential to improve traditional heat treatments by reducing treatment intensity and, thus, undesirable effects on food quality, as well as novel PEF treatments by increasing microbial inactivation in acid foods.

Changes of cell electrical parameters induced by electroporation. A dielectrophoresis study

Dielectrophoresis was employed to distinguish the electroporated from non-electroporated cells. It was found that the electric field frequency at which cells change the direction of their movement (the crossover frequency fCO) is higher when cells are electroporated. The contribution to the cell dielectrophoretic behavior of four electric and geometrical cell parameters was analyzed using a single shell model. fCO measurements were performed in media with conductivities of 0.001–0.09S/m, on B16F10 cells which were electroporated in a Mannitol solution (0.001S/m), using rectangular or exponential pulses. The control cells' fCO was found in a domain of 2 to 105kHz, while the electroporated cells' fCO was in a domain of 5 to 350kHz, depending on the external media conductivities. At exterior conductivities above ~0.02S/m, fCO of electroporated cells became significantly higher compared to controls. Even though the possible contribution of membrane permittivity to explain the observed fCO shift toward higher values cannot be excluded, the computations highlight the fact that the variation of cytosol conductivity might be the major contributor to the dielectrophoretic behavior change. Our experimental observations can be described by considering a linear dependence of electroporated cells' cytosol conductivity against external conductivity.

Implementation of a truncated cusp filter for real-time digital pulse processing in nuclear spectrometry

In this work the transfer function for a truncated cusp infinite impulse response (IIR) filter has been derived. The truncated cusp filter, when given an exponential pulse in the presence of white noise, outputs a truncated cusp pulse which is optimum pulse shape under the constraint of finite pulse duration. However it features a pole outside of the unit-circle and is therefore inherently unstable. To overcome this instability a switching algorithm with two alternating poles has been applied. The filter has been simulated with MATLAB and Simulink and implemented on-board a FPGA. The pulses from a waveform generator and silicon drift detector (SDD) have been also processed by the filter and results compared with theory. We find that the simulation and measurements were in agreement and show that energy resolution due to electronic noise can be improved by up to 7.5% using a truncated cusp instead of triangular filter. An improvement of up to 2.8% in overall energy resolution was measured with a typical X-ray spectrometer based on a SDD detector with a nominal energy resolution of 150eV at energies of MnKα line.