Zeitschriftenartikel zum Thema „Transient differential characteristics“

Research on the wide-band modelling method of the grounding grid and the analysis of the electromagnetic transients on the grounding grid has significant practical meaning on the engineering problems, e.g. overvoltage protection, insulation coordination and electromagnetic interference and the increasing levels of capacity in the power and communication systems. This paper presents strategies which establish the equivalent circuit for computing the transient performance of grounding grid base on fractional order differential theory, which takes into account the fractional frequency characteristics of soil permittivity. In order to validate the presented method, an example is considered and the transient responses are compared with the results obtained by the method of moments.

Based on the theory of hydraulic transients and the method of characteristics (MOC), a mathematic model of the differential surge tank with pressure-reduction orifices (PROs) and overflow weirs for transient calculation is proposed. The numerical model of hydraulic transients is established using the data of a practical hydropower station; and the probable transients are simulated. The results show that successive load rejection is critical for calculating the maximum pressure in spiral case and the maximum rotating speed of runner when the bifurcated pipe is converging under the surge tank in a diversion-type hydropower station; the pressure difference between two sides of breast wall is large during transient conditions, and it would be more serious when simultaneous load rejections happen after load acceptance; the reasonable arrangement of PROs on breast wall can effectively decrease the pressure difference.

In this paper, based on the choice of voltage level 500kV for large transformer differential protection of maloperation accident actually as an example, discusses how to improve the reliability and the transformer differential protection with the relationship between pressure test. Analysis found that in order to avoid the excitation transient exciting current transformer differential protection sparked the misoperation, on-site technical personnel in the differential protection setting calculation process, make use of data in conformity with the relevant parameters, rules and standards, familiar with differential protection, also need to understand the characteristics of transformer excitation transient exciting current high-voltage tests, the influence of characteristic more should fully exert the modern PC wave record device, instrument function can improve the actual effect of transformer differential protection. This factory for transformer differential protection for setting, protection greatly improves the reliability. This experience is worth popularizing.

This paper presents a non-linear math model on ship power station and numerical simulation, aiming at describing dynamic characteristic of electric propulsion ship shipboard power system precisely. Non-linear differential algebraic equations are given by differential equation modeling theory, concerning with diesel engine speed characteristics, electromagnetic and electrical transient characteristics (Φd, Φq, Ed", Eq", E'q, ω, δ as status variables) of synchronous generator and voltage characteristics of excitation system. Then the non-linear equations are solved by implicit trapezoidal integration method, finally dynamic curves of status variables such as voltage, speed of rotor, three phase current of stator and so on are drawn based on simulation program written by C#.NET. Simulation results demonstrate that the non-linear math model proposed by this paper is reasonable, and the results are theory foundation of transient stability on ship integrated power system for further research.

On the basis of explaining the basis theory on transient electromagnetic sounding, wavelet theory and imaging principle of differential conductivity for transient electromagnetic sounding data, this thesis proposes rapid imaging technology of electromagnetic sounding based on wavelet analysis, describes the characteristics of noises under wavelet decomposition, and employs wavelet packet analysis to eliminate noise of signals, at last, introduces wavelet analysis into transient electromagnetic sounding on the platform of MATLAB wavelet function toolbox and deals with differential conductivity imaging processing steps of transient electromagnetic sounding.

When expressed in the form of characteristic differential equations, the laws governing propagation of linear one-dimensional waves through heterogeneous media show that the only properties of significance are the sound speed c and the acoustic impedance ρc, either of which may vary spatially. The former occurs in the differential equations governing the (curved) characteristics, while the latter appears in the differential equations governing the evolution of particle velocity and stress along the characteristics. The present study employs an inherently stable finite difference representation of the characteristic equations, in which the spatial grid is obtained by evaluating the intersections in space-time of constant time lines with comparable increments of the characteristic variables. The numerical procedure is used to follow the propagation of a single-lobe sine pulse in cases where only ρ or c fluctuates spatially about a mean value while the other property is constant, and compares those results to the case were both material properties vary. Nonconstancy of c is shown to cause temporal shifts in waveforms, while spatial variation of ρc causes attenuation and distortion of the waveform.

Very few stochastic systems are known to have closed-form transient solutions. In this article we consider an immigration birth and death population process with total catastrophes and study its transient as well as equilibrium behavior. We obtain closed-form solutions for the equilibrium distribution as well as the closed-form transient probability distribution at any time t ≥ 0. Our approach involves solving ordinary and partial differential equations, and the method of characteristics is used in solving partial differential equations.

Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease. Congenital contractures are a heterogeneous group of various diseases with different etiology and pathogenesis. The article describes a family case of hereditary sensory-motor polyneuropathy caused by a mutation with 943GA (p Arg315Trp) in the TRPV4 gene (transient receptor potential vanilloid cation channel 4, NM_021625. 4). The article presents the clinical and neurological characteristics of the patient, the results of genetic and neurophysiological examination of the patient and his parents, differential diagnosis of this disease.

Transient saturation characteristics of TPY-type current transformer have great impact on the right action of line differential protection. This paper proposes an analytical method of line differential protection under current transformer saturation by utilizing current transformer model and test methods. The true current value of primary side can be obtained by our proposed method and therefore it yields correct assessment of line operating status. This method has high reliability applying to practical engineering examples of differential protection.

A simplified model of magnetic saturation characteristics is proposed in this paper for transient calculation of the electric networks including magnetizing branches. The model represents the magnetic saturation characteristics by the continuous function instead of the piecewise linear approximation. Based on the proposed model, an efficient transient algorithm is developed. The nonlinear differential equations describing the transient behavior of the magnetizing branches are solved by the semiexplicit Runge-Kutta method, in which noniterative computations are involved. The transient calculation for the remaining linear network is performed in terms of the solution to the magnetizing branches. A comparison is made between calculated and experimental results to confirm the validity of the algorithm.

This paper is an extension of an earlier work in which the present authors demonstrated the application of the differential quadrature method (DQM) to the steady-state analysis of incompressible and compressible lubrication problems. In the present work, the DQM is applied to the transient-state analysis of compressible lubrication problems. For this purpose, the analysis of gas-lubricated plain journal bearings under the conditions of nonuniform journal rotation is considered. The computed results from the solutions of the reference problem included in the paper provide a comparison of the convergence characteristics and computational efficiency of the differential quadrature and finite element methods.

We present a numerical code for calculating transient flow in plastic pipes, especially in the polyethylene pipe, to analysis effect of material viscoelasticity on water hammer phenomena. The set partial differential equations to be solved is obtained using conservation laws and behavior for the fluid and the pipe wall, associated with constitutive equations of the two media, and relationships compatibility of interfaces on velocities and stresses. A global digital processing is achieved using the method of characteristics. The results obtained are in good agreement with those found in the literature.

1. Baclofen, a gamma-aminobutyric acid (GABA)/B receptor agonist, was bath applied while recording the responses of second- and third-order neurons in the mudpuppy retina. Baclofen receptors were largely restricted to amacrine and ganglion cells. 2. Baclofen hyperpolarized the membrane potential of many, but not all, third-order neurons. This involved an increase in input conductance, probably associated with an opening of potassium channels. 3. The maximal increase in input conductance associated with the activation of GABA/B receptors was approximately one-third of that produced by activation of GABA/A receptors. 4. Baclofen suppressed sustained responses but enhanced transient responses. The net effect was that responses throughout the inner retina became more transient in the presence of baclofen. 5. In sustained cells baclofen not only suppressed the sustained responses but also revealed large transient responses. Thus baclofen converted the light responses of these cells from sustained to transient. This suggests that sustained cells receive significant transient excitation which is normally masked by the sustained inputs. 6. The role of the GABA/B receptor in controlling response characteristics and information content of amacrine and ganglion cells is discussed.

In this work, the problem of improving the quality of controlling the diesel engine crankshaft speed is considered. The principles that govern the control of this parameter in internal combustion engines are described. The advantages of the proportional-integral-differential (PID) control principle are shown. Calculations of the influence of the PID controller structure on the dynamic characteristics of the diesel engine rotational speed automatic control system are performed. The transient processes of acceleration–inhibition and load-dropping are investigated using a KamAZ-740 engine of a 100 kW diesel generator. Transient processes are achieved for different values of the proportional, integral and differential components of the PID control law. The influence of these coefficients on the quality indicators of the regulatory process such as the duration of the transient process and overshoot is evaluated.

The time varying currents and voltages resulting from the sudden application of sources usually due to switching are transients. An RLC circuit is an electrical circuit consisting of a resistor, an inductor, and a capacitor, connected in series or in parallel. The transient response is dependent on the value of the different characteristics of damping factor (i.e., over damped, critically damped and under damped). We have computed the numerical solutions of second order differential equation with initial value problem (IVP) by using Explicit (Forward) Euler method, Third order Runge-Kutta (RK3) methods and Butchers fifth order Runge-Kutta (BRK5). The observation compares this numerical solution of ODEs obtained by above-mentioned methods among them with necessary visualization and analysis of the error. These iterative methods will be extended and implement to analyze the transient analysis of an RLC circuit. We have examined the superiority of those methods over one another. The Butchers fifth order Runge-Kutta (BRK5) method is found to be the best numerical technique to solve the transient analysis due to its high accuracy of approximations. Moreover, we consider the possibility of discussion and analyze above mentioned iterative methods in the cases of different characteristics of damping factor. BIBECHANA 18 (2) (2021) 9-17

Abstract Rheological measurements in response to transient shear rate exhibit coupling effects between mechanical characteristics of rheometer and unsteady (thixotropic and viscoelastic) properties of fluid. This coupling is observed if the characteristic times of the latter lie in the range of those associated to mechanical properties of the apparatus. Damped oscillations observed in the stress relaxation curves obtained with some standard oils submitted to stress steps are an example of this type of anomalous responses. This work introduces a new method of standardization for a low shear rate rheometer (Contraves LS40) under unsteady flow conditions. This “standardization under transient conditions” is developed in order to obtain a correct interpretation of unsteady measurements performed on elastic and thixotropic fluids, hence to permit modelling of the latter. A second order differential operator is supposed capable to describe the fluid-rheometer coupling. A series of measurements on standard silicone oils, which include electromechanical characteristics of the instrument, allow us to determine the parameters involved in this operator. Then, a preliminary test of this method is performed on a typical system (Red Blood Cell suspension with Dextran) which presents viscoelastic and thixotropic behavior.

The introduction gives the morphological characteristics of myocardial hypertrophy, hy-pertrophic cardiomyopathy, as a subject of differential diagnosis. In the description of clinical cases of diagnostics of transient myocardial hypertrophy by echocardiographic method, the aim was to show the possibilities of such diagnostics in newborns

A numerical method based on the Rayleigh-Ritz method has been presented for the forced vibration of open cylindrical shells. The equations are derived from the three-dimensional strain-displacement relations in the cylindrical coordinate system. The middle surface of the shell represents the geometry, which is defined by an angle that subtends the curved edges, the length, and the thickness. The displacement fields are generated with a predefined set of grid points on the middle surface using considerably high-order polynomials. Each grid point has five degrees of freedom, viz., three translational components along the cylindrical coordinates and two rotational components of the normal to the middle surface. Then the strain and kinetic energy expressions are obtained in terms of these displacement fields. The differential equation governing the vibration characteristics of the shell is expressed in terms of the mass, stiffness, and the load consistent with the prescribed displacement fields. The transient response of the shell with and without damping is sought by transforming the equation of motion to the state-space model and then the state-space differential equations are solved using the Runge-Kutta algorithm.

In this work the application of delay differential equations to the modelling of mass transport in porous media, where the convective transport of mass, is presented and discussed. The differences and advantages when compared with the Dispersion Model are highlighted. Using simplified models of the local structure of a porous media, in particular a network model made up by combining two different types of network elements, channels and chambers, the mass transport under transient conditions is described and related to the local geometrical characteristics. The delay differential equations system that describe the flow, arise from the combination of the mass balance equations for both the network elements, and after taking into account their flow characteristics. The solution is obtained using a time marching method, and the results show that the model is capable of describing the qualitative behaviour observed experimentally, allowing the analysis of the influence of the local geometrical and flow field characteristics on the mass transport.

A solution technique based on implicit numerical integration combined with a condensation technique is presented to predict the transient response of large flexible rotor systems with nonlinear characteristics. The analysis directly tackles the nonlinear second-order differential equations which describe the system motion. The condensation technique can lead to a reduced model in which only the coordinates associated with nonlinear components of the system are considered. Thus, a substantial reduction of computation can be expected if the nonlinear components of system are sparse. A flexible rotor system is studied to illustrate the merits of the procedures. The results show that, if the system is of a small number of coordinates associated with nonlinear components compared to that of entire system degrees-of-freedom, the computational time can be considerably reduced using this technique.

Transient propagation of a one-dimensional dilatational wave in a harmonically heterogeneous elastic solid is studied by several techniques. A regular perturbation analysis in terms of the characteristics of the differential equation shows that initiation of a temporally harmonic excitation that generates a signal whose wavelength is twice the periodicity of the heterogeneity leads to secularity in the first approximation. The frequency at which this situation occurs matches the frequency at which Floquet theory predicts that steady-state waves may be unstable. A finite difference algorithm based on integrating along the characteristics is developed and implemented to obtain a numerical solution. In the critical case, backscattering of the wave from the heterogeneity results in a mixture of propagating and standing wave features. However, rather than being unstable, the heterogeneity in this condition is shown to result in maximum interference with forward propagation. A comparable analysis for a step excitation on the boundary provides additional insight into the underlying propagation phenomena.

Physiological studies on functionally identified myenteric neurons are scarce because of technical limitations. We combined retrograde labeling, cell culturing, and fluorescent intracellular Ca2+ concentration ([Ca2+]i) signaling to study excitatory neurotransmitter responsiveness of myenteric motor neurons. 1,1-Didodecyl-3,3,3′,3′-tetramethyl indocarbocyanine (DiI) was used to label circular muscle motor neurons of the guinea pig ileum. DiI-labeled neurons were easily detectable in cultures prepared from these segments. The excitatory neurotransmitters (10−5 M) acetylcholine, substance P, and serotonin induced a transient rise in [Ca2+]i in subsets of DiI-labeled neurons (66.7, 56.5, and 84.3%, respectively). DiI-labeled motor neurons were either inhibitory (23.8%) or excitatory (76.2%) as assessed by staining for nitric oxide synthase or choline acetyltransferase. Compared with excitatory motor neurons, significantly fewer inhibitory neurons in culture responded to acetylcholine (0 vs. 69%) and substance P (12.5 vs. 69.2%). We conclude that combining retrograde labeling and Ca2+ imaging allows identification of differential receptor expression in functionally identified neurons in culture.

The properties of Ca2+ channels in cultured rat pituitary gonadotrophs were analyzed by the patch-clamp technique. The inward Ca2+ currents, recorded in the presence of 5.2 mM Ca2+ or Ba2+, included a fast, transient component with activation-inactivation kinetics and a delayed component with slower activation. The midpoint of the activation curve lay at -30 mV for the transient component and at -12 mV for the delayed component. At the midpoint, changes in potential of 9.5 and 13 mV induced an e-fold change in the activation of the transient and delayed components, respectively. The rate of inactivation of the first component was strongly voltage dependent. At -43 mV, a 7.4-mV change in potential induced an e-fold change in the fraction of Ca2+ channels available to conduct Ca2+ current. During long-lasting (100-200 ms) low-frequency depolarizing voltage-clamp pulses, the size of the delayed component of the Ca2+ current remained constant. The differential effects of membrane potential on inactivation and the different time constants for activation of the two components of the Ca2+ conductance indicate the presence of two types of Ca2+ channels in the membrane of the gonadotroph: the rapidly inactivating current appears to be attributable to a T-type channel, and the noninactivating current corresponds to the L-type channel described in many other cell types.

Through brief analysis of characteristics of conventional control, a new type of multi-mode intelligent control algorithm based on error information is put forward. The algorithm consists of proportional acceleration control for rapidity of transient response, differential deceleration control for stationarity of transient response and steady state excitation control for accuracy of steady response. The control algorithm is applied to time-delay process, compared with other algorithms. Simulation results show its good performance with MATLAB language. The algorithm has simple structure, good generality and easy adjustment.

Abstract This paper presents numerical and experimental investigations of the combined effect on pressure transients of air pockets and homogenous water–air bubble mixtures. An air pocket can accumulate at a high point of a pipeline along the control section located at the transition between pipes with sub- and supercritical slope, forcing open channel flow conditions underneath the pocket that ends in a hydraulic jump at the downward sloping pipe. The turbulence action at the jump generates small air bubbles that are entrained and transported along the pipe producing a two-component bubbly flow within the continuous liquid phase. A numerical model is developed, combining the explicit–implicit scheme proposed by McGuire and Morris and the method of characteristics for solving the quasi-linear hyperbolic partial differential equations for transient two-phase flow expressed in conservation form. To verify the proposed model, an experimental apparatus made of PVC was used to carry out hydraulic transient experiments. Tests were conducted in a tank–pipe–valve system and a valve with a pneumatic actuator at the downstream end generated transients. Numerical results at the test section pipe compares favorably with experimental data. The results show that pressure transients are significantly reduced with increasing air-pocket volumes and bubbly flow air content.

The linear differential equation of the internal combustion engine (ICE) itself, by means of which it is possible to investigate the dynamic characteristics (transients) and throttle response of the new generation of gas engines, used as a drive for mobile vehicles, is given. At present, the need has arisen to create a new generation of ICS control systems that would combine the principles of robust and adaptive management and provide a specified quality of management in the conditions of structural or parametric uncertainty of the control facility itself, uncertainty of external conditions and management goal uncertainty. The most important contour in the engine control system is the crankshaft speed regulator. It has a determining effect on the technical, economic and environmental performance of ICE. The resulting differential equation describes the transient processes of the angular velocity variation of the crankshaft of the gas engine of vehicles in a wide range of speed and load modes of operation.

A new approach is developed for solving the initial value, steady periodic heat conduction problem in steady-state die casting. Three characteristics found in nearly all die casting processes are exploited directly: The casting is thin compared with its overall size, its thermal conductivity is high compared with that of the mold, and the cycle time is short compared with the start-up transient of the process. Under these conditions, it is reasonable to neglect the transverse temperature gradients in the casting and assume that all die temperatures below a certain depth from the cavity surface are independent of time. The transient die temperatures near the cavity surface are represented by a polynomial expansion in the depth coordinate, with time-varying coefficients determined by a Galerkin method. This leads to a set of ordinary differential equations on the cavity surface, which govern the transient interaction between the casting and the die. From the time-averaged solution of these equations, special conditions are derived that relate the transient solution near the cavity surface to the three-dimensional steady solution in the die interior. With these conditions, the steady temperatures in the bulk of the die can be determined independently of the explicit surface transients. This reduces the effort of solving a complex transient heat conduction problem to little more than finding a steady solution alone. The overall approach provides a general analytical tool, which is capable of predicting complex thermal interactions in large multicomponent dies.

The transient electromagnetic method (TEM) has sensitive characteristics of low resistivity of water containing. The equivalent plane method based on whole space theory is used in coal mine goaf water TEM detecting. The mine goaf water was forward simulation. The geoelectric model of mine goaf water was equivalented to low resistivity layer thickness. The geoelectric model was forward calculated, and it was differential imaged. Then it found the apparent longitudinal conductance differential imaging reflect the most sensitive. The field experiment was conducted in two mine goaf water in Xiezhuang coal mine. The central loop device was selected as working device. The launch wire frame is length of 2m and 8 turns. A receiving device is receiving probe and the effective area is 212m2. The Water distribution range of goaf water in-300 of the seven mining area in front of retaining wall is large, and the water body is deep.

A deformation measurement technology for barrel in the launch based on differential fiber interferometer was supposed. The PCI data acquisition system and phase demodulation algorithm was used to replace the traditional hardware phase demodulation circuit which simplifying the structure and avoid the edge distortion of phase demodulation device. Experiments were done to measure the deformation of the barrel in the launch by this system. The results show that it had good response characteristics and is suitable for the transient deformation measurement of the barrel in the launch.

Introduction. Melkersson-Rosenthal syndrome is a rare disease of unknown etiology. Histopathologically, it presents as granulomatous cheilitis. From laboratory aspect, it is a nonspecific, differential diagnostically and therapeutically complex condition. Case Report. This is a report of six cases treated at the Department of Allergology and Immunology of the Clinical Center of Serbia, who had presented with the referral diagnosis of recurring or persistent lip edema, and who were diagnosed with Melkersson-Rosenthal syndrome upon detailed evaluation. Three patients had complete triad of symptoms, two had the oligosymptomatic form and one manifested the monosymptomatic form of the disease. Histopathological findings of the oral mucosa specimens verified the presence of non-necrotic epithelioid granulomas in all patients. The patients were treated with the H1 and H2 antihistamines, corticosteroids, followed by anabolic drugs and antibiotics, resulting in transient and unfavorable effects. Conclusion. In differential diagnosis, Melkersson-Rosenthal syndrome diagnosis primarily refers to conditions of angioneurotic edema and hereditary angioedema, as well as granulomatous diseases such as sarcoidosis, tuberculosis and Chron?s disease. It is necessary to follow-up these patients in view of monitoring the effects of the therapy and possible development of systemic granulomatous diseases.

Accurate measurement of overvoltage in power grids is of great significance to study the characteristics of overvoltage and design of insulation coordination. Based on the research of D-dot voltage sensor, we designed a Dual-Differential D-dot overvoltage sensor. In order to quantify the structural parameters of the sensor, improve the performance and measurement accuracy of the sensor. The Field-Circuit Coupling method was proposed to be used in the parameter design of D-dot overvoltage sensor. The joint simulation of space electromagnetic field model and equivalent circuit model of the Dual-Differential D-dot overvoltage sensor was established with the finite element simulation software Ansoft Maxwell and circuit simulation software Simplorer. Finally, the actual sensor was manufactured. A test platform was built to verify the steady-state and transient performance of the sensor. The results show that the Dual-Differential D-dot sensor has excellent steady-state and transient performance, the error of phase and amplitude are small, and the sensor can achieve the non-contact measurement of power transmission line. Simultaneously, the rationality of the Field-Circuit Coupling method was further verified.

The dipping tube hydropneumatic tank is one of the most efficient equipments to prevent water hammer in water distribution and long distance transmission pipe systems. Due to its low costs and easy to maintain features, dipping tube hydropneumatic tank has many irreplaceable advantages, however it is difficult to determine the correct size and gas volume for real world engineering applications. This paper presents a robust method to solve the problems from theory and application. Based on the Method of Characteristics (MOC) equations, this paper derives the equations for modeling dipping tube hydropneumatic tanks in water distribution systems to prevent water hammer. The equations include MOC, differential orifice head loss equation, gas law, air mass, air velocity and etc. The IBMs scientific subroutine package (SSP) is applied to solve the equations by deriving to the form of X=f (X). The method has been integrated into HAMMER. This paper also presents an example to illustrate the methods of determining the tank size, and the comparison results with sealed hydropneumatic tank and surge tank equipment.

In traditional aeroengine modeling, the nonlinear equations of engine model are generally solved through iterative algorithm. However, due to the strong nonlinear characteristics of the equations, the iterative model often fails to converge at some points of the full envelope and has a poor real time performance. In order to solve the problems, this paper proposes a non-iterative modeling method based on volume effect. In this method, several variables and differential equations of volume dynamics in aeroengine are introduced to the nonlinear equations, as a result, the whole set of equations becomes closed-form and can be solved without iteration. The non-iterative model of a gas turbine engine is written in matlab code. Furthermore, an open-loop simulation is carried out in matlab/simulink, both under groud and altitude condition. Meanwhile, the non-iterative model is verified by GSP11. The results illustrate that the non-iterative model provides good performance both in the stability and accuracy of solutions.

Time recordings of impulse-type oscillation responses are short and highly transient. These characteristics may complicate the usage of classical spectral signal processing techniques for (a) describing the dynamics and (b) deriving discriminative features from the data. However, common model identification and validation techniques mostly rely on steady-state recordings, characteristic spectral properties and non-transient behavior. In this work, a recent method, which allows reconstructing differential equations from time series data, is extended for higher degrees of automation. With special focus on short and strongly damped oscillations, an optimization procedure is proposed that fine-tunes the reconstructed dynamical models with respect to model simplicity and error reduction. This framework is analyzed with particular focus on the amount of information available to the reconstruction, noise contamination and nonlinearities contained in the time series input. Using the example of a mechanical oscillator, we illustrate how the optimized reconstruction method can be used to identify a suitable model and how to extract features from uni-variate and multivariate time series recordings in an engineering-compliant environment. Moreover, the determined minimal models allow for identifying the qualitative nature of the underlying dynamical systems as well as testing for the degree and strength of nonlinearity. The reconstructed differential equations would then be potentially available for classical numerical studies, such as bifurcation analysis. These results represent a physically interpretable enhancement of data-driven modeling approaches in structural dynamics.

We present a simple model which can account for the electrical response characteristics of an Electrorheological (ER) parallel plate valve restrictor. We find that a self-consistent electrical model which can describe the current response to transient and biased sine wave voltage exitations must incorporate the non-linear dependence of current on voltage found at steady state. In addition, the steady state current characteristics are a function of the fluid flow rate. This can be described analytically and included in the model. Analytical solutions show that non-linearity affects the detailed shape of the current response to large voltage inputs. The initial current response is well described by a numerical solution to the model differential equation using the experimental voltage as input. In the case of the relatively small fluctuations involved in the sine wave experiments, a linearised form of this model is found to be an adequate approximation. Parameters are obtained for the model which are, within a generous margin of error, independent of valve dimension.

A model is presented for transient, cocurrent gas-liquid pipe flow in the stratified-smooth and stratified-wavy flow regimes. It is based on the equations of continuity and motion in the direction of flow and results in two hyperbolic partial differential equations, which are solved numerically using the combined methods of lines (Schiesser, 1991) and characteristics (Stoker, 1957). In wavy gas-liquid pipe flow, three different interfacial areas and corresponding shear stresses are identified. Three friction-factor correlations were derived on the basis of an extensive set of 2500 steady-state measurements. The transient behavior of inclined gas-liquid pipe flow is successfully simulated and compares well with the results obtained from on-line measurements, right up to the onset of slug flow.

A mathematical model is presented for magnetized nanofluid bio-tribological squeeze-film flow between two approaching disks. The nanofluid comprises a suspension of metal oxide nanoparticles with an electrically-conducting base fluid, making the nanosuspension responsive to applied magnetic field. The governing viscous momentum, heat and species (nanoparticle) conservation equations are normalized with appropriate transformations which renders the original coupled, non-linear partial differential equation system into a more amenable ordinary differential boundary value problem. The emerging model is shown to be controlled by a number of parameters, viz nanoparticle volume fraction, squeeze number, Hartmann magnetic body force number, disk surface transpiration parameter, Brownian motion parameter, thermophoretic parameter, Prandtl number and Lewis number. Computations are conducted with a B-spline collocation numerical method. Validation with previous homotopy solutions is included. The numerical spline algorithm is shown to achieve excellent convergence and stability in non-linear bio-tribological boundary value problems. The interaction of heat and mass transfer with nanofluid velocity characteristics is explored. In particular, smaller nanoparticle (high Brownian motion parameter) suspensions are studied. The study is relevant to enhanced lubrication performance in novel bio-sensors and intelligent knee joint (orthopaedic) systems.

This paper presents a free code for calculating 1D hydraulic transients in liquid-filled piping. The transient of focus is the Water Hammer phenomenon which may arise due to e.g., sudden valve closure, pump start/stop etc. The method of solution of the system of partial differential equations given by the continuity and momentum balance is the Method of Characteristics (MOC). Various friction models ranging from steady-state and quasi steady-state to unsteady friction models including Convolution Based models (CB) as well as an Instantaneous Acceleration Based (IAB) model are implemented. Furthermore, two different models for modelling cavitation/column separation are implemented. Column separation may occur during low pressure pulses if the pressure decreases below the vapour pressure of the fluid. The code implementing the various models are compared to experiments from the literature. All experiments consist of an upstream reservoir, a straight pipe and a downstream valve.

AbstractHip pain in the pediatric population can be a challenging presenting complaint to assess. An extensive differential list, including the possibility of infection, transient conditions, and malignancy, results in numerous questions that can render diagnosis difficult. As clinicians, it is imperative that we have the ability to recognize, properly diagnose, and possibly treat the multitude of potential pediatric hip disorders. Here the authors present the incidence, characteristics, and treatment of various benign tumors and tumor-like conditions of the pediatric hip.

Abstract Due to the existence of the metal casing in production wells, it is difficult for a conventional well-logging method to achieve satisfactory results. To study the possibility of measuring the formation conductivity through casing by using a transient electromagnetic (TEM) method, characteristics of the response signals received at different source-receiver spacing are investigated. Based on the advantages of the response signals at long spacing in the separation of the direct and indirect coupled signals, the corresponding differential response signals calculated with different formation conductivities are studied further. Results show that: (1) the differential signals are three orders of magnitude smaller than that of the original response signals; (2) there is a maximum and a minimum in the differential signal; (3) with the increase of the spacing, the profile of differential signal hardly changes, but moves backward on the timeline and the amplitude decreases slowly, which is in sharp contrast to the original response signals and (4) the differential signal is proportional to the difference of corresponding formation conductivities and the maximum and minimum values in the response difference are the most sensitive. The research reveals the characteristics of TEM responses in cased-hole and the distribution of formation conductivity information, which is predicted to provide a new perspective for the design of long-spacing through-casing in the TEM conductivity logging tool and the signal processing method.

A GaN based negative differential conductivity diode utilizing transient ballistic transport effects is proposed and large-signal circuit simulations along with preliminary experimental results are presented. The diode is an n +- n - n + structure and transport is described by an empirical velocity-field relation which is derived directly from femtosecond pulse-probe measurements available in literature and incorporated into the simulations through curve fitting. Efficient THz generation is predicted as a result of ~2.8 peak-to-valley ratio. Pulsed current-voltage characteristics were measured and N -type dependence was observed.

By calculating the concentration distributions of rock salt solutions at the boundary layer, an ordinary differential equation for describing a special dissolution rate model of rock salt under the assumption of an instantaneous diffusion process was established to investigate the dissolution mechanism of rock salt under transient but stable conditions. The ordinary differential equation was then solved mathematically to give an analytical solution and related expressions for the dissolved radius and solution concentration. Thereafter, the analytical solution was fitted with transient dissolution test data of rock salt to provide the dissolution parameters at different flow rates, and the physical meaning of the analytical formula was also discussed. Finally, the influential factors of the analytical formula were investigated. There was approximately a linear relationship between the dissolution parameters and the flow rate. The effects of the dissolution area and initial volume of the solution on the dissolution rate equation of rock salt were computationally investigated. The results showed that the present analytical solution gives a good description of the dissolution mechanism of rock salt under some special conditions, which may provide a primary theoretical basis and an analytical way to investigate the dissolution characteristics of rock salt.

The paper take the solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) as the object, studies the influence of the fuel cell on load characteristics of the distribution network. Structures based on Matlab simulation platform contains the SOFC typical distribution network, and a series of transient simulation was conducted, results indicate that the SOFC power generation system can be describe in its equivalent model based on the URL equivalent circuit-order differential equation of state. On this basis, the access to the distribution network SOFC power generation system regarded as power consumption of the negative dynamic load, proposed containing the SOFC can be to the equivalent the GSLM model containing the SOFC described distribution grid load characteristics.

In order to analyze the characteristics of secondary ignition of AP/HTPB base bleed propellant, the quenched samples of AP/HTPB base bleed propellant are made under the condition of transient depressurization, and experiments on thermal decomposition of this micro sample are carried by means of differential scanning calorimeter (DSC). The experimental results are obtained under two heating rates of 20°C/min and 40°C/min. They are analyzed and compared with the original sample of AP/HTPB. The kinetic parameters are estimated according to thermal decomposition rate equation and thermograms.

Abstract: Low-voltage asynchronous motor is the most common load used in any industrial electric facility. Due to their robustness and reliability, the induction motors have a very large application spectrum and are to be found in a variety of power units. It is assumed that over 70% of total energy used in any electric utility is dedicated to the electric motor drive systems. The paper quantitatively studies the transient state of such motors, which occurs at their start-up. The waveforms characteristics of these inrush currents are predetermined mainly by solving the associated differential equations that describe the dynamic phenomena at their start-up. An experimental investigation on an induction motor of 4 kW is also carried out. Supplementary, different solutions for the energising of these low-voltage motors are presented highlighting their performances and limits. These methods are critically rated according to their mitigation ability of the power quality issues associated with the energizing process.

When gas kick Occurs during drilling, because of pressure, temperature, coefficient of gas compressibility and other parameters changing continuously, gas will slip along the borehole and also accompany expansion some extent, and bottom hole differential pressure increases, resulting in the amount of invasion gas increasing continuously until blowout. The procedure of gas kick till blowout in the borehole is transient gas-liquid two-phase flow, studying on The development of gas-liquid two-phase flow parameters variation characteristics and bottom hole pressure variation characteristics plays an significant role to understand blowout occurrence and development characteristics. This paper using methane-mud as the circulating medium simulates the procedure of gas kick till blowout near the bottom under the condition which is almost the onsite drilling process, Analyzing the flow pattern, bottom hole pressure variation characteristics, and velocity distribution under the different stages of gas kick, different influx, and obtained an initial understanding.

In this paper, we have simulated a bi-organic polymer multilayered Light Emitting Diode (LED). It presents the transient analysis of the OLED device. Poly (9, 9-dioctylfluorene) (PFO) is used as an interlayer between Hole Transport Layer (HTL) and Lithium fluoride (LiF) which is responsible for enhancing the electron injection in the device. Hence, it is called as Electron Injection Layer (EIL). PFO acts as a photo catalyst, which improves the device performance. Silvaco TCAD is used for the extraction of electro-optical characteristics. It is done using 1 and 2-dimentional simulation process. Solution of differential equations is derived from Langevin recombination model. Transient response analysis and comparison is done for exciton density and anode current for different thickness of PFO layer. It is found that transient response with respect to anode current and exciton density is better when a Poly (9, 9-dioctylfluorene) (PFO) layer is inserted between anode and Hole Injection Layer (HIL). The analysis and comparison is done for 65 nm, 120 nm and 240 nm thick layers and it is observed that transient response is best at 65 nm layer thicknesses for both exciton density and anode current. Also, J-V characteristics has been found for the structure where current density is 1.8 A/ .m2 which is remarkably high as compared to the devices discussed in prose. The results agree well with that available in literature. Poly (3,4-ethylenedioxythiophene) poly (styrenesulphonate) (PEDOT:PSS) results in low operating voltage of the device which is 4V here.