TAC (Time to Amplitude Convertor) is one of the most important time measurement instruments which has great significance in many fields of science, especially radiation physics. A TAC unit has been designed based on the START-STOP analog method and NIM (Nuclear Instrument Modules) standards. After designing the circuit, it was simulated by PSPICE software and constructed by discrete and integrated components. Accuracy of performance, LINEARITY and time resolution of the TAC were checked in laboratory condition and a neutron-gamma discrimination experiment was carried out using this TAC. Results of these experiments and the spectrum of neutron-gamma discrimination completely agree with those from other similar TACs, and are, to some extent, better.

In the new advanced drive schemes, identification and modeling of the load complex characteristics can play an important role to predict the dynamic performance of the proposed control strategy. The novelty of this paper consists in the classification of the different types of the NONlinear loads which the electrical drive systems may encounter. In this study, NONlinear components of mechanical loads are divided into two groups. The first type includes NONlinear phenomeNON caused by the nature of load which is predictable and identifiable. Another type of loads NONlinear characteristic happens due to the occurrence of a mechanical fault in motor, coupling or load parts. Generally, this type of NON-intended NONlinear effect is not predictable and often occurs in the installation and operation stage of the drive system utilization. In this paper, the performance of an induction servo drive system has been simulated under the influence of different types of NON-linear industrial loads.

There is good reason to expect crude oil prices to follow NONlinear models. However, previous research has considered the linear assumption to investigate the existence of a unit root. Unit root linear tests such as ADF, PP, and KPSS are provided for linear models. These tests are not suitable for NONlinear time series. Because the model deviation from the linear state may be considered as a random permanent deviation. The purpose of this article is to test the NONlinear unit root of crude oil prices, specifically Brent and WTI oil in the period 2019-2020 daily. For several decades now, various classes of NONlinear models have been introduced. These models introduce a wider range of dynamics than linear models in time series. A special type of these models that economists pay attention to are TAR models. In these models, as in linear models, valid statistical analysis requires distinguishing between the deterministic trend and the stochastic trend. In this study, the Bayesian unit root test for the general SETAR (1) model has been used with respect to the necessary and sufficient conditions for the maintenance of SETAR processes based on the article by Petrocyl and Wolford (1984). A NONlinear unit root test was performed using Bayesian validity interval. The results show that Brent crude oil prices in both regimes contain a unit root that is consistent with similar findings for the production or consumption of crude oil..

Motivation of this paper is presentation of analytical solution for flexible functionally graded beams problem when carry elastic large deflection, with small strains and without concerning plastic region. The formulation of large deflection in curvilinear and Cartesian coordinate systems for the free-clamped flexible functionally graded beam, culminate in the second order NON-linear ordinary differential equation that can solve it in the analytical approach. The components of deflection that are derived with analytical solution and ANSYS approach are compared. The influence of the distribution reversing of the material property and the influence of the variable material property in the components of deflection are studied. This analytical approach can be used for verifying the other method results, if any.

In this research, using a thermomechanical constitutive model for shape memory polymers and employing the von Ká rmá n theory, a finite element analysis of a shape memory polymer beam is presented. The importance of introducing the von Ká rmá n theory for shape memory polymers is that the beam can have relatively high slopes during loading. Also, for optimization and designing processes we need to solve multiple problems and due to the high processing time the use of 3D model is not suitable. To validate the presented formulations, the reported results are compared with the 3D solution which was previously reported by the same authors. Accordingly, the effect of the hard segment volume on response of a thin beam has been investigated, and the results of the von Ká rmá n beam have been reported and compared with the 3D and Euler-Bernoulli solutions. As an example, the error of the beam response in one of the solved examples is 27% for Euler-Bernoulli beam and 1% for the von Ká rmá n solution compared to the three-dimensional solution. In general, the lower the beam thickness or the beam is longer, the Euler-Bernoulli beam error will be higher. The proposed finite element model can provide a reliable alternative response comparing to 3D modeling that requires a lot of processing time, and can be used for geometry and material parametric study.

Stiffness plays an important role in the earthquake rupture dynamics. At the main slip zone, the response of the system following a solicitation is both a function of stiffness and the heterogeneity of the surroundings. This work studies the effect of heterogeneity of Earth crust, particularly the effect of spatial dependence of stiffness during the nucleation phase of an earthquake. Based on Burridge Knopoff's 1D model, we have redesigned the dynamics of an earthquake, taking into account the spatial variation of stiffness. Given the complexity of the differential system obtained, a digital approach was used to trace solutions to the problem. We represented the variation curves of temperature, energy and displacement as well as the speed obtained when the rigidity is constant (CS) and when the stiffness is NONlinear (NLS). Then a comparative study was conducted between the two cases. The result show that by considering the space-dependent of stiffness, the stick-slip movements occurred and a succession of oscillations with decreasing amplitude in time, separate to the case where it was considering to be constant. The NON-LINEARITY of the stiffness reveals that each oscillation is separated from the next by a coseismic phase. For NON-linearities of order one and in the presence or absence of a fluid, the spatial dependence of stiffness suggests the existence of a seismic motion with decreasing amplitude, which always precedes by a steady state when the stiffness is NONlinear, which is not the case when the stiffness is constant; moreover, the amplitude of the movement decreases with the increase in the pore-fluid ratio. For NONlinearities of order three and in the presence of a fluid, the introduction of heterogeneity into the motion reduced the charging time before any seismic activity. Besides, it reveals existence of a transient phase that appears before steady state during nucleation phase. When going from TP to SH law and also to VW law, a quantitative difference is observed, which is not the case for a qualitative difference on these different laws. This work shows that before observing a steady state during nucleation, there are a multitude of micro seismic activity characterized by oscillations with time decreasing amplitudes.

These days, INTEGRAL equations govern a wide range of physical processes, including those related to electricity, mechanics, fluid dynamics, ecology, soil moisture dynamics, shallow water wave propagation, and chemical science. As a result, creating new techniques and putting them into practice for solving INTEGRAL equations becomes more crucial. In this paper, the Upadhyaya INTEGRAL transform is employed for determining the analytical solutions of the NON-linear Volterra INTEGRAL equations (NVIEs) of the first kind. Four examples suggest the effectiveness of the Upadhyaya INTEGRAL transform, particularly for NVIEs of the first kind. The calculation results suggest that the proposed method provides accurate solutions to the original problem and this method is a valuable tool for researchers and scientists working on the broader range of problems involving NVIEs of the first kind.

Analytical and Adomian decomposition methods have been developed to determine the large defection of a functionally graded cantilever beam under inclined end loading by fully accounting for geometric NONlinearities, and by incorporating the physical properties of functionally graded materials, and have also been solved. The large defection problem will also be solved by using an FEA solver. Results obtained only due to end loading are validated using a developed analytical solution. The Adomian decomposition method yields polynomial expressions for the beam configuration. The equilibrium equation of a functionally graded cantilever beam actuated through self-balanced moments has been derived and solved using the Adomian decomposition method and the FEA solver for which no closed form solution can be obtained. Some of the limitations and recipes to obviate these are included. The Adomian decomposition method will be useful toward the design of functionally graded compliant mechanisms driven by smart actuators.