Simple Numerical Calculation Research Articles

Surface plasmon resonance sensors: Temperature effects

In this paper, we present a detailed study of the temperature effect (0−100°C), on the plasmonic resonance and sensitivity of a surface plasmon resonance (SPR) to the medium detection refraction index change. We examine this SPR based on the Kretschmann multilayer configuration constituted by a BK7 prism, an Ag/Au bimetallic layer deposited on TiO2/SiO2 and a BlueP/MoS2 heterostructure monolayer. First, a simple numerical calculation is provided to analyze the temperature effect on the plasmonic resonance. The model take into account the dependence on temperature of the refractive index of different materials composing the investigated structures. The main idea is to show how the sensitivity of the SPR based sensor is influenced according to operating temperature which is critical parameter when considering bio-sensing applications.

Low Earth Orbiting (LEO) Satellite and Orbital Decay

In this article we present a simple but elegant numerical calculation to study the motion of a low earth orbiting (LEO) satellite in gravitational potential and under the influence of quadratic drag force. We solve a set of coupled differential equations to calculate the instantaneous position and velocity of the satellite and calculate the change in radial distance for different aerodynamic coefficients and altitude. We validate our numerical results with theoretical result in the high altitude where the density of air and consequently the drag force is minimum. However the LEO orbits placed in the range of 200 to 400 km faces significant effect of drag force. Satellites at an altitude of 200 km quickly decay and re-entry to earth’s atmosphere occurs. We finally do a short numerical calculation with the parameters of ISS satellite at an altitude of 400 km and compare with the existing results.

Fast Calculation Method for Predicting the Morphology of Steady-State Ablation

Predicting the surface morphology of materials during steady-state ablation is important in rocket motor nozzles and the heat shields of vehicles performing atmospheric re-entry. When designing ablative materials, a high number of calculations is required for analyzing surface morphology. To effectively design these materials and reduce the number of experiments, a fast, effective, and simple calculation method is required. Although a fundamental theory for ablation has been established, quick and effective prediction of the morphology of the composites remains a challenge. In this study, we propose a fast, effective, and simple numerical calculation method to predict the surface morphology of steady-state ablation based on the geometric characteristics of the materials. The results obtained in this study were consistent with the experimental observations. The calculation time was significantly reduced. In addition, our method was found to be useful for analyzing the physical and chemical properties and surface roughness of ablative materials.

The Linear Hygroscopic Expansion Coefficient of Cement-Based Materials and Its Determination.

A crack caused by shrinkage could remarkably increase the permeability, heavily deteriorate the durability, and heavily deteriorate the service life of a concrete structure. However, different forms of thermal shrinkage can be predicted by directly applying a temperature load on a node. The prediction of moisture-induced stresses in cement-based materials by using the common finite element method (FEM) software is a big challenge. In this paper, we present a simple numerical calculation approach by using the proposed coefficient of hygroscopic expansion (CHE) to predict the moisture-induced deformation of concrete. The theoretical calculation formula of the linear CHE (LCHE) of cement-based material was deduced based on the Kelvin–Laplace equation and the Mackenzie equation. The hygroscopic deformation of cement mortar was investigated by inversion analysis; based on the results, the LCHE could be determined. Moreover, a case analysis of the application of LCHE to concrete is also conducted. The simulated results of concrete shrinkage were close to the experimental ones. As a whole, it is feasible to predict the drying shrinkage of concrete through simple calculation by using the proposed LCHE, which is also beneficial to the direct application of moisture loads on nodes in finite element analysis (FEA).

Simple Numerical Calculation Method of Rotational Iron Loss in Silicon Steel Sheets

To evaluate the iron losses of motors and three-phase transformers, the rotational iron loss should be considered. A simple numerical calculation method of the rotational iron losses under rotational flux with high flux density and different axis ratios is proposed in this paper. First, it is shown that the method of decomposing the rotational flux into the directions of the major and minor axes of the rotational flux is effective in calculating the rotational iron losses of the non-oriented and grain-oriented electrical steel sheets in low magnetization region. Then, the simple iron loss calculation method is improved to consider the decrease of rotational hysteresis and anomalous eddy current losses in high magnetization region under circular rotational flux and verified by comparing with measurement results. Furthermore, it is improved to be applicable to rotational iron loss calculation under rotational flux with different axis ratios and verified by comparing with measurement results.

The relationship between simple numerical function and gray matter volume in normal brain aging

Objective: To explore the relationship between simple numerical function and gray matter volume (GMV) in normal brain aging using the voxel-based morphometry(VBM) approach. Methods: A total of 123 individuals from 18 to 70 years old (63 males,60 females,the average age was (43±14) years, were recruited from right-handed healthy Han Chinese volunteers at the Department of MRI at the First Affiliated Hospital of Zhengzhou University between October 2016 and June 2017. All subjects underwent magnetic resonance sagital three-dimensional imaging scanning, and statistical parameter graph (SPM) 8 software was used for voxel-based morphological analysis to compare the differences in gray matter volume between different age groups.Gray matter volume difference brain regions between different age groups were extracted as regions of interest, and correlation analysis was carried out on the score of simple numerical calculation to find the responsible atrophy brain regions related to the decline of simple digital computing ability. Results: The brain regions with different gray matter volume in different age groups mainly included bilateral frontal gyrus, bilateral anterior cingulate gyrus, bilateral middle cingulate gyrus, bilateral olfactory cortex, bilateral caudate nucleus and bilateral insula. Among them the GMV of bilateral superior frontal gyrus and anterior cingulate gyrus showed the strongest correlation with the simple numerical function. Before removing the effect of age, the correlation between the GMV of the bilateral superior frontal gyrus and medial cingulate gyrus and the corrected count of correct was significant (r=0.403,P=0.000), the correlation between GMV and the percent of correct was also significant (r=0.229,P=0.037).After removing age as a covariate, bilateral superior frontal gyrus and central cingulate gyrus were still positively correlated with the correct number after correction of simple numerical calculation function (r=0.225,P=0.014) and the correct percentage (r=0.245, P=0.007). Conclusion: There is extensive gray matter volume atrophy during the normal brain aging process. The decrease of simple numerical function in normal brain aging may be related to the decrease of frontal and anterior cingulate gray matter volume.

Finite-difference time-domain method for calculating photoexcited molecular vibration wave-packet dynamics

We propose a simple numerical calculation method for solving molecular vibrational dynamics. A finite-difference time-domain (FDTD) method is utilized to solve the Schrödinger equation for wave packet dynamics driven by incident light pulses. Vibrational wave function is discretized and divided into real and imaginary parts, and then the Schrödinger equation is solved by temporally and alternately calculating the real and imaginary parts, in a similar manner to the conventional FDTD method. Taking generation of a hot molecule by pump-dump scheme and multi-photon excitation process as examples, we show the validity and usefulness of the proposed method. The dynamics of the vibrational wave packets in the pump-dump scheme and transient virtual excitations of intermediate vibronic state in the three-photon absorption can be easily visualized, and the intensity dependence of excitation population for ultra-high intensity beyond the perturbation theory can be accurately calculated.

Simple numerical calculation method of flow velocity on roof of train running in tunnel

Simple numerical calculation method of flow velocity on roof of train running in tunnel

A Novel MPPT Algorithm Based on Particle Swarm Optimization for Photovoltaic Systems

This paper describes a new maximum-power-point-tracking method for a photovoltaic system based on the Lagrange Interpolation Formula and proposes the particle swarm optimization method. The proposed control scheme eliminates the problems of conventional methods by using only a simple numerical calculation to initialize the particles around the global maximum power point. Hence, the suggested control scheme will utilize less iterations to reach the maximum power point. Simulation study is carried out using MATLAB/SIMULINK and compared with the Perturb and Observe method, the Incremental Conductance method, and the conventional Particle Swarm Optimization algorithm. The proposed algorithm is verified with the OPAL-RT real-time simulator. The simulation results confirm that the proposed algorithm can effectively enhance the stability and the fast tracking capability under abnormal insolation conditions.

Effects of Fast Simple Numerical Calculation Training on Neural Systems.

Cognitive training, including fast simple numerical calculation (FSNC), has been shown to improve performance on untrained processing speed and executive function tasks in the elderly. However, the effects of FSNC training on cognitive functions in the young and on neural mechanisms remain unknown. We investigated the effects of 1-week intensive FSNC training on cognitive function, regional gray matter volume (rGMV), and regional cerebral blood flow at rest (resting rCBF) in healthy young adults. FSNC training was associated with improvements in performance on simple processing speed, speeded executive functioning, and simple and complex arithmetic tasks. FSNC training was associated with a reduction in rGMV and an increase in resting rCBF in the frontopolar areas and a weak but widespread increase in resting rCBF in an anatomical cluster in the posterior region. These results provide direct evidence that FSNC training alone can improve performance on processing speed and executive function tasks as well as plasticity of brain structures and perfusion. Our results also indicate that changes in neural systems in the frontopolar areas may underlie these cognitive improvements.

2A1-N01 ゆらぎを用いたモデルベーストアトラクタ選択アルゴリズムの提案

Recent reports revealed that in some cases the behavior in living things became probabilistic and in other cases became deterministic in order to adapt to the complex environment. This mechanism is called as "Yuragi", which means fluctuation in Japanese, and can be represented as a stochastic differential equation and referred to as the "Yuragi" equation. The conventional "Yuragi" equation makes use of both "task achievements" as an evaluation criterion and "ever-present noise" as an exploration source. Instead of the "task achievements", our "Yuragi" equation utilizes "the appropriateness of each attractor in the state space" and "damped noise according to the distance from the attractors", which offers an efficient and robust optimization algorithm. The convergence of solution of the proposed "Yuragi" equation was investigated through simple numerical calculation experiments.

Analysis on the progressive failure process of backfill soil under seismic loads

Knowledge of earth pressure and failure behavior of backfill soil is important to the design of retaining wall, especially in earthquake-prone region. However, most common methods, such as the Mononobe-Okabe method, only consider the equilibrium of forces, and ignore the failure behavior of backfill soil. To research the seismic response of soil-wall interaction system, the current study proposes an approximate analysis model based on three methods which are the pseudo-dynamic method, free field solution, and Mohr-Coulomb criterion. In this new model, the assumption about the shape of slip surface is not needed any more. The time-dependent earth pressure which depends on the motion pattern of the retaining wall is derived on the basis of fundamental solution of the free-field of backfill soil. Moreover, the evolution process of failure zone in backfill soil is determined by using the Melan’s basic solution. Present analysis model is fit for different motion patterns of wall. In addition, earth pressure of both active and passive state can be determined by the present model. Through the simple numerical calculation, not only the time-dependent distribution of earth pressure, but also the visualized failure zone is obtained.

A113 微小重力場における電線被覆の過電流連続通電着火現象(OS-2:微小重力環境下における燃焼および熱工学的問題)

Ignition tests of overloaded electric wire were carried out in microgravity provided by airplane parabolic flight. Polyethylene insulated NiCr core wire (inner core diameter 0.5 and outer diameter 0.8 mm) was used as a test sample. The results showed that the ignition limit in terms of supplied electric power dramatically decreased with increase in microgravity time. It was suggested that the total electric energy supplied to the wire gave the primary criteria for ignition, which was consistent with experimental findings. Further, the importance of conductive heat loss to the surroundings was pointed out for very low electric current condition according to the simple one-dimensional numerical calculation.

Potential distribution in channel of thin-film transistors

Channel voltages of ZnO thin-film transistors during operation are precisely probed at two trisecting positions between the source and drain electrode, which exactly corresponds to characteristic transistor events, such as carrier injection, carrier accumulation, pinch-off formation, and drain current saturation. Furthermore, a simple numerical calculation based on the gradual channel approximation and the current continuity equation reveals that the channel voltages have a non-linear potential distribution and an intrinsic but significant potential drop in the region near to the drain electrode in most of the linear regime.

Method for analyzing the magnetic anisotropy in non-aligned Fe nanofibers via electrospinning

In order to investigate the magnetic anisotropy of non-aligned Fe nanofibers, electrospinning and heat treatment techniques were successfully used to prepare novel Fe nanofibers. A new method was offered to characterize the magnetic anisotropy only using VSM combining with Mössbauer spectroscopy techniques. It is found that each individual nanofiber was uniform and straight on the whole measurement substrate with little breakage and Mössbauer spectroscopy result shows that all magnetic moments lied in the EA of nanofibers. With simple numerical calculation and fitting with experimental data, the magnetic anisotropy Ha of non-aligned Fe nanofibers was obtained and the result shows that the shape anisotropy dominates the overall magnetic anisotropy in the Fe nanofibers. This method provides a rapid and effective access to analyze and measure the magnetic anisotropy of soft magnetic nanofibers.

塗料の低VOC 化による塗装性能の向上効果

Improvement effect of painting efficiency by using low volatile organic compounds (VOC) paint was investigated experimentally and numerically. We measured painting efficiency of low-VOC paint and conventional paint under crosswind by wind tunnel experiment. The painting efficiency and particle size distributions of spray of the test paints were calculated by simple numerical calculation. The efficiency of low-VOC paint was clearly better than that of conventional paint. It was shown that the motions of spray particle of the low-VOC paint were predictable by the simple numerical model.

The effect of immersion oil in optical tweezers

Optimized optical tweezers are of great importance for biological micromanipulation. In this paper, we present a detailed electromagnetic-based calculation of the spatial intensity distribution for a laser beam focused through a high numerical aperture objective when there are several discontinuities in the optical pathway of the system. For a common case of 3 interfaces we have shown that 0.01 increase in the refractive index of the immersion medium would shift the optimal trapping depth by 3-4 μm (0.2-0.6 μm) for aqueous (air) medium. For the first time, We have shown that the alteration of the refractive index of the immersion medium can be also used in aerosol trapping provided that larger increase in the refractive index is considered.

EFFECTIVE MASS OF STRONG-COUPLED BOUND POLARON IN AN ASYMMETRIC QUANTUM DOT INDUCED WITH RASHBA EFFECT

In this paper, on the basis of Huybrechs' strong-coupled polaron model, the Tokuda-modified linear-combination operator method and the unitary transformation method are used to study the properties of the strong-coupled bound polaron considering the influence of Rashba effect, which is brought by the spin-orbit (SO) interaction, in an asymmetric quantum dot (QD). The expression for the effective mass of the polaron as functions of the transverse and longitudinal bound strengths, velocity, vibration frequency, and the bound potential has been derived. After a simple numerical calculation on the RbCl crystal, we found that the total effective mass of the bound polaron is composed of three parts. The interaction between the orbit and the spin with different directions has different effects on the effective mass of the bound polaron.

室戸沖南海トラフ付加体前縁部の高熱流量と地下深部の圧力・浸透率の関係

The Nankai Trough is a convergent plate boundary where the Shikoku Basin subducts beneath southwest Japan. Turbidite and hemipelagic sediments on the trough floor form an accretionary prism landward of the trough axis through a process of sediment compaction. Near the toe of the accretionary prism, a series of frontal thrusts have formed above the decollement, which is a major slipping plane on the plate boundary. In 2002, we discovered an extremely high heat flow at the second frontal thrust near the toe of the Nankai Trough off Muroto using ROV KAIKO during the KR02-10 research cruise of the Japan Agency for Marine-Earth and Technology (JAMSTEC). The background heat flow value was 160 mW/m2 and high values of 250-280 mW/m2 were obtained within 50 m above the second frontal thrust. The heat flow gradually decreases landward from this location. A simple numerical calculation was carried out to test the hypothesis that the heat flow anomaly is caused by an interstitial fluid flow through the decollement/frontal thrust system as a permeable channel. Two parameters—permeability within the fault zone (Kch) and excess pore pressure (ΔP)—at the landward boundary of the decollement were adjusted to produce the best-fit combination to explain the observed heat flow anomaly. The simulation result of 500 combination patterns indicates that Kch and ΔP cannot be determined independently. Instead, only their product (Kch × ΔP) can be estimated. The best-fit result, simulating the highest heat flow of 280 mW/m2 was achieved where the product Kch × ΔP is 8 × 1015, with a surrounding permeability of 10-17 m2. Based on the estimation of excess pore pressure in the decollement of less than 4 MPa, the most appropriate value of channel permeability is estimated to be higher than 2 × 10-15 m2. Our numerical result is generally consistent with the previously estimated fracture permeability, i.e. three orders of magnitude higher than that of ambient sediment. Thus, we attribute the surface heat flow anomaly to the influence of the fluid flow through the permeable channel along the frontal thrust.

A simple model for the magnetoelectric interaction in multiferroics

The (anti)ferromagnetic and ferroelectric transitions in some multiferroic compounds seem to be strongly correlated. Even for systems that do not show spontaneous ferroelectricity such as the LiMPO4 (M = Mn, Fe, Co, Ni) compounds, the coupling between magnetic and electric degrees of freedom is evident experimentally. Here, we present a simple numerical calculation to simulate this coupling that leads to the two transitions. We assume a magnetic sublattice consisting of classical magnetic moments coupled to a separated nonmagnetic sublattice consisting of classical electric dipoles. The coupling between them is realized through a phenomenological spin-lattice Hamiltonian, and the solution is obtained using the Monte Carlo technique. In the simplest version, the magnetic system is 2D Ising (anti)ferromagnetic lattice, with nearest neighbors interactions only, and the electric moments are permanent moments, coupled electrically. Within this approximation, the second order magnetic transition induces ferroelectricity in the electric dipoles. We show that these calculations can be extended to other magnetic systems, (x-y model and 3D Heisenberg) and to systems where the electric moments are created by strains, generated via spin-lattice coupling, so the model can be applied to model realistic systems such as the olivines mentioned above.