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Motion and Interaction of Envelope Solitons in Schrödinger Equation Simulated by Symplectic Algorithm
Issue:
Volume 7, Issue 1, January 2019
Pages:
1-7
Received:
18 November 2018
Accepted:
14 December 2018
Published:
21 January 2019
Abstract: The expression of Gaussian envelope soliton in Schrödinger equations are given and proved in this paper. According to the characteristics of the Gauss envelope soliton, further proposed that the interaction between Gaussian envelope solitons exists in Schrödinger equation. The symplectic algorithm for solving Schrödinger equation is proposed after analysis characteristics of Schrödinger equation. First, the Schrödinger equation is transformed into the standard Hamiltonian canonical equation by separating the real and imaginary parts of wave function. Secondly, the symplectic algorithm is implemented by using the Euler center difference method for the canonical equation. The conserved quantity of symplectic algorithm is given, and the stability of symplectic algorithm is proved. The numerical simulation experiment was carried out on Schrödinger equation in Gauss envelope soliton motion and multi solitons interaction. The experimental results show that the proposed method is correct and the symplectic algorithm is effective.
Abstract: The expression of Gaussian envelope soliton in Schrödinger equations are given and proved in this paper. According to the characteristics of the Gauss envelope soliton, further proposed that the interaction between Gaussian envelope solitons exists in Schrödinger equation. The symplectic algorithm for solving Schrödinger equation is proposed after ...
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Spin Dynamics in the Ferromagnetic Resonance
Issue:
Volume 7, Issue 1, January 2019
Pages:
8-13
Received:
24 December 2018
Accepted:
21 January 2019
Published:
15 February 2019
Abstract: The LLG equation including the spin-transfer torque term, and the frequency spectrum analysis method are used to study the dynamic process of ferromagnetic resonance. The effects of damping factor α, internal anisotropic field, magnetic field inclination, and spin-transfer torque caused by the spin current are studied. The following results are found as follows. The ferromagnetic resonance spectra as functions of the frequency ω for fixed magnetic field, and functions of magnetic field for fixed frequency are obtained, and it is found that the internal magnetic field also has contribution to the resonance field or frequency, and we know that the resonant frequency ω0≈he + h1 (in unit of γH0). In addition, when the damping factor increases from 0.01 to 0.03, the resonance frequencies increases slightly, and the resonance strength decreases. And the oscillatory waves of mx and my reach their stable values more quickly. Furthermore, the internal field perpendicular to the external field h0 as well as it parallel to h0 also has the effect to the resonant frequency. The positive and negative internal field will have reversed effects to the resonance field or frequency. And in the end when the spin current becomes larger the STT effect becomes stronger, even exceeds the ferromagnetic resonance effect, makes mz reversed, and mx and my decreased.
Abstract: The LLG equation including the spin-transfer torque term, and the frequency spectrum analysis method are used to study the dynamic process of ferromagnetic resonance. The effects of damping factor α, internal anisotropic field, magnetic field inclination, and spin-transfer torque caused by the spin current are studied. The following results are fou...
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Evaluation of Nanoemulsion Concentrate Botanical Fungicide from Neem, Citronella and Eugenol Oil Using Palm Oil Based Surfactant
Melati Septiyanti,
Muhammad Rizky Mulyana,
Rahmawati Putri,
Yenny Meliana
Issue:
Volume 7, Issue 1, January 2019
Pages:
14-20
Received:
14 December 2018
Accepted:
23 January 2019
Published:
22 February 2019
Abstract: Pathogenic fungi has became a problem and caused crop failure. Synthetic fungicide was commonly used to control the growth of the fungi, however it has an adverse effect which can pollute the environment. As an alternative, botanical fungicide can be used as antifungal agent which is safer for environment. Neem oil has been reported as inhibitor for pathogen fungi, while eugenol and citronella oil have been proved to have antifungal effect against Aspergillus Niger. The essential oil does not dissolved naturally in water, therefore it is important to formulate this oil using palm oil based surfactant in order to form water dispersed formulation which might enhance the effectiveness of the formulation. This study investigate the best emulsifiable concentrate (EC) formulation using palm oil based surfactant and also the residue in water and soil in order to ensure that the formulation is safe for environment. Nanoemulsion was prepared by mixing essential oil and surfactant with ratio of 60:40, 70:30, 80:20, 90:10 each. The stability was investigated by observing creaming height and particle size overtime. The residue evaluation was done by analyzing TSS, TDS, COD value for water residue and GCMS analysis for soil residue. The best formulation was achieved with composition of neem, eugenol and citronella by 33% each, surfactant MES 20%, PDO 10% and PMO 70% with oil/surfactant ratio 60/40 and solvent ethanol ratio 1:2. The droplet size ranged between 350-480 nm and polydispersity index 0.3-0.5. This fungicide formulation also considered allowable by regulatory standard where the value of TDS was in range 1-100 mg/l, TSS 0-04 mg/l, COD 30-1270 mg/l and pH was in range 5-5.7. The result of Soil residue analysis shows that the essential oil derivatives still remain in soil for five days. It is expected that this result can become reference for fungicide companies and other related stakeholder to formulate stable botanical fungicide.
Abstract: Pathogenic fungi has became a problem and caused crop failure. Synthetic fungicide was commonly used to control the growth of the fungi, however it has an adverse effect which can pollute the environment. As an alternative, botanical fungicide can be used as antifungal agent which is safer for environment. Neem oil has been reported as inhibitor fo...
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The Average Energy and Molar Specific Heat at Constant Volume of an Einstein Solid Measured by an Observer with Fluctuating Frame of Reference
Issue:
Volume 7, Issue 1, January 2019
Pages:
21-26
Received:
15 December 2018
Accepted:
11 January 2019
Published:
22 February 2019
Abstract: We report an observer effect in an Einstein solid, a quantum-mechanical system, induced by fluctuations of an observer’s frame of reference; which has been studied so far under the assumption that the observer’s frame of reference remains constant throughout the performance of a measurement, thus, what is actually measured throughout the performance of a measurement is an unresolved problem during which the observer’s frame of reference is assumed to fluctuate. We investigate the average energy and molar specific heat at constant volume of an Einstein solid measured by an observer with fluctuating frame of reference. The Einstein solid consists of N identical non-interacting simple harmonic oscillators per mole, where N is the Avogadro’s number at temperature T. The average energy and molar specific heat at constant volume of the Einstein solid are formulated for two types of fluctuations of the observer’s frame of reference in order to consider pedagogical and experimental demonstrations. The average energy of the Einstein solid is formulated from the definition of canonical ensemble average and the molar specific heat at constant volume of it is calculated by differentiating the average energy with T. The molar specific heat at constant volume of the Einstein solid exhibits novel features at low temperatures according to the distribution of fluctuations of the observer’s frame of reference: 0 and 3R at T = 0 K for square-wave and sawtooth-wave fluctuations, respectively, where R is the gas constant.
Abstract: We report an observer effect in an Einstein solid, a quantum-mechanical system, induced by fluctuations of an observer’s frame of reference; which has been studied so far under the assumption that the observer’s frame of reference remains constant throughout the performance of a measurement, thus, what is actually measured throughout the performanc...
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Chimera States in Three Populations of Pendulum-Like Elements with Inertia
Issue:
Volume 7, Issue 1, January 2019
Pages:
27-33
Received:
24 January 2019
Accepted:
6 March 2019
Published:
19 March 2019
Abstract: The aim of this study is to investigate the chimera states in three populations of pendulum-like elements with inertia in varying network topology. Considering the coupling strength between oscillators within each population is stronger than the inter-population coupling, we search for the chimera states in three populations of pendulum-like elements under the ring and the chain structures by adjusting the inertia and the damping parameter. The numerical evidence is presented showing that chimera states exist in a narrow interval of inertia in ring and chain structures. It is found that chimera states cease to exist with the decreasing of damping parameter. Furthermore, it is revealed that there is a linear relationship between the inertia (m) and damping parameter threshold (εth) in the two network structures.
Abstract: The aim of this study is to investigate the chimera states in three populations of pendulum-like elements with inertia in varying network topology. Considering the coupling strength between oscillators within each population is stronger than the inter-population coupling, we search for the chimera states in three populations of pendulum-like elemen...
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