Minimum Energy Value Research Articles

A comparison between steepest descent and non-linear conjugate gradient algorithms for binding energy minimization of organic molecules

The main intention of optimization is to bring about the “best” of any model by prioritizing the needs along with a given set of constraints. There is a wide range of optimization problems, among which, unfortunately, the problems that are formulated from nature are not convex in nature. Solving non-convex optimization problems are quite trickier than the conventional method of derivatives. One such problem is Computing the minimum value of binding free energy of various molecules. Minimization of free energy of a molecule is highly significant in the field of Molecular mechanics which is the foundation of computational biology. For any molecule, free energy refers to the amount of energy needed to separate an individual particle from a system of particles or to disseminate all particles in a system. The significance of free energy is that it can be used to compute the lowest energy conformation, which corresponds to the least Steric energy. Hence, this paper aims at computing the minimum value of binding free energy of various organic molecules in isolated conditions using the steepest descent algorithm and conjugate gradient algorithm and comparing them.

Thermal decomposition characteristics and study of the reaction kinetics of tea-waste

This study aimed to investigate waste-tea’s pyrolysis kinetics and thermodynamics to assess its potential for thermochemical processes. In this study, three primary samples of tea-waste are prepared for investigation: raw, torrefied at 200 °C, and torrefied at 600 °C. Under a nitrogen environment, thermogravimetric analyses (TGA) were conducted at seven heating rates (10, 15, 20, 25, 30, 35, and 40 °C/min) to investigate the effect of heating rates on the kinetic parameters at temperatures ranging from 27 to 1000 °C. Using seven heating rates was beneficial to take advantage of multiple heating rates techniques alongside single heating rate techniques. These heating rates were combined, forming four heating rate groups (HRG). The pyrolysis kinetic parameters are determined using two model-fit-methods, direct Arrhenius and Coats-Redfern methods, and two model-free methods, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods. Thermodynamic data comprising ΔH, ΔG, and ΔS are addressed. The X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectrum are used to assess the presence of natural minerals in tea-waste. The results indicated that the tea-waste material has the potential to produce syngas. The torrefaction process at 600 °C shows a 53% increase in the energy content compared to the raw biomass. The Coats-Redfern is shown to be more reliable than the direct Arrhenius method. The activation energy (Ea) witnesses rising with the heating rate (β) from Ea = 55.27 kJ mol−1 at β = 10 °C min−1 to 60.04 kJ mol−1 at β = 40 °C min−1 for raw tea-waste using Coats-Redfern method. For model-free approaches, the minimum activation energy values of the raw tea-waste samples are 82 kJ/mol for FWO and 78 kJ/mol for KAS, whereas the peak values are 420 kJ/mol for KAS and 411 kJ/mol for FWO. A comparison of the effect of heating rate groups for FWO method in raw material case indicated that HRG1 has the maximum activation energy average value. The resulting values of HRG1, HRG2, HRG3, and HRG4 were 269 kJ/mol, 145 kJ/mol, 174 kJ/mol, and 202 kJ/mol, respectively.

Encapsulation of hydroxycitronellal in β-cyclodextrin and the characteristics of the inclusion complex

Abstract Hydroxycitronellal has been widely used in foods, beverages, perfumery and cosmetics. It can also be used to treat anxiety. The major drawbacks regarding the use of hydroxycitronellal are related to water insolubility, volatility, instability, and sensitization. To overcome these concerns, β-cyclodextrin was adopted as wall material to encapsulate hydroxycitronellal in this work. Hydroxycitronellal-β-cyclodextrin inclusion complex was prepared and the product was characterized. The interaction of hydroxycitronellal and β-cyclodextrin, and the assembly of hydroxycitronellal-β-cyclodextrin inclusion complex were investigated by molecular simulation (MM). The results showed that hydroxycitronellal loading capacity was 8.5%. The thermal stability and lastingness of hydroxycitronellal were improved by the formation of the inclusion complex. The minimum binding energy was –151.2 kJ/mol. Among the perpendicular, staggered parallel and ideally parallel orientation of the inclusion complexes, the minimum energy value was found for the staggered parallel arrangement. These basic data are useful to understand the interaction between hydroxycitronellal and β-cyclodextrin.

Study the effect of Ni doping on structural, optical and electrical properties of Zn1-xNixO thin films deposited by spray pyrolysis technique

The effect of Ni doping on structural, optical and electrical properties of deposited Zn1-xNixO thin films on glass substrate by spray pyrolysis technique has been studied. The main objective of this research is to study the change of the physical and optical properties of Zn1-xNixO thin films that are fabricant to semiconductor with different doping levels x. These levels are 0 at.%, 2 at.%, 4 at.%, 8 at.% and 12 at.%. The transmission spectra show that the Zn1-xNixO thin films have a good optical transparency in the visible region from 88 to 95%. The optical gap energy of the Zn1-xNixO thin films varied between 3.25 and 3.35 eV. The urbach energy varied between 65 and 230 meV. However, the Zn0.88Ni0.12O thin films have many defects with maximum value of urbach energy. The Zn0.88Ni0.12O thin films have minimum value of optical gap energy. The Zn0.88Ni0.12O thin films have maximum value of the electrical conductivity which is 9.40 (Ω.cm)-1 . The average electrical conductivity of our films is about (7.52 (Ω.cm)-1 ). XRD patterns of the Zn1- xNixO thin films indicate that films are polycrystalline with hexagonal wurtzite structure.

Density Functional Theory Investigation on the Structural and Electronic Properties of Pristine, Vacancy, and Group IV Doped Zigzag Boron Nitride Nanotubes

In this work, density functional theory (DFT) calculations were conducted to study the structural and electronic properties of pure, vacancy, and group IV [i.e. carbon (C), silicon (Si), and germanium (Ge) atoms] doped boron nitride nanotubes (BNNTs). The DFT computational results obtained agree well with the literature results. The calculated B−N bond distances obtained in this study are about 1.44 Å – 1.47 Å. Among seven BNNTs, the optimized B35GeN36H12 holds the lowest local energy minimum value in this study Moreover, the structure of B35CN36H12 possesses the smallest HOMO−LUMO energy (2.17 eV) among nine BNNT models considered. The boron (B) atoms hold the positive charges, and the negative charges fall on the nitrogen (N) atoms in this work. Similar results are reported to the molecular electrostatic potentials (MEPs) of studied BNNTs. The distributions of positive and negative electrostatic potentials fall on the regions of N− and B−tips of BNNT frameworks, respectively in this report. The DFT calculations reported that the spin densities were mainly concentrated in the regions around group IV elements, such as C, Si, and Ge atoms. Therefore, we believe that these computed results will provide useful information on the adsorption of hydrogen molecules on the BNNT frameworks in the future.

Numerical investigation on the wave transformation in the ionic liquid compressor for the application in hydrogen refuelling stations

The ionic liquid compressor exhibits excellent advantages in hydrogen refuelling stations due to the specific design based on the hydraulic system and the ionic liquid piston. The application of the ionic liquid column results in a complex two-phase flow issue inside the compression chamber. This two-phase flow behaviour is critical for the compressor design as it influences the wave dynamics during the compression, but it is absent in the open literature. In this paper, transit numerical simulations were carried out to investigate the wave transformation during a compression cycle by the volume of fluid (VOF) method under different heights of the ionic liquid piston. The effect of liquid height on the wave transformation, discharged quantity of ionic liquid and hydrogen gas, and the turbulence kinetic energy was analysed. The minimum crest value of the turbulent kinetic energy was observed as 0.54 kJ in the cases of 30 and 40 mm. The optimal height of the ionic liquid piston was recommended 40 mm under the presented design condition based on the simulation results.

Introduction to the statistical theory of differential communication based on chaotic signals

The purpose of this paper is to analyse the statistical characteristics of a Direct Chaotic Differentially Coherent communication scheme based on chaotic radio pulses in a communication channel with additive white Gaussian noise, where the chaotic signal is given by different instantaneous distributions. Methods. To achieve this goal, numerical modelling of the noise immunity of Direct Chaotic Differentially Coherent communication is conducted and compared with the results of analytical research. Results. The regularities associated with the use of chaotic signals with various statistical distributions of instantaneous values were studied. The minimum values of energy per bit to white Gaussian noise power spectral density ratio were obtained, providing the required error probabilities. Conclusion. It is shown that the proposed system works efficiently at high values of processing gain, and as the processing gain increases, the dependence of noise immunity on the specific statistical distribution of the chaotic signal is levelled out.

БИОЭЛЕКТРИЧЕСКИЕ ПОТЕНЦИАЛЫ ДРЕВОСТОЯ НА ТЕРРИТОРИИ ТЮМЕНСКОЙ ОБЛАСТИ

For many of us, the forest is mainly represented as a natural part of the environment or an energetically important resource for humanity, which has not yet been fully studied and is capable of discovering something new in itself. In particular, it is proposed to investigate and test a method for determining various electrical parameters of various trees. Finding even the minimum energy values will give an impetus to development, since any electricity is a great luxury for working in a remote forest area. In this paper, the study of electrical potentials in growing coniferous and deciduous trees is considered. One venue is the Nizhnetavdinsky district of the Tyumen region, the other is a forest park in the suburbs of Tyumen. The location of the growing stands was chosen specifically in different conditions, which at the same time makes it possible to trace whether the urban infrastructure affects the internal bioelectric indicators of the growing tree. To identify the electrical parameters, a multifunctional multimeter TESLA DT 832 was used. For his work, two probes were used, one end of which was stuck into the tree, the other into the soil. The tests were carried out in two types of coniferous and deciduous trees with different diameters. To obtain a more accurate picture of the potentials, measurements were made at all periods of the year, with different ambient temperatures and humidity. According to a similar method, measurements were made in a forest park located directly within the suburbs of Tyumen. During the measurements, data on voltage, current strength and resistance in the growing stand were obtained.

Elitist Animal Migration Optimization for Protein Structure Prediction based on 3D Off-Lattice Model

Predicting the structure of protein has been the center of attraction for the researchers. The aim is to make a reliable prediction of the protein structure by obtaining the minimum energy values among amino acids interactions. According to the generated shape of amino acids, the functionality of the proteins can be determined. However, it is known as one of the most challenging tasks in the field of bioinformatics considering its high computation complexity. Metaheuristic algorithms are mainly preferred by researchers from various fields, since their performances are quite satisfactory in solving such complex problems. Animal Migration Optimization (AMO) algorithm is a metaheuristic approach which mimics the behavior of animals during the migration process. However, in this research to reach a high solution quality, an elitist version of Animal Migration Optimization (ELAMO) algorithm is considered and in particular it is applied to Protein Structure Prediction (PSP) problem. The performance of ELAMO is tested on some well-studied artificial and real protein sequences, and then compared with powerful optimization algorithms which are specially designed for solving PSP problem. The results show that ELAMO is quite capable in solving this problem. Hence, it can be used as an efficient optimizer for solving complex problems that require better solution quality in the field of bioinformatics.

The determination of urbach energy and optical gap energy by many methods for Zn doped NiO thin films fabricant semiconductor by spray pyrolysis

The effect of Zn doping on optical, structural and electrical properties of Ni1-xZnxO thin films has been successfully deposited on glass substrate by Spray Pyrolysis technique. The main objective of this research is to study the Ni1-xZnxO thin films to determine the optical gap energy by various methods and compare it with calculated values. The transmission spectra shows that the Ni1-xZnxO thin films have a good optical transparency in the visible region. The optical gap energy varied between 3.50 and 3.75 eV, which was determined by various methods and equations. they are explained in the curves of A, A2 , α, α2 (Ahυ) 2 and (αhυ) 2 as a function of the photon energy hυ. We observed that the suitable method to calculate the optical gap energy is (Ahυ) 2 versus hυ, but this method can't be related to the film thickness. The urbach energy of the Ni1-xZnxO thin films also was determined by the curves of LnA and Lnα as a function of photon energy hυ. We deduced that LnA versus hυ is also suitable to estimate the urbach energy. However, the Ni0.90Zn0.10O thin films have a few defects with minimum value of urbach energy. The Ni0.90Zn0.10O thin films have maximum value of optical gap energy. XRD patterns of the Ni1-xZnxO thin films indicate that films are polycrystalline with cubic structure. The electrical conductivity of our films is in the order of 9*10-3 (Ω.cm)-1 .

Cross electromagnetic nanofluid flow examination with infinite shear rate viscosity and melting heat through Skan-Falkner wedge

Abstract This demonstration of study focalizes the melting transport and inclined magnetizing effect of cross fluid with infinite shear rate viscosity along the Skan-Falkner wedge. Transport of energy analysis is brought through the melting process and velocity distribution is numerically achieved under the influence of the inclined magnetic dipole effect. Moreover, this study brings out the numerical effect of the process of thermophoresis diffusion and Brownian motion. The infinite shear rate of viscosity model of cross fluid reveals the set of partial differential equations (PDEs). Similarity transformation of variables converts the PDEs system into nonlinear ordinary differential equations (ODEs). Furthermore, a numerical bvp4c process is imposed on these resultant ODEs for the pursuit of a numerical solution. From the debate, it is concluded that melting process cases boost the velocity of fluid and velocity ratio parameter. The augmentation of the minimum value of energy needed to activate or energize the molecules or atoms to activate the chemical reaction boosts the concentricity.

Ab Initio Calculation of Ground- and Low-Excited-State Spectroscopic Data and Transition Properties of SBr.

In this paper, potential energy curves of Λ-S and Ω states of SBr+ are reported for the first time, and the spectrum data of some low excited bound states are obtained. The differences in the spectrum properties of main-group molecules and SBr+ were compared and analyzed, providing a sufficient theoretical basis for the subsequent study of main-group molecules. The avoided crossing that occurs in the Ω state is analyzed, and finally it is concluded that this phenomenon mainly occurs in the energy region between 20,000 and 40,000 cm-1 that is relative to the minimum energy value. Potential transitions in the Ω state capable of achieving laser cooling of SBr+ are explored. The Franck-Condon factor, radiation lifetime, and Einstein coefficient between X3Σ0+- and b1Σ0++ are calculated. From the calculation results, we concluded that direct laser cooling of SBr+ is not feasible. What we have studied in this paper provides a theoretical basis for subsequent computational exploration of the spectrum properties of SBr+.

The effect of fermentation time on fruits as a producer electrical energy

The need for electrical energy is growing, and so is the demand for alternative energy. Fruits with high acidity can generate electrical power. The fermentation process can enhance the acidity of the fruit. The lower the pH, the higher the voltage and current generated. This study aims to obtain electrical energy by testing the potential of fruits for induced current, voltage, power, resistance and electrical energy. The experimental parameters are current, voltage, power, resistance and electrical energy. Three fruits (soursop, mango, and tamarind) with three different fermentation times (9, 11, and 13 days) were used in a two-factor, fully randomised design procedure. The results show a tamarind fruit with a fermentation time of 13 days, the highest voltage, current, power and electrical energy values of 5.62 Volts, 1.52 mA, 8.54 mW, 672.30 mWh and a resistance value of 1.800 ohms. Soursop fruits with a fermentation time of 9 days provided minimum voltage, current, power, and electrical energy values of 4.52 volts, 0.93 mA, 4.20 mW, and 265.26 mWh, and a resistance value of 2.118 ohms. The type of fruit and the varying fermentation time had a very significant effect at the 1% level on current, voltage, resistance, power and energy of electricity.

ФІЗИЧНІ І ТЕХНІКО-ЕКОНОМІЧНІ АСПЕКТИ СУЧАСНИХ МЕТОДІВ ПІДГОТОВКИ ВОДИ ДЛЯ ТЕПЛОВОЇ ТА АТОМНОЇ ЕНЕРГЕТИКИ

A critical analysis of modern electric-physical and electric-chemical methods of water treatment is given in the context of the efficiency of treatment surface natural waters for the thermal and nuclear power engineering. Physical aspects of electric-chemical coagulation are considered. Theoretical values of the specific energy of destruction of passivation films on the surface of aluminum and iron electrodes, as well as the minimum voltages required for this, are calculated. The mechanisms of conversion of the energy of discharge pulses in a layer of granules of metal forming a coagulant immersed in water are described. According to the described model of energy conversion processes, the minimum theoretical values of the specific energy of the formation of erosive Al and Fe particles from molten and evaporated metal are calculated. A technique for studying the energy efficiency of plasma-erosion coagulation under laboratory conditions is described, and the results of these studies are presented. The specific energy of purification of 1 m3 of water by electric-chemical and plasma-erosion coagulation was calculated in various modes using Al and Fe as metals forming the coagulant. Based on the analysis of the obtained results, recommendations for ways to improve the energy efficiency of plasma-erosion coagulation modes are given. References 29, figure 1, table 1.

Chemical looping gasification characteristics and kinetic analysis of Chlorella and its organic components

Chemical looping gasification (CLG) characteristics and kinetic analysis of Chlorella (CHL), simulated Chlorella (V-CHL) and medium-chain triglycerides (MCT) were investigated using a thermogravimetric analyzer coupled with an online mass spectrometer. The apparent activation energy was obtained via Kissinger-Akahira-Sunose (KAS) method. In the result of the weightless behavior, the addition of oxygen carrier inhibited the decomposition of V-CHL at lower temperatures but promoted its decomposition at high temperatures. The values of chemical looping process characteristic parameters showed that a 10 wt% oxygen carrier would maximize the release of volatile products in the CLG of MCT, with 5.12 × 10−6 %·min−1·oC−3. Oxygen carriers also affected gaseous products. The LHV of gaseous products of CHL reached the largest when the oxygen carrier was 10 wt%, which was 8.13 MJ/m3. And the gaseous product of MCT had the largest LHV with 30 wt% oxygen carrier, which was 8.83 MJ/m3. According to the kinetic analysis, the minimum value of apparent activation energy of MCT chemical looping gasification was 89.54 kJ·mol−1 with the oxygen carrier of 30 wt%, which was 50% less than that of MCT pyrolysis. And the minimum value for V-CHL was obtained when the mass fraction of Fe2O3 was 50 wt%. This paper could provide a reference for the choice of algae, the design of reactors, and the targeted regulation of the gaseous product for the algae CLG process.

MWNTs on NiCu-a-C: H substrates: Study of optical linear equations, optical density, steepness and electron-phonon interaction

In this article, the optical density (Dopt) and the skin depth (δ) of films were estimated and discussed. The skin depth of NiCu-a-C: H films contenting 0% Cu in the optical band gap range was higher than other films and the maximum value is about 190 nm. Also, optical energy gap, Urbach energy, or the band tail width and Urbach parameters are calculated for thin films. By increasing the Cu percentage of films up to 5% the optical density of films was increased and then from 5% to 75% the optical density of films was decreased. The energy band gap and the width of the Urbach tail can be presented by linear relation Eg = 2.6 − 1.48 Eu. To observe the broadening of the optical absorption edge due to carrier interactions, the steepness parameter (σ) was evaluated; films deposited with 5% Cu have maximum value of the steepness parameter in about of 4.08. Electron-phonon interaction in films deposited with 5% Cu has minimum value in about of 16.4. Films deposited with 75% Cu have minimum values of the dispersion energy (Ed) and the single-oscillator energy ( E 0) in about of 17.83 and 3.46 eV, respectively. With considering Nc = 8, Za = 1, Ne = 8 for these films, the coordination number constants β were calculated and for films deposited with Ni pure (0% Cu) it has maximum value in about of 0.36.

Probable decay modes of even–even superheavy nuclei

Cluster-decay half-lives () of even–even nuclei are calculated employing interaction potential involving Coulomb and proximity potentials and, the obtained results are compared with the experimental ones. In order to study cluster radioactivity in even–even superheavy nuclei (SHN), we evaluate the required disintegration energies (Q c -values) utilizing periodic-orbit theory within microscopic-macroscopic formalism and hence, predict the logarithmic values of 's for even–even 298−312Og and 296−310120 nuclei. Among various isotopes of daughter nuclei, products produced with minimum value of Gibbs free energy are chosen for our investigation. Also, an analysis of the branching ratios enables us to determine the dominant mode of decay among α − decay, spontaneous fission (SF) and cluster-decay in these SHN. The emissions of 90Kr from 298Og and 94Sr cluster from 296,298120 SHN are found to be the dominant mode of decay. Our results are in agreement with those obtained using UDL method except for few cases. We believe that this work can play a significant role in the experiments leading to identification of exotic nuclei.

Optimization of energy surface of thiophene-benzothiazole derivative Schiff base molecule with fuzzy logic modelling

In this paper, Fuzzy Logic Approach (FLA) is utilized to optimize the energy of thiophene-benzothiazole derivative Schiff base C18H12N2OS2 molecule together with Density Functional Theory (DFT) calculations. The model has been established according to the theoretical results achieved by the DFT/B3LYP level of theory along with 6-31G(d) basis set on the Gaussian 09 program. We have constructed the continuous energy structure of the molecule depending on two torsional angles D1(C15N1C3S2) and D2(C11C10C18S22) of thiophene-benzothiazole derivative Schiff base molecule. Thus, the constructed model is used to get the results for the untested data, and to obtain minimum energy value by conceivable time cost and great accuracy. Finally, we have shown that the FLA method gives reliable results for the optimization of the structure of the thiophene-benzothiazole derivative Schiff base molecule with minimum energy, when we compared our results with the DFT results using regression analysis.

Radioactivity of even–even superheavy nuclei with Z = 122, 124 and 126

Employing Coulomb and proximity potentials, cluster-decay half-lives ([Formula: see text]) of even–even nuclei had been calculated and, the obtained results are compared with the experimental ones. To investigate cluster radioactivity in superheavy nuclei (SHN), we determine the required disintegration energies ([Formula: see text]-values) utilizing periodic-orbit theory within microscopic-macroscopic formalism and hence, predict the logarithmic values of [Formula: see text] for even–even SHN with [Formula: see text], 124 and 126. Among various isotopes of daughter nuclei, products produced with minimum value of Gibbs free energy are chosen for our investigation. Moreover, study of the branching ratios would make us to find the dominant mode of decay among [Formula: see text]-decay, spontaneous fission (SF) and cluster-decay in these SHN. Mostly, the emissions of Kr-, Sr-, Zr- and Mo-clusters from these superheavy nuclei are found to be the dominant modes of decay which can be attributed to strong shell effects in the neighborhood of [Formula: see text] region. Our results are in agreement with those obtained using UDL method except for few cases. We believe that this work can play a significant role in the study of decay properties of superheavy nuclei.

Magnetic Energy Minimization for Suppressing Magnetic Field Intensity of Inductive Power-Transfer Systems

This study solves the magnetic energy minimization problem in inductive power-transfer systems to suppress the magnetic field intensity and formulate the lowest boundary of the magnetic energy. The theoretical analysis shows that the minimum value of the magnetic energy is a function only of the coupling coefficient, quality factor of a receiver, and transmitting power and it converges to 0 under the condition that the coils and their coupling are ideal. The electromagnetic simulations verify the suppression effects of the magnetic field intensity by magnetic energy minimization and show quite a small loss in the transfer efficiency.