Induction Forces Research Articles

Calculation of resonance frequencies of electrons present in the contact area of two semiconductors

Two multielectron atoms with valence bond have been considered. Oscillations of the valence electron were determined with due regard for the influence of two nuclei and electron gas. The resonance frequencies were determined with due regard for the gradient induction forces of electric field. The electric equivalent circuit has been found. The causes of the changing polarity of the electromotive force (emf) depending on the frequency of the monochromatic electric field applied to the contact are explained.

Structures and IR/UV spectra of neutral and ionic phenol–Arn cluster isomers (n≤ 4): competition between hydrogen bonding and stacking

The structures, binding energies, and vibrational and electronic spectra of various isomers of neutral and ionic phenol-Ar(n) clusters with n ≤ 4, PhOH((+))-Ar(n), are characterized by quantum chemical calculations. The properties in the neutral and ionic ground electronic states (S(0), D(0)) are determined at the M06-2X/aug-cc-pVTZ level, whereas the S(1) excited state of the neutral species is investigated at the CC2/aug-cc-pVDZ level. The Ar complexation shifts calculated for the S(1) origin and the adiabatic ionisation potential, ΔS(1) and ΔIP, sensitively depend on the Ar positions and thus the sequence of filling the first Ar solvation shell. The calculated shifts confirm empirical additivity rules for ΔS(1) established recently from experimental spectra and enable thus a firm assignment of various S(1) origins to their respective isomers. A similar additivity model is newly developed for ΔIP using the M06-2X data. The isomer assignment is further confirmed by Franck-Condon simulations of the intermolecular vibrational structure of the S(1) ← S(0) transitions. In neutral PhOH-Ar(n), dispersion dominates the attraction and π-bonding is more stable than H-bonding. The solvation sequence of the most stable isomers is derived as (10), (11), (30), and (31) for n ≤ 4, where (km) denotes isomers with k and m Ar ligands binding above and below the aromatic plane, respectively. The π interaction is somewhat stronger in the S(1) state due to enhanced dispersion forces. Similarly, the H-bond strength increases in S(1) due to the enhanced acidity of the OH proton. In the PhOH(+)-Ar(n) cations, H-bonds are significantly stronger than π-bonds due to additional induction forces. Consequently, one favourable solvation sequence is derived as (H00), (H10), (H20), and (H30) for n ≤ 4, where (Hkm) denotes isomers with one H-bound ligand and k and m π-bonded Ar ligands above and below the aromatic plane, respectively. Another low-energy solvation motif for n = 2 is denoted (11)(H) and involves nonlinear bifurcated H-bonding to both equivalent Ar atoms in a C(2v) structure in which the OH group points toward the midpoint of an Ar(2) dimer in a T-shaped fashion. This dimer core can also be further solvated by π-bonded ligands leading to the solvation sequence (H00), (11)(H), (21)(H), and (22) for n ≤ 4. The implications of the ionisation-induced π → H switch in the preferred interaction motif on the isomerisation and fragmentation processes of PhOH((+))-Ar(n) are discussed in the light of the new structural and energetic cluster parameters.

(알니코, 사마리움-코발트) 본드자석의 제조 및 자기적 특성연구

In this study the (Alnico, Sm-Co) bonded magnets were fabricated by mixing the Sm-Co added alnico alloy powders with epoxy resin and binder, appropriately. Also, the hybrid ring magnets of (Alnico, Sm-Co)/Sr-ferrite were fabricated by coupling the Sr-ferrite composite layer with an (Alnico, Sm-Co) magnet. The magnetic properties of (Alnico, Sm-Co) ring magnets were varied with the amount of Sm-Co powders. The addition of Sm-Co powders increased a remanent induction() and coercive force(), while decreasing a surface flux density and repulsive distance. The surface flux density and repulsive distance for the (Alnico, Sm-Co) ring magnet increased with a magnetizing voltage up to about 160 V and reached an apparent saturation point. Also, the measurements of temperature and moisture characteristics showed that the surface flux densities of N-S poles and repulsive distance decreased a little within 4% after 10 days passed.

Charge-Transfer Energy in the Water−Hydrogen Molecular Aggregate Revealed by Molecular-Beam Scattering Experiments, Charge Displacement Analysis, and ab Initio Calculations

Integral cross-section measurements for the system water-H(2) in molecular-beam scattering experiments are reported. Their analysis demonstrates that the average attractive component of the water-H(2) intermolecular potential in the well region is about 30% stronger than dispersion and induction forces would imply. An extensive and detailed theoretical analysis of the electron charge displacement accompanying the interaction, over several crucial sections of the potential energy surface (PES), shows that water-H(2) interaction is accompanied by charge transfer (CT) and that the observed stabilization energy correlates quantitatively with CT magnitude at all distances. Based on the experimentally determined potential and the calculated CT, a general theoretical model is devised which reproduces very accurately PES sections obtained at the CCSD(T) level with large basis sets. The energy stabilization associated with CT is calculated to be 2.5 eV per electron transferred. Thus, CT is shown to be a significant, strongly stereospecific component of the interaction, with water functioning as electron donor or acceptor in different orientations. The general relevance of these findings for water's chemistry is discussed.

Dynamic evolution of welding residual stress field under noncontact electromagnetic force

Controlling welding residual stress and distortion has still been a challenging problem due to the complexity of welding process. In this paper, a new technique with inductive electromagnetic forces has been reported for controlling welding residual stresses and distortion in welded thin plate. In order to get better understanding the associated mechanism, a hybrid three-dimensional finite element analysis, including electromagnetic force induction, welding, and electromagnetic force impact processes, has been performed to investigate the dynamic evolution of stress and strain in the welded plate under electromagnetic force impact. It is found that transient electromagnetic impact causes the mechanical response with the obvious strain rate sensitivity, and complex variation in stress and strain states in the welded plate occurs due to combination action of electromagnetic force and welding residual stress. As a result, the incompatible degree of strain field, arising from welding thermal cycle, is reduced. The residual stresses also finally fall, although the flow stress rises during electromagnetic impact. The measurement results of microhardness also indicate that the plastic strain state in local weld region is indeed changed under electromagnetic impact. Finally, continuous electromagnetic impacts experiments are conducted, and results show that this approach is very successful for reducing welding residual stresses and distortion in welded thin plates, without any impairment of appearance and performance.

A theoretical study of hydrogen adsorption on Li, Be, Na, and Mg atoms attached to aromatic hydrocarbons

The binding energy of a hydrogen molecule on metal atoms (Li, Be, Na, and Mg) attached to aromatic hydrocarbon molecules (benzene and anthracene) was calculated using an ab initio molecular orbital method at the MP2(FC)/cc-pVTZ level with basis set superposition error (BSSE) correction. The energy tended to become more negative as the metal atom had a more positive charge and a smaller radius. The energies of Li2C6H6-H2, Li2C14H10-H2, Na2C14H10-H2, and MgC14H10-H2 were −2.7 to −2.2, −4.0 to −3.1, −2.8 to −0.3, and −1.3 kcal/mol, respectively. Most of these energies were more negative than those on the hydrocarbons without metal atoms (ca. −1 kcal/mol). Analyzing the Lennard–Jones type potential with the parameters determined by the MP2 calculations, it was found that these energies mainly consisted of the induction force caused by the positive charge of the metal atom and the dispersion force from the nearest C6-ring. The energy of BeC14H10-H2 was more negative (−8.6 kcal/mol) than of the other complexes. The hydrogen molecule in this complex had a comparatively longer H–H distance and a more positive H2 charge than the others. These data suggest that the hydrogen adsorption on this complex involves a charge transfer process in addition to physisorption interactions. The hydrogen binding energies in some Li2C14H10-H2 systems (∼−4.0 kcal/mol) and BeC14H10-H2 are promising to operate hydrogen storage/release at ambient temperature with moderate pressure.

Soluble and insoluble signals sculpt osteogenesis in angiogenesis.

The basic tissue engineering paradigm is tissue induction and morphogenesis by combinatorial molecular protocols whereby soluble molecular signals are combined with insoluble signals or substrata. The insoluble signal acts as a three-dimensional scaffold for the initiation of de novo tissue induction and morphogenesis. The osteogenic soluble molecular signals of the transforming growth factor-β (TGF-β) supergene family, the bone morphogenetic/osteogenic proteins (BMPs/OPs) and, uniquely in the non-human primate Papio ursinus (P. ursinus), the three mammalian TGF-β isoforms induce bone formation as a recapitulation of embryonic development. In this paper, I discuss the pleiotropic activity of the BMPs/OPs in the non-human primate P. ursinus, the induction of bone by transitional uroepithelium, and the apparent redundancy of molecular signals initiating bone formation by induction including the three mammalian TGF-β isoforms. Amongst all mammals tested so far, the three mammalian TGF-β isoforms induce endochondral bone formation in the non-human primate P. ursinus only. Bone tissue engineering starts by erecting scaffolds of biomimetic biomaterial matrices that mimic the supramolecular assembly of the extracellular matrix of bone. The molecular scaffolding lies at the hearth of all tissue engineering strategies including the induction of bone formation. The novel concept of tissue engineering is the generation of newly formed bone by the implantation of "smart" intelligent biomimetic matrices that per se initiate the ripple-like cascade of bone differentiation by induction without exogenously applied BMPs/OPs of the TGF-β supergene family. A comprehensive digital iconographic material presents the modified tissue engineering paradigm whereby the induction of bone formation is initiated by intelligent smart biomimetic matrices that per se initiate the induction of bone formation without the exogenous application of the soluble osteogenic molecular signals. The driving force of the intrinsic induction of bone formation by bioactive biomimetic matrices is the shape of the implanted substratum. The language of shape is the language of geometry; the language of geometry is the language of a sequence of repetitive concavities, which biomimetizes the remodelling cycle of the primate osteonic bone.

Air and landfill gas movement through passive gas vents installed in closed landfills

In a closed landfill, Japan, remedial actions have been undertaken to address the inadequate leachate collection and drainage systems. Part of this process included installing many passive gas vents in the landfill to promote stabilization of landfilled waste. This study focused on the gas velocity in vents by conducting tracer tests to elucidate the gas flow via passive gas vents. The gas composition and gas temperature in the vents was also measured. As the gas vents pass through the waste layer, both landfill gas and air flows through the vents. Therefore, passive gas vents can be used to aerate landfilled waste as well as to collect and release landfill gas. Aerobic biodegradation occurs when air migrates through the waste layer if organic matter is present; this increases the temperature of the waste layer. Inflow of air into the gas vents can occur at a wide range of depths, even 10–20 m below ground level. Air is induced not from the surface of the landfill, but horizontally along the waste layer. The driving force of air induction from outside is a buoyancy effect caused by the temperature rise due to aerobic biodegradation.

Generation of method AC Ampere force using eddy current inside a nonmagnetic thin plate and its effect on electrodynamic suspension

AbstractIn this paper, we propose a novel method for magnetic levitation force generation. In our method, we utilized three AC electromagnets that generate the inductive and AC Ampere forces. One electromagnet is installed above the surface and the other two in both sides of thin plate. Phase conditions providing the maximum levitation force are derived from 2‐dimensional finite element analysis. In order to confirm the performance of the proposed method, we performed some experiments. The experimental results show that in difference from conventional AC methods, the magnetic levitation force is increased around 5.9 times for the same eddy current inside the aluminum plate. In addition, the relations between excitation frequency, plate thickness and total levitation force are explained in details. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(3): 48–56, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20905

Ab initio Study of the Interactions between CO2 and N‐Containing Organic Heterocycles

In the garden of dispersion: High-accuracy ab initio calculations are performed to determine the nature of the interactions and the most favorable geometries between CO(2) and heteroaromatic molecules containing nitrogen (see figure). Dispersion forces play a key role in the stabilization of the dimer, because correlation effects represent about 50 % of the total interaction energy. The interactions between carbon dioxide and organic heterocyclic molecules containing nitrogen are studied by using high-accuracy ab initio methods. Various adsorption positions are examined for pyridine. The preferred configuration is an in-plane configuration. An electron donor-electron acceptor (EDA) mechanism between the carbon of CO(2) and the nitrogen of the heterocycle and weak hydrogen bonds stabilize the complex, with important contributions from dispersion and induction forces. Quantitative results of the binding energy of CO(2) to pyridine (C(5)H(5)N), pyrimidine, pyridazine, and pyrazine (C(4)H(4)N(2)), triazine (C(3)H(3)N(3)), imidazole (C(3)H(4)N(2)), tetrazole (CH(2)N(4)), purine (C(5)H(4)N(4)), imidazopyridine (C(6)H(5)N(3)), adenine (C(5)H(5)N(5)), and imidazopyridamine (C(6)H(6)N(4)) for the in-plane configuration are presented. For purine, three different binding sites are examined. An approximate coupled-cluster model including single and double excitations with a perturbative estimation of triple excitations (CCSD(T)) is used for benchmark calculations. The CCSD(T) basis-set limit is approximated from explicitly correlated second-order Møller-Plesset (MP2-F12) calculations in the aug-cc-pVTZ basis in conjunction with contributions from single, double, and triple excitations calculated at the CCSD(T)/6-311++G** level of theory. Extrapolations to the MP2 basis-set limit coincide with the MP2-F12 calculations. The results are interpreted in terms of electrostatic potential maps and electron density redistribution plots. The effectiveness of density functional theory with the empirical dispersion correction of Grimme (DFT-D) is also examined.

Prospects for sympathetic cooling of polar molecules: NH with alkali-metal and alkaline-earth atoms – a new hope

We explore the potential energy surfaces for NH molecules interacting with alkali-metal and alkaline-earth atoms using highly correlated ab initio electronic structure calculations. The surfaces for interaction with alkali-metal atoms have deep wells dominated by covalent forces. The resulting strong anisotropies will produce strongly inelastic collisions. The surfaces for interaction with alkaline-earth atoms have shallower wells that are dominated by induction and dispersion forces. For Be and Mg the anisotropy is small compared to the rotational constant of NH, so that collisions will be relatively weakly inelastic. Be and Mg are thus promising coolants for sympathetic cooling of NH to the ultracold regime.

Modeling of Linear Gas Tungsten Arc Welding of Stainless Steel

A heat and fluid flow model has been developed to solve the gas tungsten arc (GTA) linear welding problem for austenitic stainless steel. The moving heat source problem associated with the electrode traverse has been simplified into an equivalent two-dimensional (2-D) transient problem. The torch residence time has been calculated from the arc diameter and torch speed. The mathematical formulation considers buoyancy, electromagnetic induction, and surface tension forces. The governing equations have been solved by the finite volume method. The temperature and velocity fields have been determined. The theoretical predictions for weld bead geometry are in good agreement with experimental measurements.

A comparison of nonspecific solvent scales. Degree of agreement of microscopic polarity values obtained by different measurement methods

The active role of solvents in physicochemical processes in solution has long been recognized. Different solvatochromic empirical scales are aimed at describing and quantifying the nonspecific interactions at a molecular level. This work presents a new insight into the comparison of the famous ET(30) (Dimroth-Reichardt) and π* (Kamlet, Abboud, Taft) solvatochromic scales. These parameters were tested against the data derived from theoretical solvent-induced shifts in the UV-vis spectra of the corresponding reference solutes (Matyushov et al.). In each case we centered the attention on the analysis of the degree of agreement between paired values quantified through both scales by applying the methodology described by J. M. Bland and D. G. Altman. In addition, the linear correlations are assessed. The study reflects that (a) the scales involved in this comparison are clearly dependent on the type of probe used to quantify the solvent property, and (b) the experimental parameters, in general, do not agree with the theoretical ones. These results were related with the contributions of induction, dispersion and dipole-dipole forces to the overall solvent effect. It is expected that the results will contribute to the evaluation of the microscopic chemical scales ability to describe the solute-solvent interactions.

Generation Method of AC Ampere Force Using Eddy Current inside a Non-Magnetic Thin Plate and it's Effect on Electro Dynamic Suspension

In this paper, we propose a novel method for magnetic levitation force generation. In our method, we utilized three AC electromagnets that generate the inductive and AC Ampere forces. One electromagnet is installed above the surface and the other two in the both sides of a thin plate. Phase conditions providing the maximum levitation force are derived from 2-dimentional finite element analysis. In order to confirm the performance of the proposed method, we performed some experiments. The experimental results show that in difference from conventional AC methods, the magnetic levitation force is increased around 5.9 times for the same eddy current inside the aluminum plate. In addition, the relations between excitation frequency, plate thickness and total levitation force are explained in details.

Nonspecific solvation and oscillator strengths for the long-wavelength vibronic absorption band of 4-dimethylaminochalcone solutions

The 4-dimethylaminochalcone molecule is one of the most efficient spectral-luminescent probes widely used in various medical and biological studies. Experimental data on the oscillator strengths in the long-wavelength vibronic band of 4-dimethylaminochalcone solutions in a series of individual solvents of different chemical nature are analyzed using the earlier derived refined equation describing the influence of nonspecific solvation processes on the matrix elements of the dipole moment of a purely electronic transition in organic dye molecules. It is shown that the semiempirical theory developed gives a satisfactory quantitative explanation to experimentally observed regularities indicative of a relatively weak influence of the solvent reaction field (orientation and induction forces) and dispersion interactions on the integrated intensity of the studied band belonging in the category of intramolecular charge transfer bands.

Parallel algorithms for molecular dynamics with induction forces

We examine parallel algorithms for molecular dynamics simulations involving long-range induction interactions. The algorithms are tested by performing molecular dynamics simulations of water with an intermolecular potential that explicitly includes contributions from pair, three-body and induction interactions. Both cyclic and balanced force decomposition methods are implemented to decompose the parallelizable components of induction, pair and three-body interactions using a message passing interface. We report that more than 90% of the induction calculation, and 98% of the total calculation can be effectively parallelized. A reasonably good speedup of 15.7 times and an efficiency of 49.1% are obtained on 32 processors with the balance force decomposition algorithm.

Magnetic properties and α′ martensite quantification in an AISI 301LN stainless steel deformed by cold rolling

Ferromagnetic properties of cold worked AISI 304 and 304L steels have been studied by many authors. The AISI 301LN steel has lower chromium and nickel contents than AISI 304L and 0.1–0.15%N addition. This steel presents a higher work hardening rate due to its higher susceptibility to martensite formation during cold deformation. In the present work the magnetic properties (magnetization saturation, residual induction and coercive force) of cold rolled AISI 301LN steel were investigated. Different degrees of deformation were applied. The dependence of the saturation magnetization on the amount of deformation is modeled by an exponential decay law. An increase in the amount of deformation also promotes a decrease of coercive force. Heat treatments at 350 °C and 400 °C after deformation were also applied and found to increase the magnetization saturation values.

Calculating Interaction Energies Using First Principle Theories: Consideration of Basis Set Superposition Error and Fragment Relaxation

The use of computational chemistry tools has become prevalent in a wide variety of research areas. Many researchers are using computational chemistry as an additional tool to explore and gain insight into the problems they are researching. As such it is important to educate future scientists in the capabilities and proper implementation of theoretical tools. In this article we explain a difficult aspect of computational chemistry: calculating accurate interaction energy by correcting for basis set superposition error and fragment relaxation. There are four fundamental methods to calculate an interaction energy using ab initio theory, two of which take into account basis set superposition error. Using the methanol�water complex as a model, we demonstrate how to calculate an interaction energy using these four different methods. Additionally, we perform a comparison of the interaction energies and examine the magnitude of basis set superposition error as a function of basis set size. Fragment relaxation will be discussed in relation to these methods and is an indication of the magnitude of the inductive forces for each monomer.

Do Maxwell's Equations Need Revision? A Methodological Note.

We propose a modification of Maxwell's macroscopic fundamental set of equations in vacuum in order to clarify Faraday's law of induction. Using this procedure, the Lorentz force is no longer separate from Maxwell's equations. The Lorentz transformations are shown to be related to the convective derivative, which is introduced in the electrodynamics of moving bodies. The new formulation is in complete agreement with the actual set of Maxwell's equations for bodies at rest, the only novel feature is a new kind of electromotive force. Heinrich Hertz was the first to propose a similar electrodynamic theory of moving bodies, although its interpretation was based on the existence of the so called "aether". Examining the problem of a moving circuit with this procedure, it is shown that a new force of induction should act on a circuit moving through an inhomogeneous vector potential field. This overlooked induction force is related to the Aharanov-Bohm effect, but can also be related to the classical electromagnetic field when an external magnetic field is acting on the system. Technological issues, such as the so called Marinov motor are also addressed.

First principles molecular dynamics of molten NaCl

First principles Hellmann-Feynman molecular dynamics (HFMD) results for molten NaCl at a single state point are reported. The effect of induction forces on the structure and dynamics of the system is studied by comparison of the partial radial distribution functions and the velocity and force autocorrelation functions with those calculated from classical MD based on rigid-ion and shell-model potentials. The first principles results reproduce the main structural features of the molten salt observed experimentally, whereas they are incorrectly described by both rigid-ion and shell-model potentials. Moreover, HFMD Green-Kubo self-diffusion coefficients are in closer agreement with experimental data than those predicted by classical MD. A comprehensive discussion of MD results for molten NaCl based on different ab initio parametrized polarizable interionic potentials is also given.