New Method For Calculation Research Articles

A new method for calculation of island-size distribution in submonolayer epitaxial growth

In this paper, a novel method for calculation of island-size distribution in one-dimensional submonolayer epitaxial growth based on difference-differential rate equations is introduced. Moreover, precise analytic expressions for the first several Taylor coefficients of the distribution (with respect to the ratio of diffusion and deposition rates) are obtained and the corresponding error term is estimated.

Electrical resistivity of liquid binary and ternary alloys

New method of calculation of the electrical resistivity of liquid and amorphous alloys is presented. The method is based on the Morgan–Howson–S̆aub (MHS̆) model but the pseudopotentials are replaced by the scattering matrix operators. The Fermi energy is properly determined by the accurate values of the phase shifts. The model depends on a very small number of universal parameters and gives stable results. The calculated values of the resistivity agree well with available experimental data for a substantial number of binary alloys. Moreover, the results for some ternary alloys were also obtained.

Full Height Frame Integral Bridges Abutment-Backfill Interaction in Loose Granule Backfill

The abutment wall behavior of full height frame integral bridges in loose granule backfill under temperature changes was investigated within this study. Since, the effect of backfill soil resistance on behavior of abutment wall movement was mostly neglected in previous researches, the abutment-backfill interaction was selected as the research study area and therefore, deriving the final abutment displacement profile was set as the research objective. In frame abutment integral bridges, the superstructure is encased into the abutment wall in which produces a fixed connectivity. This connection results in the same movement of abutment top elevation and the bridge superstructure. Furthermore, the abutment is mostly built in reinforced concrete, thus it acts as a rigid mass with a linear deformation behavior. With regard to these points and applying a new method for calculation of bridge deck displacement, the abutment deformation profile was formulated. In the new applied method, the final bridge deck displacement was expressed as a function of backfill soil resistance utilizing some available correlations due to soil behavior, such as British Standard, Massachusetts, Canadian and Husain-Bagnaroil. Fortunately, the results obtained from these correlations were in a close agreement with each other, which confirmed the integrity of applied method. Moreover, a finite element model was built in SAP2000 for this case and subsequently the outcomes were compared with the results of applied method. It was seen that both results were consistent and in most of the cases, the British Standard concluded the closets results to the finite element as compared with the others.

Complex and bi-Hermitian structures on four-dimensional real Lie algebras

We give a new method for calculation of complex and bi-Hermitian structures on low-dimensional real Lie algebras. In this method, using non-coordinate basis, we first transform the Nijenhuis tensor field and bi-Hermitian structure relations on Lie groups to the tensor relations on their Lie algebras. Then we use adjoint representation for writing these relations in the matrix form; in this manner by solving these matrix relations and using automorphism groups of four-dimensional real Lie algebras we obtain and classify all complex and bi-Hermitian structures on four-dimensional real Lie algebras.

New method for calculation of intensities of X-rays and thermal neutrons scattered dynamically in defected single crystals

We propose a new method for calculating intensities of X-rays and thermal neutrons, dynamically scattered in defected single crystals by comparing the dynamical theory of Bragg diffraction of X-rays and thermal neutrons in perfect single crystals with the theory of their small-angle scattering.

New technique for calculation of well deliverability in gas condensate reservoirs

Well deliverability is an important issue in forecasting the performance of many gas condensate reservoirs. Condensate accumulations near the wellbore may cause a significant reduction in the well productivity, even in the case of very lean fluids. Generally, the well deliverability is affected by two pressure-drop sources due to depletion and condensate buildup. Recently rapid spreadsheet tools have been developed to evaluate the well performance using material balance equation for depletion and two-phase pseudo pressure integral for well inflow performance. Most of them account for the effects of negative inertia and positive coupling in the calculation of gas relative permeabilities. This paper introduces a new method for calculation of well productivity in gas condensate reservoirs. This method uses the concept of two-phase pseudo pressure integral without any need to estimate the radius of two-phase region. In this approach the average reservoir pressure is calculated by using a general material balance equation. The only data required for implementing this method is PVT data, relative permeability curves and a table of well flowing pressure versus time. The new technique can be encoded on a spreadsheet in order to forecast the gas condensate well performance very rapidly. To validate the proposed approach we have used several single-well fine grid compositional simulations of a hypothetical reservoir model over a typical range of gas condensate reservoir parameters. We have shown that there is a reasonable agreement between the result of fine grid simulation and the prediction from the proposed approach.

A New Method for Calculation the Ball Grading of a Ball Mill

Through the analysis of the interaction form between steel balls and the material in Micro-level, the primary form in different areas confirmed and the requirement of ball grading presented. The different methods of ball grading and the different influence on the interaction between steel balls and the material clarified. At last, a clear description of the calculation method of the ball grading made through an example.

A new method of calculation of internuclear distances in molecules and crystals

It was shown that the earlier derived equation for calculation of the lattice energy of ionic crystals contains a term that can characterize the radius of the overlap region of the electron clouds of interacting atoms. On this basis, simple and rather exact formulas were derived for the calculation of internuclear distances in crystals and molecules. The error of calculation R12 is from 1.2% (for crystalline Group IA metal halides) to 3.8–5.7% (for various gaseous molecules). The coordination of ions was shown to be essential for determining internuclear distances. The adequacy of the Stuart-Briegleb model of molecular structure was confirmed.

NEW FORMULATION OF THE ITERATIVE METHOD: APPLICATION TO A MICROWAVES ATTENUATOR

In this article, we developed a new method of calculation of the active microwaves circuits in micro ribbon technology. This technique is based on the iterative method where localised auxiliary sources are introduced to model the active elements of the circuit (ultra high frequency diodes). To validate this work, the results obtained are compared with those obtained by the software momentum of advanced design system (ADS). We show primarily the interests and the operational limits of auxiliary source in the formulation of the considered problem.

Thermodynamics in an icy world: The atmosphere and internal structure of Saturn's moon Titan

Abstract Thermodynamic principles can be applied for describing the atmospheres and the internal structure of celestial bodies using Saturn's moon Titan as a most appropriate example. Some basic physical data of Titan such as the measured temperature and pressure on its surface, the atmospheric composition, Titan’s density and diameter, and other information allow us to predict further properties which have not been determined directly by measurements. The existence of a liquid phase covering smaller parts of the surface can be confirmed, and the composition of the liquid can be predicted. The change of temperature with the height over the surface and the appearance of clouds and rainfall in the atmosphere consisting essentially of CH4 + N2 mixtures can also be predicted. By developing a new method of calculation of atmospheric scenarios, the chemical history of Titan’s surface and atmosphere can be roughly reconstructed taking into account the known rate of methane destruction caused by radiative absorption of sunlight. Finally, some estimations concerning the material structure and the pressure behavior of Titan’s interior can be made. Only basic knowledge of thermodynamics and physics is required to understand essential features in a strange world that is more than one billion kilometers away from us.

A fuzzy approach for solving a critical benchmarking problem

Nowadays, benchmarking is a widespread technique for evaluating an aspect—process, product, service, etc.—by comparing it against the best in class with the aim of improving this aspect or identifying the best alternative. There have been numerous attempts at defining a rigorous benchmarking process by specifying steps that should be taken to put benchmarking into practice. All these proposals use a method of calculation that treats the weights and ratings of each criterion as numerical variables, even if they are not. This means that the binary and linguistic variables have to be artificially translated to numerical variables, misleading us into thinking that the concepts we are dealing with are quantitative when they really are not. In this paper, we propose a new method of calculation based on fuzzy logic to rectify this key methodological error. Its definition is based on: (i) a new division operator for fuzzy numbers representing conjugated variables, as in the case outlined here; (ii) a new aggregation operator that can integrate binary, numerical and/or linguistic variables; and, finally, (iii) an operator that can translate the final fuzzy rating into the linguistic variable that best represents it. Therefore, the resulting method is: (i) closer to the user since it manages more human-understandable values and (ii) not dependent on the above artificial translation process, which could lead to sizeable variations in the benchmarking result.

Modeling of the ground motion for the Petropavlovsk earthquake of November 24, 1971 (M = 7.6)

Based on the example of the strong earthquake of November 24, 1971, with the earthquake source near the Petropavlovsk-Kamchatskii, the new modeling technique of the strong ground motions within the broadband is tested. In this technique, the seismologically-substantiated models of the radiation source and elastic medium are used. The source is represented by an array of point radiation sources-dislocations with the random seismic moments (amplitudes) and with the random time functions. The new method of calculation of the Green functions is developed to describe the propagation of waves and residual displacements of a layered medium. The method is used for the simulation of the horizontal ground motion, recorded by a S5S-ISO instrument for the strong earthquake that took place on November 24, 1971 with the source near the Petropavlovsk-Kamchatskii (with a depth of 105 km). The position of the hypocenter, the sizes and the position of the fault, and “fault mechanism” were considered to be known a priori. By a trial and error method of the duration of the source process and only two spectral parameters, it was possible to simulate successfully the fundamental characteristics of the ground vibrations: the amplitude of acceleration, the velocity and displacement of the ground, their Fourier spectrum, the duration of the vibrations, and the response spectrum. The surprisingly high level of high-frequency radiation, probably connected with the intraplate position of the source, is a specific feature of the source.

Crystal field calculations for alloys

Abstract A new method for calculations of crystal field (CF) interaction in alloys containing rare earths (4f electron CF) has been developed. The method is based on density-functional theory (DFT) and uses the full-potential local-orbitals (FPLO) method combined with the coherent-potential approximation (CPA). The method is successfully applied to calculate the CF interaction in RENi 4 Al alloys.

Calculations of Energy Levels Using the Weakest Bound Electron Potential Model Theory

In this paper, we introduce a new method for calculation of energy levels in detail and give our results for several iso-spectrum-level series as examples: [He] 2s2p P1, [He] 2s2p P0, [He] 2s2p P2, and [He] 2s3s S1 series of Be-like sequence; [Ne] 3s3d D3/2 series and [Ne] 3s 3d D5/2 series of Al-like sequences; [Ne] 4p P1/2 series, [Ne] 5d D5/2 series, and [Ne] 6f F7/2 series of Na-like sequences. In the method I(Z) = Tlim(Z) − T (Z, n), where I(Z), Tlim(Z), and T (Z, n) denote ionization potential, series limit, and energy level of a given member, respectively. The expression of non-relativistic part of I(Z) is derived from weakest bound election potential model theory and relativistic effects of I(Z) are included by using a six-order polynomial in Z. Our results are compared with the experimental data and with those obtained by other theoretical method.

Assessment of Fibrinolytic Activity by Measuring the Lysis Time of a Tissue Factor-induced Clot: A Feasibility Evaluation

A clot lysis time assay in which a tissue factor-induced fibrin clot is lysed by exogenously added tissue plasminogen activator has been recently reported. We evaluated the feasibility of clot lysis time in a routine hemostasis laboratory, and its correlation with thrombin activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 levels and changes with aging in 185 healthy participants. Clot lysis time was assessed by monitoring changes in turbidity during clot formation and subsequent lysis using a computerized kinetic spectrophotometric microtiter plate. After preliminary experiments, 100 and 160 ng/mL tissue plasminogen activator concentrations were chosen for the study. Clot lysis time was calculated by a new mathematical analysis of the lysis curve based on discrete derivative. Clot lysis time, thrombin activatable fibrinolysis inhibitor, and plasminogen activator inhibitor-1 plasma levels showed a normal distribution. For both concentrations of tissue plasminogen activator, clot lysis time progressively increased with increase in age (P < .0001) and was significantly correlated with thrombin activatable fibrinolysis inhibitor antigen, thrombin activatable fibrinolysis inhibitor activity, and plasminogen activator inhibitor-1 antigen (at least P < .01). During linear regression analysis, thrombin activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 antigen were found to significantly influence clot lysis time (at least P < .01). Clot lysis time determination has a good laboratory performance. Our new method of calculation is independent of the time of reading and allows a more accurate and consistent detection of both short and prolonged lysis times. Our data suggest the feasibility of the use of this test in the work of routine hemostasis laboratory.

Construction of a molecular model of a fragment of a lipid membrane in the gel and liquid crystalline states

A model of a lipid membrane in the liquid crystalline and gel states is constructed. The model of the membrane in the liquid crystalline state adequately reproduces the geometric parameters of the membrane, lipid packing, and the mobility parameters of molecules. The model of the membrane in the gel state of the bilayer reproduces the geometric parameters of the real membrane and lipid packing. New methods for calculation of the mobility parameters of phospholipid molecules in the plane of the bilayer are presented.

QUANTUM MEASUREMENT AND CHARGE DENSITY OSCILLATIONS IN DOUBLE QUANTUM DOTS

In this work, we have studied the post-measurement dynamics of several electrons in a double quantum dot system using a new method of calculation. We have solved the effective-mass non-linear Schrödinger equation for two electron wave packets in a double quantum well taking into account the different number of projected electrons in each quantum well after an observation. It is found the existence of a critical density that reduces strongly the tunneling dynamics between both quantum wells. In addition, we have shown the possibility of having a new kind of electromagnetic radiation emerging from a semiconductor device after a quantum observation.

Dispersion energy from density-fitted density susceptibilities of singles and doubles coupled cluster theory

A new method of calculation of the second-order dispersion energy is proposed. It is based on the Longuet-Higgins formula [Faraday Discuss. Chem. Soc. 40, 7 (1965)], which describes the dispersion interaction in terms of frequency-dependent density susceptibilities of monomers. In this study, the density susceptibilities are obtained from the coupled cluster theory at the singles and doubles level. Density fitting is applied in order to reduce the computational effort for the evaluation of density susceptibilities. It is shown that density fitting improves the scaling of the computational resources with molecular size by one order of magnitude without affecting the accuracy of the resulting dispersion energy. Numerical results are presented for several van der Waals molecules to illustrate the performance of the new approach.

Operator approach to boundary Liouville theory

We propose new methods for calculation of the discrete spectrum, the reflection amplitude and the correlation functions of boundary Liouville theory on a strip with Lorentzian signature. They are based on the structure of the vertex operator V = e - φ in terms of the asymptotic operators. The methods first are tested for the particle dynamics in the Morse potential, where similar structures appear. Application of our methods to boundary Liouville theory reproduces the known results obtained earlier in the bootstrap approach, but there can arise a certain extension when the boundary parameters are near to critical values. Namely, in this case we have found up to four different equidistant series of discrete spectra, and the reflection amplitude is modified, respectively.

Some phenomenon of the powers of certain tridiagonal and asymmetric matrices

In this paper, a new method of calculation of real (and even complex) powers of some asymmetric matrices obeying constance tridiagonals is presented.