Method For Calculation Of Coefficients Research Articles

Consolidation Coefficient Calculation Based on Consolidation Rate Attenuation Method

This paper proposes a new partial-analytical consolidation coefficient calculation method as consolidation rate attenuation method based on the 1st-order series solution to one-dimensional Terzaghi theory. According to the consolidation rate attenuation curves, consolidation coefficient can be obtained by the linear attenuation part fitting. Least square principal is used to get fitting parameters of the extracted linear attenuation data by computer. This new developed method has rigorous formula which avoids mapping human factors, the effect of initial settlement and secondary consolidation. By the evaluation comparison of different methods, this new method is accurate, which also means the test process will be speeded up

A life cycle impact assessment method based on the multi-environmental spatial dimension

As the most important and controversial phase of life cycle assessment, life cycle impact assessment (LCIA) has drawn the most attention. How to reflect the spatial characteristics of environmental impacts have become a significant problem, which is urgently needed to be solved to improve the transparency and the reliability of LCIA, especially for the distinct diversity of environments in China. Based on the multi-environmental spatial dimension, this paper proposes a new LCIA method under the framework of ISO14040. First, pollutants released or materials consumed in the life cycle of a product are related to spatial characteristics in order to reflect the diversity of the regional environment. The calculation method of the space characteristic coefficient is presented by analysing the endurance capacity of the regional environment and environmental standards. Second, midpoint and endpoint categories are combined and their relationships are discussed according to the environmental mechanism. Third, normalisation references are proposed that can reflect the latest and most detailed knowledge of environmental science. Also, the distance-to-target method is selected as the weighting method and a single index could be obtained after the weighting. Finally, this LCIA method is employed to study electro-motors in China.

Calculation Method of Moisture Flow Discharge Coefficient in Steam Turbines

This paper describes a calculation method of moisture flow discharge coefficient for designing wet-steam turbines. The flow discharge coefficient in wet-steam conditions is different from that in dry-steam conditions, because the former is affected by supersaturation phenomenon and wetness fraction. An accurate prediction of the flow discharge coefficient is required for flow-pattern design in turbine stages. The developed calculation method is divided four models according to the wetness levels in the nozzle & bucket rows, and defined by the functions of wet-steam properties, such as saturated & supersaturated isentropic exponents, wetness fraction, and pressure ratio in the nozzle & bucket rows. The calculation method is applied to a full-size & a model test turbine data for the prediction of the moisture flow discharge coefficient. As a result, the developed calculation method is found to be very effective for estimating the moisture flow discharge coefficient in a wide range of wetness fractions.

Calculation of effective diffusion coefficient in even approximations of the surface pseudo source method

The preference of even approximations of the surface pseudo source method for calculation of the diffusion coefficient is substantiated. The homogenization limit for the G0 approximation in the case of the cell size tending to zero is analytically proved.

Tribomechanical calculation method of the lateral pressure coefficient for brittle dispersed materials

A calculation procedure is proposed to analyze the lateral pressure coefficient of brittle dispersed materials with account of the joint effect of the interparticle and external (wall or boundary) friction modes The measurement range of this coefficient is defined as the ratio of the interparticle friction coefficient to the external (boundary) friction one.

A Common Method for Calculation of Flow Boiling and Flow Condensation Heat Transfer Coefficients in Minichannels With Account of Nonadiabatic Effects

Flow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena; however, their description with a single correlation has yet to be suggested. In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where bubble generation is not present. A similar picture holds for the case of inside tube condensation, where annular flow structure predominates. In such a case the heat transfer coefficient is primarily dependent on the convective mechanism. In this article a method developed earlier by the authors is applied to calculations of the heat transfer coefficient for flow condensation. The modifications of interface shear stresses between flow boiling and flow condensation are considered through incorporation of the so-called blowing parameter, which differentiates between these two modes of heat transfer. Satisfactory consistency with well-established correlations for condensation has been found, as well as with selected experimental data.

Theory Calculation of Diffussion Coefficient Based on Molten Slag Structure

The diffusion coefficients of slag constituents were calculated using Eyring equation. The Urbain slag viscosity calculation method was modified by improving the constiuents dividing method based on slag depolymerisation degree NBO/T calculation. the amphoteric oxides such as TiO2, Cr2O3, Fe2O3, B2O3 and Al2O3 were specifically dividied into glass former part and modifier part, and the diffusion dimension was calculated according to the value of NBO/T. The results of diffusion coefficients showed that, the modified method is more accurate than the Urbain method within the calculation conditions. Based on the modified diffusion coefficient calculation method, ladle slag composition was optimized to enhance the deoxidization rate.

An over-deterministic method for calculation of coefficients of crack tip asymptotic field from finite element analysis

An over-deterministic method has been employed for calculating the stress intensity factors (SIFs) as well as the coefficients of the higher-order terms in the Williams series expansions in cracked bodies, using the conventional finite element analysis. For a large number of nodes around the crack tip, an over-determined set of simultaneous linear equations is obtained, and using the fundamental concepts of the least-squares method, the coefficients of the Williams expansion can be calculated for pure mode I, pure mode II and mixed mode I/II conditions. A convergence study has been conducted to examine the effects of the number of nodes used, the number of terms in Williams expansion and the distance of the selected nodes from the crack tip, on the accuracy of the results. It is shown that the simple method presented in this paper, yields accurate results even for coarse finite element meshes or in the absence of singular elements. The accuracy of SIFs and the coefficients of higher-order terms are validated by using the available results in the literature.

Calculation Method of Lateral and Vertical Diffusion Coefficients in Wide Straight Rivers and Reservoirs

In the calculation of mixed-transport capacity of pollutants which were discharged from bank outfall of wide straight rivers or reservoirs, the lateral diffusion coefficient can better demonstrate the mixed-diffusion characteristics near the bank than the transverse diffusion coefficient. For deep rivers and reservoirs, the vertical diffusion coefficient is one of the important water quality parameters. Based on the theoretical calculation method of pollutant mixing zone, the unified equations of the standard curve and curved surface outside the borders of pollutant mixing zone were deduced, including the characteristic parameters of maximum length L s , maximum width b s and maximum depth d s et al. The shape of curve is akin to semi-elliptic, and the shape of curved surface is akin to part ellipsoid, which is similar to the pollution of the mixing zone. The calculation equation of lateral diffusion coefficient or vertical diffusion coefficient which was determined by the maximum length and maximum width or maximum depth of the outer boundary of pollutant mixing zone near the discharge outfall and the mean velocity were put forward in this paper. The calculation method of the lateral diffusion coefficient or vertical diffusion coefficient which was overall controlled by the area or volume of pollutant mixing zone and the practical method of vertical diffusion coefficient which was determined by the concentration of surface transverse integration was proposed in the paper. The lateral diffusion coefficient of the downstream of Guangfu River in low water season was given, which was 0.27 m 2 /s by analyzing the data from field observation.

Kay theory for pre-stressed media

Because of the similarity between the equations of motion governing infinitesimal vibration due to a small perturbing force superimposed on an already existing state of finite stress and the equations of linear anisotropic elasticity, methods of analysis used in one may be extended to the second. In particular, in this paper, the technique of ray expansions is considered. .Methods for calculation of rays and amplitude coefficients of the ray series are given. A seismic ray is described by a system of ordinary differential equations of first order which can be solved by standard numerical techniques. Another system of ordinary differential equations is introduced to compute amplitude coefficients.

Study of Fuzzy Random Reliability Model of Tailings Dam under Earthquake Action

Two kinds of the deficiencies exist in the traditional dam reliability and the safety coefficient calculation methods. First, it is impossible to give accurate mean to design variable in case study, because to large extent, means are greatly influenced by many objective factors or man-made effects, which degree of effects has greater degree of ambiguity. Second, the traditional reliability theory takes zero point as measure of dam’s failure or not, and on both sides of zero point the structure of state mutants from security to failure. But in fact, it’s very hard to give a definite limitation to the dam state from security to failure, because a fuzzy scope exists between stability and failure. On the basis of solving the above two issues, this paper for the first time applies fuzzy reliability theory to the stability research of tailings dam under earthquake action , considering fuzziness of both the event of tailings dam failure and the main variables and parameter. Integrating fuzziness and randomness, this paper explores fuzzy random reliability analysis methods of tailings dam engineering. The results of case study show that the calculation results agree well with the actual situation, this analysis method is more scientific and reasonable than traditional dam safety factor calculation method, and better reflects the real situation. It also provides a new way to calculate stability of tailing dam considering earthquake action.

Peter Debye and electrochemistry

Debye won the 1936 Nobel Prize in Chemistry for his contributions to molecular structure, dipole moment relationship and for diffraction of X-rays and electrons. Electrochemists, however, remember him for the Debye-Huckel limiting law that describes the behavior of strong electrolytes. In explaining the non-ideal behavior of strong electrolytes, his mathematical treatment assumes that each ion is surrounded by an ionic cloud of oppositely charged ions, which retards the movement of ions in the medium. The theory not only provides a method for calculation of activity coefficients, but has also helped, among other things, in our understanding of diffusion in ionic media, change in the rate of ionic reactions upon addition of salts, and biochemical reactions.

Calculation of Internal Force of Axial Tension Member due to Temperature Variation Accounting for Cracking

Internal force of a concrete member duo to temperature variation is related to stiffness. A reduction of stiffness occurs and the magnitude of the internal forces drops from the values existing before cracking when cracking occurred due to temperature variation. Internal force of axial tension member due to temperature variation developed in a jagged style with cracking. Calculation method of internal force and stiffness reduction coefficient of axial tension member due to temperature variation was presented accounting for cracking. Given example shows stiffness reduction coefficient has a close relationship with number of cracks and steel ratio. Member with high steel ratio subjected to the same temperature variation has more cracks and smaller crack width.

Solvatochromic Effect Studies on the Stability of Dioxovanadium(V) Complexes with Ethylene Glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic Acid in Different Water + Methanol Mixtures

The stability constants for the reaction of dioxovanadium(V) with ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA) and the dissociation constants of EGTA were determined at 25 °C and a constant ionic strength of 0.05 mol·dm−3 sodium perchlorate in ten different compositions of water + methanol by a combination of potentiometric and UV spectrophotometric methods. The Solver, Microsoft Excel 2000 optimization package, has been used to perform nonlinear least-squares curve fitting on the basis of the Gauss−Newton method for calculation of the solvatochromic regression coefficients. Nonspecific and specific solute−solvent interactions were interpreted by correlating the equilibrium data with solvent parameters using the Kamlet−Abboud−Taft (KAT) solvatochromic equation. Finally, the influence of the solvent on the stability of the complex was discussed on the basis of the correlation results and the contribution of α (hydrogen-bond donor acidity), β (hydrogen-bond acceptor basicity), an...

Comparison of methods for calculation of the partition coefficients of selected aliphatic compounds

New methods are proposed for calculation of the partition coefficients of aliphatic compounds from experimental R F values and the numerical values of selected topological indexes ( 1 χ , 2 χ ν , 0 B , and 1 B ). The experimental partition coefficient (log P exp ) of cetyl alcohol was determined for the n -octanol-water system. Numerical values obtained in this work were compared with theoretical values from a database (AlogPs, AC_logP, AB/LogP, ALOGP, milogP, and XLOGP2).

Mathematical Model for Closed-Form Solution of Parameters of Cylinder Exhaust Port in Variable-Stroke Engine

A mathematical model for getting the closed-form solution of main parameters of cylinder exhaust port is present, based on a few known parameters of variable-stroke engine (VSE). Considering lack of parameters in the initial stage of design, empirical formula is applied to solve the initial specific time-area value of exhaust port, and the initial port timing angle is solved by using logarithmic alignment method, thereby height and width of the exhaust port can be solved, then the precise specific time-area value and port timing angle are solved by using the coefficient calculation method and logarithmic alignment method respectively, so that the relative errors between initial and precise values of specific time-area value and port timing angle are defined as the relative errors of the mathematical model. Application examples show that the relative errors of the model is less than 3%.

A General Calculating Method of Rotor’s Torsional Stiffness Based on Stiffness Influence Coefficient

In order to develop a general calculating rotor’s torsional stiffness based on stiffness influence coefficient for different rotor assembling, the calculation method of the torsional stiffness influence coefficient of equal thickness disc is researched in this paper at first. Then the torsional stiffness influence coefficient λ of equal thickness disc is fit to a binary curved face and a calculation equation is obtained based on a large quantity of calculating data, which lays the foundation for research on a general calculating method of rotor torsional stiffness. Thirdly a simplified calculation method for equivalent stiffness diameter of stepped equal thickness disc and cone disc in the steam turbine generators is suggested. Finally a general calculating program for calculating rotor’s torsional vibration features is developed, and the torsional vibration features of a verity of steam turbine rotors are calculated for verification. The calculating results show that stiffness influence coefficient λ of equal-thickness disc depends on parameters of B and H, as well as the stiffness influence coefficient λ; and discs with complex structure can be simplified to equal-thickness discs with little error by using the method suggested in this paper; error can be controlled within 1% when equivalent diameter of stiffness is calculated by this method.

A General Calculating Method of Rotor’s Torsional Stiffness Based on Stiffness Influence Coefficient

In order to develop a general calculating rotor’s torsional stiffness based on stiffness influence coefficient for different rotor assembling, the calculation method of the torsional stiffness influence coefficient of equal thickness disc is researched in this paper at first. Then the torsional stiffness influence coefficient λ of equal thickness disc is fit to a binary curved face and a calculation equation is obtained based on a large quantity of calculating data, which lays the foundation for research on a general calculating method of rotor torsional stiffness. Thirdly a simplified calculation method for equivalent stiffness diameter of stepped equal thickness disc and cone disc in the steam turbine generators is suggested. Finally a general calculating program for calculating rotor’s torsional vibration features is developed, and the torsional vibration features of a verity of steam turbine rotors are calculated for verification. The calculating results show that stiffness influence coefficient λ of equal-thickness disc depends on parameters of B and H, as well as the stiffness influence coefficient λ; and discs with complex structure can be simplified to equal-thickness discs with little error by using the method suggested in this paper; error can be controlled within 1% when equivalent diameter of stiffness is calculated by this method.

Study on the Running Vibration Characteristics of Railway Vehicle

In this paper, in order to investigate a contact area between the measured profile of wheel and the designed shape of rail, we carried out calculation of the contact area strictly by a general software program, which applied the boundary element method and half-infinite body approximation. In addition, a calculation method of a creep coefficient is proposed with focus on contact areas between actual wheel and rail. Moreover, we also carried out numerical simulation of the running stability to find out how the difference of a value of an estimated creep coefficient has influence on the running stability of railway vehicle. As a result, it is shown that the contact area between the actual wheel and the rail has the shape composed of many contact areas, and the estimated creep coefficient may be smaller than the Kalker's theoretical value due to the influence of fine unevenness of wheel tread. Furthermore, we describes that the proposed method make the evaluation on running stability on the safety side.

Equation of state for ionic liquids

A simple form of equation of state for ionic liquids is proposed as an asymptotic low-temperature variant of the fluctuational equation of state developed by author. This function predicts reliably the properties of the pure substances and mixtures with the quite different molecular structures in the wide temperature- and pressure-ranges including the critical region. It is essentially important at evaluation, for example, of the near-critical carbon-dioxide’s solubility in the set of ionic liquids. Re-establishing of the gas-liquid phase diagram from the triple point up to the point of thermal decomposition on the base of measurable data at atmospheric pressure has been chosen as the method for the thermodynamically-consistent calculation of coefficients. Especially complex problem is the consistent description of very small values of isothermal compressibility and vapor pressure. The developed method is verified for water, ethylene, argon and several ionic liquids. It is applicable, in principle, to such complex molecular structures as polymers, non-organic salts, liquid metals for which the equation of state is necessary to solve a variety of the practical usage questions.