Method For Determination Of Parameters Research Articles

DETERMINATION OF THE RATIONAL GEOMETRICAL PARAMETERS OF PLATE TYPE ELEMENTS OF MAGNETIC MATRIX OF THE POLYGRADIENT SEPARATOR

Introduction. Polygradient magnetic separation has wide application in industry and in biomedicine. Working process in polygradient separators takes place in a matrix, magnetic elements of which create magnetic forces sufficient to remove small ferro- and paramagnetic inclusions. Problem. The influence of mutual arrangement of elements on character of distribution of magnetic field is not taken into account during calculation of characteristics of magnetic field in magnetic matrixes. It makes comparative analysis of matrixes of different configurations quite difficult. Fulfillment of comparative analysis of strength characteristics of magnetic fields of multicomponent matrixes of polygradient separators of various configurations requires further researches. Goal. To determine the dependence of the strength characteristics of the polygradient electromagnetic separator on the geometrical parameters of the plate type elements of the multicomponent matrix. Methodology . The finite element method for calculation of power characteristics of separator magnetic field, method of comparative analysis and simple search method for determination of rational geometric parameters of the matrix have been used during the solution of the paper problem. Results. Estimation of entire spectrum of force field in plane of working zones of investigated structures in two-dimensional location for determination of rational variants of polygradient matrixes has been done. The main stages of computational experiment are given. Method of comparative analysis of power characteristics of investigated variants of matrix structures with corresponding characteristics of basic version of separator for determination of rational geometrical variants of polygradient matrixes has been applied. By results of calculations the rational geometric parameters of polygradient matrix has been chosen. The characteristics of power magnetic fields in working gaps of matrixes of polygradient separator have been studied. It made possible to determine the rational structural variants of matrix on basis of parameter of effective area of working zone. Practical value. The results of research can be used in practice of design of electromagnetic separators with polygradient matrixes.

Generalized Optical Design of the Double-Row Circular Multi-Pass Cell

A new design of circular multi-pass cells (CMPC) with two rows of reflection spots on mirrors is presented. The effective optical path length (OPL) of this novel CMPC is double that of traditional CMPC with the same diameter and interval of spots. This OPL can be readily adjusted to have regular intervals by rough rotation adjustment. We achieved a spatial separation of pre- and post-transfer optical systems that was adequately large even in the cases with a large number of passes. Analytical chief ray tracing analysis and a generalized method for parameter determination for designing the cell are presented in detail. The stable condition of the double-row CMPC (DR-CMPC) is also derived by the ABCD matrix method. Designs with maximum effective OPL of 74.72 m, 48.67 m and 24.57 m are demonstrated and verified by ray tracing simulations within a 25 cm diameter DR-CMPC. An adjustment of the regular intervals to 1 m can be achieved in both designs. The overall astigmatism of the design with an effective OPL of 74.72 m is only 9.30 × 10−6 mm, which is four orders of magnitude smaller than that of the traditional CMPC with similar geometric parameters.

Method of Parameters Determination for Multi-Winding Transformer Equivalent Circuit in the Form of Multi-Beam Star

Method of Parameters Determination for Multi-Winding Transformer Equivalent Circuit in the Form of Multi-Beam Star

Electric conductance response on engineering properties of heavy metal polluted soils

Electrical conductivity measurements provide potentially powerful tool for estimation of physical parameters of heavy metal contaminated soil, which is on the rise in the whole world with the boost of industrialization and urbanization. The main objective of this study is to demonstrate the correlation between electric response of heavy metal contaminated soil and the engineering parameters (Atterberg limits, particle size distribution, ionic concentration and pH), which is an important indicator of site engineering investigation. Laboratory investigations were performed on three heavy metals contaminated soils (zinc, cadmium and lead) with different concentrations. It is found that the mobility of electrical charge in soil is highly affected by water and the diffuse double layer (DDL) at particle surface, which will highly affect the engineering properties of soil. On the basis of the test results, theoretically based models, which capture the intrinsic connections between the surface conductivity and physicochemical properties and is simple enough to be applied in the field, are established. In consequence, surface conductivity is a potentially well adapted alternative method for determination of the physical parameters of heavy metal contaminated soil.

Stability control of air pollutant diffusion in Weakly Decaying Delayed States

At present, the air pollution problem in our country is prominent and the air pollution is getting more and more serious. Air pollution poses a great threat to the life and health of everyone and the development of the whole society and economy. In order to effectively carry out the air pollution control, we need to accurately grasp the air pollutants in the air diffusion and migration rules, the use of aerodynamic model of weak attenuation of air pollutant particles diffusion model was studied, the Gaussian Diffusion Model The basic structure, the method of parameter determination and the secondary development of GIS were studied deeply. The mathematical model of air pollutant diffusion was constructed by the close coupling method. Furthermore, the aerodynamic analysis of air pollutant particles diffusion under weak decay conditions is given, and the decay control of air pollutants under steady meteorological conditions that are unfavourable to diffusion is pointed out. After visualizing the diffusion results, it can directly and accurately grasp the influence range of pollutants, provide strong support for the research and governance of atmospheric pollution, and at the same time, provide a scientific basis for emergency treatment of sudden atmospheric pollution incidents.

Predicting Indoor Emissions of Cyclic Volatile Methylsiloxanes from the Use of Personal Care Products by University Students.

Characterization of indoor emissions of cyclic volatile methylsiloxanes (cVMS) due to the use of personal care products is important for elucidating indoor air composition and associated health risks. This manuscript describes a mass transfer model to characterize the emission behaviors of decamethylcyclopentasiloxane (D5, the most abundant indoor cVMS) from skin lipids. A C-history method is introduced to determine the key parameters in the model, i.e., the initial concentration and diffusion coefficient of D5 inside the skin lipids. Experiments were conducted in a university classroom to examine the D5 emission behaviors by using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). Data from the first class session of two typical days was applied to obtain the key parameters, which were subsequently used for predicting D5 concentrations in other class sessions. Good agreement between model predictions and experiments demonstrates the effectiveness of the model and parameter determination method. With the model, we found that the reuse of personal care products has a significant impact on the D5 emissions. In addition, the time-dependent emission rate and remaining amount of D5 inside the skin can also be calculated. These results indicate a fast decay pattern during the initial emission period, which is consistent with prior experimental studies.

PLANETARY CONTINUOUSLY ADJUSTABLE GEAR TRAIN WITH FORCE CLOSURE OF PLANET GEAR AND CENTRAL GEAR: FROM IDEA TO DESIGN

One of the reasons constraining use of a continuously adjustable gear train with compound poly-sector gear wheels in general and its most perspective version that is a planetary continuously adjustable gear train in particular is its design complexity. For example, a complex design of the mechanism for regulation of transmission gear ratio is specified by the use of involute gearing that requires a presence of backlash and bottom clearances for normal functioning and, therefore, autonomous but synchronous movement of a planet gear, as well as sectors of a central gear. In order to simplify the design of especially this mechanism for continuously adjustable gear train the paper justifies a transition to a backlash-free gearing and during this process either a planet gear or sectors of central gear are forcibly moving for regulation of the transmission ratio without losing contact with the mating element. Contact constancy of interacting elements under load is ensured by their force closure which is meant to overcome an action of gearing forces. The paper describes options for implementation of backlash-free gearing as a result of planet gear and central gear force closure, each variant is characterized by selection of active (controlled) and passive (execution of force closure) gear element. In the case of gear transmission with planet pinion coaxial tooth rims it is appropriate to implement a version with involute gearing, passive planet gear and active gear sectors of central gears. In the case of gear transmission with planet pinion opposite tooth rims the most acceptable option is with the cycloidal pin wheel gear, active planet gear and passive gear sectors of central gears. The paper proposes to carry out the force closure for teeth of gear components by means of an elastic element (a spring). A method for determination of parameters for an elastic element has been described depending on a planet gear design and the paper also shows simplification level in the gear design.

Searching for soil models’ parameters using metaheuristics

Grounding systems are an important part of protection systems which protect people and devices in case of defects in electro energetic systems or lightning strikes. The Finite Element Method (FEM) is often used for proper dimensioning of the grounding systems. Often data about the soil in the surroundings of the grounding system are obtained using measurements. Soil parameters can be determined using analytical soil models, and the determination of the soil models’ parameters, which are based on the measured data, is an optimization problem. In this paper, different soil models are tested on different measured data and compared with each other. Different metaheuristics are used and tested for the determination of soil parameters: A Genetic Algorithm, Differential Evolution with two different strategies, Teaching-Learning Based Optimization, Artificial Bee Colony and Dynamic Optimization using Self-Adaptive Differential Evolution. Based on the test results, we improved the most appropriate method. As a result, the most appropriate soil model among those tested is selected, and a method for parameter determination is presented which combines Artificial Bee Colony and Teaching-Learning Based Optimization. The presented solution is appropriate to be used with, or as a part of, FEM calculation software.

Review of Parameter Determination for Thermal Modeling of Lithium Ion Batteries

This paper reviews different methods for determination of thermal parameters of lithium ion batteries. Lithium ion batteries are extensively employed for various applications owing to their low memory effect, high specific energy, and power density. One of the problems in the expansion of hybrid and electric vehicle technology is the management and control of operation temperatures and heat generation. Successful battery thermal management designs can lead to better reliability and performance of hybrid and electric vehicles. Thermal cycling and temperature gradients could have a considerable impact on the lifetime of lithium ion battery cells. Thermal management is critical in electric vehicles (EVs) and good thermal battery models are necessary to design proper heating and cooling systems. Consequently, it is necessary to determine thermal parameters of a single cell, such as internal resistance, specific heat capacity, entropic heat coefficient, and thermal conductivity in order to design suitable thermal management system.

A New Approach for Inspection of Selected Geometric Parameters of a Railway Track Using Image-Based Point Clouds.

The paper presents the results of testing a proposed image-based point clouds measuring method for geometric parameters determination of a railway track. The study was performed based on a configuration of digital images and reference control network. A DSLR (digital Single-Lens-Reflex) Nikon D5100 camera was used to acquire six digital images of the tested section of railway tracks. The dense point clouds and the 3D mesh model were generated with the use of two software systems, RealityCapture and PhotoScan, which have implemented different matching and 3D object reconstruction techniques: Multi-View Stereo and Semi-Global Matching, respectively. The study found that both applications could generate appropriate 3D models. Final meshes of 3D models were filtered with the MeshLab software. The CloudCompare application was used to determine the track gauge and cant for defined cross-sections, and the results obtained from point clouds by dense image matching techniques were compared with results of direct geodetic measurements. The obtained RMS difference in the horizontal (gauge) and vertical (cant) plane was RMS∆ < 0.45 mm. The achieved accuracy meets the accuracy condition of measurements and inspection of the rail tracks (error m < 1 mm), specified in the Polish branch railway instruction Id-14 (D-75) and the European technical norm EN 13848-4:2011.

A Methodology for Inverse Determination of Stress-strain Curves Based on Spherical Indentation

Instrumented indentation testing is widely used for the mechanical characterization of materials and phases. Among important mechanical parameters such as hardness and Young’s modulus the determination of yield stress and hardening behavior of metallic materials calculated from indentation results is a particular topical subject. This paper presents a methodology which allows for the reconstruction of the stress-strain curve from a single load-displacement curve measured by a spherical indenter. The method is based on the depth-dependent strain field induced by a spherical indenter. The loading part of the curve is discretised in single tuples of indentation depth and force. Since the mean strain induced by the spherical indenter is dependent on indentation depth, every depth can be assigned to a mean uniaxial strain value. The force is then used to calculate the associated uniaxial stress. The method was exemplarily applied to the carbon steel C45 in different heat treatment conditions. It could be shown that after a calibration procedure the stress-strain curves of the carbon steel can be calculated without the requirement of assuming a mathematical description of the curve (e.g. power-law material behavior). The method and its framework can easily be expanded and adjusted in order to be used as an easy and quick method for inverse determination of material parameters.

Models of Determining the Parameters of Rock Mass Oscillation Equation with Experimental and Mass Blastings

The explosion caused by detonation of explosive materials is followed by release of a large amount of energy. Whereby, a greater part of energy is used for rock destruction, and part of energy, in the form of seismic wave, is lost in the rock mass causing rock mass oscillation. Investigations of the character and behavior of the pattern of seismic wave indicate that the intensity and nature of the seismic wave are influenced by rock mass properties, and by blasting conditions. For evaluation and control of the seismic effect of blasting operations, the most commonly used equation is that of M.A. Sadovskii. Sadovskii’s equation defines the alteration in the velocity of rock mass oscillation depending on the distance, the quantity of explosives, blasting conditions and geological characteristics of the rock mass, and it is determined based on trial blasting for a specific work environment. Thus, this paper offers analysis of the method for determination of parameters of the rock mass oscillation equation, which are conditioned by rock mass properties and blasting conditions. Practical part of this paper includes the experimental research carried out at Majdanpek open pit, located in the northern part of eastern Serbia and the investigations carried out during mass blasting at Nepričava open pit, located in central Serbia. In this paper, parameters n and K from Sadovskii’s equation were determined in three ways—models in the given work environment. It was noted that, in practice, all three models can be successfully used to calculate the oscillation velocity of the rock masses.

Research on multidimensional loading device of material mechanical test

A multidimensional loading device for the material mechanical test based on Stewart Platform was proposed and manufactured in this paper. A determination method of mechanism parameters toward specific engineering requirements was analysed via inverse kinematics and contact interference boundary condition of mechanism components. A set of optimized mechanism parameters was achieved and then the pose space was obtained. Meanwhile, five repeated quasi-static standard tensile tests were performed on the multidimensional loading device and the standard tensile testing machine, respectively. The average yield strength and ultimate strength of the specimen achieved from the different testers were both merely 1.13%. Results indicated that material mechanical multidimensional loading could be conducted by the parallel mechanism.

Alternately airtight/ventilated emission method: A universal experimental method for determining the VOC emission characteristic parameters of building materials

The volatile organic compound (VOC) emissions of building materials are characterized by three key parameters: the initial emittable concentration (C0), the partition coefficient (K), and the diffusion coefficient (D). Accurate determination of these three parameters is the basis for understanding VOC emission characteristic and the prerequisite for determining appropriate control strategies. In this paper, an alternately airtight/ventilated emission (AAVE) method for efficient and accurate determination of VOC emission characteristic parameters of building materials is proposed. By switching the airtight/ventilated emission mode of the building material samples, the equilibrium concentration in the airtight state and the dynamic concentration in the ventilation state were measured. K and C0 can be simply calculated by linear fitting of experimental data. Compared to the multi-emission/flush regression method and the variable volume loading method, the AAVE method requires less pre-adjustment process and has a wide measurement range. Compared to the two remarkably efficient measurement methods, the closed/ventilated chamber C-history methods, the AAVE method requires fewer intermediate parameters, simpler calculation process, and has a better error tolerance to the process data. The formaldehyde emission characteristic parameters of four types of building materials were measured using the AAVE method and verified by independent experiment. The experimental results indicated the reliability of the AAVE method. Finally, an optimized selection method of the ventilation parameters is proposed for adapting to the characteristic parameter measurement of various building material-VOC pairs.

Influnce of the cutting conditions on voltages in the dangerous zone of the cutting tool

It’s carried out the analysis of works on durability of the blade tool and it’s offered the methodology of tension calculation, arising in a dangerous area of the cutting part of the tool. The major factors determining durability of the cutting part of the blade tool are established and it’s offered the method for determination of geometrical parameters of the cutting part of the tool by criterion of tension «zero» level on a front surface. It is shown that provided unchanged geometric parameters of cutting tool part the stress in dangerous zone is greatly influenced by the friction coefficient, for example, when applying wear-resistant coatings or using lubricating-cooling media. Considered the influence of cutting force direction action on the stresses arising in a tapered beam example. Provided examples of calculating the stresses in blade tool cutting part with changes in the front angle, the cutting edge rounding radius and the coefficient of friction in contact zone.

Ligand-Field Energy Splitting in Lanthanide-Based Single-Molecule Magnets by NMR Spectroscopy

A method for the experimental determination of ligand-field (LF) energy splitting in mononuclear lanthanide complexes, based purely on variable-temperature NMR spectroscopy, was developed. The application of this method in an isostructural series of anionic lanthanide bis(cyclooctatetraenide) double-decker compounds bearing large rigid substituents is demonstrated. Using the three-nuclei plot approach devised by Reilley, the isostructurality of the compound series and the identical orientation of the magnetic main axis of all Ln3+ ions in the series Tb3+ to Tm3+ are demonstrated. Measurement of the 2H NMR spectra of partially deuterated analogues of the complexes permitted determination of the axial magnetic susceptibility anisotropies χax for all five ions in the temperature range from 185 to 335 K. For this purpose, analysis of the hyperfine shifts was combined with structural models derived from density functional theory calculations. In a final step, the temperature dependence of the χax values was used for determination of the three axial LF parameters, adapting a method employed previously for phthalocyanine-based systems. The temperature dependence dictated by the LF parameters determined by this NMR-based approach is compared to the results of recently published ab initio calculations of the system, indicating reasonable agreement of both methods. For all ions except Dy3+, the NMR method determines the same mJ ground state as the calculations and the order and energies of the excited states match well. However, the sign of the magnetic anisotropy of the dysprosium complex in the temperature range evaluated here is not correctly predicted by the published calculations but can be described accurately by the NMR approach. This shows that our experimental method for determination of the LF parameters is an ideal complementation to other theoretical and experimental methods.

Characterisation of Ground Thermal and Thermo-Mechanical Behaviour for Shallow Geothermal Energy Applications

Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE) systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solutions, including energy geostructures, where SGE systems are coupled with foundation heat exchangers, have also been developed. The performance of these systems is dependent on a series of factors, among which the thermal properties of the soil play a major role. The purpose of this paper is to present, in an integrated manner, the main methods and procedures to assess ground thermal properties for SGE systems and to carry out a critical review of the methods. In particular, laboratory testing through either steady-state or transient methods are discussed and a new synthesis comparing results for different techniques is presented. In situ testing including all variations of the thermal response test is presented in detail, including a first comparison between new and traditional approaches. The issue of different scales between laboratory and in situ measurements is then analysed in detail. Finally, the thermo-hydro-mechanical behaviour of soil is introduced and discussed. These coupled processes are important for confirming the structural integrity of energy geostructures, but routine methods for parameter determination are still lacking.

Nonlinear distortions as nonlinear noise in coherent fibre-optic communication lines

A phenomenological model describing nonlinear distortions in coherent fibre-optic communication lines is investigated. This model makes it possible to extend the range of application of the nonlinear noise model as compared with the well-known GN model. A method for experimental determination of the main parameters of the proposed model is described, and the sources of possible errors are discussed.

Study on a Parameter Determination and Calculation Method for the Stress Loss of Prestressed CFRP Plates in Bridge Reinforcemen

On the basis of Chinese and foreign specifications and the latest research findings, an appropriate parameter determination method for bridge reinforcement with prestressed carbon-fiber-reinforced polymer (CFRP) plates was proposed to determine the key design indices and calculation coefficients. Each item of prestress loss was studied and a novel calculation method was proposed to determine the usage amount and effective stress of prestressed CFRP plates for reinforcement design, in consideration of the relevant construction technology and anchorage system. The feasibility and reliability of the suggested method in this paper were verified by using an RC simply supported beam bridge reinforcement project as an example.

Investigation of heat and mass transfer processes by the method of structured laser radiation caustics

This paper is devoted to investigation of possibilities of using the caustic method for determination of optical inhomogeneities parameters, which arise by heat and mass transfer processes. Conditions of the caustics appearance are considered for longitudinal probing of the diffusion layer of liquid by plane and cylindrical laser beams. Experimental visualization of dynamics of change in the caustics position is presented for various parameters of inhomogeneous media. New method for determination of surface temperature of a cooled body placed in transparent liquid is described.