A Stable and High-Precision Downward Continuation Method of Magnetic Data

Downward continuation is an effective technique that can be used to transform the magnetic data measured on one surface to the data that would be measured on another arbitrary lower surface. However, it suffers from amplitude attenuation and is susceptible to noise, especially when the continuation distance is large. To solve these problems, we present a stable and high-precision downward continuation method combining the ideas of equivalent source technique, Tikhonov regularization, radial logarithmic power spectrum analysis, and constrained strategy. To implement this method, the observed data is used to construct the equivalent source in the study area, and the small amount of measured magnetic data at the lower surface (relative to the original observation surface) is employed to constrain the calculation procedure simultaneously. Then the magnetic data at the target surface can be obtained by using a forward calculation procedure instead of the risky downward continuation procedure. The proposed method is tested on both synthetic model data and real magnetic data collected in the South China sea. Various obtained results demonstrate that the method reported in this study has higher accuracy and better noise resistance than the traditional downward continuation methods.

Determination of the Deformed Shape of a Masonry Wall Exposed to Fire Loading by a Homogenization Method

The present contribution shows how it is possible to determine the homogenized thermo-elastic characteristics of a natural stone masonry wall, taking into account the material properties of stone and mortar as functions of temperature increase, as well as the geometrical characteristics of their assembly. Joints are incorporated in the analysis through a numerical homogenization procedure. As a result, membrane and bending stiffness coefficients, as well as thermal-induced efforts, of an equivalent plate are obtained. Such homogenized thermomechanical characteristics make it possible to determine the deformed shape of the wall after a certain time of fire exposure. As an example, the calculation procedure is performed on a particular configuration of infinitely wide wall, illustrating the influence of the joints on its thermal deformed shape. To assess the practical validity of this homogenization-based calculation procedure, results of the numerical homogenized model (incorporating joints) are compared to those of a homogeneous model (without joints), and to available experimental results obtained on a 3 m-high, 3 m-wide wall exposed to fire loading.

Development of calculation method to study influence of end pieces and asphalt roadway impedance on total sound pressure measured at exhaust pipe mouth

The article contains a developed finite element model of the rear part of the vehicle with the mufflers made adjoining the sphere. Experimental research has been carried out in accordance with the rules of the ECE UN R51 amendment 03. Calculation procedure was made to study the influence of the reflecting surfaces on the total sound pressure by the example of the exhaust pipe mouth. The finite element model of the vehicle rear part has been developed. The results of calculations and experimental research of the sound pressures of the exhaust pipe mouth are given. The developed calculation procedure has been proved by the experiments.

Development of calculation procedure for research and refinement of suspended design natural frequencies by example of vehicle exhaust system

The article presents a finite element model exhaust system developed in the ANSA software package. Experimental research of the dynamic characteristics mounts exhaust system. and developed calculation procedure for improvement of the suspended design natural frequencies based on the experimental definition of boundary conditions by the example of the vehicle exhaust system. Requirements for natural frequencies of the exhaust system are developed; finite element models of the exhaust system are developed; physical and mechanical characteristics of mounts are defined; natural frequencies and oscillation modes of the exhaust system taking into account physical and mechanical characteristics of mounts are calculated.

Elaboration of a new calculation procedure of hydrocarbon deposit layer thickness in fuel channels of heat engines and power plants

The article is devoted to theoretical research connected with elaboration of a new calculation procedure for hydrocarbon deposit layer thickness. A common problem of deposit formation in heat engines and power plants is thoroughly investigated. In addition, the wall composition, temperature, time and a number of life cycles, etc. are mentioned as key factors that have direct influence on this heat phenomenon. The paper describes thermophysical properties of deposits in fuel feed systems of different engines. The literature search and analysis did not reveal any similar procedures of calculation of hydrocarbon deposit layer thickness that could be connected with electrical properties of a wall or a deposit. The paper presents new equations for calculating the deposit formation thickness and rate based upon thermal and electrical nature of this process. These new equations led to elaboration of the new calculation procedure of hydrocarbon deposit layer thickness on a metal wall for any fuel channel of a heat engine or a power plant based on liquid hydrocarbon fuel or coolant. The new calculation technique was verified by experiments in aviation kerosene boiling in volume, which clarified special features in the application of new equations. Owing to the universal character of the proposed technique, it can be used for calculating the deposit formation virtually in all the known heat engines and power plants, for various operating conditions, for different metal wall compositions, at various fuel flow rates and pressures, temperature regimes inside fuel-feed and cooling channels.

Creation of the System for Management of Technology-Related Risks at the Enterprise

A problem of creating a technology-related risks management system at an enterprise has been considered. On the basis of applying system approach and system modeling, a set of interrelated structural and process models was built for using them in the technology-related risks management system of an enterprise. By means of the suggested models and matrix projections between them, we can carry out the organizational analysis of a technology-related risks management system of an enterprise, which allows determining the functional workload and responsibility of structural elements of the created system. The calculation procedure of personnel in accordance with the established posts list has been developed for the technology-related risks management system of an enterprise, which would allow cutting administrative costs for the functions of risk managers.

Simultaneous simulation and optimization of multiple dividing wall columns

In this work we present a new approach that we use to simulate and optimize multiple dividing wall columns at the same time. Instead of considering all model equations as constraints and all process variables as optimization variables in a large and highly nonlinear optimization problem we only incorporate a subset of the model equations as constraints and a subset of the process variables as optimization variables. The remaining process variables are calculated from this subset by a robust and fast calculation procedure. This calculation procedure also ensures that the remaining model equations are satisfied. A comparison with the commercial process simulator Aspen Plus shows that with the new approach multiple dividing wall columns can be optimized more stable and better solutions are found. Moreover the time needed to find an optimal design decreases significantly.

Durum-Wheat Straw Bales for Thermal Insulation of Buildings: Findings from a Comparative Energy Analysis of a Set of Wall-Composition Samples on the Building Scale

The urgent need to make buildings more performant in energy and environmental terms has led to the increasing study of recycled and natural materials as viable solutions. In this context, the present study aims at comparing the energy performance of innovative wall-sample solutions (with recycled polyethylene-terephthalate panels or durum-wheat straw bales) with a basic one. Energy evaluations were performed in Piazza Armerina (a city of Sicily–Italy), where the chosen material is widespread, by applying two calculation methods: a monthly average-energy-calculation approach, mandatory by Italian regulations (UNI TS 11300), and an hourly energy-calculation procedure (EN 52016). The results documented that: (i) the new innovative wall-sample allows for significantly reducing heat loss (heating of 4–10% and cooling of 40–50%) (ii) a lower primary-energy demand was obtained by adopting the new calculation procedure of EN 52016 (energy decreasing of 20–24%); (iii) significant differences in terms of heat-loss (of 10–36%) and heat-gain (up to 75%) calculations were found for the two calculation methods. This puts emphasis upon the importance of properly selecting a calculation method by accounting for all of those key variables and features that are representative of the energy system being investigated.