Микроволновые устройства для термообработки листовых материалов с малыми диэлектрическими потерями
Theoretical and experimental research results in the field of highperformance microwave technologies of sheet materials' with small dielectric losses thermal treatment are presented. To increase the electric field decay constant amplitude in the material with small dielectric losses sections of twodimensional periodic slowwave systems are used as heating elements. The microwave construction is based on a module, which consists of two identical in design and parameters microwave heating sections, positioned one above the other, and the electromagnetic field energy propagates along these sections in opposite directions.
Processed material is positioned between two sections. Each heating section consists of the twodimensional periodic slowwave system, which on the one hand conditions with the microwave energy source, and on the other hand conditions with the water load, in which there is a sensor of passing power for the control of technological process. The long line with given boundary conditions was used as a model of microwave devices with the processed material. Special design of filters that impede microwave radiation from a working setup were used to reduce the level of a side radiation at the input and output of the processed material. Divergence of theoretical and experimental temperature distribution characteristics in the sheet material (ebonite) with small dielectric losses does not exceed 4%, and the temperature deviation in the material from the nominal temperature value does not exceed 7%. To materials with low dielectric losses in particular, relate: polystyrene, polypropylene and polyethylene with different fillings, for example, in the form of 10% carbon black or other dyes, plexiglass, ebonite and other plastics. Heat treatment of such materials by gas or by other known methods does not lead to the whole volume uniformity of heating due to the low plastics' heat conductivity and in subsequent operations, such as pressing or stamping, cracking or other unwanted defects arise.
Methods for decreasing spurious radiation for microwave devices intended for thermal treatment of sheet materials are considered. Microwave installation is created on the basis of sections slow –wave structure with variable parameter. To reduce spurious emissions to slow the system of microwave devices were placed in special screen mesh. It is shown that spurious radiation from microwave device is less than maximum permissible limit.
The experimental research results of the basalt cardboard thermal treatment with the microwave electromagnetic energy application are presented in the article. The weight change diagrams of the basalt cardboard samples during the drying process are given. Changes in the temperature behaviour are analyzed on the surface and inside the samples depending on coupling medium. An advice on the drying process parameters improvement is given.
The results of calculation and measurement of temperature distribution in the leasing out of dielectric materials which are heated up in the microwave devices wave-water type. The calculation method of microwave devices of a waveguide type of heat treatment of sheet dielectric materials. Considered microwave devices, Otley-exclusive feature of which is the change of the geometrical sizes of a narrow wall of a rectangular waveguide, working mainly on the type of waves to ensure a uniform temperature in the processed sheet the dielectric-dielectric material.
Tthe IMPI 48 program offers topics for everyone interested in learning about the latest developments in microwave power science and technology. Each year, IMPI brings together researchers, technologists and engineers from across the globe to share the latest findings of microwave and radio frequency power systems for non-communication applications, including food technology, chemical and material processing, and new emerging technologies. IMPI 48 Symposium was held at the Doubletree Hotel on Canal Street in downtown New Orleans, Louisiana, USA. New this year, IMPI 48’s Food Science and Technology Program will cover topics such as: microwavable food safety, microbiological testing, product validation, microwave oven standards, microwave leakage monitoring, industrial microwave and RF food processing.
A TWT model formed by a meta-magnetic plate and a metal screen is offered and analyzed. The dispersion equation of the model in the presence of a homogeneous electron beam filling the space between the plate and the screen is derived and solved. The coupling and depression coefficients are calculated by the method of differentiation the dispersion equation. The calculated characteristics are compared with the TWT models on a dielectric plate and an “impedance” comb.
The computational model of the temperature sensors integrated on the IC chip with power transistors is developed. The 2D/3D problem of sensor placement is mathematically described by the classic heat transfer equation coupled with the equation for current density distribution. It is shown that parasitic effects of sensor current displacement and thermo-emf generation resulting from a temperature gradients (Seebeck effect) must be taken into account. For this purpose the special differential equation is introduced. The examples of point- and strip-like temperature sensors modeling for power BJTs and ICs are demonstrated.
Questions of the even temperature distribution creation in the volumetric materials with different dielectric losses placed in the beam-type microwave device are examined. The volumetric material was irradiated by two types of antennas which provided perpendicular and parallel flux direction of the electric-field vector relatively to the material's surface. Experimental data on the temperature field distribution in the volume of material is presented. It is shown that the total temperature dispersion is less than 5ºC inside the material heated up to 80ºC.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.