Francisc Ioan Hathazi

High Frequency Electromagnetic Field Modeling and Experimental Validation of the Microwave Drying of Wheat Seeds

The aim of this study is to determine the efiects of the thermal treatment with microwaves on the germination of wheat seeds, type Apache £ Renan for difierent processing parameters. With the experimental data we intend to flnd out the optimum balance between applied energy and material humidity so that the material can be dried without its structure being adversely afiected. From the analyze of experiments regarding wheat seeds drying with the aim of obtaining a quality product we mention that the best results are referring to the situation of using the microwave power of 0.3W/g combined with hot air stream and having the measured temperature in the seed bed below the value of 75 - C.

Utilization of Microwave Energy for Decontamination of Oil Polluted Soils

Abstract Soil oil (petroleum) product pollution represents a great environmental threat as it may contaminate the neighboring soils and surface and underground water. Liquid fuel contamination may occur anywhere during oil (petroleum) product transportation, storing, handling and utilization. The polluted soil recovery represents a complex process due to the wide range of physical, chemical and biological properties of soils which should be analyzed in connection with the study of the contaminated soil behavior under the microwave field action. The soil, like any other non-metallic material, can be heated through microwave energy absorption due to the dielectric losses, expressed by its dielectric complex constant. Oil polluted soil behaves differently in a microwave field depending on the nature, structure and amount of the polluting fuel. Decontamination is performed through volatilization and retrieval of organic contaminant volatile components. After decontamination only a soil fixed residue remains, which cannot penetrate the underground anymore. In carrying out the soil recovery process by means of this technology we should also consider the soil characteristics such as: the soil type, temperature, moisture.The first part of the paper presents the theoretical aspects relating to the behavior of the polluted soil samples in the microwave field, as well as their relating experimental data. The experimental data resulting from the analysis of soils with a different level of pollution point out that the degree of pollutant recovery is high, contributing to changing the initial classification of soils from the point of view of pollution. The paper graphically presents the levels of microwave generated and absorbed power in soil samples, soil temperature during experimentations, specific processing parameters in a microwave field. It also presents the constructive solution of the microwave equipment designed for the contaminated soil in situ treatment.

Study on the extraction in microwave field of the essential oils from chilli

The paper presents a method of extracting essential oils from chili pepper by using the energy of the microwave field. The main objective of this work it is to highlight the possibilities of substitution of all or a part of the current extraction technology with the extraction technology thats uses the microwave energy, and to highlight the existence differences in quality of the extracted oils, in function of chili pepper used.

Study on microwave field extraction of the celery essential oils

The main objective of this work it is to highlight the possibilities of substitution of all or a part of the current technology with technology of extracting by using microwave energy and to highlight the existence differences in quality of the extracted oils for different temperatures using as solvent the ethyl alcohol. In this paper is studied the essential oil extraction method that was performed from the leaves, stems and roots of celeriac milled, by using ethanol as extraction solvent. In a series of experiments were examined the effect of process parameters - initial temperature, the temperature of extraction, the particle size of celery used - the rate of extraction. The results showed a significant increase in the rate of extraction of celery with decreasing particle size analyzed. A similar effect was observed with increasing solvent flow rate and the temperature decrease.

The extraction of volatile oils from parsley leaves in microwave field

The main objective of this work is to highlight the possibilities of substitution of all or a part of the current extraction technology with the microwave extraction technology, and to highlight the differences between the two type of the extraction solvents used. The work also presents the importance of the solvent used in the extraction process of volatile oils from parsley leaves, in terms of its quality and the microwave energy applied to the sample.

About the extraction in microwave field of the essential oils and beta-carotene from carrots

Carrot root has been used for medicinal purposes from ancient times, being well known its beneficial properties as follow: anti-inflammatory, anti-diabetic, antioxidant, hypoglycemic oil of carrot. The paper presents a study regarding an extraction method of volatile oil from carrot root using microwave energy and ethyl alcohol as a solvent. The yield of extraction was examined in a series of experiments in order to determine the effect of process parameters - initial temperature, the temperature of extraction and the particle size of carrot used. The experiments conducted for the extraction of beta-carotene from carrots were performed in various conditions involving different temperatures and processing of the samples using ethanol as solvent. The samples used for the extraction were tested at 40°C, 50°C, 60°C and 80°C. It was observed that the solubility and the yield of carotene from carrots depends on the temperature and time of extraction. It has been shown that the most efficient extraction was performed with samples dried, using a temperature range of 65° ÷ 75°C for a period of 4–5 hours. At higher temperatures the sample was destroyed.

The behaviour of the Direct Methanol Fuel Cell under low frequency acoustic vibrations

The applications of the Direct Methanol Fuel Cell, like energy generators for electric vehicles and mobile devices that generates electricity, need a study of the behaviour of the Fuel cell under mechanical vibrations. There are certain effects regarding the functioning of the fuel cell, which can affect the efficiency and the maintenance process.

Microwave Reticulation of Epoxy Resins Used for Single Layer Electric Insulations

Abstract The main objective of these experiments is to identify the possibilities for proving a microwave technology for thermal reticulation of electric insulations deposited on metallic supports. To avoid the occurrence of phenomena that could affect the integrity of the microwave generator, the system has been equipped with a load for absorbing the residual power in microwaves. The charge placed in the applicator is made of a microwave-transparent plastic coil through which water circulates. The insulating material used during the experiments was P772 special tape impregnated in epoxy resin deposited on a metallic support through rolling. The quality of the electric insulation obtained by means of the microwave technology is better compared with the conventional methods.

About the use of the high frequency electromagnetic field in order to improve the Quality of the Agricultural Seeds

This paper present aspects regarding the numerical modelling of the electromagnetic field in microwave drying systems. The numerical method used to solve this application will involve the use of 3D finite element method to point out the process parameters in high frequency electromagnetic field of the dielectric materials with losses, situated in an applicator, excited with energy through a wave guide. It has the character of an applicative research, the obtained results being of practical use, with the main purpose of optimizing the functioning of some heating.

Operating mode prediction of a microwave heating system using artificial intelligence techniques

For drying and decontaminating agricultural seeds a laboratory stand using microwave heating technology has been developed. In order to optimize the heating process the current paper presents an artificial intelligence based system, applied to predict the operating mode of the developed stand for different wave guide and loading bed configurations. Obtained results are used to identify the optimal microwave system configuration in case of corn seeds treatment and for future development of an industrial scale microwave treatment apparatus.