RU2798121C1 - Method for determining power density of electromagnetic radiation in isotropic aqueous solution of chlorophyll - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates namely to a method for determining the power density when exposed to electromagnetic radiation at frequencies from 45 to 60 GHz on the medium under study in the form of an oil-based isotropic homogenized solution of chlorophyll from eucalyptus leaves and deionized water, and can be used in the study homogeneity of the solution of an isotropic medium. Increasing the speed of research and the sensitivity of the method is the technical result of the invention, which is achieved by exposure to electromagnetic radiation on an isotropic homogenized aqueous solution of chlorophyll for 15 minutes and measuring the length of the precipitate, which at a power density of 0.01-0.7 mW/cm² is 0.1-1.0 cm, at a power density of 1 mW/cm² is 1.5-2.0 cm, at a power density of 2 mW/cm² the deposit length is 2.1-2.5 cm.

EFFECT: method can be used in environment-friendly wastewater treatment.

1 cl, 5 dwg, 3 ex

Description

The invention relates to the field of visualization of electromagnetic microwave radiation, in particular, in isotropic aqueous solutions.

Visualization of magnetic and electromagnetic fields is an important task, in particular, for understanding the mechanisms of the influence of microwave radiation on humans. Methods of visualization of electromagnetic radiation (EMR) are used not only in scientific research, but also in industry, environmental monitoring, and radio communications. The main characteristics in the selection of new environments for imaging are the frequency range and power density, which can be determined.

A known method for visualizing electromagnetic radiation (see RF patent No. 2356129 according to IPC class, H01L 31/14, published 05/20/2009), which consists in excitation of resonant microwave currents that heat a film made of resistive material, which is the electrical load of the antenna to a temperature corresponding to the irradiance of the antenna. Part of the infrared radiation of each film is directed by the first mirror (with the second mirror out of the field of view of the thermal imager) into the lens of the thermal imager, which converts the temperature field of the target into a visible image reproduced by the monitor. Moreover, in the process of conversion, the brightness of each element of the decomposition of the visible image on the monitor screen is determined by the temperature of the resistive film optically coupled to this element.

The disadvantage of this method is the multiple conversion of energy with losses, its low sensitivity in relation to the natural radiation of the objects under study, for example, in the submillimeter range of radiation. Another disadvantage is the low resolution of visualization due to the need for the design of each element of the decomposition of the antenna array in size, depending on the wavelength of the visualized radiation, which leads to the bulkiness of the target with decomposition elements and, accordingly, the entire device as a whole, without any increase in resolution. visualizer.

A known method for visualizing electromagnetic radiation (see https://moluch.ru/archive/22/2312/, Berezovchuk, A. V. Electromagnetic radiation and chemical reactions / A. V. Berezovchuk, A. V. Shantrokha, M. A Starshov // Young scientist - 2010. - No. 11 (22) - V. 1. - P. 109-112), which consists in the preparation of solutions of salicylic acid, iron ammonium alum and sodium tetraborate of certain concentrations. To the solutions obtained by mixing each of the previously obtained solutions, 4 ml of a 0.2% solution of iron ammonium alum is added to the analytical matrix and quantitatively diluted with a buffer solution to 100 ml. The resulting solutions are photometered at a wavelength of 335-450 nm. The temperature is measured using a mercury thermometer, the pH of the solution is measured using indicator paper. EMR exposure was carried out at frequencies of 58-73 GHz. during irradiation, the optical density of the solutions was recorded.

The disadvantage of this method is the inability to measure the power density of the radiation. In addition, a thermal effect was observed at high exposure power.

Closest to the claimed method is a method for visualizing electromagnetic radiation in an isotropic aqueous solution of chlorophyll (see www.elibrary.ru/id=46223982, N.A. Babkina, A.P. Rytik, A.M. Palaguta, “A method for visualizing electromagnetic radiation in isotropic aqueous solution of chlorophyll" / Collection of articles of the eighth All-Russian scientific school-seminar "Interaction of microwave, terahertz and optical radiation with semiconductor micro- and nanostructures, metamaterials and biological objects". Saratov, May 24, 2021. - Saratov, publishing house "Saratov source". - S. 197-203), which consists in preparing a solution of eucalyptus and recording changes in the homogeneity of a solution of an aqueous solution of chlorophyll when exposed to microwave radiation (SHF) in the range of 45-90 GHz and a power density of 0.04 mW/cm ² .

The disadvantage of this method is the inability to visualize the radiation in the form of the resulting deposit. In addition, the dependence of the power density on the parameters of the resulting precipitate of the chlorophyll solution was not analyzed.

The technical problem of the claimed invention is the development of a simple method that allows visualization of electromagnetic radiation in the microwave range, in the visible wavelength range.

The technical result is the possibility of estimating the EMR power density in the solution along the length of the deposit with a high sensitivity of the solution to radiation.

To achieve a technical result in a method for visualizing electromagnetic radiation, which consists in the effect of electromagnetic radiation at frequencies from 45 to 60 GHz on an isotropic homogenized aqueous solution of chlorophyll and recording changes in the homogeneity of the solution, according to the invention, as changes in the homogeneity of the solution, a precipitate is recorded, the length of which is judged on radiation power density, while with a deposit length of 0.1-1.0 cm, the power density is 0.01-0.7 mW / cm ² , with a deposit length of 1.5-2.0 cm, the power density is 1 mW / cm ² , with a deposit length of 2.1-2.5 cm, the power density is 2 mW/cm ² , while the exposure to radiation is carried out for 15 minutes.

The method is illustrated by illustrations, where are presented:

- in Fig. 1 - device for implementing the method of visualization of EMR in the microwave range;

- in Fig. 2 - the results of measurements of the length of the precipitate of the chlorophyll solution at a power density of 2 mW/cm ² and a frequency in the range of 45-60 GHz (statistically extreme positions of the precipitate form);

- in Fig. 3 - the results of measurements of the length of the precipitate of the chlorophyll solution at a power density of 1 mW/cm ² and a frequency in the range of 45-60 GHz;

- in Fig. 4 - the results of measurements of the length of the precipitate of the chlorophyll solution at a power density of 0.7 mW/cm ² and a frequency in the range of 45-60 GHz;

- in Fig. 5 is a graph of the dependence of the summary values of the deposit length (L, cm) on the power density of external radiation (ω, mW/cm ² ).

In the drawings, positions indicate:

1 - high-frequency signal generator (G4-142);

2 - horn metal antenna (generator output flange);

3 - cuvette with chlorophyll solution;

4 - recording device (camera).

The method is carried out as follows.

To carry out the research, an experimental setup was developed based on a G4-142 microwave signal generator and a camera to evaluate changes in the optical properties and shape of the solution precipitate (Fig. 1). As a test medium, a pre-prepared solution of chlorophyll from eucalyptus leaves based on deionized water (in a ratio of 1:1, 5 ml of distilled water and 5 ml of chlorophyll solution) was used or a ready-made solution of chlorophyllipt 2% concentration was used (in a ratio of 2:1, 2 ml of ready-made 2% solution and 1 ml of water).

To prepare a solution of chlorophyll from eucalyptus leaves, in addition to fresh eucalyptus leaves (25 crushed tablespoons), you need: a glass container (it is advisable to use a dark glass bottle with a volume of 300 ml), a tight plastic cap, sunflower oil 250 ml or grape seed oil. Pre-crushed eucalyptus leaves are placed in a bottle, mixed, closed with a lid and left to infuse in a dark place for three days so that the extract from the leaves releases the juice. After three days, the pomace of the leaves is poured with oil and left in a dark place for 7 days so that the mixture is infused. After a week, the leaves are squeezed again, the liquid is filtered, poured back into a dark glass bottle, tightly covered with a lid. Store the solution in a dark, cool place for no more than two months.

The finished solution is placed in a transparent polypropylene cuvette 3, located at the open flange of the waveguide 2 generator (figure 1).

To estimate the radiation power density and deposit shape, generator 1 and cell 3 are placed coaxially with respect to the waveguide (the side wall of the cell is irradiated). Generator 1 (G4-142) allows you to tune the frequency and output power during the study. The operating frequency range is from 45 to 60 GHz.

Using camera 4, the chlorophyll sediment at the bottom of the cuvette is recorded, and the size and shape of the sediment are analyzed.

To do this, the chlorophyll solution in cell 3 is irradiated for 15 minutes, while, depending on the power density of the incident radiation, the appearance of a deposit in the form of a drop (oval or round) or a parabola, the focus of which is on the waveguide symmetry axis, is recorded.

At the open flange of the waveguide, changes in homogeneity are observed in the solution, a precipitate forms when exposed to electromagnetic radiation in the frequency range from 45 to 60 GHz and power density from 0.01 mW/cm ² to 2 mW/cm ² .

The sediment size is determined using a program developed for a computer for mathematical and technical calculations in Mathcad, which allows performing linear measurements.

The size of the precipitate makes it possible to estimate the power density in the frequency range from 45 to 60 GHz of electromagnetic radiation: if no precipitate was formed, then the EMP power density was less than 0.01 mW/ ^cm2 , if the solution completely precipitated by volume, then the power density was more than 2 * 10 ³ W / cm ² .

Example 1 Irradiation of a solution at a frequency between 45 and 60 GHz and an output power of 100 mW (corresponding to a power density of 2 mW/cm ² ).

Irradiation is performed using a G4-142 generator, a cuvette is placed strictly horizontally at the waveguide flange. Irradiation is carried out for 15 minutes at a constant temperature and illumination in the room. At the end of the irradiation time, the solution changes its properties, a precipitate appears, the length of which is measured from the cell wall closest to the waveguide flange using the photographic method. If the deposit is 2.5 cm long, a power density of 2 mW/cm ² is concluded.

The measurement results are shown in Fig. 2. The sediment has the shape of a parabola. On average, the length of the sediment is 2.5±0.5 cm. The ordinate shows the values of the length of the sediment L, cm, and the width of the sediment x, cm, along the abscissa.

Example 2 Irradiation of a solution at a frequency between 45 and 60 GHz and an output power of 50 mW (corresponding to a power density of 1 mW/cm ² ).

Irradiation is performed using a G4-142 generator, a cuvette is placed strictly horizontally at the waveguide flange. Irradiation is carried out for 15 minutes, at a constant temperature and illumination in the room. At the end of the irradiation time, the solution changes its properties, a precipitate appears in the form of a symmetrical parabola, the length of which is measured from the cell wall closest to the waveguide flange. The structure of the sample solution is homogeneous, with a small admixture of particles of eucalyptus leaves; no oxygen bubbles are observed over the entire surface of the solution. If the deposit is 1.5 cm long, a power density of 1 mW/cm ² is inferred. The measurement results are shown in Fig. 3. The sediment has the shape of a parabola. On average, the length of the sediment is 1.5 ± 0.5 cm. The ordinate shows the length of the sediment L, cm, and the width of the sediment x, cm, along the abscissa.

Example 3 Irradiation of a solution at a frequency between 45 and 60 GHz and an output power of 20 mW (corresponding to a power density of 0.7 mW/cm ² ).

Irradiation is performed using a G4-142 generator, a cuvette is placed strictly horizontally at the waveguide flange. Irradiation is carried out for 15 minutes, at a constant temperature and illumination in the room. At the end of the irradiation time, the solution changes its properties, a precipitate appears in the form of a symmetrical parabola, the length of which is measured from the cell wall closest to the waveguide flange. The structure of the sample solution is homogeneous, with a small admixture of particles of eucalyptus leaves; no oxygen bubbles are observed over the entire surface of the solution. If the deposit is 1 cm long, a power density of 0.7 mW/cm ² is inferred.

The measurement results are shown in Fig. 4. On average, the length of the sediment is 1 ± 0.5 cm. On the ordinate axis, the values of the length of the sediment L, cm, are plotted; on the abscissa axis, the width of the sediment x, cm.

Lower power density does not give a statistically significant result.

In the course of repeated experimental tests at a frequency of 50 to 60 GHz, it was found that the isotropy of the chlorophyll solution is not disturbed until the generator is turned on and power is supplied more than 0.01 mW/cm ² . When exposed to radiation, after 45 seconds, a transparent region begins to form in the region of the cell closest to the waveguide.

When the power density is less than <0.01 mW/cm ² no deposit is observed, the deposit is formed within 15 minutes from the moment of radiation supply, the deposit parameters do not change when the exposure lasts more than 15 minutes, reliable results are not obtained at a power density of more than 2 mW/ cm ² .

The additional thermal imaging studies reliably show the absence of heating of the medium or the cell from the close contact of the cell at the waveguide flange.

The proposed method of EMR visualization can be applicable for radio indication and detection of electromagnetic radiation in the microwave range with the determination of the density of the incident power on the environment, in the future it will help to more accurately study the impact on physical and biological environments, including the impact on humans. Exposure to microwave radiation affects the homogeneity of the chlorophyll solution - the structure of the precipitate of the chlorophyll solution appears, according to which one can speak of the presence of electromagnetic radiation and estimate the power density.

The results obtained prove the possibility of using an isotropic chlorophyll medium for EMR visualization. Also, the results obtained can be useful: dosimetrists, physicists, radiobiologists and in the fields of science and technology, where the presence of radiation indication is necessary.

Claims (1)

A method for determining the power density value, which consists in the action of electromagnetic radiation at frequencies from 45 to 60 GHz on the medium under study in the form of an isotropic homogenized solution of chlorophyll from oil-based eucalyptus leaves and deionized water, placed in a transparent polypropylene cuvette and recording changes in the homogeneity of the solution, characterized in that that as an oil-based chlorophyll solution, either a solution of fresh eucalyptus leaves with the addition of sunflower oil or grape seed oil, infused in a dark place for 7 days, or a ready-made oil solution of chlorophyllipt 2% concentration is used, the side wall of the cuvette is exposed to radiation in within 15 minutes, as changes in the homogeneity of the solution, a deposit is recorded in the form of an oval or round drop or a parabola, the radiation power density is judged by its length, while with a deposit length of 0.1-1.0 cm, the power density is 0.01- 0.7 mW / cm ² , with a deposit length of 1.5-2.0 cm, the power density is 1 mW / cm ² , with a deposit length of 2.1-2.5 cm, the power density is 2 mW / cm ² , in the absence sediment power density is less than 0.01 mW / cm ² , in the presence of the entire solution in the form of a precipitate, the power density is more than 2 * 103 W / cm ² , and as the test medium, a solution is used in which deionized water is taken in an amount of 1: 1 .5 ml, and an oil-based solution of chlorophyll from fresh eucalyptus leaves is taken in an amount of 5 ml, or a solution is used in which deionized water is taken in an amount of 1 ml, and a ready-made oil solution of chlorophyllipt 2% concentration is taken in an amount of 2 ml.

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