STUDY OF THE COAGULATION OF AEROSOL PARTICLES IN THE SCRUBBER ULTRASOUND CHAMBER

В данной работе представлены результаты исследования процесса коагуляции частиц аэрозоля моноаммонийфосфата в модельной ультразвуковой (УЗ) камере скруббера. Изучено поведение аэрозольных частиц внутри камеры на расстоянии 100 мм и 400 мм от ультразвукового излучателя с частотой излучения 22 кГц. Представленные результаты показывают практически отсутствие коагуляции частиц при интенсивности звукового давления 140 dB и процесс активной коагуляции при интенсивности звукового давления 150 dB для выбранного образца. Начальная массовая концентрация фосфата аммония в камере составляла 1 г/м3. Измерения дисперсного состава аэрозоля внутри камеры показали, что более интенсивно коагуляция проходила в области 400 мм. Через 30 минут воздействия значение среднего объемно-поверхностного диаметра частиц аэрозоля в камере изменилось на 238,4 %. This paper presents the results of the study of the coagulation of the monoammonium phosphate aerosol particles in the model ultrasonic scrubber chamber. The behavior of aerosol particles inside the chamber is studied at the distance of 100 mm and 400 mm from the ultrasonic emitter with 22 kHz of the radiation frequency. The presented results show almost complete absence of particle coagulation at the sound pressure intensity of 140 DB and the active coagulation process at the intensity of 150 dB for the selected sample. The initial mass concentration of ammonium phosphate in the chamber was 1 g / m3. Measuring the dispersed composition of the aerosol showed that coagulation proceeds more intensively in the region of 400 mm. After 30 minutes of exposure the value of the average surfactant diameter of the aerosol particles in the chamber has changed by 238.4%.

Determination of the complex dielectric permeability of liquid at the radiation frequency 32 GHz

Method and device for measuring the complex dielectric constant of liquids are described. The real part of the complex dielectric constant calculated from the conditions for the maximum and minimum of the measured interference dependence of the reflection coefficient on the layer depth. The imaginary part determined by selection to the maximum coincidence of the calculated and measured dependences of the reflection coefficient.

A Terahertz Detector Based on Double-Channel GaN/AlGaN High Electronic Mobility Transistor

A double-channel (DC) GaN/AlGaN high-electron-mobility transistor (HEMT) as a terahertz (THz) detector at 315 GHz frequency is proposed and fabricated in this paper. The structure of the epitaxial layer material in the detector is optimized, and the performance of the GaN HEMT THz detector is improved. The maximum responsivity of 10 kV/W and minimum noise equivalent power (NEP) of 15.5 pW/Hz0.5 are obtained at the radiation frequency of 315 GHz. The results are comparable to and even more promising than the reported single-channel (SC) GaN HEMT detectors. The enhancement of THz response and the reduction of NEP of the DC GaN HEMT detector mainly results from the interaction of 2DEG in the upper and lower channels, which improves the self-mixing effect of the detector. The promising experimental results mean that the proposed DC GaN/AlGaN HEMT THz detector is capable of the practical applications of THz detection.

Tunable Smith–Purcell radiation from MoS2-based grating

Different from the traditional tunable Smith–Purcell (SP) radiation in the graphene-based gratings in the terahertz band, we propose a tunable SP radiation generated from an electron beam passing through a single-layer molybdenum disulfide (MoS2) based grating in the visible band. The comparison between the simulation and the theoretical results shows good agreement. By varying the Fermi energy of MoS2 from 0.025 eV to 0.125 eV for the MoS2-based grating, we can not only control the radiation frequency but also can change the radiation magnitude. The radiation frequency, angle, and magnitude varying with the Fermi energy are also discussed, respectively. These properties would have potential applications in developing tunable visible SP radiation.

Stress classification based on human electromagnetic radiation analysis

<p>Stress is a feeling of emotional or physical tension due to any events that makes one feel frustrated, angry or nervous. It a situation that trigger particular biological response when encounter a threat or challenge. This paper discussed stress classification based on human electromagnetic radiation (EMR). At first, the collected radiation frequency data is analyzed using multivariate analysis of variance (MANOVA) to identify the significance points for the classification. Then, the data is classified using locally weighted learning (LWL) algorithm. The results show stress classification using EMR based on third eye and throat chakra points obtained accuracy of more than 60%.</p>

THz linear array scanner in application to the real-time imaging and convolutional neural network recognition

Room temperature linear arrays (up to 160 detectors in array) from silicon metal- oxide-semiconductor field-effect transistors (Si-MOSFETs) have been designed for sub- THz (radiation frequency 140 GHz) close to real-time direct detection operation scanner to be used for detection and recognition of hidden objects. For this scanner, the optical system with aspherical lenses has been designed and manufactured. To estimate the quality of optical system and its resolution, the system modulation transfer function was applied. The scanner can perform real-time imaging with the spatial resolution better than 5 mm at the radiation frequency 140 GHz and contrast 0.5 for the moving object speed up to 200 mm/s and the depth of field 20 mm. The average dynamic range of real time imaging system with 160-detector linear array is close to 35 dB, when the sources with the output radiation power of 23 mW (IMPATT diodes) are used (scan speed 200 mm/s). For the system with 32-detector array, the dynamic range was about 48 dB and for the single-detector system with raster scanning 80 dB with lock-in amplifier. However, in the latter case for obtaining the image with the sizes 20×40 mm and step of 1 mm, the average scanning time close to 15 min is needed. Convolutional neural network was exploited for automatic detection and recognition of hidden items.

Effect of electromagnetic radiation on the liver structure and ultrastructure of in utero irradiated rats

The aim of this study was to observe the influence of electromagnetic radiation (EMR) on the structure and ultrastructure of the rat’s liver. The pregnant rats used in the experiment were exposed to a pulsed microwave radiation (frequency of 2.45 GHz; mean power density of 2.8 mW/cm2) daily for 2 h, throughout their pregnancy. After delivery, the offspring was not exposed to EMR. Samples of the liver of 5-week-old offspring were subjected to histopathological evaluation. They were processed for light and transmission electron microscopy. Our results indicated that EMR did not cause pronounced changes in the structure of the liver of the investigated offspring. The size and shape of liver lobuli was preserved and the amount of connective tissue in the liver parenchyma did not increase. However, electron microscopy revealed changes in the shape and number of microvilli at the vascular pole of hepatocytes, and formation of vesicles of various shapes and sizes. The endothelial cells were swollen with larger fenestrations compared to the control group. The spaces of Disse were irregular and dilated. Even though these changes were only mild, further studies are needed to determine the effect of EMR and clarify its potential risk during pregnancy.

Some features of an interaction of electromagnetic radiation quantums with a gravitational field and a problem of graviton

The problems connected to propagation of a gravitational field are considered. The law of electromagnetic radiation frequency change in gravitational field is shown. The problem of a gravitational field quantization is investigated. Energy of a graviton is found by two ways. First, on the basis of use quantum gravitational eikonal and Lagrangian of a gravitational field the energy of a solitary graviton is found. It is shown that graviton has the mass proportional to its frequency. Second, due to refusal from symmetric stresses tensor in structure of an energy-impulse tensor the quantum form of the energy-impulse tensor in Einstein's equation is found. It has allowed found the energy of a solitary graviton. Both ways of an energy graviton finding has given the identical result. It is shown that the solution of the Einsteins equation with use of the quantum form of an energy-impulse tensor for the certain direction represents the sum of a gravitational wave and a graviton. It is found out that at approach of a graviton to the massive bodies (double stars) radiating gravitational waves there is a resonant pumping of the gravitational field energy of these bodies to the gravitons with increase in their mass and frequency. It enables registration of the gravitons with the help of the detector located near to massive bodies. The assumption is made that dark energy of a gravitational field is all set of the graviton energies of a space.

CRUSHING CHARACTER OF SAND-SODIUM-SILICATE MIXTURES STRUCTURED BY STEAM-MICROWAVE TREATMENT

At the present, from among the known methods of sand-sodium-silicate mixtures structuring, the least studied, but the most promising, is the method of steam-microwave solidification. Among unexplored elements of steam-microwave solidification method is nature of mixtures destruction. This is especially important for determining the ways to increase the sand-sodium-silicate casting molds and cores strength before pouring and lowering their strength by the time when casting should be knocked out the mold and the core from cast product. Knowledge about mixture destruction nature is also necessary for appropriate technical solutions elaboration concerning sand regeneration. In this regard, the purpose of the present work has to be nature of sand-sodium-silicate mixtures structured by steam-microwave solidification method destruction establishing. Quartz sand cladded with sodium-silicate solute has been used in the present investigation. Mixture (cladded sand) structuring has been carried out by microwave radiation at nominal magnetron power of 700 W and radiation frequency of 2.45 GHz in area of standing waves. To cladded sand structuring, 1 g water portion has been added, which has been placed in bottom of container in which mixture has been microwave treated. To make decision on mixture destruction nature, images of structured mixtures destruction places within one grain (sand grain), which are typical for adhesive and cohesive character of destruction, obtained with scanning electron microscope have been used. It has been found that with sodium-silicate solute for quartz sand cladding mass content from 0.5 to 6 % (by weight) increasing, as well as with mixture processing by the method of steam-microwave solidification duration increasing, mixture compression ultimate strength increases according to dependence closed to exponential. Character of structured mixture destruction, in this case, is not depend on sodium-silicate solute used for quartz sand cladding content, but depends on steam-microwave solidification duration. With its time increasing it changes from adhesive to mix or from adhesive to mixed and cohesive.