ultra high frequency
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Author(s):  
Priscilla Swee Pei Poh ◽  
◽  
Rafidah Ngadengon ◽  

Securing and monitoring the territory have become a big challenge for everyone as the number of vehicle users have increased. The premise area must be secure with enforced entrances and exits. It should have an automated and efficient security and monitoring system. For this purpose, an automated vehicle access system with accurate and secure monitoring of vehicle entry and exit was developed with Graphical User Interface (GUI) and vehicle’s user database along with the prototype of Ultra-High Frequency RFID. The suitable configuration for the hardware prototype has also been evaluated to maximize the system’s capabilities. This system operates on frequencies from 400MHz to 950MHz and is performed at distances of 7 meters. The passive tag was attached to the various condition and sizes of the car. The result shows showed that the system was optimally performed with the speed of the vehicle up to 50 km/h, 7 m of reading range and a maximum 20% tinted windshield. The ideal angle for the reader is around 60ᵒ to 70ᵒ with 2 meters of mounting pole. For future improvement, it is suggested that the registered vehicle user data was linked with the official premise’s database and the data is saved in an off-site location (cloud storage). The GUI is also able to support more than 1 reader at a time depending on demand.


2021 ◽  
Vol 8 (6) ◽  
pp. 937-944
Author(s):  
Midhat Tuhvatullin ◽  
Yuri Arkhangelsky ◽  
Rustam Aipov ◽  
Eduard Khasanov

Ultra-high frequency (UHF) electric installations, using the energy of UHF electromagnetic oscillations, can perform thermal UHF modification of dielectric materials and products. As a result, its properties and parameters change in an object processed in a UHF electromagnetic field faster and more uniformly than when the heat is transferred to a heated dielectric by thermal conductivity, convection, thermal radiation. The exact change in the properties and parameters of polymers of living and inanimate nature, uniform in volume and significantly in a shorter time spent in a UHF electromagnetic field, can be obtained in UHF electrical installations, and practically without heating the object as a result of the so-called non-thermal UHF modification. The paper proposes the design and design of a UHF electric installation with a hybrid-type working chamber. Such a working chamber makes it possible to simultaneously carry out non-thermal UHF modification of a polymer and thermal UHF modification of a dielectric in one installation. A UHF electric installation with a hybrid-type working chamber is cheaper. It takes up less space than two separate installations producing the same products with the same productivity.


Author(s):  
Akitatsu Hayashi ◽  
Giuseppe Visconti ◽  
Guido Giacalone ◽  
Nobuko Hayashi ◽  
Hidehiko Yoshimatsu

Abstract Background Currently, microsurgeons are in the era of supermicrosurgery and perforator flap reconstruction. As these reconstructions frequently utilize vessels that are smaller than a single millimeter, understanding of location of lymphatic vessels and perforator anatomy preoperatively is essential. To change with the times, the role of ultrasound has changed from just an adjunct to primary imaging of the choice in reconstructive supermicrosurgery. Recently, a novel ultrasonographic technique involving the use of ultra-high frequency ultrasound (UHFUS) frequencies has entered the scene, and appears a promising tool in surgical planning. Methods The literatures on the applications of UHFUS in reconstructive supermicrosurgery were retrieved and reviewed from more than 60 literatures have been published on the surgical applications of UHFUS. Results Nine studies were retrieved from the literature on the applications of UHFUS in reconstructive supermicrosurgery. The articles report both application for lymphatic surgery and perforator flaps. Conclusions UHFUS application involves an increasing number of reconstructive supermicrosurgery field. UHFUS is a valuable and powerful tool for any reconstructive surgeons who are interested in performing supermicrosurgery.


2021 ◽  
Vol 24 (1) ◽  
Author(s):  
Nancy Aggarwal ◽  
Odylio D. Aguiar ◽  
Andreas Bauswein ◽  
Giancarlo Cella ◽  
Sebastian Clesse ◽  
...  

AbstractThe first direct measurement of gravitational waves by the LIGO and Virgo collaborations has opened up new avenues to explore our Universe. This white paper outlines the challenges and gains expected in gravitational-wave searches at frequencies above the LIGO/Virgo band, with a particular focus on Ultra High-Frequency Gravitational Waves (UHF-GWs), covering the MHz to GHz range. The absence of known astrophysical sources in this frequency range provides a unique opportunity to discover physics beyond the Standard Model operating both in the early and late Universe, and we highlight some of the most promising gravitational sources. We review several detector concepts that have been proposed to take up this challenge, and compare their expected sensitivity with the signal strength predicted in various models. This report is the summary of the workshop “Challenges and opportunities of high-frequency gravitational wave detection” held at ICTP Trieste, Italy in October 2019, that set up the stage for the recently launched Ultra-High-Frequency Gravitational Wave (UHF-GW) initiative.


2021 ◽  
Vol 935 (1) ◽  
pp. 012026
Author(s):  
G Novikova ◽  
I Ershova ◽  
M Prosviryakova ◽  
O Mikhailova ◽  
V Storchevoy ◽  
...  

Abstract The study is aimed at the effect substantiation of voluminous heating of the cattle frozen colostrum in the two-resonator installation. The methodology is based on the theory of the electromagnetic field, the laws of thermodynamics and the results of physical modeling. The colostrum dielectric parameters were analyzed in the temperature range from -12 °C to +40 °C. The theoretical studies were carried out for changes finding out in the absorption coefficient of the electromagnetic field and the penetration depth of the electromagnetic waves 12.24 cm long during defrosting/heating of the cow colostrum with the fat content of 6.4%. It is found that the penetration depth of the electromagnetic field into the frozen raw material at negative temperatures range (0.2-1.0 cm) is less than that at the colostrum positive temperatures (1.0-2.17 cm). With such significant difference in the dielectric characteristics of the frozen and thawed colostrum and in their penetration depths of the ultra high frequency electromagnetic field, the rate of their heating is considerably different. The developed continuous-flow ultra high frequency electromagnetic generator contains two voluminous resonators. They provide the colostrum being in different physical states with different doses of the ultra high frequency electromagnetic field exposure.


2021 ◽  
Vol 16 (3) ◽  
pp. 79-83
Author(s):  
Mar'yana Prosviryakova ◽  
Irina Ershova ◽  
Ol'ga Mihaylova ◽  
Galina Novikova ◽  
Bulat Ziganshin

The article is devoted to the development of a two-resonator ultra-high-frequency (UHF) installation for defrosting and warming up animal colostrum, which ensures electromagnetic safety during continuous operation. As well as the development and study of the parameters of a microwave installation, which allows defrosting and uniformly warming up colostrum of animals in the field of a standing wave in the electromagnetic field of a traveling wave. A microwave installation is described with working chambers arranged in tiers in the form of an annular and conical resonators, containing, respectively, dielectric containers and dielectric conical plates. The out-of-limit waveguide is calculated and the radiation of the electric field through the loading hole is considered in the absence of the out-of-limit waveguide at a distance from the ring resonator that is greater than the wavelength. For uniform defrosting of colostrum in plastic bottles, they should be moved in a ring resonator and the magnetrons should be positioned with a shift of 120 degrees around the perimeter. Then the resulting strength of the electric field consisting of several initial fields will be equal to the vector sum of their strengths. To achieve a high heating rate of raw materials in the region of positive temperatures, it is necessary to provide a condition for heating a thin layer of liquid with the help of coaxially located conical dielectric trays


2021 ◽  
Vol 16 (11) ◽  
pp. P11018
Author(s):  
P. Wang ◽  
L. Dong ◽  
H. Wang ◽  
G. Li ◽  
X. Xie

Abstract It can be ensured safe and reliable operation of a metallic structure by monitoring the positions which are easy to crack. Because the channel changes with the environment, a tag sensor in the ultra high frequency (UHF) is vulnerable to interference. This paper aims to investigate the reliability of passive RFID sensor systems with a reference tag for crack detection of aluminum alloy structures when the condition of reading distance and surrounding environment changes. The impedance and gain of tags are simulated, which provides theoretical basis for experimental analysis. With an increase of crack depth, the impedance of the sensor tag shifts to the low frequency direction, and the reference tag changes slightly. When dual tags are placed orthogonally, the gain of the sensor tag changes greatly, which means that it is more sensitive to crack depth. The backscatter power of the sensor tag shows a decline trend, and the power of the reference tag remains unchanged. The sensor features a linear response with the variation of crack depth. The sensitivity of crack characterization is better when dual tags are placed orthogonally.


2021 ◽  
Vol 5 (11 (113)) ◽  
pp. 51-60
Author(s):  
Aigul Omaraliyeva ◽  
Zhanar Botbayeva ◽  
Mereke Agedilova ◽  
Meruyert Abilova ◽  
Aidana Zhanaidarova

This paper describes the materials and results of studying the properties of such a leguminous crop as the chickpea variety Miras 07 of Kazakhstan selection in order to obtain gluten-free flour and further process it to produce confectionery products. The research involved the ultra-high-frequency (UHF) treatment of chickpea grain to improve quality indicators and reduce anti-alimentary factors. A change in the protein fraction of chickpeas was determined under exposure to ultra-high-frequency processing. The study has proven the effectiveness of ultra-high-frequency treatment of chickpea for 180 seconds. Based on chemical analysis, it was found that the exposure to ultra-high-frequency treatment fully preserved the vitamin and mineral complex, compared with untreated chickpeas. When chickpea grain is heated for 180 seconds, up to 20 % of the starch contained in the grain passes into dextrin, which is easily absorbed by humans while the toxic substances are destroyed. The change in the protein fraction of chickpeas during ultra-high-frequency processing was determined. With ultra-high-frequency treatment of chickpea flour at 180 seconds of exposure, the protein fraction content remains unchanged at 79.8 %. The result based on the IR spectrum data indicates that ultra-high-frequency processing did not affect the protein-amino acid composition of the examined Miras 07 chickpea variety. The current study has confirmed the effectiveness of ultra-high-frequency chickpea treatment, which leads to the intensification of biochemical processes in the processed product due to the resonant absorption of energy by protein molecules and polysaccharides. Under the influence of ultra-high-frequency treatment, there is a decrease in the microbiological contamination of raw materials while the organoleptic indicators improve. According to the microbiological indicators of chickpea flour, the content of microorganisms was 1×103 CFU/g, which meets the requirements for sanitary and hygienic safety


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