Radiophysicists study the properties of composites for 5G devices

by Ksenia Akentyeva, Tomsk State University

https://phys.org/news/2019-12-radiophysicists-properties-composites-5g-devices.html

TSU radiophysicists are forming a database of properties of composite materials that can be used to create 5G and space communication devices operating in the terahertz range. The scientists are creating composite materials from ABS plastic and nanotubes and measuring their properties in a frequency range from 10 MHz to 1 THz.

To create the source material, the radiophysicists are using polymers and filling them with carbon nanotubes, produced by the Boreskov Institute of Catalysis of the Siberian Branch of the Russian Academy of Sciences for the Terahertz Laboratory of the Faculty of Radiophysics.

"By adding nanotubes of different concentrations, we change the electrophysical properties of the material. For example, we can increase the dielectric constant. Then, a 3-D-printed circuit board with elements (conductors, resistors, and others) can be created," says Alexander Badyin, associate professor of the Faculty of Radiophysics. "From the material obtained on a 3-D printer, we print a control sample—plates or rings, depending on the standard of the measuring installation, and examine the properties of the composite in the terahertz range."

According to the researcher, scientists are mainly interested in household radiation up to 4-5 GHz. TSU scientists are working with a wider range—up to 1 THz, which is currently insufficiently studied. At the moment, they have studied the properties of 50 samples.

"We produce materials that are currently in demand in the creation of mobile devices, medicine, and the study of works of art," said Badyin. "It is here that the positive properties of the terahertz range are noted. The terahertz range provides the transition to the 5G standard, and is promising for communications in space. But today, there are no technical means due to a lack of materials that cannot be manufactured without the use of 3-D technology."

In the Terahertz Laboratory of the Faculty of Radiophysics, there are tools and techniques for manufacturing composite filaments based on original materials developed by the university staff. The scientists made passive elements of the terahertz range (absorbers and polarizers), which were tested experimentally on the equipment of the TSU Measurement Center and were tested at international conferences in Nagoya (Japan), Paris (France), and Moscow and Tambov (Russia).

Tomsk State University researchers develop new approach to diagnose adenocarcinoma

https://www.news-medical.net/news/20191113/TSU-researchers-develop-new-approach-to-diagnose-adenocarcinoma.aspx

Scientists have developed a new approach to the diagnosis of adenocarcinoma - a malignant tumor of the prostate gland. Artificial intelligence is used to determine oncopathology and determine the stage of the disease with this approach. The scientific model with 100% accuracy distinguishes between healthy tissue and pathology.

The gold standard for the diagnosis of cancer is histology, during which tissue from a patient is examined for malignant changes. So that the samples can be stored for a long time, they are dehydrated and poured with paraffin. Then experts make thin sections and examine these “slides” using a microscope.

Typically, several people work with prostate biopsy specimens, after examining the sections, they make a collegial decision. The human factor cannot be canceled, therefore, due to subjective assessment, there are erroneous conclusions. We tried to solve this problem using IT technologies - we developed a computer model and, through machine learning, taught her how to detect abnormal areas using a tool such as terahertz spectroscopy."

Yuri Kistenev, executive director of the TSU Institute of Biomedicine

According to Yuri Kistenev, in the process of analysis, artificial intelligence not only detects the presence of cancer cells but also evaluates the tumor according to the Gleason score. It is traditionally used in the diagnosis of prostate cancer to determine the degree of malignancy of the process (indicators from 1 to 10), which is important in terms of predicting the course of the disease.

"Using terahertz spectroscopy makes it possible to visualize a sample very well since a laser reads from 2500 to 4000 points in a small area," says Anastasia Knyazkova, one of the project executors. "In the process of training, a computer model was trained on samples of healthy and diseased tissue. Thus, AI learned to separate the norm and pathology. A test of his ability to verify adenocarcinoma was carried out on that part of the samples that were not used in training. Assessment of the malignancy of the process was carried out for samples having a rating of 4 and 8 on the Gleason scale. The accuracy of the differential diagnosis was 100 percent."

Radiophysicists will double the quality of terahertz devices

http://en.tsu.ru/news/radiophysicists-will-double-the-quality-of-terahertz-devices/

Radiophysicists from Tomsk and Novosibirsk are planning to double the resolution of the terahertz range. In particular, this will help to more thoroughly examine works of art - old books, manuscripts, and paintings - without touching them. The experiment will begin in mid-August.

- Terahertz radiation is used for various purposes, including the study of works of art, because unlike optical illumination, it penetrates deeply, but unlike X-ray, does not shine through. It is possible for example to view text or drawings in old books layer by layer at different frequencies without touching them and therefore without damaging them, - said Valentin Suslyaev, manager of the project, associate professor at TSU, head of the Laboratory of Terahertz Research. - The same radiation is used to diagnose and treat skin diseases, for example, various types of skin cancer.

In both cases, the terahertz beam must be as focused as possible, that is, its resolution must be high. The finer this beam, the greater the resolution it has, and therefore the more carefully it can identify the features of the object that needs to be studied.

- There is a physical law that limits the resolution to half the wavelength, but it can be overcome using lenses. Our colleagues from Novosibirsk, Oleg Minins and Igor Minins, showed that it is possible to use simple manufactured lenses and simple geometric shapes - cuboids and ellipsoids. Making a cube is easier than a lens, and using it, you can double the resolution, - explained Valentin Suslyaev.

Oleg and Igor Minins used mathematical modeling to prove the possibility of increasing the resolution of terahertz radiation using cuboids, and Tomsk radiophysicists will conduct an experimental study. TSU scientists have already developed an experimental design in free space and in an open resonator to prove the Minins’ theoretical results.

- One of the problems that we are solving is the influence of the tool on the object of study. We created a probe that when it is moved, makes it possible to determine the size of the area of focused terahertz radiation, but the probe affects the size of the focused radiation. Now in Minsk, our employees are developing solid-state detectors based on graphene to consider this area with less impact on the object, -added Valentin Suslyaev.

A physical experiment will take place in mid-August. According to the forecasts of TSU radiophysicists, they will get the first results by the beginning of September.

TSU and the UK National Physical Laboratory signed a general scientific cooperation agreement

http://tsu.ru/english/about_tsu/news_events/49817/

July 23, 2014 - (PressReleasePoint) -

The National Physical Laboratory (NPL) is the national measurement standards laboratory for the United Kingdom, based at Bushy Park in Teddington, London, England. It is the largest applied physics organisation in the UK. Five-year agreement includes joint research, scientific and technical information exchange, experts exchange, lectures and workshops.
- «Partnership is just beginning - said Valery Svetlichny, the head of the laboratory of new materials and advanced technologies SFTI. - Laboratory represents TSU. At this stage, TSU and the UK National Physical Laboratory conduct joint studies on physico-chemical, and nonlinear optical properties of some doped crystals GaSe, terahertz generation efficiency and its application to the study of natural objects. Also we plan the subjects expansion of scientific cooperation, exchange visits, joint participation in Russian and international scientific programs, the creation of a joint laboratory».
According to the words of Vice-Rector for International Affairs Artem Rykun, TSU cooperation with the leading research centers has great importance.
- TSU and the UK National Physical Laboratory cooperate not only with the universities, but also with large observatories or laboratories on a par with the universities. The good example is the National Physical Laboratory. Its importance should be assessed, first of all, by professionals in this field. But this is exactly the place where science is concentrated – he added. - It is notable that that the British laboratories are extremely reluctant to establish a new contact. Before starting cooperation they are looking closely at the potential partner. And the contract is a sign that you are perceived in the scientific community as a really serious partner. Therefore the agreement of TSU and NPL is not just a protocol or formality but the real business agreement.