Surface transportation engineering technology: prerequisite for accident-free traffic at signal-controlled intersections

Introduction: Improving intersection capacity will not be possible without accounting for traffic safety. Purpose of the study: We aim to determine the prerequisite for accident-free traffic at signal-controlled intersections with turning traffic flows. Methods: In our study, we used the methods of observation, comparison, and mathematical analysis. Results: We have carried out a field observation of traffic intensity at signal-controlled intersections in the city of Yekaterinburg, focusing on vehicles that moved when the green light was on. We have also analyzed traffic flow moving in three directions in the same lanes. We have discovered that traffic accident likelihood is the highest (54%) at four-way intersections. Three-way intersections account for 44% of traffic accidents, while the remaining 2% of accidents occur at multi-way intersections. Furthermore, we have determined the additional factors that impact safety in turning traffic flows at intersections. Our study demonstrates that in order to ensure maximum intersection capacity, the duration of the traffic signal cycle must be adjusted with the minimum safe distance between vehicles in mind. © St. Petersburg State University of Architecture and Civil Engineering

Evaluation of 3d Printing Materials as Tissue Equivalent Materials for Phantom Manufacturing

Развитие технологии 3D-печати стимулирует активный поиск новых способов ее применения. Создание фантомов с помощью 3D-принтера – одно из перспективных направлений. Такой подход позволит проводить более точный и индивидуальный дозиметрический контроль перед прохождением курса лучевой терапии. Основная цель этого исследования - изучить тканеэквивалентность пластиков, применяемых в 3D печати. Массовый коэффициент ослабления фотонного излучения был определен на основе химического состава путем расчета в базе данных XCom, которая представлена и поддерживается национальным институтом стандартов и технологий (NIST). Затем был осуществлен расчет линейных коэффициентов ослабления. Сравнение линейных коэффициентов ослабления проводилось с 4 тканями человека (печень, кожа, почки и грудь). Численные значения ослабления фотонного излучения тканями были получены из отчета №44 Международной комиссии по радиационным единицам и измерениям (report №44 ICRU). Среднее отношение пластик / ткань было рассчитано для выбранного диапазона энергий (10–150 кэВ). На основании экспериментальных данных получено, что наиболее тканеэквивалентным пластиком из рассмотренных является PETG. Наилучшее соответствие наблюдается с почкой и кожей. Это исследование показывает, что существующие материалы, используемые в 3D-печати, можно использовать для создания индивидуальных фантомов.The development of 3D printing technology stimulates an active search for new methods of its application. Creating phantoms using a 3D printer is one of the promising areas. This will allow for more accurate and individual dosimetric monitoring during radiation therapy. The purpose of this work is to study the tissue equivalence of plastics used in 3D printing. The mass attenuation coefficient was determined based on chemical composition by calculation in the XCom database, which is presented and maintained by the National Institute of Standards and Technology (NIST). Then the linear attenuation factors were calculated. Linear attenuation coefficients were compared with 4 human tissues (liver, skin, kidney, and breast). Tissue attenuation values for photon radiation were obtained from International Commission on Radiation Units and Measurements report №44 (ICRU report №44). The average plastic / tissue ratio was calculated for the selected energy range (10–150 keV). Based on experimental data, it was found that PETG plastic is the best for imitating kidney and skin. This study shows that existing materials used in 3D printing can be used to create customized phantoms

STATIC AND DYNAMIC PHANTOMS FOR CALIBRATION OF MOBILE MEDICAL RADIOMETRY MEASURING SYSTEMS

The abstract presents the development of a dynamic fantom of the segment of the lymphatic flow system, which is created using 3D technologies, to determine the signal lymph node. Models are used to determine the signal lymph node and the residual amount of contrast agents in the system

EXPERIMENTAL RESEARCHING MECHANICAL CHARACTERISTICS AND PLA PLASTIC APPLICABILITY AFTER ELECTRON BEAM RADIATION TREATMENT

In this work, we studied the effect of an electron beam on PLA plastic samples made on a 3D printer was carried out. The samples were irradiated at various doses from 3 to 15 kGy. The results obtained indicate an increase in the hardness and brittleness of PLA plastic com-pared to the control group

USING 3D PRINTING TECHNOLOGY TO PRODUCE PERSONALIZED BOLUSES TO OPTIMIZE RADIOTHERAPY COURSES

This work is aimed at studying the use of 3D printing technology for the manufacture of personalized boluses in order to change the distribution of the absorbed dose for various types of radiation therapy