Peculiarities of the formation of scincillation response in organic materials with stochastic character of light propagation

The paper examines the possibility of using an organic polycrystal as the “opaque” scintillator. Polycrystals are produced by pressing crystalline grains. When light propagates through a polycrystal, it is repeatedly reflected and refracted at the boundaries of the grains. This makes its propagation difficult. We studied the light output and optical transmittance of stilbene and p-terphenyl polycrystals with different fractions of crystalline grain: from 0.06…0.1 to 2.0…2.5 mm (the samples 20 mm in diameter and 2 mm in height) was conducted. Modelling of light propagation in polycrystalline samples of stilbene and p-terphenyl was carried out and the values of the light collection coefficients were calculated. It was found that in order to obtain the polycrystalline samples with sufficiently high light output and high efficiency of detection of local sites of interaction of ionizing radiations, grains in the range of 0.4…0.8 mm should be used.Досліджується можливість використання органічного полікристалa в якості “мутного” сцинтилятора. Полікристали виготовляють методом пресування кристалічних гранул. Світло при розповсюдженні крізь полікристал зазнає багаторазового відбивання та заломлення на границях гранул, що ускладнює його проходження. Проведено дослідження світлового виходу та оптичного пропускання полікристалів стильбену та п-терфенілу із різними фракціями кристалічних гранул: від 0,06…0,1 до 2,0…2,5 мм (діаметр зразків 20 мм та висота 2 мм). Проведено моделювання проходження світла в полікристалічних зразках стильбену та п-терфенілу, та розраховані значення коефіцієнтів світлозбирання в них. З’ясовано, що для отримання полікристалічних зразків із достатньо високим світловим виходом та високою ефективністю виявлення локальних місць взаємодії іонізуючого випромінювання слід використовувати гранули в діапазоні 0,4…0,8 мм

LA COOPERACIÓN ECONÓMICA ENTRE RUSIA Y LOS PAÍSES-MIEMBROS DEL MERCOSUR: EL ESTADO Y LAS PERSPECTIVAS

The authers consider Latin America as one of the most significant regions in terms of Russia’s economic and political interests. Among the numerous Latin American countries the member states of the MERCOSUR organization are supposed to be the most attractive and prospective partners for Russia. The analysis shows that in the USSR period the foreign trade turnover of our country with the South American continent was quite considerable as well as the investment cooperation that had a lot of dynamism. However the Soviet Union’s colapse effected the relations between our countries so badly that they still can’t revive. Despite the rapid growth of the bilateral trade in the recent years the economic cooperation between Russia and MERCOSUR countries remains slugish. The major Russian partners in the region Brazil and Argentina account for only 1% of the total foreign trade turnover of our state. Nevertheless in contrast to the European countries where the exports of Russian finished goods are limited the South American states are considered to be a prospective and dynamic market for the Russian advanced-technology products.Las autoras consideran América Latina como la región significativa en términos de los intereses económicos y políticos rusos. Entre los paises latinoamericanos los miembros del MERCOSUR son los socios potenciales de mas perspectiva y atractivos a nuestro país. El análisis muestra que durante el periodo de la Unión Sovética el volumen de negocio con los estados sudamericanos era bastante considerable, también teniamos la cooperación dinámica en inversiones. Sin embargo el colapso de la URSS afectó a las relaciones economicas entre nuestros paises que no pueden recuperarse hasta el día de hoy. A pesar del rápido crecimiento del comercio bilateral en los últimos años, la cooperación económica entre Rusia y los estados del MERCOSUR aún queda en un nivel bajo. Los socios principales rusos en la region son Brasil y Argentina que representan solo 1% de todo el comercio exterior de nuestro país. Con todo esto los estados sudamericanos, en contraste con los de Europa Occidental, donde se limitan las exportaciones rusas de los productos acabados, son breves, dinámicos y muy prometedoros para el mercado ruso desde el punto de vista de las altas tecnologías

THE VALUE OF SOME INDICES OF HEART RATE VARIABILITY IN THE DIAGNOSIS OF FETAL GROWTH RETARDATION

<p>Fetal growth retardation (FGR) is one of the most serious problems in current perinatology. This pathology leads not only to the deterioration of perinatal outcomes but also significantly increases morbidity during adult life. FGR is known to be featured by its delayed "neurological maturation". This is manifested in a decrease in autonomic nervous regulation according to the fetal heart rate variability (HRV) scores and indices.<br><strong>The objective</strong>: to study HRV in fetuses with normal biometric indices compared to similar parameters of growth retarded fetuses.<br><strong>Materials and methods</strong>. The 47 pregnant women who had fetuses with normal biometric indices (I group) and 33 patients with fetal growth retardation (II group) were included in the study. The investigation of the fetal HRV was performed by processing the R–R intervals obtained via non-invasive electrocardiogram (ECG) and involved the following indices: STV (short term variations), LTV (long term variations), AC/DC (acceleration capacity/deceleration capacity), TP (total power), SI (stress index), SDNN (standard deviation of normal to normal intervals), EnRE (entropy of the time series), D2 (correlation dimension of the time series), Z (temporary irreversibility) і FL (measure of fuzzy logic, integrated measure of HRV).<br><strong>Results</strong>. The obtained data indicated that the indices of fetal HRV were reduced in the patients with FGR. These indices have utility in screening programs for the detection of fetal intrauterine nutrition and growth disturbances. The results of the study allow us to believe that the ability to accelerate heart rate patterns is partly preserved even during FGR. This may indicate a very ancient phylogenetic nature of the reaction of the heart system of the fetus to its motile activity. However, decelerations according to the DC were typical for FGR. A non-invasive fetal ECG could become a useful supplementary method in the current methods' spectrum used in perinatal medicine.<br><strong>Conclusions</strong>. Therefore, the development of algorithms for the diagnosis of FGR requires the inclusion of the following HRV indices: STV, LTV, DC, TP, SI, SDNN, D2, Z, and FL. These biophysical markers of FGR can be used as a screening program in conditions of lack of access to high-quality ultrasound diagnostics or be a valuable addition to existing perinatal strategies.</p&gt

Selfie in student environment: from selfie addiction awareness to everyday practices study

The relevance of this article is to study such a social phenomenon as selfie. With the development of society, the life of each person changes, the practices of his/her behavior change, as well as new ones arise under the influence of emerging social phenomena. The article considers the views of students about selfies; it defines types of selfies in different categories. It is revealed that preference is given to individual selfies, on holidays or events that are important for the author personally, in order to capture their emotions. It is revealed that almost half of students have a low degree of activity in accounts and is expressed in monitoring the publications of other users

Selfie in student environment: From selfie addiction awareness to everyday practices study [Selfie en el entorno estudiantil: De la conciencia de adicción al selfie, hasta el estudio de prácticas cotidianas]

The relevance of this article is to study such a social phenomenon as selfie. With the development of society, the life of each person changes, the practices of his/her behavior change, as well as new ones arise under the influence of emerging social phenomena. The article considers the views of students about selfies; it defines types of selfies in different categories. It is revealed that preference is given to individual selfies, on holidays or events that are important for the author personally, in order to capture their emotions. It is revealed that almost half of students have a low degree of activity in accounts and is expressed in monitoring the publications of other users. © 2020, Universidad del Zulia. All rights reserved

Method of obtaining an organic polycrystalline scintillator for detecting beta-radionuclide sources in natural waters

The method of producing an organic polycrystalline scintillator with two-stage sorbent filled holes for detecting beta-emitting source of 90Sr in natural water is proposed. That confirms that synthetic hydroxylapatite is the optimal sorbent to solving the problem. For the polycrystalline scintillator of p-terphenyl doped by 1,4-diphenylbutadiene-1,3 which has the holes filled with hydroxylapatite as a sorbent, the efficiency of detecting beta particles of 90Sr isotope sorbed from the water sample reaches 90 %