A dual-band cold-electron bolometer with on-chip filters for the 220/240GHz channels of the LSPE instrument

We are developing multi-chroic double-slot antenna with cold-electron Bolometer (CEB) on-chip filters for the 220/240 GHz interstellar dust monitoring channels of the LSPE-SWIPE experiment. For this goal, we used a narrowband double-slot resonant antenna with CEBs connected by coplanar lines. The simulations show that we have achieved 5% bandwidth for 220 GHz and 5.5% bandwidth for 240 GHz in our numeric modeling for the single cells. A series array of unit cells using double-slot design and coplanar lines with CEBs shows proper frequency selection. Estimations of the noise properties of the CEB arrays in a voltage-biased mode with the SQUID readout show photon-noise limited operation for the optical power load of 6 pW for channel 220 GHz and 20 pW for channel 240 GHz

Response of a cold-electron bolometer on thz radiation from a long yba2cu3o7−δ bicrystal josephson junction

The response of the Cold-Electron Bolometers (CEBs), integrated into a 2-D array of dipole antennas, has been measured by irradiation from YBa2Cu3O7−δ (YBCO) 50 \ub5m long Josephson junction into the THz region at frequencies from 0.1 to 0.8 THz. The possibility of controlling the amplitude-frequency characteristic is demonstrated by the external magnetic field in the traveling wave regime of a long Josephson junction. The YBCO junction has been formed on the bicrystal Zr1−xYxO2 (YSZ) substrate by magnetron sputtering and etching of the film. CEBs have been fabricated using an Al multilayer structure by a self-aligned shadow evaporation technique on Si substrate. Both receiver and oscillator have been located inside the same cryostat at 0.3 K and 2.7 K plates, respectively

Protecting the rights of students in the learning process in higher education: the modern Russia

В статье рассматривается понятие «студенчество» и «защита прав». Проводится анализ защиты прав студентов в высшем учебном заведении в современной России.The article discusses the concept of "student" and "protection of the rights

Водный, тепловой и солевой баланс юго-восточной части Баренцева моря

The south-eastern part of the Barents Sea is located away from the main currents, with a combination of climatic, hydrological and oceanological processes creating conditions that make the region different from the rest of the Barents Sea such that it is seen as a separate region and called sometimes the Pechora Sea. Despite the intensive economic activity in the south-eastern part of the Barents Sea, it is not yet clear to what extent the general Atlantic water transport in the Barents Sea and, consequently, the transport of heat and salt, affects this region. Therefore, the aim of this study was to assess advective flows at open boundaries, as well as other components of the water, heat and salt balances of the south-eastern part of the Barents Sea. Based on monthly average data from the MERCATOR GLORYS12V1 reanalysis for the period 1993–2018, we calculated water transport, heat and salt flows at the boundaries of the south-eastern part of the Barents Sea (at 50° E in the west, at 71° N in the north and in the Kara Gate Strait); to close the balances, an assessment was made of sea-atmosphere interaction characteristics on the sea surface based on ECMWF ERA5 reanalysis data. Water, heat and salt balances were combined with a residual not exceeding 1.6 %. Linear trends for the characteristics obtained were calculated. It is revealed that the average long-term resulting water transport in the south-eastern part of the Barents Sea is directed from the north-west of the region to the Kara Gate Strait (0.40 Sv). This current is associated with the Atlantic waters and also carries heat and salt. The resulting heat input (5.92 TW) creates a heat excess in the water area, which is compensated for by interaction with the atmosphere (1.86 TW). The salt flow through the region is estimated at 13.98 t/s. During the study period, all the main flows have a statistically significant positive trend in the incoming and outgoing parts of the balances: water transport — 0.005 Sv per year; salt flow — 0.18 t/s per year. This indicates an increase in the transit of Atlantic waters through the south-eastern part of the Barents Sea. An increase in the advective heat flux (0.15 TW per year) across the western border is accompanied by an increase in its release into the atmosphere (0.07 TW per year) and an increase in evaporation of 6.9 mm per year. Sea levels are also rising at a rate of 0.27 cm per year. Thus, the increasing dynamics of the processes in the region is a factor to take into account in conducting economic activities.В статье представлены оценки адвективных потоков на открытых границах, а также других компонентов водного, теплового и солевого балансов юго-восточной части Баренцева моря (иногда называемой Печорским морем). По среднемесячным данным реанализов MERCATOR GLORYS12V1 и ECMWF ERA5 за период 1993–2018 гг. рассчитаны объемный расход воды, потоки тепла и соли на границах юго-восточной части Баренцева моря (западная граница по 50° в. д., северная граница по 71° с. ш. и разрез в проливе Карские Ворота); потоки тепла и влаги на поверхности моря. Балансы воды, тепла и соли собраны с невязкой, не превышающей 1,6 %. Выявлено, что адвекция через границы акватории играет главную роль в формировании всех балансов. Основной поток вод направлен с северо-запада акватории транзитом через пролив Карские Ворота в Карское море. На основании анализа линейных трендов показано, что все основные потоки имеют значимый положительный тренд. Это указывает на рост транзита атлантических вод через юго-восточную часть Баренцева моря. Также отмечен рост испарения и теплоотдачи с поверхности моря, связанный с ростом температуры воды

Features of the brainstem and its cavities in three-year-old children

Background: Little is known about the brainstem in healthy three-year-old children; yet there is a need for further studies because children at this age are growing and developing rapidly.Objective: To study differences in the brainstem and its cavities in healthy three-year-old children, considering the sex and bilateral asymmetry.Materials and methods: We retrospectively analyzed 120 MRI scans of healthy three-year-old children (60 boys and 60 girls) to study the brainstem features. The following parameters of the brain stem structures were assessed: 1) the length of the pons (mm), 2) the height of the pons (mm), 3) the length of the medulla oblongata (mm), 4) the height of the medulla oblongata at the upper and lower borders (mm), 5) the length and height of the vermis (mm), 6) the width of the cerebellum (mm), 7) the length, width, height of the cerebellar hemispheres (mm), 8) the length and height of the third ventricle, 9) the length of the cerebral aqueduct (mm), 10) the length and height of the fourth ventricle (mm). We assessed the compliance of quantitative parameters with the normal distribution according to the Kolmogorov-Smirnov criterion. We used Microsoft Excel 2016 tables to accumulate, correct and systemize the raw data. Statistica 10.0 software (StatSoft. Inc., USA) along with the corresponding statistical method provided the digital data. The differences were considered significant at P < .05.Results: We aimed to study sex-related differences in the basic sizes of the brainstem. The length and height of the pons, the length of the third and the fourth ventricles, and the size of the cerebellar hemispheres were greater in boys. We found a bilateral asymmetry in cerebellar hemispheres (length, width, and height).Conclusions: The changes in the complex brainstem of three-year-old children are sex-dependent and consist in active transformations of its structures

Hemispheric Asymmetry Gender Differences in Preadolescent Children

Background: Investigating various postnatal parameters of cerebral hemispheres is of great practical value.Objective: To study gender differences in hemispheric parameters and interhemispheric interactions in preadolescent children.Materials and methods: The retrospective study assessed archived brain magnetic resonance images of 60 eight-year-old boys and 60 eight-year-old girls. The analyzed parameters were as follows: 1) hemispheric length; 2) hemispheric width; 3) hemispheric height; 4) width-longitudinal index of a hemisphere; 5) altitude-longitudinal index of a hemisphere; 6) length of frontal lobes; 7) length of parietal lobes; 8) length of occipital lobes; 9) length of temporal lobes. Quantitative indicators were assessed for normal distribution using the Kolmogorov–Smirnov test. Source data were accumulated and arranged in Microsoft Excel 2016 spreadsheets. Statistica 10.0 was used for the statistical analysis. The results were considered statistically significant with P < 0.05.Results: The analysis of cephalometric indicators suggests sex-related variation in the cerebral hemispheres. Based on the obtained data we can identify morphometric parameters of interhemispheric variability that may act as one of the morphometric criteria for the brain asymmetry. The study results can be widely used for neuroimaging.Conclusions: We determined cephalometric reference values for various cerebral hemispheres parts in preadolescent children

Исследование влияния процесса модификации на групповой состав битума и модификаторов методом Фурье-ИК-спектроскопии

Objectives. This study evaluates the effect of the modification process on the group composition of bitumen and bitumen binders containing rubber powder and hybrid modifier that is based on styrene–butadiene thermoplastic elastomer and rubber crumb. The aim of the study was to determine the presence or absence of functional groups that reflect the direction of physicochemical processes during the preparation of a hybrid modifier in rotary dispersers and during the modification of bitumen binders. Methods. Rubber powder and hybrid modifier were obtained by high-temperature shear grinding using a rotary disperser. Bitumen and modified bitumen binders were investigated via Fouriertransform infrared spectroscopy. Using the method of spectral subtraction, it was determined that during the process of manufacturing modified bitumen binders, structural changes occur in both bitumen and modifiers. During this study, the extraction of modifiers (rubber powder and hybrid modifier) in toluene was performed. Results. The quantitative analysis of changes in the group composition of modifiers before and after the modification procedure was carried out. The active polymer and structural indices were determined. The general trend of the change in the active polymer and structural indices was noted for the initial spectra of the rubber powder and hybrid modifier, and their spectra were obtained after the procedure of subtraction from the spectra of bitumen binders. Conclusions. The interdiffusion of aromatic compounds between the bitumen component and modifier particles was confirmed. On the basis of the results of the extraction of modifiers in toluene, and by taking into account the infrared spectroscopy data, it was determined that during the production of hybrid modifier during the simultaneous grinding of rubber crumb and styrene– butadiene thermoplastic elastomer, there was a chemical interaction between them. Цели. В статье проанализировано влияние процесса модификации на групповой состав битума и битумных вяжущих, содержащих резиновый порошок и гибридный модификатор на основе бутадиен-стирольного термоэластопласта и резиновой крошки. Целью исследования было определение наличия или отсутствия функциональных групп, отражающих направленность физико-химических процессов при получении гибридного модификатора в роторных диспергаторах и при модификации битумных вяжущих. Методы. Резиновый порошок и гибридный модификатор получены методом высокотемпературного сдвигового измельчения на роторном диспергаторе. Битумы и модифицированные битумные вяжущие исследованы методом инфракрасной спектроскопии с Фурье преобразованием. С помощью метода вычитания спектров установлено, что в процессе изготовления модифицированных битумных вяжущих происходят структурные изменения как в битуме, так и в модификаторах. В работе также проведена экстракция модификаторов (резинового порошка и гибридного модификатора) в толуоле. Результаты. Проведен количественный анализ изменений, происходящих в групповом составе модификаторов до и после процедуры модификации. Определены активный полимерный и структурный индексы. Отмечена общая тенденция в изменении активного полимерного и структурного индексов для исходных спектров резинового порошка и гибридного модификатора и их спектров, полученных после процедуры вычитания из спектров битумных вяжущих спектра битума.Выводы. Подтверждена взаимодиффузия ароматических соединений между битумной составляющей и частицами модификаторов. На основании результатов экстракции модификаторов в толуоле и с учетом данных ИК-спектроскопии найдено, что в процессе производства гибридного модификатора совместным соизмельчением резиновой крошки и бутадиен-стирольного термоэластопласта между ними происходит химическое взаимодействие.

Spectral characteristics of the double-folded slot antennas with cold-electron bolometers for the 220/240 GHz channels of the LSPE instrument

We present the results of the experimental and theoretical study of the resonant properties and noise of a single cell of a receiving system based on cold-electron bolometers (CEB) with a double-folded slot antenna and coplanar lines. The system was designed to receive signals at 220/240 GHz frequencies with a 5% bandwidth. In measurements, we used the samples of the double-folded slot antennas with slot lengths of 162 um and coplanar line lengths from 185 to 360 um. Measurements of the resonance properties of CEB located at 0.3 K cryostat plate were carried out using a generator based on a high-temperature YBCO Josephson junction located inside the same cryostat at 4 K plate. This arrangement made it possible to obtain smooth amplitude-frequency characteristics with a clearly defined peak of a 15–21 GHz bandwidth at different frequencies. Based on these results, 2-D array of double-folded slot antennas with CEBs as 220/240 GHz LSPE channel prototype was calculated.The absorption efficiency of the array has reached 81% and 77% for 220 and 240 GHz channels, respectively

Molecular structure and properties of κ-carrageenan-gelatin gels

© 2018 Elsevier Ltd Rheological studies, FTIR spectroscopy and a molecular docking approach were used to explore the structural basis of the peculiar physicochemical properties of gelatin gels modified with a κ-carrageenan admixture. Mixed gel properties are affected by the polysaccharide-to-gelatin ratio, Z, and can be divided into two categories. At low ratios, the strength of mixed gels varies insignificantly compared to gelatin due to the similar structures of the gels. Above the threshold content of κ-carrageenan (Z > 0.1), the storage modulus and yield stress of mixed gels are significantly enhanced. The nonadditivity and threshold character of the rheological properties could be the result of conformational ordering of both gelatin and κ-carrageenan, leading to the formation of additional junction zones in the gel network. According to molecular docking studies, the junctions could be formed as a result of complementary interactions between the gelatin triple helix and the κ-carrageenan double helix. The stack formation increases the interaction energy, which explains the strengthening of the gel network

Gender differences in the structure of the cerebrospinal fluid system of pre-school children

Relevance Investigation of the cerebrospinal fluid system of children of different ages, especially pre-school and school periods of childhood, becomes essential, since the further development of the brain and its proper functioning depends on the way it functions. Considering the MRI indications of the elements of the cerebrospinal fluid system of children is important for the development of neurology and neurosurgery, it is necessary to consider gender differences in the brain size and structure.Objective To study the sex differences in the structure of the cerebrospinal fluid system in seven-year-old children.Material and Methods For the study, archival data on the sizes of the lateral ventricles of the brain of 120 children aged 7 (60 boys and 60 girls) were involved, in particular: 1) the length of the anterior horn; 2) the width of the anterior horn; 3) the length of the central part; 4) the width of the central part; 5) the length of the posterior horn; 6) the width of the posterior horn; 7) the length of the lower horn; 8) the anteroposterior size; 9) the distance between the anterior horns; 10) the distance between the posterior horns; 11) the length of the third ventricle; 12) the height of the third ventricle; 13) the length of the aqueduct; 14) the length of the fourth ventricle; 15) the height of the fourth ventricle. The studies were carried out using the method of magnetic resonance imaging. Quantitative indicators were assessed for compliance with the normal distribution using the KolmogorovSmirnov test. The accumulation, correction, systematization of the initial information were carried out in Microsoft Excel 2016. Statistical analysis was carried out using the Statistica 10.0 software (StatSoft Inc., USA). The results were considered statistically significant at p < 0.05.Results The data obtained in the study of the cerebrospinal fluid system in children during their pre-school period of childhood are indicators of the norm and can be used for diagnostic studies in the departments of radiation diagnostics. The bilateral asymmetry of the lateral ventricles of the brain in pre-school children, discovered during the work, is of crucial clinical significance. The morphometric indicators of the elements of the cerebrospinal fluid system should be considered by specialists in the study of brain neuroplasticity.Conclusion Analysis of the obtained in vivo encephalometric data indicates the presence of sexual variability of the brain and parameters of the structures of the cerebrospinal fluid