Assessment of extreme hydrological conditions in the Bothnian Bay, Baltic Sea, and the impact of the nuclear power plant “Hanhikivi-1” on the local thermal regime

The results of the study aimed to assess the influence of future nuclear power plant “Hanhikivi-1” upon the local thermal conditions in the Bothnian Bay in the Baltic Sea are presented. A number of experiments with different numerical models were also carried out in order to estimate the extreme hydro-meteorological conditions in the area of the construction. The numerical experiments were fulfilled both with analytically specified external forcing and with real external forcing for 2 years: a cold year (2010) and a warm year (2014). The study has shown that the extreme values of sea level and water temperature and the characteristics of wind waves and sea ice in the vicinity of the future nuclear power plant can be significant and sometimes catastrophic. Permanent release of heat into the marine environment from an operating nuclear power plant will lead to a strong increase in temperature and the disappearance of ice cover within a 2 km vicinity of the station. These effects should be taken into account when assessing local climate changes in the future

Modeling of Sediment Transport in Bothnian Bay in the Vicinity of the Nuclear Power Plant ‘Hanhikivi-1’ Construction Site

The intensity of sediment resuspension and sedimentation in the eastern part of the Bothnian Bay near the Hanhikivi cape, where the nuclear power plant ‘Hanhikivi-1’ will be constructed, has been assessed for the first time by means of numerical modeling under the realistic external forcing that occurred in 2014. A brief description of a coupled modeling system used in the study is given. The results of local resuspension intensity and sediment accumulation rates for one-year model run are presented. It has been determined that the main areas of sediment accumulation are located along the northern coast off the Hanhikivi peninsula and in the shallow region situated to the north-east off the cape. Sedimentation rates in the navigation channel have also been estimated. Model results obtained for 2014 suggest that sedimentation in the seaward part of the channel is absent, while sediment accumulation intensity is about 10 cm/year in the middle part of the channel and 70 cm/year in the coastal part. A temporal variability of the sedimentation rates during the year has been emphasized

Indian Ocean marine biogeochemical variability and its feedback on simulated South Asia climate

We investigate the effect of variable marine biogeochemical light absorption on Indian Ocean sea surface temperature (SST) and how this affects the South Asian climate. In twin experiments with a regional Earth system model, we found that the average SST is lower over most of the domain when variable marine biogeochemical light absorption is taken into account, compared to the reference experiment with a constant light attenuation coefficient equal to 0.06 m−1. The most significant deviations (more than 1 ∘C) in SST are observed in the monsoon season. A considerable cooling of subsurface layers occurs, and the thermocline shifts upward in the experiment with the activated biogeochemical impact. Also, the phytoplankton primary production becomes higher, especially during periods of winter and summer phytoplankton blooms. The effect of altered SST variability on climate was investigated by coupling the ocean models to a regional atmosphere model. We find the largest effects on the amount of precipitation, particularly during the monsoon season. In the Arabian Sea, the reduction of the transport of humidity across the Equator leads to a reduction of the large-scale precipitation in the eastern part of the basin, reinforcing the reduction of the convective precipitation. In the Bay of Bengal, it increases the large-scale precipitation, countering convective precipitation decline. Thus, the key impacts of including the full biogeochemical coupling with corresponding light attenuation, which in turn depends on variable chlorophyll a concentration, include the enhanced phytoplankton primary production, a shallower thermocline, and decreased SST and water temperature in subsurface layers, with cascading effects upon the model ocean physics which further translates into altered atmosphere dynamics

Зависимость диэлектрических свойств керамики титаната бария и композита на его основе от температуры спекания

In this paper, we compare the structure and dielectric properties of the samples of barium titanate ceramics that have been sintered at temperatures of 1100, 1150, 1200, 1250 and 1350 °C and dielectric characteristics of the samples of barium titanate (80 vol.%) — barium ferrite (20 vol.%). It is shown that only samples sintered at the temperature of 1250 and 1350 °C have polarization sufficient for the existence of the piezoelectric effect. For the same samples, the pyroelectric coefficient and reversal polarization significantly exceed those for samples sintered at lower temperatures. Analysis of the samples structure confirmed the dependence of the dielectric properties of the barium titanate ceramics on the grain size and, as a consequence, on the sintering temperature. Based on the studies carried out, the optimal temperature (1250 °С) for obtaining composite samples of barium titanate (80 vol.%) — barium ferrite (20 vol.%) was selected. The temperature dependence of the dielectric constant for the composite samples based on barium ferrite — barium titanate with a sintering temperature of 1250 °C is similar to the dependence for the BaTiO3 ceramic samples sintered at 1350 °C. At room temperatures, the permittivity of the composite samples is also significantly higher than that of the barium titanate ceramic samples obtained at the same sintering temperatures. The addition of barium ferrite to the barium titanate not only increased the permittivity of the composite, but also led to a diffusing of the ferroelectric phase transition and a shift in the temperature of the maximum of the dielectric constant by 10 degrees towards high temperatures.Проведено сравнение структуры и диэлектрических свойств образцов керамики титаната бария, спеченных при температурах 1100, 1150, 1200, 1250 и 1350 °С, и диэлектрических характеристик образцов композита титанат бария (80 % (об.)) — феррит бария (20 % (об.)), спеченных при температурах 1150, 1200 и 1250 °С. Показано, что поляризацию, достаточную для проявления пьезоэлектрического эффекта, имеют только образцы титаната бария, спеченные при температурах 1250 и 1350 °С. У этих же образцов величина пирокоэффициента и остаточной поляризации значительно превосходят аналогичные значения для образцов, спеченных при более низких температурах. Анализ структуры образцов подтвердил зависимость диэлектрических свойств керамики титаната бария от размера зерен и, как следствие, от температуры спекания. На основании проведенных исследований выбран оптимальный режим спекания образцов композита титанат бария (80 % (об.)) — феррит бария (20 % (об.)) —1250 °С. Дальнейшее повышение температуры до 1300 °С показало наличие у данного композита эвтектики. При этом температурная зависимость диэлектрической проницаемости для образцов композита на основе феррита бария — титаната бария с температурой спекания 1250 °С аналогичны зависимости для образцов керамики BaTiO3, спеченных при 1350 °С. При комнатных температурах у образцов композита диэлектрическая проницаемость также значительно больше, чем у образцов керамики титаната бария, полученных при тех же температурах спекания. Добавление феррита бария в состав титаната бария не только повысило диэлектрическую проницаемость композита, но и привело к размытию сегнетоэлектрического фазового перехода и смещению температуры максимума диэлектрической проницаемости на 10 градусов в сторону высоких температур.

Дипептидный аналог холецистокинина-4, ослабляет тревожную реакцию у «высокоэмоциональных» мышей BALB/с и при моделировании алкогольной абстиненции у крыс: сравнение с феназепамом

Anxiolytic effects of dipeptide endogenous cholecystokinin tetrapeptide analogue GB-115 at the dose range 0,25-2,0 mg/ kg after oral administration were studied in rodents with high emotionality. In “elevated plus-maze” test GB-115 anxiolytic activity comparable with phenazepam was shown in inbred “anxious” BALB/c mice and “aged” rats with long-term 10% ethanol experience during ethanol withdrawal. GB-115 at the doses 0,5-2,0 mg/kg didn’t induce sedation, in contrast phenazepam significantly suppressed spontaneous locomotor activity in BALB/c mice in Optovarimex. The data obtained show potent anxiolytic properties GB-115 (tablet 0,001) lacking benzodiazepine’s side-effects in animal models with high emotionality.Изучены анксиолитические свойства ГБ-115, дипептидного аналога эндогенного тетрапептида холецистокинина у животных с повышенным уровнем эмоциональности при пероральном введении в диапазоне доз 0,25-2,0 мг/кг. В тесте ПКЛ анксиолитическое действие ГБ-115, сопоставимое с феназепамом, установлено у инбредных мышей BALB/c и у «старых» крыс, потреблявших 10% раствор этанола в течение 33 недель на фоне алкогольной депривации. ГБ-115 в дозах 0,5-2,0 мг/кг не вызывал седативного действия, в то время как феназепам статистически значимо угнетал спонтанную двигательную активность мышей BALB/c в актометре. Полученные результаты демонстрируют наличие у ГБ-115 (таблетка 0,001) выраженных анксиолитических свойств, лишённых побочных эффектов, характерных для производных бензодиазепина, на экспериментальных моделях с повышенным уровнем тревожност

Георадарные исследования для подготовки взлетно-посадочной полосы на морском льду в районе полевой базы Оазис Бангера, Восточная Антарктида

When one is carrying out logistic operations at Russian Antarctic stations, organization and safe operation of snow-runways play an important role. Nowadays six of the seven existing stations and field bases of the Russian Antarctic expedition (RAE) are provided with air communication, however, the Bunger Oasis field base is still outside the air transportation structure. The aim of the investigations described in this paper was to find a safe site for organizing a snow-runway in the area of the Bunger Oasis field base. Taking into account the location of the infrastructure objects of RAE within the Bunger Oasis, the central part of the epishelf Transcription Gulf, situated 7 km away from the base, was chosen as the most appropriate site. During the summer field season of the 64th RAE (2018/2019), a geophysical survey using the GPR (Ground-penetrating radar) method was carried out within the area to obtain data on the thickness of the bay ice. The GPR survey conducted shows that the sea ice thickness varies from 2.9 to 3.1 m. Moreover, no signs of discontinuities in the ice layer were found. The area investigated was identified as a safe site suitable for the landing of light and medium aircraft. However, due to the specificity of the relief of the oasis adjacent to the Bay, the weathering products of the rocks composing the hills migrated to the surface of the ice layer. The effect of solar radiation caused the thawing in the areas of such particles to increase, and this, in turn, led to the formation of cavities on the surface, the dimensions of which do not meet the requirements for runway coatings. As a result, in the area under study, the boundaries of the sites were determined that are suitable for the organization of runways for medium and small aircraft without preliminary rolling of the landing site.В настоящей работе представлены результаты исследований, выполненных в районе полевой базы Оазис Бангера в ходе полевого сезона 64-й РАЭ (2018/19 г.). Целью работ был поиск безопасной площадки для организации посадочной полосы для самолетов средней и малой авиации. Наиболее подходящим местом для возможного аэродрома был выбран покров залива Транскрипция, располагающегося на удалении 7 км от базы. В рамках исследований были выполнены геофизические инженерные изыскания методом георадиолокации для определения мощности льда залива и выявления нарушения целостности ледяного покрова. По результатам работ был найден безопасный участок для приема мало- и среднегабаритных самолетов на лыжных шасси