Fluoride technology of obtaining REM magnetic alloys and master alloys

Rare earth permanent magnets (REPM) based on neodymium-Fe-boron system are the most promising, since they have the highest magnetic and satisfactory mechanical characteristics. The paper covers physical-chemical principles and shows the results of experimental studies of the process of obtaining REM alloys and master alloys using fundamentally new fluoride technology based on ladle calciothermal REM fluorides and Fe reduction

Корректировка шкал локальных K-индексов для высокоширотных магнитных станций

To assess the magnetic activity, various indices (numerical characteristics of the planetary and local disturbance of the Earth’s magnetic field) are used. Most widely used for various purposes are the planetary Kp-index and the local K-index, proposed by Bartels. The K-index characterizes the Earth’s magnetic field disturbance in a 3-hour interval (0–3, 3–6, etc. UTC) and is defined in a range from 0 to 9 by the amplitude of the horizontal component deviation from the quiet level. K = 0 indicates the absence of geomagnetic activity, and K = 9 corresponds to a strong geomagnetic storm. The lower limit of K = 9 is the amplitude of magnetic field horizontal component variation above which the K-index is assigned the maximum value of 9. This limit is selected individually for each station, depending on its geomagnetic latitude. The latest scales of the K-indices boundaries for the Russian Arctic stations were determined in the middle of the last century and have not been corrected since then. The significant discrepancy between the K-indices calculated using these scales and the planetary Kp-index shows that they had to be refined, and in some cases, they must be re-selected. The local indices lower boundaries (K = 9) for stations in the Arctic Russian sector were determined. K-indices lower boundaries were received for the strong magnetic storm according to the IAGA procedure. It is shown that for different magnetic field horizontal component variation values K-indices for different observation points practically coincide with the Kp-index. The lower value K = 9 dependence on the observation point geomagnetic latitude is presented. This relation can be used to obtain the lower boundary of K = 9 for any magnetic station. A table with local K-index scales for Russian Arctic magnetic stations has been compiled.Для оценки уровня геомагнитной возмущенности в каждом пункте магнитных наблюдений рассчитывается собственный K-индекс. Нижняя граница балла K = 9 — это значение амплитуды вариации горизонтальной компоненты магнитного поля, при превышении которой К-индексу присваивается максимальное значение, равное 9. Эта граница подбирается индивидуально для каждой станции в зависимости от ее геомагнитной широты. Последний раз шкалы К-индексов для российских станций были установлены в середине прошлого века и с тех пор не корректировались. Существенное расхождение K-индексов, вычисленных по этим шкалам, с планетарным Kp-индексом показывает, что они нуждаются в уточнении, а в некоторых случаях их необходимо определять заново. Составлена таблица шкал локальных K-индексов для пунктов магнитных наблюдений в Российской Арктике, и получена зависимость нижнего значения балла K = 9 от геомагнитной широты пункта наблюдений. Новые шкалы К-индексов могут быть использованы при оперативной работе на сети высокоширотных станций магнитных наблюдений Росгидромета

The relationship between variations of the atmospheric electric field in the southern polar region and thunderstorm activity

Observations of the atmospheric, near-surface vertical electric field component E-z have been carried out at the Russian-Antarctic station, Vostok, since 1998 under the framework of a cooperative Russian-Australian project. Only data satisfying "fair weather" conditions are selected for the subsequent analyses. Behavior of E-z field at Vostok station is compared with thunderstorm occurrence determined from a network of ELF magnetic field measurements in April 1998 and with simultaneous VLF emission measurements at Halley Bay (Antarctica). We find no correlation between the 5 min averages of E-z and the lightning flashes intensity or between E-z and VLF emissions, although significant correlation between E-z and VLF emissions is observed in particular cases. The same statistical results have been obtained from a comparison of hourly averaged values. Moreover, even the mean diurnal variation of electric field derived for 10 fine weather days in April 1998 turned out to be inconsistent with the mean diurnal variation of the lightning flashes for the same days. Reasons of these inconsistencies are discussed

Emission factors of SO₂, NO_<i>x</i> and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling

Emission factors of SO2, NOx and size-distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an Mi-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the Neva River in the urban area of Saint Petersburg. Most ships were running at reduced speed (10 kn), i.e., not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal, with averages of 4.6 and 18.2 gSO2 kgfuel-1 for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content Sulfur Emission Control Areas (SECA) limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal, with an average of 58 gNOx kgfuel-1. The corresponding emission related to the generated power yields an average of 12.1 gNOx kWh−1. The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 μm size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm and the other for above 2 μm. The average particle emission factors were found to be in the range from 0.7 to 2.7 &times; 1016 particles kgfuel-1 and 0.2 to 3.4 gPM kgfuel-1, respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in international traffic, but significant deviations are found for inland vessels. Regarding particulate mass, the values of the modeled data are about 2–3 times higher than the measured results, which probably reflects the assumptions made in the modeled fuel sulfur content. The sulfur contents in the fuel retrieved from the measurements were lower than the previously used assumptions by the City of Saint Petersburg when carrying out atmospheric modeling, and using these measurements it was possible to better assess the impact of shipping on air quality