109 research outputs found
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
MICU2, a Paralog of MICU1, Resides within the Mitochondrial Uniporter Complex to Regulate Calcium Handling
Mitochondrial calcium uptake is present in nearly all vertebrate tissues and is believed to be critical in shaping calcium signaling, regulating ATP synthesis and controlling cell death. Calcium uptake occurs through a channel called the uniporter that resides in the inner mitochondrial membrane. Recently, we used comparative genomics to identify MICU1 and MCU as the key regulatory and putative pore-forming subunits of this channel, respectively. Using bioinformatics, we now report that the human genome encodes two additional paralogs of MICU1, which we call MICU2 and MICU3, each of which likely arose by gene duplication and exhibits distinct patterns of organ expression. We demonstrate that MICU1 and MICU2 are expressed in HeLa and HEK293T cells, and provide multiple lines of biochemical evidence that MCU, MICU1 and MICU2 reside within a complex and cross-stabilize each other's protein expression in a cell-type dependent manner. Using in vivo RNAi technology to silence MICU1, MICU2 or both proteins in mouse liver, we observe an additive impairment in calcium handling without adversely impacting mitochondrial respiration or membrane potential. The results identify MICU2 as a new component of the uniporter complex that may contribute to the tissue-specific regulation of this channel.National Institutes of Health (U.S.) (GM0077465)National Institutes of Health (U.S.) (DK080261
Efficacy and safety of patisiran for familial amyloidotic polyneuropathy: a phase II multi-dose study
Transient Heat and Mass Transfer of Liquid Droplet Ignition at the Spreading over the Heated Substrate
Emission factors of SO<sub>2</sub>, NO<sub><i>x</i></sub> 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 × 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
- …