3,475 research outputs found
Fine structures in the atmosphere above a sunspot umbra
We present simultaneous photospheric and chromospheric observations of the
trailing sunspot in NOAA 10904, obtained with the Swedish Solar Telescope (SST)
La Palma, Canary Islands. Time series of high resolution \ion{Ca}{ii}\,
images show transient jet-like structures in sunspot umbrae are elongated,
which we call umbral microjets. These jets are directed roughly parallel to
nearby penumbral microjets, suggesting that they are aligned with the
background magnetic field. In general, first a bright dot-like structure
appears, from which a jet later emerges, although some jets appear without an
associated chromospheric dot. Bright photospheric umbral dots are associated
with umbral microjets arising in the outer umbra. Nevertheless, a one-to-one
correspondence between jet-like events and underlying umbral dots is not seen.
They are typically less than 1\arcsec ~long and less than 0\farcs3 wide. The
typical lifetime of umbral microjets is around one minute. The brightness of
these structures increases from the center of the umbra towards the
umbra-penumbra boundary along with the brightness of the local background.Comment: 5 pages, 6 figures. Accepted for publication in A&A Lette
Understanding the degeneracies in NOA data
The combined analysis of disappearance and appearance data
of NOA experiment leads to three nearly degenerate solutions. This
degeneracy can be understood in terms of deviations in appearance
signal, caused by unknown effects, with respect to the signal expected for a
reference set of oscillations parameters. We define the reference set to be
vacuum oscillations in the limit of maximal and no CP-violation.
We then calculate the deviations induced in the appearance signal event
rate by three unknown effects: (a) matter effects, due to normal or inverted
hierarchy (b) octant effects, due to being in higher or lower
octant and (c) CP-violation, whether or . We find that the deviation caused by each of these effects is the
same for NOA. The observed number of events in NOA is
equivalent to the increase caused by one of the effects. Therefore, the
observed number of appearance events of NOA is the net result of
the increase caused by two of the unknown effects and the decrease caused by
the third. Thus we get the three degenerate solutions. We also find that
further data by NOA can not distinguish between these degenerate solutions
but addition of one year of neutrino run of DUNE can make a distinction between
all three solutions. The distinction between the two NH solutions and the IH
solution becomes possible because of the larger matter effect in DUNE. The
distinction between the two NH solutions with different octants is a result of
the synergy between the anti-neutrino data of NOA and the neutrino data of
DUNE.Comment: Published version v2; with minor changes to v
Tensions between the appearance data of T2K and NOvA
The long baseline neutrino experiments, T2K and NOvA, have taken significant
amount of data in each of the four channels: (a) disappearance, (b)
disappearance (c) appearance and (d)
appearance. There is a mild tension between the disappearance and the
appearance data sets of T2K. A more serious tension exists between the
appearance data of T2K and the appearance data of NOvA.
This tension is significant enough that T2K rules out the best-fit point of
NOvA at confidence level whereas NOvA rules out T2K best-fit point at
confidence level. We explain the reason why these tensions arise. We
also do a combined fit of T2K and NOvA data and comment on the results of this
fit.Comment: matches the published versio
Waves as the source of apparent twisting motions in sunspot penumbrae
The motion of dark striations across bright filaments in a sunspot penumbra
has become an important new diagnostic of convective gas flows in penumbral
filaments. The nature of these striations has, however, remained unclear. Here
we present an analysis of small scale motions in penumbral filaments in both
simulations and observations. The simulations, when viewed from above, show
fine structure with dark lanes running outwards from the dark core of the
penumbral filaments. The dark lanes either occur preferentially on one side or
alternate between both sides of the filament. We identify this fine structure
with transverse (kink) oscillations of the filament, corresponding to a
sideways swaying of the filament. These oscillations have periods in the range
of 5-7 min and propagate outward and downward along the filament. Similar
features are found in observed G-band intensity time series of penumbral
filaments in a sunspot located near disk center obtained by the Broadband
Filter Imager (BFI) on board {\it Hinode}. We also find that some filaments
show dark striations moving to both sides of the filaments. Based on the
agreement between simulations and observations we conclude that the motions of
these striations are caused by transverse oscillations of the underlying bright
filaments.Comment: Accepted for publication in Astrophysical Journal on 8th April 201
Status of plankton diversity and biological productivity of Sahastradhara stream at Uttarakhand, India
The present contribution encompasses on plankton and biological productivity as ecological indicator for identifying the ecological quality of Sahastradhara stream (between 27 km stream stretches), located in the Doon Valley of Garhwal region in India. Monthly sampling from all the sampling sites was made for a period of 12 months (May 2009 – April 2010) at 9:00-11: 00 AM. A total of 40 taxa from different classes of plankton and zooplankton were reported. The phytoplankton (32 sp.) was found being the most abundant taxa than zooplankton (9 sp.) inSahastradhara stream. Fluctuation in the phytoplankton density was recorded highest (1536 unit/l) during winter and lowest (20 unit/l) during monsoon. Zooplanktons were reported to be maximum (147 unit/l) during summer and minimum (3 unit/l) during monsoon. The total diatoms were reported highest (1022unit/l) during starting the winter and lowest (4 unit/l) during monsoon. Green algae and blue green algae were reported to be maximum during winter and minimum during summer. The Shannon-wiener diversity index calculated for the density ofBacillariophyceae (0.2180-0.366), Chlorophyceae (0.208-0.367) and Cyanophyceae (0.391-0.366) and correlation was made between Plankton biomass and physico-chemical parameters to analyses the relative features of the both variables. The density of plankton and biological productivity were influenced by disturbances in the photic zone and indiscriminate anthropogenic activities for tourist development resulted aquatic habitat degradation in stream ecosystem
Role of hysterolaparoscopy in the evaluation of female infertility in a tertiary care centre
Background: Infertility is one of the most important and underappreciated reproductive health problems in developing countries. Inability to conceive bears a social stigma which causes societal repercussion and personal suffering. The advent of hysterolaparoscopy have redefined the evaluation and treatment of infertile women. Study aimed to assess the role of hysterolaparoscopy in the evaluation of female infertility.Methods: This prospective observational study was done in the department of obstetrics and gynaecology, Gandhi Medical College, Sultania Zanana Hospital, Bhopal, during the period between 1st December 2016 to 30th November 2017. 104 infertile patients either with primary or secondary infertility were included after thorough evaluation.Results: Out of 104 infertile patients, 82(78.8%) women had primary infertility and rest 22(21.1%) women had secondary infertility. In primary infertility group, most common laparoscopic finding was PCOD in 24(29%) women and in secondary infertility group, tubal blockage was seen in 9(40%) women. The most common pathology seen in hysteroscopy was submucous fibroid in 6(7.3%) women with primary infertility, whereas in secondary infertility group, synechiae was found in 2(9%) patients and septum was seen in 1(4.5%) patient. Out of 104 patients, 33 (31.7%) patients underwent various interventions. The most common intervention was ovarian drilling for PCOS in 21(63.3%) patients followed by hysteroscopic cannulation in 5(15.5%) patients.Conclusions: Hysterolaparoscopy is a very useful tool that can detect various structural abnormalities in multiple sites like uterus, tubes, ovaries and peritoneal cavity in the same sitting. When done by experienced hands and proper selection of patients, hysterolaparoscopy can be considered as a definitive investigative procedure for evaluation of female infertility
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