14,237 research outputs found
Dichotomous venation and anastomosis in the corolla of an orchid-Habenaria dentata (SW.) Schltr
The lip of the corolla in habenaria dentata (Sw.) Schltr. is tripartite. The lateral lobes show dichotomously branched veins. While the majority of the vein-endings are related to crenulation in the corolla and terminate at the tip, others end blindly. Usually each crenulation receives one vein. In exceptional cases two veins enter a crenulation. Cases of veins ending beneath an incision (sinus) separating two crenulations have been observed. Sinus vein dichotomies are present. Nine types of anastomoses are described. In Type I, two branches of a single vein-dichotomy remain united. Type II is characterized by the union of adjacent branches of two vein dichotomies and their separation. Type III is similar to Type II but the branches do not separate after confluence. In Type IV an arcuate vein unites with the branch of contiguous vein dichotomy and then separates. Type V is similar to Type IV but the fused branches do not separate. Type VI is formed by the union of the outer branch of a second order vein-dichotomy and the outer branch of a first order vein-dichotomy. In Type VII one outer branch each of two adjacent second order vein-dichotomies unite and separate. Type VIII is similar to Type VII but the branches do not separate after confluence. In Type IX the outer branch of a third order vein-dichotomy and the outer branch of a second order vein-dichotomy unite and separate after a short area of confluence. Cases of vein-approximations also have been observed
Comparison between Windowed FFT and Hilbert-Huang Transform for Analyzing Time Series with Poissonian Fluctuations: A Case Study
Hilbert-Huang Transform (HHT) is a novel data analysis technique for
nonlinear and non-stationary data. We present a time-frequency analysis of both
simulated light curves and an X-ray burst from the X-ray burster 4U 1702-429
with both the HHT and the Windowed Fast Fourier Transform (WFFT) methods. Our
results show that the HHT method has failed in all cases for light curves with
Poissonian fluctuations which are typical for all photon counting instruments
used in astronomy, whereas the WFFT method can sensitively detect the periodic
signals in the presence of Poissonian fluctuations; the only drawback of the
WFFT method is that it cannot detect sharp frequency variations accurately.Comment: 10 pages, 12 figure
Drive to overpower plastics: Star Polymers
The venture, “Star Polymers” is actively involved in raising the awareness of rational use
and treatment of non-biodegradable waste. The journey to overpower plastics by star
polymers begins from an existing plastic moulding facility owned by the owner’s (Mr.
CK Babu) father; which during the course of time expanded to a socially committed
organisation making good profits through plastic recycling. Taking the idea of recycling
household plastics from a government workshop, coupling with his social commitment,
the entrepreneur started the venture. At present, the polymer company perform
moulding of the waste plastic, collected from the six nearby villages into products like
electrical fittings and small household accessories. Such recycled material may be used
for anything other than for storing food. The metal coated plastic, often found used
as sachets for snacks and other food stuffs are unfit for recycling so that it is used for
road asphalting, which gives the roads better durability. At present, the organisation
is able to process 15 tonnes of waste plastics a month
To evaluate the role of Lakshadi Avachoornana in the management of Dushta Vrana with special reference to Diabetic Ulcer : A Case Study
The global prevalence of diabetics is estimated to increase from 4.0% in 1995 to 5.5% by the year 2025. The chances of secondary infection are more in diabetics as the immunity of the patients is compromised and needs prolonged hospitalization, psychological and social problem for the patients and family. In Madhumehi the vessels of lower limb become weak and is unable to expel the Doshas (along with other Dushyas) leading to Prameha Pidakas more in lower extremities, which eventually burst open precipitating an ulcer. Avachoornana is one among the Shashti Upakrama, explained by Acharya Sushrutha for management of Vrana. Numerous studies are done in the management of Dushta Vrana with the internal medication and external therapies. Here a preliminary attempt to study the effect of Avachoornana with Lakshadi Choorna in the management of the same was taken for the study
Quantitative ecology of phytoplankton in the Cochin backwater
A one-year study on the standing crop in terms of chlorophylls, primary
production and total-cell counts of four station grids has shown that there were
regional and seasonal variations in the magnitude of phytoplankton production in
the Cochin backwater. Statistically treated using a microcomputor, a multiple
regression relationship has been established between parameters within stations.
But th<^ Correlation coefBclent and Standard Regression coefficient have revealed
that the plankton production and the related parameters at all the stations were
independent of each other and the parameters varied from station to station. Probable
reasons are briefly discussed
A comparative study of night-time enhancement of TEC at a low latitude station on storm and quiet nights including the local time, seasonal and solar activity dependence
International audienceThe main characteristics of night-time enhancements in TEC during magnetic storms are compared with those during quiet nights for different seasons and solar activity conditions at Palehua, a low latitude station during the period 1980?1989. We find that the mean amplitude has both a seasonal and solar activity dependence: in winter, the values are higher for weak storms as compared to those during quiet nights and increase with an increase in solar activity. In summer, the mean amplitude values during weak storms and quiet nights are almost equal. But during equinox, the mean amplitude values for quiet nights are greater than those during weak storms. The mean half-amplitude duration is higher during weak storms as compared to that during quiet nights in summer. However, during winter and equinox, the durations are almost equal for both quiet and weak storm nights. For the mean half-amplitude duration, the quiet night values for all the seasons and equinoctial weak storm values increase with an increase in solar activity. The occurrence frequency (in percent) of TEC enhancement during weak storms is greater than during quiet nights for all seasons. The mean amplitude, the mean half-amplitude duration and the occurrence frequency (in percent) of TEC enhancement values are higher during major storms as compared to those during quiet nights. The above parameters have their highest values during pre-midnight hours. From the data analysed, this behaviour is true in the case of major storms also
Thermal conductivity of graphene in Corbino membrane geometry
Local laser excitation and temperature readout from the intensity ratio of
Stokes to anti-Stokes Raman scattering signals are employed to study the
thermal properties of a large graphene membrane. The concluded value of the
heat conductivity coefficient \kappa ~ 600 W/m \cdot K is smaller than
previously reported but still validates the conclusion that graphene is a very
good thermal conductor.Comment: 4 pages, 3 figure
Size effect in ion transport through angstrom-scale slits
It has been an ultimate but seemingly distant goal of nanofluidics to
controllably fabricate capillaries with dimensions approaching the size of
small ions and water molecules. We report ion transport through ultimately
narrow slits that are fabricated by effectively removing a single atomic plane
from a bulk crystal. The atomically flat angstrom-scale slits exhibit little
surface charge, allowing elucidation of the role of steric effects. We find
that ions with hydrated diameters larger than the slit size can still permeate
through, albeit with reduced mobility. The confinement also leads to a notable
asymmetry between anions and cations of the same diameter. Our results provide
a platform for studying effects of angstrom-scale confinement, which is
important for development of nanofluidics, molecular separation and other
nanoscale technologies
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