2,433 research outputs found
Easy methods for fluorescent staining of Neurospora nuclei.
Easy methods for fluorescent staining of Neurospora nuclei
Effect of light on perithecial production in homothallic Neurospora species
Effect of light on perithecial production in homothallic Neurospora specie
Main features of Spore killer systems in Neurospora.
Main features of Spore killer systems in Neurospora
Magnetic and Thermodynamic Properties of the Collective Paramagnet-Spin Liquid Pyrochlore Tb2Ti2O7
In a recent letter [Phys. Rev. Lett. {\bf 82}, 1012 (1999)] it was found that
the Tb magnetic moments in the TbTiO pyrochlore lattice of
corner-sharing tetrahedra remain in a {\it collective paramagnetic} state down
to 70mK. In this paper we present results from d.c. magnetic susceptibility,
specific heat data, inelastic neutron scattering measurements, and crystal
field calculations that strongly suggest that (1) the Tb ions in
TbTiO possess a moment of approximatively 5, and (2)
the ground state tensor is extremely anisotropic below a temperature of
K, with Ising-like Tb magnetic moments confined to point along
a local cubic direction
dramatically reduces the frustration otherwise present in a Heisenberg
pyrochlore antiferromagnet. The results presented herein underpin the
conceptual difficulty in understanding the microscopic mechanism(s) responsible
for TbTiO failing to develop long-range order at a temperature of
the order of the paramagnetic Curie-Weiss temperature K. We suggest that dipolar interactions and extra perturbative exchange
coupling(s)beyond nearest-neighbors may be responsible for the lack of ordering
of TbTiO.Comment: 8 POSTSCRIPT figures included. Submitted to Physical Review B.
Contact: [email protected]
Coating of alumina on ceno-spheres of fly-ash
A study is reported that fly-ash behaves as an excellent raw-material for synthesising hollow alumina composite. Coating of alumina onto the surface of ceno spheres was accomplished by controlled precipitation around pH-10. Dopants like Ni/Co have also been successfully
tried. The resultant co-precipitated composites were then characterized using DTA, XRD,Particle size analysis and specific-gravity measurements. Calcination of co- precipitated samples at 1500°C, for 1h and haracterisation of the calcined product also discussed. The results indicate that alumina can be successfully coated on ceno-spheres
Unusual landings of Aluterus monoceros (Linnaeus, 1758) along Vizhinjam coast
On the13th of July 2009, unusual heavy landings
of Aluterus monoceros (unicorn leather jacket) of the
family Monacanthidae were observed along the
coast, from Vizhinjam to Marianadu about 40 km
north of Vizhinjam (Fig. 1). These fishes, locally
known as “komban clathy” or “mara clathy” are rarely
observed in large numbers in the landings at
Vizhinjam which has become a subject of surprise
to the fishermen. This has been the first incident of
such a heavy landing of bigger sized unicorn leather
jacket in this area
First report of Spotted reef crab off Vizhinjam coast
Carpilius maculatus (Linnaeus, 1758), commonly
known as ‘Seven-eleven crab’, ‘Spotted reef crab’,
‘Dark finger coral crab’, or ‘Large spotted crab’ is a
member of the family Carpiliidae. One male specimen
of the spotted reef crab C. maculatus measuring 130
mm in carapace width was caught by a bottom set
gill net along with Portunus sanguinolentus from the
rocky area in Vizhinjam coastal waters
Static Critical Behavior of the Spin-Freezing Transition in the Geometrically Frustrated Pyrochlore Antiferromagnet Y2Mo2O7
Some frustrated pyrochlore antiferromagnets, such as Y2Mo2O7, show a
spin-freezing transition and magnetic irreversibilities below a temperature Tf
similar to what is observed nonlinear magnetization measurements on Y2Mo2O7
that provide strong evidence that there is an underlying thermodynamic phase
transition at Tf, which is characterized by critical exponents \gamma \approx
2.8 and \beta \approx 0.8. These values are typical of those found in random
spin glasses, despite the fact that the level of random disorder in Y2Mo2O7 is
immeasurably small.Comment: Latex file, calls for 4 encapsulated postscript figures (included).
Submitted to Phys. Rev. Letters
Magneto-transport characteristics of La1.4Ca1.6Mn2O7 thin film deposited by spray pyrolysis
Polycrystalline thin films of double layer manganite La_1.4Ca_1.6Mn_2O_7
(DLCMO) have been deposited by nebulized spray pyrolysis on single crystal
LaAlO_3 substrates. These single phase films having grain size in the range
70-100 nm exhibit ferromagnetic transition at T_C ~ 107K. The short range
ferromagnetic ordering due to in plane spin coherence is evidenced to occur at
a higher temperature around 225 K. Insulator/semiconductor to metal transition
occurs at a lower temperature T_P ~ 55K. The transport mechanism above T_C is
of Mott`s variable range hopping type. Below T_C the current-voltage
characteristics show non-linear behaviour that becomes stronger with decreasing
temperature. At low temperatures below T_CA ~ 30K a magnetically frustrated
spin canted state is observed. The DLCMO films exhibit resonable low field
magnetoresistance and at 77K the magnetoresistance ratio is ~ 5% at 0.6 kOe and
\~ 13% at 3 kOe.Comment: 14 pages, 7 figure
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