315 research outputs found
A variant of the Mukai pairing via deformation quantization
We give a new method to prove a formula computing a variant of Caldararu's
Mukai pairing \cite{Cal1}. Our method is based on some important results in the
area of deformation quantization. In particular, part of the work of Kashiwara
and Schapira in \cite{KS} as well as an algebraic index theorem of Bressler,
Nest and Tsygan in \cite{BNT},\cite{BNT1} and \cite{BNT2} are used. It is hoped
that our method is useful for generalization to settings involving certain
singular varieties.Comment: 8 pages. Comments and suggestions welcom
Boiling Point of Binary Liquid Mixtures Using Ultrasonic Investigation
AbstractUltrasonic velocity is a useful tool to find thermal, physical and chemical parameters. In this work using ultrasonic velocity, the boiling point has been calculated for the following binary mixtures, Toluene+Heptan-1-ol, toluene +Octan-1-ol, toluene +Decan-1-ol, 1,1,1 Tricholoroethane +1-propanol, 1,1,1 Tricholoroethane+1-Butanol, 1,1,1 Tricholoroethane +1-Pentanol, 1,1,1Tricholoroethane+1-Hexanol,1,1,1 Tricholoroethane +1-Heptanol, Benzonitrile +Butan-1-ol, Benzonitrile+Pentan-1-ol, Benzonitrile+Methylpropan-2-ol and Benzonitrile+ toluene. The results are discussed
Calcibiocavitological investigations
Calcibiocavitation is a major poroblem in the marine environment and a detailed study on these aspects has been undertaken and the salient findings are presented here. Gregarious molluscs such as the sacred chank Xancus pvrum, mussels (both green and brown), rock oysters (Crassostrea spp.), pearl oysters, Thais rudolphi (Lam.) and corals which inhabit the southwest coast of Kerala and the Gulf of Mannar have been investigated. The wide fluctuations noted in the abundance and population structure of the various pests in the molluscan beds during the short period of two years clearly indicated that they were in severe competetion for suitable substrata and the shells of gregarious mollusks which inhabit this area provide ample opportunities for the pests to flourish. The incidence of boring sponges is found to be rather high among raft-cultured pearl oysters both at Tuticorin and Vizhinjam. It is difficult to control the infection of boring animals in the natural beds, but the low rate of incidence recorded year after year under suggests that the nature controls this to lower level.Another important observation was the wide distribution of the boring sponge C.vastifica in the Ashtamudi Lake, Quilonwhich may form a major threat to our future rock oyster farms along the estuaries
Abel-Jacobi maps for hypersurfaces and non commutative Calabi-Yau's
It is well known that the Fano scheme of lines on a cubic 4-fold is a
symplectic variety. We generalize this fact by constructing a closed p-form
with p=2n-4 on the Fano scheme of lines on a (2n-2)-dimensional hypersurface Y
of degree n. We provide several definitions of this form - via the Abel-Jacobi
map, via Hochschild homology, and via the linkage class, and compute it
explicitly for n = 4. In the special case of a Pfaffian hypersurface Y we show
that the Fano scheme is birational to a certain moduli space of sheaves on a
p-dimensional Calabi--Yau variety X arising naturally in the context of
homological projective duality, and that the constructed form is induced by the
holomorphic volume form on X. This remains true for a general non Pfaffian
hypersurface but the dual Calabi-Yau becomes non commutative.Comment: 34 pages; exposition of Hochschild homology expanded; references
added; introduction re-written; some imrecisions, typos and the orbit diagram
in the last section correcte
Underwater observations in the lagoons
The paper deals with the results of the
underwater observations carried out on the
faunistic and topographical features by direct
underwater observations at selected localities
covering the entire length and breadth of the
lagoons of Minicoy, Suheli paar, Kalpeni,
Kavaratti Androth, Agatti, Bangaram, Amini,
Kadmat, Kiltan, Bitra and Chetlat between
January and April 1987. In each island a
week long survey was carried out by means of
diving The scope of this report is limited and
by no means exhaustive It enables us to provide
first hand information on the nature of
substratum, disposition of coral reefs, fauna and
flora of the lagoon
Invasion of Cliona margaritifera Dendy and C.lobata Hancock on the molluscan beds along the Indian coast
In the recent past the invasion of two new sponge pests Cliona margaritifera Dendy and C. lobata
Hancock on the molluscan beds of the southwest coast of India is reported. These two new pests
made their first appearance on cultured pearl oysters on raft at Vizhinjam in 1980 and thence started
spreading to the economically important molluscan beds in and around Vizhinjam. The spreading
of these pests along the southwest coast of India was rather fast and from this coast C. margaritifera
could migrate to the raft-cultured pear! oysters at Tuticorin and C. lobata to the chank beds off
Tbiruchendur (southeast coast) within two years i.e. by 1982
The spawning of the holothurian Actinopyga mauritiana (Quoy and Gaimard) on board FORV Sagar Sampada
Four specimens of Actinopyga mauHtlana collected on 27th September 1988 in Andaman waters
south of Burmanalla near Port Blair, were left in the Aquarium on board FORV Sagar Sampada
for observations. The surface temperature of the sea water was 25.0° C and the sea water in the
Aquarium was 29.2° C. The higher temperature in the Aquarium triggered the male holothurians
to spawn first followed by the female. The fertilized eggs developed only upto four-celled stage
Molluscan resources
A critical review of literature on the fauna
of Lakshadweep reveals that there is only
scanty reports on the occurrence of molluscs
from various islands (Smith, 1906; Appukuttan
1973; Nair and Dharmaraj, 1983 and George
ef a/., 19S6). A survey on the fisheries potential
of Lakshadweep was undertaken by the scieniists
of Central Marine Fisheries Research Institute
to provide adequate informations on the molluscan
fisheries potential of the islands for future
planning and development. The present status of
fishery of potentially important molluscs, fishing
methods, occurrence and abundance are dealt
with in the present account. The island surveyed
for molluscan resources are Minicoy, Suheh
pear, Kalpeni, Kavaratti, Androth, Agathi,
Bangaram, Amini, Kadamat, Kiltan, Bitra and
Chetlat. To understand the distribution pattern,
population density and habitat, transect method
of sampling was adopted uniformly in ail the
'slands. The sampling areas were broadly
classified intointertidal area, lagoon, reef cres^
in the lagoon side and leward side and reef
slopes of both sides. Quadrat method of
sampling for few bivalves and gastropods were
done for quantitative estimates. By diving and
hand-picking, samples were collected from
various stations and relative abundance were
noted by visual estimates. The maps of islands
shows the distribution of commercially importtant
molluscs
From Atiyah Classes to Homotopy Leibniz Algebras
A celebrated theorem of Kapranov states that the Atiyah class of the tangent
bundle of a complex manifold makes into a Lie algebra object in
, the bounded below derived category of coherent sheaves on .
Furthermore Kapranov proved that, for a K\"ahler manifold , the Dolbeault
resolution of is an
algebra. In this paper, we prove that Kapranov's theorem holds in much wider
generality for vector bundles over Lie pairs. Given a Lie pair , i.e. a
Lie algebroid together with a Lie subalgebroid , we define the Atiyah
class of an -module (relative to ) as the obstruction to
the existence of an -compatible -connection on . We prove that the
Atiyah classes and respectively make and
into a Lie algebra and a Lie algebra module in the bounded below
derived category , where is the abelian
category of left -modules and is the universal
enveloping algebra of . Moreover, we produce a homotopy Leibniz algebra and
a homotopy Leibniz module stemming from the Atiyah classes of and ,
and inducing the aforesaid Lie structures in .Comment: 36 page
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