Graphoidal Tree d - Cover

Acharya and Sampathkumar defined a graphoidal cover as a partition of edges into internally disjoint (not necessarily open) paths. If we consider only open paths in the above definition then we call it as a graphoidal path cover

System reliability and risk assessment task goals and status

The major focus for continued development of the Numerical Evaluation of Stochastic Structures Under Stress (NESSUS) codes is in support of system testing and certification of advanced propulsion systems. Propulsion system testing has evolved over the years from tests designed to show success, to tests designed to reveal reliability issues before service use. Such test conditions as performance envelope corners, high rotor imbalance, power dwells, and overspeed tests are designed to shake out problems that can be associated with low and high cycle fatigue, creep, and stress rupture, bearing durability, and the like. Subsystem testing supports system certification by standing as an early evaluation of the same durability and reliability concerns as for the entire system. The NESSUS software system is being further developed to support the definition of rigorous subsystem and system test definition and reliability certification. The principal technical issues are outlined which are related to system reliability, including key technology issues such as failure mode synergism, sequential failure mechanisms, and fault tree definition

Exactly isochoric deformations of soft solids

Many materials of contemporary interest, such as gels, biological tissues and elastomers, are easily deformed but essentially incompressible. Traditional linear theory of elasticity implements incompressibility only to first order and thus permits some volume changes, which become problematically large even at very small strains. Using a mixed coordinate transformation originally due to Gauss, we enforce the constraint of isochoric deformations exactly to develop a linear theory with perfect volume conservation that remains valid until strains become geometrically large. We demonstrate the utility of this approach by calculating the response of an infinite soft isochoric solid to a point force that leads to a nonlinear generalization of the Kelvin solution. Our approach naturally generalizes to a range of problems involving deformations of soft solids and interfaces in 2 dimensional and axisymmetric geometries, which we exemplify by determining the solution to a distributed load that mimics muscular contraction within the bulk of a soft solid

Hydro-dynamical models for the chaotic dripping faucet

We give a hydrodynamical explanation for the chaotic behaviour of a dripping faucet using the results of the stability analysis of a static pendant drop and a proper orthogonal decomposition (POD) of the complete dynamics. We find that the only relevant modes are the two classical normal forms associated with a Saddle-Node-Andronov bifurcation and a Shilnikov homoclinic bifurcation. This allows us to construct a hierarchy of reduced order models including maps and ordinary differential equations which are able to qualitatively explain prior experiments and numerical simulations of the governing partial differential equations and provide an explanation for the complexity in dripping. We also provide a new mechanical analogue for the dripping faucet and a simple rationale for the transition from dripping to jetting modes in the flow from a faucet.Comment: 16 pages, 14 figures. Under review for Journal of Fluid Mechanic

Fin fish Culture

The potential inshore area in less than 18 m depth available for near sea farming along our coast is estimated to be of the order of 9 million hectares. After the initial experiments at Mandapam during 60's, C.M.F.R.I formulated projects and experiments on fin fish culture. From these experiments varying results regarding the production capability have been obtained for different locations and for different methods of culture. In most of the experiments in the ponds, natural food availability has been supplemented with the addition of artificial feed in the form of oil cakes and rice bran at 10% of the body weight of fishes

Taxonomy and ecology of cultivable molluscs

The sorting of specimens into various species or sub-species and identifying them is known as taxonomy. The most comprehensive work on this subject has been brought out by Blackwelder (1967). While stuiying the taxonomy of molluscs one is bewildered by the amount of differences and variations evoo amongst two individuals belonging to same species

Fishing for pearls in India

The oysters of the genus Pinelada are valued and exploited in many countries for the pearls they produce although' different species form the fishery in different parts of the world. In the case of Japan it is P. martensi, in Australia it is P. Maxima and in the Persian Gulf it is P. mugaritifera which constitute the commercially important species

Mussel seed collection and production

All leading mussel farming countries in the world producing annually 330000 tons (weight in the shell) of mussels depend on natural seed resources to meet their requ- ir ement of seed, whether it is for bottom culture (Netherlands), bauchot culture (France), raft culture (Spain), rack culture (Italy) or submerged pole culture (Phillippines). Hatchery system of mass seed production, therefore, has not become necessary unlike in the culture of other edible molluscs like oysters , clams a nd abalones wher in suitable techniques are employed by the industry