Design and Fabrication of cross corrugated recuperator fins for a micro gas turbine

The National Aerospace Laboratories, Bangalore is involved in the development of a 10kW micro gas turbine (MGT). A recuperator is mandatory for an MGT to boost the thermal efficiency of the unit. This paper describes in detail the fabrication process of efficient corrugated fins for deploying in the recuperator of an MGT. The use of corrugated fins in the recuperator of the MGT gives higher effectiveness compared to conventional flat fins. The paper, in detail, describes the various materials used and the heat treatment process used for manufacturing the forming and shearing die sets. All manufacturing accuracy requirements were achieved to get the required fin geometry. The formed corrugated fins were qualified through a series of tests and large number fins were formed for use in the annular recuperator of the Micro Gas Turbine

General Account on the Problems of Marine Fisheries Research and Development in Maharashtra.

Maharashtra with a coastline of 720 km has a shelf area of about 90,000 sq.km. The EEZ confers an additional 20,000 sq.km approximately for exploitation. At present only 30% of the shelf area upto a depth of about 50 m is intensively exploited. The strategy to boost marine fish production in Maharashtra will be to increase production from the currently exploited groimds through increased effort in a phased manner, effective utilisation of the EEZ resources through offshore fishing, improvement of infrastructure facilities such as berthing, cold storage, etc

Theoretical Calculation of Shifts in Substituted Benzenes

Using the M. O. method of Herzfeld the effect of CH3 and NH2 substitutions in benzene in shifting the 0,0 position of the band system of benzene has been calculated. It is suggested that the inductive effect is also to be taken into account

Trawl fisheries; south Kanara coast

The trawl catci and the catch rate showed great fluctuations during Jhe different years at Mangalore. Best catches were generally during February-May. Prawns constituted the single largest group, followed by flat fishes, silver-bellies, and sciaenids. High catch rates for prawns and fish were observed in the southern and northern parts of this coast respectively. The catch rate for all fish showed a decline during 1969-70 throughout the entire coast, that at Malpe, being exceptionally low, despite a four-fold increase in fishing effori there

Interaction of mixed mode loading on cyclic debonding in adhesively bonded composite joints

A combined experimental and analytical investigation of an adhesively-bonded composite joint was conducted to characterize the fracture mode dependence of cyclic debonding. The system studied consisted of graphite/epoxy adherends bonded with EC 3445 adhesive. Several types of specimens are tested which provide the cyclic debond growth rate measurements under various load conditions: mode 1, mixed mode 1 to 2, and mostly mode 2. This study shows that the total strain-energy-release rate is the governing factor for cyclic debonding

LIDA: A Working Model of Cognition

In this paper we present the LIDA architecture as a working model of cognition. We argue that such working models are broad in scope and address real world problems in comparison to experimentally based models which focus on specific pieces of cognition. While experimentally based models are useful, we need a working model of cognition that integrates what we know from neuroscience, cognitive science and AI. The LIDA architecture provides such a working model. A LIDA based cognitive robot or software agent will be capable of multiple learning mechanisms. With artificial feelings and emotions as primary motivators and learning facilitators, such systems will ‘live’ through a developmental period during which they will learn in multiple ways to act in an effective, human-like manner in complex, dynamic, and unpredictable environments. We discuss the integration of the learning mechanisms into the existing IDA architecture as a working model of cognition

Relaxation of Collective Excitations in LJ-13 Cluster

We have performed classical molecular dynamics simulation of $Ar_{13}$ cluster to study the behavior of collective excitations. In the solid ``phase'' of the cluster, the collective oscillation of the monopole mode can be well fitted to a damped harmonic oscillator. The parameters of the equivalent damped harmonic oscillator-- the damping coefficient, spring constant, time period of oscillation and the mass of the oscillator -- all show a sharp change in behavior at a kinetic temperature of about $7.0^oK$. This marks yet another characteristic temperature of the system, a temperature $T_s$ below which collective excitations are very stable, and at higher temperatures the single particle excitations cause the damping of the collective oscillations. We argue that so long as the cluster remains confined within the global potential energy minimum the collective excitations do not decay; and once the cluster comes out of this well, the local potential energy minima pockets act as single particle excitation channels in destroying the collective motion. The effect is manifest in almost all the physical observables of the cluster.Comment: Revised and enlarged. 6 pages RevTeX style. 7 eps figures available on request. To appear in J Chem Phy