5,491 research outputs found
Some trends observed in the deep-sea lobster catches of the vessel "Blue Fin" during the period January '69 to December '71
During the past two decades there
have been sporadic attempts to explore
the lobster resources especially the
deep-sea lobster along the Kerala coast.
Even as early as 1901 (Alcock, A) the
occurrence of deep-sea lobster off the
Travancore coast has been recorded
Comparative vibration study of EN 8 and EN 47 cracked cantilever beam
Since earlier days, most of the failures encountered by the structures or machines are mainly due to material fatigue. The dynamic behaviour of the beam may change when cracks begin to appear in it. Knowledge of these changes in the dynamic individualism is important in crack detection as well as in structure or in machine design. This paper deals with systematic study on the free vibration of Euler-Bernoulli beam containing open edge transverse cracks. In this study, two springs steel materials (EN 8 and EN 47) are considered. The effect of the top side cracks and bottom side cracks on the natural frequency of a cantilever beam is discussed. The natural frequency of a cracked case cantilever beam is investigated numerically using FE analysis software ANSYS. Experimental work is done by using DeweFRF to investigate the natural frequency of cracked beams for strong validation of the numerical results. The results of this study suggest that the average value of natural frequencies for all top side cracked beams are identical to the average value of natural frequency for all bottom side cracked beams. This is true for both EN 47 and EN 8. Hence, it is clear that the dynamic characteristic (natural frequency) is not changing, when same configuration of cracks is either on top or bottom side of the beam. The natural frequencies for EN 8 material are comparatively on higher side than EN 47 material for the same crack configurations. In most of the cracked cases, the damping effect of EN 47 is greater than EN 8. It is also found that as crack location increases at constant crack depth, then natural frequency increases. At the last location, as crack depth increases, natural frequencies almost remain same. It is observed that, the presence of top side crack and bottom side crack of the same configuration in the cantilever beam is not a function of natural frequency, when cantilever beam is of a square cross section
Gymnosperms of Nilgiris District, Tamil Nadu
Gymnosperms are seed bearing vascular plants; an intermediate of Pteridophytes and Angiosperms occupying an important place in the plant kingdom. In the present study 43 species belonging to 20 genera comes under 10 families. The wild and exotic species are catalogue in Government botanical garden at Udhagamandalam for conservation strategies
Failure of Aileron Control Cable in Ajeet Aircraft MK-E-2015
The Aileron control cable of an Ajeet aircraft was found snapped . On ootical and scanning electron microscopic examination, it was found that the majority of the strands
of the cable had thinned due to excessive contact wear with a oulley and subsequently failed in tension
Minimizing Link Utilization in Selfish Overlay Routing
The rapid growth and increasing requirements for service quality, reliability had made everyone to choose the traffic engineering essential for the large public networks. The multi Protocol label switching is a protocol used when there is interaction between the traffic engineering and the overlay networks. This MultiProtocol Labeled Switching (MPLS) with the help of the nash equilibrium algorithm has given optimized performance better by reducing the latency and increasing the link utilization. But increase in link utilization will gradually increase the congestion in the network as the link is being used by all the nodes. So, to overcome this specific problem we have performed a formulation called dual programming formulation which has set of constraints that have to be satisfied, along with Open Shortest Path First(OSPF) protocol so as to reduce the maximum link utilization. We have simulated the results in five queuing models which includes BPR,PD1,PM1,MM1,MD1 using source, compliant, optimal overlay routing. The results are simulated using Ns2 with linux as platform.Link utilization is reduced based on the parameters such as traffic demands and the distance between the nodes with their respective demands
Root Activity Distribution and Inter-plant Root Competition in 'Robusta' Banana (Musa Sp., 'AAA') under High-Density Planting Determined by Tracer Technique
By applying soil injection technique using carrier-free 32P as a tracer in 'Robusta' banana (Musa sp. 'AAA') planted at 1.5m x 1.5m spacing, during the 8th leaf stage of growth, 52.04 and 62.96% of active roots were present at 25cm across and 15cm depth, respectively. At the 16th leaf stage, only 40.5% of active roots were traced at 25cm across, and root activity increased at wider distances and deeper layers. At flower-initiation stage, a significant gain in root activity was seen at 45cm depth. Distance-wise distribution, however, did not change appreciably. At the shooting stage, 46.89% and 43.98% of the active roots were present closest to the pseudostem (25cm distance) and soil surface (15cm), respectively. However, the greatest depth (45cm) gained active roots (38.51%) at shooting-stage, creating an hour-glass pattern of root distribution, mainly owing to migration of roots from the surface (15cm deep) soil. However, a strong presence of active roots persisted close to the base of the plant, and in the surface-soil. A small proportion (>1%) of phosphorus applied to the main plant was absorbed by the orthogonal neighbour located at 1.5m distance, indicating practically insignificant competition with its closest neighbour. None of the diagonal neighbours located farthest (at 2.1m distance from the main plant) showed any activity of the tracer indicating that the root competition with the main plant was absent. Results indicate that a spacing of 1.5m × 1.5m in high-density planting of 'Robusta' banana raised in sandy-loam is optimum, with practically no untoward competition from the root for nutrients applied to each plant
Effect of trace elements on the rate of carbon production in marine photyplankton at different temperature
The alteration ih trace metal (Cu. Mu and Zn) toxicity was assessed in terms of rate of carbon
production at different temperature in two unicellular algae Synechocystis salina, Wislouch and Isochrysis
galbana Parke. m e rate of carbon production was maximum at lS°C for S. salina and at 30°C for
I. galbnna. Metal toxicity increased at higher temperature (40°C) by inhibiting carbon production to a
larger extent
Effect of copper on the ultrastructure Of marine phytoplankton
Electron microscopy technique was used to study the copper induced ultrastructural changes in the
blue green alga, Synechocyslis salina. Wislouch and golden yellow flagellate /sochrysis ga/bana Parke. The
blue green alga exhibited significant deterioration in the cell's internal organisation. Presence of membrane
whorls. disorganisation of cell envelop. Photosynthetic lamelleae at certain regions of the cell, reduction in
cellsize increase in number of polyhedral bodies and absence of lipid inclusion was observed. Drastic
change was not noticed in the golden yellow flagellate except for the presence of enlarged vacuoles and
more number of osmophilic bodies. Toxicity and detoxification mechanisms are discussed and the utili zation
of electron microscopic analysis is established in the studies of metal toxioity at the cellular leve
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