975 resultados para Flat diaphragm


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Post larval stages of Psettina Iijimae ranging from 1.8 mm NL to 44.6 mm SL collected during Naga Expedition and International Indian Ocean Expedition (IIOE) are described. The characteristics which help to identify larval stages of Psettina are: the presence of pigmented urohyal appendage in early stages which is progressively reduced during flexion stages and which disappears in later postflexion stages, the meristics, the spines on urohyal and posterior basipterygial processes and the absence of spines on cleithra. The P. iijimae can be distinguished by the presence of spines on the median fin rays which differentiate near the baseosts along the dorsal and ventral body wall much before the fin rays. The larvae of P.iijimae were more abundant in the Gulf of Thailand compared to South China Sea and Indian Ocean.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Attempts have been made to correlate the abundance of eggs and larvae of flat fishes belonging to families Cynoglossidae and Soleidae with the hydrographical parameters of the environment, particularly the salinity. The eggs and larvae were found to occur in the Cochin backwater during the pre-monsoon period but not during the south west monsoon period. During the south west monsoon period larvae belonging to very early stages were found at the marine end (Fairway Buoy). The continued or prolonged existence of very low salinity appears to restrict the distribution of flat fish larvae. In the post-monsoon period also the eggs and larvae were not found in regions of very low salinity. Larvae of Cynoglossus puncticeps (Richardson), C. brevis Gunther, C. cynoglossus (Ham. Buch), C. lida (Bleeker) and Solea heinii Steindachner were obtained in the collection taken from the estuary. From the data it is seen that each species has specific spawning period.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The design and construction of the otter board is a subject of great importance for economy in trawling. This review incorporates a historical resume tracing the change and development• of otter boards. The size of the otter board and its relationship with the horse power of the engine and size of the net and the methods of rigging are dealt with. The factors influencing the horizontal spread are discussed. The effect of the angles of attack, heel and tilt and the ground reaction on the force coefficients have been reviewed and discussed with particular reference to flat rectangular otter boards used for bottom trawling. A short account of other designs of otter boards used for improved efficiency is given. Suggestion for improving the efficacy of otter boards based on the work hitherto done has been made. The contributions relating to the various aspects of design and performance of trawl boards carried out till 1969 have been considered.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The communication deals with the results of comparative fishing operations conducted to study the effectiveness of rectangular flat and rectangular curved otter boards. Based on the analysis of data gathered during the course of actual field trials, following conclusions have been drawn: the average catch per hour of trawling was more by 22 kg during attachment of rectangular curved otter boards. The average horizontal spread between rectangular curved otter boards in action was more by 13% and works out to 50% of the head-rope length of the net including sweeps. The towing resistance of the gear with horizontally curved otter boards was more by 10%.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Five species of flat fishes, namely Cynoglossus semifaciatus, C. lida, C. bilineatus, C. macrolepidotus and Psettodes erumei caught in trawlers off Mangalore were analysed for proximate composition of different body parts. These data are discussed in terms of their variability and applications. In whole body of C. lida and C. semifaciatus mean values for moisture, protein, fat and ash content on dry basis respectively were 75.9%, 75.3%, 7.1%, 16.1% and 78.9%, 75.6%. 7.9% and 16.6%. Mean values of these constituents of edible parts in the same order for C. semifaciatus and Psettodes erumei were 77.3%, 80.7%, 7.8%, 10.8% and 77.4%, 86.2%, 3.5% and 11.1% respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

V shaped all steel boards, with their inherent stability to tide over obstacles and mud, interchangeability of starboard and portside boards are found to be superior to conventional flat rectangular boards for bottom trawling. These are cheaper in construction, offer less resistance and give longer service. Comparative trials with the two types of boards showed significant difference in tension between the boards but not in catch or horizontal opening.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We study the information rates of non-coherent, stationary, Gaussian, multiple-input multiple-output (MIMO) flat-fading channels that are achievable with nearest neighbour decoding and pilot-aided channel estimation. In particular, we analyse the behaviour of these achievable rates in the limit as the signal-to-noise ratio (SNR) tends to infinity. We demonstrate that nearest neighbour decoding and pilot-aided channel estimation achieves the capacity pre-logwhich is defined as the limiting ratio of the capacity to the logarithm of SNR as the SNR tends to infinityof non-coherent multiple-input single-output (MISO) flat-fading channels, and it achieves the best so far known lower bound on the capacity pre-log of non-coherent MIMO flat-fading channels. © 2011 IEEE.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Learn how nanotechnologies will be used to transform future wireless and Internet communications.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this presentation, we report excellent electrical and optical characteristics of a dual gate photo thin film transistor (TFT) with bi-layer oxide channel, which was designed to provide virgin threshold voltage (V T) control, improve the negative bias illumination temperature stress (NBITS) reliability, and offer high photoconductive gain. In order to address the photo-sensitivity of phototransistor for the incoming light, top transparent InZnO (IZO) gate was employed, which enables the independent gate control of dual gate photo-TFT without having any degradation of its photosensitivity. Considering optimum initial V T and NBITS reliability for the device operation, the top gate bias was judiciously chosen. In addition, the speed and noise performance of the photo-TFT is competitive with silicon photo-transistors, and more importantly, its superiority lies in optical transparency. © 2011 IEEE.