Rearing of major carp spawn at high stocking density under air lift water circulation system

The present studies are aimed to achieve a high survival rate of carp spawn to fry stage under Air Lift Water Circulation system at high stocking density. Three experiments using Labeo rohita and Cirrhinus mrigala were conducted in one cement tank of 50 sq.m. area. The results showed a survival rate ranging from 90.5 to 95.2% at stocking density of 20 to 25 million/ha. By this technique it is possible to rear high number of spawn in limited area with high rate of survival up to fry stage.

Application of a wind-driven barotropic model to simulate the seasonal circulation of the northern Arabian Sea

A two dimensional numerical barotropic model based on the depth-integrated equations is presented here. Sensitivity of the model is analyzed by using wind stresses of different months. Real wind data and actual bathymetry are used as an input to obtain the circulation patterns of the northern Arabian Sea during specific seasons. However, the model is also tested with constant depth for comparison. A number of numerical simulations are performed to study the combined effects of wind stress, bathymetry and basin geometry. Since the goal of this study is to simulate the circulation of the northern Arabian sea in accordance with the observed wind stress, therefore, wind stresses of different months like July (the peak os SW monsoon), October (the transition period from SW to NE monsoon), January (the peack of NE monsoon) and April (the transition period from NE to SW monsoon) are used to examine the circulation patterns. The results obtained are satisfactory in that they resemble known patterns.

Circulation pattern of the Egyptian Mediterranean waters during winter and summer seasons

The water circulation of the Egyptian Mediterranean waters was computed during winter and summer seasons using the dynamic method. The reference level was set at the 1000db surface. The results showed that the surface circulation is dominated by the Atlantic water inflow along the North African coast and by two major gyres, the Mersa Matruth anticyclonic gyre and El-Arish cyclonic gyre. The results showed a seasonal reversal of El-Arish gyre, being cyclonic in winter and anticyclonic in summer. El-Arish gyre had not been previously measured. The geostrophic current velocity at the edges of the Mersa Matruth gyre varied between 12.5 and 29.1cm/sec in winter and between 6.5 and 13.1cm/sec in summer. The current velocity reached its maximum values (>40cm/sec) at El-Arish gyre. The current velocity at the two gyres decreased with increasing depth. The North African Current affects the surface waters down to a depth of 100m, and that its mean velocity varies between 6 and 38cm/sec.

Water masses and circulation of the Mozambique Channel

From 1977 to 1980, several research cruises were carried out in the coastal waters of Mozambique to collect oceanographic data. The distribution of hydrographic and bathythermograph stations is given. The water masses and circulation were mapped and wind data gathered.

Circulation system and areas of potentially successful tuna fishing with surface methods off Mozambique

Charts with 3-months running means of thermal data collected during 1977-1982 are used to describe the seasonal variability of the circulation pattern off Mozambique, and to identify the areas of tuna vulnerability to surface gears. The main conclusions reached by Sætre and Jorge da Silva (1984) have received further support. Areas of potentially successful exploitation of tunas by surface methods have been identified during the whole year, with emphasis for November-April.

Structural features of geostrophic circulation in open region of the South China Sea

On the basis of observation data of water temperature and salinity the mean seasonal geostrophic circulation in open region of the South China Sea (SCS) was computed by the dynamic method relative to the 800 decibar reference surface. The results of computation let go to following notices: In both main monsoons (winter and summer) there are two main geostrophic eddies: the anticlockwise eddy in the northern and northwestern part, and the clockwise eddy in the southern part of the SCS with corresponding divergent and convergent zones. The main frontal zones go along the middle latitudes of the sea from the southern continental shelf of Vietnam to the area west of Luzon Island. The strength and stability of the current in winter are higher than in summer. The Kuroshio has an enough strong branch intruding into the SCS through Bashi Strait in winter creating in the sea the water structure similar to that of the Northwest Pacific subtropical and tropical regions. In summer the Kuroshio water can intrude directly only into the area southwest of Taiwan.

Guidewire retention following central venous catheterisation: a human factors and safe design investigation.

BACKGROUND: Central Venous Catheterisation (CVC) has occasionally been associated with cases of retained guidewires in patients after surgery. In theory, this is a completely avoidable complication; however, as with any human procedure, operator error leading to guidewires being occasionally retained cannot be fully eliminated. OBJECTIVE: The work described here investigated the issue in an attempt to better understand it both from an operator and a systems perspective, and to ultimately recommend appropriate safe design solutions that reduce guidewire retention errors. METHODS: Nine distinct methods were used: observations of the procedure, a literature review, interviewing CVC end-users, task analysis construction, CVC procedural audits, two human reliability assessments, usability heuristics and a comprehensive solution survey with CVC end-users. RESULTS: The three solutions that operators rated most highly, in terms of both practicality and effectiveness, were: making trainees better aware of the potential guidewire complications and strongly emphasising guidewire removal in CVC training, actively checking that the guidewire is present in the waste tray for disposal, and standardising purchase of central line sets so that differences that may affect chances of guidewire loss is minimised. CONCLUSIONS: Further work to eliminate/engineer out the possibility of guidewires being retained is proposed.

Study on biomass circulation and gasification performance in a clapboard-type internal circulating fluidized bed gasifier

We investigated the solid particle flow characteristics and biomass gasification in a clapboard-type internal circulating fluidized bed reactor. The effect of fluidization velocity on particle circulation rate and pressure distribution in the bed showed that fluidization velocities in the high and low velocity zones were the main operational parameters controlling particle circulation. The maximum internal circulation rates in the low velocity zone came almost within the range of velocities in the high velocity zone, when uH/umf = 2.2-2.4 for rice husk and uH/umf = 3.5-4.5 for quartz sand. In the gasification experiment, the air equvalence ratio (ER) was the main controlling parameter. Rice husk gasification gas had a maximum heating value of around 5000 kJ/m3 when ER = 0.22-0.26, and sawdust gasification gas reached around 6000-6500 kJ/m3 when ER = 0.175-0.24. The gasification efficiency of rice husk reached a maximum of 77% at ER = 0.28, while the gasification efficiency of sawdust reached a maximum of 81% at ER = 0.25.

Multiple expansions of C-4 plant biomass in East Asia since 7 Ma coupled with strengthened monsoon circulation

IEECAS SKLLQG