Evaluation of Escape Modifications in Traps for Prawn, Pandalus platyceros

1991 ◽  
Vol 48 (5) ◽  
pp. 784-791
Author(s):  
J. A. Boutillier ◽  
N. A. Sloan
Keyword(s):  
British Columbia ◽  
Carapace Length ◽  
Construction Material ◽  
Wire Mesh ◽  
Size Limit ◽  
Nylon Mesh ◽  
Wire Material ◽  
Trap Fishery ◽  
Pandalus Platyceros

Experimental fishing was done in 1986 to evaluate variables considered important in developing escape modifications for the prawn, Pandalus platyceros, trap fishery in British Columbia. Three major trap categories were used: flexible nylon mesh, rigid wire mesh, and solid sided. The efficacy of escape modifications depended upon the size of openings, the type of construction material, the placement of the modification on the trap, and soak time. The 44-mm web and wire material used for modifications allowed for escapement of prawns well above the 30.0-mm carapace length legal size limit. The rigid wire mesh used in escape modifications retained smaller prawns than did similar-sized flexible nylon mesh. In partially modified traps, escape material on the side/bottom combination was more effective for escapement than when just on the bottom or in the tunnels of the trap. Soak time was important in some traps which had escape material in ineffective locations. In these cases, longer soak times allowed the small prawns time to find their way out of the traps.

Behavior of Self Compacted Concrete Ferrocement Beams

2021 ◽  
pp. 1-14
Author(s):  
Abeer M. Erfan ◽  
Tamer H. K. Elafandy ◽  
Mahmoud M. Mahran ◽  
Mohamed Said
Keyword(s):  
Energy Absorption ◽  
Low Cost ◽  
Steel Wire ◽  
Construction Material ◽  
Point Load ◽  
Wire Mesh ◽  
Experimental Program ◽  
Cracking Behavior ◽  
Group B ◽  
Wire Meshes

Many researchers have been conducted on the ferrocement as a low cost construction material and a flexible structural system. This experimental investigation on the behavior of ferrocement beams after exposed to different type of ferrocement and different of ferrocement layer are presented in this paper. The experimental program consisted of seven simply supported beams tested up to failure under four-point load. The dimensions of 150mm×250mm×2000mm. Each beam was reinforced using steel 2 f 12 in top and 2 f10 in bottom and the stirrups was 10 f 10/m. In addition to six of them contains ferrocement different steel wire meshes and different of ferrocement layer. The test specimens are divided in three groups and the results of each one compared with the control specimen. The first group (A) which used the welded wire mesh. The second group (B) which used the expanded wire mesh. But the third group (C) which reinforced using woven wire mesh. The mid span deflection, cracks, reinforcement and concrete strains of the tested beams were recorded and compared. The performance of the test beams in terms of ultimate flexure load cracking behavior and energy absorption were investigated. The experimental results emphasized that high ultimate loads, better crack resistance control, high ductility, and good energy absorption properties could be achieved by using the proposed ferrocement beams. The cracks propagation decreased and its number and width decreased by using woven, expanded and welded wire mesh especially in specimens with two layers of wire mesh. Theoretical calculation was carried out to compare the oplained results with the theoretical ones, which show good agreement.

Tag Retention of the Spot Prawn, Pandalus platyceros, Injected With Coded Wire Tags

1977 ◽  
Vol 34 (11) ◽  
pp. 2196-2199 ◽  
Author(s):  
Earl F. Prentice ◽  
John E. Rensel
Keyword(s):  
Key Words ◽  
Carapace Length ◽  
Needle Insertion ◽  
Behavioral Changes ◽  
Control Group ◽  
Growth And Survival ◽  
Tag Retention ◽  
Pandalus Platyceros ◽  
Spot Prawn ◽  
Coded Wire Tags

Juvenile spot prawns, Pandalus platyceros (initial carapace length 15.0–22.5 mm), were successfully tagged with Bergman–Jefferts coded wire tags in the thoracic sinus. Tagged prawns, prawns subject to tagging needle insertion but without tags, and a control group were tested. No significant differences in growth and survival within or between test groups occurred and no behavioral changes were observed among tagged animals. All tagged prawns molted at least twice during the 6-mo experiment. Average tag retention was 95%. Key words: Pandalus platyceros, tagging, tag retention, molting, survival

scholarly journals Strength and Durability Performance of Ferrocement Panels with the Influence of Corrosion Inhibitor

2019 ◽  
Vol 9 (2) ◽  
pp. 374-383
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Construction Material ◽  
Wire Mesh ◽  
Load Carrying Capacity ◽  
Cell Potential ◽  
Load Carrying ◽  
Corrosion Risk ◽  
Ultimate Load Carrying Capacity ◽  
Strength And Durability

Success of Ferrocement, as with other construction material, depends largely upon its durability. ACI-549R strongly recommends that studies be undertaken to suggest durable and long-term anti-corrosion techniques to prevent penetration of water and salts that could lead to the corrosion of reinforcing wire mesh. The main objective of this study is to develop a durable Ferrocement panel by incorporating corrosion inhibitors as admixtures. The inhibitor used is sodium nitrate based inhibitor. Totally 24 Ferrocement panels are subjected to strength and durability study to ascertain the influence of inhibitor modification in cement mortar. Inhibitor admixed mortar offers marginally improved resistance against water absorption irrespective of tested dosage levels as compared to control mortar. There is a appreciable reduction in current development in the order of 18% for inhibitor admixed mortar as compared to control mortar, which is an indication of improved resistance against chloride penetration. Half-cell potential readings on galvanized Ferrocement panels should not be interpreted for corrosion probability as per ASTM C876. Ferrocement panels with crimped wire mesh and inhibitor modification offered low corrosion risk at the end of test period as per ASTM C876. There is an improvement in ultimate load carrying capacity for galvanized mesh Ferrocement panels of the order of 11-16% upon inhibitor modification in mortar. Similar ultimate load carrying capacity for crimped wire mesh Ferrocement panels for control and inhibitor modified mortar. Ductile behavior associated with multiple crack formation before failure is observed for all tested panels. It can be concluded that crimped wire mesh panel Ferrocement panels offered appreciable stiffness, load carrying capacity and ductility as compared to galvanized mesh Ferrocement panel. Inhibitor incorporation appreciably improves the durable performance of Ferrocement panels.

Escape panels to reduce by-catch in the New South Wales demersal trap fishery

2002 ◽  
Vol 53 (8) ◽  
pp. 1179 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell
Keyword(s):  
New South ◽  
New South Wales ◽  
Body Height ◽  
Mesh Size ◽  
Wire Mesh ◽  
Turn On ◽  
South Wales ◽  
Fish Traps ◽  
Trap Fishery ◽  
By Catch

Various sizes of wire mesh were tested as escape panels in fish traps in the New South Wales demersal trap fishery. The mesh selectivities of these escape panels were estimated using a 'parlour' trap, which is analogous to the 'covered codend' designs used to test selectivity in trawls. The results showed that we could estimate the selection size (l50) for most species based on their maximum body height and the maximum aperture of the escape panel mesh. This enabled us to make escape panel mesh that selected the main species in the fishery, snapper (Pagrus auratus), at a predetermined size. Placing the escape panel meshes with the longest axis orientated either vertically or horizontally showed that fish behaviour is important in determining mesh size selectivity. However, the selection size of some species was unaffected by the orientation of the mesh, suggesting that they were able to turn on their sides to escape. Silver trevally (Pseudocaranx dentex) formed tight schools within traps and were selected at smaller sizes when the meshes were oriented with the longest axis horizontally, suggesting that they do not turn on their sides to escape. Selectivity ogives were used with estimates of the sizes of retained and discarded fish captured in the fishery to estimate the impacts of using the escape panels tested on current landings. The results show the difficulty in designing effective escape panels in a multispecies fishery.

Cost and Practice Size Limit Adoption of EHRs

2006 ◽  
Vol 39 (14) ◽  
pp. 63
Author(s):  
JANE NEFF ROLLINS
Keyword(s):  
Size Limit ◽  
Practice Size
Sign in / Sign up

Export Citation Format

Share Document