On the importance of ship-bottom fouling by marine organisms: a techno-economic survey

A high attention has been paid for constant research on the preservation of materials in the marine environment. This includes all phases of design, development, applied engineering and economics which may influence the construction and operation of ships and underwater installations.

Vertical distribution of marine wood boring and fouling organisms from the estuarine areas of the south west coast of India

Vertical distribution of marine wood boring and fouling organisms from three different estuarine areas namely, the Ernakulam channel in the Cochin backwaters, Ayiramthengu in the Kayamkulam Lake and Neendakara in the Asthamudi Lake during the post-monsoon, the pre-monsoon and the monsoon periods is presented. The boring organisms noticed during the present study were Martesia striata, Teredo furcifera, Nausitora hedleyi and Sphaeroma terebrans. The dominant fouling organisms were Balanus amphitrite amphitrite, calcareous worms and Modiolus sp. Algae and diatoms were very common on the sub-tidal panels during the monsoon. The incidence of Teredo, Nausitora and calcareous tube worms were significantly high on the bottom panels. Sphaeroma, Balanus and Modiolus occurred in greater numbers on the intertidal panels.

Modified water spray chumming system for pole and line fishing of tuna

A water spray chumming system consisting of a 65 x 50 mm centrifugal pump driven by the propulsion engine through a PTO clutch and 'V' pulley power transmission system has been developed for the pole and line fishing of tuna. Water is sprayed through pipe loop system fitted on the edge of the fishing platform of the boat through small holes. The distance of the spray length can be adjusted by controlling the flow of the pump discharge water through a wheel valve.

Growth performance evaluation of genetically improved silver barb (Barbonymus gonionotus Bleeker) in different agro-ecological zones in Bangladesh

On farm trials of silver barb with other carps were carried out in 40 ponds during May to October 2005 in four agro-ecological zones viz., Trishal, Muktagacha, Parbotipur and Paikgacha in Bangladesh. In Trishal and Muktagacha zones, ponds were stocked with silver barb, silver carp and common carp at the stocking density of 11,500 fish/ha, whereas in Parbotipur and Paikgacha zones, ponds were stocked with silver barb, rohu, catla and mrigal at the stocking density of 10,000/ha. Among the ponds, 50% (20 ponds) were stocked with BFRI improved stock of silver barb (Treatment-1) and rest of the 20 ponds stocked with local silver barb stock (Treatment-2). The harvest weight of BFRI improved silver barb were 149±16.01, 168±18.06, 198±14 and 230±9.25g in Trishal, Muktagacha, Paikgacha and Parbotipur, whereas the data obtained at 113±15.52, 136±20.66, 170±17.0 and 205±12.10g for local stock of silver barb, respectively. In all trials, the harvest weight of BFRI improved stock showed significantly higher growth performance (P<0.05) over the local stocks.

A method of immersion of panels for ecological studies on marine fouling and boring organisms

The importance of studies on the biology of marine foulers and borers needs no emphasis since they cause damage to submerged wooden structures resulting in considerable economic loss. In order to study their occurrence, settlement and to assess the rate of destruction to timber, several immersion techniques using iron racks, cages and rafts have been adopted. On the east and west coasts of India, at the Marine Centres of Forest Research Institute (Waltair, Madras, Cohin and Bombay) investigations have so far been carried out employing the first two methods.

Study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis, C. grimmi and C. cultriventris) in two vacuum packaging and modified atmosphere packaging at different environmental factors

Fish protein concentrate (FPC) is a healthy, sustainable and high nutritive product which sanitized produced from fishes in which, protein and other nutrients are more concentrated than in fresh fishes. The aim of this research is to study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis , C. grimmi and C. cultriventris) in two Vaccum Packaging and Modified Atmosphere Packaging at different environmental factors during six months. In our study the analysis of FPC protein showed 91.2%, lipid: 0.5%, ash: 3.6%, moisture: 2.3%, Total Volatile Nitrogen: 10 ml/100gr and peroxide: 5meq/kg. Amino acids and fatty acids were also determined. Bacteria and Fungi were lower than 1000 colony. Samples are kept in different condition of temperature (5, 20 and 35 degree centigrade), humidity (25, 40 and 90 percent) and light and dark environment in six month. Lipid rate in FPC after 6 months in VP and MAP (60% C02, 30 % N2 and 10% O2), packages was decreased but was not significant (P>0.05). It was also detected that increase temperature lead to more decrease in lipid content. Protein rate of FPC was decreased from 91.2% to 73.6% during six months at 35°C in VP Package and from 91.2% to 69.4% in MAP package. These changes were significant (P<0.05). TVN and PV rate in FPC after 6 months in VP and MAP packages was increased but was significant (P<0.05). Amino acids and fatty acids were also determined. But more changes in MAP packages was detected.

Extraction and structure elucidation of natural compounds of some gorgonians of the Persian Gulf and also physiological and pharmacological effects of gorgonian extract on some selected organisms

In the present research, investigations were carried out for structure elucidation of natural compounds and also for studing biological and teratogenical effects of two Genus of soft corals named as " Echinogorgia cf. indica" and "Sinularia erecta" in Persian Gulf. First, 350 gr Echinogorgia was extracted by Acetone, then, the extract was separated by ether from aqueos phase to give 4.5 gr oil. The oil eluted with Petrol - ether Et2 o (9:1) which was recovered Linderazulene and it's derivative as purple Cristals (350 mg/ca 0.1 %). In order to determine molecular structure, the Samples were used for spectroscopic method as: H1- NMR , C13- NMR and 2D NMR. Also, for extraction and structure elucidation of natural compounds, the soft coral " sinularia erecta " were used 1187/37 gr and extracted by Aceton. The extract was concentrated and resulting aqueous suspension and extracted by using ether to give 8.41 gr oil. The oil , was Chromatographed on a column of silica gel and some different fractions were gathered. Initial fraction (1-11) which were nonpolar compounds were seprated by GC/MS. Mass spectrum were prepared and much compounds were recognized.

Biodiversity values of different aquatic systems, habitats and organisms in relation to restoration and sustaining of biodiversity

Biodiversity values provide objective data and advice from which policy makes could assess the conservation options and determine optimal policies that would balance the needs of conservation with the socia-economic needs of the people in the area.

Analysis of CFRP strap-strengthened reinforced concrete beams using the modified compression field theory (MCFT)

External, prestressed carbon fiber reinforced polymer (CFRP) straps can be used to enhance the shear strength of existing reinforced concrete beams. In order to effectively design a strengthening system, a rational predictive theory is required. The current work investigates the ability of the modified compression field theory (MCFT) to predict the behavior of rectangular strap strengthened beams where the discrete CFRP strap forces are approximated as a uniform vertical stress. An unstrengthened control beam and two strengthened beams were tested to verify the predictions. The experimental results suggest that the MCFT could predict the general response of a strengthened beam with a uniform strap spacing < 0.9d. However, whereas the strengthened beams failed in shear, the MCFT predicted flexural failures. It is proposed that a different compression softening model or the inclusion of a crack width limit is required to reflect the onset of shear failures in the strengthened beams.

The nature and origin of deep ocean clay crust from the Gulf of Guinea

Deep ocean sediments off the west coast of Africa exhibit a peculiar undrained strength profile in the form of a crust, albeit of exceptionally high water content, overlying normally consolidated clay. Hot-oil pipelines are installed into these crustal sediments, so their origins and characteristics are of great interest to pipeline designers. This paper provides evidence for the presence of burrowing invertebrates in crust material, and for the way sediment properties are modified through their creation of burrows, and through the deposition of faecal pellets. A variety of imaging techniques are used to make these connections, including photography, scanning electron microscopy and X-ray computer tomography. However, the essential investigative technology is simply the wet-sieving of natural cores, which reveals that up to 60% by dry mass of the crustal material can consist of smooth, highly regular, sand-sized capsules that have been identified as the faecal pellets of invertebrates such as polychaetes. Mechanical tests reveal that these pellets are quite robust under effective stresses of the order of 10 kPa, acting like sand grains within a matrix of fines. Their abundance correlates closely with the measured strength of the crust. While this can easily be accepted in the context of a pellet fraction as high as 60%, the question arises how a smaller proportion of pellets, such as 20%, is apparently able to enhance significantly the strength of a sediment that otherwise appears to be normally consolidated. A hypothesis is suggested based on the composition of the matrix of fines around the pellets. These appear to consist of agglomerates of clay platelets, which may be the result of the breakdown of pellets by other organisms. Their continued degradation at depths in excess of 1 m is taken to explain the progressive loss of crustal strength thereafter.

A genetically mediated bias in decision making driven by failure of amygdala control.

Genetic variation at the serotonin transporter-linked polymorphic region (5-HTTLPR) is associated with altered amygdala reactivity and lack of prefrontal regulatory control. Similar regions mediate decision-making biases driven by contextual cues and ambiguity, for example the "framing effect." We hypothesized that individuals hemozygous for the short (s) allele at the 5-HTTLPR would be more susceptible to framing. Participants, selected as homozygous for either the long (la) or s allele, performed a decision-making task where they made choices between receiving an amount of money for certain and taking a gamble. A strong bias was evident toward choosing the certain option when the option was phrased in terms of gains and toward gambling when the decision was phrased in terms of losses (the frame effect). Critically, this bias was significantly greater in the ss group compared with the lala group. In simultaneously acquired functional magnetic resonance imaging data, the ss group showed greater amygdala during choices made in accord, compared with those made counter to the frame, an effect not seen in the lala group. These differences were also mirrored by differences in anterior cingulate-amygdala coupling between the genotype groups during decision making. Specifically, lala participants showed increased coupling during choices made counter to, relative to those made in accord with, the frame, with no such effect evident in ss participants. These data suggest that genetically mediated differences in prefrontal-amygdala interactions underpin interindividual differences in economic decision making.

Development of accurate, robust liquid equations of state for multi-phase CFD simulations with a modified AUSM+-up scheme

Eight equations of state (EOS) have been evaluated for the simulation of compressible liquid water properties, based on empirical correlations, the principle of corresponding states and thermodynamic relations. The IAPWS-IF97 EOS for water was employed as the reference case. These EOSs were coupled to a modified AUSM+-up convective flux solver to determine flow profiles for three test cases of differing flow conditions. The impact of the non-viscous interaction term discretisation scheme, interfacial pressure method and selection of low-Mach number diffusion were also compared. It was shown that a consistent discretisation scheme using the AUSM+-up solver for both the convective flux and the non-viscous interfacial term demonstrated both robustness and accuracy whilst facilitating a computationally cheaper solution than discretisation of the interfacial term independently by a central scheme. The simple empirical correlations gave excellent results in comparison to the reference IAPWS-IF97 EOS and were recommended for developmental work involving water as a cheaper and more accurate EOS than the more commonly used stiffened-gas model. The correlations based on the principles of corresponding-states and the modified Peng-Robinson cubic EOS also demonstrated a high degree of accuracy, which is promising for future work with generic fluids. Further work will encompass extension of the solver to multiple dimensions and to account for other source terms such as surface tension, along with the incorporation of phase changes. © 2013.