Regional cooperation for managing marine fish stocks in the APFIC region

For effective management of straddling fish stocks, regional cooperation of the participating countries is required. Formation of regional fisheries forums and intergovernmental consultative machinery's is very vital. The functions of the existing regional bodies and the factors which should form the basis for effective management of fish stocks are discussed

A comparative account of the small pelagic fisheries in the APFIC region

The production of the small pelagics in the APFIC region was 1.2 mt/sq. km during 1995. Among the four areas in the region, the small pelagics have registered (i) the maximum annual fluctuations in the western Indian Ocean; (ii) the highest increase duri'}i the past two decades along the west coast of Thailand in the eastern Indian Ocean; and (iii) the consistent decline in the landings during the past one decade along the Japanese coast in the northwest Pacific Ocean

Fisheries environment in the APFIC region with particular emphasis on the northern Indian Ocean

The stocks of the small pelagics in the northern Indian Ocean are governed by different environmental jactors such as wind pattern, currents, convergence, temperature, salinjty, dissolved oxygen and vertical mixing processes. An attempt is made in this paper to correlate these factors with the fisheries for the small pelagics, In the northwest Pacific Ocean, successes or failures of recruitment of pelagic fishes are related to oceanographic factors, especially the direction of Kuroshio current. The information available on these aspects has been briefly reviewe

Status, prospects and management of small pelagic fisheries in India

The annual small pelagic fish production increased from 0.30 million mt during 1950-54 to 1.24 million mt during 1996 along the Indian coast. The 4 fold increase was possible due to several technological advancements. The potenrial yield from the pelagic resources of the EEZ is estimated to be 2.2 million mt. As there is no further scope for increasing the production from the inshore waters, there is need to bring the outer shelf and oceanic waters into increasing levels of exploitation

Incorporation of LNG into Small Gas Networks via FSRUs

Geopolitical risks on pipeline gas imports, increasing natural gas demand and the need to ensure continuous power supply with ever increasing fluctuating renewable power generation require diversification of gas sources to ensure supply security. With the global liquefied natural gas (LNG) trade increasing every year and natural gas prices remaining relatively low, more and more countries are interested in investing in regasification infrastructure. Establishing a floating storage and regasification unit (FSRU) and importing LNG has several advantages: lower cost compared to an onshore terminal, flexibility in relocation and the availability of short-term contracts all of which help serve small markets. FSRUs can also be operated in standby mode or used as an LNG storage facility. Operating an FSRU as a storage facility while beneficial for small networks introduces the challenges of LNG weathering and managing of the boil-off gas (BOG). To investigate these challenges on operation, a mathematical model is developed to determine the boil-off rate (BOR) over various time frames. The initial BOR is 0.129% of the initial storage volume increased to 0.143% after 10 weeks. Subsequent use of Aspen HYSYS to determine the change in LNG composition determined that Wobbe Index (WI) of the LNG varied from 51.58 to 51.616 MJ/Nm3 after 10 weeks of storage. An annual economic estimation of operating FSRU as a storage facility was carried out determining that the per unit price of gas obtained from regasified LNG is at least 42% lower than the current per unit price of gas in Ireland

Synthetic Natural Gas Production: Production Cost, Key Cost Factors and Optimal Configuration

The volatile nature of the renewable energy sources requires energy storage to compensate for the imbalances and to provide reliable base load. Power-to-Methane technology facilitates long-term high capacity renewable energy storage in the form of Synthetic Natural Gas (SNG) in the gas network. Unlike hydrogen, SNG usage in the network has no restrictions and natural gas appliances can operate on SNG. The two inputs required to produce SNG in the methanator are hydrogen and CO2 and they can be obtained from several sources. This leads to multiple possible process flow configurations in SNG production, each of them with varying performance. An optimization model has been developed in GAMS to analyse the performance of these various configurations. The objective of this research is to determine the optimal configuration, key cost factors and their effects on the production cost to identify the areas that require further development for cost reduction. This work also aims to determine the production cost per unit of SNG and the factors with most significant influence on the production cost by implementing a factorial design and a multivariate analysis (analysis of variance) approach. Methanator, electrolyser, biogas upgrader and hydrogen storage are considered as the fundamental process units in this work. The lowest production cost identified in the first year of production is 0.432 €/kWhSNG. The discounted production cost obtained shows that the lowest cost in 20 years from now is 0.143 €/kWhSNG. The variable with the most influence on the production cost is the capex of the methanator followed by the capacity of the methanator

Collapse of a non-axisymmetric, impact-created air cavity in water

The axisymmetric collapse of a cylindrical air cavity in water follows a universal power law with logarithmic corrections. Nonetheless, it has been suggested that the introduction of a small azimuthal disturbance induces a long term memory effect, reflecting in oscillations which are no longer universal but remember the initial condition. In this work, we create non-axisymmetric air cavities by driving a metal disc through an initially-quiescent water surface and observe their subsequent gravity-induced collapse. The cavities are characterized by azimuthal harmonic disturbances with a single mode number $m$ and amplitude $a_m$. For small initial distortion amplitude (1 or 2% of the mean disc radius), the cavity walls oscillate linearly during collapse, with nearly constant amplitude and increasing frequency. As the amplitude is increased, higher harmonics are triggered in the oscillations and we observe more complex pinch-off modes. For small amplitude disturbances we compare our experimental results with the model for the amplitude of the oscillations by Schmidt et al. (2009) and the model for the collapse of an axisymmetric impact-created cavity previously proposed by Bergmann et al. (2009b). By combining these two models we can reconstruct the three-dimensional shape of the cavity at any time before pinch-off.Comment: 18 pages, 13 figure