• Ocean and Polar Research
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• v.32 no.4
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• pp.475-482
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• 2010

Hydrothermal deposits on deep-sea floors are expected to provide potential metal resources for future demands. Korea was recently granted a prospecting licence to undertake exploration for hydrothermal metal deposits in the exclusive economic zone (EEZ) of the Kingdom of Tonga in the Pacific Ocean. The Korean Deep Seabed Mining Group (KDSMG), which consists of four Korean companies involved in marine technologies, oil and gas shipping, and smelter industries, has conducted research to evaluate the region's resource potential in cooperation with the Ministry of Land, Transport and Maritime Affairs (MLTM) of Korea. Here we present and reflect on the exploration results of these companies and their strategic plans. We also evaluate Research and Development (R&D) progress for the commercial development of seafloor hydrothermal deposits. Our own strategies and prospects for the commercial development of this potential resource are also outlined. We do acknowledge that other potentially important information regarding the amount of ore body, the inside structure, and the metal yields have not yet been clarified sufficiently. As such it is necessary to address these problems through experimental R&D and surveys.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.591-595
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• 1993

A trial involving 200 day-old 288 Shaver chicks in a randomized experimental design tested the effects of using diets based on local feed materials (LF). Commercial imported counterpart feeds (CF) served as control diets. Birds were raised from 0-6 w on Chick Starter feed, from 7-17 w on Pullet Developer feed and from 18 to 72 w on Layer feed. The results obtained indicated that there were no significant differences in the performance of birds fed LF and CF diets during the Chick Starter and Pullet Developer phases. During the Laying phase, there were also no differences in laying percentage, (66 vs 65) and in egg size (62 vs 63 g) between LF and CF diets. Feed cost was lower on LF diet had a better egg yolk colour score, (4 vs 1) than those fed on CF diet. Feed cost was lower on LF than CF diets and the feed cost for producing eggs was approximately 50 percent lower on LF compared to CF (P$ 0.06 vs P$ 0.12). It was concluded that the use of locally available feed resources produces comparable performance to that obtained using commercial imported feeds. Secondly, using local materials markedly reduces feed cost and cost of producing eggs.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.145-145
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• 2018

Small islands rely heavily on groundwater resources in addition to rainwater as the source of freshwater since surface water bodies are often absent. The groundwater resources are vulnerable to sea level rise, coastal flooding, saltwater intrusion, irregular pattern of precipitation resulting in long droughts and flash floods. Increase in population increases the demand for the limited groundwater resources, thus aggravating the problem. In this study, the effects of climate change on Tongatapu Island, Kingdom of Tonga, a small island in Pacific Ocean, are investigated using a sharp interface transient groundwater flow model. Twenty nine downscaled General Circulation Model(GCM) predictions are input to a water balance model to estimate the groundwater recharge. The temporal variation in recharge is predicted over the period of 2010 to 2099. A set of GCM models are selected to represent the ensemble of 29 models based on cumulative recharge at the end of the century. This set of GCM model predictions are then used to simulate a total of six climate scenarios, three each (2010-2039, 2040-2069, and 2070-2099) under RCP 4.5 and RCP 8.5. The impacts of predicted climate change on groundwater resources is evaluated in terms of freshwater volume changes and saltwater ratios in pumping wells compared to present conditions. Though the cumulative recharge at the end of the century indicates a wetter climate compared to the present conditions the large variability in rainfall pattern results in frequent periods of groundwater drought leading to saltwater intrusion in pumping wells. Thus for sustaining the limited groundwater resources in small islands, implementation of timely assessment and management practices are of utmost importance.