• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.1
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• pp.73-80
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• 2016

The aim of this study is to analyze the contribution of regional water resources through the gap between water used for rice production and water used for consumption. The blue water use for rice production and for consumption was quantified and the regional blue water flows were estimated using the virtual water concept from 1995 to 2010. About $1134.4Mm^3/yr$ of blue water flowed among the provinces and metropolises of Korea, and about 28.5 % of total blue water flows came from Jeonnam province. In addition, blue water usage for rice was classified into three categories: water for production, internal consumption, and overproduction in each region. In Jeonnam, $633.8Mm^3/yr$ of blue water totally used for rice production, and 50.9 % and 15.5 % were used for external and internal rice consumption, respectively. The other 33.6 % was used for over production of rice for food security. This study assumed the blue water flows depended on the gap between virtual water use for rice production and consumption. However, the analysis of regional blue water usage and flows might show the importance of other region's water resources, and make policy decision-makers aware of the integrated water management among the regions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.6
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• pp.480-486
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• 2006

The radiation characteristics of a high-luminance light-emitting diode (LED) light source were studied to evaluate its potential as an energy-saving light source for fishing lamps. The angle of the LED light source with 50% illuminance was $8-15^{\circ}$, and it had strong directional characteristics. The wavelengths at which the radiance and irradiance were maxima were 709, 613, 473, 501, 525, and 465 nm for red, orange, blue, peacock blue, green, and white light, respectively. The underwater transmission characteristics of the LED light source were superior in the order blue, white, peacock blue, and green in optical water type I: blue, peacock blue, white, and green in optical water type II; and blue, peacock blue, green, and white in optical water type III. Setting the underwater transmission characteristics of the LED light source in optical water type I at 100%, the transmission of water types II and III decreased to 67 and 17%, respectively. Based on the underwater transmission characteristics calculated in optical water types I-III, the blue and peacock blue LED light sources can be used as an energy-saving light source for fishing lamps.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.291-300
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• 1998

Recently, upwelling of anoxic bottom water mass have been frequently observed in northeast part of Tokyo Bay in Japan during summer to autumn. Since the colour of water surface becomes milkyblue or milkygeen, the upwelling phenomenon Is called 'Blue Tide'. The data analysis of field surveys during 'Blue Tide' appearance have been performed for understanding the physical features of the 'Blue Tide' phenomena In Tokyo Bay. It becomes clear that (1) the formation of the anoxic bottom water correlates well with the temperature difference between the surface and bottom waters, (21 there are two necessary conditions for generating 'Blue Tide': that Is, strong stratincation and off-shore wind. The strong southwest(on-shored wand before the 'Blue Tide' appearance may play an iniportant role to make the striancation strengthen. When these conditions are larger and the northeast or east-northeast (off-shored wind stronger than S ifs blows In succession, the 'Blue Tide' upwelling appears at the head of Tokyo Bay.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.393-399
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• 2017

In order to determine the optimal water intake point, the distribution of blue-Green algae and water quality factors in relation to the depth of the Mulgum and Maeri stations located downstream of the Nakdong River were investigated from Jun. 2015 to Sep. 2016. When the current surface water intake system was converted to the deep water intake system, Chl-a concentration and blue-Green algae were reduced by 64.1% and 80.5%, respectively. Microcystin-LR was reduced by 50% to 100%, while geosmin and 2-MIB of the odorant substances were reduced by 42.9% and 11.8%, respectively. The water quality factors such as pH, water temperature, TOC and COD were gradually decreased by 30% in deep water. Therefore, if we used the deep water intake system selectively in the summer season when blue-Green algae masses occur, the concentration of the influx of blue-green algae and its by-products can be expected to decrease, leading to reduced operation costs in tap water production and improved of raw water quality.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2180-2182
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• 2000

Laser emission, a part of electromagnetic wave, has short propagation length in water, and the underwater applications of laser are limited. The acquisition of underwater imaging is possible only by using a blue-green laser since the blue-green range has relatively small absorption coefficient in water. We introduce the conditions of the laser required for underwater imaging and the attenuation characteristics of a blue-green laser used in water.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.3
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• pp.65-74
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• 2014

Water footprint is defined as the total volume of direct and indirect water used to produce a good and service by consumer or producer, and measured at the point of production based on virtual water concept. The green and blue water footprint refers to the volume of the rainwater and the irrigation water consumed, respectively. Crop water footprint is expected to be used as the basic data for agricultural water resources policies at production, consumption and trade aspect. Thus, it is necessary to estimate suitable green and blue water footprint for South Korea. The objective of this paper is to quantify the green and blue water footprint and usage of upland crops during the period 2001-2010. To estimate the water footprint, 43 upland crop production quantity and harvested area data were collected for 10 years and FAO Penman-Monteith equation was adopted for calculating crop water requirement. As the results, the water footprint of cereals, vegetables, fruits and oil crops accounted for 1,994, 165, 605, and 4,226 $m^3/ton$, respectively. The usage of water footprint for crop production has been estimated at 3,499 (green water) and 216 (blue water) $Mm^3/yr$ on average showing a tendency to decrease. Fruits and vegetables have the largest share in the green water usage, consuming about 1,200 and 1,060 $Mm^3/yr$ which are about 65 % of gross usage. The results of this study are expected to be understood by the agricultural water footprint as well as by the total water footprint from both a production and consumption perspective in Korea.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.243-249
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• 2015

To improve stability of the water resources that were seriously affected by climate change and various environmental effects and to supply the clean water always, continuous efforts are essential. Provision of measures with respect of hardware is basically essential to improve the water resources stability due to the topographic characteristic in Korea. However, building a new dam becomes gradually very difficult because of a hardship in selecting right places, opposition forces such as environment and local residents, negative publicity for large civil engineering projects, and so on. The present study, therefore, proposes the Blue dam as an alternative for securing the water resources of a new concept considering domestic conditions. To evaluate the effect of the Blue dam, the Hec-ResSim model is used and the probabilistic discharge flow rate is applied. As a result, when Dam Yeongcheon is applied as a study area, securing water resources of 14 million tons are predicted be secured and the flood control of 15.4 million tons is expected, in comparison with operation of the existing dam only. Consequently, Blue dams are supposed to carry out the function of securing water resources, controling flood, maintaining eco-environmental instream flow, generating hydroelectric power, and providing spaces for recreational activities.

• Korean Journal of Agricultural Science
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• v.16 no.2
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• pp.201-211
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• 1989

This experiment was carried out to study the practical utility of Mucor rennet in making Blue cheese and to investigate the changes in the level of various nitrogen compounds. 1. The Mucor rennet cheese, the calf rennet cheese and the mixed rennet cheese did not show any significant difference in their yields. 2. The dry matter contents of Blue cheese was increased during the ripening and the levels of Mucor rennet did not have any influence in these respect. 3. The water soluble nitrogen contents of Blue cheese increased during ripening. On 0 day of ripening the Mucor rennet cheese contained water soluble nitrogen than the calf rennet cheese. On 40 days of ripening the mixed cheese contained less water soluble nitrogen than the calf rennet cheese. 4. Non protein nitrogen, peptone amino nitrogen, water soluble protein nitrogen, proteose nitrogen and peptone nitrogen appeared to contain similar levels of water soluble nitrogen. 5. The results of electrophoresis indicated a greater degredation on as-casein and ${\beta}$-casein in the Blue cheese made with Mucor rennet than in those made with calf rennet. On 60 days of ripening the mixed cheese more casein than did the Mucor rennet cheese. 6. The free amino acid contents of the Mucor rennet cheese was higher than the calf rennet cheese at 60 days of ripening.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.171-177
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• 2019

Smart farm is a breakthrough technology that can maximize crop productivity and economy through efficient utilization of space regardless of external environmental factors. This study was conducted to investigate the optimal growth and physiological conditions of Chinese matrimony vine (Lycium chinense) with LED light sources in a smart farm. The light source was composed of red+blue and red+blue+white mixed light using a LED system. In the red+blue mixed light, red and blue colored LEDs were mixed at ratios of 1:1, 2:1, 5:1, and 10:1, with duty ratios varied to 100%, 99%, and 97%. The experimental results showed that the photosynthetic rate according to the types of light sources did not show statistically significant differences. Meanwhile, the photosynthetic rate according to the mixed ratio of the red and the blue light was highest with the red light and blue LED ratio of 1:1 while the water use efficiency was highest with the red and blue LED ratio of 2:1. The photosynthetic rate according to duty ratio was highest with the duty ratio of 99% under the mixed light condition of red+blue+white whereas the water use efficiency was highest with the duty ratio of 97% under the mixed light of red+blue LED. The results indicate that the light source and light quality for the optimal growth of Lycium chinense in the smart farm using the LED system are the mixed light of red+blue (1:1) and the duty ratio of 97%.

• Journal of Electrochemical Science and Technology
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• v.7 no.1
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• pp.76-81
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• 2016

An anatase TiO₂ nanotube array (NTA) was fabricated by anodization and successive heat treatments. When the anatase TiO₂ NTA was cathodically polarized, its color changed to blue, and it could be used as an electrochemically active anode for an oxygen evolution reaction (OER) in alkaline water electrolysis. The structure of the blue anatase TiO₂ NTA was controlled by the anodization conditions and its catalytic activity increased with an increase of the surface area. The activity of the blue anatase TiO₂ NTA gradually reduced with the continued OER because of the partial oxidation of Ti³⁺ to Ti⁴⁺. However, an intermittent cathodic regeneration process could significantly slow its reduction rate. The blue anatase TiO₂ NTA could be an alternative anode for alkaline water electrolysis.