• 한국어병학회지
• /
• 제13권2호
• /
• pp.97-102
• /
• 2000

WSBV를 염소소독 효과를 조사하기 위하여 유효농도 5, 10, 30 ppm의 차아염소산나트륨 용액을 처리한 결과 전혀 폐사가 일어나지 않았으나, 대조구에서는 전량 폐사되었다. 포비돈 요오드 10, 20, 30 ppm에서는 불활성화를 나타내지 않았는데 이는 유기물의 다량함유나 요오드 독성에 의해 시험새우가 폐사할 가능성이 있다. 일광소독에서는 2, 4시간 처리한 시험구에서는 폐사가 일어나지 않으므로 WSBV를 불활성화 시키는 것 같다. 건조처리에서는 1, 2, 3시간 처리한 시험구에서는 WSBV가 불활성화가 되었다. 담수처리에서는 담수 60% 첨가한 시험구(비중 1.015)에서 효과가 가장 크게 나타났다.

• 한국물환경학회지
• /
• 제24권2호
• /
• pp.164-168
• /
• 2008

Perchlorate, which is still unregulated, is found in tap water, posing a threat to public health. In and out of Korea, there is no clear standard for drinking water quality or discharge. To make matters worse, Perchlorate study is in its infancy in Korea. This research tracked fresh water and purified water of water purification facility A and B located at the city of D, where Nak-dong River is being utilized as the purified water. And it was found that purified water shows no particular pattern in Perchlorate concentrations but represented a higher level of concentration compared to fresh water. With utilizing the research results, the study sought the impact of activated-carbon treatment process on Perchlorate elimination and found out that Perchlorate concentrations increased 38% after the process. The result proves that conventional water purification process can't eliminate Perchlorate. Therefore, it is reasonable that Perchlorate discharge from sources should be minimized.

• 한국응용과학기술학회지
• /
• 제37권4호
• /
• pp.860-869
• /
• 2020

본 연구는 근해에서 잡은 고등어의 신선도유지효과를 확인하기 위해 해수 슬러리얼음(SS), 해수 큐브얼음(SC), 수돗물 슬러리얼음(TS), 수돗물 큐브얼음(TC)에 저장하며, 신선도분석을 시행하였다. 각 얼음 성분 중 세균수는 음용수 기준 이하였고, 암모니아성 질소는 해수 기준치인 11 mg/L를 초과했다. 민물에 비해 바닷물의 탁도가 심했다. 고등어의 일반성분 분석결과 수분 함량이 72.7%, 단백질 20.5%, 지질 5.25%, 회분 함량이 1.3%로 나타났다. 해수 슬러리 얼음은 수돗물 얼음과 비교하여 pH가 낮게 유지되었다. 저장 초기에는 모든 저장소에서 VBN 증가가 억제되었다. 전반적으로 해수빙이 담수 얼음보다 휘발성 염기질소(VBN) 값이 낮게 유지 되었다.

• 한국축산식품학회지
• /
• 제37권2호
• /
• pp.210-218
• /
• 2017

The intake of dietary salt through food now exceeds current nutritional recommendations and is thought to have negative effects on human health, such as the increasing prevalence of hypertension. This study was performed to investigate whether $W_1/O/W_2$ double emulsions can be used to enhance the saltiness of cheese without increasing the salt content ($W_1$ is distilled water or 1% abalone hydrolysate, and $W_2$ is 1% NaCl or 1% abalone hydrolysate + 1% NaCl solution). We also investigated the effect of adding abalone hydrolysate to the double emulsion as a saltiness enhancer. The cheeses were physico-chemically evaluated to determine curd yield, pH value, moisture content, color, texture, salt release rate, and sensory properties. No significant differences were observed in curd yield, pH value, moisture content, lightness, or redness between the cheeses made with and without the double emulsion. However, in the evaluation of salt release rate, fresh cheese made with double emulsion ($W_1$ = distilled water, $W_2$ = 1% NaCl + 1% abalone hydrolysate) was detected earlier than the control or the other treatments. In the sensory evaluation, fresh cheese made with the double emulsion showed higher scores for saltiness and overall preference than the control or the other treatments. We concluded that abalone hydrolysate encapsulated in a double emulsion ($W_1$ is water and $W_2$ is abalone hydrolysate and NaCl solution) could enhance the saltiness of fresh cheese while maintaining the same salt concentration, without altering its physical properties.

• 한국수자원학회논문집
• /
• 제46권7호
• /
• pp.783-794
• /
• 2013

지하수 의존도가 높은 제주도에서는 담수 지하수는 물론 어류의 육상 양식을 위한 염분이 높은 지하수도 활발하게 개발되고 있다. 본 연구는 제주도 성산유역을 대상으로 담수와 염수 지하수 개발이 지하수계에 미치는 영향을 분석하였다. 경계면 모델을 이용하여 담수와 염수의 흐름을 모의하고 담수와 염수 개발의 영향을 조사하였다. 담수 개발은 기존의 연구 결과에서 익히 알려진 바와 같이 지하수위 강하와 해수쐐기 침투를 야기하는 것으로 나타났다. 염지하수 개발은 지하수위를 강하시키는 부정적 영향과 함께 해수침투를 저감시키는 긍정적 효과도 있는 것으로 나타났다. 담-염수사이의 유한한 두께의 천이대에 대한 수정 Ghyben-Herzberg 비율을 유도하고 해수침투 관측정에서 관측된 자료와 비교하였다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.606-609
• /
• 2006

In this study, it was selected that in order to make an investigation into the status of the unit water content control of the ready-mixed concrete plants in the country, Capacitance Measurement Method out of various methods which are able to gauge the amount of unit water content in fresh concrete. Then, it were estimated that the quantity of unit water in fresh concrete and the technical standard of every mixture design of the six ready-mixed concrete plants chosen at random in the country. Finally, based on this study, it was proposed as fundamental data to utilize measurement techniques of the quantity of unit water for the quality control of the ready-mixed concrete in construction field.

• 기술사
• /
• 제42권6호
• /
• pp.47-52
• /
• 2009

According to increasing demand of water mainly due to the growth of population and increased water consumption, many countries either face or worry about the shortage of fresh water. Proportionately, importance and efforts of each country to develop the potable water has been gradually increasing as well. Among others, desalination of seawater has been developed to one of the solutions mainly from the middle east and other arid regions to produce large quantity of fresh water from seawater. We installed beach seawater collector wells to develop the filtered seawater supply for desalination in a refinery. We came to a conclusion that the beach seawater collector well is one of the recommendable alternatives of seawater pre-treatment for desalination applications with lower operating cost and higher efficiency.

• 한국해양학회지
• /
• 제22권3호
• /
• pp.207-215
• /
• 1987

금강 하구(Keum River Estuary)에서의 chlorophyll-a의 분포를 규제하는 제 과정등을 이해하기 위하여, 1986년 4월과 7월 두차례에 걸쳐 현장 조사를 실시하고, chlorophyll-a, 영양염, ph, SPM, 용존산소, 수온, 염분 등의 분포 양상을 조사하였 다 갈수기인 4월은 방조제에서 약 35km 상류의 강경까지 염수의 침입이 있었으나, 풍수기였던 7월은 약 3km 상류역까지만 염수의 영향이 관측되었다. 4월의 경우 전 강하구 (estuary)에 걸쳐 평균 $500m{\ell}/{\ell}$이상의 높은 SPM분포를 보인 반면, 7월은 증가된 담수의 영향으로 SPM의 농도가 평균 $10m{\ell}/{\ell}$정도 밖에 이르지 않았다. chlorophyll-a의 분포는 시기, 위치에 따라 많은 변화를 보여, 7월의 경우 4월에 비 하여 매우 높은 chlorophyll-a의 분포를 보였으며, 두 시기 모두 담수-해수 경계역 에서 급격한 감소를 보였다. (4월 평균:담수역 $6.5\mu\textrm{g}/{\ell}$, 강하구 $1.4{\;}\mu\textrm{g}/{\ell}$; 7월 평균: 담수역 $35{\;}\mu\textrm{g}/{\ell}E, 강후구 $6.8\mu\textrm{g}/{\ell}$). 영양염이 항상 충분히 존재하는 금강 하구에 있 어서, 두 시기간의 chlorophyll-a농도에 큰 차이를 보인 것은, 주로 SPM 농도의 현 격한 차이에 의한 빛 에너지 효용성의 차이에 기인된 것으로 생각된다. 담수-해수 경계지역에서의 chlorophyll-a의 급격한 감소는, 주로 ionic strength의 증가로 야기 된 삼투압의 변화에 적응하지 못한 식물 plankton들의 대소멸(mass mortality)에 기인된 현상으로 생각된다. 초기혼합지역에서 AOU, ammonia의 증가를 보인 4월, ph의 급격한 감소를 보인 4월 및 7월의 자료들은, 식물 plankton의 죽음으로 인하여 공급된 유기물들의 분해과정을 통하여 나타날 수 있는 현상들로서, 위의 결론을 뒷 받침하여 주고 있다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권4호
• /
• pp.529-537
• /
• 1998

Currently as due to the rapid development of industry and increase in population we meet serious problems concerning the shortage and pollution of water. In the country many experts predict a shortage of water approaching 450 million tons by the year 2006. To cope with this serious problem it is necessary to construct desalination plants. In the adoption of a desalination system the most important factor is the cost of fresh water production,. In general LNG is stored in a tank as a liquid state below $-162^{\circ}C$. When it is serviced, however the LNG absorbs energy from a heat source and transforms to a high pressure gaseous state. During this process a huge amount of cold energy accumulated in cooling LNG is wasted. This wasted cold energy can be utilized to produce fresh water by using a sea water freezing desalination system. In order to develop a sea water freezing desalination system and to establish its design technique qualitative and quantitative data regarding the freezing behavior of sea water is required in advance, The goals of this study are to reveal the freezing behavior of sea water is required in advance. The goals of this study are to reveal the freezing mechanisms of sea water to measure the freezing rate and to investigate the freezing heat-transfer characteristics,. The experimental results will provide a general understanding of sea water freezing behavior in a rectangular vessel cooled from above.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
• /
• pp.373-376
• /
• 2008

The objective of this study is to investigate the properties of fresh concrete with recycled fine aggregates. Three different kinds of fine aggregate with natural, high and low quality recycled aggregates were prepared. The concrete mixtures were produced with test parameters of replacement ratio of recycled fine aggregate. The properties of the fresh concrete were measured by means of slump and air content according to elapsed time. Quality control method to maintain the constant total mixing water for recycled aggregate concrete was suggested. The all concrete mixtures were produced with approximately the same slump on the job site after an hour. Test results indicated that compressive strength of the concrete mixtures with constant slump is not affected by the replacement ratio of recycled fine aggregate. Therefore, the practical way for the quality control of recycled aggregate concrete is to maintain the constant total mixing water.