• Tribology and Lubricants
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• 제36권6호
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• pp.385-390
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• 2020

It rains heavily, such as long rain and typhoons, during a typical rainy season in Korea. In this season, several fuel contamination accidents by water and vehicular problems caused by water contaminated fuel occur. Many research groups have studied the effects of water contaminated fuel on vehicles and environment. However the characteristics of water contaminated fuel have not been studied. In this study, we prepared diesel samples with a constant ratio of water (0~30 volume %) using an emulsifier. Then, we analyzed these diesel samples for their representative fuel properties. In the analytical results, diesel with 30% water showed an increase in fuel properties such as density (823→883 kg/㎥), kinematic viscosity (2.601→6.345 ㎟/s), flash point (47→56℃), pour point (-22→2℃), CFPP (cold filter plugging point) (-17→20℃) and copper corrosion number (1a→2a). The low temperature characteristics, such as low pour point and CFPP, blocks the fuel filter in the cold season. In addition, water contaminated diesel decreases lubricity (190→410 ㎛) under high frequency reciprocating rig (HFRR) and derived cetane number (54.81→34.25). The low lubricity of fuel causes vehicle problem such as pump and injector damage owing to severe friction. In addition, the low cetane diesel fuel increases exhaust gases such as NOx and particulate matters (PM) owing to incomplete combustion. This study can be used to identify the problems caused by water contamination to vehicle and fuel facilities.

• 한국식품영양학회지
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• 제32권2호
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• pp.98-105
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• 2019

In this study, bread was prepared using various amount of 'Fuji' apple juice, and quality and antioxidant properties investigated. Bread was prepared with water, butter, yeast, salt, sugar, wheat flour, skim milk powder and 10, 20 and 30% (w/w) 'Fuji' apple juice. Leavening ability and pH of dough were also investigated. Volume, pH, specific volume, baking-loss rate, chromaticity and texture were investigated as quality properties, whereas the total polyphenol content, ABTS and DPPH radical scavenging activity as the antioxidant properties of bread containing various amount of apple juice. The pH and leavening ability of dough were observed to decrease with increasing amount of apple juice. In the quality properties of bread, pH, volume, specific volume, and baking-loss rate decreased. Regarding chromaticity and texture of bread prepared with increasing amount of 'Fuji' apple juice, L (bright) values at crust and crumb of bread decreased, while hardness, chewiness and gumminess increased. Total polyphenol content increased with increasing amount of apple juice, while DPPH and ABTS radical scavenging activities showed no significant differences. Consequently, these results support the possible use of apple juice for baking foods in food industry, as addition of apple juice enhances the quality and antioxidant properties of bread.

• 한국수자원학회논문집
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• 제54권2호
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• pp.135-144
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• 2021

본 논문은 근래 급속하게 진행되는 온난화가 수온의 상승과 수량 변동을 수반하여 수질에도 큰 영향을 줄 것으로 전망됨에 따라 방류량 및 수온과 오염도 지수간의 인과관계 분석을 통해 효율적인 수자원 관리 및 수질 개선을 위한 시사점을 도출하고자 하였다. 이를 위해 우리나라 주요 수계의 10개 다목적댐을 대상으로 방류량 및 수온, BOD, COD, DO 등 오염도 지수에 대해 시계열 자료를 활용하여 단위근 검정 및 공적분 검정, 그랜저 인과분석을 실시하여 방류량 보다는 수온이 오염도 지수와 더 많은 인과관계가 있어 수온의 변동이 방류량의 변동보다 오염지수에 더 영향을 미치는 것으로 분석되었다. 또한, 수질과 방류량의 인과관계가 높아 이에 따른 댐의 수량 및 수질관리가 가장 우수한 댐은 합천댐과 충주댐이었으며, 2순위 대청댐이었다. 다음으로 수질과 방류량의 인과관계가 낮은 3순위 그룹의 용담 및 안동댐, 4순위 그룹은 나머지 5개 댐으로 밝혀졌다.

• 동아시아식생활학회지
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• 제14권1호
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• pp.47-53
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• 2004

$\pi$-water는 일반적인 물과는 달리 뛰어난 침투성으로 인해 많은 기능성을 발휘하는 것으로 주목 받고 있다. $\pi$-water를 첨가하여 취반시 나타나는 노화속도의 지연 및 보존기간의 증가 등은 제빵 제품에서도 기대할 수 있으며 보다 신선한 상태로 보존 및 판매도 가능할 것이다. 따라서 $\pi$-water를 빵 제품에 사용하여 반죽의 변화와 발효 그리고 보존성을 측정 분석함으로서, $\pi$-water의 사용을 위한 기초 자료를 제공하고자 하였다. 실험은 $\pi$-water의 함량을 0.0%, 0.1%, 0.5%, 1.0%, 1.5% 비율로 높여가며 제빵시험, 색도측정, 제빵적성평가, 조직감 특성, 관능평가를 하여 제품의 품질과 상품성을 평가하였다. 제빵시험에서는 $\pi$-water를 많이 첨가한 반죽일수록 발효속도와 발효량이 컸으며 반죽의 끈적거리는 촉감을 느낄 수 있었다. 하지만 그 격차가 심하게 나타나지는 않았다. 제빵적성은 빵의 용적 비용적(specific volume)으로 평가하였는데 전체적으로 $\pi$-water의 함량이 높을수록 높이가 높고 가벼운 조직의 제품이 만들어졌다. 조직감 특성과 관능 평가는 식빵의 보존성을 평가하기 위하여 제조 3일 후 측정하였는데 0.1%의 $\pi$-water를 함유하고 있는 제품의 조직감이 가장 뛰어난 것으로 나타났고 전체적으로 함유량이 높을수록 좋은 조직감을 나타내었다. 하지만 관능평가에서는 0.1%를 함유한 제품을 제외한 나머지는 0.0% 함유하고 있는 제품보다 좋지 않은 것으로 나타났다. 전체적으로 $\pi$-water의 함량이 높을수록 조직이 부드럽고 씹힘성, 부피감이 좋아지는 등 0.1%정도의 $\pi$-water를 첨가하여 제조한 제품이 우월한 특성을 보였으며 관능평가 등을 고려할 때 0.1% 정도의 $\pi$-water 함유량이 가장 적합한 것으로 보이며 제품에 긍정적인 영향을 미치는 것으로 판단된다.

• 한국환경보건학회지
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• 제43권1호
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• pp.87-94
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• 2017

Objectives: This study was conducted to determine the impact of aquariums on indoor air quality for improving humidity and reducing indoor air pollutants. Methods: An air-conditioning chamber was used to determine humidity increase by aquarium volume at three different temperatures ($20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$). Humidity increase was measured for 21 hours ($20^{\circ}C$) and 12 hours ($25^{\circ}C$, $30^{\circ}C$) while placing five different volume of aquarium in the chamber. Concentrations of several volatile organic compounds and formaldehyde were measured after a known amount was injected into the chamber with and without an aquarium. Results: The humidity inside the chamber increased when the aquarium was inside the chamber. Humidity change was similar at $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$, but slightly higher at higher temperatures. The bigger the aquarium volume, the higher was the humidity increase that occurred. Humidity increase by the aquarium was sufficient to increase indoor humidity in winter and negligible in summer. Concentrations of some water-soluble indoor air pollutants and formaldehyde were decreased with the aquarium inside the chamber. Conclusions: An aquarium could increase indoor humidity in winter, while the humidity increase is negligible in summer. An aquarium could decrease some water-soluble indoor air pollutants, including formaldehyde. This result implies that an aquarium may have positive effects on indoor environmental quality.

• 한국관개배수논문집
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• 제21권1호
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• pp.55-63
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• 2014

A sedimentation basin for agricultural water quality improvement was researched to analyze the water quality purification characteristics. The sedimentation basin constructed at the inlet of Gamdon reservoir in Muan-gun, Jeollanam-do was selected as the research field of this study. The surface area of the sedimentation basin is $34,000m^2$, volume is $122,000m^3$, and hydraulic retention time is 0.3hr~7.3day. The average influent loading of SS was 156.6kg-SS/d, and the effluent loading was 67.5kg-SS/d with the average removal rate of 56.9%. The average influent loadings of BOD and COD were 33.0kg-BOD/d and 60.3kg-COD/d respectively, and the effluent loadings were 26.4kg-BOD/d and 48.6kg-COD/d with the average removal rate of 20.1% and 19.3% respectively. Therefore, the results of this study show that a sedimentation basin can purify SS and organic matters. The average influent loadings of T-N and T-P were 28.7kg-TN/d and 2.97kg-TP/d respectively, and the effluent loadings were 16.3kg-TN/d and 1.41kg-TP/d with the average removal rate of 43.0% and 52.6% respectively. In conclusion, the overall results of this study show that a sedimentation basin is a feasible alternative to purify organic matters and nutrients.

• 환경위생공학
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• 제21권3호
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• pp.61-72
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• 2006

This study was carried out for verification of efficiency of seawater exchange breakwater which was installed in joomoongin harbor for the first time in our country. The joomoongin harbor, where seawater exchange breakwater has been constructed, shows typical for fishery and tourist port city specifics of greatest pollutants discharge volume in spring and summer, when tourist inflow and fishery activity is most vigorous. On the East Sea seawater flux through seawater exchange breakwater for the smallest waves (up to 0.5 m) was found out to be $1,526-3,052m^3/day$. After construction of seawater exchange breakwater, Zone 1 and Zone 2 of stagnant water inside the port were found to be a lot improved. Zone 3, adjacent to outport area, was found to be lower comparing with Zone 1 and Zone 2. The results of statistical analysis show that comparing with water quality improvement effect before and after seawater exchange, water quality after installation of seawater exchange breakwater became much better, primarily because of physical change around the harbour.

• Preventive Nutrition and Food Science
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• 제22권3호
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• pp.246-250
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• 2017

This study was performed to investigate the quality characteristics of noodles made from four different potato varieties: Atlantic, Go-un, Sae-bong, Jin-sun, and wheat flour. Quality characteristics of five noodles were analyzed by general components analysis, cooking quality (rate of water absorption, cooking loss, and volume increase), and mechanical textural properties. Some variations existed in wheat- or potato-based noodles for the general components analysis, but no clear trend was observed. Higher values in the rates of water absorption, cooking loss, and volume increase were observed for the wheat flour noodle, while some variations were observed for potato noodles depending on the variety. The wheat flour noodles exhibited higher values of textural characteristics obtained from the texture profile analysis, except for adhesiveness. Higher gluten contents as well as lower ash contents in the wheat flour noodles compared to the potato noodles are thought to be the two key factors contributing to this finding.

• Journal of Crop Science and Biotechnology
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• 제10권3호
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• pp.133-140
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• 2007

Protein characteristics of Korean wheat were evaluated to determine the effects of protein content and quality on processing and textural properties of white salted noodles compared to US wheat flours with various wheat classes and commercial flours for making noodles. Protein quality parameters, which were independent of protein content and included SDS sedimentation volume with constant protein weight, mixograph mixing time and proportion of 50% 1-propanol insoluble protein, of Korean wheat flours with 2.2+12 subunits in high molecular weight glutenin subunit compositions were comparable to those of commercial flours for making noodles. Parameters related to noodle making, including optimum water absorption, thickness and color of noodle dough sheet, correlated with protein content and related parameters, including SDS sedimentation volume with constant flour weight, mixograph water absorption and gluten yield. No significant relationship was found in protein parameters independent of protein content. Hardness of cooked noodles from Korean wheats was lower than that of US wheat flours compared to similar protein content of commercial noodle flours. Adhesiveness, springiness and cohesiveness of cooked noodles from Korean wheats were similar to US wheat flours. Hardness of cooked noodles correlated with protein content and related parameters.

• 한국작물학회지
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• 제56권2호
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• pp.107-112
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• 2011

Oat flour was purchased and investigated for quality characteristics of oat bread. Antioxidant and flour pasting properties of oat flour, and water content, weight, volume, Hunter color value, texture of bread were measured. DPPH radical scavenging capacity (%) of oat extract was 68.49%. Pasting temperature of oat flour ranged between $66.60^{\circ}C$ and $70.93^{\circ}C$. Flour pasting properties of sample added with 10 and 30% oat flour was shown similar results compared with wheat flour. Final viscosity of sample was increased by adding concentration of oat flour (up to 311.65 RVA). Water content (%) of bread was shown increasing trend by adding oat flour. Weight of bread loaf with 100% oat flour was shown higher score than other samples. Volume of loaf by adding oat flour of 10, 30, and 50 % ratio was 550, 450, and 388 mL, respectively. The Hunter color $L^*$ values of bread by adding oat flour was dark compared with wheat bread. Color value of bread added 10% oat flour was similar results with $L^*$ values of bread with wheat flour. The bread added with 20 and 30% oat flours had the higher hardness, gumminess, and chewiness compared with other samples. Cohesiveness of the bread with wheat flour showed higher than that of bread added with oat flour and increased by storage period. The growth of total viable cell was inhibited depending on the concentration of oat flour during storage.