• Journal of Biosystems Engineering
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• 제29권6호
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• pp.521-530
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• 2004

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which electrical power is not available. The average solar radiation power is $3.488\;kWh/(m^2{\cdot}day)$ in Korea. In this study, the experimental system of the water pump driven by the radiation energy were designed, assembled, tested and analyzed fur realizing the solar powered water pump. Energy conversion ken radiation energy to mechanical energy by using n-pentane as operating material was done and the water pumping cycles were able to be continued. The quantity of the water pumped per cycle ranged from 2 L to 10 L depending on the level of the valve open area far the vapour supply. The average quantity was about 4,366 cc. The thermal efficiency was about $0.018\%$. The pressure level of the n-pentane vapour in flash tank was about $110\~150\;kPa$ and that in the water tank was $93\~130\;kPa$. The pressure in the condenser during cycles was maintained as about 70 kPa. The condensation of the n-pentane vapour in the water tank was increased with the cycles even though the internal and external insulation were done. Air tank performance was better with increasing of the water piston displacement and the water could be pumped with the water piston displacement becoming higher than 6,500 cc.

• 한국식품과학회지
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• 제39권2호
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• pp.209-216
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• 2007

본 연구에서는 뽕잎 당단백질의 활성을 알아보기 위하여 뽕잎 당단백질의 안정성 및 특성을 알아보고, hydroxyl 라디칼, superoxide anion 라디칼, DPPH 라디칼 등의 활성 산소종에 대한 항산화 효과를 살펴보았다. 또한 Raw 264.7 세포에 환경호르몬의 일종인 BPA와 뽕잎 당단백질(32 kDa)을 함께 처리 하여, 뽕잎 당단백질의 활성산소종과 NO의 소거 능력뿐만 아니라 염증 매개성 단백질들 [$NF-{\kappa}B(p50)$와 iNOS]의 활성 억제능력 대하여 평가하였다. 뽕이 당단백질은 금속이온에는 다소 약하지만 온도와 pH에는 안정적인 특징을 지니고 있었으며, 탁월한 hydroxyl 라디칼, superoxide anion 라디칼, DPPH 라디칼 소거 능력을 가지고 있었다. 이러한 항산화 능력을 지닌 뽕잎 당단백질을 BPA와 함께 Raw 264.7 세포에 처리한 결과, BPA만 처리된 Raw 264.7 세포의 활성 산소종 양은 8시간째에, 그리고 NO 양은 24시간째에 현저히 증가한데 반해, BPA와 함께 뽕잎 당단백질을 처리한 Raw 264.7 세포에서는 같은 시간 동안에 농도에 비례하여 활성 산소종 및 NO양이 유의적으로 감소한 것을 알 수 있었다. 또한 8시간 동안 BPA처리에 의해 활성화된 Raw 264.7 세포의 $NF-{\kappa}B(p50)$와 iNOS 단백질들은 함께 처리한 뽕잎 당단백질의 농도에 비례하여 현저히 억제되었다. 따라서, 이러한 결과를 종합해 보면, 뽕잎 당단백질은 높은 안정성과 강력한 항산화 효과를 가지고 있었으며, 이러한 항산화 효과가 환경 호르몬(BPA)에 의한 활성산소종 및 NO 생성을 저해할 뿐만 아니라, $NF-{\kappa}B(p50)$와 iNOS의 활성을 억제함으로써 Raw 264.7 세포의 염증 신호전달을 막는데 영향을 끼쳤을 것으로 생각 된다.

• 수산해양기술연구
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• 제52권4호
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• pp.325-338
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• 2016

Properties of aggregation and spatial distribution of fish were examined based on three lines in the South Sea of Korea using three frequencies (18, 38, and 120 kHz) of a scientific echosounder. The vertical distribution of fish was displayed using acoustic biomass namely nautical area scattering coefficient (NASC). As a result, at 120 kHz high NASC showed from water surface to 20 meters in deep while at 18 and 38 kHz very high NASC presented in 70 ~ 90 meters in depth, especially at line 3. Among three lines, the line 2 had lowest NASC. The horizontal distribution of fish using three frequencies together exhibited high NASC between the eastern South Sea and center of South Sea. In especial, NASC ($801{\sim}1,920m^2/n{\cdot}mile^2$) was observed along coastal waters from Busan to Tongyeong, Geoje, and Namhae. In regard with the property of aggregation of fish schools, the volume back-scattering strength ($S_V$) of three lines presented close each other, however, the range of $S_V$ in the line 2 was shortest (-53.5 ~ -43.4 dB). The average distributional depth was deep in the order of L3 ($32.8{\pm}9.0m$), L1 ($45.2{\pm}9.5m$), L2 ($49.7{\pm}5.6m$). The average altitude was high in the order of L3 ($13.4{\pm}10.3m$), L1 ($17.0{\pm}12.6m$), L2 ($56.7{\pm}5.6m$). The average length, thickness, and area were large in the order of L1, L3, and L2. This means that small sized fish schools were distributed near water surface in the line 2 while relatively large and similar sized fish aggregations between line 1 and line 3 appeared however, fish schools at line 3 had lower distributional depth and smaller compared to those at line 1. Acoustic data were visualized for demonstrating the entire circumstances of survey area. Additionally, there was no correlation between acoustic and trawl results.

• 전기학회논문지
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• 제57권11호
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• pp.2015-2022
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• 2008

The effect of content of $Al_2O_3+Y_2O_3$ sintering additives on the densification behavior, mechanical and electrical properties of the pressureless-sintered $SiC-ZrB_2$ electroconductive ceramic composites was investigated. The $SiC-ZrB_2$ electroconductive ceramic composites were pressurless-sintered for 2 hours at 1,700[$^{\circ}C$] temperatures with an addition of $Al_2O_3+Y_2O_3$(6 : 4 mixture of $Al_2O_3$ and $Y_2O_3$) as a sintering aid in the range of $8\;{\sim}\;20$[wt%]. Phase analysis of $SiC-ZrB_2$ composites by XRD revealed mostly of $\alpha$-SiC(6H), $ZrB_2$ and In Situ YAG($Al_5Y_3O_{12}$). The relative density, flexural strength, Young's modulus and vicker's hardness showed the highest value of 89.02[%], 81.58[MPa], 31.44[GPa] and 1.34[GPa] for $SiC-ZrB_2$ composites added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at room temperature respectively. Abnormal grain growth takes place during phase transformation from $\beta$-SiC into $\alpha$-SiC was correlated with In Situ YAG phase by reaction between $Al_2O_3$ and $Y_2O_3$ additive during sintering. The electrical resistivity showed the lowest value of $3.l4{\times}10^{-2}{\Omega}{\cdot}cm$ for $SiC-ZrB_2$ composite added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at 700[$^{\circ}C$]. The electrical resistivity of the $SiC-TiB_2$ and $SiC-ZrB_2$ composite was all negative temperature coefficient resistance (NTCR) in the temperature ranges from room temperature to 700[$^{\circ}C$]. Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of SiC-based electroconductive ceramic composites.

• 수산해양기술연구
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• 제40권3호
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• pp.196-205
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• 2004

종횡비, 다각형 모양에 따른 평판과 범포의 유체역학적 특성을 규명하고자 직사각형, 사다리꼴 모양으로 모형 평판과 범포를 제작하고 회류수조에서 양 ${\cdot}$ 항력 실험을 수행하였다. 그 결과를 요약하면 다음과 같다. 1. 직사각형 평판의 경우, 종횡비가 1 이하인 모형에서는 영각 40${\sim}$42$^{\circ}$에서 최대 $C_L$이 1.46${\sim}$1.54, 1.5 이상인 모형에서는 20${\sim}$22$^{\circ}$에서 10.7${\sim}$1.11 정도였다. 직사각형 범포의 경우, 종횡비가 1 이하인 모형에서는 영각 32${\sim}$40$^{\circ}$에서 최대 $C_L$이 1.75${\sim}$1.91, 1.5 이상인 모형에서는 18${\sim}$22$^{\circ}$에서 1.248${\sim}$1.40 정도였다. 같은 직사각형 모형에서는 범포가 평판보다 $C_L$은 크게, 양항비는 작게 나타났다. 2. 사다리꼴 범포의 경우, 종횡비가 1.5 이하인 모형에서는 영각 34${\sim}$44$^{\circ}$에서 최대 $C_L$이 1.65${\sim}$1.89, 2인 모형에서는 14${\sim}$48$^{\circ}$에서 $C_L$이 약 1.00 전후였다. 역사다리꼴 범포의 경우, 종횡비가 1.5 이하인 모형에서는 영각 24${\sim}$36$^{\circ}$에서 최대 $C_L$이 1.57${\sim}$1.74, 2인 모형에서는 18$^{\circ}$에서 1.21이었다. 같은 사다리꼴 범포 모형에서는 전자의 모형이 후자보다 $C_L$은 조금 크게, 양항비는 작게 나타났다. 3. 모형에서 물의 유체력을 많이 받을 수 있는 곳에서 만곡꼭지점이 만들어지며, 직사각형, 사다리꼴 모형에서는 종횡비가 클수록, 역사다리꼴 모형에서는 종횡비가 클수록, 역사다리꼴 모형에서는 작을수록 만곡꼭지점의 위치도 컸다. 4. 만곡도는 전 모형에서 종횡비가 클수록 컸으며, 직사각형, 사다리꼴 모형에서 영각의 클수록 컸고 직사각형 모형이 사다리꼴 모형보다 컸다.

• Applied Biological Chemistry
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• 제46권1호
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• pp.16-22
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• 2003

갈색에서부터 흑자색까지의 색상을 가지는 국.내외에서 수집한 23종류 유색미의 항산화 활성, 색소체 함량의 변기 및 상관성을 검정하였다. 유색미 에탄올 추출물 시료가 나타내는 환원력은 일반미 품종인 추청에 비해서 거의 모든 품종에서 높게 나타났으며, 환원력이 특히 높은 품종은 LK 1-3-6-12-1-1, Elwee, DZ 78, Jumlalocal-1, SC-45 등이었다. 전자공여능이 높은 품종은 HP 883-1-1-1-B-1-1, HP 833-1-3-1-1-1, LK-2-7-12-1-1, DZ 78 등이었고 hydroxy radical 소거활성이 큰 품종은 DK-1, IR 1544-38-2-2-1-2-2, SC-5, SC-45 등이었으며, LK 2-7-12-1-1은 오히려 산화촉진효과를 나타내는 품종이었다. 자동산화에 의한 지질 과산화물 형성을 강하게 억제하는 품종들은 RGS No. 336, LK IB-2-1-1, LK 1B-4-12-1-1, LK 1A-2-12-1-1, LK 2-7-12-1-1, HP 833-1-1-1-B-1-1등이었고 Elwee, Jumlalocal-1, SC-45 등의 품종은 산화적인 활성을 나타내고 있었다. 23품종의 유색미 중에서 색소체의 함량이 가장 많은 품종은 Elwee이었으며, 색소체 함량은 환원력과 정의 상관성이 있었고, 추출물이 고농도로 처리되었을 때 높은 환원력을 보인 유색미 품종은 linoleic acid 자동산화반응에서 지질 과산화를 촉진하는 경향이 있었다. 유색미 23품종 중에서 SC-5는 모든 반응계에서 비교적 높은 항산화 활성을 나타내었다.

• 한국식품과학회지
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• 제26권6호
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• pp.770-775
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• 1994

포장김치의 유통기간 연장과 관련하여 저장은도(0, 10, $20^{\circ}C$)별로 발효가스 압력변화와 PH, 총산합량, 색상 및 관능적 품질변화를 측정하여 그 상관관계를 검토하였다. 발효가스압력은 각 온도에서 모두 일정 정체기틀 갖은 후 S자형으로 증가하는 경향을 나타내었으며, 저장 중 가스압력이 중가함에 따라 $20^{\circ}C$에서는 40시간, $10^{\circ}C$에서는 5일,$0^{\circ}C$에서는 30일 이후부터 포장이 팽대하기 시작하였다. 이때의 각 포장구 내루압력은 $1.2{\sim}1.4\;psig$ 범위였고 이후 가스압력이 계속 증가하여 $20^{\circ}C$에서 저장 3일째, $10^{\circ}C$에서 저장 8일째에 포장이 파열되었으나$0^{\circ}C$에서는 파열되지 않았다. 또한 가스압력이 증가할수록 pH는 비례적으로(r>0.968) 감소하였으며, 총산 함량은 비례적으로(r>0.973) 중가하였다. 김치액상의 색변화에서 L과 b값은 지수적으로 감소하였으나 a값은 서서히 증가하였고, 김치 숙성과 관련있는 색지수$(L{\cdot}b/a)$도 저장중 지수적으로 감소하였다. 관능검사 결과, 신맛온 pH가 감소함에 따라 증가하였고 조직감은 점차 감소하였으며, 전체 기호도는 $20^{\circ}C$에서 저장 2일후에 가장 높았다가 5일후부터 현저히 낮아졌고, $10^{\circ}C$에서는 저장 5일후에 가장 기호도가 높았으며, $0^{\circ}C$에서는 24일까지 전체 기호도가 증가하다가 그 이후에 서서히 감소하였다. 결론적으로 저장온도가 높을수록 저장기간 중 김치 자체는 상미를 유지함에도 불구하고 포장이 팽대되는 현상이일어나므로서 상품성을 잃는 결과를 초래하였다.

• 한국폐기물자원순환학회지
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• 제34권2호
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• pp.205-213
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• 2017

The current study was performed to investigate the effect of recycling coir substrates on the growth, fruit yield, and quality of strawberry plants. Analysis of physical properties revealed that the pH of a fresh coir substrate was 5.04 while those of substrates reused for one and two years were 5.20 and 5.33, respectively. The electrical conductivity (EC) of a new substrate was as high as $4.58dS{\cdot}m^{-1}$. This can cause salt stress after transplanting. The EC tended to decrease as the substrate was recycled, and the EC of a two-year recycled substrate was $1.48dS{\cdot}m^{-1}$. The fresh substrate had lower nitrogen and calcium concentrations, but higher phosphate, potassium, and sodium concentrations than the recycled coir substrate. The coir substrates recycled for one or two years maintained better chemical properties for plant growth than the fresh substrate. Strawberry growth varied depending on the number of years that the coir substrate was recycled. In general, strawberries grown in substrates that had been reused for two years did better than those grown in substrates that had been reused once or were fresh. Ninety days after transplanting, a plant grown in a substrate that had been reused for two years contained 25 leaves, which was 3.6 more than with a fresh substrate. In addition, the plants grown in a substrate that had been reused for two years exhibited larger leaf areas than those grown in other substrates. Coir substrates that had been reused for one year increased the number and area of leaves, but not as much as the substrate that had been reused for two years. One- and two-year reused coir substrates increased the weight of strawberries produced relative to the unused substrate, but the difference was not statistically significant. The plants grown in two-year reused substrates were longer and wider, as well. Also, the number of fruits per plant was higher when substrates were reused. Specifically, the number of fruits per plant was 28.7 with a two-year reused substrate, but only 22.2 with a fresh substrate. The fruit color indices (as represented by their Hunter L, a, b values) were not considerably affected by recycling of the coir substrate. The Hunter L value, which indicates the brightness of the fruit, did not change significantly when the substrate was recycled. Neither Hunter a (red) nor b (yellow) values were changed by recycling. In addition, there were no significant changes in the hardnesses, acidities, or soluble solid-acid ratios of fruits grown in recycled substrates. Thus, it is thought that recycling the coir substrate does not affect measures of fruit quality such as color, hardness, and sugar content. Overall, reuse of coir substrates from hydroponic culture as high-bed strawberry growth substrates would solve the problems of new substrate costs and the disposal of substrates that had been used once.

• 동아시아식생활학회지
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• 제15권6호
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• pp.728-737
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• 2005

This study was conducted to evaluate the physicochemical characteristics of pound cake made of substituted flour with different amount of $\beta-glucan$ i.e. 3, 6 and $9\%$ respectively. $\beta-glucan$ is a functional food material produced from Agrobacterium sup. R259 KCTC 10197BP. The specific gravity and pH of dough were found to be increased according to $\beta-glucan$ content Rheological property such as adhesiveness of dough has no difference between control and $\beta-glucan$ added groups. The pH of baked pound cake was not significantly different between control and $\beta-glucan$ groups. The volume of baked pound cake wag not significantly different between control and the ones with up to $6\%$ $\beta-glucan$, Lightness (L), redness (a) and yellowness (b) value of Hunter color system of cake crumb were not significantly different among teated groups, except a value of crust in $9\%$ $\beta-glucan$ group. the moisture content of cake increased according to $\beta-glucan$ content. Hardness by texture analyser was decreased with increasing $\beta-glucan$ content although cohesiveness wag not changed in β$\beta-glucan$ groups, compared with the control. Sensory evaluation results showed that the mean scores of over·all acceptability in 3 and $6\%$ $\beta-glucan$ were higher than that of control. Based on these results, the addition of $\beta-glucan$ to pound cake up to $6\%$ was considered to be desirable especially in terms of texture.

• Journal of Neurogastroenterology and Motility
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• 제24권4호
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• pp.570-576
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• 2018

Background/Aims Swallows with viscous or solid boluses in different body positions alter esophageal manometry patterns. Limitations of previous studies include lack of standardized viscous substrates and the need for chewing prior to swallowing solid boluses. We hypothesize that high-resolution impedance manometry (HRiM) using standardized viscous and super-viscous swallows in supine and upright positions improves sensitivity for detecting esophageal motility abnormalities when compared with traditional saline swallows. To establish normative values for these novel substrates, we recruited healthy volunteers and performed HRiM. Methods Standardized viscous and super-viscous substrates were prepared using "Thick-It" food thickener and a rotational viscometer. All swallows were administered in 5-mL increments in both supine and upright positions. HRiM metrics and impedance (bolus transit) were calculated. We used a paired two-tailed t test to compare all metrics by position and substrate. Results The 5-g, 7-g, and 10-g substrates measured 5000, 36 200, and 64 $700mPa{\cdot}sec$, respectively. In 18 volunteers, we observed that the integrated relaxation pressure was lower when upright than when supine for all substrates (P < 0.01). The 10-g substrate significantly increased integrated relaxation pressure when compared to saline in the supine position (P < 0.01). Substrates and positions also affected distal contractile integral, distal latency, and impedance values. Conclusions We examined HRiM values using novel standardized viscous and super-viscous substrates in healthy subjects for both supine and upright positions. We found that viscosity and position affected HRiM Chicago metrics and have potential to increase the sensitivity of esophageal manometry.