• Applied Microscopy
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• 제42권2호
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• pp.95-103
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• 2012

연잎효과는 연꽃의 잎에서 규명된 현상으로 표피세포에서 기원하는 미세구조에 의해 물방울이 잎 표면이나 내부조직에 침투하지 않고 경사면으로 흘러내리며 표면 위 먼지나 이물질을 함께 떨어지게 한다. 잎 표면을 항상 깨끗한 상태로 유지하는 자기정화 능력인 연잎효과에 대해서는 여러 영역에서 연구되고 다방면으로 응용되고 있으나 구조적인 측면에서 연잎을 생장단계별 또는 표피조직 부위별로 비교 조사한 연구는 거의 없는 실정이다. 이에 본 연구에서는 연잎과 줄기를 대상으로 생장단계별, 부위별 표피조직의 미세 표면구조를 연구하여 연잎효과 표면 특성을 조사하였다. 본 연구에서 조사된 연잎효과는 미세돌기와 왁스결정체가 발달한 잎의 상피조직에서만 나타나고, 왁스결정체만 발달한 하피 및 줄기의 표피조직에서는 확인되지 않았다. 이는 미세돌기의 발달이 연잎효과를 나타내는데 가장 중요한 요인이고, 왁스결정체가 돌기표면 위에 축적되면 연잎효과는 더 증가하는 것으로 밝혀졌다.

• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.340-347
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• 2008

This study was conducted to develop a recipe for a nutritional cookie with lotus root powder that had the optimal composition of ingredients and texture resulting in high preference by all age groups. Wheat flour was partially substituted with lotus root powder to reduce its content. Response Surface Methodology was used to analyze the measured results, which showed 16 experimental points including 2 replicates for lotus root powder, sugar and butter. The compositional and functional properties were measured, and these values were applied to a mathematical model. A canonical form and perturbation plot showed the influence of each ingredient on the final mixture product. The sensory evaluation results showed significant values in color (p<0.01), texture (p<0.05) and overall quality (p<0.05). As a result, the optimal sensory ratio was determined to be 22.59 g of lotus root powder, and 53.08 g of sugar for every 120 g of butter.

• Natural Product Sciences
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• 제25권1호
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• pp.44-48
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• 2019

Nelumbo nucifera Gaertn. (Nymphaeaceae) is commonly called lotus and its leaves are widely been used as functional ingredients due to its antioxidant activity. For maximum efficacy, optimized extraction condition was established using response surface methodology. The high F-values, low p-values and insignificant p-value for lack-of-fit supported the fitness of the model and yielded the second-order polynomial regression for the antioxidant activity. The optimized extract was obtained by the extraction of 1 g of lotus leaves with 40 mL of 50% MeOH at $10.0^{\circ}C$, which exerted 70.1% antioxidant activity. Close correlation between phenolic content and antioxidant activity suggested phenolic compounds as active constituents of lotus leaves. In addition, comparison of different parts of lotus demonstrated the most potent antioxidant activity of flowers, followed by leaves and roots. Taken together, these results provide useful information about lotus leaves for the development as antioxidant ingredients. In addition, flowers and roots as well as leaves are suggested as good sources for antioxidant activity.

• 한국식생활문화학회지
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• 제29권3호
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• pp.298-306
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• 2014

The purpose of this study was to investigate the quality characteristics of steamed bread using mixed flour containing bamboo leaf and lotus leaf powders. Properties of the steamed breads were tested by colorimeter, water activity, rheometer, SEM, and sensory tests. The L values and a values were higher in steamed bread with bamboo leaf powder. On the other hand, the b values of streamed bread with bamboo leaf powder were lower than lotus leaf powder. During storage, the hardness of steamed bread with bamboo leaf and lotus leaf powders increased control. Furthermore, steamed bread with lotus leaf powder showed hardness than bamboo leaf powder. The springiness of all steamed breads decreased with storage, and steamed breads with bamboo leaf powder showed lower values than lotus leaf powder. The cohesiveness of the control was the highest, and all samples showed significant differences each other. The gumminess of the control was higher than steamed bread with bamboo leaf and lotus leaf powders. Moreover, longer storage time yielded higher gumminess. control relatively smoother surface than that of 1% bamboo leaf powder. The steamed bread with lotus leaf powder had a rougher surface than bamboo leaf powder. sensory characteristics of steamed bread, green color of the samples with bamboo leaf powder was darker than lotus leaf powder. Leaf odor was similar throughout. Freshness of steamed bread containing 1% bamboo leaf powder the highest. The overall acceptability of consumer acceptance was the control, followed by steamed bread containing 1% lotus leaf powder.

• 한국해양공학회지
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• 제27권2호
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• pp.114-120
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• 2013

A superhydrophobic surface means that the contact angle between the solid surface and a water droplet is more than $150^{\circ}$. Materials with a superhydrophobic surface have a self-cleaning function because of the Lotus effect, in which water is not absorbed by the material but rolls off of it. If such a Lotus effect can be applied to the surface of underwater vessels, submarines, torpedos, and so on, enhanced vessels can be made based on this lubricant effect reducing the friction coefficient for the liquid. Because polymer composites can be easily applied in various nanotechniques, they are more advantageous than conventional materials like iron in terms of a superhydrophobic surface. Furthermore, a superhydrophobic surface bring enhanced anticorrosion and ecotechnology because no paint is needed on underwater vessels.

• Journal of Applied Biological Chemistry
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• 제53권4호
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• pp.232-238
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• 2010

In order to investigate the treatment efficiency of pollutants in free water surface constructed wetlands (FWS CWs) with lotus (Nelumbo nucifera) cultivation pond, the experiment was consisted of two sites (site I and II) in Lake Juam, Korea. The sites were configured a lotus cultivation pond (with fertilizer application) - a dropwort bed - a reed bed for site I, and a lotus cultivation pond (without fertilizer application) - a dropwort bed - a reed bed for site II. Removal rate of COD in site I and II were 13.3% and 26.0%, respectively. Removal rate of total nitrogen (TN) was 29.7% for site I, and 36.3% for site II. Removal rate of total phosphorus (TP) in site I and II were 36.0% and 36.5%, respectively. COD, TN and TP in effluent from site I (with fertilizer) was higher than that in site II (without fertilizer), showing that COD, TN and TP in effluent were strongly influenced by fertilizer addition. Therefore, in order to satisfy established water-quality standards, the amount of fertilizer used in lotus cultivation showed be evaluated.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.384.2-384.2
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• 2016

Recent publications reported the self-propelled jumping of coalescing dew droplets on superhydrophobic surfaces [1-2]. We further investigated the initial growth, coalescence, and removal by self-propelled ejection of nano and microscopic water droplets on the superhydrophobic surface of lotus leaves under condensing conditions. By using a high-speed digital camera mounted on an optical microscope, we have found: (1) sub-micrometer droplets form and grow on nanoscale waxy hairs; (2) growing droplets coalesce rapidly upon contact, but never jump off the surface unless the diameter of merged droplets exceeds ${\sim}15{\mu}m$; (3) the diameter and direction of jumping droplets are very narrowly distributed, centered at $20-30{\mu}m$ and ${\sim}20$ degrees from the surface normal, respectively. We present a rationale for these observations on the basis of: (a) the hierarchically rough surface structure on nano- and micro-scales; (b) its chemical composition; and (c) the balance among competing forces of cohesion (surface tension), adhesion and gravity.

• 한국산학기술학회논문지
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• 제16권9호
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• pp.5756-5762
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• 2015

본 논문에서는 자연에서 영감을 얻은 생체 모방 공학 중의 하나인 연잎 효과에 초점을 맞추었다. 생체 모방 공학은 자연의 시스템을 관찰하여 동식물, 곤충 등의 구조와 기능을 모방하여 공학적으로 활용하는 것이다. 나노 기술의 발전은 생체 모방 공학의 발전도 함께 일으켜왔다. 본 과제에서는 연잎 표면의 소수성과 특징에 대해 살펴본 뒤 나노 측정 장비인 SEM (주사선전자 현미경)과 AFM (원자력간 현미경)을 이용하여 측정 후 비교, 분석하였다. 연잎의 표면에는 수많은 나노 돌기들이 존재하며, 그 작은 돌기들이 소수성을 갖게 하고 표면장력을 극대화 시키는 역할을 한다. 연잎의 표면에서는 물방울이 동그랗게 모여 있는 것을 볼 수 있는데 그것을 연잎 효과라고 하며, 나노 돌기로부터 생성된 효과이다. 이러한 연잎의 표면을 배율 별로 2D와 3D로 측정하여 분석하였다. 또한, 그 결과를 기존의 법칙들에 어떻게 적용되는지 살펴보았으며 나아가 소수성을 판별할 수 있는 새로운 방법에 대해 논의하여 보고자 하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.389-390
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• 2012

In this study, we fabricate a superhydrophobic surface made of hierarchical nanostructures that combine wax crystalline structure with moth-eye structure using vacuum cluster system and measure their hydrophobicity and durability. Since the lotus effect was found, much work has been done on studying self-cleaning surface for decades. The surface of lotus leaf consists of multi-level layers of micro scale papillose epidermal cells and epicuticular wax crystalloids [1]. This hierarchical structure has superhydrophobic property because the sufficiently rough surface allows air pockets to form easily below the liquid, the so-called Cassie state, so that the relatively small area of water/solid interface makes the energetic cost associated with corresponding water/air interfaces smaller than the energy gained [2]. Various nanostructures have been reported for fabricating the self-cleaning surface but in general, they have the problem of low durability. More than two nanostructures on a surface can be integrated together to increase hydrophobicity and durability of the surface as in the lotus leaf [3,5]. As one of the bio-inspired nanostructures, we introduce a hierarchical nanostructure fabricated with a high vacuum cluster system. A hierarchical nanostructure is a combination of moth-eye structure with an average pitch of 300 nm and height of 700 nm, and the wax crystalline structure with an average width and height of 200 nm. The moth-eye structure is fabricated with deep reactive ion etching (DRIE) process. $SiO_2$ layer is initially deposited on a glass substrate using PECVD in the cluster system. Then, Au seed layer is deposited for a few second using DC sputtering process to provide stochastic mask for etching the underlying $SiO_2$ layer with ICP-RIE so that moth-eye structure can be fabricated. Additionally, n-hexatriacontane paraffin wax ($C_{36}H_{74}$) is deposited on the moth-eye structure in a thermal evaporator and self-recrystallized at $40^{\circ}C$ for 4h [4]. All of steps are conducted utilizing vacuum cluster system to minimize the contamination. The water contact angles are measured by tensiometer. The morphology of the surface is characterized using SEM and AFM and the reflectance is measured by spectrophotometer.

• 대한영양사협회학술지
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• 제26권1호
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• pp.1-13
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• 2020

This study was undertaken to optimize preparation of sweet rice muffins using lotus (Nelumbo nucifera Gaertn) seed powder. The experimental conditions used in the preparation included lotus seed powder (X₁) and soybean oil (X₂). The muffin formulation was optimized using rheology. Lightness (P<0.01) displayed a quadratic model pattern, whereas yellowness (P<0.01) and redness (P<0.05) was presented a linear model. Texture properties significantly differed in cohesiveness (P<0.05). Evaluating the sensory characteristics of muffins, except for flavor and texture, the remaining properties of color (P<0.01), taste, overall quality, and appearance (P<0.05) were found to be significantly different. The overall quality was also affected by the proportion of lotus seed powder, rather than the amount of soybean oil. The optimal ratio for palatability of muffins was determined to be 47.80 g lotus seed powder and 95.28 g soybean oil. Taken together, our results indicate that sweet rice muffins prepared using lotus seed powder are sufficiently competitive in terms of function and quality.