• 한국식품과학회지
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• 제25권5호
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• pp.552-557
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• 1993

대두 펩타이드의 아미노산 조성 및 평균소수도가 혈청 콜레스테롤의 농도에 미치는 영향을 조사하기 위하여, 대두 단백질(ISP), 카세인(CNP), 이들 단백질을 펩신으로 가수분해하여 pH에 다른 펩타이드 침전 획분들(SHT, SH8, SH6, SH4, CHT) 및 각 단백질과 같은 조성의 아미노산 혼합물(SAA, CAA)을 흰쥐에 섭취시키고 혈청콜레스테롤 농도를 측정하였다. 각 펩타이드의 아미노산 조성을 분석하고, 이로부터 구한 Lys/Arg 비율 및 소수성 아미노산의 몰분율은 혈청 콜레스테롤의 농도와 상관관계가 없었으며, Tanford, Manavalan 및 Meirovitch법으로 구한 평균소수도와도 상관관계가 없었다. 그러나, Krigbaum법으로 구한 평균소수도와는 상관계수가 -0.736으로 음의 상관관계이어서, 식이 펩타이드의 krigbaum 평균소수도가 높을 수록 래트의 혈청 콜레스테롤 농도가 낮아졌다.

• 대한수의학회지
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• 제39권3호
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• pp.554-559
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• 1999

The purpose of this study was to evaluate effect of chitosan-oligosaccharides (CHIOL) on hydrophobicity of pathogenic E coli including a field isolate from suckling piglet with diarrhea, E coli-O157 : H7, and E coli-O149 : K88ac. E coli field isolate appeared adhesion of 100% to n-hexadecane between 0.00125% and 0.05% CHIOL. E coli-O157 : H7 occurred adhesion of 69% and 64% under the level of 0.00125% and 0.025% CHIOL, respectively. E coli-O149 : K88ac showed adhesion of 100% in higher than 0.025% CHIOL. For cationic action, the adhesion of E coli isolate and E coli-O149 : K88ac to n-hexadecane were inhibited at level of higher than 10mM $Ca^{2+}$ but did not induce any difference among the concentrations used(p < 0.01). However, the adhesion of E coli-O157 : H7 to n-hexadecane was inhibited at level of higher than 50mM $Ca^{2+}$. In a field trial, control piglets showed average mortality of up to 58% during 3 days after the onset of diarrhea. In contrast, the prevalence of E coli-induced diarrhea in CHIOL-treated groups without mortality was dropped down to average 34% on the 1st day after the treatment of CHIOL, and average 2% on the 4th day. After then, piglets with diarrhea was not present. In conclusion, the low concentrations of CHIOL were most likely to associate with the enhancement of hydrophobicity to pathogenic E coli. Calcium inhibited the hydrophobicity of E coli by CHIOL. These results suggested that CHIOL could be played an efficient and reliable role in treating enteric colibacillosis of piglets.

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1073-1077
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• 2002

Binding of dodecyl trimethylammonium bromide (DTAB) to human and bovine hemoglobin and globin samples has been investigated in 50 mM glycine buffer pH = 10, I = 0.0318 and 300 K by equilibrium dialysis and temperature scanning spectrophotometry techniques and method for calculation of average hydrophobicity. The binding data has been analyzed, in terms of binding capacity concept $({\theta})$, Hill coefficient (nH) and intrinsic Gibbs free energy of binding $({\Delta}Gbv).$ The results of binding data, melting point (Tm) and average hydrophobicity show that human hemoglobin has more structural stability than bovine hemoglobin sample. Moreover the results of binding data analysis represent the systems with two and one sets of binding sites for hemoglobin and globin, respectively. It seems that the destabilization of hemoglobin structure due to removal of heme group, is responsible of such behavior. The results indicating the removal of heme group from hemoglobin caused the depletion of first binding set as an electrostatic site upon interaction with DTAB and exposing the hydrophobic patches for protein.

• 한국식품과학회지
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• 제17권4호
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• pp.276-282
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• 1985

단백발효식품에서의 쓴맛 펩타이드의 특성을 규명하기 위하여 여러 시료로부터 소수성 펩타이드를 2 1(v/v) chloroform-methanol로 추출하였다 이 중 모짜렐라치즈와 된장으로부터 얻은 쓴맛 텝타이드 추출물을 다시 Sephadex C-25 겔 크로마토그라피한 결과 분획 I II, III을 얻었는데 이들 시료 자체와 각각의 크로마토그라피 분획을 구성하고 있는 펩타이드의 아미노산 조성을 분석하여 평균소수도를 계산하였다. 시료들 자체는 쓴 맛을 나타내지 않았으나 용매로 추출된 소수성 펩타이드 분획은 강한 쓴 맛을 나타내었다. 시료의 용매추출 수율은 총 질소 함량의 0.08내지 62.50%의 범위로 나타났다. 모짜렐라치즈 질소물의 평균 소수도는 1.376cal/mole, 용매추출 분획은 1.623cal/mole. 젤 크로마토그라피 분획 I은 1,797cal/mole, 분적 II 는 2,454cal/mole, 분획 III은 1,559cal/mole 이었다. 된장의 경우 된장 자체, 용매추출 분획, 겔 크로마토그라피 분획 I, II, III의 평균소수도는 각각 1,229. 1,654, 1900, 2016, 998cal/mole 이었다. 쓴맛 펩타이드에서 중요한 아미노산을 leucine, Phenylal anine. p-roline, valine으로 나타났다.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.598-606
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• 2000

In this paper we investigated the relation between the surface degradations and anti-pollution characteristics of Room Temperature Vulcanized(RTV) silicone rubber coating that has different roughness through immersing into saline water. We utilized several analytic techniques such as atomic force microscopy(AFM) scaning electron microscopy(SEM) contact angle Salt Deposit Density(SDD) and average leakage current under the condition of salt fog. It is found that the surface roughness of treated RTV silicone rubber increased and the hydrophobicity of sample surface decreased with increasing the duration o immersion into water due to the erosion of base polymer the melting down alumina trihydrate(ATH) and the diffusion of Low Molecular weight(LMW) fluid. Despite the roughness of surface had been increased by water immersion excellant anti-pollution and recovery characteristics were maintained and SDD saturated to 0.1~0.14mg/cm$^2$. The average leakage current under salt fog increased with surface roughness. Measurement of average leakage current will be helpful to investigate surface degradation and lifetime expectation of RTV silicone coating.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.886-889
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• 2001

Silicone rubber is being used for the housing material of outdoor high voltage insulators such as composite insulator, bushing, surge arrestor and cable terminator because of good tracking and erosion resistance, good hydrophobicity and recovery of hydrophobicity and chemical stability. But, the leakge current occurs on surface of the composite polymeric insulation materials when the insulator is used for a long time with severe contaminative condition and it can lead the contamination flashover. So the leakage current is important to estimate the condition of the silicone rubber surface. In this paper, aging characteristics of silicone rubber used for outdoor insulation have been hydrophobicity of silicone rubber in salt fog chamber with average leakage current monitoring for observing the transformation of surface degradation properties of silicone rubber with different ATH(alumina trihydrate, A1$_2$O$_3$$.$3H$_2$O) filler contents. The experimental results show that a higher peak leakage current and to raise a long time for tracking with increasing amount of ATH by the salt fog and heat recycle ageing.

• 한국식품과학회지
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• 제29권3호
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• pp.417-426
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• 1997

미강을 혈중 콜레스테롤 저하 효과가 있는 기능성 식품소재의 원료로 활용하는 데 필요한 기초 자료를 얻기 위하여 미강 단백질의 가수 분해물을 제조하여 담즙산 결합 획분을 분리하고 일부 물리화학적 특성을 조사하였다. 미강 단백질을 탈지 미강으로부터 알칼리 추출과 등전점 침전 방법을 이용하여 제조하였다. 미강 단백질을 기질로 하여 pH-drop method로 측정한 효소의 상대적 활성과 가수분해시 가수분해율의 변화를 비교 평가하여 기질의 가수분해에 적합한 효소를 선택하였다. Esperase에 의한 가수분해물을 한외여과(MWCO : 10 kDa)하여 두 부분으로 나누었다. 각 분획물을 cholic acid를 공유결합 시킨 ${\omega}-aminohexyl$ Sepharose 4B column에 걸어, 소수성 상호작용에 의해 cholic acid와 결합하는 폴리펩티드 및 펩티드를 deoxycholate 완충용액으로 용출시켜 분리하였다. 겔투과 크로마토그래피(Sephadex G-50)를 이용하여 한외여과 여과백의 담즙산 결합물에 대해 분자량 분포를 측정한 결과, 대부분 $2\;kDa{\sim}10\;kDa$에 걸쳐 넓게 분포하였고 일부는 $0.2\;kDa{\sim}0.6\;kDa$사이에 존재하였다. 한외여과 잔류액의 담즙산 결합물에 대해서는 preparative reverse phase HPLC를 실시하여 미강 단백질 가수분해물에서 3개(R-1, 2, 3)의 Peak를 분리하였다. 각 peak의 총 아미노산과 유리 아미노산 조성을 분석하여 단백질, 폴리펩티드 및 펩티드 부분의 아미노산 조성을 조사하였다. 그 결과 미강 단백질 가수분해물에서 얻은 peak의 경우 proline 함량이 미강 단백질의 4배에 달했고, 평균 소수도가 높은 peak일수록 유리 아미노산이 함량이 높았으며 평균 소수도는 미강 단백질보다 다소 높은 것으로 나타났다.

• Corrosion Science and Technology
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• 제18권6호
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• pp.232-242
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• 2019

In this study, hydrophobically modified fumed silica was added to the PVDF coating to improve corrosion protection performance. Two types of silane modifiers, trimethylchlorosilane (TMCS) and hexamethyldisilazane (HMDZ), were used for hydrophobic modification of the fumed silica. The composition of modified fumed silica was analyzed by Fourier transform infrared, X-ray photoelectron spectroscopy, and elemental analysis. The dispersion of modified fumed silica in the PVDF coating was observed by the transmission electron microscopy, and the hydrophobicity of PVDF coating was analyzed by the water contact angle. Surface properties were examined by the field emission scanning electron microscopy and scanning probe microscopy. Potentiodynamic polarization was conducted to confirm corrosion protection performance of PVDF coating in terms of hydrophobically-modified fumed silica contents. As a result, the average surface roughness and the water contact angle of the PVDF coating increased with modifier contents. The results of the potentiodynamic polarization test showed an increase of the E_corr values with increase of the hydrophobicity of PVDF coating. Thus, it clearly indicates that the corrosion protection performance of PVDF coating improved with the addition of the hydrophobic-modified fumed silica that prevents the penetration of moisture into the PVDF coating.

• 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.

• 한국수산과학회지
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• 제51권5호
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• pp.542-548
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• 2018

We investigated the effects of Na-alginates's average molecular weight (AMW), their concentrations and divalent metal ions on hydrophobic interaction of solution of Na-alginates in sea tangle produced Saccharina japonicus in East Coast of Korea. As the AMWs of Na-alginates decreased, the formations rates of hydrophobic micro domains and pre-micelles between intermoleculars of Na-alginates were increased. The pre-micelles between Na-alginates chains fully were formed when their concentrations reached 0.2%. In the effects of $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ on the hydrophobicity of Na-alginates solution, when the AMWs of Na-alginates were increased, the formation rates of hydrophobic micro domains produced by $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ in alginates chains were increased. When $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ concentrations that were needed to form gels of alginates solutions were insufficient, the formations of pre-micelle in alginates having large AMW were more incomplete than those of small AMW. In the increasing range from 0.01 to 0.1 mM in divalent metal ion concentration, the formation rate of pre-micelle in alginates solution added $Ca^{{+}{+}}$ were more faster than that of $Mg^{{+}{+}}$.