• 폴리머
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• 제39권2호
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• pp.311-316
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• 2015

고경도의 LED 봉지재로 치밀한 구조를 가지는 polyhedral oligomeric silsesquioxane(POSS)를 첨가제로 사용한 실리콘 젤을 제조하였다. 실록산 수지와의 상용성을 증가시키기 위하여 알킬기와 올리고실록산기를 가지로 갖는 POSS를 합성하였다. Hydrosilylation 반응을 통하여 가지와 POSS를 연결하였고, 1-decanol과 9-decen-1-ol의 반응에는 $H_2PtCl_6$을, 말단에 비닐기를 가지는 올리고실록산의 반응에는 1,3-divinyl tetramethyldisiloxane[Pt(dvs)]을 촉매로 사용하였다. 알킬기를 가지는 POSS(Decyl-POSS, Decenyl-POSS)를 사용한 실리콘 젤의 경우 실록산 수지와의 혼화성이 낮아서, 가시광선 영역의 투과도가 낮았으며 경도값도 낮았다. 이에 비해 올리고실록산기를 가지로 가지는 POSS(Siloxy-POSS)를 적용하였을 경우에는 실록산 수지와 혼화성이 우수하여 높은 투명도를 보였으나, POSS의 첨가로 인한 경도 증가는 뚜렷하게 나타나지 않았다.

• 한국식품조리과학회지
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• 제7권4호
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• pp.63-69
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• 1991

1. 이화학적 특성 1) 선화녹두의 일반성분 조성은 수분 13.19%, 지방 1.02%, 단백질 23.57%, 회분 3.13%였고 선화녹두 조전분의 일반성분 조성은 수분 12.45%, 지방0.63%, 단백질 0.94%, 회분 0.13%로 나타났다. 2) 거피시킨 녹두로부터 얻은 건조 전분(수분 12.48%)의 수율은 22.84% 이었고 이는 통 녹두로부터의 수율로 환산하면 20.35%로 도토리 전분의 수율과 비교해 볼 때 전분 함랑이 상당히 낮은 것으로 나타났다. 3) 물결합 능력은 183.1%였고 팽윤력은 온도가 높아짐에 따라 증가하는 양상인데 $70^{\circ}C$까지는 미약하게 증가하나 그 이상의 온도가 되면서 팽윤도가 현저하게 증가하였다. 또한 용해도의 변화도 팽윤도와 비슷한 양상을 보였다. 4) amylose와 amylopectin함량은 22.5%, 77.5%로 나타났고 amylograph에 의한 조전분의 호화는 8%와 10% 전분에서 모두 최고 점도가 나타났으며 농도에 따른 차이는 점성의 크기에만 나타났고 전체적인 양상은 비슷했다. 2. 기계적 검사결과 기계적 검사 결과는 8% 녹두 전분 Gel과 10% 녹두전분 Gel에서 같은 양상이었다. 지방 첨가량이 증가할수록 Hardness와 Fractuability는 감소하는 경향이었고 Elasticity, Adhesiveness, Chewiness는 증가하는 경향을 보였으며 L, a, b값도 증가하는 경향을 보임으로서 지방 함량이 증가할수록 명도는 높고 적색 및 황색에 가까와짐을 알 수 있다. 또한 $\Delta$E 값도 지방 첨가량이 많아질수록 증가하는 경향을 보였다. 이상의 결과에서 지방의 첨가는 녹두전분 Gel의 Texture에 상당한 영향을 미치는 것으로 평가되었다. 따라서 관능검사까지 실험을 확대하여 주관적 평가를 하고자 하며 기계적 특성과 관능적 특성간의 상호 관련성에 대하여 연구를 계속하고자 한다.

• 한국식품저장유통학회지
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• 제20권3호
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• pp.372-378
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• 2013

본 연구는 폴리페놀이 다량 함유되어 있는 복숭아씨(桃仁)를 분말상태로 우리나라의 전통 식품인 청포묵에 적용하여 품질특성 및 항산화성에 미치는 영향을 알아보았다. 복숭아씨 분말의 비율을 각각 0, 0.5, 1.0, 1.5%로 하여 제조한 청포묵은 비율이 높아질수록 명도(L)와 적색도(a)는 낮아지는 경향을 보였으나, 황색도(b)는 1.5%에서 가장 높은 값인 -58.96을 나타내었다. 청포묵의 기계적 품질 특성은 대조군이 모든 특성면에서 가장 높았고, 복숭아씨 분말이 첨가될수록 경도, 응집성, 탄력성, 씹힘성, 부서짐성이 모두 유의적으로 낮아지는 경향을 보였다. 총 폴리페놀 함량의 경우는 복숭아씨 분말을 첨가한 청포묵이 대조군에 비해 높았으며 복숭아씨 분말을 1.5% 첨가하였을때 가장 높은 값을 나타내었다. 또한 복숭아씨 분말 첨가량이 높은 청포묵이 높은 DPPH 라디칼소거능을 나타내었다. 관능적 품질 특성은, 다른 관능적 특성은 비슷한 경향을 보였으나 향과 맛에 있어서는 차이점을 보였다. 특히 0.5%를 첨가한 청포묵에서 향 6.0점, 맛 5.5점으로 가장 높은 기호도를 보였고, 첨가량이 증가하게 되면 오히려 기호도가 줄어드는 경향을 보였다. 이러한 결과를 종합해 보면, 기호도 측면에서 대조구와의 차이가 크지 않은 0.5%를 첨가하는 것이 청포묵의 항산화성도 증진시키고 기계적 및 관능적 품질 특성에도 기여할 것으로 사료된다.

• 한국축산식품학회지
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• 제38권1호
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• pp.14-25
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• 2018

Chemical compositions, trypsin inhibitory activity, and gelling properties of albumen from duck egg during salting of 30 days were studied. As the salting time increased, moisture content decreased, the salt content and surface hydrophobicity increased (p<0.05). Trypsin inhibitory activity and specific activity were continuously decreased throughout the salting time of 30 days (p<0.05). This coincided with the decrease in band intensity of inhibitor with molecular weight of 44 kDa as examined by inhibitory activity staining. Nevertheless, no differences in protein patterns were observed in albumen during the salting of 30 days. Based on texture profile analysis, hardness, springiness, gumminess, chewiness, and resilience of albumen gel decreased with increasing salting time. Conversely, salted albumen gels exhibited higher cohesiveness and adhesiveness, compared to those of fresh albumen. Scanning electron microscopic study revealed that gel of salted albumen showed the larger voids and less compactness. In general, salting lowered trypsin inhibitory activity and gelling property of albumen from duck egg to some extent. Nevertheless, the salted albumen with the remaining inhibitor could be an alternative additive for surimi or other meat products to prevent proteolysis.

• Restorative Dentistry and Endodontics
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• 제41권3호
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• pp.196-201
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• 2016

Objectives: The aim of this in vitro study was to evaluate the effect of incorporating three different nanobiomaterials into bleaching material on microhardness of bleached enamel. Materials and Methods: The crowns of 24 extracted sound human molars were sectioned. Sixty enamel specimens ($2{\times}3{\times}4 mm$) were selected and divided into five groups (n = 12): Group 1 received no bleaching procedure (control); Group 2 underwent bleaching with a 40% hydrogen peroxide (HP) gel; Groups 3, 4, and 5 were bleached with a 40% HP gel modified by incorporation of bioactive glass (BAG), amorphous calcium phosphate (ACP) and hydroxyapatite (HA), respectively. The enamel microhardness was evaluated. The differences in Knoop microhardness data of each group were analyzed by one-way ANOVA, followed by post hoc Tukey tests. Results: Significant differences were observed between the study groups. The enamel microhardness changes in Groups 1, 3, 4, and 5 were significantly lower than that of Group 2 (p < 0.001). Conclusions: Within the limitations of this study, it can be concluded that incorporation of each one of the three tested biomaterials as remineralizing agents might be effective in decreasing enamel microhardness changes subsequent to in-office bleaching.

• 한국재료학회지
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• 제26권5호
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• pp.271-280
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• 2016

When a single inorganic precursor is used for the synthesis of a sol-gel coating, there is a problem of cracking on the surface of coating layer. In order to solve this problem of surface cracking, we synthesized inorganic-organic coatings that have hybrid properties of inorganic and organic materials. Sols of various ratios (1:0.07, 0.2, 0.41, 0.82, 1.64, 3.26, 6.54, 13.2) of an inorganic precursor of Tetrabutylorthotitanate ($Ti(OBu)_4$, TBOT) and an organic precursor of ${\gamma}$-Methacryloxy propyltrimethoxysilane (MAPTS) were prepared and coated on stainless steels (SUS316L) by dip coating method. The binding structure and the physical properties of the synthesized coatings were analyzed by FT-IR, FE-SEM, FIB (Focused Ion Beam), and a nano-indenter. Dynamic polarization testing and EIS (electrical impedance spectroscopy) were carried out to evaluate the micro-defects and the corrosion properties of the coatings. The prepared coatings show hybrid properties of inorganic oxides and organic materials. Crack free coatings were prepared when the MAPTS ratio was above a critical value. As the MAPTS ratio increased, the thickness and the corrosion resistance increased, and the hardness decreased.

• Food Science and Biotechnology
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• 제18권4호
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• pp.900-903
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• 2009

An oat gum was extracted from whole seeds of a drought harvested oat (Avena sativa). Oat gum presented a ${\beta}-glucan$ content of 65%(w/w) and an intrinsic viscosity of 141 mL/g. Gelling capability of oat gum at different concentrations was investigated. Gel hardness increased from 0.08 to 0.25 N as the oat gum concentration changed from 5 to 10%(w/v). Whippability, foam stability, emulsion stability, and reduced viscosity of oat gum at different pH were also investigated. Oat gum whippability was maximum at pH 7 (146%), while the higher foam and emulsion stability values were found at pH 9 (88 and 96%, respectively). The gum reduced viscosity increased from 715 to 958 mL/g as the pH changed from 7 to 9. Oat gum shows great potential as a gel forming, thickening, and stabilizing agent.

• 한국지역사회생활과학회지
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• 제17권2호
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• pp.61-68
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• 2006

This Study was conducted to investigate the processing quality of high-amylose content rice(goami) flour for noodle. The potassium and magnesium contents of rice flour were negatively associated with gross score of noodle making mixed with wheat flour. The high-amylose content of rice flour was closed associated with gel consistency negatively and with hardness of rice noodle positively, Setback viscosity of rice flour measured in a rapid visco-analyser(RVA) was significantly affected by amylose content as well as gel consistency. Also the amylose content decreased, the amylogram pasting temperature and the breakdown ratio increased. The low-amylose content rice(Chucheong) flour showed higher values in solubility. Cooking quality and texture were measured, and sensory evaluation was performed with the noodles prepared. Texture measurement showed that the noodles of composite flour containing 40% goami rice flour were superior to those wheat flour alone. Water binding capacity of the composite flour containing 40% goami rice flour was lower than that of 40% chucheong rice flour. In sensory evaluation, chewiness, overall acceptability of noodle with 40% goami ricer was evaluated as the best.

• 한국식품과학회지
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• 제21권4호
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• pp.486-491
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• 1989

단립종인 천마벼, 중립종인 용문벼, 장립종인 Mahatma등 3품종 설에 대한 취반미의 텍스쳐 특성과 아밀로오스의 분자량 분포를 rheometer와 겔 크로마토그래피 방법을 통하여 연구하였다. Mahana 품종 쌀로 만든 밥은 천마벼나 용문벼로 만든 밥보다 경도가 컸고 부착성이 낮았다. 가용성 아밀로오스는 경도와 정의 상관관계가 있었으나 총 아밀로오스 함량이나 불용성 아밀로오스 함량과는 뚜렷한 상관관계를 보이지 않았다. 분리한 아밀로오스의 ${\beta}-amylolysis$ limit는 $77.2{\sim}78.5%$였으며 iodine binding capacity는 $16.5{\sim}18.2%$였다. 겔 크로마토그래피에 의하여 분리한 아밀로오스의 분자량 분포는 천마벼, 용문벼, Mahatma의 순으로 컸다.

• 한국재료학회지
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• 제23권1호
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• pp.72-80
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• 2013

Recently, consumption of magnesium alloys has increased especially in the 3C (computer, communication, camera) and automobile industries. The structural application of magnesium alloys has many advantages due to their low densities, high specific strength, excellent damping and anti-eletromagnetic properties, and easy recycling. However, practical application of these alloys has been limited to narrow uses of mild condition, because they are inferior in corrosion resistance and wear resistance due to their high chemical reactivity and low hardness. Various wet and dry processes are being used or are under development to enhance alloy surface properties. Various conversion coating and anodizing methods have been developed in a view of eco-friendly concept. The conventional technologies, such as diffusion coating, sol-gel coating, hydrothermal treatment, and organic coating, are expected to be newly applicable to magnesium alloys. Surface treatments for metallic luster or coloring are suggested using the control of the micro roughness. This report reviews the recent R&D trends and achievements in surface treatment technologies for magnesium alloys.