• Title/Summary/Keyword: Strength properties

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Influence of Lipid Contents in Human Hair on the Hair Volume and Hair Frizzing Phenomena (모발 내부 지질 함량이 모발 부피 변화 및 잔머리 프리즈에 미치는 영향)

  • Song, Sang-Hun;Im, Byung Taek;Hwang, Byung Woo;Joo, Jang Ho;Son, Seongkil;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.2
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    • pp.89-103
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    • 2020
  • A frizz hair is referred to the fly-away hairs that have become bulky or deviated from the regular hair and the cause of that is not clear known. The internal lipids are related to the physical properties of hair such as elasticity and tensile strength and interracial studies have previously conducted to relate the lipid mass and Afrikaan hair, which has a lot of frizzy hair. Although washing hair is the only way to control the hair loss without damage of hair surface, the number of washing and lipid loss are not linearly correlated. In this study, the amount of lipid hair was analyzed by washing the hair with a few different types of shampoos containing various conditioning polymers and oils of different polarities. The results confirmed that the higher the polarity of the oil, the higher the lipid content. This method was applied to Indian frizzy hair to evaluate the degree of frizziness and found that the frizzy volume was more severe for a hair with less lipids. On the other hand, the frizzy hair volume of fly-away hairs was observed more broadly for the hairs with higher lipid contents. In addition, the friction on the surface of the hair did not differ due to the oil treatment. Taken together, it was concluded that hair frizzing was affected by the amount of lipids in the hair rather than by the adhesion between the oils. Thus, this study suggests that controlling the lipid contents in hair may be an important solution in the development of hair anti-frizzy technology.

Finite Element Analysis of Reinforced Concrete Masonry Infilled Frames with Different Masonry Wall Thickness Subjected to In-plane Loading (채움벽 두께에 따른 철근콘크리트 조적채움벽 골조의 면내하중에 대한 유한요소해석)

  • Kim, Chungman;Yu, Eunjong;Kim, Minjae
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.1
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    • pp.85-93
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    • 2016
  • In this study, finite element analyses of masonry infilled frames using a general purpose FE program, ABAQUS, were conducted. Analysis models consisted of the bare frame, infilled frames with masonry wall thickness of 0.5B and 1.0B, respectively. The masonry walls were constructed using the concrete bricks which were generally used in Korea as infilled wall. The material properties of frames and masonry for the analysis were obtained from material tests. However, four times increased the tensile strength was used for 1.0B wall, which is seemingly due to the differences in locating the bricks. The force-displacement relation and development of crack from the FE analysis were very similar to those from the experiments. From the FEA results, contact force between the frame and masonry, distribution of shear force and bending moments in frame members were analyzed. Obtained contact stress shows a trianglur distribution, and the contact length for 0.5B speciment and 1.0B specimen were close to the value estimated using ASCE 41-06 equation and ASCE 41-13 equation, respectively. Obtained shear force and bending moment distribution seems to replicate actual behavior which originates from the contact stress and gap between the frame and masonry.

Structures and some Properties of the Antimicrobial Compounds in the Red Alga, Symphyocladia latiuscula (참보라색우무에서 추출한 항균물질의 구조 및 특성)

  • LIM Chi-Won;LEE Jong-Soo;CHO Young-Je
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.4
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    • pp.280-287
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    • 2000
  • Three antimicrobial compounds (SL-l, SL-2 and SL-3) were isolated and identified from the marine red alga, Symphyocladia latiuscula. In addition, their biological functionalities such as cytotoxicity and desmutagenic activity were investigated. From the cryophyllized S. JatiuscuJa, SL-l, SL-2 and SL-3 were purified by solvent extractions and HPLC.SL-2 was crystallized in benzene-diethyl ether solvent. On the EI-MS spectra, it was found that they had three bromines in their structure which showed typical signal strength ratios at $M^+, [M+2]^+, [M+4]^+, [M+6]^+ (13: 38: 37: 12)$. $SL-l$ was identified as 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol ($C_8H_7Br_3O_3, MW=374$) by NMR and MS spectra. SL-2 was assigned as 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether ($C_8H_7Br_3O_3, MW=388$) and confirmed by X-ray crystallographic analysis. SL-3 was presumed as an isomer of SL-2. Methanol extract of the S. latiuscula showed antimicrobial activities against all strains tested (bacteria, 15 strains; yeasts, 17 strains; fungi, 4 strains), much or less. The strongest inhibition activity of the methanol extract was to the Vibrio mimicus ($50 {\mu}g/ml$) and V. vulnificus ($50 {\mu}g/ml$). The mice injected intraperitoneally with 3 mg of SL-l and 5 mg of 5L-2 showed no acute toxicity response. SL-2 showed higher desmutagenic activity than SL-l against PhIP and MeIQx.

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A Trial for Preparation of Jam using Sea Mustard Stem (미역줄기를 이용한 잼의 제조조건)

  • AHN Chang-Bum;SHIN Tai-Sun;NAM Taik-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.423-430
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    • 2000
  • Preparation of sea mustard stem jam (SMSJ) with addition of commercial ingredients, sucrose, high methoxyl pectin (HM pectin) or low methoxyl pectin (LM pectin), organic acid (or its salt), and synthetic strawberry flavor to sea mustard stem paste was investigated. The sea mustard stem paste was produced by crushing sea mustard stem and homogenizing it with 2.5 times water of sea mustard stem, then followed by filtering ($30{\~}35 mesh$), The effects of those ingredients on the physical properties and the sensory score of SMSJ were evaluated. The SMSJ prepared with combination of $65{\%}$ (w/w) sugar, $1.0{\%}$ (w/w) pectin, and $0.3{\%}$ (w/w) citric acid or with combination of $65{\%}$ (w/w) sugar, $1.0{\%}$ (w/w) U pectin, and $0.08{\%}$ (w/w) calcium lactate, which finally adjusted to $62{\cdot}Brix$, was similar to commercial strawberry or apple jam in gel strength, Addition of over $0.06{\%}$ (v/w) synthetic strawberry flavor to sea mustard stem paste showed a good effect of masking the undesirable sea mustard flavor.

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Synthesis of Novel Prepolymers Containing No Bisphenol A and Preparation of Organic Matrices for Dental Applications (비스페놀 A를 함유하지 않은 치과용 신규 프리폴리머의 합성 및 유기 매트릭스의 제조)

  • Son, Jun-Sik;Lee, Ki-Baek;Park, Kwi-Deok;Kim, Jae-Jin;Ahn, Kwang-Duk;Kim, Jung-Hyun;Han, Dong-Keun
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.538-544
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    • 2006
  • Two kinds of novel bifunctional methacrylated prepolymers (170-2MA and 631-2MA) which have similar structure with 2,2-bis[4- (2'-hynroxy-3'-methacryloyloxypropoxy)phenyl] propane (Bis-GMA) was synthesized for dental applications as an alternative to Bis-GMA containing bisphenol A that is doubtful as an endocrine disrupter. The organic matrices were prepared by mixing a diluent and/or a monomer with the synthesized methacrylated prepolymers. The yield, viscosity, and chemical structures of the prepolymers and the physical and methanical properties of the organic matrices were evaluated. The yields of the prepolymers synthesized through a ring-opening reaction of epoxy compound and methacrylic acid were above 90% and the viscosities of the prepolymers were much lower than that of the Bis-GMA control. From the results of $^1H-NMR$ and FTIR analyses, the chemical structures of the prepolymers were similar to that of Bis-GMA. In addition, the curing time, poly-merization shrinkage, photoconversion, polymerization depth, and compressive strength of the organic matrices formulated with 170-2MA and 631-2MA prepolymers exhibited comparable to or better than those of the existing Bis-GMA-based one. These results suggest that the novel methacrylated prepolymers which have no endocrine disrupter can be an alternative to Bis-GMA and be applicable to dental polymer materials.

Development of Structural Glued Laminated Timber with Domestic Cedar (국산 삼나무를 이용한 구조용 집성재 이용기술)

  • Kim, Kwang-Mo;Shim, Sang-Ro;Shim, Kug-Bo;Park, Joo-Saeng;Kim, Wun-Sub;Kim, Byoung-Nam;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.3
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    • pp.184-191
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    • 2009
  • In the southern part of the Korean Peninsula including Jeju-island, the production amount of domestic cedar has increased gradually. However, their low qualities, expected to be caused by the low density and frequent knots, have restricted their practical utilization as the high value-added products. In this study, it is aimed to look for the new uses of domestic cedar and to examine the applicability for lamination lumbers of structural glued laminated timber (glulam). Above all, machine stress ratings for individual sawn lumbers confirmed that modulus of elasticity (MOE) of cedar lumber was lower than that of other common softwood species in Korea. On the other hand, cedar lumbers have enough stiffness to manufacture the structural glulam in accordance with Korean Industrial Standard (KS). The bonding strength and durability also met the KS limitation. Nevertheless, from the result of bending tests for cedar glulam, it was shown that the modulus of elasticity (MOE) did not meet the KS limitation. Therefore, it was concluded that additional researches were needed for reinforcing the stiffness of cedar glulam.

Characterization and Comparative Evaluation of Milk Protein Variants from Pakistani Dairy Breeds

  • Yasmin, Iqra;Iqbal, Rabia;Liaqat, Atif;Khan, Wahab Ali;Nadeem, Muhamad;Iqbal, Aamir;Chughtai, Muhammad Farhan Jahangir;Rehman, Syed Junaid Ur;Tehseen, Saima;Mehmood, Tariq;Ahsan, Samreen;Tanweer, Saira;Naz, Saima;Khaliq, Adnan
    • Food Science of Animal Resources
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    • v.40 no.5
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    • pp.689-698
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    • 2020
  • The aim of study was to scrutinize the physicochemical and protein profile of milk obtained from local Pakistani breeds of milch animals such as Nilli-Ravi buffalo, Sahiwal cow, Kajli sheep, Beetal goat and Brela camel. Physicochemical analysis unveiled maximum number of total solids and protein found in sheep and minimum in camel. Buffalo milk contains the highest level of fat (7.45%) while camel milk contains minimum (1.94%). Ash was found maximum in buffalo (0.81%) and sheep (0.80%) while minimum in cow's milk (0.71%). Casein and whey proteins were separated by subjecting milk to isoelectric pH and then analyzed through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed heterogeneity among these species. Different fractions including αS1, αS2, κ-casein, β-casein and β-lactoglobulen (β-Lg) were identified and quantitatively compared in all milk samples. Additionally, this electrophoretic method after examining the number and strength of different protein bands (αS1, αS2, β-CN, α-LAC, BSA, and β-Lg, etc.), was helpful to understand the properties of milk for different processing purposes and could be successfully applied in dairy industry. Results revealed that camel milk was best suitable for producing allergen free milk protein products. Furthermore, based on the variability of milk proteins, it is suggested to clarify the phylogenetic relationships between different cattle breeds and to gather the necessary data to preserve the genetic fund and biodiversity of the local breeds. Thus, the study of milk protein from different breed and species has a wide range of scope in producing diverse protein based dairy products like cheese.

An Experimental Study on the Engineering Properties of Lightweight Aggregate Concrete (경량골재 콘크리트의 공학적 성질에 관한 실험적 연구)

  • ;R. N. Swanmy
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.1
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    • pp.75-82
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    • 1997
  • 건설기술과 산업의 발전에 따라 구조물은 대형화되어 가고, 건설공사의 급격한 팽창으로 골재 수용량이 급증함에 따라 천연골재자원은 점차 부족현상을 면치 못할 처지에 있다. 또한, 무리한 천연골재의 채취는 자연환경을 훼손시킬 뿐만 아니라 자연보호 측면에서도 심각한 공해문제로 대두되고 있어 공급량 부족현상은 날로 심화되고 있다. 이에 세계 몇몇 나라에세는 산업부산물을 이용한 골재 생산으로 공해예방과 폐기물 활용방법을 연구하고 있다. 산업부산물중 플라이 애쉬 생산량은 전 세계적으로 매년 약 2억여톤에 달하고 있으나 이중 일부만 활용되고 있는 실정이다. 이와같은 부산물을 활용하기 위한 일환으로 산업부산물인 PFA(Pulverized Fuel Ash)로 만든 인공경량골재의 년생산량이 영국은 600,000$m^3$, 미국은 300,000$m^3$이며, 매년 증가주세에 있다. 고성능 경량골재 콘크리트는 단위중량의 증가없이 내구성과 강도를 향상시켜 실용화 측면에서 경제적인 효과가 있으며, 플라이 애쉬로 만든 경량골재는 시멘트와의 친화력이나 접착면에서 우수한 것으로 알려져 있다. 본 시험에 사용한 골재는 플라이 애쉬로 만든 인공경량 조골재와 강모래이고, 결합제로서 프틀랜드 시멘트를 사용하였다. 부수적인 결합재로서는 플라이 애쉬, 슬래그, 실리카 흄을 사용하였으며, 고성능 경량골재 콘크리트를 개발코자 재령 28일과 180일의 압축강도가 각각 50MPa와 60MPa가 되도록 배합설계를 하였다. 본 연구에서는 플라이 애쉬, 슬래그, 시리카 흄과 같은 산업부산물을 혼입했을때 경량골재 콘크리트의 압축강도, 휨강도, 동탄성계수, 공극체적, 공극률, 단위중량, 공극 크기별 분포등의 변화를 실험적으로 구명하여 재반 구조용 콘크리트에 활용하기 위한 기초자료를 마련코저 한다.있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가

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Physicochemical Properties of Jelly Prepared with Garlic (마늘을 이용하여 제조한 젤리의 이화학적 품질 특성)

  • Jung, Eun-Young;Lee, Hyun-Sun;Oh, Yoon-Ho;Son, Heung-Soo;Suh, Hyung-Joo
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.4
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    • pp.627-634
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    • 2009
  • In this study, the physicochemical and sensory characteristics of jellies prepared with various types and amounts of garlic were investigated; jellies with dried garlic powder (0.5%, 1%, 1.5%, 2%), jellies with $50^{\circ}$ brix fresh garlic extract (0.5%, 1%, 1.5%, 2%), jellies with $15^{\circ}$ brix black garlic extract (5%, 10%, 15%, 20%). The total polyphenols, flavonoids and crude protein contents of the black garlic extract were similar to those of the fresh garlic extract. The ability of the black garlic extract to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzthiazoline-6 -sulfonate) (ABTS) radicals were significantly (p<0.01) higher than those of the fresh garlic extract. The Hunter b values decreased as the amount of added garlic increased. In addition, the hardness and gel strength of texture also decreased as the amount of added garlic increased. The flavor preference of jellies prepared with the dried garlic powder (1% and 1.5%) was significantly lower compared to normal jelly (p<0.05). Jelly prepared with 20% black garlic extract showed the highest texture preference of all the tested jellies (p<0.05). There were no significant differences in color, taste and overall preference between normal jelly and garlic jellies.

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Analysis of Optimum Antenna Placement Considering Interference Between Airborne Antennas Mounted on UAV (무인항공기 탑재 안테나 간 간섭을 고려한 안테나 최적 위치 분석)

  • Choi, Jaewon;Kim, Jihoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.6
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    • pp.32-40
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    • 2015
  • In this paper, the optimum antenna placement is analyzed by considering the interference between airborne antennas mounted on the unmanned aerial vehicle(UAV). The analysis is implemented by selecting the antennas that the distance and operational frequency band between airborne antennas is close to each other among the omni-directional antennas. The analyzed antennas are the control datalink, TCAS(Traffic Collision & Avoidance System), IFF(Identification Friend or Foe), GPS(Global Positioning System), and RALT(Radar ALTimeter) antennas. There are three steps for the optimum antenna placement analysis. The first step is selecting the antenna position having the optimum properties by monitoring the variation of radiation pattern and return loss by the fuselage of UAV after selecting the initial antenna position considering the antenna use, type, and radiation pattern. The second one is analyzing the interference strength between airborne antennas considering the coupling between airborne antennas, spurious of transmitting antenna, and minimum receiving level of receiving antenna. In case of generating the interference, the antenna position without interference is selected by analyzing the minimum separation distance without interference. The last one is confirming the measure to reject the frequency interference by the frequency separation analysis between airborne antennas in case that the intereference is not rejected by the additional distance separation between airborne antennas. This analysis procedure can be efficiently used to select the optimum antenna placement without interference by predicting the interference between airborne antennas in the development stage.