• Title/Summary/Keyword: adhesion test

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The Study of Nano-vesicle Coated Powder (나노베시클 표면처리 분체의 개발연구)

  • Son, Hong-Ha;Kwak, Taek-Jong;Kim, Kyung-Seob;Lee, Sang-Min;Lee, Cheon-Koo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.32 no.1 s.55
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    • pp.45-51
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    • 2006
  • In the field of makeup cosmetics, especially, powder-based foundations such as two-way cake, pact and face powder, the quality of which is known to be strongly influenced by the properties of powder, surface treatment technology is widely used as a method to improve the various characteristics of powder texture, wear properties, dispersion ability and so on. The two-way cake or pressed-powder foundation is one of the familiar makeup products in Asian market for deep covering and finishing purpose. In spite of the relent progress in surface modification method such as composition of powders with different characteristics and application of a diversity of coating ingredient (metal soap, amino acid, silicone and fluorine), this product possess a technical difficulty to enhance both of the adhesion power and spreadability on the skin in addition to potential claim of consumer about heavy or thick feeling. This article is covering the preparation and coating method of nano-vesicle that mimic the double-layered lipid lamellar structure existing between the corneocytes of the stratum corneum in the skin for the purpose of improving both of two important physical characteristic of two-way cake, spreadability and adhering force to skin, and obtining better affinity to skin. Nano-vesicle was prepared using the high-pressure emulsifying process of lecithin, pseudo ceramide, butylene glycol and tocopheryl acetate. This nano-sized emulsion was added to powder-dispersed aqueous phase together with bivalent metal salt solution and then the filtering and drying procedure was followed to yield the nano-vesicle coated powder. The amount of nano-vesicle coated on the powder was able to regulated by the concentration of metal salt and this novel powder showed the lower friction coefficient, more uniform condition of application and higher adhesive powder comparing with the alkyl silane treated powder from the test result of spreadability and wear properties using friction meter and air jet method. Two-wav cake containing newly developed coated powder with nano-vesicle showed the similar advantages in the frictional and adhesive characteristics.

A Study on Damage factor Analysis of Slope Anchor based on 3D Numerical Model Combining UAS Image and Terrestrial LiDAR (UAS 영상 및 지상 LiDAR 조합한 3D 수치모형 기반 비탈면 앵커의 손상인자 분석에 관한 연구)

  • Lee, Chul-Hee;Lee, Jong-Hyun;Kim, Dal-Joo;Kang, Joon-Oh;Kwon, Young-Hun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.7
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    • pp.5-24
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    • 2022
  • The current performance evaluation of slope anchors qualitatively determines the physical bonding between the anchor head and ground as well as cracks or breakage of the anchor head. However, such performance evaluation does not measure these primary factors quantitatively. Therefore, the time-dependent management of the anchors is almost impossible. This study is an evaluation of the 3D numerical model by SfM which combines UAS images with terrestrial LiDAR to collect numerical data on the damage factors. It also utilizes the data for the quantitative maintenance of the anchor system once it is installed on slopes. The UAS 3D model, which often shows relatively low precision in the z-coordinate for vertical objects such as slopes, is combined with terrestrial LiDAR scan data to improve the accuracy of the z-coordinate measurement. After validating the system, a field test is conducted with ten anchors installed on a slope with arbitrarily damaged heads. The damages (such as cracks, breakages, and rotational displacements) are detected and numerically evaluated through the orthogonal projection of the measurement system. The results show that the introduced system at the resolution of 8K can detect cracks less than 0.3 mm in any aperture with an error range of 0.05 mm. Also, the system can successfully detect the volume of the damaged part, showing that the maximum damage area of the anchor head was within 3% of the original design guideline. Originally, the ground adhesion to the anchor head, where the z-coordinate is highly relevant, was almost impossible to measure with the UAS 3D numerical model alone because of its blind spots. However, by applying the combined system, elevation differences between the anchor bottom and the irregular ground surface was identified so that the average value at 20 various locations was calculated for the ground adhesion. Additionally, rotation angle and displacement of the anchor head less than 1" were detected. From the observations, the validity of the 3D numerical model can obtain quantitative data on anchor damage. Such data collection can potentially create a database that could be used as a fundamental resource for quantitative anchor damage evaluation in the future.

Isolation and Characterization of Lactic acid bacteria Leuconostoc mesenteroides DB3 from Camellia japonica Flower (백꽃으로부터 분리한 Leuconostoc mesenteroides DB3의 특성)

  • Sam Woong Kim;Da Hye Shin;Sang Wan Gal;Kyu Ho Bang;Da Som Kim;Won-Jae Chi
    • Journal of Life Science
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    • v.33 no.11
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    • pp.915-922
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    • 2023
  • Lactic acid bacteria (LAB) are widespread in a variety of environments including fermented dairy products, gastroinstetinal and urogenital tracts of human and animals, plant, soil and water. Leuconostoc mesenteroides DB3 was detected by the strongest antibacterial activities among 24 Leuconostoc strains isolated from Camellia japonica flowers. Acid tolerance of L. mesenteroides DB3 existed up to pH 2.5, but the resistance did not show at pH 2.0, which relatively excellent acid resistance existed. Bile acid tolerance was very stable within the test range to 1.2%. L. mesenteroides DB3 exhibited the optimal growth at 30℃, and showed a slight slow growth when compared with L. mesenteroides KCTC3505, which reached a stationary phase at 18 hr. The pH was changed along with the growth curve, but was maintained above pH 3.98. L. mesenteroides DB3 had higher initial antibacterial activities when compared to L. mesenteroides KCTC3505, but it showed similar activities with the standard strain after the latter part of the logarithmic growth phase. Although lactic acid production in L. mesenteroides DB3 was induced by lower amount in the initial part to the standard strain, it was exhibited by similar amounts after the late logarithmic growth phase. Muicin adhesion of L. mesenteroides DB-3 maintained superior to L. mesenteroides KCTC3505. Both strains showed excellent emulsification ability for kerosene. In summary, we evaluate that L. mesenteroides DB-3 has a high potential for application as probiotics owing to its excellent antibacterial activity, acid resistance, bile acid resistance, and muicin adhesion.

Experimental Study on Long-term Characteristics of Sprayable Waterproofing Membrane (차수용 박층 멤브레인의 장기 성능 변화에 관한 실험 연구)

  • Choi, Soon-Wook;Kim, Jintae;Choi, Myung-Sik;Chang, Soo-Ho;Kang, Tae-Ho;Lee, Chulho
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.4
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    • pp.15-23
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    • 2019
  • The sprayable waterproofing membrane is a recently introduced material in the civil engineering field, and is a material that sprays and attaches a single phase or two phase powder or liquid material to a surface to be covered using a pump and nozzle. Although the material properties are gradually reported through researches, there is a lack of studies on long-term performance compared to concrete materials used with the membranes. In this study, the long-term performance of materials was estimated using the Arrhenius equation. The temperature conditions used in this study were 65℃, 80℃ and 95℃, and the temperature was maintained with the membrane attached to the concrete block for long-term behavior. Then the membranes were tested for tensile strength and adhesion strength in the order of 30, 90, 150, 200, and 300 days. The long-term performance of the material was determined from a long-term perspective by estimating the activation energy by the Arrhenius equation. Consequently, the time to reach 50% of the performance standard could be estimated by long-term test.

An Evaluation of Flexural Behavior of Fume Pipe Repaired by Hybrid Concrete Repair Materials (하이브리드 콘크리트 보수재료로 보수된 흄관의 휨 거동 평가)

  • Yoo, Sung Won;Choi, Young Cheol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.6
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    • pp.92-98
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    • 2019
  • In this study, we developed a repair material incorporating PVA powder resin and nylon fiber into cemented carbide used in the existing field to improve adhesion performance and water tightness with existing concrete. Flexural behavior evaluation was performed. The main experimental variables were PVA powder resin, nylon fiber mixing rate and damage type, and performance tests were conducted to evaluate compressive strength and flexural behavior after repairing materials. It was found that all formulations fully satisfied the required performance of the repair material. The flexural strength test results of the repaired tube specimens showed that the performance of the repaired materials was maximized when the nylon fiber was added and the PVA powder was added in an appropriate amount. The flexural behavior of all the specimens showed the flexural behavior of the structural members with a low rebar ratio, suggesting that the amount of iron wire in the domestic fume pipe was somewhat insufficient. That is, it was confirmed that the amount of reinforcement of the steel wire was somewhat small, so that the concrete was cracked before the behavior of the concrete and the steel wire reached the extreme state, and the concrete was immediately destroyed beyond the tensile strength of the concrete.

Physical and Antibacterial Evaluation of Copper/Bioglass Nanoparticles (Cu/Bioglass Nano Particles; Cu-BGn) in Mineral Trioxide Aggregate(MTA) (구리/생체활성유리나노입자(Cu/Bioglass nano particles;Cu-BGn)를 첨가한 Mineral Trioxide Aggregate (MTA)의 물성 및 항균 평가)

  • Kim, Dong-Ae;Jun, Soo-Kyung
    • The Journal of the Korea Contents Association
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    • v.20 no.6
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    • pp.425-432
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    • 2020
  • For this study copper ions-containing bioactive glass nanoparticles commonly used in mineral trioxide aggregate (MTA) was developed to improve the mechanical properties and promote antibacterial effect of MTA with the original material. The mechanical properties and antibacterial activity of Cu-BGn incorporating varying amounts cooper incorporated bioactive glass nano particles(BGn) 0.5,1.0,2.0 and 4.0 wt% in MTA were characterized composition of the resulting were investigated. The compressive strength was calculated by weighing specimens with a diameter of 4 mm and a thickness of 6 mm according to ISO 6876 (2012). The antimicrobial effect was evaluated using two strains of S. mutans and E. faecalis. The mechanical properties of the test results was Cu-BGn increased no statistically significant difference was observed (p>0.05). Adhesion experiment results S. mutans in contrast to the control group Ortho MTA, 4.0 wt% of Cu-BGn added experimental group showed a significant difference was observed (p<0.05). Also, E. faecalis statistical analysis indicated a significant difference for antibacterial agents between control and Cu-BGn containing(p<0.05). It seems that this Cu-BGn proved that even a antibacterial effect was demonstrated. Therefore, it was suggest that it is necessary for in-depth research into various environments that can reproduce the oral environment.

Effect of Timing of Light Curing on the Shear Bond Strength of Three Self-adhesive Resin Cements

  • Yoo, Yeon-Kwon;Kim, Sung-Hun;Ryu, Jae-Jun;Ryu, Jae-Jun
    • Journal of Korean Dental Science
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    • v.1 no.1
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    • pp.28-34
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    • 2008
  • Objectives. The objectives of this study were: 1) to compare the effect of varying timing of light curing on shear bond strength, and; 2) to compare the shear bond strength of three self-adhesive cements. Materials and methods. A total of 72 extracted non-carious teeth were divided into 24 for Unicem tests, 24 for Maxcem tests, and 24 for Biscem tests; they were assigned 3 * 2 subgroups of 12 teeth each. The specimens were prepared as follows: 1) The calculus and periodontal ligament were removed from the teeth; 2) The teeth were stored in normal saline; 3) The occlusal enamel of each tooth was removed using high-speed coarse diamond burs under water cooling, and; 4) Finally, the teeth were flattened by 600-grit silicone carbide paper disks. Resin blocks were adhered using either Unicem, Maxcem, or Biscem. Light curing timing was divided into two groups: U10, M10, and B10 were exposed to light after 10 seconds, and; U150, M150, and B150 on the other side were exposed to light after 150 seconds. Shear bond strength was measured by a Universal testing machine with cross head speed of 1mm/min. T-test and One way ANOVA were used for the statistical analysis of data. Results. The shear bond strength of U150 was not significantly higher than that of U10 (U150: 20.55.7Mpa, U10: 18.73.80Mpa). On the other hand, the shear bond strength of M150 was significantly higher than that of M10. The shear bond strength of B150 was also significantly higher than that of B10 (M150:14.45.7Mpa, M10: 9.94.2Mpa, B150: 24.38.3Mpa, B10: 17.27.3Mpa). When the light curing timing was 10sec after bonding, the shear bond strength of Unicem was highest; the shear bond strength of Biscem was highest when the light curing timing was 150sec after bonding (U10: 18.73.80Mpa, B150: 24.38.3Mpa). Significance. Since Unicem is less sensitive based on light curing timing, dentists seem to use it without considering the light curing timing. Maxcem showed the lowest bonding strength (especially M10). Thus, when using Maxcem, dentists need to delay the light curing after adhesion.

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Experimental Study on the Development of EMP Shielded Concrete Using Industrial By-products (산업부산물을 사용한 EMP차폐 콘크리트 개발에 관한 실험적 연구)

  • Min, Tae-Beom;Kim, Hyeong-Cheol;Choi, Hyun-Kuk;Roh, Jeong-Heon;Kim, Kuk-Joo;Park, Young-Jun
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.6
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    • pp.477-484
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    • 2019
  • The purpose of this study is to present basic data for developing concrete with EMP shielding as the structure materials when constructing an EMP shielded building structure. In order to use metal-based recycled aggregates with excellent conductivity and easy procurement for EMP shielding concrete, an evaluation of the stability evaluation and EMP shielding performance was performed. Through the stability evaluation, it was found that the coarse aggregate stability criterion was satisfied, but the oxidized slag did not satisfy the fine aggregate stability criterion, the oxidized slag is not satisfied. In addition, as a result of fresh concrete, the workability is increased and the air volume is decreased. The compressive strength is increased due to the high density and coarse granularity of the recycled aggregates, which increased the cement paste and adhesion, thereby increasing the compressive strength. The results of an EMP shielding test show that aggregates with high shielding performance are electronic arc furnace(EAF) Oxidizing Slag and Cooper Slag. The shielding performance is expected to increase if the average particle size of aggregate is small or uniformly distributed.

Grain Shattering Resistance and Its Screening Method of Sesame (참깨 내탈립성의 원인과 검정 방법)

  • Kim Dong-Hwi;Kang Chul-Whan;Park Chang-Hwan;Chae Young-Am;Seong Nak-Sul
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.49 no.6
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    • pp.491-495
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    • 2004
  • The existing shattering-resistant sesames had low adaptability and yield potential in Korean environment. Great improvements have been made in these shattering-resistant sesames. We take an optimistic view of success for development of shattering-resistant sesames with high yield potential and superior agronomic characters. This study was carried out to investigate cause of shattering resistance and testing method of effective shattering habit. Shattering-resistant sesames had some specific tissue structures. Shattering resistance of placenta adhesion (PA) sesames was caused by strong seed holding of placenta in capsule, and that of seamless (SL) sesames was caused by nonexistence of seam in capsule. Shattering resistance of indehiscent(ID) sesames resulted because they had thicker mesocarp barrier at the zone of dehiscence compared with that of normal varieties. SL, ID and PA sesames had some variation plants who had high shattering rate. This was judged that evolution direction of these sesames means direction that shattering habit increase. Effective drying method in order to measure shattering resistance was drying condition over 20 days in natural temperature $(20^{\circ}C)$ and 10 days in drying oven $(40^{\circ}C)$.

Anti-inflammatory Effects of Quercetin and Vitexin on Activated Human Peripheral Blood Neutrophils - The effects of quercetin and vitexin on human neutrophils -

  • Nikfarjam, Bahareh Abd;Hajiali, Farid;Adineh, Mohtaram;Nassiri-Asl, Marjan
    • Journal of Pharmacopuncture
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    • v.20 no.2
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    • pp.127-131
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    • 2017
  • Objectives: Polymorphonuclear neutrophils (PMNs) constitute the first line of defense against invading microbial pathogens. Early events in inflammation involve the recruitment of neutrophils to the site of injury or damage where changes in intracellular calcium can cause the activation of pro-inflammatory mediators from neutrophils including superoxide generation, degranulation and release of myeloperoxidase (MPO), productions of interleukin (IL)-8 and tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$), and adhesion to the vascular endothelium. To address the anti-inflammatory role of flavonoids, in the present study, we investigated the effects of the flavonoids quercetin and vitexin on the stimulus-induced nitric oxide (NO), $TNF-{\alpha}$, and MPO productions in human neutrophils. Methods: Human peripheral blood neutrophils were isolated, and their viabilities were determined by using the Trypan Blue exclusion test. The polymorphonuclear leukocyte (PMNL) preparations contained more than 98% neutrophils as determined by morphological examination with Giemsa staining. The viabilities of cultured neutrophils with various concentrations of quercetin and vitexin ($1-100{\mu}M$) were studied using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without quercetin and vitexin ($25{\mu}M$) for 45 min, and stimulated with phorbol 12-myristate 13-acetate (PMA) ($10^{-7}M$). NO production was carried out through nitrite determination by using the Griess method. Also, the $TNF-{\alpha}$ and the MPO productions were measured using enzyme-linked immunosorbent assay (ELISA) kits and MPO assay kits. Results: Neutrophil viability was not affected up to a concentration of $100{\mu}M$ of quercetin or vitexin. Both quercetin and vitexin significantly inhibited $TNF-{\alpha}$, NO, and MPO productions in human neutrophils (P < 0.001). Conclusion:The present study showed that both quercetin and vitexin had significant anti-inflammatory effects. Thus, treatment with either quercetin or vitexin may be considered as a therapeutic strategy for treating patients with neutrophil-mediated inflammatory diseases.