• Title/Summary/Keyword: school bonding

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Dyeability of the Fabrics dyed with Herb Extracts (허브 추출물에 의한 직물의 염색 특성)

  • Goo, Sin Ae;Kang, In Sook;Bae, Hyun Sook
    • Textile Coloration and Finishing
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    • v.28 no.1
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    • pp.23-32
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    • 2016
  • This study examined the dyeability of fabrics dyed with rosemary, mint, sage, and thyme herb extracts. The herb extracts were pulverized and characterized by UV and FT-IR analysis. Dyeing properties of herb colorants on cotton, silk and wool fiber and effect of dyeing conditions on dye uptake were compared. The constituents of four different herbs were shown to be similar to each other. The dye uptake of rosemary and sage were shown to be larger than those of mint and thyme regardless of the fiber types. Affinity of herb colorants to protain fibers was higher than to cellulose fiber. Compared with silk and wool, the dyeability of cotton was the worse, the dye uptake of silk and wool fibers were increased along with dyeing time and dyeing temperature. As the dye uptake increased with increasing of the dye concentration, and its isothermal adsorption curves were langmuir type, indicating that ionic bonding was involved in the adsorption of herb colorants to the fibers.

Impact of glycosylation on the unimpaired functions of the sperm

  • Cheon, Yong-Pil;Kim, Chung-Hoon
    • Clinical and Experimental Reproductive Medicine
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    • v.42 no.3
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    • pp.77-85
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    • 2015
  • One of the key factors of early development is the specification of competence between the oocyte and the sperm, which occurs during gametogenesis. However, the starting point, growth, and maturation for acquiring competence during spermatogenesis and oogenesis in mammals are very different. Spermatogenesis includes spermiogenesis, but such a metamorphosis is not observed during oogenesis. Glycosylation, a ubiquitous modification, is a preliminary requisite for distribution of the structural and functional components of spermatids for metamorphosis. In addition, glycosylation using epididymal or female genital secretory glycans is an important process for the sperm maturation, the acquisition of the potential for fertilization, and the acceleration of early embryo development. However, nonemzymatic unexpected covalent bonding of a carbohydrate and malglycosylation can result in falling fertility rates as shown in the diabetic male. So far, glycosylation during spermatogenesis and the dynamics of the plasma membrane in the process of capacitation and fertilization have been evaluated, and a powerful role of glycosylation in spermatogenesis and early development is also suggested by structural bioinformatics, functional genomics, and functional proteomics. Further understanding of glycosylation is needed to provide a better understanding of fertilization and embryo development and for the development of new diagnostic and therapeutic tools for infertility.

Fabrication and Cell Culturing on Carbon Nanofibers/Nanoparticles Reinforced Membranes for Bone-Tissue Regeneration

  • Deng, Xu Liang;Yang, Xiao Ping
    • Carbon letters
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    • v.13 no.3
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    • pp.139-150
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    • 2012
  • Poly-L-lactic acid (PLLA), PLLA/hydroxyapatite (HA), PLLA/multiwalled carbon nanotubes (MWNTs)/HA, PLLA/trifluoroethanol (TFE), PLLA/gelatin, and carbon nanofibers (CNFs)/${\beta}$-tricalcium phosphate (${\beta}$-TCP) composite membranes (scaffolds) were fabricated by electrospinning and their morphologies, and mechanical properties were characterized for use in bone tissue regeneration/guided tissue regeneration. MWNTs and HA nanoparticles were well distributed in the membranes and the degradation characteristics were improved. PLLA/MWNTs/HA membranes enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion of gingival epithelial cells by 30%. Osteoblast-like MG-63 cells on the randomly fiber oriented PLLA/TEF membrane showed irregular forms, while the cells exhibited shuttle-like shapes on the parallel fiber oriented membrane. Classical supersaturated simulated body fluids were modified by $CO_2$ bubbling and applied to promote the biomineralization of the PLLA/gelatin membrane; this resulted in predictions of bone bonding bioactivity of the substrates. The ${\beta}$-TCP membranes exhibit good biocompatibility, have an effect on PDLC growth comparable to that of pure CNF membrane, and can be applied as scaffolds for bone tissue regeneration.

Development of Wafer Bond Integrity Inspection System Based on Laser Transmittance

  • Jang, Dong-Young;Ahn, Hyo-Sok;Mehdi, Sajadieh.S.M.;Lim, Young-Hwan;Hong, Seok-Kee
    • Journal of the Microelectronics and Packaging Society
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    • v.17 no.2
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    • pp.29-33
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    • 2010
  • Among several critical topics in semiconductor fabrication technology, particles in addition to bonded surface contaminations are issues of great concerns. This study reports the development of a system which inspects wafer bond integrity by analyzing laser beam transmittance deviations and the variations of the intensity caused by the defect thickness. Since the speckling phenomenon exists inherently as long as the laser is used as an optical source and it degrades the inspection accuracy, speckle contrast is another obstacle to be conquered in this system. Consequently speckle contrast reduction methods were reviewed and among the all remedies have been established in the past 30 years the most adaptable solution for inline inspection system is applied. Simulation and subsequently design of experiments has been utilized to discover the best solution to improve irradiance distribution and detection accuracy. Comparison between simulation and experimental results has been done and it confirms an outstanding detection accuracy achievement. Bonded wafer inspection system has been developed and it is ready to be implemented in FAB in the near future.

Finite element analyses of the stability of a soil block reinforced by shear pins

  • Ouch, Rithy;Ukritchon, Boonchai;Pipatpongsa, Thirapong;Khosravi, Mohammad Hossein
    • Geomechanics and Engineering
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    • v.12 no.6
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    • pp.1021-1046
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    • 2017
  • The assessment of slope stability is an essential task in geotechnical engineering. In this paper, a three-dimensional (3D) finite element analysis (FEA) was employed to investigate the performance of different shear pin arrangements to increase the stability of a soil block resting on an inclined plane with a low-interface friction plane. In the numerical models, the soil block was modeled by volume elements with linear elastic perfectly plastic material in a drained condition, while the shear pins were modeled by volume elements with linear elastic material. Interface elements were used along the bedding plane (bedding interface element) and around the shear pins (shear pin interface element) to simulate the soil-structure interaction. Bedding interface elements were used to capture the shear sliding of the soil on the low-interface friction plane while shear pin interface elements were used to model the shear bonding of the soil around the pins. A failure analysis was performed by means of the gravity loading method. The results of the 3D FEA with the numerical models were compared to those with the physical models for all cases. The effects of the number of shear pins, the shear pin locations, the different shear pin arrangements, the thickness and the width of the soil block and the associated failure mechanisms were discussed.

Corporate Marketing Strategy Using Social Media: A Case Study of the Ritz-Carlton Seoul

  • Lee, Jung Wan;Kwag, Michael
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.1
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    • pp.79-86
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    • 2017
  • With the increasing trend of popularity of websites and social networking sites, it is quite evident that companies need to take cautionary measures in protecting the reputations with respect to company and brands. In this process, every company should indulge in enhancing their company and brand image through websites and social networking sites that fortify the bonding nature among them. The always-on nature of websites and social networking sites has contributed to their phenomenal marketing power and altered the balance of power between consumers and firms. Websites and social networks are used by hundreds of millions of people to communicate about a huge range of topics, including personal interests, activities, social events and even public issues. The paper explores a case study of the Ritz-Carlton hotel for their marketing strategy and organizational use of their website and social media in communicating with their customers. Even for the normal luxury traveler who would not have previously used the Internet to research a hotel or make a reservation, ritzcarlton.com is making it possible for them to do so in a sense of the luxury and typical Ritz-Carlton style. It seems to be a staple of the company for years to come.

Photo-induced inter-protein interaction changes in the time domain; a blue light sensor protein PixD

  • Terazima, Masahide
    • Rapid Communication in Photoscience
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    • v.4 no.1
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    • pp.1-8
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    • 2015
  • For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

Characteristics of Perovskite Solar Cell with Nano-Structured MoO3 Hole Transfer Layer Prepared by Hydrothermal Synthesis (수열합성법으로 제막한 MoO3 나노 구조체를 정공수송층으로 갖는 페로브스카이트 태양전지 특성분석)

  • Song, Jae-Kwan;Ahn, Joon-Sub;Han, Eun-Mi
    • Korean Journal of Materials Research
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    • v.30 no.2
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    • pp.81-86
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    • 2020
  • MoO3 metal oxide nanostructure was formed by hydrothermal synthesis, and a perovskite solar cell with an MoO3 hole transfer layer was fabricated and evaluated. The characteristics of the MoO3 thin film were analyzed according to the change of hydrothermal synthesis temperature in the range of 100 ℃ to 200 ℃ and mass ratio of AMT : nitric acid of 1 : 3 ~ 15 wt%. The influence on the photoelectric conversion efficiency of the solar cell was evaluated. Nanorod-shaped MoO3 thin films were formed in the temperature range of 150 ℃ to 200 ℃, and the chemical bonding and crystal structure of the thin films were analyzed. As the amount of nitric acid added increased, the thickness of the thin film decreased. As the thickness of the hole transfer layer decreased, the photoelectric conversion efficiency of the perovskite solar cell improved. The maximum photoelectric conversion efficiency of the perovskite solar cell having an MoO3 thin film was 4.69 % when the conditions of hydrothermal synthesis were 150 ℃ and mass ratio of AMT : nitric acid of 1 : 12 wt%.

Current Status of Thin Film Silicon Solar Cells for High Efficiency

  • Shin, Chonghoon;Lee, Youn-Jung;Park, Jinjoo;Kim, Sunbo;Park, Hyeongsik;Kim, Sangho;Jung, Junhee;Yi, Junsin
    • Current Photovoltaic Research
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    • v.5 no.4
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    • pp.113-121
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    • 2017
  • The researches on the silicon-based thin films are being actively carried out. The silicon-based thin films can be made as amorphous, microcrystalline and mixed phase and it is known that the optical bandgap can be controlled accordingly. They are suitable materials for the fabrication of single junction, tandem and triple junction solar cells. It can be used as a doping layer through the bonding of boron and phosphorus. The carbon and oxygen can bond with silicon to form a wide range of optical gap. Also, The optical gap of hydrogenated amorphous silicon germanium can be lower than that of silicon. By controlling the optical gaps, it is possible to fabricate multi-junction thin film silicon solar cells with high efficiencies which can be promising photovoltaic devices.

The Effect of Nitriding/DLC Coating on the High Cycle Fatigue Properties of Fe-3.0Ni-0.7Cr-1.4Mn-X Steel (Fe-3.0Ni-0.7Cr-1.4Mn-X강의 고주기피로특성에 미치는 질화/DLC코팅의 영향)

  • Jang, Jae Cheol;Kim, Song-Hee
    • Journal of the Korean institute of surface engineering
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    • v.49 no.6
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    • pp.587-594
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    • 2016
  • Various surface treatments and thin film coating processes on the surface of injection die steel have been developed to extend the life. Most of previous studies were mainly focused on investigating the wear and static bonding behavior of thin films. In this study complex surface treatments of DLC coating combined with ion nitriding were applied to increase fatigue life and wear resistance. Ion nitriding, DLC coating, and DLC coating following nitriding on the surface of Fe-3.0Ni-0.7Cr-1.4Mn-X steel were investigated to uncover the beneficial effect which is applicable to injection die. The effect of various surface treatments and coating conditions on high cycle fatigue resistance was studied. Surface morphology change during fatigue tests were observed with AFM. Fatigue life of the die steel increased by 10 to 1,000 times at the various level of stress amplitudes in the condition of DLC coating following the ion nitriding for 3 hrs comparing with the only DLC coated condition.