• Title/Summary/Keyword: Quality properties

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The properties of glass ceramics of Li2O-Al2O3-SiO2 system according to nucleation agent (조핵제 원료에 따른 Li2O-Al2O3-SiO2계 결정화 유리 특성)

  • Park, Hyun-Wook;Lee, Ji-Sun;Lim, Tae-Young;Hwang, Jonghee;Ra, Yong-Ho;Noh, Myoung-Rae;Seo, Kwan-Hee;Kim, Jin-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.28 no.6
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    • pp.229-234
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    • 2018
  • The glass-ceramic of $Li_2O-Al_2O_3-SiO_2$ system was synthesized by using $ZrO_2$, $ZrSiO_4$, $ZrOCl_2$ and $Zr(SO_4)_2$, which is a raw material of Zr serving as a nucleation agent. It was confirmed that Avrami parameter of these four glasses is over 3 for bulk crystallization. The glass synthesized by $ZrOCl_2$, and $Zr(SO_4)_2$ showed high melting quality during the melting process. It is also observed that the Zr component is uniformly distributed in the glass. Various characterizations was evaluated, including composition analysis and bending strength.

High Purification of Hg2Br2 Powder for Acousto-Optic Tunable Filters Utilizing a PVT Process (PVT공정을 이용한 음향광학 가변 필터용 Hg2Br2 파우더의 고순도 정제)

  • Kim, Tae Hyeon;Lee, Hee Tae;Kwon, In Hoi;Kang, Young-Min;Woo, Shi-Gwan;Jang, Gun-Eik;Cho, Byungjin
    • Korean Journal of Materials Research
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    • v.28 no.12
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    • pp.732-737
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    • 2018
  • We develop a purification process of $Hg_2Br_2$ raw powders using a physical vapor transport(PVT) process, which is essential for the fabrication of a high performance acousto-optic tunable filter(AOTF) module. Specifically, we characterize and compare three $Hg_2Br_2$ powders: $Hg_2Br_2$ raw powder, $Hg_2Br_2$ powder purified under pumping conditions, and $Hg_2Br_2$ powder purified under vacuum sealing. Before and after purification, we characterize the powder samples through X-ray diffraction and X-ray photoelectron spectroscopy. The corresponding results indicate that physical properties of the $Hg_2Br_2$ compound are not damaged even after the purification process. The impurities and concentration in the purified $Hg_2Br_2$ powder are evaluated by inductively coupled plasma-mass spectroscopy. Notably, compared to the sample purified under pumping conditions, the purification process under vacuum sealing results in a higher purity $Hg_2Br_2$ (99.999 %). In addition, when the second vacuum sealing purification process is performed, the remaining impurities are almost removed, giving rise to $Hg_2Br_2$ with ultra-high purity. This high purification process might be possible due to independent control of impurities and $Hg_2Br_2$ materials under the optimized vacuum sealing. Preparation of such a highly purified $Hg_2Br_2$ materials will pave a promising way toward a high-quality $Hg_2Br_2$ single crystal and then high performance AOTF modules.

Expanding the Concept of Cultural Heritage Utilization and Classifying the Types (문화재 활용의 개념 확장과 활용 유형 분류체계 구축)

  • Ryu, Ho-cheol
    • Korean Journal of Heritage: History & Science
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    • v.47 no.1
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    • pp.4-17
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    • 2014
  • The more income and free time people have, the more interest in cultural heritage they get to improve the quality of life. In light of this, Local governments put more effort to create colorful events using their cultural heritage resources, and the central government also starts to implement policies to enhance the value of cultural heritage. To keep those efforts on utilizing cultural heritage, however, several issues seem to be addressed in advance. Firstly, it needs to define the concept of cultural heritage utilization that could cover its current policy trend. Secondly, the utilization methodology should be categorized and classified. Therefore, the study for those issues should be carried out to utilize the cultural heritage efficiently and systematically. This study contains the current status of the relevant policies and projects; the trend and meaning of the utilization. And, in this study, the cultural heritage utilization was defined as all activities producing positive effects or influences by cultural heritage such as enjoying cultural heritage values and creating additional profits. Furthermore, the cultural heritage utilization was categorized according to several criteria; the value, the objective, and the type of cultural heritage utilization. Finally, the final part of the study includes proposals on the future policy direction of cultural heritage utilization.

Effect of κ-Carrageenan on Sperm Quality in Cryopreservation of Canine Semen (개 정액의 냉동보존 시 κ-Carrageenan이 정자 성상에 미치는 영향)

  • Kim, Eun-Ji;Talha, Nabeel A.H.;Jeon, Yu-Byeol;Yu, Il-Jeoung
    • Journal of Animal Reproduction and Biotechnology
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    • v.34 no.1
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    • pp.57-63
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    • 2019
  • This study was conducted to find out the effect that ${\kappa}-Carrageenan$ has on the properties of dog sperm when it was added to the cryoprotectant. Extender basically was contained 1.21 g Trizma base, 0.67 g citric acid, 0.4 g glucose, 0.03 g penicillin G, 0.05 g streptomycin sulfate. Extender1 was added with 0.1%, 0.2%, 0.3%, and 0.5% carrageenan, while extender2 was supplemented with glycerol. After freezing-thawing, the motility, viability, acrosome integrity, apoptosis, and ROS (reactive oxygen specifications) of sperm were measured to analyze the effects of the supplementation of carrageenan. Total Motile (TM), Rapid Progressive Motile (RPM), Medium Progressive Motile (MPM), and Immotile were measured through the CASA system after thawing in 37 degree water. Extender with 0.2% ${\kappa}-carrageenan$ ($64.26{\pm}0.49$) was significantly higher than control ($40.24{\pm}8.27$) (p < 0.05). RPMs of extender with 0.1%, 0.2% ${\kappa}-carrageenan$ ($57.64{\pm}6.34$, $56.47{\pm}1.35$) were significantly higher than the other groups (p < 0.05). Acrosome integrity was measured by dyeing to PSA-FITC with an epifluorescence microscope. Normal acrosome ratio of extender with 0.5% ${\kappa}-carrageenan$ ($61{\pm}8.03$) was higher than the other groups (p < 0.05). Apoptosis was measured with a FACSCalibur flow cytometer using FITC (FITC Annexin V Apoptosis Detection Kit). Treated groups of ${\kappa}-carrageenan$ of 0.1% ($0.81{\pm}0.05$), 0.2% ($0.85{\pm}0.05$) were significantly higer (p < 0.05) than control. Modified SYBR/PI staining was used for determination of viability and DCF staining was used for evaluation of ROS. Viability and ROS were not significantly different from other groups. In conclusion, adding a certain concentration of carrageenan to the extender of cryopreservation, carrageenan contributes to the improvement of the sperm motility, acrosome integrity and prevention of apoptosis.

Environmental Fate Tracking of Manure-borne NH3-N in Paddy Field Based on a Fugacity Model (Fugacity 모델에 기초한 논토양에서의 액비살포에 따른 암모니아성 질소 거동추적)

  • Kim, Mi-Sug;Kwak, Dong-Heui
    • Journal of Korean Society on Water Environment
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    • v.35 no.3
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    • pp.224-233
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    • 2019
  • Nitrogen components in liquid manure can reduce safety and quality of environment harmfully. To minimize the environmental risks of manure, understanding fate of manure in environment is necessary. This study aimed at investigating applicability of a simplified Level III fugacity model for simulating $NH_3-N$ component to analyze environmental fate and transport of $NH_3-N$ in liquid manure and to provide basis for improving management of N in the liquid manure system and for minimizing the environmental impacts of N. The model simulation conducted for four environmental compartments (air, water, soil, and rice plants) during rice-cropping to trace $NH_3-N$ component and provided applicability of the Level III fugacity model in studying the environmental fate of $NH_3-N$ in manure. Most of $NH_3-N$ was found in water body and in rice plants depending upon the physicochemical properties and proper removal processes. For more precise model results, the model is needed to modify with the detailed removal processes in each compartment and to collect proper and accurate information for input parameters. Further study should be about simulations of various N-typed fertilizers to compare with the liquid manure based on a modified and relatively simplified Level III fugacity model.

Characteristics of Filtration Treatment Using Diatomite Filter Aids for Sewage Water Reuse (하수처리수 재이용을 위한 가압식 규조토 여과의 처리성능평가)

  • Lim, Byung Ran;Kim, Hee Seo;Go, Yeon Sil;Kim, Hyun Kab;Kim, Jong Hak;Lee, Tae Jin
    • Journal of Korean Society on Water Environment
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    • v.35 no.2
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    • pp.145-151
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    • 2019
  • The purpose of this study was to investigate treatment characteristics of diatomite filtration, that would allow water recovery from biologically-treated effluent for reuse. Diatomite, Celpure 100, and acid clay were used as filter-aids, with a support filter manufactured from polyethylene (PE), and polypropylene (PP). This pre-coating process using diatomite filter-aids, is used in the filtration range of pressure filters, and has consistently provided high-quality separation. The results showed that variations in average removal efficiency of SS, and T-P from biologically treated effluent by the diatomite-coated PE filter, were approximately 82.2 ~ 88.9 % and 4.8 ~ 21.1 %, respectively. T-P treatment efficiency of the PP filter pre-coated with diatomite and $Celpure^{(R)}100$ at $57.64g/m^2$, was approximately $24{\pm}10%$ and $40{\pm}15%$ on average, respectively. Particle size distribution of secondary effluent varied from 0.05 to $200{\mu}m$, and $d_{50}$ value was $20.76{\mu}m$. The size distribution of particles in the diatomite filtrate ranged from 1.26 to $101.1{\mu}m$ when pre-coated with diatomite filter-aid, at a content of $57.64g/m^2$. Diatomite filter aids, i.e., the particles that form the pre-coating layer, capture very fine particles as well as macromolecules, owing to their complex structure with numerous fine microscopic pores, and surface properties. The filtration process using diatomite and $Celpure^{(R)}100$ as filter aids, has been successfully applied, to recover water from sewage for reuse. The disadvantage of the process, is that the particle size of the filter-aid is spent, because of pressurization.

An Outstanding Universal Value and the Management of Historic Gardens in Suzhou, China (쑤저우 정원의 세계유산 OUV와 보호관리의 운영방식)

  • Park, Hee-Soung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.1
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    • pp.76-84
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    • 2019
  • This study was conducted for the purpose of examining the Outstanding Universal Value, World Heritage Values, in Suzhou classical gardens and the operational method of the protection management of historic gardens, and the results of the study are as follows; The first, as a world heritage, Suzhou gardens proved OUV by showing the taste and lifestyle of the literati, the unique class of Chinese history, to the natural environment of the East Yangtze Delta region. In addition, it showed the exchange of international culture with unique Chinese garden techniques. Second, a authentic reconstruction of garden have original value because it exist records of the near past. The 20th-century archives described by the contemporary language and describing the heritage through images using such media as photography and drawing played a decisive role in restoring gardens. Third, the protection management of Suzhou gardens, which began in the 1950s, was carried out in detail, including the reconstruction of components such as buildings, the restoration of plant materials and horticulture technique, the creation of a list through the records of trees, the maintenance of props such as plaque, furniture, and the project to improve water quality and restore waterscape. The last, after the World Heritage inscribing, Garden's protection management was proceeded in two directions. One is that through the reorganization of the administrative management system and the enactment of laws related to Suzhou classical Gardens, the listing heritage is strictly protected and managed, and the other is that the historical gardens are used to establish urban masterplan and urban identity in Suzhou. The range of garden properties greatly expanded by distinguishing the principle of conservation from protection to rational use and the grade of protection, such as whole protection, maintenance protection and protection of historical sites.

Identification and Fermentation Characteristics of Lactic Acid Bacteria that Produce Soy Curd With Low Sour Taste (저산미의 두유 커드를 생성하는 젖산균의 동정과 발효 특성)

  • Kim, Su-In;Jung, Min-Gi;Lee, Seung-Min;Kang, Moon-Sun;Seong, Jong-Hwan;Lee, Young-Geun;Kim, Han-Soo;Chung, Hun-Sik;Kim, Dong-Seob
    • Food Engineering Progress
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    • v.21 no.3
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    • pp.242-248
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    • 2017
  • The acidity of soy curd fermented by lactic acid bacteria is a major factor degrading the sensory properties of soy curd. For preparation of soy curd with low sour taste, lactic acid bacteria were separated from kimchi. The lactic acid bacteria which showed yellow-clear zone around the colonies on BCP plate and formed soy curd with low level of acidity were selected. The selected strain was analyzed by 16S rDNA sequence and named as Pediococcus inopinatus Y2. The maximum viable cell number of the soy curd fermented by P. inopinatus Y2 was obtained at 10.73 log CFU/mL at $25^{\circ}C$ for 24 h of fermentation. By the results of panel test, the overall sensory quality of the soy curd produced by P. inopinatus Y2 was higher than that of Leuconostoc mesenteroides No. 4395 and Lactobacillus sakei strain No. 383.

Purchasing Japanese Brand Products According to the Patriotism of Consumers in Their 20s (20대 소비자의 애국심에 따른 일본브랜드 구매 특성)

  • Kim, Jisu;Seo, Wooyoung;Na, Youngjoo
    • Science of Emotion and Sensibility
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    • v.24 no.1
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    • pp.11-24
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    • 2021
  • This study investigates the buying behavior pertaining to Japanese brands according to the degree of patriotism of consumers in their 20s. A survey of 235 university students was conducted; the survey questioned the basic purchasing attitudes of consumers in their 20s regarding outerwear and underwear and then surveyed the purchasing attitudes regarding U brand's (representative Japanese brand) outerwear and underwear. To detect the correlation between patriotism and U brand purchases, this study asked questions about patriotism and investigated basic personal information. The research results were as follows. First, there was a significant difference in consumer's purchasing attitude toward outerwear and underwear. When of consumers who are in their 20s purchase outerwear, its design was the most important factor, whereas when purchasing underwear, functionality was the most crucial factor. Second, it was confirmed that consumer's attitudes toward U brand's outerwear and underwear differed. Although the evaluation of U brand's outerwear design was not positive, the consumer tended to be satisfied with the price. U brand's score concerning the functionality of underwear products received a slightly positive response. Third, a total of 235 respondents were divided into a high- and low-patriotism-group based on questions about patriotism. There were significant differences in their attitudes toward clothing and consumer's purchasing behavior at U brand. Highly patriotic consumers thought negatively about U brand outerwear products in terms of price and product quality than low patriotic consumers; however, there was no significant difference only regarding design evaluation. For underwear products, low patriotic consumers were more positive about the price, design, and functionality of U brand products than high patriotic consumers.

A Study on the Atmospheric Pressure Control of the VARTM Process for Increasing the Fiber Volume Fraction and Reducing Void (섬유부피분율 증가와 공극 감소를 위한 VARTM 공정의 대기압 제어에 관한 연구)

  • Kwak, Seong-Hun;Kim, Tae-Jun;Tak, Yun-Hak;Kwon, Sung-Il;Lee, Jea-Hyun;Kim, Sang-Yong;Lee, Jong-Cheon
    • Composites Research
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    • v.34 no.2
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    • pp.88-95
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    • 2021
  • VARTM (Vacuum-assisted resin transfer molding) process is a low-cost process technology and affiliated with OoA (Out of Autoclave). Besides, it has been widely used in various fields. However, because of its lower quality than the autoclave process, it isn't easy to apply the VARTM process to the aerospace industry, which requires high reliability. The main problem of the VARTM process is the loss of mechanical properties due to the low fiber volume fraction and high void content in comparison to the autoclave. Therefore, many researchers have studied to reduce void and increase fiber volume fraction. This study examines whether the method of controlling atmospheric pressure could increase the fiber volume fraction and reduce void during the resin impregnation process. Reliability evaluation was confirmed by compressive strength test, fiber volume fraction analysis, and optical microscopy. As a result, it was confirmed that increasing the atmospheric pressure step by step in the VARTM process of impregnating the preform with resin effectively increases the fiber volume fraction and reduces void.