• 제목/요약/키워드: crystalline

검색결과 4,560건 처리시간 0.03초

A Numerical analysis of Underground Repository Cavern in Korean Crystalline rocks (우리나라 결정질암내 동굴처분장에 대한 수치해석)

  • 윤건신
    • The Journal of Engineering Geology
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    • 제1권1호
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    • pp.68-84
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    • 1991
  • A numerical analysis using Universal Distinct Element Code program for the nuclear waste disposal cavern has been performed for a typical Korean crystalline rock condition with same geometry of Swedish low and intermediate nuclear waste disposal repository(S.F.R). The stress concentration, displacement and safety factor for the typical single cross section of cavern, 5 caverns and a silo are analyzed.

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Studies on Manufacturing of Gouda Type Cheese by using of Crystalline Mucor Rennin (Crystalline Mucor Rennin을 이용한 치즈제조에 관한 연구)

  • Yu, Ju-Hyun;Kim, Yu-Sam;Hong, Yun-Myung
    • Korean Journal of Food Science and Technology
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    • 제3권1호
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    • pp.6-14
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    • 1971
  • Crystalline Mucor rennin and Mucor rennet from Mucor pusillus var. Lindt was compared with Hansen's calf rennet in its properties as a milk clotting enzyme. The method of Gouda type cheese from domestic milk was established by using of Crystalline Mucor rennin and Mucor rennet. The cheese produced by using of Mucor rennet as a milk clotting enzyme sometimes had bitter taste, it can be reduced with using Crystalline Mucor rennin, instead of Mucor rennet. It was also found out that these cheeses could be colored by the pigment from Cape Jasmine which is wildly ubiquitous in Korea.

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Ultrastructure of the Compound Eye of the Rice Brown Planthopper, Nilaparvata lugens (StaL) (Homopteera : Auchenorhyncha : Delphacidae) (벼멸구 겹눈의 미세구조)

  • Young Nam Youn
    • Korean journal of applied entomology
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    • 제34권3호
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    • pp.266-277
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    • 1995
  • The adult brown planthopper possesses tow oval shaped compound eyes which, on their ventral borders, curve around the base of the antennae. Compound eye of the adult brown planthopper is recognised apposition eye which each ommatidium is optically isolated from it surroundings, the rhabdoms receiving light only from their own corneal lens. Each ommatidium possesses its own dioptric apparatus formed from the cuticular cornea and an underlying crystalline cone. The retinula cells lying immediately beneath the crystalline cone have their individual rhabdomeres tightly opposed to form one central, closed rhbdom. The rhabdom stretches from the spex of the crystalline cone nearly to the basement membrane and is approximately 110~120 $\mu\textrm{m}$ in length. The crystalline cone is surrounded by a pair of primary pigment cells an these in turn are surrounded by accessory pigment cells. Accessory pigment cells extend beyond the crystalline cone surrounding the retinular cells in the distal region of the eye. The crystalline cone is surrounded by the distal-most regions of the retinula cells show the presence of seven cells and sections taken proximally in the last quarter of the omatidium before the basement membrane is reached, reveal the presence of a small, eighth retinula cell which also contributes to the central rhabdom. Each ommatidium has a central rhabdom formed from the modified inner border of all of the retinula cells. Th rhabdom consists of micrvilli arising from the inner wall of each retinula cell. In cross section th microvilli exhibit a characteristic honeycomb appearance. Pigment cells comprise the primary pigment cells enveloping the crystalline cone, the accessory pigment cells extending from the inner surface of the comea to the basement membrane and the small pigment cells of the basement membrane.

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Analysis of Quartz Contents by XRD and FTIR in Respirable Dust from Various Manufacturing Industries Part 2 - Ceramics, Stone, Concrete, Glass and Briquets, etc. (제조업체에서 발생하는 호흡성분진중 XRD와 FTIR를 이용한 결정형유리규산 농도의 분석 제2부 : 요업, 석재, 콘크리트, 유리, 연탄 및 기타사업장)

  • Kim, Hyunwook;Phee, Young Gyu;Roh, Young Man;Won, Jeoung Il
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • 제9권1호
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    • pp.99-111
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    • 1999
  • The purpose of this study was to evaluate crystalline silica contents in airborne respirable dusts from various manufacturing industries and to compare analytical ability of two different methods of quantifying crystalline silica, X-ray diffraction(XRD) and Fourie transform infrared spectroscopy(FTIR). Various manufacturing industries with a history of having pneumoconiosis cases and also known to generate dusts containing crystalline silica were investigated. These industries include: ceramics, brick, concrete, and abrasive material etc. The personal respirable dust samples were collected using l0mm, Dorr-Oliver nylon cyclone equipped with 37mm, $5{\mu}m$ pore size. polyvinylchloride (PVC) filters as collection media. All samples were weighed before and after sampling and were pretreated according to the NIOSH sampling and analytical methods 7500, and 7602 for dust collection and quartz analysis. A total of 48 samples were collected from these industries. Initial analyses of these samples showed log-normal distributions for dust and quartz concentrations. Some results from ceramics and stone exceeded current Korean Occupational Exposure Limits. The average concentrations of personal respirable dust by cyclone were 0.43, 0.24, 0.26, 0.42, 0.53 and $0.29mg/m^3$ in ceramics, stone, concrete, glass, briquets, and others, respectively. A comparison of performance of two analytical methods for quantifying crystalline silica was performed using data from ceramics. The results showed that no significant difference was found between two methods for ceramics. The mean crystalline silica contents determined by XRD were 3.41 % of samples from briquets and 7.18 % from ceramics and were 2.58 % from concrete and 10.33 % from ceramics by FTIR. For crystalline silica analysis, two analytical techniques were highly correlated with $r^2=0.81$ from ceramics. Both cristobalite and tridymite were not detected by XRD and FTIR.

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Analysis of Mechanism for Photovoltaic Properties and Bypass Diode of Crystalline Silicon and CuInxGa(1-x)Se2 Module in Partial Shading Effect (결정질 실리콘 및 CuInxGa(1-x)Se2 모듈의 부분음영에 따른 태양전지 특성 변화 및 바이패스 다이오드의 작동 메커니즘 분석)

  • Lee, Ji Eun;Bae, Soohyun;Oh, Wonwook;Kang, Yoonmook;Kim, Donghwan;Lee, Hae-Seok
    • Korean Journal of Materials Research
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    • 제25권4호
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    • pp.196-201
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    • 2015
  • This paper presents the impact of partial shading on $CuIn_xGa_{(1-x)}Se_2(CIGS)$ photovoltaic(PV) modules with bypass diodes. When the CIGS PV modules were partially shaded, the modules were under conditions of partial reverse bias. We investigated the characterization of the bypass diode and solar cell properties of the CIGS PV modules when these was partially shaded, comparing the results with those for a crystalline silicon module. In crystalline silicon modules, the bypass diode was operated at a partial shade modules of 1.67 % shading. This protected the crystalline silicon module from hot spot damage. In CIGS thin film modules, on the other hand, the bypass diode was not operated before 20 % shading. This caused damage because of hotspots, which occurred as wormlike defects in the CIGS thin film module. Moreover, the bypass diode adapted to the CIGS thin film module was operated fully at 60% shading, while the CIGS thin film module was not operated under these conditions. It is known that the bypass diode adapted to the CIGS thin film module operated more slowly than that of the crystalline silicon module; this bypass diode also failed to protect the module from damage. This was because of the reverse saturation current of the CIGS thin film, $1.99{\times}10^{-5}A/cm^2$, which was higher than that of crystalline silicon, $8.11{\times}10^{-7}A/cm^2$.

Liquid Crystalline Aromatic Polyesters (액정성 전방향족 폴리에스테르)

  • Kwon Young-Wan;Choi Dong Hoon;Jin Jung-Il
    • Polymer(Korea)
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    • 제29권6호
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    • pp.523-535
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    • 2005
  • Linear aromatic polyesters are representative examples of thermotropic liquid crystalline polymers (TLCPs), which have been the subject of many researches. This article reviews the structure-LC properties relationship in wholly aromatic CLCPs mostly based on the results obtained for the past quarter of a century. Especially, this review deals with the structural details of aromatic polyester TLCPs that influence the liquid crystalline and thermal properties. In the last part of this article the liquid crystalline properties of combined type and hyperbranched polyester also are discussed. Introduction to various synthetic methods are included in the last section.

Synthesis and Properties of Side Chain Liquid Crystalline Polymers with Siloxane Flexible Chain

  • Park, Jong-Ryul;Bang, Moon-Soo;Choi, Jae-Kon
    • Elastomers and Composites
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    • 제52권3호
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    • pp.173-179
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    • 2017
  • Side-chain liquid crystalline polymers having polysiloxane skeletons were synthesized by a thiol-ene reaction, using two kinds of mesogenic groups: a cholesteryl group for induction into a cholesteric liquid crystal phase and a triazomesogenic group for imparting light-sensitivity. All the synthesized polymers were crystalline, except the one with a single cholesteryl group. Crystallinity, glass transition temperature, and melt transition temperature increased with increasing content of the azomesogenic group. The polymer (P-C10A0) with a single cholesteryl group has a cholesteric phase, the one (P-C0A10) with a single azomesogenic group has a smectic phase, and those with both types of mesogenic groups showed both smectic and cholesteric phases. The temperature ranges of the two liquid crystalline phases in the co-polymers were independent of the contents of the two types of mesogenic groups. The rate of photoisomerization of the light-sensitive azobenzene group in the polymer decreased with increasing azobenzene content due to steric hindrance between the azomesogenic groups.