• Economic and Environmental Geology
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• v.10 no.2
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• pp.67-74
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• 1977

Biggest talc deposits of South Korea, localized in Choong-Chung-Nam-do, are known as a products of hydrothermal metamorphism of serpentine. From studying mineral paragenesis and localization, three types of talc mineralization is presumed as follows: 1) Extended talc mineralization from autometamorphism (serpentinization) of ultra-basic igneous rocks, 2) Schistose talc rock as green schist facies of regional metamorphism and 3) Late hydrothermal mineralization and purification of serpentine and pre-existing low grade ores.

• ETRI Journal
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• v.44 no.1
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• pp.147-154
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• 2022

We demonstrate a new double-layer structure for stretchable interconnects, where the top surface of a serpentine polyimide support is coated with a thin eutectic gallium-indium liquid metal layer. Because the liquid metal layer is constantly fixed on the solid serpentine body in this liquid-on-solid structure, the overall stretching is accomplished by widening the solid frame itself, with little variation in the total length and cross-sectional area of the current path. Therefore, we can achieve both invariant resistance and infinite fatigue life by combining the stretchable configuration of the underlying body with the freely deformable nature of the top liquid conductor. Further, we fabricated various types of double-layer interconnects as narrow as 10 ㎛ using the roll-painting and lift-off patterning technique based on conventional photolithography and quantitatively validated their beneficial properties. The new interconnecting structure is expected to be widely used in applications requiring high-performance and high-density stretchable circuits owing to its superior reliability and capability to be monolithically integrated with thin-film devices.

• Journal of the Mineralogical Society of Korea
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• v.10 no.2
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• pp.126-138
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• 1997

Serpentinite of the Yesan-Gongju-Cheongyang area has been formed by serpentinization of ultramafic rocks. The ultramafic rock might be composed mainly of oilvine with minor pyroxene and amphibole. Olivine has a considerably restricted chemical compositional ranging from Fo90 to Fo93. Fresh serpentinite containing large amount of oilvine is usually massive in occurrence and dark green to black in color. Serpentine minerals occur not only as major mineral of serpentinite, but also as remnants in the talc ore which was formed from serpentinite. XRD study indicates that antigorie is the most abundant serpentine mineral of the serpentinite. Serpentinite consisting of antigorite usually shows non-pseudomorphic texture, whereas that consisting of lizardite shows pseudomorphic texture. Antigorite is found along the margins or fractures of olivine grains resulting in the formation of network of magnetite which was formed at the time of serpentinization. Lizardite, subordinate constituent mineral of serpentinite, frequently shows pseudomorphic mesh-texture after olivine. The chemical differences between antigorite and lizardite/chrysotile are small, so both minerals are not easily discernible with the electron microprobe. Antigorite occuers as elongate blades, flakes, or plates forming interpenetrating texture to obliterate previous textures. SEM study also shows that most serpentine minerals occur in platy or tabular form rather than in asbestiform. Fractures formed after main serpentinization are observed within the pseudomorphic central olivine grain. Careful observation of the serpentine pseudomorphs gives a great deal of data on the pre-serpentinization nature of the serpentine pseudomorphs gives a great deal of data on the pre-serpentinization nature of the ultramafic rocks. It is inferred that the serpentinization took place after the emplacement of ultramafic body into the relatively wet environment ceased and the cooling intrusive body crossed into the stability field of serpentine. It is inferred that the final pervasive serpentinization took place over a long time, by hydrothermal water supplied through the fracture system produced during emplacement of ultramafic rock.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.241-245
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• 2006

In this study, the characteristics of large area internal linear ICP sources of 1020mm X 920mm(substrate area is 880 X 660mm) were investigated using two different types of antenna, that is, a conventional serpentine-type antenna and a newly developed multiple U-type antenna. The multiple antenna showed a higher plasma density, a higher radical density, and more plasma stability compared to the serpentine-type antenna, and it appeared from the higher inductively coupling and less standing wave effect compared to the serpentine-type antenna. Using the multiple U-type antenna, the plasma density of $2\times10^{11}/cm^3$ with the plasma uniformity of 4% could be obtained using 15mTorr Ar and 5000W of RF power.

• Journal of the Mineralogical Society of Korea
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• v.21 no.1
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• pp.85-98
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• 2008

Calc-silicate rock sheet occurs within the Precambrian metasedimentary rocks in Bonghwa area, Kyungsangbuk-do, Korea. The calc-silicate rock runs parallel to bedding plane with $14{\sim}18$ meters in width. Calcite, dolomite, serpentine and tremolite are occurred as major minerals and talc is occurred as a miner mineral. Serpentine mainly occurs in the upper part and tremolite occurs in lower part of calc-silicate rock sheet. Colors of calc-silicate rock change to deeper green with increasing amounts of serpentine mineral. XRD, FT-IR analyses indicates that serpentine mineral is antigorite. Platy structure of antigorite is well observed by SEM analysis. EPMA data indicates that chemical composition of antigorite is very close to ideal ($SiO_2$: 44.3 wt% and MgO: 40.8 wt%). The chemical formula of antigorite is calculated as $Mg_{2.82}Al_{0.04}Fe^{3+}_{0.04}Si_{2.05}O_5(OH)_4$. From careful study by comparing mineralogical analysis data and occurrence, calc-silicate rock sheet was formed by metamorphism of calcareous sedimentary rocks having different mineralogical and chemical compositions. It is considered that the host rock of serpentine enriched upper part was more Mg-rich rocks than the host rocks of tremolite enriched lower part.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.4
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• pp.265-273
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• 2009

Proton Exchange Membrane Fuel Cell (PEMFC) has low operating temperature and high efficiency. And PEMFC consists of many components as bipolar plate, gas diffusion layer, membrane etc.. Flow-field in bipolar plate roles path for transporting reactants to membrane. Therefore a design of flow-field has an effect on PEMFC's performance. In this study, Computational Fluid Dynamics (CFD) simulations were performed for comparing mixed multiple serpentine (MMS) flow-field and multiple serpentine (MS) flow-field. And we studied an effect according to change mixing region design in MMS flow-field. Finally the applicability of results is verified by performing CFD simulation about fixed MMS flow-field which is combined good designs.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.147-151
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• 2007

A serpentine channel geometry often used in a polymer electrolyte membrane fuel cell has a strong pressure gradient between adjacent channels in specific regions. The pressure gradient helps some amount of reactant gas penetrate through a gas diffusion layer(GDL). As a result, the overall serpentine flow structure is slightly different from intention of a designer. The purpose of this paper is to examine the effect of serpentine flow structure on current density distribution. By using a commercial code, STAR-CD, a numerical simulation is performed to analyze the fuel cell with relatively high aspect ratio active area. To increase the accuracy of the numerical simulation, GDL permeabilities are measured with various compression conditions. Three-dimensional flow field and current density distribution are calculated. For the verification of the numerical simulation results, water condensation process in the cathode channel is observed through a transparent bipolar plate. The result of this study shows that the region of relatively low current density corresponds to that of dropwise condensation in cathode channels.

• Korean Journal of Materials Research
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• v.9 no.8
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• pp.810-816
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• 1999

The variations of crystalline structures and physical proerties of serpentine and talc mineral which was treated in a planetary ball mill, wre investigated by means of X-ray diffraction, FT-IR, DSC-TG, particle size analysis and SEM observation. The crystalline peaks of serpentine and talc in the XRD patterns were gradually reduced with the increase of grinding time and after 120 minutes turned into the amorphous phase, which is attributed to the disordering of the local structure around magnesium. The endothermic peaks for the ground serpentine and talc sample are observed at a considerably lower temperatures than that for the starting sample. A morphological change from the originally flat and irregular shape to spherically agglomerated particles was clearly observed.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.679-684
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• 2003

급속한 경제성장과 산업발달로 인해 국내외 에너지 소비량은 매년 크게 증가하고 있으며 이에 따라 화석연료의 사용도 증가하는 추세이다. 연소반응을 통한 화석연료의 사용은 GHG 중 가장 큰 요인인 $CO_2$를 배출한다. 따라서 막대한 양으로 배출되고 있는 $CO_2$ 발생을 억제하기 위하여 다양한 이산화탄소 고정화 기술이 연구 중에 있다. 그 중에서 경제성이 있고, 환경친화적이며 대량의 $CO_2$를 안정적이고 영구적으로 처리할 수 있는 기술로 주목되고 있는 연구가 광물질을 이용한 $CO_2$ 미네랄 Carbonation 처리기술에 대하여 반응특성을 고찰하였다. 대상 광물질로 Ca 보다 $CO_2$ 처리 시 친화적인 것으로 알려진 Mg가 많이 함유된 Silicate 계열의 사문석(Serpentine[Mg$_3$Si$_2$O$_{5}$(OH)$_4$])을 대상으로 Carbonation 반응특성을 실험을 통하여 고찰하였다. 실험은 TGA를 이용한 분석실험과 200cc 급 Autoclave를 이용한 $CO_2$의 직접주입실험을 수행하였다. TGA분석과 200cc 급 Autoclave를 이용한 실험을 통해서 Serpentine 의 경우 실험에서 정한 운전조건에서 $CO_2$와의 Carbonation 반응에 적합한 물질로 판단된다는 결론을 도출하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1261-1268
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• 2006

This paper reports low-cost microreactor $(10{\mu}{\ell})$ biochip for the DNA PCR (polymerase chain reaction). The microbiochip $(20mm{\times}28mm)$ is a hybrid type which is composed of PDMS (polydimethylsiloxane) layer with serpentine micochannel $(360{\mu}m{\times}100{\mu}m)$ chamber and glass substrate integrated with microheater and thermal microsensor. Undesirable bubble is usually created during sample loading to PMDS-based microchip because of hydrophobic chip surface. Created bubbles interrupt stable biochemical reaction. We designed improved microreactor chamber using microfluidic simulation. The designed reactor has a coner-rounded serpentine channel architecture, which enables stable injection into hydrophobic surface using micropipette only. Reactor temperature needed to PCR reaction is controlled within ${\pm}0.5^{\circ}C$ by PID controller of LabVIEW software. It is experimentally confirmed that SRY gene PCR by the fabricated microreactor chip is performed for less than 54 min.