• 보존과학연구
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• 통권6호
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• pp.247-258
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• 1985

Conservation laboratory was attached to Keimyung University Museum inMarch 1980 and ever since it has been devoted mainly to the processing andconservation of metal objects. A number of objects have been processed inthis laboratory during the period, including those already in the collection ofthe Museum, those which were discovered during the three major excavationsof Kaya tombs conducted by the Museum, and those processed on commissionfrom other museums in the country,The activities of this laboratory include: (1) conserving the objects againstfurther erosion; (2) raising the archaeological value of the objects by revealingthe structure of such parts of the objects as concealed under rust; and (3)recovering the original shape of damaged objects.The methods adopted by the laboratory include: (1) removing from theobjects the ionized chlorine which usually are the major cause of erosion; (2)strengthening the objects by soaking them in acrylic resins; and (3) applyingresins to the surface of the objects to protect them from further erosion.Chemicals much employed by the laboratory includes the acrylic resin(Ruschot; developed jointly by the Cultural Property Research Institute ofKorea and Samwha Paint Company), the sodium sesquicarbonate, the sodiumhydroxide, the lithium hydroxide, and the benzotriazole.Major apparatus in the laboratory includes the vacuum immersion tank, theairbrasive, the ultrasonic cleaner, the pH-ion meter, the water bath, the zoomstereo microscope, the drying oven, and the drill.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2005년도 아시안 푸드의 기능성과 세계화 전략에 관한 국제심포지움
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• pp.112-123
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• 2005

For thestudying and utilizing the thorn sea cucumber synthetically, the method preparing polysaccharide and polypeptide from sea cucumber was studied. The comparatively rational craft for preparing crude polysaccharide is fresh raw materials deal with oar form, $60\%$ of the ethanol precipitate after hydrolyzed by pretense and vibrated with ultrasonic wave auxiliary. The purification of polysaccharide and removal of protein fromcrude polysaccharide were made through precipitation method using the acetate. The polypeptide is obtained by concentrating in vacuum, freeze-drying after mixing precipitations of two times. Polysaccharide acute poisoning experiment indicate there is no bad reaction when LD50>5000g/kg, there strain rate of liver tumor H11 approach present generally acknowledged tumor treat medicine cyclophosphamide, and there is no side effect. The fatigue resistance function of polypeptide experiment also indicates that the fatigue resistance ability of mouse which fed on added sea cucumber polypeptide has a great improvement.

• 펄프종이기술
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• 제46권6호
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• pp.78-86
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• 2014

Since cellulose nanofibrils (CNF) has large specific surface area and high water holding capacity, it is very difficult task to remove water from the CNF suspension. However, dewatering of CNF suspension is a prerequisite of following processes such as mat forming and drying for the application of CNF. In this study, we evaluated the drainage of cellulose fibers suspension under vacuum and pressure conditions depending on the number of grinding passes. Also, the effect of the addition of cationic polyelectrolyte on dewatering ability of CNF suspension was investigated. Regardless of dewatering condition, the total drained water amount as well as the drainage rate were decreased with an increase in the number of grinding passes. Pressure dewatering equipment enables us to prepare wet CNF mat with relatively higher grammage. The cationic polyelectrolytes improved the dewatering ability of CNF suspension by controlling the zeta potential of CNF. The fast drainage was obtained when CNF suspension had around neutral zeta potential.

• 수산해양기술연구
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• 제34권2호
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• pp.185-190
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• 1998

The aim of this study was to develop the artificial trap baits being able to replace the natural anchovy or sardine baits. The fishing trials for evaluating the fishing efficiencies of the artificial baits were conducted with commercial traps at coastal areas near Tongyoung, southern Korea. The preferable artificial baits which were made of minced anchovy, sardine, mackerel, or fish surplus products mixed with wheat flour into dry or wet pelleted or crumbled types, were showed some merits as the following. \circled1 Fishing efficiencies of the artificial baits were same or little higher level than that of the natural bait anchovy; \circled2 bait cost were same or little lower level; \circled3 dry artificial baits stocked in the room condition showed good fishing efficiencies; \circled4 making of artificial baits were very simple; \circled5 there were no harm to the fish and little pollution to the environment; \circled6 the releasing rate of attractants in the artificial or natural bait showed similar patterns. The artificial baits using the fish by-products which were vacuum freeze-drying extract of boiled anchovy or tunas extract, showed lower catches in the conger eel, Coner miriaster, but similar catches in the crabs, mainly Charybdis japonica, to the those of natural anchovy bait.

• 전기학회논문지
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• 제66권11호
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• pp.1600-1604
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• 2017

Mo-Cu alloys have been widely used for heat sink materials, vacuum technology, automobile and many other applications due to their excellent physical and electronic properties. Especially, Mo-Cu composites with 5~20 wt% copper are widely used for the heavy duty service contacts due to their excellent properties like low coefficient of thermal expansion, wear resistance, high temperature strength and prominent electrical and thermal conductivity. In most of the applications, high dense Mo-Cu materials with homogeneous microstructure are required for high performance, which has led in turn to attempts to prepare ultra-fine and well-dispersed Mo-Cu powders in different ways, such as spray drying and reduction process, electroless plating technique, mechanical alloying process and gelatification-reduction process. However, most of these methods were accomplished at high temperature (typically degree), resulting in undesirable growth of large Cu phases; furthermore, these methods usually require complicated experimental facilities and procedure. In this study, Mo-Cu alloying were prepared by planetary ball milling (PBM) and spark plasma sintering (SPS) and the effect of Cu with contents of 5~20 wt% on the microstructure and properties of Mo-Cu alloy has been investigated.

• 한국세라믹학회지
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• 제44권5호
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• pp.144-147
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• 2007

Calcium metaphosphate (CMP) nanofibers with a diameter of ${\sim}600nm$ were prepared using electrospun CMP/polyvinylpyrrolidone (PVP) fibers through a process of drying for 5 h in air followed by annealing for 1 h at $650^{\circ}C$ in a vacuum. The viscosity of the CMP/PVP precursor containing 0.15 g/ml of PVP was 76 cP. Thermal analysis results revealed that the fibers were crystallized at $569^{\circ}C$. The crystal phase of the as-annealed fiber was determined to be ${\delta}-CMP\;({\delta}-Ca(PO_3)_2)$. However, the morphology of the fibers changed from smooth and uniform (as-spun fibers) to linked-particle characteristics with a tubular form most likely due to the decomposition of the inner PVP matrix. It is expected that this large amount of available surface area has the potential to provide unusually high bioactivity and fast responses in clinical hard tissue applications.

• Macromolecular Research
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• 제16권2호
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• pp.103-107
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• 2008

Carbon nanodots were prepared by the pyrolysis of a triblock copolymer. The triblock copolymer, poly(methyl methacrylate)-b-polystyrene-b-poly(methyl methacrylate) was synthesized by atom transfer radical polymerization using an initiator containing a diacetylene group. A polymer thin film on a mica substrate was prepared by spin-casting at 2,000 rpm from a 0.5 wt% toluene solution of the triblock copolymer. After drying, the cast film was vacuum-annealed for 48 h at $160^{\circ}C$. The annealed film formed a spherical morphology of polystyrene domains with a diameter of approximately 30 nm. The film was exposed to UV irradiation to induce a cross-linking reaction between diacetylene groups. In the subsequent pyrolysis at $800^{\circ}C$, the cross-linked polystyrene spheres were carbonized and the poly(methyl methacrylate) matrix was eliminated, resulting in carbon nanodots deposited on a substrate with a diameter of approximately 5 mn.

• 한국자기공명학회논문지
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• 제23권1호
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• pp.1-5
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• 2019

$^{19}F$ NMR experiments were carried out to observe the change of the characteristics of the PVdF binder which is an auxiliary material of the lithium ion battery. PVdF has various crystalline or amorphous phases by thermal treatment. A mixture of cathode and auxiliary materials including PVdF was coated on aluminum foil as an electron collector and then subjected to thermal treatment at various temperatures. The overlapped $^{19}F$ NMR signals obtained from the various phases were separately convoluted into the respective phases, and it was found that there was a relative ratio change of these phases. In addition, the crystal and amorphous phase of PVdF was changed during the vacuum drying, which is the last step of the actual electrode manufacturing. It was observed that the relative amount of amorphous phase, which may affect the flexibility of the electrode or the wettability of the electrolyte, abruptly changes after a certain temperature.

• KSBB Journal
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• 제23권5호
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• pp.375-380
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• 2008

생 및 반건참가자미의 저장성 향상을 위하여 아가미를 제거하지 않은 것 (WG)과 제거한 것 (OG), 건조도에 따라 생것(0 D), 20%건조한 것 (20 D), 40%건조한 것 (40 D), 0.1% chitosan-ascorbate (CA)의 처리와 무처리로 구분, 진공 포장하여 $5{\sim}10^{\circ}C$에서 10일간 저장하면서 미생물의 증식정도를조사하였다. $10^{\circ}C$에서 저장 중 생 참가자미의 WG와 OG를 비교한 결과, OG가 WG에 비하여 total aerobacter는 $0.3{\sim}0.5$ log cycle이 감소되었으며, coliform과 E. coli의 수도 낮았다. $10^{\circ}C$에서 저장 중 0 D, 20 D 및 40 D를 비교한 결과, total aerobacter, coliform 및 E. coli 모두 20 D에서 가장 낮았으며 total aerobacter의 경우는 생것에 비하여 $0.42{\sim}1.20$ log cycle이 낮았다. 진공포장한 생 참가자미를 $5^{\circ}C$와 $10^{\circ}C$에서 10일간 저장한 결과, $5^{\circ}C$의 경우는 total aerobacter가 log 4.17 CFU/g로 $10^{\circ}C$보다 $0.6{\sim}1.3$ log cycle이 낮았다. 가자미로부터 분리한 3종의 미생물 [aerobacter (A1), coliform (C12), E-coli (E7)]에 대한 CA의 항균효과를 조사한 결과 0.1%에서 3종 모두 생육이 완전히 억제되었다. 생 참가자미에 0.1% CA를 처리한 후 진공 포장하여 $10^{\circ}C$에서 10일간 저장한 결과 CA 비처리에 비하여 total aerobacter는 1.5 log cycle이 감소되었으며, coliform 및 E. coli도 감소되었으며, CA처리 반건참가자미 (20 D)에서도 유사한 경향을 나타내었다. 0 D 및 20 D를 CA처리한 후 진공 포장하여 $10^{\circ}C$에서 10일간 저장한 생시료 또는 조리하여 관능검사를 행한 결과, 0 D와 20 D 모두 CA 처리군에서 외관, 신선도, 조직감 및 종합적기호도 값이 비처리군의 "보통"에 비하여 우수한 것 (좋다$\sim$매우좋다)으로 평가되었다.

• 센서학회지
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• 제10권5호
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• pp.292-303
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• 2001

본 연구에서는 수평형 전계 방출 소자를 제작하고 그 특성을 측정하였다. 이를 진공자장 센서에 이용하기 위하여 Lorentz 원리를 응용하여 센서를 설계하고 제작하였다. $POCl_3(10^{20}cm^{-3})$ 도핑된 다결정 실리콘을 전계 방출 소자의 음극 및 양극 재료로 이용하였으며 그 두께는 각각 $2\;{\mu}m$였다. PSG(두께 $2\;{\mu}m$)를 희생층으로 사용하여 최종 단계에서 불산을 이용하여 제거하고 승화건조법을 이용하여 소자의 기판 점착 현상을 방지하였다. 제작된 소자를 유리기판 #1 위에 silver paste로 고정시키고 Cr 전극 패드와 와이어본딩 한 뒤 진공내에서 양극접합공정을 이용하여 소자를 $1.0{\times}10^{-6}\;Torr$에서 진공 실장하였다. 실장 후 게터를 활성화하여 내부진공도를 향상시켰다. 이렇게 패키징된 소자는 두달여 기간 동안 특별한 특성저하 없이 잘 동작되었으며 그 이상의 기간에 대해서는 확인하지 못하였다. 패키징된 자장 센서는 패키징하기 전 진공챔버 내에서 보인 특성치와 별다른 차이 없이 잘 동작되었으며 단지 약간의 전류 감소 현상만이 관찰되었다. 측정된 센서의 감도는 약 3%/T로서 작은 값이었으나 그 가능성을 확인할 수는 있었다.