• 한국결정성장학회지
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• 제13권5호
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• pp.235-240
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• 2003

대면적 GaN 기판재료의 개발은 GaN 계열의 응용 가능성을 확대하기 위한 중요한 과제중 하나이다. 이러한 가능성을 조사하고자 본 연구에서는 seed 기판으로 MOCVD-GaN 박막과 소스 물질로서 상업용 GaN 분말을 이용하여 승화법에 의해 GaN 후막 성장을 시도하였다. 일정한 $N_2$ gas와 $NH_3$ gas 유량으로 성장실의 압력을 대기압으로 유지할 때 후막성장에 대한 승화소스물질과 seed 기판 사이의 거리, 상ㆍ하부 히터의 온도, 성장시간 등의 영향들을 연구하였다. 성장된 GaN후막은 SEM 및 XRD등을 이용하여 후막성장 형태 및 구조를 관찰하였고 상온에서 PL특성측정을 통하여 후막의 광학적인 밴드갭 및 결함 등을 조사하였다. 이로부터 양호한 GaN 후막성장에 필요한 공정요소로서 소스와 seed 기판 간 거리, 상ㆍ하부 히터의 온도 및 성장시간 등의 조건들을 정할 수 있었다.

• 한국가구학회지
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• 제10권1호
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• pp.1-12
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• 1999

Of the vast number of plant taxa in the world, the wood is one of the most useful resources. It is important to identify the fibers of wood and pulp for the plant taxonomy and for the uses, but we do not have enough information on them, on them, especially for the computerizd data. The fiber identification is one of the difficult tasks. In addition to the plant taxonomy and the fiber-using industries, such identification is also important in many other fields, including education. document examiners, etc. For these purpose, the fibers should be exactly distinguished. The TISS system I have programed to identify various woods would also be useful in the identification of fibers by the genus and species in the features of unknown samples and in searching the features of a species based on its scientific name. Such searching programs are being developed in many other countries with a view to searching for the species name by using the features of the cells of the woody materials. With the survey of all the available literature, the features of the fibers of 124 species both of softwood and hardwood were examined under the electron and optical microscopies. Each species were coded and carded by the feature, and the databases were built. The microscopic were inputted into a personal computer program called and by a slide film scanner. The new computer program called TISS 2 was developed using C computer language. Korean language fonts were added to the TISS 2. The TISS 2 can be in adding and searching a image of fiber features both of a known fiber and an unknown fiber. The databases were corded for the DELTA system with was developed by Dallwitz and Paine in Australia, 1986.

• 한국진공학회지
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• 제16권3호
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• pp.181-186
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• 2007

본 연구에서는 플라즈마 디스플레이 패널의 방전 특성과 MgO 보호막 물성에 영향을 미치는 MgO 증착률에 대해 분석을 하였다. 물성 특성으로 결정 방향과 표면 거칠기 결정 구조 및 음극선 발광을 XRD (X-ray Diffraction), AFM (Atomic Force Microscopy), Mono-CL (Mono Cathode Luminescence analysis)등을 이용하여 측정하였고, 방전 특성으로는 방전개시전압과 방전 전류, 휘도를 진공 챔버와 오실로스코프 (TDS 540C), 전류 프로브 (TCP 312A), 휘도 색차계 (CS-100A)를 이용하여 측정하였다. 실험 결과 $5{\AA}/sec$의 증착률이 최적의 증착률임을 확인하였고, 또한 MgO의 증착률에 따라서 MgO 보호막의 물성특성이 변화하고 이에 의해서 전기적 광학적 특징이 영향을 받는 것을 확인하였다. 즉, 증착률 $5{\AA}/sec$을 기준으로 증착률이 증가할수록 (200) 결정 방향 및 음극선 발광의 밀도가 감소되고, 동작 전압은 증가하며 점차 효율이 나빠지는 경향을 보인다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.43.2-43.2
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• 2011

Single-walled carbon nanotubes (SWCNT) are transparent in the visible and show conductivity comparable to copper, and are environmentally stable. SWCNT films have high flexibility, conductivity and transparency approaching that indium tin oxide (ITO), and can be prepared inexpensively without vacuum equipment. Transparent conducting Films (TCF) of SWCNTs has the potential to replace conventional transparent conducting oxides (TCO, e.g. ITO) in a wide variety of optoelectronic devices, energy conversion and photovoltaic industry. However, the sheet resistance of SWCNT films is still higher than ITO films. A decreased in the resistivity of SWCNT-TCFs would be beneficial for such an application. We fabricated SWCNT sheet with $KAuBr_4$ on PET substrate. Arc-discharge SWCNTs were dispersed in deionized water by adding sodum dodecyl sulfate (SDS) as surfactant and sonicated, followed by the centrifugation. The dispersed SWCNT was spray-coated on PET substrate and dried on a hotplate at $100^{\circ}C$. When the spray process was terminated, the TCF was immersed into deionized water to remove the surfactant and then it was dried on hotplate. The TCF film was then treated with AuBr4-, rinsed with deionized water and dried. The surface morphology of TCF was characterized by field emission scanning electron microscopy. The sheet resistance and optical transmission properties of the TCF were measured with a four-point probe method and a UV-visible spectrometry, respectively. $HNO_3$ treated SWCNT films with Au nano-particles have the lowest 61 ${\Omega}$/< sheet resistance in the 80% transmittance. Sheet resistance was decreased due to the increase of the hole concentration at the washed SWCNT surface by p-type doping of $AuBr_4{^-}$.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1259-1259
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• 2001

Meat becomes brown and rancid during storage in the refrigerator and display in the case. Color changes, metmyoglobin formation and lipid oxidation are the important problems in the transportation / distribution of meat and retail display. The freshness of meat is determined by the sense of vision and smell. Since conventional method determining lipid oxidation is time consuming and destructive (it needs to homogenize meat with reagents, filtrate, time for reaction and read optical density using spectroscopy), more rapid and nondestructive technical tools are desired. The objective of this work was to evaluate near-infrared spectroscopy as an analytical tool for determining meat color, metmyoglobin formation and lipid oxidation. in beef, pork and chicken. Semitendinosus and longissimus thoracis muscles from six beef steers, biceps femoris and longissimus thoracis muscles from twelve LWD crossbred pigs, and superficial pectoral muscles from twenty-four broilers were used. About a 5-cm diameter and 1-cm thick sample (20.0g) was cut from the muscle and placed on plastic foam, over-wrapped with PVC film, and displayed under flourescent lights at 4 degrees C. during 10 days for beef and pork or 4 days for chicken. The spectra was measured by NIR systems Model 5500 Spectrophotometer using fiber optic scan at range of 400 - 1100 nm. Data were recorded at 2 nm intervals and 10 scans / 10 sec were averaged for every sample. Data obtained were saved as log 1/Re, where Re is the reflectance energy, and then mathematically transformed to second derivatives to reduce effects of differences in particle size. $L^{*}$, $a^{*}$ and $b^{*}$, and metmyoglobin formation were determined by conventional spectrophotometer using the integrating sphere unit. 2-Thiobarbituric acid reactive substances (TBARS) were measured for lipid oxidation. A multiple linear regression was used to find the equation which would best fit the data. The number of wavelengths used in the equation was selected based on the fewer number compared to the increasing multiple correlation and Decreasing standard error. (omitted)

• 폴리머
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• 제34권6호
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• pp.588-593
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• 2010

실리콘, 게르마늄, 주석이 결합된 7개의 아크릴 단량체가 개발되었고 이를 광경화시킨 필름의 굴절률을 측정하였다. 공단량체로 가교도가 높은 triacrylate(Trimer)를 사용하여 형성된 공중합체의 굴절률로부터 단일중합체의 굴절률을 계산하였다. 공유 결합된 $Ph_3Si$, $Ph_3Ge$, $Ph_3Sn$은 각각 아크릴 고분자 필름의 굴절률을 향상시키는데 기여하였고 주석이 게르마늄에 비해 약간 높은 기여도로 나타났다. 주석에 의한 굴절률 향상 효과는 $Bu_3Sn$을 도입한 결과와 aliphatic acrylate의 비교로 보다 명확하게 입증되었다. 주석과 황의 안정된 결합을 이용하여 $Ph_3SnS$가 도입된 아크릴 고분자의 굴절률은 589 nm에서 1.671로 높게 측정되었다. 측정 파장으로 656, 830, 1310, 1550 nm에서도 비슷한 굴절률이 관찰되었다.

• 보존과학회지
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• 제22권
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• pp.61-76
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• 2008

청동문화재 보존처리의 강화처리제로 가장 많이 쓰이고 있는 아크릴 수지인 Paraloid B72와 용제 4종(Acetone, MEK, Toluene, Xylene)을 선정하여 각 용제별 코팅 특성을 비교 분석하였다. 코팅 전 후의 표면을 현미경과 AFM을 통해 관찰하고 박막의 두께와 코팅 표면의 접촉각을 측정하여 표면에너지를 계산하였다. 그리고 Scratch Test를 통해 코팅 박막의 접착력을, 황변실험을 통해 코팅의 지속성을 조사하였다. 그 결과 Xylene을 용제로 사용하는 것이 육안으로 보았을 때 색 얼룩이 적고 적절한 소수성과 고른 표면을 가짐을 확인했다. 또한 코팅의 조건인 박막 두께가 얇으면서 접착력이 우수하며 황변에도 안정해야 한다는 점에서도 10% Paraloid B72 in xylene이 다른 용제에 비하여 우수한 코팅 성질을 가진다는 것을 확인하였다. 그러나 Paraloid B72의 적정농도를 찾기 위해서는 더 많은 실험과 분석이 이루어져야 할 것이다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.154-154
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• 2003

A stoichiometric mixture of evaporating materials for CuGaSe2 single crystal thin films was prepared from horizontal electric furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal CuGaSe2, it was found tetragonal structure whose lattice constant at and co were 5.615 ${\AA}$ and 11.025 ${\AA}$, respectively. To obtain the single crystal thin films, CuGaSe2 mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (MWE) system. The source and substrate temperatures were Slot and 450$^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (UXD). The carrier density and mobility of CuGaSe2 single crystal thin films measured with Hall effect by van der Pauw method are 5.0l${\times}$10$\^$17/ cm$\^$-3/ and 245 $\textrm{cm}^2$/V$.$s at 293K, respectively. The temperature dependence of the energy band gap of the CuGaSe2 obtained from the absorption spectra was well described by the Varshni's relation, Eg(T) = 1.7998 eV - (8.7489${\times}$10$\^$-4/ eV/K)T$^2$/(T + 335 K. After the as-grown CuGaSe2 single crystal thin films was annealed in Cu-, Se-, and Ca-atmospheres, the origin of point defects of CuGaSe2 single crystal thin films has been investigated by the photoluminescence(PL) at 10 K The native defects of V$\_$CU/, V$\_$Se/, Cu$\_$int/, and Se$\_$int/ obtained by PL measurements were classified as a donors or accepters type. And we concluded that the heat-treatment in the Cu-atmosphere converted CuGaSe2 single crystal thin films to an optical n-type. Also, we confirmed that Ga in CuGaSe2/GaAs did not form the native defects because Ga in CuGaSe2 single crystal thin films existed in the form of stable bonds.

• 조명전기설비학회논문지
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• 제24권2호
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• pp.106-112
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• 2010

플라즈마 디스플레이 패널(Plasma Hsplay Panel :PDP)이 다른 평판 디스플레이 분야(Liquid Crystal Displays(LCDs) and organic light emitting diodes(OLEDs)등)와 경쟁에서 이기기 위해서는 제품의 고화질화, 저소비전력와 고속구동 등의 성능향상이 필요하다. 본 논문에서는 PDP의 성능향상을 위하여 유전체 보호층으로 쓰이는 MgO 박막에 Fe를 미량 첨가한 박막을 증착하고, 그 특성에 대하여 연구하였다. e-beam 증착법으로 증착된 Fe 도핑 된 MgO 박막의 표면특성과 전기광학적 특성을 4인치 테스트 패널을 제작하여 연구하였다. Fe가 도핑된 MgO 박막을 가지는 PDP는 Fe가 도핑되지 않은 PDP에 비해 낮은 방전전압 특성을 나타내었으며, 이는 박막에서 측정된 2차전자방출계수의 실험결과와 잘 일치되었다. 증착된 박막의 결정성과 표면 거칠기는 XRD 와 AFM 측정방법을 통하여 결정되었다. 또한, Fe가 도핑된 PDP는 고속구동을 위한 향상된 어드레스 방전 늦음의 특성을 나타내었다.

• 전기학회논문지P
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• 제64권3호
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• pp.182-186
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• 2015

We investigated that effects of annealing ambient on the characteristics of functional nano thin film synthesized on glass substrate. The functional nano thin films were annealed by using rapid thermal annealing (RTA) equipment in vacuum, oxygen and nitrogen ambient, respectively. The hardness of the functional nano thin films were measured by a standard hardness testing method (ASTM D3363) such as a H-9H, F, HB and B-6B pencil (Mitsubishi, Japan). Also, the adhesion of the functional nano thin films were measured by a standard adhesion testing method (ASTM D3359) using scotch tape (3M, Korea). The contact angle of the functional nano thin films was measured by a contact angle analyzer (Phoenix 300 Touch, S.E.O.). The optical property of functional nano thin films was measured via UV-visible spectroscopy (S-3100, Scinco).