• Journal of Plant Biology
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• 제19권3호
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• pp.85-91
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• 1976

A comparison betwen the productivity of Pinus rigida which is native in the Eastern United States, and P. rigitaeda which is F1 hybrid between P. rigida and P. taeda, has been established. For each tree the diameter at breast height (D) and the height of tree (H) were measured in three years. The standard sample trees were down and then weighed each organ. From obtained data the allometric relation between $D_2H$ and dry weight of the trunk (Ws), the branches (Wb) and the leaves (Wl) of P. rigida were approxmated by $$Ws=0.0592 (D^2H)^{0.837}$$ $$Wb=0.0065 (D^2H)^{0.989}$$ $$Wl=0.0447(D^2H)^{0.690}$$ and those of P. rigitaeda were approximated by $$Ws=0.0522 (D^2H)^{0.843}$$ $$Wb=0.0037 (D^2H)^{1.117}$$ $$Wl=0.0207 (D^2H)^{0.856}$$ From the above, the standing crops of above ground of P. rigida were estimated to be as much as 16.93-34.35 ton dry matter per ha, and those of P. rigitaeda were 20.45-45.55 ton per ha. Annual net production was appraised at 8.07-9.35 ton/ha.yr in P. rigida and at 11.59-13.41 ton/ha.yr in P. rigitaeda (1.0:1.4). It is assumed that high productivity of P. rigitaeda stand compared with P. rigida resulted from an increase of the leaf amount with age. Photosynthetic ability under the saturated light of the current and theold leaves of P. rigida were respectively 2.62 and 0.66mg CO2/g. d. wt..hr and those of P. rigitaeda were 1.17 and 0.96mg CO2/g.d. wt.hr. Respiration of the current and the old leaves at $25^{\circ}C$ were 1.00 and 0.90 mg CO2/g. d. wt..hr. in P. rigida and 0.90 and 0.45mg CO2/g.d.wt.hr in P. rigitaeda. It is assumed that photosynthetic longevity of P. rigitaeda leaves was vigorously maintained longer than that of P. rigida.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권7호
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• pp.347-351
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• 2004

The $ZnNb_2O_{6}$ ceramics with CuO(1, 3, 5wt%) were prepared by the conventional mixed oxide method. The ceramics were sintered at the temperature of $950^{\circ}C$∼$1075^{\circ}C$ for 3hr in air The structural properties and the microwave dielectric properties of $ZnNb_2O_{6}$ ceramics were investigated with sintering temperature and the addition of CuO. Increasing the addition of CuO, the peak of second phase($Cu_3Nb_2O_{8}$) was increased. The grain size of the $ZnNb_2O_{6}$ ceramics with CuO was increased with CuO addition at same temperature. The dielectric constant of $ZnNb_2O_{6}$ ceramics with CuO was increased with sintering temperature and CuO addition. While the quality factor of the $ZnNb_2O_{6}$ ceramics with lwt% CuO depended on sinterability, the quality factor of $ZnNb_2O_{6}$ with 3wt% and 5wt% CuO depended on second Phase due to the CuO addition. The optimum dielectric Properties of $\varepsilon$$_{r}$ = 21.73 Q${\times}$f = 19,276 were obtained from the condition of 3wt% CuO addition and sintering temperature of $1025^{\circ}C$(3hr).

• 자원환경지질
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• 제28권6호
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• pp.541-551
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• 1995

The Yeongdeog gold-silver deposits at Jipum, Gyeongsangbugdo, is of a middle Paleogene $(45.52{\pm}1.02Ma)$ vein type, and is hosted in shale and sandstone of Cretaceous age. Based on mineral paragenesis, vein structure and mineral assemblages, the ore mineralization can be divided into two distinct depositional stages. The early stage is associated with base-metals such as pyrite, arsenopyrite (27.99~30.99 at%), hematite, rutile, pyrrhotite, sphalerite (10.53~18.42 FeS mole%), chalcopyrite and galena with wallrock alteration such as chlorite, sericite and pyrite. The late stage is characterized by the Au-Ag mineralization such as electrum, Ag-bearing tetrahedrite, freibergite, pyrargyrite, unidentified mineral, pyrite, sphalerite (1.08~5.57 FeS mole%), chalcopyrite and galena. Fluid inclusion data indicate that fluid temperatures and salinities range from 343 to $227^{\circ}C$ and from 8.3 to 5.7 wt% eq. NaCl in early stage, respectively. Temperatures and salinities of NaCl eq. wt% range from 299 to $225^{\circ}C$ and from 12.9 to 4.3 in late stage, respectively. They suggest that complex cooling histories were occured by the mixing of the fluids. Sulfur fugacity $(-logfs_2)$ deduced by mineral assemblages and composition ranges from 8.3 to 14.7 atm. in early stage, and from 8.8 to 14.5 atm. in late stage. It suggests that the mineralization was related to decrease of temperature in early stage and fluctuations of $fS_2$ with decrease of temperature in late stage. Sulfur and oxygen isotope compositions are 4.48~5.60‰ and 9.25~10.8% in early stage, and late stage is 4.84~7.00‰ and 5.7‰, respectively. It indicated that hydrothermal fluids may be magmatic origin with some degree of mixing of another water during paragenetic time.

• 한국재료학회지
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• 제8권8호
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• pp.737-743
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• 1998

$SrAI_2O_4:Eu^{2+}$를 합성하여 장잔광 축광재료로서 가장 중요한 발광특성과 장잔광특성을 조사하였다. 융제로서 $B_2O_3$를 3wt% 첨가한 $SrCO_3$, $Eu_2O_3$, $AI_2O_34의 혼합분말은 $1000^{\circ}C$이상에서 모체결정인 $SrAl_2O_4$의 단일상이 형성되었으나, 장잔관 형광체로서 최적의 합성조건은 $1300^{\circ}C$, 3시간이었다. 그리고 $SrAI_2O_4:Eu^{2+}$는 부활제인 $Eu^{2+}$의 $4f^65d^1$ $\rightarrow$$4f^7$천이에 기인하여 황록색발광영역의 520nm(2.384eV)를 최대 발파장으로 하는 450~650nm의 폭넓은 발광스펙트럼을 보였으며, 또한 발광파장을 520nm로 고정하여 측정한 여기스펙트럼의 최대 흡수피크는 360nm이고 250nm에서 480nm의 넓은 범위에서 흡수스펙트럼이 관찰되었다.

• 한국도로학회논문집
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• 제8권1호
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• pp.1-13
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• 2006

본 논문은 가열 재생아스팔트 흔합물의 성능을 향상시키기 위한 방법을 개발하기 위한 연구의 일부분이다. 새로이 개발된 혼합 방법은 회수 아스팔트 포장의 기존 바인더를 훨씬 많이 회생시켜 재생 혼합물에서 균일한 바인더의 정도를 갖게 한다. 본 연구의 목적은 새로이 개발된 혼합 방법으로 제조된 재생아스팔트 혼합물의 소성변형 저항 특성을 평가하는 것이다. 두 종류 골재(편마암 화강암), RAP의 두 가지 함량(15, 30%), LDPE의 두 가지 첨가량(0, 6%)를 이용하였으며, 혼합방법은 바인더의 불균등 상태를 개선하기 위한 두 가지 방법, 즉 일반적인 기존의 A 방법과 새롭게 개발한 F 방법을 이용하였다. 재생 혼합물 내의 바인더 산화 정도의 차를 조사하기 위하여 GPC분석을 실시하였고, 흔합 방법에 따른 소성변형 저항성을 평가하기 위하여 각 혼합 방법에 따라 제작한 재생 흔합물을 휠 트랙킹 시험과 변형강도를 측정하였다. 소성변형 저항 특성과 변형강도와의 상관관계는 기존의 A 방법보다 새롭게 개발된 F 방법이 더 높게 나타나, F 방법으로 제조된 혼합물의 품질이 보다 일관성 있는 소성변형 저항성을 나타내는 것을 알 수 있었다.

• Molecules and Cells
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• 제41권8호
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• pp.733-741
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• 2018

Mutations in spliceosome components have been implicated in carcinogenesis of various types of cancer. One of the most frequently found is U2AF1 S34F missense mutation. Functional analyses of this mutation have been largely limited to hematological malignancies although the mutation is also frequently seen in other cancer types including lung adenocarcinoma (LUAD). We examined the impact of knockdown (KD) of wild type (wt) U2AF1 and ectopic expression of two splice variant S34F mutant proteins in terms of alternative splicing (AS) pattern and cell cycle progression in A549 lung cancer cells. We demonstrate that induction of distinct AS events and disruption of mitosis at distinct sub-stages result from KD and ectopic expression of the mutant proteins. Importantly, when compared with the splicing pattern seen in LUAD patients with U2AF1 S34F mutation, ectopic expression of S34F mutants but not KD was shown to result in common AS events in several genes involved in cell cycle progression. Our study thus points to an active role of U2AF1 S34F mutant protein in inducing cell cycle dysregulation and mitotic stress. In addition, alternatively spliced genes which we describe here may represent novel potential markers of lung cancer development.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.151.2-151.2
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• 2015

본 연구에서는 indium-tin-oxide(ITO)/1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile(HAT-CN)/N,N'-di(naphthalene-lyl)-N,N'-diphenyl-benzidine(NPB)/4,4'-Bis(N-carbazolyl)-1,1'-biphenyl(CBP)/2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)TPBi/tris-(8-hydroxyquinoline) aluminum($Alq_3$)/LiF/Al 구조를 가진 유기 발광 다이오드 소자의 발광층에 $Ir(ppy)_3$(2% wt)을 도핑하여 소자의 특성 변화를 살펴보았다. $Ir(ppy)_3$의 두께는 5nm이고 도핑 위치는 정공 수송층과 발광층 계면의 0nm에서부터 25nm까지 5nm간격으로 도핑을 하였다. 실험 결과 소자의 효율은 도핑 위치가 정공 수송층에서 25nm떨어진 위치일 때 가장 높았고, 10nm일 때 가장 낮았다. 이는 도핑 부분의 위치가 정공 차단층에 가까워질수록 정공과 전자의 균형이 좋아지는 것이 소자 성능을 향상시키는 원인으로 추측된다.

• 폴리머
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• 제36권1호
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• pp.22-28
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• 2012

그래핀의 우수한 열적 특성을 이용하여 에폭시 수지의 열전도 특성을 향상시키며 전기 절연성질을 유지하는 기능화된 그래핀/에폭시 복합체를 제작하여 전기 및 열전도도를 측정하였다. 기능화된 그래핀은 Hummers법을 이용하여 산화그래핀(GO)을 얻어낸 후 aluminum isopropoxide를 졸-젤 반응을 통해 $Al(OH)_3$를 그래핀 표면에 도입하여 제작하였다(Al-GO). GO와 Al-GO의 기능화 여부 확인을 위하여 XPS, FE-SEM, FE-TEM 분석을 시행하였으며 GO 표면에 $Al(OH)_3$ 층이 생성된 것을 확인하였다. 기능화된 그래핀/에폭시 복합체는 bisphenol A(DGEBA) 계열의 에폭시에 1, 3 wt%의 GO와 Al-GO를 첨가하여 전기저항을 측정하였으며 Al-GO가 GO와 비교하여 전기 절연성질이 우수하였다. 또한 DGEBA와 bisphenol F(DGEBF) 계열의 에폭시에 1 wt%의 GO와 Al-GO를 첨가하여 열전도 특성을 비교하였으며 순수 에폭시 레진과 비교하여 Al-GO/DGEBF는 23.3%, Al-GO/DGEBA는 21.8%의 열전도도 증가를 보였다.

• 한국세라믹학회지
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• 제41권8호
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• pp.599-604
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• 2004

무선 이동통신 산업에서 소형화와 RF모듈을 구현하기 위해 저온 동시 소성 세라믹(LTCC)기술이 부각되고 있다. LTCC용 재료는 90$0^{\circ}C$ 이하의 온도에서 소성이 되어야 한다 본 연구는 BaO-N $d_2$ $O_3$-Ti $O_2$ (BNT：20∼40wt%) 세라믹과 L $a_2$ $O_3$- $B_2$ $O_3$-Ti $O_2$ (LBT：80∼60wt%) 유리를 혼합하여 유리를 결정화시킴으로, 나타나는 부수적인 효과를 얻고자 하였다. 이에 소결 거동, 결정상 분석, 상대밀도 그리고 유전특성을 평가하였다 80wt% 유리의 첨가는 90%에 가까운 상대밀도를 갖는 복합체로서 15에 가까운 유전율과 10000GHz의 품질계수와 같은 우수한 유전특성을 보였다. 이와 같은 결과는 유리 결정화를 이용하여 LTCC용 유전체에 적용될 수 있는 가능성을 부여하였다.

• 한국분말재료학회지
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• 제22권2호
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• pp.116-121
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• 2015

$WS_2$-W-WC embedded carbon nanofiber composites were fabricated by using electrospinning method for use in high-performance supercapacitors. In order to obtain optimum electrochemical properties for supercapacitors, $WS_2$ nanoparticles were used as precursors and the amounts of $WS_2$ precursors were controlled to 4 wt% (sample A) and 8 wt% (sample B). The morphological, structural, and chemical properties of all samples were investigated by means of field emission photoelectron spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. These results demonstrated that the embedded phases of samples A and B were changed from $WS_2$ to $WS_2$-W-WC through carbothermal reaction during carbonization process. In particular, sample B presented high specific capacitance (~119.7 F/g at 5 mV/s), good high-rate capacitance (~60.5%), and superb cycleability. The enhanced electrochemical properties of sample B were explained by the synergistic effect of the using 1-D structure supports, increase of specific surface area, and improved conductivity from formation of W and WC phases.