• 한국응용곤충학회지
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• 제61권1호
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• pp.165-172
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• 2022

곤충은 주변환경에 적응하며 발육과 번식을 통해 진화하여 왔다. 온도발육모형을 이용하여 곤충과 응애 분류군별 공통고유최적온도, 발육최적온도, 산란최적온도를 산출하기 위해 112편의 논문에서 응애류 14종, 딱정벌레목 8종, 파리목 5종, 노린재목 31종, 벌목 7종, 나비목 18종, 메뚜기목 1목, 다듬이벌레목 5종, 총채벌레목 5종의 온도발육과 산란자료를 분석하였다. 분석을 통하여 총채벌레목을 제외하고 공통고유최적온도는 발육최적온도보다는 산란최적온도와 차이가 적었다. 본 종설을 통해 공통고유최적온도는 발육최적온도보다는 산란최적온도와 밀접한 관계가 있을 가능성이 높음을 제안하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.381.1-381.1
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• 2014

In this study, we investigated the deposition behavior and the etch resistivity of plasma polymerized carbon hardmask (ppCHM) film with the variation of process temperature. The etch resistivity of deposited ppCHM film was analyzed by thickness measurement before and after direct contact reactive ion etching process. The physical and chemical properties of films were characterized on the Fourier transform infrared (FT-IR) spectroscope, Raman spectroscope, stress gauge, and ellipsometry. The deposition behavior of ppCHM process with the variation of temperature was correlated refractive index (n), extinction coefficient (k), intrinsic stress (MPa), and deposition rate (A/s) with the hydrocarbon concentration, graphite (G) and disordered (D) peak by analyzing the Raman and FT-IR spectrum. From this experiment we knew an optimal deposition condition for structure of carbon hardmask with the higher etch selectivity to oxide. It was shown the density of ppCHM film had 1.6~1.9 g/cm3 and its refractive index was 1.8~1.9 at process temperature, $300{\sim}600^{\circ}C$. The etch selectivity of ppCHM film was shown about 1:4~1:8 to undoped siliconoxide (USG) film (etch rate, 1300 A/min).

• 응용통계연구
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• 제17권2호
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• pp.281-301
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• 2004

본 논문에서는 일변량 정규분포를 따르는 확률변수의 관측치열에 대한 변화점 문제(change point problem)를 고찰한다. 변화점의 존재유무, 그리고 만일 변화점이 존재한다면 어떠한 유형으로 발생했는지 즉, 변화점 발생 이후로 평균만 변화, 분산만 변화, 또는 평균과 분산 모두가 변화했는지를 밝힌다. 가능한 여러 유형의 변화모형들 가운데 최적의 모형을 선택하기 위해 베이지안 모형선택 기법을 이용하고, 선택된 모형에 내재된 모수를 추정 하기 위해 메트로폴리스-혜스팅스 알고리 즘을 포함한 깁스샘플링 을 이용한다. 이러한 방법론은 모의실험을 통해 검토되고, 또한 서울지역의 겨울철 평균기온 자료에 적용된다.

• 농약과학회지
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• 제9권3호
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• pp.221-230
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• 2005

국내에 서식하는 주요 물벼룩에 대한 독성시험기준 마련의 필요성에 따라 국내환경에서의 대표성, 실내사육가능성 및 독성시험에 적합한 크기 등을 고려하여 선발된 4종의 한국산물벼룩(Daphnia sp., Daphnia obtusa, Moina macrocopa, Simocephalus vetulus)과 Daphnia magna를 대상으로 사육온도(16, 20, 24, $28^{\circ}C$)에 따른 번식영향을 조사하였다. 그 결과 실험에 사용한 5종 물벼룩 모두 온도가 높을수록 탈피횟수, 새끼출산수 및 내적자연증가율이 증가하고 성체가 되는데 걸리는 기간과 생존율은 낮아지는 경향을 보였다. 따라서 높은 온도조건에서 높은 내적자연증가율을 보여줌에도 불구하고 고온에서의 높은 모체사망율을 고려한다면 대부분은 $20^{\circ}C$ 내외가 가장 적절한 사육온도임을 알 수 있었다. 다만 D. obtusa의 경우에는 $16^{\circ}C$에서 더 높은 모체생존율을 보여주었으며 내적자연증가율도 $20^{\circ}C$와 비교하여 큰 차이가 없어 $16^{\circ}C$ 내외가 더 적절한 온도인 것으로 판단되었다.

• Transactions on Electrical and Electronic Materials
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• 제10권3호
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• pp.75-79
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• 2009

An intrinsic silicon thin film passivation layer is deposited by the microwave remote-plasma enhanced chemical vapor deposition at temperature of $175^{\circ}C$ and various gas ratios for solar cell applications. The good quality amorphous silicon films were formed at silane $(SiH_4)$ gas flow rates above 15 seem. The highest effective carrier lifetime was obtained at the $SiH_4$, flow rate of 20 seem and the value was about 3 times higher compared with the bulk lifetime of 5.6 ${\mu}s$ at a fixed injection level of ${\Delta}n\;=\;5{\times}10^{14}\;cm^{-3}$. An annealing treatment was performed and the carrier life times were increased approximately 5 times compared with the bulk lifetime. The optimal annealing temperature and time were obtained at 250 $^{\circ}C$ and 60 sec respectively. This indicates that the combination of the deposition of an amorphous thin film at a low temperature and the annealing treatment contributes to the excellent surface and bulk passivation.

• BMB Reports
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• 제42권5호
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• pp.293-298
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• 2009

Temperate mycobacteriophage L1 encodes an unusual repressor (CI) for regulating its lytic-lysogenic switching and, in contrast to the repressors of most temperate phages, it binds to multiple asymmetric operator DNAs. Here, ions like $Na^+$, $Cl^-$, and $acetate^-$ ions were demonstrated to facilitate the optimal binding of CI to cognate operator DNA, whereas $K^+$, $Li^+$, ${NH_4}^+$, $Mg^{2+}$, $carbonate^{2-}$, and $citrate^{3-}$ ions significantly affected its operator binding activity. Of these ions, $Mg^{2+}$ unfolded CI most severely at room temperature and, compared to $Mg^{2+}$, $Na^+$ provided improved thermal stability to CI. Furthermore, the intrinsic tryptophan fluorescence of CI was changed notably upon replacing $Na^+$ with $Mg^{2+}$ and these opposing effects of $Mg^{2+}$ and $Na^+$ were also noticed in their actions on the C-terminal fragment (CTD) of CI. Taken together, $Na^+$ appeared to be more appropriate than $Mg^{2+}$ for maintaining the biologically active conformation of CI needed for its optimal binding to operator DNA.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.494-499
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• 2005

The chemical, physical, and emulsifying properties of BSF-1, which is an extracellular lipopolysaccharide biosurfactant produced by Klebsiella oxytoca strain BSF-1, were studied. BSF-1 was found to be composed mainly of carbohydrate and fatty acids. The average molecular weight was $1,700{\sim}2,000 kDa$. The polysaccharide fraction contained L-rhamnose, D-galactose, D-glucose, and D-glucuronic acid at a molar ratio of 3:1: 1:1. The fatty acid content was 1.1 % (w/w) and consisted mainly of palmitic acid (C16:0), 3-hydroxylauric acid (3-OH-C12:0), and lauric acid (C12:0). In terms of thermal properties, BSF-1 was revealed to have inter- and intra-molecular hydrogen bonds. The hydrodynamic volume (intrinsic viscosity) of BSF-1 was 22.8dL/g. BSF-1 could be maintained as a stable emulsion for 48 h through a low-level reduction in surface tension. The optimal emulsification temperature was $30^{\circ}C$. Emulsification by BSF-1 was efficient at both acidic and neutral pH values.

• 한국수산과학회지
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• 제29권6호
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• pp.843-848
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• 1996

As the first step of studies related to production of chitooligosaccharides by physical methods, chitosan solution were sonicated with 20 kHz and various treatment effects were examined to present fundamental data of sonicated chitosan solution. Intrinsic viscosity of chitosan solution sharply decreased from 3.76 dl/g to 2.90 dl/g until 5 minutes of sonication and then slowly decreased. With low volume of chitosan solution, sonication was very effective and temperature of chitosan solution slightly affected the efficiency of sonication. In case of changing the solvent, no significant differences were observed on the effect of sonication, however, acetate buffer had highest sonication effect among various solvents. The sonication effect was increased as the increasement of the value of pH, on the contrary, ionic strength and type of counterions showed no effect on sonication. With these results, we assumed that optimal sonication treatment would be as follows, solution volume was $10\~20\;ml$, temperature range was $20\~30^{\circ}C$, pH value of solution was 4.5 and type of solvent was acetate buffer.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.421-428
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• 1989

물성조정제로서 고전도의 다당류를 생산하는 토양세균을 분리 선발하여 동정한 결과 Pseudomonas delafieldii로 판단되었다. 이 세균의 증식을 위한 pH와 온도는 6.5 및 3$0^{\circ}C$이었다. 최대 비성장속도는 0.25 h$^{-1}$이며 염류배지에서 다당류의 비생산속도, 증식수율 및 다당류 생산수율은 6.25mg/g-cell/h, 54.5%, 38.39%이었다. 본 다당류는 포도당과 gluconolactone을 몰비로 1.9：1.0로 함유한 $\beta$-glucan 으로 추정되었으며 원인 분석결과 탄소 31.85% 수소 31.85% 수소 5.l5%를 함유하고 아세틸기를 1.35%가지고 있었으며 고유점도는 42.84dl/g, 분자량은 5.64$\times$$10^7$이었다.

• 소성∙가공
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• 제21권4호
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• pp.240-245
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• 2012

With the increasing demand for light-weight materials to reduce fuel consumption, the automobile industry has extensively studied magnesium alloys which are light weight metals. The intrinsic poor formability and poor ductility at ambient temperature due to the hexagonal close-packed (HCP) crystal structure and the associated insufficient number of independent slip systems restricts the practical usage of these alloys. Hot working of magnesium alloys using a forging or extrusion enables net-shape manufacturing with enhanced formability and ductility since there are several operative non-basal slip systems in addition to basal slip plane, which increases the workability. In this research, the thermomechanical properties of AZ80 Mg alloy were obtained by compression testing at the various temperatures and strain rates. Optical microscopy and EBSD were used to study the microstructural behavior such as misorientation distribution and dynamic recrystallization. The results were correlated to the hardening and the softening of the alloy. The experimental data in conjunction with a physical explanation provide the optimal conditions for net-shape forging under hot or warm temperatures through control of the grain refinement and the working conditions.