• 미생물학회지
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• 제42권1호
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• pp.19-25
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• 2006

치아우식중의 원인균 중 하나인 Streptococcus mutans를 종 수준에서 동정할 수 있는 중합효소연쇄반응 프라이머를 개발하기 위하여 본 연구를 시행하였다. 표준균주인 S. mutans ATCC $25175^T$및 본 연구에서 이용된 S. mutans 균주들의 16S rRNA 유전자 핵산염기서열을 바탕으로 S. mutans 종-특이 중합효소연쇄반응 프라이머(ChDC-SmF2와 ChDC-SmR2)를 설계 및 제작하였다. 프라이머의 특이도는 S. mutans 11균주와 구강 내 존재하는 12세 균 종(22균주)을 대상으로 실시하였다. 프라이머의 민감도는표준균주인 S. mutans ATCC $25175^T$의 유전체 DNA를 추출하여 실시하였다. 프라이머의 특이도 실험결과 10균주의 S. mutans 유전체 DNA에서만 종-특이 중합효소 연쇄반응 산물이 증폭되었고, 다른세균종의 유전체 DNA에서는 증폭되지 않았다. 또한 감수성 실험 결과 본 연구에서 사용된 프라이머는 direct PCR에 의해 S. mutans ATCC $25175T\^T$ 유전체 DNA 100 pg까지 검출 할 수 있었다. 또한 27F와 1492R 프라이머로 16S rDNA를 먼저 증폭한 다음, 이 증폭물 10배 회식한 것을 표적으로 해서 nested PCR을 시행한 결과 S. mutans ATCC $25175^T$ 유전체 DNA를 2 fg까지 검출할 수 있었다. 이상의 결과를 종합할 때, ChDC-SmF2와 ChDC-SmR2 프라이머들은 S. mutans 균주 유전체 DNA에 대한 높은 민감도를 가지고 있으며, 종-특이적으로 동정 및 검출하는 데 이용될 수 있을 것으로 생각된다.

• 대한화학회지
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• 제30권1호
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• pp.33-39
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• 1986

Sm$O_{1.5+x}$와 Zr$O_{2+x}$로 표시되는 사마늄 산화물과 지르코륨산화물의 비화학양론적 조성식의$x^-$값을 500$^{\circ}$C에서 1000$^{\circ}$C까지의 온도 영역과 2 ${\times} 10^{-1}$ ~ 1 ${\times}10^{-5}$기압 산소압력까지의 영역에서 중량 분석법에 의하여 측정하였다.$x^-$값은 온도가 상승하면 증가하고 산소압력이 높아짐에 따라 또한 증가하였다. 비화학양론적 조성의 생성엔탈피 ${\Delta}H_f$는 산소압력이 낮아지면 감소하였고 그 값은 양의 값을 갖는다. 산소압력 의존성 n/1은 온도가 상승하면 커지고 양의 값을 갖는 것으로 고온일수록 산소압력 의존성이 커짐을 나타낸다. $x^-$값과 열역학적 자료들로 부터 비화학양론적 결함은 이온화된 금속공위이다. 이들 계의 전도성 메카니즘을 비화학양론적 조성과 관련시켜 고찰하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1308-1318
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• 2010

The purpose of this study was to evaluate the effect of replacing soybean meal with treated castor meal with (CMT) or without lime (CMNT) on the nutrient intake, performance, carcass characteristics, and yield of commercial cuts of beef cattle from a feedlot. Thirty male, castrated, crossbreed zebu cattle were used in the study, with an average initial weight of $360{\pm}30.27\;kg$. Five animals were used as a control group and were slaughtered at the beginning of the experiment; the remaining animals (n = 25) were distributed in random blocks (repetitions), with body weight as the criterion for block assignment. The animals were fed a diet containing 65% corn silage and 35% of concentrate on dry matter (DM) basis. Five diets consisted of four levels of soybean meal (SM) substituted with CMT (0, 33, 67 and 100%) on a DM basis and a diet with 100% of SM replaced with CMNT. At the end of the experiment, all animals were slaughtered, and their gastrointestinal tracts were emptied to determine their empty body weights (EBW). No significant effects were observed (p>0.05) for the substitution of soybean meal with CMT on intake of dietary nutrients, the average daily body weight gain (ADG) or EBW gain (EBWG). In spite of greater (p<0.05) ricin intake for the diet containing CMNT (3.06 mg/kg BW) compared to the CMT diet (0.10 mg/kg BW/d), there were no effects (p>0.05) on intake of dietary nutrients, ADG or EBWG. The average intake of DM and the ADG were 10,664.63 and 1,353.04 g/d, respectively. Regarding carcass characteristics, only carcass yield in relation to body weight was linearly reduced (p<0.05) upon substitution of SM by CMT. There was no effect (p>0.05) of the substitution of SM by CMT or CMNT on the yield of carcass basic cuts. CMT prices that are higher than 85% of the SM price do not economically justify the use of CMT. For CMT prices between 20 and 80% of the SM price, the optimal level was 67% substitution, while for prices below 15% of the SM price, the optimal level was 100% substitution with CMT. It can be concluded that treated castor meal with 6% lime can totally replace soybean meal in beef cattle diets.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.852-858
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• 2004

Crystal structures of lanthanide complexes with NTA (NTA = nitrilotriacetate) are reported. The complexes of $[Ln(NTA)_2{\cdot}H_2O]^{3-}$ (Ln = Sm, Eu, Gd, Tb and Ho) crystallize in the orthorhombic space group Pccn. In the structures, the trivalent lanthanide ions are completely encapsulated via coordination to the two nitrogen atoms and the six carboxylate oxygen atoms of the two NTA ligands, and one water oxygen atoms. The complexes form a slightly distorted capped-square-antiprism polyhedron. Of the complexes, $[Eu(NTA)_2{\codt}H_2O]^{3-}$,\;[Tb(NTA)_2{\cdot}H_2O]^{3-}\;and\;[Dy(NTA)_2{\cdot}H_2O]^{3-}$ excited at the 325 He-Cd line produce very characteristic luminescence features, arising mostly from the f ${\to}$ f transitions. The absolute quantum yields of these complexes are determined at room temperature. Surprisingly, the $[Dy(NTA)_2{\cdot}H_2O]^{3-}$ complex is more luminescent than the $[Eu(NTA)_2{\cdot}H_2O]^{3-}\;and\;[Tb(NTA)_2{\cdot}H_2O]^{3-}$ complexes.

• Bulletin of the Korean Chemical Society
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• 제17권4호
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• pp.321-324
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• 1996

Sr1+xSm1-xFeO4-y solid solutions with a composition range 0.00 ≤x≤1.00 have been prepared at 1200 ℃ in air under normal atmospheric pressure. All the solutions exhibit the K2NiF4-type structure of tetragonal system. Mohr salt analysis shows that the mole ratio of Fe4+ ion to Fe3+ ion or the τ value increases with the x value. Nonstoichiometric chemical formulas have been formulated from the x, τ, and y values. Electrical conductivity was measured in the temperature range of 173-373 K under atmospheric air pressure. The conductivities of each sample are varied within the semiconductivity range. The conductivity at constant temperature increases steadily with x value and activation energies are varied from 0.14 to 0.32 eV. The conduction mechanism of the ferrite system may be proposed as a hopping model of conduction electrons between the mixed valence states. The Mossbauer spectrum for the composition of x=0.00 shows a six line pattern by which the existence of Fe3+(I.S.=0.32 mm/sec) can only be identified. The spectra for the compositions of x=0.50 and 1.00 presents broad single line patterns showing a mixed valence state.

• 적정기술학회지
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• 제7권2호
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• pp.151-161
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• 2021

The application of appropriate technologies in a developing country is an opportunity to introduce green technology which may lead people to imagine a better life. This point is at the intersection of appropriate technology and sustainable development. This research focuses on Hatphain village where there is no clean water, sewage system, or power lines. Two environmental technologies (an unpowered water purification system, Ongdalsaem and an eco-toilet system, BeeVi toilet) were introduced, based on the concepts of the environmental self- sustainable village and feces Standard Money (fSM). We found that the Ongdalsaem was effective in reducing the concentration of nitrogen and lead in the water in Hatphain. The BeeVi water-free toilet was installed, allowing urine and feces to be separated and used as compost. We strived to spread ideas of sustainability using new eco-circulation experiences and encouraging learning about environmental technology through practical and playing facilities that residents managed themselves.

• 한국융합학회논문지
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• 제8권10호
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• pp.75-84
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• 2017

본 연구는 간호대학생의 사회적 성숙도, 학습관련 자기주도성 및 전문직자아개념 간의 관련성을 파악하고 전문직 자아개념에 미치는 영향요인을 융복합적으로 분석하기 위해 실시되었다. 대상은 I지역과 K지역에 소재한 간호학과 학생 221명이었다. 자료는 구조화된 설문지를 이용하여 수집하였고, PASW 22.0 프로그램을 이용하여 분석하였다. 연구 결과 간호대학생의 전문직자아개념은 사회적 성숙도 및 학습관련 자기주도성과 순 상관관계가 있었고, 전문직 자아개념에 영향요인을 확인하기 위한 회귀모형은 유의한 것으로 나타났다(F=22.505). 전공만족도(${\beta}=.179$), 간호직 의미(${\beta}=.274$), 사회적 성숙도(${\beta}=.118$), 자기주도성(${\beta}=.211$)이 모두 유의한 예측요인으로 나타났고, 이들 변수의 설명력은 34.4%이었다. 본 연구결과를 토대로 올바른 간호전문직 자아개념의 증진을 위해 사회적 성숙도와 자기주도성의 향상을 위한 교육과정 및 사회성 향상 프로그램 등의 개발이 필요함을 확인하였다.

• 한국세라믹학회지
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• 제39권3호
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• pp.222-225
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• 2002

Microwave dielectric properties of the layered and functionally graded materials (FGMs) of $Mg_{0.93}Ca_{0.07}TiO_3$ (MCT) and $(Ca_{0.3}Li_{0.14}Sm_{0.42})TiO_3$(CLST) were investigated as a function of the volume ratio of two components. Dielectric constant was decreased with an increase of the volume ratio of MCT which had a lower dielectric constant thant CLST. For the layered FGMs specimens, the difference of thermal expansion coefficients between two components induced thermal strain to dielectric layers, which was confirmed by the plot of ${\Delta}$k (X-ray diffraction peak width0 versus k (scattering vector) using the double-peak Lorentzian function, f(x). Quality factor of the specimens was affected by the thermal strain of dielectric layer, especially MCT layer. For the specimen with the volume ratio of MCT/CLST = 2, the qulaity factor of the specimen showed a minimum value due to the maximum thermal strain fo MCT layer.

• Journal of Magnetics
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• 제21권1호
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• pp.25-28
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• 2016

In the present study, bulk anisotropic nanocrystalline $SmCo_5$ magnets were prepared by hot deformation. The effect of deformation temperature on the texture and magnetic properties are presented, based on which the mechanism of plastic deformation and texture formation during the hot deformation process is discussed. Our analyses reveal that deformation temperature is one of the most important parameters that determine the texture of $SmCo_5$ grains. We suggest that diffusion creep plastic deformation occurs during hot deformation, which is very sensitive to the energy gain provided by an increase in temperature.

• 한국정밀공학회지
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• 제15권9호
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• pp.43-49
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• 1998

The deep hole drilling has an increasing demands because of its wide range applications and its good productivity. The BTA drills are capable of machining for having a large length to diameter ratio in single pass to higher degree of accuracy and surface finish. It's really necessary that the investigation for the deep hole drilling by the BTA drill because its required quality should be satisfied with single pass. This thesis deal with the experimental results obtained during single tube BTA system machining on SM55C steel for different machining conditions. The results of the investigation on the optimum cutting condition selecting and tool life reveals as follows. (1) The optimum cutting condition was cutting speed, V = 42 m/min and feed speed. F = 90 mm/min and the tool life was about 10 meters. (2) Surface roughness was $12\mum$ and the roundness was less using $16mum$single edge BTA drill in testing cutting condition.