• Nuclear Engineering and Technology
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• 제51권2호
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• pp.518-525
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• 2019

The mechanical and corrosion behavior of the Russian zirconium fuel cladding alloy E110, predominantly used in VVERs, has been investigated for many decades. The recent commercialization of a new, optimized E110 alloy, produced on a sponge zirconium basis, gave the opportunity to compare the mechanical properties of the old and the new E110 fuel claddings. Axial and tangential tensile test experiments were performed with samples from both claddings in the MTA EK. Due to the anisotropy of the cladding tubes, the axial tensile strength was 10-15% higher than the tangential (measured by ring tensile tests). The tensile strength of the new E110G alloy was 11% higher than that of the E110 cladding at room temperature. Some samples underwent chemical treatment - slight oxidation in steam or hydrogenation - or heat treatment - in argon atmosphere at temperatures between 600 and $1000^{\circ}C$. The heat treatment during the oxidation had more significant effect on the tensile strength of the claddings than the oxidation itself, which lowered the tensile strength as the thickness of the metal decreased. The hydrogenation of the cladding samples slightly lowered the tensile strength and the samples but they remained ductile even at room temperature.

• 대한전자공학회논문지SD
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• 제42권2호
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• pp.89-96
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• 2005

본 논문은 ATM 망에서 멀티미디어 데이터 서비스를 지원하기 위한 가입자단 플랫폼을 제안한다. AAL2 프로토콜, 스케줄러 알고리듬 등이 별도의 AAL2 프로세서로 설계되어 제안된 플랫폼은 AAL/ATM 관련 기능이 소프트웨어로 처리되던 기존 플랫폼에 비해 호스트 프로세서의 부하를 크게 줄일 수 있으며 ATM망을 통한 멀티미디어 데이터의 실시간 처리가 용이하게 하였다. 2중 타임 슬롯 링 구조를 적용한 ATS(Adaptive Time Slot) 스케쥴러는 VBR-rt, UBR, CBR 트래픽의 데이터 스케쥴링을 위한 효과적이고 간단한 방안을 제공한다 음성 압축 및 처리를 위하여 TI의 TMS320C5402 DSP를 적용하였고 AAL2 프로세서는 0.35 마이크론 공정에서 칩으로 제작되었다. VoDSL(Voice over DSL) 서비스를 위한 프로토콜을 구현하여 가입자 단말을 설계 제작하고 시험망에서 실험을 해 본 결과 $97\%$이상의 통화 성공율과 안정된 음성 서비스를 보장할 수 있음을 알 수 있다.

• 한국재료학회지
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• 제27권7호
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• pp.386-391
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• 2017

Using a customized diffusion bonder, we executed diffusion bonding for ring shaped white gold and red gold samples (inner, outer diameter, and thickness were 15.7, 18.7, and 3.0 mm, respectively) at a temperature of $780^{\circ}C$ and applied pressure of 2300 N in a vacuum of $5{\times}10^{-2}$ torr for 180 seconds. Optical microscopy, field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS) were used to investigate the microstructure and compositional changes. The mechanical properties were confirmed by Vickers hardness and shear strength tests. Optical microscopy and FE-SEM confirmed the uniform bonding interface, which was without defects such as micro pores. EDS mapping analysis confirmed that each gold alloy was 14K with the intended composition; Ni and Cu was included as coloring metals in the white and red gold alloys, respectively. The effective diffusion coefficient was estimated based on EDS line scanning. Individual values of Ni and Cu were $5.0{\times}10^{-8}cm^2/s$ and $8.9{\times}10^{-8}cm^2/s$, respectively. These values were as large as those of the melting points due to the accelerated diffusion in this customized diffusion bonder. Vickers hardness results showed that the hardness values of white gold and red gold were 127.83 and 103.04, respectively, due to solid solution strengthening. In addition, the value at the interface indicated no formation of intermetallic compound around the bonding interface. From the shear strength test, the sample was found not to be destroyed at up to 100,000 gf due to the high bonding strength. Therefore, these results confirm the successful diffusion bonding of 14K white-red golds with a diffusion bonder at a low temperature of $780^{\circ}C$ and a short processing time of 180 seconds.

• Plant Resources
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• 제4권1호
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• pp.41-47
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• 2001

This study was conducted to investigate the occurrence of Soil borne wheat mosaic virus(SbWMV) in barley fields in Korea and to examine the host pathogenicity of SbWMV. By using the ELISA test, SbWMV was detected in the six regions : Suwon, Milyang, Jinju, Youngkwang, Iksan, and Chonju. SbWMV was isolated from the two strains, Albori strain from Jinju and Eunpamil strain from Milyang. SbWMV was collected from leaves showing mosaic, yellowing and necrosis stripes. SbWMV was inoculated mechanically on 1∼1.5 leaf stages with leaf-rubbing to identify the host pathogenicity of 36 Korean barley cultivars, a wheat cultivar, two rye cultivars, three Japanese barley cultivars and Chenopodium amaranticola. Viral sympoms of inoculated leaves appeared on moulted loaves about 4 to 6 weeks of inoculation. Baegdong and Tapgolbori, infected from Albori strain and Eunpamil strain infected from Samdobori showed much higher susceptibility than C. amaranticola and C. quinoa which showed ring spots and chlorotic spots respectively. Virus particles were observed by the electron microscope. They were rod-shapes, which are bipartite, of 142 nm or 281 nm in length with 20 nm diameter on infected leaves. Specific detection and identification of SbWMV was set up using the RT-PCR. PCR fragments of SbWMV(0.5kb) were obtained by using the designed primers for SbWMV RNA 2.

• 한국임상약학회지
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• 제8권2호
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• pp.107-112
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• 1998

Lovastatin is a lipid lowering agent for the treatment of hypercholesterolemia and belongs to a new class of pharmacologic compounds called the 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors. By competitively inhibiting HMG CoA reductase, lovastatin disrupts the biosynthesis of cholesterol in hepatic and peripheral cells and increases the synthesis of high-density-lipoprotein HDL) receptors. Following oral administration, the lactone ring of lovastatin is hydrolysed to the active inhibitor of HMG CoA reductase, lovastatin acid. Lovastatin is known to have poor oral absorption and wide individual variation. In this study, bioequivalence test of two lovastatin formulations, the test drug ($Lovaload^{TM}$, Chong Kun Dang Pharmaceutical Co.) and the reference drug ($Mevacor^{TM}$, Chung Wae Pharmaceutical Co.) were conducted according to the guidelines of Korea Food and Drug Administration (KFDA). A total of 18 healthy male volunteers, $31.90\pm3.60$ years old and $72.17\;7.88$ kg of body weight in average, were evaluated in a randomized crossover manner with a 2-week washout period. Concentrations of lovastatin acid in plasma were measured upto 12 hours following a single oral administration of eight tablets (20 mg of lovastatin per tablet) by high-performance liquid chromatography with UV detection at 238 nm. The area under the concentration-vs-time curve from 0 to 12 hours $(AUC_{0-12h})$ was calculated by the trapezoidal summation method. The statistical analysis showed that there are no significant differences in $AUC_{0-12h),\;C_{max}\;and\;T_{max}$ between the two formulations ($6.72\%,\;1.52\%,\;and\;0.88\$, respectively). The least significant differences between the formulations at $\alpha$=0.05 were less than $20\%\;(11.65\%,\;19.73\%,\;and\;14.81\%\;for\;AUC_{0-12h},\;C_{max}\;and\;T_{max}$, respectively). The $90\%$ confidence intervals for these parameters were also within $\pm20\%\;(-1.50{\leq}{\delta}{\leq}15.00$, $-12.50{\leq}{\delta}{\leq}15.50,\;and\;-9.64{\leq}{\delta]{\leq}11.40{\leq}\;for\;\;AUC_{0-12h}$ ,$C_{max}\;and\;T_{max}$, respectively). In conclusion, the new generic product $Lovaload^{TM}$ was proven to be bioequivalent with the reference drug.

• 한국작물학회지
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• 제39권2호
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• pp.146-157
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• 1994

본 연구는 항암식물로 효능이 인정되는 와송에 대한 기초적인 연구로 와송의 해부형태적 관찰, 대량증식을 위한 발아실험, 자생지의 토양분석 및 토양적응실험을 실시하였다. 와송의 잎은 끝에 가시가 있는 건생형이며, 엽세포엽록체는 유관속주위에 집중분포하고, 크고 엽록체를 갖지 않는 저수조직을 갖고 있으며 기공이 양면에 있는 양면기공엽이다. 줄기는 외사포위형유관속이며 중심주는 원기둥상이고 원생중심주이다. 뿌리는 다원형이며, 원생목부가 후생목부주위에 환상으로 배열되어 있고 외원형이다. 꽃의 구조는 꽃잎이 5개, 수술은 10개, 자방은 5개이며, 자방상위이고, 2심피 중축태좌이다. 와송종자 발아적온는 명상태 $25^{\circ}C$에서 22.5%로 가장 좋았고, 휴면타파는 5$^{\circ}C$에서 6~8일, $GA_3$ 100 ppm처리에서 가장 효과가 좋았다. 와송 자생지 토양분석결과 적정수준의 밭토양보다 유기물, 유효인산 석회 등은 높았고, 보비력, 치환성가리는 차이가 없었으며, 고토는 낮았다. 토양적응실험에서 돌가루 조합과 기와가루 조합에서 돌가루와 기와가루가 많이 첨가될수록 생육상태가 불량하였고, 배수가 양호한 처리구에서는 생육상태가 양호하였다.

• 식물병연구
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• 제19권1호
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• pp.55-59
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• 2013

이 연구는 국내에 보고되지 않은 로즈마리 점무늬병이 남원과 전주의 재배 온실에서 발생하여 구명하고자 실험하였다. 이 병은 주로 고온 다습한 시기인 장마끝 무렵에 발생이 많았다. 로즈마리의 잎과 줄기에 검은점무늬(직경 3-5 mm) 및 시들음 증상이 나타났다. 병든 조직을 습실 처리하면 분생자경과 분생포자가 형성되었다. 로즈마리 점무늬병균의 분생포자는 체인상의 가늘고 긴 원통형으로, 길이는 $55-275{\times}7-14{\mu}m$이었다. 분생포자는 분생자경 위에 형성되었고, 분생포자의 위격벽의 수는 8-10개이었다. 또한 생장적온은 감자한천 배지와 암흑조건에서 $30^{\circ}C$이었다. 포트 식물에 병원성 검정결과 분리한 병원균은 접종 3일 후에 잎과 줄기에서 자연 병징과 같은 점무늬 및 시들음 증상이 재현되었고, 병든 부위에서 동일한 균이 재 분리되었다. 따라서 병원성이 있음이 확인되었다. rDNA ITS 영역의 염기서열 분석결과 로즈마리에 점무늬병을 일으키는 병원균은 Corynespora cassiicola로 GenBank accession number JQ595296, JQ595297, FJ852715, AY238606와 염기서열이 100% 일치하였고, C. cassiicola와 같은 계통군에 속하였다. 따라서, 로즈마리 잎 및 가지 점무늬병균은 C. cassiicola로 보고하고자 한다.

• 구강회복응용과학지
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• 제21권1호
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• pp.69-81
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• 2005

The objective of this study was to evaluate the toothbrush abrasion characteristics of class V restorations. Thirty extracted human premolars, which were collected from oral surgery clinics were used. We mounted five teeth in a metal ring mold of 50 mm in diameter and 15 mm in height using chemically cured acrylic resin. Class V cavities were prepared in lingual cervical root surfaces and restored using one of following restorative materials : Dentin Conditioner/Fuji II LC (Group FL), All Bond II/Z-250 (Group ZT), One-up Bond F/Palfigue Estelite (Group PE), F2000 Primer/Adhesive (Group FT), and Prime & Bond 2.1/Dyract AP (Group DR). They were stored under distilled water at $37^{\circ}C$ for seven days. The toothbrush abrasion test was conducted using a wear testing machine of pin-on disk type under a load of 1.5 N for 100,000 cycles. We have examined the bonded interfaces, the changes of surface roughness and color of abraded surfaces. From this experiment, the following results were obtained. 1. The change of surface roughness showed high degree: RMGIC>compomer>composite resin (p<0.05). 2. Because of the protrusion and missing of filler particles, SEM observation of abraded surfaces of RMGIC and compomers revealed the increase of surface roughness due to the selective removal of matrix resin. 3. The color change by toothbrush abrasion was affected in large part by the change of $L^*$ and $b^*$ of resin composites (p<0.05). 4. The color change by toothbrush abrasion was so small to detect by human eyes. 5. SEM observation of abraded surfaces revealed the interface bonding was the best in the FT group.

• 한국의상디자인학회지
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• 제7권3호
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• pp.75-81
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• 2005

The experiment aimed at knowing the effect of physiology and psychology according to season on color preference. Two tests, one of the spring and the other of the autumn was conducted. Seventy subjects with normal color vision served as subjects. The subjects entered a bioclimatic chamber controlled at a temperature of $25\pm1^{\circ}C$, a relative humidity of $50\pm5\%$ and a light of 1000 1x. The subjects wearing white shirts and trousers sat quietly on a sofa for one our. Sensation from warm to cool colors might be possibly different individually Therefore, a subject asked to array 41 randomly placed cloth colors from very warm to very cool colors during rest quietly for one our. All subjects arrayed these cloth colors in the order from red through yellow and green to blue, which had the reproducibility. After rest, they were instructed to choose a single one out of 41 cloth colors, preferred by themselves, every 10min during one our 0-ring test were measured to red, yellow, white, blue, black, favorite color, and dislike color. Most subjects preferred warmer color in April than in December. Tympanic temperature was significantly lower in December than in April. Finger presser was significantly higher in like color than in dislike color but it was no significant differences between spring and autumn. The preferring the warm color in April toward summer when basal metabolic rate is decreased than in December toward winter when it is increased can explain that physiology reaction by load error between actual core temperature and set-point induces psychological reaction to pursue visual alliesthesia. Our present experiment revealed that the preferred color could be determined by the relationship between the internal temperature and its set point according to season. It should be emphasized that the alliesthesia was observed also in the realm of visual system.

• 원예과학기술지
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• 제19권2호
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• pp.179-185
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• 2001

원예용 배지의 물리화학적 특성을 파악하기 위해 전세계적으로 다양한 분석 방법이 사용되고 있다. 유럽은 배지 분석방법의 표준화 연구를 지속적으로 수행해왔다. 유럽표준화 위원회에서는 유럽표준방법으로 CEN methods를 최종안까지 제출하였으며 사실상 유럽표준 배지분석방법의 제정을 확립하는 단계에 있다. 물리적 특성 중 건물함량과 수분함량은 건조 후 분석하였고, 실험 가밀도는 일정한 부피에 채워진 시료의 무게로 측정하였다. 가밀도, 진밀도, 공극률, 액상, 기상, 부피 감소율은 double ring과 sand suction table이라는 장치를 사용하여 배지를 포화, 배수시킨 후 건조시켜 분석하였다. 화학적 특성 중 pH와 EC는 부피 기준 1:5로 침출하여 분석하였다. 유기물과 회분함량은 건조와 연소 과정을 통해 분석하였다. CEN methods는 유럽표준방법으로 확립을 앞두고 있으나 더 지속적인 연구가 필요할 것이다.