• 한국세라믹학회지
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• 제30권12호
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• pp.1029-1038
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• 1993

The microstructures of aluminas, included of dissolved CaO as $\alpha$-alumina seeded pseudo-boehmite hydrosol was gelled in plaster mold and doped of MgO as dipping of calcines(120$0^{\circ}C$-2h) into Mg-nitrate solution, were compared to the one of which additives are excluded during the gellation. It was formed the boundary layer of 300~350${\mu}{\textrm}{m}$ distance from surface to the inside, containing of approximately 500ppm CaO by dissolved Ca from plaster mold. As the MgO addition to the boundary layer with dissolved CaO, the microstructure of the layer was uniformed and inhibited the grian growth, compared to one of that additives be excluded specimen and of MgO doped-inside region. This result was considered as abnormal grain growth and effect of flat boundary formation be appeared by effects of dissolved CaO, were decreased by MgO co-doping.

• 한국재료학회지
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• 제14권2호
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• pp.115-120
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• 2004

Perovskite barium-strontium titanate, $(Ba, Sr)TiO_3$ was prepared and effects of $Sb_2$O$_3$ additives on its PTCR properties were investigated. $The (Ba,Sr)TiO_3$ with 0.05～0.25 mol% $Sb_2$$O_3$ showed semiconducting PTCR behavior and anomalous grain growth was also observed when it was sintered above $1330^{\circ}C$. It was considered that charge compensation by doping 8b203 as well as abnormal grain growth by sintering lead to resistivity reduction from insulating to semiconducting transition.

• The Korean Journal of Ceramics
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• 제2권2호
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• pp.63-69
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• 1996

Barium titanyl oxalates, strontium titanyl oxalates and calcium zirconyl oxalates were prepared with variation of solution concentration and method of adding mixed metal ion solution into oxalic acid. Then they were aged in distilled water, ethanol or methanol, respectively. Barium titanyl oxalates and calcium zironyl oxalates were grown in water and strontium titanyl oxalates were groun in both water and methanol. They were supposed to be grown through the solutionl and reprecipitation mechanism. Nonuniform dispersion of particles in liquid phase is thought to cause abnormal particle growth.

• 한국세라믹학회지
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• 제37권7호
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• pp.625-631
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• 2000

In this study, the characteristics and sinterablities of TiO2 powders which were fabricated on sol-gel process and supercritical fluid process were examined. The powders fabricated on sol-gel process were amorphous. The particle size and shape were changed with the amount of water used for hydrolysis of titanium ethoxide. The powders were changed from amorphous to crystalline by heating at 400℃. The crystalline anatase TiO2 powders were directly prepared in ethanol supercritical fluid condition that temperature was 270±3℃ and pressure was 7.3 MPa. It's primary crystalline size was 20 nm and agglomerated as spherical shape whose size was 0.7∼1㎛. The powders prepared on sol-gel process were not sintered densely at 900℃ because of abnormal grain growth. However, the powders which prepared on supercritical fluid process were sintered densely at the comparatively low temperature of 800℃ by ideal growth of grain, which are fired at 900℃.

• 한국세라믹학회지
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• 제56권3호
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• pp.269-276
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• 2019

This article reports on the conditions required for the growth of crystalline boron films on silicon substrates by hot filament chemical vapor deposition method. The reactive gas was 3% diborane diluted in hydrogen. The films were characterized by optical, electronic, and atomic force microscopies; x-ray diffraction; and energy dispersive, electron energy loss, Raman, x-ray photoelectron, and Auger spectroscopies. The parameters that affect the morphologies of the films have been investigated. It was concluded that faceted crystals are produced at low B₂H₆ flows and working pressures below 200 mT. α-boron is produced between 530 and 600℃. Deposition outside this range produces thin films with a wide variety of morphologies. This result indicates that the films crystallize through a process called "abnormal or discontinuous grain growth." It is assumed that this is due to the anisotropic surfaces of boron allotropes.

• 한국환경과학회지
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• 제28권1호
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• pp.147-158
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• 2019

In this study, we investigated the influences of abnormal high temperature on growth, yield and physiologically active substances of the strawberry. General strawberry cultivars in the $20^{\circ}C$ growth condition showed much better growth of leaf number, length, diameter along with plant height, compared with those in $22.5^{\circ}C$ or $25^{\circ}C$. But the cultivars of both 'Sulhyang' and 'Mehyang' showed good growth and development at $25^{\circ}C$ with the roots showing great growth at $20^{\circ}C$. The quality and yield of the strawberry were best in the $20^{\circ}C$ growth condition, but the merchantability deteriorated in the $25^{\circ}C$ high temperature condition. As for the content of the physiologically active substances of the strawberry, it increased at $20^{\circ}C$, the optimum growth temperature, but decreased at $25^{\circ}C$. The physiologically active substances in the strawberry differed among the cultivars, the contents of cyanidin-3-glucoside, cinchonine, ellagic acid and cinnamic acid higher in the 'Mehyang', whereas the content of fisetin is higher in the 'Sulhyang' cultivar.Consequentially, the high temperature in summer has a negative effect on the physiological active ingredients of the strawberry, which was increased in the strawberry cultivated at proper temperature, and high quality strawberry production was possible.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제16권4호
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• pp.261-268
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• 2013

Purpose: To investigate the clinical characteristics and outcomes among infants and toddlers with failure to thrive (FTT). Methods: This retrospective study was done with 123 patients who had visited Pusan National University Children's Hospital during their first two years of life and had received an FTT diagnosis. We compared the clinical characteristics of the patients based on the causes of their FTT and their ages at the time of first hospital visit. We investigated triggering factors, feeding practices, and outcomes in 25 patients with nonorganic FTT (NOFTT). Results: Eighty cases (65.0%) were NOFTT. The gestational ages, birth weights, and weights at the first visits were significantly lower in patients with organic FTT (OFTT) (p<0.05). Infants who had first visited the clinic at age <6 months had the least z-score. The percentage of patients with severe weight decline was higher in OFTT than in NOFTT (60.0% vs. 17.3%). The z-scores at the follow-up visits were improved after treatment in both of the groups. Preceding infection was the most common triggering factor of NOFTT and persecutory feeding as abnormal behavior of caregiver was observed in 22 cases (88.0%). After treatment with feeding method modification, all patients with NOFTT showed normal growth. Conclusion: Weight decline is more severe in OFTT patients and in younger patients at the first visit. Infants with FTT can attain normal weight gain growth by treating organic diseases and supplying proper nutrition in OFTT, and by correcting abnormal dietary behavior of caregiver in NOFTT.

• 마이크로전자및패키징학회지
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• 제15권2호
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• pp.47-54
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• 2008

컴포넌트에서의 비정상적인 금속간화합물 성장이 보드 레벨 기계적 신뢰성에 미치는 영향을 연구하기 위하여, 전기 도금된 Ni/Au UBM과 Sn2.5Ag0.5Cu 솔더의 리플로우 횟수 및 고온 시효 시간에 따른 금속간 화합물 성장거동을 관찰하였다. 각 조건별로 처리된 컴포넌트에서 솔더 접합부의 기계적 특성을 비교하기 위하여, 전단 속도 변화에 따른 볼 전단 시험을 실시하여 전단에너지 값을 측정하였다. 마지막으로, 보드 레벨에서의 기계적 신뢰성 시험을 위하여 조건별로 처리된 컴포넌트를 PCB 보드에 실장하여, 3점 굽힘 시험 및 충격 시험을 실시한 후 파괴모드를 분석하였다.

• Clinical and Experimental Pediatrics
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• 제51권5호
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• pp.538-541
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• 2008

멘케스병은 성염색체 열성으로 유전되는 질환으로 APT7A 유전자의 돌연변이에 의해 발생한다. 기전은 장에서의 구리 흡수와 운반에 결손이 있는 것으로 혈청 구리 및 ceruloplasmin 이 낮다. 특징적인 임상양상은 경련발작, 근육긴장저하, 저체온증을 나타내며 얼굴은 특징적으로 통통하며 저색소 피부색, 꼬이고 윤택이 없고 잘 부스러지는 머리카락을 보인다. 성장장애를 보이는 경우가 흔하며 심한 정신지체와 발달장애를 동반한다. 멘케스병에서 간비대가 간병증을 보이는 경우는 현재까지 보고되지 않았다. 저자들은 유전자 검사를 통해 멘케스병으로 확진된 4개월 소아가 영아연축, 발달장애, 머리카락 이상 외에도 이전에 잘 알려져 있지 않은 간비대를 보인 1례를 보고하는 바이다.

• 한국환경과학회지
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• 제32권2호
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• pp.121-130
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• 2023

This study was conducted to investigate changes in seed vigor based on temperature of dry heat and duration treatment of watermelon seeds and examine the effect on percent of emergence and seedling vigor. When the upper limit temperature of dry heat treatment was raised to 80℃, the percent of the germination decreased. Moreover, T₅₀ was delayed as the upper limit temperature of dry heat treatment increased. The higher the upper limit temperature of dry heat treatment and the longer the treatment period, the higher the percentage of abnormal seedlings. The optimum upper limit temperature for dry heat treatment was 72℃, and the treatment period was five days. Seed vigor was better maintained at 30℃, 45℃, and 52℃, followed by stepwise exposure to high temperatures of 72℃, the upper limit of dry heat treatment, rather than dry heat treatment at a high temperature of 72℃ for 5 days from the initial stage of treatment. When the fungicide was added during the dry heat treatment process, the germination percentage decreased and the percent of the abnormal seedling percentage increased. However, the addition of 10 mg/kg fungicide did not significantly reduce seed vigor.