• Geomechanics and Engineering
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• 제8권1호
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• pp.81-95
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• 2015

The permeability behavior of Ariake clays has been investigated by constant rate of strain (CRS) consolidation tests with vertical or radial drainage. Three types of Ariake clays, namely undisturbed Ariake clay samples from the Saga plain, Japan (aged Ariake clay), clay deposit in shallow seabed of the Ariake Sea (young Ariake clay) and reconstituted Ariake clay samples using the soil sampled from the Saga plain, were tested. The test results indicate that the deduced permeability in the horizontal direction ($k_h$) is generally larger than that in the vertical direction ($k_v$). Under odometer condition, the permeability ratio ($k_h/k_v$) increases with the vertical strain. It is also found that the development of the permeability anisotropy is influenced by the inter-particle bonds and clay content of the sample. The aged Ariake clay has stronger initial inter-particle bonds than the young and reconstituted Ariake clays, resulting in slower increase of $k_h/k_v$ with the vertical strain. The young Ariake clay has higher clay content than the reconstituted Ariake clay, resulting in higher values of $k_h/k_v$. The microstructure of the samples before and after the consolidation test has been examined qualitatively by scanning electron microscopy (SEM) image and semi-quantitatively by mercury intrusion porosimetry (MIP) tests. The SEM images indicate that there are more cut edges of platy clay particles on a vertical plane (with respect to the deposition direction) and there are more faces of platy clay particles on a horizontal plane. This tendency increases with the increase of one-dimensional (1D) deformation. MIP test results show that using a sample with a larger vertical surface area has a larger cumulative intruded pore volume, i.e., mercury can be intruded into the sample more easily from the horizontal direction (vertical plane) under the same pressure. Therefore, the permeability anisotropy of Ariake clays is the result of the anisotropic microstructure of the clay samples.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.218-224
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• 2018

Objective: This study evaluated the effects of different levels of protein concentrate supplementation on the growth performance of yak calves, and correlated the growth rate to changes occurring in the plasma- amino acids, -insulin profile, and signaling activity of mammalian target of rapamycin (mTOR) cascade to characterize the mechanism through which the protein synthesis can be improved in early weaned yaks. Methods: For this study, 48 early (3 months old) weaned yak calves were selected, and assigned into four dietary treatments according to randomized complete block design. The four blocks were balanced for body weight and sex. The yaks were either grazed on natural pasture (control diet) in a single herd or the grazing yaks was supplemented with one of the three protein rich supplements containing low (17%; LP), medium (19%; MP), or high (21%; HP) levels of crude proteins for a period of 30 days. Results: Results showed that the average daily gain of calves increased (0.14 vs 0.23-0.26 kg; p<0.05) with protein concentrates supplementation. The concentration of plasma methionine increased (p<0.05; 8.6 vs $10.1-12.4{\mu}mol/L$), while those of serine and tyrosine did not change (p>0.05) when the grazing calves were supplemented with protein concentrates. Compared to control diet, the insulin level of calves increased (p<0.05; 1.86 vs $2.16-2.54{\mu}IU/mL$) with supplementation of protein concentrates. Addition of protein concentrates up-regulated (p<0.05) expression of mTOR-raptor, mammalian vacuolar protein sorting 34 homolog, the translational regulators eukaryotic translation initiation factor 4E binding protein 1, and S6 kinase 1 genes in both Longissimus dorsi and semitendinosus. In contrast, the expression of sequestosome 1 was down-regulated in the concentrate supplemented calves. Conclusion: Our results show that protein supplementation improves the growth performance of early weaned yak calves, and that plasma methionine and insulin concentrations were the key mediator for gene expression and protein deposition in the muscles.

• 한국정보통신학회논문지
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• 제4권5호
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• pp.1127-1134
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• 2000

RF magnetron reactive sputtering 법으로 $RuO_2$ 박막을 제작하여, O2/(Ar+O2) 비와 기판온도에 따른 박막의 결정화 특성, 미세구조, 표면거칠기, 전기적 비저항을 조사하였다. O2/(Ar+O2) 비가 감소하고 기판온도가 증가함에 따라 $RuO_2$ 박막은 (110) 면에서 (101) 면으로 우선배향방향이 변하였다. O2/(Ar+O2) 비가20% 에서 50% 로 증가함에 따라, $RuO_2$박막의 표면거칠기는 2.38nm 에서 7.81nm로, 비저항은 $103.6 \mu\Omega-cm\; 에서\; 227 \mu\Omega-cm$로 증가하는 추세를 나타내는 반면에, 증착속도는 47nm/min에서 17nm/min 로 감소하였다. 기판온도가 상온에서 $500^{\circ}C$ 로 증가함에 따라 비저항은 $210.4\mu\Omega-cm\; 에서\; 93.7\mu\Omega-cm$로 감소하였고, 표면거칠기는$300^{\circ}C$ 에서 증착한 박막이 2.3nm 로 가장 우수하였다. 열처리 온도가$400^{\circ}C$에서$650^{\circ}C$ 로 증가함에 따라 비저항은 $RuO_2$ 박막의 결정성 향상으로 인해 감소하였다. 이들 결과로부터 02/(Ar+02) 비 20%, 기판온도 loot 에서 증착한 $RuO_2$ 박막의 표면거칠기 및 비저항 특성이 가장 우수하여 강유전체 박막의 하부전극으로 사용하기에 적합함을 알 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권4호
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• pp.324-331
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• 2001

The present study was aimed to investigate the effects of latency period on alveolar ridge distraction using the intraoral distraction device. Nine adult mongrel dogs of either sex, weighing about 15kg, were used. They were divided into 3-day, 5-day, and 7-day groups according to the latency period. The left upper and lower premolars and first molars were extracted. Twelve weeks after the extraction, an osteotomy was performed and the distraction device was applied. After the latency period, the distraction was applied at a rate of 1.2mm for 8 days. The distraction device was left in place for 2 weeks to allow consolidation and was then removed. The animals were sacrified at 8 weeks after completion of distraction and were examined macroscopically, radiographically, and histologically. After completion of the distraction, the alveolar crest protruded prominently, showing the vertical augmentation of the alveolar bone. Soft tissues were broken down after the 6th day of distraction in 3-day latency group, and premature union occurred on the 7th day of distraction in the 7-day latency group. The average distance was $9.40{\pm}0.3mm$ in 3-day latency group, $9.35{\pm}0.1mm$ in 5-day latency group, and $8.85{\pm}0.1mm$ in 7-day latency group. In the radiograph taken at 8 weeks after distraction, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in all groups. Fibrous tissues were present in a part of the buccal cortical bone area of the distraction gap, and the woven and lamellar bones were observed in the distracted gap. There were bony bridges in the distraction gap in all animals examined. These results suggest that optimal time of latency period on alveolar ridge distraction using the intraoral distraction device is about 5 days in dogs, and about 7days in human beings.

• 한국자기학회지
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• 제17권2호
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• pp.95-98
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• 2007

본 연구에서는 하지층으로 사용한 Mo(MoN)의 두께 변화에 따른 스핀밸브 구조의 자기적 특성과 열처리 결과를 비교 검토하였다. 사용된 스핀밸브는 Si 기판/Mo(MoN)$(t{\AA})/NiFe(21{\AA})/CoFe(28{\AA})/Cu(22{\AA})/CoFe(18{\AA})/IrMn(65{\AA})/Ta(25{\AA})$ 구조이다. 또한 본 연구에서는 MoN 하지층을 Si 기판에 증착하여 열처리후 특성을 분석하였다. Mo 박막에 비해 MoN 박막의 질소량이 증가할수록 증착률은 감소하였고, 비저항은 증가하였다. MoN 하지층을 사용한 경우 Mo의 경우보다 하지층 두께 변화($51{\AA}$까지)에 따라 자기저항비와 교환결합력의 변화는 소폭이었다. Mo 하지층의 열처리 온도별 자기저항비는 열처리 전 상온에서 2.86% 이었고, $200^{\circ}C$ 열처리 때 2.91 %로 증가하였다. 이후 열처리 온도를 $300^{\circ}C$까지 증가시키면 자기저항비는 2.91 %에서 2.16%로 감소하였다. 질소 유입량이 1 sccm인 MoN의 열처리 온도별 자기저항비는 열처리 전 상온에서 5.27%, $200^{\circ}C$일때 5.56%증가하였다. 이후 열처리 온도를 $300^{\circ}C$까지 증가시키면 자기저항비는 5.56%에서 4.9%로 감소하였다.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.619-625
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• 2008

패시베이션 및 절연 목적으로 이용하는 플라즈마 화학기상증착(PECVD)법에 의해 증착된 무기막과 웨이퍼 간 본딩 접착제로 이용하는 유기 박막 적층면의, 열 순환에 의한 잔류 응력 및 본딩 결합력의 효과를 4점 굽힙 시험법과 웨이퍼 곡률 측정법에 의해 평가하였다. 무기막으로는 산화 규소막($SiO_2$)과 산화 질화막($SiN_x$)이, 유기 박막으로는 BCB(Benzocyclobutene)가 이용되었다. 이를 통해, 열 순환 동안 무기막과 유기막 사이에서의 잔류 응력과 본딩 결합력의 상관관계에 대한 모델식을 개발하였다. 최대 온도 350 및 $400^{\circ}C$에서 수행한 열 순환 공정에서, PECVD 산화 질화막과 BCB로 구성된 다층막에서, 본딩 결합력은 첫 번째 순환 공정 동안 감소한다. 이는 산화질화막 내 잔류인장응력의 증가가 다층막의 잔류응력에 의해 변형되는 에너지 및 본딩 결합력의 감소를 유도한다는 모델식의 예측과 일치하며, PECVD 산화 규소막내 잔류 압축 응력의 감소가 다층막의 잔류응력에 의해 변형되는 에너지 및 본딩 결합력 상승을 이끄는 산화 규소막과 BCB 구조의 본딩 결합력 결과와 비교된다. 이러한 산화 규소막과 산화 질화막을 포함한 다층막의 상반된 본딩 결합력은 증착 공정 후 막 내에 형성된 수소 결합이 고온 순환 공정 동안 축합 반응을 통해 더 밀집되어 인장응력을 형성하기 때문임을 알 수 있었다.

• 공업화학
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• 제8권4호
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• pp.645-652
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• 1997

백금 회전전극을 이용하여 확산지배영역에서의 구리 착화합물의 환원에 대한 전기화학적 특성조사 및 이에 대한 속도인자들을 구하였다. 황산염 용액내에서 Cu(II)의 환원은 2전자, 1단계 반응이며, 염화물 용액내에서의 Cu(II)는 1전자, 2단계 반응으로 환원된다. 환원반응에서의 전달계수는 황산염 용액내에서 Cu(II)가 가장 작으며, 할로겐염 중에서 Cu(I)의 전달계수는 1에 가까운 값을 나타내었다. 염화물 용액안에서 구리이온의 환원에 대한 표준속도상수는 Cu(II)의 환원이 Cu(I)을 출발물질로 할 경우보다 100배 정도 빠른 값을 나타내었다. 그리고 확산계수는 $Cl^-$존재시의 Cu(II), $I^-$, $Br^-$, $Cl^-$존재시의 Cu(I) 및 $SO_4^{-2}$존재시의 Cu(II)의 순으로 증가하였으며, 각 용액 내에서의 구리이온의 반지름 및 확산에 대한 활성화 에너지도 위의 순서와 동일하게 감소하였다. 회전전극상의 구리전착의 경우 전착전위 및 농도에 따라 불균일한 전착표면을 형성하였으며, 이러한 전착표면의 불균일성은 UV/VIS로 분석이 가능하였다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2010년도 임시총회 및 하계학술연구발표회
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• pp.79-79
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• 2010

Semimetallic bismuth (Bi) has been extensively investigated over the last decade since it exhibits very intriguing transport properties due to their highly anisotropic Fermi surface, low carrier concentration, long carrier mean free path l, and small effective carrier mass $m^*$. In particular, the great interest in Bi nanowires lies in the development of nanowire fabrication methods and the opportunity for exploring novel low-dimensional phenomena as well as practical application such as thermoelectricity[1]. In this work, we introduce a self-assembled interconnection of nanostructures produced by an on-film formation of nanowires (OFF-ON) method in order to form a highly ohmic Bi nanobridge. A Bi thin film was first deposited on a thermally oxidized Si (100) substrate at a rate of $40\;{\AA}/s$ by radio frequency (RF) sputtering at 300 K. The sputter system was kept in an ultra high vacuum (UHV) of $10^{-6}$ Torr before deposition, and sputtering was performed under an Ar gas pressure of 2m Torr for 180s. For the lateral growth of Bi nanowires, we sputtered a thin Cr (or $SiO_2$) layer on top of the Bi film. The Bi thin films were subsequently put into a custom-made vacuum furnace for thermal annealing to grow Bi nanowires by the OFF-ON method. After thermal annealing, the Bi nanowires cannot be pushed out from the topside of the Bi films due to the Cr (or $SiO_2$) layer. Instead, Bi nanowires grow laterally as a mean s of releasing the compressive stress. We fabricated a self-assembled Bi nanobridge (d=192 nm) device in-situ using OFF-ON through annealing at $250^{\circ}C$ for 10hours. From I-V measurements taken on the Bi nanobridge device, contacts to the nanobridge were found highly ohmic. The quality of the Bi nanobridge was also proved by the high MR of 123% obtained from transverse MR measurements. These results manifest the possibility of self-assembled nanowire interconnection between various nanostructures for a variety of applications and provide a simple device fabrication method to investigate transport properties on nanowires without complex patterning and etching processes.

• 한방안이비인후피부과학회지
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• 제29권4호
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• pp.14-23
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• 2016

Objectives : One of major complications of diabetes, diabetic ulcer is also one of the main reasons for amputation, and the prevalence rate is 4-10%. Laser therapy is widely used for leg ulcer and diabetic ulcer, and it is known to improve wound epithelialization, cellular content, and collagen deposition. The purpose of this study is to investigate the properties of the laser and the spectrum of laser instruments for diabetic ulcer. Methods : We performed literature search using the PubMed, Cochrane, CINAHL and Web of science for the data in English. In addition, other databases were checked for different languages such as OASIS and NDSL for the literature in Korean, CNKI in Chinese, and CiNii and J-STAGE written in Japanese. We excluded all review article and experimental studies, and only clinical studies using laser or light emitting diode (LED) for diabetic ulcer were selected. Results : A total twenty papers were selected. Different light sources were used as follows: LED, HeNe, InGaAlP, GaAlAs, GaAs, CO2, and KTP. The number of LED studies was 9, and HeNe laser was 7, and InGaAlP and GaAlAs laser was 2, GaAs, CO2, and KTP laser was 1 for each. Various energy density of the clinical study were reported. Conclusions : It is suggested that to select appropriate laser type and give the adequate output power to treat diabetic ulcer. Further evaluation and research for the condition of laser therapy to treat diabetic ulcers are warranted.

• 한국환경농학회:학술대회논문집
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• 한국환경농학회 2009년도 정기총회 및 국제심포지엄
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• pp.329-338
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• 2009

대기 중으로 휘산 되는 대부분의 암모니아는 농경지에 시용하는 가축분뇨, 퇴비 및 질소비료에서 유래하며, 휘산된 암모니아는 강하 (Deposition)를 통해서 자연생태계의 산성화를 초래하고 수계의 부영양화를 유발하는 원인물질로 작용한다. 본 연구에서는 돈분뇨 및 퇴비 시용방법에 따른 암모니아 휘산량을 정량적으로 평가하였다. 돈분퇴비 표층살포 (SA), 표층살포 후 즉시 경운(IRA), 표층살포 3일후 경운 (RA-3d) 처리구의 13일동안 암모니아 휘산량은 각각, 28.7, 8.7, 24.3 kg N/ha 로 IRA 처리구는 SA 처리구에 비해 약 70% 저감효과를 가져왔다. 돈분 액비 표층 살포 후 즉시 경운은 무경에 비해 봄과 가을 각각 26, 50% 의 암모니아 휘산량 저감 효과가 있었다. 그리고 수분 함량에 따른 암모니아 휘산량은 수분 함량이 높을수록 건조 토양에 비해 증가 하였다. 돈분 액비 시용 전후 담수 조건에 따른 암모니아 휘산량은 담수 상태에서 액비를 시용하는 것이 건토에 액비 살포 1일 후 담수 보다 약 4.7배의 암모니아 휘산량 증가가 있었다.