• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.22.2-22.2
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• 2009

Currently, metal silicides become increasingly more essential part as a contact material in complimentary metal-oxide-semiconductor (CMOS). Among various silicides, NiSi has several advantages such as low resistivity against narrow line width and low Si consumption. Generally, metal silicides are formed through physical vapor deposition (PVD) of metal film, followed by annealing. Nanoscale devices require formation of contact in the inside of deep contact holes, especially for memory device. However, PVD may suffer from poor conformality in deep contact holes. Therefore, Atomic layer deposition (ALD) can be a promising method since it can produce thin films with excellent conformality and atomic scale thickness controllability through the self-saturated surface reaction. In this study, Ni thin films were deposited by thermal ALD using bis(dimethylamino-2-methyl-2-butoxo)nickel [Ni(dmamb)2] as a precursor and NH3 gas as a reactant. The Ni ALD produced pure metallic Ni films with low resistivity of 25 $\mu{\Omega}cm$. In addition, it showed the excellent conformality in nanoscale contact holes as well as on Si nanowires. Meanwhile, the Ni ALD was applied to area-selective ALD using octadecyltrichlorosilane (OTS) self-assembled monolayer as a blocking layer. Due to the differences of the nucleation on OTS modified surfaces toward ALD reaction, ALD Ni films were selectively deposited on un-coated OTS region, producing 3 ${\mu}m$-width Ni line patterns without expensive patterning process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.521-522
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• 2006

In this paper, hybrid air-water discharges were used to develop an optimal condition for providing a high level of water decomposition for hydrogen yield. Electrical and optical phenomena accompanying the discharges were investigated along with feeding gases, flow rates, and point-to-plane electrode gap distance. The primary focus of this experiment was put on the optical emission of the near UV range, with the energy threshold sufficient for water dissociation and excitation. The $OH(A^{2+},'=0\;X^2,"=0$) band's optical emission intensity indicated the presence of plasma chemical reactions involving hydrogen formation. In the gaseous atmosphere saturated with water vapor the OH(A-X) band intensity was relatively high compared to the liquid and transient phases although the optical emission strongly depended on the flow rate and type of feeding gas. In the gaseous phase discharge phenomenon for Ar carrier gas transformed into a gliding arc via the flow rate growth. OH(A-X) band's intensity increased according to the flow rate or residence time of He feeding gas. Reciprocal tendency was acquired for $N_2$ and Ar carrier gases. The peak value of OH(A-X) intensity was observed in the proximity of the water surface, however in the cases of Ar and $N_2$ with 0.5 SLM flow rate peaks shifted to the region below the water surface. Rotational temperature ($T_{rot}$) was estimated to be in the range of 900-3600 K, according to the carrier gas and flow rate, which corresponds to the arc-like-streamer discharge.

• 한국지반공학회논문집
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• 제33권9호
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• pp.61-69
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• 2017

본 연구에서는 사질토에서의 EICP에 의한 탄산칼슘 침전량을 정량적으로 평가하였다. 생성된 탄산칼슘은 염산과의 반응에 수반되는 이산화탄소 기체 압력 증분을 통해 간접적으로 측정하였으며, 이는 반응이 진행됨에 따라 특정 값으로 수렴하는 경향을 보였다. EICP 용액으로 포화된 주문진표준사의 전단파 속도 및 전기전도도값은 측정된 탄산칼슘량의 수렴시간보다 선행하여 일정한 값에 도달함을 확인하였다. 결정화 모델은 탄산칼슘이 흙 입자간 접촉점과 입자표면에서 생성됨을 나타내며, 이를 통해 최종 전단파 속도 및 최종 전기전도도에 도달하는 시간과 탄산칼슘 생성량의 수렴시간 간의 불일치가 설명 가능함을 보였다. 또한, 용액 농도 0.5g/L를 이용한 최종 전단파 속도는 0.1g/L의 것보다 224% 높은 효율을 나타내었다. 더불어 효소의 농도와 무관하게 전기전도도와 전단파 속도의 상관관계가 있음을 확인하였으며 주사전자현미경과 X-ray CT 이미지 분석을 통해 생성된 탄산칼슘의 공간적 분포를 확인하였다.

• Geomechanics and Engineering
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• 제6권2호
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• pp.153-172
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• 2014

In order to investigate the effect of different perforation angles (the angle between the perforation direction and the maximum horizontal principal stress) on the fracture initiation and propagation during hydraulic fracturing of highly deviated well in oil & gas saturated formation, laboratory experiments of the hydraulic fracturing had been carried out on the basis of non-dimensional similar criteria by using 400^3 $mm^3$ cement cubes. A plane fracture can be produced when the perforations are placed in the direction of the maximum horizontal principal stress. When the perforation angle is $45^{\circ}$, the fractures firstly initiate from the perforations at the upper side of the wellbore, and then turn to the maximum horizontal principal stress direction. When the well deviation angle and perforation angle are both between $45^{\circ}$ and $90^{\circ}$, the fractures hardly initiate from the perforations at the lower side of the wellbore. Well azimuth (the angle between the wellbore axis and the maximum horizontal principal stress) has a little influence on the fracture geometries; however it mainly increases the fracture roughness, fracture continuity and the number of secondary fractures, and also increases the fracture initiation and propagation pressure. Oriented perforating technology should be applied in highly deviated well to obtain a single plane fracture. If the well deviation angle is smaller, the fractures may link up.

• 대한금속재료학회지
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• 제49권5호
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• pp.355-361
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• 2011

Creep behaviors of the Zr-1.Nb-0.5Cu (HANA-6) alloy strips with different orientations were investigated. Anisotropy was observed in the samples depending on their physical orientations due to the formation of texture in their microstructures. The creep strain rate was increased as the test stress and temperature increased. The rate was higher along the rolling-direction than in the transverse-direction irrespective of annealing conditions. However, the samples with $45^{\circ}$ direction showed different behaviors depending on the annealing temperature. When strips were finally annealed at $600^{\circ}C$ for 10 min, the primary creep rate of the $45^{\circ}$ strip was the highest among the various orientations although the saturated creep rate was the lowest. In the case of final annealing at $660^{\circ}C$ for 4 h, the highest creep rate occurred throughout the creep test in the $45^{\circ}$ strip. It is considered that the fraction of (100) planes along the direction of creep deformation affect the creep rates.

• Journal of Forest and Environmental Science
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• 제37권2호
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• pp.116-127
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• 2021

Predicting carbon distribution of soil aggregates is difficult due to complexity in organo-mineral formation. This limits global warming mitigation through soil carbon sequestration. Therefore, knowledge of land use effect on carbon stabilization requires quantification of soil mineral cations. The study was conducted to quantify carbon and base cations on soil mineral fractions in Natural Forest, Plantation Forest and Farm Land. Five 0.09 ha were demarcated alternately along 500 m long transect with an interval of 50 m in Natural Forest (NF), Plantation Forest (PF) and Farm Land (FL). Soil samples were collected with soil cores at 0-15, 15-30 and 30-45 cm depths in each plot. Soil core samples were oven-dried at 105℃ and soil bulk densities were computed. Sample (100 g) of each soil core was separated into >2.0, 2.0-1.0, 1.0-0.5, 0.5-0.05 and <0.05 mm aggregates using dry sieve procedure and proportion determined. Carbon concentration of soil aggregates was determined using Loss-on-ignition method. Mineral fractions of soil depths were obtained using dispersion, sequential extraction and sedimentation methods of composite soil samples and sieved into <0.05 and >0.05 mm fractions. Cation exchange capacity of two mineral fractions was measured using spectrophotometry method. Data collected were analysed using descriptive and ANOVA at α_0.05. Silt and sand particle size decreased while clay increased with increase in soil depth in NF and PF. Subsoil depth contained highest carbon stock in the PF. Carbon concentration increased with decrease in aggregate size in soil depths of NF and FL. Micro- (1-0.5, 0.5-0.05 and <0.05 mm) and macro-aggregates (>2.0 and 2-1.0 mm) were saturated with soil carbon in NF and FL, respectively. Cation exchange capacity of <0.05 mm was higher than >0.05 mm in soil depths of PF and FL. Fine silt (<0.05 mm) determine the cation exchange capacity in soil depths. Land use and mineral size influence the carbon and cation exchange capacity of Gambari Forest Reserve.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.895-911
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• 2023

Processed meat products play a vital role in our daily dietary intake due to their rich protein content and the inherent convenience they offer. However, they often contain synthetic additives and ingredients that may pose health risks when taken excessively. This review explores strategies to improve meat product quality, focusing on three key approaches: substituting synthetic additives, reducing the ingredients potentially harmful when overconsumed like salt and animal fat, and boosting nutritional value. To replace synthetic additives, natural sources like celery and beet powders, as well as atmospheric cold plasma treatment, have been considered. However, for phosphates, the use of organic alternatives is limited due to the low phosphate content in natural substances. Thus, dietary fiber has been used to replicate phosphate functions by enhancing water retention and emulsion stability in meat products. Reducing the excessive salt and animal fat has garnered attention. Plant polysaccharides interact with water, fat, and proteins, improving gel formation and water retention, and enabling the development of low-salt and low-fat products. Replacing saturated fats with vegetable oils is also an option, but it requires techniques like Pickering emulsion or encapsulation to maintain product quality. These strategies aim to reduce or replace synthetic additives and ingredients that can potentially harm health. Dietary fiber offers numerous health benefits, including gut health improvement, calorie reduction, and blood glucose and lipid level regulation. Natural plant extracts not only enhance oxidative stability but also reduce potential carcinogens as antioxidants. Controlling protein and lipid bioavailability is also considered, especially for specific consumer groups like infants, the elderly, and individuals engaged in physical training with dietary management. Future research should explore the full potential of dietary fiber, encompassing synthetic additive substitution, salt and animal fat reduction, and nutritional enhancement. Additionally, optimal sources and dosages of polysaccharides should be determined, considering their distinct properties in interactions with water, proteins, and fats. This holistic approach holds promise for improving meat product quality with minimal processing.

• Journal of Animal Science and Technology
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• 제46권3호
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• pp.355-372
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• 2004

식물성유 첨가시 배양시간에 따른 지방산염의 형성 정도와 발효성상 및 NDF 소실율에 미치는 영향을 규명하고자 in vitro 시험을 실시 하였다. 기질은 알팔파 건초로 하고 1) oil 무첨가구, 2) 대두유 10%첨가구 및 3) 옥수수유 10%첨가구로 하였으며, oil 첨가 수준은 기질중량 건물 기준으로 첨가하였다. 발효성상 및 NDF 소실율을 위한 시험에서는 120ml serum bottle을 사용하여 3반복 실시하여 pH, $NH_3-N$, VFA농도 및 건물과 NDF 소실율을 분석하엿다. 지방산 분획을 위한 시험에서는 60ml serum bottle을 사용하요 3반복 실시하여 NEFA, EFA 및 FAS의 형성 정도를 분석하였다. pH는 배양시간이 증가함에 따라 유읭적으로 감소하였고, $NH_3-N$ 농도는 유의하게 증가하였다(P<0.0001). 건물 및 NDF 소실율은 처리구, 배양시간 및 oil간 유의하게 차이를 보여주었다(P<0.05). 총 휘발성 지방산 농도는 배양시간이 증가함에 따라 유의하게 증가하였다(P<0.0001). Acetate는 시험구 모두 배양시간이 증가함에 따라 유의적으로 감소하였고(P<0.0001), 대조구에 비해 oil 첨가구가 유의적으로 낮아졌다(P<0.05). Propionate는 시험구 모두 배양시간이 증가함에 따라 유의적으로 증가하였지만(P<0.0001), 처리구 및 oil간 효과는 없었다. Oil 첨가구에서 A/P비율이 유의하게 낮아졌다(P<0.05). EFA는 배양시간이 증가함에 따라 유의하게 감소하였고(P<0.0001), NEFA는 EFA의 가수분해로 인하여 증가하였다. 배양시간 48시간에서는 NEFA가 양이온과 결합하여 FAS의 형성 비율이 유의적으로 증가하였다(P<0.0001). 특히 $C_{18:0)$의 FAS 형성은 배양시간 48시간에서 대두유 및 옥수수유 첨가구에서 각각 12.53 및 15.17mg/g DM으로 0시간에 비해 각각 27.5 및 32.5배 증가하였다(P<0.0001). 배양시간이 증가할수록 칼슘을 포함한 양이온 함량이 높은 알팔파가 분해되면서 양이온이 용해되어 유리된 지방산과 결합하여 지방산염을 형성하게 된다. 이때 불포화지방산보다는 포화지방산이 양이온과 반응하여 지방산염을 형성하기 쉽다. 또한 $C_{16:0}$ 이상의 장쇄지방산이 주로 지방산염을 형성하였다. 이러한 특성 때문에 배양액내에 유리된 지방산이 염을 형성하기 쉽고 oil 첨가시 발생하는 발효성상 및 NDF소실율에 미치는 부의 영향을 최소화 한 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1256-1266
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• 2004

2-Bromooctanoic acid (2-BrOA) is known to block the formation of polyhydroxyalkanoic acid (PHA) in Pseudomonasfluorescens BM07 without any influence on the cell growth when grown on fructose, but it inhibits the cell growth when grown on octanoate (OA) (Lee et al., Appl. Environ. Microbiol. 67: 4963- 4974, 2001). We investigated the role of 2-BrOA in the PHA synthesis of the bacterium grown with mixtures of fructose and fatty acids. OA, 11­phenoxyundecanoic acid (1 1-POU), and 5-phenylvaleric acid (5-PV) were selected as model substrates. When supplemented with 50 mM fructose, all these carboxylic acids suppressed the formation of PHA from fructose, however, the ~-oxidation coenzyme A monomers derived from the carboxylic acids were efficiently polymerized, but the conversion yield [(mol of carboxylate substrate converted into PHA)/(mol of carboxylate substrate in the feed)] was low (e.g., maximally $\~53\%$ for 5 mM 11-POU). Addition of 2-BrOA (up to 5 mM) to the mixed carbon sources raised the conversion yield sensitively and effectively only at low levels of the acid substrates (e.g., 2 mM 1 1-POU or 5 mM OA): For instance, $100\%$ of 2 mM ll-POU were converted into PHA in the presence of 5 mM 2-BrOA, whereas only $\~10\%$ of the 1 1-POU were converted in the absence of 2-BrOA. However, at highly saturated suppressing levels (e.g., 5 mM ll-POU), 2-BrOA inhibitor showed no significant additional effect on the conversion ($60- 70\%$ conversion irrespective of 2-BrOA level). The existence of competitive and compensative relationship between 2­BrOA and all the carboxylic acid substrates used may indicate 'Present address: Section on Brain Physiology and Metabolism, Bldg. 10, Rm. 6N202, National Institute on Agmg, National Institute of Health, Bethesda, MD 20892, U.S.A. that all the acid substrate-derived inhibiting species bind to the same site as the 2-BrOA inhibiting species does. We, therefore, suggest that 2-BrOA can be used for efficiently increasing the yield of conversion of expensive substituted fatty acids into PHA and then substituted 3-hydroxyacids by hydrolyzing it.

• Journal of Nutrition and Health
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• 제32권4호
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• pp.384-393
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• 1999

The degree of platelet aggregation, thromboxane B2(TXB2)formation and fatty acid composition of platelet phospholipids(PL) were investigated in 24 healthy male subjects who for five weeks consumed either corn oil(CO) rich in linoleic acid(LA), perilla oil (PO) rich in $\alpha$-linoleic acid($\alpha$-LAN), or canola oil(CNO) rich in oleic acid(OA) as a major fat source. Total fat intake was 30% of total calories and prescribed oil intake of each dietary group was 50% of the total fat intake. In the CO group, significantly decreased contents of polyunsaturated fatty acids(PUFA), n-6 PUFA, n-3 PUFA and eicosapentanoic acid(EPA) were observed, and significantly increased contents of OA and saturated fatty acids(SFA) were observed in platelet PL after 3 weeks and 5 weeks of dietary treatment. In the PO group, contents of OA and docosahexanoic acid(DHA) were increased, and the ratio of n-6/n-3 was decreased significantly in platelet PL after dietary treatment. The CNO group showed significatnlty decreased contents of PUFA, P/S ratio, n-6 PUFA, LA,(EPA+DHA)/arachidonic acid(AA), and significantly increased SFA contents after 3 weeks of the oil-based diet. The dietary-induced effects on fatty acid composition of platelet PL were observed mostly after 3 weeks of the oil-based diet. The dietary-induced effects on fatty acid composition of platelet PL were observed mostly after 3 weeks. Plasma TXB2 levels were increased after 3 and 5 weeks of dietary treatment. However, only the CO and CNO groups showed significantly increased plasma TXB2 levles after 3 and 5 weeks of dietary treatment. However, only the CO and CNO groups showed significantly increased plasma TXB2 levels after 5 weeks of experimental diets, when compared with initial values. Degree of platelet aggregation increased only in the CO group after dietary treatment. As a result, at week 5 the degree of platelet aggregation of the CO group was significantly higher than those of the PO and CNO groups. Among the three oil-based diets, the PO-based diet seems to have beneficial effects on atherosclerosis by influencing plasma TXB2 levels and the degree of platelet aggregation, while the CO-based diet showed the most adverse effects. Our results imply that plasma TXB2 levels might be affected by dietary fatty acid composition.