• Nuclear Engineering and Technology
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• 제49권5호
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• pp.1019-1030
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• 2017

Diffusion is a crucial mechanism that regulates the migration of radioactive nuclides. In this study, an innovative numerical method was developed to simultaneously calculate the diffusion coefficient of both parent and, afterward, series daughter nuclides in a sequentially reactive through-diffusion model. Two constructed scenarios, a serial reaction (RN_1 ${\rightarrow}$ RN_2 ${\rightarrow}$ RN_3) and a parallel reaction (RN_1 ${\rightarrow}$ RN_2A + RN_2B), were proposed and calculated for verification. First, the accuracy of the proposed three-member reaction equations was validated using several default numerical experiments. Second, by applying the validated numerical experimental concentration variation data, the as-determined diffusion coefficient of the product nuclide was observed to be identical to the default data. The results demonstrate the validity of the proposed method. The significance of the proposed numerical method will be particularly powerful in determining the diffusion coefficients of systems with extremely thin specimens, long periods of diffusion time, and parent nuclides with fast decay constants.

• 한국심리학회지 : 문화 및 사회문제
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• 제29권4호
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• pp.477-496
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• 2023

본 연구는 대학생을 대상으로 거부민감성이 반응적 공격성과 어떠한 관련이 있는지 알아보고. 거부민감성이 반응적 공격성에 미치는 영향에서 자기개념 명확성과 적대적 귀인편향의 매개효과가 있는지 확인하기 위하여 진행되었다. 이를 위하여 만 18세 이상 대학생을 대상으로 자기 보고식 설문을 온라인으로 실시하였으며, 총 250명의 자료를 분석에 사용하였다. 자료분석은 SPSS 27.0을 사용하여 변수의 기초통계량을 확인하였고 빈도분석, 신뢰도분석, 상관분석을 실시하였다. 또한 AMOS 21.0을 사용하여 모델의 적합도를 확인하였으며, 부트스트래핑(Bootstrapping) 방식으로 간접효과의 유의성을 검증하였다. 본 연구의 결과는 다음과 같다. 첫째, 거부민감성이 자기개념 명확성을 통해 반응적 공격성에 정적인 영향을 미치는 것으로 나타났다. 둘째, 거부민감성이 적대적 귀인편향을 증가시키고 이로 인해 반응적 공격성이 증가하는 것으로 나타났다. 셋째, 거부민감성이 자기개념 명확성과 적대적 귀인편향을 통해 순차적으로 반응적 공격성에 간접적으로 정적인 영향을 주는 것으로 나타났다. 이러한 결과는 대학생의 반응적 공격성에 영향을 미치는 심리적 요인을 확인함으로써 범죄와 같은 사회문제와 관련이 있는 반응적 공격성에 대한 개입에서의 심리학적 접근의 필요성과 치유 및 예방을 위한 기초자료를 제시하였다는 점에서 의의가 있다. 마지막으로 본 연구의 제한점 및 후속 연구에 필요한 시사점을 제안하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.35-41
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• 2006

It is well known that concentration of C-reactive protein(CRP) in the serum increase as nonspecific reaction of the various tissue injury. The CRP, synthesized in the hepatocyte, is one of 'acute phase proteins' in the serum. The main signal patterns of this protein are regulated by synthesis of interleukin-I secreted from macrophage in the area of tissue injury. Many studies were performed for quantitative analysis for CRP according to various surgical operation, but the study for fracture patients associated with trauma, especially in mandible, are rare. The mandible fracture have intrinsic danger for infection in oral bacteria associated with open wound in oral cavity, and, are difficult for detection of tissue reaction between surgical swelling and infection by facial swelling. In this study, quantitative analysis for CRP associated tissue injury in mandibular fracture and surgical intervention was done, the results were as follows: 1. After initial mandibular trauma, the value of serum CRP diminished sequentially, most high value was presented in post-traumatic 2 days. 2. The CRP was diminished significantly 2 days after surgical intervention, and maintained normal value in 5 days after surgery. 3. The change of CRP are higher value in surgical intervention than initial trauma, it suggested that tissue injury from surgery was severe than trauma. 4. The high value of CRP was obtained in mandibular fracture combined soft tissue injury than no associated soft tissue injury. 5. In measurement of CRP according to surgical approach, highest serum value in patients of combined intra-oral and extra-oral approach was showed, and intra-oral approach, extra-oral approach, in sequential orders. 6. The CRP value are more higher in patient of 2 fracture site than only one fracture site. From the results obtained in this study, CRP has showed different values in mandibular fracture associated with severity of tissue injury and surgical intervention, and quantitative analysis of CRP value in serum can be applied to the clinical management of mandibular fracture.

• International Journal of Oral Biology
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• 제35권3호
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• pp.129-135
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• 2010

Recent studies have implicated reactive oxygen species (ROS) as determinants of the pathological pain caused by the activation of peripheral neurons. It has not been elucidated, however, how ROS activate the primary sensory neurons in the pain pathway. In this study, calcium imaging was performed to investigate the effects of NaOCl, a ROS donor, on the intracellular calcium concentration ($[Ca^{2+}]i$) in acutely dissociated dorsal root ganglion (DRG) neurons. DRG was sequentially treated with 0.2 mg/ml of both protease and thermolysin, and single neurons were then obtained by mechanical dissociation. The administration of NaOCl then caused a reversible increase in the $[Ca^{2+}]i$, which was inhibited by pretreatment with phenyl-N-tertbuthylnitrone (PBN) and isoascorbate, both ROS scavengers. The NaOCl-induced $[Ca^{2+}]i$ increase was suppressed both in a calcium free solution and after depletion of the intracellular $Ca^{2+}$ pool by thapsigargin. Additionally, this increase was predominantly blocked by pretreatment with the transient receptor potential (TRP) antagonists, ruthenium red ($50\;{\mu}M$) and capsazepine ($10\;{\mu}M$). Collectively, these results suggest that an increase in the intracellular calcium concentration is produced from both extracellular fluid and the intracellular calcium store, and that TRP might be involved in the sensation of pain induced by ROS.

• 대한금속재료학회지
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• 제48권11호
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• pp.1028-1034
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• 2010

In the development of 3D package, through silicon via (TSV) formation technology by using deep reactive ion etching (DRIE) is one of the key processes. We performed the Bosch process, which consists of sequentially alternating the etch and passivation steps using $SF_6$ with $O_2$ and $C_4F_8$ plasma, respectively. We investigated the effect of changing variables on vias: the gas flow time, the ratio of $O_2$ gas, source and bias power, and process time. Each parameter plays a critical role in obtaining a specified via profile. Analysis of via profiles shows that the gas flow time is the most critical process parameter. A high source power accelerated more etchant species fluorine ions toward the silicon wafer and improved their directionality. With $O_2$ gas addition, there is an optimized condition to form the desired vertical interconnection. Overall, the etching rate decreased when the process time was longer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.385-388
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• 1994

This paper presents a new configure rectifier which has improved input power factor and efficiency for DC arc weldings. Two rectifiers are series connected and they are single-phase full-wave phase controlled rectifiers that use a transformer with two center-tapped secondary. The input power factor can be improved by controlling the each phase of rectifiers sequentially, and then the efficiency can be also improved because the reactive component currents will be reduced. It is confirmed that the proposed rectifiers has about 80% of input power factor and efficiency with the experimental results which are carried out at the output ranges of 100A to 300A.

• Molecules and Cells
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• 제43권12호
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• pp.989-1001
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• 2020

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular pathogen that causes salmonellosis and mortality worldwide. S. Typhimurium infects macrophages and survives within phagosomes by avoiding the phagosome-lysosome fusion system. Phagosomes sequentially acquire different Rab GTPases during maturation and eventually fuse with acidic lysosomes. Lysophosphatidylcholine (LPC) is a bioactive lipid that is associated with the generation of chemoattractants and reactive oxygen species (ROS). In our previous study, LPC controlled the intracellular growth of Mycobacterium tuberculosis by promoting phagosome maturation. In this study, to verify whether LPC enhances phagosome maturation and regulates the intracellular growth of S. Typhimurium, macrophages were infected with S. Typhimurium. LPC decreased the intracellular bacterial burden, but it did not induce cytotoxicity in S. Typhimurium-infected cells. In addition, combined administration of LPC and antibiotic significantly reduced the bacterial burden in the spleen and the liver. The ratios of the colocalization of intracellular S. Typhimurium with phagosome maturation markers, such as early endosome antigen 1 (EEA1) and lysosome-associated membrane protein 1 (LAMP-1), were significantly increased in LPC-treated cells. The expression level of cleaved cathepsin D was rapidly increased in LPC-treated cells during S. Typhimurium infection. Treatment with LPC enhanced ROS production, but it did not affect nitric oxide production in S. Typhimurium-infected cells. LPC also rapidly triggered the phosphorylation of IκBα during S. Typhimurium infection. These results suggest that LPC can improve phagosome maturation via ROS-induced activation of NF-κB pathway and thus may be developed as a therapeutic agent to control S. Typhimurium growth.

• 한국세라믹학회지
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• 제34권5호
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• pp.483-490
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• 1997

Al2O3/metal composites were fabricated by oxidation and reaction of molten Al-alloy into two types of commercial Al2O3-SiO2 fibrous insulation board. The growth rate, composition and microstructure of these materials were described. An AlZnMg(7075) alloy was selected as a parent alloy. Mixed polycrystalline fiber and glass phase fiber were used as a filler. The growth surface of an alloy was covered with and without SiO2. SiO2 powder was employed as a surface dopant to aid initial oxidation of Al-alloy. Al-alloy, SiO2, fiber block and growth inhibitor CaSiO3 were packed sequentially in a alumina crucible and oxidized in air at temperature range 90$0^{\circ}C$ to 120$0^{\circ}C$. The growth rate of composite layer was calculated by measuring the mass increasement(g) per unit surface($\textrm{cm}^2$). XRD and optical microscope were used to investigate the composition and phase of composites. The composite grown at 120$0^{\circ}C$ and with SiO2 dopant showed rapid growth rate. The growth behavior differed a little depending on the types of fiber used. The composites consist of $\alpha$-Al2O3, Al, Si and pore. The composite grown at 100$0^{\circ}C$ exhibited better microstructure compared to that grown at 120$0^{\circ}C$.

• 반도체디스플레이기술학회지
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• 제8권4호
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• pp.49-52
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• 2009

We have investigated the effect of the surface roughness of TCO substrate on the characteristics of OLED (organic light emitting diodes) devices. In order to control the surface roughness of ITO thin films, we have processed photolithography and reactive ion etching. The micro-size patterned mask was used, and the etching depth was controlled by changing etching time. The surface morphology of the ITO thin film was observed by FESEM and atomic force microscopy (AFM). And then, organic materials and cathode electrode were sequentially deposited on the ITO thin films. Device structure was ITO/$\alpha$-NPD/DPVB/Alq3/LiF/Al. The DPVB was used as a blue emitting material. The electrical characteristics such as current density vs. voltage and luminescence vs. voltage of OLED devices were measured by using spectrometer (minolta CS-1000A). The current vs. voltage and luminance vs. voltage characteristics were systematically degraded with increasing surface roughness. Furthermore, the retention test clearly presented that the reliability of OLED devices was directly influenced with the surface roughness, which could be interpreted in terms of the concentration of the electric field on the weak and thin organic layers caused by the poor step coverage.

• 반도체디스플레이기술학회지
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• 제9권4호
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• pp.25-29
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• 2010

We have investigated the effect of surface roughness of TCO substrate on the characteristics of OLED (organic light emitting diodes) devices. In order to control the surface roughness of AZO thin films, we have processed photo-lithography and reactive ion etching. The micro-size patterned mask was used, and the etching depth was controlled by changing etching time. The surface morphology of the AZO thin film was observed by FESEM and atomic force microscopy (AFM). And then, organic materials and cathode electrode were sequentially deposited on the AZO thin films. Device structure was AZO/${\alpha}$-NPD/DPVB/$Alq_3$/LiF/Al. The DPVB was used as a blue emitting material. The electrical characteristics such as current density vs. voltage and luminescence vs. voltage of OLED devices were measured by using spectrometer. The current vs. voltage and luminance vs. voltage characteristics were systematically degraded with increasing surface roughness. Furthermore, the retention test clearly presented that the reliability of OLED devices was directly influenced with the surface roughness, which could be interpreted in terms of the concentration of the electric field on the weak and thin organic layers caused by the poor step coverage.