• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.429-429
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• 2012

To investigate the gettering effect of B-doped n-type monocrystalline silicon wafer, we made the p-n junction by diffusing boron into n-type monocrystalline Si substrate and then oxidized the boron doped n-type monocrystalline silicon wafer by in-situ wet and dry oxidation. After oxidation, the minority carrier lifetime was measured by using microwave photoconductance and the sheet resistance by 4-point probe, respectively. The junction depth was analyzed by Secondary Ion Mass Spectrometry (SIMS). Boron diffusion reduced the metal impurities in the bulk of silicon wafer and increased the minority carrier lifetime. In the case of wet oxidation, the sheet resistance value of ${\sim}46{\Omega}/{\Box}$ was obtained at $900^{\circ}C$, depostion time 50 min, and drive-in time 10 min. Uniformity was ~7% at $925^{\circ}C$, deposition time 30 min, and drive-in time 10 min. Finally, the minority carrier lifetime was shown to be increased from $3.3{\mu}s$ for bare wafer to $21.6{\mu}s$ for $900^{\circ}C$, deposition 40 min, and drive-in 10 min condition. In the case of dry oxidation, for the condition of 50 min deposition, 10 min drive-in, and O2 flow of 2000 SCCM, the minority carrier lifetime of 16.3us, the sheet resistance of ${\sim}48{\Omega}/{\Box}$, and uniformity of 2% were measured.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.211-218
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• 2004

The objective of this study is to enhance the ultimate bearing capacity of piles embedded in marine clay by electrokinetic(EK). The focus of improvement is at interlace between soil and pile. A series laboratory test was performed in EK cell. In each of test, the pile in the centre as anode is surrounded by cathode and it was installed in the vicinity of pile with triangular layout. The pile was made by stainless and embedded with 30cm of depth. Afterward, the DC voltage was applied to electrode over period of time. It caused flowing water from anode to cathode, thus the soil in the center of box has higher bearing capacity value than in the side of box has. It is shown by increasing of un-drained shear strength(Cu) near the pile and also ultimate bearing capacity of pile increase after EK treatment. In the future work, the continuous of this study is finding the effective DC voltage and makes EK treatment more applicable in the field.

• 한국식품과학회지
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• 제30권6호
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• pp.1307-1311
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• 1998

절임배추의 장기저장에 적합한 포장방법을 연구하기 위하여 해남산 월동배추를 절여서 20 kg씩 대형으로 포장하여 $0^{\circ}C$ 저온저장고에서 8주간 저장하면서 절임배추의 염도, pH, 환원당함량, 총균수, 유산균수의 변화를 조사하였다. 그 결과 플라스틱 상자에 포장하여 덮개를 덮은 것이 가장 빠르게 변질되었고, LDPE로 포장한 것이 품질이 가장 잘 유지되었으며, HDPE 포장은 LDPE보다 약간 빠르게 변화하였는데, 모든 포장구에서 즙액에 잠긴 부분은 품질이 6주이상 양호하였으나 잠기지 않은 부분이 초기부터 빠르게 변질되었으므로, 절임배추는 즙액에 잠기도록 포장하는 것이 품질유지에 아주 중요하였다.

• IMMUNE NETWORK
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• 제8권2호
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• pp.39-45
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• 2008

Background: Down regulation of major histocompatibility complex class II transactivator (CIITA) has been identified as a major factor of immunosuppression in sepsis and the level of CIITA expression inversely correlates with the degree of severity. However, it has not been fully elucidated whether the lower expression of CIITA is a cause of disease process or a just associated sign. Here we determined whether the CIITA deficiency decreased survival rate using murine sepsis model. Methods: Major histocompatibility complex class II (MHC-II) deficient, CIITA deficient and wild type B6 mice were subjected to cecal ligation puncture (CLP) surgery. CIITA and recombination activation gene (RAG)-1 double deficient mice were generated to test the role of lymphocytes in CIITA-associated sepsis progression. Results: Sepsis mortality was enhanced in CIITA deficient mice, not by impaired bacterial clearance resulted from CD4 T cell depletion, but hyper-inflammatory response such as excessive release of a pro-inflammatory cytokine, high-mobility group box 1 (HMGB1). Conclusion: Our results demonstrate that CIITA deficiency affects the course of sepsis via the unexpected function of CIITA, regulation of cytokine release.

• 대한의생명과학회지
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• 제11권2호
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• pp.249-252
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• 2005

The mammalian unfolded protein response (UPR) protects the cell. against the stress of unfolded or misfolded proteins in the endoplasmic reticulum (ER). It has recently demonstrated that IRE1, PERK, ATF6, and X-box protein 1 (XBP-l) directly or indirectly participate in this process. Upon accumulation of unfolded/misfolded proteins in the ER lumen, release of BiP from Ire1p permits dimerization and autophosphorylation to activate its kinase and endoribonulease activities to initiate XBP-1 mRNA splicing. Spliced XBP-1 mRNA removed middle part of 23 bp and encodes a potent transcription factor, XBP-l protein that binds to the unfolded protein response element (UPRE) or endoplasmic reticulum stress element (ERSE) sequence of many UPR target genes and produces several kind of ER chaperones. In this study, we described both the result and the detailed experimental procedures of XBP-1 mRNA splicing induced by ER stress, this result might help to elucidate the roles of the UPR and early diagnosis in a number of human diseases involving endoplasmic reticulum storage disease (ERSD).

• 대한의생명과학회지
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• 제28권1호
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• pp.9-24
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• 2022

The aim of this study was to identify the expression of zinc finger E-box binding homeobox 1 (ZEB1), its prognostic significance, and correlation between ZEB1 and infiltrating immune cells in lung cancer. Correlation between ZEB1 and telomerase was also analyzed in different types of cancers. RNA sequencing analysis and survival rates of patients were confirmed by Gene Expression Profiling Interactive Analysis (GEPIA). The Kaplan-Meier plotter and PrognoScan databases were used to analyze the prognostic value of ZEB1 in various cancers. The Tumor IMmune Estimation Resource (TIMER) was used to determine the correlation between ZEB1 and infiltrating immune cells. Lower ZEB1 expression was lower in lung cancer and was related to poor prognosis in lung adenocarcinoma (LUAD). ZEB1 expression exhibited a significantly positive correlation with infiltration levels of immune cells in LUAD and lung squamous cell carcinoma. Furthermore, we found that the ZEB1 expression correlated with subunits of telomerase. Our findings suggest ZEB1 as a potential biomarker to be used for prognostic significance and tumor immunology in lung cancer. The correlation between the expression of ZEB1 and telomere-related gene will help in understand the cancer-promoting mechanisms.

• Korean Chemical Engineering Research
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• 제61권2호
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• pp.328-339
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• 2023

Methanol steam reforming (MSR) is a promising method for hydrogen supplying as a critical step in hydrogen fuel cell commercialization in mobile applications. Modelling and understanding of the reactor behavior is an attractive research field to develop an efficient reformer. Three-layer feed-forward artificial neural network (ANN) and Box-Behnken design (BBD) were used to modelling of MSR process using the Cu-SiO₂ aerogel catalyst. Furthermore, impacts of the basic operational variables and their mutual interactions were studied. The results showed that the most affecting parameters were the reaction temperature (56%) and its quadratic term (20.5%). In addition, it was also found that the interaction between temperature and Steam/Methanol ratio is important on the MSR performance. These models precisely predict MSR performance and have great agreement with experimental results. However, on the basis of statistical criteria the ANN technique showed the greater modelling ability as compared with statistical BBD approach.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.403-403
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• 2011

결정질 태양전지는 태양전지 시장에 큰 서막을 장식하였다. 현재 여러 종류의 태양전지 기술들이 많이 나오고 있지만 결정질 태양전지는 변환 효율이 좋고 신뢰성이 높아서 높은 시장 점유율을 차지하고 있다. 하지만 응용 분야가 적고 기판 가격이 비싸다는 단점이 있다. 현재에는 응용분야 개선을 위하여 Flexible solar cell에 대한 연구가 활발하다. Flexible solar cell에 상부전극은 결정질 태양전지에서 사용되는 Ag나 Al 전극 대신 TCO 종류의 일종인 ITO를 많이 사용한다. Flexible Solar cell은 Organic Solar cell과 Amorphous Solar Cell 두 가지 범주를 가지고 있다. 본 연구에서는 Amorphous Solar Cell의 전극에 사용되는 ITO의 온도 Stress에 따른 특성을 연구함으로써 Engineer의 근본적인 이슈인 저비용, 고효율에 초점을 맞추어 소자특성을 확인해 보도록 한다. Glass에 E-beam evaporation 장비를 이용하여 ITO를 증착하였고 제작된 소자를 200, 250, 300, 350$^{\circ}C$의 온도변수를 두어 1시간동안 Annealing 하였다. 각 Annealing 온도에 따른 Sheet resistivity,와 visible 영역의 transmittant를 측정하였다. visible영역에서의 transmittant는 Annealing 200$^{\circ}C$에서 300$^{\circ}C$로 온도가 증가함에 따라 transmittant는 증가하다가 350$^{\circ}C$에서 감소하였다. Sheet resistivity의 경우 Annealing 200$^{\circ}C$에서 300$^{\circ}C$로 온도가 증가함에 따라 ITO의 Sheet resistivity가 줄어들다가 350$^{\circ}C$에서 증가하였다. 300$^{\circ}C$로 Annealing한 ITO가 가시광선 영역에서 transmittant가 가장 높은 80%로 측정 되었다. Sheet resistivity역시 300$^{\circ}C$로 Annealing한 ITO가 8${\Omega}/{\Box}$로 가장 낮았다. Annealing 온도가 ITO의 electrical 특성과 optical 특성에 변화를 주었음을 알 수 있었다. Resistivity가 낮은 ITO 전극으로 박막 셀을 제작한다면 좋은 효율을 얻을 수 있을 거라 생각된다.

• Fisheries and Aquatic Sciences
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• 제26권6호
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• pp.406-422
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• 2023

Sarcopenia is an age-related, progressive skeletal muscle disorder involving the loss of muscle mass and strength. Previous studies have shown that γ-aminobutyric acid (GABA) from fermented oysters aids in regulatory T cells (Tregs) cell expansion and function by enhancing autophagy, and concomitantly mediate muscle regeneration by modulating muscle inflammation and satellite cell function. The fermentation process of oysters not only increases the GABA content but also enhances the content of branched amino acids and free amino acids that aid the level of protein absorption and muscle strength, mass, and repair. In this study, the effect of GABA-enriched fermented sarco oyster extract (FSO) on reduced muscle mass and functions via Treg modulation and enhanced autophagy in aged mice was investigated. Results showed that FSO enhanced the expression of autophagy markers (autophagy-related gene 5 [ATG5] and GABA receptor-associated protein [GABARAP]), forkhead box protein 3 (FoxP3) expression, and levels of anti-inflammatory cytokines (interleukin [IL]-10 and transforming growth factor [TGF]-β) secreted by Tregs while reducing pro-inflammatory cytokine levels (IL-17A and interferon [IFN]-γ). Furthermore, FSO increased the expression of IL-33 and its receptor IL-1 receptor-like 1 (ST2); well-known signaling pathways that increase amphiregulin (Areg) secretion and expression of myogenesis markers (myogenic factor 5, myoblast determination protein 1, and myogenin). Muscle mass and function were also enhanced via FSO. Overall, the current study suggests that FSO increased autophagy, which enhanced Treg accumulation and function, decreased muscle inflammation, and increased satellite cell function for muscle regeneration and therefore could decrease the loss of muscle mass and function with aging.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.257-262
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• 2008

In this paper, we study the electric characteristics of shading effects in photovoltaic module in case of outdoor operation. When fabricating PV module, solar cells are connected serially to obtain the high voltage because of its low open circuit voltage. And total current is determined by lowest current among solar cells. When the shading happens on PV module's surface, the current of shaded solar cell determine the total current flow. Because of this, generally by-pass diode is installed on junction box. The bypass diode operate when revered and shaded solar cell's voltage is over 0.6 voltage. The reverse-biased solar cell gives reduced maximum power of PV module and might give negative effect on durability. So, adequate by-pass installation and selection is needed.