• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제30권3호
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• pp.192-197
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• 2017

Hydrogenated Amorphous Silicon (a-Si:H) is used as an emitter layer in HIT (heterojunction with Intrinsic Thin layer) solar cells. Its low band gap and low optical properties (low transmittance and high absorption) cause parasitic absorption on the front side of a solar cell that significantly reduces the solar cell blue response. To overcome this, research on CSC (carrier Selective Contacts) is being actively carried out to reduce carrier recombination and improve carrier transportation as a means to approach the theoretical efficiency of silicon solar cells. Among CSC materials, molybdenum oxide ($MoO_x$) is most commonly used for the hole transport layer (HTL) of a solar cell due to its high work function and wide band gap. This paper analyzes the electrical and optical properties of $MoO_x$ thin films for use in the HTL of HIT solar cells. The optical properties of $MoO_x$ show better performance than a-Si:H and ${\mu}c-SiO_x:H$.

• Current Photovoltaic Research
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• 제1권2호
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• pp.73-81
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• 2013

Heterojunction with Intrinsic Thin-layer (HIT) solar cells are currently an important subject in industrial trends for thinner solar cell wafers due to the low-temperature of production processes, which is around $200^{\circ}C$, and due to their high-efficiency of 24.7%, as reported by the Panasonic (Sanyo) group. The use of thinner wafers and the enhancement of cell performance with fabrication at low temperature have been special interests of the researchers. The fundamental understanding of the band bending structures, choice of materials, fabrication process, and nano-scale characterization methods to provide necessary understanding of the interface passivation mechanisms, emitter properties, and requirements for transparent oxide conductive layers is presented in this review. This information should be used for the performance characterization of the developing technologies for HIT solar cells.

• Biomolecules & Therapeutics
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• 제16권2호
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• pp.100-105
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• 2008

The sphingolipid metabolites act as lipid mediator for cell proliferation and apoptosis in mammalian cells. In bacteria, sphingolipid metabolism remains unknown. The purpose of this study was to investigate whether sphingolipid metabolism is potential target for fumonisin $B_1$($FB_1$) and desipramine in Sphingomonas chungbukensis, Gram-negative bacteria, by comparing the intracellular contents of bacterial sphingolipids with ones of HIT-T15 ${\beta}$-cells, hamster pancreatic cells. The concentrations of ceramide and dihydroceramide were 18.0 ${\pm}$ 12.0 and 0.025 ${\pm}$ 0.018 nmol/mg protein, respectively, in HIT-T15 cells. However, the concentrations of ceramide and dihydroceramide in the bacterial culture were 2.0 ${\pm}$ 1.2 and 10.6 ${\pm}$ 5.5 nmol/mg protein, respectively. $FB_1$ decreased the level of ceramide from 18.0 to 3.8 nmol/mg protein in HIT-T15 ${\beta}$-cells. However, dihydroceramide content in $FB_1$-treated HIT-T15 cells was slightly decreased compared with the control culture. When S. chungbukensis was treated with either $FB_1$ or desipramine, dihydroceramide level was increased by 5- and 4-fold, respectively, compared with the control bacteria. These results indicate that $FB_1$ and desipramine may act as an activator in bacterial sphingolipid biosynthetic pathway, and bacterial sphingolipid metabolism pathway appears to be different from the pathway of mammalian cells.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.281-286
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• 2010

A Pseudomonas fluorescens strain was isolated and found to show antagonistic activity against phytopathogenic fungi and to possess a gene responsible for production of antibiotic 2,4-diacetylphloroglucinol. For the extension of biocontrol range, a gene for an Androetonus australis Hector insect toxin 1 (AaHIT1), one of the most known toxic insect-selective peptides, was designed and synthesized according to the preferred codon usage of Pseudomonas fluorescens, cloned, and transformed into the strain by pSUP106 vector, a broad-host-range plasmid. Bioassays indicated that the engineered strain was able to produce AaHIT1 with insecticidal activity, and at the same time retain the activity against plant pathogen. The experiments for nonplanted soil and rhizosphere colonization showed that, similar to the population of the wild-type strain, that of the engineered strain remained relatively constant in the first 10 days, and the subsequent 50 days, suggesting that AaHIT1 expression in the bacterial cell does not substantially impair its long-term colonization. It is first reported that a Pseudomonas fluorescens strain expressing an active scorpion neurotoxin has dual activity against phytopathogenic fungi and insects, making at attractive for agronomic applications.

• Microbiology and Biotechnology Letters
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• 제19권6호
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• pp.553-560
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• 1991

In the previous paper (10). a new temperate phage, Sigma FA1 had been isolated from B. circulans. Sigma FA1 had an icosahedral head with a diameter of about 70 nm, and a tail about 15 nm long, and beared a circularly permuted, linear duplex DNA. Signla FA1 killed sensitive cells by a single-hit process. Phage DNA injected into the cell immediately after infection was degraded slowly. Our results indicate that the killing action of Sigma FA1 is different from the phenomenon of abortive infection and suggest that the killing might be caused by a proteinaceous component of Sigma FA1.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.366-366
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• 2010

Simulation Program (AFORS-HET 2.4.1) was used, include the basic structure of crystalline silicon thin film as above, below Intrinsic a-Si:H films bonded symmetrical structure (Symmetrical structure) were used. Efficiency with variation of the concentration was grown by the a-Si p-type with increasing concentrations of Na, efficiency with increasing a-Si n-type of Nd Concentrations was not changed, was decreased rapidly when concentrations were decreased. Efficiency was increased when c-Si n-type of Nd concentration was increased, otherwise efficiency was decreased when concentration was decreased.

• Proceedings of the PSK Conference
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.95.1-95.1
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• 2003

Sopungsungi-won has been used as a traditional medicine for diabetes and it has been proved evidently as a potential remedy for type 2 diabetes mellitus. Both in vivo and in vitro experiments with water extract of Sopungsungi-won have been reported to exhibit anti-diabetic effects in our previous studies. In the present study, we have chosen Rheum undulatum (RU), which is the main component of Sopungsungi-won, to examine its anti-apoptotic effect on pancreatic b-cells, HIT-T15, against oxidative stress induced by hydrogen peroxide (H$_2$O$_2$). (omitted)

• Current Photovoltaic Research
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• 제7권1호
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• pp.9-14
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• 2019

Carrier selective solar cell structure has allured curiosity of photovoltaic researchers due to the use of wide band gap transition metal oxide (TMO). Distinctive p/n-type character, broad range of work functions (2 to 7 eV) and risk free fabrication of TMO has evolved new concept of heterojunction intrinsic thin layer (HIT) solar cell employing carrier selective layers such as $MoO_x$, $WO_x$, $V_2O_5$ and $TiO_2$ replacing the doped a-Si layers on either front side or back side. The p/n-doped hydrogenated amorphous silicon (a-Si:H) layers are deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD), which includes the flammable and toxic boron/phosphorous gas precursors. Due to this, carrier selective TMO is gaining popularity as analternative risk-free material in place of conventional a-Si:H. In this work hole selective materials such as $MoO_x$, $WO_x$ and $V_2O_5$has been investigated. Recently $MoO_x$, $WO_x$ & $V_2O_5$ hetero-structures showed conversion efficiency of 22.5%, 12.6% & 15.7% respectively at temperature below $200^{\circ}C$. In this work a concise review on few important aspects of the hole selective material solar cell such as historical developments, device structure, fabrication, factors effecting cell performance and dependency on temperature has been reported.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.82-82
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• 2015

Industrial crystalline silicon (c-Si) solar cells with using a screen printing technology share the global market over 90% and they will continue to be the same for at least the next decade. It seems that the $2^{nd}$ generation and the $3^{rd}$ generation technologies have not yet demonstrated competitiveness in terms of performance and cost. In 2014, new world record efficiency 25.6% (Area-$143.7cm^2$, Voc-0.740V, $Jsc-41.8mA/cm^2$, FF-0.827) was announced from Panasonic and its cell structure is Back Contact $HIT^*$ c-Si solar cell. Here, amorphous silicon passivated contacts were newly applied to back contact solar cell. On the other hand, 24.9% $TOPCon^{**}$ cell was announced from Fraunhofer ISE and its key technology is an excellent passivation quality applying tunnel oxide (<2 nm) between metal and silicon or emitter and base. As a result, to realize high efficiency, high functional technologies are quite required to overcome a theoretical limitation of c-Si solar cell efficiency. In this presentation, Si solar cell technology summarized in the International Technology Roadmap for Photovoltaics ($^{***}ITRPV$ 2014) is introduced, and the present status of R&D associated with various c-Si solar cell technologies will be reviewed. In addition, national R&D projects of c-Si solar cells to be performed by Korea University are shown briefly.

• Food Science and Preservation
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• 제18권6호
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• pp.1002-1008
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• 2011

This study aimed to examine the effect of the Schizandra chinensis fruit and Morus alba leaf on insulin expression in HIT-T15 cells, which is exposed by glucose. The total polyphenol contents of the S. chinensis fruit ethanol extract and the M. alba leaf hot-water extract were $20.11{\pm}0.35$ mg/g and $50.02{\pm}0.62$ mg/mL, respectively. The S. chinensis fruit ethanol extract and the M. alba leaf hot-water extract contained $2.85{\pm}0.15$ and $8.76{\pm}0.43$ mg/g flavonoids, respectively. The antioxidant ability of the M. alba leaf hot-water extract was found to be superior to that of the S. chinensis fruit ethanol extract. Compared to the HIT-T15-treated 10 mM 2-deoxy-D-glucose, the $100{\mu}g/mL$ S. chinensis ethanol extract was found to have a two fold increase in insulin productivity. Moreover, the $100{\mu}g/mL$ M. alba leaf hot-water extract promoted the insulin secretion of high-glucose-damaged HIT-T15 almost ten fold. The above results showed that the S. chinensis fruit ethanol extract and M. alba leaf hot-water extract may improve the insulin productivity of the beta cell with glucose-induced oxidative damage. These data suggest that the S. chinensis fruit ethanol extract and the M. alba leaf hot-water extract can be used as food materials for the regulation of insulin secretion.