• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.81.2-81.2
• /
• 2011

The gas diffusion layer (GDL) consists of two main parts, the GDL backing layer, called as a substrate and the micro porous layer (MPL) coated on the GDBL. In this process, carbon particles of MPL penetrates to the GDBL consequently forms MPL penetration part. In this study, the micro porous layer (MPL) penetration thickness is determined as a design parameter of the GDL which affect pore size distribution profile through the GDL inducing different mass transfer characteristics. The pore size distribution and water permeability characteristics of the GDL are investigated and the cell performance is evaluated under fully/low humidification conditions. Transient response and voltage instability are also studied. In addition, to determine the effects of MPL penetration on the degradation, the carbon corrosion stress test is conducted. The GDL that have deep MPL penetration thickness shows better performance in high current density region because of enhanced water management, however, loss of penetrated MPL parts is shown after aging and it induces worse water management characteristics.

• Journal of Korea Society of Industrial Information Systems
• /
• v.21 no.4
• /
• pp.13-20
• /
• 2016

It is possible to implement an optical character recognition system using a high-resolution camera mounted on smart phones in the modern society. Further, characters extracted from the implemented application is possible to provide the voice service for the visually impaired person by using TTS. But, it is difficult for the visually impaired person to properly shoot the objects that character information are included, because it is very hard to accurately understand the current state of the object. In this paper, we propose a method of inducing an appropriate shooting for the visually impaired persons by using a smartphone gyro sensor. As a result of simulation using the implemented program, we were able to see that it is possible to recognize the more character from the same object using the proposed method.

• The Journal of Korean Medicine
• /
• v.29 no.5
• /
• pp.1-13
• /
• 2008

Objective : This study is investigate the effects of Sagunjatang-Ga-Nokyong(SGJ-NY) treatment on regenerative responses of corticospinal tract(CST) axons in the injured spinal cord. Methods :Using rats, we damaged their spinal cord, and then applied SGJ-NY extract to the lesion. Then we observed GAP-43 and NGF protein, astrcyte, axonal regeneration responses and axonal elongation. Result :Determination of GAP-43 and NGF protein levels were increased. And increased proliferation of astrocyte and enhanced processes in astrocytes were observed by SGJ-NY treatment. Higher number of astrocytes within the injury cavity in SGJ-NY treated group were showed, yet CSPG proteins were a weaker staining in the cavity in SGJ-NY. CST axons extended into the cavity and to the caudal area in SGJ-NY treated group were increased. Conclusion : SGJ-NY treatment might increase neural activity in the injured spinal cord tissue, and improved axonal regeneration responses. In this process, activation of astrocytes may play a role in promoting enhanced axonal elongation. the current study show that SGJ-NY exerts positive activity on inducing nerve regeneration responses by elevating neural tissue migration activities.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.3
• /
• pp.416-421
• /
• 2012

Current influenza vaccines elicit antibodies effective against homologous strains, but new strategies are urgently needed for protection against emerging epidemic or pandemic strains. Although influenza vaccine candidates based on the viral nucleoprotein (NP) or matrix protein do not elicit sterilizing immunity, they have the advantage of inducing immunity that may cover a larger number of viral strains. In this study, recombinant NP produced in Escherichia coli was purified and formulated in combination with the adjuvant ISCOMATRIX. This formulation increased a NP-specific immunity in mice, with a Th1 profile, and may constitute a promising low-cost influenza vaccine candidate, with ability to stimulate humoral and cellular immune responses.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.15 no.3
• /
• pp.179-187
• /
• 2010

This paper proposes a new anti-islanding method for single-phase grid-connected photovoltaic (PV) systems using Goertzel algorithm. The proposed scheme is based on inducing increases or decreases of frequencies of load voltage and current that is in the form of existences or periodical variations of the reactive power components. The frequency detection is needed to apply this power variation method to the grid-connected power converter. The proposed method is able to get a fast detection for anti-islanding without the effect of harmonics and noises. The simulation and experiment results validate the effectiveness of the proposed method.

• Journal of Ginseng Research
• /
• v.39 no.4
• /
• pp.299-303
• /
• 2015

Panax ginseng is a well-known economic medical plant that is widely used in Chinese traditional medicine. This species contains a unique class of natural products-ginsenosides. Recent clinical and experimental studies have presented numerous lines of evidence on the promising role of ginsenosides on different diseases including neurodegenerative diseases, cardiovascular diseases, and certain types of cancer. Nowadays, most of the attention has focused on ginsenoside Rd as a neuroprotective agent to attenuate ischemic stroke damages. Some of the evidence showed that ginsenoside Rd ameliorates ischemic stroke-induced damages through the suppression of oxidative stress and inflammation. Ginsenoside Rd can prolong neural cells' survival through the upregulation of the endogenous antioxidant system, phosphoinositide-3-kinase/AKT and extracellular signal-regulated protein kinase 1/2 pathways, preservation of mitochondrial membrane potential, suppression of the nuclear factor-kappa B, transient receptor potential melastatin, acid sensing ion channels 1a, poly(ADP-ribose) polymerase-1, protein tyrosine kinase activation, as well as reduction of cytochrome c-releasing and apoptosis-inducing factor. In the current work, we review the available reports on the promising role of ginsenoside Rd on ischemic stroke. We also discuss its chemistry, source, and the molecular mechanism underlying this effect.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.411-414
• /
• 2013

In order to enhance the photovoltaic property of the CdS/CdSe co-sensitized quantum dot sensitized solar cells (QDSSCs), the surface of nanoporous $TiO_2$ photoanode was modified by ultrathin $Al_2O_3$ layer before the deposition of quantum dots (QDs). The $Al_2O_3$ layer, dip-coated by 0.10 M Al precursor solution, exhibited the optimized performance in blocking the back-reaction of the photo-injected electrons from $TiO_2$ conduction band (CB) to polysulfide electrolyte. Transient photocurrent spectra revealed that the electron lifetime (${\tau}_e$) increased significantly by introducing the ultrathin $Al_2O_3$ layer on $TiO_2$ surface, whereas the electron diffusion coefficient ($D_e$) was not varied. As a result, the $V_{oc}$ increased from 0.487 to 0.545 V, without appreciable change in short circuit current ($J_{sc}$), thus inducing the enhancement of photovoltaic conversion efficiency (${\eta}$) from 3.01% to 3.38%.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1790-1794
• /
• 2012

Recently, it has been suggested that $p27^{Kip1}$, the cell cycle regulatory protein, plays a pivotal role in the progression of normal differentiation in murine embryonic stem (mES) cells. In the current study, we investigated the role of $p27^{Kip1}$ in the regulation of differentiation and apoptotic induction using Western blotting, quantitative real-time RT-PCR, and small interfering RNA (siRNA) assays and confocal laser scanning microscopic analysis of H9 human ES (hES) cells and H9-derived embryoid bodies (EBs) grown for 10 ($EB_{10}$) and 20 days ($EB_{20}$). Our results demonstrate that the proteins $p27^{Kip1}$ and cyclin D3 are strongly associated with cellular differentiation, and, for the first time, show that up-regulation of $p27^{Kip1}$ protects hES cells from inducing differentiation-associated and caspase 3-dependent apoptosis.

• Journal of the Korean Institute of Gas
• /
• v.19 no.6
• /
• pp.110-115
• /
• 2015

In this paper it is proposed to solve the problem of particulate matter reducing apparatus of the current DPF. One exhaust gas passage 2-way controlled to purify the exhaust gas generated during combustion efficiently. Through the control of the rotary valve within a single device, it is possible to prevent the exhaust pressure increases due to particulate matter accumulate inside the developing DPF. Develop DPF device capable of inducing a high efficiency of the output in order to improve the problem of reducing the engine output and fuel efficiency.

• Current Applied Physics
• /
• v.18 no.12
• /
• pp.1534-1539
• /
• 2018

SnSe single crystal showed a high thermoelectric zT of 2.6 at 923 K mainly due to an extremely low thermal conductivity $0.23W\;m^{-1}\;K^{-1}$. It has anisotropic crystal structure resulting in deterioration of thermoelectric performance in polycrystalline SnSe, providing a low zT of 0.6 and 0.8 for Ag and Na-doped SnSe, respectively. Here, we presented the thermoelectric properties on the K-doped $K_xSn_{1-x}Se$ (x = 0, 0.1, 0.3, 0.5, 1.5, and 2.0%) polycrystals, synthesized by a high-temperature melting and hot-press sintering with annealing process. The K-doping in SnSe efficiently enhances the hole carrier concentration without significant degradation of carrier mobility. We find that there exist widespread Se-rich precipitates, inducing strong phonon scattering and thus resulting in a very low thermal conductivity. Due to low thermal conductivity and moderate power factor, the $K_{0.001}Sn_{0.999}Se$ sample shows an exceptionally high zT of 1.11 at 823 K which is significantly enhanced value in polycrystalline compounds.