• 제목/요약/키워드: Cell density

검색결과 3,238건 처리시간 0.035초

배향막 응용을 위한 이온 빔 조사된 ZnO 박막에 관한 연구 (Study on ZnO Thin Film Irradiated by Ion Beam as an Alignment Layer)

  • 강동훈;김병용;김종연;김영환;김종환;한정민;옥철호;이상극;서대식
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
    • /
    • pp.430-430
    • /
    • 2007
  • In this study, the nematic liquid crystal (NLC) alignment effects treated on the ZnO thin film layers using ion beam irradiation were successfully studied for the first time. The ZnO thin films were deposited on indium-tin-oxide (ITO) coated glass substrates by rf-sputter and The ZnO thin films were deposited at the three kinds of rf power. The used DuoPIGatron type ion beam system, which can be advantageous in a large area with high density plasma generation. The ion beam parameters were as follows: energy of 1800 eV, exposure time of 1 min and ion beam current of $4\;mA/cm^2$ at exposure angles of $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$. The homogeneous and homeotropic LC aligning capabilities treated on the ZnO thin film surface with ion beam exposure of $45^{\circ}$ for 1 min can be achieved. The low pretilt angle for a NLC treated on the ZnO thin film surface with ion beam irradiation for all incident angles was measured. The good LC alignment treated on the ZnO thin film with ion beam exposure at rf power of 150 W can be measure. For identifying surfaces topography of the ZnO thin films, atomic force microscopy (AFM) was introduced. After ion beam irradiation, test samples were fabricated in an anti-parallel configuration with a cell gap of $60{\mu}m$.

  • PDF

DAAQ와 SPEEK를 이용한 전고상 슈퍼커패시터의 전기화학적 특성 (Electrochemical Characteristics of all solid supercapacitor based on DAAQ(1,5-diaminoanthraquinone) and SPEEK(sulfonated polyether ether ketone))

  • 김진용;김홍일;김한주;박수길
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
    • /
    • pp.371-372
    • /
    • 2005
  • Supercapacitors are promising devices for delivering high power density. Digital communications, electric vehicles and other devices that require electrical energy at high power levels in relatively short pulses have prompted considerable research on supercapacitors. In recent years, solid electrolytes have been investigated for supercapacitors. Solid electrolytes are advantageous over liquid electrolytes in respect of easy handling and reliability without electrolyte leakage. In this preliminary study, an electrochemical supercapacitor in all solid configuration has been fabricated using CNF-DAAQ and poly-vinylidenefluoride(PVdF). A new type of Supercapacitor was constructed by using carbon nanofibers(CNFs) and DAAQ(l,5-diaminoanthraquinone) monomer. DAAQ was deposited on the carbon nanofibers by chemical polymerization with $(NH_4)_2S_2O_8$ as oxidant in the 0.1M $H_2SO_4$. Dried SPEEK powder was mixed with N-methyl pyrrolidone to make 10 wt.% solution in an ultrasonic bath, the slurry was cast over a glass substrate heated to $70^{\circ}C$ for solvent evaporation. And then we used solid electrolyte of SPEEK. The unit cell consist of DAAQ-CNF/electrolyte/Pt. From the analysis, it is clear that surface of carbon nanofibers was quite uniformly coated with DAAQ. The performance characteristics of the supercapacitors have been evaluated using Cyclic Voltammetry.

  • PDF

Carbon계 Hybrid Capacitor의 전기 화학적 기술 및 Li-ion Battery의 혼성 동력원 특성 (Electrochemical Characteristics of Carbon/Carbon Hybrid Capacitor and Li-ion Battery/Hybrid Capacitor Combination)

  • 이선영;김익준;문성인
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
    • /
    • pp.597-598
    • /
    • 2005
  • Recently, the performance of portable electric equipment can often improved by a Li-ion battery assisted by a supercapacitor. A supercapacitor can provide high power density as well as a low resistance in the hybrid system. In this study, we have prepared, as the pluse power souce, a commercially supplied Li-ion battery with a capacity of 700mAh and AC resistivity of $60m\Omega$ at 1kHz and nonaqeous asymmetric hybrid capacitor composed of an activated carbon cathode and MCMB anode, and have examined the electrochemical characteristics of hybrid capacitor and the pulse performances of parallel connected battery/hybrid capacitor source. The nonaqueous asymmetric hybrid capacitor, the stacks of 10 pairs of the cathode, the porous separator and the anode electrode were housed in Al-laminated film cell. The hybrid capacitor, which was charged and discharged at a constant current at $0.25mA/cm^2$ between 3 and 4.3V, has exhibited the capacitance of 100F. And the equivalent series resistance was $32m\Omega$ at 1kHz. By combining a Li-ion battery and a hybrid capacitor, the pulse performance of battery can be improved 23% in run time under a pulse discharge of 7C-rate.

  • PDF

이하선관에 발생한 MALT 림프종 1예 (A Case of MALT Lymphoma in Parotid Gland Duct)

  • 김기엽;양원용;권석민;강상윤
    • Archives of Plastic Surgery
    • /
    • 제36권5호
    • /
    • pp.663-666
    • /
    • 2009
  • Purpose: Primary malignant lymphomas of the salivary glands are uncommon. The parotid gland was most frequently involved, followed by the submandibular gland, minor salivary gland and sublingual gland. The most common subtype is mucosa - associated lymphoid tissue(MALT) lymphoma. We experienced a case of salivary MALT lymphoma involving parotid gland duct, so report a case with a review of the literature. Methods: A 65 year old female presented with a palpable mass on the left side of her cheek. There was no clinical or laboratory evidence of pre - existing autoimmune disease. Preoperative facial and neck CT with contrast showed $2.1{\times}1.7cm$ sized, ill defined, homogeneous low density mass near left masseter muscle, and no evidence of other enlarged lymph nodes. Results: At operation, a yellowish oval shaped mass was found slightly adhered to middle portion of the parotid gland duct, meaduring $2{\times}1.5{\times}0.7cm$. Microscopic finding showed that centrocyte - like cells, monocyte B cells and plasma cells were diffusely infiltrated. Immunophenotyping was preformed on fixed section. The majority of the small cells were immunoreactive for the B cell marker CD20. Based on the typical histological findings supported by immunostaining, the mass was defined as MALT lymphoma. Conclusion: We report that very rare case of MALT lymphoma involving parotid gland duct in 65 year old female patient was experienced with clinical characteristics, histologic features and references.

Improved Uniformity in Resistive Switching Characteristics of GeSe Thin Film by Ag Nanocrystals

  • Park, Ye-Na;Shin, Tae-Jun;Lee, Hyun-Jin;Lee, Ji-Soo;Jeong, Yong-Ki;Ahn, So-Hyun;Lee, On-You;Kim, Jang-Han;Nam, Ki-Hyun;Chung, Hong-Bay
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
    • /
    • pp.237.2-237.2
    • /
    • 2013
  • ReRAM cell, also known as conductive bridging RAM (CBRAM), is a resistive switching memory based on non-volatile formation and dissolution of conductive filament in a solid electrolyte [1,2]. Especially, Chalcogenide-based ReRAM have become a promising candidate due to the simple structure, high density and low power operation than other types of ReRAM but the uniformity of switching parameter is undesirable. It is because diffusion of ions from anode to cathode in solid electrolyte layer is random [3]. That is to say, the formation of conductive filament is not go through the same paths in each switching cycle which is one of the major obstacles for performance improvement of ReRAM devices. Therefore, to control of nonuniform conductive filament formation is a key point to achieve a high performance ReRAM. In this paper, we demonstrated the enhanced repeatable bipolar resistive switching memory characteristics by spreading the Ag nanocrystals (Ag NCs) on amorphous GeSe layer compared to the conventional Ag/GeSe/Pt structure without Ag NCs. The Ag NCs and Ag top electrode act as a metal supply source of our devices. Excellent resistive switching memory characteristics were obtained and improvement of voltage distribution was achieved from the Al/Ag NCs/GeSe/Pt structure. At the same time, a stable DC endurance (>100 cycles) and an excellent data retention (>104 sec) properties was found from the Al/Ag NCs/GeSe/ Pt structured ReRAMs.

  • PDF

연속파형 Nd:YAG 레이저를 이용한 Hastelloy C-276의 용접특성에 관한 연구 (A Study on the Welding Characteristics of Hastelloy C-276 using a Continuous Wave Nd:YAG Laser)

  • 나기대;유영태;신호준;오용석
    • Journal of Welding and Joining
    • /
    • 제26권5호
    • /
    • pp.49-59
    • /
    • 2008
  • Hastelloy C-276, corrosion resistant alloy at high temperature, is used in chemical plant and power generation industry. In this study, process parameter of laser welding for welding property in Hastelloy C-276 using a continuous wave Nd:YAG laser was studied. As the result of experiment, laser welding did not show segregation or crack at heat affected zone compared to conventional GTWA welding. The melting zone showed cell dendritic structure along with welding line. In addition, planer front solidification is occurred from welding structure, and it was progressed to cellular solidification. Optimal process parameter for butt welding was 1.2kW and 2.0 m/min for laser power and welding speed, respectively. While heat input, output density, tensile stress, and longitudinal strain was $441.98{\times}103$ J/cm2, $29.553{\times}103$ W/cm2, 768 MPa, and 0.689, respectively. Lap welding of the same material showed greater discrepancy in tensile property during 1 line and 2 line welding. For 1 line welding, tensile stress was about 320 MPa, and 2 line showed slightly larger tensile stress. However, strain was decreased by 20%. From this result, lap welding of the same material, Hastelloy C-276, with 2 line welding is considered to be more effective process than 1 line welding with consideration of mechanical property.

고과당식이 랫드모델에서 복분자 투여에 의한 대사증후군 개선효과 (Beneficial Effect of Rubus Coreanus Miq in a Rat Model of High Fructose Diet-induced Metabolic Syndrome)

  • 고민철;이윤정;윤정주;강대길;이호섭
    • 동의생리병리학회지
    • /
    • 제29권1호
    • /
    • pp.11-17
    • /
    • 2015
  • Overconsumption of fructose results in dyslipidemia, hypertension, which have documented as a risk of cardiovascular diseases. This experimental study was designed to investigate the beneficial effects of Rubus coreanus Miq.(RCM) in high-fructose diet-induced metabolic syndrome. Animals were divided into three groups; Control group fed regular diet and tap water, fructose groups were fed the 65% high-fructose (HF) diet with/without RCM 100 mg/kg/day for 8 weeks, respectively. Chronic treatment with RCM significantly decreased body weight, fat weight and adipocyte size. Moreover, RCM significantly prevented the development of the metabolic disturbances such as hyperlipidemia and hypertension. RCM also led to increase in high density lipoprotein level in the HF group. In addition, RCM suppressed vascular cell adhesion molecule-1 (VCAM-1) expression and significantly recovered the levels of endothelial nitric oxide synthase (eNOS) expression in aorta. These results demonstrates that RCM may be a beneficial therapeutic for metabolic syndrome through the improvement of hyperlipidemia, obesity, and hypertension.

음곡(陰谷)(KI10) 산수유 약침이 난소적출 생쥐의 골다공증에 미치는 영향 (Effects of the Herbal-Acupuncture with Corni Fructus Extract at Eumgok(KI10) on Osteoporosis in Ovariectomized Mice)

  • 김광성;이병렬;양기영;안택원;임윤경
    • Korean Journal of Acupuncture
    • /
    • 제27권1호
    • /
    • pp.63-85
    • /
    • 2010
  • Objective & Method: The purpose of this study is to investigate the effects of herbal-acupuncture with Corni Fructus extract (CF-HA) at Eumgok(KI10) on osteoporosis in ovariectomized (OVX) ddy mice. I carried out several experimental items to analyze the changes in body weight, uterine weight, uterus index, tibial length, the ash bone weight, tibial BMD, the levels of serum ALP, osteocalcin, Ca, P and the levels of tibial Ca, P, Ca/P ratio, and we performed histological and histomorphological analysis as well. Result: 1. CF-HA at Eumgok(KI10) significantly did not increase the level of bone mineral density in overiectomized mice. 2. CF-HA at Eumgok(KI10) significantly decreased the level of serum phosphorus in ovariectomized mice and sinificantly increased the level of serum calcium in ovariectomized mice. 3. CF-HA at Eumgok(KI10) significantly increased the levels of tibial calcium and phosphorus in ovariectomized mice. 4. CF-HA at Eumgok(KI10) significantly decreased the number of tibial osteoclast like cell in ovariectomized mice. 5. In the histomorphometric analysis of tibia, GPL(growth plate length) was significantly decreased by CF-HA at Eumgok(KI10) in ovariectomized mice. Conclusions: These results suggest that CF-HA at Eumgok(KI10) may have useful therapy effects on osteoporosis in ovariectomized mice.

Physicochemical Properties and Intestinal Bacterial Growth-Promoting Effect of Cell-Wall Polysaccharides from Cucumber Peel

  • Jun, Hyun-Il;Song, Geun-Seoup;Lee, Young-Tack;Kim, Young-Soo
    • Food Science and Biotechnology
    • /
    • 제14권3호
    • /
    • pp.375-379
    • /
    • 2005
  • Physicochemical properties, intestinal microbial growth, and inhibitory effects of alcohol-insoluble polysaccharide (AIP) extracted from cucumber peel were investigated. AIP was composed of 14.54% crude protein, 1.04% crude lipid, 13.74 % crude ash, 9.1% soluble dietary fiber, and 41.2% insoluble dietary fiber. AIP showed low bulk density (0.18 g/mL) and water-holding capacity (6.39 g/g), and high oil-holding capacity (3.96 g/g). Pectic substance fractions [water-soluble pectic substance (WSP), ethylenediaminetetraacetic acid-soluble pectic substance (ESP), and alkali-soluble pectic substances (ASP)] and hemicellulose fractions [1 M KOH-soluble hemicellulose (KHP1) and 4 M KOH-soluble hemicellulose (KHP4)] were obtained from sequential chemical fractionation of AIP. WSP showed higher total sugar contents than total uronic acid contents, whereas opposite results were observed in ESP and ASP. Molecular weight distributions of three pectic substance fractions were in order of ASP>ESP>WSP. Ion exchange chromatogram pattern of WSP was different from those of ESP and ASP. Major component of WSP was fraction eluted by 0.05 M ammonium acetate buffer, whereas that of ESP and ASP was fraction eluted by 0.2 M NaOH. WSP and ASP showed growth-promoting activities against Lactobacillus brevis, Bifidobacterium bifidum, and B. longum, whereas B. bifidum and B. longum for ESP. KHP1 and KHP4 fractions had significant growth-promoting activities against B. bifidum.

Epigallocatechin gallate attenuates L-DOPA-induced apoptosis in rat PC12 cells

  • Lee, Myung-Yul;Choi, Eun Joo;Lee, Myung-Koo;Lee, Jae-Joon
    • Nutrition Research and Practice
    • /
    • 제7권4호
    • /
    • pp.249-255
    • /
    • 2013
  • In this study, the protective effects of EGCG on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced oxidative cell death in catecholaminergic PC12 cells, the in vitro model of Parkinson's disease, were investigated. Treatment with L-DOPA at concentrations higher than $150{\mu}M$ caused cytotoxicity in PC12 cells, as determined using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry detection. The apoptotic ratio was similar in cells treated with $100{\mu}M$ EGCG plus $150{\mu}M$ L-DOPA (5.02%) and the control (0.96%) (P > 0.05), and was lower than that of cells treated with L-DOPA only (32.24%, P < 0.05). The generation level of ROS (% of control) in cells treated with EGCG plus L-DOPA was lower than that in cells treated with L-DOPA only (123.90% vs 272.32%, P < 0.05). The optical density in production of TBARS in cells treated with L-DOPA only was higher than that in the control ($0.27{\pm}0.05$ vs $0.08{\pm}0.04$, P < 0.05), and in cells treated with EGCG only ($0.14{\pm}0.02$, P < 0.05), and EGCG plus L-DOPA ($0.13{\pm}0.02$, P < 0.05). The intracellular level of GSH in cells treated with EGCG plus L-DOPA was higher than that in cells treated with L-DOPA only ($233.25{\pm}16.44$ vs $119.23{\pm}10.25$, P < 0.05). These results suggest that EGCG protects against L-DOPA-induced oxidative apoptosis in PC12 cells, and might be a potent neuroprotective agent.