• Title/Summary/Keyword: VS reduction

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Disposable Electrochemical Immunosensors for the Detection of Herbicide (제초제 검출을 위한 전기화학적 일회용 면역센서)

  • Chang, Seung-Cheol
    • Journal of Sensor Science and Technology
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    • v.20 no.1
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    • pp.35-39
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    • 2011
  • A disposable electrochemical immunosensor system has been developed for the detection of herbicide in aqueous samples. Disposable screen printed carbon electrodes(SPCE) were used as basic electrodes and an enzyme, horseradish peroxidase (HRP), and anti-herbicide antibodies was immobilised on to the working electrode of SPCE by using avidin-biotin coupling reactions. An herbicide-glucose oxidase conjugates have been used for the competitive immunoreaction with sample herbicides. The enzymatic reaction between the conjugated glucose oxidase and glucose added generates hydrogen peroxide, which was reduced by the peroxidase immobilised. The latter process caused an electrical current change, due to direct re-reduction of peroxidase by a direct electron transfer mechanism, which was measured to determine the herbicides in the sample. The optimal operational condition was found to be: $20\;{\mu}gl-1$ deglycosylated avidin loading to the working electrode and working potential +50 mV vs. Ag/AgCl. The total assay time was 15 min after sample addition. The detection limits for herbicides, atrazine and simazine, were found to be 3 ppb and 10 ppb, respectively.

Methanol Partial Oxidation over Commercial CuO-ZnO-Al2O3 Catalysts (CuO-ZnO-Al2O3 상업용 촉매에서의 메탄올 부분산화반응)

  • Lim, Mee-Sook;Suh, Soong-Hyuck;Ha, Ki-Ryong;Ahn, Won-Sool
    • Journal of Hydrogen and New Energy
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    • v.13 no.2
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    • pp.119-126
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    • 2002
  • The methanol partial oxidation using commercial $CuO/ZnO/Al_2O_3$ catalysts in a plug flow reactor was studied in the temperature range of $200{\sim}250^{\circ}C$ at atmospheric pressure, It was achieved the high activities by Cu-based catalysts and the selectivity of $CO_2$/$H_2$ was 100% when $O_2$ was fully convened. The reactivity changes and their hysteresis with increasing/decreasing temperatures were observed due to the chemical state differences between the oxidation and the reduction on the Cu surface, It was suggested as the two-step reaction: the complete oxidation and the following steam reforming for methanol, which was indicated by the distributions of final products vs. the residence time. In addition, the complete oxidation step was shown to be extremely fast and the total reaction rate can be controlled by the steam reforming reaction.

Electrical and Optical Characteristics of Isoelectronic Al-doped GaN Films

  • Lee, Jae-Hoon;Ko, Hyun-Min;Park, Jae-Hee;Hahm, Sung-Ho;Lee, Jung-Hee
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2002.11a
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    • pp.81-84
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    • 2002
  • The effects of the isoelectronic AI-doping of GaN grown by metal organic chemical vapor deposition were investigated for the first time using scanning electron microscopy (SEM), Hall measurements, photoluminescence (PL), and time-resolved PL. When a certain amount of Al was incorporated into the GaN films, the room temperature photoluminescence intensity of the films was approximately two orders larger than that of the undoped GaN. More importantly, the electron mobility significantly increased from 130 for the undoped sample to $500\textrm{cm}^2/Vs$ for the sample grown at a TMAl flow rate of $10{\mu}mol/min$, while the unintentional background concentration only increased slightly relative to the TMAl flow. The incorporation of Al as an isoelectronic dopant into GaN was easy during MOCVD growth and significantly improved the optical and electrical properties of the film. This was believed to result from a reduction in the dislocation-related non-radiative recombination centers or certain other defects due to the isoelectronic Al-doping.

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Electrochemical behavior and Application of Osmium-Cupferron Complex (오스뮴-쿠페론의 전기화학적 행동 및 응용)

  • Kwon, Young-Soon;Chong, Mee-Young
    • Analytical Science and Technology
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    • v.16 no.3
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    • pp.198-205
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    • 2003
  • The ammonium salt of nitrosophenylhydroxylamine, called cupferron, has been used not only as the ligand but also as an oxidizing agent for adsorptive catalytic stripping voltammetry (AdCtSV). Cyclic voltammetry was used for elucidating the electrochemical behavior of Os-cupferron complex in 1 mM phosphate buffer. The optimal conditions for osmium analysis were found to be 1 mM phosphate buffer solution (pH 6.0) containing 0.1 mM cupferron at scan rate of 100 mV/s. By using the plot of reduction peak currents of linear scan voltammograms vs. osmium concentration, the detection limit was $1.0{\times}10^{-7}M$.

Dependency of the Device Characteristics on Plasma Nitrided Oxide for Nano-scale PMOSFET (Nano-scale PMOSFET에서 Plasma Nitrided Oixde에 대한 소자 특성의 의존성)

  • Han, In-Shik;Ji, Hee-Hwan;Goo, Tae-Gyu;You, Ook-Sang;Choi, Won-Ho;Park, Sung-Hyung;Lee, Heui-Seung;Kang, Young-Seok;Kim, Dae-Byung;Lee, Hi-Deok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.7
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    • pp.569-574
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    • 2007
  • In this paper, the reliability (NBTI degradation: ${\Delta}V_{th}$) and device characteristic of nano-scale PMOSFET with plasma nitrided oxide (PNO) is characterized in depth by comparing those with thermally nitrided oxide (TNO). PNO case shows the reduction of gate leakage current and interface state density compared to TNO with no change of the $I_{D.sat}\;vs.\;I_{OFF}$ characteristics. Gate oxide capacitance (Cox) of PNO is larger than TNO and it increases as the N concentration increases in PNO. PNO also shows the improvement of NBTI characteristics because the nitrogen peak layer is located near the $Poly/SiO_2$ interface. However, if the nitrogen concentration in PNO oxide increases, threshold voltage degradation $({\Delta}V_{th})$ becomes more degraded by NBT stress due to the enhanced generation of the fixed oxide charges.

Multi-Level Motion Estimation Algorithm Using Motion Information in Blocks (블록 내의 움직임 정보를 이용한 다단계 움직임 예측 알고리즘)

  • Heak Bong Kwon
    • Journal of Korea Multimedia Society
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    • v.6 no.2
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    • pp.259-266
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    • 2003
  • In this paper, we propose a multi-level block matching algorithm using motion information in blocks. In the proposed algorithm, the block-level is decided by the motion degree in the block before motion searching procedure, and then adequate motion searching performs according to the block-level. This improves computational efficiency by eliminating the unnecessary searching Process in no motion or low motion regions, and brings more accurate estimation results by deepening motion searching Process in high motion regions. Simulation results show that the proposed algorithm brings the lower estimation error about 20% MSE reduction with the fewer blocks pet frame and the operation number was reduced to 56% compared to TSSA and 98% compared to FS -BMA with constant block size.

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Synthesis and Crystal Structure of Manganese(II) Complexes with 2-Acetylpyridine Methyldithiocarbazate

  • 모성종;임우택;구본권
    • Bulletin of the Korean Chemical Society
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    • v.19 no.11
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    • pp.1175-1179
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    • 1998
  • The aerobic reaction of 2-(acetylpyridine)-S-methyldithiocarbazate (acpy-mdtcH) and 2-(acetylpyridine)-N-phenylthiosemicarbazate(acpy-phTscH) with manganese(Ⅱ) acetate affords Mn(acpy-mdtc)2 and Mn(acpyphTsc)2, respectively. The spectroscopic data and X-ray structure of Mn(acpy-mdtc)2 are reported. Crystal data for Mn(acpy-mdtc)2; C18H20N6S4Mn, mol wt 503.58, monoclinic crystal system(P21/c) a=12.240(5) Å, b= 10.918(l) Å, c=17.651(3) Å, β=105.93(2), and V=2268(l) Å3, Z=4, 5071 data collected with 0°< 2θ < 52.64°, 2995 data with I > 3σ(I), R= 0.046, Rw= 0.065. The ligands act as tridentate NNS donors. The two Mn-S distances are not equal, and respectively 2.512(2) Å and 2.541(2) Å. The average Mn-N (azomethine) length, 2.242(5) Å, is slightly shorter than the average Mn-N (pyridyl) length, 2.262(5) Å. The coordination environment about MN(Ⅱ) center deviates considerably from octahedral geometry. The manganese(Ⅱ)-manganese(Ⅰ) and manganese(Ⅰ)-manganese(0) reduction potentials of Mn(acpy-mdtc)2 are ∼-l.71 and ∼-l.98 V while those of Mn(acpy-phTsc)2 are ∼-l.87 and ∼-2.11 V vs. Ag/Ag+ in dimethyl sulfoxide, respectively.

Probabilistic Estimation of LMR Fuel Cladding Performance Under Transient Conditions

  • Kwon, Hyoung-Mun;Lee, Dong-Uk;Lee, Byung-Oon;Kim, Young ll;Kim, Yong-Soo
    • Nuclear Engineering and Technology
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    • v.35 no.2
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    • pp.144-153
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    • 2003
  • The object of this paper is the probabilistic failure analysis on the cladding performance of WPF(Whole Pin Furnace) test fuel pins under transient conditions, and analysis of the KALIMER fuel pin using the preceding analysis. The cumulative damage estimation and Weibull probability estimation of WPF test are performed. The probabilistic method was adapted for these analyses to determine the effective thickness thinning due to eutectic penetration depth. In the results, it is difficult to assume that a brittle layer depth made by eutectic reaction is all of the thickness reduction due to cladding thinning. About 93% cladding thinning of the eutectic penetration depth is favorable as an effective thickness of cladding. And the unreliability of the KALIMER driver fuel pin under the same WPF test condition is lower than that of the WPF pin because of the higher plenum-fuel volume ratio and lower cladding inner radius vs. thickness ratio. KALIMER fuel pin developed from conceptual design has a more stable transient performance for a failure mechanism due to fission gas buildup than the WPF pin.

Physiotherapy Approach to Patients with Chronic Plantar Fasciitis : Comparison of the Effects of Specific Stretching Exercise and High-Load Strengthening Exercise (만성 발바닥 근막염 환자에 대한 물리치료적 접근법: 특이적 뻗침운동과 고부하 강화 운동의 효과 비교)

  • Choo, Yeon-Ki;Bae, Won-Sik
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.1
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    • pp.151-161
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    • 2021
  • Purpose : This study was to investigate the effectiveness of ESWT and plantar fascia-specific stretching exercise vs ESWT and high-load strengthening exercise in patients with chronic plantar fasciitis. Methods : The subjects were randomized to extracorporeal shock wave therapy ( ESWT, for 3 weeks) and daily plantar-specific stretching (Group I: Stretch group) or ESWT and high-load progressive strength (Group II: Strength group) performed every second day. The main outcome measures were ultrasound, visual analogue scale (VAS), and Korean Foot Function Index (KFFI). The ultrasound (plantar fascia thickness), pain intensity I, II (the most painful of the day?, the pain when you first step in the morning?) and KFFI (functional performance) were compared between the groups. Results : No significant difference was observed between the groups in the plantar fascia thickness but pain intensity I, II was significantly lower in Group 2 than in Group 1 at only 12weeks and functional performance was also significantly increased in Group 2 compared to Group 1 at only 12 weeks. Conclusion : The high-load strengthening exercise consisting of the progressive exercise protocol, resulted in superior after 12 weeks compared with plantar-specific stretching. High-load strength exercise may aid in a quicker reduction in pain and improvements in functional performance.

The effect of nuclear energy on the environment in the context of globalization: Consumption vs production-based CO2 emissions

  • Danish, Danish;Ulucak, Recep;Erdogan, Seyfettin
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1312-1320
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    • 2022
  • The earlier studies have analyzed theoretical links between nuclear energy and carbon dioxide (CO2) emissions concerning territorial (or production-based) emissions. Here using the latest available dataset, this study explores the impacts of nuclear energy on production-based and consumption-based CO2 emission in the era of globalization for the Organization for Economic Co-operation and Development (OECD) countries. The Driscoll-Kraay regression method reveals that nuclear energy is beneficial for the reduction of production-based CO2 emissions. However, it is revealed that nuclear energy does not reduce consumption-based CO2 emissions that are traded internationally and hence not comprised in conventional production-based emissions (territory) inventories. Globalization tends to reduce both production-based and demand-based carbon emissions. Finally, Environmental Kuznets Curve (EKC) is validated for both kinds of CO2 emissions. The findings may deliver practical policy implications related to nuclear energy and CO2 emissions for selected countries.