낙동강 물 관개논의 농업환경 특성과 질소, 인산 요구량

강위금,이재생,고지연,박창영,정기열 한국환경농학회 2004 한국환경농학회지 Vol.23 No.3

낙동강 물을 관개하여 벼를 재배하는 강 상류의 안동 풍산에서부터 하류의 부산 구포까지 7개 지역 논토양의 농업환경 특성을 1999년부터 2년간 비교 분석하였다. 토양의 중금속 함량은 자연함량 안팎이었으며 가장 높았던 곳은 부산 강서 지역이었고 다음으로는 고령 성산 지역이었다. 그러나 현미중의 중금속은 자연함량 이하를 보였다. 토양의 화학성은 고령 성산지역과 부산 강서지역에서 높았는데, 1999~2000년도의 영농 후 토양에서 고령은 pH (5.9~6.1), EC(0.8~0.9 dS/m), 유효인산(155~201 mg/kg), 치환성 칼슘(6.7~7.4 cmol^(+)//kg), 치환성 마그네슘(1.92~2.50 cmol^(+)/kg), 치환성 칼리(0.18~0.21 cmol^(+)//kg )가 가장 높았고 부산에서는 유기물(23.0~29.1 g/kg), 총질소(1.6~l.8 mg/kg)가 가장 높았다. 낙동강 물의 관개수질과 토양화학성을 고러한 벼의 진단시비량은 질소의 경우 110 kg/ha를 기준으로 안동 21.4%, 상주 11.85, 구미지역에서 8.8% 정도 증시할 필요가 있었으나, 고령에서는 14.9%, 창녕은 4.6%, 밀양 하남은 4.55, 부산 강서지역은 11.5% 내외로 줄일 수 있을 것으로 분석되었다. 그리고 인산질 비료는 45 kg/ha 기준으로 창녕 도천에서만 18.9% 줄여 주고 다른 지역에서는 기본시비량인 30 kg/ha만 시용하여도 무방할 것으로 판단되었다. 논토양에 분포하는 세균과 사상균, 방선균, 중온성 Bacillus, 형광성 Pseudomonas, Biomass C는 유기물과 총 질소, 인산 등의 양분함유량이 많았던 고령 성산과 그 하류지역에서 높았다. Agroenvironmental characteristics in paddy fields irrigated with the water of Nagdong river were analyzed along the river watershed for two years from 1999. The sites monitored from upper reaches of the river were Andong, Sangju, Gumi, Goryeong, Changnyeong, Milyang and Pusan. In paddy soils, the contents of heavy metals such as Cd, Cr, Cu, Pb, Ni, Zn and As were around natural values showing the highest values in Pusan followed by Goryeong. In brown rice, the contents of heavy metals were lower than natural values. Soil chemical properties appeared higher values in the lower reaches including Goryeong than the upper ones. The highest parameters in Goryeong were pH (5.9~6.1), EC (0.8~0.9 dS/m), Av.P₂O_(5) (155~201 mg/kg), exchangeable Ca (6.7~7.4 cmol^(+)/kg), Mg (1.92~2.50 cmol^(+)/kg), K (0.18~0.21 cmol^(+)/kg) and those in Pusan were organic matter (23.0~29.1 g/kg) and T-N (1.6~1.8 mg/kg). In conclusion, the recommended rates of N fertilizer for rice cropping were 21.4%, 11.8% and 8.8% high for Andong, Sangju and Gumi, respectively and 14.9%, 4.6%, 4.5% and 11.5% low for Goryeong, Changnyeong, Milyang and Pusan, respectively reflecting the chemical properties of soils and the quality of irrigation water on the basis of 110 kgN/ha. In the case of phosphorous, the rates were 18.9% and 33.3% low for Changnyeong and others, respectively on the basis of 45 kgP₂O_(5)/ha. The populations of bacteria, fungi, actinomycetes, Bacillus, fluorescent Pseudomonas and Biomass C were high at the lower reaches including Goryeong, which showed relatively much nutrient contents of organic matter, total N and phosphorous etc..

Ultrahigh Gauge Factor in Graphene/MoS₂ Heterojunction Field Effect Transistor with Variable Schottky Barrier

Lee, Ilmin,Kang, Won Tae,Shin, Yong Seon,Kim, Young Rae,Won, Ui Yeon,Kim, Kunnyun,Duong, Dinh Loc,Lee, Kiyoung,Heo, Jinseong,Lee, Young Hee,Yu, Woo Jong American Chemical Society 2019 ACS NANO Vol.13 No.7

<P>Piezoelectricity of transition metal dichalcogenides (TMDs) under mechanical strain has been theoretically and experimentally studied. Powerful strain sensors using Schottky barrier variation in TMD/metal junctions as a result of the strain-induced lattice distortion and associated ion-charge polarization were demonstrated. However, the nearly fixed work function of metal electrodes limits the variation range of a Schottky barrier. We demonstrate a highly sensitive strain sensor using a variable Schottky barrier in a MoS<SUB>2</SUB>/graphene heterostructure field effect transistor (FET). The low density of states near the Dirac point in graphene allows large modulation of the graphene Fermi level and corresponding Schottky barrier in a MoS<SUB>2</SUB>/graphene junction by strain-induced polarized charges of MoS<SUB>2</SUB>. Our theoretical simulations and temperature-dependent electrical measurements show that the Schottky barrier change is maximized by placing the Fermi level of the graphene at the charge neutral (Dirac) point by applying gate voltage. As a result, the maximum Schottky barrier change (ΔΦ<SUB>SB</SUB>) and corresponding current change ratio under 0.17% strain reach 118 meV and 978, respectively, resulting in an ultrahigh gauge factor of 575 294, which is approximately 500 times higher than that of metal/TMD junction strain sensors (1160) and 140 times higher than the conventional strain sensors (4036). The ultrahigh sensitivity of graphene/MoS<SUB>2</SUB> heterostructure FETs can be developed for next-generation electronic and mechanical-electronic devices.</P> [FIG OMISSION]</BR>

Extrinsic orbital-Hall effect of light in cyclic group symmetric metasurface

Yeon Ui LEE,Igor OZEROV,Frederic BEDU,Ji Su KIM,Frederic FAGES,Jeong Weon WU 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Outstanding Performance Cu Nanowire Transparent Electrode enabled by Flash-Induced Plasmonic Nanowelding

Ui Yeon Nam(남의연),Yu Mi Woo(우유미),Yeon Uk Kim(김연욱),Jae Hun Yang(양재훈),Pyeong An Kim(김평안),Jae Jun Lee(이재준),Jung Hwan Park(박정환) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

Herein, a outstanding performance Cu nanowires with sheet resistance of 17Ω sq<SUP>-1</SUP> and transmittance of 88% was fabricated by flash-induced plasmonic nanowelding process. The high-intensity flashlight (in the region of visible wavelength) significantly enhanced plasmonic welding of Cu NW intersections without any oxidation. Simultaneously, near-infrared (NIR) spectrum of flash light interlocked the interface between polyethylene terephthalate substrate and Cu NWs. To investigate the adhesion enhacement of interlocked Cu NWs, we conducted a quantitative peel test. the measured NW interfacial fracture force increased by 208% compared to that of a pristine Cu NW electrode. To demonstrate versatile uses of flash-induced Cu NW conductors, transparent resistive memory devices and touch screen panel were successfully fabricated on plastics by employing the flash-welded excellent performance Cu NW network.

Optical Spectroscopic Analysis of Muscle Spasticity for Low-Level Laser Therapy (LLLT)

Yeon Ui Lee,이상관,윤종인 한국광학회 2011 Current Optics and Photonics Vol.15 No.4

Current therapeutic methods for suppressing muscle spasticity are intensive functional training, surgery,or pharmacological interventions. However, these methods have not been fully supported by confirmed efficacy due to the aggravation of the muscle spasticity in some patients. In this study, a combined system was developed to treat with a low-level laser and to monitor the region of the treatment using an optical spectroscopic probe that measures oxygen saturation and deoxygenation during low-level laser therapy (LLLT). The evaluation of the wavelength dependence for LLLT was performed using a Monte Carlo simulation and the results showed that the greatest amount of heat generation was seen in the deep tissue at λ = 830 nm. In the oxy- and deoxygenation measurements during and after the treatment, oxygen-Hb concentration was significantly increased in the laser-irradiated group when compared to the control group. These findings suggest that LLLT using λ = 830 nm may be of benefit in accelerating recovery of muscle spasticity. The combined system that we have developed can monitor the physiological condition of muscle spasticity during the laser treatment in real time and may also be applied to various myotonia conditions such as muscle fatigue, back-pain treatment/monitoring, and ulcer due to paralysis.

Electro-optic switching in metamaterial by liquid crystal

Lee Yeon Ui,Kim Junghee,Wu Jeong Weon 나노기술연구협의회 2015 Nano Convergence Vol.2 No.23

Electro-optic switching of reflection and refraction is experimentally demonstrated in metasurface liquid crystal cell. Negative metasurface is fabricated by focused-ion-beam milling, and twisted nematic cells are constructed with complementary double-split ring resonator and V-shape slot antenna metasurface. By application of an external voltage, electro-optic switchings are achieved in reflection and refraction. It has a strong implication for applications in spatial light modulation and wavelength division multiplexer/demultiplexer in a near-IR spectral range.

Healing effects and superoxide dismutase activity of diode/Ga-As lasers in a rabbit model of osteoarthritis.

Lee, Jae Yeon,Lee, Sang Ui,Lim, Taekjoo,Choi, Seok Hwa Dr. J.G. Delinassios 2014 IN VIVO -ATHENS- Vol.28 No.6

<P>Osteoarthritis is a major cause of pain and disability in joints. The present study investigated the effects of differences of wavelengths and continuous versus pulsed delivery modes of low-level laser therapy (LLT) in a rabbit model of osteoarthritis. Comparison of the healing effects and superoxide dismutase (SOD) activity between therapy using diode and Ga-As lasers was our primary interest.</P>

Ectopic ureterocele abscess mimicking vaginal Gartners duct cyst

( Seon Ui Lee ),( Jae Young Park ),( Hyun Kyung Kim ),( Su Lim Lee ),( Yeon Hee Kim ) 대한산부인과학회 2018 대한산부인과학회 학술대회 Vol.104 No.-

Background: To classify and differentiate vulvovaginal cysts and abscess is challenging for clinicians. Mostly we often rely on clinical history and examination for diagnosis and treatment. Case: A 45-year-old women complained of persistent fever, dysuria and pelvic pain with a history of operation for congenital anomaly of urinary system. On physical examination, vaginal bulge was found at right side and anterior to the vagina, with transverse vaginal septum. In trans-vaginal ultrasound, multiple cysts filled with mixed echogenic content appeared along the right side of vagina and uterus. A computed tomogram revealed about 16 sized tubular lesion extending from the right side of uterus to pelvic brim, and multiple cystic lesion in anterolateral portion of the upper vagina, and duplication of the left ureter. She got the cystoscopic evaluation for vesicoureteral reflux, which was negative. She underwent surgical drainage and excision of abscess wall through the vaginal approach to relieve her symptoms and diagnose the origin of the abscess. Pathologic examination reported chronic inflammation and fibrosis of the ureterocele, and the colony of Escherichia coli was cultured in the pus from the abscess. After surgical and medical treatments, follow-up imaging and examination of vagina at one month later showed the resolution of the initial lesion and well-healed vagina. Conclusion: We reported an interesting case, which was first suspected of Gartner duct cyst but eventually diagnosed of an abscess come from ureterocele. From this case, general evaluation of overall the genitourinary system and careful history taking is important to exactly differentiate and treat the vulvovaginal cyst.

이기종 무선 네트워크 연동을 위한 상호연동기술 개발에 관한 연구

이재홍(Lee jae hong),김대연(Kim dae yeon),한정석(Han jung seok),이형의(Lee hyong ui),이종성(Lee jong sung),신영식(Shin Young Sigk),김범곤(Kim Bum gon),이헌수(Lee heon soo) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.1

Very high open-circuit voltage in dual-gate graphene/silicon heterojunction solar cells

Won, Ui Yeon,Ly, Thuc Hue,Kim, Young Rae,Kang, Won Tae,Shin, Yong Seon,Lee, Ki Young,Heo, Jin Seong,Kim, Kun Nyun,Lee, Young Hee,Yu, Woo Jong Elsevier 2018 Nano energy Vol.53 No.-

<P><B>Abstract</B></P> <P>Two dimensional (2D) layered materials and their heterojunctions with other materials are attracted because of their remarkable electrical and optical properties. In particular, graphene/semiconductor Schottky heterojunction is used for high performance solar cells. Here, we demonstrated very high open circuit voltage (<I>V</I> <SUB> <I>oc</I> </SUB> <I>)</I> in graphene/silicon heterojunction solar cell by dual-gate electric field application. The low density of states near Dirac point in graphene allows large modulation of graphene Fermi-level and corresponding Schottky barrier in a graphene/silicon junction. The top and bottom gate electric fields independently adjust the built-in potentials of respective upper and lower silicon energy band to induce higher band bending (1.22 eV) than the bandgap (1.12 eV). As a result, a maximum <I>V</I> <SUB> <I>oc</I> </SUB> of 0.94 V is achieved at the − 8 V of top-gate voltage and 10 V of bottom-gate voltage, exceeding highest known <I>V</I> <SUB>oc</SUB> for previous graphene/silicon solar cell (<I>V</I> <SUB>oc</SUB> = 0.61 V) and the S-Q Limit (0.84 V) of conventional silicon solar cell – a thermodynamic limit for the energy conversion efficiency of solar cells with a single band gap energy. The ratio of output power gain to input gate power (Δ<I>P</I> <SUB>G</SUB>/Δ<I>P</I> <SUB>C</SUB>) is approximately 10<SUP>12</SUP>–10<SUP>14</SUP> with negligible power consumption in the gate (<I>P</I> <SUB>C</SUB> = 1 fW/cm<SUP>2</SUP>–10 pW/cm<SUP>2</SUP>), resulting in the significant advances in the power generation (<I>P</I> <SUB>G</SUB> = 40 mW/cm<SUP>2</SUP>).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Graphene/silicon hetero-junction solar cell was demonstrated by applying dual gate bias in 1-sun condition. </LI> <LI> Highest Open circuit voltage over the S-Q limit was recorded by modulating electrostatic doping. </LI> <LI> The ratio of output power gain to input gate power (Δ<I>P</I> <SUB>G</SUB>/Δ<I>P</I> <SUB>C</SUB>) is approximately 10<SUP>12</SUP>–10<SUP>14</SUP> with negligible power consumption in the gate (<I>P</I> <SUB>C</SUB> = 1 fW/cm<SUP>2</SUP> – 10 pW/cm<SUP>2</SUP>). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>