가역 투자율 측정에 의한 1Cr-1Mo-0.25V 강의 열화도 평가

유권상,김용일,남승훈,유광민,조육,손대락 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.5

고온에서 운용 중인 설비의 안전성을 평가하기 위해서는 사용기간동안 열화된 재료의 물성을 측정하여야 한다. 실제 사용되고 있는 화력발전소 터빈의 로터에서 열화도가 다른 여러 종류의 시편을 입수하기 어렵기 때문에, 터빈 로터재로 널리 사용되고 있는 1Cr-1Mo-0.25V 강을 인공열화시켜 시편으로 사용하였다. 열화도의 비파괴적 평가를 위하여 교류 섭동 자기장을 인가하여 가역 투자율을 측정하는 자기적 방법을 사용하였다. 열화도의 증가에 따라 경도와 가역 투자율 피크 사이의 간격은 감소하였는데, 경도와 가역 투자율 피크 간격과의 선형관계를 이용하여 비파괴적으로 터빈 로터강의 열화도를 평가할 수 있는 기초를 마련하였다. The integrity of the turbine totors can be assessed by measuring reversible permeability and Vickers hardness of the aged rotors at service temperature. The measurement system of reversible permeability, which measured by applied alternating perturbing magnetic field, was constructed in order to evaluate matrial degradation, nondestructively. The test specimen was 1Cr-1Mo-0.25V steel used widely for turbine rotor material, and the specimens were prepared by the isothermal heat treatment at 630 ℃. The reversible permeability of the test materials were measured at room temperature. The peak interval of reversible permeability and Vickers hardness decreased with the increase of degradation. The degradation of test material may be determined nondestructively by the lineality of Vickers hardness and the peak interval of reversible permeability.

몰리브덴 퍼어말로이의 자기저항 효과에 관한 연구

장충근,유중렬,송재용,윤만영,박재형,손대락 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

자기저항센서를 제작하기 위하여 Mo-permalloy(Ni:79.43%, Fe:14.47%, Mo:5.7%, Mn:0.38%, C:0.013%)를 슬라이드 그라스에 진공증착하여 sensor element를 제작한 후 포화자속밀도(B_(s)), 보자력(H_(c)), 자기이방성상수(K//), 자기저항변화율(ΔR/R)을 조사하였다. 진공증착된 permalloy 박막의 포화자속밀도는 0.746T 이었으며, 자화주파수 1kHz에서 보자력은 2.90A/cm(//),1.98A/cm(⊥) 이었고, 열처리 후에 1.79A/cm(//). 1.37A/cm(⊥)로 감소되었다. 한편 이 소자의 자기이방성상수는 1.38X10^(4)erg/cm^(3) 이었으며 5x1^(0-3)T의 자장변화에 대만 저항변화율(ΔR/R)은 2.0% 이었다. 앞으로 이 소자의 온도특성, 잡음특성 및 내열성 등을 조사하고자 한다. To fabricate magnetoresistive sensor, Mo-permalloy(Ni:79.43%, Fe:14.47%, Mo:5.7%, Mn:0.38%, C:0.013%) was evaporated on the slide glass. Saturation magnetic induction(B_(s)), coercive field strength(H_(a)), magnetic anisotropy constant(K), and magnetoresistance were measured for the fabricated samples. The evaporated samples show that saturation magnetic induction was 0.746T, and coercive field strengthes were 2,90A/cm(//) and 1.98A/cm(⊥), and this values were reduced to 1.79A/cm(//) and 1.37A/cm(⊥) respectively after annealing. For the measurement of coercive field strength, magnetizing frequency of 1kHz was used. For the fabricated sensor element, magnetic anisotropic constant was 1.38X10^(4)erg/cm^(3) and magneto-resistance change(ΔR/R) was 2.0% under the magnetic field change of 5X10^(-3)T, We will continue study on the characteristics for the temperature, heat resistance, and noise.

La이 혼입된 고유전체/메탈 게이트가 적용된 나노 스케일 NMOSFET에서의 PBTI 신뢰성의 특성 분석

권혁민,한인식,박상욱,복정득,정의정,곽호영,권성규,장재형,고성용,이원묵,이희덕,Kwon, Hyuk-Min,Han, In-Shik,Park, Sang-Uk,Bok, Jung-Deuk,Jung, Yi-Jung,Kwak, Ho-Young,Kwon, Sung-Kyu,Jang, Jae-Hyung,Go, Sung-Yong,Lee, Weon-Mook,Lee, Hi-De 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.3

In this paper, PBTI characteristics of NMOSFETs with La incorporated HfSiON and HfON are compared in detail. The charge trapping model shows that threshold voltage shift (${\Delta}V_{\mathrm{T}}$) of NMOSFETs with HfLaON is greater than that of HfLaSiON. PBTI lifetime of HfLaSiON is also greater than that of HfLaON by about 2~3 orders of magnitude. Therefore, high charge trapping rate of HfLaON can be explained by higher trap density than HfLaSiON. The different de-trapping behavior under recovery stress can be explained by the stable energy for U-trap model, which is related to trap energy level at zero electric field in high-k dielectric. The trap energy level of two devices at zero electric field, which is extracted using Frenkel-poole emission model, is 1,658 eV for HfLaSiON and 1,730 eV for HfLaON, respectively. Moreover, the optical phonon energy of HfLaON extracted from the thermally activated gate current is greater than that of HfLaSiON.

Biological control of root-knot nematode(Meloidogyne incognita) by Lysobacter antibioticus HS124

Yong-Seong Lee(이용성),Seong-Jun Kang(강성준),So-Youn Lee(이소연),Geun-Young Yun(윤근영),Rong-De Jin(김영덕),Kil-Yong Kim(김길용) 한국토양비료학회 2009 한국토양비료학회 학술발표회 초록집 Vol.2009 No.5

Modelling and Experimental Study of Halbach Array Magnetic Coupler

De-yong Li,Shuang Wang,Yongcun Guo,Xin Ma 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.1

In order to effectively solve the current problems of magnetic couplers such as large area and complex internal coil, the Halbach array magnetic coupler was proposed. According to the specific characteristics of the hybrid magnetic coupler structure, the mathematical model of air gap magnetic flux density is established by using the combination of electric circuit and electromagnetic field solution. Based on the current superposition, the current is converted to the surface of the copper conductor, and the electromagnetic torque model of the space magnetic field is established by integrating the induced electromotive force along the circumferential direction. In order to verify the correctness of theoretical analysis, the 1:4 prototype was designed and manufactured. Then simulation verification and experiment measurement on its mechanical behaviour are performed. The results show that the maximum error of theoretical value, simulation value and test value is 9.3%. Under the same volume size, the output torque of Halbach array magnetic coupler is increased by 16.1% compared with the ordinary disk magnetic coupler. The research could provide the reference for the design and experimental research of magnetic coupler.

Enhancement of Wear Resistance of CoCrNiAlTi Plasma Sprayed Coatings Using Titanium Carbide

De-Yong Li,이철희 한국트라이볼로지학회 2023 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.39 No.1

Large drill bits may face high hardness ore and high working pressure when working. To optimize the use effect of large drill bits and prolong the use time, it is necessary to add a layer of pressure-resistant, wear-resistant, and low-friction coating on the surface of the drill bit. In this study, CoCrNiAlTi high-entropy alloy coatings and CoCrNiAlTi (70 wt%)-TiC (30 wt%) composite coatings are successfully prepared on Q235 steel by plasma spraying. The CoCrNiAlTi (70 wt%)-TiC (30 wt%) coating consists of FCC solid solution and a small amount of TiC phase. The effect of TiC on the composition phase, microhardness, and elastic modulus of HEA coating is studied by X-ray diffractometer (XRD) and microhardness tester. The effect of TiC on the friction and wear properties of HEA coatings is investigated using a wear tester. By improving the process parameters, the metallurgical bonding between the coating and the substrate is well combined, and a coating without pores and cracks is obtained. The experimental results confirm that the microhardness, elastic modulus, and wear resistance of CoCrNiAlTi-TiC composite coating are better, and the friction coefficient is lower.

MR T1 Image Segmentation of a Prostate Based on Distance Regularized Level Set Evolution

Yong-de Zhang,Jing-chun Peng,Gang Liu,Jin-gang Jiang,Yan-jiang Zhao 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.7

Prostate segmentation from MRI is a necessary first step and plays an important role in clinical decision making process. A MR T1 Image segmentation method of the prostate based on distance regularized level set evolution (DRLSE) is proposed. To smooth the prostate image to reduce the noise, a preprocessed prostate image with Gaussian kernel and get an edge indicator is convolved. We construct an energy function with a distance regularization term and an external energy term containing the edge indicator and minimize it by solving the gradient flow which can be implemented with a finite difference scheme. In segmentation experiments, the impact of parameters λ , μ , α and ε in DRLSE model on the image segmentation is analyzed, and an optimal value of these parameters is given. The experiment results confirm the effectiveness of the MRI segmentation method of prostate for different situation of different patients.

Cloning of gonadal aromatase gene Cyp19a in an endemic fish (Schizothorax kozlovi) of the Upper Yangtze River, and temperature effects on its expression

De-guo Yang,Yong-feng He,Xing-bing Wu,Yong-jiu Zhu 한국유전학회 2016 Genes & Genomics Vol.38 No.9

In order to elucidate the role of Cyp19a in sex differentiation of Schizothorax kozlovi, the full length cDNA of Cyp19a was cloned from the mature ovary of S. kozlovi by using rapid amplification of cDNA ends method, and then its relative mRNA expression levels among tissues and temperature groups were determined by using quantitative real-time PCR. The complete Cyp19a cDNA of 1795 bp of S. kozlovi was obtained, which encoded 517 amino acids and belonged to gonadal aromatase. Its deduced amino acid sequence had the above 70 % identity compared with gonadal aromatase genes of teleost fishes, but only 62–67 % when compared with brain aromatase genes of fishes. It was expressed only in heart and gonad, but no expression in other tissues, presenting relatively high tissue specificity. It also exhibited sex-specific expression pattern in gonads, but no sex differences in heart. Comparing with the Cyp19a expression levels at 12 days post hatching (dph), significant temperature effects were revealed in low temperature group (10 C) at 18 dph, and in high temperature group (26 C) at 40 dph. It suggested that gonadal aromatase Cyp19a gene may play important roles on the feminization or masculinization of S. kozlovi affected by temperature during the early developmental stage.

The Design of Control System for the Magnetic Bearing

Yong De Jin,Yan Zhou,Zhi Qiang Long 대한전자공학회 1991 International Conference on Electronics, Informati Vol.1 No.1

臨時動量詞的語義和句法初步分析

왕영덕 ( Yong De Wang ),가춘매 ( Chun Mei Jia ) 한국중국언어학회 2015 중국언어연구 Vol.0 No.57

漢語部分名詞可以臨時用動量詞,以對相關動詞表述的動作進行動量。臨時動量詞前加數詞構成數量短語,數量短語和動詞組合構成動量短語。本文從臨時動量詞自身的詞義和詞性出發,分析其語義特征與動詞的語義聯繫,探討타構成動量短語時內部構成分間的句法語義關係。 Some nouns can be used as temporary verbal classifiers in Mandarin Chinese, to measure action which the relevant verb expressed. A numeral preceding a temporary verbal classifier constitutes a numeral classifier phrase, a numeral classifier phrase and a verb can combine a syntagme named a verbal classifier phrase. Viewing from meaning of temporary verbal classifier and its part of speech, this paper analyzed its semantic features and semantic relation between it and the verb, explored the relationships on the syntax and semantics among internal components when it constitutes a verbal classifier phrase.