• Journal of the Korean Magnetic Resonance Society
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• v.25 no.1
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• pp.1-7
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• 2021

Employing of 13C stable-isotopes in NMR metabolomics can give unique splitting patterns and coupling constants information originated from 13C-13C coupling interaction that provide an important structural information regarding the cellular metabolic process. But it has been known that an undesirable signal distortion in 2D heteronuclear correlation study, due to 13C-13C interaction, hampers an analysis of the coupling information. Recently, we proposed J-scaled distortion-free heteronuclear single-quantum coherence (HSQC) sequence which provides a distortion-free 13C-13C coupling information with a selective resolution enhancement of JCC splitting. In this paper, we dicuss theoretical aspect and practical feature of J-scaled HSQC pulse sequence. The conceptual explanation of orgin of the signal distortion by 13C-13C coupling interaction and design of J-scaled HSQC through exemplified results are provided in brief.

• Korean journal of applied entomology
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• v.52 no.2
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• pp.109-113
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• 2013

A greenhouse soil infested with an obligate nematode parasitic bacterium, Pasteuria penetrans, was used to test the effect of temperatures on the endospore attachment to root-knot nematode, Meloidogyne arenaria, juveniles (J2). Freshly hatched J2s were inoculated to the soil in petri dish and incubated under different temperatures of $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$ for 7 days. The endospore attachment rates were 100% in all the temperatures, while the number of endospores attached per J2 was highest in $25^{\circ}C$ with 28.3 endospores/J2 followed by 20.2, 18.6, and 13.6 in $30^{\circ}C$, $20^{\circ}C$, and $35^{\circ}C$, respectively. When the soil was pre-treated under different temperatures before the J2 inoculation, the endospore attachment rates significantly decreased from 60% in room temperature to $25^{\circ}C$, 31.7, 8.3, 5.0, and 0% after the soil incubation in $-30^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$ for 10 days, respectively. The endospore numbers attached per J2 were 3.5, 4.3, 1, 1, and 0 when the soil was pre-treated in $-30^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$, respectively, which were lower than 5.3/J2 of room temperature treated soil. The P. penetrans isolate in the soil showed nematode species-specific endospore attachment characteristics with 100% attachment rate only on M. arenaria J2s while the rates were 0% on M. hapla and M. incognita J2s.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1798-1804
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• 2012

To prolong the shelf-life of domestic peaches, samples were treated with UV-C (0~10.0 $kJ/m^2$) and the spoiling rate and changes in physico-chemical and sensory properties were investigated. No spoiled peaches were observed within the first four days of storage in the control and 2.5 $kJ/m^2$ UV-C treatment groups. However, spoilage was observed in these groups on day six, and 29.17% and 25.0% of the samples showed spoilage on 10 day, respectively. Moreover, samples treated with greater than 5.0 $kJ/m^2$ of UV-C showed a higher percentage (41.67% or higher) of spoilage than those of the control or 2.5 $kJ/m^2$ UV-C treatment groups on 10 day. Additionally, weight changes in the peaches were the lower in the control group and 2.5 $kJ/m^2$ UV-C treatment group than in those treated with 5.0 $kJ/m^2$ of UV-C treatment or higher during 10 days of storage. There was no difference in pH among treatments, regardless of storage time. The hardness of the samples was not changed immediately after UV-C treatment, but that of samples treated with 5.0~10.0 $kJ/m^2$ of UV-C decreased rapidly after four days, when compared to the control and 2.5 $kJ/m^2$ UV-C treatment groups. No significant changes in the lightness and redness of the samples were observed in response to UV-C treatment, however, UV-C treatment led to a slight decrease in the yellowness of the samples. The initial taste, flavor, color, texture, and overall acceptance did not differ among control and UV-C treatments. The sensory score of the samples was the highest after 2 and 4 days of storage, while it decreased thereafter. In general, samples in the control and the 2.5 $kJ/m^2$ UV-C treatment groups showed higher sensory quality than those treated with UV-C at 5.0 $kJ/m^2$ or higher.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.60-67
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• 1998

In this study, the J-Resistance Curve and material tearing modulus of SA508-C3 steel, which is one of the used nuclear pressure vessel steel, are measured ar room temperature, $200^{circ}C$ and $300^{circ}C$ according to load ratio analysis and ASTM E813, ASTM E1152, respectively. It is observed that J-R curve and Tmat value decrease as the temperature level increase. Applicability of $T_j$ proposed by Paris et al as instability parameter for ductile material is investigated. It is concluded that results are the $T_j$ parameter may be used as a crack instability parameter.

• Elastomers and Composites
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• v.40 no.1
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• pp.3-11
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• 2005

The ruling kinetics of epoxy resins with 3 different kinds or alkenylsuccinic anhydride (ASA) having C-8, C-12, and C-16 pendant side chain length with two different catalysts was studied by using differential scanning calorimetry (DSC). Nonisothermal and isoconversional method has been used for characterizing the effect of the pendant side chain length in the curing process. Results or nonisothermal method showed that there was no significant difference in the effect of the pendant side chain length of ASA. But isoconversional analysis showed that the value of the activation energy for the initiation reaction or C-8, C-12, and C-16 were $61.7{\sim}57.7kJ/mol$, $63.0{\sim}57.3 kJ/mol$, and $130.4{\sim}94.2 kJ/mol$, respectively, depending on the catalyst used. The values of activation energy for the initiation is different as reported value of 20 kJ/mol which indicating the difference in the effect of the pendant side chain length of ASA in the initial stage of the reaction.

• Progress in Superconductivity and Cryogenics
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• v.18 no.4
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• pp.15-20
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• 2016

The effects of electron beam (EB) irradiation on the superconducting critical temperature ($T_c$) and critical current density ($J_c$) of YBCO films were studied. The YBCO thin films were irradiated using a KAERI EB accelerator with an energy of 0.2 MeV and a dose of $10^{15}-10^{16}e/cm^2$. A small $T_c$ decrease and a broad superconducting transition were observed as the EB dose increased. The value of $J_cs$ (at 20 K, 50 K and 70 K) increased at doses of $7.5{\times}10^{15}$ and $2.2{\times}10^{16}e/cm^2$. However, $J_cs$ decreased as the dose increased further. The X-ray diffraction (XRD) analysis showed that the c axis of YBCO was elongated and the full width at half maximum (FWHM) increased as the dose increased, which is strong evidence of the atomic displacement by EB irradiation. The transmission electron microscopy (TEM) showed that the amorphous layer formed in the vicinity of the surfaces of the irradiated films. The amorphous phase was often present as an isolated form in the interior of the films. In addition to the formation of the amorphous phase, many striations running along the a-b direction of YBCO were observed. The high magnification lattice image showed that the striations were stacking faults. The enhancement of $J_c$ by EB irradiation is likely to be due to the lattice distortion and the formation of defects such as vacancies and stacking faults. The decrease in $J_c$ at a high EB dose is attributed to the extension of the amorphous region of a non-superconducting phase.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.1
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• pp.17-25
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• 1993

The Cu - $Nb_3Sn$ composites wire as a superconducting material was prepared by in situ method as follow: Cu - 15wt.% Nb alloys which were melted in a high -frequency induction furnace and casted in bar were cold-worked up to the final diameter of 0.24 mm, electroplated with Sn, pre-treated in two steps and then diffused at $550{\sim}650^{\circ}C$ for 24 ~ 96 hrs. The overall $J_c$ and $T_c$ of the specimens were measured by the four point-probe method at 10 K in the magnetic field of 0 Tesla. The overall $J_c$ of the composites wire which diffused at $550^{\circ}C$ after pre-treating in two steps were generally higher than those of the wire at either $600^{\circ}C$ or $650^{\circ}C$. For the specimens diffused at $550^{\circ}C$, the overall $J_c$ were increased until 72 hrs. of diffusion time and then decreased. However, in case of diffusion at $600^{\circ}C$ and $650^{\circ}C$, the overall $J_c$ were gradually decreased from the beginning. The maximum overall $J_c$ obtained in this experiment was $1.3{\times}10^4\;A/cm^2$, which was measured for the specimen diffused at $550^{\circ}C$ for 72 hrs. When the specimens were diffused at $550^{\circ}C$ for 72 hrs, after pre-treating, the measured critical temperature, $T_c$ was 16.19 K. Similar $T_c$ value were obtained in other specimens regardless of diffusion time and temperature.

• Electronics and Telecommunications Trends
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• v.22 no.5
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• pp.78-85
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• 2007

최근 핸드폰 및 정보통신기기가 급속도로 발전함에 따라 그 핵심 부품이라 할 수 있는 비메모리 반도체의 발전이 최대 관심사로 떠오르고 있다. 비메모리 반도체를 대표하는 SoC의 발전은 한 국가의 정보통신 발전 및 국가 경제에 지대한 영향을 미친다고 볼 수 있다. 삼성전자로 대표되는 메모리 위주의 우리나라 반도체 산업도 지난 몇 년간 SoC를 개발하는 국내 팹리스 업체들에 의해 많이 발전하였다. 그럼에도 불구하고, 세계적으로 블루오션 시장으로 각광 받고 있는 SoC의 필수 요소인 IP 시장의 경우, 현재 국내에서는 불모지나 다름 없다. 이에, 본 고에서는 세계 IP 시장의 현 상황을 분석해 보고 국내 팹리스 업체의 SoC 개발 현황과 IP의 활용도를 알아보도록 한다. 또한, 국내 IP 시장의 활성화를 위한 정부 지원 프로그램을 알아보고, 개발 및 시장 활성화를 위한 방안을 찾아보고자 한다.

• Bulletin of the Korean Mathematical Society
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• v.37 no.4
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• pp.803-810
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• 2000

Let N($d_1,...,{\;}d_n;c_1,...,{\;}c_n$) be the number of solutions $(x_1,...,{\;}x_n){\in}F^{n}_p$ of the diagonal equation $c_lx_1^{d_1}+c_2x_2^{d_2}+{\cdots}+c_nx_n^{d_n}{\;}={\;}0{\;}n{\geq},{\;}c_j{\;}{\in}{\;}F^{*}_q,{\;}j=1,2,...,{\;}n$ where $d_j{\;}>{\;}1{\;}and{\;}d_j{\;}$\mid${\;}q{\;}-{\;}1$ for all j = 1,2,..., n. In this paper, we find all n-tuples ($d_1,...,{\;}d_n$) such that the reduced form of ($d_1,...,{\;}d_n$) and N($d_1,...,{\;}d_n;c_1,...,{\;}c_n$) are the same as in the theorem obtained by Sun Qi [3]. Improving this, we also get an explicit formula for the number of solutions of the diagonal equation, unver a certain natural restriction on the exponents.

• Journal of Welding and Joining
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• v.14 no.1
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• pp.38-46
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• 1996

High temperature low cycle fatigue crack growth behavior is investigated over a range of two temperatures and various frequencies in SUS 304 stainless steel. It is found that low frequency and temperature can enhance time-dependent crack growth. With high temperature, low frequency and long crack length, ${\Delta}J_c/{\Delta}J_ f$, the ratio of creep J integral range to fatigue J integral range is increased and time-dependent crack growth is accelerated. Interaction between ${\Delta}J_f$ and ${\Delta}J_c$ is occured at high frequency and low temparature and ${\Delta}J_c$, creep J integral range is fracture mechanical parameter on transition from cycle-dependent to time dependent crack growth in creep temperature region.