• The Plant Pathology Journal
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• v.35 no.3
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• pp.280-286
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• 2019

In this study, PVF11 was selected among 20 candidate pathogenesis-related genes in Burkholderia glumae based on its effect on virulence to rice. PVF11 was found to interact with several plant defense-related WRKY proteins as evidenced through yeast-two hybrid analysis (Y2H). Moreover, PVF11 showed interactions with abiotic and biotic stress response-related rice proteins, as shown by genome-wide Y2H screening employing PVF11 and a cDNA library from B. glumae-infected rice. To confirm the effect of PVF11 on B. glumae virulence, in planta assays were conducted at different stages of rice growth. As a result, a PVF11-defective mutant showed reduced virulence in rice seedlings and stems but not in rice panicles, indicating that PVF11 involvement in B. glumae virulence in rice is stage-dependent.

• Journal of the Korean Electrochemical Society
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• v.13 no.3
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• pp.198-202
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• 2010

Lithium co-polyelectrolyte-ionic liquid systems, using poly (lithium 2-acrylamido-2-methyl propanesulfonate; PAMPSLi) and polyvinyl formamid (PVF) were prepared and their electrochemical and physical properties were measured. The conductivity of co-polymer systems, PAMPSLi/PVF/N, N-dimethyl-N-propyl-N-butylammonium tricyanomethanide (PAMPSLi/PVF/$N_{1134}$TCM) and PAMPSLi/PVF/N, N-dimethyl-N-propyl-N-butylammonium dicyanamide (PAMPSLi/PVF/$N_{1134}$DCA) exhibited low viscosity ($N_{1134}$TCM:$N_{1134}$DCA 28.6cP, 28.7cP) and higher conductivity ($2.48{\times}10^{-3}Scm^{-1}$, $2.2{\times}10^{-3}Scm^{-1}$) than homopolymer system. The ionic conductivity PAMPSLi/PVF/1-ethyl-3-methyl imidazolium dicyanamide (PAMPSLi/PVF/emImDCA) exhibited $1.54{\times}10^{-3}Scm^{-1}$ and low viscosity (emImDCA: 28.09cP). High flexibility of imidazolium cation and dissociation of lithium cation from the co-polymer chains were affected by high conductivity and low viscosity.

• Korean Journal of Materials Research
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• v.14 no.4
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• pp.260-264
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• 2004

The problem of polyaniline (PANi) sensor has been poor mechanical and chemical stability under atmosphere condition. In order to overcome these problems, the PANi sensor coated with polyvinylidenefluoride ($PVF_2$) was employed. The morphology of $PVF_2$ coated-PANi layer was showed smooth and transparent properties at 15% concentration of coating solution. The resistance of $PVF_2$ coated-PANi was kept at constant value and had a good stability at long-term periods in presence of humidity.

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.177-178
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• 1985

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1102-1104
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• 1995

This study presents the results of an investigation on the electrical characteristics of $PVF_2$ film, to be regarded as the excellent piezo and pyroelectricity, using dielectric relaxation technique by the variation of temperature and frequency. As one of the results, we confirmed that crystal form with Infrared absorption and XRD was ${\alpha}$ type and its crystalline was 59[%]. Also, the results of observation conformed to Debye theory for frequency variation of relative permitivity and dielectric relaxation. Especially, we confirmed each constant values in comparision with equation related to diffusion behavior of ion, so we obtained that activation energy was computed 17.25[kcal/mole] from the relation curve with frequency and temperature.

• Korean Journal of Materials Research
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• v.4 no.7
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• pp.792-797
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• 1994

Force fields of syndiotactic isoregic PVF crystal have been extracted by optimizing a structure of 2,4,6-trifluoroheptane with ab initio Quantum mechanical method with 6-31G * * basis set, and applied to calculate the structure parameters and elastic constants of the material. The cell parameters turned out to be 5.205$\AA$, of a axis(chain axis), 8.457$\AA$, of b axis and 4.621$\AA$ of c axis. These parameters are in fair agreement with those of the atactic X-ray structure(5.04$\AA$, 8.57$\AA$, and 4.95$\AA$,respectively). The young's modulus of defect free syndiotactic PVF crystal was computed to be 267 GPa comparable to those of polyvinilidene fluoride(277-293 GPa) and polyethylene(264-337 GPa) crystals. Bulk modulus value obtained at optimum geometry is more than twice greater than that obtained at experimental geometry due to large difference of elastic compliance constant (especially Sgj element) at these two different geometries.

• Electrical & Electronic Materials
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• v.3 no.2
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• pp.99-104
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• 1990

두께 30[.mu.m]의 코로나 대전된 포리비닐후로라이드 박막에 전압 -3~-6[kV]를 인가한 후, 온도범위 -100~200[.deg.C]에서 열자격 전류를 측정하였다. 결과로 .betha., .alpha. 그리고 .delta. 피크가 온도 -40, 40 그리고 90[.deg.C] 부근에서 각각 나타났다. 이들 피크의 기원으로 첫째 .betha. 피크는 카보닐기의 기여로 둘째로 .alpha. 피크는 주쇄와 비정질 영역의 측쇄에 트랩된 캐리어의 탈트랩의 기여로 나타났고 끝으로 .delta. 피크는 비정질 영역 또는 비정질과 결정질 영역 사이의 경계에 트랩된 캐리어의 탈트랩에 기여로 사료된다.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.109-116
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• 2017

Objective: This study aimed to investigate the relationship between leg stiffness and kinematic variables according to load while running. Method: Participants included eight healthy men (mean age, $22.75{\pm}1.16years$; mean height: $1.73{\pm}0.01m$; mean body weight, $71.37{\pm}5.50kg$) who ran with no load or a backpack loaded with 14.08% or 28.17% of their body weight. The analyzed variables included leg stiffness, ground contact time, center of gravity (COG) displacement and Y-axis velocity, lower-extremity joint angle (hip, knee, ankle), peak vertical force (PVF), and change in stance phase leg length. Results: Dimensionless leg stiffness increased significantly with increasing load during running, which was the result of increased PVF and contact time due to decreased leg lengths and COG displacement and velocity. Leg length and leg stiffness showed a negative correlation (r = -.902, $R^2=0.814$). COG velocity showed a similar correlation with COG displacement (r = .408, $R^2=.166$) and contact time (r = -.455, $R^2=.207$). Conclusion: Dimensionless leg stiffness increased during running with a load. In this investigation, leg stiffness due to load increased was most closely related to the PVF, knee joint angle, and change in stance phase leg length. However, leg stiffness was unaffected by change in contact time, COG velocity, and COG displacement.

• Journal of Climate Change Research
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• v.8 no.1
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• pp.31-39
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• 2017

The emission quantity of nitrous oxide is second largest among non-$CO_2$ greenhouse gas in Korea. In this study, we investigated loss rate of nitrous oxide which was filled in PVF and Al-PE bag as time goes on. Concentrations of tested samples were about 25 ppmv, 50 ppmv, 75 ppmv prepared by standard reference gas. In case of all experiments, loss rate of PVF bag was higher than Al-PE bag. After 18 days, loss rate of PVF bag was from 29.7% to 38.6% while Al-PE bag was from 21.7% to 23.7%. Especially the differential growed bigger when initial concentration of $N_2O$ in PVF bag was lower. And we also studied the effect of cock opening/closing procedures on loss rate. Prepared samples in experimental group were analyzed several times for 20 days and samples in control group were analysed only 1 time after 20 days. The experimental results showed that cock opening/closing procedures appeared to have little impact on loss rate.

• Transactions on Electrical and Electronic Materials
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• v.15 no.2
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• pp.60-65
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• 2014

This article explains the experimental results of ferroelectric polarization switching (FPS) of potassium nitrate ($KNO_3$) with different polymers such as polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF) using simple melt-press techniques. To analyze the ferroelectric polarization switching in potassium nitrate ($KNO_3$) composite films at room temperature, we applied the Ishibashi and Takagi theory (based on Avrami model) to the switching current transient. To investigate the dimensionality of domain growth, the ferroelectric polarization switching current (FPS current) was observed from the square - wave bipolar signals across a resistance of $0.1k{\Omega}$ in series with the composite films. The existence of a switching current transient pulse confirmed the ferroelectricity and indicated the stability of the ferroelectric phase (phase III) of $KNO_3$ at room temperature. Polarization hysteresis (P-E) characteristics supported the prominent features of ferroelectric polarization switching in the composite films at room temperature.