• Asian Journal of Turfgrass Science
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• v.6 no.2
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• pp.89-98
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• 1992

Cultural characteristics and pathogenicity on the isolates of Rhizoctonia oryzae, R. oryzae-sativae and anastomosis group of R. solani and evaluation of selected fungicides on brown patch disease of creeping bentgrass and large patch disease of zoysia grass were studied comparatively. From effect of temperature on the rate of mycelia growth, the result indicated that the temperature groups were separated into four types : isolates of R. oryzae and R. oryzae-sativae had an optimum temperature of $30~35^{\circ}C$. Anastomosis groups of R. solani were separated into three temperature types as followings : high temperature type had an optimum temperature from 25 to $30^{\circ}C$, moderate type had grown from 20 to $25^{\circ}C$ for optimum and low temperature type had an optimum temperature of $20^{\circ}C$ but at $35^{\circ}C$ did not grow. Inoculation tests showed that AG-1( I A), AG-1( I B), bentgrass isolate of R. solani and R. oryzae were strongly pathogenic on creeping bentgrass, followed by AG-2-1, AG-4, AG-5 and AG-2-2 isolates of R. solani moderately to weakly. Zoysia grass isolate of R. solani and R. oryzae were strongly pathogenic on zoysia grass but AG-1( I B) and AG-5 isolates of R. solani showed moderately pathogenic. Capro(iprodione oxine-copper) and mytan(myclobutanil) were extremely effective against brown patch disease of creeping bentgrass and large patch disease of zoysia grass followed by thiopan (thiopanate-methyl) and pencycuron for brown patch disease and tolos(tolclofos-methyl) and thiopan for large patch disease.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.551-554
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• 2011

One of the key issues in the research of organic field-effect transistors (OFETs) is the low-voltage operation. To address this issue, we synthesized poly(styrene-r-benzocyclobutene-r-methyl methacrylate) (P(S-r-BCB-r-MMA)) as a thermally cross-linkable gate dielectrics. The P(S-r-BCB-r-MMA) showed high quality dielectric properties due to the negligible volume change during the cross-linking. The pentacene FETs based on the 34 nm-thick P(S-r-BCB-r-MMA) gate dielectrics operate below 5 V. The P(S-r-BCB-r-MMA) gate dielectrics yielded high device performance, i.e. a field-effect mobility of $0.25cm^2/Vs$, a threshold voltage of -2 V, an sub-threshold slope of 400 mV/decade, and an on/off current ratio of ${\sim}10^5$. The thermally cross-linkable P(S-r-BCB-r-MMA) will provide an attractive candidate for solution-processable gate dielectrics for low-voltage OFETs.

• Journal of the Chungcheong Mathematical Society
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• v.25 no.4
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• pp.717-723
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• 2012

In this paper, we investigate when gr-multiplication modules are finitely generated and show that if M is a finitely generated gr-multiplication R-module then there is a lattice isomorphism between the lattice of all graded ideals I of R containing ann(M) and the lattice of all graded submodules of M.

• Journal of the Korean Mathematical Society
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• v.25 no.2
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• pp.315-324
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• 1988

• Journal of IKEEE
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• v.26 no.2
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• pp.329-332
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• 2022

In this paper, retention characteristics of lateral charge migration according to parameters of 3D NAND flash memory to which ferroelectric (HfO₂) structure is applied and ∆V_th were analyzed. The larger the P_s, the greater maximum polarization possible in ferroelectric during Programming. Therefore, the initial V_th increases by about 1.04V difference at P_s 70µC/cm² than at P_s 25µC/cm². Also, electrons trapped after the Program operation causes lateral charge migration over time. Since ferroelectric maintains polarization without applying voltage to the gate after Programming, regardless of P_s value, polarization increases as P_r increases and the ∆V_th due to lateral charge migration becomes smaller by about 1.54V difference at P_r 50µC/cm² than P_r 5µC/cm².

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.467-472
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• 2017

In this study, the reforming reaction of vacuum residue (VR) was carried out using aquathermolysis reaction. VR showed a prone to decrease the amount of resins and asphaltenes in the constituents, and to increase saturates and aromatics when reacting with steam at 30 bar and above $300^{\circ}C$ for 24 h. This tendency became more evident when the amount of steam used was excessive than the amount of VR. When the aquathermolysis reaction was performed at $300^{\circ}C$ and 30 bar for 48 h, the VR composition was changed from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to final state (S/A/R/A = 6.8%/57%/12.2%/24.0%), and the contents of the resins decreased by 13% and the aromatic compounds increased by 13%. The viscosity decreased from 880,000 cp to 290,000 cp by 68%. When 10% of decalin, which is easy to provide hydrogen, was added, the viscosity decreased by 68% in 24 h. The VR composition showed a reduction in the contents of resins and asphaltenes from 49% to 17% from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to the final state (S/A/R/A = 4.5%/63.5%/12.5%/20.0%), and the content of aromatics was maximized to 63.5%. The gas layer formed by the aquathermolysis reaction in the reactor chamber was collected and analyzed by GC-MS spectroscopy. As a result, various hydrocarbon compounds such as ethylbenzene, octane and dimethylbenzene were detected.

• East Asian mathematical journal
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• v.25 no.4
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• pp.441-447
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• 2009

Jat and Choudhari defined a near-ring R with left bipotent or right bipotent condition in 1979. Also, we can dene a near-ring R as subcommutative if aR = Ra for all a in R. From these above two concepts it is natural to investigate the near-ring R with the properties aR = $Ra^2$ (resp. $a^2R$ = Ra) for each a in R. We will say that such is a near-ring with (1,2)-potent condition (resp. a near-ring with (2,1)-potent condition). Thus, we can extend a general concept of a near-ring R with (m,n)-potent condition, that is, $a^mR\;=\;Ra^n$ for each a in R, where m, n are positive integers. We will derive properties of near-ring with (1,n) and (n,1)-potent conditions where n is a positive integer, any homomorphic image of (m,n)-potent near-ring is also (m,n)-potent, and we will obtain some characterization of regular near-rings with (m,n)-potent conditions.

• The Microorganisms and Industry
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• v.25 no.2
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• pp.2-6
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• 1999

151 strains which belong to the gens Rhizopus were isolated from 750 specimens collected through all over South Korea, and 19 species of the genus, all of which are unrecorded in Korea, were identified according to the modified Takeda-Yamamoto's classification key. The species identified are as follows ; R. nigricans, R.formosaensis, R.achlamydosporus, R.tritici, R.javanicus, R.cuiuniang, R liquefaciens, R.chungruoensis, R.acidus, R.chinensis, R.delemar, R.hangchow, R.japonicus, R.arrhizus, R.bahrnenesis, R.tonrinensis, and R.shanghaiensis.

• The Journal of the Acoustical Society of Korea
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• v.36 no.5
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• pp.361-369
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• 2017

Hemodynamic information in the carotid artery bifurcation is very important for understanding the development and progression mechanisms of cerebrovascular disease and for its early diagnosis and prediction of the progress. In this paper, we constructed a mock pulsatile blood circulation system using an anthropomorphic elastic vessel of the carotid artery bifurcation and ex vivo pig blood to acquire ultrasound images from blood and vessels synchronized with internal pressure while controlling the blood flow. Echogenicity, blood flow velocity, and blood vessel wall motion from the ultrasound images, and internal blood pressure were extracted over a cycle averaged from five cycles when the pulsatile pump rates are 20 r/min, 40 r/min, and 60 r/min. As a result, respectively, the peak systolic blood flow velocities were 20 cm/s, 25 cm/s, and 40 cm/s, the blood pressure differences were 30 mmHg, 70 mmHg, and 85 mmHg, the arterial walls were expanded to 0.05 mm, 0.15 mm, and 0.25 mm. Time-delayed cyclic variation of echogenicity compared to blood flow and pressure was observed, but the variation was minimal at 20 r/min. Time-synchronized cyclic variations of these parameters are important information for accurate input parameters and validation of the computational hemodynamic experiments which will provide useful information for the development and progress mechanisms of carotid artery stenosis.

• Journal of the Korean Ceramic Society
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• v.38 no.12
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• pp.1180-1186
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• 2001

W $O_3$-Sn $O_2$thin film sensors with approximately 1${\mu}{\textrm}{m}$ in thickness were fabricated by using a high-vacuum resistance-heating evaporator, were annealed at 50$0^{\circ}C$ for 4 hours in air, and then their crystallinities and surface microstructures were analyzed. As results of gas-sensing characteristics to oxidizing gas, N $O_2$, and reducing gas, CO, of 100 ppm, the highest gas sensitivities (S= $R_{gas}$/ $R_{air}$) were the W $O_3$thin-film sensor measured at 25$0^{\circ}C$ for N $O_2$(S≒1000) and the Sn $O_2$thin-film sensor measured at 15$0^{\circ}C$ to 25$0^{\circ}C$ range for CO (S≒0.25), respectively.ely.