• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.55-61
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• 1979

Since rice high yielding practices with blast resistant varieties induced severe and earlier infestation of sheath blight recently, it is strongly suggested to spray at least 10 days earlier than the present recommendation and more than 2 sprays from early July to early August seems to be essential for the efficient control of sheath blight in the future. Among organo-arsenic fungicides, MAFe (Neo Asozin) is known as the most effective and economic as well as with the advantages of free phytotoxicity and safe residure on rice, and applications of the mixed formulation with other fungicide and insecticide is suitable for the one-hit control of rice diseases and insect pests in connection with cooperative mass control system. Present level of arsenic $(As_2O_3)$ residue in .ice is summarized as 0.2ppm to 0.65 ppm in highest average, and there are more possibilities of extensive MAFe fungicide uses for the efficient and economic control of this disease. During the past few years, the acreage of sheath blight control has been extended several times while the increase of the fungicides used for sheath blight showing about 10 times in quantity and mort than 15 times in amount, and also the fungicide cost estimated for the control is differ from 1 to 12 billion 1on by the use of MAFe or antibiotic fungicide in a year.

• Research in Plant Disease
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• v.13 no.3
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• pp.131-136
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• 2007

Occurrence of popcorn disease on mulberry fruits was surveyed in several locations in Korea from 2005 to 2007. The diseased fruits turned grayish white and changed to hard and black sclerotia during overwintering after falling onto the ground. Apothecia produced from overwintered sclerotia in the fields of mulberry trees were observed in early May. Two types of apothecia were produced from the sclerotia, which were cup-shaped or club-shaped. The fungus with cup-shaped apothecia was identified as Ciboria shiraiana, and that with club-shaped apothecia as Scleromitrula shiraiana. C. shiraiana occurred at the ratio of about 6 vs. 4 in the fields. Occurrence of the disease differed remarkably depending on years, locations, and varieties of mulberry trees investigated. Field survey of the disease incidence showed that Baekhahyeongsang, Dahojosaeng, Hasusang, a native variety and Sawonppong 22 were resistant to the disease, Cheongilppong, Daeseongppong, Guksang 20 and Turkey-D were moderately susceptible, and Cateneo, Moreji and Sanggwa were highly susceptible. Disease incidence in the fields mulched with nonwoven fabrics or plastic films was much lower than that in the non-mulched fields. Disease incidence in the fields mulched with rice straws was similar to that in the non-mulched fields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.129-136
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• 2020

A Cut Out Switch (COS) is used for line protection and pole transformer protection in power systems. The COS used to protect the pole transformer is installed on the power side of the pole transformer to protect the electric equipment from fault currents. The COS is composed largely of a body and a fuse holder, and when the fault current is energized, the element of the fuse link in the fuse holder is melted to block the fault current. The arc generated when the COS fuse link is blown causes fire and noise, causing discomfort to residents in the surrounding area, and the arc flame can cause secondary damage to the peripheral device. In this study, a current-limiting COS fuse with improved overcurrent blocking performance rather than explosion type was developed to solve the arc and noise problems during COS operation. The overcurrent breaking performance of the current-limiting COS improves the reliability by developing a striker and COS fuse bracket. In addition, this study aimed to verify the performance of the developed current-limiting COS fuse through a test at an authorized institution.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.94-102
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• 2020

Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

• Journal of Korean Physical Therapy Science
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• v.11 no.1
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• pp.14-19
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• 2004

Objective : This study obtained normative values for variable parameters of lumbar function with the isoinertial triaxial dynamometer in patients with chronic low back pain. Subjects and Methods : 30 patients(male 15, female 15) with chronic low back pain in this study. Variable parameters that were measured with the Isostation B-200 were lumbar range of motion, isometric maximum torques, and maximum velocities in three axis. Results : In patient male group mean R.O.M. was $82.9{\pm}12.5$ degrees in lumbar rotation, $76.5{\pm}17.1$ degrees in lumbar flexion/extension, and $64.3{\pm}14.5$ degrees in lumbar lateral flexion. In patient female group mean R.O.M. was $78.4{\pm}18.5$ degrees in lumbar rotation, $71.7{\pm}20.4$ degrees in lumbar flexion/extension, and $63.2{\pm}14.4$ degrees in lumbar lateral flexion. In patient male group mean isometric maximum torques was $64.7{\pm}23.8ft-lbs$ in lumbar rotation, $81.1{\pm}42.0ft-lbs$ in lumbar flexion, $122.2{\pm}43.6ft-lbs$ in lumbar extension, and $101.0{\pm}37.0ft-lbs$ in lumbar lateral flexion. In patient female group mean isometric maximum torques was $41.9{\pm}9.2ft-lbs$ in lumbar rotation, $49.9{\pm}23.9ft-lbs$ in lumbar flexion, $90.1{\pm}26.8ft-lbs$ in lumbar extension, and $62.0{\pm}16.7ft-lbs$ in lumbar lateral flexion. In patient male group mean maximum velocity of isoinertial exercise with low (25%) resistance was $102.4{\pm}28.8deg/sec$ in lumbar rotation, $108.9{\pm}32.2deg/sec$ in lumbar flexion/extension, and $103.5{\pm}30.4deg/sec$ in lumbar lateral flexion. In patient female group mean maximum velocity of isoinertial exercise with low (25%) resistance was $84.1{\pm}24.4deg/sec$ in lumbar rotation, $93.2{\pm}32.9deg/sec$ in lumbar flexion/extension, and $98.5{\pm}33.7deg/sec$ in lumbar lateral flexion. In patient male group mean maximum velocity of isoinertial exercise with high (50%) resistance was $74.0{\pm}20.9deg/sec$ in lumbar rotation, $98.7{\pm}32.8deg/sec$ in lumbar flexion/extension, and $85.0{\pm}25.8deg/sec$ in lumbar lateral flexion. In patient female group mean maximum velocity of isoinertial exercise with high (50%) resistance was $67.3{\pm}26.4deg/sec$ in lumbar rotation, $82.5{\pm}31.0deg/sec$ in lumbar flexion/extension, and $79.7{\pm}23.9deg/sec$ in lumbar lateral flexion. Conclusion : Maximum isoinertial velocities were more reliable and more significant than isometric maximum torque for the objective assessment of chronic low hack pain.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.176-182
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• 2018

The purpose of this study was to investigate the safety and rationality of buckling strength and length coefficient by comparing with the design standards of domestic and foreign compression materials based on the buckling test results of circular steel pipe with ball joints. The types of round steel pipes selected for buckling performance evaluation were ø$48.6{\times}2.8t$, ø$60.5{\times}3.2t$ and ø$76.3{\times}3.2t$. For the design of domestic and foreign compression materials, Korea 's Load Resistance and Factor Design, Japan' s Limit State Design, and British Standard BS5950 standard were applied. In this study, we compared and analyzed the buckling performance between the experimental results of the previous research and the domestic and foreign design standards. The results were summarized as follows. As a result of applying the full length of the member to the buckling length in the compression materials design standards of each country, it was 64-89% of the buckling strength by the experiment. Therefore, it is deemed desirable to perform the member design according to the current design standard formula for safety. Experimental results show that the measured buckling strength was 1.02-1.43 times higher than the buckling strength of pure cylindrical steel tubes in the design standards of Korea, Japan and the United Kingdom compression materials. Consequently, it seemed that the buckling strength of individual member in the design of space frame structure should be considered buckling coefficient as the length of pure round steel pipe rather than the length of inter-node.

• Journal of Life Science
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• v.26 no.10
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• pp.1163-1168
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• 2016

Plant growth-promoting rhizobacteria (PGPR) have gained worldwide importance and acceptance due to their agricultural benefits. These microorganisms are potential tools for sustainable agriculture, with effects on plant growth, biofertilization, induced systemic resistance, and biocontrol of plant pathogens. In this study, four different Pantoea species were isolated from field soil, and their plant growth-promoting characteristics were studied. Based on 16S rDNA gene sequencing analyses, the se were grouped into Pantoea ananatis, Pantoea citrea, Pantoea dispersa, Pantoea vagans and named as Pa1, Pc1, Pd1, Pv1, respectively. All of these strains have their ability for solubilization of insoluble phosphate depending on pH decrease at the range around pH 5 at 1days after inoculation and production of plant hormone indole acetic acid (IAA) with 85.3±16.3 μg/ml of Pa1, 183.9±16.8 μg/ml of Pc1, 28.8±17.3 μg/ml of Pd1 and 114.1±16.5 μg/ml of Pv1, respectively. Pa1, Pc1 and Pd1 also have high activity for production of gibberellin (GA₃) hormone with 331.1±19.2 μg/ml of Pa1, 288.5±16.8 μg/ml of Pc1, 309.2±18.2 μg/ml of Pd1, but Pv1 does not. Furthermore, all these species have significantly promoted the growth of the lettuce seedling plants at the range around 32~37% for fresh weight and 10~15% for shoot length enhancement, so that these microbe could be used as a potential bio-fertilizer agents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.220-227
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• 1997

Water deficit stress during early soybean[Glycine max (L.) Merrill] growth stage is the most important environmental factor limiting productivity. Eight soybean genotypes were grown in replicated pot under well-watered(control: near 0 bar) and drought(-5 and -10 bars) conditions. Soybean plants were subject to drought stress for 20 days at 10 days after seed emergence. Significant genotypic variation was observed for leaf area(LA) and total dry weight (TDW). At the end of water stress, LA and TDW of Hwanggeumkong and Paldalkong, which had large LA in the non-stressed control, were more sensitive to water stress than those of the other cultivars, while those of Suwon 93 with small LA were insensitive. Leaf proline and abscisic acid(ABA) contents increased after water stress. However, changes in proline and ABA contents were not consistently related to the changes in LA as affected by water stress. As the soil water potential decreased, the yield reduction of Hodgson 78 showing large decrease in LA and TDW in response to water deficit was severe when compared to that of Baegunkong with small decrease in LA and TDW. Relatively greater yield stability and higher average yield across soil water potential were observed in Baegunkong. Of specific interest was the small reduction in yield of Paldalkong in spite of its significant decrease in LA and TDW.

• Journal of the Korean Institute of Gas
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• v.7 no.2 s.19
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• pp.22-32
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• 2003

Al-brass material is generally used at the state of plastic deformation, for example; bending, extension of bell mouth at shell and tube type heat exchanger. And SCC(stress corrosion cracking) of Al-brass material will be affected by residual stress as plastic deformation. SCC results from synergism between mechanical factor and corrosion environment. Mechanical factor is stress that directly relates with stress intensity factor at the crack tip. This paper was studied on the effect of stress on SCC of Al-brass tube under in $3.5\%$ NaCl. + $0.1\%\;NH_4OH$ solution by constant displacement tester. Increasing of acidified water flow into sea and speeds up corrosion rate of Al-brass which is used as a tube material of vessel heat exchanger by polluted coast seawater. The experimental results are as follow The latent time of SCC occurrence gets longer as the initial stress intensity factor($K_{Ii}$) gets lower The main crack was propagated as the initial stress intensity factor($K_{Ii}$) gets higher, and secondary cracks occurred by electro-chemical factor a(ter stage of released stress. Dezincification phase showed around the crack, and the range of dezincification gets wider as the initial stress intensity factor($K_{Ii}$) gets higher.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.171-182
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• 1998

A total of nine Korean native kids and two Corriedale lambs, 1-20 days old, were each inoculated per os with a single dose of 2 × 107 oocysts of Cwptospori,mum muris (strain MCR) originated from mice to elucidate the kinetics and developmental stages of the coccidium in small ruminants. Irrespective of host's age, the prepatent period for both animals ranged from 19 to 35 days (28.1 days, on the average) and the patent period 16-85 days (47.8 days), and the total oocyst outputs showed enormous differences. Infection with greater numbers of oocyst outputs was not ordinarily established by transmission experiments. Oocysts discharged from the kids retained their infectivity by the mouse titration method. The immunogenicity of the coccidium and oocyst reproduction were proven by challenge infection and administration of prednisolone acetate. respectively. All the developmental stages of the coccidium in parasitophorous vacuoles were found by transmission electron microscopy in the pits of the gastric glands of a kid inoculated with oocysts and then necropsied on day 44 postinoculation. It indicated the full course of the host-parasite relationship in kids and lambs as well as mice.