• Korean Journal of Weed Science
• /
• v.6 no.2
• /
• pp.134-145
• /
• 1986

The experiment was crried out to evaluated the herbicidal properties of bensulfuron methyl [methyl 2-[[[[[(4, 6-dimethoxy pyrimidine-2yl) amino] carbonyl] amino] sulfonyl] methyl] benzoate]. No phytotoxicity was observed when bensulfuron methyl was applied at 3 and 6 g a.i./ 10a while the application rate 12 g a.i./10a slightly retared the growth of rice. The phytotoxicity decreased as the application time was delayed. The effect of application rate, leaching grade, transplanting depth, soil type and temperature on crop injury was little. Japonica variety (Dong-Jin) was more sensitive to bensulfuron methyl than indica X japonica variety (Sam-Kang). Bensulfuron methyl controlled effectively perennial weeds such as Sagittaria pygmaea Miq., Potamogeton diatinctus A. Benn., Cyperus serotinus Rottb., Sagittaria trifolia L., Eleocharis kuroguwai Ohwi. including most annual weeds except Echinochloa crus galli P. Beauv. The effect slightly decreased with lowering the temperature increasing the leaching grade. Application time and soil type employed did not affect the weeding effect.

• Korean Journal of Weed Science
• /
• v.13 no.1
• /
• pp.62-70
• /
• 1993

There was intraspecific variation in Echinochloa crus-galli var, crus-galli in response to quinclorac, showing that plan height and dry weight of a locally collected barnyardgrass(Chinjupi) from Chinju were 90.5 and 37.8% of the untreated control, while those of a locally collected one(Iripi) from Iri showed 19.1 and 14.4%, respectively. The normal distribution curve was obtained from frequency distribution of 89 rice cultivars as affected by the application rates of quinclorac at 30, 300, and 3,000g ai/ha. Protein patterns(SDS-PAGE) of two barnyardgrasses belonging to E, crus-galli var. crus-galli such as Iripi and Chinjupi were not affected by the quinclorac application, indicating that inhibition of enzyme and/or protein biosynthesis seems to be not the primary action target of quinclorac. Electronmicroscopic observation on the injured leaf of Iripi which is considered as a susceptible one showed prominent membrane disruption. Chuchungbyeo(rice variety) resulted in a greater inhibition of tomato growth than those from Chinjupi or Iripi, indicating a great amount of quinclorac discharged from rice root, Chinjupi which is relatively tolerant to quinclorac than Iripi, discharged more quinclorac causing a greater inhibition of tomato growth.

• Weed & Turfgrass Science
• /
• v.1 no.4
• /
• pp.44-49
• /
• 2012

The objective of this study was to know the herbicidal activity of the essential oil from amyris (Amyris balsamifera). In a seed bioassay experiment, the amyris essential oil inhibited the growth of rapeseed (Brassica napus) by fifty percent at 8.8 ${\mu}g\;g^{-1}$. And in a greenhouse experiment, sorghum, barnyard grass and Indian jointvetch, which was applied in above-ground parts, with the amyris essential oil at 4,000 ${\mu}g\;ml^{-1}$ showed visual injuries of 90, 70, and 70, respectively (0, no damage; 100, total damage). However, soil application of the essential oil did not show such herbicidal injuries. In a field experiment, foliar application of the amyris essential oil at 5% controlled effectively weeds such as barnyardgrass, shepherd's purse, and clover in 24 hours. Our results indicated that the amyris essential oil had herbicidal activity. To understand the composition of the amyris essential oil, the oil was analyzed by gas chromatography-mass spectometry with solid-phase micro-extraction apparatus. There were 15 organic chemicals in the oil and the major constituents were calarene, elemol, ${\gamma}$-eudesmol, curcumene, ${\beta}$-sesquiphellandrene, zingiberene, selina-3,7(11)-diene, 1,3-diisopropenyl-6-methyl-cyclohexene, ${\beta}$-bisabolene, and ${\beta}$-maaliene. Overall results suggest that the amyris essential oil had a herbicidal activity with fast, contact, and non-selective mechanism.

• Geotechnical Engineering
• /
• v.11 no.3
• /
• pp.55-68
• /
• 1995

This paper is the analysis of the relationship between RQD and decay constant, blasting vi bration constant of cube root scaling and square root scaling, through experimental blast ins test in subway construction for excavation of shaft hole by bottom blasting. The magnitude of particle velocity is largely effected by the distance from blasting source, the maximum charge per delay and the properties of ground. In order to verify the effects of ground properties on blast-induced vibration, the relation-ship between magnitude of blasting vibration and Rock Quality Disignation which stands for joint property was studied. The results of test are verified that blasting vibration constant "K" and the absolute value("n") of decay constant relatively increse as RQD increased. According to the result, it can be predict the particle velocity by the blast -induced vibration in bottom blasting pattern.om blasting pattern.

• Explosives and Blasting
• /
• v.29 no.2
• /
• pp.89-99
• /
• 2011

Recently on Jeju island there has been a lot of development and construction. However random distribution of porous basalt and clinker seam generated from volcanic activities often interrupt and greatly reduce efficiency of blasting necessary for construction. Three test blasts were operated to solve the inefficiency problem and results indicated that a powder factor of 0.40~0.45 $kg/cm^3$ is necessary to increase the efficiency of blasting. Also the blasting scheme should be concerned whether clinker seams exists in excavation levels or not.

• Korean journal of applied entomology
• /
• v.18 no.4 s.41
• /
• pp.149-152
• /
• 1979

The relative toxicity of some of the insecticides which have been used for the control of paddy rice insect pests in Korea was evaluated in the laboratory with the brown planthopper (BPH) Nilaparvata lugens, and a predaceous paddy spider Pirata subpiraticus. In order of the relative toxicity (LD5O value to spider/LD50 value to BPH) were PAP (0.4), MPP(0.1), MEP(1.8), diazinon(2.8), carbofuran(7.5), NAC(11.3), BPMC(17.5), Pyridaphenthion(35.9) and MIPC(65.7). MIPC and Pyridaphenthion were considered as having the desirable selective toxicity for the spider and the BPH.

• Explosives and Blasting
• /
• v.28 no.1
• /
• pp.40-54
• /
• 2010

The messer shield method applys mainly to a tunnel with small cross-section of a weathered soil or weathered rock district and is fulfilled mostly by man-power excavation. but in case that hard rock exposes on tunnel face, incredible is an application of the rock-splitting method using a hydraulic power or a blasting method. This study represents the case of a blasting method which can control to be practiced by the minimum charges of 125 g an initial vibration occurring at the cut instead of the rock-splitting method, even though water pipe and gas pipe are closely adjacent.

• Explosives and Blasting
• /
• v.23 no.4
• /
• pp.19-29
• /
• 2005

Blasting design methods applied in Korea were originally made for foreign rock conditions and blasting environments. Therefore, it has not been fully fitted to the Korean rock renditions. Since 1998, several studies for the automated pattern design of tunnel blasting have been carried out. As the result, a new blasting design method which can settle the problems was developed. Through it is more complex than prior method, it call provide a variety of advantages for us. Through the method, it is possible to vary charge weight according to the changing advance. It ran also be applied to the various design for contour holes. In this study, the newly developed method is introduced.

• The Korean Journal of Pesticide Science
• /
• v.6 no.1
• /
• pp.45-48
• /
• 2002

New benzenesulfonylurea derivatives possessing bicyclic ketal subgroup were synthesized and shown to have interesting herbicidal activities under upland greenhouse screening.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.5
• /
• pp.327-333
• /
• 2003

Characteristics of vibration propagation of borehole blasting were analyzed with 578 borehole vibration data obtained from 23 sites which were used in tunnel and underground space design, and 221 tunnel vibration data fron 4 sites of tunnel under construction. Analysis results on the damping of vibration velocity show that site factors in borehole blasting were higher than those in tunnel blasting. And the critical charge calculated from regression equations at large scaled distance was lower in borehole blasting. Dominant frequency was in the range of 30∼60Hz for the borehole blasting and 60∼90Hz for the tunnel blasting. As a conclusion, the borehole blasting data should not be used on the tunnel blasting design without careful statistical analysis.