• Korean Journal of Weed Science
• /
• v.12 no.2
• /
• pp.102-109
• /
• 1992

There was significant reduction in the mitotic indices of oat roots treated with alachlor. Uniform decrease in prophase, metaphase, anaphase, and telophase as treatment time increasing was observed. Alachlor did not disrupt mitosis, but rather inhibited the onset of mitosis. Labeled dividing cells were significantly inhibited, but the number of labeled interphase cells of all treatment were increased, as compared with control in 8 hr and 12hr period. Labeled dividing cells which entered mitosis thru $G_2$ were inhibited approximately 68% at 8hr after treatment with $1{\times}10^{-5}$ M of alachlor. Alachlor apparently inhibited from the $G_2$stage into mitosis of dividing cells. After 24 hr treatment, 12.1% abd 46.6% inhibition of coleoptile growth occurred at $1{\times}10^{-5}$ M and $1{\times}10^{-4}$ M, respectively. Cell elongation was inhibited by alachlor but was less sensitive than cell division. The longitudinal section cells of oat roots treated with $1{\times}10^{-4}$ M alachlor for 12 hr were observed to be enlarged central cylinder and also showed degradation of apical meristem zone, as compared with the untreated roots.

• Economic and Environmental Geology
• /
• v.40 no.2 s.183
• /
• pp.191-207
• /
• 2007

A paleomagnetic investigation for the Cretaceous rocks in the Buyeo and Hampyeong Basins, located out of the Gyeongsang Basin, was carried out in order to elucidate the paleomagnetic directions in conjunction with the formation of the basins. Typical stepwise thermal demagnetization and measurement methods were used to determine the directions of characteristic remanent magnetizations (ChRMs). The mean direction of the sedimentary rocks from the Buyeo Basin after bedding correction $(D/I=356.5^{\circ}/61.5^{\circ},\;k=39.3\;\alpha_{95}=7.4^{\circ})$, is more dispersed than that before bedding correction $(D/I=356.5^{\circ}/61.5^{\circ},\;k=39.3\;\alpha_{95}=7.4^{\circ})$, which suggests that the rocks in the Buyeo Basin were remagnetized. However, the statistics and dispersion of the ChRM directions after bedding correction are still acceptable and the paleomagnetic pole position after tilt correction $(Lat./Long.=69.3^{\circ}N/186.7^{\circ}E,\;K=11.6\;A_{95}=14.0^{\circ})$ is closer to that of the Late Cretaceous pole of the Korean Peninsula. More detailed study is needed to confirm the nature of the remagnetization in the Buyeo Basin. On the other hand, the paleomagnetic pole before bedding correction $(Lat./Long.=81.6^{\circ}N/106.9^{\circ}E,\;K=25.1\;A_{95}=9.3^{\circ})$ is positioned near the paleogene pole of the Eurasian APWP. The mean ChRM direction of the sedimentary rocks from the Hampyeong Basin after bedding correction is $D/I=32.5^{\circ}/55.4^{\circ},\;(k=35.6,\;\alpha_{95}=8.7^{\circ})$. It is more clustered than that before bedding correction $D/I=18.3^{\circ}/62.5^{\circ},\;k=14.1,\;\alpha_{95}=14.2^{\circ})$, indicating that the ChRM was acquired before tilting of the strata. The paleomagnetic pole position of the Cretaceous sedimentary rocks in the Hampyeong Basin, averaged out of site pole positions calculated from the tilt-corrected ChRMs, is $Lat./Long.=63.9^{\circ}N/202.7^{\circ}E,\;(K=21.3,\;A_{95}=7.6^{\circ})$, similar to the Late Cretaceous paleomagnetic pole of the Korean Peninsula $(Lat./Long.=70.9^{\circ}N/215.4^{\circ}E,\;A_{95}=5.3^{\circ})$, suggesting that the Hampyeong Basin has been stable since the Late Cretaceous period. One normal and two reversed ChRM directions are revealed through the measurements of the volcanic rocks from the Hampyeong Basin. Although these normal and reversed directions are not exactly antipodal, it is interpreted that the normal direction is the representative primary direction of the volcanic rocks of the Hampyeong Basin and the mixed polarity is the records of geomagnetic field at the time of the formation of the volcanic rocks. Paleomagnetic poles are at $Lat./Long.=70.2^{\circ}N/199.5^{\circ}E,\;(K=18.1,\;A_{95}=9.6^{\circ})$ for the normal direction, and $Lat./Long.=65.5^{\circ}S/251.3^{\circ}E,\;(K=7.1,\;A_{95}=20.7^{\circ})$ for the reversed direction. Compared with the representative pole positions of the Cretaceous period of the Korean Peninsula, it is concluded that the age of the volcanic rocks in the Hampyeong Basin is of the Late Cretaceous.

• The Journal of the Petrological Society of Korea
• /
• v.26 no.3
• /
• pp.235-254
• /
• 2017

We investigate the geological history that formed geology and landscapes of the Juwangsan National Park and its surrounding areas. The Juwangsan area is composed of Precambrian gneisses, Paleozoic metasedimentary rocks, Permian to Triassic plutonic rocks, Early Mesozoic sedimentary rocks, Late Mesozoic plutonic and volcanic rocks, Cenozoic Tertiary rhyolites and Quaternary taluses. The Precambrian gneisses and Paleozoic metasedimentary rocks of the Ryeongnam massif occurs as xenolithes and roof-pendents in the Permian to Triassic Yeongdeok and Cheongsong plutonic rocks, which were formed as the Songrim orogeny by magmatic intrusions occurring in a subduction environment under the northeastern and western parts of the area before a continental collision between Sino-Korean and South China lands. The Cheongsong plutonic rocks were intruded by the Late Triassic granodiorite, which include to be metamorphosed as an orthogneiss. The granodiorite includes geosites of orbicular structure and mineral spring. During the Cretaceous, the Gyeongsang Basin and Gyeongsang arc were formed by a subduction of the Izanagi plate below East Asia continent in the southeastern Korean Peninsula. The Gyeongsang Basin was developed to separate into Yeongyang and Cheongsong subbasins, in which deposited Dongwach/Hupyeongdong Formation, Gasongdong/Jeomgok Formation, and Dogyedong/Sagok Formation in turn. There was intercalated by the Daejeonsa Basalt in the upper part of Dogyedong Formation in Juwangsan entrance. During the Late Cretaceous 75~77 Ma, the Bunam granitoid stock, which consists of various lithofacies in southwestern part, was made by a plutonism that was mixing to have an injection of mafic magma into felsic magma. During the latest Cretaceous, the volcanic rocks were made by several volcanisms from ubiquitous andesitic and rhyolitic magmas, and stratigraphically consist of Ipbong Andesite derived from Dalsan, Jipum Volcanics from Jipum, Naeyeonsan Tuff from Cheongha, Juwangsan Tuff from Dalsan, Neogudong Formation and Muposan Tuff. Especially the Juwangsan Tuff includes many beautiful cliffs, cayon, caves and falls because of vertical columnar joints by cooling in the dense welding zone. During the Cenozoic Tertiary, rhyolite intrusions formed lacolith, stocks and dykes in many sites. Especially many rhyolite dykes make a radial Cheongsong dyke swarm, of which spherulitic rhyolite dykes have various floral patterns. During the Quaternary, some taluses have been developed down the cliffs of Jungtaesan lacolith and Muposan Tuff.

• KOREAN POULTRY JOURNAL
• /
• v.5 no.10 s.48
• /
• pp.57-72
• /
• 1973

1. 육추율, 육성율, 성계생존율 육추율은 99.9$\%$로서 1회 98.5$\%$, 2회 99.2$\%$, 3회 99.8$\%$, 4회 98.3$\%$, 5회 98.7$\%$, 6회 99.7$\%$와 비슷하였다. 육성율은 평균 98.8$\%$로서 1회 97.5$\%$, 2회 97.2$\%$, 3회 96.6$\%$, 4회 97.9$\%$와는 큰차가 없었고 5회 89.7$\%$ 6회 87.1$\%$ 보다는 약 12$\%$가 높게 나타났다. 이는 MD 백신접종 때문인 것으로 생각되며 성계생존율은 평균 86.3$\%$로서 87.3$\%$ 보다는 약 1$\%$낮았고 1회 80.3$\%$ 2회 84.8$\%$보다는 약 4.6$\%$ 높고 3회 71.8$\%$, 5회 71.4$\%$, 6회 75.3$\%$에 비하면 19$\%$나 높았다. 2. 성성숙일령 전체평균은 157.3일로 가장 빠른 구는 4구의 146일이고 가장 늦은 구는 10구와 17구의 161일이였다. 3. 산란율, 산란지수 산란율은 평균 62.0$\%$이고 가장 높은 구는 15구의 68.9$\%$ 이였다. 산란지수는 평균 205.1개로 1회 190.8, 2회 198.3, 3회 184.2, 5회 186.5, 6회 189.7개에 비하여 높고 4회때와 근사하였다. 4. 사료요구율 전체평균 3.23으로 1회 3.54, 2회 3.1과는 근사하나 3회 2.98, 4회 2.87 5회 2.83에 비하여 낮은 것은 사양표준은 작년도와 같으나 원료사료 특히 단백질 사료의 품질저하에 원인이 있었다. 5. 난평균 중량 검정계군 전체의 평균난중은 61.2g으로 최상위구는 64.70g, 최하위구는 58.3g이였다. 6. 체중 검정계의 전체의 평균제중은 300일령 1925.1g, 500일 1938.4g이며 유색품종은 300일령 1986.7g, 500일령 1948.4g이였다. 7. 사료섭취량 사료섭취량 평균은 1일수당 육추기 32.1g 육성기 73.0g 산란기 115.6g이었다. 8. 경제성 총 수입은 7,269,072.34으로 전체수입의 85$\%$가 계란수입이고 15$\%$는 폐계수입이었다. 지출은 5049,690으로 전체 지출의 99.95$\%$가 사료비 0.05$\%$가 초생추대이었다. 9. 후기 검정수수미달은 참고구로 처리하였고 축산시험장과 대천종축장에서는 당초부터 참고구로 출품하였다. 대신의 개리슨, 신기의 하바드 코메트는 수정율이 낮아서 검정수수가 미달되었으며 영국의 Sykes International Co. 에서 출품한 Sykes Tinted(WL$\times$RIR BX)는 출품회사에서 직접 종란을 항공편에 보내 인수 부화하여 검정하였다. 7회 부터는 초생추에 MD(뎁타백) 백신을 하여 초산전후에 폐사율이 적었으며 72년 11월부터 국산어분에 의한 염도의 과다에 의하여 약 2주일 설사를 하여 상당히 스트레스를 받은 바 있었다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.3
• /
• pp.231-240
• /
• 1987

With a purpose to obtain basic informaton for improving poorly drained soil, a pot experiment was conducted about the effect of percolation rate on growth and yield of rice under application of wollastonite and rice straw as soil conditioner. The sandy and clayey soils were selected to compare difference in effectiveness of poor drainage. The results were summarized as follows: 1. Increasing or percolation rate increased rice yield in both sandy and clayey soils, but the effectiveness on yield increase was greater in clayey soil than in sandy. 2. Various materials of soil solution produced from the process of soil reduction were high at the early growing stage, but they were gradually decreased at the later growing stage. 3. With increasing percolation rate, the contents of N, $P_2O_5$ and $K_2O$ in rice plant were decreased, but that of $SiO_2$ was increased. 4. The number of roots at harvest was greater with increased extension as infiltration rate was increased.

• Economic and Environmental Geology
• /
• v.47 no.1
• /
• pp.29-38
• /
• 2014

Recently developed illite-age-analysis (IAA) approach has been applied to determine the multiple events for the Singal and Wangsukcheon faults in the Chugaryeong fault belt, Korea. Fault reactivated events during Late Cretaceous to Paleogene events($69.2{\pm}0.3$ Ma and $27.2{\pm}0.5$ Ma) for the Singal fault and of $75.4{\pm}0.8$ Ma for the Wangsukcheon fault were determined by combined approach of the optimized illite-polytype quantification and the K-Ar age-dating of clay fractions separated from the fault clays. These absolute geochronological determinations of the multiple tectonic events recorded in the Chugaryeong fault belt are crucial to establish the tectonic evolution of the Korean Peninsula since Late Cretaceous.

• Economic and Environmental Geology
• /
• v.8 no.4
• /
• pp.223-230
• /
• 1975

South Korea is divided tectonically into four segments. The Kyonggi-Ryongnam massif is composed of Precambrian schists and gneisses and consititutes a base for the succeeding formations. The Okcheon geosynclinal zone in the Kyonggi-Ryongnam massif strectches from southwest to northeast diagonally across the peninsula in a direction known as the Sinian direction. Its northeastern part is composed primarily of Paleozoic to early Mesozoic sedimentary formations and the southwestern part of the late Precambrian Okcheon metamorphic series. The Kyongsang basin occupies the southeast and southwest of the peninsula and is made up of a thick series of Cretaceous terrestrial sedimentary and andesitic rocks. A few small Tertiary basins are scattered in the eastern coastal area and in Cheju Island, and are composed of marine sedimentary and basaltic rocks. Jurassic Daebo granites intrude the Kyonggi-Ryongnam massif and the Okcheon zone in the Sinian direction, whereas late Cretaceous Bulkuksa granites are scattered randomly in the Kyongsang basin.

• Economic and Environmental Geology
• /
• v.32 no.4
• /
• pp.323-337
• /
• 1999

Late Cretaceous to early Tertiary volcanic rocks in the Kyongsang basin exhibit high-K calc-alkaline characteristics, and originated from the magmatism related genetically to subduction of Kula-Pacific plate. They represent HFSE depletion and LlLE enrichment characteristics as shown by magmas related to subduction. Early studies on the depth of magma generation has been estimated as 180-230 km based on K-h relation should be reevaluated, because the depth of peridotite partial melting with 0.4 wt. % water is 80-120 km at subduction zone, and subducting slab in premature arc can melted even lower than 70 km. Moreover the increase of potassium contents depends on either contamination of crustal material and fluids of subducting slab or low degree of partial melting. If the inclination of subduction zone is 30 degrees and the depth to the Benioff zone is 180-230 km, the calculated distance between the volcanic zone and trench axis would be 310-400 km. It is unlikely because the distance between the Kyongsang basin and trench during late Cretaceous to early Tertiary is closer than this value and not comparable with generally-accepted models in subduction zone magmatism. $K_{55}$ of the volcanics in the Kyongsang basin is 0.3-2.3 wt.% and the average indicate that the depth ranges between 80-170 km on the diagram of Marsh, Carmichael (1974). Fractionation from garnet lherzolite, assumed the depth of 180-230km, is not consistent with the REE patterns of the volcanoes in the Kyongsang basin. Futhermore, the range of depth suggested by many workers, who studied magmatism related to subduction, imply shallower than this depth. Crustal thickness calculated by the content of CaO and $Na_2O$ is about 30 km and about 35 km, respectively. Paleo-crustal thickness during late Cretaceous to early Tertiary times in the Kyongsang basin inferred about 30 km calculated by La/Sm versus LaJYb data, which is also supported by many previous studies.

• Korean Journal of Soil Science and Fertilizer
• /
• v.17 no.3
• /
• pp.265-273
• /
• 1984

To investigate nitrogen supplying effect of some slowrelease N-fertilizers on barley in upland soil sulfurcoated urea(SCU), ureaform and melamine (1,3,5-Triazine-2,4,6-triamine) were treated and compared to urea. In addition, thiourea as a nitrification inhibitor was also tested. Effects of variable soil condition such as moisture content, pH and temperature on nitrogen supplying ability of the fertilizers and on growth of barley were studied through incubation test and pot culture and the obtained results were summarized as follows: The releasing rate of ammonia from urea, SCU, ureaform and melamine were resulted as 27-59%, 25-39%, 9-34% and 0.7-4.3% at maximum conversion rate, respectively. Nitrification rate of the tested fertilizers was higher at pH 6.54 markedly than at pH 4.73. Addition of thourea depressed the formation of $NO_3$ during four weeks of incubation period. Mixed application of ureaform with small amount of urea contributed to nitrogen supply till latter growth stage of barely Basal application of melamine showed lowest nitrogen supplying ability and injurious response on barley growth.

• KOREAN POULTRY JOURNAL
• /
• v.4 no.10 s.36
• /
• pp.34-46
• /
• 1972

1. 육추율 육성율 성계생존율 육추율 99.7$\%$는 1회 98.5$\%$, 2회 99.2$\%$, 3회 99.8$\%$, 4회 98.3$\%$ 5회 98.7$\%$와 근사하다. 육성율 평균 87.1$\%$는 1회 97.5$\%$, 2회 97.2$\%$, 3회 96.6$\%$, 4회 97.9$\%$에 비하여 10$\%$정도 낮으며 5회 89.7$\%$보다도 2.6$\%$ 낮은데 이는 근년 많이 발생하는 마렉병 및 백혈병이 주원인이며,(7회 검정계 부터 마렉병 예방접종)현 김포검정사 신축이 장마로 인하여 지연되므로서 더욱 임시육추사에서의 육성기간에 스트레스를 받았기 때문이며 성계생존율은 평균 75.3$\%$이며, 1회 80.3$\%$, 2회 84.8$\%$, 3회 71.8$\%$, 4회 87.3$\%$, 5회 71.4$\%$ 이었다. 이를 폐사원인별로 보면 세균성 질환으로 인한 폐사가 전체폐사수의 8.9$\%$ 병독(마렉병 및 백혈병)이 61.5$\%$원충 0.7$\%$ 대사장애 9.2$\%$ 생식기장애 3.4$\%$ 내장파열(간파열 탈항등) 5.7$\%$ 곰팡이 1.1$\%$ 기타(복막염 장염등) 9.5$\%$로 마렉병 및 백혈병이 주인이며 이를 검정각회별로 보면 1.2회 32.3$\%$, 3회 43.3$\%$, 4회 41.3$\%$, 5회 56.2$\%$, 6회 61.5$\%$로 매년 증가하고 있다. 2. 성성숙일령 전체평균 155.9일로 가장 빠른 구는 4구의 144일이고 가장 늦은 구는 23구의 166일이며 1일 189.2일, 2회 181.2일 보다 30일 정도 빨라진 것은 1.2회 검정은 산란율 50$\%$ 연2일 산란한 전일로 계산하였으며 3회 검정부터는 산란율 50$\%$에 달한 일령으로 계산하였기 때문이다. 3. 산란율 산란지수 산란율 평균 64.6$\%$이고 최상위구는 77.1$\%$, 최하위구는 52.8$\%$이며 유색품종 평균산란율은 58.4$\%$ 백색품종은 66.6$\%$이며 성성숙일령이 빨라짐에 따라 전체산란율은 약간 떨어지고 있다. 산란지수-평균은 189.7개로 200개 이상 산란한 상위군이 모두 성계생존율이 높은 구임을 알 수 있다. 4. 사료요구율 전체평균 2.8로 1회 3.54, 2회 3.1., 3회 3.98 4회 2.87, 5회 2.83으로 점차 개선되어 가고 있으며 유색품종의 사료요구율 평균은 3.3이었다. 5. 난평균중량 평균 58.4g로 최상위구는 60.8g, 최하위구는 56.6g 이며 국산계의 평균난중은 57.9g 외국제 평균난중 58.6g이었다. 6. 체중 평균체중은 300일령 2,117.g, 500일령 2,207이며 유색품종은 300일령 2.6160g, 500일령 2.656.7g이었다. 7. 사료 섭취량 사료섭취량 평균은 1일수당 육추기 33.6g, 육성기 68.5g, 산란기 109.9g이었다. 8 경제성 총수입은 2,539,799 으로 전체수입의 85.3$\%$가 계란수입이고, 폐계 수입은 14.7$\%$이다. 지출은 총계 1,854.517원으로 전체 지출의 92.5$\%$가 사료비, 7.5$\%$가 초생추대이었다. 9. 후기 마렉병 백신이 71년 중반기부터 수입되므로써 마렉병 예방접종을 하지 못하므로서 전체 폐사 수의 61.5$\%$를 차지하는 많은 피해를 보았다.