• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.88-93
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• 1977

The following is the result of experiment on consolidation test under various load increment ratios by alternation of standard load increment ratio. The more load increment ratio was, the more settlement was resulted. But expansions were not associated with load increment ratios. Primary consolidation took longer period to complete as load increment ratio was decreased. And under the condition of over-consolidated range, the completion of primary consolidation took longer period as the load was incremented. Under the condition of normal consolidated range, there was no change in time of completing primary consolidation. The coefficient of consolidation was decreased with increment of consolidation load, and the coefficient of consolidation had high values as the load increment ratio was increased. The values of ratio of secondary consolidation was highest near the transition point of consolidation curve.

• The Journal of Korean Medicine
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• v.29 no.5
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• pp.67-76
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• 2008

Objectives : Amnesia is theloss or impairment of memory, caused by physical injury, disease, drugs, or emotional trauma. Recently, the average life span is increasing, while at the same time, the incidence of dementia-like diseases in conjunction with amnesia are also increasing. Therefore learning and memory are very important issues in modern society. Ancient Korean physicians used several herbs to treat dementia and these herbal effects were described in Korean herbal books. Among them are some reports on several cognitive-enhancing herbs which have since been shown to improve dementia in recent pharmacological studies, such as Panax ginseng; however, the facilitatory effects of many Korean cognitive-enhancing herbs on learning and memory are limited. Learning and memory are essential requirements for every living organism in order to cope with environmental demands; cholinergic systems are known to be involved in learning and memory. Methods : In this study, the effects of Acori graminei rhizoma (AGR, 石菖蒲) on learning and memory were investigated by Morris water maze, eight-arm radial maze, and the effects on the central cholinergic system of rats injected with scopolamine. Results : In the water maze, the experimental animals were trained to find a platform in a fixed position for 6 days and then received a 60 sec probe trial in which the platform was removed from the pool on the 7th day. In the eight-arm radial maze, the animals were tested four times per day for 6 days. Scopolamine impaired performance of the maze tests and reduced activity of acetylcholinesterase (AchE) in the hippocampus, which is a marker for the central cholinergic system. There were significant reversals from the scopolamine-induced deficits on learning and memory in these tests, through daily administrations of AGR (100 mg/kg, p.o.) over 14 consecutive days. These treatments also reduced the loss of cholinergic activity in the hippocampus induced by scopolamine. Conclusions : These results demonstrated that AGR ameliorated learning and memory deficits by affecting the central acetylcholine system.

• Korean journal of applied entomology
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• v.17 no.1 s.34
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• pp.7-13
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• 1978

Experiments were conducted to study the integrated control of one of the major pests of citrus, the citrus red mite, Panonychus citri (McGregor). Studies were conducted in Seogwipo, Cheju Island, 1973-1976. Results obtained were: 1. The major peak of citrus red mite occurrence was mid-July to mid-August. 2. Standard field populations of citrus red mite were also high in September, October, and November. 3. A total of 10 species of natural enemies of citrus red mite were found. These included; Oligota yasumatusi Kistner, Anystis baccarum L., Hemerobiid sp., Semidalis albate E., Orius sp., Agistemus terminalis Q., 3 species of lady beetles (Coccinellidae), and one unidentified species of predacious mite. 4. Annual occurrence of citrus med mite tended to decrease in unsprayed fields, but increased in fields receiving standard treatments. 5. With fungicides, there was an increase in mite populations associated with use of Bordeaux mixture and copperpowder sprays. Streptomycin, however, did not effect on increase in mite numbers.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.157-166
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• 1977

These experiments were carried out to analyse the correlation among various soil parameters which characterize the mechanical properties of the disturbed and undisturbed soil, and to analyse Atterberg Limits for the basin of downstream of Hanriver Keum river, Nakdong river, and Asan bay. 1. Wet density of soil was the lowest in the basin of Nakdong river which contains the highest amount of clay minerals among the soil samples, and was increased in the order of Han river, Keum river and Asan bay. It was appeared that the unit weight of natural soil was changed in accordance with the clay mineral content which determines the moisture content. 2. Curved relationship was recognized, showing that dry density of soil was decreased with increasing the moisture content. Soils from the basin of Asan bay were appeared to have the highest dry density and the next was those of Keum river, the second lowest Han river, and the lowest Nakdong river. 3. When the liquid limit of soils was over 40 percent, their plastic index was above the A-line of plastic chart. 4. Between dry density and void ratio of soils, a curved relationship was found, in which dry density was decreased as void ratio increased, and the differences between them became greater in soils containing higher amount of coarse grained soil. Decreasing tendency of dry density in accordance with increase of void ratio was the most significant at Asan bay which contained the lowest clay content, and other decreasing order of dry density was Keum river, Han river, and Nakdong river.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.592-599
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• 2014

This study presents trends and projected estimates of methane and nitrous oxide emissions from livestock of India vis-$\grave{a}$-vis world and developing countries over the period 1961 to 2010 estimated based on IPCC guidelines. World enteric methane emission (EME) increased by 54.3% (61.5 to $94.9{\times}10^9kg$ annually) from the year 1961 to 2010, and the highest annual growth rate (AGR) was noted for goat (2.0%), followed by buffalo (1.57%) and swine (1.53%). Global EME is projected to increase to $120{\times}10^9kg$ by 2050. The percentage increase in EME by Indian livestock was greater than world livestock (70.6% vs 54.3%) between the years 1961 to 2010, and AGR was highest for goat (1.91%), followed by buffalo (1.55%), swine (1.28%), sheep (1.25%) and cattle (0.70%). In India, total EME was projected to grow by $18.8{\times}10^9kg$ in 2050. Global methane emission from manure (MEM) increased from $6.81{\times}10^9kg$ in 1961 to $11.4{\times}10^9kg$ in 2010 (an increase of 67.6%), and is projected to grow to $15{\times}10^9kg$ by 2050. In India, the annual MEM increased from $0.52{\times}10^9kg$ to $1.1{\times}10^9kg$ (with an AGR of 1.57%) in this period, which could increase to $1.54{\times}10^9kg$ in 2050. Nitrous oxide emission from manure in India could be $21.4{\times}10^6kg$ in 2050 from $15.3{\times}10^6kg$ in 2010. The AGR of global GHG emissions changed a small extent (only 0.11%) from developed countries, but increased drastically (1.23%) for developing countries between the periods of 1961 to 2010. Major contributions to world GHG came from cattle (79.3%), swine (9.57%) and sheep (7.40%), and for developing countries from cattle (68.3%), buffalo (13.7%) and goat (5.4%). The increase of GHG emissions by Indian livestock was less (74% vs 82% over the period of 1961 to 2010) than the developing countries. With this trend, world GHG emissions could reach $3,520{\times}10^9kg$ $CO_2$-eq by 2050 due to animal population growth driven by increased demands for meat and dairy products in the world.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.492-500
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• 2008

Since vegetation significantly influences on soil carbon and nutrient storage, vegetation change has been focused on terrestrial carbon and nutrient cycling studies. In this study we investigated soil carbon and major nutrient capitals at the abandoned fields, which had different vegetation composition: a three year abandoned field ($AGR_3$), two ten years abandoned fields ($PD_{10}$ dominant with Pinus densiflora and Fraxinus rhynchophylla and $PM_{10}$ dominant with Populus maximowiczii), and an over sixty years forest ($FOR_{60}$). which were located at Hongcheon-gun, Kangwon-do, South Korea. Both main effects for organic matter (%) were significant: shallow soil > deep soil and $FOR_{60}=PM_{10}$ > $AGR_3=PD_{10}$. Nitrogen concentrations at $PM_{10}$ were the highest, while the lowest at $PD_{10}$. Available phosphorus concentrations were the highest at $PD_{10}$, which were over 10 times of site $FOR_{60}$ and $AGR_3$ at 0-10 cm soil depth. The average organic matter ($173Mg\;ha^{-1}$) and nitrogen contents ($10Mg\;ha^{-1}$) of $PM_{10}$ and $FOR_{60}$ were higher than those of $AGR_3$ and $PD_{10}$ by 57% and 42%, respectively. The available phosphorus contents above 30 cm mineral soil at $PD_{10}$ ($3.8Mg\;ha^{-1}$) and $PM_{10}$ ($1.3Mg\;ha^{-1}$) were over 120 times and 40 times more than at $FOR_{60}$. Calcium ($3.7Mg\;ha^{-1}$) and magnesium contents ($2.8Mg\;ha^{-1}$) at $FOR_{60}$ were twice or three times higher than at other sites. Organic matter amounts in 0-10 cm and 10-30 em soil had significant positive relationships with nitrogen, calcium, and magnesium contents, but not available phosphorus and potassium contents. This study could not identify the effect of chronological factor and vegetation composition on soil carbon and nutrient capital owing to diverse topography as well as limited study sites. However, this study suggests the accuracy of investigation for regional carbon and nutrient sequestration can be achieved by considering the period of abandoned time on the fields and the land use types. These results may suggest the benefits of forest restoration for soil carbon and nutrient accumulation in marginal agricultural lands in South Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.275-280
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• 1990

In order to obtain the basic informations on the reasonable fertilization and soil management systems for a high soybean yield, both soybean leaves and soils were collected from 24 soybean-cultivated fields in central area of Korea, and analyzed. For this study, soybean leaves and soil were sampled together in July of 1988(growing season), and soil alone in October of 1988 (harvesting season) and April of 1989(sowing season) at each sampling site. The results might be summarized as follows: 1. The soil pH ranged between 4.8 and 6.8. and the pH after harvest decreased to 5.4 which compared with the pH 5.7 of growing season. 2. Both the 1N KCl extractable Al and the 1N $NH_4OAc$ extractable Al in soils were inversely correlated with the soil pH. the former concentration was negligible above pH 5.8. 3. The soil total-N and Bray 1-P after harvest were lower than those of growing season. The Bray 1-P's of sample soils were very high irrespective of sampling time. 4. The exchangeable Ca and Mg in soils even after harvest varied little whereas the exchangeable K decreased with time. 5. The N content in soybean leaves was not correlated with soil total-N, but highly correlated with the K content in soybean leaves. The Mg content in soybean leaves was also highly correlated with Ca content in suybean leaves and exchangeable Mg in soils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.489-494
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• 1993

The amount of maize being imported from other countries to meet the national demand are increasing every year. Regardless of the usage whether it is for silage or for human consumption, amount of seeds for farmers are ever being increased. In order to solve the problems arising from the seed import, a program for developing waxy hybrids with high quality was set up at the College of Agr., Chungnam National University. The main breeding targets for high quality waxy hybrids are focused on the pericarp thickness. In order to obtain basic information needed for developing hybrids with thin pericarp, six inbred lines all derived from open pollinated Korean waxy lines were diallel crossed. Results obtained indicate that waxy hybrids with thin pericarp can be developed by choosing proper parental lines. Of the six inbreds, Jewon inbred had utmost thin pericarp compared with other lines. Hybrids crossed with Jewon showed also thinner pericarp than other hybrids. However, Danyang which has thick pericarp showed thicker pericarp in hybrid combinations. Variance due to general combining abilities was greater than the variance due to the specific combining abilities, indicating that additive gene effects are more important. The pericarp thickness of waxy hybrid endosperm varied with the parts of pericarp. The germinal side of the pericarp is comparatively thinner than the abgerminal side. The upper part (crown) has thicker pericaip than lower part (tip) of the kernel.

• Korean Journal of Weed Science
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• v.18 no.1
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• pp.54-62
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• 1998

This experiment was conducted to find out the effects of ABA and IAA on activities of antioxidant enzymes, antioxidant content, and growth of tobacco under exposure to ozone. The exposure to ozone in tobacco plant significantly decreased plant height, but it did not show any difference in vegetative characteristics except plant height of IAA $10^{-3}$M treated. Total chlorophyll content of NC 82 was dramatically decreased with increase in days after ozone treatment. However, reduction of chlorophyll was minimized when plant growth regulators were treated before ozone exposure. Three days treament of ozone in tobacco increased ascorbic acid of oxidised form, while slightly decreased `in reduced ascorbic acid by IAA treatment. But seven days of ozone treatment showed increase in ascorbic acid and decrease in dehydroascorbic acid. Ozone treatment did not show any difference in glutathione content and glutathione reductase activity when plant growth regulators were treated. Activities of superoxide dismutase(SOD), ascorbate peroxidase(AP) and guaiacol peroxidase(GP) were increased by the exposure to ozone for three days. However, there were no difference in activities of SOD, AP and GP due to exposure to ozone for seven days. These reactions may be interpreted as protective responses to prevent or alleviate the damage of tobacco plant by ozone exposure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.280-287
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• 1989

In order to know growing habit of the maize bearing tillers, IK//IRI/B68 with tillers was grown and compared with Jinjoo Ok which is not tillering, and several parameters were measured for analysis. The results obtained were summarized as follows. 1. The plant height and fresh weight of IK//IRI/B68 were lower than those of Jinjoo Ok until the tasseling stage of IK/ /IRI/B68, while then plant height and fresh weight of IK//IRI/B68 were higher than those of Jinjoo Ok after the tasseling stage of IK//IRI/B68. 2. The average number of tillers per plant of IK//IRI/B68 at maturity was 3.7 and the average tiller height of IK//IRI/B68 was almost the same as the height of the main stem. 3. The dry weight of IK//IRI/B68 at the early growing stage was lower than the check hybrid Jinjoo Ok, while it was higher than Jinjoo Ok at the later growing stage. 4. The LAI of IK//IRI/B68 after full expansion of the leaves was greater than that of Jinjoo Ok The LAIs of IK//IRI/B68 and Jinjoo Ok were 12.6 and 5.8, respectively. 5. The CGR of Jinjoo Ok was greater than that of IK//IRI/B68 until earey July while the CGR of Jinjoo Ok was lower than that of IK//IRI/B68 as the tillers of IK//IRI/B68 were fully developed. 6. The LAR and RGR of IK//IRI/B68 were greater than those of Jinjoo Ok until mid-July. The RGR of IK//IRI/B68 seemed to be affected by both NAR and LAR. The RGR of Jinjoo Ok seemed to be affected by LAR.