• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.28-53
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• 1975

Experiments on the physiological root activity and its related characteristics of rice varieties were carried out in order to obtain some basic informations for the application of the results obtained to a rice breeding program. A significant positive correlation was found not only among the various characteristics related to conducting and ventilating systems which connects top and root of rice plant, but also between these characteristics and root activity. On the other hand, a significant difference in physiological root activity was recognized among different varieties and also between different groups of recognized 7 rice varieties differing in the their origin. It was also found that varieties with higher root activity (root activity indices) after ear formation stage tended to have more number of lower green leaves and consequently resulted in higher grain yield. Therefore, it may be possible to diagnose indirectly the root activity by examining the number of green leaves of the rice plant at later growth stage when breeders make selections of parent material for crossing or of hybrid lines in pedigree nurseries.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.469-478
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• 2004

Pig slurry, urine and fermented liquid manure were evaluated measuring electrical conductivity (EC), dry matter (DM) contents and other components. Samples were collected during a period from February to April, 2001: slurry samples from 70 storage tanks, urine samples from 19 and 20 fermented liquid manure samples from 109 pig farms in Jeju. Samples were analyzed for pH, EC, DM, $NH_4$-N, K, P, Ca, Mg, Na, BOD, S-S, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and OM. Relationships between EC or DM and various mineral and $NH_4$-N contents were examined using linear regression. EC, DM, all mineral contents and $NH_4$-N were higher in slurry samples than in urine or fermented liquid manure. EC, $NH_4$-N, Ca, Mg and Na concentration was similar in urine and fermented liquid manure, but K and DM values in liquid manure were twice as much as in urine. P concentration was higher in urine than in liquid manure. $NH_4$-N and Na in slurry, $NH_4$-N in urine and $NH_4$-N, P and Ca in fermented liquid manure were highly correlated with EC, while $NH_4$-N, P, Ca and Mg in slurry, $NH_4$-N and Ca in urine, and K, P, Ca, Mg, and Na in fermented liquid manure with DM (P<0.05). BOO in slurry (22,520 mg/mL) was higher than that in urine (4,763) and fermented liquid manure (2,701). Results indicated that slurry is a better fertilizer source than urine or fermented liquid manure. However, slurry may pollute soil more than urine or fermented liquid manure when applied to land, although the levels are not above the permit.

• Applied Biological Chemistry
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• v.9
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• pp.111-118
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• 1968

A pot experiment with $P^{32}$ was carried out to investigate the soil phosphorus availability to four leguminous forage crops and three graminaceous, of black volcanic ash soil and red one. Soil phosphorus was extracted with 6 different extractants and also fractionated in Fe, Al and Ca phosphorus. The results were: 1) Soil phosphorus availability was in decreasing order of Italian rye grass${\gg}$ soybean> cassia> corn> weeping love grass${\gg}$ Korean lespedeza> Red clover and they might be grouped into three levels by A-value, over 1000, 200-500 and below 40 $p_{2}O_{5}\;kg/ha$. 2) The amount of various available phosphorus and phosoborus fraction in the black soil was higher than that in the red soil. No difference in phosphorus availabiliy to forage crops was shown between two soils. Therefore an extractant able to draw out similar amount of phosphorus from two soil will be suitable for determining the phosphorus availability index. 3) Two extractants, one extracting 20 ppm as maximum and the other extracting 100 ppm as minimum will be recommendable for determining the availability of phosphorus; the former for red clover and Lespedeza and the latter for others. Truog method may be good for the former but no appropriate method for the latter was found in the methods used. 4) T/R ratios of legumes were negatively correlated at 5% level with % phosphorus from fertilizer (% pdF). Legumes showed below 50 of % pdF over 5 of T/R ratio and over 80 of % pdF below 5 of T/R.

• Food Science and Preservation
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• v.17 no.4
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• pp.519-525
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• 2010

Kwamegi, a traditional Korean food, is made from the flesh of Pacific saury (the fish Cololabis saira semi-dried in a cold wind off the sea, and is well known in Korea as a valuable health food. Recently, several functional materials have been developed for supplementation of Kwamegi. Here, we compared and analyzed the nutrient composition, including overall composition and mineral, vitamin, fatty acid, and amino acid levels, of several commercial Kwamegi samples prepared with addition of functional components (unsupplemented Kwamegi, Kwamegi with chitosan, and Kwamegi overlaid with gold leaf). The levels of moisture (26.4-30.8%), crude protein (29.1-32.7%), and crude ash (1.6-1.9%) did not differ greatly among samples. However, the crude lipid content of Kwamegi overlaid with gold leaf (KOGL, 32.2%) was greater than that of untreated Kwamegi (CK, 24.5%) or of Kwamegi with added chitosan (KAC, 22.9%). The levels of vitamin $B_2$ (1.8-2.0 mg/100 g) and vitamin C (6.6-6.7 mg/100 g) did not differ greatly among Kwamegi samples. However, CK had a higher vitamin A content and a greater vitamin A potency than did KAC or KOGL. The various Kwamegi samples tested contained similar levels of fatty acids and amino acids. In conclusion, no particular differences in nutrient composition were evident when commercial Kwamegi samples supplemented with functional ingredients were tested

• Proceedings of the Technology Innovation Conference
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• 1997.07a
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• pp.222-223
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• 1997

By analyzing the successful innovation case of potato microtuber mass production technology, a representative case of technology-push type creative innovation in an imitation oriented research culture, this paper attempts to figure out conceptual model of creative innovation that is initiated by the public laboratories in catching-up country, Stages of creative innovation can be divided into the internal R&D stage and the external commercialization stage. Success of the internal R&D stage depended on autonomy to secure creative research idea and commitment of individual researchers. Psychological pressure evoked from sportlights of mass media and commitment of sponsor increased the intensity of research efforts of the researcher Recognition of research problem and its significance was intensified by site visits of agricultural fields, and the recognized higher impacts of expected research results and knowledge creation achieved were a fundamental source of self-motivation. In the stage of commercialization stage, various legal, socio-economic, and psychological barriers were confronted. In a catching-up country lacking of experiences of creative innovation, creative innovation process can be regarded as a barrier elimination and cultural revolution process. Among the barriers, psychological refusal of farmers to corn-sized potato seeds was critical, which finally enforced to further researches to enlarge the size of potato seeds. In addition, the researcher has concentrated his research efforts in one specialized research area by getting a series of similar research project funds rather than diversification. It was lucky for him to have a chance to carry out a series of similar researches in one research area during the last 10 years. In getting research funds from government and private companies continuously in one research area, both internal and external promoters played significant roles.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.450-458
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• 2012

In order to reduce the effects of greenhouse gas (GHG) emissions, the South Korean government has announced a special platform of technologies as part of an effort to minimize global climate change. To further this effort, the Korean government has pledged to increase low-carbon and carbon neutral resources for biofuel derived from biomass to replace fossil and to decrease levels of carbon dioxide. In general, second generation biofuel produced form woody biomass is expected to be an effective avenue for reducing fossil fuel consumption and greenhouse gas (GHG) emissions in road transport. It is important that under the new Korean initiative, pilot scale studies evolve practices to produce biomass-to-liquid (BTL) fuel. This study reports the quality characteristics of F-T(Fischer-Tropsch) diesel for production of BTL fuel. Synthetic F-Tdiesel fuel can be used in automotive diesel engines, pure or blended with automotive diesel, due to its similar physical properties to diesel. F-T diesel fuel was synthesized by Fischer-Tropsch (F-T) process with syngas($H_2$/CO), Fe basedcatalyst in low temperature condition($240^{\circ}C$). Synthetic F-T diesel with diesel compositions after distillation process is consisted of $C_{12}{\sim}C_{23+}$ mixture as a kerosine, diesel compositions of n-paraffin and iso-paraffin compounds. Synthetic F-T diesel investigated a very high cetane number, low aromatic composition and sulfur free level compared to automotive diesel. Synthetic F-T diesel also show The wear scar of synthetic F-T diesel show poor lubricity due to low content of sulfur and aromatic compounds compared to automotive diesel.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.519-526
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• 1992

The gene coding for urease of alkalophilic Bacillus pasteurii had been cloned in Escherichia coli previously. The urease protein was purified 63.1-fold by TEAE-cellulose, DEAE-Sephadex A-50, Sephadex G-150 and Sephadex G-200 chromatographies with a 7.3% yield from the sonicated fluid of the E. coli HB1Ol(pBUll) encoding B. pasteurii urease gene. The ureases of E. coli (pBUll) and B. pasteurii possessed as a $K_m$ for urea, 42.1 mM and 40.4 mM, respectively. They hydrolyzed urea with $V_{max}$ of 86.9$\mu$mol/min and 160$\mu$mol/min, respectively. Both ureases were composed with four subunits (Mrs 67,000) and a subunit (Mr 20,000). The molecular weight of both native enzymes was Mr 280,OOO$pm$10,000 determined by gel filtration chromatography and Coomassie blue staining of the subunits. The optimal reaction pH of both ureases were pH 7.5. The ureases were stabled in pH 5.5-10.5. The optimal reaction temperature of both ureases were $60^{\circ}C$, and the ureases were stable for an hour at $50^{\circ}C$, 40min at $60^{\circ}C$ and 10 min at $70^{\circ}C$ The activity of both enzymes were inhibited completely by $Ag^{2+}$, $Hg^{2+}$, $Zn^{2+}$, $Cu^{2+}$, and were inhibited 60% by CoH, 30% by $Fe^{2+}$ and 10% by $Pb^{2+}$. However it was increased by the addition of $Sn^{2+}$, $Mn^{2+}$, $Mg^{2+}$ at concentration of $1{\times}10^{-3}$M. Both ureases were inhibited completely by p-CMB and acetohydroxamic acid. The urease expressed in E. coli (pBU11) was inhibited 70% by SDS. The urease of B. pasteurii was inhibited 40% by hydroxyurea, whereas the recombinant urease of E. coli strain was inhibited 17%. Both enzymes were not inhibited by cyclohexanediaminetetraacetic acid (CDTA) and ethylendiaminetetraacetic acid (EDTA).

• Food Science and Preservation
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• v.23 no.2
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• pp.225-232
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• 2016

This study investigated the quality characteristics (chemical composition, amino acid content, lipid content, and rutin content) of common and tartary buckwheats cultivated from Korea and China. The moisture, crude protein, crude fat, crude ash, and carbohydrate contents of various common and tartary buckwheats were 8.78~13.37%, 11.00~12.11%, 2.87~3.18%, 1.80~2.58%, and 70.2~73.8%, respectively. The major amino acids in Korean and Chinese buckwheats were aspartic acid (1,105.1~1,403.5 mg/100 g), glutamine (2,250.9~2,996.1 mg/100 g), and arginine (932.5~1,388.6 mg/100 g). The major minerals were K (423.7~569.4 mg/100 g), Mg (181.8~255.9 mg/100 g), and P (328.6~555.0 mg/100 g). Palmitic acid (14.2~16.1%) was the major saturated fatty acid, and oleic (37.0~40.8%) and linoleic (31.7~38.6%) acids were the major unsaturated fatty acids. Tartary buckwheats (261.0~265.0 mg/g) had significantly higher rutin contents than that of common buckwheats (4.39~5.68 mg/g). These results suggested that common and tartary buckwheats cultivated in Korea and China contain naturally occurringnutrients in an abundance.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.436-447
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• 2004

Wetland plants have evolved specialized adaptations to survive in the low-oxygen conditions associated with prolonged flooding. The development of internal gas space by means of aerenchyma is crucial for wetland plants to transport $O_2$ from the atmosphere into the roots and rhizome. The formation of tissue with high porosity depends on the species and environmental condition, which can control the depth of root penetration and the duration of root tolerance in the flooded sediments. The oxygen in the internal gas space of plants can be delivered from the atmosphere to the root and rhizome by both passive molecular diffusion and convective throughflow. The release of $O_2$ from the roots supplies oxygen demand for root respiration, microbial respiration, and chemical oxidation processes and stimulates aerobic decomposition of organic matter. Another essential mechanism of wetland plants is downward water movement across the root zone induced by water uptake. Natural and constructed wetlands sediments have low hydraulic conductivity due to the relatively fine particle sizes in the litter layer and, therefore, negligible water movement. Under such condition, the water uptake by wetland plants creates a water potential difference in the rhizosphere which acts as a driving force to draw water and dissolved solutes into the sediments. A large number of anatomical, morphological and physiological studies have been conducted to investigate the specialized adaptations of wetland plants that enable them to tolerate water saturated environment and to support their biochemical activities. Despite this, there is little knowledge regarding how the combined effects of wetland plants influence the biogeochemistry of wetland sediments. A further investigation of how the Presence of plants and their growth cycle affects the biogeochemistry of sediments will be of particular importance to understand the role of wetland in the ecological environment.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.209-215
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• 1990

Some preliminary studies were conducted to find out whether the levee-burning could justifiable for the suppression of insect pests, particularly the smaller brown planthopper (Laodelphax striatellus F.). Density surveys on pests and their enemies (mostly spiders) were carried out upto the mid May at an experimental paddy field located in Suwon after of it's levee $(72\times1m)$ was burned on Feb. 20, 1987. Results were discussed in relation to density recovering of both pests and their possible enemies (spiders) and summarized as below. Not a single individual of any pest or enemy was found from the levee upto sometime after the levee-burning. Grasses started to grow more vigorously in burned ares than in unburned upto about 60 days after the burning. And densities of both pest and enemies grew higher in burned areas than in unburned from about 75 days after the burning (in Early may). It is suspected that all individuals of pests and enemies fond from the burned areas could have immigrated from the surrounding areas. If levee-burning was carried out in much wider areas, much longer time would be needed to recover the density of both pests and enemies to the center region of the burning. Wingless spiders would require even longer time than winged pest species to re-establish in the center region of the widely burned field. Pirata subpiraticus, the most abundant spider species in Korean paddy fields, starts to move about and searches for food at above $9^{\circ}C$ which is somewhat lower than the critical temperature for the pest species. Thus P. subpiraticus would require more food than other pest species early in the spring, and therefore, it would have lower probability to survive than pest species particularly in burned areas. Experiments for pest suppression with levee-burning would better be carried on in much wider areas, and its justification seems to be discussed after man other disciplines related to both pests and their natural enemies were throughly studied together with their density surveys. However, according to the present point of vie, the opinion that levee-burning is helpful for controlling pests which over winter on levee areas could not be justifiable.