• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.363-363
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• 2017

The NPK are known as macro elements that affect crop growth and yield. In 1989, Cambodia Agricultural Research and Development Institute (CARDI) gave a recommendation rate of fertilizer on rice production based on soil types. This recommended rate of NPK seems however relatively low as compared to farmers' practices nowadays and the amount in the neighboring countries. The CARDI recommended rate for Prateah Lang soil type is 50kg N, 25kg P2O5, 25kg K2O ha-1 while recent farmers' practice rates are 55 - 64kg N, 24 - 46kg P2O5, 30kg K2O ha-1. However, the overuse of chemical fertilizer will lead to un-preferable plant growth, insect pest, disease and economic yield. Thus, we examined the effect of different NPK application rates on the growth and yield components in Prateah Lang soil type in Takeo province to investigate appropriate rates for improving rice productivity with economic efficiency. This study was conducted from July to November during wet season in 2013. A multi-locational trial with 6 treatments (T0 - T5) of NPK rates in 5 locations (trial 1 - 5) with 3 replications was conducted. The different combinations of NPK application were employed from 0, 50, 60, 80, 100, 120kg N ha-1, 0, 25, 30 45, 60kg P2O5 ha-1 and 0, 15, 25, 30, 45kg K2O ha-1. Urea, DAP and KCl were used for fertilization. Split application was employed [basal: 20% of N, 100% of P and K, top dressing-1st: 40% of N (30DAT), 2nd: 40% of N (PI stage)]. Three-week-old seedlings of var. Phka Rumdoul were transplanted with 2 - 3 seedlings hill-1 with $20cm{\times}20cm$ spacing. Plant length, tiller number at the maximum tillering stage and yield components were measured. The different rates of NPK application affected some yield components. The panicle number per hill was the most important key component followed by the spikelet number per panicle. However, the other parameters such as the filled grain percentage and 1000 grains weight had small effect or weak relation with the yield. Although the panicle number per hill had a significantly positive correlation with the stem number per hill, it was not correlated with the percentage of productive culms. The variation in the grain yield among the 5 trials was small and the difference was not significant. Although the yield tended to be higher at higher N and P application, there was no significant difference above 60kg N and 30kg P2O5. The yield was the highest at 15, 30 and 45kg K2O followed by 25kg K2O. The relationships between N, P and the stem number per hill were significantly linear positive, though it was not linear between K and the stem number. From these results, to increase rice productivity in the target area, farmers' effort to increase N and P input rather than CARDI recommendation up to 60kg N and 30kg P2O5 will be sufficient considering economic efficiency. Besides, the amount of K application should be reconsidered.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.461-474
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• 2005

Physicochemical parameters, plankton community structure, and sediment were surveyed from 1988 to 2002, at two months interval, in a eutrophic coastal lagoon (Lake Songji, Korea). The lake basin is separated from the sea by a narrow sand dune, and a shallow sill divides the lake basin into two sub-basins. The stable stratifications and chemoclines are maintained all through the year at 1-2 m depth. DO was often very low (<1 $mgO_2\;{\cdot}\;L^{-1}$) in the monimolimnion. Secchi disc transparency was in the range of 0.5-2.7 m. TP, TN, and Chl. a concentration in the mixolimnion were 0.015-0.396 $mgP\;{\cdot}\;L^{-1}$), 0.223-3.521 $mgN\;{\cdot}\;L^{-1}$, and 0.5-129.8 mg ${\cdot}\;m^{-3}$, respectively. TSI was in the eutrophic range of 54 to 62. Sediment was composed of silt and coarse silt. COD, TP, and TN content of the sediment were 51.4-116.9 $mgO_2\;{\cdot}\;gdw^{-1}$, 0.04-1.46 $mgP\;{\cdot}\;gdw^{-1}$ and, 0.12-1.03 $mgN\;{\cdot}\;gdw^{-1}$, respectively. The 49 phytoplankton species were identified. The maximum phytoplankton abundance obscured the lake in September 2001 (max. density: 23,350 cells ${\cdot}\;mL^{-1}$. The Chlorophyte Schroederia judayi was dominant species in summer (max. density: 20,417 cells ${\cdot}\;mL^{-1}$). The lake showed unique limnological features of a brackish lagoon in respect to biological community, chemical characteristics, and physical phenomena.

• Korean Journal of Environmental Agriculture
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• v.28 no.1
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• pp.20-24
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• 2009

This study was conducted to investigate the roles of co-existed organic materials (OM) with different biodegradability in composting of cattle manure in terms of $CO_2$ emission and $NH_3$ volatilization. Either sawdust (SD, low biodegradability) or rice bran (RB, high biodegradability) was mixed with cattle manure at a various rate and the amounts of $CO_2$ emission and $NH_3$ volatilization were determined periodically during 4 weeks of composting. Percentage of dry matter loss during the composting period was also calculated. The amount of $CO_2$ emitted increased with increasing rate of OM and was significantly (P<0.01) higher in the RB treatment than in the SD treatment by 43 to 122% depending on the rate of OM Accordingly, % of dry matter loss during 4 weeks of composting was higher in the RB (rang: from 35.1 % to 41.5%) than that in the SD treatments (from 18.7% to 22.6%), showing that RB is more biodegradable than SD. During the early composting period up to 8 days, negligible amount of ammonia volatilization was detected in both treatments regardless of application rates. In the RB treatment, substantial amount of ammonia volatilization was detected thereafter, however, no meaningful ammonia volatilization was observed in the SD treatment until the end of composting. Such differences could be attributed to the different properties of SD and RB. For example, the high C/N ratio of SD could enhance $NH_4^+$ immobilization and thus decrease $NH_4^+$ concentration that is susceptible to ammonia volatilization. Binding of $NH_4^+$ on to phenolic compounds of SD may also contribute to the decrease in $NH_4^+$ concentration. Meanwhile, as RB has a relatively low C/N ratio, remineralization of immobilized $NH_4^+$ could increase $NH_4^+$ concentration as high as the level for the occurrence of ammonia volatilization. Therefore, our study suggests that OM which is resistant to biodegradation can reduce $NH_3$ volatilization largely by physico-chemical pathways across the entire composting period and that easily biodegradable OM can retard $NH_3$ volatilzation via microbial immobilization in the early period of composting followed by rapid remineralization, leading to substantial volatilization of $NH_3$ in the middle stage of composting.

• Natural Product Sciences
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• v.8 no.1
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• pp.1-15
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• 2002

An International Cooperative Biodiversity Group (ICBG) program based at the University of Illinois at Chicago initiated its activities in 1998, with the following specific objectives: (a) inventory and conservation of of plants of Cuc Phuong National Park in Vietnam and of medicinal plants of Laos; (b) drug discovery (and development) based on plants of Vietnam and Laos; and (c) economic development of communities participating in the ICBG project both in Vietnam and Laos. Member-institutions and an industrial partner of this ICBG are bound by a Memorandum of Agreement that recognizes property and intellectual property rights, prior informed consent for access to genetic resources and to indigenous knowledge, the sharing of benefits that may arise from the drug discovery effort, and the provision of short-term and long-term benefits to host country institutions and communities. The drug discovery effort is targeted to the search for agents for therapies against malaria (antimalarial assay of plant extracts, using Plasmodium falciparum clones), AIDS (anti-HIV-l activity using HOG.R5 reporter cell line (through transactivation of the green fluorescent protein/GFP gene), cancer (screening of plant extracts in 6 human tumor cell lines - KB, Col-2, LU-l, LNCaP, HUVEC, hTert-RPEl), tuberculosis (screening of extracts in the microplate Alamar Blue assay against Mycobacterium tuberculosis $H_{37}Ra\;and\;H_{37}Rv),$ all performed at UIC, and CNS-related diseases (with special focus on Alzheimer's disease, pain and rheumatoid arthritis, and asthma), peformed at Glaxo Smith Kline (UK). Source plants were selected based on two approaches: biodiversity-based (plants of Cuc Phuong National Park) and ethnobotany-based (medicinal plants of Cuc Phuong National Park in Vietnam and medicinal plants of Laos). At mc, as of July, 2001, active leads had been identified in the anti-HIV, anticancer, antimalarial, and anti- TB assay, after the screening of more than 800 extracts. At least 25 biologically active compounds have been isolated, 13 of which are new with anti-HIV activity, and 3 also new with antimalarial activity. At GSK of 21 plant samples with a history of use to treat CNS-related diseases tested to date, a number showed activity against one or more of the CNS assay targets used, but no new compounds have been isolated. The results of the drug discovery effort to date indicate that tropical plant diversity of Vietnam and Laos unquestionably harbors biologically active chemical entities, which, through further research, may eventually yield candidates for drug development. Although the substantial monetary benefit of the drug discovery process (royalties) is a long way off, the UIC ICBG program provides direct and real-term benefits to host country institutions and communities.

• Journal of Sericultural and Entomological Science
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• no.11
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• pp.31-44
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• 1970

This experiment is conducted fer method cf bring to perfectly from defective cutting sapling 25 a production method of sapling which is to substitute for conventional graf ting. 1. In green wood cutting root comes out after 15 days of cutting with nearly straight development of root system; after 40 days of cutting, roots with total length of 1119 mms 43 roots, and 5.4 grs a root in total weight obtained. 2. Survival percentage of green wood cutting ranges between 56％ and 90％, average 73％ of that and it varies with natural characteristics of varietes. The results show variety of Gaeryang-Suban and Iljiroe with 80％ as a best ones in contrast with the variety of Shipyung. 3. The varietics or Gaeryang-Suban. Iljiroe, Suwon-Sang No.4, Rosang makes of much more roots than Yongchonchuwoo and Shipyung do. 4. Root ability made good number of roots commercially, when cutting is conducted soaking in 0.01 ％ NAA solution or 0.02％ NAA solution for 2 or 3 seconds as a chemical promoter. 5. Economical measures for increase of scion adapted 1) 2 scions from a green wood 50 cm long should be taken and basal pan of scion at its middle portion should be cut right under the node. 2) Scions below 50cm long may be used. Small scions or growthceased shoots h3ve also considerable root ability enough to be used. 3) Thus far, up 100,000 scions might be produced in 10 a. 6. We can find number of root increased, when cutting the opposite side in obliquity manner at 450. 7. When 110,000 saplings in 10 a. for the production of bring to perfectly from defective cutting sapling planted, quality of stocks does not go to bad condition without any obstacles in practical use. 8. Although the times or grafting delayed until middle of July, quality of sapling goes just a little down. Grafting may be conducted from early June to middle of July separately in several times, and the green wood of prunned mulberry in spring is available for a scion after end of June. 9. 10 grs weight of defective cutting sapling makes 95％ of complete sapling, otherwise 5 or 10 grs in weight of one becomes 80％ of complete sapling with its quality as similar as grafted one. 10. When the sapling planted, its branches should be cut, leaving 3 or 4 buds at the bottom of new branches. 11. In view of economical stand point, production cost of bring to perfectly from defective cutting sapling obtains 52％ of grafting cost.

• Journal of Sericultural and Entomological Science
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• v.15 no.1
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• pp.37-48
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• 1973

The purpose of this studies is to improve the cohesion of raw silk through various analyses on cocoon drying, cooking, reeling, re-reeling, and on the properties of water. Also we investigated the correlation between silk testing items which we have reached to the following results. 1. Drying of cocoon When cocoons were slowly dried with 100$^{\circ}C$, the results of cohesion became much better. On the other hand, the results were considerably decreased in case the temperature with 115$^{\circ}C$. 2. Cooking of cocoon In case of the cooking of cocoon, we found that the result of cohesion was best with incomplete cooking, that of the control was next, while in over cooking, the results were very low. Also the results of cohesion were much better when using the method of over cooking with sericin arrestive agent than that of incomplete cooking with sericin agglutinating agent. 3. Reeling of cocoon A) When the temperature of reeling bath was 25-45$^{\circ}C$, the results of cohesion test were much better, but at the temperature below 25$^{\circ}C$ or above 45$^{\circ}C$, the results became worse. B) With out the process of croissieur, the results of cohesion were too bad, but in case of croissieur more than 1cm, cohesion became better rapidly. Further more, we understood that the results of cohesion were improving slightly with longer length of croissieur. C) When the velocity of reeling was increased, the results of cohesion also improved. The best results were shown when reeling velocity was 180-220 r.p.m. But when the velocity was increased more than 220 r.p.m., the results of cohesion got worse more or less. D) When the temperature of the drying pipe in reeling machine was raised, the results of cohesion also showed a tendency to improve. 4. Re-reeling A) We could net reach a conclusion as to have correlation between the number of dipping repeat in vacuum tank and the results of cohesion before re-reeling process. B) When we used Seracol 500 as an agglutination protective agent with l/1000 to l/2000 of water, the results of cohesion test were better. C) When we used Pearl-lite as an agglutination protective agent with 1/1000 to 1/2000 of water, the results of cohesion were considerably better. D) We gained tile best results when used Cohesion Improving Chemical, A-80, with 500-1500 times diluted. 1) Results of cohesion was improved when humidity was low or temperature was high in the rereeling machine. 5. Filature water A) The water pH near the isoelectric point of protein showed the best cohesion, but the farther water pH, the worser results were obtained. B) With the increasing of M-alkalinity in filature water, the results of cohesion were worse. Above all, we understood the tendency of the results of cohesion get worse when the M-alkalinity is increased above 200 ppm. C) By increasing the total hardness of the filature water, it improved the results of cohesion. Especially, when the total hardness was above 300ppm, the results were extremely high. 6. Effects combination of each results A) The result of effects combination in filature processes with the obtained best conditions was distinctively improved. But the results could not reach in mathematicaly double effect. When reelied under worse conditions, the results of cohesion test were too bad. There was "effect limit" for the promotion. B) Generally the results of cohesion were bad when the filature conditions(the temperature, pressure and the properties of water, etc) are processed as sericin loss to be high. On the other hand, the results were very good when lower sericin loss was controlled in filature conditions. C) When filature conditions such as reeling velocity and croissieur length provide pysical cohesion ability and when raw silk dry fast during reeling and re-reeling, we found the result of cohesion was better. 7. Correlation of silk testing items. A) A negative correlation exists between the results of cohesion test and cleanness defect. Another word, the result of cohesion test was found to be worse as cleanness defect increased. B) In cleanness, cohesion has negative correlation against the number of slugs, but we could not find any correlation against long loops, loose ends. C) Cohesion has negative correlation against average neatness and low neatness defect. The better the results of neatness respectively, the better the results of cohesion found. D) There is no correlation between tenacity and the results of cohesion test, but there was high positive correlation between the results of elongation and those of cohesion test. The more elongation, the better the results of cohesion was found.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.249-254
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• 1992

This research was conducted to investigate the effects of fly ash applications on growth and yield parameters of corn (Zea mays L.), and soil chemical properties. Corn height at silking stage, and height and dry matter ratio at harvesting stage were enhanced by applications of fly ashes derived from bituminous coal and anthracite, respectively. Effects of fly ash treatment on growth parameters of corn were varied with kinds and levels of fly ash application and growth periods, but relatively small without revealing a major negative effect as compared to the control. Yield of corn was increased by applying fly ash of anthracite origin, but other yield components were not influenced negatively by fly ash treatment. Soil total carbon contents, cation exchange capacity, and phosphorus contents of soils sampled after harvest of corn were significantly increased by fly ash treatment, although there were slightly different effects according to kinds and levels of fly ash application. Exchangeable cations of soils were varied within an experimental error range. Phosphorus taken up by corn was enhanced by treating fly ash of the bituminous coal to the soil and there were a positive correlation between phosphorus uptake and soil Phosphorus level. Cation uptake by corn was changed a little, but no significant reduction was observed in cation uptake due to fly ash treatment. It seems to be difficult to figure out the mechanism of fly ash effects on growth and nutrient uptake by corn with one year field experiment, however treatment of fly ash enhanced some parameters of growth and yield, and nutrient uptake by corn without revealing any major negative effects. To determine the value of fly ash as a fertilizer source, continuous researches under various soil and crop conditions were considered to be necessary.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.166-172
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• 2004

When compare with blebectomy or bullaectomy simply and pleurodesis together in treatment of primary spontaneous pnevmthorax, the later has been realized as the method that can reduce the recurrent rate after surgical operation. Therefore, in this study, we compared the merits and demerits of the clinical result of chemical pleurodesis that use Talcum powder in pleurodesis and mechanical pleurodesis that use apical pleurectomy and analyzed the reappearance rate etc. Material and Method: The Pleurodesis through the apical pleurectomy and talc powder insufflation had been used as secondary procedure after blebectomy of spontaneous pneumothorax from January 1, 2000 to June 30, 2002. This study consisted of a retrospective review of 68 patients who were treated with apical pleurectomy, and 84 patients treated with talc powder insufflation. We compaired the apical pleurectomy and talc powder insufflation in terms of age, sex, cause of operation, number of used autosuture staple, tine duration of procedure after blebectomy, severity of pain and complication after operation, postoperative air leakage period, duration of chest tube insertion, hospitalization, and recurrence rate of pneumothorax. Result: Time required for secondary procedure was longer in apical pleurectomy than talc powder insufflation. Postoperative pain was more severe in talc powder insufflation than apical pleurectomy. Otherwise there was no significant difference between two methods. Conclusion: Although Talc powder insufflation is more convenient than apical pleurectomy, the difference is not large and, the severity of postoperative pain is worse in talc powder insufflation. Therefore apical pleurectomy can be recommended for the secondary surgical procedure after blebectomy of primary spontaneous pneumothorax can be recommended.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.1-7
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• 2002

This study was performed to investigate the possibility of water purification by a wild train of Oenanthe javanica DC. Three commercially available dishwashing detergents and a standard surfactant, linear alkylbenzene sulfonate (LAS), were used for this study. The experiment was done in 1.5 ι transluscent aquariums. The plants were distributed into various concentrations of detergents and various kinds of detergent in the separate aquariums. The wet weight of the plants was significantly decreased (p<0.05), and the visual vitality of the plants also decreased in 2 days. The higher the concentration of detergent was, and the more time the plants were exposed to the detergents, the more decrease of growth was observed. The pH value of the culture media decreased in 2 days and in 4 days, then slightly increased in 6 days. However, the pH value of the media did not return to the initial neutral level of pH in 6 days. The pH value of the culture media containing the LAS remarkably increased in 6 days and increased to a neutral pH value in 18 days (p<0.01) as the pH of the other culture media. The chemical oxygen demand (COD) of the culture media gradually increased over the 4 days. A decrease of COD was observed in 6 days, but no tendency was observed between 12 and 18 days. The detergent in the culture media was highly significantly decreased in 2 days (p<0.01) and gradually decreased after this. After 6 days the remaining detergent was 12.4∼23.7% from the various levels of initially added concentration, and 22.4 ∼34.2% from the flour kinds of detergents. These results show that the reduction of detergent was caused by Oenanthe javanica and the effect was significant during the first 6 days when the plants were still growing well. These results indicate that the plant purifies contaminated water for several days and the effect could be variable according to the level of contamination and the environment in which the plant grows.

• Korean journal of food and cookery science
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• v.20 no.4
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• pp.342-351
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• 2004

Rice flour was roasted at different temperatures and times and tarakjuk was made from these roasted rice flours. Chemical composition, in vitro starch digestibility (IVSD) and protein digestibility (IVPD) of the roasted rice flours and tarakjuk were determined. Changes in quality characteristics such as pH, viscosity, IVSD and IVPD of tarakjuk during refrigerated storage were also investigated. For roasted rice non, the protein content ranged from 6.52∼7.13% on a dry basis, while for tarakjuk, the range was 3.74 ∼4.0%. On the other hand, the Ca level of tarakjuk ranged from 1,278.36∼1,340.87 ppm. Rice flours showed decreasing IVSD and increasing IVPD on roasting at 145$^{\circ}C$ and 165$^{\circ}C$, whereas they showed increasing IVSD and decreasing IVPD at 185$^{\circ}C$, respectively. Roasting also influenced the pH, viscosity, IVSD md IVPD of tarakjuk made from these roasted rice flours. As the roasting temperature and time increased, tarakjuk showed lower pH and viscosity, however it showed higher IVSD and IVPD. The pH of tarakjuk, except that of control, decreased with storage, whereas viscosity increased significantly. IVSD decreased up to 4 days of storage, after which it increased again until 14 days of storage. On the other hand IVPD increased up to 7 days of storage, but there was no additional significant increase after 14 days of storage. These results suggest that depending on the nutritional purpose, appropriate conditions for roasting of rice flour and storage of tarakjuk may be recommended for the commercialization of tarakjuk.