• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.1
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• pp.29-41
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• 2019

Terrestrial Gross Primary Production (GPP) is the largest global carbon flux, and forest ecosystems are important because of the ability to store much more significant amounts of carbon than other terrestrial ecosystems. There have been several attempts to estimate GPP using mechanism-based models. However, mechanism-based models including biological, chemical, and physical processes are limited due to a lack of flexibility in predicting non-stationary ecological processes, which are caused by a local and global change. Instead mechanism-free methods are strongly recommended to estimate nonlinear dynamics that occur in nature like GPP. Therefore, we used the mechanism-free machine learning techniques to estimate the daily GPP. In this study, support vector machine (SVM), random forest (RF) and artificial neural network (ANN) were used and compared with the traditional multiple linear regression model (LM). MODIS products and meteorological parameters from eddy covariance data were employed to train the machine learning and LM models from 2006 to 2013. GPP prediction models were compared with daily GPP from eddy covariance measurement in a deciduous forest in South Korea in 2014 and 2015. Statistical analysis including correlation coefficient (R), root mean square error (RMSE) and mean squared error (MSE) were used to evaluate the performance of models. In general, the models from machine-learning algorithms (R = 0.85 - 0.93, MSE = 1.00 - 2.05, p < 0.001) showed better performance than linear regression model (R = 0.82 - 0.92, MSE = 1.24 - 2.45, p < 0.001). These results provide insight into high predictability and the possibility of expansion through the use of the mechanism-free machine-learning models and remote sensing for predicting non-stationary ecological processes such as seasonal GPP.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.409-425
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• 2021

Carbon dioxide has been known to be a typical greenhouse gas causing global warming, and a number of efforts have been proposed to reduce its concentration in the atmosphere. Among them, carbon dioxide capture and storage (CCS) has been taken into great account to accomplish the target reduction of carbon dioxide. In order to commercialize the CCS, its safety should be secured. In particular, if the stored carbon dioxide is leaked in the arable land, serious problems could come up in terms of crop growth. This study was conducted to investigate the effect of carbon dioxide leaked from storage sites on soil fertility. The leakage of carbon dioxide was simulated using the facility of its artificial injection into soils in the laboratory. Several soil chemical properties, such as pH, cation exchange capacity, electrical conductivity, the concentrations of exchangeable cations, nitrogen (N) (total-N, nitrate-N, and ammonia-N), phosphorus (P) (total-P and available-P), sulfur (S) (total-S and available-S), available-boron (B), and the contents of soil organic matter, were monitored as indicators of soil fertility during the period of artificial injection of carbon dioxide. Two kinds of soils, such as non-cultivated and cultivated soils, were compared in the artificial injection tests, and the latter included maize- and soybean-cultivated soils. The non-cultivated soil (NCS) was sandy soil of 42.6% porosity, the maize-cultivated soil (MCS) and soybean-cultivated soil (SCS) were loamy sand having 46.8% and 48.0% of porosities, respectively. The artificial injection facility had six columns: one was for the control without carbon dioxide injection, and the other five columns were used for the injections tests. Total injection periods for NCS and MCS/SCS were 60 and 70 days, respectively, and artificial rainfall events were simulated using one pore volume after the 12-day injection for the NCS and the 14-day injection for the MCS/SCS. After each rainfall event, the soil fertility indicators were measured for soil and leachate solution, and they were compared before and after the injection of carbon dioxide. The results indicate that the residual concentrations of exchangeable cations, total-N, total-P, the content of soil organic matter, and electrical conductivity were not likely to be affected by the injection of carbon dioxide. However, the residual concentrations of nitrate-N, ammonia-N, available-P, available-S, and available-B tended to decrease after the carbon dioxide injection, indicating that soil fertility might be reduced. Meanwhile, soil pH did not seem to be influenced due to the buffering capacity of soils, but it is speculated that a long-term leakage of carbon dioxide might bring about soil acidification.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.371-380
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• 2009

This study was conducted to assess effects of supplying different types of nitrogen sources as fertilizers on productivity and feed values of barley and rye as winter forage crops, and ultimately done to get good quality of organic forages with higher fertilization of soil. For barley, N+P+K plots were significantly (P<0.05) higher in annual dry matter (DM) and total digestible nutrients (TDN) yields than other plots. However, cattle manure plots had significantly (P<0.05) higher annual DM and TDN than P+K and non-fertilizer plots. Plots of 50%-cattle manure and mixed sowing with hairy vetch or forage pea were higher than only 50%-cattle manure plot, particularly, these were significantly higher than non-fertilizer, and their crude protein (CP) yields were much higher than other plots. Crude protein contents were significantly higher in N+P+K and 50%-cattle manure slurry plots than non-fertilizer and P+K plots, and plots of mixed sowing with hairy vetch or forage pea in application of 50%-cattle manure had higher CP content than other plots. ADF content was lowest in 50%-cattle manure+forage pea plots, but highest in 100%-cattle manure plots. NDF content was lowest in legumes-mixed sowing, but highest in 100%-cattle manure plots. TDN content was the highest in forage pea plots, and plots of 50%-cattle manure and legumes-mixed sowing had high RFV, but cattle manure plots rich in ADF and NDF content had the lowest TDN and RFV. For rye, plots of 50%-cattle manure+hairy vetch mixed sowing, and N+P+K application had significantly higher annual DM, CP and TDN than other plots except for cattle manure. DM productive efficiency to nitrogen fertilization was markedly higher for cattle manure plots than for chemical fertilizer. This tendency was more conspicuous in plots of 50% cattle manure+legumes-mixed sowing. CP content was higher for N+P+K plot than for all plots, and plots of 50%-cattle manure + legumes-mixed sowing were significantly higher than other plots. On the contrary, forage pea-mixed sowing plot had the lowest ADF and NDF, but TDN and RFV were significantly (P<0.05) higher than other plots. Grass crop cultivation together with legumes by applying livestock manure to soil may lead to higher palatability of livestock, and better quality of forage. Furthermore, cattle manure application increased production yield per ha and CP contents. Thus, when applying forage crops produced by cattle manure application and mixed sowing to organic livestock production, it was conceived that forages produced might become a substitute for foreign organic grain as protein sources.

• The Korean Journal of Nuclear Medicine
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• v.37 no.6
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• pp.382-392
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• 2003

Purpose: Uptakes of Tc-99m MIBI (MIBI) and Tc-99m tetrofosmin (tetrofosmin) in human non-small cell lung cancer A549, multidrug-resistance associated protein (MRP) expressing cell, were investigated in vitro and in vivo. Materials and Methods: Western blot analysis and immunohistochemistry were used for detection of MRP in A549 cells with anti-MRPr1 antibody. Cellular uptakes of two tracers were evaluated at $100{\mu}M$ of verapamil (Vrp), $50{\mu}M$ of cyclosporin A (CsA) and $25{\mu}M$ of butoxysulfoximide (BSO) after incubation with MIBI and tetrofosmin for 30 and 50 min at $37^{\circ}C$, using single cell suspensions at $1{\times}10^6cells/ml$. Radioactivities in supernatants and pellets were measured with gamma well counter. A549 cells were inoculated in each flanks of 24 nude mice. Group 1 (Gr1) and Gr3 mice were treated with only MIBI or tetrofosmin, and Gr2 and Gr4 mice were treated with 70mg/kg of CsA i.p. for 1 hour before injection of 370KBq of MIBI or tetrofosmin. Mice were sacrificed at 10, 60 and 240 min. Radioactivities of organs and tumors were expressed as percentage injected dose per gram of tissue (%ID/gm). Results: Western blot analysis of the A549 cells detected expression of MRPr1 (190 kDa) and immunohistochemical staining of tumor tissue for MRPr1 revealed brownish staining in cell membrane but not P-gp. Upon incubating A549 cells for 60 min with MIBI and tetrofosmin, cellular uptake of MIBI was higher than that of tetrofosmin. Coincubation with modulators resulted in an increase in cellular uptakes of MIBI and tetrofosmin. Percentage increase of MIBI was higher than that of tetrofosmin with Vrp by 623% and 427%, CsA by 753% and 629% and BSO by 219% and 140%, respectively. There was no significant difference in tumoral uptakes of MIBI and tetrofosmin between Gr1 and Gr3. Percentage increases in MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively higher by the time up to 240 min with CsA. Conclusion: These results indicate that MIBI and tetrofosmin are suitable tracers for imaging MRP-mediated drug resistance in A549 tumors. MIBI may be a better tracer than tetrofosmin for evaluating MRP reversal effect of modulators.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.273-284
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• 1996

Embryos and fetuses are more sensitive to various environmental agents than are adults or children. The biological effects such as intrauterine death and malformation are closely connected with prenatal exposure very various agents. The sensitivity of these embryonic/fetal effects depends on the stage of pregnancy. From the viewpoint of fetal development, embryonic and fetal stages can be divided into three stages : Preimplantation, organogenetic and fetal. Each stage corresponds to 0 to 4.5days, 4.5 to 13.5days, and 13.5days of gestation in mice, respectively. Many studies on the biologcal effects of mice irradiated by ${\gamma}-rays$ at various stages during organogenesis and fetal period have been performed. Based on these results, the dose-effect and dose-response relationships in malformations, intrauterine death, or retardation of the physical growth have been practically modeled by the ICRP(International Commission on Radiological Protection) and other international bodies for radiation protection. Many experimental studies on mice have made it clear that mice embryos in the preimplantation period have a higher sensitivity to radiation for lethal effects than the embryos/fetuses on other prenatal periods. However, no eratogenic effects of radiation at preimplantation stages of mice have been described in many textbooks. It has been believed that 'all or none action results' for radiation of mice during the preimplantation period were applied. The teratogenic and lethal effects during the preimplantation stage are one of the most important problems from the viewpoint of radiological protection, since the preimplantation stage is the period when the pregnancy itself is not noticed by a pregnant woman. There are many physical or chemical agents which affect embryos/fetuses in the environment. It is assumed that each agents indirectly effects a human. Then, a safety criterion on each agent is determined independently. The pregnant ICR mice on 2, 48, 72 or 96 hours post-conception (hpc), at which are preimplantation stage of embryos, were irradiated whole body Cesium-gamma radiation at doses of 0.1, 0.25, 0.5, 1.5, and 2.5 Gy with dose rate of 0.2 Gy/min. In the embryos from the fetuses from the mice irradiated at various period in preimplantation, embryonic/fetal mortalities, incidence of external gross malformation, fetal body weight and sex ratio were observed at day 18 of gestation. The sensitivity of embryonic mortalities in the mice irradiated at the stage of preimplantation were higher than those in the mice irradiated at the stage of organogenesis. And the more sensitive periods of preimplantation stage for embryonic death were 2 and 48 hpc, at which embryos were one cell and 4 to 7 cell stage, respectively. Many types of the external gross malformations such as exencephaly, cleft palate and anophthalmia were observed in the fetuses from the mice irradiated at 2, 72 and 96 hpc. However, no malformations were observed in the mice irradiated at 48 hpc, at which stage the embryos were about 6 cell stage precompacted embryos. So far, it is believed that the embryos on preimplantation stage are not susceptible to teratogens such as radiation and chemical agents. In this study, the sensitivity for external malformations in the fetuses from the mice irradiated at preimplantation were higher than those in the fetuses on stage of organogenesis.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.60-77
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• 1973

The non-enzymatic browning phenomenons of red ginseng were studied to identify these compounds which function as the factors for browning. The samples were classified into five divisions; Fresh ginseng, blanched ginseng, sun dried red ginseng, dehydrated red ginseng, and browning accelerated red ginseng respectively, and the various compounds in each of them were analyzed quantitatively and investigated the compounds which were thought to function for browning during the drying and the dehydration processes; the results were as follows. 1. The chemical compositions among five divisions did not show any difference except a) total and reducing sugars, b) total acids, c) water soluble extracts; a) and b) were decreased during the drying process, c) was decreased about 6-7% in red ginseng divisions. 2. Sixteen free amino acids; asp., thr., ser., glu., gly., ala., val., cys., met., ileu., leu., tyr., phe., lys., his., and arg, were identified in each division. Among them the arg, was extremly high. All of the essential amino acids were contained, while generally these amino acids were decreased in drying period and their rates were smaller in dehydrated red ginseng than in sun dried red ginseng. 3. Three kinds of sugars; fructose, glucose and sucrose were identified and other four kinds of unidentified sugars were seperated. The content of sucrose was 80% and all kind of sugars were generally less in red ginseng divisions than in the other two divisions. The decreasing rate of sngars was higher in the sun dried red ginseng than in the dehydrated red ginseng. Especially the decreasing rate of the reducing sugars was high as compared with that of sucrose. 4. Almost all the ascorbic acid was decomposed during the blanching whereas there could'nt be shown any change of the ascorbic acid content during the period of drying. 5. Eleven kinds of volatile acids; acetic acid, propionic acid, acrylic acid, iso-butyric acid, n-butyric acid, isovaleric acid, n-valeric acid, isoheptylic acid, n-heptylic acid, and an unknown volatile acid were identified. They showed a little decrease during the period of blanching perhaps on account of their volatility whereas they were increased in drying period. 6. Six kinds of non-volatile acids; citric acid, malic acid, ${\alpha}-ketoglutaric$ acid, succinic acid, pyruvic acid and glutaric acid were identified. The content of them were decreased during the drying procedures in red ginseng but only that of succinic acid was increased. 7. Three kinds of polyphenols; 3-caffeyl quinic acid, 4-caffeyl quinic acid, 5-caffeyl quinic acid and an unknown polyphenol were identified. The content of them showed considerable decrease during the drying procedures, especially in sun drying. 8. The intensity of the browning in each divisior was as follows; browning accelerated red ginseng> sun dried red ginseng> dehydrated red ginseng. 9. In the process of red ginseng preparation, a. certain relationship could be found between the decreasing rates of amino acids, reducing sugars, polyphenols and the intensity of browning. Therefore the browning phenomenon may be concluded that nonenzymatic browning reactions of the amino-carbonyl reaction and autoxidation of polyphenols are the most important processes, furthermore, as their reactions could be controlled it is thought to be possible to accelerate effectively browning within a relatively short period.

• Applied Biological Chemistry
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• v.9
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• pp.9-27
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• 1968

Studies were carried out in order to elucidate chemical components and microflora in three types of soy-sauce, 12-year aged soy-sauce prepared by improved method. 7-year aged and 20-year aged soy-sauce prepared by ordinary method. They results are summarized as follows: 1. The followings are found to be the important factors affecting the quality of soy sauce. a. Organic acids, reducing sugars and free amino acids were increased in the course of storage. b. In the aged soy-sauces under study non-volatile organic acid increased while volatile organic acid decreased and the total acidity was dependent only upon tie latter. c. It was found that suit concentration decreased during the storage. 2. The results of investigation of microflora in the stored soy-sauce are shown as follows. Soy-sauce Improved Ordinary Microbe 12-Y. 20-Y. 7-Y. Aerobic bacteria colony/1ml. 6 123 2 Halophilic lactic acid bacteria colony/1ml. 4 6 10 Osmophilic yeast colony/1ml. $828{\times}10^4$ 248 - b. In the stored soy-sauces, aerobic bacteria are incapable of growing due to drop in pH value and the influence of salt concentration. c. Halophilic lactic acid bacteria are incapable of growing due to drop in pH value, even the salt concentrations decreased during the storage. d. Osmophilic yeast are still growing in low pH value and in the decreasing salt concentration during the strage. 3. The results of amino acid analysis by paper partition chromatographic and calorimetric methods are shown as follows. a. Fourteen kinds of amino acid and thirteen amino acids were detected in the soy-sauce of 12-year aged improved soy-sauce and 7-year aged and 20-year aged ordinary one, respectively. b. The contents of aspartic acid, glutamic acid, serine, valine, leucine, lysine, histidine and methionine increased in the 20-year aged ordinary soy-sauce compared to the 7-year aged one. On the other hand those of alanine, tyrosine, phenylalanine and cystine decreased. 4. The results of sugar analysis by paper chromatography are as follows. a. In the 12-year aged improved soy-sauce, galactose, glucose, arabinose, xylose, rhamnose, maltose and an unknown were detected, and their amounts were in the above order except maltose and an unknown. b. Both in the 7 and 12-year aged ordinary soy-sauces, galactose, arabinose, xylose, glucose and rhamnose were detected and the amounts of the sugars were in the above order. c. In the non-aged ordinary soy-sauce, glucose was not detected but detected from 7-year and 20-year aged ordinary soy-sauce. 5. The results of organic acid analysis by paper chromatography were as follows. a. As volatile acids, acetic, propionic and butyric acids were detected in the 7-year aged ordinary soy-sauce. On the other hand in both the 20-year aged ordinary soy-sauce and the 12-year aged improved ones, only acetic acid was abundant while propionic and butyric acids were round in trace. It was found that propionic and butyric acids, as the unpleasant flavor components, decreased during the storage. b. In the ordinary soy-sauce, citric acid were produced during the storage and lack, malic and tartaric acids increased in the course of aging while succinic, glycolic, fumaric and malonic acids were shown to decrease. Glutaric and oxalic acids disappeared. Citric acid was produced also in the improved soy-sauce, but lactic, tartaric, succinic, malic, and glycolic acids decreased, while both malonic and glutaric acids disappeared. From the above results the citric acid production was considered to be a favorable factor for the taste. c. In the aged soy-sauces, pyruvic, α-ketoglutaric and probably acetoacetic and oxaloacetic acids (both in trace) were present and their amounts were in the above order. All of the α-keto acid abruptly decreased during the storage.

• Food Science and Preservation
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• v.16 no.6
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• pp.830-837
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• 2009

A total of 24 processed barley samples produced in Korea, 9 split and 15 pressed, were analyzed for protein, $\beta$-glucan, and amylose content whiteness cooking characteristics (water absorption and expansibility) and pasting properties, with respect to the areas in which they were grown. Split and pressed barley products from Japan were compared. Both forms of barley products had similar contents of protein and $\beta$-glucan. Whiteness was higher in pressed barley than in split barley. Split barley produced in Korea had a higher water absorption (342-436%) and expansibility (449-608%) than did pressed barley. Japanese processed barley products were much lower in protein (4.4-6.6%, w/w) and showed a higher whiteness grade than did Korean products. Whiteness of pressed barley ranged from 57.2-68.3 and was higher than that of split barley, but split barley product showed better cooking characteristics than did pressed barley. Japanese products were similar to Korean materials in this respect. A negative correlation was observed between protein content in and whiteness of processed barley products (r=-0.5112, p<0.01). Waxy barley products had a lower pasting temperature, and showed higher breakdown and lower setback than did non-waxy barley products. The pasting properties of Japanese products were different from those of Korean materials. The pasting temperatures of Japanese split and pressed barley were lower, and the setback much higher, than seen with Korean products. The results show that both splitting and pressing efficiently improve the cooking characteristics of barley. The processing of waxy barley was particularly effective.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.154-155
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• 2012

The promise of nano-crystalites (nc) as a technological material, for applications including display backplane, and solar cells, may ultimately depend on tailoring their behavior through doping and crystallinity. Impurities can strongly modify electronic and optical properties of bulk and nc semiconductors. Highly doped dopant also effect structural properties (both grain size, crystal fraction) of nc-Si thin film. As discussed in several literatures, P atoms or radicals have the tendency to reside on the surface of nc. The P-radical segregation on the nano-grain surfaces that called self-purification may reduce the possibility of new nucleation because of the five-coordination of P. In addition, the P doping levels of ${\sim}2{\times}10^{21}\;at/cm^3$ is the solubility limitation of P in Si; the solubility of nc thin film should be smaller. Therefore, the non-activated P tends to segregate on the grain boundaries and the surface of nc. These mechanisms could prevent new nucleation on the existing grain surface. Therefore, most researches shown that highly doped nc-thin film by using conventional PECVD deposition system tended to have low crystallinity, where the formation energy of nucleation should be higher than the nc surface in the intrinsic materials. If the deposition technology that can make highly doped and simultaneously highly crystallized nc at low temperature, it can lead processes of next generation flexible devices. Recently, we are developing a novel CVD technology with a neutral particle beam (NPB) source, named as neutral beam assisted CVD (NBaCVD), which controls the energy of incident neutral particles in the range of 1~300eV in order to enhance the atomic activation and crystalline of thin films at low temperatures. During the formation of the nc-/pm-Si thin films by the NBaCVD with various process conditions, NPB energy directly controlled by the reflector bias and effectively increased crystal fraction (~80%) by uniformly distributed nc grains with 3~10 nm size. In the case of phosphorous doped Si thin films, the doping efficiency also increased as increasing the reflector bias (i.e. increasing NPB energy). At 330V of reflector bias, activation energy of the doped nc-Si thin film reduced as low as 0.001 eV. This means dopants are fully occupied as substitutional site, even though the Si thin film has nano-sized grain structure. And activated dopant concentration is recorded as high as up to 1020 #/$cm^3$ at very low process temperature (＜ $80^{\circ}C$) process without any post annealing. Theoretical solubility for the higher dopant concentration in Si thin film for order of 1020 #/$cm^3$ can be done only high temperature process or post annealing over $650^{\circ}C$. In general, as decreasing the grain size, the dopant binding energy increases as ratio of 1 of diameter of grain and the dopant hardly be activated. The highly doped nc-Si thin film by low-temperature NBaCVD process had smaller average grain size under 10 nm (measured by GIWAXS, GISAXS and TEM analysis), but achieved very higher activation of phosphorous dopant; NB energy sufficiently transports its energy to doping and crystallization even though without supplying additional thermal energy. TEM image shows that incubation layer does not formed between nc-Si film and SiO2 under later and highly crystallized nc-Si film is constructed with uniformly distributed nano-grains in polymorphous tissues. The nucleation should be start at the first layer on the SiO2 later, but it hardly growth to be cone-shaped micro-size grains. The nc-grain evenly embedded pm-Si thin film can be formatted by competition of the nucleation and the crystal growing, which depend on the NPB energies. In the evaluation of the light soaking degradation of photoconductivity, while conventional intrinsic and n-type doped a-Si thin films appeared typical degradation of photoconductivity, all of the nc-Si thin films processed by the NBaCVD show only a few % of degradation of it. From FTIR and RAMAN spectra, the energetic hydrogen NB atoms passivate nano-grain boundaries during the NBaCVD process because of the high diffusivity and chemical potential of hydrogen atoms.

• Korean journal of applied entomology
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• v.15 no.1 s.26
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• pp.7-16
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• 1976

In order to increase utility efficiency of red wood ants, Formica rufa truncicola var. yessonesis Forel as a resource of natural enemy of pine caterpillar, Dendrolimus spectabilis Butler, by finding out ecological and environmental factors in the habitat of red wood ants, the nest distribution and its density in habitat, plant distribution and density, stand-density of red pine, nest building and fixing plants, relative humidity of surface soil, physical and chemical natures of soil, and breeding rate were examined. The obtained results are summarized as follows: 1. The nest of red wood ants was densely distributed, in the lower-and middle top of mountain but no nest was found in the top. 2. The economical distribution of nest of habitat was estimated as $2.85/m^2$ and the lowest density as $1.93/m^2$ and these estimation lead us to confirm that pine caterpillar could be controlled. 3. The ecological characteristics of habitat seemed to be represented as higher stand-density of red pine of 10-20 years of age with large areas of eroded land under trees. The major grasses prevailing in this area were Andropogon brevifolius. Arundinella hirta, Miscanthus purpurasens, Eulia speciosa, Themeda japonica, Cymbopogon goeringii, and Eccoilpus cotulifer 4. Red wood ants seemed to build the nest by using red pine, Arundinella hirta, Miscanthus purpurascens, Themeda japonica or Cymbopogon goeringii as a fixing plant. 5. The limited point of humidity percent in habitat of red wood ants was estimated as $76\%$ during the acting period of May to September and as $72\%$ during pre-period of hibernation of October to November. 6. Soil analysis in habitating region showed higher concentration of organic matters and lower concentration of calcium and magnesium, and habitat was largely composed of silt and fine sand rather than coarse sand. 7. When the separated colony was transplanted to non-habitating red pine forest that seemed to have the similiar conditions as those of habitat, propagation and establishment of nest was possible.