• Particle and aerosol research
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• v.9 no.1
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• pp.31-36
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• 2013

In this study, Mo metal powder was prepared by hydrogen reduction of Mo trioxides with different purity of 2N and 3N grades. We have obtained Mo metal powder with oxygen content of 1450 ppm by hydrogen reduction and subsequent heat treatment for degassing. Using the Mo metal powder, a low-oxygen Mo ingot was prepared by repetitive vacuum arc melting. The oxygen content of the obtained Mo ingot was less than 70 ppm after vacuum arc melting for 30 min. The purity of the Mo metal powder and the ingot was evaluated using glow discharge mass spectrometry. The purity of the respective Mo ingots was increased to 3N and 4N grades from the Mo powder of 2N and 3N grades after the repetitive vacuum arc melting. The low oxygen Mo ingot thus can be used as a raw material for sputtering targets.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.191-202
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• 2001

Experiments were conducted on established grassland sward at Gongiam, Kwangju, and Kyung-gi in Korea from 1995 to 1997. The influence of mineral-N fertilizer or animal manure(AW) on herbage dry matter(DM) yield, N yield, the recovery of AM-N, and soil N and organic matter(0M) content in the mixed sward('potomac' orchardgrass, 'fawn' tall fescue, and 'kenblue' Kentuky bluegrass) was investigated. The treatments were replicated three times in a split plot block design. AM(the main plots) was applied at 200kg N ha ' year ' on each plot. The types of AM were cattle feedlot manure(CFM), pig manure fermented with sawdust(PMFS) and Korea native cattle slurry(KNCS). Three levels of mineral-N fertilizer, as urea, ranging from 0 to 200kg N $ha^{-1}\;year^{-1}$ in 100kg increments, were superimposed on each plot. The fertilizers and AM were applied in two equal dressings(the end of March and middle of November). AM and mineral fertilizer had significant effects(p<0.05) on herbage DM and N yields. Herbage yields in KNCS were higher than those in CFM and PMFS(p

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.43-48
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• 1998

No-tillage silage corn with legume hairy vetch(Vicia villosa Roth, HV) has renewed interest in supply of mineral N, soil erosion control at sloping land and weed control by cover of HV killed. This study was conducted to monitor concentration of soil mineral N ($NO_3^-$ -N + $NH_4^+$-N) and to find out variation of growth, yield and N uptake of silage corn according to quantity of HV cover; HV-removed, 1X-HV, 2X-HV at field of Crop Experiment Station in 1996. HV groM in early spring decreased the mineral N of soil depth 7.5 -22cm before corn seeding. But, killed HV cover increased the concentration of soil mineral N at surface soil (0-7.5cm) up to 45.4mglkg at early growth stage of corn. Dry matter(Dh4) of corn at harvest was lower in W-removed than in Okg FNlha. But DM and N uptake of corn at harvest were increased by quantity of HV-cover increasing liom HV-removed to 2X-HV. Hairy vetch could substitute N fertilizer for silage corn by N mineralized h m HV killed, but reduced early growth and N uptake of corn before silk by reducing soil mineral N of plow layer.

• Ocean and Polar Research
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• v.41 no.3
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• pp.169-181
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• 2019

The purpose of this study is to develop geochemical tracers to identify a specific source desert of mineral dust in China using the published data. In addition, we tested the applicability of these tracers to wet-deposits and soil samples collected in Jeju, Korea. Because of similarity in trace elemental compositions of mineral dust from the major arid regions in China, such as Taklimakan, West Ordos (Badain Jaran), East Ordos (Mu Us and Hobq), East Northern China (Horqin), West Northern China (Gurbantunggut), and Chinese Loess Plateau, there has been limited to the use of geochemical data for source identification. Here we propose the four (4) plots using combination of seven (7) geochemical variables as a source indicator to distinguish one from other source regions in China: $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$, where $_N$ and $\(\frac{Ce}{Ce}\)_N^*$ stand for values normalized to Post-Archean Average Shale composition and Ce anomaly, respectively. Mineral dusts from aforementioned six major deserts are distinguished one from the others by the combined use of these variables. Jeju rock and soil samples form a separate domain from Chinese mineral dusts in all four plots. In contrast, most of Jeju dust samples were comparable with the West Ordos desert (Badain Jaran) domain, indicative of strong influence of Badain Jaran dust in Jeju in spring season when the mineral dust was collected. A weak positive Ce anomaly in Jeju samples implies minimal local contribution. Our study suggests that the combination of $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$ can be used to identify a specific source region of mineral dust in China as well as Jeju mineral particles.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.351-358
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• 2013

A suitable supply of mineral elements into shoot via a root system from growth media makes plants favorable growth and yield. The shortage or surplus of minerals directly affects overall physiological reactions to plants and, especially, strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake and synthesis and translocation of soluble carbohydrates in N, P or K-deficient tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Four-weeks-old tomato plants were grown in a hydroponic growth container adjusted with suboptimal N ($0.5mmol\;L^{-1}\;Ca(NO_3)2{\cdot}4H_2O$ and $0.5mmol\;L^{-1}\;KNO_3$), P ($0.05mmol\;L^{-1}\;KH_2PO_4$), and K ($0.5mmol\;L^{-1}\;KNO_3$) for 30 days. The deficiency of specific mineral element led to a significant decrease in its concentration and affected the concentration of other elements with increasing treatment period. The appearance of the reduction, however, differed slightly between elements. The ratios of N uptake of each treatment to that in NPK sufficient tomato shoots were 4 (N deficient), 50 (P deficient), and 50% (K deficient). The P uptake ratios were 21 (N deficient), 19 (P deficient), and 28% (K deficient) and K uptake ratios were 11 (N deficient), 46 (P deficient), and 7% (K deficient). The deficiency of mineral elements also influenced on carbohydrate metabolism; soluble sugar and starch was substantially enhanced, especially in N or K deficiency. In conclusion, mineral deficiency leads to an adverse carbohydrate metabolism such as immoderate accumulation and restricted translocation as well as reduced mineral uptake and thus results in the reduced plant growth.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.1
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• pp.15-24
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• 2010

This study was conducted to investigate the effects of swine manure (SM) application with additional nitrogen (N) fertilizer on productivity of corn and environmental pollution in com cultivation soil. The experiment was conformed in lysimeter which was constructed with 30 cm diameter, and 100 cm height. Swine manures used in this study were the compost of swine manure fermented with sawdust (SMFWS) and soft rice hulls treated with high temperature and high pressure (SRH), and swine slurry (SS). The application rates of the additional N, as urea, with swine manure were 50 and 100 kgN/ha on each plot. This study was arranged in completely randomized design with three replication. DM yields in SM treatments with mineral N were increased significantly compared to those in SM treatment without mineral N (zero-mineral N) (P<0.05) and increased as the rate of mineral N application increased (P<0.05). DM yields in SMFWS and SS treatments with mineral 100 kgN/ha showed trends similar to those of chemical fertilizer (control) but higher than those of 50 kg N/ha. DM yields tended to be higher in SMFWS and SS treatments than in SRH treatment. Total N contents in SMFWS, SRH and SS treatments with mineral N were increased, compared with SM treatment without mineral N. N contents in SM treatments with mineral N were lower than those of chemical fertilizer treatment, but N content of chemical fertilizer treatment showed trends similar to that of SS treatments with mineral 100 kgN/ha. $NO_3$-N concentration in SM treatments with mineral N were increased significantly, compared to those in SM treatment without mineral N and in chemical fertilizer (P<0.05). $NH_4$-N concentrations in SMFWS and SS treatments with mineral 100 kgN/ha showed trends similar to those of chemical fertilizer, but higher than those of 50 kg N/ha. $PO_4$-P concentration in SM treatments with mineral N were increased significantly, compared to those in SM treatment without mineral N (P<0.05). $PO_4$-P concentration in chemical fertilizer treatment showed trends similar to that of SS treatments with mineral 100 kgN/ha. The concentrations of $NO_3$-N $NH_4$-N and $PO_4$-P increased as the rate of mineral N application increased (P<0.05). The concentrations of $NO_3$-N $NH_4$-N and $PO_4$-P were highly elevated in the concentrated rainy season in the early stage among experimental period. The maximum $NO_3$-N $NH_4$-N and $PO_4$-P concentrations in the leaching water were 3.46 mg/L, 1.11 mg/L and 0.14 mg/L, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.158-163
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• 1990

This experiment was to study the effect of pure mineral nitrogen fertilizing on seasonal distribution of dry matter yield and the advisable mineral nitrogen amounts on grassland. The results were as follows: 1. With longer regrowth periods the absolute dry matter yields and the nitrogen-efficiences due to nitrogen fertilizing increased substantially, whereas the quality declined at the relatively lesser cutting frequencies. 2. The first cut at 3-cut regimes, the first and fourth cut at 4-cut regimes, and the second and last cut at 5-and 6-cut regimes showed the highest nitrogen-efficiency, respectively. 3. By the sigmaformed process of production curve the most efficient mineral N-dressing rate per ha and cut was calculated: 42-56kg N on the 3-cut areas, 39-55kg N on the 4-cut areas, 38-47kg N on the 5-cut areas and 35-48kg N/ha/cut on the &cut areas. 4. In dependence on site and kind of calculation the economical borders were reached with the following dressings of mineral N/ha/cut: 90-100kg on the 3-cut areas, 70-100kg on the 4-cut areas and 50- 90kg on the 5-and 6-cut areas.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.53-63
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• 1994

In order to investigate the effects of application rates of mineral N and cattle slurry on the dry matter yield of Reed canarygrass grown in different cutting frequency, was was cernpared for the efficiency of N utilization. Annual rates of mineral N and cattle slurry N of 0 (control), 90kg, 180kg, 270kg and 360kg/ha in 3 cuttings, 0, 120kg, 240kg, 360kg and 480kg/ha in 4 cuttings, and 0, 150kg, 300kg, 450kg and 600kg/ha were applied as urea and cattle slurry in 5 cuttings, respectively. The results were summarized as follows: 1. The annual dry matter yields were increased with application rates of mineral N and cattle slurry. The annual dry matter yields of mineral N obtained were 14.4 ton/ha(ranged from 10.46 ton to 16.91 ton/ha) in 3 cuttings, 13.88 ton/ha(ranged from 9.91 ton to 16.53 ton/ha) in 4 cuttings and 15.98 ton/ha(ranged from 12.0 ton to 18.25 ton/ha) in 5 cuttings. The annual dry matter yields of cattle slurry obtained were 12.14ton/ha(ranged from 8.92 ton to 11.79ton/ha) in 3 cuttings, 10.81ton/ha(ranged from 8.92 to 11.79 ton/ha) in 4 cuttings and 12.98ton/ha(ranged from 10.68 ton to 14.85ton/ha) in 5 cuttings. 2. Relative dry matter yield of cattle slurry as compared to mineral N were 84.3%, 77.9% and 81.2% in 3, 4 and 5 cuttings. 3. Average increase in dry matter production(kgDM/kgN) tended to decrease with application rates of mineral N and cattle slurry, and higher cutting frequencies. Average increase in dry matter production obtained were higher values at rates of 30kg/ha/cut in both of mineral N and cattle slurry. Average increase in dry matter production to mineral N were 23.9kg, 18.8kg and 15.2kgin 3, 4 and 5 cuttings, respectively. 4. Average increase in total nitrogen yield(kgTN/kgN) to mineral N obtained were 0.46kg at rates of 60kg/ha/cut in 3 cuttings, and 0.45kg and 0.40kg at rates of 30kg/ha/cut in 4 and 5 cuttings. 5. Average increase in dry matter production(kgDM/kgN) to cattle slurry obtained were 13.7kg and 19.5kg at rates of 30kg/ha/cut in 3 and 4 cuttings, and 9.7kg at rates of 60kg/ha/cut in 5 cuttings. 6. Average increase in total nitrogen yield(kgTN/kgN) to cattle slurry was not concern to the rates of application. Average increase in total nitrogen yield to cattle slurry obtained were 0.11kg, 0.20kg and 0.21kg in 3, 4 and 5 cuttings. 7. Relative average increase in dry matter production of cattle slurry as compared to mineral N were 33.1%, 52.1% and 50.0% in 3, 4 and 5 cuttings. Relative average increase in total nitrogen yield of cattle slurry as compared to mineral N were 28.9%, 51.3% and 55.3% in 3, 4 and 5 cuttings.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.2
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• pp.102-109
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• 1990

This experiment was carried out to study the effect of pure mineral nitrogen fertilizing on dry matter yield of grassland and the advisable mineral nitrogen amounts in long duration under practical conditions at the "Federal Institute for Agriculture in the Alps" in Austria. The application rates were 0, 30, 60,90 and 120 kg N/ha/cut, the cutting regimes 3-, 4-, 5- and 6-cuts/year. In order to explain the nitrogen-profitability were determined that 1 kg pure mineral nitrogen have to produce 8 - 16 kg DM/kg N in dependence on cutting regimes and requiring of nitrogen efficiencies. The results were as follows: 1. With only PK-fertilizaing average dry matter yields from 4.0 to 7.6 tons per ha and year were obtained. 2. Within all applied cutting regimes 60 kg min. Nlhalgrowth have proved to be the most efficient application rate witn 13 - 24 kg DM/kg N in dependent of cutting regimes. Comapred with only PK-treatment the DM yields increased by 3.9 - 4.7 t/ ha nad year. 3. By the sigmaformed process of Input-Output curve the highest marginal yield (the "most efficient" Ndressing rate) per ha and year was calculated: 152 kg N at 3-cut regimes, 204 kg N at 4-cut regimes, 220 kg N at 5-cut regimes and 240 kg N/ha/year at 6-cut regimes. 4. With required efficiencies of 16 and 12 kg DM/kg N 240 - 300 kg N per ha and year respectively would have to be applied at 3-cut regimes; with required efficiencies of 12 and 10 kg DM/kg N at 4-cut regimes the appropriate figures ranged from 320 to 420 kg N/ha and year, at 5- and 6-cut regimes and efficiencies of 10 and 8 kg DM/kg N results of 360 - 460 kg N and 380 - 500 kg N respectively were obtained. 5. At the relatively dry location Piber the highest dressing rates were needed in order to obtain the efficiencies from 8 to 16 kg DM/kg N, about 30 - 60 kg N/ha/year more than at the relatively moist location Admont.ist location Admont.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.774-779
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• 2011

S-N fatigue behavior of cast 304 stainless steel was studied at 25, -50 and $-196^{\circ}C$ and at a stress ratio of -1 in uniaxial and bending loading condition. It was found that the resistance to S-N fatigue was greatly improved with decreasing testing temperature. The normalized S-N fatigue curves by tensile strength at three different testing temperatures matched each other, suggesting that tensile strength determines the S-N fatigue resistance of cast 304 stainless steel at low temperatures. The effects of different loading on the resistance to S-N fatigue of cast 304 stainless steel were quantified. The S-N fatigue curves at 25, -50 and $-196^{\circ}C$ were described by using Basquin's law the relationship between the S-N fatigue curve and the testing temperature was obtained by using a simple regression method.