• Korean Journal of Soil Science and Fertilizer
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• v.22 no.3
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• pp.239-244
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• 1989

This work was for the elucidation of heterogeneity in a natural population of Rhizobium japonicum existing in Seoul National University's Experiment Field and of sensitivities of R. japonicum isolates for several antibiotics by using a method based on intrinsic antibiotic resistance (IAR). In addition, the suitability of IAR method for the recognition of R. japonicum strain was elucidated. Twenty seven isolates from various soybean cultivars cultivated at SNU's Experiment Field were tested to 4 antibiotics (streptomycin sulphate, kanamycin sulphate, ampicillin, oxytetracycline);There were 21 different IAR patterns among 27 isolates. It demonstrated diverse distribution of R. japonicum strains in SNU's Experiment Field. Their growth was inhibited at from a low concentration of about $1{\mu}g/ml$ to a high concentration of $400{\mu}g/ml$ for streptomycin sulphate, ampicillin, and oxytetracyclin. For kanamycin sulphate, on the contrary, all 27 isolates showed their growth inhibitances at below the concentration of $12.5{\mu}g/ml$. Two isolates identified as different strains from each other by the previous seroimmunological tests showed the same sensitivities for 4 antibiotics, and it seemed that IAR method was not perfect for the exact recognition of R. japonicum strain.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.437-442
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• 2010

Sodium hydrogen sulphate ($NaHSO_4$), n-tetra butyl ammonium bromide (TBAB) as a phase transfer catalyst (PTC) in water, and 1-butyl-3-methyl imidazolium hydrogen sulphate [bmim]$HSO_4$ as ionic liquid (IL) has been used as a mild reaction promoter for the cyclocondensation of formalin, ${\beta}$-naphthol and aromatic amines to afford respective 2,3-dihydro-2-phenyl-1H-naphtho-[1,2-e] [1,3] oxazine derivatives. The present protocols are greener, high yielding and involved the nonchromatographic isolation procedure.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2926-2936
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• 2021

Rare-earth (RE) industries generate a massive amount of radioactive residue containing high thorium concentrations. Due to the fact that thorium is considered a non-economic element, large volume of these RE processed residues are commonly disposed of without treatment. It is essential to study an appropriate treatment that could reduce the volume of waste for final disposition. To this end, this research investigates the applicability of carbon-based adsorbent in separating thorium from aqueous phase sulphate is obtained from the cracking and leaching process of solid rare-earth by-product residue. Adsorption of thorium from the aqueous phase sulphate by carbon-based electrodes was investigated through electrosorption experiments conducted at a duration of 180 minutes with a positive potential variable range of +0.2V to +0.6V (vs. Ag/AgCl). Through this research, the specific capacity obtained was equivalent to 1.0 to 5.14 mg-Th/g-Carbon. Furthermore, electrosorption of thorium ions from aqueous phase sulphate is found to be most favorable at a higher positive potential of +0.6V (vs. Ag/AgCl). This study's findings elucidate the removal of thorium from the rare-earth residue by carbon-based electrodes and simultaneously its potential to reduce disposal waste of untreated residue.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.1
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• pp.17-23
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• 1981

The effects of potassium chloride and potassium sulphate on the volatilization of ammonia from acidic clayloam and tidal sandy clay loam soils applied with urea under flooded conditions were studied in a laboratory experiment. Results obtained were as follows; 1. The application of potassium to the acidic soil promoted the volatilization of ammonia through increasing soil pH. 2. The application of potassium to urea treated on the tidal soil which lead pH over 8.0 under flooded reduced conditions decreased the wet soil pH and reduced the volatilization of ammonia from the soil. These effects of potassium were more pronounced in the potassium sulphate treatment than in the potassium chloride. 3. More ammonia was volatilized from the acidic soil applied with potassium sulphate, however, the effects of potassium fertilizers applied to the high pH tidal soil seemed to be masked by high salt content of the soil. 4. Urea brought up soil pH significantly. Potassium sulphate was more effective than potassium chloride in raising pH of the acidic soil, though the reverse could be true in the tidal soil with high pH. The reduction of sulphate might be a major cause for the pH change.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.325-329
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• 2004

Ten male buffalo calves (aged 6-8 months, average body wt. $88.5{\pm}0.5kg$) were divided into two groups of five animals in each. All the animals were fed on urea-ammoniated wheat straw (4% urea, 50% moisture) along with concentrate mixture (50:50 on DM basis). In addition animals in group II were given sodium sulphate to see the effect of sulphur on the utilization of nitrogen added through urea-ammoniation. This feeding practice continued for a period of 120 d, during which fortnightly body weights were taken to assess their growth rate. A metabolism trial was conducted after 90 days of feeding to know the digestibility of nutrients and their balance. Results revealed no significant difference in the intake of DM and other nutrients in two groups. The digestibility of DM, OM, EE, NDF, ADF and cellulose was alike in animals fed ammoniated straw and ammoniated straw+sodium sulphate supplemented group, whereas the digestibilities of CP and hemicellulose was significantly (p<0.01) more in group I and II respectively. There was no significant difference in intake of nitrogen, calcium and phosphorus in 2 groups. Similarly, the balance of these 3 nutrients was positive and statistically alike in two groups. Intake and excretion of sulphur through faeces and urine was significantly (p<0.01) more in group II than in group I. Inspite of higher excretion of sulphur through faeces and urine in group II, the sulphur balance was significantly (p<0.05) more in group II than in group I, probably due to significantly (p<0.01) higher intake of sulphur in this group. There was no significant difference in total body weight gain or average daily gain between two groups, indicating that addition of sodium sulphate did not have any positive effect on these parameters. Similarly the intake of DM, DCP and TDN were also alike in two groups. The DCP and TDN values of the two diets were 8.0, 60.4 and 6.8, 56.6% respectively. Feeding cost/unit gain was alike in both the groups.

• Journal of the Korean Wood Science and Technology
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• v.11 no.3
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• pp.23-30
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• 1983

This experiment was carried out for diminishing the material loss and the damage of human life due to the fire disaster by treating plywood with fire retardant chemical solution. At this study, we observed and measured chemical retention, burning point, maximum flame length, flame exausted time, carbonized area, and weight loss of plywood treated by each solution of ammonium sulphate [$(NH_4)_2SO_4$] and monoammonium phosphate [$NH_4H_2PO_4$]. Obtained results at the study may be summarized as follows: 1. In case of monoammonium phosphate-treated plywood, every tested item of fire retardancy was shown more excellent at the 25% chemical concentration and shown also at 9 hours treatment except maximum flame length compared with ammonium sulphate-treated plywood. 2. However in case of ammonium sulphate-treated plywood, 6 hours treatment of fire retardancy was better than 9 hours treating time. 3. Monoammonium phosphate was generally better than ammonium sulphate in every tested item.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.482-487
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• 2007

This study was conducted to investigate the effect of long-term continuous application of fertilizers for rice cultivation. Changes of physical and chemical properties of paddy soil and the rice yield by continuous application of NPK fertilizers, ammonium sulphate, and urea over fifty years, from 1954 to 2003, were investigated. The rice yield index of each treatment were 100 of NPK plots, 84 of ammonium sulphate plots, 81 of urea plots, and 62 of no fertilizer plots. The variance of yield was large according to the quality of irrigation water. Nutrient uptakes by rice plants in ammonium sulphate and urea plots were significantly smaller than those in NPK plots; 86 and 75% in T-N, 79 and 82% in $P_2O_5$, 64 and 58% in $K_2O$, and 94 and 90% in $SiO_2$, respectively. Bulk density of soil in NPK plots significantly decreased compared to those in no fertilizer, ammonium sulphate, and urea plots, whereas CEC in NPK plots increased compared to other plots. Soil pHs of all plots were higher than that before experiment which was 5.2; 6.0 in no fertilizer, 5.9 in urea and NPK, and 5.4 in ammonium sulphate plots. The available phosphate in soil increased by $2.5mg\;kg^{-1}\;yr^{-1}$ when $70kg\;ha^{-1}$ of P fertilizer applied for rice cultivation, and decreased by $1.8mg\;kg^{-1}\;yr^{-1}$ when no P fertilizer applied.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.69-73
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• 2001

The effect of topical application 100,300 and 500 $\mu$g/ ml with Mineral Salts of magnesium sulphate and potassium nitrate on economic parameters was ana- lyzed following treatment of last larval stadium. The treated larvae showed significantly decreased larval weight and silk gland weight in all the treated groups along with other decreased Iarval, cocoon and adult parameters. The female cocoon weight was significantly decreased in all the treated groups with decreased female cocoon shell weight and male cocoon weight at 300 and 500$\mu$g/ml respectively. The length and weight of filament was significantly decreased at 300 and 500 $\mu$g/ml respectively and denier at 500 $\mu$g/ ml. The fecundity decreased significantly in 300 and 500 $\mu$g/ml treated groups when compared with the corresponding parameters of the carrier control.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.3
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• pp.197-202
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• 1991

It is observed that the outbreak of dust storms (yellow sand) from Northern China and Mongolia occurs a few times in April 1988 and 1990. It is found that a dust storm initiated with strong gusty winds after the passage of a cold front, particularly after defrost of the ground surface of a source region in the early spring. According to meteorological chart, satellite images and trajectory analyses, dust clouds invaded Korea in April 1988 and 1990 were landing in the sink area after 2 $\sim$ 4 days travelling for 2,000 $\sim$ 3,000 km from a source region. It was also observed that in the west coast total suspended particulated (TSP) were 100 $\sim$ 200 $\mug m^{-3}$ and sulphates $(SO_4=)$ were 3 $\sim$ 10 $\mug m^{-3}$. These values clearly exceed the concentrations of a background level measured in the Arctic and Atlantic Ocean. Trajectory analyses and meteorological analyses suggest that the high values occurred with prevailing westerly flows coming from anthropogenic sources in China. High concentrations of air pollutants occurred in the backside of an anticyclone and in the area "col".col".uot;.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.64-69
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• 1999

Slags are by-products of the metallurgical industry. The most important slag from the standpoint of the quantity used as building material is iron blastfurnace slag. Slags are either crystalline stable solid used as aggregates or glassy material used as hydraulic binder. Slag cements are low heat of hydration cements. Slags react more slowly with than portland cement but they can be activated chemically. Activatiors can be either alkaline activators such as soda, lime, sodium carbonate, sodium silicate or sulphate activators such as calcium sulphate or phosphogypsum. So, in this study slaked lime was used as an activator that the compressive strength of this modified cement(M1 type) is high range in early age. And initial setting time of M1 type cement was shorter than conventional cements.