• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.76.2-76.2
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• 2013

Advanced electronic application areas have strongly required new materials due to the continuous shrinking dimensions of their devices. Specially, the development and use of metal precursors for atomic layer deposition has been extensively focused on application to electronic devices. Thus the systematic design and synthesis of metal compounds with relevant chemical and physical properties, such as stability, volatility, and resistance to air and moisture are very important in the vacuum deposition fields. In many case, organic ligands for metal precursors are especially focused in the related research areas because the large scale synthesis of the metal complexes with excellent properties exclusively depends on the potential usefulness of the ligands. It is recommended for metal complexes to be in monomeric forms because mononuclear complexes generally show high vapor pressures comparing with their oligomeric structure such as dimer and trimer. Simple metal alkoxides complexes are involatile except several examples such as Ti(OiPr)4, Si(OEt)4, and Hf(OtBu)4. Thus the coordinated atom of alkoxide ligands should be crowded in its own environment with some substituents by prohibiting the coordinated atoms from bonding to another metal through oxygen-bridging configuration. Alkoxide ligands containing donor-functionalized group such as amino and alkoxy which can induce the increasing of the coordinative saturation of the metal complexes and the decreasing of the intermolecular interaction between or among the metal compounds. In this presentation, we will discuss the development of metal compounds which adopted donor-functionalized alkoxide ligands derived from their alcohols for electronic application. Some recent results on ALD using metal precursors such as tin, nickel, ruthenium, and tungsten developed in our group will be disclosed.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.197-206
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• 2002

Volumetric soil water contents through a soil profile were monitored to identify the effects of tillage systems and soil physico-chemical characteristic on soil water movement from the soil profile. Water content profiles under no tillage (NT) and conventional tillage (CT) practices were compared at two commercial farms in central Illinois from 1992 through 1994, using neutron-scattering techniques in weekly intervals during each growing season. The volumetric water content of surface soil layers was affected more by tillage systems and rainfall amounts, whereas that of the subsoil layers was more strongly affected by soil types. Soil water percolated faster through Saybrook and Catlin soils than through Drummer, Flanagan, and Ipava soils because Saybrook and Catlin soils have lower clay content and water-retention capacity and higher permeability than Drummer, Flanagan, and Ipava soils. Increased soil organic matter (SOM) in Drummer, Flanagan, and Ipava soils would be attributable to the higher soil water retention than other soil types. Soil water contents in the corn root zone were consistently higher under CT plots than under NT plots.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.735-739
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• 2007

A thermoacidophilic bacterium was isolated from the compost and designated as Bacillus sp. SJ-15 by physiological and biochemical characteristics. The optimum temperature and pH for growth were at $55^{\circ}C$ and pH 5.0, respectively. The strain SJ-15 was adapted in process of accelerated high-temperature composting of garbage. The highest viable cell count of composting process reached to $9.2{\times}10^9/ml$ in 16 hours. After running times of 100 days, the composting process showed a reduction rate of approximately 88%, and the concentrations of components were sufficiently high or low to satisfied the standard of organic compost except for salinity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.242-247
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• 2017

Humic acid (HA) is a complex organic matter found in the environments, especially in grassland soils with a high density. The bioactivity of HA to promote plant growth depends largely on its extraction sources. The quality-control of HA and the quality improvements via an artificial synthesis are thus challenging. We recently reported that a polymeric product from fungal laccase-mediated oxidation of catechol and vanillic acid (CAVA) displays a HA-like activity to enhance seed germination and salt stress tolerance in a model plant, Arabidopsis. Here, we examined whether HA or CAVA enhances the growth of Italian ryegrass seedling. Height and fresh weight of the plant with foliar application of HA or CAVA were bigger than those with only water. Interestingly, enhanced root developments were also observed in spite of the foliar treatments of HA or CAVA. Finally, we proved that HA or CAVA promotes the regrowth of Italian ryegrass after cutting. Collectively, CAVA acts as a HA mimic in Italian ryegrass cultivation, and both as a biostimulant enhanced the early growth and regrowth after cutting of Italian ryegrass, which could improve the productivity of forage crops.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.248-253
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• 2017

Humic acid (HA) is known to consist of various kinds of polymeric organics, their detailed structures can vary depend on sample sources such as organic manure, composts, peat, and lignite brown coal, and largely exists in grassland soils. HA possesses diverse positive effects that not only increase plant growth but also improve soil fertility. Recently, we have manufactured a co-polymeric product of catechol and vanillic acid (CAVA) synthesized artificially, and found that CAVA as a HA mimic increases seed germination and salt tolerance in Arabidopsis. In this study, we examined whether HA or CAVA affects to seedling growth in alfalfa. Foliar application of HA or CAVA increased alfalfa seedling growth including aerial and in root parts. HA or CAVA dramatically enhanced size of leaf and root, whereas HA significantly displayed higher bioactivity than CAVA. Taken together, CAVA acts like as a HA mimic in alfalfa that could apply as an alternation supplement to enhance plant growth and productivity.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.49-54
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• 2002

This study was conducted to investigate physicochemical and microbiological properties on waste composts of mushroom. The waste compost of mushroom consisted of 43.29% organic matter(O.M.), 27.0 O.M./Nitrogen, 1.60% total nitrogen, 46.48% water content, 0.64% salt content, 1.32% $P_2O_5$ 1.18% $K_2O$ and dry base. The microorganisms in the waste compost of mushroom were counted $1.6{\times}10^{10}cfu/g$. The main population of aerobic bacteria were Bacillus lentimobus, B. coagulans, B. brevis, Clostridium thermocellum, Escherichia coli, Streptomyces thermovulgaris, S. thermofuscus, Micropolyspora faeni, Aspergillus sp. and Penicillum sp..

• Journal of the Korean institute of surface engineering
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• v.16 no.4
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• pp.199-214
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• 1983

Up to this date, numerous methods of analysis of electroplating solutions are published. Some, however, need lots of works before reaching final results, or require high technique and special instruments, and also some are unaccurate due to unclearnes of end point. Like our undevelope countries, technicians of electoplating shops are most high school gradutes or under, and have not much knowledge on chemistry. Furthermore, those technicians have to control their plating solutions by themselves without having enough analytical laboratory equiIJment. Therefore, in this paper the simplest, besides accurate method is investigated after comparing nu.merous methods published. Among the methods of 'copper determinations from acid and alkaline copper plating baths, EDT A titration method are chosen, due to these methods are the simplest and fastest for the evaluation of metal content, without requiring any special instrument. For acid copper solutions, chelate titrations were accurate enough. Since the end point of titration of chelate method is variable according to the kind of .indicators androther metal's coexsistence as well as solution comIJonent, many difficulties were encountered from cyanide' copper, on the contrary of acid copper bath. PAN, PV, and MX indicators were tried, but it is found that MX is the best. In cyanide solution, due to cyanide is the masking reagent, elimination of this component is essential, and finally found that elimination eN- by precipitation with AgN03 solution was the simplest and the most accurate way among others. This method was very accurate for the new plating solutions even coexistence with organic brightners. However used solutions for long months running have to be predetermined the accurate copper value by thiosulfate method from time to time, before chelate titration by means of AgN03 precipitation. Always some constant deviatioJ;ls will be seen according to the solutions nature. Therefore those deviation values have to be compensated each time.

• Resources Recycling
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• v.20 no.2
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• pp.45-53
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• 2011

We devised a procedure for the recovery of silicon and tempered glass from waste photovoltaic (PV) modules using optimized conditions. The tempered glass was recovered without any damage using organic solvents. The surface material is removed by applying an acid solution on the surface of the PV cell. Through our proposed method, we offer a much more efficient approach for recycling solar cells with a surfactant than the conventional method. This process, we obtained pure silicon with a yield of 90% by chemical treatment with the surfactant at room temperature for 18 min. The silicon yield was characterized using an inductively coupled plasma-atomic emission spectrometer.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.262-270
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• 2015

The scientific information between microbial community and chemical properties of reclaimed tidal soil is not enough to understand the land reclamation process. This study was conducted to investigate the relation between chemical properties and microbial activities of soils from reclaimed tidal lands located at south-western coastal area (42 samples from Goheuong, Samsan, Bojun, Kunnae, Hwaong and Yeongsangang sites). Most of the reclaimed soils showed chemical characteristics as salinity soil based on EC. Only $Na^+$ in exchangeable cation was dependent on EC of reclaimed soil, whereas other cations such as $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were independent on EC. The mesophilic bacteria decreased with an increase in EC of soil. Microbial population increased with soil organic content in the range of $0{\sim}10g\;kg^{-1}$ and dehydrogenase activity less than $100{\mu}g-TPF\;g^{-1}h^{-1}$. Microbial population of soils from reclaimed tidal lands was closely related to the microbial community containing hydrolytic enzyme activities of cellulase, amylase, protease, and lipase.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.623-633
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• 2017

Food waste has been recognized as a organic sources for composting and many research was conducted to efficiently utilize or treat. This study was to evaluate a feasibility for producing food waste compost under co-composting with mixture of food and animal waste. The mixing ratio of food and animal waste was 35% as main material, which additionally mixed 30% of sawdust for co-composting. Total days of composting experiment were 84 days and each sub samples were collected at every 7 days from starting of composting. Results showed that inner temperature in composting was rapidly increased to $70{\pm}4^{\circ}C$ within 3~5 days depending on mixing animal waste of cattle, pig, and chicken base compared to sole food waste base. Expecially, the CN ratio in the mixture of food and pig water was the highest (16.2) among compost. After finishing composting experiment, maturity was evaluated with solvita and germination test. Maturity index (MI) of the mixture of food and animal waste was ranged between 6~7, but was 3 in sole food waste. Calculated germination index (GI) was at the range of about 100 irrespectively of mixing of food and animal waste. However, NaCl content and heavy metal as Cr, Cu, Ni, Pb, and Zn contents was increased in the mixture of food and animal waste. which was the highest in compost mixed the food and pig waste. Both MI and GI showed that manufactured fertilizer was suitable for fertilizer criteria while sole food waste was not adequate for composting due to composting periods. Overall, mixing the food and animal waste can be utilized for improving compost maturity, but more research should be conducted to make high quality of food waste compost with animal waste in agricultural fields.