• Journal of the Korean Ceramic Society
• /
• v.34 no.12
• /
• pp.1227-1234
• /
• 1997

ZnO thin films were prepared by rf-magnetron sputter at various conditions. Crystallinity, microstructure, chemical composition, and optical composition, and optical properties of the films were investigated as functions of substrate temperature (R. T.-50$0^{\circ}C$) an sputter gas (O2/Ar=0-50%). ZnO thin films grown at 50$0^{\circ}C$ with sputter gas of pure argon as well as at R. T. with sputter gas of a mixture of argon & oxygen(O2/Ar=2%) exhibit a strong tendency of (002) preferred orientation, compared with a considerable random orientation at the other conditions. The thin films with (002) preferred orientation has a chemical stoichiometry of Zn/O-1.01, a band gap of 3.3eV, and a packing density of 98% respectively.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.10a
• /
• pp.43-47
• /
• 2011

In woody waste separated from municipal solid waste, medium density fiberboard was major contributors with particleboard, paper, plywood and log, with different composition based on collected period. In chemical compositional analysis of woody waste, it was similar to softwood based on carbohydrate composition analysis. Based on the carbohydrate composition, saccharified solution from MWW could be good resource for biorefinery.

• Journal of Forest and Environmental Science
• /
• v.26 no.2
• /
• pp.75-82
• /
• 2010

The biometry, morphological properties and chemical composition of bagasse, corn, sunflower, rice, and rapeseed residues plants were analyzed. The results revealed differences in biometry properties and chemical composition of the different types of agricultural resides investigated. The greatest proportion of fiber length (1.32 mm) and cellulose (55.56%) was found in residues of bagasse plants, with a low ash (1.78%) and lignin (20.5%). The lignin of all types of agricultural resides was less than hardwood and softwood. In addition, the rice and rapeseed residues plants had highest amount of ash and extractive component. The slenderness and flexibility ratios of the all types of agricultural resides fibers were similar to some of hardwood and softwood species.

• Journal of Adhesion and Interface
• /
• v.18 no.2
• /
• pp.68-74
• /
• 2017

Epoxy resins are widely used in various fields due to their excellent thermal, mechanical and chemical properties. In order to improve the mechanical properties of the epoxy composition after curing, various materials are mixed in the epoxy resin. Among the nano materials, CNT is the most widely used. However, CNT has limitations in terms of manufacturing process and manufacturing cost. Therefore, there is a growing interest in naturally occurring HNTs having similar structure to that of CNT. In this study, the thermal and mechanical properties of epoxy compositions containing HNTs treated with two types of silane compounds were investigated. The mechanical properties of silane-treated HNT were measured by using a universal testing machine. The differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and thermomechanical analysis (TMA) were used to measure thermal properties. As a result of the above tests, when the HNT was surface-treated with aminosilane, the tensile strength of the epoxy composition containing the HNT was higher than that of the epoxy composition containing epoxy silane treated HNT. The linear thermal expansion coefficients (CTE) obtained from the thermomechanical analysis of the two epoxy compositions for the comparison of dimensional stability showed that the HNT composition treated with aminosilane showed a lower value of CTE than that of epoxy composition including the pristine HNT.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.2
• /
• pp.194-200
• /
• 2014

This study investigated the chemical composition and ruminal degradability of corn stover in three maize-planting regions in Qiqihaer, Heilongjiang Province, China. The whole stover was separated into seven morphological fractions, i.e., leaf blade, leaf sheath, stem rind, stem pith, stem node, ear husk, and corn tassel. The assessment of nutritive value of corn stover and its fractions was performed based on laboratory assays of the morphological proportions, chemical composition, and in situ degradability of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF). The chemical composition of corn stover was significantly different from plant top to bottom (p<0.05). Among the whole corn stover and seven morphological fractions, leaf blade had the highest crude protein (CP) content and the lowest NDF and ADF contents (p<0.05), whereas stem rind had the lowest CP content and the highest ADF and acid detergent lignin (ADL) contents (p<0.05). Ear husk had significantly higher NDF content and relatively lower ADL content than other corn stover fractions. Overall, the effective degradability of DM, NDF, and ADF in rumen was the highest in leaf blade and stem pith, followed by ear husk. The results indicate that leaf blade, ear husk, and stem pith potentially have higher nutritive values than the other fractions of corn stover. This study provides reference data for high-efficiency use of corn stover in feeding ruminants.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.7
• /
• pp.935-940
• /
• 2001

To determine the effect of different growth stages and cultivars on the chemical composition of sorghum plant and its morphological fractions, samples of whole plant, leaf and stem of J.S-263, J.S-88 and Hegari cultivars, harvested at various growth stages were drawn for analysis. All the samples were analysed for their dry matter contents and various cell wall components such as NDF, ADF. hemicellulose, cellulose, lignin, cutin and silica. Significant increase in DM contents of whole sorghum plant, leaf and stem was observed with advancing stage of growth. The highest DM content was recorded in leaf fraction of the plant. All the cell wall constituents increased significantly in whole sorghum plant, leaf and stem as the plant matured. The maximum NDF, ADF, cellulose and lignin contents were observed in stem fraction, followed by whole plant. However, the hemicellulose, cutin and silica contents were higher in leaf fraction of the plant. The cultivars were found to have some effect on the chemical composition of whole plant, leaf and stem fractions. The results indicated that plant maturity had a much greater effect on the chemical composition of sorghum plant, whereas it was little affected by cultivars.

• Journal of the Semiconductor & Display Technology
• /
• v.4 no.4 s.13
• /
• pp.1-4
• /
• 2005

The chemical composition and uniaxial compressive stress are varied to observe their effect on the current-voltage characteristics of ZnO based ceramics. The variation of chemical composition produces two kinds of ceramics showing ohmic and nonohmic current-voltage characteristics. The current at a fixed voltage increased with the increase of the compressive stress for both ohmic and nonohmic ceramics. Ceramics showing nonohmic behavior exhibit better reversible return of current-voltage curve when the applied compressive stress is removed from the ceramics than those showing ohmic behavior do. We found an appropriate chemical composition showing linear relation between current and stress at a fixed voltage. The ceramic materials with an appropriate chemical composition can be used as a potential sensing material in pressure sensors.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.1
• /
• pp.6-12
• /
• 2000

This study was performed to investigate the changes in chemical composition of Panax ginseng leaf by harvesting at July, August and September. The levels of crude protein of dried ginseng leaf were decreased from 17.12mg% to 14.26% by harvesting month, however, crude fat contents of dried ginseng leaf were increased slightly from 1.90% to 2.49%. Three kinds of free sugar, i.e. glucose, fructose and sucrose were found in dried ginseng leaf and maltose was not found. Free sugar contents were increased by delaying harvest, but free amino acid were decreased. Total free amino acid was decreased in delayed harvesting month, serine was revealed superior in free amino acid composition, and valine was revealed next order. In minerals, contents of Ca were from 1,306.1mg% to 1,923mg%, that of K were higher than others patricualy as 1,266.9∼1,216.0mg%. The contents of minerals were existence in order of Mg, P, Na, Fe, Mn, Zn and Cu, abundantly. Total vitamin C were present of 391.0∼336.1mg%, and the contents were decreased as delayed as harvesting period despite of the plentiful content. In fatty acid composition of ginseng leaf, the palmitic acid content was as 40% higher than other fatty acids, remarkably.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.12
• /
• pp.3825-3828
• /
• 2013

In this study, the influences of aniline to acid composition were investigated on the electrical conductivity of PANI-PAAMPSA. The ratio of aniline to sulfonic acid groups was optimized for the maximum conductivity of PANI-PAAMPSA. The conductivity is strongly correlated with the electronic structure of PANI-PAAMPSA; the highest conductivity of PANI-PAAMPSA was observed when PANI has the longest conjugation length.

• Journal of Korean Society for Atmospheric Environment
• /
• v.15 no.2
• /
• pp.101-111
• /
• 1999

In previous study, the local trends in dustfall chemistry and deposition were determined and the characteristics of chemical compositions among dustfall, TSP and rainwater were also compared. Based on the previous results, in this study, the effects of sea salts and soil and soil on the chemical composition of dustfall were studied and then the sources of dustfall in Cheju area were tentatively identified by principal component analysis(PCA)