• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.205-212
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• 1979

Red pepper paste were prepared by using various raw materials such as rice, glutinous rice, polished barley, polished wheat and corn powder, and their chemical compositions including reducing sugar, amino-N and ethanol were analyzed during the period of aging in order to elucidate effects of these starchy materials on the compositions and qualities of the products. The results obtained are summarized as follows: 1) Koji of these materials were manufactured respectively by inoculating a strain of Asporyzae and their activities of protease and saccharifying amylase were determined. Wheat koji was found to have the highest level of protease activity among the koji, while glutinous rice koji had the strongest amylase activity. 2) Contents of moisture, crude protein, crude fat, and sodium chloride in the red pepper pastes were not changed significantly, however total sugar content was decreased during the period of aging. 3) After 60 days of aging, the highest amount (160mg%) amino nitrogen was detected in the red pepper paste of polished wheat, but higher levels of reducing sugar and ethanol contents were detected in that of glutinous rice. 4) Amino acids in the products were analyzed after 60 days of aging: a) Total 17 amino acids were detected. b) Free amino acid ratio to total amino acid content was approximately 35 percent in average. c) Free glutamic acid was higher than any other free amino acid In the amount and free ratio, but free methionine was lower. d) Lysine content was relatively high, while histidine and glycine were detected in trace. 5) Sensory tests including color, odor and taste on the products resulted in the highest mark for the red pepper paste of glutinous rice but in the lowest mark for that of corn powder.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.557-562
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• 1999

The reaction properties of Pd. Pd-Ce and Pd-La catalysts supported on ${\gamma}-Al_2O_3$ were investigated in the oxidation reaction of methane($CH_4$) exhausted from the compressed natural gas vehicle in a U-tube flow reactor with gas hourly space velocity of $72,000h^{-1}$. The catalysts were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), BET surface area and hydrogen chemisorption. Pd catalyst prepared by $Pd(NO_3)_2$ as a palladium precursor and calcined at $600^{\circ}C$ showed the highest activity for a methane oxidation. Catalytic activity of calcined $Pd/{\gamma}-Al_2O_3$ in which most of palladium was converted into palladium oxide species was higher than that of reduced $Pd/{\gamma}-Al_2O_3$ in which most of palladium existed in palladium metal by XRD. As increasing the number of reaction cycles in the wide range of redox, the catalytic activity of $Pd/{\gamma}-Al_2O_3$ was decreased and the highly active window became narrower. Lanthanum oxide promoted Pd catalyst, $Pd/La/{\gamma}-Al_2O_3$ showed enhanced thermal stability compared with $Pd/{\gamma}-Al_2O_3$ even after aging at $1000^{\circ}C$, which was ascribed to the role of La as a promoter to suppress the sintering of palladium metal and ${\gamma}-Al_2O_3$ support. Almost all of methane was removed by the reaction with NO at the redox ratio of 1.2 in case of oxygen excluded steam, but that activity was significantly decreased in the steam containing oxygen.

• The Journal of Engineering Research
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• v.8 no.1
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• pp.31-50
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• 2006

Shrinkage may cause cracking in concrete. In practice such cracking must be considered in most concrete applications because, under normal conditions, drying of the concrete is unavoidable, and when drying takes place shrinkage occurs. Cracked concrete is an inferior concrete because it is weaker, more permeable, and more susceptible to chemical attack. The development of the strength of LAC with aging depends on a few factors such as type of the cement, W/C ratio, curing conditions and periods. The higher the strength of LAC, the lower the possibility of shrinkage cracking. Hence, the strength of LAC in the hypocaust system depends to a large extent on the effect of cracking decrease of the antifoaming rate to drying shrinkage in cement.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.203-210
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• 2004

Consolidation properties were analysed by means of depositional environments. Depositional environments including geochemical properties, porewater chemistry, sediment structures, particle size distributions and carbon age dating were analysed using undisturbed samples retrieved successively from a boring hole in the study area. Laboratory oedometer tests and anisotropic consolidated triaxial tests(CKoUC) were performed to examine the overconsolidation phenomenons. Based on the carbon age dating results and profiles of geochemical properties, porewater chemistry, salinity and pH, it was founded that the upper silt/clay complex layer was deposited under marine condition while sand and clay layers were deposited under fluvial condition. Planar laminated structures of silts and clays were dominant in marine deposits. Although there was no clear evidences that geological erosion had been occurred in marine deposits, overconsolidation ratio obtained from oedometer tests were greater than unity. Stress paths of samples behaved similar to those of normally consolidated clays. Data plotted in stress state charts proposed by Burland(1990) and Chandler(2000) showed that the marine deposits were geologically normally consolidated. These apparent overconsolidations can be explained by the fabric and chemical bonding due to the difference of the rate of deposition.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.26-33
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• 2008

In order to fully understand the chemical properties of Asian dust particles, especially their transformation and aging processes, it is desirable to investigate the nature of original sands collected at local source areas in China. This study presents the detailed properties of sands collected at four different desert regions (Yinchuan, Wuwei, Dulan, and Yanchi) in China. Most of sands have irregular shape with yellowish coloration, whereas some of them show peculiar colors. The relative size distribution of sands collected at Yinchuan, Wuwei, and Dulan deserts exhibits monomodal with the maximum level between 200 and $300{\mu}$, whereas that of Yanchi desert is formed between 100 and $200{\mu}$. The mass concentration ratio of each element to that of Si (Z/Si) determined by PIXE analysis has a tendency towards higher Z/Si ratios for soil derived elements. It was possible to visually reconstruct the elemental maps on the surface of individual sands by XRF microprobe technique. In addition, the multielemental mass concentration could be quantitatively calculated for numerous spots of desert sands.

• Analytical Science and Technology
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• v.32 no.3
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• pp.113-119
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• 2019

Enhancement of footwear impressions in urine on the surface of tiles by using p-dimethylaminocinnamaldehyde (DMAC), which react with urea, and ninhydrin, 1,8-diazafluoren-9-one (DFO), 1,2-indanedione/zinc (1,2-IND/Zn), which react with amino acid, was studied. As a result of comparing the application methods of reagents, the ninhydrin and the 1,2-IND/Zn were suitable for application with spray method, which is spray directly on footwear impression, DFO and DMAC were suitable for application with dry contact method, which is applying heat with press to DMAC impregnated paper on footwear impression. In addition, DMAC applied with dry contact method showed best contrast and enhancement result in both white and black colored tiles by comparing of the sensitivity by different dilution ratio of urine and the aging time of footwear impressions in urine. And the result of applied with DMAC (with dry contact method) on the floor tiles collected at various places in a building's men's and women's bathrooms, it can be successfully enhanced that footwear impressions in urine. So it is believed that the method can be used to recover footwear impressions in urine from real crime scenes.

• Elastomers and Composites
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• v.36 no.4
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• pp.225-236
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• 2001

In order to improve the properties of the copolymer and the terpolymer that was used as removal-type pressure sensitive adhesive(PSA), we synthesized quaterpolymer with the variation of the types of monomer, initiator, and solvent, and concentration, the monomer/solvent ratio, reaction temperature and time. and determined the properties of this adhesive: the viscosity, molecular weight, conversion, solid content and structure of polymer. The prepared polymer was crosslinked by changing the type of crosslinking agent and concentration, and then we investigated the characteristics or adhesive such as peel adhesion, shear adhesion, heat resistance, weathering resistance and peel adhesion to aging. The optimum performance of RA/2- EHA/MMA/2-HEMA as a PSA were obtained when benzoyl peroxide was used as an initiator with the reactant mixture consisted of 80% BA and 2-EHA, 15%, MMA, and 5% 2-HFMA. The optimum reaction temperature and time were $80^{\circ}C$ and 8 hours, respectively. For BA/2-EHA/MMA/AA, the optimum performance was obtained when the polymerization was performed at the monomer composition of 80% BA/2-EHA, 15% MMA, and 5% AA. BPO was used as initiator and the optimum reaction temperature and time were identical to those of BA/2-EHA/MMA/ 2-HEMA. Isocyanate and melamine were used to crosslink BA/2-EHA/MMA/2-HEMA and BA/2-EHA/MMA/AA, respectively. No effect on the type of cross-linking agent on the peel adhesion was observed with aging. The quarterpolymers crosslinked with melamine left residues on the counter surface after weathering resistance test, while the polymers crosslinked with isocyanate did not.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.351-360
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• 1992

In order to improve the qualities of Doenjang were investigated on the enzyme activity in the koji and changes in chemical composition, flavors and sensory envaluation of Doenjang which were prepared with Rh. delemar koji, Asp. oryzae koji and traditional Meju with mixed koji and soybean as the ratio of optimum mixture. Asp. oryzae koji was indicated highest activities ${\alpha}$ and ${\beta}-amylase$ as 312 mg/ml, 235 mg/ml while Rh. delemar the lowest activities as 16 mg/ml, 38 mg/ml in aging for 40 days amino type ntrogen was the highest in the Asp. oryzae and Rh. delmear mixture koji(D group), Asp. oryzae(A group), and Asp. oryzae koji and Rh. delemar koji(C group) as 460 mg%, 440 mg% and 426 mg% in aging for 40 days. The main flavor components of Doenjang were detected as fellows phenol-2-kmethoxy, 4H-pyran-4-one-3-hydroxy-2-methyl, benzenthanol, 1-octan-3-ol, tetra-methyl pryrazine, 1,3,6 cyclooctatrien. Asp. oryzae(A) and Asp. oryzae koji with Rh. delemar koji mixture(C), group were the most excellent in taste, flavor color for fermented Doenjang at 40 days.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.639-647
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• 1998

Al-containing titanium silicalite-1 ([Al]-TS-1) catalyst was prepared hydrothermally, and the effects of synthesis parameters such as silica/alumina sources, $SiO_2/TiO_2$ ratio, and aging treatment were investigated. The structure, crystal size, and shape were examined by XRD and SEM, and the extent of titanium incorporation into the zeolite framework was examined using UV-vis DRS spectroscopy. For [Al]-TS-1 catalyst preparation, aging of ca. 24h was essential, and the faster crystallization rates were achieved with Cab-O-Sil than with Ludox or TEOS as a silica source. In addition, the higher crystallinity and faster crystallization rate were obtained using sodium aluminate as an aluminum source. 2-butanol oxidation using $H_2O_2$ as an oxidant was carried out to confirm the redox property of the [Al]-TS-1. Acid sites catalyzed toluene alkylation study indicated that lattice titanium species in [Al]-TS-1 weakened the acid strength, and the para-ethyltoluene selectivity was enhanced as a results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.637-642
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• 1996

This study was carried out to investigate the change of palatability improvement of cooked meat by the physico-chemical properties and sensory characteristics as aging at $3^{\circ}C$ after thawing of frozen Holstein tenderloin. Shear force value(SFV), myofibrillar fragmentation ratio(MFR), appearance of 30ki1o dalton (30KD) component, raw meat aroma, tenderness, palatability of cooked meat, content of free amino acid and ATP related compound were measured. Raw meat aroma (p< 0.01), tenderness(p<0.05), SFV(p<0.05), MFR(p<0.01) and 30KD(p<0.001) of unfrozen beef tenderloin aged at $3^{\circ}C$ were superior than frozen beef tenderloin. As aging at $3^{\circ}C$ after thawing of frozen beef tenderloin SFV(p<0.05) decreased, MFR(P<0.001) and 30KD(p<0.001) increased, and raw meat aroma and tenderness improved(p<0.05). Also, cooked meat aroma, texture and palatability improved(p<0.05), without changing the taste. The content of aspartic acid and leucine of tenderloin aged thawing of frozen beef abounded were more than frozen beef(p<0.05), concentration of IMP(P<0.05) decreased, the hypoxanthine(p<0.05) and inosine increased.