• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.403-411
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• 1999

The steel plate for shadow mask is used in a Cathode-ray tube of TV monitor and is the strictest product in surface quality because hundreds thousand of holes are perforated in a plane of 25 ${\times}$25 inches. To mass-produce this product, a reversible cold rolling mill for silicon steel was used and the rolling technology and the activity for quality improvement are described in this work. Because the steel plate is a mild steel, which is very sensitive to strip-breakage even in a low tension, we reset the minimum tension values matching to the operating conditions. The roll mark due to the multi-segmented araangement of shape controlling roll was prevented by hardening the intermediate shape controlling roll and by changing the existing working-roll into a HSS (Hig Speed Steel) roll. The scratch caused by the speed difference between a idle roll and a strip was prevented by increasing the roll roughness. With these activities, the steel plate for shadow mask can be stable. The continuous improvement of quality is, however, required for the customer satisfaction both of domestic and overseas market.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.112-117
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• 2002

This study was conducted to induce the optimal composting conditions of pig manure mixed with sawdust and dried paper-mill sludge in the composting for production of high quality compost. Pig manure contains high water content and How C/N ratio because of comparatively high nitrogen content than sawdust and dried paper-mill sludge. Therefore the addition of dried paper-mill sludge and sawdust to the raw materials helps controlling the C/N and the water content of compost pile. The composting system used in the experiment was agitated static bed system. The physical properties of the mixed raw materials was not good at the working conditions in the early stage of composting. The temperature of compost heap reaches at $60^{\circ}C$within 5 day after starting composting in P-2 treatment mixed with pig manure and sawdust(56.6 : 43.4). Then the water content of P-2 was 58%. The pH in all treatments were slowly decreased as the composting was proceeded. Although the changes of T-C and T-N were not extended because of the short composting experiment period. Reduction rates of T-C in treatments were 5-12% without special difference. By considering the efficiency of composting in each of five treatments with pig manure the optimal water contents was about 57% level. Mixing a sawdust as a bulking agent was more positive than dried paper-mill sludge from a viewpoint of compost quality.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.05a
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• pp.57-62
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• 2002

• Journal of Ginseng Research
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• v.26 no.2
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• pp.79-84
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• 2002

In this study, cell cracker method as a non-collision method was evaluated for the possibility in manufacturing red ginseng powder. In color value of red ginseng powder, the L values indicating brightness were 68.18 for hammer mill (group A) and 72.08 for cell cracker (group B). The a values (redness) and b values (yellowness) were 4.21 26.56 for group A and 5.73, 28.36 for group B, respectively. As an extraction time increased, the absorbances at 420 nm of water extract of both groups were increased. In the loose bulk density, tapped bulk density and volume reduction radio indication the of powder in group A were less than those in group B. In both groups, the angles of side of red ginseng powder were shown less value than the angles of side of the powder. These two angles in group A were lets than those in group B. In sensory evaluation, the touchness between both groups was, not observed significant difference. In the contrary, the color and flavor, main factors affecting the overall quality of red ginseng powder product of group B were shown superior to those of group A. The overall preference of group B was shown higher than that of group A.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.38-47
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• 2002

Machining quality has been improved with the development of cutting tools. However, it is difficult to obtain a high degree of quality in machining a deep pocket with a long end mill, since machining accuracy is mainly dependent on the stiffness of the cutting tool and tool holder. To improve machining quality in machining a deep pocket using an end mill, the performance by cutting condition compare with others. Owing to this problem, it is necessary to select suitable tool and holder in the deep pocket machining. In this study, the hydraulic holder for the high speed machining is introduced and the performance of that is compared with others according to cutting conditions. The cutting parameters involved were; slenderness ratio in the range of 3 to 6 (L/D), radial depth of cut from 0.01 to 0.05 mm. Cutting force and surface roughness, precision of form were observed during the experiment to investigate cutting state.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.225-229
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• 2003

When hot strip is trimmed in the side trimming process at the entry side of tandem cold rolling mill, due to bad quality of trimming face and burr, product quality(saw ear)becomes so bad that it causes drop of yield and claim from customers. Therefore, it was examined that applying ultrasonic vibration is an effective method to improve quality of strip trimming face and decrease burr magnitude by decreasing shear force acting between strip trimming face and knife in side trimming process of cold rolling.

• Environmental Engineering Research
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• v.24 no.2
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• pp.263-270
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• 2019

Palm oil mill effluent (POME) is the largest pollutant discharged into the rivers of Malaysia. Thus UF membrane study was conducted to investigate the effect of pressure and stirring speed on performance of POME treatment and fouling of membrane. Two types of membrane polyethersulfone (PES) and regenerated cellulose (RC) with molecular weight cut-off (MWCO) 5 and 10 kDa were used in this study. Results showed that, as pressure increased, fouling increased however permeate quality improved, the best pressure was 1.0 bar, where the fouling was not too high and produce good permeate quality. As stirring speed increased, fouling reduced and permeate quality improved, however, when stirring speed increased from 600 rpm to 800 rpm, there was no significant improvement on the permeate quality. Therefore, the best condition was at 1.0 bar and 600 rpm. PES membrane with MWCO 5 kDa showed the best permeate quality, even fouling slightly higher than RC membrane. The permeate quality obtained were analyzed in term of dissolved solid, turbidity, suspended solid, biological oxygen demand ($BOD_5$) and chemical oxygen demand (COD) were 538 mg/L, 1.02 NTU, < 25 mg/L, 27.7 mg/L and 62.8 mg/L, respectively with dominant type of fouling is cake resistance. Thus, it can be concluded water reuse standard was successfully achieved in terms of $BOD_5$ and suspended solid.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1621-1621
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• 2001

The quality of sugarcane grown on the NE Australian tropical coast ($16^{\circ}$15'- $18^{\circ}$15' S Lat.) has declined markedly in the past seven years. This has been linked to dilution of mill-supply cane with increasing levels of non mature-stalk material consisting of leaves and sucker culms. The prime research objective was to examine the transition from the pre-harvest, in-field crop to harvested material sent for processing, in terms of quality and crop fraction proportions. A secondary objective was to quantify the effects of preharvest-season crop habit and culm condition on crop quality. Ten quadrat samples from each of 54 random crop sites (17 in 1999 and 37 in 2000), covering a wide range of variables (cultivar, crop class, and edaphic, topographic, climatic, and temporal factors) were collected immediately before harvest. Samples were partitioned into four fractions:- sound and unsound mature stalks (culms), sucker culms, and extraneous matter (leaves). Material harvested from each site was sampled and partitioned into four fractions:- sound and unsound billets (culm pieces), culm-spindle pieces, and leaf. In 2000, before harvest, 14 additional sites were sampled monthly, on three occasions, from March - June. Erect and non-erect culms were divided into sound and unsound classes. All samples were disintegrated and presented to a remote reflectance module of a scanning spectrophotometer using the BSES large cassette module. Near infra-red spectroscopic (NIS) analyses were developed for the rapid determination of quality components (Brix, commercial cane sugar (CCS), fibre, moisture, and polariscope reading). Calibrations for three material groups (culm (n = 639), non-culm (n = 496), and combined) were developed for all components using the 1999 data set. Two sub-sets (n = 178, and 190) of about 10% of the preharvest-season and harvest populations scanned in 2000 also were subjected to full routine laboratory analyses. The 1999 combined calibrations were excellent, but the culm calibrations produced consistently lower standard errors. Non-culm calibrations were marginally better than the combined for only CCS and pol. reading. Analysis of the 2000 culm data with calibrations using all 1999 and 2000 culm data resulted in better predictions relative to the 1999 culm calibrations. This also was true for the combined calibrations. Assessment of quality components in pre- and post-harvest sugarcane using NIS calibrations was more cost effective than using routine laboratory techniques. Outcomes from this NIS-facilitated research will have important economic consequences for the Australian sugarcane industry. Potential CCS present in mature culms is being discounted by dilution with leaves and sucker culms, threatening farm viability. The results question the efficacy of current harvesting technology. The CCS of harvested cane is improved only marginally over that of the in-field crop. Current harvesting technology requires either supplementary, innovative pre-mill processing or a design revolution to improve mill-supply cane quality, and therefore whole of industry economics. NIS-facilitated analyses, before the harvest season, highlighted the benefits of growing erect, sound crops. Loss of CCS then, can be minimized only by a combination of crop improvement and agronomic solutions, applied as part of sound on-farm management.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.2
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• pp.146-151
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• 2015

Recycled aggregate by the recycling construction waste has a lot of advantage such as the developing the alternative resource and protecting of environment. However, recycled aggregate is used as the low quality grade, because it is difficult to remove old mortar from aggregate. To use the recycled aggregate as high quality grade, it is important to develop the technology to produce the high quality recycled aggregate. To manufacture the high quality recycled aggregate, old mortar attached on the aggregates should be removed efficiently. Therefore, in this study, we suggested the optimum condition to remove old mortar effectively using sulfuric acid and low speed wet rotary mill for high quality recycled fine aggregate. The results shows that the recycled aggregate satisfy on the standards of KS F 2573 in density, absorption and solid volume, when adequate condition of sulfuric mole ratio and aggregate ratio are make.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.370-374
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• 2003

Cell cracking method using a non-collision was evaluated for the possibility of new red ginseng grinding technique. Based on particle size distribution analysis by 1size shaker, the ratios of 100 mesh penetrated particles were 94.9% for hammer mill (group A) and 95.6% for cell crack (group B). The ratio of 120 mesh penetrated particle of group A was higher than that in group B. The particle size distributions for 100 mesh non-penetrated Powder between 2 groups were not significantly different, and particle size distribution analysis by laser scattering analyzer showed that the particle size ranges were 0.77~128.07 ${\mu}{\textrm}{m}$ for group A and 4.24~180.07 ${\mu}{\textrm}{m}$ for group B. The Particle size distribution in group A was more broad than that in group B. The mean particle size in group B was larger than that in group A, while the standard deviation of particle size distribution in group B was less than that in group A. Structural surface characteristics, in group A, particle size distribution was broad and the distribution curve was amorphous. The structure of individual particles was similar to unequal stone which was roughly grinded and had soft cotton-like surface. In the contrary, in group B, particle size distribution was relatively narrow and also individual size particles were ubiquitously distributed. The structure of individual particles was unequal cut stone shape.