• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.253-253
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• 2017

Recently, strong interest in the well-being and healthy food trends lead a spreading of rice processing products such as rice noodles, rice breads, and rice cakes. However, most of rice varieties developed in Korea showed very limited processing properties in processing of noodles compare to that of wheat flour. Moreover, low competitiveness as a raw processing materials due to high price give poor evaluations for rice noodles processing. To cope those barriers, 'Saemimyeon' a Tongil type high yielding variety with a high amylose contents was developed in RDA. 'Saemimyeon' showed about 10~32 % of increase in yield as 7.08MT/ha and 26.7% of high amylose contents together with easy grinding property of 65.7% of high chalkiness ratio. The both of milled as well as brown rice of 'Saemimyeon' were well fit for processing properties in rice pasta where the contents of rice flour for rice pasta was 99% (1% of Tapioka starch was intermixed in to the rice flour). A spaghetti type for wet noodles and macaroni type for dry noodles were developed, respectively. Each of pasta were showed relatively more or less an equal quality and panel test compare to that of durum wheat pasta products. Finally, rice pasta products could suggest an alternative idea for a new rice processing items where rice noodles market was stagnant.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.34-41
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• 2013

In this study, we investigated the physical properties of powders made from agricultural byproducts, including rice straw, peanut husks, and garlic stems, to manufacture a new organic filler used for making paperboard. These materials were collected individually, and then we measured their chemical compositions. The byproducts were ground with a laboratory grinder and fractionated with 60-, 100-, and 200-mesh sieves to make many grades of organic fillers. After the grinding and fractionation, the yield, mean particle size, and particle size distribution of each grade were measured. Particle shapes were also investigated using a scanning electron microscope. The organic filler made from rice straw had the highest yield of the largest particle size group and higher contents of cellulose and hemicellulose than those made from peanut husks and garlic stems. The rice straw also showed more regular particle shapes and a lower aspect ratio than the other agricultural byproducts.

• Journal of the Mineralogical Society of Korea
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• v.25 no.3
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• pp.123-130
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• 2012

Leaching experiments of gold and silver from roasted concentrate were carried out using a chlorine-hypochlorite solution. The leaching rate of gold was 75% at 1.5:1 ratio of chlorine and hypochlorite and increased to 81% with adding 1 M NaCl. However, at 1% pulp density and at $65^{\circ}C$, the leaching rates of Au were close to 100%. XRD analysis identified quartz in the solid residues after digestion of roasted concentrate with aqua regia or chlorine-hypochloride leaching solution. This suggests that the gold may not be leached out of the quartz in aqua regia or chlorine-hypochlorite solution. In order to leach the gold from the quartz, the concentrate will have to be pre-treated through ultra-fine grinding or treated with stronger oxidative agents.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.317-325
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• 2008

As a result of recent research, it is reported that the periodic replacements criterion of rails is able to extend as grinding rail surface and using the continuous welded rail (CWR). This study evaluated correlation between conditions of track and load capacity of rail by analysing the dynamic response of track while the metro train is running. Also, it was converted the measured stress waveform into stress frequency histogram by the rain-flow counting methods, and then accumulated fatigue damage ratio and remaining service life of laid rail were calculated so as the apply the equivalence of stress to S-N curve of a new welded rail. Finally, this study suggests a revision of the periodic replacements criterion of CWR, which was based on accumulated passing tonnage, classified by the types and conditions of track system.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.3
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• pp.124-131
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• 2007

Aspheric glass lenses was fabricated by glass molding press(GMP), which is a plano-aspheric convox shape and intended for use as an optical design of 3 megapixel and 2.5 magnifications zoom in a camera phone module. Transcription ratio of form accuracy (PV) as well as resolution properties was measured for evaluation the molded lens. Form accuracy (PV) of the mold surface was $0.127\;{\mu}m$ in an aspheric and $0.168\;{\mu}m$ in a plano, in case of the molded lens it shows $0.205\;{\mu}m$ and $0.223\;{\mu}m$, respectively. Resolution of the molded lens was measured as a MTF[Contrast]. The molded lens shows contrast of 32.9% at 80 1p/mm and the value is similar with contrast of 33% obtained simulation.

• Resources Recycling
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• v.12 no.3
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• pp.25-30
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• 2003

The synthesis of SiC used for the parts of the gas turbine and the heat exchanger, was carried out. In this study, wire cutting slurry of silicon wafer and the graphite rod of spent zinc-carbon battery were applied to the starting materials for the synthesis. The powders of Si or Si+SiC were obtained from the waste material by filtration, gravity separation and magnetic separation. Graphite powder was produced by dismantling, grinding and gravity separation from spent zinc-carbon battery. The synthesis of SiC could be completed from the mixture powders of Si and C or Si+SiC and C at the condition of equivalent ratio of Si and C, atmosphere of Ar or vacuum, temperature of above 1$600^{\circ}C$ and 2 hours reactions. The purity of synthesized Si-C was above 99%.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.145-151
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• 2019

The Physical performance of use materials was evaluated to improve durability of fast-paced repair mortar used at rapid construction sites. The fastening performance and basic performance were evaluated by substituting ferronickel grinding slag residues, rapid settlement, and EVA-based polymer for mortar. As a result, the compressive strength, flexural strength and adhesion strength were increased due to the use of FS Fine Aggregate and RS Fine Aggregate. The chloride ion promotion test of fast-polymer mortar kept the chloride inhibitory performance from 7 days to 28 days when fNS was used less than 50%. Durability degradation due to the use of FS Fine Aggregate and RS Fine Aggregate has not been found, and it is believed that further consideration of economic and long-term durability will be required for use as alternative Aggregate for construction and civil engineering.

• Plant Journal
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• v.18 no.3
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• pp.28-40
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• 2022

As the proportion of renewable energy generation is expected to increase, public power generation businesses need to actively consider implementing the expansion of biomass mixing, In this study, the biomass co-firing rate is being changed from 0wt.% to 5.0wt.% at 500MW coal-fired power plant, measuring the major operation characteristics of the pulverizer. First, the composition analysis and grinding characteristics of lignocelluosic biomass were examined, and the effect of volume increase on dirrerential bowl pressure difference, motor current, coal spillage, outlet temperature, and internal fire count was analyzed. As the co-firing rate increased, it was confirmed that the difference in the differential bowl pressure, motor current, and coal spillage treated increased, and the outlet temperature was minimal. The number of internal fires is difficult to find a clear correlation, but it has been confirmed that it is highly likely to occur in combination with other driving factors.

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.23-37
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• 2023

One type of biomass that has promising potential for bio pellet production is spent coffee grounds (SCGs). However, previous studies have shown that SCGs in bio pellets cause a lot of smoke. Therefore, they need to be mixed with a material that has a higher calorific value to produce better quality pellets. One material that can be used is pine wood because it has a natural resin content that can increase the calorific value. The aim of this study was to examine the quality of bio pellets produced with SCGs and pine wood charcoal at different particle sizes. The charcoal was ground using either a hammer mill (HM) or a ball mill (BM). Pine wood charcoal was mixed with SCGs at ratios of SCGs to pine wood charcoal of 4:6 and 6:4 by weight, respectively, and the adhesive used a tapioca with a composition ratio 5% of the raw material. The bio pellets were produced using a manual pellet press. The quality of the bio pellets was assessed based on Indonesian National Standard (SNI) 8021-2014, and the physical observations include flame length, burning rate, and compressive strength. The average water content, ash content, and calorific value of the bio pellets were in accordance with SNI 8021-2014, but the density and ash content values were below the standard values. The BM variation of bio pellets had a higher compressive strength than the HM variation, and the 4:6 BM variation had the longest burning time compared with 4:6 HM.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.321-331
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• 2005

The purpose of this study was to compare the effectiveness of mechanical and acid treatment on enamel surfaces for the retention of pit and fissure sealants and evaluate the presence of a prismless layer. The etch pattern produced on enamel from immature and mature premolar teeth extracted with varying period of acid etching using 37% phosphoric acid was examined using a scanning electron microscope(SEM). The composition of each groups was evaluated using an energy dispersive x-ray(EDX) spectroscopy. The result of present study can be summarized as follows: 1. Prismless layer was commonly observed on the fissure enamel in young and mature premolar. 2. There were no differences in micro-structure and etching pattern on fissure enamel between the young and the mature premolar. 3. The most effective etching pattern for retention of pit and fissure sealant was observed in 60 seconds of etching time and no apparent difference of etching pattern was found among 15, 30, and 45 seconds of etching time which showed non-retentive etching patterns. 4. The etching pattern obtained by grinding enamel surface with bur followed by 60 seconds of etching was similar to that of 60 seconds of etching without any pretreatment of fissure surface. 5. Type 2 etching pattern was commonly found on fissure enamel in both young and mature premolar. 6. The calcium content and P/Ca ratio in fissure enamel between the young and the mature premolar were significantly different(P<0.05). But content of calcium, phosphate and P/Ca ratio on various regions of fissure enamel in both young and mature premolar did not showed any difference. Based on these results, prismless layer may negatively influence the retention of pit and fissure sealants. Therefore, the mechanical removal of the prismless layer by grinding prior to etching or by prolonged etching time of enamel within the fissure system should result in an improved bonding of a pit and fissure sealant.