• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.516-521
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• 2008

This study was conducted to optimize the analysis condition and quantify the 2-acetyl-1-pyrroline (2AP) in the brown aroma rice. Extraction effect of the solvent for 2AP was the order of ethanol>acetonitrile>methanol in the range from 30 to $90^{\circ}C$. In the extraction time of 15, 30, 60, and 90 min, the 30 min had the highest 2AP concentration, and it was decreased according to lapse of time. At grinding time, 5 sec resulted in highest 2AP concentration. It was recommended that five sec grinding time, using ethanol, at $90^{\circ}C$ for 30 min was the optimization conditions to quantify the 2AP. Hyangmibyeo2ho and Aranghyangchalbyeo were mild aroma. In the foreign aroma rice, 11 of 19 accessions of Indica types and 2 of 6 accessions of Japonica types were more than mild aroma. Finally, 30 accessions of aroma rice were selected based on their 2AP concentration and agronomic traits.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.1
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• pp.1-7
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• 2016

Mastication is the process to help digestion by chewing or grinding food. Masticatory system consists of maxilla, mandible, temporomandibular joints, ligaments, dentitions, and musculatures. Assessing the bite force can be one of the methods to estimate the masticatory system. Bite force is influenced by facial morphology, age, sex, periodontal status, temporomandibular joint disorder and dental condition, and so forth. In general, higher maximum bite force is seen in those who have a square-shaped face and in male rather than female. In addition, bite force tends to be increased by age 20, maintained constantly until age 40 - 50, and then decreased. Periodontal disease is known as a causative factor for decreased bite force while temporomandibular disorder (TMD) remains controversial as to whether it affects the force. The status of teeth is considered as an important factor to determine the maximum bite force.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.603-608
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• 2004

Traditional Jeju tofu with a hard texture was manufactured by traditional method with a compounded coagulant. The processing condition for industrial production was optimized by determining soaking of soybean, extraction and heat treatment of soymilk as well as concentration and composition of coagulant. Maximum yield of soymilk was obtained by grinding one part of soaked soybean with eight parts of water, and the soluble solid of soymilk was about 8$^{\circ}$Brix. The free thiol group in soymilk was maximally exposed by heating at 10$0^{\circ}C$ for 2 min. A vacuum cooker for heating soymilk was effective for the improvement of yield and texture properties of tofu. The hardness of traditional Jeju tofu was obtained by increasing pressing time and drying by a fan instead of soaking in cold water. Optimization of a traditional tofu production resulted in the increase of total yield and improvement of quality control. Texture of traditional Jeju tofu prepared in industrial production scale was analyzed by instrumental analysis and sensory evaluation. Traditional Jeju tofu showed higher score in the hardness, roasting taste and overall preference compared with a commercial tofu, showing significant difference in 5% significant level..

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.1
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• pp.35-43
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• 2015

A large amount of radioactively-contaminated gravel can be produced on the demolition/restoration of facilities related the back end of fuel cycle. However, because of the lacking in basic knowledge for decontamination of radioactive-contami-nated gravel, this study has performed the basic tests using for soil-washing. To find effective decontamination condition, several experiments were carried out for the selection of optimal decontamination agents. Washing by 0.1 M nitric acid was proved to be more effective than that by distilled water or surfactant for decontamination of uranium-contaminated gravel. In addition, crushing/grinding of uranium-contaminated gravel prior to washing was contributed to increase in of removal efficiency of uranium and reduction of decontamination time. The smaller the sizes of crushed gravel was, the more the removal efficiency increased. Also, small the sized particles improved chances for meeting the clearance requirement of the treated gravel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.1
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• pp.79-91
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• 2012

A curved fiber reinforced polymer (FRP) panel is produced with a certain width depending on allowances of manufacturing processes and facilities. An targeted arch-shaped structure could be built by sequential connection of series of the FRP panels. The connection manner between the FRP panels could be given by chemical treatment, mechanical treatment and hybrid method. Among those, the connection between the panels by chemical treatment is commonly adopted. Therefore, For an optimized design of the connected part between FRP pannels, a number of direct shear tests have been undertaken in terms of a number of parameters: surface treatment conditions, bonding materials, etc.. As results, surface grinding condition by sand paper or surface treatment by sand blasting appear properly acceptable methods, and epoxy and acryl resins are shown to be effective bonding materials for the purpose in this study.

• 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%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.354-361
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• 2005

In high speed cutting process, due to the friction between the tool and workpiece, a temperature rise of contacting part is serious. It need to develop cutting tool for overcoming such a poor condition. So now, some studies, the optimization of tool shapes, the fine grains of tool material, multi-layer coating of tools are processing. If mirror finishing on the tool is processed, there is advantage of relation between chip and tool, because of less friction, and also tool's lift would be increased. As a result mirror like finishing is expected efficient enhancement of tool. Generally, it is too difficult to process by a general way for tools of complex shapes, it is required a new method to process such complex shape tools. The magnetic fluid polishing technique can polish the workpiece of complex shape, because the polishing method which polishes as compress the workpiece by the magnetism abrasives to arrange to the linear according to the line of magnetic force. In this paper, We polished the surface of the high speed cutting tool using the magnetic fluid polishing technique, to enhance the performance of the high speed cutting tool.

• Resources Recycling
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• v.25 no.6
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• pp.98-104
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• 2016

The purpose of this study is to obtain an optimum condition of the concentrate by floatation using Australian low grade copper ore of suitable particle size by crushing, grinding and sizing. The effect of the dosage of collector, activator, depressant and change of acidity on the floatation was investigated. The floatation conditions comprising of pH 9.0 acidity, 500g/t $CuSO_4{\cdot}5H_2O$ activator, 500g/t K.E.X. collector, 1500g/t $Na_2SO_3$ depressant and 25wt.% plup density were optimized. Grade and recovery of copper in the concentrate obtained by froth floatation under optimum conditions were 4wt.% and 65wt.% respectively.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.114-125
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• 1993

In the present study the newly developed CAD/CAM system is applied to the process of the molding design, machining for mini-sized and precise processive die, and the production of press-stamped parts. When the design of a die was completed by means of CAD, wire cut NC data were generated with the aid of a design drawing in the CAD system and then inputed into the wire cut machine, and with the aid of a hole chart which had been made for this purpose, all the data were classified into the categories of CNC milling, jig boring, jig grinding, and machine center, and then developing a program of generating NC data, errors in process were reduced and programming time was shortened. The program was developed by using Autolisp language which was built-in the CAD, and realizing the intergation of designing a die, generating and processing NC data directly by a designer, designing time and machinery processing time were shorted. And the traditionally required working time for design. NC program required 6 days of work becomes 4 days of work by using the developed CAD/CAM system so that the efficiency shows 150% of the reduction working time. The prpgram of the design of the automation a progressive die mold was developed in the PC-Class Autocad system, therefore development expense could be reduced, and the integration of the CAD/CAM of the progressive die mold with the standard DB being built could be realized.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.362-367
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• 2006

Waste activated sludge(WAS) collected from domestic wastewater treatment plant is biomass that contains large quantities of organic matter. However, relevant literature show that the bio-hydrogen yield using WAS was too low. In this study, the effect of pretreatment of WAS on hydrogen yield was investigated. Pretreatment includes acid and alkali treatments, grinding, heating, ozone and ultrasound methods. After pretreatment organic matters of WAS were solubilized and soluble chemical oxygen demand(SCOD) was increased by 14.6 times. Batch experiments were conducted to investigate the effects of pre-treatment methods and buffer solution, hydrogen partial pressure, and sodium ion on hydrogen production from WAS by using heated anaerobic mixed cultures. Experimental results showed that addition of buffer solution, efficient pre-treatment method with alkali solution, and gas sparging condition markedly increased the hydrogen yield to 0.52 mmol $H_2/g$-DS.