• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.1
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• pp.1-5
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• 2017

This study investigated the mechanical tearing of a cell membrane using a nanostructured alumina filter for easy and quick mechanical cell disruption. Nanostructured alumina filters were prepared by a multi-step aluminum anodizing process and nanopore etching process. Six different types of nanostructures were formed on the surface of the nanoporous alumina filters to compare the mechanical cell disruption characteristics according to the shape of the nanostructure. The prepared alumina filter was assembled in a commercial filter holder, and then, NIH3T3 fibroblast cells in a buffer solution were passed through the nanostructured alumina filter at a constant pressure. By measuring the concentration of proteins and DNA, the characteristics of mechanical cell disruption of the nanostructured alumina filter were investigated.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.2
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• pp.35-44
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• 2009

Long stroke Fast Tool Servo (LFTS) with maximum stroke of $432{\mu}m$ is designed, manufactured and tested for fabrication of optical free-form surfaces. The large amount of stroke in LFTS has been realized by utilizing the hinge and lever mechanisms which enable the displacement amplification ratio of 4.3. In this mechanism the peculiar shape was devised for maximizing the displacement of end tip in LFTS and special mechanical spring has been mounted to provide the sufficient preload to the piezoelectric actuator. Also, its longitudinal motion of tool tip can be measured by capacitive type displacement sensor and closed-loop controlled to overcome the nonlinear hysteresis. In order to verify the static and dynamic characteristics of designed LFTS, several features including step response, frequency response and cut-off frequency in closed-loop mode were experimentally examined. Also, basic machining result shows that the proposed LFTS is capable of generating the optical free-form surface as an additional axis in diamond turning machine.

• Journal of Microbiology
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• v.38 no.3
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• pp.187-191
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• 2000

A validation study was conducted to determine the efficacy of solvent/Detergent (S/D) inactivation and Q-Sepharose column chromatographic removal of the human immunodeficiency virus (HIV) during the manufacturing of a high purity antihemopilic factor VIII (GreenMono) from human plasma. S/D treatment using the organic solvent, tri (n-butyl) phosphate, and the detergent, Trition X-100, was a robust and effective step in eliminating HIV-1. The HIV-1 titer was reduced from an initial titer of 8.3 log10 TCID50 to undetectable levels within one minute of S/D treatment, HIV-1 was effectively partitioned form factor VIII during Q-Sepharose column chromatography with the log reduction factor of 4.1 . These results strongly assure the safety of GreenMono From HIV.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.10
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• pp.1633-1643
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• 2009

The knitwear industry requires ways to satisfy a changing environment. This study suggests a knitwear design process using a knit CAD program. Such a process needs to implement a CAD system that develops a sufficient knit design system to advance the knitwear industry in both planning and manufacturing. In order to contextualize this research, this study reviewed the current state and problems of the knitwear industry and the market, and investigated the actual condition in which the CAD system is used in knit design by CAD system service providers. The findings of the study are as follows: First, All brands had individual ways to reduce the amount of lead-time. The knit designers pointed out that any given sample product is made in the form of a swatch; after the knitting step and prior to the manufacturing process. In women's wear brands, basting was inserted into the production process in order to reduce the amount of sample losses. Second, a CAD program enables the uses of swatches to see the adequacy of yams, textures, and style that simulate the completed style. Third, this study examined the efficiency of knit design process conducted by the knit design CAD system based on expert assessments, showing that the use of a knit CAD program in commercial knit design proved to be more efficient than in previous models.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.3
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• pp.42-48
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• 2010

The aim of this study is to investigate the influence of driving atomizing nozzle position, the slope of sludge entering tube and supplying air flow rate on the performance of sludge air dryer. This paper deals with optimization of the geometry of the atomizing nozzle for sludge drying using computational fluid dynamics and drying performance test using pilot air dryer. The air drying system was composed of the atomizing nozzle which made high-speed fluid field. dewatered cake was crushed at the high-speed zone as the first step and formed intto dried powder of sphere shape by the collision between particles at the circling zone. The CFD analysis results show when the slope of entering sludge tube is smaller, suction air amount is increased. It is shown that the developed atomizing nozzle is very excellent in the drying performance through pilot test.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.14-20
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• 2016

This paper describes a green stripping process to effectively strip the remaining DFR layer on a non-alkali-based ITO glass surface after an etching process. A stripper, water-soluble amine compound, is used to investigate the characteristics of stripping ability and to suggest a valid method for the green process. Increasing the composition (5-30% concentration) of the ethanol amine-based stripper was found to greatly reduce the stripping time applied in the dipping method. The composition (30%) achieved an excellent stripping effect and free-residue impurities. Additionally, it was possible to obtain the effect of stripping in a way to sustain the release before generating DFR sludge from the ITO glass surface by using dipping condition (stripping time) in the composition. An Additional stripping process (buffering) out of dipping can realize productivity improvement and cost reduction because of the higher proportion of re-use of the stripping solution used in the DFR removal step.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.440-445
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• 2011

This paper presents a new regenerative brake system of electric vehicles that employs a continuous variable transmission(CVT) and a flywheel. The developed device has advantages over existing regenerative brakes from a standpoint of reliability and versatility in actual driving conditions. The system consists of a CVT, two wheels, a flywheel, a coupling and auxiliary powertrain components. The CVT is designed as a combination of two cones and a roller, which causes the velocity difference between the wheel and the flywheel. The power flow of the flywheel system is controlled by the CVT roller and the coupling through step motors. A prototype has been developed and then its performance has been investigated for various operating conditions. Results show that the storage efficiency of the flywheel is much affected by the vehicle's velocity and it is reduced below 20% for high speed, as compared to the 25% efficiency for an ideal condition. The CVT is a primary factor for lowering the flywheel efficiencies due to large friction and slipping between the cone and the roller.

• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.227-233
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• 2004

The main objectives of this study were to identify from literature review the potential sources and to provide a preliminary national emission inventory for the unintentionally produced polychlorinated biphenyls (PCBs) (i.e., by - product PCBs). In Korea, fuel combustion, waste combustion, thermal industrial processes, and transportation were identified as potential sources of by -product PCB s. According to the availability of the emission factors and/or activity data, emission inventory could be assessed only for fuel combustion, waste combustion, steel industry, non-ferrous industry, and non-metallurgical industry. The total national emission of by-product PCBs was estimated to be 1087kg for the year 2000. The preliminary estimation further indicated that the steel manufacturing was the single dominant emission category, contributing 93％ to the total emission. Of the steel manufacturing processes, the contribution of the electric arc furnace was about 80％ of the total emission. Due to high uncertainty associated with both the emission factors and activity statistics, the emission estimates in this study are likely to contain significant errors. However, the results of the present work could serve the first step toward future efforts to establish national source and emission inventories of by-product PCBs.

• Journal of the Korea Convergence Society
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• v.8 no.10
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• pp.185-191
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• 2017

Recently, for such reasons as its inexpensive price and eco-friendliness, LNG has been under the limelight as an alternative fuel for vessels and is expected to grow rapidly in the industry. However, the technology level of domestic shipbuilders in manufacturing the cryogenic pump designed to supply LNG for vessels is so low that design and manufacturing technology of core parts are in urgent need. Therefore, this study describes the stepwise development procedure of cryogenic submerged centrifugal pump for ship LNG supply system. And it aims to suggest practical and specific development methods of the pump by approaching the characteristics of each step and major development items from the standpoint of engineering and management.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.126-133
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• 2015

To enhance the productivity and quality of the compound process of progressive dies and transfer dies, the semi-progressive method is applied in the material supply step to produce blanks, and then the transfer method is applied. Parts are transferred among processes by means of the finger and transfer bar in the transfer die, and the final seat cushion panel is produced. The main challenge in the current study is how to deform a seat cushion panel while meeting the design specifications without any defects. In order to obtain this technology, a sheet metal-forming simulation and die forming of the seat cushion panel were adopted; as a result, a compound die-forming technology for the automotive seat cushion panel, combining both semi-progressive die and transfer die for continuous production, was successfully developed.