• Applied Chemistry for Engineering
• /
• v.5 no.4
• /
• pp.681-697
• /
• 1994

The enzymatic hydrolysate of gelatin extracted from fish skin was fractionated and recycled through the membrane reactor according to the molecular weight for the purpose of using as functional material. In addition, the enzymatic hydrolysis conditions of gelatin, enzyme stability by membrane and mechanical shear, and effect on the long-term operational stability of the recycle membrane reactor were investigated. Using the pH-drop technique, Alcalase, pronase E and collagenase were identified as the most suitable enzymes for the hydrolysis of fish skin gelatin. The optimum hydrolysis conditions in the 1st-step membrane reactor(1st-SMR) by Alcalase were enzyme concentration 0.2mg/ml, substrate-to-enzyme ratio(S/E) 50(w/w), $50^{\circ}C$, pH 8.0, reaction volume 600ml and flow rate 6.14ml/min. In the 2nd-SMR by pronase E were enzyme concentration 0.3mg/ml, S/E 33(w/w), $50^{\circ}C$, pH 8.0, reaction volume 600ml and flow rate 6.14ml/min. In the case of 3rd-SMR, enzyme concentration 0.1mg/ml, S/E 100(w/w), $37^{\circ}C$, pH 7.5, reaction volume 600ml and flow rate 10ml/min. Decreased enzyme activities by mechanical shear and membrane were 30% and 15% in the 1st-SMR, were 14% and 5% in the 2nd-SMR, and 18% and 8% in the 3rd-SMR, respectively. Under the optimum conditions, the degree of hydrolysis in the 1st, 2nd and 3rd-SMR were 3.5%(Kjeldahl method, 87%), 3.1%(77%) and 2.7%(70%), respectively. The productivity of hydrolysate in the continuous three-step membrane reactor was 430mg per enzyme(mg) for 10 times of volume replacements.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.340-343
• /
• 2002

We report here our recent progress in the development and commercialization of polyfluorenes emitting red, green and blue (ROB) colors as materials for light emitting diodes (LEDs). Our patented version of the Suzuki coupling process has been used to synthesize a variety of fluorenebased homopolymers and copolymers emitting colors across the entire visible spectrum. The optical and electronic properties of the polymers are tailored through selective incorporation of different aromatic units into the polyfluorene backbone. Our latest green emitter, reported herein, provides very efficient devices with a low turn-on voltage of 2.25 V, a peak efficiency of 10.5 Cd/A at 6,600 Cd/$m^2$ at 4.85 V. These devices maintain an efficiency of greater than 10 Cd/A up to 50,000 Cd/$m^2$ and demonstrate very good stability as exemplified by a device half-life of greater than 1,500 hours starting from 1,100 Cd/$m^2$. Considerable progress has also been made with red and blue emitters and will be the subject of this presentation.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.2 s.46
• /
• pp.171-180
• /
• 2007

The financial crime that used morale anger Phishing, Pharming, Vishing, SMiSing etc. will gain during recent cyber crimes. We are study systematically whether or not leakage of information and infringement can how easily occur to Phishing, Vishing, SMiSing using a social engineering technique and VoIP at these papers through experiment. A hacker makes Phishing, Vishing site, and test an information infringement process of a user through PiSing mail and a virus, a nasty code, Vishing, a SMiSing character, disarmament of Keylogger prevention S/W etc. as establish server. Information by Phishing, Vishing, SMiSing is infringed with leakage in the experiment results, and confirm, and test certified certificate and White List and a certified authentication mark, plug-in program installation etc. to prevention, and security becomes, and demonstrate. Technical experiment and prevention regarding Phishing of this paper and Vishing attack reduce the damage of information infringement, and be education for Ubiquitous information security will contribute in technical development.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.172.2-172.2
• /
• 2010

This study was carried out in order to reduce the installation expense of heating system for greenhouse comparing to geothermal heat pump and develope the coefficient of performance (COP) for a heat pump. For getting plenty of heat flux from geothermal energy. Surface water in river channel was used for getting a lots of geothermal heat by penetrating water through underground soil layer of the river bank that make heat transmission to passing water. The range of water temperature after the process of Ground filtration is 13~18 degrees celsius which is very similar to low heat source of geothermal heat pump system and the plenty amount of heat source from that make the number of geothermal heat exchanging hole and the expense for geothermal heat exchanger construction reduced. Drainage well is also used for returning filtration water to the aquifer that keep the water good recirculation from losing geothermal heat and water resource. For the COP improvement of Heat pump, thermal storage tank with separating insulation plate according to the temperature difference make the COP of Heat pump that is similar to thermal storage tank with diffuser. Developed thermal storage tank make construction expense cheaper than customarily used one's. and that sand filter and oxidation sand (FELOX) are going to be used for improving ground filtration water quality that make heat exchanger efficiency better. All above developed component skill are going to be set on the Ground filtration water source heat pump system and applied for medium, large scale for protected greenhouse in riverside area and on-site experiment is going to do for optimizing the heating system function and overcome the problem happening in the process of on-site application afterward.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.903-908
• /
• 2001

A web-based client/server program, MOVIDIK(Motor-Operated-Valve Integrated Database Information of KEPCO) has been developed to perform a design basis safety evaluation for a motor-operated-valve(MOV) in the nuclear power plant. The MOVIDIK consists of seven analysis modules and one administrative module. The analysis module calculates a differential pressure on the valve disk, thrust/torque acting at a valve stem, maximum allowable stress, thermal-overload-relay selection, voltage degradation, actuator output and margin. In addition, the administrative module manages user information, approval system and code information. MOVIDIK controls a huge amount of evaluation data and piles up the safety information of safety-related MOV. The MOVIDIK will improve the efficiency of safety evaluation work and standardize the analysis process for the MOV.

• Transactions of Materials Processing
• /
• v.27 no.4
• /
• pp.201-210
• /
• 2018

An airbag is an essential automotive component used in all kinds of vehicles such as an internal combustion engine and an electric motor vehicle and is used to minimize the damage of an occupant in the event of an accident. Airbag-related parts are being monopolized by a small number of foreign companies around the world. In this situation, it is necessary to develop and research the airbag-related part molding technology for expansion of the domestic airbag-related market and corporate export. As a part of this research, we have developed a mold for airbag inflator cap. The development consists of three steps which are the design of components, analysis of the design and verification of it. In the case of the design, the transfer type mold was designed for the multi-cylindrical shaped feature. Analysis was then conducted on the design. By examining the results of analysis, changing features and numbers of punches and dies were added in the analysis and repeatedly analyzed. After the addition, proper dimensions from the analysis were achieved, and prototypes were practically produced and verified. In the case of prototype verification, Pressurizing Burst Test was conducted on the existing products and the prototype. By comparing the results of the test, the possibility of replacing the existing product of the airbag inflator cap is presented in this paper.

• Proceedings of the Ginseng society Conference
• /
• 1993.09a
• /
• pp.127-131
• /
• 1993

The effects of total ginseng saponin. extracts of Panax ginseng C.A. Meyer, on the differentiation of F9 teratocarcinoma stem cells were studied. F9 stem cells cultured in the presence of ginseng saponin together with dibutyric cAMP became parietal endoderm - like cells. Moreover, the expressions of differentiation marker genes. laminin. type IV collagen. and retinoic acid $receptor-{\beta}(RAR{\beta})$ were increased after treatment of ginseng saponin. Among various ginsenosides purified from crude ginseng saponin, $Rh_1\;and\;Rh_2$ caused the differentiation of F9 cells most effectively. Since ginsenosides and steroid hormone show resemblance in chemical structure. we studied the possibility of the involvement of a steroid receptor in the differentiation process induced by ginsenosides. According to Southwestern blot analysis, a 94 kDa protein regarding as a steroid receptor was detected in F9 cells cultured in the medium containing ginseng saponin. Based on these data, we suggest that ginseng saponin, especially ginsenosides $Rh_1\;and\;Rh_2$ cause the differentiation of F9 cells and the effects of ginsenosides might be exerted via binding with a steroid receptor or its analogous nuclear receptor.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.4 no.1
• /
• pp.41-44
• /
• 2004

The trend of decreasing the minimal structure sizes in microelectronics is still being continued. Therefore in its roadmap the Semiconductor Industries Association predicts a printed minimum MOS-transistor channel length of 10 nm for the year 2018. Although the resolution of optical lithography still dramatically increases, there are known and proved solutions for structure sizes significantly below 50 nm up to now. In this work a new method for the fabrication of extremely small MOS-transistors with a channel length and width below 50 nm with low demands to the used lithography will be explained. It's a further development of our deposition and etchback technique which was used in earlier research to produce transistors with very small channel lengths down to 30 nm, with a scaling of the transistor's width. The used technique is proved in a first charge of MOS-transistors with a channel area of W=200 nm and L=80 nm. The full CMOS compatible technique is easily transferable to almost any other technology line and results in an excellent homogeneity and reproducibility of the generated structure size. The electrical characteristics of such small transistor will be analyzed and the ultimate limits of the technique will be discussed.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1697-1698
• /
• 2008

PLS(Pohang Light Source) is 2.5 Gev synchrotron radiation source in Pohang, Korea, which is under operation since 1995. The hardware and software of the old BPM(Beam Position Monitor) data acquisition system for the PLS storage ring was completely upgraded to increase its performance and stability. The new BPM data acquisition system is based on VME-based EPICS (Experimental Physics and Instrument Control System) IOC system. We used 16-bit resolution analog-to-digital conversion board to digitize analog BPM signals. We developed a data average software to average raw BPM data using reflective memory board. We also developed device drivers for VME I/O boards used, IOC database for PV's(Process Variables). The new BPM data acquisition system is currently running for routine operation with good performance and stability. In this paper, we present the hardware and software of the new BPM data acquisition system DTL water skid cooling system and Resonant Control Cooling.

• The KSFM Journal of Fluid Machinery
• /
• v.13 no.5
• /
• pp.11-16
• /
• 2010

The development of lifting pumps that lift minerals to a mining vessel are one of the vital parts of the commercial mining process. The purpose of this study is to investigate internal flow and its effect on the performance of a mixed flow pump in order to improve the pump's performance. Numerical analysis was performed by commercial code of ANSYS CFX-11 based on flow rate and length of flexible hose. The rated rotational speed of the impeller is 1750rpm. For taking into account the turbulence, k-$\omega$ SST model was selected to guarantee more accurate prediction of flow separation. The simulated results are in good agreement with the experimental results and showed that its efficiency and the head of the pump are related mainly to the flow rate and the length of flexible hose. A lesser flow rate caused more secondary flow through the guide vane passage. The length of flexible hose and flow rate exert much more influence on the pump's performance than the shape of the flexible hose.