• Journal of Hydrogen and New Energy
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• v.5 no.2
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• pp.59-63
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• 1994

Thermally evaporated Pd films on substrate were hydrogenated upto 1 bar of hydrogen gas at room temperature. Thickness dependence on hydrogenation on Pd film is examined in the thickness range between $60{\AA}$ and $800{\AA}$. Hydrogenation kinetics of thinner films(thinner than $500{\AA}$) and that of thicker films are different. Thin film(thickness < $200{\AA}$, substrate temp. = RT) showed recrystallization due to hydrogen induced heat. Hydrogen was absorbed by chemisorption process in ${\alpha}$ phase of thinner films, and diffusion process in ${\alpha}'$ phase of thicker films respectively.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.193-197
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• 2002

Polyurethane casting wing fairings included in F-5E/F 15% spar kit are to be installed on aircraft wing surfaces and used for compensating the changes of the aerodynamic configuration by the leading edge extension fairings. These fairing are mandatory items in repairing wing areas and was imported from foreign supplier with long term delivery and high cost. Accordingly, local manufacturing is necessary to get rid of above disadvantages such as long term delivery and high cost. Basic properties test of specimen to be developed and part's requirements after localization was taken and its values were similar or higher when comparing with the original's even in low temp test at -55C. Casting mold process was used to manufacture the polyurethane fairings and its demensional stability ＆ physical condition was proper and met to the related specification and drawing's requirements

• Journal of Korean Society of Water and Wastewater
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• v.21 no.1
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• pp.83-89
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• 2007

A biological anoxic-aerobic reactor filled with porous media was operated in lab scale for the advanced wastewater treatment. The experiments were conducted for 6 months with three HRTs (4, 6, 8hr) and temperature of $23{\sim}25^{\circ}C$. Some other experimental conditions were as follows; nitrification reactor (MLSS 4,500mg/L, DO 3.3mg/L, $23{\sim}28^{\circ}C$), denitrification reactor(MLSS 8,000mg/L, ORP -100mV, Temp.$19{\sim}23^{\circ}C$). Average removal efficiencies of SS, $BOD_5$, $COD_{Cr}$, T-N, and T-P were 97.8%, 95.5%, 94.5%, 80.2%, and 60.6%, respectively. The reactor filled with porosity media showed stable removal capacity for organics and nutrients. Fast and complete nitrification and denitrification were accomplished. Maintaining high MLSS with porous media in the nitrification and denitrification reactor appears to enhance the nitrogen removal process. For the higher T-P removal, some coagulant addition process will be needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.586-592
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• 1999

Microwave assisted extraction(MAE) is known as a more environmental friendly process with economic advantages in terms of less time, less solvent, less energy and less wastes than the current time consuming reflux method. It was applied to develop a rapid extraction method for soluble ginseng components that are major materials used for the processing of ginseng products. In a comparative study between pre established MAE(ethanol 60%, power 80 W, process time 4 min$\times$5) and current extraction method(ethanol 80%, temp. 85oC, time 8 hr$\times$5), MAE was more efficient than the current method to obtain an extract yield(soluble solid), but it was insufficient to extract individual ginsenosides, total phenols, reducing components and acidic polysaccharides. MAE with 80% ethanol by 5 times showed, however, that its extraction efficiency on soluble solid, crude saponin, major ginsenosides, and the other components was equal or superior to that of the current method, indicating that ethanol concentration is one of the critical parameters influencing the MAE process. The quality of ginseng extracts from MAE was assured by evaluating the corresponding standards and by comparing TLC and HPLC patterns with the control.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.523-531
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• 2020

Extraction and anti-solvent crystallization were proposed to recover octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) from pressed polymer bonded explosives(PBXs). DXC-57 and DXC-59, whose polymeric binders are Estane and HyTemp with dioctyl adipate plasticizer, respectively, were used as pressed PBX models. Estane of DXC-57 was removed by washing with tetrahydrofuran prior to extraction, which enabled the crystallization of HMX at a low degree of supersaturation, sufficient to obtain β-form HMX. Using dimethyl sulfoxide and ethanol as the extraction solvent and the anti-solvent for crystallization, respectively, HyTemp and dioctyl adipate in DXC-59 were separated from HMX. The purity of recovered β-form HMX was higher than 99 %.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.703-711
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• 2016

The purposes of this study is to identify the problems arising from current Test & Evaluation process of the naval ship acquisition program and to suggest methods to increase the acquisition efficiency. Considering that the present rule of developmental test &evaluation(DT&E) and operational test & evaluation(OT&E) has caused an inefficiency effect on the acquisition procedures due to the limited practices on it, the DT&E and OT&E procedures through test & evaluation master plan(TEMP) is proposed based on the selective practices of the defense instruction articles. Also, considering characteristics of naval ship acquisitions, efficient procedure systems are derived through case analysis results by comparing each performances of the system. The suggested methods are able to meet the requirements of the changed acquisition environments and also increase efficiency of acquisition systems by adoption of DT&E and OT&E combined test scheme.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.270-277
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• 2018

The adsorption of Eosin Y by the activated carbon (WCAC) prepared from waste citrus peel was investigated by using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. Experiments were carried out as per BBD with three input parameters, the Eosin Y concentration (Conc. : 30~50 mg/L), the solution temperature (Temp. : 293~313 K), and the adsorbent dose (Dose : 0.05~0.15 g/L). Regression analysis showed a good fit of the experimental data to the second-order polynomial model with coefficients of the determination ($R^2$) value of 0.9851 and P-value (Lack of fit) of 0.342. An optimum dye uptake of 59.3 mg/g was achieved at the dye concentration of 50 mg/L, the temperature of 333 K, and the adsorbent dose of 0.1056 g. The adsorption process of Eosin Y by WCAC can be well described by the pseudo second order kinetic model. The experimental data followed the Langmuir isotherm model.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2007.04a
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• pp.37-47
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• 2007

Factor : Structure Metal pad & SMO size Board level TC test : - Large SMO size better Board level Drop test : - Large SMO size better Factor : Structure Substrate thickness Board level TC test : - Thick substrate better Board level Drop test : - Substrate thickness is not a significant factor for drop test Factor : Material Solder alloy Board level TC test : - Not so big differences over Pb-free solder and NiAu, OSP finish Board level Drop test : - Ni/Au+SAC105, CuOSP+LF35 are better Factor : Material Pad finish Board level TC test : - NiAu/NiAu is best Board livel Drop test : - CuOSP is best Factor : Material Underfill Board level TC test - Several underfills (reworkable) are passed TCG x500 cycles Board level Drop test : - Underfill lots have better performance than non-underfill lots Factor : Process Multiple reflow Board level TC test : - Multiple reflow is not a significant actor for TC test Board level Drop test : N/A Factor : Process Peak temp Board level TC test : - Higher peak temperature is worse than STD Board level Drop test : N/A Factor : Process Stack method Board level TC test : - No big difference between pre-stack and SMT stack Board level Drop test : - Flux dipping is better than paste dipping but failure rate is more faster

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.2
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• pp.144-149
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• 2015

In this study, the effective technology readiness assessment (TRA) method for system development project is suggested. We analyze the domestic and foreign TRA practice and derive the new idea to resolve the problems found from the analysis. Domestic and foreign organizations develop and use checklist for the precise TRA, but the checklist has some problems in type of questions and analysis of assessment. TRA method using the original TRL definition or the checklist should be selected depending on the project characteristic. Questions of the checklist should be classified into critical or non-critical according to their importance. Finally, Test and evaluation master plan (TEMP) in system engineering process can provide an obvious criteria to assess technology readiness level (TRL) of critical technology elements (CTE) composing the system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.172-179
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• 1999

As the martensite structure cause fracture failure during drawing from 5.5mm rod to 3.05mm dia. wire without additional heat treatment, the optium cooling condition to inhibit the occurrence of martensite was investigated. In order to get SAE9254+V quality, the effects of alloying element, vanadium on the mechanical properties were investigated. Based upon CCT and TTT curves and the results form cooling test in mill, optimun cooling was found in the condition of the laying head temp of 780$^{\circ}C$ and of the conveyor speed at 0.15m/sec with the whole cover closed. The wire rods produced under the condition showed the best mechanical properties of 120kg/$\textrm{mm}^2$ in TS and 50% in RA, having an excellent drawability. In vanadium added steels, tensile strength was improved without degrading elongation and charpy impact value. That means the strengthening by vanadium is mainly due to the grain refinement by the fine precipitates during tempering process.