• Optical Science and Technology
• /
• v.9 no.1
• /
• pp.29-35
• /
• 2005

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.723-729
• /
• 2019

Turbochargers are an effective device to reduce the fuel consumption. In this study, the mass flow rate of pulsating flow in the twin-scroll turbocharger for the gasoline engine of passenger vehicles was measured. Pulsating flow was achieved using a pulse generator and the mass flow rate of the unsteady pulsating flow was analyzed by comparing it with those of the steady flow. The pulse generator consisted of a rotating upper plate and a fixed lower plate. To measure the mass flow rate of unsteady flow, the orifice flow meter equipped with the difference pressure transducer was used. To analyze the low speed performance of the turbocharger, the measurement was carried out in the speed of turbocharger from 60,000rpm to 100,000rpm. The mass flow parameters of the unsteady pulsating flow showed a large difference compared to those of the steady flow. Those of the unsteady flow showed the hysteresis loop surrounding the mass flow parameters of the steady flow and the maximum variation of the mass flow parameters were 5.0 times those of the steady flow. This phenomenon is the result of the filling and emptying the turbine volute space due to pulsating flow.

• Journal of Plant Biotechnology
• /
• v.29 no.3
• /
• pp.161-170
• /
• 2002

For the hairy root of Panax ginseng, we have got mass spectrums from MALDI/TOF/MS analysis and Tandem mass spectrums from ESI/Q-TOF/MS analysis. While mass spectrum provides the molecular weights of peptide fragments digested by protease such as trypsin, tandem mass spectrum produces amino acid sequence of digested peptides. Each amino acid sequences can be a query sequence in BLAST search to identify proteins. For the specimens of animals or plants of which genome sequences were known, we can easily identify expressed proteins from mass spectrums with high accuracy. However, for the other specimens such as ginseng, it is difficult to identify proteins with accuracy since all the protein sequences are not available yet. Here we compared the mass spectrums and the peptide amino acid sequences with ginseng expressed sequence tag (EST) DB. The matched EST sequence was used as a query in BLAST search for protein identification. They could offer the correct protein information by the sequence alignment with EST sequences. 90% of peptide sequences of ESI/Q-TOF/MS are matched with EST sequences. Comparing 68% matches of the same sequences with the nr database of NCBI, we got more matches by 22% from ginseng EST sequence search. In case of peptide mass fingerprinting from MALDI/TOF/MS, only about 19% (9 proteins of 47 spots) among peptide matches from nr DB were correlated with ginseng EST DB. From these results, we suggest that amino acid sequencing using tandem mass spectrum analysis may be necessary for protein identification in ginseng proteome analysis.

• Journal of Convergence for Information Technology
• /
• v.11 no.2
• /
• pp.107-116
• /
• 2021

In this study, an analytical method was developed for estradiol-17��, testosterone, and progesterone, which are growth promoters as veterinary drug residues in animal food. The analytes were separated using liquid chromatography, and was injected into a mass spectrometer through the electrospray ionization(ESI) process and detected in multiple reaction monitoring(MRM) mode. As the method was validated by CODEX CAC/GL 71-2009 guideline, it met the acceptable. The analysis of beef, pork, and chicken distributed in Korea was conducted with an established method to confirm the applicability of the actual sample. It was confirmed that the developed method can be quickly and reliably in the analysis for the growth promoters identified in domestic distributed livestock products. Through subsequent research, a highly utilized analysis method will be completed if the number of growth promoters is expanded based on the method and the simultaneous analytical method is established by including all of it.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.16 no.4
• /
• pp.19-26
• /
• 2012

For a seismic design or performance evaluation of a structure, an experimental investigation on a scale model of the structure or numerical analysis based on the finite element model is considered. Regarding the numerical analysis, a three-dimensional finite element analysis is performed if a high accuracy of the results is required, while a sensitivity or fragility analysis which uses huge seismic ground motions leads to the use of a lumped-mass stick model. The conventional modeling technique to build the lumped-mass stick model calculates the amount of the lumped mass by considering the geometric shape of the structure, like a tributary area. However, the eigenvalues of the conventional model obtained through such a calculation are normally not the same as those of the actual structure. In order to overcome such a deficiency, in this study, a new lumped mass stick model is proposed. The model is named the "frequency adaptive-lumped-mass stick model." It provides the same eigenvalues and similar dynamic responses as the actual structure. A non-prismatic column is considered as an example, and its natural frequencies as well as the dynamic performance of the new lumped model are compared to those of the full-finite element model. To investigate the damping effect on the new model, 1% to 5% of the critical damping ratio is applied to the model and the corresponding results are also compared to those of the finite element model.

• Polymer Science and Technology
• /
• v.15 no.1
• /
• pp.83-92
• /
• 2004

• Rubber Technology
• /
• v.21 no.1
• /
• pp.11-28
• /
• 2020

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2005.11a
• /
• pp.63-64
• /
• 2005

• Polymer Science and Technology
• /
• v.11 no.6
• /
• pp.798-805
• /
• 2000

• Resources Recycling
• /
• v.32 no.6
• /
• pp.25-33
• /
• 2023

With the growth of the battery industry, a rapid increase in the production and usage of lithium-ion batteries is expected, and in line with this, much interest and effort is being paid to recycle waste batteries, including production scrap. Although much effort has been made to recycle cathode material, much attention has begun to recycle anode material to secure the supply chain of critical minerals and improve recycling rates. The proximate analysis that measures the content of coal can be used to analyze graphite in anode material, but it cannot accurately analyze due to the interaction between the components of the black mass. Therefore, in this study, thermogravimetric analysis of each component of black mass was measured as the temperature increased up to 950℃ in an oxygen atmosphere. As a result, in the case of cathode material, no change in mass was measured other than a mass reduction of about 5% due to oxidation of the binder and conductive material. In the case of anode material, except for a mass reduction of about 2% due to the binder, all mass reduction were due to the graphite(fixed carbon). In addition, metal conductors (Al, Cu) were oxidized and their mass increased as the temperature increased. Thermal analysis results of mixed samples of cathode/anode show similar results to the predictive values that can be calculated through each cathode and anode analysis results.