• Food Science and Preservation
• /
• v.24 no.4
• /
• pp.542-549
• /
• 2017

In this study, a peptide exhibiting antioxidant activity was isolated from sandfish (Arctoscopus japonicus) roe hydrolysate (SRH) in order to evaluate their practical uses as materials for manufacturing functional foods. The A. japonicus roe protein was hydrolyzed using Collupulin MG, and isolation of antioxidant peptide was performed using ultrafiltration (UF), prep-HPLC, and RP-HPLC. The SRH with a molecular weight below 3 kDa constituted about 38% of the whole hydrolysate, and the fraction with a molecular weight below 3 kDa showed significantly greater antioxidant activity compared to the original SRH and other fractions. The isolation fold of the antioxidant peptide isolated from SRH throughout the four-step procedure was 7.11-fold, and protein yield was 14.8%. The DPPH radical scavenging activity of isolated antioxidant peptide was above 90% at a concentration of 1.0 mg/mL, which was similar to that of the Trolox at a concentration of 0.1 mg/mL. These results suggested that the antioxidant peptide derived from A. japonicus roe could be a useful additive for producing functional foods and protein supplements. However, it is necessary to perform further study the structural characteristics of this antioxidant peptide isolated from A. japonicus roe.

• Restorative Dentistry and Endodontics
• /
• v.40 no.4
• /
• pp.276-285
• /
• 2015

Objectives: The purpose of this study was to evaluate the efficacy of mineral trioxide aggregate (MTA), Biodentine and Propolis as pulpotomy medicaments in primary dentition, both clinically and radiographically. Materials and Methods: A total of 75 healthy 3 to 10 yr old children each having at least one carious primary molar tooth were selected. Random assignment of the pulpotomy medicaments was done as follows: Group I, MTA; Group II, Biodentine; Group III, Propolis. All the pulpotomized teeth were evaluated at 3, 6, and 9 mon clinically and radiographically, based on the scoring criteria system. Results: The clinical success rates were found to be similar among the three groups at 3 and 6 mon where as a significant decrease in success rate was observed in Group III (84%) compared to both Group I (100%) and Group II (100%) at 9 mon. Radiographic success rates over a period of 9 mon in Groups I, II, and III were 92, 80, and 72%, respectively. Conclusions: Teeth treated with MTA and Biodentine showed more favorable clinical and radiographic success as compared to Propolis at 9 mon follow-up.

• Journal of Plant Biology
• /
• v.39 no.1
• /
• pp.23-29
• /
• 1996

Morphology and reproduction of Polysiphonia atlantica Kapraun et J. Norris were studied on the basis of field and laboratory cultured materials collected from the coast of Korea. The plants consisted of prostrate and erect axes with an extremely soft flaccid texture. Axes were ecorticated and had four pericentral cells. The plants except for female gametophytes had few trichoblasts. Branches in the upper portion of the thallus grew to the same level, resulting in a flat-top form. Tetrasporangia were arranged in straight series. Spermatangial branches replaced whole trichoblasts and had a 1-2 celled serile tip. The procarp had a four celled carpogonial branch. After fertilization, the carpogonium contancted the surface of the supporting cell. The formation of the auxiliary cell from the supporting cell was somewhat delayed P. atlantica from Korea was similar to P. subtilissima Montagne in some features. However, the taxonomic differences between the two species were identified in the development of branches and the number of sterile cells at the tip of spermatangial branches.

• Transactions of Materials Processing
• /
• v.13 no.3
• /
• pp.225-229
• /
• 2004

Chemical Mechanical Polishing(CMP) process becomes one of the most important semiconductor processes. But the basic mechanism of CMP still does not established. Slurry fluid dynamics that there is a slurry film between a wafer and a pad and contact mechanics that a wafer and a pad contact directly are the two main studies for CMP. This paper based on the latter one, especially on the abrasion wear model. Material Removal Rate(MRR) is calculated using the trajectory length of every point on a wafer during the process time. Both the rotational velocity of a wafer and a pad and the wafer oscillation velocity which has omitted in other studies are considered. For the purpose of the verification of our simulation, we used the experimental results of S.H.Li et al. The simulation results show that the tendency of the calculated MRR using the relative velocity is very similar to the experimental results and that the oscillation effect on MRR at a real CMP condition is lower than 1.5%, which is higher than the relative velocity effect of wafer, and that the velocity factor. not the velocity itself, should be taken into consideration in the CMP wear model.

• Transactions of Materials Processing
• /
• v.19 no.6
• /
• pp.357-362
• /
• 2010

Dry sliding wear behavior of pure Fe and Cu which have BCC and FCC crystal structure, respectively, was investigated. The wear characteristics of the pure metals with different crystal structure were compared. Dry sliding wear tests were carried out using a pin-on-disk wear tester at various loads under the constant sliding speed condition of 0.15 m/s against a silica ball at room temperature. Sliding distance was fixed as 600 m for all wear tests. Wear rate of a specimen was calculated by dividing the weight loss of the specimen after the test by the specific gravity and sliding distance. Worn surfaces and wear debris were analyzed by SEM. The wear of both pure Fe and Cu proceeded with surface deformation, resulting in similar wear rates despite of their structure difference under the current test conditions. Wear rates of both metals were low if the surface deformation due to wear forms thick surface-deformation layer that is strain hardened beneath the wearing surface. The pure Cu specimens showed a lot of oxides on the worn surface when tested at low loads less than 5 N, which resulted in very low wear rate.

• Transactions of Materials Processing
• /
• v.22 no.4
• /
• pp.183-188
• /
• 2013

Scroll compressors are widely used in air conditioning systems and in automobiles due to their low pressure loss, minimal vibrations, and light-weight. Open-die forging with back pressure is used to forge the rotating scroll, and it requires special care since the forging die can be severely damaged at the fixed end of the spiral cavity similar to a fracture of a cantilever beam. To overcome the inevitable weakness of the forging die due to such damage, an innovative design is necessary. In this study, structural analysis using the finite element method was conducted to determine the reason for the fracture of the forging die. A novel design to avoid stress concentrations and vertical deflection, causing serious damage to the die, is suggested.

• Journal of the Korean Wood Science and Technology
• /
• v.24 no.1
• /
• pp.17-26
• /
• 1996

This research was accomplished to evaluate possibility of using paper sludge for the raw materials of wood based panel products. The experimental panels were manufactured by four mixed ratios, the proportion of paper sludge to wood particle: 20:80, 30:70, 40:60, 50:50% (oven dry weight basis) and by three composition types, sludge-particle mixed board, three layered sludge-particle board and three layered particle board. They were tested mechanical (bending strength and internal bond) and physical properties (water absorption, thickness swelling and linear expansion). From the results they were shown that bending strength of mixed and three layered sludge-particle board were decreased with increasing of composition ratios of sludge. And the mechanical and physical properties of the boards of three layered composition types have superior to those of mixed composition type. Although composition ratios of sludge increased, the internal bond strength and dimensional stability of sludge-particle board not decreased quantitatively. We concluded that the mechanical and physical properties of three layered sludge-particle board were similar w those of three layered particle-board (control) made by our laboratory design. Therefore, it was recognized that paper sludge can be used as potential raw material in particle-board manufacturing industry.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.5 no.4
• /
• pp.263-272
• /
• 2009

Nowadays, lots of software that have similar functions is being produced. Hence it is getting more important to select the best and suitable software for each individual or company. Moreover, there are few trustworthy materials regarding to the objective procedure and criteria for the best evaluation of the software quality. To overcome these problems, benchmarking has been carried out. However, benchmarking is also confronting the limit of quality evaluation verification due to the difficult of the objectification of the major test items. To solve these problems, some others try to evaluate the quality of software using objective criteria of evaluation based on ISO/IEC standards. Nevertheless, this method using these defined evaluation items and criteria may result in not very reliable outcome. Therefore, this paper offers the evaluation items reflected in the characteristics of each software in order to prove the validity of the proposed method. Moreover, the objective and quantitative criterion which analyzes and reflects the organization characteristics using AHP methodology is applied to the experiment and performance evaluation. Hence we expect that the proposed method provides the needs of the re-establishment of software quality evaluation criteria and the improvement of process in terms of management.

• Radiation Oncology Journal
• /
• v.12 no.3
• /
• pp.285-293
• /
• 1994

Purpose : The study was designed to investigate the effect of cis-dichlorodiammineplatinum(II)(cis-DDP) on the radiation-induced cardiomyopathy in the rat. Materials and Methods : The myocardial damage was assessed by histopathologic changes. In radiation alone group, radiation dose ranged from 10-40 Gy X-ray in a single dose and in combined group, cis-dichlorodiammineplatinum(II) at a dose of 6 mg/kg was given intraperitoneally immediately after irradiation of same dose with X-ray alone group. Results : The early changes by radiation included congestion, inflammatory cell infiltrations and fibrosis in myocardial interstitium with focal myocardial necrosis, which was noted in 10 Gy group, Myocardial fibrosis was increased by increasing dose of radiation but myocardial necrosis was not Proportional to radiation dose. cis-DDP alone group showed minimal degeneration of myocardium with surrounded by inflammatory cell infiltrations. In combined group, myocardial fibrosis in 10 Gy group were similar to radiation alone group, but 30 Gy and 40 Gy groups showed severer changes. Electron microscopic examination showed disruption of Z-band and edema of mitochondria with decreased matrix density in 20 Gy radiation group which were severer in 40 Gy radiation group. Combined group showed endothelial changes and disruption of Z-band worse than radiation alone group as well as increased connective tissue, which was considered as a hallmark of late change in radiation-induced heart disease. Conclusion : This results showed minimal enhancement of the radiation-induced cardiomyopathy in rats by cis-DDP.

• Proceedings of the KIEE Conference
• /
• 1997.07a
• /
• pp.47-50
• /
• 1997

The FEM(Finite Element Method) can be used to analysis SRM(Switched Reluctance Motor) as it can account for the salient pole geometry of the stator and rotor and the nonlinear properties of the magnetic materials. However, FEM requirers a lot of computer memory and computing time because, the kind of SRM drivers is verity and the switching strategies are various for one SRM driver. In this paper we proposed the method of analysis of a SRM which results are similar to FEM and has very short computing time. The Inductance and torque for each phase current at each rotor position are calculated by using two-dimensional nonlinear FEM analysis. Using the look-up table of inductance and torque and the voltage equations of SRM we obtained the phase current and torque. To verify proposed algorithm, 3 phase 6/4 SRM is analysed and found a good agreement with FEM results. And computing time is about 1/1600 of the FEM analysis.