• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.232-241
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• 1979

For the effective utilization of the fish resource in coastal regions, an investigation on optimum processing conditions and meat quality textured fish protein concentrate (FPC) was carried out with the fish meat of filefish and sardine. Optimum pH and sodium chloride content of fish meat were 7.5 and 1.0 %, respectively. The most effective soaking conditions were as follows ; soaking time, 30 min ; temperature of ethanol, 5 to $20^{\circ}C$ ; amount of added ethanol, 3 times the weight of the fishmeat paste ; repeated number of soaking in ethanol for filefish and sardine, 2 and 4, respectively. The ethanol remaining is meaty textured FPC could be removed effectively by forced-air drying. Yields of the product to the minced meat weight and the contents of protein lipid in meaty textured from filefish were 21.1, 77.6 and 0.2 % and those from sardine were 24.3, 75.8 and 3.6 %, respectively. Contents of essential amino acids in meaty textured FPC of filefish and sardine were not inferior to those of beef, textured soybean protein and FAO pattern. Beef meat could be substituted with the meaty textured FPC up to 50 % in the processing of typical meat balls and hamburger without any significant loss in its taste, odor and texture.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.731-739
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• 2014

This paper describes the evaluation of the impact performance of steel fiber-reinforced concrete based on high-velocity impact experiments using hard spherical balls. In this experimental study, panel specimens with panel thickness to ball diameter (h/d) ratios of 3.5 or less were tested with variables of steel fiber volume fraction, panel thickness, impact velocity, and aggregate size. Test results were compared with each other to evaluate the impact resistance. The results showed that the percentage of weight and surface loss decreased as the steel volume fraction increased. However, the penetration depth increased with up to steel fiber volume fraction of 1.5%. Particularly the results of specimens with 20 mm aggregates showed poorer performance than those with 8 mm aggregates. The results also confirmed that the impact performance prediction formulas are conservative with (h/d) ratios of 3.5 or less. Despite the conservative predictions, the modified NDRC formula and ACE formula predict the impact performance more consistently than the Hughes formula.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.134-135
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• 2003

The dental implant materials required good mechanical properties, such as fatigue strength, combined with a high resistance to corrosion. For increasing fatigue resistance and delaying onset of stress corrosion cracking, shot peening has been used for > 50 years to extend service life of metal components. However, there is no information on the electrochemical behavior of shot peened and hydroxyapatite(HA) coated Ti-6Al-4V alloys. To increase fatigue strength, good corrosion resistance, and biocompatibility, the electrochemical characteristics of Ti/TiN/HA coated and shot peened Ti-6Al-4V alloys by electron beam physical vapor deposition(EB-PVD) have been researched by various electrochemical method in 0.9%NaCl. Ti-6Al-4V alloys were prepared under the condition of hydrogen and vacuum arc furnace. The produced materials were quenched at 1000$^{\circ}C$ under high purity dried Ar atmosphere and were hold at 500$^{\circ}C$ for 2 hrs to achieve the fatigue strength(1140㎫) of materials. Ti-6Al-4V alloys were prepared under the condition of hydrogen and vacuum arc furnace. Shot peening(SP) and sand blasting treatment was carried out for 1, 5, and 10min. On the surface of Ti-6Al-4V alloys using the steel balls of 0.5mm and alumina sand of 40$\mu\textrm{m}$ size. Ti/TiN/HA multilayer coatings were carried out by using electron-beam deposition method(EB-PVD) as shown Fig. 1. Bulk Ti, powder TiN and hydroxyapatite were used as the source of the deposition materials. Electrons were accelerated by high voltage of 4.2kV with 80 - 120mA on the deposition materials at 350$^{\circ}C$ in 2.0 X 10-6 torr vacuum. Ti/TiN/HA multilayer coated surfaces and layers were investigated by SEM and XRD. A saturated calomel electrode as a reference electrode, and high density carbon electrode as a counter electrode, were set according to ASTM GS-87. The potentials were controlled at a scan rate of 100 mV/min. by a potentiostat (EG&G Co.273A) connected to a computer system. Electrochemical tests were used to investigate the electrochemical characteristics of Ti/TiN/HA coated and shot peened materials in 0.9% NaCl solution at 36.5$^{\circ}C$. After each electrochemical measurement, the corrosion surface of each sample was investigated by SEM.

• Tribology and Lubricants
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• v.27 no.6
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• pp.308-313
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• 2011

In this study, friction tests were performed in order to investigate the effect of sliding velocity and normal load on the friction characteristics of DLC (a-C:H) and WC/C (a-C:H:W) using a ball-on-disk type friction tester. DLC and WC/C were deposited on AISI 52100 steel balls. Friction tests against carburized SCM 415 Cr-Mo steel disks were carried out under various sliding velocity (0.1, 0.78, 1.56, 3.13, 6.25, 12.5, 25, 50 and 100 mm/s) and normal load (2.4, 4.8 and 9.6 N) conditions while the relative humidity was 20~40 % R.H. and air temperature was $16{\sim}24^{\circ}C$. As results, kinetic friction coefficients of DLC and WC/C were obtained under each test condition. The results show that the kinetic friction coefficients of DLC and WC/C generally increase with the increase in sliding velocity. And, under the same sliding velocity condition, the kinetic friction coefficients are almost constant regardless of normal load. In addition, the kinetic friction coefficients of DLC are lower than those of WC/C under the same test conditions.

• Korean Journal of Materials Research
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• v.9 no.3
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• pp.288-294
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• 1999

In the flip chip interconnection using solder bump, the Under Bump Metallurgy (UBM) is required to perform multiple functions in its conversion of an aluminum bond pad to a solderable surface. In this study, various UBM systems such as $Al 1\mu\textrm{m} / Ti 0.2\mu\textrm{m} / Cu 5\mu\textrm{m}, Al 1\mu\textrm{m} / Ti 0.2\mu\textrm{m} / Cu 1\mu\textrm{m}, al 1\mu\textrm{m}/Ni 0.2\mu\textrm{m} / Cu 1\mu\textrm{m} and Al 1\mu\textrm{m}/Pd 0.2\mu\textrm{m} / Cu 1\mu\textrm{m}$ for flip chip interconnection using the low melting point eutectic 63Sn-37Pb solder were investigated and compared to their metallurgical properties. $100\mu\textrm{m}$ size bumps were prepared for using an electroplating process. The effects of the number of reflows and aging time on the growth of intermetallic compounds(IMC) were investigated. $Cu_6Sn_5$ and $Cu_3Sn$ IMC were abserved after aging treatment in the UBM system with thick coper $(Al 1\mu\textrm{m}/Ti 0.2\mu\textrm{m}/Cu 5\mu\textrm{m})$. However only the $Cu_6Sn_5$ was detected in the UBM system with $1\mu\textrm{m}$ thick copper even after 2 reflow and 7 day aging at $150^{\circ}C$. Complete Cu consumption by Cu-Sn IMC growth gives rise to a direct contact between solder inner layer such as Ti, Ni and Pd, and hence to possibly cause reactions between two of them. In this study, however, only for the Pd case, IMC of PdSn. was observed by Cu consumption. UBM interfacial reactions with s이der affected the adhesion strength ot s이der balls after s이der reflow and annealing treatment.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.1-6
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• 1998

An epidemiological survey was carried out to determine the first intermediate host of Clinostomum complanatum among freshwater snails in Korea. Two species of snails belonging to the family Lymnaeidae were collected in Kaum-ji (pond) , Uisong-gun, Kyongsangbuk-do. Twelve (0.9%) out of 1,273 Radiae auricularia corecna examined were found to liberate cercariae of C. complcnatum, which were identified by morphologital characteristics and experimental infections in freshwater fish, Pseunorosborc pnnjc. The cercariae were brevifurcate and clinostomatoid. They had a transparent dorsal fin, a well developed penetrating organ and a pair of eye spots. The body measured $119-147{\;}{\times}{\;}33-36{\mu\textrm{m}}$, tail stem, tailstem은 $275-370{\;}{\times}{\;}19-26{\;}{\mu\textrm{m}}$, and furcae, $72-104{\;}{\mu\textrm{m}}$. Rediae were demonstrated in the infected snail after crushing. Redia, $527-1,630{\;}{\mu\textrm{m}}$ long and 121-368${\;}{\mu\textrm{m}}$ wide, contained 10-45 germ balls and cercariae in various developmental stapes. The metacercariae recovered from fish experimentally infected with C. complanntum cercariae were morphologically identical to those from naturally infected fish.

• Resources Recycling
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• v.29 no.4
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• pp.67-72
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• 2020

Recycling processes of spent copper wires cosisnt of several steps of cutting and chopping processes for peeling covering materials followed by gravity separation processes, where copper is recovered. Because copper thin wires could be lost during further recycling processes, the wire may need to be further treated. In the present study, the copper thin wire was treated with ball milling to prevent the loss. Since the aggregation of the copper wire could be formed by bending and entangling the copper wire each other, the degree of flexion of the copper wire was measured after ball milling. When the 0.5 cm and 3 cm copper wires were used, the 0.5 cm copper wire was not bent and the 3 cm copper wires were aggregated regardless of the ball addition. When the 1 cm and 2 cm copper wires were used, the degree of flexion was remarkable when the balls were added. In the tests using 2 cm copper wires, the aggregation ratio of the copper wire gradually increased with the amount of the 20 mm alumina ball, and when 200 ml of 30 mm alumina ball was used, the aggregation ratio increased to 89.29 %, but after increasing the ball amount further, the aggregation ratio decreased. Thus, it is expected that the loss of the copper wire could be reducedif when the copper thin wire is treated with ball milling by the aggregation of copper thin wires.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.1-12
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• 2019

We investigated the nutritional components of the major commercial frozen seafood products (MCFSP) [sliced frozen-skipjack tuna (ST), -bigeye tuna (BET), -bluefin tuna (BFT), -yellowfin tuna (YT), fish steaks (FST), fish pancakes (FP), fish cutlets (FC), seafood cake balls (SCB), fried shrimp (FS), shrimp patties (SP), shrimp cutlets (SC)] in Korea. All species of sliced frozen tuna and FST were classified as low-calorie foods; the other frozen seafood products were classified as medium-calorie foods. The MCFSP were significant sources of nutritional and functional minerals: the SCB and SC provided calcium; the FST, FC, and SCB provided phosphorus; the BET, YT, and FST provided potassium; the FST, FC, and BFT provided magnesium; the FST, FP and SC provided iron; the SCB, FS, SP, and SC provided zinc; the YT and SCB provided copper; and the FC provided manganese. The total amino acid contents of the MCFSP were in the range of 6.85-26.34 g/100 g. Glutamic acid was the major amino acid in the SCB, FS, SP, and SC. Fatty acid contents were in the range of 386-2,925 mg/100 g; the major fatty acids in the ST, BFT and YT were 16:0, 18:1n-9, 22:6n-3. The MCFSP were not a significant source of vitamin A or riboflavin.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.262-276
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• 2021

Purpose: Although, the rate of skipping breakfast among adolescents has increased in recent years, there has been an increase in the consumption of home meal replacement (HMR). This study examines the recognition and preference of rice-based Korean style HMR for breakfast among adolescents in located at Jeollabuk-do. Methods: Total of 550 middle- and high-school students of Jeollabuk-do enrolled in this study signing a consent of participation. After conducting a preliminary survey, the questionnaire employed was modified according to the purpose of this study, and the self-recording method was appliedto fill out the questionnaire. Data were analyzed using IBM SPSS Statistics 25. The 𝛘²-test was performed for categorical variables, whereas continuous variables were analyzed by the independent t-test. Results: Results of this study determined that 272 students (54.6%) belonged tobreakfasteating group and 226 (45.4%) were in the breakfast-skipping group. The reasons specified by both groups for eating HMR were 'convenient to cook', 'delicious', and 'time-saving'. The a result of analyzing perception of the importance of HMR by classifying as whether to eat or not to eat breakfast, revealed that compared to the breakfast-skipping group, the breakfast-eating group considered 'hygiene and cleanliness' as important factors (p < 0.001). Considering the gender, school, and breakfast consumption, the most preferred Korean HMR were 'triangular gimbap', 'gimbap', and 'rice balls'. Conclusion: Results of this study indicate, when considering adolescents, there is a necessary for continuous researches to develop convenient breakfast substitutes that are easily consumed. Moreover, we believe that it is essential to impart proper cooking education and recipe distribution of the menu.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.3
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• pp.55-61
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• 2022

In this study, properties of Pb-free solder joints which were combined using Sn-3.0Ag-0.5Cu (SAC305) Pb-free solder with a mid-temperature type of melting temperature and Sn-57Bi-1Ag Pb-free solder with a low-temperature type of melting temperature were reported. Combined Pb-free solder joints were formed by reflow soldering processes with ball grid array (BGA) packages which have SAC305 solder balls and flame retardant-4 (FR-4) printed circuit boards (PCBs) which printed Sn-57Bi-1Ag solder paste. The reflow soldering processes were performed with two types of temperature profiles and interfacial properties of combined Pb-free solder joints such as interfacial reactions, formations of intermetallic compounds (IMCs), diffusion mechanisms of Bi, and so on were analyzed with the reflow process conditions. In order to compare reliability characteristics of combined Pb-free solder joints, we also conducted thermal shock test and analyzed changes of mechanical properties for joints from a shear test during the thermal shock test.