• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.139-149
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• 2005

In order to study about the lobule and layer formation and cell migration of the mouse cerebellum from at the birth to 15th day effected by 2.5, 5 and 10 Gy r-raddiation at the 19th pregnancy. The routine tissue preparation and staining procedure, Immunohistochemical staining method by the several antibody and western brotting method were utilized from the birth to the15th day. The results were as followings. 1. The body and cerebellum weights were more slowly increase of the the 2.5 Gy, 5 Gy and 10 Gy irradiation group compare to the control group, and the health condition of the 2.5 Gy group was a little bad. but the 10 Gy group was more severe and begun to die from the 12th day after birth. 2. The thickness, proliferation and migration of the 2.5, 5 and 10 Gy irradiated external granular cells from the maginal zone to the medullary area forming the molecular layer from the 6th day to the 15th day after birth were thinner, weaker and more slower according to the radiated dosages than the control group in the cresyl violet staining. 3. The proliteration, migration and lobulation of the 5 Gy radiated groups from the first day to the 15th day after birth were more weak, incomplete and irregular shape in the immunostaining with Dab, Cdk5, P35, calbindin and Zebrin antibody. 4. In the western blotting analysis using the Reelin, Dab, Cdk5 and P35 antibody. The Bands were in the 60 KD, 80 KD, 33 KD and 35 KD, and there were no differences between the control and irradiated groups in the molecular band except the Reelin. 5. As a results, the proliferation and migration of the outer granular and purkinje cells, and lobulation of the cerebellum by the several dosaege of the ${\gamma}$-ray radiation were proportionally incomplete according to dosage.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.720-727
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• 2001

This study was carried to investigate the changes in physical and chemical properties of Yukwa during preparation with addition of antioxidants and to develop its storage condition. Antioxidants (tocopherol and Oxyfos) were used in syrup coating and the packaging materials used were PET/EVOH $(16\;{\mu}m)/PL$ : P1 and PET/EVOH $(24\;{\mu}m)/PL$ : P2 (YOP1: P1 with Oxyfos, YOP2 : P2 with Oxyfos, YTP1 : P1 with tocopherol, YTP2 : P2 with tocopherol). Color values measured for Yukwa showed that L values of YOP1, YOP2, YTP1 and YTP2 were changed little during storage while a and b values of YOP1, YOP2, YTP1 and YTP2 were slightly decreased. Hardness and chewiness in textural properties were also decreased during storage. Yukwa packed in YOPl and YOP2 maintained less than 40 in peroxide value during for 12 weeks of storage period. The major fatty acid composition of frying oil were linoleic acid (54.2%), oleic acid (23.4%), palmitic acid (11.3%), linolenic acid (6.5%) and stearic acid (4.6%). There was no difference in composition of fatty acid during storage. Sensory evaluation (Yukwa odor and rancid odor) showed very similar results with determined by electronic nose. YTP1 and YTP2 had maintained sensory characteristics of Yukwa during 10 weeks storage.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.802-812
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• 2016

Silicone foam is very useful as flame resistant material for many industrial areas such as high performance gasketing, thermal shielding, vibration mounts, and press pads. A silicone foam was prepared through simultaneous crosslinking and foaming by hydrogen condensation reaction of a vinyl-containing polysiloxane (V-silicone) and a hydroxyl-containing polysiloxane (OH-silicone) with hydride containing polysiloxane (H-silicone) in the presence of platinum catalyst and imorganic filler at room temperature. This is more convenient process for silicone foam manufacturing than the conventional separated crosslinking and foaming systems. Funtionalized silicones we used in this experiment were consisted with a V-silicone containing 1,0 meq/g of vinyl groups and a viscosity of 20 Pa-s, an OH-silicone with 0.4 meq/g of hydroxyl groups and a viscosity from 50 Pa-s, and an H-silicone containing 7.5 meq/g of hydride groups and a viscosity of 0.06 Pa.s. The effects of compositions of functionalized silicones and additives, such as catalyst and filler on the structure and mechanical properties of silicone foam were studied. 0.5 wt% of Pt catalyst was enough to accelerate the foaming rate of silicone resins. The addition of OH-silicone with lower viscosity accelerates the initial foaming rate and decreases the foam density, but the addition of V-silicone with lower viscosity reduces the tensile strength as well as the elongation. The final foam density, tensile strength, and elogation of silicone foam prepared under the SF-3 condition increase maximum to $0.58g/cm^3$, $3,51kg_f/cm^2$, and 176 %, repectively. We found out the filler alumina also played an important role to improve the mechanical properties of silicone foams in our foaming system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.9-15
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• 2006

As a part of the investigation for utilizing pearl oyster by-products, a rapid salt-fermented pearl oyster using commercial enzyme was prepared and also examined on the characteristics. The salt-fermented pearl oyster prepared by optimal condition, which was prepared by mixing of minced pearl oyster, 15% salt, and 1% $Protamex^\circledR$ and fermented for 4 weeks, was superior in hydrolysis degree (28.7%) and ACE inhibitory activity (92.6%) to salt-fermented pearl oyster prepared by other conditions, such as the use of whole tissue, different enzymes $(Alcalase^\circledR,\;Neutrase^\circledR\;and\;Flavourzyme^\circledR)$, different salt concentrations (20 and 25%), and different fermentation periods (2, 6 and 8 weeks). There were, however, some shortcomings with this product. It showed a dark green color and an unfavorable bitter taste. These shortcomings were improved by the addition of seasoning paste. The calcium and phosphorus contents of the seasoned salt-fermented pearl oyster were 64.2 mg/100 g and 71.6 mg/100 g, respectively, and the calcium content based on phosphorus was a good ratio for absorbing calcium. The total amino acid content of the seasoned and salt-fermented pearl oyster was 7,054 mg/100 g and the major amino acids ware aspartic acid (555.1 mg/100 g), glutamic acid (1,131.2 mg/100 g), alanine (658.2 mg/100 g), and lysine (695.5 mg/100 g). The seasoned salt-fermented pearl oyster, along with angiotensin I converting enzyme (ACE) inhibitory activity (98.3%), also showed a recognizable level (87.5%) of anti-oxidative activity.

• Restorative Dentistry and Endodontics
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• v.31 no.1
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• pp.50-57
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• 2006

The purpose of this study was to investigate influence of each file step of $ProTaper^{(R)}$ system on canal transportation. Twenty simulated canals were prepared with either engine-driven $ProTaper^{(R)}$ or manual $ProTaper^{(R)}$, Group R-resin blocks were instrumented with rotary $ProTaper^{(R)}$ and group M-resin blocks were instrumented with manual $ProTaper^{(R)}$. Pre-operative resin blocks and post-operative resin blocks after each file step preparation were scanned. Original canal image and the image after using each file step were superimposed for calculation of centering ratio The image after using each file step alld image after using previous file step were superimposed for calculation of the amount of deviation. Measurements were taken horizontally at five different levels (1 2, 3, 4 and 5 mm) from the level of apical foramen. In rotary $ProTaper^{(R)}$ instrumentation group, centering ratio and the amount of deviation of each step at all levels were not significantly different (p>0.05). In manual $ProTaper^{(R)}$ instrumentation group, centering ratio and the amount of deviation of each step at all levels except of 1 mm were not significantly different (p>0.05). At the level of 1 mn, F2 file step had significantly large centering ratio and the amount of deviation (p<0.05). Under the condition of this study, F2 file step of manual ProTaper tended to transport the apical part of the canals than that of rotary $ProTaper^{(R)}$.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.867-872
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• 2002

This study was performed to investigate the optimum process conditions for manufacturing yeast extract from waste brewer's yeast using various enzymes. Contents of IMP, GMP, free amino acids, and crude protein of yeast extracts were measured by enzymes treatment. Crude protein contents of yeast extracts subjected to cell wall digestion enzyme treatment were 21.1, 33.6, and 28.0% for the control grouup, glucanase (0.5%, 12 h), and tunicase (1%, 18 h), respectively. Crude protein contents of yeast extracts subjected to protease treatment were 22.0, 30.8, and 29.8% for control group, bromelin (1%, 3 h), and protamex (1%, 3 h), respectively. Crude protein content of yeast extract subjected to glucanase and protamex mixed treatment was 34.4%. The total contents of IMP and GMP of yeast extracts subjected to G+P+A (glucanase+phosphodiesterase+adenyldeminase) and G+Pro+P+A (glucanase+protamex+phosphodiesterase+adenyldeaminase) treatments were 1,066 and 1,047 mg/100 g, respectively. The content of free amino acids of yeast extract was the highest (2,302 mg/100 g) in G+Pro+P+A treatment. Optimum concentration and process condition of enzyme treatment to obtain yeast extract with high IMP, GMP, and free amino acid content were in the order of glucanase (0.5%, 12 h), protamex (1%, 3h), phosphodiesterase (0.1%, 3 h) and adenyldeaminase (1%, 1.5 h) treatments.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.446-460
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• 2000

All-ceramic restorations have had a more limited life expectancy than metal ceramic crowns be-cause of their lower strength. The relatively lower strength has limited the use of all-ceramic crowns to the areas where occlusal loads are lower Therefore many researches have been done to increase the strength of all-ceramic crowns. IPS Empress 2 is a new type of lithium disilicate glass-ceramic with enhanced physical characteristics which has been in use clinically since 1998. Previous researches reported that the flexural strength of all-ceramic material was greater than 300 MPa, and all-ceramic crowns can be used in staining or layering technique. The objective of this study was to investigate the influence of the thickness of IPS Empress 2 ceramic on fracture strength. Both staining technique and layering technique was investigated. Vita VMK was used as control. For all three groups, five specimens each of 0.8mm, 1.0mm, 1.4mm, 1.8mm, and 2.2mm thick-ness (a total of 75 specimens) were prepared. Control group : Vita VMK Porcelain specimens were prepared with dentine ceramic and liquid glazing was done. Group I : IPS Empress 2 were prepared with staining technique and stained twice and glazed once. Group II : IPS Empress 2 were prepared with layering technique and glazed after wash firing. The thickness and diameter of the specimen were measured and controlled after specimen preparation. Biaxial Flexure Test (ASTM Standard F394-78) was adopted as this test method produces results least affected by the edge condition of the specimens. Fracture strength was measured with Instron Universal Testing Machine. Conclusions are as follow : 1. The fracture strength was increase in order of control group, test group I, test group II. 2. Fracture strength of the group I (Empress 2 Staining) was 65.54 N in 0.8mm, 155.2 N in 1.0mm, 233.5 N in 1.4mm, 434.5 N in 1.8mm, and 600.1 N in 2.2mm. 3. Fracture strength of the group II (Empress 2 Layering) was 190.0 N in 0.8mm, 283.5 N in 1.0mm. 437.2 N in 1.4mm, 732.0 N in 1.8mm, and 1115.0 N in 2.2mm. 4. No statistical difference was found in flexural strengths according to thickness in a specified group(p>0.05).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.369-375
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• 2004

In this study, liquid crystalline (LC) is formed using Gemini surfactant (GS) type and moisturizing effect in vivo is measured. $3.0\;wt\%$ of sodium dicocoyl ethylene diamine (PEG)-15 sulfate (SCD-PEG-15S) is used as GS and $4.0\;wt\%$ of hydrogenated dimer acid esters (HDAE) as booster. For stabilizers, $2.0\;wt\%$ of behenyl alcohol (BA) and $1.0\;wt\%$ of Iyso-lecithin (LyL) are utilized. It is stabilized in pH from 4.0 to 10.5 and the best condition is in pH 6.5. The value of viscosity is $8,000\pm500$ cP. The most excellent particles are formed within the range of 4.0 to 15.5 um. Formed LC is observed around LC particles using polarization microscope. It is also observed that lamellar gel network structure is formed around LC particles. Moisturizing effect is improved by $13.6\%$ (P<0.05) compared to control when measured 30 min later after coating samples. After 1 h, moisturizing effect is improved by 1$12.6\%$ (P<0.05) than control while showing $28.3\%$ (P<0.05) of improvement after 4 h. These results may be caused from that manufactured LC forms lamellar structure so that it has better water-holding ability and absorbance of oil increases. This formula could be utilized by delivery system (DS) on skin so that this technology can be applied for manufactuing pharmaceuticals and cosmetics.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.5
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• pp.343-349
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• 2013

Crashworthy fuel cells have a great influence on improving the survivability of crews. Since 1960's, the US army has developed a detailed military specification, MIL-DTL-27422, defining the performance requirements for rotorcraft fuel cells. In the qualification tests required by MIL-DTL-27422, the crash impact test should be conducted to verify the crashworthiness of fuel cell. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. Because the crash impact test itself takes a long-term preparation efforts together with costly fuel cell specimens, the failure of crash impact test can result in serious delay of a entire rotorcraft development. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error with full-scale fuel cells. Present study performs the numerical simulation using SPH(smoothed particle hydro-dynamic) method supported by a crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the resulting equivalent stresses of fuel cell itself are calculated and vulnerable areas are also evaluated.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.306-313
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• 1973

With the intention of obtaining technical data for the industrial production of ${\gamma}-MnO_2$ for dry cell depolarizer by electrolytic oxidation of acidic manganese sulfate solution made from domestic rhodochrosite, optimum conditions of ore leaching, purification of leached solution and electrolytic oxidation of divalent manganes to tetravalent were investigated using simulated micro pilot plant having a production capacity of 4 kg of $MnSO_4$ per day. The nature and quality of the products were investigated by means of chemical analysis, DTA, X-ray diffraction and electron microscopy. The cell activity of $MnO_2$were examined by cell discharging character measurements. The optimum electrolysis conditions were as follow: Temperature of the electrolyte, above $90^{\circ}C$; current density, 0.7${\sim}A/dm^2$; anode materials, graphite or lead ; concentration of electrolyte, $MnSO_4 50{\sim}150g/l $ g/l and $H_2SO_4/MnSO_4 = 0.15{\sim}0.25$. Under the best condition the current efficiency was 99% and the products were almost pure ${\gamma}-MnO_2$. The cell discharging character were good and almost the same as that of regular grade commercial electrolytic manganese dioxide.