• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.432-437
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• 2007

In this study, we examined the conditions for an auto-aging system placed within a kimchi refrigerator for optimal fermentation, and to prolong the storage time of kimchi. Various characteristics of kimchi fermented at different temperatures ($5-23^{\circ}C$) were compared. We observed that the higher the fermentation temperature, the less desirable the overall acceptability of the product. To establish the time point in which to convert the fermentation mode to the storage mode, kimchi was stored at $-1^{\circ}C$ for 1 week once it reached the designated acidity (0.4, 0.6, and 0.8%). The results indicated that the lower the kimchi acidity, the higher the sensory score. The storage temperature of $-1^{\circ}C$ was not low enough to retard microorganism growth completely; however, the kimchi stored at $-2{\pm}0.5^{\circ}C$ became frozen. Accordingly, $15^{\circ}C$ and $-2{\pm}0.5^{\circ}C$ are suggested as the fermentation and storage temperatures for the kimchi refrigerator, respectively. A kimchi acidity of 0.4% can be used as an index for the time point to convert fermentation to storage. Subsequently, the time required for the fermentation course can be calculated based on this.

• Food Science and Preservation
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• v.15 no.6
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• pp.796-803
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• 2008

To aid in manufacturing, this study investigated quality characteristics of onion Jangaji during maturation at 0C, 10C, 20C and room temperature. [Please check that the rewriting of the previous sentence retains the intended meaning]The $^{\circ}Brix$ of onion Jangaji and the maturation solution were 1516% at the end of the maturation process. The salinity of onion Jangaji and the solution increased, and the pH declined to 3.934.31 during processing. The L, a and b color values of onion Jangaji and the solution changed slightly. The total acidity of onion Jangaji and the solution rose slowly. The texture (hardness, fracturability, adhesiveness, cohesiveness, springiness, gumminess and chewiness) of onion Jangaji was determined using a texture analyzer, and varied with storage temperature. In the sensory evaluation of onion Jangaji, low temperature storage gave higher acceptability ratings than room temperature with respect to taste, color, flavor, texture and overall acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.84-88
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• 2011

Some thermally processed foods have higher biological activities due to their various chemical changes during heat treatment. Especially, 5-hydroxymethylfurfural (HMF) is derived from dehydration of sugars and has been identified in processed garlic. The biological function of HMF have revealed as antisickling agent and thyrosinase inhibitor. This study was carried out to examine the formation of HMF and free sugars from the aged garlics when it is treated at 60 and $75^{\circ}C$ and different incubation periods from 7 to 35 days. HMF and free sugars from the hot-water extracts of aged garlics were analyzed with GC/MS, LC/MS, and HPLC. The amount of HMF was higher than at $75^{\circ}C$ and increasing incubation period. Among free sugars, the only fructose except glucose and sucrose was formed and converted to HMF at high temperature and long incubation period. However, fructose formed in low temperature during making of aged garlic was rarely converted to HMF. This result indicates that formation of HMF can be dependent on the temperature and incubation period for making aged garlic.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.518-524
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• 2004

The feasibility of Y(z) curve method of scanning acoustic microscope using high frequency transducer was experimentally studied for assessment of the thermal degradation in Co-based superalloy. Thermal degradation was performed to simulate the microstructural changes in Co-based superalloy arising from long term exposure at high temperature. Longitudinal wave velocity measured by pulse echo method using 10MHz transducer and leaky surface acoustic wave (LSAW) velocity measured by V(z) curve method using 200MHE transducer were measured to investigate the effect on thermal degradation. Ultrasonic velocity decreased as the aging time increased in both ultrasonic waves. Moreover, the low frequency longitudinal wave velocity decreased a little. Otherwise, the high frequency LSAW velocity drastically decreased up to a maximum of 4.7% at the aging time of 4,000hours. A good correlation was found between LSAW and Vickers hardness. Consequently, V(z) curve method of SAM using high frequency transducer could be a potential tool for assessing thermal degradation.

• Journal of Life Science
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• v.24 no.2
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• pp.167-172
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• 2014

Optimal conditions for extraction of bakkenolide B from Petasites japonicus leaves were determined by using response surface methodology. A second-order Box-Behnken design representing three extraction temperatures (80, 100, $120^{\circ}C$), three extraction times (30, 45, 60 min), and three solvent pH's (5, 7, 9) was executed. The efficiency of the extraction conditions was defined using the ${\beta}$-hexosamidase assay by comparing both the bakkenolide B content and its anti-allergic activity expressed as extract inhibition on degranulation. The response surface plot described for the bakkenolide B content showed that the maximum content was predicted as 121.6 ${\mu}g/g$ with extraction conditions of $127.1^{\circ}C$, 46.6 min, and pH 7.7. Extraction temperature and time were important factors in determining bakkenolide B content. Using regression analysis, correlation between the inhibition effect of mast cell degranulation and bakkenolide B content was found to be low.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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• pp.509-519
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• 2013

Through the study on judgment of Body form and settle Energy flow(立形定氣) before diagnose the patients, the results are as follows. The observation of the body form is to determine prosperity and deficiency of each internal organ. It is necessary to distinguish Body form loss(形脫) and Body form fullness(形充). Fat man(肥人), Thin man(瘦人), Creamy man(膏人), Muscular man(肉人), Small Fat man(脂人) are discriminated by fat distribution, fat content, and muscle mass. The observation of the body form means the observation of structure disorder, color change, develop part at body, head and face. The observation of the body form that is to determine prosperity and deficiency of each internal organ is from the limited knowledge of the anatomy. The observation of face color is considered by blood perfusion, blood oxygenation and accumulation of carotinoid, bilirubin and change of melanin in the facial skin. The prosperity and the deficiency of energy flow is considered by symptom combined with growth (<40 years) and aging (>40 years). The prosperity of energy flow includes the anger, anxious emotion and the deficiency of energy flow includes the fear, depressive emotion. The breathing type is expiratory exhalation like asthma patients in the prosperity of energy flow. The deficiency of energy flow is weakness to overcome the disease. The prosperity and the deficiency of energy flow are considered by body metabolic ratios (Basal metabolic Rate: BMR, Resting metabolic rate: RMR, Physical activity ratios: PASs). Development of subcutaneous fat is good in the person of prosperous energy flow. The person of prosperous energy flow is hard to overcome to heat weather than cold weather. The person of deficiency of energy flow has tendencies of low blood pressure, insufficiency of blood flow in the peripheral and being shocked. The person of deficiency of energy flow has tendencies of chronic fatigue syndrome or automatic nerve disorder. If the patient who has deficiency of energy flow has severe weight loss should be checked for the presence of disease. The observation of small and large of bone is to check the development and disorder of bone growth and aging. The observation of thickness and weakness of muscle is to check the development of muscle, particularly biceps, gastrocnemius, and rectus abdominal muscle. The observation of thickness and weakness of skin is to check the ability of regulating body temperature by sweating.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.2
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• pp.1-9
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• 1986

To study the effects of surface structure of fiber on the decrement of fatty soil removal at high temperature, the following variables were selected: controled and alkali-treated P.E.T.(polyester) fabrics and chopped fibers as substrates to estimate the detergencies, different aging methods of soiled substrates, and different washing temperatures and surfactant solutions. Radiotagged tripalmitin was used as soil and the detergency was estimated by means of liquid scintillation counting method. The results were as following: The surface of the fiber became rough with many grooves and the hydrophilicity of the fiber was increased and the structure of the fabric became loose by alkali treatment. While the detergency of alkali-treated P.E.T. fabric was better than that of controled P. E. T. fabric, there was no significant differences between the detergencies of controled and alkali-treated chopped fibers. These results indicate that the increment of detergency of alkali-treated P.E.T. fabric is mainly resulted from the changes of fabric structure and the improved hydrophilicity of fiber by alkai treatment. The detergency of tripalmitin was increased with elevating temp. below the m.p. of tripalmitin, was decreased around the m.p., and again was increased above the m.p ..It is considered that the decrement of detergency around the m.p. is due to the diffusion of molten tripalmitin into the grooves on fiber surface, the inner part of fiber, and between fibers. When controled and alkali-treated soiled fabrics and soiled chopped fibers were washed in the distilled water and in the Na-DBS solution respectively, below $60^{\circ}C$ detergencies of alkali-treated fabrics and chopped fibers were improved. However above $60^{\circ}C$ this result was reversed. Therefore these results are regarded as the effects of grooves on fiber surface at high temp. and improved hydrophilicity at low temp. by alkali treatment. When controled and alkali-treated soiled fabrics and soiled chopped fibers were hot-aged before washing, the detergencies of both species were decreased generally. Because the soil was diffused into the grooves on fiber surface, the inner part of fiber, and between fibers during hot-aging. The detergencies of hot-aged species were also decreased above certain temp.. These results suggest that the decrement of detergency at high temp. be resulted not only from the diffusion of soil into the grooves on fiber surface, the inner part of fiber, and between fibers, but also from the characteristics of surfactant solutions.

• Composites Research
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• v.12 no.6
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• pp.74-82
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• 1999

The static and fatigue characteristics of polyurethane foam cored sandwich structures are investigated. Three types of the specimens with the glass fabric faces and the polyurethane foam core are used; non-stitched. stitched, and stiffened sandwich specimen. Especially additional structural reinforcements with the twisted polyester and glass fiber for thickness direction are made to stitched sandwich structure panel to minimize the delamination of structure which is stitched the upper and lower faces through the core and the resin is impregnated Into stitched fiber with the characteristics of low viscosity of resin at resin flow temperature and cured together with during the curing process. Bending strength of stitched specimen which is 50 mm $50{\times}50{\;}mm$ pitched is improved by 50 % as com-pared with non-stitched specimen and stiffened specimen is improved 10 times more than non-stitched structure. After fatigue testing of $10^6$cycles by 20% of ultimate load under monotonic load, the bending fatigue strength of non-stitched specimen is decreased by 27% of monotonic bending strength, 39% for stitched structure and 20% for stiffened specimen. To verify the aging effect of polyurethane form core, Ultrasonic C-scanning equipment is used to detect the damage of skin laminate alone after fatigue test. From results of UT C-scan images, there is no defect that can be damaged occurred during fatigue test. It is concluded that the decrease of bending strength for foam cored sandwich specimen is caused by the decrease of stiffness due to the aging of polyurethane foam core during fatigue cycles.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2498-2508
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• 1993

$Al/SiC/Al_{2}O_{3}$ hybrid composites are fabricated by squeeze infiltration method. From the misconstructive of $Al/SiC/Al_{2}O_{3}$ hybrid composites fabricated by squeeze infiltration method, uniform distribution of reinforcements and good bondings are found. Hardness value of $Al/SiC/Al_{2}O_{3}$ hybrid composites increases linearly with the volume fraction of reinforcement because SiC whisker and $Al_{2}$O$_{3}$ fiber have an outstanding hardness. Optimal aging conditions are obtained by examining the hardness of $Al/SiC/Al_{2}O_{3}$ hybrid composites with different aging time. Tensile properties such as Young's modulus and ultimate tensile strength are improved up to 30% and 40% by the addition of reinforcements, respectively. Failure mode of $Al/SiC/Al_{2}O_{3}$ hybrid composites is ductile on microstructural level. Through the abrasive wear test and wear surface analysis, wear behaviour and mechanism of 6061 aluminum and $Al/SiC/Al_{2}O_{3}$ hybrid composites are characterized under various testing conditions. The addition of SiC whisker to $Al/SiC/Al_{2}O_{3}$ composites gives rise to improvement of the wear resistance. The wear resistance of $Al/SiC/Al_{2}O_{3}$ hybrid composites is superior to that of Al/SiC composites. The wear mechanism of aluminum alloy is mainly abrasive wear at low speed range and adhesive and melt wear at high speed range. In contrast, that of $Al/SiC/Al_{2}O_{3}$ hybrid composites is abrasive wear at all speed range, but severe wear when counter material is stainless steel. As the testing temperature increases, wear loss of aluminum alloy decreases because the matrix is getting more ductile, but that of $Al/SiC/Al_{2}O_{3}$ hybrid composites is hardly varied. Oil lubricant is more effective to reduce the wear loss of aluminum alloy and $Al/SiC/Al_{2}O_{3}$ hybrid composites at high speed range.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.95-108
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• 1984

Even though the tarnishing and corrosion problems characteristic with dental silver-palladium alloy are not yet fully solved, it is recently widely used because of its low cost. However the effects of major alloying elements on the various properties of this system are not fully understood. The object of this research is to clarify the effects of In and Zn additives on the corrosion and tarnishing resistances and precipitation hardening behavior of this sytem, using electrodynamic polarization, immersion, and Vicker's microhardness test and X-ray diffraction and electron probe micro analysis methods. The obtained results were as follows: I. As indium content is increased, both the corrosion resistance in Cl-solution and microhardness are also increased while the tarnishing resistance is decreased. 2. As Zinc content is increased, the corrosion resistance is decreased, but tarnishing resistance is increased 3. At 70Ag-25Pd-2.5Zn-2.5In composition, the precipitation harding behavior was mot significant. The optimum aging temperature was $450^{\circ}C$ and the time was 2 hrs. The resulting specimen of this work carried 180VHN. 4. Under the heat treatment, the changes in the mechanical property are due to the changes in the shape and composition of dendrite matrix, namely, it is because of the precipitation hardening behavior which has been proved by electron probe micro analysis and optical microscopic finding.