• Journal of Korea Soil Environment Society
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• v.5 no.2
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• pp.99-105
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• 2000

The purpose of this study was to show the application of the Biofilter for treatment of the soil contaminated by lead and to investigates the effect of the biofilter on the retardation of lead with pilotplants that were simulated with different media and the number of bed. and to testify the inoculation by seeding microbes. The ratio of the degradation of soil contaminant was verified as CODcr/TOC in order to find a variation of the stabilization index in soil. The Biofiltration was one of biological processing methods for treatment. The contaminants were transported through the biofilter that was filled with the media. The surface of media formed biofilm which was surrounded by microbes and through its boundary, some materials were exchanged and migrated into the cell of microbes in an orderly manner. To investigate the effect of the Biofiltration, contaminated soil with lead nitrate of 1000mg/kg in dry was made artificially. The tests were simulated such as compost, Bioceramic and compost with bioceramic by 7:3 in weight. The bed consisted of three layers in order to find effect of the number of bed. Aspergillus niger was used as a biosorbent could probe the effect on the retardation of lead.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.76-88
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• 1997

Constant .DELTA.K fatigue crack growth rate experiments were performed by applying an intermediate single and multiple overload for structural steel, SM45C. The purpose of the present study is to investigate the influence of multiple overloads at various stress intensity factor ranges and the effect of statistical variability of crack retardation behavior. The normalized delayed load cycle, delayed crack length and the minimum crack growth rate are increased with increasing baseline stress intensity factor range when the overload ratio and the number of overload application were constant. The crack retardation under low baseline stress intensity factor range increases by increasing the number of overload application, but the minimum crack growth rate decreases by increasing the number of overload application. A strong linear correlation exists between the minimum crack growth rate and the number of overload applications. And, it was observed that the variability in the crack growth retardation behavior are presented, the probability distribution functions of delayed load cycle, delayed crack length and crack growth life are 2-parameter Weibull. The coefficient of variation of delayed load cycle and delayed crack length for the number of 10 overload applications data are 14.8 and 9.2%, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.103-113
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• 1987

Fatigue tests using a single-peak loading and a two-step loading were carried out to examine the fatigue crack growth behaviar and to find the appropriate analysis method. C-T specimens were made using structural steel SWS58 for the tests. From this, just after a single-peak loading acceleration effect was occured and after some times retardation effect was found. And eminent retardation effect was found after High-Low two-step loading. The transition effect of crack growth due to this variable loading was occured owing to the residual stress and the plastic zone size at the crack tip. And the behaviors of these are well explained by Elber's Crack Closure Model. Also I could find that the Wheeler's Retardation Model is a simple and appropriate theory among analysis methods of fatigue crack growth under the variable loading.

• Journal of Photoscience
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• v.9 no.2
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• pp.158-161
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• 2002

UV-B radiation gives harmful effects on plants, such as production of several types of DNA lesions, and growth inhibition. On the other hand, plants have some protective mechanisms, including filtering effect due to accumulation of phenolic compounds in epidermal cells and reactivation of DNA lesions, which are enhanced by UV-B irradiation. We have investigated the mechanism of UV-B effects on plants using cucumber seedlings as plant materials. Cucumber plants were cultivated in an artificially lit growth chamber. Supplemental UV-B irradiation, of which intensity was almost equal to the level of natural sunlight, retarded the growth of first leaves. The growth retardation must result trom the inhibition of cell division and/or cell growth. Microscopical observation of leaf epidermis suggested that the growth retardation might be mainly caused by cell growth inhibition. The retardation was, however, restored within 2 or 3 days after the termination of UV-B irradiation. It is known that UV-B irradiation lowers the activity of photo system II (PS II). In the present experimental conditions, however, UV-B irradiation has little effect on PS II activity as estimated by chlorophyll fluorescence. The stomatal conductance, a major factor determining photosynthetic rate, of first leaves increased during the growth. The increase of stomatal conductance was suppressed by UV-B irradiation and restored by termination of the irradiation. It has not been clear, however, what mechanisms are involved in the suppression of increase of stomatal conductance.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.689-695
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• 1996

In order to prove physiological function of ${\beta}-Glucan$ isolated from barley flour by enzymatic method, in vitro experiments simulating the passive membrane transport of gastrointestinal tract were carried out using dialysis membrane. The yield of ${\beta}-Glucan$ from barley flour was $6.2{\%}$ and its constituents were determined to give $81.6{\%}$ total dietary fiber, $72.9{\%}$ soluble dietary fiber, $8.7{\%}$ insoluble dietary fiber, $8.5{\%}$ moisture, $2.5{\%}$ protein and $7.4{\%}$ ash. The water holding capacity of the ${\beta}-Glucan$ preparation was 6 g water/g dry material. The glucose retardation index after 30 minute dialysis was $13.5{\%}$ in the presence of $3{\%}$ ${\beta}-Glucan$. As the dialysis period became longer, the retarding effect toward glucose absorption decreased and the effect was close to zero after 2 hour dialysis. The bile acid retardation index after 30 minute dialysis was 3, 12 and $18{\%}$ in the presence of 1, 3 and $5{\%}$ ${\beta}-Glucan$, respectively. The effect was higher than the glucose retardation index and decreased as the dialysis time elapsed.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1117-1123
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• 2003

The effects of heat treatment on the physical and physical and physiological properties of wax gourd (Benincasa hispida) were examined. The applied heat treatments were autoclaved at $121^{\circ}C$ for 1 hr, boiled for 30 min, and microwaved at 680 W for 5 min. The water retention capacity (WRC) of the wax gourds was 9.43 g/g for the microwaved samples, 5.12 g/g for the boiled samples, 4.63 g/g for the raw samples, and 2.61 g/g for the autoclaved samples. Heat treatment caused to increase swelling by up to $4.4{\sim}7.8\;mL/g$. Calcium binding capacity of heat-treated wax gourd increased in the order of microwaved, boiled, raw, autoclaved samples. Scanning electron microscopy (SME) showed that autoclaving caused the most severe structural modifications, while microwave treatment produced the least modifications. The retarding effect on glucose and bile acid transport depended on the heat treatment. Only boiling showed the glucose retardation effect. Bile acid retardation effect increased in order of boiling (22.9%), autoclaving (17.1%), microwave treatment (14.3%), and raw wax gourd (8.6%). The cadmium retardation effect was significantly high in all samples.

• Journal of Sasang Constitutional Medicine
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• v.20 no.3
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• pp.151-163
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• 2008

1. Objective This study was done to identify the anti-stress effect of Hyeongbangdojeok-san (HDS), Yanggyeoksanhwa-tang(YST) in Soyangin. 2. Methods Experimental animals were composed of YST, HDS+stress groups which were administered each by 200mg/kg, 400mg/kg and the Saline+stress group. On the 1st day, making the rats forced swim and on the 2nd day, applying Forced swimming test to the rats. After FST, the levels of Corticosterone in the blood were measured. For the study of learning retardation, memory ability and anxiety reaction, experimental animals were composed of YST, HDS+restraint stress groups which were administered each by 400mg/kg, no stress group and the Saline+restraint stress group. Restraint stress were applied 2 hours a day for 3 weeks. On the last day of the 3rd week, Elevated Plus Maze(EPM) was applied to the groups and Morris Water Maze(MWM) was applied to the groups for 7 days. 3. Results 1. As the results of measuring FST which reflects depression, the YST+stress group and the HDS+stress group showed significant effect in comparison with the Saline+stress group. The levels of Corticosterone in the blood were decreased only in the 400mg/kg YST+stress group. 2. As the results of measuring how long EPM which reflects anxiety reaction stayed in the open arm, there was the trend which can suppress anxiety reaction in the HDS+restraint stress group bur no statistical significance. But there was any suppression of anxiety reaction in the YST+restraint stress group. 3. According to the result of MWM, the saline+restraint stress group showed the learning retardation which means increased time arriving at goal compared to the normal group at the second and third day of measurement. On the contrary, a learning retardation was significantly decreased in the YST+restraint stress group at the third day of measurement. 4. Among the Probe trial test a memory loss occurred in the saline+restraint stress group, but memory ability was significantly increased in the YST+restraint stress group. 4. Conclusion: As the results above, Soyangin Yanggyeoksanhwa-tang has significant influence to the antidepression effect, the learning retardation, the anxiety reaction and also in the Hormone level. Hyeongbangdojeok-san has significant influence to the antidepression effect, in the Hormone level, bur not to the learning retardation and anxiety reaction. prefer to drink cold water, and who are suffering from chronic gastritis.

• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.2
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• pp.41-48
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• 1989

This paper investigates the relationship between strain hardening exponents(n) of various marine materials and fatigue crack retardation effect after applying single overload. Using the four different sheet materials, following results are obtained. (1) The fatigue crack propagation rate after applying single overload was retarded and the effects of this retardation were closely related to the strain hardening exponent. (2) The larger the strain hardening exponents were, the more were the fatigue crack retardation effects after applying single overload. (3) The considerable crack closure with the applying of a overload was observed in matrals with large strain hardening exponent. When n is smaller than 0.1, the fatigue crack retardation effects are negligible. On the contrary, when n is larger than 0.2 the fatigue crack retardation effects are significant.

• The Journal of Korean Physical Therapy
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• v.16 no.1
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• pp.208-246
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• 2004

The purpose of this study was to investigate the effect of aqua exercise program on the static balance of child with mental retardation. The subjects were seven male child and three female child with mental retardation(age ranges from 5 to 6). The subjects were practiced with focusing on the aqua exercise program for 8 weeks, from 7, January 2003 to 28, February 2003. The results of this study were as follows : 1. After the exercise program, the balance of double-stance by BPM was significantly reduced of lateral sway number by $12.2\%$(P<.01) with eyes obstruct. 2. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of left leg by $8.5\%$(P<.05) with eyes obstruct. 3. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of right leg by $8.3\%$(P<.05) with eyes obstruct. 4. After the exercise program, the balance of double-stance by BPM was significantly reduced of lateral sway number by $13.2\%$(P<.01) with eyes open. 5. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of left leg by $10.3\%$(P<.05) with eyes open. 6. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of right leg by $10.3\%$(P<.01) with eyes open. As we can see the results of this study, the aqua exercise program improved the static balance of child with mental retardation. Futhermore, it is reasonable program that can improvability of static balance for the children with mental retardation using aqua exercise program. And then it is necessary to develop much better program than now for the children with mental retardation's health and to provide the adequate pool for their aqua exercise.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.4
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• pp.67-77
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• 2002

This paper introduces the calibration results of the fatigue crack growth models for damage tolerance analysis of the aircraft structures. Generalized Willenborg model and Wheeler model are calibrated with experimental data tested under the load spectrum of a trainer. The retardation factors such as, shut-off ratio in Generalized Willenborg model and shaping exponent in Wheeler model, are evaluated for aluminum alloys AL2024-T3511, AL7050-T7451 and AL7075-T73511. It is shown that the retardation effect of the crack growth rate depends on the yield strength of material and the maximum stress in the load spectrum. Generalized Willenborg model and Wheeler model give satisfactory prediction of crack growth life but the calibration of the experimental parameters with test is required.