• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2977-2981
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• 2021

Corrosion fatigue crack growth (FCG) behavior of 316LN stainless steel was investigated in high-temperature pressurized water at different temperatures, load ratios (R = K_max/K_min) and rise times (t_R). The environmental assisted effect on FCG rate was observed when both the R and t_R exceeded their critical values. The FCG rate showed a linear relation with stress intensity factor range (ΔK) in double logarithmic coordinate. The environmental assisted effect on FCG rate depended on the ΔK and quantitative relations were proposed. Possible mechanisms of environmental assisted FCG rate under different testing conditions are also discussed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.329-334
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• 2002

High-speed machining is one of the most effective technology to improve productivity. Because of the high speed and high feed rate, high-speed machining can give great advantages for the machining of dies and molds. This paper describes on the improvement of machining accuracy in high-speed machining. Depth of cut, feed rate, spindle revolution and cutting force are control factors. The effect of the control factors on machining accuracy is discussed for the results of surface roughness and machining error in Z-direction for the high speed machining of STD11.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.4
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• pp.482-492
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• 1998

With the purpose of developing a objective fitness evaluation system for knits, the basic bodice pattern for knit was drafted and the suitability of the altered pattern was evaluated. For each of nine different knits, six sleeveless shirts were made with patterns that were altered by different pattern alteration rate: 0%, 30%, 40%, 50%, 60%, or 70% of the stretch rate of the knit. The panel that was composed of 25 clothing specialists evaluated the fitness of the garments. The distance from the dress form landmark to the garment landmark was measured from each experimental garment. And the results of garment fitness evaluation and the measurement of distance from the dress form landmark to garment landmark were compared. The results of this study are as follows: There was high correlation(r$\geq$0.9) between the evaluation of the panel about the garment fit and the landmarks distance. The stretch rate of knits affected the evaluation of the garment fit. The stretch rate in course of knits affected on the garment fit at crosswise direction. The suitable pattern alteration rate was lower than 30% for the knits with high stretch rate in course. It was concluded that in order to get the appropriate knit bodice pattern length, the front bodice pattern must be less shorten than the back bodice pattern. The alteration rate at hip line must be lower than for waist or bust line.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.337-346
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• 1996

The purpose of this study was to provide basic data of the growth characteristics of the landscape trees for better landscape planting design, construction and maintenance through the prediction of landscape change as time passes fly the analysis of survival rate, distribution patterns & increment percent of tree height, width, stem diameter (breast or surface) of widely used six tree species in Seongnam-si Eunhang-jugong apartment housing areas (8 years have passed after landsape alanting work). The main results can be summarized as followed. The tree survival rate of Pinus parviflora was the highest rate 89.2% than any other species, but Acer buergerianum showed the lowest survival rate at that of it 35.0%, & that of Picea abies 70.5 %, Metasequoia glyptostroboides 71.6%, Maknolia denudata 38.9%, Acer paimatum was 71.7%, As a whole, the tree survival rate of coniferous trees were relatively high. The tree height increment percent of the deciduous species wert relatively high. And that of Metasequoia glyptostroboides was the highest rate 11.61% than any other species, but that of Magnolia denudata was the lowest rate 5.59% than any other species. According to this results, the increment percent of trees in this apartment areas were comparatively lower than that of each related species planted in nursery area. And this results would be considered when landscape experts do landscape planting design, construction & maintenance. The distribution patterns of present tree size showed a Normal Distribution like any other biological features.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.8
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• pp.1085-1096
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• 2000

An experimental study was performed to examine the heat and mass transfer characteristics of $LiBr-H_2O$ solution flowing over a single horizontal tube with the water vapor absorption. Effects of the flow rate and the temperature of the solution at the top of the tube, the absorber pressure and the drainage pattern were considered. The absorption rate depends highly on the absorber pressure at the low flow rate condition while on the solution inlet temperature at the high flow rate condition. Also, when the flow rate is low, the absorption performance with the sheet flow drainage appeared to be higher than that with the dripping/jet drainage. However, at the high flow rate condition, the case became reversed. The liquid film became wavy with the higher absorption rate. The waves were more probable to form with the lower flow rate and temperature of the solution, and with the higher absorber pressure.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.15-23
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• 1994

This study was carried out to investigate the effects of concentration, kinds of cryoprotectants, equilibration time, optimum thawing temperature on the survival rate of rapidly frozen porcine embryos. The porcine embryos following dehydration by cryoprotectants containing sucrose were directly plunged into liquid nitrogen and thawed in 30, 35 or 37$^{\circ}C$ water bath, Survival rate was defined as development rate on in vitro culture or FDA-test. The results are summarized as follows : 1. The high survival rate of porcine frozen embryos after rapidly thawed in freezing medium was attained 2.0M DMSO, 2.0M glycerol, 2.0M propanediol, 1.5M ethyleneglycol. 2. The high survival rate of porcine frozen embryos after rapidly thawed in freezing medium was obtained using single cryoprotectant(16.6~40.0%) than mixed cryoprotectants(12.5~33.3%). 3. The eqilibration time on the survival rate of rapidly thawed porcine frozen embryos was attained after short period of time(15.0~33.3%) in the freezing medium higher than long period of time(9.10~30.0%). 4. The thawing temperature on the survival rate of rapidly thawed porcine frozen embryos was attained at 3$0^{\circ}C$ of thawing temperature(33.3~40.6%) in the freezing medium higher than 25 or 37$^{\circ}C$ of thawing temperature.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.148-151
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• 2005

This paper is concerned with the thermo-mechanical behavior and temperature dependent strain rate sensitivity of steel sheet for an auto-body. In order to Identify the temperature dependent strain rate sensitivity of SPRC35R and SPRC45E, uniaxial tension tests are performed with the variation of the strain rates from 0.001/sec to 200/sec, and the variation of environmental temperatures from $-40^{\circ}C\;to\;200^{\circ}C$. The thermo-mechanical response at the quasi-static state is obtained with the static tensile test and at the intermediate strain rate is from the high speed tensile test. The experimental results show that the strain rate sensitivity increases at low temperature and it decreases at high temperature. It means that as the strain rate getting increasing, the variation of flow stress is more sensitive on the temperature. The results also indicates that the material properties of SPRC35R is more depend on the changes of strain rates and temperature than those of SPRC45E.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.3
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• pp.190-194
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• 1993

This experiment was conducted to investigate the effects of concentrated sulfate on the germination rate, growth rate and the productivity of weight of kudzu (Pueraria thwnbergiana Bentham). The germination rate of kudzu seed by one or two treatment retreatment with the concentrated sulfate for minutes of 5. 10, 15 and 20 were determined respectively. The results obtained were summarized as follows; 1. In the time of concentrated sulfate treatment, the germination rate was the highest in the once treatment for 20 minute. and the retreatment was higher than the once treatment in the germination rate. 2. The changes of plant length by growth stage was grown gradually until for 60 day and rapidly after for 60 day. The growth rate was the highest in treatment for 15 minute than in other treatments. 3. The stem diameter. stem weight. fresh weight and root weight by the treatment with sulfate 15 minute as the treatment with once were high degree of productivity. 4. The number of branch. number of nodes and root weight by the growth stage were higher growth rate before for 90 day than after for 90 day, however stem weight and fresh weight were high degree of productivity after for 60 day.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.2
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• pp.107-112
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• 2002

There are many combination with the porosity of tipping paper and plug wrap for a design of ventilation rate of cigarette. This study was carried out to determine the effect of a design of permeability of tipping paper and inner or outer of plug wrap on the ventilation rate of cigarette with constant pressure drop in column part and filter part. Our results indicated that the higher the plugwrap porosity, the higher the ventilation rate and the less variable of cigarette in case of mono filter. But, in case of duel filter, the ventilation rate of cigarette was depended on the manufacturing method of filter plug, even though using the same porous plug wrap on inner and outer of filter. We also found that the porosity of outer plug wrap was more effect on the ventilation rate than the porosity of inner plug wrap. As the high porosity of inner plug wrap compared with the porosity of outer plug wrap, the less variable of ventilation rate of cigarette in any combination of the porosity of plug wrap. When we used the higher porous outer plug wrap than inner plug wrap, the ventilation rate of cigarette was high. Also, the higher the inner plug wrap porosity, the less variable of ventilation rate of cigarette.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1598-1602
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• 2009

The particle size of Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ cathode powder was controlled effectively by dispersion using lauric acid as a surfactant. The samples treated by lauric acid showed smaller particles of approximately half the original size compared to the particles of a pristine sample. A structural change due to the dispersion of Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ powder was not detected. The rate performance of the Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ cathode was improved by dispersion using lauric acid, which was likely due to the decrease of the particle size. In particular, a sample dispersed pristine powder using lauric acid (L2) presented a greatly enhanced discharge capacity and capacity retention at a high C rate. The discharge capacity of a pristine sample was only 133 m$Ahg^{-1}$ (3C rate) and 96 m$Ahg^{-1}$ (12C rate) at the tenth cycle. In contrast, the L2 electrode delivered higher discharge capacities of 160 m$Ahg^{-1}$ (3C rate) and 129 m$Ahg^{-1}$ (12C rate) at the tenth cycle. The capacity retention at a rate of 12C/2C was also enhanced from ~ 45% (pristine sample) to 57% (L2) by treatment with lauric acid.