• Journal of the Korea Concrete Institute
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• 제24권6호
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• pp.685-693
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• 2012

The yield strength of shear reinforcement is restricted in the present design codes. In this study, the possibility of the yield strength increase in shear reinforcement is evaluated according to ACI318-08, EC2-02 and CSA-04 by comparing the experimental and calculated results. Three cases were used to analyze the shear strength of the beam. One had no limitation in the yield strength of shear reinforcement, another had restriction on the yield strength of shear reinforcement, and the other had a restriction on the yield strength of shear reinforcement and the shear reinforcement ratio. The study results showed that the case with unlimited shear reinforcement yield strength predicted the test result better than other two cases. Even though the rebar yield strength higher than the strength required in present code was applied to existing shear design equation, the result was reasonable. Therefore, the design equation seemed to be appropriate even if the high-strength shear reinforcement is used in practice based on the existing shear design method.

• Microbiology and Biotechnology Letters
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• 제24권2호
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• pp.217-221
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• 1996

Various treatments of naked barley with commercial liquefying enzymes have been emploved to reduce high viscosity of naked barley in cooking as a raw material for alcohol production and to increase alcohol yield. The enzyme BAN used for cooking and liquefaction of naked barley was able to make a reduction of one third of viscosity and to enhance alcohol yield of 4 l/Ton of raw material than the T120L was. Of course, alcohol yield depended in part on the applied saccharifying enzymes. The low temperature cooking of naked barley with BAN was favorable compared with high temperature cooking for both of reducing viscosity (210 vs. 237 cp) and final alcohol yield (Yp/so: 0.397 vs. 0.395 g/g) in industrial scale.

• Journal of Welding and Joining
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• 제31권5호
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• pp.1-6
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• 2013

In carrying out the elastic-plastic analysis, four conditions (equilibrium equation, constitutive equation, condition of compatibility and yield condition) should be satisfied. In welding, the temperature largely changed from a melting temperature to a room temperature. So, yield stress of materials largely changed, too. In particular, yield stress becomes about zero over $700^{\circ}C$. The analysis should be carried out under the condition that equivalent stress generated in temperature increment ${\Delta}T$ did not exceed yield stress of materials at high temperature over $700^{\circ}C$. It should be sufficiently recognized that the obtained results were not reliable if this condition was not satisfied.

• Journal of the Korea Institute of Military Science and Technology
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• 제6권1호
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• pp.108-115
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• 2003

TNAZ is a high explosive material because it is a highly strained ring compound containing one nitramine and gem dinditro groups. 1-t-butyl-3-nitroazetidine which was used as an intermediate previously, which declined the overall yield in synthesizing TNAZ. We obtained 1-t-butyl-3-hydroxymethyl-3-nitroazetidine in 64% yield from advances process which was used in synthesis of 1-t-butyl-3-nitroazetidine. The reaction pathway, shortening of reaction time, together with improvement of yield were studied too. We have obtained TNAZ in 85% yield.

• Archives of Pharmacal Research
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• 제25권4호
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• pp.453-456
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• 2002

Tonin(Persicae Semen) is the herb medicine that contains amygdalin as a major ingredient. Amygdalin in water is decomposed into benzaldehyde, HCN, and glucose by emulsin, a hydrolysis enzyme in tonin. A useful and practical method for the optimum extraction condition of amygdalin without enzymatic hydrolysis is required. The extraction yield of amygdalin of natural formula to nin was 0.1 % from crude powders, 1.4% from small pieces, 3.5% from half pieces and 2.4% from whole pieces. The extraction yield of amygdalin of outer shell-eliminated to nin was 0.3% from crude powders, 1.4% from small pieces, and 3.5% from half pieces and whole pieces respectively. The extraction yield of amygdalin was most high when using the size larger than half.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2232-2240
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• 2018

We applied methanesulfonic acid (MSA) as a green catalyst to produce levulinic acid (LA) from monomeric sugars. To optimize reaction factors and assess the effect of reciprocal interactions, a statistical experimental design was applied. Optimized result of 40.7% LA yield was obtained under the following conditions: 60 g/L galactose, 0.4 M MSA at $188^{\circ}C$ for 26.7 min. On the other hand, 66.1% LA yield was achieved under 60 g/L fructose and 0.4 M MSA at $188^{\circ}C$ for 36 min conditions. For the effect of combined severity factor on the LA yield from galactose, the LA yield showed a peaked pattern, which was linearly increased until a CSF 3.2 and then diminished with a high CSF. Moreover, it was closely fitted to a non-linear Gaussian peak pattern with a high regression value of 0.989. These results suggest that MSA and galactose, derived from marine red macro-algae, can potentially be applied for the conversion into platform chemicals.

• Journal of Korean Society of Steel Construction
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• 제24권4호
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• pp.479-490
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• 2012

Flexural tests on full-scale H-shaped beams, built up from high-strength steels (HSB800 and HSA800) with a nominal tensile strength of 800 MPa, was carried out to study the effect of flange slenderness of high-strength steel on flexural strength and rotation capacity. The primary objective was to investigate the appropriateness of extrapolating current stability criteria (originally developed for ordinary steel) to high-strength steel. The performance of high-strength steel specimens was very satisfactory from the strength, but not from the rotation capacity, perspective. The inferior rotation capacity of high-strength steel beams was shown to be directly attributable to the absence of a distinct yield plateau and the high yield ratio of the material. Residual stress measurements reconfirmed that the magnitude of the residual stress is almost independent of the yield stress of the base metal.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제62권4호
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• pp.367-372
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• 2017

This work was conducted to identify sweet potato [(Ipomoea batatas (L.) Lam.)] cultivars showing high yield and processing suitability in the Jeonbuk region of Korea. Shoot-slips (30 cm in length) of 14 cultivars were planted with a planting density of $75{\times}25cm$ on May 30, and cultivated with black film mulching. Vine elongation at 30 days after planting was significantly increased (> 90 cm) in 'Dahomi' and 'Sinhwangmi', and was excellent (> 250 cm) 120 days after planting in 'Sinhwangmi', 'Shinyulmi', 'Daeyumi', 'Jinhongmi', and 'Yeonhwangmi'. The branch number per plant showed a dramatic increase in 'Shinzami' 30 and 120 days after planting. The leaf number per plant showed the highest increase in 'Shinzami' 30 days and in 'Sinhwangmi' 120 days after planting. Total weight, mean weight, and number of marketable tubers per plant were significantly higher 150 days after planting than that 120 days after planting. Marketable tuber yield at 120 days was high, over 2.5 ton/10a in 'Daeyumi', 'Dahomi', and 'Jeonmi', and was considerably increased, from 3.2 ton/10a to 3.5 ton/10a, 150 days after planting. Total weight of marketable tubers per plant and marketable tuber yield 120 and 150 days after planting had significant positive correlations with vine length and number of nodes 30 days after planting. Starch value was significantly higher 150 days after planting than that 120 days after planting. 'Daeyumi' and 'Jeonmi' had good growth vigor, high yield, and high starch content; 'Dahomi' also exhibited beneficial traits such as good growth vigor, high yield, and bright orange-colored flesh.

• Magazine of the Korean Society of Agricultural Engineers
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• 제39권1호
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• pp.93-101
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• 1997

This paper presents yield surfaces and hardening laws for describing the state of an unsaturated soil under isotropic compression and suction changes. The yield surface is formulated within the framework of hardening plasticity using two independent sets of stress variables : the excess of total stress over air pressure and the suction. And the application of the yield surfaces and hardening laws are confirmed from the result of the experiment. To this end a series of suction-controlled isotropic tests are conducted on clayey soils. Matric suction is controlled by the axis translation technique using high air entry ceramic disk. The specimens are compacted using a half of Proctor compaction energy with 5 % lower of water content than the optimum moisture contents. From test results, existence of the yield surfaces and an application of hardening laws to samples are confirmed by comparison between test and predicted results. And it is confirmed that LC yield locus is extened with the total plastic deformations induced by suction or stress changes, however, SI yield locus is only extended with the plastic deformations by induced suction changes.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제37권4호
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• pp.361-371
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• 1992

For the increase of grain yield potential in rice, a low-tillering large panicled type has been suggested as an ideotype. A low-tillering plant type may have different yield potential and needs different cultural practices from that used in a high-tillering type for the maximum yield. This study was conducted to evaluate the grain yield performances of a low-tillering large panicled rice and high-tillering small panicled rice at different plant spacings, nitrogen(N) levels and seedling numbers per hill. A low-tillering large panicled genotype, IR25588 was compared with a high-tillering small panicled IR58. The grain yield of IR25588 was significantly higher than that of IR58 under a narrow spacing with high N level. The maximum yields of IR58 and IR25588 were reached at about 35,000 and 40,000 spikelets per m$^2$, respectively. The increased grain yield in IR25588 was mainly due to the increase in spikelet number per unit area which is the most precise indicator of grain yield in rice. The optimum spacing for the maximum yield was denser for IR25588 than that for IR58 under high N level. The intra-hill competition of the low-tillering type was lower than that of the high-tillering type. The higher dry matter production and bigger leaf area and culm weight were the main factors for increased grain yield in a low-tillering panicle weight type. Based on the results, the yield potential of a low-tillering panicle weight type was higher than that of a high-tillering panicle number type, especially under a close spacing with high N level.