• Journal of the Korean Geotechnical Society
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• v.36 no.1
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• pp.17-28
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• 2020

This study presents the experimental results of ground improvement efficiency induced by enzyme-induced carbonate precipitation (EICP) in soils. First, the optimal mixture ratio of EICP solution was determined by comparing the amount of induced carbonate depending on the different ratio among urea, CaCl₂, and urease. Next, we evaluated the shear stiffness and strength of EICP-treated sandy soil by performing shear wave velocity measurement and triaxial shear test. Furthermore, induced carbonate in treated soil was visually investigated by X-ray CT and SEM analysis. The results showed that the maximum shear stiffness evolved 19~30 times after 6 hours of reaction time compared with non-treated sands. Also, the cohesion and the friction angle tended to increase and decrease, respectively, as the amount of induced carbonate increased.

• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.101-107
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• 2006

While a Study with regard to the measurement on Concrete Strength and the Change of Drying Shrinkage in accordace with Content Ratio of Crushed Stone Powder, it is being analyzed as the result that the strength according to Content Ratio of crushed Stone Powder is somewhat lowering. Accordingly, it is the real situation that the Concrete mixed with Crushed Stone Powder is utilized for non-structural material, not for the structural material. Therefore, this Research willing to furnish the suitable utilizing scheme for construction site as well as practical life by means of conduct the experiment on both Concrete Pressure Strength according to mixture with Crushed Stone Powder and Elastic Modulus, it also presumes the optimum Elastic Modulus Equation after analysis of comparison with common concrete strength. As the result of the experiment, in case of the Content Ratio of Crushed Stone Powder is less than 5%, it did not display a big difference in its both strength and matter-property compare with common concrete. In case of Elastic Modulus, when the Pressure Strength is 50% and 40% respectively, the Elastic Modulus Equation accords very well with the provided condition of Quadratic function, and as the result of the Presumption on Elastic Modulus according to Content of Crushed Stone Powder, in case the Pressure Strength is 50%, Elastic Modulus Equation showed that Error Ratio of Cubic function is at degree of 0.0005%, in case the Pressure Strength is 40%, Elastic Modulus Equation was accorded well with the value of the experimental data likely as the Error Ratio of Cubic function is at the degree around 0.0034%, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.31.2-31.2
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• 2012

We present the Yonsei Evolutionary Population Synthesis (YEPS) models for spectroscopic and photometric evolutions of simple and composite stellar populations. The models are based on the most up-to-date Yonsei-Yale stellar evolutionary tracks and BaSel 3.1 flux libraries, and provide integrated spectroscopic quantities of Lick/IDS system including high-order Balmer absorption-lines. Special care has been taken to incorporate the systematic variation of horizontal branch (HB) morphology as functions of metallicity, age, alpha-element mixture, and helium abundance of simple stellar populations. Our models for normal-helium stellar populations indicate that the realistic modeling of HB and alpha-element brings about 5 Gyr and 0.1 dex differences in age and metallicity estimations, respectively, compared to those without these effects. The HB effect does not depend on the specific choice of stellar libraries and alpha-element enhancements, and this effect is non-negligible even in the metal sensitive absorption indices, such as Mg2 and Mg b. Comparison of the models to observations reveals that the HB and alpha-element effects are critical in understanding otherwise inexplicable phenomena found in globular cluster systems in the Milky Way and nearby galaxies, including the observed bimodality of the line strengths of globular clusters in massive galaxies. In addition, we found that helium-enhanced stellar populations, which are the major sources of extreme HB stars, bring about increased FUV, NUV fluxes, and thus the model colors of those filters become extremely blue. Age dating based on the YEPS model with normal-helium stellar populations reveals that the evidence for 'downsizing' of elliptical galaxies is found not only in the local field but also in Coma cluster, and that the mean age of elliptical galaxies in Coma cluster is about 1.4 Gyr younger than the mean age of those in the local field. We also find that our models with helium-enhanced subpopulations can naturally reproduce the strong UV-upturns observed in giant elliptical galaxies assuming an age similar to that of old GCs in the Milky Way.

• Investigative Magnetic Resonance Imaging
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• v.20 no.1
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• pp.53-60
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• 2016

Purpose: To develop a technique for quantifying the $^{13}C$-metabolites by performing frequency-selective hyperpolarized $^{13}C$ magnetic resonance spectroscopy (MRS) in vitro which combines simple spectrally-selective excitation with spectrally interleaved acquisition. Methods: Numerical simulations were performed with varying noise level and $K_p$ values to compare the quantification accuracies of the proposed and the conventional methods. For in vitro experiments, a spectrally-selective excitation scheme was enabled by narrow-band radiofrequency (RF) excitation pulse implemented into a free-induction decay chemical shift imaging (FIDCSI) sequence. Experiments with LDH / NADH enzyme mixture were performed to validate the effectiveness of the proposed acquisition method. Also, a modified two-site exchange model was formulated for metabolism kinetics quantification with the proposed method. Results: From the simulation results, significant increase of the lactate peak signal to noise ratio (PSNR) was observed. Also, the quantified $K_p$ value from the dynamic curves were more accurate in the case of the proposed acquisition method compared to the conventional non-selective excitation scheme. In vitro experiment results were in good agreement with the simulation results, also displaying increased PSNR for lactate. Fitting results using the modified two-site exchange model also showed expected results in agreement with the simulations. Conclusion: A method for accurate quantification of hyperpolarized pyruvate and the downstream product focused on in vitro experiment was described. By using a narrow-band RF excitation pulse with alternating acquisition, different resonances were selectively excited with a different flip angle for increased PSNR while the hyperpolarized magnetization of the substrate can be minimally perturbed with a low flip angle. Baseline signals from neighboring resonances can be effectively suppressed to accurately quantify the metabolism kinetics.

• Fire Science and Engineering
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• v.24 no.6
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• pp.139-144
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• 2010

Fire fighting foam is expanded when it mix with many water in mechanical method. It have adaptability, mass production possibility, long-time storage possibility. But foam isn't recommended that it use for extinguish the fire in winter. Because of, expansion ratio is changed according to exterior temperature and environment. In this study, we analysis to effect of expansion according to temperature and develop auto mixing system available for fire engine. As a result of non-standard drug mixture is 3.0% up to 30.08% depending on the temperature of the fire showed that the difference in performance occurs. In addition, analysis of the applicability of automatic mixing system design values and actual experimental data as 0.012% maximum error of the applicability of the system obtained according nataname was judged.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.816-824
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• 2005

The effects of the nonionic surfactant Tween 80 and a mixture of fibrolytic enzymes on total tract digestion, in situ disappearance (ISD) and ruminal fermentation characteristics of orchardgrass hay and barley grain were investigated in a 4${\times}$4 Latin square experiment with 4 non-lactating Holstein cows and 4 diets in 4 periods. Cows were offered a total mixed ration of 50% rolled barley grain and 50% orchardgrass hay treated with either 1) water (control), 2) 0.2% (vol/wt) Tween 80, 3) 0.2% (vol/wt) hydrolytic enzyme, or 4) 0.2% hydrolytic enzyme plus 0.2% Tween 80. Total tract digestibility coefficients of DM, nitrogen, NDF and ADF were not affected (p>0.05) by dietary treatment. Compared to the control, the rate of ISD of DM from orchardgrass hay was faster (p<0.05) in cows receiving diets treated with the enzyme alone or with enzyme plus Tween 80 (0.06/h vs. 0.076 and 0.069/h). The rate of digestion was lower (p<0.05) as compared to control when barley grain was treated with these additives. Ruminal fluid pH and concentrations of total VFA, acetate, isobutyrate and butyrate were not affected (p>0.05) by treatments. Cows that consumed diets treated with enzyme plus Tween 80 had higher (p<0.05) ruminal concentrations of propionate and isovalerate, and lower (p<0.05) acetate:propionate ratios. Compared to the control, microbial protein synthesis tended (p = 0.13) to increase with the addition of enzyme to the diet while nonammonia nitrogen flow to the duodenum increased (p<0.05) with both enzyme and Tween 80 treatments. The study indicated that fibrolytic enzymes alone or in combination with Tween 80 could enhance ISD of orchardgrass hay and ruminal concentrations of propionate, valerate and iso-valerate, but do not affect total tract digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.619-624
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• 2000

Low-quality roughages [banana wastes (B), wheat straw (WS) and dried broiler litter (BL)] were ensiled using either sweet whey (W) or diluted molasses (M) as rehydration media to study their effects on milk yield, milk composition and some parameters of blood plasma. The feeding trial involved 25 lactating buffaloes in five groups (five animals each). Buffaloes as control animals received diets of concentrate feed mixture, rice straw and wastelages (70:30:00). In the other 4 treatments, the wastelages replaced 50% of rice straw in the control diets. The wastelages were BL:B:M(3:2:10) (T1), BL:WS:M (3:2:10) (T2), BL:B:W (3:2:10) (T3) and BL:WS:W (3:2:10) (T4) on a fresh matter basis, during the 1st 17 weeks of lactation period. Results indicated that feeding lactating buffaloes on wastelages resulted in slightly higher (p>0.05) milk yield, 4% fat-corrected-milk yield and feed efficiency, and slightly lowered (p>0.05) contents of milk total solids, fat and protein. Wastelages, especially BL-B-M, increased (p<0.05) milk non-protein-nitrogen and ash contents and plasma urea, GOT and GPT. The results demonstrate that banana plant wastes with some additives in silage form may be good untraditional roughage for lactating buffaloes without any adverse effect on milk production.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.599-604
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• 2011

In typical proteomic analysis, trypsin digestion is one of the most time-consuming steps. Conventional proteomic sample preparation methods use an overnight trypsin digestion method. In this study, we compared high-pressure cycling technology (PCT) during enzyme digestion for proteome analysis to the conventional method. We examined the effect of PCT on enzyme activity at temperatures of 25, 37, and $50^{\circ}C$. Although a fast digestion (1 h) was used for the standard protein mixture analysis, the PCT-assisted method with urea showed better results for protein sequence coverage and the number of peptides identified compared with the conventional method. There was no significant difference between temperatures for PCT-assisted digestion; however, we selected PCT-assisted digestion with urea at $25^{\circ}C$ as an optimized method for fast enzyme digestion, based on peptide carbamylation at these conditions. The optimized method was used for stem cell proteome analysis. We identified 233, 264 and 137 proteins using the conventional method with urea at $37^{\circ}C$ for 16h, the PCT-assisted digestion with urea at $25^{\circ}C$ for 1 h, and the non-PCT-assisted digestion with urea at $25^{\circ}C$ for 1 h, respectively. A comparison of these results suggests that PCT enhanced the enzyme digestion by permitting better access to cleavage sites on the proteins.

• The Journal of Internal Korean Medicine
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• v.40 no.6
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• pp.1081-1100
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• 2019

Objectives: This study is an overview of the meta-analysis and systematic review of randomized controlled trials investigating the clinical effectiveness and safety of pharmacopuncture for patients with stroke. Methods: Core electronic databases were searched from their inception to 21 May 2019. A measurement tool to assess systematic reviews (AMSTAR 2) was applied to screen high-quality studies. The results of these studies were summarized, and additional meta-analysis was conducted. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the certainty of evidence. Results: Sixteen studies met eligibility criteria. Four were excluded owing to insufficiency of AMSTAR 2 or low data reliability. The finally selected 12 studies were about pharmacopuncture using either a single herb extract, such as Dengzhan xixin, Sanch, Ginkgo biloba, or Acanthopanax, or a mixture of herbs, such as Compound danshen, Shenxiong, Xingnaojing, or Mailuoning. Most of the patients were from China, with acute ischemic stroke. All the studies using a pharmacopuncture versus a non-pharmacopuncture design reported the significant superiority of pharmacopuncture on every outcome measure. On the other hand, in a few studies, pharmacopuncture was inferior to active control in improving neurological deficit. Few studies reported adverse events. Conclusions: It is difficult to apply the results of this study directly to Korea, because the level of evidence is generally low and the clinical settings and social acceptance of pharmacopuncture therapy differ in Korea and China. Further studies are warranted to confirm the domestic applicability of evidence generated in China and to create evidence that supports the domestic situation.

• Tribology and Lubricants
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• v.15 no.1
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• pp.77-82
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• 1999

The processing conditions fur the synthesis of platelet W $S_2$ lubricant powder through a solid-gas reaction were optimized. The mixture of tungsten and sulfur powders were sealed in a vacuum of 10$^{-6}$ torr, prior to heat-treating at 85$0^{\circ}C$ fur 8 days. The reaction product showed a well-developed platelet W $S_2$ powder with an average size of 3.8 ${\mu}{\textrm}{m}$. The TGA/DTA analysis of the synthesized W $S_2$ powder was performed up to 120$0^{\circ}C$ at a rate of 1$0^{\circ}C$/min in flowing air (100 ${\mu}{\textrm}{m}$/min) atmosphere. The weight loss was about 6% up to 120$0^{\circ}C$ compared to the original weight. A rapid weight loss of about 5% occurred in the temperature range of 44$0^{\circ}C$ to 66$0^{\circ}C$ and an exothermic peak observed due to the transition of W $S_2$ to W $O_3$. The synthesized W $S_2$powder was coated on the commercial deep grooved ball bearing (No. 6203) to examine the effect of W $S_2$, coating layer on the noise and endurance of the ball bearing. The level of noise obtained from W $S_2$, coated-ball bearing (56 ㏈) was higher. than the value (32 ㏈) occurred in the case of greece lubrication. The endurance of the ball-bearing assembled after the coating of W $S_2$ powder onto each part increased 50 times compared to the non-coated ball-bearing..