• Geomechanics and Engineering
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• v.8 no.1
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• pp.53-66
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• 2015

Plastic wastes, particularly polyethylene terephthalate (PET) generated from used bottled water constitute a worldwide environmental issue. Reusing the PET waste for geotechnical applications not only reduces environmental burdens of handling the waste, but also improves inherent engineering properties of soil. This paper investigated factors affecting shear strength improvement of PET-mixed residual soil. Four variables were considered: (i) plastic content; (ii) plastic slenderness ratio; (iii) plastic size; and (iv) soil particle size. A series of unconfined compression tests were performed to determine the optimum configurations for promoting the shear strength improvement. The results showed that the optimum slenderness ratio and PET content for shear strength improvement were 1:3 and 1.5%, respectively. Large PET pieces (i.e., $1.0cm^2$) were favorable for fine-grained residual soil, while small PET pieces (i.e., $0.5cm^2$) were favorable for coarse-grained residual soil. Higher shear strength improvement was obtained for PET-mixed coarse-grained residual soil (148%) than fine-grained residual soils (117%). The orientation of plastic pieces in soil and frictional resistance developed between soil particles and PET surface are two important factors affecting the shear strength performance of PET-mixed soil.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.3
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• pp.11-18
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• 2001

A simple and convenient method of analysis for obtaining the individual stress intensity factors in a three-dimensional mixed mode crack is proposed. The procedures presented here are based on the path independence of J integral and mutual or two-state conservation integral, which involves two elastic fields. The problem is reduced to the determination of mixed mode stress intensity factor solutions in terms of conservation integrals involving known auxiliary solutions. Some numerical examples are presented to investigate the effectiveness and applicability of the method for a three-dimensional penny-shaped crack problem under mixed mode. This procedure is applicable to a three-dimensional mixed mode curved crack.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.90-96
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• 2009

The loading condition of actual construction works is complex. The shear effect of mixed-mode load component are crack propagation mechanism in step larger than the crack initial mechanism. Therefore, in this study received a mixed-mode loading on fatigue crack stress ratio on crack propagation path and speed of progress to learn whether stress affects crack propagation. ${\Delta}$ P a constant state of fatigue tests in Mode I, II give the same stress ratio, frequency 10Hz, sinusoidal waveform was used. A lower stress ratio fatigue crack propagation angle is small. This is less affected by the Mode II. Therefore, a mixed-mode fatigue crack propagation is to progress by the Mode. Stress ratio in a mixed mode crack in the path of progress and found a lot of impact.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.66-70
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• 1997

A mixed-culture of Gluconobacter suboxydans IFO 3172 and Saccharomyces uvarum IFO 0751 was per-formed in a synthetic medium. the optimal inculum ratio of G. suboydans and S. uvarum for mixed-culture fermentation was 150:1. The optimum pH, incubation temperature and aeration rate for mixed-culture fer- mentation were 5.0, 3$0^{\circ}C$ and 2.25vvm, reapectively. As a result of batch pure-and mixed-culture fer-mentation, specific growth rate in pure-culture of both strain was lower than that in mixed-culture. The yield of cell mass from S. uvarum exclusively decreased. The growth rate of the mixed-culture was very similar to the pure-culture in the begining of culture, but it has been decreased after 16hrs. In the mean time, S. uvarum in mixed-culture fermentation could grow due to fructose converted, but it could not row in pure-culture fermentation. Thus, the relationship was a sort of commensalism. The kinetic parameters cal-culated through steady-state results during continuous fermentations are as follows :{TEX}$$\mu$_{max1}${/TEX}=0.118({TEX}$h^{-1}${/TEX}), {TEX}$Ks_{1}${/TEX}=0.330(g/L),:{TEX}$$\mu$_{max2}${/TEX}=0.162({TEX}$h^{-1}${/TEX}), {TEX}$Ks_{2}${/TEX}=0.038(g/L). The yield of bacterial cell mass relatively constant, but yield of yest cell mass was gradually decreased.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.9
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• pp.711-716
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• 2020

Injection visualization of heated mixed simulant droplets based on hydrocarbon fuel was performed under supercritical state environment. Mixed simulant consisted of Decane and Methylcyclohexane with different critical pressure and critical temperature. Flows injected into the supercritical state environment created droplet by Rayleigh breakup mechanism, and the Oh number and Re number were determined to confirm the breakup area. The temperature of the mixed simulant varied from Tr=0.49 to Tr=1.34. The flow rate was maintained at 0.7 to 0.8 g/s. Droplet became shorter in breakup length as heated and into a lumped form. Second droplet was formed and when Tr=1.34, the phase was not visible in the supercritical state with local unsteady flow.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4C
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• pp.581-593
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• 2004

The interest in wireless LAN security is on the increase owing to a role of high-speed wireless Internet infrastructure of wireless LAN. Wi-Fi has released WPA standard in order to overcome drawbacks of WEP algorithm that is security element of current IEEE 802.11-based wireless LAN system. Pairwise key management and group key management in a mixed-mode which supports both terminals running WPA and terminals running original WEP security are very complicate. In this paper, we analyze flaws in WPA authenticator key management state machine for key distribution and propose the countermeasures to overcome the analyzed problems. Additionally, WPA authenticator key management state machine to which the solutions are applied is described. The reconstructed WPA authenticator key management state machine helps the AP perform efficiently group key exchange and group key update in the mixed-mode.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.313-320
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• 2014

Black liquor (BL) is a by-product of rice straw pulping process. It is a low costs raw material for production value-adding proteins and enzymes, which has been paid more and more attention to reduce its environmental pollution. Mixed cultures of micelial fungi, Trichoderma reesei Northern Regional Research Laboratory (NRRL)11236, Trichoderma reesei NRRL 6165 and Aspergillus niger strains NRC 5A, NRC 7A, and NRC 9A were evaluated for their ability to produce xylanase using crude hemicellulose (CHC) prepared from BL and peat moss as an inert support under solid state fermentation (SSF). The most potent strains, A. niger NRC 9A (818.26 U/g CHC) and T. reesei NRRL 6165 ($100.9{\pm}57.14$ U/g CHC), were used in a mixed culture to enhance xylanase production by co-culturing under SSF. In the mixed culture, xylanase production ($1070.52{\pm}12.57$ U/g CHC) was nearly1.3 and 10.6-fold increases over the activities attained in their monocultures, A. niger NRC 9A and T. reesei NRRL 6165, respectively. Optimization of the culture parameters of the mixed culture SSF process, concentration of ammonium sulfate and corn steep liquor, CHC/peat moss ratio, inoculum size and ratios of the two strains, initial pH value, initial moisture content and incubation time, exhibited a significant increase ($2414.98{\pm}84.02$ U/g CHC) in xylanase production than before optimization.

• Communications of the Korean Mathematical Society
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• v.30 no.1
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• pp.23-34
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• 2015

We use mixed norm estimates for the spherical averaging operator to obtain some results concerning pinned distance sets.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.856-864
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• 2019

Objective: The objective of this study was to investigate effects of mixed organic acids (MOA) on nutrient digestibility, volatile fatty acids composition and intestinal microbiota in growing-finishing pigs fed high wheat bran diet. Methods: Six crossbred barrows ($Duroc{\times}Landrace{\times}Yorkshire$), with an average body weight $78.8{\pm}4.21kg$, fitted with T-cannulas at the distal ileum, were allotted to a double $3{\times}3$ Latin square design with 3 periods and 3 diets. Each period consisted of a 5-d adjustment period followed by a 2-d total collection of feces and then a 2-d collection of ileal digesta. The dietary treatments included a corn-soybean-wheat bran basal diet (CTR), mixed organic acid 1 diet (MOA1; CTR+3,000 mg/kg OA1), mixed organic acid 2 diet (MOA2; CTR+2,000 mg/kg OA2). Results: Pigs fed MOA (MOA1 or MOA2) showed improved (p<0.05) apparent total tract digestibility (ATTD) of gross energy, dry matter and organic matter, and pigs fed MOA2 had increased (p<0.05) ATTD of neutral detergent fiber compared to CTR. Dietary MOA supplementation decreased (p<0.05) pH value, and improved (p<0.01) concentrations of lactic acid and total volatile fatty acids (TVFA) in ileum compared to CTR. Pigs fed MOA showed higher (p<0.05) concentration of acetic acid, and lower (p<0.05) content of formic acid in feces compared to CTR. Pigs fed MOA1 had increased (p<0.05) concentration of TVFA and butyric acid in feces. Pigs fed MOA1 showed higher concentration of Lactobacillus and lower concentration of Escherichia in feces compared to CTR. Conclusion: Dietary supplementation of MOA 1 or 2 could improve nutrients digestibility, TVFA concentration and intestinal flora in growing-finishing pigs fed high fiber diet.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.2
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• pp.90-98
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• 2013

The k-out-of-n system with mixed redundancy is defined as k-out-of-n system which both includes warm-standby and cold-standby components. In case that operating components in the system fail and the system needs quick transition of standby components to operation state, the k-out-of-n system with mixed redundancy is useful for decreasing system failure rate and operational cost. Reliability-Redundancy Optimization Problem (RROP) involves selection of components with multiple choices and redundancy levels for maximizing system reliability with constraints such as cost, weight, etc. A solution methodology by using harmony search algorithm for RROP of the k-out-of-n system with mixed redundancy to maximize system reliability was suggested in this study.