• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.307-316
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• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.453-459
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• 2019

In this study, the influence factors on the stability of the O/W (oil in water) emulsions prepared with coconut oil and the nonionic mixed surfactant (Tween 80-Span 80) were evaluated. The concentration and HLB value of the nonionic mixed surfactant, and the degree of agitation were used as manufacture factors. The stability of prepared O/W emulsions were measured with the mean droplet size, zeta-potential, emulsion stability index (ESI), and thermal instability index (TII). The mean droplet size of the prepared O/W emulsions was from 100 to 200 nm. As the concentration of mixed surfactant and the homogenization speed increased, the droplet sizes decreased, while the zeta-potential values increased. The effect of HLB values increased in the order of 6.0, 10.0 and 8.0, and at the HLB value of 8 the smallest mean droplet size as 120 nm was obtained whereas the largest value of the zeta-potential between 10 and 60 mV. From the results of ESI and TII, the stability of prepared O/W emulsions increased in order of 6.0, 10.0 and 8.0 of HLB values, and ESI and TII values were above 80% and below 20% respectively at HLB value of 8.0.

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.17-26
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• 1996

This research was accomplished to evaluate possibility of using paper sludge for the raw materials of wood based panel products. The experimental panels were manufactured by four mixed ratios, the proportion of paper sludge to wood particle: 20:80, 30:70, 40:60, 50:50% (oven dry weight basis) and by three composition types, sludge-particle mixed board, three layered sludge-particle board and three layered particle board. They were tested mechanical (bending strength and internal bond) and physical properties (water absorption, thickness swelling and linear expansion). From the results they were shown that bending strength of mixed and three layered sludge-particle board were decreased with increasing of composition ratios of sludge. And the mechanical and physical properties of the boards of three layered composition types have superior to those of mixed composition type. Although composition ratios of sludge increased, the internal bond strength and dimensional stability of sludge-particle board not decreased quantitatively. We concluded that the mechanical and physical properties of three layered sludge-particle board were similar w those of three layered particle-board (control) made by our laboratory design. Therefore, it was recognized that paper sludge can be used as potential raw material in particle-board manufacturing industry.

• Journal of the Korea Safety Management & Science
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• v.2 no.4
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• pp.187-195
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• 2000

Electrochemical promotion of the reaction rate was investigated for CO oxidation in a solid electrolyte catalytic reactor where a thin film of Pt was deposited on the yttria stabilized zirconia as an electrode as well as a catalyst. It was shown under open circuit condition that potential was a mixed potential of $O_2$exchange reaction and electrochemical reaction induced by CO. The effect of electrochemical modification on the CO oxidation rate was studied at various overpotentials and $P_{CO}$$P_{O2}$.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.52-66
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• 2005

Tension and Membrane have the potential to enable the realization of lightweight structures that have the attractive features of structures efficiency and aesthetical expression. Compared with pure (thorough-bred) tension structures such as cable net, air dome and tensegrity, so called hybrid tension structures such as beam string, tensegric system and other mixed structures have Potential still to be realized. After synnaruzubg the simple definition of tensegric structure, some holistic designs for hybrid tension structures completed recently in the author's practice are given.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.10a
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• pp.95-98
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• 1999

The goal of present study is to evaluate the potential of soil washing for removing metal contaminants from a contaminated soil. Remediation of a soil contaminated with copper, cadmium and phenol were performed by a soil washing using a biosurfactant. The removal of copper, cadmium and phenol from soil (sandy, kaoline, mixed one) was evaluated as a function of biosurfactant (wt %) concentration in the batch process. The results showed that overall rejection coefficient for copper, cadmium and phenol were grater than 50 %, 25 %, respectively.

• International Journal of High-Rise Buildings
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• v.7 no.3
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• pp.197-214
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• 2018

Tall buildings which began from about 40 m tall office towers in the late $19^{th}$ century have evolved into mixed-use megatall towers over 800 m. It is expected that even mile-high towers will soon no longer be a dream. Structural systems have always been one of the most fundamental technologies for the dramatic developments of tall buildings. This paper presents structural systems employed for the world's tallest buildings of different periods since the emergence of supertall buildings in the early 1930s. Further, structural systems used for today's extremely tall buildings over 500 m, such as core-outrigger, braced mega-tube, mixed, and buttressed core systems, are reviewed and their performances are studied. Finally, this paper investigates the potential of superframed conjoined towers as a viable structural and architectural solution for mile-high and even taller towers in the future.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.292-296
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• 1999

The high density mixed mode adsorbent known by the trade name of Mimo-AD was used to purify lysozyme directly from the hen egg white (HEW). The homogenized hen egg white was treated with the adsorbent in a stirred vessel for lysozyme adsorption, and then the adsorbent, easily separated from the HEW by sedimentation, was packed into a column. The remaining HEW and contaminant proteins were removed by washing with pH 11 distilled water in an expanded-bed state, and subsequently the elution was performed with pH 12 distilled water in a packed-bed state. By this simple and rapid adsorption, washing, and elution procedure, lysozyme was purified to＞95％ with an overall recovery yield of 66％. This process offers a great potential for industrial application by allowing the extraction of lysozyme while retaining the commercial value of HEW.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.112-122
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• 1995

As an alternative fuel producing less exhaust emissions, natural gas is of interest for use both in SI and CI engines. The potential of natural gas fuelled dual-fuel engine is considered high enough. However, much effort has to be made so that gaseous fuel is used efficiently with simultaneous minimum use of pilot oil. Hence, a simplified three-dimensional model, using a finite volume method in cylindrical coordinates, has been developed to facilitate an understanding of the dual-fuel combustion phenomena and to predict the complex interactions between the pilot distillate and natural gas. The computer model was calibrated by comparing it with the experimental results obtained from diesel engine like combustion bomb tests. In the pre-mixed natural gas combustion, the fuel burning was highly reliant on the injection condition and subsequent burning nature of the pilot distillate.

• Journal of the Korean Ceramic Society
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• v.28 no.12
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• pp.1012-1018
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• 1991

SiC whisker-reinforced LAS matrix composites were developed by a mixed colloidal processing route. An optimization of processing conditions was made using the zeta potential data of silica, boehmite, and SiC whisker dispersions. Similarly, the SiC whisker-reinforced composites were also fabricated by the conventional sol-gel process using the hydrolysis-condensation reaction of relevant metal alkoxides. The composites fabricated by the mixed colloidal processing route were characterized by a uniform spatial distribution of SiC whisker throughout the matrix. The fracture toughness increased from 1.3 MPa.m1/2 for the LAS specimen to 5.0 Mpa.m1/2 for the hot-pressed composite (95$0^{\circ}C$ and 20 MPa for 20 min) containing 20 wt% SiC whisker. The increase in fracture toughness appears to result mainly from the crack deflection and the crack bridging by whiskers with some additional toughenings from the whisker pullout and the matrix prestressing mechanisms.