• Mycobiology
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• v.51 no.2
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• pp.94-108
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• 2023

Termitomyces sp. that grow in symbiosis with fungus-farming Termites have medicinal properties. However, they are rare in nature, and their artificial culture is challenging. The expression of AXL receptor tyrosine kinase and immune checkpoint molecules favor the growth of cancer cells. The study evaluated the optimal conditions for the artificial culture of Termitomyces and their inhibitory activity on AXL and immune checkpoint molecules in lung adenocarcinoma and melanoma cell lines. The culture of 45 strains of Termitomyces was compared. Five strains with marked growth rates were selected. Four of the selected strains form a single cluster by sequence analysis. The mycelium of 4 selected strains produces more fungal mass in potato dextrose broth than in a mixed media. The bark was the most appropriate solid substrate for Termitomyces mycelia culture. The mycelium of all five selected strains showed a higher growth rate under normal CO₂ conditions. The culture broth, methanol, and ethyl acetate of one selected strain (T-120) inhibited the mRNA relative expression of AXL receptor tyrosine kinase and immune checkpoint molecules in cancer cell lines. Overall, these results suggest the potential usefulness of Termitomyces extracts as a coadjuvant therapy in malignant diseases.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.3
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• pp.284-290
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• 2014

Aluminum alloy is a core material for structural parts of aircraft and automobiles to reduce the weight and maintain high specific strength. This study evaluates the machinability and investigates the optimal cutting conditions considering the surface integrity and productivity for Al7050-T7451 milling. The machining variables considered are the feed per tooth, spindle speed, axial depth of the cut, and radial depth of the cut. The machinability evaluation of Al7050-T7451 is conducted by analyzing the cutting force signals, acceleration signals, AE signals, and machined surface conditions. The optimal cutting conditions are determined by analyzing the experimental results using response surface methodology for stable machining considering the productivity and surface integrity.

• Journal of Power Electronics
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• v.9 no.5
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• pp.757-771
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• 2009

This paper proposes a systematic approach to the modeling of the small-signal characteristics of three-phase bridge boost rectifiers under non-sinusoidal conditions. The main obstacle to the conventional synchronous d-q frame modeling approach is that it is unable to identify a steady-state under non-sinusoidal conditions. However, for most applications under non-sinusoidal conditions, the current loops of boost rectifiers are designed to have a bandwidth that is much higher than typical harmonics frequencies in order to achieve good current control for these harmonic components. Therefore a quasi-static method is applied to the proposed modeling approach. The converter small-signal characteristics developed from conventional synchronous frame modeling under different operating points are investigated and a worst case point is then located for the current loop design. Both qualitative and quantitative analyses are presented. It is observed that operating points influence the converter low frequency characteristics but hardly affect the dominant poles. The relationship between power stage parameters, system poles and zeroes is also presented which offers good support for the system design. Both the simulation and experimental results verified the analysis and proposed modeling approach. Finally, the practical case of a parallel active power filter is studied to present the modeling approach and the resultant regulator design procedure. The system performance further verifies the whole analysis.

• The Korean Journal of Community Living Science
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• v.16 no.3
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• pp.47-55
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• 2005

The purposes of this study are to examine the economic conditions and parenting of custodial fathers/mothers and to explain their impacts on the children's social adjustment after divorce. A total of 185 custodial parents divorced within the last 5 years completed a structured questionnaire. Children's social adjustment was the dependent variable in this study and was defined as their school performance and behavior problems. Results show that compared with divorced custodial fathers, divorced custodial mothers demonstrate more effective parenting, but there were no differences in economic conditions between them. In addition, children in single-father divorced families have lower school grades and more behavior problems than those in single-mother divorced families. Results also indicate that the economic conditions and parenting have different effects for children across family type. For children raised with a custodial father in divorced families, the economic conditions and the divorce duration are associated with lower school grades and behavior problems. For children with a custodial mother, however, the effective of parenting and the children's age have significant effects on the children's social adjustment after the parent divorced. Based on these results, this study proposes strategies for the improvement of children's adjustment in divorced families.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.520-529
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• 2020

Experimental investigations were attempted to simultaneously observe the vapor behaviors and critical heat flux under static and rolling conditions. From visualization results, vapor initiated, grew, and detached individually in a vertical direction from the static heated surfaces (at 10, 20, and 30°). While under rolling motion, initiated vapor grew, and interacted with each other, resulting in forming a wider dry spot on the heated surface. Also, it was observed that the vapor drifted upward and stayed on the heated surface longer compared to under static condition. The faster the platform rolls, the longer the vapor stay on the heated surface, significantly decreasing the CHF. On the other hand, as the platform rolls slower (at high rolling period), CHF increases. CHF was decreased with increasing maximum rolling amplitude and inclination angle under both conditions (static and rolling). CHF under rolling conditions was noticed to be lower than under static condition except at maximum rolling amplitude of 10°. The bubble departure frequency at a maximum rolling amplitude of 10° was the highest among all of rolling amplitudes, thereby enhancing the CHF. These results indicate that rolling motion significantly affects vapor behaviors and CHF.

• Journal of computational fluids engineering
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• v.20 no.4
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• pp.102-108
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• 2015

Recently, There are many studies in progress in order to improve the efficiency of the gas turbine. Leakage in losses of the gas turbine account for the largest proportion. Seal is a sealing device to reduce the flow from leaking by the pressure difference inside the turbine. Compressor has another value according to the shape and pressure conditions in each stage. Thus, it is necessary to seal design for boundary conditions in order to minimize leakage. At the actual operating conditions of the compressor, numerical analysis of honeycomb labyrinth seal was performed in accordance with pressure, temperature, rotor speed for CFD. As a result, when the temperature increases, the leakage is decreased. Also, when the pressure increases linearly with increased leakage, and there was no effect of the rotation speed.

• Korean Journal of Materials Research
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• v.18 no.6
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• pp.302-306
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• 2008

Polycrystalline germanium (Ge) thin films were grown by metal organic chemical vapor deposition (MOCVD) using tetra-allyl germanium [$Ge(allyl)_4$], and germane ($GeH_4$) as precursors. Ge thin films were grown on a $TiN(50nm)/SiO_2/Si$ substrate by varying the growth conditions of the reactive gas ($H_2$), temperature ($300-700^{\circ}C$) and pressure (1-760Torr). $H_2$ gas helps to remove carbon from Ge film for a $Ge(allyl)_4$ precursor but not for a $GeH_4$ precursor. $Ge(allyl)_4$ exhibits island growth (VW mode) characteristics under conditions of 760Torr at $400-700^{\circ}C$, whereas $GeH_4$ shows a layer growth pattern (FM mode) under conditions of 5Torr at $400-700^{\circ}C$. The activation energies of the two precursors under optimized deposition conditions were 13.4 KJ/mol and 31.0 KJ/mol, respectively.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.569-575
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• 2017

One of the important requirements for the application of reduced-activation ferritic/martensitic (RAFM) steel is to retain proper mechanical properties under irradiation and high-temperature conditions. To simulate the yield strength and stress-strain curve of steels during high-temperature and irradiation conditions, a multiscale simulation method consisting of both microstructure and strengthening simulations was established. The simulation results of microstructure parameters were added to a superposition strengthening model, which consisted of constitutive models of different strengthening methods. Based on the simulation results, the strength contribution for different strengthening methods at both room temperature and high-temperature conditions was analyzed. The simulation results of the yield strength in irradiation and high-temperature conditions were mainly consistent with the experimental results. The optimal application field of this multiscale model was 9Cr series (7-9 wt.%Cr) RAFM steels in a condition characterized by 0.1-5 dpa (or 0 dpa) and a temperature range of $25-500^{\circ}C$.

• Geomechanics and Engineering
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• v.18 no.4
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• pp.363-371
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• 2019

In this study, the load carrying behavior of piled rafts installed in inclined bearing rock layer was investigated for rock-mounted and -socketed conditions. It was found that settlements induced for an inclined bearing rock layer are larger than for a horizontal layer condition. The load capacity of piled rafts for the rock-mounted condition decreased as rock-layer inclination angle (${\theta}$) increased, while vice versa for the rock-socketed condition. The load capacities of raft and piles both decreased with increasing ${\theta}$ for the rock-mounted condition. When bearing rock layer was inclined, loads carried by uphill-side piles were greater than those by downhill-side piles. The values of differential settlements of rock-mounted and -socketed conditions were not significantly different whereas slightly higher for the rock-socketed condition. The values of load sharing ratio (${\alpha}_p$) and its variation with settlement were not markedly changed by the inclination of bedrock. It was shown that ${\alpha}_p$ for piled rafts installed in rock layer was not affected by ${\theta}$ whereas actual loads carried by raft and piles may vary depending on the pile installation and rock-layer inclination conditions.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.72-79
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• 2021

Background and Objectives: The speech-in-noise test is typically performed using an audiometer. The results of the digit-in-noise recognition (DIN) test may be influenced by the flat frequency response of free-field audiometry and frequency of the hearing aid fit based on fitting rationale. This study aims to investigate the DIN test in unaided and aided conditions. Subjects and Methods: Thirty four adults with moderate and severe sensorineural hearing loss (SNHL) participated in the study. The signal-to-noise ratio (SNR) for 50% of the DIN test was obtained in the following two conditions: 1) the unaided condition, performed using an audiometer in a free field; and 2) aided condition, performed using a hearing aid with an unvented individual earmold that was fitted based on NAL-NL2. Results: There was a statistically significant elevation in the mean SNR for the severe SNHL group in both test conditions when compared with that of the moderate SNHL group. In both groups, the SNR for the aided condition was significantly lower than that of the unaided condition. Conclusions: Speech recognition in hearing-impaired patients can be realized by fitting hearing aids based on evidence-based fitting rationale rather than by measuring it using free-field audiometry measurement that is utilized in a routine clinic setup.