• Journal of the Korean Society for Heat Treatment
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• v.24 no.3
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• pp.144-148
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• 2011

Change in damping capacity with strain amplitude was studied in Mg-Al-Si alloy in as-cast, solution-treated and aged states, respectively. The as-cast microstructure of the alloy is characterized by eutectic ${\beta}$($Mg_{17}Al_{12}$) phase and Chinese script type $Mg_2Si$ particles. The solution treatment dissolved the ${\beta}$ phase into the matrix, while the aging treatment resulted in the distribution of continuous and discontinuous type ${\beta}$ precipitates. The solution-treated microstructure showed better damping capacity than as-cast and aged microstructures both in strain-dependent and strain-independent damping regions. The decrease in second-phase particles which weakens the strong pinning points on dislocations and distribution of solute atoms in the matrix, would be responsible for the enhanced damping capacity after solution treatment.

• Advances in nano research
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• v.8 no.2
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• pp.149-156
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• 2020

The present paper explores forced vibrational properties of porosity-dependent functionally graded (FG) cylindrical nanoshells exposed to linear-type or triangular-type impulse load via classical shell theory (CST) and nonlocal strain gradient theory (NSGT). Employing such scale-dependent theory, two scale factors accounting for stiffness softening and hardening effects are incorporated in modeling of the nanoshell. Two sorts of porosity distributions called even and uneven have been taken into account. Governing equations obtained for porous nanoshell have been solved through inverse Laplace transforms technique to derive dynamical deflections. It is shown that transient responses of a nanoshell are affected by the form and position of impulse loading, amount of porosities, porosities dispensation, nonlocal and strain gradient factors.

• Journal of Advanced Marine Engineering and Technology
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• v.7 no.1
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• pp.34-39
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• 1983

Development of modern internal combustion engine requires more precise indicator. In the case of strain gage-strain tube type indicator, thermal expansion of the indicator's fixed part makes zero-shift in spite of water cooling. Therefore, the authors analyzed the cause of zero-shift phenomenon on strain gage-strain tube type indicator and proposed a new device to compensate the zero-shift of indicator by electrical method without detoriorating the dynamic charcteristic. As the results, we found that the zero-shift is varied linearlly according to temperature variation of the indicator's fixed part and appling a new device, we can improve the zero-shift of indicator about 0.63% (0.63 kg/$cm^2$) of full scale, though we got 10% of it without the device at the cylinder head operating temperature (c.a. $200^{\circ}C$).

• The Plant Pathology Journal
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• v.36 no.4
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• pp.355-363
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• 2020

Bacterial traits for virulence of Ralstonia solanacearum causing lethal wilt in plants were extensively studied but are not yet fully understood. Other than the known virulence factors of Ralstonia solanacearum, this study aimed to identify the novel gene(s) contributing to bacterial virulence of R. solanacearum. Among the transposon-inserted mutants that were previously generated, we selected mutant SL341F12 strain produced exopolysaccharide equivalent to wild type strain but showed reduced virulence compared to wild type. In this mutant, a transposon was found to disrupt the murI gene encoding glutamate racemase which converts L-glutamate to D-glutamate. SL341F12 lost its motility, and its virulence in the tomato plant was markedly diminished compared to that of the wild type. The altered phenotypes of SL341F12 were restored by introducing a full-length murI gene. The expression of genes required for flagella assembly was significantly reduced in SL341F12 compared to that of the wild type or complemented strain, indicating that the loss of bacterial motility in the mutant was due to reduced flagella assembly. A dramatic reduction of the mutant population compared to its wild type was apparent in planta (i.e., root) than its wild type but not in soil and rhizosphere. This may contribute to the impaired virulence in the mutant strain. Accordingly, we concluded that murI in R. solanacearum may be involved in controlling flagella assembly and consequently, the mutation affects bacterial motility and virulence.

• Korean Journal of Poultry Science
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• v.17 no.1
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• pp.7-15
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• 1990

The present study was undertaken to determine the effect of different body hair color (Native type) and commercial white laying hen (Improvement, Nick Chick strain) on cholesterol, triglyceride and protein concentration in serium. Experimental hens were selected out of yellow-brown body hair color strain (10 heads), green-black body hair color strain (13 heads), white body hair color strain (7 heads), black-bone strain (10 heads) as native type and commercial white laying hen (30 head,3) as improved variety. Experimental diet was fed identically for 4 weeks in total groups. The results of the experiment obtained were summerized as follows：1. Serium cholesterol contents were the highest in commercial white laying hen ($172.50\pm$13.45 mg/100 $m\ell$) (p＜0.01;, and higher in white color strains than body hair color strain groups. Body hair color strain groups were similar in serium cholesterol contents. 2, Serium triglyceride concentration also showed no response among native type groups, however commercial white laying hen group shelved significatly difference. (p＜0.01) 3. Serium protein contents were the highest in commercial white laying hen group ($6.24\pm$0.23 mg/100 $m\ell$). (p＜0,01) Increasing the serium cholesterol, triglyceride and protein contents in commercial white laying hen group than color strain group of native type was considered to improved grade.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.363-368
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• 2007

Traditional kochujang samples were collected from the folk village in Sunchang to find the major microbial composition and correlation between the taste and the microbial properties. Among the 29 samples, 17 samples showed Bacillus licheniformis as dominant strain with 11 samples Bacillus subtilis and 1 sample Staphylococcus pasteuri. Subdominant strain of 17 samples was Bacillus licheniformis with 12 samples Bacillus subtilis. Dominant strain numbers varied in rage of $6.60{\sim}8.38$ logCFU/g with subdominant strain number $5.90{\sim}7.86$ logCFU/g and total microbial number $6.64{\sim}8.56$ logCFU/g respectively. Bacterial type number varied in range of $6{\sim}18$ with the average 10.5 types. Fungi were found only in 2 samples and identified all to be Aspergillus oryzae. Yeasts were found in 25 samples. The dominant yeast strain of 23 samples was identified to be Zygosaccharomyces pseudorouxii and that of 2 samples Zygosaccharomyces rouxii. Yeast type variety showed that only single type was found in 15 samples, 2 types in 8 samples, 3 types in 1 sample and 4 types in 1 sample. Fungal number was 3.90 and 4.08 logCFU/g and yeast numbers varied in range of $3.90{\sim}6.43$ logCFU/g. The sensory scores of kochujang showed positive correlation with type numbers, but no significant correlation with the other microbial properties like total bacterial number, dominant bacterial number, subdominant bacterial number and dominant yeast number.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.99-105
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• 1994

Clotridium bovis sp. nov, is described on the basis of 5 strains isolated from the feces of Holstein cattle. The isolate are gram-positive, motile, strict anaerobic spore forming rods. They differ from all the validly described related species of the genus Clostridium in carbohydrate fermentation pattern, G+C mol% and DNA homologies. Acid is produced from arabinose, xylose, glucose, mannose, fructose, galactose, sucrose, maltose, cellobiose, lactose, trehalose, melibiose, raffinose, inulin and salicin. Major end products in PYFG broth are large amounts of butyric acid and lactic acid, and trace amounts of acetic and succinic acids. The G+C mol% of DNA from the type strain is 26 mol%. The type strain of Clostridium bovis is Catt $66^T$ strain.

• Structural Engineering and Mechanics
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• v.89 no.4
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• pp.349-362
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• 2024

High-performance fiber-reinforced cement composites (HPFRCC) are new materials created and used to repair, strengthen, and improve the performance of different structural parts. When exposed to tensile tension, these materials show acceptable strain-hardening. All of the countries of the globe currently seem to have a need for these building materials. This study aims to create a low-carbon HPFRCC (high ductility) that is made from materials that are readily available locally which has the right mechanical qualities, especially an increase in tensile strain capacity and environmental compatibility. In order to do this, the effects of fiber volume percent (0%, 0.5%, 1%, and 2%), and determining the appropriate level, filler type (limestone powder and silica sand), cement type (ordinary Portland cement, and limestone calcined clay cement or LC3), matrix hardness, and fiber type (ordinary and oxygen plasma treated polypropylene fiber) were explored. Fibers were subjected to oxygen plasma treatment at several powers and periods (50 W and 200 W, 30, 120, and 300 seconds). The influence of the above listed factors on the samples' three-point bending and direct tensile strength test results has been examined. The results showed that replacing ordinary Portland cement (OPC) with limestone calcined clay cement (LC3) in mixtures reduces the compressive strength, and increases the tensile strain capacity of the samples. Furthermore, using oxygen plasma treatment method (power 200 W and time 300 seconds) enhances the bonding of fibers with the matrix surface; thus, the tensile strain capacity of samples increased on average up to 70%.

• Journal of Life Science
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• v.7 no.4
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• pp.322-328
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• 1997

Two phosphorylated proteins having molecular weights of 57kD and 72kD were detected from the slubilized membrane protein fraction of mating type a cells of Rhodosporidium toruloides which belongs to heterobasidiomycetous yeast. The phosphorylation of the protein was inhibited by a sexual pheromone, Rhodotorucine A (Rh. A), which is secreted from mating type a cells. On the other hand, counterpart mating type A cells and M-39 strain which is a styerile mutant derived from a cells, had also the same two phosphorylated proteins, However, the phosphorylation of the protein from A cells, and M-39 strain were not inhibited by the Rh. A. It suggests that inhibition of the phosphorylation reaction by the Rh. A in mating type a cells is a mating-type-specific reaction that relate to transduction mechanism of sexual pheromone signaling.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.222-231
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• 2009

Statements of the problem: Over the past decades, conventional complete dentures were used for various patients although they have incomplete function. Overdentures using dental implants could help the improvement of denture function. Purpose: The purpose of this study was to compare the strains of abutment and bone on implant overdenture between splinted and unsplinted type of prosthesis. Additionally, the strain values of parallel placed implant model and unparallel placed implant model were compared. Material and methods: Two acrylic resin model were prepared and two implants were placed at the canine positions in each model. In the first model, two implant were placed parallel. In the second model, two implants were placed with 10 degree labiolingual divergence. Two types of abutment were connected to the fixtures alternatively. One was splint type of Hader bar, the other was unsplint type of ball abutment. Overdentures were fabricated with corresponding attachment systems and seated on abutments. Strains of abutments and labial bone simulants were measured with electric resistance strain gauges when static load from 100 N to 200 N were applied to overdentures. Results: 1. Splinted type of overdentures using bar and clip showed higher absolute strain values. But the strain was compressive and the load was shared by two implants(P<.05). 2. Unsplinted type overdentures using ball and O-ring showed low absolute strain values(P<.05). 3. Labially inclined implant showed higher tensile strain values in unsplinted type of prosthesis than in splinted type of prosthesis. Lingually inclined implant showed rather low strain values under load(P<.05). 4. Non parallel implant model showed higher absolute strain values than parallel placed implant model comprehensively(P<.05).