• Genes and Genomics
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• v.40 no.11
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• pp.1181-1197
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• 2018

Tropical plant rubber tree (Hevea brasiliensis) is the sole source of commercial natural rubber and low-temperature stress is the most important limiting factor for its cultivation. To characterize the gene expression profiles of H. brasiliensis under the cold stress and discover the key cold stress-induced genes. Three cDNA libraries, CT (control), LT2 (cold treatment at $4^{\circ}C$ for 2 h) and LT24 (cold treatment at $4^{\circ}C$ for 24 h) were constructed for RNA sequencing (RNA-Seq) and gene expression profiling. Quantitative real time PCR (qRT-PCR) was conducted to validate the RNA-Seq and gene differentially expression results. A total of 1457 and 2328 differentially expressed genes (DEGs) in LT2 and LT24 compared with CT were respectively detected. Most significantly enriched KEGG pathways included flavonoid biosynthesis, phenylpropanoid biosynthesis, plant hormone signal transduction, cutin, suberine and wax biosynthesis, Pentose and glucuronate interconversions, phenylalanine metabolism and starch and sucrose metabolism. A total of 239 transcription factors (TFs) were differentially expressed following 2 h or/and 24 h of cold treatment. Cold-response transcription factor families included ARR-B, B3, BES1, bHLH, C2H, CO-like, Dof, ERF, FAR1, G2-like, GRAS, GRF, HD-ZIP, HSF, LBD, MIKC-MADS, M-type MADS, MYB, MYB-related, NAC, RAV, SRS, TALE, TCP, Trihelix, WOX, WRKY, YABBY and ZF-HD. The genome-wide transcriptional response of rubber tree to the cold treatments were determined and a large number of DEGs were characterized including 239 transcription factors, providing important clues for further elucidation of the mechanisms of cold stress responses in rubber tree.

• Elastomers and Composites
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• v.27 no.4
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• pp.262-266
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• 1992

A number of tin-containing elastomers are produced commercially by Korea Kumho Petrochemical Co., Ltd. (KKPC) under the Kosyn Sol tradename. The effect of mastication of commercial and laboratory polymerized S-SBR has, been investigated using chemical mixer(ML-500), NMR, GPC and Mooney viscometer. Mastication of polymers containings coupling bonds is affected by the amount of stearic acid, the temperature of mixing and the time length of mixing.

• International Journal of High-Rise Buildings
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• v.10 no.3
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• pp.173-178
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• 2021

In this paper we introduce Shinagawa HEART, located in Shinagawa district, Tokyo. It is a mixed-use building with residences on the upper floors, offices on the lower floors, and commercial uses on the first and second floors, and is intended to meet the various needs of a building on the border between residential and commercial areas. The upper floors of the building are made of reinforced concrete, while the middle and lower floors are made of steel with CFT columns. First, an overview of the structural plan of the building is presented. Next, the adoption of the middle layer seismic isolation and the switch between the lower steel structure and the upper reinforced concrete structure, which are the features of this building, are explained. Finally, the construction method adopted to achieve the design performance is explained.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.123-133
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• 2000

The kinetic analysis was carried out for commercial rubbers such as NR, IR, BR, SBR 1500, and SBR 1700. Kinetic analysis for the commercial rubbers was performed using the thermogravimetric method, with which the activation energies of NR obtained by Kissinger, Friedman, and Ozawa's method were 195.0, 198.3 and 186.3kJ/mol, whereas that of SBR 1500 were 246.4, 247.5 and 254.8kJ/mol, respectively. It was shown that the yield of pyrolytic oil was generally increased with final temperature increasing, yet slightly decreased or increased over $700^{\circ}C$. Considering the effect of heating rate, it was found that the yield of pyrolytic oil was not consistent for each sample. The number average molecular weight of SBR 1500 was in the range of 740~2486. The calorific value of SBR 1500 was 39~40kJ/g, which were made comparative study of the conventional fuel such as kerosene, diesel, light fuel, and heavy fuel. Therefore it was essential that the selection of the suitable kinetic model and the mathematical solution because of the difference in parameters obtained from each method. It was proposed that the range of $600~700^{\circ}C$ in final temperature and high heating rate due to short run time. It was suggested that the pyrolytic oil be available to use to the fuel.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.4 s.109
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• pp.372-379
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• 2006

Little attention has been paid to static-strain-dependence of dynamic complex modulus of viscolelastic materials in computational analysisso far. Current commercial Finite Element Method (FEM) codes do not take such characteristics into consideration in constitutive equations of viscoelastic materials. Recent experimental observations that static-strain-dependence of dynamic complex modulus of viscolelastic materials, especially filled rubbers, are significant, however, require that solutions somehow are necessary. In this study, a simple technique of using a commercial FEM code, ABAQUS, is introduced, which seems to be far more cost/time saving than development of a new software with such capabilities. A static-strain-dependent correction factor is used to reflect the influence of static-strains in Merman model, which is currently the base of the ABAQUS. The proposed technique is applied to viscoelastic components of rather complicated shape to predict the dynamic stiffness under static-strain and the predictions are compared with experimental results.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.74-85
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• 2010

In order to formulate the compounded polypropylene(C-PP) which is suitable to an automotive door trim panel, 9 sorts of properties were measured after manufacturing the C-PP using an extruder and an injection machine with polypropylene(PP), ethylene-octene rubber(EOR) and talc. Mixture design, especially extreme vertices design, in DOE with MINITAB - commercial software was used to analyze the data. The relations between each property and each component, for example, $y=0.00907222x_1+0.00870556x_2+0.0155722x_3$ for specific gravity, were found out by the regression analysis and the variance analysis. The optimized formulation of the C-PP for an automotive door trim panel was acquired at PP(77.6962), EOR(11.0238) and talc(10.2800) by use of the response optimizer(mixture) in MINITAB.

• Journal of Welding and Joining
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• v.21 no.2
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• pp.42-49
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• 2003

The protection of steel surfaces against wear is a practical problem far agricultural, mining and manufacturing industries. Commercial processes are available in which a hard tungsten carbides rich steel layer is formed on the surface of carbon steel digging, drilling and gouging tools to improve their wear resistance. The nature of the interaction of the tungsten carbide with the steel matrix is important in determining the wear and corrosion properties of the resulting metal matrix composites(MMC). In the study, WC-12%Co/low carbon steel MMC overlays have been prepared by gas metal arc welding(GMAW) according to size of WC-12%Co grits. The characteristics wear resistance and wear mechanism have been investigated in relation to the experiment conditions each other. After MMC overlay had been tested by rubber wheel abrasion test, it was known that MMC overlay has a excellent wear resistance. Fe$_{6}$W$_{6}$C carbides of matrix in overlays were not important to restrain rubber wheal abrasion wear. Wear loss is proportioned to a applied load according to time. On the case of low load, wear occurred severely in the matrix of overlay more than WC-12%Co grit, on the contrary it is reverse on the case of high load because of fracture of WC-12%Co grits.its.

• Journal of the Korean Society for Railway
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• v.3 no.3
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• pp.117-124
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• 2000

The rubber wheel-type AGT has two major kinds of bogie; one is the bogie type and the other steering one. Both are important vehicular structure to support the whole running vehicle and passenger loads. This paper deals with the static analysis for the two types of bogie frame subjected to combined external forces, as well as independent ones specified in UIC 515-4. Furthermore, the dynamic analysis is performed under vibrational loading conditions so as to compare dynamic characteristics, Numerical results by using commercial packages, I-DEAS and NASTRAN show that maximum stresses do not exceed the yield strength level of material used for both bogies. From an overall viewpoint of strength, the bogie type turns out to be superior to the steering type except for the case of a lateral loading. It is also observed that the steering type shows a characteristics of low frequency behavior during a course of searching for structurally weak areas to be stiffened. The vibrational fatigue analysis for each bogie frame depends on the loading time history conditions which is applied. Time History Central Database List in the NASTRAN package. Subsequent1y, the fatigue life of bogie type is longer than the steering type.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.9 s.114
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• pp.919-925
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• 2006

An accurate mathematical model for complex stiffness of the pneumatic spring would be necessary for an efficient design of a pneumatic spring used in vibration isolation tables for precision instruments such as optical devices or nano-scale equipments. A diaphragm, often employed for prevention of air leakage, plays a significant role of complex stiffness element as well as the pressurized air itself Therefore, effects of the diaphragm need to be included in the dynamic model for a more faithful description of dynamic behavior of pneumatic spring. But the complex stiffness of diaphragm is difficult to predict In an analytical way, since it is a rubber membrane of complicated shape in itself. Moreover, the diaphragm should be expandable in response to pressurization inside a chamber, which makes direct measurement of complex stiffness of diaphragm extremely difficult. In our earlier research, the complex stiffness of diaphragm was indirectly measured, which was just to eliminate the theoretical stiffness of pressurized air from the measured complex stiffness of the pneumatic spring. In order to reflect complex stiffness of inflated diaphragm on the total stiffness at the initial design or design improvement stage, however. it is required to be able to predict beforehand. In this paper, how to predict the complex stiffness of inflated rubber diaphragm by commercial FE codes (e.g. ABAQUS) will be discussed and the results will be compared with the indirectly measured values.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.10-16
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• 2013

Hevea brasiliensis is a natural source of rubber and an important plantation tree species in Malaysia. Leaf blight disease caused by Fusicoccum substantially reduces the growth and performance of H. brasiliensis. The aim of this study was to use a combination of both morphological characteristics and molecular data to clarify the taxonomic position of the fungus associated with leaf blight disease. Fusicoccum species were isolated from infected leaves collected from plantations at 3 widely separated locations - Selangor, Perak, and Johor states - in Peninsular Malaysia in 2010. All the isolates were identified according to their conidial patterns and DNA sequences generated from internal transcribed spacers (ITS1 and ITS2), the 5.8S rRNA, and an unknown locus (BotF15) containing microsatellite repeats. Based on taxonomic and sequence data, Neofusicoccum ribis was identified as the main cause of leaf blight disease in H. brasiliensis in commercial plantations in Malaysia. A pathogenicity trial on detached leaves further confirmed that N. ribis causes leaf blight disease. N. ribis is an important leaf pathogen, and its detection in Malaysia has important implications for future planting of H. brasiliensis.