• Elastomers and Composites
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• v.7 no.2
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• pp.175-182
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• 1972

As a series of the studies of EPDM-Polymer blonds, the experiments are concentrated to the investigation of the physical properties of the EPDM-CR blends. The results are shown as follows: 1. In blending, tensile strength decreased with increase in EPDM contents and decreasing value was good results than various EPDM blending. 2. As EPDM Addition ratio is increased physical properties such as elongation have also improved, on the other hand, hardness and abrasion resistance decreased. 3. Aging resistance is less influenced by blending. 4. Tear strength is less influenced by blending and character after aging exhibited the same result. 5. Ozone resistance was much improved after blending. It was effective more than the ratio of EPDM/CR is 25/75.

• Elastomers and Composites
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• v.7 no.2
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• pp.183-192
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• 1972

As a series of tile studies of EPDM-Polymer blends, tile experiment are concentrated to the investigation of the physical properties of tile EPDM-NR-SBR blends. The results are shown as follows: 1. In blending, tensile strength decreased with increase in EPDM contents, especially the ratio of EPDM/NR-SBR is 75/25. 2. Elongation and tear strength were much influenced by blending, especially the ratio of EPDM/NR-SBR is 50/50. 3. Ozone resistance is much improved after blending. It was effective more than tile ratio of EPDM/NR-SBR is 25/75. 4. Aging resistance is much improved after blending. It was effective more than the ratio of EPDM/NR-SBR is 50/50. 5. Hardness increased with increase in EPDM contents and on the other hand, abrasion resistance decreased.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.371.2-371.2
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• 2016

Graphene electronics is one of the promising technologies for the next generation electronic devices due to the outstanding properties such as conductivity, high carrier mobility, mechanical, and optical properties along with extended applications using 2 dimensional heterostructures. However, large contact resistance between metal and graphene is one of the major obstacles for commercial application of graphene electronics. In order to achieve low contact resistance, numerous researches have been conducted such as gentle plasma treatment, ultraviolet ozone (UVO) treatment, annealing treatment, and one-dimensional graphene edge contact. In this report, we suggest a fabrication method of one-dimensional graphene metal edge contact without using graphene exfoliation. Graphene is grown on Cu foil by low pressure chemical vapor deposition. Then, the graphene is transferred on $SiO_2/Si$ wafer. The patterning of graphene channel and metal electrode is done by photolithography. $O_2$ plasma is applied to etch out the exposed graphene and then Ti/Au is deposited. As a result, the one-dimensional edge contact geometry is built between metal and graphene. The contact resistance of the fabricated one-dimensional metal-graphene edge contact is compared with the contact resistance of vertically stacked conventional metal-graphene contact.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.1
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• pp.112-116
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• 2010

Fuel cell as a renewable energy source is clean and has a lot of advantages. The source can solve energy crisis and environmental problems such as greenhouse effect, air pollution and the ozone layer destruction. This paper introduces hybrid system(hydro-Genius Professional, heliocentris) of solar cell and fuel cell. Also, this paper shows the I-P, V-I characteristics of fuel cells which are connected in parallel and series. From these results, we also found the maximum power was transferred at 0.5[${\Omega}$]. The terminal voltage was also decreased according to the current because of the internal resistance. The power transfer in series was two times than that in parallel.

• Elastomers and Composites
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• v.7 no.1
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• pp.45-52
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• 1972

As a series of the studies of EPDM-Polymer blends, the experiments are concentracted to the investigation of the physical properties of the EPDM-NBR blends. The results are shown as follows; 1. As EPDM addition ratio is increased, the physical properties such as resistance to ozone and aging have also improved, on the other hand, elongation and abrasion resistance decreased. 2. Tear strength is less influenced by blending and character after aging exhibited the same result. 3. Tensile strength decreased with increase in EPDM contents, especially the ratio of EPDM/NBR are 50/50 and 75/25.

• Elastomers and Composites
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• v.35 no.2
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• pp.149-156
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• 2000

trans-octylene rubber(TOR) was melt-blended with an incompatible NBR/EPDM (70/30) blend. Mixing torque and temperature were reduced as TOR was added to the NBR/EPDM blend. Rheometer results indicated that TOR participated in vulcanization and became a part of network. A scanning electron micrograph demonstrated that EPDM was dispersed in NBR matrix in the blend and the addition of TOR led to a finer dispersion of EPDM particles. On the addition of TOR, the tensile strength, the tensile strain as well as the modulus of the blend vulcanizates increased. The ozone resistance of the blends determined in terms of critical stress-strain parameter was significantly enhanced in the blend as TOR was added. Improvements in the properties were believed to be associated with fine morphology and the increase in crosslink density due to the chain entanglement of the ternary blends.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.161-169
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• 1992

Studies were conducted to examine the effects of single or combined treatment of uniconazole [(E)-1-(4-chlorophenyl)-4, 4-dimethyl 2(1, 2,-4-triazol-1-yl)-1-penten-3-ol)] and silver thiosulfate (STS) on reducing ozone injury to snap beans (Phaseolus vulgaris L. 'Strike'). Two weeks after seeding, plants were given a soil drench of uniconazole(XE-1019) solution at concentrations of 0.001, 0.005 and 0.025 mg/pot, and then two days prior to ozone fumigation, 0.3 and 0.6 mM STS containing 0.01% Tween-20 were also sprayed. Uniconazole was effective in providing protection against ozone injury through increase activities of free radical scavengers such as superoxide dismutase (SOD) and peroxidase (POD) as well as the increase of chlorophyll content and stomatal resistance resulted from plant growth retardation. The phytoprotective effects of STS seemed to be related to its properly of blocking the ethylene action and increasing activities of SOD and POD. Even at low concentrations, a combined treatment with uniconazole drench, STS spray significantly reduced ozone injury compared to single application.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.424-431
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• 1995

This study was conducted to evaluate resistance and physiological responses of Zelkova serrata Makino seedlings to ozone in open-top chamber. One-year-old seedlings of Zelkova serrata were planted in pots in April and grown in greenhouse until August. The plants were transferred into two out-door open-top chambers with a dimension of 2.0 m in diameter and 2.0 m in height. First chamber served as a control and was supplied with ambient air. Ozone was added to the second chamber for 5 hours per day(10.00 AM-15.00 PM) for 23 consecutive days at 0.1 ppm. Each chamber housed 70 pots. Every two, three or five days after initiation of exposure, ten pots were randomly removed from the chamber and determined for the contents of chlorophyll a, b, total chlorophyll and ${\beta}$-carotene in the leaves. Photosynthesis and dark respiration were estimated by measuring $CO_2$ absorption in a gas exchange chamber and oxygen absorption by oxygen monitoring system, respectively. Superoxide dismutase(SOD) activity in the leaves was assayed by a xanthine oxidase method. First visible injury of translucent(water-soaked looking) spots appeared on the leaves 14 days after the initial exposure, and ozone accelerated senescence of old leaves. Contents of chlorophyll a and b decreased by 17%, and 31%, respectively, in ozone treatment two days after exposure. The decrease in chlorophyll b was greater than that of chlorophyll a. Content of ${\beta}$-carotene in ozone treatment decreased by 25% two days after initiation of exposure, but the reduction was recovered with time. Photosynthesis decreased by 45%, and the respiration increased by 28% in the ozone treatment. SOD activity started to increase 4 days after beginning of exposure and increased by 285% 7 days after exposure, and decreased to the level below the control treatment with the advancement of the visible injury.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.29-34
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• 2004

Reduction in stratospheric ozone layer increases the amount of ultraviolet-B radiation (UVB: 280-320 nm) that reaches the earth ’ s surface. UVB radiationcan damage plants, resulting in decrease in growth and productivity. UVB-augmentation studies have indicated that the sensitivity to UVB radiation in plants varies among the species and cultivars. However. there are no definitive answers for the mechanisms of UVB-resistance in higher plants and for bioengineering design and development of UVB-tolerant plants. We have been studying physiological and biochemical aspects of the effects of UVB radiation on growth and yield of rice COryza sativa LJ. aiming to clarify the mechanism of resistance to UVB radiationin rice. At this meeting. weintroduce our research as followed: (1) supplementary UVB radiation has inhibitory effects on the growth. yield and grain development of rice; (2) UVB sensitivity of rice varies widely among cultivars; (3) among Japanese rice cultivars. Sasanishiki. a leading variety in northeast Japan. is more resistant to UVB. while Norin 1. a progenitor of Sasanishiki. is less resistant; (4)UV-sensitive Norin 1 cultivar is deficient in photorepair of UVB-induced cyclobutane pyrimidine dimer (CPD). and this deficiency results from one amino acid residue alteration of CPD photolyase. These results suggest that spontaneously occurring mutation in CPD photolyase gene could lead to difference in UVB sensitivity in rice. and that CPD photolyase might be a useful target for improving UVB-sensitivity in rice by selective breeding or bioengineering of UVB-tolerant rice.

• Membrane Journal
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• v.14 no.1
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• pp.66-74
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• 2004

Total resistance of membrane in a micro-filtration system using a metal membrane was mainly attributed to the permeate resistance of cake layer($R_c$), which was formed by deposited particles from the physico-chemical interactions of solids on membrane surface. Intermittent back ozonation was highly effective than the air backwashing for fouling reduction. As far the operational effect, under same ozone injection, the increase of gas flow-rate was more favorable than the increase of injection time far the recovery of permeation flux. As the filtration time was longer, the effect of flux recovery by intermittent back-ozonation decreased. Therefore, it is preferable to operate membrane cleaning before the foulant is consolidated on membrane surface.