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이소프로판올의 탈수반응에서 지르코니아 촉매의 결정상에 따른 영향
신채호 ( Chae Ho Shin ),심혜인 ( Hye In Sim ),박정현 ( Jung Hyun Park ),조준희 ( Jun Hee Cho ),안지혜 ( Ji Hye Ahn ),최민석 ( Min Seok Choi ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.2
Zirconium hydroxide was synthesized by varying the aging time of the zirconyl chloride octahydrate at 100 oC in aqueous solution and the resulting hydroxides were calcined at 700 oC for 6 h to obtain the crystalline ZrO2. The materials used in this study were characterized by differential thermal analysis (DTA), X-ray diffraction (XRD), N2- sorption, transmission electron microscopy (TEM), NH3 temperature-programmed desorption (NH3-TPD), CO2-TPD and iso-propanol TPD analyses to correlate with catalytic activity for the dehydration of iso-propanol. The pure tetragonal ZrO2 phase was obtained after 24 h aging of zirconium hydroxide and successive calcination at 700 oC. The increase of aging time showed the production of smaller particle size ZrO2 resulting that the higher specific surface area and total pore volume. NH3-TPD results revealed that the relative acidity of the catalysts increased along with the increase of aging time. On the other hand, the results of CO2-TPD showed the reverse trend of NH3-TPD results. The best catalytic activity for the dehydration of iso-propanol to propylene was shown over ZrO2 catalyst aged for 168 h which had the highest SBET (178 m2 g-1). The catalytic activity could be correlated with high surface area, relative acidity and easy desorption of iso-propanol.
스쿼트 운동 시 발목 관절에 키네시오 테이프의 적용이 넙다리 네갈래근과 뒤넙다리근의 활성에 미치는 영향
박재흥,이승희,김소정,조승주,박현희,이유진,심혜지,최보람,Park, Jae-heung,Lee, Seung-hee,Kim, So-jung,Cho, Seung-ju,Park, Hyun-hee,Lee, Yu-jin,Sim, Hye-ji,Choi, Bo-ram 대한물리치료과학회 2021 대한물리치료과학회지 Vol.28 No.2
Background: During squat exercises, Ankle joint stability during squat movement transfers forces produced by unstable supports or various loads to the leg joints and trunk, reducing the risk of injury; therefore, a reference is needed for correct ankle joint posture during squat exercises. The purpose of this study was to examine the effect of ankle joint stability on quadriceps femoris and hamstring activation during squat exercises. Design: Quasi-experiment one group pretest-posttest design. Methods: The participants in this study were 20 volunteers who performed squat exercises with and without kinesiology tape. We measured quadriceps femoris and hamstring activation using surface electromyography. The ankle joint was stabilized with kinesiology tape using the ankle balance taping (ABT) method. A paired t-test was performed to compare differences between taping conditions. Results: Vastus medialis and vastus lateralis activation were greater following squat exercises with kinesiology tape than without; however, the difference was not significant. Medial and lateral hamstring activation was not significantly different between taping conditions. Conclusion: Although it is difficult to maintain stability using kinesiology tape alone, ankle joint stability is believed to affect quadriceps femoris muscle activity, which increases the effectiveness of the squat exercise.