• Korean Journal of Materials Research
• /
• v.10 no.1
• /
• pp.21-28
• /
• 2000

Refractory metals, W and Ti, and their nitrides, $W_2N$ and TiN, were investigated for using as an ohmic contact material with SiC single crystalline thin films. The possibility of nitride materials for using as a stable ohmic contact material of SiC at high temperatures was examined by considering the thermal stability depending on the heat treatment temperature, their electrical properties and protective behavior from the interdiffusion. W contact with SiC thin films, deposited by using new organosilicon precursor, bis-trimethylsilylmethane, showed the lowest resistivity, $2.17{\times}10^{-5}$Ω$\textrm{cm}^2$. On the other hand, Ti-based contact materials showed higher contact resistivity than W-based ones. The oxidation of contact materials was restricted by applying Pt thin films on those electrodes. Nitride electrodes had rather stable electrical properties and better protective behavior from interdiffusion than metal electrodes.

• Journal of the Korean Arthroscopy Society
• /
• v.13 no.1
• /
• pp.46-52
• /
• 2009

Purpose: To evaluate the usefulness of minimally invasive arthroscopy-assisted plate removal of a laterally inserted periarticular distal femur plate used for the treatment of AO type-C distal femur fractures. Materials and Methods: From October 2002 to November 2005, we evaluated 17 patients whose plates were removed through minimally invasive arthroscopy-assisted plate-removal technique and 15 patients who got their plates removed through conventional method without using arthroscopy, 32 patients in total. All these patients included in this study initially underwent open reduction and internal fixation of the distal femoral fractures with a lateral plate, and complained of continued pain over the lateral femoral condyle after the fracture fixation. The average age was 42.6 (ranges: 20~66) and initial fracture types included 16 cases of C1, 11 cases of C2, and 5 cases of C3 following AO/ASIF classification guidelines. Measured outcomes included: associated intra-articular pathologies, time needed to return to activities of daily living, patients' overall satisfaction, complications following the removal of hardware, and pain before and 6 months after the operation. Results: The distal-most end of the plate was placed in the knee joint in all cases and damage of the lateral articular capsule was found in 23 cases. Continuous wound discharge after surgery was found in one case who underwent arthroscopy-assisted plate removal, and it was treated by irrigation and re-suture. Average time needed to return to activities of daily living was 7 days in arthroscopy assisted group and 7.6 days in conventionally removed group. Fourteen patients (82.4%) who underwent arthroscopyassisted plate-removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 4.9 to 1.9, six months after the plate removal. Thirteen patients(86.7%) who underwent conventional plate removal reported above 'fair' satisfaction and the Visual analog scale pain score decreased from 5.2 to 2.5, six months after the operation. Conclusion: Through minimally invasive arthroscopic-assisted plate removal, intrarticular pathology of the knee joint was able to be simultaneously identified and treated at the time of hardware removal. Damage of lateral capsule of the knee joint caused by the inserted plate for the treatment of type C distal femoral fracture was very frequently found and following the plate removal, patients experienced an improvement in pain score. We therefore recommend routine lateral distal femoral plate removal if the bony union is attained in such cases as type C distal femoral fractures whose distal most end of the plates are located in the joint.

• Korean Journal of Materials Research
• /
• v.8 no.12
• /
• pp.1138-1145
• /
• 1998

The sliding wear behavior of Ni-base hardfacing alloy, Deloro 50, was investigated at the contact stresses of 15ksi and 30ksi under the various wear environments. In air at room temperature, Deloro 50 showed lower wear resistance than Stellite 6 even at 15ksi due to the occurrence of severe adhesive wear. This seems to be caused by the lower hardness and work- hardening rate of Deloro 50 than those of Stellite 6. In water at room temperature, Deloro 50 showed as good wear resistance as Stellite 6 at 15ksi. It was considered to be due to that water could effectively prevent metal to metal contact through contacting asperities. However, Deloro 50 showed severe adhesive wear at 30ksi in water at room temperature. It seems to be that the water could not suppress adhesion wear at 30ksi. At $300^{\circ}C$ in air, Deloro 50 exhibited higher wear resistance than Stellite 6 even at 30ksi. It was considered that the oxide glaze layers formed on wear surface during sliding, effectively prevented direct metal-to-metal contacts.

• Applied Chemistry for Engineering
• /
• v.8 no.6
• /
• pp.934-938
• /
• 1997

Acrylic acid was grafted onto the peroxidized cellulose which was stored at room temperature for 20 days after ${\gamma}$-ray irradiation in air. The effect of acids and metallic salts on the grafting yields was determined. The addition of both the acid and metallic salt was found to accelerate the grafting yield much more than the only metallic salt, and the addition of $FeSO_4{\cdot}7H_2O$ led to much higher grafting yield than that of $CuSO_4{\cdot}5H_2O$. The effect of acid on the grafting yield increased by the order $H_2>SO_4>HCl>HNO_3>CH_3COOH$. With the addition of $H_2SO_4$, the grafting yield rapidly increased up to $7{\times}10^{-2}$M, and then levelled off.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.6
• /
• pp.1092-1103
• /
• 1989

본 논문에서는 기존의 금속성형의 유한요소해석에서 사용한 바 있는 기하적경 계조건을 직접 유한요소방정식에 대입하는 방법들을 비교검토하고 3차원박판성형에 적용하기 위하여 개선된 방법을 개발하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.307-308
• /
• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.209-210
• /
• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.10a
• /
• pp.244-245
• /
• 2010

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 1997.05a
• /
• pp.39-44
• /
• 1997

자동차 에어백(Air bag)의 가스발생제로 쓰이는 나트륨 아지드의 실용성과 열적인 특성에 대하여 상당히 연구1-4)가 진행되고 있고, 특히 안전성에 대한 문제점중에서 중금속과의 접촉하면 예민한 폭발성 물질을 생성할 수 있다고 지적한 바 있다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.04a
• /
• pp.254-255
• /
• 2009