The objective of this study is to investigate the influence of powder shape and densification mechanism on the microstructure and mechanical properties of Ti-6Al-4V components. BE powders are uniaxially and isostatically pressed, and PA ones are injection molded because of their high strengths. The isostatically compacted samples exhibit a density of 80%, which is higher than those of other samples, because hydrostatic compression can lead to higher strain hardening. Owing to the higher green density, the density of BE-CS (97%) is found to be as high as that of other samples (BE-DS (95%) and P-S (94%)). Furthermore, we have found that BE powders can be consolidated by sintering densification and chemical homogenization, whereas PA ones can be consolidated only by simple densification. After sintering, BE-CS and P-S are hot isostatically pressed and BE-DS is hot forged to remove residual pores in the sintered samples. Apparent microstructural evolution is not observed in BE-CSH and P-SH. Moreover, BE-DSF exhibits significantly fine grains and high density of low-angle grain boundaries. Thus, these microstructures provide Ti-6Al-4V components with enhanced mechanical properties (tensile strength of 1179 MPa).

최근 들어 연구기관 및 기업에서 특허 출원 및 등록이 지속적으로 증가함에 따라 특허 관련 비용뿐만 아니라 특허의 양적 질적 관리도 매우 중요한 요소로 대두되고 있다. 따라서 기업 및 기관이 보유하고 있는 많은 특허 중에서 활용 목적에 맞는 우수 특허를 선별 하고 관리하는 것이 특허경영의 한 방안으로 강조되고 있다. 본 연구는 기업이 보유하고 있는 특허를 대상으로 QFD를 적용하여 가치 있는 우수 특허를 효과적으로 선별하는 방안을 제시하였다. QFD를 이용하여 특허를 분류하고 품질을 정량적으로 평가하기 위해서 우선 특 허에 대한 기업의 요구사항 및 특허품질 특성지표를 도출하였다. 기업의 요구사항의 경우 AHP의 쌍대비교 방식으로 중요도를 결정하였으며, 이를 바탕으로 고객의 요구를 충족시킬 수 있는 특허지표의 값을 결정하고, 이에 대한 해석 및 활용방안에 대해서 논했다. 본 연구에서 제시한 우수특허 선별 방식을 실제 기업의 보유 특허에 적용하여 결과를 비교 분석하였으며 개별 특허지표 및 특허복합지표를 통해 우수 특허를 비교적 손쉽게 선별할 수 있음을 보여 주었다.

PURPOSES : The recent increase in the application of reclaimed asphalt pavement (RAP) calls for more research focusing the evaluation of pavement performance. For this matter, this study aims at evaluating pavement performance using the application rate of RAP. METHODS: To obtain mixtures with RAP aggregate application rates of 10%, 25% and 30%, the gyratory compaction method was applied regarding the mix design process for determining the optimum asphalt content (OAC). Additionally, the in-direct tension (IDT) test, deformation strength test (DST), tensile strength ratio (TSR) test and dynamic modulus (DM) test were conducted to verify the effect of RAP application rate on pavement performance. Based on the above-mentioned results, performance evaluation was done to these RAP application of design or utilization to construction site. The performance evaluation analysis was performed using the Korean Pavement Research Program (KPRP) of second level for the pavement design. RESULTS: From the DST results, the rutting resistance was improved as the application rates of RAP were increased. Additionally, all the IDT and toughness results satisfied the quality standards of the asphalt concrete pavement. However, the results did not conform with the tensile strength ratio standards with the application rates of RAP of 25% and 30%. This means that the standards, which should be considered when the addictive regeneration material is applied to the mixture when the RAP application rate is over 25%, were reflected. CONCLUSIONS : The predicted performance decreased from the second level performance analysis with the increase in the RAP application rates. All the cases satisfied the design standards (fatigue cracking, rutting depth and international roughness index (IRI)). However, the results of them closed to these standards (up to 94% (Fatigue)).

Ni hydroxides (Ni(OH)2) are synthesized on Ni foam by varying the hexamethylenetetramine (HMT) concentration using an electrodeposition process for pseudocapacitor (PC) applications. In addition, the effects of HMT concentration on the Ni(OH)2 structure and the electrochemical properties of the PCs are investigated. HMT is the source of amine-based OH− in the solution; thus, the growth rate and morphological structure of Ni(OH)2 are influenced by HMT concentration. When Ni(OH)2 is electrodeposited at a constant voltage mode of -0.85 V vs. Ag/AgCl, the cathodic current and the number of nucleations are significantly reduced with increasing concentration of HMT from 0 to 10 mM. Therefore, Ni(OH)2 is sparsely formed on the Ni foam with increasing HMT concentration, showing a layered double-hydroxide structure. However, loosely packed Ni(OH)2 grains that are spread on Ni foam maintain a much greater surface area for reaction and result in the effective utilization of the electrode material due to the steric hindrance effect. It is suggested that the Ni(OH)2 electrodes with HMT concentration of 7.5 mM have the maximum specific capacitance (1023 F/g), which is attributed to the facile electrolyte penetration and fast proton exchange via optimized surface areas.

This study is focused on effects of factors that affect the formation of THMs during chlorination in drinking water treatment. During the chlorination, chlorine consumption is increased by increasing the initial chlorine dose, the pH and the total dissolved solid (TDS) concentration. Also THMs formation is increased up to 58.82 μg/L and 55.54 μg/L by increasing initial chlorine concentration and increasing pH. However, concentration of chloroform is decreased by increasing TDS concentration. This is caused the cation(Na+) of the total dissolved solids preferentially reacts with the functional groups of the organic material which influence the trihalomethane formation. But total trihalomethane formation is increased up to 127.46 μg/L by Br- contained in the total dissolved solids. DOC reduction was not influenced by any of the factors.

Calcifying Epithelial OdontogenicTumor(CEOT), also known as Pindborg tumor is a rare lesion comprising about 1% of all odontogenic tumors mostly rising in the posterior of the mandible. It generally occurs in patients between 30-60 years old. This paper describes a case of CEOT in a 17 year-old female affecting the right mandible. Histopathologic findings showed sheets of polygonal tumor cells and pools of amorphous, eosinophilic amyloids with calcifications. 1 year after resection of the tumor, no clinical and radiographic signs of recurrence were observed.

(트리플로로아세톡시)메틸 기능기를 갖는 디프로파길 단량체인 4-(트리플로로아세톡시)메틸-1,6- 헵타 디인을 합성하고 그 중합실험을 수행하였다. 여러 가지 전이금속촉매를 사용한 4-(트리플로로아세톡시)메틸 -1,6-헵타디인의 고리화중합을 통하여 해당 고분자인 폴리[4-(트리플로로아세톡시)메틸-1,6-헵타디 인]을 높은 수율로 합성하였다. 본 중합에서는 몰리브데늄 계 촉매가 텅스텐 계 촉매보다 더 효과적이였 다. 반응과정 중에 생성된 고분자의 가교화반응으로 합성 고분자들은 대부분 유기용매에 용해하지 않았다. 고분자의 IR 스펙 트럼에서는 단량체의 아세틸렌 C≡C 및 ≡C-H 신축진동띠를 보여주지 않았다. 이 고분자는 XRD 회절분석 결과 대부분 무정형상임이 밝혀졌다.

PURPOSES : The use of reclaimed aggregate has been recently increasing with the increase in the amount of waste asphalt concrete. The application of these materials can reduce the properties of the asphalt pavement when compared with the case when recycled aggregate is not used. The objective of this study is to evaluate the performance of the asphalt mixtures with various mix ratios of reclaimed aggregate. METHODS : To measure the performance, the following tests using the mixtures prepared in accordance with the Korea Standards were conducted: Hamburg wheel-tracking test, third-scale model mobile loading simulator test, and dynamic modulus test. RESULTS : The test results of the Hamburg wheel-tracking test indicate that the water resistance was similar in each mixture and the plastic deformation resistance was good in the high-ratio reclaimed aggregate mixture. In the case of the third-scale model mobile loading simulator test, the plastic deformation demonstrated a high resistance in the high-ratio reclaimed aggregate mixture. The results were similar to those of the Hamburg wheel-tracking test; however, the cracking resistance was poor with a high recycled aggregate incorporation ratio. The dynamic modulus test results demonstrated excellent resistance to plastic deformation at a relatively high ratio of reclaimed aggregate admixture. The crack resistance was weakened when a high ratio of reclaimed aggregate mixture was used. CONCLUSIONS: As the reclaimed aggregate content increased, the plastic deformation resistance increased and the crack resistance decreased.

본 논문에서는 다기능성 마스크 팩의 제조 및 이를 이용한 마스크 팩 제조 및 평가에 대한 것이다. 여기서 다 기능성이란 폴리인산에 의한 원적외선 효과, 포접화합물에 의한 기미치료 효과 및 필링효과, 라벤다 추출물에 의한 피부진정 효과를 의미한다. 제조한 다기능성 마스크 팩의 용제에 대한 유해물질의 측정결과 0.001mg/Kg 이하로 검출되었으며, 점도는 280 cP, pH=6.92 이었다. 마스크 시트에 다기능성 용제를 침지시켜 제조한 다기능성 마스크 팩의 원적외선 방사율은 0.882 μm이고 원적외선 방사에너지는 3.40x102 W/mᆞ, 37℃이었다. 다기능성 마스크 팩의 착용 후, 5일간 사용 후의 보습율은 사용전보다 14.5% ~ 35.5% 우수하였으며, 피부 온도는 24 ~ 26℃ 나타내었으며, 30명의 볼란티어 피부접촉 자극성 평가에서도 매우 안정적이었다.

백두산에서는 밀레니엄 대분화 이후로도 수차례의 화산활동이 계속되어 마그마 거동 감시 연구의 필요성이 지속적으로 제기되고 있다. 마그마방의 깊이 및 규모를 파악하기 위해서는 다양한 지구물리학적 접근이 필요하며, 본 연구에서는 전기비저항 탐사의 적용성을 검토하고자 한다. 국경으로 인해 공간적 제한이 있는 백두산에서 심부에 위치한 마그마를 탐사하기 위해서는 측선의 길이가 수십 킬로미터 이상이 되는 대규모 전기탐사가 이루어져야 하며, 이를 위해 서는 분산계측 시스템의 도입과 이에 최적화된 탐사 설계가 필수적으로 요구된다. 따라서 자체 개발된 분산계측 시스템을 활용하는 탐사설계안을 제시하고 전산실험을 통해 적용 가능성을 분석하였다. 단일 측선과 비동일선상 송신원 배열을 사용한 탐사설계안을 이용하여 다수의 측선 설치가 필요한 일반적인 3차원 탐사에 준하는 역산 해석 결과를 얻을 수 있음을 확인하였으며, 이 탐사설계안이 백두산 심부 물리탐사에 유용하게 적용될 수 있을 것으로 기대된다.