In this study, the refinement of Multiwalled Carbon Nanotubes (MWCNTs) derived from chemical vapor decomposition is investigated. An ultrasonic pretreatment method is employed to disentangle carbon and metal impurities intertwined with MWCNTs. The pretreated MWCNTs exhibit a marginal decrease in C–O/C = O content from 8.9 to 8.8%, accompanied by a 2.5% increase in sp3 carbon content, indicating a mildly destructive pretreatment approach. Subsequently, selective oxidation by CO2 and hydrochloric acid etching are utilized to selectively remove carbon impurities and residual metal, respectively. The resulting yield of intact MWCNTs is approximately 85.65 wt.%, signifying a 19.91% enhancement in the one-way yield of pristine MWCNTs. Notably, the residual metal content experiences a substantial reduction from 9.95 ± 2.42 wt.% to 1.34 ± 0.06 wt.%, representing a 15.68% increase in the removal rate. These compelling findings highlight the potential of employing a mild purification process for MWCNTs production, demonstrating promising application prospects.

Pretreatment system of desalination process using seawater reverse osmosis(SWRO) membrane is the most critical step in order to prevent membrane fouling. One of the methods is coagulation-UF membrane process. Coagulation-UF membrane systems have been shown to be very efficient in removing turbidity and non-soluble and colloidal organics contained in the source water for SWRO pretreatment. Ferric salt coagulants are commonly applied in coagulation-UF process for pretreatment of SWRO process. But aluminum salts have not been applied in coagulation-UF pretreatment of SWRO process due to the SWRO membrane fouling by residual aluminum. This study was carried out to see the effect of residual matal salt on SWRO membrane followed by coagulation-UF pretreatment process. Experimental results showed that increased residual aluminum salts by coagulation-UF pretreatment process by using alum lead to the decreased SWRO membrane salt rejection and flux. As the salt rejection and flux of SWRO membrane decreased, the concentration of silica and residual aluminum decreased. However, when adjusting coagulation pH for coagulation-UF pretreatment process, the residual aluminum salt concentration was decreased and SWRO membrane flux was increased.

In this present investigation, Metal Injection Moulding (MIM) of M2 High Speed Steel (HSS) parts using a wax-High Density Polyethylene (HDPE) binder is shown. The elimination of organic binder was carried out by thermal debinding under inert atmosphere. In order to keep carbon in the sample that could improve the sintering process, incomplete debinding was performed between 450 and . The specimens were sintered at temperatures between 1210 and in high vacuum atmosphere, obtaining the 98% of the theoretical density. In the samples with higher residual carbon content, the sintering window was extended up to 20 degrees and the optimum temperature was lower.

Ag-Cu-Ti 삽입금속을 이용하여 제조된 AlN/Cu와 AlN/W 활성금속브레이징 접합체의 잔류응력을 유한요소법으로 탄성 및 탄소성 해석을 행하여 그 결과를 접합강도 측정 결과와 파단 거동 관찰 결과와 비교, 분석하였다. 최대 잔류 주응력의 크기는 AlN/W 접합체보다 모재간 열팽창계수 차이가 큰 AlN/Cu 접합체에서 더 크게 나타났으며, 접합계면에 인접한 AlN 세라믹스 자유표면에 인장 성분의 응력집중이 확인되었다. 모재와 삽입금속의 탄소성 변형을 모두 고려할 경우, AlN/Cu 접합체의 경우 연질의 삽입금속에 의해 최대 잔류 주응력이 감소하여 소성변형에 의한 응력완화 효과가 있음을 확인하였으나, 100μm 이상으로 삽입금속 두께를 증가시키더라도 잔류 주응력의 크기는 더 이상 크게 감소하지 않았다. 측정된 최대 접합강도는 AlN/Cu와 AlN/W 접합체에서 각각 52 MPa와 108 MPa이었으며, 파단 형태는 AlN/Cu 접합체는 AlN 자유표면으로부터 AlN 내부로 큰 각도를 이루면 진행되는 돔형의 파단이, AlN/W 접합체에서는 접합계면의 삽입금속층을 따라 AlN 측에서 파단이 일어나는 형태를 보였다.