• 한국소음진동공학회논문집
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• 제26권6_spc호
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• pp.687-696
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• 2016

A series of process to design an acoustic lens for underwater imaging is reviewed and the method to evaluate characteristics of the lens is investigated. If the target specification of lens is given, the design process consists of the material selection, evaluation of its properties, lens geometry design, prediction of lens characteristics, manufacturing, and evaluation by measurement. In this study, an actual acoustical lens is made by cutting polymethylpentene block. The characteristics of lens are predicted by the hybrid method, combination of ray tracing and Rayleigh integral. For the direct comparison between the prediction and measurement results, a simulation method based on the equivalent source method is suggested to reflect the actual radiation pattern of transducer used for measurements. Finally, the measurement is conducted in a small water tank to observe the actual characteristics of the manufactured lens.

• 멤브레인
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• 제13권2호
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• pp.73-80
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• 2003

폴리메틸펜텐 막(polymethylpentene membrane, PMP)을 Ar, NH_3$ 플라즈마로 표면 처리하고, 처리 전후의 투과 도와 선택도의 변화를 관찰하였다. Ar 플라즈마로 처리하였을 때 O/C의 비율이 증가하며 친수성기 (OH, COOH, C=O)의 도입이 확인되었고 $NH_3$ 플라즈마로 처리하였을 때 아민, 아미노기가 도입되었다. 플라즈마 처리된 폴리메틸펜텐막에서 $CO_2$의 투과도와 $N_2$,에 대한 선택도 (Actual Separation Factor)의 최적조건은 Ar 플라즈마 처리 (30 W-6 min)의 경우 각각 182 Barrer ［$10^{-10}\;cm^3(STP)cm/cm^2$.s.cmHg］와 6.17이며, $NH_3$, 플라즈마 처리 (30 W-8 min)의 경우 각각 144 Barrer [$10^{-10}/cm^2(STP)cm/cm^2$.s.cmHg] 와 6.13을 얻었다.