Surface Modification of High Energetic Materials by Molecular Self-assembly

Abstract

Self-assembly of organic molecules is formed spontaneously on surfaces by electrostatic interaction with substrate. This research has shown that the self-assembly improves safety and handling tractability of high-energetic materials (HEMs). According to the recent study, control of the specific crystal size for reducing the internal defects is mightily important, because the internal defects are a factor in unstability of HEMs. In turn, we performed self-assembly of organic molecules and HEMs by using nano-sized HEMs, which were produced by drowing-out or milling/crystallization. Surface modification efficiency was decided by size distribution, zeta-potential, friction sensitivity and electrostatic charge. 입도/표면전하/마찰감도/정전기 전하 등을 측정하여 표면개질 여부를 확인하였다.

Pre-Swirl Ducts, Pre-Swirl Fins and Wake-Equalizing Ducts for the DTC Hull: Design and Scale Effects

“…The extrapolation of the PSF closely resembles the assumptions of [47] and, consequently, those of the ITTC'21 procedure. As the PSF is purely a swirling device, a good correlation with full-scale data is found with a relatively small contribution of the axial The extrapolation of the PSF closely resembles the assumptions of [47] and, consequently, those of the ITTC'21 procedure. As the PSF is purely a swirling device, a good correlation with full-scale data is found with a relatively small contribution of the axial component, that in the current case corresponds to a value of 0.18, close to the suggested coefficient of 0.3.…”

“…In this respect, the available calculations allow for comparisons of the several extrapolation methods proposed by ITTC [35,36,38] and available in the literature [46] to address the scaling issues of ESDs. In particular, attention is focused on the recently proposed procedure [38], based on the work of Kim et al [47], to account for the "potential" (and, then, not subjected to scaling) nature of the swirling flow induced by stator fins in front of the propeller by using dedicated CFD calculations. Based on the results of the tangential disturbance modifications from model-to full-scale just observed, this seems a crucial aspect to be addressed.…”

“…The ITTC'21 values, computed using the suggested values of axial and tangential coefficients, are between those of ITTC'78 and ITTC'99 for PSD and PSF and almost identical to ITTC'78 for the WED. Since the weights for axial and tangential components are based on few preliminary calculations of two ESDs for KCS and KVLCC ships only [47], Figure 13 collects the predicted full-scale wakes as functions of the axial coefficient (the tangential is 1-F x ). The extrapolation of the PSF closely resembles the assumptions of [47] and, consequently, those of the ITTC'21 procedure.…”

“…Since the weights for axial and tangential components are based on few preliminary calculations of two ESDs for KCS and KVLCC ships only [47], Figure 13 collects the predicted full-scale wakes as functions of the axial coefficient (the tangential is 1-F x ). The extrapolation of the PSF closely resembles the assumptions of [47] and, consequently, those of the ITTC'21 procedure. As the PSF is purely a swirling device, a good correlation with full-scale data is found with a relatively small contribution of the axial The extrapolation of the PSF closely resembles the assumptions of [47] and, consequently, those of the ITTC'21 procedure.…”