Competitive effect between roughness and mask pattern on charging phenomena during plasma etching

In plasma etching process, the edge roughness and mask pattern usually play a significant role in the deformation of holes under the influence of charging effect. The competitive effect between these two factors has been investigated, focusing on the surface charging in a hexagonal array, with various values of roughness parameters (amplitude (A) and wavelength (W)) and distances between holes (L). A series of classical particle dynamic simulations of surface charging, surface etching and profile evolution were used to investigate the effect of roughness and pattern on charging. This study showed that various roughness and patterns (represented by different values of L) can significantly influence surface distributions of the electric-field (E-field) and the etching rates on the mask surface. The simulations also showed that (1) the shape of the pattern array influences the mask hole profile during etching process, i.e. a hexagonal array pattern tends to deform the profile of a circular mask hole into a hexagonal hole; (2) pattern roughness is aggravated during etching process. These factors were found to be significant only at a small feature pitch and may be ignored at a large feature pitch. Possible mechanisms of these results during etching process are discussed. This work sheds light on the ways to maintain pattern integrity and further improve the quality of the pattern transfer onto the substrate.

Research on 3D reconstruction method of wear particle dynamic image based on multi contour space mapping

Aiming at the problems of current image monitoring methods of lubrication oil wear particles, this paper designs and builds a dynamic monitoring system for oil wear particles based on microfluidic microscopic images. A contour-based 3D reconstruction method of debris particle images is proposed. The image sequences of rotating wear particles tracked by a single target are used as data, and the contour of the wear particle is extracted and the data is stored. The minimum area external rectangle method is used to correct the rotation of the particle images for the problem of deflection. And an algorithm based on cylindrical coordinate space conversion is used to convert the discrete contour point data into three-dimensional space. Complete the 3D model reconstruction of microfluidic wear particles. The ability to analyse wear particles in oil online monitoring technology is improved, which also shows new ideas for wear status monitoring and fault diagnosis technology.

Construction of a Novel Doxorubicin Nanomedicine Using Bindarit as a Carrier: A Multiscale Computer Simulation-Assisted Design-Based Study

Nanomedicines typically use polymeric materials or liposomes as carriers. This provides targeting advantages but may lead to a series of defects, such as low drug loading, high risk in terms of safety, and high production costs. Herein, we report a computer simulation-assisted designing method for the construction of a novel doxorubicin (DOX) nanomedicine without any polymer carriers. We used a small molecular drug, bindarit (BIN), as a carrier of DOX to provide synergistic antitumor effects. First, the intermolecular forces between DOX and BIN were calculated for evaluating the interaction and potential conformation of the DOX/BIN complex. Then, the potential assembly ability of the DOX/BIN complex was predicated here by using dissipative particle dynamic stimulation. These computational simulation results suggested that BIN could form an amphiphilic complex with DOX through π–π stacking, hydrogen bonding, and electrostatic interaction and then self-assemble to nanoaggregates at the mesoscopic scale. Under the computational guidance, doxorubicin/bindarit nanoparticles (DOX/BIN NPs) in a spherical morphology were successfully prepared, and these NPs possess the original cytotoxic activity of DOX. Thus, this multiscale computer simulation-assisted design strategy can serve as an effective approach to develop nanomedicines using small molecules as a carrier.

Characteristic Structural Knowledge for Morphological Identification and Classification in Meso-Scale Simulations Using Principal Component Analysis

Meso-scale simulations have been widely used to probe aggregation caused by structural formation in macromolecular systems. However, the limitations of the long-length scale, resulting from its simulation box, cause difficulties in terms of morphological identification and insufficient classification. In this study, structural knowledge derived from meso-scale simulations based on parameters from atomistic simulations were analyzed in dissipative particle dynamic (DPD) simulations of PS-b-PI diblock copolymers. The radial distribution function and its Fourier-space counterpart or structure factor were proposed using principal component analysis (PCA) as key characteristics for morphological identification and classification. Disorder, discrete clusters, hexagonally packed cylinders, connected clusters, defected lamellae, lamellae and connected cylinders were effectively grouped.

3D Direct Numerical Simulation on the Emergence and Development of Aeolian Sand Ripples

A sand surface subjected to a continuous wind field exhibits a regular ripple surface. These aeolian sand ripples emerge and develop under the coupling effect between the wind field, bed surface topology, and sand particle transportation. Lots of theoretical and numerical models have been established to study the aeolian sand ripples since the last century, but none of them has the capability to directly reproduce the 3D long-term development of them. In this work, a novel numerical model with wind-blow sand and dynamic bedform is established. The emergence and long-term development of sand ripples can be obtained directly. The statistical results extracted from this model tally with those deduced from wind tunnel experiments and field observations. A simplified bed surface particle size description procedure is used in this model, which shows that the particle size distribution makes a very important contribution to sand ripples’ final steady state. This 3D bedform provides a more holistic view on the merging of small bumps before regular ripples’ formation. Analyzing the wind field results reveals an ignored development on the particle dynamic threshold during the bedform deformation.

Numerical Assessment of Packing Structures for Gas-Particle Trickle Flow Heat Exchanger for Application in CSP Plants

The centrifugal particle receiver (CentRec), a direct absorbing receiver operating with ceramic particles, demonstrated at the Julich solar power tower under solar conditions technical large-scale feasibility, generating particle outlet temperatures up to 965 °C. To push particle based CSP technology further towards commercial application the high particle temperatures have to be transferred to a working fluid, like air. A gas-particle trickle flow direct contact heat exchanger (TFHX) has been identified with great potential for high efficiency heat transfer. Inspired by chemical trickle flow reactors and previous work in literature focusing on the gas-particle TFHX concept for temperatures up to 500 °C, the approach and its applicability for high temperature heat exchanger shall be developed further in future. In preparation for subsequent research activities, the present work focuses on the preliminary selection of suitable packing structures for the TFHX. Packing assessment criteria are defined and used to assess the particle behavior within a variety of 44 different packing geometries. The analysis was performed using the open source DEM software LIGGHTS-PUBLIC whereas at this early stage of investigation gas presence was neglected. In the analysis process the packing structures are assessed with the previously defined assessment criteria and reduced to one type of a favorable geometry type. In conclusion, the advantageous characteristics of the identified geometry type are discussed. The presented study gives a methodical selection for packing structures and first starting point for further investigating in the field of the gas-particle TFHX whereas in subsequent work the influence of gas flow to the particle dynamic must be investigated by experimental and simulation work.

PENGEMBANGAN MODUL FISIKA BERBASIS KONTEKSTUAL MATERI DINAMIKA PARTIKEL

This reserch is a research and development with the aim of developing Contextual-Based Physics Module on Particle Dynamic to Improve Learning Achievement of Students Grade X of SMA Negeri 5 Jayapura. The total number samples of this research is 32 students of SMA Negeri 5 Jayapura grade X, using one group pre-test post-test design with percentage descriptive data analysis technique to know the feasibility of the module. The research shows that: 1) the development of module with collecting information phase through bibliography research and field research, product design includes draft writing, design validating, and product design revising, and development phase consists of validating and trial, 2) the feasibility of the module compiled based on material validator resulted on average of 92% with feasible category and students response category of 88% with feasible category, 3) there is progress of achievement of studens grade X with learning using contextual-based physic module in particle dynamic with n-Gain RPP1 0,52, RPP2 0,58, RPP3 0,61, and the average is 0,57 medium category, and 4) the strengths of contextual-based physics module are: simple language used, providing material with contextual illustrations and examples, and equipped with guidance manual that eases the students to do individual learning