A two-dimensional (2D) numerical simulation of convective-diffusive transport of LDL in the artery wall, coupled with the wall shear stress gradient (WSSG)-dependent LDL consumption of smooth muscle cells (SMCs) is pr...
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Conventional photomasks consisting of chromium films on fused silica or glass substrates are widely used. However, it is becoming apparent that interfacial stress between the chromium and the transparent substrate, as...
Conventional photomasks consisting of chromium films on fused silica or glass substrates are widely used. However, it is becoming apparent that interfacial stress between the chromium and the transparent substrate, as well as the need for wet chemical processing for pattern production, will ultimately limit a photomask’s ability to be patterned reproducibly. An alternative approach is to chose an opaque layer which exhibits minimum interfacial stress with respect to the substrate while having the ability of being patterned by fluorocarbon gas plasma processing. This work describes the use of silicon/germanium as an alternative opaque layer, which can be deposited uniformly by co-sputtering and patterned by fluorocarbon reactive ion etching. The suitability of the material in terms of interfacial stress is demonstrated by the use of microfabricated silicon dioxide cantilever structures. In addition, the influence of Si/Ge ratio on optical properties, the plasma processing performance, and chemical compatibility with the rest of the photomask making process is described.
The study is aimed at investigating the mean flow and turbulence characteristics in scour geometry developed near a circular cylinder of length 10cm placed over the sand bed transverse to the *** obstacle placed on a ...
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The study is aimed at investigating the mean flow and turbulence characteristics in scour geometry developed near a circular cylinder of length 10cm placed over the sand bed transverse to the *** obstacle placed on a sand bed,on the way of a unidirectional flow,develops a crescent-shaped scour mark on the *** scour is caused by generation of vortex developed on the upstream side of the *** grains eroded by this vortex,are deposited on the downstream side of the obstacle as *** turbulent flow field within the scour mark was measured in a laboratory flume using an Acoustic Doppler Velocimeter(ADV).The scour marks named as current crescents preserved in geological record are traditionally used as indicators of palaeocurrent *** distribution of mean velocity components,turbulent intensities and Reynolds stresses at different positions of the mark are *** experimental evidence also shows that the geometric characteristics of the scour mark(width) depend primarily on the cylinder aspect ratio,cylinder Reynolds number and sediment Froude number.
Estimation of the symbol rate has important applications in receiver synchronization for symbol time recovery. In this paper the problem is investigated using Smoothen Non-Linear Energy Operator (SNEO). Unlike wavelet...
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The synthesis and peirastic characterisation of two new organogold(III) complexes with a high molar ratio of gold content is described. The proposed formulae for the complexes in the present study are [C2H2Au4F8(PPh3)...
The synthesis and peirastic characterisation of two new organogold(III) complexes with a high molar ratio of gold content is described. The proposed formulae for the complexes in the present study are [C2H2Au4F8(PPh3)4]n and [C2H2Au4F8(NCCH3)4]n (Figure 1). These complexes were found to be stable to the atmosphere. The aim of this work was to demonstrate that such materials have a high metal to ligand ratio, suitable for physical vapour deposition process (PVD) and, hence, can be used as precursors for the deposition of pure metallic features. Physical and chemical characterisation methods were employed to obtain information about i) the structures, ii) the thermal and chemical stability, iii) the volatility and iv) the adhesion of these materials to specific substrates. These include n.m.r. (1H, 19F, 13C and 31P) IR spectroscopy, EDX (Energy Dispersive X-ray analysis), DSC ( Differential Scanning Calorimetry), TGA (Thermogravimetric Analysis), Powder X-ray Diffraction and Electron Microscopy (Scanning, Transmission and Atomic Force).
Thermal properties of hydrogenated amorphous carbon (a-C:H) thin-films are measured using an ultrafast optical pump-probe technique. The a-C:H samples were grown in a home-built direct-current (DC) plasma enhanced che...
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Thermal properties of hydrogenated amorphous carbon (a-C:H) thin-films are measured using an ultrafast optical pump-probe technique. The a-C:H samples were grown in a home-built direct-current (DC) plasma enhanced chemical vapor deposition (PECVD) system with varying hydrogen (H2) diluents to methane (CH4) flow-rate ratios. Thermal diffusivities of samples are extracted by comparing thermoreflectance measurements with numerical calculations so that thermal conductivities (k) can be determined. Although the dependence of thermal property on H2 dilution was not significant, our films show lower k (0.10-0.15 W/mK ± 20%) compared to the results of previous studies.
This paper demonstrates that Sequential Lateral Solidification (SLS) of Si can be carried out on films as thin as–and potentially much thinner than–250 Å. When compared to thicker Si films, however, the SLS-pro...
This paper demonstrates that Sequential Lateral Solidification (SLS) of Si can be carried out on films as thin as–and potentially much thinner than–250 Å. When compared to thicker Si films, however, the SLS-processed ultra-thin films contain more twins, and successful processing requires irradiation within a narrower laser energy density range and a smaller per-pulse translation distance. The physical interpretation of these findings is formulated by analyzing the details of the microstructures observed in single-pulse-irradiation-induced Controlled Super-Lateral Growth (C-SLG) experiments. SEM and TEM analyses reveal complicated microstructural details that we interpret as originating from breakdown of epitaxial growth during lateral solidification, an effect that is detrimental to the SLS process. Based on considerations of far-from- equilibrium solidification behavior of Si, it is argued that undercooling of the solidification interface below a threshold value at which solidification no longer proceeds epitaxially–arising from reduction in interfacial recalescence during lateral solidification of ultra-thin Si films, relative to that of thicker films–is responsible for the breakdown. Based on this model, we discuss how external parameters may be adjusted so as to permit optimal crystallization of ultra-thin Si films using SLS.
We mimic nature to fabricate photonic nanostructures with only short-range order. Despite lack of long range order, light is effectively confined in such structures, leading to efficient lasing. Lasing frequency is tu...
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In this paper, the Transmission Line Method (TLM) is applied to generate a voice signal by simulating the acoustic propagation of a glottal signal, obtained by inverse filtering of the voice signal, through an /a/ vow...
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ISBN:
(纸本)9781618392596
In this paper, the Transmission Line Method (TLM) is applied to generate a voice signal by simulating the acoustic propagation of a glottal signal, obtained by inverse filtering of the voice signal, through an /a/ vowel shaped vocal tract uniform TLM mesh. The vocal tract TLM mesh is constructed over a segmented Magnetic Resonance(MR) volume image. The tools for segmentation, mesh extraction and the TLM itself were implemented as part of the ModaVox program, which is an open source application constructed during the research presented here. The methodology was validated, firstly, simulating the acoustic propagation of a probe signal through tube model meshes. Then, the same probe signal was used as the input for the vocal tract TLM mesh and the resonant frequencies obtained by simulation were compared with those of the real vocal tract. Finally, the glottal signal is used as input for the vocal tract mesh and the reflective boundary conditions of the vocal tract walls were designed to reproduce the consistency of the soft tissues. The voice signal simulated was then compared with the original voice signal generated by the subject when his vocal tract was imaged.
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