Experimental Investigation and Numerical Analysis of Mechanical Ruling for an Aluminum-Coated Diffraction Grating

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Baoqing Zhang ◽  
Qinghua Wang ◽  
Ninggang Shen ◽  
Hongtao Ding
Keyword(s):  
Diamond Tool ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Fe Model ◽  
Loading Conditions ◽  
Gradient Plasticity ◽  
X Ray Diffraction ◽  
Film Properties ◽  
Scratch Tests ◽  
Deposited Film

The mechanical ruling process using a diamond tool is an important method for fabrication of low-density diffraction gratings. In mechanical ruling, a deposited film of aluminum or gold is mechanically burnished by the diamond tool to form equally spaced and high-quality grooves. The goal of this work is to evaluate the effects of Al film properties and ruling tool loading conditions on the resultant groove formation. The microstructure of the Al film is first studied using scanning electron microscope (SEM) and X-ray diffraction (XRD). The mechanical properties of the Al film are measured by nano-indentation and scratch tests. Mechanical ruling experiments are then carried out on a 10.5 μm thick Al film under various ruling loads ranging from 20 to 105 g. The groove geometry is investigated, and the tool wear of the diamond tool is inspected after the mechanical ruling tests. Finally, a three-dimensional (3D) thermomechanical-coupled finite-element (FE) model is developed to predict the deformation and temperature fields for the micron-scale groove formation by incorporating the Al film properties and a strain-gradient plasticity for modeling the size effect. Multiruling pass simulations are performed to analyze the groove formation under different loading conditions. Through comparison of simulation results with experimental measurement, this model is demonstrated as a useful numerical tool for modeling the mechanical ruling process using a diamond tool.

Mechanical Ruling of Diffraction Grating: Part II — Experimental Investigation and Numerical Simulation

2016 ◽  
Author(s):  
Qinghua Wang ◽  
Ninggang Shen ◽  
Baoqing Zhang ◽  
Hongtao Ding
Keyword(s):  
Diffraction Grating ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Temperature Fields ◽  
Fe Model ◽  
Preparation Process ◽  
Gradient Plasticity ◽  
Film Preparation ◽  
Scratch Tests ◽  
Series Study

This is Part II of a two-part series study on mechanical ruling of diffraction grating. In Part I, effects of the Al film preparation process on the film attributes were investigated in terms of surface morphology, microstructure and mechanical properties using SEM, XRD, nanoindentation and scratch tests. In this part, mechanical ruling experiments were carried out on the prepared Al films with various thicknesses. The effect of ruling loads on the groove geometry were investigated. The tool wear after the mechanical ruling tests was inspected. A three-dimensional thermomechanical coupled finite element (FE) model was developed to predict the deformation and temperature fields during mechanical ruling. The strain gradient plasticity model was used in the FE analysis to model the size effect during the process. The multi-pass effect on the variation of groove geometry was predicted and analyzed with the FE model under different loading conditions.

scholarly journals Numerical Analysis of Temperature Field in a Disc Brake at Different Cover Angle of the Pad

2014 ◽  
Vol 8 (4) ◽  
pp. 185-188
Author(s):  
Piotr Grześ
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Disc Brake ◽  
Fe Model ◽  
Dimensional Finite Element ◽  
Braking Process ◽  
The Moment ◽  
Three Dimensional Finite Element

Abstract In the paper an influence of the cover angle of the pad on temperature fields of the components of the disc brake is studied. A three-dimensional finite element (FE) model of the pad-disc system was developed at the condition of equal temperatures on the contacting surfaces. Calculations were carried out for a single braking process at constant deceleration assuming that the contact pressure corresponds with the cover angle of the pad so that the moment of friction is equal in each case analysed. Evolutions and distributions of temperature both for the contact surface of the pad and the disc were computed and shown.

Ribosome Structural Organization

1974 ◽  
Vol 32 ◽  
pp. 332-333
Author(s):  
James A. Lake
Keyword(s):  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Small Subunit ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Specific Antibodies ◽  
X Ray ◽  
E Coli ◽  
Complete Sequences

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.

Electron Microscopy of Cytoplasmic Contractile Proteins

1978 ◽  
Vol 36 (3) ◽  
pp. 606-614 ◽  
Author(s):  
T.D. Pollard ◽  
P. Maupin
Keyword(s):  
Electron Microscopy ◽  
Actin Filaments ◽  
Three Dimensional ◽  
Uranyl Acetate ◽  
Contractile Proteins ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Cytoplasmic Matrix ◽  
Computer Image Processing ◽  
Nonmuscle Cells

In this paper we review some of the contributions that electron microscopy has made to the analysis of actin and myosin from nonmuscle cells. We place particular emphasis upon the limitations of the ultrastructural techniques used to study these cytoplasmic contractile proteins, because it is not widely recognized how difficult it is to preserve these elements of the cytoplasmic matrix for electron microscopy. The structure of actin filaments is well preserved for electron microscope observation by negative staining with uranyl acetate (Figure 1). In fact, to a resolution of about 3nm the three-dimensional structure of actin filaments determined by computer image processing of electron micrographs of negatively stained specimens (Moore et al., 1970) is indistinguishable from the structure revealed by X-ray diffraction of living muscle.

Chemical synthesis and study of structural and optoelectronic properties of CdS thin films: Effect of SILAR growth cycles

2015 ◽  
Vol 9 (3) ◽  
pp. 2461-2469
Author(s):  
S. R. Gosavi ◽  
K. B. Chaudhari
Keyword(s):  
Thin Films ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Silar Method ◽  
Growth Cycles ◽  
Glass Substrates ◽  
Layer Adsorption ◽  
Cds Thin Films ◽  
Structural And Optoelectronic Properties ◽  
Deposited Film

CdS thin films were deposited on glass substrates by using successive ionic layer adsorption and reaction (SILAR) method at room temperature. The effect of SILAR growth cycles on structural, morphological, optical and electrical properties of the films has been studied.  The thickness of the deposited film is measured by employing weight difference method. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) studies showed that all the films exhibit polycrystalline nature and are covered well with glass substrates. The values of average crystallite size were found to be 53 nm, 58 nm, 63 nm and 71 nm corresponding to the thin films deposited with 30, 40, 50 and 60 SILAR growth cycles respectively. From the UV–VIS spectra of the deposited thin films, it was seen that both the absorption properties and energy bandgap of the films changes with increasing number of SILAR growth cycles. A decrease of electrical resistivity has been observed with increasing SILAR growth cycle. 

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

scholarly journals A Numerical Study of Sub-Millisecond Integrated Mix-and-Inject Microfluidic Devices for Sample Delivery at Synchrotron and XFELs

2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey
Keyword(s):  
Molecular Dynamics ◽  
Flow Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Liquid Jets ◽  
Mixing Efficiency ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Time Required

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.

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