scholarly journals Numerical Simulations of Light Scattering in Soft Anisotropic Fibrous Structures and Validation of a Novel Optical Setup from Fibrous Media Characterization

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 579
Author(s):  
Francesco di Bartolo ◽  
Emanuele Vignali ◽  
Emanuele Gasparotti ◽  
Antonio Malacarne ◽  
Luigi Landini ◽  
...  
Keyword(s):  
Light Scattering ◽  
Numerical Study ◽  
Scattered Light ◽  
Quantitative Information ◽  
Numerical Results ◽  
Fibrous Media ◽  
Optical Setup ◽  
3D Printed ◽  
Non Destructive ◽  
Fibrous Tissues

The insight of biological microstructures is at the basis of understanding the mechanical features and the potential pathologies of tissues, like the blood vessels. Different techniques are available for this purpose, like the Small Angle Light Scattering (SALS) approach. The SALS method has the advantage of being fast and non-destructive, however investigation of its physical principles is still required. Within this work, a numerical study for SALS irradiation of soft biological fibrous tissues was carried out through in-silico simulations based on a Monte Carlo approach to evaluate the effect of the thickness of the specimen. Additionally, the numerical results were validated with an optical setup based on SALS technique for the characterization of fibrous samples with dedicated tests on four 3D-printed specimens with different fibers architectures. The simulations revealed two main regions of interest according to the thickness (thk) of the analyzed media: a Fraunhofer region (thk < 0.6 mm) and a Multiple Scattering region (thk > 1 mm). Semi-quantitative information about the tissue anisotropy was successfully gathered by analyzing the scattered light spot. Moreover, the numerical results revealed a remarkable coherence with the experimental data, both in terms of mean orientation and dispersion of fibers.

Using Ansys for Design and Numerical Study of a Specific Fixed Wing UAV

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Unmanned Aerial Vehicle ◽  
Numerical Study ◽  
Flight Time ◽  
Cluster System ◽  
Numerical Results ◽  
Operational Performance ◽  
Gliding Flight ◽  
Aerial Vehicle ◽  
Constant Altitude

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.

A Time-Resolved Low-Angle Light Scattering Apparatus. Application to Phase Separation Problems in Polymer Systems

2001 ◽  
Vol 66 (6) ◽  
pp. 973-982 ◽  
Author(s):  
Čestmír Koňák ◽  
Jaroslav Holoubek ◽  
Petr Štěpánek
Keyword(s):  
Phase Separation ◽  
Light Scattering ◽  
Signal To Noise Ratio ◽  
Scattered Light ◽  
Ccd Camera ◽  
Time Resolved ◽  
Polymer Systems ◽  
Software Analysis ◽  
Phase Separation Kinetics ◽  
Small Angle Light Scattering

A time-resolved small-angle light scattering apparatus equipped with azimuthal integration by means of a conical lens or software analysis of scattering patterns detected with a CCD camera was developed. Averaging allows a significant reduction of the signal-to-noise ratio of scattered light and makes this technique suitable for investigation of phase separation kinetics. Examples of applications to time evolution of phase separation in concentrated statistical copolymer solutions and dissolution of phase-separated domains in polymer blends are given.

scholarly journals Light-Scattering Simulations from Spherical Bimetallic Core–Shell Nanoparticles

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Bimetallic Nanoparticles ◽  
Dominant Role ◽  
Scattered Light ◽  
Specific Interaction ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Core Shell ◽  
The Core

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.

Experimental and Numerical Study on Grinding Temperature during Surface Grinding with Different Cooling Methods

2009 ◽  
Vol 416 ◽  
pp. 514-518 ◽  
Author(s):  
Qing Long An ◽  
Yu Can Fu ◽  
Jiu Hua Xu
Keyword(s):  
Numerical Study ◽  
Specific Energy Consumption ◽  
Ground Surface ◽  
Numerical Results ◽  
Surface Grinding ◽  
Grinding Temperature ◽  
Air Jet ◽  
The Difference ◽  
High Specific Energy ◽  
Cooling Methods

Grinding, characterized by its high specific energy consumption, may generate high grinding zone temperature. These can cause thermal damage to the ground surface and poor surface integrity, especially in the grinding of difficult-to-machine materials. In this paper, experimental and fem study on grinding temperature during surface grinding of Ti-6Al-4V with different cooling methods. A comparison between the experimental and numerical results is made. It is indicated that the difference between experimental and numerical results is below 15% and the numerical results can be considered reliable. Grinding temperature can be more effectively reduced with CPMJ than that with cold air jet and flood cooling method.

scholarly journals Oil in Water Monitoring Using Advanced Light Scattering

2013 ◽  
Author(s):  
Gernot Seebacher ◽  
Axel A. Schmidt ◽  
Jochen Offermann
Keyword(s):  
Light Scattering ◽  
Oil Content ◽  
Scattered Light ◽  
Discharge Process ◽  
Water Mixture ◽  
Effluent Quality ◽  
Light Pattern ◽  
Bilge Water ◽  
Oil In Water ◽  
Wide Range

The paper provides background on how bilge water has changed over the years and how technology has enabled manufacturers to stay ahead of the curve by borrowing technological breakthroughs from other areas to the measurement of oil content in the marine environment. Light scattering provides today a universal and reliable method, able to measure the wide range of oils present in a wildly variable and unpredictable bilge water mixture. Bilge water regulations were put in place to reduce the potential of harm to the environment from oily bilge water discharges. Regulations require that instruments verify effluent quality continually during the discharge process, which precludes the adoption for shipboard use of standard laboratory style testing with the associated time delays to complete the analysis. Measuring oil content with the light scattering measuring instrument is a tried and tested means for compliant bilge water verification. State of the art instruments employ sophisticated light measuring systems and they use complex algorithms to convert the scattered light pattern values into oil content reading, thereby considering interference from other than oil suspended matter, they prevent harm to the environment from bilge water discharges. Paper published with permission.

Modeling of Solder Fatigue Failure due to Ductile Damage

2010 ◽  
Vol 26 (4) ◽  
pp. N23-N27 ◽  
Author(s):  
K. Aluru ◽  
F.-L. Wen ◽  
Y.-L. Shen
Keyword(s):  
Numerical Study ◽  
Fatigue Cracks ◽  
Damage Model ◽  
Quantitative Information ◽  
Ductile Damage ◽  
Element Analysis ◽  
Cyclic Shear ◽  
Rate Dependent ◽  
Solder Fatigue ◽  
Temporal And Spatial

ABSTRACTA numerical study is undertaken to simulate failure of solder joint caused by cyclic shear deformation. A progressive ductile damage model is incorporated into the rate-dependent elastic-viscoplastic finite element analysis, resulting in the capability of simulating damage evolution and eventual failure through crack formation. It is demonstrated that quantitative information of fatigue life, as well as the temporal and spatial evolution of fatigue cracks, can be explicitly obtained.

A Conceptual Model of Flapping-Wing Mechanism Inspired from the Results of Numerical Study

2013 ◽  
Vol 397-400 ◽  
pp. 783-788
Author(s):  
Xing Wei Zhang ◽  
Chao Wang ◽  
Hang Liu
Keyword(s):  
Conceptual Model ◽  
Power Efficiency ◽  
Stokes Equations ◽  
Numerical Study ◽  
Flapping Wing ◽  
Numerical Results ◽  
Navier Stokes ◽  
Active Deformation ◽  
Navier Stokes Equations ◽  
Wing Model

This paper investigates the aerodynamic forces of several plunging wing models by means of computational fluid dynamics. A finite volume method was used to solve the two-dimensional unsteady incompressible Navier-Stokes equations. The forces and power efficiency have been calculated and compared between sets of different models. Current work found that the nonsymmetrical moving can enhance the lift and thrust forces. The numerical results also prove that the flexible wing model can be use to improve the efficiency and reduce the input. Additionally, a new conceptual model for flapping wing mechanism with active deformation and adaptive nonsymmetrical driving motion is proposed base on the numerical results.

scholarly journals Characterisation of 3D printed sand moulds using micro-focus X-ray computed tomography

2019 ◽  
Vol 25 (2) ◽  
pp. 404-416 ◽  
Author(s):  
Tharmalingam Sivarupan ◽  
Mohamed El Mansori ◽  
Keith Daly ◽  
Mark Noel Mavrogordato ◽  
Fabrice Pierron
Keyword(s):  
Computed Tomography ◽  
Gas Permeability ◽  
Experimental Result ◽  
Pore Connectivity ◽  
Content Type ◽  
X Ray ◽  
3D Printed ◽  
X Ray Computed ◽  
Sand Mould ◽  
Non Destructive

Purpose Micro-focus X-ray computed tomography (CT) can be used to quantitatively evaluate the packing density, pore connectivity and provide the basis for specimen derived simulations of gas permeability of sand mould. This non-destructive experiment or following simulations can be done on any section of any size sand mould just before casting to validate the required properties. This paper aims to describe the challenges of this method and use it to simulate the gas permeability of 3D printed sand moulds for a range of controlling parameters. The permeability simulations are compared against experimental results using traditional measurement techniques. It suggests that a minimum volume of only 700 × 700 × 700 µm3 is required to obtain, a reliable and most representative than the value obtained by the traditional measurement technique, the simulated permeability of a specimen. Design/methodology/approach X-ray tomography images were used to reconstruct 3D models to simulate them for gas permeability of the 3D printed sand mould specimens, and the results were compared with the experimental result of the same. Findings The influence of printing parameters, especially the re-coater speed, on the pore connectivity of the 3D printed sand mould and related permeability has been identified. Characterisation of these sand moulds using X-ray CT and its suitability, compared to the traditional means, are also studied. While density and 3PB strength are a measure of the quality of the moulds, the pore connectivity from the tomographic images precisely relates to the permeability. The main conclusions of the present study are provided below. A minimum required sample size of 700 × 700 × 700 µm3 is required to provide representative permeability results. This was obtained from sand specimens with an average sand grain size of 140 µm, using the tomographic volume images to define a 3D mesh to run permeability calculations. Z-direction permeability is always lower than that in the X-/Y-directions due to the lower values of X-(120/140 µm) and Y-(101.6 µm) resolutions of the furan droplets. The anisotropic permeability of the 3D printed sand mould is mainly due to, the only adjustable, X-directional resolution of the furan droplets; the Y-directional resolution is a fixed distance, 102.6 µm, between the printhead nozzles and the Z-directional one is usually, 280 µm, twice the size of an average sand grain.A non-destructive and most representative permeability value can be obtained, using the computer simulation, on the reconstructed 3D X-ray tomography images obtained on a specific location of a 3D printed sand mould. This saves time and effort on printing a separate specimen for the traditional test which may not be the most representative to the printed mould. Originality/value The experimental result is compared with the computer simulated results.

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