scholarly journals The study of full cone spray using interferometric particle imaging method

2012 ◽  
Vol 25 ◽  
pp. 01033 ◽  
Author(s):  
Darina Jašíková ◽  
Michal Kotek ◽  
Tadeáš Lenc ◽  
Václav Kopecký
Keyword(s):  
Imaging Method ◽  
Particle Imaging

scholarly journals Single Particle Hopping as an Indicator for Evaluating Electrocatalysts

2022 ◽  
Author(s):  
Jungang Wang ◽  
Linjuan Zhang ◽  
Jing Xie ◽  
Di Li
Keyword(s):  
Single Particle ◽  
High Throughput Screening ◽  
Phase Interface ◽  
Vertical Motion ◽  
Catalytic Performance ◽  
Side Reactions ◽  
Imaging Method ◽  
Gas Evolution ◽  
Particle Imaging ◽  
Multi Phase

Abstract Design and screening electrocatalysts for gas evolution reactions suffer from scanty understanding of multi-phase processes at the electrode-electrolyte interface. Due to the complexity of multi-phase interface, it is still a great challenge to capture gas evolution dynamics under operando condition to precisely portray the intrinsic catalytic performance of interface. Here, we establish a single particle imaging method to real time monitor a potential-dependent vertical motion or hopping of electrocatalysts induced by electrogenerated gas nanobubbles. The hopping feature of single particle is closely correlated with intrinsic activities of electrocatalysts, thus is developed to be an indicator to evaluate gas evolution performance of various electrocatalysts. This optical indicator diminishes interferences from heterogeneous morphologies, non-Faradaic processes and parasitic side reactions that are unavoidable in conventional electrochemical measurements, therefore enables precise evaluation and high-throughput screening of catalysts for gas evolution systems.

scholarly journals CHARACTERISTICS OF ALCOHOL-COAL-WATER SLURRIES SPRAYING

2021 ◽  
pp. 30-39
Author(s):  
D. Gvozdyakov ◽  
V. Gubin ◽  
A. Zenkov
Keyword(s):  
Cross Sections ◽  
Thermal Power ◽  
Isoamyl Alcohol ◽  
Fuel Oil ◽  
Practical Significance ◽  
Imaging Method ◽  
Fuel Droplets ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Particle Imaging

The aim of this work is to substantiate the efficiency of ethyl or isoamyl alcohol application as the third component of coal-water fuels based on the results of experimental study of coaxial spraying. Studies of alcohols influence on spraying characteristics of coal-water fuels can rarely be found in the literature. Instantaneous fields of fuel droplets velocities in several cross-sections of the jet were determined using Particle Image Velocimetry method. Interferometric Particle Imaging method was used to determine droplets distribution by size in the jet of sprayed coal-water fuel. It was experimentally established that substitution of water (no more than 3 % by weight) in the composition of coal-water slurry by fairly typical alcohols leads to decrease in droplet velocities of alcohol-coal-water slurries in comparison with conventional coal-water fuel by 15–18 %. Concentration of sufficiently small fuel droplets (up to 200 microns) increases by 13.4±0.2 % and by 6.6±0.2 % during atomization of alcohol-coal-water slurries with addition of ethyl and isoamyl alcohol, respectively. Introduction of no more than 5 % by weight of the studied alcohols into the coal-water slurry will reduce the cost of fuel by 15–73 % in comparison with fuel oil. Influence of small additives of ethyl and isoamyl alcohol in the composition of coal-water fuel on spraying characteristics proves the possibility of efficient application of such three-component slurries in thermal power engineering. The results obtained are of practical significance, since they illustrate the possibility of reducing the ignition delay time for droplets of alcohol-coal-water slurries after they are sprayed in the furnaces of boiler units.

scholarly journals Application of Particle Imaging Method for Measurement of Solid Volume Fraction in Carbon Nanotube Particles Fluidized Bed

2018 ◽  
Vol 7 (3.33) ◽  
pp. 85 ◽  
Author(s):  
Sung Won Kim ◽  
. .
Keyword(s):  
Carbon Nanotube ◽  
Fluidized Bed ◽  
Volume Fraction ◽  
Particle Density ◽  
Solid Volume Fraction ◽  
Fixed Bed ◽  
Apparent Volume ◽  
Previous Method ◽  
Imaging Method ◽  
Particle Imaging

Solid volume fraction in the carbon nanotube (CNT) fluidized bed reactors is an important parameter which is responsible of fluidization quality and the design of reactor. The solid volume fraction can be obtained from the pressure drop across the bed with the information of gas and particle densities. However, previous method such as the Hg-porosimetry for the measurement of the particle density did not adequately draw the solid volume fraction of the CNT aggregates with entangled nanotubes network. A new method to measure the apparent particle density of the CNT aggregates was proposed to calculate the solid volume fraction in the CNT fluidized bed. The density of the vertically aligned CNT particle was measured based on the apparent volume by shape analysis using two dimensional imaging. The solid fraction based on imaging method showed a significant value of 0.69 for the fixed bed, which describes well the entangled structure of the CNT aggregates. The distribution of solid volume fraction in the CNT fluidized bed with variation of gas velocity was determined based on the imaging method. The method was verified by applying the obtained values to the Richardson-Zaki equation on the bed expansion in the fluidized bed.  

scholarly journals Magnetic Particle Imaging and its Application

2021 ◽  
Author(s):  
Farzaneh Ghorbani ◽  
Somayyeh Seyedi ◽  
Alireza Montazerabadi
Keyword(s):  
Quantitative Method ◽  
Magnetic Nanoparticle ◽  
Magnetic Particle ◽  
Imaging Modality ◽  
High Sensitivity ◽  
Imaging Method ◽  
External Excitation ◽  
Magnetic Particle Imaging ◽  
Nanoparticle Imaging ◽  
Particle Imaging

Magnetic particle imaging was introduced in 2005 as a new tomographic medical imaging modality and is still under development. Magnetic particle imaging determines the spatial distribution of magnetic nanoparticles by their interaction with an external excitation magnetic field. Therefore, there is no ionizing radiation dose in this trace-based modality. Magnetic nanoparticle imaging provides characteristics, including high spatial and temporal resolution, high sensitivity, expected from an ideal imaging method, and it is also an inherently quantitative method. In this paper, the properties of magnetic fields and particles used in Magnetic particle imaging, as well as its applications are discussed.

Magnetic Particle Imaging–Guided Stenting

2019 ◽  
Vol 26 (4) ◽  
pp. 512-519 ◽  
Author(s):  
Stefan Herz ◽  
Patrick Vogel ◽  
Thomas Kampf ◽  
Philipp Dietrich ◽  
Simon Veldhoen ◽  
...  
Keyword(s):  
Magnetic Particle ◽  
Superparamagnetic Iron Oxide ◽  
Reconstruction Algorithm ◽  
Imaging Method ◽  
Phantom Model ◽  
Balloon Catheters ◽  
Magnetic Particle Imaging ◽  
Custom Made ◽  
Stent Lumen ◽  
Particle Imaging

Purpose:To assess the feasibility of magnetic particle imaging (MPI) to guide stenting in a phantom model. Materials and Methods: MPI is a new tomographic imaging method based on the background-free magnetic field detection of a tracer agent composed of superparamagnetic iron oxide nanoparticles (SPIOs). All experiments were conducted on a custom-built MPI scanner (field of view: 29-mm diameter, 65-mm length; isotropic spatial resolution 1–1.5-mm). Stenosis phantoms (n=3) consisted of polyvinyl chloride (PVC) tubes (8-mm inner diameter) prepared with centrally aligned cable binders to form a ~50% stenosis. A dedicated image reconstruction algorithm allowed precise tracking of endovascular instruments at 8 frames/s with a latency time of ~115 ms. A custom-made MPI-visible lacquer was used to manually label conventional guidewires, balloon catheters, and stainless steel balloon-expandable stents. Vascular stenoses were visualized by injecting a diluted SPIO tracer (ferucarbotran, 10 mmol iron/L) into the vessel phantoms. Balloon angioplasty and stent placement were performed by inflating balloon catheters and stent delivery balloons with diluted ferucarbotran. Results: After deployment of the stent, the markers on its ends were clearly visible. The applied lacquer markers were thin enough to not relevantly alter gliding properties of the devices while withstanding friction during the experiments. Placing an optimized flexible lacquer formulation on the preexisting radiopaque stent markers provided enough stability to withstand stent expansion. Final MPA confirmed successful stenosis treatment, facilitated by the disappearance of the lacquer markers on the stent due to differences in SPIO concentration. Thus, the in-stent lumen could be visualized without interference by the signal from the markers. Conclusion: Near real-time visualization of MPI-guided stenting of stenoses in a phantom model is feasible. Optimized MPI-visible markers can withstand the expansion process of stents.

scholarly journals Development and characterization of superparamagnetic coatings

2015 ◽  
Vol 1 (1) ◽  
pp. 1-4
Author(s):  
I. Kuschnerus ◽  
K. Lüdtke-Buzug
Keyword(s):  
Magnetic Particle ◽  
High Spatial Resolution ◽  
Three Dimensional ◽  
Superparamagnetic Iron Oxide ◽  
High Sensitivity ◽  
Surgical Instruments ◽  
Imaging Method ◽  
Magnetic Particle Imaging ◽  
Particle Imaging

AbstractSince 2005, Magnetic Particle Imaging (MPI) is handled as a key technology with great potential in medical applications as an imaging method [1]. The superparamagnetic iron oxide nanoparticles (SPIONs) which are already used as a tracer in MPI, combined with various polymers, are being investigated in order to enhance this potential. A combination of polymers such as polyethylene (PE) and polyurethane (PU) and SPIONs could be used as a coating for medical devices, or added to semi-rigid polyurethane for the production of surgical instruments [2]. This would be of great interest, since the method provides high sensitivity with simultaneous high spatial resolution and three-dimensional imaging in real time. Therefore various superparamagnetic coatings were developed, tested and characterized. Finally SPIONs and various polymers were combined directly and used for MPI-compatible models.

scholarly journals A simulation study of excitation coil design in single-sided mpi scanner for human body application

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Nurmiza Othman ◽  
Muhamad Fikri Shahkhirin Birahim ◽  
Wan Nurshazwani Wan Zakaria ◽  
Mohd Razali Md Tomari ◽  
Md Nor Ramdon Baharom ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
Human Body ◽  
Simulation Study ◽  
Complex Surface ◽  
Imaging Method ◽  
Magnetic Field Generation ◽  
Excitation Coil ◽  
Particle Imaging

Magnetic particle imaging (MPI), a tomographic imaging method has been introduced for 3D imaging of human body with some potential applications such as magnetic hyperthermia and cancer imaging. It involves three important elements: tracer development using magnetic nanoparticles (MNPs), hardware realization (scanner using excitation and pickup coils), and image reconstruction optimization. Their combination will produce a high quality of image taken from any biological tissue in the human body based on the secondary magnetic field signal from the magnetized MNPs that are injected into human body. A homogeneous and adequate magnetic field strength from an excitation coil is needed to enhance the quality of the secondary signal. However, the complex surface topography of human body and physical properties of an excitation coil influence the strength and the homogeneity of the magnetic field generation at the MNPs. Therefore, this work focused on finding alternative design of excitation coil used in single sided MPI to produce up to 2 mT with high homogeneity of field distribution in the MNPs at the varied depth of 10 to 30 mm under the excitation coil. We proposed several designs with variation in physical properties and coil arrangement based on simulation study carried out by using Ansys Maxwell.

Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

1976 ◽  
Vol 34 ◽  
pp. 590-591
Author(s):  
T. Y. Tan ◽  
W. K. Tice
Keyword(s):  
Fast Neutron ◽  
Rapid Determination ◽  
Stacking Faults ◽  
Imaging Method ◽  
Large Reduction ◽  
Dislocation Loops ◽  
Fringe Spacing ◽  
Weak Beam ◽  
Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

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