Influence Of Scanning Parameters Research Articles

Universal Behavior of the Image Resolution for Different Scanning Trajectories

This study examines the characteristics of various scanning trajectories or patterns under the influence of scanning parameters in order to develop a theory to define their corresponding image resolutions. The lack of an accurate estimation of pixel size for a specified set of scanning parameters and their connection is a key challenge with existing scanning methods. Thus, this research aimed to propose a novel approach to estimate the pixel size of different scanning techniques. The findings showed that there is a link between pixel size and a frequency ratio NP, which is the ratio of two waveform frequencies that regulates the density of the scanning pattern. A theory has been developed in this study to explain the relationship between scanning parameters and scanning density or pixel size, which was not previously considered. This unique theory permitted the a priori estimate of the image resolution using a particular set of scanning parameters, including the scan time, frequencies, frequency ratio, and their amplitudes. This paper presents a novel and systematic approach for estimating the pixel size of various scanning trajectories, offering the user additional flexibility in adjusting the scanning time or frequency to achieve the desired resolution. Our findings also reveal that in order to achieve a high-quality image with high signal-to-noise and low error, the scanning trajectory must be able to generate a fairly uniform or regular pattern with a small pixel size.

Определение рациональных технологических параметров селективного лазерного сплавления порошка алюминиевого сплава AlSi10Mg

Chemical and granulometric analysis of AlSi10Mg alloy powder was carried out. It was found that the powder particles are generally non-spherical, with a significant number of inclusions in the form of satellites. Particle size distribution ranges from 5 to 60 μm. The presence of conglomerates up to 70 μm in size is observed. The study of the influence of scanning parameters on the tensile strength and relative elongation of the samples has been carried out. It was found that in the range of the scanning speed range of 910 – 930 mm/s, local mechanical minima are observed. In order to optimize the scanning parameters, complex quality indicators are used. The greatest desirability from the point of view of obtaining the maximum strength and plasticity of the material is a combination of scanning parameters: laser power — 350 W, scanning step — 0.19 mm, scanning speed — 980 mm/s, with a layer thickness of 50 μm. The results of tests of cylindrical specimens made at angles of 0° and 90° relative to the construction platform are presented.

Influence of scanning parameters on the estimation accuracy of control points of B-spline surfaces

Abstract This contribution deals with the influence of scanning parameters like scanning distance, incidence angle, surface quality and sampling width on the average estimated standard deviations of the position of control points from B-spline surfaces which are used to model surfaces from terrestrial laser scanning data. The influence of the scanning parameters is analyzed by the Monte Carlo based variance analysis. The samples were generated for non-correlated and correlated data, leading to the samples generated by Latin hypercube and replicated Latin hypercube sampling algorithms. Finally, the investigations show that the most influential scanning parameter is the distance from the laser scanner to the object. The angle of incidence shows a significant effect for distances of 50 m and longer, while the surface quality contributes only negligible effects. The sampling width has no influence. Optimal scanning parameters can be found in the smallest possible object distance at an angle of incidence close to 0° in the highest surface quality. The consideration of correlations improves the estimation accuracy and underlines the importance of complete stochastic models for TLS measurements.

High speed indentation measures by FV, QI and QNM introduce a new understanding of bionanomechanical experiments

Structural and mechanical mapping at the nanoscale by novel high-speed multiparametric Quantitative Imaging (QI) and PeakForce Quantitative Nanomechanical Mapping (PF-QNM) AFM modes was compared to the classical Force Volume (FV) mapping for the case of living Pseudomonas aeruginosa bacterial cells. QI and PF-QNM modes give results consistent with FV for the whole cells in terms of morphology and elastic modulus, while providing higher resolution and shorter acquisition time. As an important complement, the influence of scanning parameters on elastic modulus values was explored for small 0.22μm2 central area on top of cells. The modulus decreases with the indentation depth due to the effect of the hard cell wall, while it increases vs. tip oscillation frequency, displaying viscoelastic behaviour of the living bacterial cells. The ability of different AFM modes to follow correctly the bacteria viscoelastic behaviour at high oscillation frequency was tested.

Influence of cone beam CT scanning parameters on grey value measurements at an implant site

The aim of this study was to determine the grey value variation at the implant site with different scan settings, including field of view (FOV), spatial resolution, number of projections, exposure time and dose selections in two cone beam CT (CBCT) systems and to compare the results with those obtained from a multislice CT system. A partially edentulous human mandibular cadaver was scanned by three CT modalities: multislice CT (MSCT) (Philips, Best, the Netherlands), and two CBCT systems: (Accuitomo 170(®), Morita, Japan) and (NewTom 5G(®), QR, Verona, Italy). Using different scan settings 36 and 24 scans were obtained from the Accuitomo and the NewTom, respectively. The scans were converted to digital imaging and communications in medicine 3 format. The analysis of the data was performed using 3Diagnosys(®) software (v. 3.1, 3diemme, Cantù, Italy) and Geomagic studio(®) 2012 (Morrisville, NC). On the MSCT scan, one probe designating the site for pre-operative implant placement was inserted. The inserted probe on MSCT was transformed to the same region on each CBCT scan using a volume-based three-dimensional registration algorithm. The mean voxel grey value of the region around the probe was derived separately for each CBCT. The influence of scanning parameters on the measured mean voxel grey values was assessed. Grey values in both CBCT systems significantly deviated from Hounsfield unit values measured with MSCT (p = 0.0001). In both CBCT systems, scan FOV and spatial resolution selections had a statistically significant influence on grey value measurements (p = 0.0001). The number of projections selection had a statistically significant influence in the Accuitomo system (p = 0.0001) while exposure time and dose selections had no statistically significant influence on grey value measurements in the NewTom (p = 0.43 and p = 0.37, respectively). Grey-level values from CBCT images are influenced by device and scanning settings.

Accelerating image acquisition in 64-MDCT: the influence of scan parameters on image resolution and quality in a phantom study

Computed tomographic (CT) image resolution and quality were evaluated utilizing varying scan protocols with accelerated image acquisition.A resolution phantom with hole diameters from 0.2 to 1.0 mm was scanned in axial, coronal, and sagittal plane using a 64-slice multidetector CT with varying scan parameters.No relevant differences in image resolution and quality were detected between the fastest scan protocol, with the shortest rotation time and highest pitch, and the slowest protocol.Accelerated CT protocols resulted in diagnostic images with adequate resolution and quality.

Analysis of the BOLD characteristics in pass‐band bSSFP fMRI

Balanced steady-state free precession (bSSFP) has been proposed as an alternative method to acquire the blood oxygenation level dependent contrast. Particularly, pass-band bSSFP functional magnetic resonance imaging (fMRI) is believed to utilize the T2 sensitivity of bSSFP in a relatively wide and flat off-resonance frequency band of the bSSFP profile. The method has a potential to provide higher signal to noise ratio (SNR) efficiency with reduced imaging artifacts compared to conventional approaches. Previous experimental results suggested that the level of the functional contrast and its characteristics are significantly influenced by the sequence parameters. However, few of these contrast characteristics have been investigated systematically. In this study, a computer simulation was performed to investigate the sources of functional contrast and the influence of scan parameters on the functional contrast to elucidate the contrast characteristics of pass-band bSSFP fMRI. Experiments were performed to validate the simulation results.

AFM-based Study of the Best Imaging Conditions for Human Hepatoma Cells

What is the main reference and influencing factor for getting a more precise image at atomic force microscopy (AFM) imaging system? In this paper, the quadratic regression orthogonal rotation experiment is performed to analyze the imaging factors, such as scan rate, proportional gain P and integral gain I. The fractal dimension of cell image obtained by AFM is the determining factor for image fineness. The influence of scanning parameters on the imaging will be analyzed afterwards. The optimal experimental parameters and best imaging conditions can be obtained through the above mentioned method. The results will show that the smaller the cell image fractal dimension is, the higher the reflected microscopic information and the degree of approximation to the true surface are. At the same time, the higher the fractal dimension, the bigger the possibility of image distortion caused by interference and other factors will be. Hepatoma cells SMMC-27721 are used as samples to study the optimal parameters for AFM imaging. The results will help providing more useful information to other fields of biological micro-imaging with AFM.

Advances in multiple square wave techniques for ion-exchange voltammetry at ultratrace levels: the europium(III) case

This paper reports on the use of multiple square wave voltammetry, MSWV, for the determination of europium(III) preconcentrated by ion-exchange at glassy carbon electrodes coated with Nafion ® . For this aim, a double-differential (DD) mode of MSWV is implemented; with this mode, background signals are always straight lines while the analyte signal is given as a twin opposite peak system which corresponds approximately to the instrumental double differential of the classical voltammetric wave. The influence of scan parameters and experimental conditions on MSW-DD responses for europium(III) determinations at the modified electrode is examined. Detection limits and sensitivities obtained using MSW-DD are significantly superior to those achievable by classical pulsed techniques. The method is applied to the determination of ultratrace europium(III) concentrations in the 10 11 ‐10 10 M range in the cooling water of a nuclear plant; results obtained by the MSW-DD ion-exchange voltammetric approach compare well with those obtained by ICP-MS. © 2001 Elsevier Science B.V. All rights reserved.

Surface structure of the PAN‐based carbon fibres studied by the scanning probe microscopy (SPM)

AbstractScanning tunnelling microscopy (STM) and scanning force microscopy (SFM) have been applied to characterize the surface topography of carbon fibres before and after activating electrochemical treatment. Electrochemical activation is seen to have a significant effect on the structure of the surface layers. The influence of scanning parameters on STM and SFM images was examined and it was found that alteration of the scanning direction allows important additional information about surface structure of carbon fibres to be obtained. It also makes it possible to estimate the contribution of the artefacts to resulting images. The results indicate the great potential of both STM and SFM for three‐dimensional surface characterization of carbon fibres.