Probe Sphere Research Articles

Extreme heterogeneity in the microrheology of lamellar surfactant gels analyzed with neural networks.

The heterogeneity of the viscoelasticity of a lamellar gel network based on cetyl-trimethylammonium chloride and cetostearyl alcohol was studied using particle-tracking microrheology. A recurrent neural network (RNN) architecture was used for estimating the Hurst exponent, H, on small sectionsof tracks of probe spheres moving with fractional Brownian motion. Thus, dynamic segmentation of tracks via neural networks was used in microrheology and it is significantly more accurate than using mean square displacements (MSDs). An ensemble of 414 particles produces a MSD that is subdiffusive in time, t, with a power law of the form t^{0.74±0.02}, indicating power law viscoelasticity. RNN analysis of the probability distributions of H, combined with detailed analysis of the time-averaged MSDs of individual tracks, revealed diverse diffusion processes belied by the simple scaling of the ensemble MSD, such as caging phenomena, which give rise to the complex viscoelasticity of lamellar gels.

Shear viscosity of a near-critical binary system analyzed with variable-temperature atomic force microscopy

Variation in shear viscous drag in a near-critical binary mixture was measured between a hydrophilic probe sphere and a hydrophilic substrate down to a distance range comparable to or smaller than the correlation length ξ using a magnetic excitation method of atomic force microscopy at temperatures T=Tc−∆T with ∆T varying from 0.1 to 0.7 K. As the temperature approached the Tc, the increase in the drag coefficient toward the zero distance was observed to be less pronounced in the distance range below ca. 100 nm. The data was discussed as arising from suppression in a concentration gradient in the intersurface region due to the overlap of the affected layers on similar surfaces.

Reconstructing fresh green leaf spectra in the SWIR-2 region (2001–2500 nm) collected in a humid environment by referring to publicly available green leaf spectral databases

Leaf spectra (reflectance and transmittance) are commonly measured using a portable spectroradiometer and an integrating sphere or contact probe with an artificial light source. However, spectral data may be obscured due to water vapor and low signal-to-noise ratios, especially in the shortwave infrared-2 region (SWIR-2, 2001–2500 nm). Therefore, we proposed a spectral reconstruction approach to retrieve noise-free SWIR-2 fresh green leaf spectra by referring to the previously published quality-controlled fresh green leaf spectral reference databases. We processed 896 pairs of fresh tea (Camellia sinensis var. sinensis) leaf reflectance/transmittance from Alishan in central Taiwan. We selected a subset (500–1900 nm) of the spectra in the visible, near-infrared, and SWIR-1 regions (VNS-1) that were relatively insensitive to atmospheric conditions. We matched those spectra with publicly available reference green leaf spectral databases, and selected the one that was most similar to each Alishan VNS-1 spectrum. We then used multivariable linear regression, linear parameter multiplication and spectral reversion to reconstruct SWIR-2 spectra. Finally, we used another set of green leaf spectral databases to assess the performance of the proposed method. The performance of the reconstruction approach was satisfactory, with mean (± standard deviation) root-mean-square errors (RMSEs) of 0.0041 ± 0.0019 (reflectance) and 0.0054 ± 0.0027 (transmittance) for each spectrum and RMSEs of 0.0058 ± 0.0027 (reflectance) and 0.0055 ± 0.0043 (transmittance) for each SWIR-2 band. The proposed approach successfully modeled SWIR-2, which could be further improved with the availability of a more comprehensive set of green leaf reference spectral databases.

Generalized geometric pore size distribution code GPSD-3D for periodic systems composed of monodisperse spheres

The generalized geometric pore size distribution P(r;rp|rc) as function of pore radius r, probe sphere radius rp, and coating thickness rc for a periodic two-dimensional system composed of circles (GPSD-2D) had been defined recently. For rp=rc=0 it reduces to the widely accepted pore radius distribution P(r) introduced by Gelb and Gubbins. The three-dimensional counterpart GPSD-3D for periodic systems composed of spheres is implemented here using an efficient Voronoi-based semi-analytic strategy that offers significant advantages compared with both a grid-based implementation and constrained nonlinear optimization with respect to speed, precision and memory requirements. Moreover, GPSD-3D is fully parallelized using OpenMP. Program summaryProgram title:GPSD-3DCPC library link to program files:https://doi.org/10.17632/ntcr87fgr5.1Developers repository link:https://github.com/mkmat/CODE-GPSD-3DLicensing provisions: MITProgramming languages:fortran, c++, perlNature of problem: Calculation of a set of pore radii for a user-provided configuration of (material) spheres contained in a periodic three-dimensional, rectangular box. This set depends on the user-specified radius rp of a probe sphere, and a user-specified hypothetical coating thickness rc of the material spheres. The variable size of the set, and thus the resolution of the resulting generalized geometric pore size distribution increases linearly with computing time.Solution method: Analytic calculation of pore radii from the Voronoi faces for the case of monodisperse systems, constrained nonlinear optimization or grid-based approach for polydisperse systems.Additional comments: This code requires a c++ compiler such as g++, a OpenMP-supporting fortran compiler such as gfortran, perl, and the voro++ library. Download links will be automatically provided during installation of GPSD-3D.

Using micro spheres as reference artifacts for the in-situ characterization of tactile 3D micro probes along the probing sphere’s equator

Abstract Nano and micro coordinate measuring machines (CMMs) have been developed for the characterization of small dimensional features. They require a procedure which enables a traceable and precise characterization of probing spheres. In this contribution we explore the use of well characterized micro spheres as reference artifacts for the in-situ characterization of probing spheres along the probing sphere’s equator. The spheres are characterized using a strategy which is based on a set of tactile surface scans in conjunction with a stitching-algorithm. These micro spheres serve as a reference for the in-situ characterization of a tactile 3D micro probe on a nano measuring machine (NMM-1). Our investigations are based on a sample of eight spheres sourced from two different suppliers. Although the sample is small, we could already observe characteristics which seem to be typical for spheres of a certain type (i.e. nominal radius and material). The experiments indicate that micro spheres are a suitable reference artifact for tactile 3D micro probes. We were able to reproduce the measured mean radius of the probing sphere with a standard deviation of 31 nm using reference spheres whose nominal radius covers a range of 89 µm (61 µm up to 150 µm).

The Effect of Slicer Infill Pattern on the Electrochemical Performance of Additively Manufactured Electrodes

AbstractIn this work we report the dramatic effects that changing the infill pattern has on the electrochemical performance of an additively manufactured electrode made from commercial filament. Electrodes were produced using six different slicing patterns and imaged to confirm how the infill pattern altered the working electrode surface. These electrodes were then electrochemically characterised against the near‐ideal outer sphere redox probe [Ru(NH3)6]3+, the common inner sphere probe [Fe(CN)6]3−, and then used for the electroanalytical determination of acetaminophen. It was found that changing the infill pattern had a dramatic effect on the electrochemical performance of the electrodes. Over the course of the manuscript, it can be seen that Aligned Rectilinear and Rectilinear infill patterns perform consistently well and offer good reproducibility. On the other hand, Concentric infill pattern had noticeably poor inter‐electrode reproducibility and the Hilbert Curve infill was one of the worst performing electrodes in many categories. For future work in this field, we recommend the infill pattern is always reported within the experimental section to allow other researchers to repeat work properly. Additionally, when optimising an electroanalytical sensing platform, we encourage researchers to optimise the infill pattern as it has direct influence on the analytical parameters.

SiteFerret: Beyond Simple Pocket Identification in Proteins.

We present a novel method for the automatic detection of pockets on protein molecular surfaces. The algorithm is based on an ad hoc hierarchical clustering of virtual probe spheres obtained from the geometrical primitives used by the NanoShaper software to build the solvent-excluded molecular surface. The final ranking of putative pockets is based on the Isolation Forest method, an unsupervised learning approach originally developed for anomaly detection. A detailed importance analysis of pocket features provides insight into which geometrical (clustering) and chemical (amino acidic composition) properties characterize a good binding site. The method also provides a segmentation of pockets into smaller subpockets. We prove that subpockets are a convenient representation to pinpoint the binding site with great precision. SiteFerret is outstanding in its versatility, accurately predicting a wide range of binding sites, from those binding small molecules to those binding peptides, including difficult shallow sites.

Use of Inner/Outer Sphere Terminology in Electrochemistry—A Hexacyanoferrate II/III Case Study

Salts of hexacyanoferrate II/III anions have been widely used as redox couple probe molecules to determine the characteristics of electrode surfaces. Examples include the assessment of electrocatalysts for energy applications and electrocatalysts for the detection of biological or chemical species, as well as the determination of electrochemically active surface areas. An examination of the electrochemical literature, based largely on cyclic voltammetric investigations, reveals a wide range of peak separation and/or heterogeneous electron transfer rate constants, classified sometimes as inner or outer sphere electron transfer processes. Originally developed for the mechanistic interpretation of inorganic transition metal compounds in solution, this terminology has since been extended to account for heterogeneous electron transfer occurring at electrodes. In the case of the hexacyanoferrate II/III anions, there can be a number of reasons why it sometimes behaves as an outer sphere probe and at other times displays inner sphere electron transfer characteristics. After examining some of the structural and chemical properties of the hexacyanoferrate II/III species, the methods used to determine such classifications are described. The most common method involves measuring peak-to-peak separation in a cyclic voltammogram to ascertain a heterogeneous rate constant, but it has inherent flaws. This paper reviews the reasons for the classification disparity, including the effects of various oxygen surface species, the influence of organic surface films, the nature of the cation counter-ion, surface adsorption and surface hydrophilicity/hydrophobicity. Other surface interactions may also take place, such as those occurring with Au corrosion or pH effects. These can impact the electrical double layer and thus may affect the electron transfer process. Consequently, it is recommended that hexacyanoferrate II/III should be considered a multi-sphere or alternatively a surface-sensitive electron transfer species.

Rapid determination of free amino acids and caffeine in matcha using near-infrared spectroscopy: A comparison of portable and benchtop systems

Matcha is gaining popularity around the globe, because of its worthy compositions and health benefits. This work proposed to predict free amino acids (FAA) and caffeine contents in matcha using a portable near-infrared (NIR) spectroscopy system combined with two different acquisition techniques (integrating sphere, IS; and fiber probe, FP) in comparison to a benchtop Fourier transform-NIR (FT-NIR) spectroscopy system. The prediction models were built using multi-variable selection algorithms such as synergy interval (Si), competitive adaptive reweighted sampling (CARS), and bootstrapping soft shrinkage (BOSS). Results in the current work showed that BOSS-PLS (BOSS-partial least squares) models yielded satisfactory results for both NIR spectroscopy types. In addition, the portable NIR-IS system has a prediction ability comparable to the benchtop FT-NIR, with coefficients of prediction (Rp) of 0.8920 and 0.8992 for FAA and caffeine, respectively. Consequently, the portable NIR-IS system has great compatibility for the rapid, accurate and on-site prediction of matcha compositions.

Acceptance and reverification testing for industrial computed tomography – a simulative study on geometrical misalignments

Abstract. Acceptance and reverification testing for industrial X-ray computed tomography (CT) is described in different standards (E DIN EN ISO 10360-11:2021-04, 2021; VDI/VDE 2630 Blatt 1.3, 2011; ASME B89.4.23-2020, 2020). The characterisation and testing of CT system performance are often achieved with test artefacts containing spheres. This simulative study characterises the influence of different geometrical error sources – or geometrical misalignments – on these sphere measurements. The two measurands on which this study focuses are the sphere centre-to-centre distances and the sphere probing form errors. One difference between the current draft of the ISO 10360-11 standard (E DIN EN ISO 10360-11:2021-04, 2021) and the VDI/VDE standard 2630 part 1.3 (VDI/VDE 2630 Blatt 1.3, 2011) as well as the ASME standard B89.4.23 (ASME B89.4.23-2020, 2020) are the differences for the sphere centre-to-centre distances that need to be measured. The VDI/VDE standard and the ASME standard require measurements of these kinds of distances of up to 66 % of the possible maximum distance within the measurement volume, while the ISO draft asks for measurements of up to 85 % of the possible maximum distance. This requirement needs to be considered in connection with the maximum permissible error (MPE) specification for these sphere distance measurements. This MPE should be specified as a linear function of the nominal distance or a constant value or a combination thereof (compare definition 9.2 of ISO 10360-1:2000 + Cor.1:2002 (DIN EN ISO 10360-1:2003-07, 2003)), and thus, the linearity of the length-dependent maximum measurement error of the sphere distance measurements is of interest. This simulative study inspects to what extent this linearity can be observed for CT measurements under the influence of different geometric errors. Further, the question is whether measurement lengths above 66 % necessitate a change in the MPE specification. Thus, an automatic identification of cases that might affect the MPE specification is proposed, and these cases are inspected manually. A second aspect of this study is the impact of geometrical misalignments on the probing form errors of a measured sphere. The probing form error also needs to be specified. Thus, whether and how it is influenced by the misalignments is also of interest. Based on our simulations, we conclude that probing form errors and sphere centre-to-centre distances of up to 66 % of the maximum possible measurement length within the measurement volume are sufficient for acceptance testing concerning geometrical misalignments – each geometrical misalignment can be detected well with at least one of these two measurands.

Experimental Investigation of Dimensional Accuracy in Non-traditional Sheet Metal Spinning Process for Producing Rectangular Spun Part

The non-conventional spinning process was adopted for producing polygons, but one of the process limitations is the error between design and the final product especially with no-mandrel. Dimensional accuracy was adopted for this purpose which gives an indicator of the ability of the formed part to matches the design and checking validated of the adopted methodology for producing rectangular cross-section spun parts, by comparing the coordinating points of real part with the points of the design model. The point of a real part was measured by using a sphere probe fixed on the three-axis milling machine and capturing the data of machine axis movements for the center location of the probe, also, the measurements oppositely took place, by offsetting the points of design along the normal vector for comparison with the real part points. Three parameters were invested for study the effects on the dimensional accuracy, these parameters are spindle speed (48, 68, and 135 RPM), feed ratio (0.16, 0.22, and 0.32 mm/rev), and the ball diameter of the forming tool (16, 22 and 25 mm). The results show that tool ball diameter mainly affecting dimensional accuracy with a higher value of average error reach (6.47mm) when 16mm diameter of tool ball was used, on the other hand, the minimum average error was 1.705mm at low spindle speed.

Estimation of total extractive content of wood from planted and native forests by near infrared spectroscopy

The aim of this study was to evaluate the performance of multivariate models using Near infrared (NIR) spectra for predicting total extractives content of solid and powdered wood of planted and native species from tropical savanna. NIR spectra were recorded on the milled wood and radial surface of solid wood specimens of Cedrela sp., Jacaranda sp., Apuleia sp., Aspidosperma sp. and clones of Eucalyptus hybrids via an integrating sphere and fiber optics probe. NIR spectral signatures were evaluated by Principal Component Analysis (PCA) and then associated to the total extractive content quantified by extraction in toluene/ethanol (2:1) solutions, pure ethanol and hot water by Partial Least Squares (PLS) regressions. PCA revealed that NIR spectra measured in solid wood by integrating sphere gave a better discrimination of wood species. A global PLS model was developed based on NIR obtained by integrating sphere with satisfactory estimations both for solid wood (R²cv= 0.87, RMSECV= 1.08%) and wood powder (R²cv= 0.85, RMSECV= 1.19%). An independent test-set validation was performed with 25% of the samples and yielded R²p= 0.93 and RMSEP= 0.95% (for solid wood) and R²p= 0.87 and RMSEP= 1.40% (for wood powder). Both models can be applied for rapid screenings, though models developed from NIR spectra by integrating sphere on solid wood are considered more suitable for rapid predictions of extractive content in unknown wood specimens.

The limited contribution of early visual cortex in visual working memory for surface roughness.

Are visual representations in the human early visual cortex necessary for visual working memory (VWM)? Previous studies suggest that VWM is underpinned by distributed representations across several brain regions, including the early visual cortex. Notably, in these studies, participants had to memorize images under consistent visual conditions. However, in our daily lives, we must retain the essential visual properties of objects despite changes in illumination or viewpoint. The role of brain regions-particularly the early visual cortices-in these situations remains unclear. The present study investigated whether the early visual cortex was essential for achieving stable VWM. Focusing on VWM for object surface properties, we conducted fMRI experiments, while male and female participants performed a delayed roughness discrimination task in which sample and probe spheres were presented under varying illumination. By applying multi-voxel pattern analysis to brain activity in regions of interest, we found that the ventral visual cortex and intraparietal sulcus were involved in roughness VWM under changing illumination conditions. In contrast, VWM was not supported as robustly by the early visual cortex. These findings show that visual representations in the early visual cortex alone are insufficient for the robust roughness VWM representation required during changes in illumination.

Estimating wood moisture by near infrared spectroscopy: Testing acquisition methods and wood surfaces qualities

ABSTRACT Moisture is one of the most important wood properties because its variation directly influences the material strength and density. Thus, the aim of this study was to develop near infrared (NIR) spectroscopic models in order to estimate the moisture content in wood specimens. Moreover, predictive models built from NIR signatures recorded by different acquisition methods and on wood surfaces were compared and discussed. Mass and NIR spectra were measured on forty (40) Eucalyptus wood specimens in 10 steps during drying from the fiber saturated point to anhydrous condition. NIR spectra were recorded by means of an integrating sphere and optical fiber probe on four surface. Thus, wood moisture values were correlated with the corresponding NIR spectra by Partial Least Squares (PLS) Regression. The best models for estimating wood moisture were developed from NIR spectra recorded on the transverse surface produced with the band saw by integrating sphere method (R²p = 0.96 and RMSEP = 8.56%) and fiber optic probe (R²p = 0.83 and RMSEP = 20.09%). Therefore, NIR spectrum recorded by integrating sphere taken on transverse or radial wood surface cut by band saw are the most suitable for generating NIR models for estimating the moisture content in Eucalyptus wood.

Holographic molecular binding assays

We demonstrate that holographic particle characterization can directly detect binding of proteins to functionalized colloidal probe particles by monitoring the associated change in the particles’ size. This label-free molecular binding assay uses in-line holographic video microscopy to measure the diameter and refractive index of individual probe spheres as they flow down a microfluidic channel. Pooling measurements on 104 particles yields the population-average diameter with an uncertainty smaller than 0.5 nm, which is sufficient to detect sub-monolayer coverage by bound proteins. We demonstrate this method by monitoring binding of NeutrAvidin to biotinylated spheres and binding of immunoglobulin G to spheres functionalized with protein A.

Biofouling affects the redox kinetics of outer and inner sphere probes on carbon surfaces drastically differently - implications to biosensing.

Biofouling imposes a significant threat for sensing probes used in vivo. Antifouling strategies commonly utilize a protective layer on top of the electrode but this may compromise performance of the electrode. Here, we investigated the effect of surface topography and chemistry on fouling without additional protective layers. We have utilized two different carbon materials; tetrahedral amorphous carbon (ta-C) and SU-8 based pyrolytic carbon (PyC) in their typical smooth thin film structure as well as with a nanopillar topography templated from black silicon. The near edge X-ray absorption fine structure (NEXAFS) spectrum revealed striking differences in chemical functionalities of the surfaces. PyC contained equal amounts of ketone, hydroxyl and ether/epoxide groups, while ta-C contained significant amounts of carbonyl groups. Overall, oxygen functionalities were significantly increased on nanograss surfaces compared to the flat counterparts. Neither bovine serum albumin (BSA) or fetal bovine serum (FBS) fouling caused major effects on electron transfer kinetics of outer sphere redox (OSR) probe Ru(NH3)63+ on any of the materials. In contrast, negatively charged OSR probe IrCl62- kinetics were clearly affected by fouling, possibly due to the electrostatic repulsion between redox species and the anionically-charged proteins adsorbed on the electrode and/or stronger interaction of the proteins and positively charged surface. The OSR probe kinetics were less affected by fouling on PyC, probably due to conformational changes of proteins on the surface. Dopamine (DA) was tested as an inner sphere redox (ISR) probe and as expected, the kinetics were heavily dependent on the material; PyC had very fast electron transfer kinetics, while ta-C had sluggish kinetics. DA electron transfer kinetics were heavily affected on all surfaces by fouling (ΔEp increase 30-451%). The effect was stronger on PyC, possibly due to the more strongly adhered protein layer limiting the access of the probe to the inner sphere.

Estimation of moisture in wood chips by Near Infrared Spectroscopy

In order to assess the moisture content of wood chips on an industrial scale, readily applicable techniques are required. Thus, near infrared (NIR) spectroscopy was used to estimate moisture in wood chips by means of partial least squares regressions. NIR spectra were obtained in spectrometer with an integrating sphere and optical fiber probe, on the longitudinal and transverse surface of Eucalyptus wood chips. The specimens had their masses and NIR spectra measured in 10 steps during drying from saturated to anhydrous condition. Principal Component Analysis was performed to explore the effect of moisture of wood chip on NIR signatures. The values of moisture content of chips were associated with the respective NIR spectra by Partial Least Squares Regression (PLS-R) and Partial Least Squares Discriminant Analysis (PLS-DA) to estimate the moisture content of wood chips and its moisture classes, respectively. Model developed from spectra recorded on the longitudinal face by the integrating sphere method presented statistics slightly better (R²cv = 0,96; RMSEcv = 7,15 %) than model based on optical fiber probe (R²cv = 0,90; RMSEcv = 11,86 %). This study suggests that for calibration of robust predictive model for estimating moisture content in chips the spectra should be recorded on the longitudinal surface of wood using the integrating sphere acquisition method.

Effect of the Solute Cavity on the Solvation Energy and its Derivatives within the Framework of the Gaussian Charge Scheme.

The treatment of the solvation charges using Gaussian functions in the polarizable continuum model results in a smooth potential energy surface. These charges are placed on top of the surface of the solute cavity. In this article, we study the effect of the solute cavity (van der Waals-type or solvent-excluded surface-type) using the Gaussian charge scheme within the framework of the conductor-like polarizable continuum model on (a) the accuracy and computational cost of the self-consistent field (SCF) energy and its gradient and on (b) the calculation of free energies of solvation. For that purpose, we have considered a large set of systems ranging from few atoms to more than 200 atoms in different solvents. Our results at the DFT level using the B3LYP functional and the def2-TZVP basis set show that the choice of the solute cavity does neither affect the accuracy nor the cost of calculations for small systems (< 100 atoms). For larger systems, the use of a vdW-type cavity is recommended, as it prevents small oscillations in the gradient (present when using a SES-type cavity), which affect the convergence of the SCF energy gradient. Regarding the free energies of solvation, we consider a solvent-dependent probe sphere to construct the solvent-accessible surface area required to calculate the nonelectrostatic contribution to the free energy of solvation. For this part, our results for a large set of organic molecules in different solvents agree with available experimental data with an accuracy lower than 1 kcal/mol for both polar and nonpolar solvents.

Classification of commercial charcoal for domestic use by near infrared spectroscopy

Charcoal for domestic use presents great variation in quality because in most furnaces the carbonization process is difficult to and often inadequate raw material is used, generating a heterogeneous product. Near infrared (NIR) spectroscopy is a fast and reliable method to classify bio-based materials. Thus, the aim of this study was to apply NIR spectroscopy coupled with multivariate statistics in order to classify commercial vegetable charcoal for domestic use into categories and estimate its quality. Seventy-six charcoal specimens from nine producers were selected for NIR spectra acquisition on the transverse (TV) and rolling surface (RS) using the integrating sphere and fiber optic probe on raw (untreated) and sanded charcoal. Principal Component Analysis (PCA) of the spectra was performed to verify possible clusters among producers or quality classes (in terms of FCC levels). Discriminant Analyses based on Partial Least Squares (PLS-DA) were performed to classify the charcoals according to their producers and to predict their quality class. The PCA of spectra was not able to distinguish groups indicating high heterogeneity between treatments. However, PLS-DA models correctly classified up to 95% of the charcoal specimens both by producers and quality classes using spectra obtained by the integrating sphere or fiber optic probe. NIR spectroscopy coupled with multivariate analyses presented potential to be an efficient and rapid technique to classify charcoal. PLS-DA models can be applied in unknown charcoal specimens for reliable classification.

Comparing Channel Emulation Algorithms by Using Plane Waves and Spherical Vector Waves in Multiprobe Anechoic Chamber Setups

This paper evaluates the performances of channel emulation algorithms in the multiprobe anechoic chamber (MPAC) by using plane wave (PW) and spherical vector wave (SVW) theories. Channel emulation in MPAC enables the over-the-air (OTA) testing of performances of wireless devices under realistic propagation scenarios, through setting excitation voltages of probes and utilizing the polarized radiation patterns, locations, and orientations of probe antennas to emulate desired fields in test zone. Accurate emulation of radio wave propagation in target scenario guarantees that the device under test (DUT) be assessed fairly in the laboratory. Dynamic multipath scenario and orthogonal polarization can be emulated by exciting the multiple probes in such a way that the total fields from probes resemble the target impinging field in the test zone. The excitation voltages can be either calculated by PW or SVW theories. Despite the fact that PW and SVW are mathematically equal in the far field, different treatments on rotation and translation of waves as well as different linear equations used in two methods result in different computed voltages, hence, different emulated fields. The emulation performances of the two methods with different MPAC setups (e.g., test zone size, probe number, probe sphere radius, and probe directivity) are investigated. Both scenarios of the 2-D field emulation with the 2-D probe configuration and the 3-D (or 2.5-D) field emulation with the 3-D probe configuration are discussed, and instructions on how to wisely use the emulation algorithm are provided.