Relative Misalignment Research Articles

Experimental characterization of leading edge cracking on bulk tungsten divertor components during 2017–2019 WEST operation

During the 2017–2019 WEST operation, a set of ITER-like plasma-facing units consisting of tungsten monoblocks was installed on the lower divertor. Despite modest heating power, 27 % of these monoblocks had cracks on their poloidal leading edges, which were not protected by a toroidal bevel. A comprehensive experimental characterization of the 133 cracked monoblocks indicates that damage occurs near the plasma strike point areas where neat cracks separated by 0.15–0.5 mm in the poloidal direction were observed. Cracks are up to 1 mm long and 1 mm deep and did not affect the lower divertor ability to sustain long pulses. The most important parameter affecting crack formation is the relative vertical misalignment between components.

Effect of Motor Shaft Eccentricity on the Performance of a High-Speed Magnetic Fluid Sealer

The objective of the study is to develop recommendations for accounting during the design stage and the feasibility of operating a magnetic fluid seal with a significant eccentricity of the rotating shaft relative to stationary pole attachments. This goal is achieved through conducted experimental research, the selection of necessary equations, boundary conditions, assumptions, and physical properties of the magnetic fluid when constructing a numerical mathematical model of the working gap of the magnetic fluid seal. The most important results of the study include obtained and analyzed distributions of the magnetic field, velocity field, and pressure in the magnetic fluid, as well as the evaluation results of the impact of absolute and relative shaft misalignment in the magnetic fluid seal, centrifugal forces arising during shaft rotation, on the retained pressure drop by the seal. A significant reduction in the retained pressure drop occurs at an eccentricity of up to 40% of the working gap, and with further in-creases in eccentricity, the rate of pressure drop reduction slows down. The significance of the results lies in the potential utilization of the provided numerical model, as well as the outcomes of physical and mathematical experiments, in the development of a magnetic fluid seal operating with significant misalignment between the rotating shaft and the housing. The dimensionless dependencies obtained allow for consideration, during the design stage, of the reduction in retained pressure drop with shaft eccentricity, taking into account the magnitude of the working gap, magnetic induction, and linear velocity.

Interaction of [formula omitted] prismatic screw dislocations with the [formula omitted] interface side face in [formula omitted] Ti alloys

Slip transmission across α−β interfaces is of great significance in understanding the strength of α−β Ti alloys for aerospace applications. Molecular statics (MS) and molecular dynamics (MD) simulations were conducted to investigate the mechanisms of slip transmission of 〈a〉 prismatic screw dislocations across the α−β interface side face. In these simulations, the α phase consisted of pure HCP Ti whereas the β phase was modeled as Ti60Nb40 BCC random alloy using a Ti–Nb interatomic potential. Firstly, the misfit dislocations structure on the α−β interface side face has been characterized from MS simulations. This predicted dislocation structure is in good agreement with experimental observations in Ti-alloys. Secondly, MD simulations of the interaction of [a1], [a2], and [a3] prismatic screw dislocations with the interface side face in an α−β bi-crystal were performed at different temperatures. A distinct barrier of the interface side face to different types of dislocation transmission was found. The origin of this anisotropy in the slip transmission is due to the relative misalignment of the slip systems between the α and the β phases from the Burgers orientation relationship. Finally, the mechanisms of slip transmission of each dislocation type were analyzed in a detailed atomistic description and compared to experimental observations.

Computational Fluid Dynamics Study of the Dispersion Caused by Capillary Misconnection in Nano-Flow Liquid Chromatography.

It is well known that high-speed/high-efficiency separations in nano-flow liquid chromatography (LC) are very sensitive to the quality of the connections between the column and the rest of the instrument. In the present study, two types of connection errors (capillary misalignment and the occurrence of an inter-capillary gap) have been investigated using computational fluid dynamics. Interestingly, it has been found that large degrees of capillary misalignment (assuming an otherwise perfect contact between the capillary end-faces) can be afforded without introducing any significant dispersion over the entire range of investigated relative misalignment errors (0 ≤ ε/dcap ≤ 75%), even at the largest flow rates considered in nano-LC. On the other hand, when an inter-capillary gap is present, the dispersion very rapidly increases with the radial width Dc of this gap (extra variance ∼Dcn with n even reaching values above 4). The dependency on the gap length Lc is however much smaller. Results show that, when Dc ≤ 30 μm and Lc ≤ 200 μm, dispersion losses can be limited to the order of 1 nL2 at a flow of 1.5 μL/min, which is generally very small compared to the dispersion in the capillaries (20 μm i.d.) themselves. This result also reconfirms that zero-dead volume connectors with a sufficiently narrow bore can in theory be used without compromising peak dispersion in nano-LC, at least when the capillaries can be matched perfectly to the connector in- and outlet faces. The results are also indicative of the extra dispersion occurring inside microfluidic chips or in the connections between a microfluidic chip and the outer world.

Frequency-dependent reflection of a misaligned beam by a Fabry–Pérot cavity

Gravitational-wave detectors, such as Virgo, LIGO, and KAGRA, are modified Michelson interferometers, with a system of coupled Fabry–Pérot cavities, to increase its sensitivity and bandwidth. In order to control the detector, several radio frequency sidebands, not resonant in the kilometric arm cavities but resonant in the central cavities of the interferometer, are added to the carrier frequency to extract longitudinal and alignment error signals. Misalignment of the laser in the Fabry–Pérot cavities causes sensitivity degradation through different mechanisms and results in non-superposition of carrier and sidebands. These relative misalignment between fields at different frequency contain clues to optimally align the interferometer, but the question of the direction of a reflected beam by a Fabry–Pérot cavity, as a function of the state of resonance of the incoming electromagnetic field, is neither straightforward nor intuitive. While numerical optical simulations used in the gravitational-wave detector community are able to answer the question, they do not give a qualitative and handy understanding of the observed phenomenon, useful for the commissioning and operation of the detectors. In this Letter, we present a model based on Gaussian beam first-order modal expansion to calculate analytically how misalignment on the input beam in a Fabry–Pérot cavity translates into misalignment of the reflected and circulating beams. We find a strong dependence not only on the beam resonance condition but also on the mirror geometry. Finally, we checked the consistency of our model by comparing its predictions with existing numerical simulators.

Exchange rate misalignments, capital flows and volatility

This study investigates the effect of three dimensions of exchange rate misalignments—(i) distance (absolute misalignments), (ii) direction (overvaluation or undervaluation), and (iii) degree (small or large misalignments)—on the overall as well as short-cycle exchange rate volatility. Using data from 1988 to 2014, we find that relative PPP-based exchange rate misalignments increase exchange rate volatility. For developed and developing countries, this increase in volatility is driven mainly by large undervalued misalignments of the U.S. dollar. This finding might be linked to interventions targeting the loss in domestic producers’ competitiveness in global markets. Interestingly, in the case of developed countries, we find this adverse effect on exchange rate volatility also for small absolute misalignments; exchange rate movements close to equilibrium may be associated with ambiguity with respect to future movements in developed countries, which can result in higher exchange rate volatility. Further, the results suggest that, when the dollar is highly undervalued, capital flows have a stabilizing effect on exchange rate volatility in developed countries but a destabilizing effect in developing countries. The finding is consistent with investors’ strategy of taking exchange rate overvaluation and undervaluation into account when engaging in cross-border investments.

Attitude sensors relative angular misalignment estimation in integrated navigation systems

When using modern navigation systems as part of an on-board system, the navigation task can be solved in several ways: using positional, velocity and angular corrections, and systems using measurements of various physical nature—radio, such as short-range and long-range navigation radio systems, GLONASS/GPS satellite global navigation systems, optical—celestial navigation systems—can operate as correctors. The best performance of INS and its sensors (gyroscopes and accelerometers) errors estimation can be obtained when all types of correction are implemented simultaneously. At the same time, it is particularly difficult to implement correction according to attitude parameters due to the fact that the measuring axes of the INS and correctors may not match on board of moving objects. Such a mismatch is commonly called relative angular misalignment. The paper considers a possible approach to the attitude sensors relative angular misalignment estimation in integrated navigation systems (NS), carried out in motion when the NS is in operating mode.

Angular MIMO for Underwater Wireless Optical Communications: Link Modeling and Tracking

Angular imaging multiple-input--multiple-output (A-MIMO) is investigated for short-range, high-speed underwater wireless optical communications (UWOCs) where, unlike conventional imaging MIMO (C-MIMO), data are transmitted in an angle rather than in space. In this approach, the strict requirements of on-axis alignment and fixed channel length are relaxed. This technique also allows for simpler estimation of the relative misalignment between the transmitter and the receiver from the received image. For the first time, we derive a comprehensive model for the underwater A-MIMO link by taking into account link misalignment, background noise, as well as seawater absorption and scattering. Power distributions at the receiver are modeled by the angle of arrival of the received signal on the lens and its position of arrival on the focal plane of the detector. We further propose and model a tracked A-MIMO (TA-MIMO) system that maintains the alignment between the two ends of the link, for which the distribution of the residual tracking error is calculated. The UWOC channel capacity is then estimated for buoyed-to-fixed (B2F) (which has dominant angular misalignments) and mobile-to-fixed (M2F) (which has dominant off-axis misalignment) communication scenarios. Numerical results indicate that in the B2F scenario, A-MIMO is sensitive to angular misalignments; however, TA-MIMO outperforms C-MIMO. In the case of M2F links, A-MIMO greatly outperforms C-MIMO when off-axis misalignments are present. This work serves as a design guide to determine the selection of A-MIMO, TA-MIMO, or C-MIMO receivers depending on the misalignment conditions for a particular underwater application.

A precise architecture characterization of theπMensae planetary system

Context.The bright starπMen was chosen as the first target for a radial velocity follow-up to test the performance of ESPRESSO, the new high-resolution spectrograph at the European Southern Observatory’s Very Large Telescope. The star hosts a multi-planet system (a transiting 4M⊕planet at ~0.07 au and a sub-stellar companion on a ~2100-day eccentric orbit), which is particularly suitable for a precise multi-technique characterization.Aims.With the new ESPRESSO observations, which cover a time span of 200 days, we aim to improve the precision and accuracy of the planet parameters and search for additional low-mass companions. We also take advantage of the new photometric transits ofπMen c observed by TESS over a time span that overlaps with that of the ESPRESSO follow-up campaign.Methods.We analysed the enlarged spectroscopic and photometric datasets and compared the results to those in the literature. We further characterized the system by means of absolute astrometry with HIPPARCOSandGaia. We used the high-resolution spectra of ESPRESSO for an independent determination of the stellar fundamental parameters.Results.We present a precise characterization of the planetary system aroundπMen. The ESPRESSO radial velocities alone (37 nightly binned data with typical uncertainty of 10 cm s−1) allow for a precise retrieval of the Doppler signal induced byπMen c. The residuals show a root mean square of 1.2 m s−1, which is half that of the HARPS data; based on the residuals, we put limits on the presence of additional low-mass planets (e.g. we can exclude companions with a minimum mass less than ~2M⊕within the orbit ofπMen c). We improve the ephemeris ofπMen c using 18 additional TESS transits, and, in combination with the astrometric measurements, we determine the inclination of the orbital plane ofπMen b with high precision (ib=45.8−1.1+1.4deg). This leads to the precise measurement of its absolute massmb=14.1−0.4+0.5MJup, indicating thatπMen b can be classified as a brown dwarf.Conclusions.TheπMen system represents a nice example of the extreme precision radial velocities that can be obtained with ESPRESSO for bright targets. Our determination of the 3D architecture of theπMen planetary system and the high relative misalignment of the planetary orbital planes put constraints on and challenge the theories of the formation and dynamical evolution of planetary systems. The accurate measurement of the mass ofπMen b contributes to make the brown dwarf desert a bit greener.

Spirals, shadows & precession in HD 100453 – II. The hidden companion

ABSTRACT The protoplanetary disc HD 100453 exhibits a curious combination of spirals, shadows, and a relative misalignment between the observed outer disc and inferred inner disc. This disc is accompanied by a secondary star on a bound orbit exterior to the disc. Recent observations have suggested there may be an additional low-mass companion residing within the disc inner cavity. In our companion paper, the orbit of the secondary was shown to be misaligned by 61° to the plane of the outer disc. Here, we investigate the properties of the inner companion and the origin of the misalignment between the inner and outer discs. Using numerical simulations and synthetic observations, we show that the disc structure and kinematics are consistent with a ≲ 5 MJ planet located at 15 − 20 au. We find that the disc evolution over ∼50 binary orbits (∼105 yr) is governed by differential precession and to a lesser extent, the Kozai–Lidov effect. In our proposed model, the misalignment observed between the outer and inner disc arises naturally as a result of the misaligned outer companion driving the outer disc to precess more rapidly than the inner disc.

Quantifying Water Friction in Misaligned Graphene Channels under Ångström Confinements.

Two-dimensional (2D) materials, such as graphene (GE), hold great potential to be employed as the fundamental building blocks of novel nanofluidic devices for a wide range of applications. Recent advances in experimental techniques are materializing such prospects by enabling the assembly of 2D material-based fluidic channels with heights as small as few Ångströms. Here, we conduct molecular dynamics simulations to probe the effect of the relative misalignment between the walls of the GE fluidic channel with Ångströms height on the resistance to water transport through the channel. Two types of misalignments are studied, namely, translational and rotational misalignments. Our results show that the relative misalignment of the GE lattices can lead to a substantial reduction in the friction between water and the channel walls. Moreover, a dependence of the friction on the degree of misalignment and flow direction is found for the cases with translational misalignment. In contrast, the resistance exerted by the channels with rotational misalignment is found to be independent of the rotation angle (θ) for 0° < θ < 60° but always lower than the perfectly aligned case. We associate such lowering of the resistance to water transport to the corrugation and the anisotropy in the corresponding potential energy landscape associated with each degree of misalignment. The findings, therefore, point to an unprecedented possibility of significantly enhancing the water transport in Ångströms height GE channels by engineering the misalignments of the GE channel walls.

Using the Chemical Noise Background in MALDI Mass Spectrometry Imaging for Mass Alignment and Calibration.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is an established tool for the investigation of formalin fixed paraffin embedded (FFPE) tissue samples and shows a high potential for applications in clinical research and histopathological diagnosis. The applicability and accuracy of this method, however, heavily depends on the quality of the acquired data, and in particular mass misalignment in axial time-of-flight (TOF) MSI continues to be a serious issue. We present a mass alignment and recalibration method that is specifically designed to operate on MALDI peptide imaging data. The proposed method exploits statistical properties of the characteristic chemical noise background observed in peptide imaging experiments. By comparing these properties to a theoretical peptide mass model, the effective mass shift of each spectrum is estimated and corrected. The method was evaluated on a cohort of 31 FFPE tissue samples, pursuing a statistical validation approach to estimate both the reduction of relative misalignment, as well as the increase in absolute mass accuracy. Our results suggest that a relative mass precision of approximately 5 ppm and an absolute accuracy of approximately 20 ppm are achievable using our method.

Moiré‐Potential‐Induced Band Structure Engineering in Graphene and Silicene

A moiré pattern results from the projection of one periodic pattern to another with relative lattice constant or misalignment and provides great periodic potential to modify the electronic properties of pristine materials. In this Review, recent research on the effect of the moiré superlattice on the electronic structures of graphene and silicene, both of which possess a honeycomb lattice, is focused on. The moiré periodic potential is introduced by the interlayer interaction to realize abundant phenomena, including new generation of Dirac cones, emergence of Van Hove singularities (vHs) at the cross point of two sets of Dirac cones, Mott-like insulating behavior at half-filling state, unconventional superconductivity, and electronic Kagome lattice and flat band with nontrivial edge state. The role of interlayer coupling strength, which is determined by twist angle and buckling degree, in these exotic properties is discussed in terms of both the theoretical prediction and experimental measurement, and finally, the challenges and outlook for this field are discussed.

The Role of Misorientation in Direct Wafer Bonded III-V Materials

Direct wafer-bonding is a promising approach to materials integration for heterojunction structures not realizable through epitaxial means. Without lattice-parameter mismatch restrictions, wafer-bonding opens up a myriad of possibilities of materials combinations for many novel electronic device structures. In fact, wafer-bonding of III-V semiconductor materials was used to fabricate high-efficiency multijunction solar cells [1,2]. In this work, the effect of misorientation (both relative tilt and rotation) on the electronic properties across the bonded interface was studied by fabricating GaAs and InP homojunction and heterojunctions. To study the role of relative tilt, (001) n-type GaAs and (001) n-type InP wafers with offcut angles of 4° towards <111>A and nominal on-axis substrates were bonded to form relative tilts of 0°, 4°, and 8°. Current-voltage (I-V) curves were measured at various temperatures ranging from 90 K to 340 K to determine the interfacial barrier heights using the Seager and Pike electron model [3]. Then, to study the effect of rotation, (001) n-type InP wafers with twist angles ranging from 0° to 90° in 15° increments were bonded. Prior to bonding, the wafers were first cleaved into quarters and submerged in an NH4OH solution to remove the native surface oxide and then submerged in a 20% aqueous (NH4)2S solution for 5 minutes. After drying the wafers with N2, the wafers were brought face-to-face and very low pressure (kPa) was applied manually at room temperature and in ambient air pressure. The relative rotational misalignment was induced by rotating the top wafer prior to applying pressure. The wafers were then annealed at 400 °C for 2 hours to strengthen the bonded interface. Metal Ohmic contacts were deposited on each semiconductor surface and samples were diced into ~2 x 2 mm squares. We find that higher relative tilt across the interface leads to larger barrier heights. For example, in the GaAs/GaAs system the barrier height increased from 0.56 eV to 1.00 eV when increasing the tilt from 0° to 8°, respectively. Additionally, systems with at least one side InP (whether in an InP homojunction or InP/GaAs heterojunction) corresponded to lower barrier heights than the GaAs homojunction system. Regarding rotation, there is a discrepancy in literature on the effect of rotational misalignment. Kish et al. [4] claimed rotationally misaligning (001) III-V wafers by 20° and 90° result in the same decrease in electrical conductivity across the bonded interface compared to their 0° bonded wafers. However, Okuno et al. [5, 6] found that 0° and 90° bonded samples result in nearly equal electrical performance. Our findings show that the lowest interfacial resistance corresponded to misorientations of 0° and 90° while the greatest resistance corresponded to 45°, which was 30% higher than the lowest interfacial resistance. We conclude that the effect of rotational misalignment on the electrical conduction across bonded interfaces follows a sinusoidal pattern and its periodic effect on interfacial conductivity depends on the lattice symmetry of the wafer’s surface orientation, which has implications for bonding wafers with different surface symmetry. Electrical characterization of the interface enables us to understand the key factors that influence the properties of a bonded interface. We concluded that surface passivation, materials choice, and relative misorientation of the bonded materials are the determining factors that control the electrical performance of the bonded structure.

Effect of electron cyclotron beam width to neoclassical tearing mode stabilization by minimum seeking control in ITER

We report the effect of the electron cyclotron (EC) beam width on the full suppression time of neoclassical tearing mode (NTM) using the finite difference method (FDM) based minimum seeking controller in ITER. An integrated numerical system is setup for time-dependent simulations of the NTM evolution in ITER by solving the modified Rutherford equation together with the plasma equilibrium, transport, and EC heating and current drive. The calculated magnetic island width and growth rate is converted to the Mirnov diagnostic signal as an input to the controller to mimic the real experiment. In addition, 10% of the noise is enforced to this diagnostic signal to evaluate the robustness of the controller. To test the dependency of the NTM stabilization time on the EC beam width, the EC beam width scan is performed for a perfectly aligned case first, then for cases with the feedback control using the minimum seeking controller. When the EC beam is perfectly aligned, the narrower the EC beam width, the smaller the NTM stabilization time is observed. As the beam width increases, the required EC power increases exponentially. On the other hand, when the minimum seeking controller is applied, NTM stabilization sometimes fails as the EC beam width decreases. This is consistently observed in the simulation with various representations of the noise as well as without the noise in the Mirnov signal. The higher relative misalignment, misalignment divided by the beam width, is found to be the reason for the failure with the narrower beam widths. The EC stabilization effect can be lower for the narrower beam widths than the broader ones even at the same misalignment due to the smaller ECCD at the island O-point. On the other hand, if the EC beam is too wide, the NTM stabilization time takes too long. Accordingly, the optimal EC beam width range is revealed to exist in the feedback stabilization of NTM.

A wirelessly powered RFID-based smart contact lens system

This paper presents a wireless smart contact lens system, comprising a capacitive sensor interface circuitry and a wirelessly powered radio frequency identification (RFID)-compatible system, for sensor control and data communication. To improve compliance and reduce user discomfort, the capacitive sensor was embedded on a 200-μm-thick soft contact lens using commercially available biocompatible lens material and a standard sandwich manufacturing process. The proposed lens can communicate with RFID equipment at an ultra-high frequency (UHF) RFID frequency of 920 MHz. A successful communication distance of 2 cm was achieved under 18 dBm incident radio frequency (RF) power, and a maximum distance of 4 cm was achieved under 28 dBm incident power. The uniform magnetic field distribution of the transmitting antenna enhances energy transmission and provides robust operation against shifts in relative location and misalignment of the contact lens and the glass caused by eye movement and blinking.

Representing Misalignments of the STAR Geometry Model using AgML

The STAR Heavy Flavor Tracker (HFT) was designed to provide high-precision tracking for the identification of charmed hadron decays in heavy-ion collisions at RHIC. It consists of three independently mounted subsystems, providing four precision measurements along the track trajectory, with the goal of pointing decay daughters back to vertices displaced by less than 100 microns from the primary event vertex. The ultimate efficiency and resolution of the physics analysis will be driven by the quality of the simulation and reconstruction of events in heavy-ion collisions. In particular, it is important that the geometry model properly accounts for the relative misalignments of the HFT subsystems, along with the alignment of the HFT relative to STARs primary tracking detector, the Time Projection Chamber (TPC).The Geometry Modeling Language (AgML) provides a single description of the STAR geometry, generating both our simulation (GEANT 3) and reconstruction geometries (ROOT). AgML implements an ideal detector model, while misalignments are stored separately in database tables. These have historically been applied at the hit level. Simulated detector hits are projected from their ideal position along the track’s trajectory, until they intersect the misaligned detector volume, where the struck detector element is calculated for hit digitization. This scheme has worked well as hit errors have been negligible compared with the size of sensitive volumes. The precision and complexity of the HFT detector require us to apply misalignments to the detector volumes themselves. In this paper we summarize the extension of the AgML language and support libraries to enable the static misalignment of our reconstruction and simulation geometries, discussing the design goals, limitations and path to full misalignment support in ROOT/VMC-based simulation.

Ultrafast electron dynamics in twisted graphene by femtosecond photoemission electron microscopy

Twisted multilayer graphene (tMLG) present electronic properties that depend on the relative misalignment and interaction between layers. These interactions affect the band structures and the carrier dynamics upon photonic excitation. These structures are being under scrutiny and recent work high-lighted the strong potential they offer for optoelectronic devices. However, the ultrafast carrier dynamics is still at an early stage, often due to the instrumental limitations. Here, we investigated the carrier dynamics by femtosecond photoemission electron microscopy of chemical vapor deposited (CVD) twisted graphene super lattices presenting different interlayer rotation angles. The photo-generated carrier lifetimes in these selected regions show a longer lifetime compared to monolayer graphene (1 ML). This observation is assigned to the presence of band gap and sub bands in the trilayer graphene and has been supported by DFT calculations.

The PPP approach revisited: A study of RMB valuation against the USD

We analyze the alleged undervaluation of the Chinese renminbi against the US dollar through an application of the relative PPP hypothesis, the PPP approach. The PPP approach measures the relative misalignment of a currency by estimating the relationship between log price levels and log per capita real incomes from a cross section of countries. We estimate this relationship by using ICP 2011 and incorporating model selection tests. Our results confirm that price level-real income relationship is best approximated by a quadratic functional form. We show that, using this functional form, the PPP approach does not reveal any evidence of renminbi undervaluation as of 2011, and this result is robust to various sensitivity tests.

Multicamera rig calibration by double‐sided thick checkerboard

A multi‐camera rig calibration algorithm based on a double sided planar target is proposed. Due to their inherently simple realisation, low cost and accuracy, planar calibration targets came out as one of the most largely adopted calibration tools both for intrinsic and extrinsic camera parameters. However, concerning the estimation of extrinsic parameters, one of the major drawbacks of these targets is their requirement for distinct target visibility from both cameras. This prevents many configurations from being adopted where, e.g. two cameras are facing each other. An inexpensive solution could be based on printing/pasting a planar pattern on both target sides, however, the relative misalignment between the patterns on the two sides and the target thickness could be unknown. The authors propose a solution where double‐sided target displacement error is estimated together with the extrinsic parameters allowing the reuse of all the available planar calibration tools in less constrained configurations. To assess their approach the authors tested the system in two scenarios, one using two professional 4K cameras and one using two smartphones.