Yz Planes Research Articles

Intrinsic bitunable magnetism/polarity behavior in 2D Janus Cr2I3Y3 (Y = F, Cl, or Br) systems

Two-dimensional (2D) magnetoelectric (ME) materials with spontaneous magnetism and polarity have drawn a lot of research interest due to their potentially valuable physics and spintronic applications. One of the obstacles in the current study of 2D ME materials is to achieve flexible magnetism/polarity switches because of a fundamental contradiction between magnetism and polarity. In this work, we propose an intrinsic magnetism/polarity switchable 2D Janus structure Cr2I3Y3 (Y = F, Cl, or Br) with mechanical and thermodynamic stability. Janus Cr2I3Y3 monolayers show indirect-gap semiconductors with ferromagnetic ordering. Intrinsic vertical electric polarity (EP) in Janus Cr2I3Y3 structures is investigated by surface potential difference analysis and dipole calculations. We discover that there is an obvious ME coupling between magnetic anisotropy energy (MAE) and EP. MAE can be obviously tuned by rotating the orientations of spins within yz and zx vertical planes, and the easily distinguishable MAE on vertical planes has strong inherent relevance with vertical EP. Simultaneously, magnetic phase transition and magnetic moments can be manipulated by introducing vertical strain, which directly corresponds to the linear response of the EP strength. Our work provides a promising candidate for realizing the spintronic devices with multiple functionalities.

Multi‐view convolutional neural network‐based target classification in high‐resolution automotive radar sensor

In this study, a target classification method based on point cloud data in a high-resolution radar sensor is proposed. By using multiple antenna elements arranged in horizontal and vertical directions, pedestrians, cyclists and vehicles can be expressed as point cloud data in the three-dimensional (3D) space. To perform target classification using the spatial characteristics (i.e. length, height and width) of the target, the 3D point cloud data is orthogonally projected onto the xy, yz and zx planes, respectively, and three types of images are generated. Then, a multi-view convolutional neural network (CNN)-based target classifier using those three images as inputs is designed. To this end, a method for synthesising the detection results of three directions in series or in parallel is proposed. The proposed classifier can learn the spatial characteristics of the target by using the detection results of multiple viewpoints. Compared to the CNN-based classifier that uses only the detection result of a single plane as input, the proposed method shows 4.5%p higher classification accuracy in terms of the target with the lowest classification accuracy. In addition, the proposed multi-view CNN structure shows improved classification performance and shorter training time compared to the well-known deep learning methods for image classification.

Optical SCMA coding technique based on fully interleaved 3D codebook

In the paper, an optical Sparse code division multiple access (SCMA) coding technique based on fully interleaved 3D codebook is proposed. We design a completely interleaved 3D codebook, the projection of all constellation points in the joint constellation on the XY, XZ and YZ planes are all interleaved, which is beneficial for making the complexity of message passing algorithm (MPA) lower. We used 3D amplitude and phase modulation (3D-CAP) to modulate 3D-SCMA signal, and then transmitted the signal with 7-core fiber. The feasibility of 3D-SCMA is proved by experiments. Our proposed 3D-SCMA has the same resource block efficiency as traditional two-dimensional SCMA: 150%. Due to the larger Euclidean distance of the 3D joint constellation, 3D-SCMA has lower decoding complexity and better reception sensitivity. Compared with 2D-SCMA, the complexity of 3D-SCMA is 66.66% lower and the receiving sensitivity is 3.5 dBm higher, which indicates that it not only reduces the complexity of the MPA algorithm, but also reduces the energy consumption of the system and saves the transmission cost. In this paper, optical 3D-SCMA is proposed creatively, which is an effective improvement on the traditional optical 2D-SCMA. This research can be applied in the future access network.

Constant-Beamwidth Kronecker Product Beamforming With Nonuniform Planar Arrays

In this paper, we address the problem of constant-beamwidth beamforming using nonuniform planar arrays. We propose two techniques for designing planar beamformers that can maintain different beamwidths in the XZ and YZ planes based on constant-beamwidth linear arrays. In the first technique, we utilize Kronecker product beamforming to find the weights, thus eliminating matrix inversion. The second technique provides a closed-form solution that allows for a tradeoff between white noise gain and directivity factor. The second technique is applicable even when only a subset of the sensors is used. Since our techniques are based on linear arrays, we also consider symmetric linear arrays. We present a method that determines where sensors should be placed to maximize the directivity and increase the frequency range over which the beamwidth remains constant, with a minimal number of sensors. Simulations demonstrate the advantages of the proposed design methods compared to the state-of-the-art. Specifically, our method yields a 1000-fold faster runtime than the competing method, while improving the wideband directivity factor by over 8 dB without compromising the wideband white noise gain in the simulated scenario.

Circularly polarized rectangular dielectric resonator antenna with metallic strips load for WLAN application

AbstractThis article presents a circularly polarized rectangular dielectric resonator antenna (CP RDRA) loaded with metallic strips. The dielectric resonator (DR) with metallic strips on the top surface is excited by a slot aperture feed that excites two orthogonal modes to provide circular polarization. The proposed CP RDRA does not require any complex‐shaped dielectric resonator and simplifies the overall design. A prototype of the proposed antenna has been fabricated and validated. It has measured impedance bandwidth between 4.8 and 5.6 GHz and 3 dB axial ratio bandwidth between 5.1 and 5.43 GHz. The axial ratio beamwidth of more than 155° in the XZ and YZ planes is obtained.

Design and Characterization of 10-Elements MIMO Antenna With Improved Isolation and Radiation Characteristics for mm-Wave 5G Applications

A ten-elements MIMO antenna with improved isolation and reduction of X-polar radiation (XPR) in millimeter (mm) wave region is presented. The individual antenna element consists of stub loaded coplanar waveguide (CPW) structure with elliptical shaped radiator. Defected ground structure (DGS) has been incorporated by engraving partial elliptical shaped slots at the coplanar ground to reduce the mutual coupling effect between the adjacent antenna pairs of the MIMO. The backside of the substrate has a metallic plane with defects which is not connected to the coplanar ground of the antenna. This defected metal structure (DMS) acts as a reflector to improve the radiation characteristics by lowering of XPR as well as improving the co-pol to X-pol isolation. The proposed MIMO structure has a fractional bandwidth of 23.52% (22.5GHz-28.5 GHz) which entails the mm-wave 5G frequency spectrum n258 (24.25-27.5 GHz). The isolation| characteristics of the proposed MIMO antenna are below -35 dB over the operating bandwidth for any pair of adjacent antenna elements which imply significantly improved isolation between the adjacent antenna elements with highly compact layout area of 3.4λ × 8.5λ, where λ is wavelength corresponding to the mid-point of the bandwidth. The inter-element spacing of the MIMO structure is 0.44 λ. The main attractive feature offered by this structure is reduction of XPR in the operating frequency range thus improving the co-pol to X-pol isolation up to 20 dB and 28 dB in the boresight direction in both the XZ and YZ planes respectively. Furthermore, the co-pol to X-pol isolation is maintained above 15 dB almost throughout the elevation angular region -180° to 180° thereby negating the hindrance imposed by surface waves in mm-wave region. The diversity performances in terms of Envelope Correlation Coefficient (ECC), Diversity Gain (DG) and Channel Capacity Loss (CCL) are obtained as 0.1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> , 10 dB and 0.005 bps/Hz respectively which are within the acceptable limits. Mean effective gain (MEG) values with respect to the excited port 2 and port 3 is identical and approximately -3dB thus indicating the mean value of these two ports to be almost 1 dB. The multiplexing efficiency of the proposed MIMO antenna is satisfactory over the bandwidth. The group delay is investigated and found to be almost constant with a variation of 1.2 ns thus indicating linear phase characteristic of the antenna. The proposed structure is compared with other mm-wave MIMO antennas and found to be advantageous with respect to the number of antenna elements, compactness, low mutual coupling, co-pol to X-pol isolation, and ECC. A prototype of the proposed 10-elements MIMO is fabricated, and the measured results resemble with the simulated results.

Improved accuracy of an FDM 3D printer using a face-diagonal length test using an artifact and a Vernier caliper

PurposeThe purpose of this study is to improve the accuracy of a fused deposition modeling three-dimensional (3D) printer by identifying and compensating for position-independent geometric errors using a face-diagonal length test featuring a designed artifact and a Vernier caliper.Design/methodology/approachAn artifact that does not require support when printing was designed and printed to allow performance of the face-diagonal length test. A Vernier caliper was used to measure the lengths of diagonals in the XY, YZ and ZX planes of the printed artifact specimen; this completed the face-diagonal length test. The relationships between position-independent geometric errors of the linear axes X, Y and Z and the measured diagonal lengths of the three planes were determined to identify geometric errors.FindingsThe approach was applied to a commercial fused deposition modeling 3D printer, and three position-independent geometric errors were rapidly identified. The artifact was re-printed after model-based compensation for these errors and the diagonal lengths were re-measured. The results were verified via coordinate measuring machine measurement of a simple test piece without and with model-based compensation for identified geometric errors. Furthermore, the proposed approach was applied to a commercial 3D printer.Research limitations/implicationsThe measured diagonal lengths of the printed artifacts varied greatly. Thus, further studies should investigate the effects of printing materials and parameters on the length discrepancies of 3D printed artifacts.Practical implicationsA software-based compensation of identified position-independent geometric errors has to be used at commercial 3D printers for accuracy improvements of printed parts.Originality/valueThus, the approach is of practical utility; it can be periodically used to identify position-independent geometric errors and ensure that the 3D printer is consistently accurate.

Axial accuracy and signal enhancement in acoustic-resolution photoacoustic microscopy by laser jitter effect correction and pulse energy compensation.

In recent years, photoacoustic imaging has found vast applications in biomedical imaging. Photoacoustic imaging has high optical contrast and high ultrasound resolution allowing deep tissue non-invasive imaging beyond the optical diffusion limit. Q-switched lasers are extensively used in photoacoustic imaging due to the availability of high energy and short laser pulses, which are essential for high-resolution photoacoustic imaging. In most cases, this type of light source suffers from pulse peak-power energy variations and timing jitter noise, resulting in uncertainty in the output power and arrival time of the laser pulses. These problems cause intensity degradation and temporal displacement of generated photoacoustic signals which in turn deteriorate the quality of the acquired photoacoustic images. In this study, we used a high-speed data acquisition system in combination with a fast photodetector and a software-based approach to capture laser pulses precisely in order to reduce the effect of timing jitter and normalization of the photoacoustic signals based on pulse peak-powers simultaneously. In the experiments, maximum axial accuracy enhancement of 14 µm was achieved in maximum-amplitude projected images on XZ and YZ planes with ±13.5 ns laser timing jitter. Furthermore, photoacoustic signal enhancement of 77% was obtained for 75% laser pulses peak-power stability.

QUANTIFICAÇÃO DA DEFORMAÇÃO EM MIGMATITOS METATEXITOS ESTROMÁTICOS E ROCHAS ASSOCIADAS DO COMPLEXO ATUBA, PORÇÃO LESTE DO ESTADO DO PARANÁ

RESUMO – O Complexo Atuba aflora na porção leste do Estado do Paraná, segundo uma faixa alongada de direção NE-SW e compreende a parte sul do Cinturão Ribeira. Este trabalho tem como objetivo principal elucidar os processos deformacionais do Complexo Atuba. A investigação foi desenvolvida por meio de investigação de campo, petrografia e análise estrutural quantitativa e, complementa vários estudos tectônicos já realizados anteriormente. Os migmatitos metatexitos estromáticos possuem médio a alto grau metamórfico e são compostos por neossomas residuais tonalíticos intercalados com leucossomas graníticos ou granodioríticos-tonalíticos e melanossomas máficos. Muitas vezes podem ser classificados como pertencentes à série dos milonitos. Observam-se também anfibolitos, xistos, gnaisses granulíticos, diatexitos schollen, quartzitos e granitoides. Dois planos de foliação, ambos gerados por cisalhamento dúctil, foram identificados: o primeiro é caracterizado pela foliação Sn-1 associada à tectônica de cavalgamento (Dn-1) e o segundo pela foliação Sn produzido por tectônica transpressiva sinistral (Dn). Os resultados confirmam que a última fase foi acomodada pela partição da deformação. A quantificação da deformação foi desenvolvida por intermédio dos métodos de Fry, Polar e Rf/φ, com base na análise de cristais de quartzo e feldspatos em 26 lâminas delgadas. As amostras revelaram razões de deformação similares para todos os métodos utilizados nos planos XZ e YZ. Os elipsoides possuem forma oblata e correspondem ao campo do achatamento aparente.&#x0D; Palavras-chave: análise estrutural, migmatitos, transpressão.

ЧИСЕЛЬНЕ ВИЗНАЧЕННЯ ЕФЕКТИВНИХ ПРУЖНИХ ХАРАКТЕРИСТИК ТРИВИМІРНОАРМОВАНОГО ВОЛОКНИСТОГО КОМПОЗИЦІЙНОГО МАТЕРІАЛУ

The processes occurring in composite materials are determined by differential equations in partial derivatives with variable coefficients. Most composite materials have a periodic structure, so the coefficients in the equations are rapidly oscillatory periodic functions. The most effective method for studying the stress and deformation field in structures made of composite materials is the method of finite elements, where a nonhomogeneous composite material is replaced by an equivalent homogeneous anisotropic material. To determine averaged characteristics of a composite material with a periodic structure requires a verified methodology allowing to do this. Therefore, the fundamental goal of the mechanics of composite materials is to calculate the effective elastic characteristics of the material. The paper considers the urgent issue of determining effective elastic characteristics of three-dimensional reinforced composite materials based on known elastic properties of fibers and matrix and distribution of reinforcing fibers by volume of composite material.The paper presents the mathematical modeling of the minimum three-dimensional representative volume element based on the specified reinforcement scheme and geometrical dimensions of components. Numerical experiments are performed with the ANSYS software package. A series of numerical experiments simulate six deformation cases: uniaxial tension in the X, Y, Z directions, and shear in the XY, YZ, and XZ planes. Numerical studies of the stress and strain state of the representative volume element of composite material determine the effective elastic constants of equivalent homogeneous material. Two series of calculations are performed with specifying appropriate symmetry and periodicity conditions.The results of the experimental study allow for the verification of the proposed methodology for determining the effective elastic characteristics of three-dimensional reinforced fiber composite materials. The developed numerical methodology enables us to solve the issues of the mechanics of composite materials with the help of modern software packages in the mathematical framework of which the finite element method is used.

Petrographic, structural and textural analysis of the Atuba Complex, Southern Ribeira Belt: Case study in the Greca quarry

The Greca quarry is located in the Colombo municipality, close to the Curitiba Shear Zone, south of the Lancinha Shear Zone in the State of Paraná. It is inserted in the Atuba Complex (Curitiba Terrane) and comprises the meridional portion of the Ribeira Belt. This work was carried out by means of field work, petrography, electron backscattered diffraction analysis and strain analysis using the Fry, Polar and Rf/φ methods. Thus, it aims to analyze meso and micro scale strain in tectonites in a key area of the Atuba Complex. The heterogeneous ductile strain observed at a microscopic and macroscopic scale resulted in stromatic, protomylonitic and mylonitic metatexites, of submillimetric to metric widths. The occurrence of quartz and leucocratic veins of centimetric to metric thickness is rare, either discordant or concordant to the foliation of migmatites. Two deformation phases were found, both derived from ductile shear: the first is associated with the thrusting tectonics (Dn-1); and the second has a sinistral transcurrent-transpressive nature (Dn). The presence of new quartz grains observed by subgrain rotation (SGR) recrystallisation and new grains by bulging (BLG) recrystallisation in the feldspar crystals indicates temperatures above 450 °C (lower amphibolite facies) during the shear of both phases. The strain analysis was generated based on the investigation of quartz crystals of 2 samples and 4 thin sections (XZ and YZ planes). The analyzes indicated approximate strain ratios (R) for all methods used in the XZ and YZ planes. Quartz presented values between 2.250 and 1.304 (XZ section) and 2.237 to 1.110 (YZ section). The ellipsoids are mainly oblate and are equivalent to the apparent flattening group. The tectonites are predominantly of S or SL type. According to the EBSD data, it was possible to identify that the strain occurred by dislocation creep mechanisms, associated with the dynamic recrystallisation processes. The samples analyzed by EBSD indicated that the feldspar crystals have poles (010) in the <001> direction and the quartz crystals show the activation of the basal sliding system with the aid of the rhombohedral system. The results also indicate low temperatures, probably due to the retrometamorphic event that occurred in the last strain stage of the Atuba Complex.

Effect of Loop Tilting on the Heat Transfer and Pressure Drop in Two-Phase CO2 Based Natural Circulation Loop: An Experimental Study

Abstract The natural circulation loop (NCL) is widely used where the safe and economic heat transfer device is desired. However, the instability associated with the regular change in fluid flow behavior due to the imbalance between friction and buoyant forces is a major disadvantage. One of the erudite solutions to overcome this is to tilt the entire loop by a certain angle, with an inherent penalty in heat transfer and pressure drop. In the present study, experimental studies have been carried out on two-phase carbon dioxide (CO2) based NCL, which has gained popularity because of its compactness and higher heat transfer rate. Pressure drop and heat transfer performance of the loop for various tilt angles (0 deg, 30 deg, and 45 deg) in different planes (XY and YZ planes) have been investigated. Methanol is used as the external fluid in cold and hot heat exchangers in order to maintain low operating temperature in the loop. Results show that the tilting of the loop causes a marginal drop in the heat transfer rate of two-phase CO2 based NCL. Hence, tilting of the loop could be a solution to instability problem without conceding the performance of the loop.

A Broadband, Wide-Angle Scanning, Linear-to-Circular Polarization Converter Based on Standard Jerusalem Cross Frequency Selective Surfaces

A broadband and wide-angle scanning linear polarization (LP)-to-circular polarization (CP) converter based on a dual-layer structure is presented. The elementary cell is composed of conventional Jerusalem crosses (JCs). The design procedure is based on transmission line circuit model and on full-wave simulations. The proposed equivalent circuit has been generalized to include the oblique incidence in the model. Simulated results demonstrate a 24% axial ratio bandwidth for an incidence angle θ = ±50° in both xz and yz planes. The proposed converter provides a unique combination of wide bandwidth, thin profile, and stable response with respect to the angle of incidence. It can be integrated into any LP antenna system to generate CP without significantly affecting the antenna performances.

Switchable Bidirectional/Unidirectional LWA Array Based on Half-Mode Substrate Integrated Waveguide

A novel leaky-wave antenna array with switchable radiation patterns is designed and manufactured at X-band based on a half-mode substrate integrated waveguide. It generates endfire and broadside radiation patterns in two orthogonal planes. The endfire radiation is bidirectional in the xz plane, and the broadside radiation is unidirectional in the yz plane. These two radiations can be controlled by triggering in-phase or out-of-phase port excitations. The excitations also enable the scanning beams to switch between xz and yz planes. A feeding network is designed with a 3 dB coupler and a phase tuner to generate the in-phase and out-of-phase excitations. In the feeding network, the phase difference is realized without using any phase shifter. The feeding network has two input ports, one for the in-phase excitation and one for the out-of-phase excitation. A prototype antenna was manufactured and tested to validate the concept.

Assessment of the Stress-Strain State of a Tube Sheet of the Heat Exchanger at Rotary Friction Welding Application

The aim of the study described in this paper is to assess the effect of forces acting on the tube sheet during friction welding on the stress-strain state of the tube sheet.For this, we calculated the stresses and displacements arising in the tube sheet during friction welding. The calculations were carried out in the ANSYS (finite element analysis software package). To carry out the calculations, solid-state models of tube sheets with diameters of 400, 600, 800, 1000, 1200, 1400 mm and thicknesses of 30, 40, 50, 60, 70 mm were created. The diameter of the holes for the heat exchange tubes was chosen equal to 25 mm, the holes are placed on the vertices of an equilateral triangle with a step equal to 32 mm. Then, based on geometric models, grids of 8-node finite elements were created. The calculation model takes into account the symmetry of the geometric model and the character of loading relative to the YZ and XZ planes. The material used was steel with a Poisson's ratio of 0.3 and an elastic modulus of 2,11·105 MPa.As a result of the calculations, it was found that as a result of the action of force factors during friction welding, significant stresses and deformations arise in the tube sheet. The greatest values of deflection and stresses occur in the central sector of the tube sheet in the area of application of force. In this case, the zone of maximum stresses is significantly localized: they are concentrated around the central hole, and movements smoothly increase from the periphery to the center of the tube sheet.The value of this study is that it allowed to determine the need to use special equipment that increases the local stiffness of the tube sheet sector subjected to friction welding.

Fracture orientation and fluid flow direction recognition in carbonates using diffusion-weighted nuclear magnetic resonance imaging: An example from Permian

The vertical permeability of carbonate reservoir rocks bearing complex, diagenetically altered pore systems may neglect fluid flow possibilities in remaining directions. Therefore, the main aim of this article was to present an alternative method for the potential examination of 3D fluid flow possibilities using diffusion-weighted NMR imaging (DWI). A cylindrical plug sample was withdrawn from the Permian Zechstein Limestone's drill core (West Poland). The plug was selected upon microscopic research, according to which it contained numerous, bendy dissolution channels formed after former foraminifer encrustations surrounding the bryozoans (ideal for DWI tests). Firstly, the diffusion coefficients (D) were calculated by comparing the signal components with (S) and without (S0) the diffusion weighting. The former was obtained under the presence of three, separately activated gradients, acting perpendicularly to each other (x, y, z). The diffusion coefficients were examined within xy, xz and yz planes (in 3 mm-thick slices) and utilized to construct 3D models, presenting their values in space. “Diffusion vectors” were constructed based on the average D values and helped to resolve channels' orientation. The spatially presented values of diffusion coefficients themselves allowed for drawing preliminary conclusions regarding the fluid flow possibilities. For comparison, this kind of information was supported by Kozeny-Carman's formula-based and nitrogen (N2) permeability derivation. In case of the former, the surface to volume ratio (S/V) was derived via PGSTE experiments, through the linear fitting to the normalized, time-dependent diffusion coefficients, in the short diffusion time regime. The effective NMR porosity (12.1%) was measured using a low-field, 0.05 T spectrometer with the echo time of 100 μs. The T2 cut-off value was assigned by comparing the 70 °C-dried and saturated sample's response. The potential fluid flow through the sample was found to be chiefly controlled by the z-oriented (nearly vertical) structures, with a significant support of the x-oriented pores, generally confirmed by the vertical permeability of the sample, ranging between 100 (N2) and 169 mD (DWI). It was also concluded that DWI allows for spatial, quantitative analysis of flow possibilities through fractured or highly dissolved carbonate samples. Despite their relative expensiveness, the 3D models of diffusion coefficients could be considered as an alternative or addition to the standard permeability tests in the case of complex pore systems. It also seems that combining DWI and X-ray microtomography in future work could help to bridge the gap between resolution limitations and dynamically resolved fluid mobility, which can be translated into pore system connectivity. Finally, the construction of diffusion vectors appeared to facilitate magnetic field gradient's direction calibration, which should depend on the trend of pore space elongation, thus giving more reliable, diffusion-based permeability values.

Perturbations of a dielectric tensor induced by domain walls of periodic domain structures in ferroelectric crystals: contribution to the Bragg diffraction of light waves

We consider the perturbations of a dielectric tensor induced by 180 degree domain walls parallel to the YZ and XZ crystal planes (Y-walls and X-walls), which are intrinsic to periodic domain structures produced in ferroelectric crystals belonging to the symmetry class 3m. The conditions for realization of different types of Bragg-diffraction processes, including the collinear process, as applied to lithium niobate and lithium tantalate crystals, are discussed. It is shown that light diffraction on the domain walls is responsible for significant contribution to the diffraction efficiency of electrically controllable Bragg deflectors using a periodically poled lithium niobate.

Robotic CT-guided out-of-plane needle insertion: comparison of angle accuracy with manual insertion in phantom and measurement of distance accuracy in animals

ObjectivesTo evaluate the accuracy of robotic CT-guided out-of-plane needle insertion in phantom and animal experiments.MethodsA robotic system (Zerobot), developed at our institution, was used for needle insertion. In the phantom experiment, 12 robotic needle insertions into a phantom at various angles in the XY and YZ planes were performed, and the same insertions were manually performed freehand, as well as guided by a smartphone application (SmartPuncture). Angle errors were compared between the robotic and smartphone-guided manual insertions using Student’s t test. In the animal experiment, 6 robotic out-of-plane needle insertions toward targets of 1.0 mm in diameter placed in the kidneys and hip muscles of swine were performed, each with and without adjustment of needle orientation based on reconstructed CT images during insertion. Distance accuracy was calculated as the distance between the needle tip and the target center.ResultsIn the phantom experiment, the mean angle errors of the robotic, freehand manual, and smartphone-guided manual insertions were 0.4°, 7.0°, and 3.7° in the XY plane and 0.6°, 6.3°, and 0.6° in the YZ plane, respectively. Robotic insertions in the XY plane were significantly (p < 0.001) more accurate than smartphone-guided insertions. In the animal experiment, the overall mean distance accuracy of robotic insertions with and without adjustment of needle orientation was 2.5 mm and 5.0 mm, respectively.ConclusionRobotic CT-guided out-of-plane needle insertions were more accurate than smartphone-guided manual insertions in the phantom and were also accurate in the in vivo procedure, particularly with adjustment during insertion.Key Points• Out-of-plane needle insertions performed using our robot were more accurate than smartphone-guided manual insertions in the phantom experiment and were also accurate in the in vivo procedure.• In the phantom experiment, the mean angle errors of the robotic and smartphone-guided manual out-of-plane needle insertions were 0.4° and 3.7° in the XY plane (p < 0.001) and 0.6° and 0.6° in the YZ plane (p = 0.65), respectively.• In the animal experiment, the overall mean distance accuracies of the robotic out-of-plane needle insertions with and without adjustments of needle orientation during insertion were 2.5 mm and 5.0 mm, respectively.

Superconducting 3D-sample with general boundary conditions in a tilted magnetic field

We consider a mesoscopic superconducting three-dimensional cube immersed in a tilted magnetic field H oriented along an angle θ with respect to the z-axis, in the xz plane. The sample is in contact with a metallic material or with another superconductor in the xz and yz planes, while the z=0 plane remains in contact with a dielectric material. These boundary conditions are simulated by the de Gennes extrapolation length b. We analyzed the magnetic induction, the superconducting electron density, and the magnetization curves as functions of H for different values of b on the lateral surfaces of the sample. We show that the magnetization and the vortex configuration depend on θ and b. An analytical linear and exponential dependence of the maximum of the magnetization on θ and b, respectively, was found.

Prediction of tensile strength of 3D printed part using response surface methodology

In the recent past, rapid prototyping, especially powder-based inkjet 3D printing technology, has been most popular for complex and customised production. 3D printing also referred to as additive manufacturing involves a successive layering process through part fabrication. In this study, the effects of 3D printing parameters such as part orientation and layer thickness on tensile strength of fabricated part have been ascertained experimentally. Part orientation in XY, XZ and YZ planes has been considered for experimentation. Moreover, computer-aided design model has been used to fabricate a 3D prototype. Furthermore, a set of 27 experimental runs have been performed using Box–Behnken design of experiment. These experimental observations have been used to develop mathematical models for the tensile strength of fabricated part considering response surface methodology. Analysis of variance has been performed in order to check the statistical significance of control parameters. It has been deduced that on increasing the layer thickness, tensile strength of the fabricated part reduces.