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A novel physical effect has been found to be illuminated of being physically self-consistent to take into account in further calculating the dynamics of magnetically-induced asteroid rotation, surface of which has mostly a conducting structure (whereas such mostly metallic-formed asteroid is assumed to be moving in an external magnetic field of planet but in the meantime to be orbiting preferably outside its sphere of effective attraction). The last condition of asteroid surface's having conducting structure means the existence of the applied external torques stemming from the physical interactions between external magnetic field and iron asteroid itself (including long-term effect due to torques stemming from arising eddy-currents on metallic surface of asteroid). Such eddy-currents should heat the conducting surface of asteroid with further non-uniformly re-directing the heat flow from surface of asteroid into outer space via fluxes of thermal photons which carry momentum (in orthogonal direction to the surface which is in most cases far from the ideal surface of sphere). This leads by taking into account the overall outcome of heat flow (from the non-ideal surface of asteroid) to a kind of long-term magnetic second-grade YORP effect. System of Euler equations for aforementioned dynamics of asteroid magnetic rotation has been investigated in regard to existence of semi-analytical solution. Various perturbations (such as collisions, YORP effect) may destabilize the rotation of asteroid deviating it from the current spin state, whereas the electric(eddy)current-induced dissipation of energy reduces kinetic one of asteroid spin. So, dynamics of the asteroid rotation should result in a spinning about maximal-inertia axis with the proper spin state corresponding to minimal energy with a fixed angular momentum. • New physical effect is found for magnetically-induced metallic asteroid rotation. • Metallic-formed asteroid is assumed to be moving in an external magnetic field. • Conducting structure means torques stemming from an eddy-currents on its surface. • Overall outcome of non-iniform heat flow forms magnetic second-grade YORP effect. • Evolution of spin towards rotation about maximal-inertia axis is approximated. [ABSTRACT FROM AUTHOR]

In practical conditions, near-field acoustic holography (NAH) requires the measurement environment to be a free sound field. If vibrating objects are located above the reflective ground, the sound field becomes non-free in the presence of a reflecting surface, and conventional NAH may not identify the sound source. In this work, two types of half-space NAH techniques based on the Helmholtz equation least-squares (HELS) method are developed to reconstruct the sound field above a reflecting plane. The techniques are devised by introducing the concept of equivalent source in HELS-method-based NAH. Two equivalent sources are tested. In one technique, spherical waves are used as the equivalent source, and the sound reflected from the reflecting surface is regarded as a linear superposition of orthogonal spherical wave functions of different orders located below the reflecting surface. In the other technique, some monopoles are considered equivalent sources, and the reflected sound is considered a series of sounds generated by simple sources distributed under the reflecting surface. The sound field is reconstructed by matching the pressure measured on the holographic surface with the orthogonal spherical wave source in the vibrating object and replacing the reflected sound with an equivalent source. Therefore, neither technique is related to the surface impedance of the reflected plane. Compared with the HELS method, both methods show higher reconstruction accuracy for a half-space sound field and are expected to broaden the application range of HELS-method-based NAH techniques. [ABSTRACT FROM AUTHOR]

Applications of thermoset epoxy resins in load-bearing fibre-reinforced polymer (FRP) composites are decisive, mainly due to their excellent material properties, low viscosity before hardening and good adhesion with the reinforcing fibres. Although numerous experiences on the machinability of FRPs have been published, these experiences can be only indirectly adapted to pure epoxy resins. Reflecting on the lack of knowledge on the machinability of epoxy resins, the main aim of the present study is to compare the machinability of aged and freshly manufactured epoxy resins. Half of the epoxy specimens were naturally aged in a continental climate environment for a year, while the other half was manufactured prior to the orthogonal machining experiments. The experiments were conducted in a dry condition in a Kondia B640 machining centre. The cutting speed and the uncut chip thickness were varied systematically. The cutting force was measured by a KISTLER 9257B dynamometer, and the machined surfaces were characterised by a Mitutoyo SJ400 surface tester and a Keyence VR-5000 3D profilometer. The experimental results prove that the aged epoxy degraded significantly; thus, the specific cutting force is significantly smaller than that of freshly manufactured epoxy. However, the surface quality was not significantly influenced by the polymer degradation. [ABSTRACT FROM AUTHOR]

Frenet and Darboux trihedrons are the objects of research. At the current point of the direction curve of the Frenet trihedron, three mutually perpendicular unit orthogonal vectors can be uniquely constructed. The orthogonal vector of the tangent is directed along the tangent to the curve at the current point. The orthogonal vector of the main normal is located in the plane, which is formed by three points of the curve on different sides from the current one when they are maximally close to the current point. It is directed to the center of the curvature of the curve. The orthogonal vector of the binormal is perpendicular to the two previous orthogonal vectors and has a direction according to the rule of the right coordinate system. Thus, the movement of the Frenet trihedron along the base curve, as a solid body, is determined. The Darboux trihedron is also a right-hand coordinate system that moves along the base curve lying on the surface. Its orthogonal vector of the tangent is directed identically to the Frenet trihedron, and other orthogonal vectors in pairs form a certain angle ε with the orthogonal vectors of the Frenet trihedron. This is because one of the orthogonal vectors of the Darboux trihedron is normal to the surface and forms a certain angle ε with the binormal. Accordingly, the third orthogonal vector of the Darboux trihedron forms an angle ε with the orthogonal vector of the normal of the Frenet trihedron. This orthogonal vector and orthogonal vector of the tangent form the tangent plane to the surface at the current point of the curve, and the corresponding orthogonal vectors of the tangent and the normal of the Frenet trihedron form the tangent plane of the curve at the same point. Thus, when the Frenet and Darboux trihedrons move along a curve with combined vertices, there is a rotation around the common orthogonal vector point of the tangent at an angle ε between the osculating plane of the Frenet trihedron and the tangent plane to the surface of the Darboux trihedron. These trihedrons coincide in a separate case (for a flat curve) (ε = 0). The connection between Frenet and Darboux trihedrons – finding the expression for the angle ε, is considered in the article. The inverse problem – the determination of the movement of the Darboux trihedron at a given regularity of the change of the angle ε, is also considered. A partial case is considered and it is shown that for a flat base curve at ε = const, the set of positions of the orthogonal vector of normal forms a developable surface of the same angle of inclination of the generators. In addition, the inverse problem of finding the regularity of the change of the angle ε between the corresponding orthogonal vectors of the trihedrons allows constructing a ruled surface for the gravitational descent of the load, conventionally assumed to be a particle. At the same time, the balance of forces in the projections on the orthogonal vectors of the trihedron in the common normal plane of the trajectory is considered. This balance depends on the angle ε [ABSTRACT FROM AUTHOR]

Crystalline active pharmaceutical ingredients with comparable size and surface area can demonstrate surface anisotropy induced during crystallization or downstream unit operations such as milling. To the extent that varying surface properties impacts bulk powder properties, the final drug product performance such as stability, dissolution rates, flowability, and dispersibility can be predicted by understanding surface properties such as surface chemistry, energetics, and wettability. Here, we investigate the surface properties of different batches of Odanacatib prepared through either jet milling or fast precipitation from various solvent systems, all of which meet the particle size specification established to ensure equivalent biopharmaceutical performance. This work highlights the use of orthogonal surface techniques such as Inverse Gas Chromatography (IGC), Brunauer–Emmett–Teller (BET) surface area, contact angle, and X-ray Photoelectron Spectroscopy (XPS) to demonstrate the effect of processing history on particle surface properties to explain differences in bulk powder properties. [ABSTRACT FROM AUTHOR]

• 3D thermography from MWIR reflectography images obtained with the same IR camera. • Creation of a 4D model of the manuscript, explorable in real time, including visible and invisible elements. • Integration of the results of chemical and biological investigations into the model. • Semantic annotations of the manuscript 4D model. • Virtual reality environments in the web and engaging holographic showcase for museum. In an effort to try and improve the dissemination of cultural heritage, in this paper a novel method for the four-dimensional (4D) digitization of artefacts, based on images recorded in the mid-wave infrared spectral range, is presented. Such a method is here applied to ancient manuscripts in the frame of the "Codex 4D: journey in four dimensions into the manuscript" project. In the proposed approach, the three-dimensional geometry of the manuscript is reconstructed by processing the reflectographic images, obtained from different points of view with respect to the artefact, through Structure from Motion techniques. Thermograms obtained by means of Pulsed Thermography are also recorded since they provide a depth-resolved characterization of the artefact that is also integrated into the digital reconstruction along the orthogonal direction to the surface, hereafter referred to as the fourth dimension. The results gathered from humanities and scientific studies, are also mapped onto the 4D model in the form of interactive semantic annotations. The goal of such a reconstruction is to allow users to browse the subsurface elements into the 4D model, thus facilitating the study and the exploration of the manuscripts through the inclusion of information about their literary and art-historical contents, materials, execution techniques, and state of conservation. In addition, virtual and mixed reality environments have been developed for different kind of audience such as expert users and museum public. Despite the experimentation presented here was carried out exclusively on manuscripts, in our opinion the methodology can be successfully applied to other types of artefacts. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel approach to realize a compact and highly isolated dual-polarized holographic antenna using a pillbox feeding structure. The proposed antenna feeds dual orthogonal surface waves with low distortion phase distribution and high isolation through a compact three-layer pillbox feeding structure. This antenna also consists of a shared aperture dual-polarized hologram pattern calculated to radiate the objective wave in the desired direction without increasing the antenna size. As a result, the proposed holographic antennas (HA) have a compact size and support forward-to-backward continuous scanning with minimal gain degradation. The simulated and measured results are in good agreement, validating the efficiency of the proposed antenna design, which has the ability to scan the beam direction from +18° to −25°, passing through the broadside within the frequency range of 21–27 GHz. Finally, the proposed antenna has a broadside gain of 18.5 dBi in each polarization and a gain variation of less than 2 dB within the operating bandwidth. [ABSTRACT FROM AUTHOR]

In this paper, we apply a numerical integration strategy recently developed for determining the deformation shapes of structures constituted by Cosserat rods, to predict the behavior of panto-cylinders. Panto-cylinders have, as microstructure, a set of two families of helicoidal beams interconnected by perfect or elastic joints. The pivot's free rotation axis is, in the reference configuration, orthogonal to the cylindrical surfaces spanned by the beams. We perform a series of numerical simulations looking for the mechanical parameters which exalt the chirality effects in the structure. For the performed compression, extensions, shear, and torsion tests, we find chiral deformation patterns with a dependence on the type of joint and its length. [ABSTRACT FROM AUTHOR]

End-of-life management of fibre-reinforced thermoset composites is challenging due to the difficult-to-recycle reinforcements and the irreversibly polymerised thermoset matrix; therefore, researchers proposed the vitrimers as a sustainable alternative to thermosetting polymers. Although the early results of the material scientists are promising, the machinability of vitrimers has yet to be explored. Therefore, this paper aims to present a comparative machinability study of polyimine vitrimer, pentaerythritol-based epoxy (PER) and polycarbonate polymers through orthogonal machining experiments. Reflecting on the temperature-dependent properties of vitrimers, the starting temperature of the cutting tool was varied between room temperature and an elevated temperature above 155 °C. The cutting tool was heated by a 2000-W hot air gun until the surface temperature of the cutting tool, monitored by a VariocamHD thermographic IR camera (with Jenoptik IR 1.0/60 LW lens) and checked by a Fluke 51 II thermometer with a type K thermocouple, was permanently above 155 °C for 5 min. The cutting force was measured by a Kistler 9257B dynamometer, and the machined surface was characterised by a Mitutoyo Surftest SJ-400 surface roughness tester and Keyence VHX-5000 (with VH-Z20UT VH lens) microscope. The analysis of variances (ANOVA) results show that the sustainable vitrimer polymer is an appropriate substitute for thermosetting epoxy polymers, especially at low cutting temperatures. [ABSTRACT FROM AUTHOR]

PURPOSE: In low-dose-rate brachytherapy, iodine-125 seeds are implanted based on a treatment plan, generated with respect to different dose constraints. The quality of the dose distribution depends on a precise seed placement, however, during treatment planning the impact on the dose parameters when certain seeds fail to be placed precisely is not clear. METHODS AND MATERIALS: We developed a method using automatic differentiation to calculate gradients of dose parameters with regard to the seeds' positions. Thus, we understand their sensitivity with respect to the seed placement. A statistical analysis is performed on a data set with 35 prostate brachytherapy patients. RESULTS: The most sensitive seeds regarding the dosimetric parameters of both rectum and urethra are close to the corresponding organ. Their gradient directions are mainly orthogonal to their surfaces. However, not all seeds close to the surface are equally sensitive with regard to the dose parameter. The most sensitive seeds regarding the prostate's dose parameters are distributed throughout the prostate and the direction of the gradients are mainly parallel to its surface. A linear regression with respect to different patient parameters shows that dose constraints which are barely fulfilled have large gradients and thus are additionally sensitive to misplacement. CONCLUSION: Automatic differentiation can be used to analyze dose parameter sensitivity with respect to seed placement. Integrating this into treatment planning systems is valuable as it speeds up the planning procedure, making it more robust and less dependent on user experience while showing the operating physician which needle placements require greater accuracy than others. [ABSTRACT FROM AUTHOR]

This paper proposes a solution to the problem of tight population in the filling area of traditional air suction seed metering devices during quinoa sowing, which leads to inaccurate adsorption. The proposed method disperses the population into a stable seed flow and absorbs the seeds in a flow posture. The flow adsorption precision seed metering device is designed and improved, and the key structure parameters are optimized based on the shape and size parameters of quinoa seeds. A four-factor and three-level response surface orthogonal test is conducted using the Box–Behnken experimental design. The number of seeds, flow angle, negative pressure at the suction hole, and advancing speed are taken as experimental factors, and the qualified index of grain number per hole, qualified index of hole distance, and coefficient of variation of hole distance are used as evaluation indices. The results are optimized using extreme value theory, and it is found that when the seed amount is 5.82 mm, the flow angle is 31.08°, the negative pressure of the air chamber is 1.7 kPa, and the advancing speed is 3.82 km·h−1, and the qualified index of hole number is 94.37%, the qualified index of hole distance is 95.39%, and the coefficient of variation of hole distance is 4.51%. The results are in general agreement with the prediction through the bench validation test, which meets the requirements of quinoa seed metering devices. [ABSTRACT FROM AUTHOR]

The use of micro/nano-scale machining in the production of miniaturized products that are used in various industrial applications such as biotechnology, electronics, optics, medicine, and aviation has increased drastically in the past two decades. To maintain the functional quality of these products, it is essential to investigate and know the machining parameters that are needed to produce high-quality products. An attempt was made to investigate the effects of tool geometry, cutting speed, and undeformed chip thickness on the residual stresses and quality of the machined surface using an orthogonal micro-machining process. A modified deflection-etching technique was used for the residual stress analysis and determination, and the machined surfaces were examined using a scanning electron microscope. For the cutting conditions used in this experiment, compressive residual stresses were formed in the surface region. Surface damage in the form of grooves, cracks, voids, fractured areas, and scratches were observed for all the specimen machined in this study. The radius of the tool cutting edge measured from the photomicrograph of the scanning electron microscope was approximately 50 µm, which was higher than the depth of the undeformed chip thicknesses used in this work, which resulted in an inefficient cutting process wherein a significant portion of the energy was expended to plastically deform the machined surface region. This has led to surface damage in the form of grooves, cracks, voids, fractured areas, and scratches and induced compressive residual stresses in the surface region. [ABSTRACT FROM AUTHOR]

Silicon carbide, a third-generation semiconductor material, is widely used in the creation of high-power devices. In this article, we systematically study the influence of three crucial parameters on the polishing rate of a silicon carbide surface using orthogonal experiments. By optimizing the parameters of chemical mechanical polishing (CMP) through experiments, we determined that the material removal rate (MRR) is 1.2 μm/h and the surface roughness (Ra) is 0.093 nm. Analysis of the relevant polishing mechanism revealed that manganese dioxide formed during the polishing process. Finally, due to the electrostatic effect of the two, M n O 2 adsorbed on the A l 2 O 3 , which explains the polishing mechanism of A l 2 O 3 in the slurry. [ABSTRACT FROM AUTHOR]

Ultrasonic field and rib surfaces are very important factors that affect the thermal performance in pool boiling. The paper has investigated the significance testing of thermal performance of the rib arrangement, the distance of ultrasonic field and the ultrasonic power in pool boiling with ultrasonic field and ribs surfaces by the orthogonal experiment. The deionized water is used as the working coolant. Then, the synergistic heat transfers and bubble motion characteristics in pool boiling are carried out at different rib arrangement, distance of ultrasonic field and the ultrasonic power by the single factor experiment. It is obtained that, compared with the single heat transfer technology of rib surface or ultrasonic field in the pool boiling, the thermal performance of compound heat transfer enhancement can be improved more significantly by combining the rib surfaces and ultrasonic field as a result of the expanded areas of heat exchange surface of rib and the cavitation effect and acoustic streaming effect of the ultrasonic field. The most significant affecting factor on the thermal performance is the rib arrangement, followed by ultrasonic power and distance of ultrasonic field. The increasing rate of heat transfer coefficient (HTC) of the best optimal scheme combination A3B3C1 with the rib arrangement of Rib II, the distance of ultrasonic field of 50 mm and the ultrasonic power of 528 W is 29.9%, which is higher than those of all the other schemes. The research results can effectively optimize the pool boiling performance of the heat transfer enhancement and provide useful support for the development of heat dissipation in related fields. [ABSTRACT FROM AUTHOR]

Osteocytes form a cellular network by gap junctions between their cell processes. This network is important since intercellular communication via the network is essential for bone metabolism. However, the factors that influence the formation of this osteocyte network remain unknown. As the early stage of osteocyte network formation occurs on the bone surface, we observed a newly formed trabecular bone surface by orthogonal focused ion beam-scanning electron microscopy. The embedding late osteoblast processes tended to avoid bundled collagen fibrils and elongate into sparse collagen fibrils. Then, we examined whether the inhibition of bundling of collagen fibrils using a potent lysyl oxidase inhibitor, β-aminopropionitrile (BAPN) changed the cellular network of the chick calvaria. The osteocyte shape of the control group was spindle-shape, while that of the BAPN group was sphere-shaped. In addition, the osteocyte processes of the control group were elongated vertically to the long axis of the cell body, whereas the osteocyte processes of the BAPN group were elongated radially. Therefore, it was suggested that the bundling of collagen fibrils influences normal osteocyte network formation during bone modeling. [ABSTRACT FROM AUTHOR]

Laser powder bed fusion (LPBF) is used as an additive manufacturing (AM) technique to fabricate complex structures. In this study an orthogonal response surface test was designed to optimize the relative density of an 18Ni300 maraging steel sample fabricated through LPBF. The results demonstrated that the influence of the process parameters on the relative density of the maraging steel sample decreased in the order of laser power > scanning speed > hatch spacing. At a laser power of 150 W, scanning speed of 793.658 mm/s, and hatch spacing of 65 µm, the relative density of the sample was 99.797%, which was consistent with the theoretical relative density of 99.80% predicted by the multivariate linear binary regression model and higher than the relative density of 99.13% optimized through the orthogonal test. The ultimate tensile strength of the sample was 1.43 GPa, which is higher than that optimized through the orthogonal test. In addition, the surface of the sample was smoother and flatter, the melt track more continuous and regular, and the pores fewer in number as compared to unoptimized sample. [ABSTRACT FROM AUTHOR]

Gas-related disasters have become a major threat to mining safety of coal resources. Investigation into the optimization approach for inseam borehole gas extraction is important for improving extraction efficiency. By establishing control equations for coal seam deformation, porosity-permeability properties, and gas flow, effects of extraction time, initial gas pressure, initial coal permeability, and borehole diameter on gas flow pattern and effective extraction radius are analyzed. Based on response surface methodology and orthogonal experimental design, a regression analysis model of effective extraction radius and multiple influencing factors is established. Meanwhile, the interaction mechanism between effects of multiple factors is analyzed, thus identifying optimal parameters for gas extraction. Results show that effective extraction radius is positively correlated with initial permeability, extraction time, and borehole diameter, and negatively associated with original gas pressure. In terms of effect on effective extraction radius, those parameters could be ranked as follows: initial gas pressure, extraction time, initial coal permeability, then borehole diameter. Interaction between multiple factors could inhibit the impact of individual factors on extraction radius. An increase in initial gas pressure reduces the positive effect of permeability on extraction radius. Growing initial gas pressure inhibits the contribution of extraction time to effective drainage radius. Prolonged duration of extraction suppresses the positive effect of permeability on extraction radius. Interaction between initial gas pressure and initial permeability has the most significant influence on extraction radius. Results from orthogonal experimental design correspond to those of response surface methodology. These findings could provide guidance for dynamically adjusting drilling extraction parameters and improving gas-extraction outcomes. [ABSTRACT FROM AUTHOR]

Peony seed meal is a very important feed protein raw material with a high potential for development; however, the presence of some anti-nutritional factors, such as saponins, reduces its reusability. This study aimed to establish ideal microbial fermentation conditions for the degradation of saponins in peony seed meal for its subsequent use in poultry feed. First, saponins were extracted via two methods: ethanol extraction and reflux. Then, response surface methodology and orthogonal array testing were used to establish the optimal conditions for the degradation of saponins by (a) liquid fermentation of single bacteria, (b) liquid fermentation of compound bacteria, and (c) solid-state fermentation. The degradation efficiencies were 40.21% (±1.62), 59.82% (±1.54), and 69.31% (±2.95), respectively. The maximum degradation was obtained via solid-state fermentation, and the soluble protein content for this fermentation product was found to be 14% higher than that of unfermented peony seed meal. [ABSTRACT FROM AUTHOR]

Aiming at the problems of large water secretion, poor suspensibility and low strength of cemented aeolian sand (AS)-fly ash (FA) backfill (CAFB) mixtures, CAFB was doped with fine coal gangue (CG) particles crushed to less than 4 mm and configured as cemented aeolian sand-coal gangue-fly ash backfill (CACFB) mixtures, in which coal gangue accounted for 8% of the mass ratio of the slurry. Through UCS and rheological experiments, using the response surface methodology and an orthogonal design, the following conclusions were drawn: (1) With the increase in ordinary Portland cement (PO) and slurry concentration, the UCS of the CACFB increased. (2) With the increase in the FA dosage, the UCS of the CACFB decreased first and then increased due to the gradual increase in FA dosage, destroying the reasonable ratio of the material and leading to the reduction in the material's UCS, and with the growth in time, the volcanic ash effect of the FA caused the UCS of the material to increase. (3) With the increases in slurry concentration, the yield stress and viscosity coefficient of the slurry increased. (4) Reasonable proportions for CACFB should ensure the strength characteristics and rheological properties of the material. Through theoretical and experimental research, the final reasonable proportions were as follows: the concentrations of slurry, AS, CG, FA and PO were 77.5%, 42%, 8%, 17.5% and 10%, respectively. This ensured that the UCSs of the CACFB at 3 d, 7 d and 28 d were 1.2 MPa, 2.5 MPa and 4.3 MPa, respectively; the yield stress of the CACFB was 495 Pa, and the viscosity coefficient was 3.97 Pa·s. These reasonable proportions of the CACFB can meet the strength index and flow property of material industrial experiments. [ABSTRACT FROM AUTHOR]

Compared to traditional two-dimensional frequency selective surfaces, three-dimensional frequency selective surface has become a hot research direction due to its ability to generate more resonance points, provide larger bandwidth, efficiently meet miniaturization requirement, and bring more stable frequency response. A novel three-dimensional frequency selective surface with a multi-level orthogonal diamond structure is proposed in this paper. Its basic unit structure is an orthogonal diamond-shaped metal wire, and a polymer with dielectric constant of 2. 2 is injected externally as support structure. The common bandwidth of this frequency selective surface exceeds 9. 2 GHz with a relative bandwidth exceeding 50%, and the average insertion loss of TE and TM polarization does not exceed 1 dB when the incident angle in the range of 0° to 50°. This three-dimensional frequency selective surface has three resonance points. Their formation reasons are the resonance of the orthogonal diamond metal structure, the resonance generated by the coupling between the structure and the dielectric end face, and the first-order Fabry Perot resonance of the dielectric end face. If the dielectric constant of the filling medium is adjusted, higher order of Fabry Perot resonance can be utilized, and a spatial filter with broader bandwidth requirement can be designed. At the same time, the impact of this three-dimensional frequency selective surface on the far-field pattern of the antenna is also evaluated. [ABSTRACT FROM AUTHOR]

A Novel Hybrid Choke High Gain Antenna (HCHGA) that operates at 15 GHz is presented in this article, HCHGA is a circularly polarized one that effectively mitigates the multipath effects. The proposed antenna has good impedance matching with S11 of −20.99 dB with a gain of 10.26 dB, and an axial ratio of 1.74 dB. The radiation patterns of the antenna are orthogonal to the antenna surface without any nulls. The proposed antenna is fabricated using RT Duroid 5880 substrate. Simulations are done on a basic patch antenna mounted on different types of ground planes including extended flat ground plane, concentric choke ring, and Hybrid choke ring. The effects of variation in the parameters of grooves thickness, grooves height, and grooves shape on antenna performance parameters are observed. The design of the hybrid chokes facilitated higher values of gain and front-to-back ratio development for mitigating the multipath. From the prototype of the proposed antenna, the measured and simulated results are in good agreement with each other and this proposed antenna is suitable for satellite communication applications. [ABSTRACT FROM AUTHOR]

In response to the structural optimization problem of PCB stator coreless disc motors, the orthogonal response surface method was used to optimize the motor structure, preliminarily determine the basic parameters of the motor, and conduct orthogonal experiments on the motor parameters based on the optimization design objectives. The optimization factors were the quantity of the magnetic pole of the motor rotor p, the ratio of the main/auxiliary pole sizes Rnd, the thickness Tm of the permanent magnet, and the air gap length δ. The motor torque Td, the amplitude of the magnetic density of the air gap Bδ, and the waveform distortion rate THD were used as optimization objectives. The motor parameters that cause the motor torque to reach a maximum cause the air gap magnetic density to reach a maximum and the waveform distortion rate to reach a minimum. Due to the use of PCB plates instead of motor stator cores in the PCB coreless disc motors, the service life of the PCB board during motor operation will be reduced with the temperature increase generated by the stator winding. To solve this problem, a response surface analysis of the motor was carried out to reduce the increase in the temperature of the stator windings during the operation of the motor. The PCB board and stator winding are the main factors affecting the motor's temperature increase. Taking the thickness of the PCB board, the hole diameter on the board, and the uneven width of the stator winding as optimization factors, the motor parameters with the lowest increase in the temperature of the motor winding were obtained. A simulation analysis was conducted using Ansys/Maxwell software, and the results prove the feasibility of the optimization. [ABSTRACT FROM AUTHOR]

Eolian sand is widely distributed in desert areas, and can easily trigger sandstorms under the combined effects of wind and thermal conditions. In this paper, an eolian sand solidification test via microbially induced calcium carbonate (CaCO3) precipitation (MICP) was conducted to explore prospective applications of MICP in the field of dust prevention and sand fixation. A bacterial growth test and a MICP mineralization reaction test were performed based on the response surface method and an orthogonal experiment. Based on eolian sand solidification test, the effects of cementation number and dry density on the permeability and strength characteristics of solidified eolian sand, as well as the content of CaCO3 generated were analyzed. The results showed that the bacteria grew best at a temperature of 35 °C, a pH of 9, and a shaking frequency of 170 rpm. Both urease activity and bacterial concentration increased as the temperature and pH increased but showed a trend of rising before falling as the shaking grew faster. The optimal conditions for MICP mineralization were a bacterial concentration of OD600=1.5, a consolidating fluid concentration of 1 mol/L, a reaction time of 16 h, a pH of 9, and a temperature of 25 °C. The permeability coefficient of solidified eolian sand decreased as the dry density and the number of cementations increased, whereas the CaCO3 content increased with the number of cementations. As the number of cementations increased, the unconfined compressive strength (UCS) of eolian sand initially rose before stabilizing and then increasing again. The CaCO3 content had a positive relationship with UCS, which with the correlation coefficient reached 0.80. [ABSTRACT FROM AUTHOR]

Horizontal feeding devices and plate hob chopping devices are the key component of silage maize harvester. To solve the problem of feeding blockage, reduce energy consumption, and improve the chopping quality of the chopping device a horizontal different diameter five-rollers device (HDDFD) was designed and the plate hob chopping device was simultaneously optimized and analyzed. Through the dynamic analysis, the feeding conveying speed was determined to be 2.0-4.5 m/s. The distance equation of the actual and theoretical cutting-edge curve and the position of the fixed blade were finally obtained. Single factor and response surface orthogonal tests in the bench site were carried out with feeding speed, rotating speed of chopping cylinder, feeding amount, and feeding direction as influencing factors, standard grass length rate (SGLR), and energy consumption per unit mass (ECPUM) as evaluation indexes. The optimal working parameters for chopping performance could be concluded as a feeding speed of 3.39 m/s, rotating speed of the chopping cylinder of 1016.17 r/min, feeding amount of 8.04 kg/s, and feeding direction of 52.2°. In addition, the SGLR and ECPUM were obtained as 95.35% and 37.63 kJ/kg, respectively. The relative error between the experimental results with round parameter combination and the predicted value was verified to be less than 5%. Field tests verified the reliability of the optimized feeding and chopping device. It can be seen that the HDDFD and optimized plate hob chopping device can meet the requirements of mechanized silage harvesting which obviously improves the working quality and reduce the energy consumption of chopping. [ABSTRACT FROM AUTHOR]

The article presents the results of an experiment related to wildlife inventory control with the use of data from terrestrial laser scanning. The measurements were performed with the terrestrial laser scanning system – Riegl VZ-400i. The study area was the Obrońców Westerplatte square in Wrocław. The collected measurement data were pre-processed in a commercial – dedicated RiSCAN Pro environment. Operations related to point cloud georeferencing and its filtering were performed. The tree parameters were measured on the basis of a cloud point obtained in field surveys. This operation was performed with the use of the 3D Forest software. The investigations covered the main parameters of the tree (height and diameter) along with additional parameters, such as the distance between two points of the tree located furthest apart, the surface area of the orthogonal projection of the tree on the reference surface (terrain surface) and the height of the tree crown above the terrain surface. As a result of the performed analyses, an inventory of 70 trees was made within the Obrońców Westerplatte square in Wrocław. Part of the experiment was also to prepare a 3D model of a tree by using some available modeling algorithms. This part was performed in Sequoia software - dedicated to such operations. The software offers three modeling algorithms: Zhu/Bridson, metaballs and union of spheres. [ABSTRACT FROM AUTHOR]

Changes in object morphology can be quantified using 3D optical scanning to generate 3D models of an object at different time points. This process requires registration techniques that align target and reference 3D models using mapping functions based on common object features that are unaltered over time. The goal of this study was to determine guidelines when selecting these localized features to ensure robust and accurate 3D model registration. For this study, an object of interest (tibia bone replica) was 3D scanned at multiple time points, and the acquired 3D models were aligned using a simple cubic registration block attached to the object. The size of the registration block and the number of planar block surfaces selected to calculate the mapping functions used for 3D model registration were varied. Registration error was then calculated as the average linear surface variation between the target and reference tibial plateau surfaces. We obtained very low target registration errors when selecting block features with an area equivalent to at least 4% of the scanning field of view. Additionally, we found that at least two orthogonal surfaces should be selected to minimize registration error. Therefore, when registering 3D models to measure multi-temporal morphological change (e.g., mechanical wear), we recommend selecting multiplanar features that account for at least 4% of the scanning field of view. For the first time, this study has provided guidelines for selecting localized object features that can provide accurate 3D model registration for 3D scanned objects. [ABSTRACT FROM AUTHOR]

Introduction: The three-dimensional (3D) microstructure of the cortical and trabecular bone of the proximal ulna has not yet been described by means of high-resolution 3D imaging. An improved characterization can provide a better understanding of their relative contribution to resist impact load. The aim of this study is to describe the proximal ulna bone microstructure using micro-computed tomography (micro-CT) and relate it to gross morphology and function. Materials and methods: Five dry cadaveric human ulnae were scanned by micro-CT (17 μm/voxel, isotropic). Both qualitative and quantitative assessments were performed on sagittal image stacks. The cortical thickness of the trochlear notch and the trabecular bone microstructure were measured in the olecranon, bare area and coronoid. Results: Groups of trabecular struts starting in the bare area, spanning towards the anterior and posterior side of the proximal ulna, were observed; within the coronoid, the trabeculae were orthogonal to the joint surface. Consistently among the ulnae, the coronoid showed the highest cortical thickness (1.66 ± 0.59 mm, p = 0.04) and the olecranon the lowest (0.33 ± 0.06 mm, p = 0.04). The bare area exhibited the highest bone volume fraction (BV/TV = 43.7 ± 22.4%), trabecular thickness (Tb.Th = 0.40 ± 0.09 mm) and lowest structure model index (SMI = – 0.28 ± 2.20, indicating plate-like structure), compared to the other regions (p = 0.04). Conclusions: Our microstructural results suggest that the bare area is the region where most of the loading of the proximal ulna is concentrated, whereas the coronoid, together with its anteromedial facet, is the most important bony stabilizer of the elbow joint. Studying the proximal ulna bone microstructure helps understanding its possible everyday mechanical loading conditions and potential fractures. Level of evidence: N.A. [ABSTRACT FROM AUTHOR]

In this study, we give the curves and tubular surfaces in Galilean space G3 with modified orthogonal frame. Firstly, we consider any curve in G3 and we obtain derivative formulas of modified orthogonal frame of any curve in G3. Therefore, we get tubular surface with modified orthogonal frame in Galilean space G3. Consequently, we give some examples and figures. [ABSTRACT FROM AUTHOR]

The effort is presented to numerical examine the flow behavior of non-Newtonian fluid through orthogonal porous surfaces. A two-phase model of nanofluids simulations is considered which represents speculative features of materials that are obliged in biomechanics, lubricants formation, polymer solution, suspension, etc. The mechanism of interfacial nano layer at surfaces is deliberated through thermal conductivity. Numerical sculpting of non-Newtonian CNT fluid including the impact of chemical reaction, heat flux and mass transfer source is manifested in the form of partial differential equations. Similarity variables are capitalized to transmute governing modeled conservation laws into ordinary non-dimensional expressions. Assessment of flow attributing profiles is disclosed by implementing the Runge-Kutta procedure in collaboration with the shooting method. The numerical stability with convergence rate is also discussed here. Graphical visualization and numerical data about surface drag coefficients and heat and mass transfer rates are also presented. The effect of expansion and contraction (−2 < α < 2) on boundary layer thickness is discussed in detail. The rate of heat transfer increases with the increase of boundary layer thickness in the presence of single-wall carbon nanotubes (SWCNT) is observed. An increase in heat transfer profile due to the presence of SWCNTs with the variation of thickness and radius of sustainable particles is perceived. The nano layer thickness is a significant effect related to the heat transfer rate. [ABSTRACT FROM AUTHOR]

In this study, we give the curves and tubular surfaces in Galilean space G3 with modified orthogonal frame. Firstly, we consider any curve in G3 and we obtain derivative formulas of modified orthogonal frame of any curve in G3. Therefore, we get tubular surface with modified orthogonal frame in Galilean space G3. Consequently, we give some examples and figures. [ABSTRACT FROM AUTHOR]

Laminated natural materials, exemplified by laminated bamboo veneers, have been extensively used in architectural and engineering applications due to their cost-effectiveness, outstanding toughness, and sustainable characteristics. However, conventional applications of laminated bamboo veneers typically exhibit continuous surfaces with parallel or orthogonal fiber orientations. Given the anisotropic properties and manufacturability of bamboo veneers, there is significant potential to optimize fiber orientations for laminated bamboo veneers while simultaneously reducing structural weight through topology optimization. The foldability of thin bamboo veneers can also be leveraged to improve structural performance while reducing manufacturing costs. This paper presents an innovative coupled optimization approach specifically designed for laminated natural composites in curved folded configurations. The approach integrates concurrent optimization of local fiber orientation and global structural topology by incorporating developable surface parameterization, principal stress alignment, and bi-directional evolutionary structural optimization. Two distinct filtering schemes are proposed to meet different design specifications across the laminated plies. Results from numerical analyses demonstrate that substantial compliance and weight reductions can be achieved by using the proposed approach. To further facilitate assembly and fabrication, member connections within each bamboo veneer patch are realized with minimal material usage. By maximizing the structural contribution of bamboo veneer fibers and reducing weight through the removal of inefficient materials, the proposed approach expands the potential of laminated natural fiber materials in sustainable fabrication practices. • An approach is developed to optimize the fiber orientation and topology for laminated curved folded bamboo veneer shells. • Strategies for patch division and assembly are proposed to facilitate fabrication. • Two filter schemes are introduced to address different cross-ply-topology requirements for laminated shells. • The proposed approach can produce laminated bamboo veneer shells with reduced compliance and weight, simultaneously. [ABSTRACT FROM AUTHOR]

In this letter, a low-profile metasurface (MS) antenna with multi-polarization and pattern reconfigurability is presented. The antenna mainly consists of two parts, including a loop antenna fed by balun, and a MS antenna excited by the coupled aperture.When switching the PIN diode and rotating the MS, the multi-polarization and pattern reconfigurable ability of the antenna is obtained. While the loop antenna is excited, a horizontally linear polarized (HLP) wave and omnidirectional pattern are obtained. Besides, when the MS is operated, due to the differential phase between the orthogonal surface impedance components, the antenna can be switched between vertical linear polarization (VLP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP). Furthermore, the antenna could achieve a directional pattern. As the simulated and measured results shown, the proposed antenna has an overlapped impedance bandwidth (IMBW) of 24.7% for all polarization modes and a 3-dB axial ratio (AR) bandwidth of 11.8% for L/RHCP modes. Moreover, the antenna owns a low profile of 0.06 λ (under the operating centre frequency). [ABSTRACT FROM AUTHOR]

Gears are usually measured by the contact metrology method in gear measuring centers or coordinate measuring machines. Recently, three-dimensional (3D) optical scanning, a non-contact metrology method, has been applied in the industry as an advanced measurement technology mainly due to its high efficiency. However, its applications to gears with complicated geometry, such as face gears, are still limited due to its relatively low accuracy and the void of related measurement solutions. In this work, an accurate measurement solution with 3D optical scanning is proposed for the tooth surface deviations of orthogonal face gears. First, point cloud collection is carried out by the 3D scanner. Furthermore, the measurement solution is implemented with a three-stage algorithm by aligning point clouds with the design model. Subsequently, 3D modeling is studied by numbering the points and reconstructing the real tooth surfaces. An example with a measurement experiment and loaded tooth contact analysis is given to show the validity of the proposed method. [ABSTRACT FROM AUTHOR]

Based on 16,283 early-type galaxies (ETGs) in 0.025 ≤ z spec < 0.055 from Sloan Digital Sky Survey data, we show that the fundamental plane (FP) of ETGs is not a plane in the strict sense but is a curved surface with a twisted shape whose orthogonal direction to the surface is shifted as the central velocity dispersion (σ 0) or mean surface brightness within the half-light radius (ÎĽ e ) changes. When ETGs are divided into subsamples according to σ 0, the coefficient of ÎĽ e of the FP increases, whereas the zero-point of the FP decreases at higher σ 0. Taking the z band as an example, the coefficient of ÎĽ e rises from 0.28 to 0.36 as σ 0 increases from ∼100 to ∼300 km sâˆ'1. At the same time, the zero-point of the FP falls from âˆ'7.5 to âˆ'9.0 in the same σ 0 range. The consistent picture on the curved nature of the FP is also reached by inspecting changes in the FP coefficients for ETG subsamples with different ÎĽ e . By examining scaling relations that are projections of the FP, we suggest that the warped nature of the FP may originate from dry merger effects that are imprinted more prominently in ETGs with higher masses. [ABSTRACT FROM AUTHOR]

This paper proposes a double propeller wall-climbing robot (DP-Climb) with a hybrid adhesion system based on the biomimetic design principle to address the problems of single adhesion-powered wall climbing robots (WCRs). Such problems include poor maneuverability and adaptability to orthogonal working surfaces with different roughness and flatness, weak flexibility of ground-wall transition motion, and easy stand stilling of transition,. Based on the clinging characteristics of different creatures, the hybrid system combines the rotor units' reverse thrust, the drive wheels' driving torque, and the adhesion force offered by the coating material to power the robot through a coupled control strategy. Based on the Newton–Euler equations, the robot's kinematic characteristics during the ground-wall internal transition motion were analyzed, the safe adhesion conditions were obtained, and a dynamics model of the robot's ground-wall transition was established. This provided the basis for the coupling control between different power units. Finally, an internal transition PID control strategy based on DP-Climb was proposed. Through mechanical and aerodynamic characteristic experiments, it is verified that the robot's actual output pulling force can meet the transition motion demand. The experimental results show that the proposed strategy can enable the DP-Climb to complete the ground-wall mutual transition motion smoothly with a speed of 0.12 m/s. The robot's maximum wall motion speed can reach 0.45 m/s, which verifies that the hybrid adhesion system can flexibly and quickly reach the specified position in a target area flexibly and quickly. The robustness and adaptability of WCR to complex application environments are improved. [ABSTRACT FROM AUTHOR]

Tailoring thermal transport by structural parameters could result in mechanically fragile and brittle networks. An indispensable goal is to design hierarchical architecture materials that combine thermal and mechanical properties in a continuous and cohesive network. A promising strategy to create such a hierarchical network targets additive manufacturing of hybrid porous voxels at nanoscale. Here we describe the convergence of agile additive manufacturing of porous hybrid voxels to tailor hierarchically and mechanically tunable objects. In one strategy, the uniformly distributed porous silica voxels, which form the basis for the control of thermal transport, are non-covalently interfaced with polymeric networks, yielding hierarchic super-elastic architectures with thermal insulation properties. Another additive strategy for achieving mechanical strength involves the versatile orthogonal surface hybridization of porous silica voxels retains its low thermal conductivity of 19.1 mW m−1 K−1, flexible compressive recovery strain (85%), and tailored mechanical strength from 71.6 kPa to 1.5 MPa. The printed lightweight high-fidelity objects promise thermal aging mitigation for lithium-ion batteries, providing a thermal management pathway using 3D printed silica objects. Nanoscale porous building blocks hold great promise for a range of thermal management technologies but often porous nanoparticle assemblies are intrinsically brittle. Here, the authors report 3D printing of porous silica voxels with polymeric additives to enable the coupling between additive manufacturing and hierarchical assembly for superior machinability and structural controllability. [ABSTRACT FROM AUTHOR]

The rate of erosion of a landscape depends largely on local gradient and material fluxes. Since both quantities are functions of the shape of the catchment surface, this dependence constitutes a mathematical straitjacket, in the sense that – subject to simplifying assumptions about the erosion process, and absent variations in external forcing and erodibility – the rate of change of surface geometry is solely a function of surface geometry. Here we demonstrate how to use this geometric self-constraint to convert a gradient-dependent erosion model into its equivalent Hamiltonian, and explore the implications of having a Hamiltonian description of the erosion process. To achieve this conversion, we recognize that the rate of erosion defines the velocity of surface motion in its orthogonal direction, and we express this rate in its reciprocal form as the surface-normal slowness. By rewriting surface tilt in terms of normal slowness components and deploying a substitution developed in geometric mechanics, we extract what is known as the fundamental metric function of the model phase space; its square is the Hamiltonian. Such a Hamiltonian provides several new ways to solve for the evolution of an erosion surface: here we use it to derive Hamilton's ray-tracing equations, which describe both the velocity of a surface point and the rate of change of the surface-normal slowness at that point. In this context, gradient-dependent erosion involves two distinct directions: (i) the surface-normal direction, which points subvertically downwards, and (ii) the erosion ray direction, which points upstream at a generally small angle to horizontal with a sign controlled by the scaling of erosion with slope. If the model erosion rate scales faster than linearly with gradient, the rays point obliquely upwards, but if erosion scales sublinearly with gradient, the rays point obliquely downwards. This dependence of erosional anisotropy on gradient scaling explains why, as previous studies have shown, model knickpoints behave in two distinct ways depending on the gradient exponent. Analysis of the Hamiltonian shows that the erosion rays carry boundary-condition information upstream, and that they are geodesics, meaning that surface evolution takes the path of least erosion time. Correspondingly, the time it takes for external changes to propagate into and change a landscape is set by the velocity of these rays. The Hamiltonian also reveals that gradient-dependent erosion surfaces have a critical tilt, given by a simple function of the gradient scaling exponent, at which ray-propagation behaviour changes. Channel profiles generated from the non-dimensionalized Hamiltonian have a shape entirely determined by the scaling exponents and by a dimensionless erosion rate expressed as the surface tilt at the downstream boundary. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp) coating electrodeposition was performed on three orthogonal surfaces of duplex-annealed Ti6Al4V alloy. This approach made it possible to investigate the effect of substrate crystallographic texture on hydroxyapatite coating properties exclusively from its microstructure. The coating characteristics were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), laser surface profilometry, and potentiodynamic polarization test. The results showed that the presence of (1010 ) low-surface energy planes leads to smaller HAp deposits of 39 ± 4 μm due to the higher nucleation rate during electrodeposition. The highest surface roughness value of 75 ± 1 μm, as well as the lowest degree of crystallinity, equal to 23.5%, belonged to the surface in which (0001) and (1120) planes of high-surface energy placed in parallel to the surface. The electrochemical test results showed that the protective efficiency of HAp coatings was the highest for the surface with (1010) planes in parallel. This was attributed to the increased thickness and the low porosity content of the coating. [ABSTRACT FROM AUTHOR]

\nIMPACT STATEMENTIn a deep-learning-based algorithm, generative adversarial networks can generate images similar to an input. Using this algorithm, an artificial three-dimensional (3D) microstructure can be reproduced from two-dimensional images. Although the generated 3D microstructure has a similar appearance, its reproducibility should be examined for practical applications. This study used an automated serial sectioning technique to compare the 3D microstructures of two dual-phase steels generated from three orthogonal surface images with their corresponding observed 3D microstructures. The mechanical behaviors were examined using the finite element analysis method for the representative volume element, in which finite element models of microstructures were directly constructed from the 3D voxel data using a voxel coarsening approach. The macroscopic material responses of the generated microstructures captured the anisotropy caused by the microscopic morphology. However, these responses did not quantitatively align with those of the observed microstructures owing to inaccuracies in reproducing the volume fraction of the ferrite/martensite phase. Additionally, the generation algorithm struggled to replicate the microscopic morphology, particularly in cases with a low volume fraction of the martensite phase where the martensite connectivity was not discernible from the input images. The results demonstrate the limitations of the generation algorithm and necessity for 3D observations.This study provided the comparison between experimentally observed and computationally generated 3D microstructures of dual-phase steels in the macro- and microscopic material behaviors with finite element analysis method for periodic microstructure. [ABSTRACT FROM AUTHOR]

A simple method for structuring of the surface of a magnetoactive elastomer (MAE) on the tens of micrometers scale, which capabilities extend beyond conventional mold‐based polymer casting, is reported. The method relies on the ablation of the material by absorption of nanosecond infrared pulses from a commercial laser. It is shown that it is possible to fabricate parallel lamellar structures with a high aspect ratio (up to 6:1) as well as structures with complex scanning trajectories. The method is fast (fabrication time for the 7 × 7 mm2 is about 60 s), and the results are highly reproducible. To illustrate the capabilities of the fabrication method, both orthogonal to the MAE surface and tilted lamellar structures are fabricated. These magnetosensitive lamellae can be easily bent by ±45° using an external magnetic field of about 230 mT. It is demonstrated that this bending allows one to control the sliding angle of water droplets in a great range between a sticky (>90°) and a sliding state (<20°). Perspectives on employing this fabrication technology for magnetosensitive smart surfaces in microfluidic devices and soft robotics are discussed. [ABSTRACT FROM AUTHOR]

Metal–organic polyhedra (MOPs) are a subclass of coordination cages that can adsorb and host species in solution and are permanently porous in solid‐state. These characteristics, together with the recent development of their orthogonal surface chemistry and the assembly of more stable cages, have awakened the latent potential of MOPs to be used as building blocks for the synthesis of extended porous networks. This review article focuses on exploring the key developments that make the extension of MOPs possible, highlighting the most remarkable examples of MOP‐based soft materials and crystalline extended frameworks. Finally, the article ventures to offer future perspectives on the exploitation of MOPs in fields that still remain ripe toward the use of such unorthodox molecular porous platforms. [ABSTRACT FROM AUTHOR]

In this paper, we study canal surfaces with modified orthogonal frame in Minkowski 3-space. Some characterizations of the canal surface will be given using curvature-modified orthogonal frame in Minkowski 3-space. [ABSTRACT FROM AUTHOR]

This work develops a method to perform surface treatment tasks using a bimanual robotic system, i.e. two robot arms cooperatively performing the task. In particular, one robot arm holds the workpiece while the other robot arm has the treatment tool attached to its end-effector. Moreover, the human user teleoperates all the six coordinates of the former robot arm and two coordinates of the latter robot arm, i.e. the teleoperator can move the treatment tool on the plane given by the workpiece surface. Furthermore, a force sensor attached to the treatment tool is used to automatically attain the desired pressure between the tool and the workpiece and to automatically keep the tool orientation orthogonal to the workpiece surface. In addition, to assist the human user during the teleoperation, several constraints are defined for both robot arms in order to avoid exceeding the allowed workspace, e.g. to avoid collisions with other objects in the environment. The theory used in this work to develop the bimanual robot control relies on sliding mode control and task prioritisation. Finally, the feasibility and effectiveness of the method are shown through experimental results using two robot arms. [ABSTRACT FROM AUTHOR]

Fault evolution in oblique and orthogonal rift systems in the brittle upper crust of the Rukwa rift basin was simulated using scaled sandbox modelling by varying the angle between the rift axis and the extension direction, α, through 45° and 90°, over a 10 cm displacement. The 45° oblique model exhibits a half-graben architecture bounded by a planar fault, intra-rift faults and a conjugate fault in some vertical sections. The map view of the model's basin trends in the NW-SE direction, and is comparable with the Rukwa rift basin orientation. The 90° oblique model forms a basin structure which is orthogonal to the extension direction of the model in aerial photos. Its linear fault remains orthogonal to the extension direction, while the flexural side of the model segments into sinuous normal faults. Planar to slightly curved intra-rift faults are observed in vertical sections. The half-grabens have similar geometries in vertical sections for both models, while intra-rift faults elongate in vertical sections. The results of the oblique model are similar to natural examples of rift fault systems like the Rukwa rift. The fault geometries of the sandbox models can serve as examples for recognizing fault styles in oblique rift systems. [ABSTRACT FROM AUTHOR]

Discovering mechanisms governing organelle assembly is a fundamental pursuit in biology. The centriole is an evolutionarily conserved organelle with a signature 9-fold symmetrical chiral arrangement of microtubules imparted onto the cilium it templates. The first structure in nascent centrioles is a cartwheel, which comprises stacked 9-fold symmetrical SAS-6 ring polymers emerging orthogonal to a surface surrounding each resident centriole. The mechanisms through which SAS-6 polymerization ensures centriole organelle architecture remain elusive. We deploy photothermally-actuated off-resonance tapping high-speed atomic force microscopy to decipher surface SAS-6 self-assembly mechanisms. We show that the surface shifts the reaction equilibrium by ~104 compared to solution. Moreover, coarse-grained molecular dynamics and atomic force microscopy reveal that the surface converts the inherent helical propensity of SAS-6 polymers into 9-fold rings with residual asymmetry, which may guide ring stacking and impart chiral features to centrioles and cilia. Overall, our work reveals fundamental design principles governing centriole assembly. The centriole exhibits an evolutionarily conserved 9-fold radial symmetry that stems from a cartwheel containing vertically stacked ring polymers that harbor 9 homodimers of the protein SAS-6. Here the authors show how dual properties inherent to surface-guided SAS-6 self-assembly possess spatial information that dictates correct scaffolding of centriole architecture. [ABSTRACT FROM AUTHOR]