Horizontal Rotation Research Articles

Hybrid System of Dual Axis Photovoltaic Tracking System Using ANFIS-ACO

In this paper, the efficiency of the photovoltaic panels is improved by adding two solar tracking systems. The solar tracking system is used to track the sun so that the photovoltaic always faces the sun. This system uses a dual axis consisting of a horizontal rotation axis and a vertical rotation axis. The motion of the horizontal axis of rotation follows the sun's azimuth angle from north to south. Then to follow the sun's azimuth angle from east to west is the vertical axis motion. Both types of movements are controlled using PID and Fuzzy controllers, which are optimized with an artificial intelligence approach, namely Ant Colony Optimization (ACO). Experiments with PID control, Fuzzy control, and ANFIS control approaches optimized by the ACO method (ANFIS-ACO Hybrid method). The experimental results show that ANFIS-ACO has the best performance in terms of settling time and overshoot.

Subassemblage test and gusset rotation response of buckling-restrained braced steel frames

Gusset rotation would cause adverse influence on the buckling-restrained brace (BRB) end zone and even lead to premature buckling of the BRB end zone. However, limited studies to date referred to the gusset rotation response. To evaluate the cyclic behavior and gusset rotation response, five 1/2-scaled buckling-restrained braced frame (BRBF) subassemblages with various gusset connections, i.e., pinned gusset connection, bolted gusset connection, welded gusset connection, pinned-welded gusset connection, and pinned-bolted gusset connection, were conducted under horizontal cyclic loading. The effects of gusset connection type on the failure modes, horizontal initial stiffness, energy dissipation and rotation response of specimens were analyzed in detail. It showed that all specimens performed plump and stable hysteresis behavior. The upper gusset rotation of the specimen with pinned gusset connection was larger than that of bolted gusset connection, followed by welded connection. Meanwhile, the finite element (FE) models were established and validated by test results. Furthermore, the standard FE model of a full-scale one-story one-bay steel moment BRBF with a single diagonal BRB was developed and then extended to a large number of models to investigate the contribution of various parameters on the upper gusset rotation. Finally, the gusset rotational formulae for predicting its response, as the steel moment BRBF reached to either 2.0% or 3.0% drift, were proposed on the basis of the results of the extensive parametric analysis. It could be used to determine the rotation of the BRB end zone, and the flexural moment acting on the BRB end zone and corresponding practical design procedure can be finally derived to avoid the potential premature failure of the BRB end zone.

The Cabo Frio Thrust: A folded suture zone, Ribeira belt, SE Brazil

Kinematic evolution of thrust systems in which vergence changes along strike result in divergent interpretations regarding the subduction polarity. The Ribeira belt, located in southeastern Brazil, resulted from progressive amalgamation of several terranes against the southeastern margin of the São Francisco Craton (SFC) between ca. 620 and 580 Ma. This study brings new structural analysis of the Cabo Frio Thrust (CFT) located in the Ribeira belt, that displays strike variations and apparently double thrusting vergence, generating current debate on subduction vergence for the region. Four major stages of deformation (Dn-1, D1cf, D2cf and D3cf) have been identified in the southwestern segment of the CFT. The Dn-1 affected only the metasedimentary rocks of the Oriental Terrane previously the collision. The D1 phase is associated with the thrusting of orthogneisses of the Cabo Frio Terrane onto the metasedimentary rocks of the Oriental Terrane, with the development of a penetrative S1 foliation and L1 stretching lineation. The D2 deformation phase produced a recumbent synform in the early/syn-D2 stages that overturned the CFT. This resulted in F2 isoclinal folds and S2 axial plane schistosity with F2 axis plunges towards W-SW, parallel to the L1 stretching and L2 intersection lineations. During the late-D2 stage, the recumbent F2 fold was sheared and refolded, leading to horizontal rotation of linear and planar elements, changing the CFT strike from W-SW to N–S. A series of irregular upright folds were developed in the D3 deformation phase. The double vergence and strike variations of the CFT are a result of the major F2 fold geometry, influenced by the granitic batholith (Tinguí Complex) that acted as an indenter during continuous crustal shortening towards northwest.

The adaptation and investigation of cone-beam CT reconstruction algorithms for horizontal rotation fixed-gantry scans of rabbits

Fixed-gantry radiation therapy has been proposed as a low-cost alternative to the conventional rotating-gantry radiation therapy, that may help meet the rising global treatment demand. Fixed-gantry systems require gravitational motion compensated reconstruction algorithms to produce cone-beam CT (CBCT) images of sufficient quality for image guidance. The aim of this work was to adapt and investigate five CBCT reconstruction algorithms for fixed-gantry CBCT images. The five algorithms investigated were Feldkamp–Davis–Kress (FDK), prior image constrained compressed sensing (PICCS), gravitational motion compensated FDK (GMCFDK), motion compensated PICCS (MCPICCS) (a novel CBCT reconstruction algorithm) and simultaneous motion estimation and iterative reconstruction (SMEIR). Fixed-gantry and rotating-gantry CBCT scans were acquired of 3 rabbits, with the rotating-gantry scans used as a reference. Projections were sorted into rotation bins, based on the angle of rotation of the rabbit during image acquisition. The algorithms were compared using the structural similarity index measure root mean square error, and reconstruction time. Evaluation of the reconstructed volumes showed that, when compared with the reference rotating-gantry volume, the conventional FDK algorithm did not accurately reconstruct fixed-gantry CBCT scans. Whilst the PICCS reconstruction algorithm reduced some motion artefacts, the motion estimation reconstruction methods (GMCFDK, MCPICCS and SMEIR) were able to greatly reduce the effect of motion artefacts on the reconstructed volumes. This finding was verified quantitatively, with GMCFDK, MCPICCS and SMEIR reconstructions having RMSE 17%–19% lower and SSIM 1% higher than a conventional FDK. However, all motion compensated fixed-gantry CBCT reconstructions had a 56%–61% higher RMSE and 1.5% lower SSIM than FDK reconstructions of conventional rotating-gantry CBCT scans. The results show that motion compensation is required to reduce motion artefacts for fixed-gantry CBCT reconstructions. This paper further demonstrates the feasibility of fixed-gantry CBCT scans, and the ability of CBCT reconstruction algorithms to compensate for motion due to horizontal rotation.

Revolution-assisted direct writing of highly controllable spiral graphene fibers with ultrasensitive photoelectric response

Spiral graphene-based fibers have enticing advantages in high breakage elongation and stable electrical property during the tensile process, but the conventional manufacturing methods are complicated and hard to produce in large quantities. Herein, we demonstrated a facile and effective revolution-assisted direct writing strategy for controllably constructing spiral graphene fiber, with a spinneret revolving along a revolution axis in the coagulation bath. The resulting spiral graphene fiber displayed excellent mechanical and electrical stability even when stretched 20000 times at 320% elongation, as well as easily regulatable radius (0.1–3.5 mm) and pitch (1–8 mm) through changing the revolution radius (distance between spinneret and revolution axis) and the motion (horizontal movement and rotation speed) of the spinneret, respectively. Moreover, functionalized with TiO2 nanoparticles, the obtained spiral composite fiber featured a highly sensitive photoelectric response to its tiny deformation, implying a great potential for liquid micro-vibration detection. This study provides a new strategy to fabricate controllably spiral graphene-based fibers with high properties.

Dissociating Sensorimotor Recovery and Compensation During Exoskeleton Training Following Stroke.

The quality of arm movements typically improves in the sub-acute phase of stroke affecting the upper extremity. Here, we used whole arm kinematic analysis during reaching movements to distinguish whether these improvements are due to true recovery or to compensation. Fifty-three participants with post-acute stroke performed ∼80 reaching movement tests during 4 weeks of training with the ArmeoSpring exoskeleton. All participants showed improvements in end-effector performance, as measured by movement smoothness. Four ArmeoSpring angles, shoulder horizontal (SH) rotation, shoulder elevation (SE), elbow rotation, and forearm rotation, were recorded and analyzed. We first characterized healthy joint coordination patterns by performing a sparse principal component analysis on these four joint velocities recorded during reaching tests performed by young control participants. We found that two dominant joint correlations [SH with elbow rotation and SE with forearm rotation] explained over 95% of variance of joint velocity data. We identified two clusters of stroke participants by comparing the evolution of these two correlations in all tests. In the “Recoverer” cluster (N = 19), both joint correlations converged toward the respective correlations for control participants. Thus, Recoverers relearned how to generate smooth end-effector movements while developing joint movement patterns similar to those of control participants. In the “Compensator” cluster (N = 34), at least one of the two joint correlations diverged from the corresponding correlation of control participants. Compensators relearned how to generate smooth end-effector movements by discovering various new compensatory movement patterns dissimilar to those of control participants. New compensatory patterns included atypical decoupling of the SE and forearm joints, and atypical coupling of the SH rotation and elbow joints. There was no difference in clinical impairment level between the two groups either at the onset or at the end of training as assessed with the Upper Extremity Fugl-Meyer scale. However, at the start of training, the Recoverers showed significantly faster improvements in end-effector movement smoothness than the Compensators. Our analysis can be used to inform neurorehabilitation clinicians on how to provide movement feedback during practice and suggest avenues for refining exoskeleton robot therapy to reduce compensatory patterns.

Sustainable Measures for Protection of Structures Against Earthquake Induced Liquefaction

Soil liquefaction can cause excessive damage to structures as witnessed in many recent earthquakes. The damage to small/medium-sized buildings can lead to excessive death toll and economic losses due to the sheer number of such buildings. Economic and sustainable methods to mitigate liquefaction damage to such buildings are therefore required. In this paper, the use of rubble brick as a material to construct earthquake drains is proposed. The efficacy of these drains to mitigate liquefaction effects was investigated, for the first time to include the effects of the foundations of a structure by using dynamic centrifuge testing. It will be shown that performance of the foundation in terms of its settlement was improved by the rubble brick drains by directly comparing them to the foundation on unimproved, liquefiable ground. The dynamic response in terms of horizontal accelerations and rotations will be compared. The dynamic centrifuge tests also yielded valuable information with regard to the excess pore pressure variation below the foundations both spatially and temporally. Differences of excess pore pressures between the improved and unimproved ground will be compared. Finally, a simplified 3D finite element analysis will be introduced that will be shown to satisfactorily capture the settlement characteristics of the foundation located on liquefiable soil with earthquake drains.

A deep region-based pyramid neural network for automatic detection and multi-classification of various surface defects of aluminum alloys

Aluminum alloys have a wide range of applications in building and civil infrastructure. During the process of production, transportation and storage, various defects inevitably occur on the material, including blisters, scratches, base exposure, dirty points, etc. The efficiency and accuracy of defect detection and classification can be greatly improved by replacing the conventional manual approaches with modern deep learning techniques. This paper proposes to use computer vision and deep learning techniques to achieve automatic detection of various defects of aluminum alloys. Faster region-based convolutional neural network (Faster R–CNN) is selected as the fundamental framework due to its advantages in efficiency and accuracy. According to the characteristics of defects in aluminum alloys, the framework is optimized by (1) feature pyramid networks (FPN) for integration of low-level structural information with high-level semantic information, as well as increasing the feature mapping resolution of small targets; (2) deformable-ConvNets for feature extraction at the most appropriate places; and (3) contextual ROI pooling for fine adjustment of region proposal taking the entire image as a reference. To make full use of the limited samples, the training process is also optimized by (1) utilizing samples without defects; and (2) sample duplication by horizontal and vertical rotation. The proposed approach is validated on a dataset with 10000 images and is shown to have outstanding performance compared to other existing deep learning approaches in defect detection and classification. • A deep learning model is proposed for defect detection in aluminum alloys. • Feature pyramid network is incorporated to improve feature mapping for small targets. • Deformable-ConvNets is utilized to improve detection for irregular defects. • Contextual ROI pooling is implemented to predict bounding boxes more accurately. • Defect-free samples are used to enhance the training process.

A system for detection of moving caption text in videos: a news use case

Extraction of news text captions aims at a digital understanding of what is happening in a specific region during a certain period that helps in better communication between different nations because we can easily translate the plain text from one language to another. Moving text captions causes blurry effects that are a significant cause of text quality impairments in the news channels. Most of the existing text caption detection models do not address this problem in a way that captures the different dynamic motion of captions, gathers a full news story among several frames in the sequence, resolves the blurring effect of text motion, offers a language-independent model, or provides it as an end-to-end solution for the community to use. We process the frames coming in sequence and extract edge features using either the Hough transform or our color-based technique. We verify text existence using a Convolutional Neural Network (CNN) text detection pre-trained model. We analyze the caption motion status using hybrid pre-trained Recurrent Neural Network (RNN) of Long Short-Term Memory (LSTM) type model and correlation-based model. In case the motion is determined to be horizontal rotation, there are two problems. First, it means that text keeps rotating with no stop resulting in a high blurring effect that affects the text quality and consequently resulting in low character recognition accuracy. Second, there are successive news stories which are separated by the channel logo or long spaces. We managed to solve the first problem by deblurring the text image using either Bicubic Spline Interpolation (BSI) technique or the Denoising Autoencoder Neural Network (DANN). We solved the second problem using a Point Feature Matching (PFM) technique to match the existing channel logo with the channels’ logo database (ground truth). We evaluate our framework using Abbyy® SDK as a standalone tool used for text recognition supporting different languages.

Material properties and effect of preconditioning of human sclera, optic nerve, and optic nerve sheath

The optic nerve (ON) is a recently recognized tractional load on the eye during larger horizontal eye rotations. In order to understand the mechanical behavior of the eye during adduction, it is necessary to characterize material properties of the sclera, ON, and in particular its sheath. We performed tensile loading of specimens taken from fresh postmortem human eyes to characterize the range of variation in their biomechanical properties and determine the effect of preconditioning. We fitted reduced polynomial hyperelastic models to represent the nonlinear tensile behavior of the anterior, equatorial, posterior, and peripapillary sclera, as well as the ON and its sheath. For comparison, we analyzed tangent moduli in low and high strain regions to represent stiffness. Scleral stiffness generally decreased from anterior to posterior ocular regions. The ON had the lowest tangent modulus, but was surrounded by a much stiffer sheath. The low-strain hyperelastic behaviors of adjacent anatomical regions of the ON, ON sheath, and posterior sclera were similar as appropriate to avoid discontinuities at their boundaries. Regional stiffnesses within individual eyes were moderately correlated, implying that mechanical properties in one region of an eye do not reliably reflect properties of another region of that eye, and that potentially pathological combinations could occur in an eye if regional properties are discrepant. Preconditioning modestly stiffened ocular tissues, except peripapillary sclera that softened. The nonlinear mechanical behavior of posterior ocular tissues permits their stresses to match closely at low strains, although progressively increasing strain causes particularly great stress in the peripapillary region.

Out-of-Plane Alignment of Conjugated Semiconducting Polymers by Horizontal Rotation in a High Magnetic Field.

The effective control of film morphology and molecular packing in the out-of-plane direction of semiconductor polymers plays a critical role in governing charge carrier transport in the direction perpendicular to the substrate. In this study, a highly out-of-plane alignment of the n-type polymer P(NDI2OD-T2) film has been successfully achieved by horizontal rotation in a high magnetic field (HR-HMF). The out-of-plane alignment of the P(NDI2OD-T2) film has showed a change from 72% face-on to 98.2% face-on lamellar texture as well as a 1.6-fold increase of the π-π stacking crystalline correlation length compared with that of as-cast polymer films without HR-HMF-induced alignment. Meanwhile, the film with near-perfect face-on molecular packing exhibited more than 18-fold enhancement of electron mobility compared to the unaligned film. The excellent electrical performance achieved with the HR-HMF process indicates its application potential for fabricating high-performance sandwich-type organic electronic devices, such as solar cells and light-emitting diodes.

Study on Migratory Behavior of Aggregate in Asphalt Mixture Based on the Intelligent Acquisition System of Aggregate Attitude Data

In order to provide a new method to study the migration behavior of coarse aggregates in the compaction process of asphalt mixtures, the “Intelligent Aggregate Attitude Acquisition System (IAS)” is developed based on 3D printing technology and wireless intelligent sensing technology, and the “Intelligent Attitude Aggregate (IAA)” is prepared as the acquisition terminal. The Superpave Gyratory Compaction (SGC) test and the Internet of Things (IOT) wireless sensor technology are combined to collect and analyze the attitude data of an SMA-20 asphalt mixture built in IAA at different compaction stages, and the migration behavior of coarse aggregate in the compaction process is quantitatively characterized. The result shows that the IAA is suitable as a “tracking aggregate” to study the aggregate transfer behavior in asphalt mixtures. The IAA in the upper layer tends to move vertically downward, while the particles in the lower layer tend to move horizontally and spatial rotation in the process of rotating compaction. With the increase in asphalt content, the lubrication effect between aggregate particles is obvious, and the friction resistance of aggregate particles decreases when it is embedded downward. Affected by shear force in the process of rotary compaction, the aggregate particles are easier to overcome friction and cause large horizontal migration and spatial rotation. With the increase in compaction temperature, the viscosity of asphalt binder decreases, and the contact friction between aggregate particles decreases. The asphalt content has a significant effect on the displacement in the horizontal plane Dxoy of the aggregate. The asphalt content and compaction temperature have significant effects on the spatial rotation angle Φ of aggregate, but the asphalt content has a greater impact on it.

Pre-treatment and real-time image guidance for a fixed-beam radiotherapy system

Purpose. A radiotherapy system with a fixed treatment beam and a rotating patient positioning system could be smaller, more robust and more cost effective compared to conventional rotating gantry systems. However, patient rotation could cause anatomical deformation and compromise treatment delivery. In this work, we demonstrate an image-guided treatment workflow with a fixed beam prototype system that accounts for deformation during rotation to maintain dosimetric accuracy. Methods. The prototype system consists of an Elekta Synergy linac with the therapy beam orientated downward and a custom-built patient rotation system (PRS). A phantom that deforms with rotation was constructed and rotated within the PRS to quantify the performance of two image guidance techniques: motion compensated cone-beam CT (CBCT) for pre-treatment volumetric imaging and kilovoltage infraction monitoring (KIM) for real-time image guidance. The phantom was irradiated with a 3D conformal beam to evaluate the dosimetric accuracy of the workflow. Results. The motion compensated CBCT was used to verify pre-treatment position and the average calculated position was within −0.3 ± 1.1 mm of the phantom’s ground truth position at 0°. KIM tracked the position of the target in real-time as the phantom was rotated and the average calculated position was within −0.2 ± 0.8 mm of the phantom’s ground truth position. A 3D conformal treatment delivered on the prototype system with image guidance had a 3%/2 mm gamma pass rate of 96.3% compared to 98.6% delivered using a conventional rotating gantry linac. Conclusions. In this work, we have shown that image guidance can be used with fixed-beam treatment systems to measure and account for changes in target position in order to maintain dosimetric coverage during horizontal rotation. This treatment modality could provide a viable treatment option when there insufficient space for a conventional linear accelerator or where the cost is prohibitive.

Implementation of Dual Axis Solar Tracking System

As a future inexhaustible and non-polluting energy sources, solar energy is advancing to meet our ever-growing energy requirements. The automated solar tracking system based on the Arduino prototype is mainly built using the Arduino Microcontroller, four LDRs and three stepper motors. A mixture of hardware and firmware programming is used to run the machine. Four light based resistors (LDRs) are used for the capture of maximum incident light in hardware production. To shift the solar panel according to the extent incident light operated by LDRs, three stepper motors are used. The software controls the solar panel’s vertical tilt angle and horizontal rotation. Thus, according to the incident sunlight on the solar panel, it can follow the direction of the Sun, not only the vertical rotation, but also the horizontal rotation. This device can also achieve optimum illumination and reduce the cost of generating energy by requiring a minimum number of solar panels.

3D sandbox and numerical modeling of coseismic surface rupture induced by oblique-slip faulting and its interaction with embedded shallow foundation

A series of downscaled physical sandbox experiments are conducted to observe the evolution of the surface rupture induced by the oblique-slip faulting and estimate its impact on a rigid embedded shallow foundation. High-resolution orthoimages and digital surface model of the experiments are generated through the photogrammetry technique to quantify the ground deformation pattern.The distinct element model (DEM) is performed to validate the three-dimensional ground deformation pattern and the fault rupture-soil-foundation interaction (FR-SFI). The surface displacement profile reflects the fault-affected width being approximately 1.10 times the soil thickness. And the deformation gradients reveal the migration of the surface rupture on the ground surface. The distribution of accumulative strain in the numerical model shows the propagation of the fault rupture.The embedded rigid shallow foundation undergoes substantial displacement, inclination, and horizontal rotation with increasing oblique-slip faulting. However, the degrees of damage is strongly related to the spatial geometric relationship between the foundation and the fault rupture. The DEM simulation provides mechanical insights into the propagation of the fault rupture and shows the potential to elucidate the interaction between the shallow foundations and the coseismic surface rupture.

Radiographic assessment of carpal conformation in the horse, part 2: Finding acceptable limits to postural and rotational variations during radiography.

Finding an appropriate location for perpendicular positioning of the X-ray machine to produce zero lateromedial (ZLM) and zero dorsopalmar (ZDP) carpal images (views) and finding an acceptable range of rotational variations for measurement of carpal conformational parameters were two major challenges identified during field radiography of equine forelimbs. 16 cadaver forelimbs transacted at antebrachial midshaft from 10 horses (aged 9.13±4.59years) were axially mounted into a custom-built frame, and the radiographic machine and plate were perpendicularly aligned with the limb. Each limb was then radiographed at 2.5° interval of vertical rotation of the machine until ZLM and ZDP images were acquired, and at 24 other postural and rotational positions from ZLM and ZDP at 5° interval for comparison of measurements with the standardized ZLM and ZDP images. ZLM radiographs were produced at a mean vertical projection angle (VPA) of 9.84±3.47° palmarolateral-dorsomedial oblique (PaL-DMO), while ZDP was acquired at VPA of 6.41±2.73° dorsolateral-palmaromedial oblique (DL-PaMO). Changes in limbs' postural tilts, vertical plate rotations (VPR) and horizontal beam rotations (HBR) had no effect on the quality of the radiographs and on carpal measurements, while vertical beam rotation (VBR) of X-ray beam produced significant changes on the quality of radiographs and on measurements of carpal parameters. It is recommended that field radiographs of equine forelimbs intended for carpal measurement be obtained within a proposed range of VPA of 2.5° to 12.5° PaL-DMO for ZLM and 2.5° to 10° DL-PaMO for ZDP in order to minimize potential errors attributable to vertical rotational movements.

Active Head Auto-Rotations in Patients With Benign Paroxysmal Positional Vertigo.

BackgroundUtricular degeneration is the source of traveling otoconia inside the semicircular canals in patients with benign paroxysmal positional vertigo (BPPV). The underlying pathology is not clear. The aim of this study was to analyze vestibulo-ocular reflex (VOR) during sudden head accelerations in those patients since clinical reports designating an association of BPPV with inner ear problems are increasing.MethodsVOR reaction to impulsive head rotations were tested in 34 patients with BPPV (13 lateral, 21 posterior canal BPPV) and 15 healthy subjects in a prospective controlled study. Main outcome measure was the gain (the ratio of head and eye velocity) of vertical and horizontal head auto-rotations to the pathologic and normal sides.ResultsAll patients with BPPV and control subjects had normal gain (≥ 0.9) at 1 and 2 Hz but the gain decreased at higher frequencies. No statistically significant difference was found when comparing the gain between the horizontal head rotations toward the pathologic and those toward the normal side (P = 0.89, P = 0.90, P = 0.78, P = 0.20 and P = 0.16, at 1, 2, 3, 4 and 5 Hz, respectively) and between upward and downward vertical head rotations (P = 0.28, P = 0.53 and P = 0.15, at 1, 2 and 3 Hz, respectively) in patients with lateral and posterior canal BPPV.ConclusionVOR gain was reduced in some patients. However, head auto-rotation test (HART) does not show any functional abnormality of VOR during head rotations toward the pathologic side. HART is not suitable as a screening test for BPPV.

Measurements of human tolerance to horizontal rotation within an MRI scanner: Towards gantry-free radiation therapy.

Recent advances in image guidance and adaptive radiotherapy could enable gantry-free radiotherapy using patient rotation. Gantry-free radiotherapy could substantially reduce the cost of radiotherapy systems and facilities. MRI guidance complements a gantry-free approach because of its ability to visualise soft tissue deformation during rotation. A potential barrier to gantry-free radiotherapy is patient acceptability, especially when combined with MRI. This study investigates human experiences of horizontal rotation within an MRI scanner. Ten healthy human participants and nine participants previously treated with radiotherapy were rotated within an MRI scanner. Participants' anxiety and motion sickness was assessed before being rotated in 45-degree increments and paused, representing a multi-field intensity-modulated radiotherapy treatment. An MR image was acquired at each 45-degree angle. Following imaging, anxiety and motion sickness were re-assessed, followed by a comfort questionnaire and exit interview. The significance of the differences in anxiety and motion sickness pre- versus post-imaging was assessed using Wilcoxon signed-rank tests. Content analysis was performed on exit interview transcripts. Eight of ten healthy and eight of nine patient participants completed the imaging session. Mean anxiety scores before and after imaging were 7.9/100 and 11.8/100, respectively (P=0.26), and mean motion sickness scores were 5.3/100 and 13.7/100, respectively (P=0.02). Most participants indicated likely acceptance of rotation if MRI were to be used in a hypothetical treatment. Physical discomfort was reported to be the biggest concern. Horizontal rotation within an MRI scanner was acceptable for most (17/19) participants.

Mechanical responses of bell‐and‐spigot joints in buried prestressed concrete cylinder pipe under coupled service and surcharge loads

AbstractPrestressed concrete cylinder pipe (PCCP) is widely used in hydraulic engineering. The bell‐and‐spigot joint is a weak point along a PCCP pipeline, since damage of joint can affect the operation of the whole pipeline. In this paper, a three‐dimensional numerical model of buried PCCP, considering the simulation of rubber gasket in bell‐and‐spigot joint is established. The fluid–structure coupling of PCCP is accomplished using the Mesh‐based parallel Code Coupling Interface (MpCCI), where the pipe and the surrounding soil are characterized in the software ABAQUS, and the pressurized water is modeled in the software FLUENT. The force and rotation angle at joints of PCCP under different conditions, including surcharge load, loading location, cover depth, and internal pressure, are analyzed. It is shown that the rotation angle of joint exceeds the allowable value, when the surcharge load is greater than 180 kPa. Compared with the effect of surcharge load, the offset distance (i.e., distance between the loading position and the pipe axis) has a greater influence on the development of horizontal displacement and rotation angle. As the offset distance increases, both the horizontal displacement and rotation angle at joints increase first, and they decrease after the peak.

АНАЛИЗ ОТЕЧЕСТВЕННЫХ И ЗАРУБЕЖНЫХ ТЕХНИЧЕСКИХ СРЕДСТВ ДЛЯ ВОЗДЕЛЫВАНИЯ КАРТОФЕЛЯ И ТОПИНАМБУРА НА ГРЯДАХ

Growing potatoes involves extensive ground preparation. Factors affecting the crop are air and moisture permeability of the soil. (Research purpose) The research purpose is in analyzing existing domestic and foreign technical means for growing potatoes and Jerusalem artichoke on seed plot. (Materials and methods) The article presents the advantages and disadvantages of using vertical and horizontal tillage cutters. Authors have analyzed existing domestic and foreign tillage cutters and tools and their applications. (Results and discussion) For high-quality pre-planting tillage there are widely used cutters with horizontal and vertical rotation axes; for loosening the lower layers of soil under a seed plot there are used various paws installed on the cutters; in order to perform several operations by one machine, in particular, continuous milling with loosening the lower layers and strip milling with cutting ridges, separate designs of horizontal cutters contain replaceable both a roller and an apron-ridgeformer. Due to the use of replaceable tools, horizontal cutters are more suitable for performing different operations than vertical ones; a rational design of a milling cultivator for pre-planting soil treatment should contains replaceable organs for continuous milling and leveling the top layer of soil and forming ridges before planting and when caring for potato and Jerusalem artichoke plantings. (Conclusions) Pre-planting milling of the soil for potatoes is better than traditional. Despite the high energy intensity of the process of preparing the soil for planting potatoes, the quality of milling cultivators exceeds the agrotechnical performance of non-driving machines.