Carbon Fiber Rods Research Articles

Design of an active wing-folding biomimetic flapping-wing air vehicle

In nature, birds and bats dynamically alter their wing shapes to suit various flight environments and tasks. This paper focuses on the design and validation of a biomimetic flapping-wing aerial vehicle, named FlexiWing, which features a unique mechanism for active wing deformation. This mechanism allows the wings to adjust their shapes flexibly in response to flight demands, significantly enhancing attitude control and maneuverability.’ ‘This study began with an in-depth exploration of biomimetic principles, focusing particularly on how birds and bats achieve precise control during flight through active wing deformation. Subsequently, we present a detailed account of the design and fabrication process of the active folding biomimetic flapping-wing aerial vehicle, including the design of mechanical mechanisms and material selection. Utilizing lightweight nylon materials and hollow carbon fiber rods, we successfully constructed a mechanically foldable wing structure. To achieve precise control over the aircraft’s movement, an embedded control system was designed, comprising an onboard embedded flight controller and ground-based equipment. The onboard controller uses a high-performance ESP32-C3 processor and a JY901 inertial measurement unit to acquire real-time attitude information of the aircraft. The control system incorporates Wi-Fi communication technology, enabling operators to send commands via a remote control or personal computer to manage flight modes and attitudes. Ultimately, a series of flight experiments were conducted to validate the performance of FlexiWing. The results demonstrate that FlexiWing exhibits remarkable maneuverability and stability, capable of achieving high-precision attitude control through active wing folding, making it adaptable to complex environments and tasks.’

The LHCb VELO Upgrade module construction

The LHCb detector has undergone a major upgrade for LHC Run 3. This Upgrade I detector facilitates operation at higher luminosity and utilises full-detector information at the LHC collision rate, critically including the use of vertex information. A new vertex locator system, the VELO Upgrade, has been constructed. The core element of the new VELO are the double-sided pixelated hybrid silicon detector modules which operate in vacuum close to the LHC beam in a high radiation environment. The construction and quality assurance tests of these modules are described in this paper. The modules incorporate 200 μm thick, n-on-p silicon sensors bump-bonded to 130 nm technology ASICs. These are attached with high precision to a silicon microchannel substrate that uses evaporative CO2 cooling. The ASICs are controlled and read out with flexible printed circuits that are glued to the substrate and wire-bonded to the chips. The mechanical support of the module is given by a carbon fibre plate, two carbon fibre rods and an aluminium plate. The sensor attachment was achieved with an average precision of 21 μm, more than 99.5% of all pixels are fully functional, and a thermal figure of merit of 3 Kcm2W-1 was achieved. The production of the modules was successfully completed in 2021, with the final assembly and installation completed in time for data taking in 2022.

Enhancing UAV safety with an innovative anti-collision cage: Design, testing, and future prospects

The rapid evolution of Unmanned Aerial Vehicles (UAVs) or Unmanned Aircraft Systems (UAS) has revolutionized aviation across military and civilian domains with their pilotless flight capabilities. Despite their versatility, UAVs pose challenges in in-flight piloting precision, leading to potential mishaps. Addressing these concerns, this research introduces an innovative UAV Anti-Collision Cage designed to enhance drone safety. Constructed from C60-shaped carbon fiber rods and 3D-printed connectors, the cage resembles a footballs geometry, offering 360 protection. Experimental validations, including rolling, collision, and flying tests, were conducted to assess the cages performance. While the cage demonstrated resilience against minor impacts, significant impacts posed challenges. The study concludes with recommendations for future improvements, emphasizing geometric refinements, material choices, enhanced rolling abilities, sensor integration, and payload capacity. This research underscores the importance of safety mechanisms in UAV operations, paving the way for safer and more efficient drone operation in confined and complex environments.

Comparing the efficiency of strengthening timber beams reinforced with carbon composite rods and plates

This study reports the results of experiments comparing the effect of structural reinforcement for timber beams strengthened with different carbon composite materials. Samples of one series were strengthened by gluing a carbon fiber plate from the outside to the face of the beam. The samples of the other series were strengthened by laterally gluing two carbon fiber rods inside the beam. According to the bending research program, the ultimate loads and deflections were determined for both series. As a result of the analysis of the results and comparison with unreinforced samples from the control series, the effect of beam reinforcement and the model of their destruction were determined. Studies have shown that the effect of external reinforcement with a plate was 86.7 % according to the criterion of full failure load, 20.5 % according to the criterion of ultimate load, 13.4 % according to the criterion of ultimate deflection. The effect of rod reinforcement was 48.6 %, 18.6 %, and 4.1 %, respectively. The theoretical analysis of the results showed a convergence of up to 8.2 % with the experimental results. External reinforcement with a plate compared to lateral gluing of rods showed better results due to the placement of the plate in the zone of maximum tensile stresses. This arrangement more effectively limited the spread of ultimate stresses and the development of cracks. The reinforcement parameters of the samples (materials, placement, percentage of reinforcement) were selected under the condition of the same theoretically predicted bearing capacity after reinforcement. However, comparative experimental studies have revealed differences in the processes of deformation and destruction of reinforced beams. The results will contribute to making rational project decisions and for choosing a relevant technique of strengthening timber beams with carbon composite materials

Static structural and aerodynamics analysis of 3D printed flapping wing mechanism of butterfly inspired ornithopter

The wing flapping motion of butterfly is more straight forward, and its wing morphology is simple. The wingspan is also large enough to make it as a mid-size ornithopter. Based on these reasons, the ornithopter based upon the morphology of butterfly is studied. The objective of this three-dimensional numerical study is to investigate the butterfly ornithopter for its aerodynamic parameters for varied angle of attacks (-6° to 6°) and perform static structural analysis on the 3D printed flapping wing mechanism. The materials chosen for the wing is polypropylene fumarate, carbon fibre rods and Mylar films. The investigations are carried out using ANSYS Mechanical Workbench and ANSYS Fluent. The shear stress is evenly distributed throughout the wing structure for both the applied load conditions. Moreover, the maximum values of equivalent stress and equivalent elastic strain is observed in local concentrations at the position where the Mylar film material wing membrane is connected to the carbon fibre rod. The deformation pattern is maximum at the wingtips (0.08569 for pressure 4.8 Pa; 0.067697 for pressure 3.8 Pa) and minimal near the support sections. The maximum lift with minimum drag is observed at angle of attack + 2°.

Headless cannulated screw and external fixator in the treatment of type C distal femur fractures: Effect of early mobilization on clinical outcomes.

Distal femur fractures occur due to high-energy trauma in young patients and with low-energy traumas in osteoporotic elderly patients. Implants selected for use in the treatment of distal femur fracture should provide stable fixation and allow early mobilization especially at elder patients. We aimed to investigate the effects of the headless cannulated screw and external fixator combination on the early mobilization of the patients and postoperative complications. Twenty-one patients with Type C distal femur fracture were included in the study.The fracture lines were temporarily fixed with K wires. After the fracture reduction with headless cannulated screws a tubular external fixator with carbon fiber rods was applied to bridge the knee joint. The external fixators were removed at the 6th week follow-up, and the patients were forced to perform knee flexion as much as they could tolerate. The 6th month KSS scores of the patients were 44.3 (34-60) and the 18th month KSS scores were 77.5 (60-88).Preoperative VAS score was 8(7-10) and postoperative VAS score was 4(3-6).Knee flexion of the patients at 6th months was 95.9 (80-110 degrees) and at 6th months knee flexion was 114.5 (100-125 degrees). Superficial pin site infection was observed at 4 patients and regressed with antibiotic therapy. Combination of cannulated screws with an external fixator for joint restoration in type C distal femur fractures allows early mobilization and reduces postoperative morbidity.

Evaluation of Carbon Fiber and Titanium Surgical Implants for Proton and Photon Therapy

Impending and actual pathologic fractures secondary to metastatic bone disease, lymphoma, or multiple myeloma often require intramedullary fixation followed by radiation therapy. Because of carbon's low atomic number, there are reduced computed tomography (CT) imaging artifacts and dose perturbation when planning postoperative radiation for carbon fiber (CF) rods. Herein, we characterize the dosimetric properties of CF implants compared with titanium alloy (TA) for proton and photon. TA and CF samples were acquired from an implant manufacturer. Material characteristics were evaluated by CT scans with and without metal artifact reduction (MAR). Relative stopping power (RSP) was determined from the range pull-back of each sample in a 20-cm range proton beam. Photon transmission measurements were made in a solid water phantom and compared with the modeled dosimetry from the RayStation planning system. CF caused no visible CT artifacts, and MAR was not necessary for Hounsfield unit (HU) determination (median, 364 HU) or contouring, whereas TA (median, 3071 HU) caused substantial artifacts, which were improved, but not eliminated by MAR. The proton RSP was measured as 3.204 for TA and 1.414 for CF. For 6 MV photons, the measured transmission was 89.3% for TA and 98% for CF. CF RSP calculation and transmission from CT HU showed a physical density overestimate compared with measurements, which would cause a slight, but acceptable, dose uncertainty (<10% proton range or 1% photon transmission). With a density similar to bone, CF implants did not cause imaging artifacts and minimal dose perturbation compared with TA. Although the CF proton RSP is underestimated and the photon attenuation is overestimated by the HU, both effects are relatively small and may be most easily accounted for by planning with a 2-mm expansion around organs at risk beyond or in close proximity to the implant.

Modelling of space antenna deployment using open source software

The goal of this article is to develop a dynamic model of a space antenna with the pantograph structure and to study the processes of its deployment using open-source software. Methods of theoretical mechanics, multibody dynamics, computational mechanics, and computer modeling were used in the research. A mesh antenna of the novel design, which is recommended for mini-satellites, is considered as the object for modeling. The most significant difference between this antenna and others is the design of the support ring in the form of a pantograph. To develop a model of the space antenna dynamics and implement it using open-source software, some simplifications were made due to the complexity of the structure. The antenna model is represented as a system of rigid and flexible bodies connected by hinges. Carbon fiber rods are modeled with the help of a flexible finite element using the method of absolute nodal coordinates, which allows one to model large deformations of the structure. Aluminum hinge assemblies are modeled as several rotation joints connected by conventional rigid elements. The main modeled properties of these hinge assemblies are the stiffness, location, and direction of the axes of rotation of the hinges. The tension forces created by the stretched mesh are modeled using springs. The cable drive of the antenna deployment mechanism is modeled as a load acting on the corresponding elements in defined local positions. An algorithm for building a model of the space antenna to simulate the reflector deployment process in the HotInt open-source software is presented. Using the built model, antenna deployment simulations are carried out for different cases, which differ in the forces used for the deployment. Values of deployment time, variations of angles between the V-folded bars, and tensions in the diagonal rods of the antenna sections during the antenna deployment are obtained. The approach proposed in the article can be implemented using free software, ensures flexibility of modeling, and reduces the model development time.

Abdominal Movements in Insect Flight Reshape the Role of Non-Aerodynamic Structures for Flight Maneuverability I: Model Predictive Control for Flower Tracking.

SynopsisResearch on insect flight control has focused primarily on the role of wings. Yet abdominal deflections during flight can potentially influence the dynamics of flight. This paper assesses the role of airframe deformations in flight, and asks to what extent the abdomen contributes to flight maneuverability. To address this, we use a combination of both a Model Predictive Control (MPC)-inspired computational inertial dynamics model, and free flight experiments in the hawkmoth, Manduca sexta. We explored both underactuated (i.e., number of outputs are greater than the number of inputs) and fully actuated (equal number of outputs and inputs) systems. Using metrics such as the non-dimensionalized tracking error and cost of transport to evaluate flight performance of the inertial dynamics model, we show that fully actuated simulations minimized the tracking error and cost of transport. Additionally, we tested the effect of restricted abdomen movement on free flight in live hawkmoths by fixing a carbon fiber rod over the thoracic-abdomen joint. Moths with a restricted abdomen performed worse than sham treatment moths. This study finds that abdominal motions contribute to flight control and maneuverability. Such motions of non-aerodynamic structures, found in all flying taxa, can inform the development of multi-actuated micro air vehicles.

Practical Assessment of Real‐Time Suspended Sediment Load Monitoring Using Time Domain Reflectometry

AbstractSuspended sediment concentration (SSC) and sediment load are essential factors in water resource management, hydraulic engineering, soil and water conservation, sedimentation, and environmental ecology. A novel real‐time SSC monitoring approach involving time domain reflectometry (TDR) was proposed. The previous results obtained indicated that the soil particle size does not affect the TDR SSC method and that this method is applicable at high suspended sediment concentrations (≥600,000 ppm). To further improve the measurement stability and accuracy of this method for long‐term monitoring of rivers and reservoirs, several practical problems were solved in this study, including noise interference, probe fouling, and the effect of ambient temperature on the TDR device used. With the proposed improvements in the analysis of the modified frequency domain phase velocity, the new method was examined in a laboratory setting, and a measurement standard deviation of 1,000 ppm was found. In addition, a novel carbon fiber rod with a novel detachable probe was proposed to decrease the nonlinear SSC variations resulting from the coating effect as part of the electromagnetic sensing field. As observed during the experiment, the use of a fully digital TDR device decreased the ambient temperature effect. Several TDR SSC measurements were performed at the Shihgang Reservoir, revealing long‐term SSC and sediment load typhoon events from 2013 to 2021. Subsequently, real‐time TDR SSC monitoring with sediment load quantification was performed to establish the relationship between sediment load and outflow discharge, and the results obtained indicated that this method helped characterize suspended sediment load.

P121. Carbon fiber reinforced PEEK implants for spine tumors: a single center experience

<h3>BACKGROUND CONTEXT</h3> Titanium is the most common material used to manufacture spinal implants; however, its metallic properties are associated with imaging artifacts on CT and MRI scans which impede treatment planning and clinical follow among oncologic patients. Carbon fiber-reinforced Polyether ether ketone (CFR-PEEK) based spinal implants are an alternative to titanium, offering less image artifact as its titanium counterparts while maintaining similar biomechanical and biocompatibility properties. Its use in the management of spinal tumors has been reported, however the perceived advantages related to improved imaging quality, radiation treatment planning, and detection of tumor recurrence have not been fully assessed. <h3>PURPOSE</h3> We report our experience at the MD Anderson Cancer Center with the use of CFR-PEEK implants in the treatment of oncological patients. <h3>STUDY DESIGN/SETTING</h3> Retrospective single-arm single-center study. <h3>PATIENT SAMPLE</h3> All consecutive patients from September 2019 to July 2021 who were operated for spine conditions and had carbon fiber-reinforced implants. <h3>METHODS</h3> We performed a retrospective review of the medical records and imaging studies of patients treated with CFR-PEEK implants from September 2019 to July 2021. Histology type, tumor location, construct features, time of follow up, type of adjuvant radiation, recurrences, overall survival and hardware related complications were recorded. <h3>RESULTS</h3> Seventy-one consecutive patients were assessed (20 primary tumors, 47 metastases, 4 others). The median time for followup was 5.4 months (Q1 1.13, Q3 11.9, IQR 10.77). Of those 6 patients received conventional external beam radiotherapy, 31 received spinal stereotactic radiosurgery with a median time to radiation of 35 days among primary tumors and 30 days among metastatic cases. A total of 4 patients with primary tumors presented recurrence at a median time of 4.7 months (N=4, Q1 2.7, Q3 7, IQR 4.3) and 7 patients with metastatic disease presented recurrence at a median time of 3.4 months (N=6, Q1 2.0, Q3 5.1, IQR 3.1). Hardware complications were observed in a total of 5 cases (7.04%) and included screw loosening, intraoperative screw breakage and loosened set screw. Imaging review demonstrated significant reduction in imaging artifact and enhanced detection of local recurrence when compared to similar cases operated with standard titanium spinal instrumentation. <h3>CONCLUSIONS</h3> Carbon fiber reinforced PEEK implants provided safe and effective spinal stabilization for patients with both primary and metastatic tumors while integrating into postoperative imaging and radiation planning. The associated reduction in imaging artifacts enhanced postoperative radiation planning and the ability to detect local recurrence. <h3>FDA DEVICE/DRUG STATUS</h3> Carbon fiber thoracolumbar screws and rods (Icotec AG, Altstätten, Switzerland) (Approved for this indication)

Defect identification method of carbon fiber sucker rod based on GoogLeNet-based deep learning model and transfer learning

Carbon fiber sucker rods are widely used in oil production site due to their light weight, high strength and corrosion resistance, but there is still a lack of effective internal defect detection methods during production and installation. Aiming at the characteristics of irregular interface in the sucker rod, a novel defect identification method of carbon fiber sucker rod based on multi-sensor information fusion and GoogLeNet-based deep learning model was proposed to identify online the internal defects of carbon fiber sucker rod. First, the full coverage scan of the sucker rod in the cross-section was performed by a water-immersed ultrasonic array containing 32 probes, and the corresponding ultrasonic reflection signals was obtained. Then, a multi-sensor information fusion method was proposed to integrate amplitude and flight time of received ultrasonic reflection signals with the spatial angle information of each probe into defect images. Time signal waveforms of ultrasonic signals with different defects were mapped into different defect images, so that we can rely on deep learning models in the field of image identification to identify those defects. Finally, A GoogLeNet-based deep learning model were trained to identify the image-based defect of the carbon fiber rod. The transfer learning method, which transferred weights of the pre-trained GoogLeNet model by ImageNet large database to the GoogLeNet-based defect identification model, was adopted to enhance the convergence speed and generalization ability of the model for insufficient training samples. The testing results show that the overall defect identification accuracy of the trained GoogLeNet-based deep learning model was 99.72%, which can identify effectively four typical defects and no defects of carbon fiber sucker rods.

Defect Detection Method of Carbon Fiber Sucker Rod Based on Multi-Sensor Information Fusion and DBN Model.

Because of its unique characteristics of small specific gravity, high strength, and corrosion resistance, the carbon fiber sucker rod has been widely used in petroleum production. However, there is still a lack of corresponding online testing methods to detect its integrity during the process of manufacturing. Ultrasonic nondestructive testing has become one of the most accepted methods for inspection of homogeneous and fixed-thickness composites, or layered and fixed-interface-shape composites, but a carbon fiber sucker rod with multi-layered structures and irregular interlayer interfaces increases the difficulty of testing. In this paper, a novel defect detection method based on multi-sensor information fusion and a deep belief network (DBN) model was proposed to identify online its defects. A water-immersed ultrasonic array with 32 ultrasonic probes was designed to realize the online and full-coverage scanning of carbon fiber rods in radial and axial positions. Then, a multi-sensor information fusion method was proposed to integrate amplitudes and times-of-flight of the received ultrasonic pulse-echo signals with the spatial angle information of each probe into defect images with obvious defects including small cracks, transverse cracks, holes, and chapped cracks. Three geometric features and two texture features from the defect images characterizing the four types of defects were extracted. Finally, a DBN-based defect identification model was constructed and trained to identify the four types of defects of the carbon fiber rods. The testing results showed that the defect identification accuracy of the proposed method was 95.11%.

Dynamic Simulation Analysis of Carbon-Steel Hybrid Sucker Rod String in Vertical and Directional Wells

Carbon fiber composite continuous sucker rod string is more and more widely used in deep and ultradeep wells because of its light weight, high strength, and corrosion resistance. In order to analyze the dynamic problems of carbon fiber sucker rod string in actual oil wells, a transverse vibration simulation model of carbon fiber and steel (carbon-steel) hybrid rod string excited by buckling deformation in vertical wells is established with the compression buckling deformation of weighting rod. Considering the influence of wellbore trajectory and the constraint of tubing, the transverse vibration simulation model of carbon-steel hybrid rod string in directional wells under borehole trajectory excitation is also established in this paper. The finite difference method is used to discretize the well depth node, the numerical integration method (Newmark-β) is used to discretize the reciprocating periodic time node, and simulation methods for the contact and collision dynamics of rod-tubing in vertical wells and directional wells are formed. Through programming calculation, the distribution laws of transverse displacement, contact force, collision force, and bending stress of carbon-steel hybrid sucker rod string in vertical wells and directional wells along well depth are obtained. The simulation results in vertical wells show that the strong collision between the rod and tubing occurs near the bottom steel rod, while the upper load is small and the rod-tubing collision load of the upper rod of the carbon-steel hybrid rod string is much lower than that of the traditional steel rod string at the same position. Furthermore, the bending stress of the upper carbon fiber is also much less than that of the bottom steel rod. The simulation results in directional wells show that the collision phenomenon of the deflecting section and the bottom weighting rod compression section are the strongest and the rod-tubing contact pressure is also the largest. Second, the impact force of the upper carbon fiber rod is also much lower than that of the steel rod. Again, the maximum bending stress of the whole well occurs near the deviation section where the deviation angle changes suddenly. The transverse vibration mechanical model in directional wells in this paper lays a theoretical foundation and provides theoretical support for the optimal design of fracture and splitting prevention measures of carbon fiber sucker rod.

Synthesis and Characterization of Novel Nickel Coated Carbon Fibre Rod Reinforced Aluminium Metal Matrix Composite Material for using in Automobile Application

A carbon fibre (CF) in the form of a rod (continuous fibre) was used as reinforcement due to its superior strength and modulus properties. Carbon fibre rod reinforced aluminium 6061 alloy metal matrix composite material was synthesized using the stir casting liquid metallurgy route. Aluminium based metal matrix composite materials are light in weight. Very few researchers were worked on carbon fibre rod reinforced metal matrix composites (MMC). Electroless nickel deposition on carbon fibre rods (2mm and 3mm diameter) were carried out for improvement in wettability. On carbon fibre rods, the effectiveness of electroless nickel coating was validated using SEM (scanning electron microscopy) and EDAX (Energy Dispersive X-Ray Spectroscopy) analysis. A further coating thickness of nickel was improved using nickel electroplating. In a cast iron mould, nickel-coated carbon fibre rods were arranged in a circular pattern. Completely degassed molten aluminium 6061 alloy was poured in cast iron mould at 600-700 °C. The enhancement in Tribological and mechanical properties is always a prerequisite for technological advancement in automobile sector. From synthesized composites (11.11% Vol. CF and 25% Vol. CF reinforcement) specimen were prepared for density tests, bulk and microhardness tests, friction and wear tests. Synthesized composite has low density, increased bulk and microhardness, low coefficient of friction and reduced wear rate in comparison with aluminium 6061 alloy. Keywords: Carbon Fibre (CF) rod, MMC, Nickel coating, Casting, Mechanical, Tribological

Design and Fabrication of a Flapping-Wing Robot Based on Slider-Crank Mechanism

&#x0D; Tailless Flapping-Wing Micro Air Vehicles (FW-MAVs) have gained more attention recently because they utilize energy more efficiently compared to fixed-wing aircraft and rotorcrafts. FW-MAVs could be used commercially to explore confined spaces with insufficient air or serve as surveillance robots. However, due to their use of unsteady aerodynamics and small size, the research and design process is very complicated. In this paper, I propose a flight mechanism for a light-weighted, two-winged, hummingbird-inspired flapping-wing robot. Five versions of the robot were built; each version improved upon the issues of the previous one. Calculations were performed to optimize the stroke amplitude and the transmission ratio of the gears. Four groups of control experiments were conducted to investigate the relationship between different factors (voltage, motor type, wing area, and the number of veins) and the robot’s lift, which was monitored by a pressure sensor. I analyzed the results from the experiments and built a final version of the robot based on a slider-crank mechanism. The main structure of the final version is made of three 3mm carbon fiber boards, and the wings are made of 0.025mm PET (polyethylene terephthalate) material, reinforced by three carbon fiber rods: two 0.5mm ones across the membrane and a 1mm one at the leading edge. The robot weighs 16.3g and can produce enough lift to overcome its gravity under 9V with an off-board power source by exhibiting an upward trend during a tethered flight test.&#x0D;

A robotic magnetic resonance-guided high-intensity focused ultrasound platform for neonatal neurosurgery: Assessment of targeting accuracy and precision in a brain phantom.

Intraventricular hemorrhage (IVH) is one of the most serious neurovascular complications resulting from premature birth. It can result in clotting of blood within the ventricles, which causes a buildup of cerebrospinal fluid that can lead to posthemorrhagic ventricular dilation and posthemorrhagic hydrocephalus. Currently, there are no direct treatments for these blood clots as the standard of care is invasive surgery to insert a shunt. Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) has been investigated as a noninvasive treatment to lyse blood clots. However, current MRgHIFU systems are not suitable in the context of treating IVH in neonates. We have developed a robotic MRgHIFU neurosurgical platform designed to treat the neonatal brain. This platform facilitates ergonomic patient positioning and directs treatment through their open anterior fontanelle while providing a larger treatment volume. The platform is based on an MR-compatible robot developed by our group. Further development of the platform has warranted investigation of its targeting ability to assess its feasibility in the neonatal brain. This study aimed to quantify the platform's targeting accuracy, precision, and repeatability using a brain phantom and clinical MRI system. A thermosensitive brain-mimicking phantom was developed to test the platform's targeting accuracy. Rectangular grid patterns were created with HIFU thermal energy "lesions" in the phantoms by targeting specific coordinate points. The intended target locations were demarcated by inserting carbon fiber rods through a targeting assessment template. Coordinates for the intended and actual targets were derived from T2-weighted MRI scans, and the centroid distance between them was measured. Subsequently, the platform's targeting accuracy was quantified according to equations derived from ISO Standard 9283:1998. HIFU ablation resulted in distinct thermal lesions within the thermosensitive phantoms, which appeared as discrete hypointense regions in T2-weighted MR scans. A total of 127 target points were included in the data analysis, which yielded a targeting accuracy of 0.6mm and targeting precision of 1.2mm. The robotic MRgHIFU platform was shown to have a high degree of accuracy, precision, and repeatability. The results demonstrate the platform's functionality when targeting through simulated brain matter. These results serve as an initial verification of the platform targeting ability and showed promise toward the final application in a neonatal brain.

Vibration from Electric Hand-Held Harvesters for Olives

Olive harvesting is the most expensive cultivation operation in areas where full mechanization is not possible due to structural conditions such as low tree density, old trees, irregular spacing, and terraced fields, which are very frequent in many small Italian farms. Under these conditions the use of hand-held vibrating harvesters is quite wide spread, because they are capable of approximately three times the productivity of workers using manual harvesting methods. Unfortunately, the use of these machines exposes the operators to hand-arm vibration risk and acceleration values are affected by several factors, including harvester kinematics, rod material and geometry, and load conditions. In this study several models of electrical portable harvesters, obtained by combining six harvester heads and four rods (one telescopic), were tested under idling and load conditions, measuring acceleration values on the rod, near the hand positions. Assuming the use of the machinery for 4 h per day, the result is a level of daily vibration exposure A(8) for the most exposed hand ranging from about 11 to 40 m/s2, much higher than the daily exposure limit value of 5 m/s2 stated by the European Directive 2002/44/EC. With the same harvester head, reduction in vibration may be achieved by using carbon fiber rods rather than aluminum ones or by increasing the rod diameter. The most significant reduction is achievable by designing harvester heads whose kinematics inherently incorporate oscillation compensation.

Magnetic Induction Tomography Using Multi-Channel Phase-Domain Transceiver for Structural Health Monitoring

This article aims to develop a miniaturized magnetic induction tomography (MIT) system with a multi-channel phase-domain transceiver integrated circuit (IC). MIT is an imaging technique using phase shift between a primary magnetic field and induced field caused by the conductivity of a target object. Due to the weak strength of time-varying magnetic field, it is difficult to differentiate the magnetic field interaction. In particular, if the conductivity of the target object is low, the induced field is too small to identify the phase difference. The magnetic dipole model is applied to modeling the MIT system and analyzing performance. The model offers an effective means to analyze and visualize magnetic field interaction in multi-channel by the sum of magnetic dipoles. Then, a multi-channel MIT detection device is developed to include the phase-domain transceiver for automatic high-resolution phase measurement and wireless connectivity, achieving enhanced power efficiency and miniaturization. Finally, the multi-channel MIT system is applied to identify the various sizes of cracks on carbon fiber rods. The sensitivity of the system is analyzed by imaging the cracks by multi-channel measurement. The results show that the multi-channel MIT system can be successfully miniaturized and perform the nondestructive test (NDT).

Material Parameters Identification for Modelling of Carbon Rod Structures Delamination

The aim of the present work is to compare the interlaminar shear strength and fracture toughness of glued carbon fiber rods obtained using different experimental approaches and provide the effective way to characterise the interlaminar properties for reliable simulation of the delamination. Five different test methods (tension, single shear test, and double shear test, mode I and mode II delamination tests) were performed. Using the explicit LS-DYNA code the finite element model capable of simulating the damage process of bonded connection was developed. The interlaminar connection and delamination criteria were calibrated using the parameter identification methodology implemented in LS-OPT optimization tool.