Individual preferences for sound tool design in a parrot.

The rarity of tool manufacture in wild parrots is surprising because they share key life-history traits with advanced tool-using species, including large brains, complex sociality and prolonged parental care. When it does occur, tool manufacture in parrots tends to be innovative, spontaneous and individually variable, but most cases have been in captivity. In the wild, only palm cockatoos (Probosciger aterrimus) have been observed using tools regularly. However, they are unusual because they use tools to enhance their displays rather than for foraging or self-maintenance. Males in northern Australia make two types of tool from sticks and seed pods, which they tap rhythmically against a tree during display. We analysed 256 sound tools retrieved from 70 display trees. Drumsticks (89% of tools) were used more often than seed pod tools; most males manufactured only drumsticks, but some made both types. Individual males differed significantly in the design of their drumsticks including the length, width and mass but we found no evidence that neighbours copied each other. We discuss the highly individualized preferences for sound tool design in context of the behavioural predispositions behind the rarity of tool manufacture in wild parrots.

Learning by concordance (LbC) to develop professional reasoning skills: AMEE Guide No. 141.

Developing effective clinical reasoning is central to health professions education. Learning by concordance (LbC) is an on-line educational strategy that makes learners practice reasoning competency in case-based clinical situations. The questions asked are similar to those professionals ask themselves in their practice and participant answers are compared to those of a reference panel. When participants answer the questions, they receive an automated feedback that is two-fold as they see (1) how the panelists respond and (2) justifications each panelist gives for their answer. This provides rich contextual knowledge about the situation, supplemented by a synthesis summarizing crucial points. As many educators in the health sciences are engaging in introducing innovative approaches, many consider building LbC learning modules. Elaborating, designing and implementing a LbC tool remain a challenge. This AMEE Guide describes the steps and elements to be considered when designing a LbC tool, drawing on examples from distinct health professions: medicine, nursing, physiotherapy, and dentistry. Specifically, the following elements will be discussed: (1) LbC theoretical underpinnings; (2) principles of LbC questioning; (3) goals of the concordance-based activity; (4) nature of reasoning tasks; (5) content/levels of complexity; (6) reference panel; (7) feedback/synthesis messages; (8) on-line learning platforms.

Effect of hollow bit local exhaust ventilation on respirable quartz dust concentrations during concrete drilling.

Drilling large holes (e.g., 10-20 mm diameter) into concrete for structural upgrades to buildings, highways, bridges, and airport runways can produce concentrations of respirable silica dust well above the ACGIH® Threshold Limit Value (TLV® = 0.025 mg/m3). The aim of this study was to evaluate a new method of local exhaust ventilation, hollow bit dust extraction, and compare it to a standard shroud local exhaust ventilation and to no local exhaust ventilation. A test bench system was used to drill 19 mm diameter x 100 mm depth holes every minute for one hour under three test conditions: no local exhaust ventilation, shroud local exhaust ventilation, and hollow bit local exhaust ventilation. There were two trials for each condition. Respirable dust sampling equipment was placed on a "sampling" mannequin fixed behind the drill and analysis followed ISO and NIOSH methods. Without local exhaust ventilation, mean respirable dust concentration was 3.32 (± 0.65) mg/m3 with a quartz concentration of 16.8% by weight and respirable quartz dust concentration was 0.55 (± 0.05) mg/m3; 22 times the ACGIH TLV. For both LEV conditions, respirable dust concentrations were below the limits of detection. Applying the 16.8% quartz value, respirable quartz concentrations for both local exhaust ventilation conditions were below 0.007 mg/m3. There was no difference in respirable quartz dust concentrations between the hollow bit and the shroud local exhaust ventilation systems; both were below the limits of detection and well below the ACGIH TLV. Contractors should consider using either local exhaust ventilation method for controlling respirable silica dust while drilling into concrete.

Cardiac patients' beliefs about their illness and treatment: A sequential exploratory mixed methods design.

Background: Cardiac patients' beliefs about illness and treatment can disturb their treatment process, treatment regimen adherence, and daily activities. Exploring these beliefs by the use of appropriate, valid, and accurate scales can be helpful in false beliefs reforming by nurses and finally, result in life quality promotion. Therefore, this study is conducted to design and psychometry a questionnaire probing about cardiac patients' beliefs about illness and treatment. Methods: The sequential combination exploratory mixed methods design was used to develop the questionnaire format, which involved two sections: the quantitative and qualitative step. The qualitative step included probing the role of cultural beliefs about illness and treatment in two steps, including the literature and related tools review and fieldwork (semi-structured interviews with cardiac patients). Seventeen studies were checked in the literature review. Twenty-two cardiac patients were selected and interviewed by purposive sampling. The interviews continued up to the data saturation. The data analysis was conducted in both steps using conventional content analysis and textual content analysis. The quantitative step was a methodology study accomplished in two parts. The questionnaire items were formed using the data and items pool in the first part while the psychometric properties of the questionnaire were checked using face, content and construct validity and the reliability was probed using internal consistency and stability in the second part. The data were transferred into SPSS software program, version 18.0 for Windows (α<0.05). Results: 319 codes were extracted from the analyzing phase which formed 6 categories including prognosis, prevention, contexts, treatment efficiency, mentality and lifestyle as well as 9 sub-categories including understanding the danger, attitude toward disease, attitude toward treatment, society's culture, feeling hopeless, treatment regimen ignorance, self-curing, trying to survive and physical outcomes. The items pool was formed using literature reviews and interviews. A 30-itemed questionnaire was formed after the psychometric process. The Kaiser-Meyer-Olkin (KMO) index and the Bartlett's test of sphericity showed good results. Six components from the exploratory content analysis including prognosis, prevention, contexts, treatment efficiency, mentality, and lifestyle gained 51.7% variance totally. The interclass correlation coefficient was 0.83 in responding to the items for two times. Conclusion: This study developed a questionnaire about cardiac patients' beliefs regarding their illness and treatment. It can be used for the educational, research, and treatment purposes as a questionnaire with short, easy, and grammatically simple items that have appropriate validity and reliability. Using this scale can be helpful in evaluating clients' beliefs and recognize their educational needs.

Effect of bit wear on hammer drill handle vibration and productivity.

The use of large electric hammer drills exposes construction workers to high levels of hand vibration that may lead to hand-arm vibration syndrome and other musculoskeletal disorders. The aim of this laboratory study was to investigate the effect of bit wear on drill handle vibration and drilling productivity (e.g., drilling time per hole). A laboratory test bench system was used with an 8.3 kg electric hammer drill and 1.9 cm concrete bit (a typical drill and bit used in commercial construction). The system automatically advanced the active drill into aged concrete block under feed force control to a depth of 7.6 cm while handle vibration was measured according to ISO standards (ISO 5349 and 28927). Bits were worn to 4 levels by consecutive hole drilling to 4 cumulative drilling depths: 0, 1,900, 5,700, and 7,600 cm. Z-axis handle vibration increased significantly (p<0.05) from 4.8 to 5.1 m/s2 (ISO weighted) and from 42.7-47.6 m/s2 (unweighted) when comparing a new bit to a bit worn to 1,900 cm of cumulative drilling depth. Handle vibration did not increase further with bits worn more than 1900 cm of cumulative drilling depth. Neither x- nor y-axis handle vibration was effected by bit wear. The time to drill a hole increased by 58% for the bit with 5,700 cm of cumulative drilling depth compared to a new bit. Bit wear led to a small but significant increase in both ISO weighted and unweighted z-axis handle vibration. Perhaps more important, bit wear had a large effect on productivity. The effect on productivity will influence a worker's allowable daily drilling time if exposure to drill handle vibration is near the ACGIH Threshold Limit Value. [1] Construction contractors should implement a bit replacement program based on these findings.

A New Test Bench System for Hammer Drills: Validation for Handle Vibration.

Workers' can be exposed to high levels of hand vibration when drilling into concrete or rock using hammer drills; exposures that can cause hand arm vibration syndrome. Exposure levels may be reduced by different drill and bit designs and drilling methods, but these interventions have not been systematically evaluated. The purpose of this project was to develop a robotic test bench system for measuring handle vibration on drills in order to compare differences in drill designs, power sources, bit designs and drilling methods. The test bench is a departure from the ISO method for measuring drill handle vibration (ISO 28927-10), which requires drilling by humans. The test bench system was designed to repeatedly drill into concrete blocks under force control while productivity and handle vibration were measured. Handle vibration levels with different drills and bit sizes were similar to those collected following ISO methods. A new robotic test bench system for measuring handle vibration is presented and validated against ISO methods and demonstrates dynamic properties similar to human drilling.

On density measurement using various radiation sources: Cs-137, X-ray and pulsed neutron.

The use of controllable sources for density measurement is gaining more attention as a safer alternative to chemical sources, since chemical sources pose risks to both humans and the environment. Nuclear density tools using electronically controlled sources, such as X-ray tubes and pulsed neutron generators, are being researched as a replacement for radiological gamma sources such as Cs-137. This study, based on the real gamma density tool structure, optimizes the design of the X-ray and pulsed neutron-gamma density tools, providing a reference for the optimization of source-less density tools. Firstly, the study gives a comparison of density measurement using three sources through a combination of theory and simulation results. And the performance of the tools is evaluated using indicators such as detection efficiency, formation density sensitivity, and depth of investigation. Finally, based on the characteristics of different sources, the aforementioned indicators are balanced to obtain the optimal value of the source-to-detector distance, thus the structure of the X-ray density tool and pulsed neutron-gamma density tool are optimized.

Exploration of a somatosensory interactive assessment tool for children with intellectual disabilities.

Based on the functional assessment concept and embodied assessment requirements, the present study aimed to design and develop an assessment tool for children with intellectual disabilities with the help of somatosensory interactive (SI) technology. The sample in this study consisted of 73 children with intellectual disabilities and 70 children with typical development. Data were collected through three SI tasks, four traditional executive function tasks, and user experience interviews to analyse the effectiveness of the SI assessment tool. The results showed that the SI assessment tool had good scale validity, discriminant validity, and the ability to identify intellectual disabilities. Children preferred SI tasks and showed higher involvement and more positive emotions. The SI tool with three SI tasks is a more scientific, effective, and advanced tool for assessing children with intellectual disabilities.

FC-EODR: Immersive Humanoid Dual-Arm Dexterous Explosive Ordnance Disposal Robot.

In this study, we proposes a humanoid dual-arm explosive ordnance disposal (EOD) robot design. First, a seven-degree-of-freedom high-performance collaborative and flexible manipulator is developed, aiming at the transfer and dexterous operation of dangerous objects in EOD tasks. Furthermore, an immersive operated humanoid dual-arm dexterous explosive disposal robot (FC-EODR) is designed, which has a high passability to complex terrains such as low walls, slope roads, and stairs. It can remotely detect, manipulate, and remove explosives in dangerous environments through immersive velocity teleoperation. In addition, an autonomous tool-changing system is constructed, which enables the robot to flexibly switch between different tasks. The effectiveness of the FC-EODR is finally verified through a series of experiments, including the platform performance test, manipulator load test, teleoperated wire trimming, and screw-screwing experiments. This letter provides the technical foundation for robots to replace humans in EOD tasks and emergency situations.

Design of a High-Speed Rotary Ultrasonic Machining Machine Tool for Machining Microstructure of Brittle Materials.

Aiming at the problems of low machining accuracy and more serious tool wear in the traditional diamond grinding machining (DGM) microstructure of hard and brittle materials, this paper proposes high-speed rotary ultrasonic machining (HRUM) technology and develops a HRUM machine tool. The hardware part of the machine tool mainly includes the spindle module, micro-motion system module, ultrasonic machining tank module, and data acquisition (DAQ) system module. The LabView-based controlled machining control system, including motion selection, initialization, coarse tool setting, constant force tool setting, control machining, and coordinate display module, is developed. Comparative experimental research of the HRUM and DGM of small holes in Al2O3 ceramics is carried out in the developed HRUM machine tool. The results demonstrate that HRUM effectively reduces axial cutting forces, reduces binder adhesion, and suppresses slippage while improving tool-cutting ability and extending tool life compared to DGM under the same machining parameters. This technology has essential research significance for the high-precision and efficient machining of microstructures in hard and brittle materials.

Optimal tool design in micro-milling of difficult-to-machine materials.

The limitations of significant tool wear and tool breakage of commercially available fluted micro-end mill tools often lead to ineffective and inefficient manufacturing, while surface quality and geometric dimensions remain unacceptably poor. This is especially true for machining of difficult-to-machine (DTM) materials, such as super alloys and ceramics. Such conventional fluted micro-tool designs are generally down scaled from the macro-milling tool designs. However, simply scaling such designs from the macro to micro domain leads to inherent design flaws, such as poor tool rigidity, poor tool strength and weak cutting edges, ultimately ending in tool failure. Therefore, in this article a design process is first established to determine optimal micro-end mill tool designs for machining some typical DTM materials commonly used in manufacturing orthopaedic implants and micro-feature moulds. The design process focuses on achieving robust stiffness and mechanical strength to reduce tool wear, avoid tool chipping and tool breakage in order to efficiently machine very hard materials. Then, static stress and deflection finite element analysis (FEA) is carried out to identify stiffness and rigidity of the tool design in relation to the maximum deformations, as well as the Von Mises stress distribution at the cutting edge of the designed tools. Following analysis and further optimisation of the FEA results, a verified optimum tool design is established for micro-milling DTM materials. An experimental study is then carried out to compare the optimum tool design to commercial tools, in regards to cutting forces, tool wear and surface quality.

Design of a Template-Based Electrophoretically Assisted Micro-Ultrasonic Machining Micro-Channel Machine Tool and Its Machining Experiment.

In order to achieve the high-precision and high-efficiency machining of micro-channels for hard and brittle materials, the authors innovatively proposed a new technology called template-based electrophoretically assisted micro-ultrasonic machining (TBEPAMUSM). This technology transfers the micro-channel shape punch-pin to the workpiece material through micro-ultrasonic machining to form a micro-channel. At the same time, it uses the electrophoretic properties of ultra-fine abrasive particles to ensure the existence of abrasive particles in the machining area by applying a DC electric field. According to the new technology machining principle, a machine tool of TBEPAMUSM was designed and developed. The machine tool hardware adopts a C-shaped structure, including a marble platform, an ultrasonic vibration system, a micro three-dimensional motion platform, a working fluid tank, and a pressure sensor. The machine tool intelligent control system is developed based on LabVIEW, including the initialization module, fast positioning module, constant force tool setting module, constant force control machining module, and real-time coordinate display module. Micro-channels with different structures are machined on single-crystal silicon and soda-lime glass using the designed machine tool and the developed control system. The results show that: when electrophoresis assistance is applied in machining, the edge chipping phenomenon of the micro-channel is significantly reduced, the surface roughness is reduced by about 20%, and the machining efficiency is increased by about 4%.

Design of an ultrasound-emitting drill guide for freehand pedicle screw navigation.

BACKGROUND: Accurate pedicle screw placement in spinal surgery is critical as inaccuracies can lead to morbidity and suboptimal outcomes. Navigation and robotics have reduced malplacement rates, but their adoption is limited by high costs, learning curves, surgical time, and radiation. The authors propose an ultrasound-emitting and self-localising drill guide for precise screw placement that overcomes the limitations of current techniques. MATERIALS AND METHODS: The preliminary configuration analysis involves systematically varying design parameters and assessing localization performance using lumbar spine MRI based simulations. The authors evaluate localization techniques based on accuracy and optimization capture range. RESULTS: Results suggest that feasible designs can accurately estimate position. A promising design features a 5 mm radius cannula with ten 35mm-long ultrasound strips, 32 elements per strip, and a fanned-out emission profile. A multi-start active-set optimization algorithm with six initial estimates ensures reliable and efficient localization. CONCLUSIONS: The simulation suggests that the proposed design can achieve sufficient localization accuracy for pedicle screw navigation. These findings will guide the fabrication of a novel ultrasound-emitting drill guide for further evaluation and physical testing.

A Study of the Friction Stir Lap Welding of AA5052 and Polypropylene.

Friction stir lap welding (FSLW) remains a pioneering technique for creating hybrid joints between AA5052 aluminium alloy and polypropylene (PP), particularly with the metal-on-top configuration. Building upon previous research, this study introduces a tapered fluted pin tool design and investigates its effectiveness in the welding process. Our results, supported by ANOVA, chemical, and microstructural analyses, reiterate that the optimal welding parameters stand at a rotational speed of 1400 RPM and a traverse speed of 20 mm/min. This combination produces a joint tensile strength of 3.8 MPa, signifying 16.54% of the weaker material's inherent strength. Microstructural evaluations revealed a unique composite of aluminium chips intermeshed with PP, strengthened further by aluminium hooks. Crucially, mechanical interlocking plays a predominant role over chemical bonding in achieving this joint strength. The study underscores the absence of significant C-O-Al bonds, hinting at the PP degradation without the thermo-oxidation process. Additionally, joint strength was found to inversely correlate with the interaction layer's thickness. The findings fortify the promise of FSLW with the novel fluted pin design for enhancing joints between AA5052 and PP, emphasising the potential of mechanical interlocking as a principal factor in achieving high-quality welds.

Mechanical and Microstructural Properties of HDPE Pipes Manufactured via Orbital Friction Stir Welding.

In recent decades, extensive research has been performed on the friction stir welding of flat-shaped materials while pipe welding, particularly polymer pipes, still encounters challenging issues. This work presents a feasible route for joining high-density polyethylene (HDPE) pipes using an orbital friction stir welding (OFSW) set-up properly designed with a retractable pin tool. Fully consolidated joints were achieved using a portable heating-assisted OFSW system suited for on-site pipeline welding. The obtained joined pipes were characterized by a high-quality weld surface and a lack of defects arising from the tool-pin hole. The samples welded with the optimum parameters presented comparable properties with the base materials and even a slight increase in the tensile strength. The highest tensile and impact strengths were 14.4 MPa and 2.45 kJ/m2, respectively, which is 105% and 89% of those of the base material. XRD, FTIR, and SEM were also applied to assess the property changes in the HDPE pipes after the FSW process. The morphological analysis evidenced that the crystalline structure of the welded sample was similar to that of the base material, proving the effectiveness of the proposed technology.

Study on the Control Method of Sidewall Taper in Electrolytic Broaching of Micro Multi-Grooves.

Micro multi-grooves are important functional structures widely used in new heat exchanger types, chemical reactors, and other applications. Electrolytic broaching is an efficient and low-cost technology for processing micro multi-grooves. In the conventional electrolytic broaching of multi-grooves, the cathode tools are usually designed as a wedge-shaped tooth structure array with a constant tooth width, and the sidewalls are covered with insulating layers. The machined groove sidewall is always tapered because of stray current corrosion, which strongly affects the groove contour accuracy. Cathode tools with variable tooth width structures are proposed to solve this problem. Based on the simulation results of the electrolytic broaching anode forming process, the optimal front tooth width is obtained through the golden section optimization method, and comparative tests of the conventional and optimized cathode tools were carried out. At an electrochemical broaching feed rate of 120 mm/min, array microgrooves with widths of about 550 µm and depths of about 520 µm were processed. With the optimized variable tooth width tool, the sidewall tapers of the grooves were reduced from 7.254° to 0.268°. The experimental results verify the effectiveness of the simulation and cathode structure optimization.

Simulation and Experimental Study on Reverse Helical Milling with the Gradual-Removal Reverse Edge Milling Cutter under Ultrasonic-Assisted Condition.

As a new machining method, ultrasonic-assisted bi-direction helical milling has obvious advantages in making holes on carbon fiber-reinforced plastics (CFRP). However, cutting edges of the flat-bottomed milling cutter are easy to wear, which may cause severe defects such as burrs and tears in the outlet of the hole. In order to improve the hole-making quality of CFRP, the gradual-removal reverse edge milling cutter was proposed and designed. The finite method models of reverse helical milling CFRP with the flat-bottomed reverse edge milling cutter and the gradual-removal reverse edge milling cutter under an ultrasonic vibration were established, and the comparative cutting experiments of the two cutters were carried out. By comparing the cutting performance of the two milling cutters under the condition of ultrasonic vibration assistance, the cutting mechanism of improving the hole wall quality by the gradual-removal reverse edge milling cutter was studied. The results showed that when the reverse cumulative cutting depth reached about 60 mm, compared with the flat-bottomed reverse edge milling cutter, the gradual-removal reverse edge milling cutter transferred part of the cutting task of the peripheral edge to the end edge, and the wear of the reverse peripheral edges which directly affects the hole quality was effectively alleviated. This mechanism made the cutting state of the peripheral edge dominated by shear failure, which led to the significant improvement of the quality at the outlet of the hole.

Development and testing of a wearable wrist-to-forearm posture measurement system for hand-tool design evaluation.

This study reports on the development and testing of a wearable wrist-to-forearm angle-measurement system for flexion/extension and radial/ulnar deviation of the wrist, and pronation/supination of the forearm. The system is based on inertial sensors and a microcontroller mounted on a glove and a forearm pad. The developed system was tested through the comparison of two off-the-shelf screwdrivers, one long and one short. Twelve male subjects participated in a within-subject experimental design test and performed a horizontal and a vertical screwing task for each screwdriver. Results indicated that the use of a long screwdriver causes significantly higher ulnar deviation of the wrist in both set-ups, while the short screwdriver promotes higher wrist extension in both set-ups. Clarity of the obtained results indicates that the proposed system is adequate for ergonomics studies on hand-tool design evaluation, while it addresses common pitfalls of other motion-capture methods.

3D Finite Element Model on Drilling of CFRP with Numerical Optimization and Experimental Validation.

When drilling Carbon Fibre-Reinforced Plastic (CFRP) materials, achieving acceptable hole quality is challenging while balancing productivity and tool wear. Numerical models are important tools for the optimization of drilling CFRP materials in terms of material removal rate and hole quality. In this research, a macro-Finite Element (FE) model was developed to accurately predict the effect of drill tip geometry on hole entry and exit quality. The macro-mechanical material model was developed treating the Fiber-Reinforced Plastic (FRP) as an Equivalent Homogeneous Material (EHM). To reduce computational time, a numerical analysis was performed to investigate the influence of mass scaling, bulk viscosity, friction, strain rate strengthening, and cohesive surface modelling. A consideration must be made to minimize the dynamic effects in the FE prediction. The experimental work was carried out to investigate the effect of drill tip geometry on drilling forces and hole quality and to validate the FE results. The geometry of the drills used were either double-point angle or a "candle-stick" profile. The 3D drilling model accurately predicts the thrust force and hole quality generated by the two different drills. The results highlight the improvement in predicted results with the inclusion of cohesive surface modelling. The force signature profiles between the simulated and experimental results were similar. Furthermore, the difference between the predicted thrust force and those measured were less than 9%. When drilling with a double-angle drill tip, the inter-ply damage was reduced. This trend was observed in FE prediction.

Electromyographic evaluation of different handle shapes of masons' trowels.

The effects of five different handle shapes of masons' trowels on muscle activity of the arm and forearm muscles (through electromyographic measurements of the biceps brachii [BB], flexor digitorum superficialis [FDS], pronator teres [PT] and extensor carpi ulnaris [ECU]) were evaluated in a simulated masonry task. The results showed a significant effect of handle shape on the muscle activity of the BB, PT and ECU. The muscle activity of the extensor (ECU) and flexor (FDS) were generally larger than those of the supinator (BB) and pronator (PT). Some improvements were found in terms of muscular exertions with prototype designs C, D and E, which had either handles with variable diameter (designs C and E) or a slightly bent handle (design D). These findings have practical implications for the design of single-handle hand tools but may need further validation for specific contexts of use.