No abstract

A 3D model of a middle-size olive tree has been analyzed considering various shaking conditions by using an attached trunk shaker to improve the harvesting rate as regards the critical nodal acceleration and displacement. The effects of shaking frequency, loading type as well as temperature and loading height were simulated and investigated on olive-stem-twig joint rupture. Comparing the results of finite element modal analysis in ABAQUS 6.10 with those of field experiments, utilizing a hydraulic eccentric-mass trunk shaker, exhibits less than 5% deviation at frequencies between 10 to 25 Hz at the first four vibration modes with damping ratio of 16-30%. The experiments and simulations show the maximum harvested quantity of sample middle-size olive trees is 92% and 96%, respectively. It is acquired at f=20 Hz, T=28°C for 45% moisture content of wood in late November 2012, without chemicals. The optimized mechanical harvesting yielded the lower number of workers, time saving (~12 tree/hr), and to improve the obtained productivity (293 kg/hr). The results imply that accurate 3D analysis of mechanized olive harvesting can be an efficacious solution to obtain desired parameters and optimal efficiency, which is comparable to manual method.

Structural health monitoring of rotary aerospace structures is investigated in this research. A monitoring system is proposed based on the electromechanical impedance spectrum of piezoelectric transducers and a portable transceiver. To investigate the applicability and preliminary results of this method, a turbomachine prototype (laboratory device) is developed, and integrated composite piezoelectric films are deposited on the blades. Next, a self-diagnostic characterization is initially implemented to the piezo-films. Transceiver functionality and accuracy is verified using an Ivium impedance analyzer. The verified measuring path was used in structural health monitoring of pristine and damaged blades at rotational speed of 0 and 1000 r/min. The effects of damage formation and rotational speed on the impedance signature are discussed based on the variations in mechanical impedance using a two-dimensional model. Once damage occurs in a blade at each speed, it results in a frequency shift of the impedance signature at antiresonance peaks compared to the corresponding baseline. The results show a clear frequency shift of existing peaks and the appearance of new peaks as damage grows to a secure minimal detectable size. This achievement confirms the applicability of this method for incipient damage detection on rotary structures prior to any failure.

Surgical error and resulting complication have significant patient and economic consequences. Inappropriate exertion of tool-tissue force is a common variable for such error, that can be objectively monitored by sensorized tools. The rich digital output establishes a powerful skill assessment and sharing platform for surgical performance and training. Here we present SmartForceps data app incorporating an Expert Room environment for tracking and analysing the objective performance and surgical finesse through multiple interfaces specific for surgeons and data scientists. The app is enriched by incoming geospatial information, data distribution for engineered features, performance dashboard compared to expert surgeon, and interactive skill prediction and task recognition tools to develop artificial intelligence models. The study launches the concept of democratizing surgical data through a connectivity interface between surgeons with a broad and deep capability of geographic reach through mobile devices with highly interactive infographics and tools for performance monitoring, comparison, and improvement.

The composition of fine-ground lead zirconate-titanate powder Pb(Zr0.52Ti0.48)O3, suspended in PZT and bismuth titanate (BiT) solutions, is deposited on the curved surface of IN718 and IN738 nickel-based supper alloy substrates up to 100 µm thickness. Photochemical metal organic and infiltration techniques are implemented to produce smooth, semi-dense, and crack-free random orientated thick piezoelectric films as piezo-sensors, free of any dopants or thickening polymers. Every single layer of the deposited films is heated at 200 °C with 10 wt.% excess PbO, irradiated by ultraviolet lamp (365 nm, 6 watt) for 10 min, pyrolyzed at 400 °C, and subsequently annealed at 700 °C for one hour. This process is repeated successively until reaching the desired thickness. Au and Pt thin films are deposited as the bottom and top electrodes using evaporation and sputtering methods, respectively. PZT/PZT and PZT/BiT composite films are then characterized and compared to similar PZT and BiT thick films deposited on the similar substrates. The effect of the composition and deposition process is also investigated on the crystalline phase development and microstructure morphology as well as the dielectric, ferroelectric, and piezoelectric properties of piezo-films. The maximum remnant polarization of Pr = 22.37 ± 0.01, 30.01 ± 0.01 µC/cm2, the permittivity of εr = 298 ± 3, 566 ± 5, and piezoelectric charge coefficient of d33 = 126, 148 m/V were measured versus the minimum coercive field of Ec = 50, 20 kV/cm for the PZT/PZT and PZT/BiT thick films, respectively. The thick film piezo-sensors are developed to be potentially used at frequency bandwidth of 1–5 MHz for rotary structural health monitoring and also in other industrial or medical applications as a transceiver.