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During oven drying of abalone muscle, microwave treatment was conducted at regular time intervals (0, 30, 60, 90 and 120 days). Abalone muscle digestion products (AMDP) were prepared by subjecting dried abalone to in vitro simulated digestion. Our aim was to investigate the effect of microwave treatment during the drying of abalone muscle on the in vitro and in vivo antioxidant activities of AMDP. The results showed that the half maximal inhibitory concentration (IC50) values of AMDP from fresh abalone muscle for scavenging capacity against hydroxyl (·OH) radicals, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) and 1,1-diphenyl-2-phenylhydrazine (DPPH) radical were 3.04, 15.18 and 21.12 mg/mL, respectively. The IC50 values for the scavenging of these three radical species decreased gradually with increasing the drying time of abalone muscle. After being fed AMDP from abalone muscle dried for 120 days, the body length of Caenorhabditis elegans increased from 768.90 to 1 034.62 μm, the head swing frequency increased from 206 to 281 times/min, and the life span was extended by 36.16% under normal conditions and by 59.41% and 38.48% under heat stress and oxidative stress conditions, respectively compared with the control group. Meanwhile, with prolonging the drying time of abalone muscle, the antioxidant enzyme activities, reduced glutathione (GSH) content and total antioxidant capacity of C. elegans fed AMDP increased, and the reactive oxygen species (ROS) content decreased. In summary, prolonging the drying time and using microwave treatment during the drying process could improve the antioxidant capacity of AMDP.

The patterns of changes in the physicochemical properties and volatile flavors of abalone muscle during drying at 50 ℃ and 65% relative humidity were investigated in this study. With an increase in drying time, the browning intensity and fluorescence intensity of both surface and internal muscles of abalone increased gradually, which started to decrease after reaching a peak on the 90th day. The contents of reducing sugar and lysine in the surface muscle were 3.11 mg/g and 2.60% after pretreatment, and decreased to 1.95 mg/g and 1.61% after 120 days of drying, respectively. High molecular mass polymers were observed in the electrophoretic pattern of abalone muscle after 30 days of drying. Fourier transform infrared spectra showed that the intensity of the characteristic absorption peaks (1 403 and 1 026 cm-1) of glycoproteins gradually enhanced with increasing drying time. The response values of the electronic nose sensors W1W (sulfides) and W2S (alcohols, aldehydes and ketones) increased, and the content of 1-octen-3-ol decreased while the contents of linalool and (E,E)-2,4-decadienal increased after 30 days of drying, as determined by gas chromatography-mass spectrometry (GC-MS). At the same drying time, the intensity of Maillard reaction in the surface muscle was weaker than that in the internal muscle.

A magnetostrictive tactile sensor unit with a large force measurement range and high sensitivity is designed using L-shaped Galfenol wires, tunnel magnetoresistive elements, and cylindrical permanent magnets. The output voltage model of the sensor unit is established based on the inverse magnetostrictive effect, tunnel magnetoresistance, and elastodynamic theory. Structures of the sensor unit and array are optimized using COMSOL. The static, dynamic, and temperature characteristics are tested. The interaction between the output voltages of each unit in a $3\times $ 3 tactile sensor array is described. The experimental results show that the sensitivity of the sensor unit is 85.5 mV/N at 0-10 N and 28.4 mV/N at 10-16 N under a biased magnetic field of 1.671 kA/m. The dynamic force sensitivity of the sensor unit does not vary by more than 1.4%. The magnetic field lateral coupling and longitudinal coupling of the sensor array do not exceed a maximum of 2.3%. The array can accurately distinguish the force distribution when multiple contacts are subjected to force at the same time. The sensitivity does not vary by more than 3.9% over the ambient temperature range of 23- $59~^{\circ }\text{C}$. The tactile sensor array is mounted on the mechanical fingertips to grasp bar-shaped objects with different tilt angles. The output voltage of the sensor array obtained from the robotic grasping experiments is analyzed using Probabilistic Neural Network, which can determine the tilt angle of the grasped objects, and the accuracy rate of object tilt recognition is 96.74%. [ABSTRACT FROM AUTHOR]

Based on the Jiles-Atherton model and transducer's structural dynamics principle, the magnetoelastic dynamic strain model of giant magnetostrictive transducer is founded. This model takes into account the eddy current losses and the variety of stress. Simulation results are in a good agreement with the experimental ones. This indicates that the dynamic strain model can characterize the magnetization intensity and strain behavior at different frequency. The proposed model is suitable to describe the relation between the applied field and the output vibration at a wide range of exciting frequency. Index Terms--Bode diagram, dynamic model, eddy current effects, giant magnetostrictive transducer.

According to the hysteresis characteristics of the giant magnetostrictive actuator (MA), a dynamic recurrent neural network (DRNN) is constructed as the inverse hysteresis model of the MA, and an on-line hysteresis compensation control strategy combining the DRNN inverse compensator and a proportional derivative (PD) controller is used for precision position tracking of the MA. Simulation results validate the excellent performances of the proposed strategy. Index Terms--Dynamic recurrent neural network (DRNN), hysteresis, inverse compensator, magnetostrictive actuator (MA).

This paper establishes a simple and novel dynamic hysteresis model for giant magnetostrictive actuator by considering the eddy current loss, anomalous loss and structural dynamic mechanical behavior of the actuator. To obtain parameters of the model, a hybrid genetic algorithm is proposed. Comparisons between the experimental and calculated results show the validity and practicability of the model. Index Terms--Dynamic hysteresis model, hybrid genetic algorithm (HGA), Jiles--Atherton model, magnetostrictive actuator (MA).

The dynamic model with hysteretic nonlinearity for magnetostrictive actuators is developed, combined with Jiles-Atherton model. The simulation and experimental results demonstrate the effectiveness of the model and parameter identification approach.

Magnetostrictive materials have excellent magneto-mechanical properties and are widely used in the field of energy conversion. Temperature has an important influence on the magnetic properties of them. Accurately studying the temperature dependence of magnetostrictive materials is a necessary prerequisite for the design of precision actuators. In this paper, we constructed a high-frequency magnetic property measurement system that can control the temperature. The magnetic characteristics of Terfenol-D, Fe-Ga and Fe-Co were measured at temperatures ranging from 10 °C to 80 °C, the frequencies from 1 kHz to 20 kHz and magnetic induction amplitudes from 0.01 T to 0.07 T. The temperature dependence of the three materials under different exciting conditions was comprehensively compared. The variation trends and temperature sensitivities of the coercivity, permeability, equivalent inductance, equivalent resistance and the magnetic energy losses are analyzed respectively. The results of this paper are oriented to practical engineering applications and can be used for high-frequency loss prediction and temperature control system design. [ABSTRACT FROM AUTHOR]

A new high-sensitivity magnetostrictive tactile sensor array is designed based on the inverse magnetostrictive effect and tunnel magnetoresistance to enable intelligent robots to have a sensitive sense of touch and perform delicate operations. The output voltage model of the tactile sensor is developed. The optimal bias field and spacing of the sensor unit are determined using COMSOL Multiphysics. Test platforms for static and dynamic characteristics are built. The output characteristics of the tactile sensor under static and dynamic forces are tested. The sensitivity is compared with that of other types of tactile sensors. The tactile sensor units are set into a $2\times3$ sensor array and the coupling effect of the output voltage of each unit in the array is tested. The experimental results show that the experimental value of the output voltage matches the calculated value with a maximum error of 3.47%. The sensitivity of the tactile sensor is 323 mV/N at 0–4 N static force, which is higher compared to other types of tactile sensors. The sensitivity of the sensor unit changes less than 1.15% at 1–4 Hz dynamic force. The interaction of output voltage between units in the $2\times3$ tactile sensor array does not exceed 1.5% and is negligible. The $2\times3$ tactile sensor array is attached to a three-finger manipulator for grasping objects with a different hardness. The results of the study have guiding significance to the design of high-sensitivity tactile sensors for intelligent robots. [ABSTRACT FROM AUTHOR]

A non-contact torque sensor based on a magnetostrictive Fe30Co70 rod wound with an excitation coil and a pickup coil is proposed in this paper. In the magnetic field range 0–30 kA/m, the changing rate and linearity of magnetostriction with a loading magnetic field of Fe30Co70 samples are significantly improved after heat treatment. Maximum magnetostriction is 103 ppm in the annealed sample in the parallel direction, while its tensile strength and allowable shear stress are 608 and 194.56 MPa, respectively. According to the mathematical model presented in this work, there is a linear relationship between the output voltage and torque. An apparent increase in the induced voltage signal (peak voltage) of 48.23 mV is observed as the torque increases to 20 Nm in the case of applying sinusoidal excitation signals. In addition, the experimental results are consistent with the calculated values within the torque range 0–16 Nm, and a good sensitivity of 2.87 mV/Nm is obtained. This work shows the prospect of Fe30Co70 alloy for non-contact torque sensing for the appropriate magnetostrictive property with no orientation requirement. [ABSTRACT FROM AUTHOR]

The dynamic magnetic characteristic curves of TbDyFe alloy (TbxDy1−xFe1.9–2.0, $0.27 \leq x \leq 0.3$) under varying temperatures at different high-frequency excitation conditions were measured. The results show that when the excitation amplitude and frequency keep constants, the dynamic hysteresis loop, the permeability, and the magnetic energy loss all vary with the increase in temperature (from 10 °C to 80 °C). Their trends of temperature dependence are analyzed in detail. Based on the Bertotti loss separation method and experimental data, a magnetic energy loss calculation model for TbDyFe alloy under variable temperature conditions is proposed. The model considers the influence of high-frequency hysteresis characteristics and skin effect. It introduces temperature-related terms to modify the loss coefficients. The calculation results are compared with the experimental ones at different temperatures. It shows that this calculation method can accurately calculate the magnetic energy losses under variable temperature at higher frequencies (1–20 kHz). This research can provide an experimental and theoretical support for high-frequency engineering application of magnetostrictive materials. [ABSTRACT FROM AUTHOR]

A new type of rare-earth giant magnetostrictive transducer, working in ultrasonic frequencies, is designed by the structural dynamic model and the dynamic coupling model. Based on the vibration, wave, and frequency equations, the structural dynamic model of the transducer is established. Using COMSOL Multiphysics software parametric design method, considering the influence of materials, shapes, and dimensions on the output characteristics of the transducer, the optimum mechanical structure of the ultrasonic transducer is determined. The magnetic circuit structure is analyzed by the dynamic coupling model based on the Jiles–Atherton model, Maxwell’s equations, and magneto-mechanical coupling effect. The prototype of the ultrasonic transducer is fabricated. The relationship between the output characteristics and the frequency is studied. The results demonstrate that the ultrasonic transducer can work in the range of 18–22 kHz and exhibits higher magneto-mechanical conversion efficiency at the frequency of 19.5 kHz. [ABSTRACT FROM AUTHOR]

According to the actual operation conditions, a kind of high-frequency losses testing system of magnetostrictive materials under dc bias is built. The dynamic hysteresis loops for Terfenol-D samples at different ac driving frequencies and magnetic densities are studied experimentally under variable dc bias excitation. The magnetic energy losses are obtained from these dynamic hysteresis loops. The three-variable magnetic energy loss matrix is established by these measured data. On the basis of Bertotti loss separation theory, the high-frequency losses calculating model of magnetostrictive materials considering variable dc bias excitation is proposed by using the algorithm of Levenberg–Marquardt and the method of matrix transformation. In this model, according to the multivariate parametric regression, the loss coefficients are modified by introducing dc bias-related terms. The loss comparison at different operating conditions shows that the computed results in this proposed model are in good agreement with the experimental ones. [ABSTRACT FROM AUTHOR]

The novel mechanism of action of immunotherapy agents, in treatment of various types of cancer, poses unique challenges during the designing of clinical trials. It is important to account for possibility of a delayed treatment effect and adjust sample size accordingly. This paper provides an analytical approach for computing sample size in the presence of a delayed effect using a piece-wise proportional hazards model. Failing to account for an anticipated treatment delay may result in considerable loss in power. The overall hazard ratio (HR), which now represents the average HR across the entire treatment period, can remain a meaningful measure of average benefit to patients in the trial. We show that, special consideration needs to be given for the designing of interim analyses related to futility, so as not to increase the probability of incorrectly stopping an effective agent. It is shown that the weighted log-rank test, using the Fleming-Harrington class of weights, can be used as supportive analysis to better reflect the impact of a delayed effect and possible long-term benefit in a subset of the overall population. [ABSTRACT FROM AUTHOR]

Tactile sensors enabling human-like perception are crucial for modern intelligent robotics. This study developed a biomimetic magnetostrictive tactile sensor consisting of Galfenol wires, permanent magnets, and a Hall sensor. This novel tactile sensor exhibits a static sensitivity of 23.86 mV/N and a measurement range up to 3 N. The sensitivity is stable up to 4 Hz. A theoretical model of the tactile sensor unit was derived to correlate the output voltage with the applied force. The modeling result shows an error of 1.65% in sensitivity compared to the experimental data. The response time and recovery time of the sensor are only 11 ms and 10 ms, faster than nanoscale type of sensor. A 3 × 3 magnetostrictive sensor array was constructed by integrating multiple magnetostrictive tactile sensors on a flexible printed circuit board. Since the outputs of the sensing units are not affected by each other, the array can be expanded as needed. Experimental results show that the sensor array is able to detect the geometry of the object in contact. [ABSTRACT FROM AUTHOR]

The effect of variable compressive stress on hysteresis, eddy-current, and anomalous losses in magnetostrictive materials is investigated by the built magnetic characteristic testing system. Based on experimental results of Terfenol-D and loss separation theory, the trends of loss coefficients of three variables, magnetic frequency f, peak flux magnetic density Bm, and compressive stress σ, are analyzed. The reasons for the change in losses are explained from the point of view of micro-magnetism and physical mechanism. A variable coefficient magnetic energy loss calculating model considering compressive stress is derived using the algorithm of Levenberg–Marquardt and the method of multivariate parametric regression. The experimental and computed results of magnetic energy losses are compared and analyzed under different operating conditions. The analysis results show that the proposed model could well predict the losses under compressive stress at high-frequencies (5–20 kHz). The average error of the computed and experimental results is 5.5%. This research has improving significance in giving theoretical guidance for magneto-mechanical design in the high-frequency operated conditions of magnetostrictive devices. [ABSTRACT FROM AUTHOR]

Accurate calculation of magnetic energy losses for magnetostrictive material is a necessary step in designing high-power magnetostrictive transducer. In this article, based on the losses separation formula and measured data of Terfenol-D, the changing trends of the losses coefficients are investigated. An improved magnetic energy losses calculation method with variable coefficients is established. The measured and calculated values of magnetic energy losses at different frequencies and flux densities of driving magnetic field are compared and analyzed. The results show that the calculation method can accurately calculate the magnetic energy losses at higher frequencies (1–20 kHz). The average error between the calculated and the measured values is 4.32%. This research can provide theoretical and experimental guidance for the higher frequency applications of magnetostrictive materials. [ABSTRACT FROM AUTHOR]

It is of great significance to adjust bandgaps (BGs) of laminated Galfenol phononic crystal (PC) by using nonlinearity of Villari effect and shunt elements for effectively reducing vibration. Based on the modified constitutive equations, the effective elastic modulus, and transfer matrix method (TMM), a dynamic nonlinear model with tunable elastic modulus for the PC is established. Comparisons between the calculated and measured results show that the model can describe the changing laws of the Galfenol rod’s effective elastic modulus with frequency and shunt capacitance, and can predict nonlinearity of the rod. The effects of stress and bias field on the attenuation constant peak and cutoff frequency of Bragg BGs (BBGs) are analyzed, and the optimal and suboptimal operating points of BBGs are determined. The effects of shunt capacitance and stress on BBGs, resonant BGs (RBGs), and common BGs (CBGs) are analyzed, and it is found that larger magnetomechanical coupled factor and smaller shunt capacitance can effectively reduce vibration. [ABSTRACT FROM AUTHOR]

Background: Durvalumab has shown meaningful clinical activity in patients with metastatic urothelial carcinoma (mUC) in Study 1108 (NCT01693562). An important focus in treatment is health-related quality of life (HRQOL). Here, patient-reported outcomes (PROs) from Study 1108 and their relationship with inflammatory biomarkers are explored.Methods: Disease-related symptoms, functioning, and HRQOL were assessed with the Functional Assessment of Cancer Therapy-Bladder (FACT-Bl) and the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30). Relationships between PRO improvements and the best changes in the tumor size, albumin level, and neutrophil-lymphocyte ratio (NLR) were assessed with Spearman correlation analysis.Results: The mean FACT-Bl total score improved from 107.5 (standard deviation [SD], 23.0) at the baseline to 115.4 (SD, 22.6) on day 113, with similar increases found for the Trial Outcome Index (TOI) and Bladder Cancer Subscale (BLCS) scores. The mean FACT-Bl total scores improved over time, and the FACT-Bl TOI scores significantly improved by day 113 (P < .05). The mean EORTC QLQ-C30 Global Health Status/Quality of Life score improved from 57.1 (SD, 24.8) at the baseline to 69.0 (SD, 21.4) on day 113; the functional scale and symptom scores (day 113) were higher than the baseline scores (P < .05) for EORTC Social Functioning. The FACT-Bl total, BLCS, and TOI scores improved in 32.6%, 34.9%, and 32.6% of the patients by day 113; 26.3% to 37.8% of the patients exhibited improvements in EORTC QLQ-C30 functional scores. The best tumor shrinkage and posttreatment improvements in serum albumin and NLR correlated with increases in FACT-Bl total, TOI, and BLCS scores and in EORTC Physical Functioning and Role Functioning scores (P < .05).Conclusions: Durvalumab was associated with improvements in disease-related symptoms, functioning, and HRQOL in patients with mUC. Improvements in systemic inflammation may contribute to PRO improvements in these patients. [ABSTRACT FROM AUTHOR]

A novel flexible three-axial tactile sensor, which is composed of four interdigital capacitors, is presented in this paper. The operation of the sensor is based on the measurement of a load-induced capacitance change. For the configuration of the electrodes, four sensing electrodes and a public electrode are in the same plane, which is based on the fringing effect of the electric field. There are no floating electrodes which are beneficial to flexibility. The dielectric layer consists of air gap and polydimethylsiloxane (PDMS), and the equivalent dielectric constant of the dielectric layer will be changed when the sensor is under external force, which causes the capacitance change. Different from the existing fringing effect tactile sensor, interdigital electrodes are adopted here to enhance the sensitivity and stability of the sensor. Finite element simulation and experimental results show that there is a great enhancement in sensitivity and stability. [ABSTRACT FROM AUTHOR]

Tactile sensing is used to explore and manipulate objects, which is essential for the interaction with the environment. A novel magnetostrictive tactile sensor array for use in robotic fingers based on smart material, Fe83Ga17 alloy (Galfenol), was proposed. According to the electromagnetism theory, cantilever beam theory, and inverse magnetostrictive effect, the force measurement model of the sensor has been established. The theoretical analysis and experimental verification for the sensor have been carried out. The sensor is sensitive to the force 0–2 N, the maximum value of output voltage is 96.13 mV. We implement the feature extraction and the tactile object recognition on data acquired during an underactuated manipulator equipped with the magnetostrictive tactile sensor array. The actuator positions and tactile sensor values were considered to be available feature data. The proposed approach does not require force modulation and is suitable for gripping arbitrary initial position and orientation of object, so the tactile sensing system can be integrated into the actual robotic gripping and recognizing scenes. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical and experimental study on high-frequency (>5000 Hz) output characteristics of the giant magnetostrictive transducer (GMT) at varied operating conditions. Based on the Jiles–Atherton model, Maxwell’s equations, Newton’s law, and Fourier’s heat transfer equation, a nonlinear electromagnetic–mechanical–thermal multi-field coupled finite element model for GMT is established. The output displacement amplitude of the magnetostrictive rod and the acceleration of vibrating horn at the GMT device are measured and analyzed at varied exciting amplitude of ac magnetic field and frequencies (from 5600 to 7000 Hz). The frequency dependences of permeability and magnetoelastic coupling coefficient obtained from the experimental results are used in revising the model parameters. These output characteristics analysis results can provide theoretical and experimental guidance in the optimization of structural design and precise controlling for high-frequency GMT system. [ABSTRACT FROM AUTHOR]

A magnetization model for magnetostrictive alloy (Galfenol) rods with uniaxial anisotropy is established, based on the theory of the Jiles-Atherton model and the Armstrong model. The magnetization under different magnetic fields and applied stresses at different directions has been calculated by the constitutive model. The magnetic properties of a Galfenol rod were made and are consistent with the calculated results. The proposed model accurately describes the relationship between the magnetization and applied magnetic field under different stresses for Galfenol rods, in particular, and can be applied to general ferromagnetic materials with uniaxial anisotropy due to crystallography or shape. [ABSTRACT FROM AUTHOR]

A novel magnetostrictive tactile sensor has been designed, based on the inverse magnetostrictive effect and bionics, which can be used to test the gripping force of a manipulator and to detect the stiffness of the manipulated objects. Based on the electromagnetics theory, the inverse magnetostrictive effect, and the Hooke's law, the force measurement model and the stiffness detection model have been established. A magnetostrictive tactile sensor is designed to measure the applied force from 0 to 5 N with a sensitivity of 114 mV/N. The stiffness classification of the manipulated objects has been tested with four different types of sample materials. The results indicate that the output voltage and slope can be applied as a criteria for classifying the stiffness of the manipulated objects. The magnetostrictive tactile sensor has a simple structure with a rapid response and can realize the precise perception of the manipulated objects. [ABSTRACT FROM AUTHOR]

Experimental and calculating analysis of magnetic losses for Terfenol-D is a necessary step for the design of high-power magnetostrictive transducer. In order to further research the magnetic energy losses characteristics, a Terfenol-D rod is sectioned along different directions, and these slices are made into several square annular sheet samples. The influences of material magnetization direction on the losses are compared and analyzed. The values of magnetic energy losses are measured to investigate their variations at different frequencies and magnetic densities of driving magnetic field. Furthermore, the traditional losses formula is improved. The values of the hysteresis losses, eddy-current losses, and anomalous losses are separated out, and the losses coefficients are achieved through polynomial curve fitting. This paper can provide theoretical and experimental guidance for the high-frequency applications of magnetostrictive materials. [ABSTRACT FROM AUTHOR]

Tactile sensing is important for the exploration and manipulation of an object. In this paper, a magnetostrictive tactile sensing system has been found. A robotic gripper with one sensor mounted on its fingers performs a palpation procedure on a set of objects. By gripping an object, the robot actively explores the material properties, and the system acquires tactile information corresponding to the pressure and stiffness. Based on the extreme learning machine classifier algorithm, taking the output voltage rising gradient and steady-state voltage as the eigenvalues, an object is detected and identified. The complex matrixes at the best classification accuracy are plotted to show the identification rate of each object. This magnetostrictive tactile sensing system implements real-time operation and the object can be identified during the grasping process. It means that the system is able to identify object successfully. [ABSTRACT FROM AUTHOR]

In order to improve the high-frequency performance of magnetostrictive composites, the work fabricated a polymer-bonded Tb-Dy-Ho-Fe fiber composite. Its magnetic properties were investigated and compared with that of polymer-bonded Tb-Dy-Fe fiber composite. An experimental system was setup to measure the major and minor hysteresis loops of the given magnetostrictive composites at different frequencies. The results showed that Tb-Dy-Ho-Fe fiber composites demonstrates superior magnetic properties, such as lower saturation magnetic field (220 kA/m), smaller coercivity force (5 kA/m) and less dynamic magnetic loss (115 W/m3 at 20 kHz, only 60% of Tb-Dy-Fe fiber composites), compared with Tb-Dy-Fe fiber composites. The proposed composite is suitable for the application of sensing and ultrasonic. [ABSTRACT FROM AUTHOR]

Based on the Wiedemann effect and inverse magnetostritive effect, the output voltage model of a magnetostrictive displacement sensor has been established. The output voltage of the magnetostrictive displacement sensor is calculated in different magnetic fields. It is found that the calculating result is in an agreement with the experimental one. The theoretical and experimental results show that the output voltage of the displacement sensor is linearly related to the magnetostrictive differences, (λl-λt), of waveguide wires. The measured output voltages for Fe-Ga and Fe-Ni wire sensors are 51.5mV and 36.5mV, respectively, and the output voltage of Fe-Ga wire sensor is obviously higher than that of Fe-Ni wire sensor under the same magnetic field. The model can be used to predict the output voltage of the sensor and to provide guidance for the optimization design of the sensor. [ABSTRACT FROM AUTHOR]