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In this paper, we demonstrate the possibility of direct protein sensing beyond the Debye length limit using a molecular-charge-contact (MCC)-based ion-sensitive field-effect transistor (ISFET) sensor combined with a microfluidic device. Different from the MCC method previously reported, biotin-coated magnetic beads are set on the gate insulator of an ISFET using a button magnet before the injection of target molecules such as streptavidin. Then, the streptavidin&mdash, a biotin interaction, used as a model of antigen&mdash, antibody reaction is expected at the magnetic beads/gate insulator nanogap interface, changing the pH at the solution/dielectric interface owing to the weak acidity of streptavidin. In addition, the effect of the pH or ionic strength of the measurement solutions on the electrical signals of the MCC-based ISFET sensor is investigated. Furthermore, bound/free (B/F) molecule separation with a microfluidic device is very important to obtain an actual electrical signal based on the streptavidin&ndash, biotin interaction. Platforms based on the MCC method are suitable for exploiting the advantages of ISFETs as pH sensors, that is, direct monitoring systems for antigen&ndash, antibody reactions in the field of in vitro diagnostics.

We first review the literature on machine behavior which may contain the interaction between machines, and then discuss the methodology and the related case involving collaboration between robots to instantiate the concept with AI empowerment. The navigation case aims to a security application with autonomous control and roadside agent embedded in a mobile edge computing structure. In the studied navigation based on the artificial potential field method, robots need to use position information to calculate the moving direction frequently. In the case of high motion speed as well as GPS positioning error, the path trajectory may show a sharp change of direction. In order to mitigate the trajectory oscillation, this paper proposes a path planning design where training process and motion direction prediction are integrated by using artificial neural network. The auxiliary navigation agent near multiple obstacles can first extract the past movement information of the robot and then determines whether there is a serious path jitter event. Computer simulation analysis shows that the combination of autonomous control and cooperative behavior can effectively reduce the path jitter so as to achieve a fast and safe path planning.

Solenoids can be used as linear or incremental motion actuators, most often by coupling the solenoid armature to a linear spring. In this configuration, its limited open-loop stable range (less than one-third of the full range) affects performance and limits applications. The input–output linearization control method is an effective technique to extend the stable range. But in practice, however, the time-delay effect from both measurement and actuation can make the system less damped and therefore more sensitive to disturbances. This effect was analyzed and a digital proportional and integrator controller plus extended state observer (ESO) is proposed to enhance the performance of the electromagnetic actuator. Simulation and experimental tests show that this combined proportional and integral and ESO technique can extend the stable range of motion to 77.6% of full stroke with less sensitivity to external disturbances.

Tick-borne pathogens (TBPs) seriously affect cattle production and can be economically damaging. The epidemiology of these organisms in the Chongqing municipality of China is not well described. This study aimed to investigate the prevalence and risk factors of TBPs including Anaplasma spp., Babesia spp. and Theileria spp. in cattle in Chongqing municipality. The results showed that 43.48% (150/345) of cattle were infected with at least one TBP, of which single infections were detected in 104 (30.14%), double infections in 34 cattle (9.86%) and triple infections in 12 (3.48%) of the cattle. The overall prevalence of Anaplasma spp., Theileria spp. and B. bigemina were 22.32%, 23.19% and 7.24%, respectively. Among these, the prevalence of A. bovis, A. central, A. phagocytophilum, A. platys, A. marginale, T. sinensisi and T. orientalis were 8.41%, 7.83%, 4.93%, 4.35%, 2.61%, 22.32% and 2.60%, respectively. We could not detect B. bovis, T. annulata, T. luwenshuni or T. uilenbergi in cattle. Cattle ≥1-year-old were more likely to be infected with Theileria spp. [adjusted odd ratio (AOR) = 2.70, 95% CI = 1.12-6.56)] compared with younger cattle, while cattle ≥1-year-old had reduced susceptibility to B. bigemina (AOR = 0.14, 95% CI = 0.03-0.60). Cattle living at higher altitude (≥500 m) were more susceptible to B. bigemina (AOR = 6.97, 95% CI = 2.08-23.35) and Theileria spp. infection (AOR = 1.87, 95% CI = 1.06-3.32). The prevalence of Theileria spp. on farms with cats was significantly higher than that without cats (AOR = 2.56, 95% CI = 1.12-5.88). Infection with A. bovis and A. central were significantly associated with A. phagocytophilum infection. Furthermore, there were significant associations between A. bovis and A. central infection, T. sinensisi and A. marginale infection, and B. bigemina and T. orientalis infection. This study provides new data on the prevalence of Anaplasma spp., Babesia spp. and Theileria spp. in cattle in Chongqing, and for the first time we reveal a possible relationship between the afore-mentioned pathogens, which will help in formulating appropriate control strategies for these pathogens in this area.

A series of experiments were performed to investigate fretting behavior of electrical connectors subjected to axial vibration input. A random vibration test used to study vibration behavior of the connector systems revealed that multiple transverse modes were excited by the axial input. Through tests with single-frequency vibration inputs, the threshold behaviors at various frequencies for the onset of fretting corrosion were identified. It is demonstrated that the threshold amplitudes are at micrometer scale for these types of connectors. The results also exhibit that the thresholds vary with vibration frequencies, and at the frequency of one mode, the threshold is lowest over the testing spectrum. Threshold amplitudes at this mode of the connector systems with various wiring tieoff lengths were also tested. Based on the understanding of the dynamics of the connector systems, a discrete vibration model was developed to predict the threshold behavior at this mode. The estimated threshold amplitudes correlate well with the experimental results through a parametric best fit of the vibration transfer functions.

The transmissibility reveals two very useful characteristics of a micro-electro-mechanical systems (MEMS) device, the resonant frequency and the mechanical quality factor. Real time knowledge on these two important factors can enhance application performance or avoid potential problems from environmental disturbances due to fabrication tolerances and the resulting operational differences in otherwise identical devices. Expensive laboratory equipment is typically used to measure the transmissibility. However, these test systems are not readily adaptable to field use. Therefore, it is important to be able to measure the transmissibility using a real time technique with a simplified test setup. This study proposes a technique that can compute the transmissibility in real time using a low cost microcontroller. This technique utilizes two laser vibrometers to detect the input and output motions of the proof mass in a MEMS device, which are fed to high speed 500 KHz analog to digital converters (ADC) in the microcontroller. A filtering step is performed to decrease noise. After the sampling and pre-filtering, a Fast Fourier Transform (FFT) is performed to convert the time-domain signals to frequency domain signals. The amplitude of the output signal at each frequency is divided by the amplitude of the corresponding input signal at each frequency to obtain the transmissibility. To overcome the difficulties resulting from measurement and quantization noise, a recursive calculating algorithm and a de-quantization filter are introduced. The recursive calculating process guarantees that the system updates the results continually, which results in a transmissibility plot covering the entire bandwidth. The de-quantization filter considers the validity of the data and performs the transmissibility division step accordingly. A cantilevered structure was chosen as the device-under-test to verify and evaluate this technique. The cantilevered device was attached to an electromechanical shaker system for vibratory stimulation. Two laser vibrometers were used to detect the input and output motion and this data was fed into a microcontroller. The microcontroller was STM32F407, which is 32-bit and 168 MHz controller. The tests demonstrated that this technique can measure the transmissibility and therefore the resonant frequency and mechanical quality factor accurately compared to a professional signal analyzer.

Fretting degradation is generally recognized as one of the major failure mechanisms for electrical connector systems. The major driver of fretting damage is relative motion at the contact interface, producing material displacement and transfer. For non-precious metal plated contact interfaces, this fretting damage serves to repeatedly expose fresh metal to atmospheric oxidation. The result is a substantial and rapid increase in contact resistance due to a localized buildup of an insulating layer. Relative motion at the contact interface can be induced by thermal expansion/contraction, vibration, or by a combination of the two mechanisms. There has been considerable recent work on this topic, including experimental investigations and model development work. Much of this previous work on fretting degradation has focused on the increase in electrical resistance resulting from the buildup of corrosion products (the insulating layer) in the interface between the blade and the receptacle. However, the physical separation of the blade and receptacle by the corrosion products also produces a capacitance effect that has not been previously explored in detail. The present study seeks to explore this phenomenon and develop an understanding of its significance. An experimental study was performed to investigate the fashion of the capacitance build-up subjected to vibration induced fretting motion. A simple model is also developed which relates the capacitance behavior to connector characteristic, vibration profile and resistance behavior. A series of experiments and simulation studies have been performed to explore the physical behavior of such systems and study the capacitance effects of the insulating layer. Of particular interest is the effect on signal phase and frequency response across the connector interface and how these effects might be employed to monitor the health of connector systems used for communication signals.

Random and single frequency vibration tests were used to investigate vibration behaviors and thresholds of the fretting corrosion of connector samples with different wiring tie-off lengths. Multiple vibration modes and the rocking style motion of the connector systems were observed. Through running threshold tests, the threshold behavior at various frequencies for the onset of fretting degradation was revealed. Typically the micrometer-scale axial vibration was able to trigger the fretting corrosion of the connector samples. It is also found that the threshold amplitude at the natural frequency of one of the modes was the lowest. Thresholds at this mode of the connectors with different wiring tie-off lengths were also tested. In addition, a discrete vibration model was developed to explain and predict the threshold behavior. Through a fit of vibration transfer functions, the thresholds predicted by the model correlated well with the experimental results. The analysis exhibited that the thresholds are greatly affected by the stiffness and damping as a result of tie configurations. Consequently, it is concluded that the dynamic response of the mechanical system under various tie off configurations can remarkably influence the performance of the vibration induced fretting corrosion of a connector system.