For the investigation of the carrier concentration and mobility, Hall effect measurements were performed using an Ecopia HMS 3000. The thicknesses of the Pd-doped and Pd microparticle embedded ZnO films were estimated to be between 250 and 300 nm, as measured by TFProbe from Angstrom Advance Inc.The current-voltage characteristics were measured using a
Humidity detection has been attracting increasing interest over the past years in the fields of industrial and agricultural production, food storage, meteorology, environment protection, etc. [1]. Recently, surface acoustic wave (SAW)-based humidity sensors have attracted much attention since they exhibit the advantages of very fast response (several seconds), high sensitivity, small size, integrated electronic circuitry, and easy to realize wireless communication over the current impedance-type or capacitance type humidity sensors [2�C4], and also the optical sensors coated with chiral sculptured thin films or thin dielectric waveguide [5,6].

The schematic and working principle of a typical SAW-based humidity sensor with a dual-oscillator configuration is shown in Figure 1, where the SAW devices are used as frequency control elements in the feedback path of an oscillator circuit. A sensitive interface allowing analytes to be sorbed onto the device surface was deposited along the acoustic wave propagation path of the sensing device. The physical adsorption between the sensing film and the target water vapor species modulates the phase velocity of the SAW propagating along the SAW device, and the target relative humidity can be characterized by the oscillation frequency shift.

Figure 1.The schematic and principle of the SAW-based humidity sensor.However, even though there are attractive reports about SAW-based humidity sensors, they still suffer from poor corrosion resistance of the sensor chip itself because of their use of Al electrodes. Additionally, deficiencies of the optimized design parameter extraction of the SAW devices leads to poor oscillator frequency stability, and thus directly affects the limit of detection and stability of the gas sensor. Up to now, two types of SAW device configuration were reported to be used as the feedback element of the oscillator for gas sensing [7].

One is delay line structured Brefeldin_A by two interdigital transducers (IDTs) and a delay path, that can provide enough sensitive film deposition area but relatively low Q-value and larger insertion losses affecting the frequency stability of the oscillator. The other is a resonator configuration composed of two reflectors and the adjacent transducers. The two-port SAW resonators with aluminum (Al) electrodes are widely used as the frequency feedback element due to their high electrical quality factor (Q) value and low insertion loss over the delay line patterns, resulting in excellent noise immunity and high measurement resolution and accuracy [8�C10].

Figure 2.Image acquisition system.The system provides adaptive but rigid joints between its components which, together with the control of the position of the table and the camera, allows us to carry out studies of repeatability in the capture and the subsequent analysis.The image acquisition system is based on the phenomenon of light retroreflection [5,6], that enhances the existing distortions on a flat surface. This kind of method has been applied to enhance the surface variations in different fields, such as plastic materials [7,8], aerospace industry [9,10], squeezing processes in general [11], and the automobile industry in particular [5,12].3.?General Description of the Algorithms for the Determination of the Geometrical Parameters of the ImperfectionsTo characterize the imperfection, an algorithm has been developed that extracts the information from the imperfection once it is firstly selected.

There are algorithms that try the surface reconstruction using least-squares techniques [13], but they do not allow the numerical quantification of imperfections of a size around 20 mm, such as the ones to be analyzed in this case. In [14] a collection of algorithms for the analysis of textures is shown, but most of them are for the classification of patterns. The work in [15] deals with a method based on the evaluation of local wall thickness and other imperfections, such us creases, using a medial axis transformation.All the information regarding the sheet deformation is available in the profile obtained from the captured image.

Taking into account that this information is the variation of the sheet deformation, the profile (signal) to Entinostat work on is the derivative of the original profile. The inflection points of this signal coincide with the maxima and minima of the original profile (sheet profile). The light areas of the image coincide with the prominences and the dark ones with the valleys of the sheet. The information of the highest elevation of the imperfection is related to the value of the maximum gradient of the signal. To track the imperfection, the maximum deflection is followed. Therefore, the algorithm must search for this maximum gradient and move along the imperfection with this searching criterion.The algorithms developed for the determination of the geometrical parameters of the imperfection and its quality index are:Algorithm for the obtaining of the profiles.

Algorithm for the automated monitoring of the imperfection.Extraction of the parameters of the imperfection and classification.4.?Algorithm for the Obtaining of Profiles4.1. Profile AnalysisThe first step to take is the analysis of the profile obtained from an image. The profile is typically of the form shown in Figure 3b. To get this profile, firstly a media filter is applied in the direction in which the imperfection is analyzed.

According to the specific application, the loops are adjusted. The classical four loops include: amplitude control loop, frequency control loop, orthotropic control loop and rate control loop. The amplitude control loops and frequency control loops usually work together to make the mode shape stable. The orthotropic control loops and rate control loops work together. The orthotropic control loops are responsible for adjusting the mode shape and suppressing frequency cracking, and the rate control loops are responsible for extracting the input angular rate [7,12�C14]. In real applications, Coriolis vibratory gyros that use a second order derivative linear variable structure and classical four-loop control method cannot effectively estimate variable structure arguments.

Many scholars have designed the control loops of these kinds of gyros with adaptive theory, sliding mode variable structure control theory and any other modern control theories to solve the problem [15�C17]. However, the inconveniences that using advanced control methods brings are the high requirement for signal calculating systems and the difficulty of operating the system. In practical engineering, studying the advanced control method is still ongoing and does not have detailed product application information.Combining traditional vibratory gyros’ electrical designing ideas with the characteristics of gyros, the article designs a circuit system of a BVG, including the driving components, detecting components and control loops. The BVG works in the force balance mode and uses classical four-loop control to make the mode shape stabilized.

In chapter two, the BVG’s working principle is described and the equivalent dynamic model is given. In chapter three, the whole design plan Brefeldin_A of the BVG for the signals’ characteristics is given. Chapter four studies the circuit system’s driving components, detecting components and control loops, discusses theory analysis, simulation verification and experimental testing and gives the detailed design and analysis process. In chapter five, an experiment is done to test the BVG’s circuit system, to extract the input angular rate effectively and to prove its effectiveness and practicality.2.?Overview of Bell-Shaped Vibratory Angular Rate GyroThe BVG is a kind of axisymmetric shell resonator gyroscope inspired by the traditional Chinese bell, and the core component is a bell-shaped resonator-like Chinese traditional bell. It uses the piezoelectric elements stuck to the resonator’s wall to detect the standing waves’ precession to calculate the input angular rate.2.1.