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Mechanical Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
How does QCM work? When the electrodes are connected to an oscillator and an AC voltage is applied across these electrodes, the quartz crystal vibrates and thickness shear acoustic waves called bulk acoustic waves (BAWs), arising from the piezoelectric effect, undergo constructive interference, such that resonances occur at particular frequencies. Essentially, the quartz crystal starts oscillating at its resonance frequency, acting as a piezoelectric resonator.
Introduction to Customized Board with 8051 Microcontroller and NuttyFi/ESP8266
Published in Anita Gehlot, Rajesh Singh, Praveen Kumar Malik, Lovi Raj Gupta, Bhupendra Singh, Internet of Things with 8051 and ESP8266, 2020
Anita Gehlot, Rajesh Singh, Praveen Kumar Malik, Lovi Raj Gupta, Bhupendra Singh
A crystal oscillator is an electronic oscillator circuit, which is used for the mechanical resonance of a vibrating crystal of piezoelectric material. It will create an electrical signal with a given frequency. This frequency is commonly used to keep track of time for example: wrist watches are used in digital integrated circuits to provide a stable clock signal and also used to stabilize frequencies for radio transmitters and receivers. Quartz crystal is mainly used in radio-frequency (RF) oscillators. Quartz crystal is the most common type of piezoelectric resonator; in oscillator circuits we are using them so it became known as crystal oscillators. Crystal oscillators must be designed to provide a load capacitance, as shown in Figure 4.6.
Electro-optic Ceramics and Devices
Published in Lionel M. Levinson, Electronic Ceramics, 2020
An even broader category of materials to which ferroelectrics belong is that of piezoelectrics. Unlike ferroelectrics and pyroelectrics, piezoeleetries are not spontaneously polarized but do become polarized while under the influence of an external stress; i.e., they develop an electric charge (electric field) with the application of a mechanical force. Conversely, piezoelectrics will also undergo mechanical deformation (strain) when subjected to an externally applied electric field. The former behavior is known as the direct piezoelectric effect, and the latter is known as the converse effect. Although there are many examples of piezoelectric materials that are not ferroelectric, by far the most notable and practical example is quartz. Quartz is used in practically every modern-day reference oscillator and timing circuit, ranging from simple clocks and watches to multiplexed displays and computers. High-Q and vibrational stability as a function of time and temperature are the key characteristics.
Examinations of vibration frequency and mode shape variations of quartz crystal plates in a thermal field with strain and kinetic energies
Published in Journal of Thermal Stresses, 2020
Qi Huang, Rongxing Wu, Longtao Xie, Aibing Zhang, Bin Huang, Jianke Du, Ji Wang
Quartz crystal resonators are key components of electronic products and widely used in our daily life as an enabler of communication, sensor, timing, and many critical applications. By taking the advantage of the converse piezoelectric effect, quartz crystal plates can provide us with the desired vibration frequency of high stability in electronic devices for frequency control and timing applications [1]. To satisfy these objectives, it is important to analyze and identify vibration modes to realize the optimal design of a quartz crystal resonator. Actually, there are many complication factors that will affect the vibration behavior of the resonator, such as the electrodes [2,3], plate geometry [4], crystal orientations [5], and temperature [6,7]. It has been known that the temperature can cause the variation of the vibration state [8] and lead to mode conversion which may bring up a typical state of failure known as frequency jump or activity dip [9]. For practical applications, it is necessary to trace the frequency-temperature behavior during the temperature variation to ensure the change of vibration mode is kept to the desired state for the proper functioning of a resonator. In our previous papers [5,10], the temperature effect on quartz crystal plates are analyzed and discussed by plotting the frequency spectra and mode shapes with temperature changes [4] and the variation trend of resonator frequency can be clearly illustrated with the frequency-temperature relationship curves.
Developing a Piezoelectric Generator for Military Equipment – A Feasibility Study
Published in Electric Power Components and Systems, 2023
Karthikeyan Sathasivam, Ilhan Garip, Hayder Sharif, Jamal K. Abbas, Ali Adhab Hussein, Shahad K. Khaleel, Mustafa Asaad Rasol
The quartz crystal is constituted of molecules of silicon dioxide (SiO2), formed by oxygen (O) and silicon (Si). In the crystal, the SiO molecules rearrange themselves, with each silicon ring connected to four oxygen rings and each oxygen ring attached to two silicon rings. This rearrangement results in interconnected SiO4 groups, which present a tetrahedral structure. The SiO groups are connected in a spiral, in the direction of the Z-axis. When we look from a particular perspective, verifying an arrangement of the spiral groups in the Z-axis is possible. Figure 1 shows the view of Quartz crystals [13].
Review on the mineral processing in ionic liquids and deep eutectic solvents
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Quartz is an oxide mineral with stable chemical and physical properties, mainly composed of SiO2. It is primarily used for preparing silica refractories, silica sand, and sintered ferrosilicon, as well as purification and separation materials of high-purity silica. Quartz is a widely used and widely distributed mineral resource that can meet the global industrial demand. However, quartz is one of the impurity minerals in the separation process of the most natural ores, such as iron ore, phosphate rock, feldspar, cassiterite, kaolin, etc. Therefore, the enrichment and separation of quartz minerals are very important for industry. Foam flotation is one of the effective methods to selectively separate the required minerals released from fine particles. In this technology, collectors play a major role in enhancing the quality of the required mineral species. The selection of collectors plays an important role in enriching the required flotation minerals in the flotation process (Shen et al. 2016; Wang et al. 2015; Yang et al. 2019; Zhang et al. 2021). At present, dodecyl amine chloride and acetate are the most widely used collectors of flotation desilication, such as cetyltrimethylammonium bromide (CTAB), dodecylamine chloride (DDA), ester amine or ether, and quaternary ammonium salt, which are applied as collectors of for quartz flotation (Wang et al. 2015). The final beneficiation efficiency selectivity, and collection capacity of collectors are affected by various factors. Some works have been performed to study the effects of carbon-chain length, and anion type on amine collectors (Shen et al. 2016). Researchers have been looking for more effective reagents and using various methods to reduce the dosage and improve the effect of flotation (Yang et al. 2019; Zhang et al. 2021).