Simple Transducer Research Articles

Evaluation of a Ru‐bipod Complex as a Redox Transducer for Membrane‐Based Voltammetry of Anions**

AbstractMolecular redox compounds show promise for the development of solid contact ion selective electrodes (SC‐ISEs) for anion determinations. In this work, a hydrophobic bis‐tridentate Ru‐bipod complex was studied as a molecular redox transducer in voltammetric SC‐ISEs. Thin film voltammetric behavior was achieved in films comprised of the Ru‐bipod complex, polyvinylchloride (PVC) and a plasticiser, nitrophenyloctylether (NPOE). Importantly, the choice of plasticiser had a significant effect on the SC‐ISE response of the Ru‐bipod complex; i. e., voltammetric responses of the Ru‐bipod complex in NPOE films were sharper and more intense than in bis(2‐ethylhexyl) sebacate (DOS) films. Moreover, addition of tetradodecylammonium tetrakis(4‐chlorophenyl)borate (ETH 500) to the membrane had an unfavorable impact on detection of anions due to oxidation of this salt in the film. Although the thin film electrode showed close‐to‐Nernstian behavior in anion responses, the detection responses in the presence of very hydrophilic anions such as sulfate ion were shifted to higher potentials (>1 V) with a subsequent loss of sensitivity. Overall, the Ru‐bipod complex operates as a simple transducer in SC‐ISEs with benefits in anion detection.

Trends in the development of measurement microphones

Measurement microphones are, in principle, simple transducers that convert dynamic pressure fluctuations into an electrical output signal. The range of applications is, however, extremely wide-from measuring exceptionally low-level signals (below 0 dB; for example, measuring tiny insects) to the 190 dB signal of large rocket launches. The frequency range of interest spans from below 0.1 Hz for sonic boom measurements to 200 kHz or more for detailed investigations of very short impulses or wind tunnel scale modelling. At the same time, the individual application may mandate specific mounting conditions with specialized form factors for the microphone and associated preamplifier design. This trend towards application-specific testing has led to the development of a wide range of specialized microphones and accessories. Still, this wide variety of measurement microphones must measure accurately and be calibrated to be traceable to the basic unit of measure as, for example, defined by the SI system. This is ensured by maintaining reference to the basic IEC definition of measurement microphones in the IEC 61094 series of standards for microphones and calibration methods.

Trends in the development of measurement microphones

Measurement microphones are, in principle, simple transducers that convert dynamic pressure fluctuations into an electrical output signal. The range of applications is, however, extremely wide—from measuring exceptionally low-level signals (below 0 dB; for example, measuring tiny insects) to the 190 dB signal of large rocket launches. The frequency range of interest spans from below 0.1 Hz for sonic boom measurements to 200 kHz or more for detailed investigations of very short impulses or wind tunnel scale modelling. At the same time, the individual application may mandate specific mounting conditions with specialized form factors for the microphone and associated preamplifier design. This trend towards application-specific testing has led to the development of a wide range of specialized microphones and accessories. Still, this wide variety of measurement microphones must measure accurately and be calibrated to be traceable to the basic unit of measure as, for example, defined by the SI system. This is ensured by maintaining reference to the basic IEC definition of measurement microphones in the IEC 61094 series of standards for microphones and calibration methods.

Factors Influencing the Purchase Rate of Cartilage Conduction Hearing Aids.

Innovated hearing aids (HAs), termed cartilage conduction hearing aids (CC-HAs), show good performance in patients with closed ears and continuous otorrhea. However, factors other than the ear condition that influence the purchase rate of CC-HAs remain unclear. To identify the factors that influence the purchase rate of CC-HAs. A correlational study. A total of 249 patients were enrolled. The patients' demographics, clinical characteristics, outcomes, and CC-HA transducer types were compared. The data were analyzed for six groups classified based on the ear condition. In the unilateral closed-ear group, the purchase cases were significantly younger than the nonpurchase cases (p < 0.05). Regarding the outcomes in the bilateral closed-ear group, the purchase cases showed significantly better-aided thresholds at 0.25 and 0.5 kHz than the nonpurchase cases. No significant differences in the functional gains and speech recognition scores were found between purchase and nonpurchase cases in all six groups. Regarding the transducer type, the continued-use rate of the simple transducer type was significantly lower in the bilateral chronic continuous otorrhea, bilateral open, and unilateral open groups. In the closed ears, no remarkable negative factors were found. Transducer type had a significant influence on the continued-use rate in the nonclosed ears including the ears with chronic continuous otorrhea, although the purchase rate of CC-HAs in the bilateral chronic continuous otorrhea group was comparable to the closed ears.

Weighted differential evolution heuristics for improved multilayer piezoelectric transducer design

Piezoelectric transducers are designed for wide applications of underwater sonar, energy harvesting, biomedical and nondestructive testing in terms of higher sensitivity and broad bandwidth. Multilayer transducers have well-known advantages of higher sensitivity and thus can be optimized by varying layer thicknesses of active material. The present study deals with mathematical optimization of multilayer transducers exploiting weighted differential evolution (WDE) based computational heuristics for optimized piezoelectric transducer design while satisfying the constraint of constant total thickness. Fitness evaluation is carried out on the basis of one dimensional model (ODM) for simple multilayer, multilayer with bondlines and transducer with bondlines and matching for piezoelectric materials including PZT5h, PMN-PT and piezocomposite with PMN-PT for different loading media. WDE exploited along with ODM for the transducer models has demonstrated the efficacy, reliability and applicability of the proposed scheme. Comparative study of the proposed WDE-ODM with its counterparts including simulated annealing, genetic algorithms, and particle swarm optimization, reveal better performance in terms of accuracy, complexity and convergence metrics for different number of layers for simple transducers. Applicability of WDE-ODM on piezoelectric structures with bondlines, and matching layers has also been accessed and validated.

Parametric Study of Ultrasonic De-Icing Method on a Plate with Coating

Ultrasonic de-icing is a promising method to de-ice structures by using lightweight and simple transducers, with the advantage of low power consumption. A successful ultrasonic de-icing technique requires the understanding of the effects of different parameters on de-icing. This paper presents a thorough parametric study of the ultrasonic de-icing method on a plate with coating. First, the dispersion equations of shear horizontal (SH) and Lamb waves were derived based on the global matrix method. Meanwhile, interface shear concentration coefficients (ISCC) were introduced to represent the ability of ultrasonic de-icing, which was further integrated into Lamb wave and SH waves dispersion curves for the selection of optimal frequencies. Second, a three-layer plate model (host plate-coating-ice) was used to demonstrate the effect of different parameters of coating and the thickness of ice on ultrasonic de-icing. The theoretical model provided the design principle of coating and ultrasonic parameters required for efficient de-icing. Finally, an experiment was conducted on an ultrasonic de-icing platform to validate the proposed ultrasonic de-icing method. In this process, material parameters including the Young’s modulus, thickness of coating, and thickness of the ice layer were analyzed. The trends of power consumption and optimal frequency of experiments are in good agreement with the analytical calculated results.

A Simple Instrumentation System for Health Monitoring of Concrete Structures

The objective of this work is to develop a simple instrumentation system to assess the healthiness of small concrete structures. There are various methods available for crack detection in concrete structures such as visual inspection, thermography, ultrasonic testing etc. This work emphasizes on a simple resistance transducer sensor for detection of crack in small concrete structures. The system is integrated with NodeMCU based micro controller which measures the change in resistance with respect to the crack developed. A simple prototype concrete structure is developed and the performance results is discussed. The experimental results show that proposed method seems to be simple and effective in comparison with other techniques.

Distinct mechanisms of signal processing by lamina I spino-parabrachial neurons

Lamina I spino-parabrachial neurons (SPNs) receive peripheral nociceptive input, process it and transmit to the supraspinal centres. Although responses of SPNs to cutaneous receptive field stimulations have been intensively studied, the mechanisms of signal processing in these neurons are poorly understood. Therefore, we used an ex-vivo spinal cord preparation to examine synaptic and cellular mechanisms determining specific input-output characteristics of the neurons. The vast majority of the SPNs received a few direct nociceptive C-fiber inputs and generated one spike in response to saturating afferent stimulation, thus functioning as simple transducers of painful stimulus. However, 69% of afferent stimulation-induced action potentials in the entire SPN population originated from a small fraction (19%) of high-output neurons. These neurons received a larger number of direct Aδ- and C-fiber inputs, generated intrinsic bursts and efficiently integrated a local network activity via NMDA-receptor-dependent mechanisms. The high-output SPNs amplified and integrated the nociceptive input gradually encoding its intensity into the number of generated spikes. Thus, different mechanisms of signal processing allow lamina I SPNs to play distinct roles in nociception.

A Novel Transducer for Measurement of Skin Blood Flow Using Radio Frequency Energy

Abstract The rate of blood flow in the skin has relevance to several cardiovascular conditions of clinical significance. However, there is no accepted fast, easy way to noninvasively measure the volumetric rate of blood flow per unit tissue volume. Previous work has suggested the potential for using skin heating from radio frequency (RF) energy in the millimeter wave (MMW) band, with simultaneous monitoring of skin surface temperature as a means for noninvasive skin blood flow measurement. This work presents a design and in vitro test results for a simple transducer for MMW blood flow measurement. The transducer consists of a Ka band microstrip antenna and an infrared temperature sensor integrated in a thermoplastic housing. A prototype was tested in a controlled flow chamber, using a commercial tissue phantom material. The device was tested at eight flow rates ranging from 0.25 ml min−1 to 20 ml min−1, equivalent to approximately 10–800 ml min−1·per 100 cm3 of tissue. The differences in temperature increase at exposure time t=60 s were statistically significant (n = 5) so as to allow resolution of flow rates of 0.25, 0.50, 1.0, 2.0, 10, and 20 ml min−1. The ensemble average of temperature increase versus time over the 60 s exposure window were described by a simple two-parameter lumped model which can be correlated with the flow rate. The flow rate model parameter does not scale directly with the flow in the experimental chamber however. This may suggest limitations either in the model or the experimental procedure.

A Modified Impedance-Frequency Converter for Inexpensive Inductive and Resistive Sensor Applications.

In this paper an exceptionally simple transducer is presented that is developed for experimental and custom-made sensors with inductive or resistive impedance output. It is based on a venerable 555 Integrated Circuit in a modified astable configuration. Due to single supply 5 V operation, it is directly compatible with most modern microcontroller systems, such as the popular Arduino platform. Various exemplary sensor characteristics are presented, including displacement, force, magnetic field, temperature and light sensing applications. While the transducer is not designed for high accuracy, it allows for fast and inexpensive application of various experimental sensors, such as magnetoelastic or GMI (Giant Magneto Impedance) sensors.

Representation and the active consumer

One of the central tasks for naturalistic theories of representation is to say what it takes for something to be a representation, and some leading theories have been criticised for being too liberal. Prominent discussions of this problem have proposed a producer-oriented solution; it is argued that representations must be produced by systems employing perceptual constancy mechanisms. However, representations may be produced by simple transducers if they are consumed in the right way. It is characteristic of representations to be consumed by systems which are capable of independent action. This paper defends this claim; discusses more precise, naturalistic formulations; and shows how it can illuminate the explanatory payoffs which science achieves by appealing to representation.

Photonic Crystal Fiber Transducers for an Optical Fiber Multilevel Temperature Threshold Sensor

Thermo-optical properties of the optical fiber transducers based on a filled Photonic Crystal Fiber used as a temperature threshold sensor were shown in this paper. A simple transducer is a piece of a partially filled PCF spliced with a standard single-mode fibers. As a filling material, a selected group of n-alkanes with the carbon atoms’ number within the range of 12–28 were used. The main advantages of these materials are phase transitions between solid and liquid states for temperatures from −10 up to 60 °C. Each transducer has a bistable switch on/off transmission characteristics depended on a given n -alkane physical state liquid or solid. These properties allow us to propose an optical warning system as a multilevel temperature threshold sensor. This system can be used in industrial applications to control temperature as a point sensor.

Finite-State Tokenization for a Deep Wolof LFG Grammar

This paper presents a finite-state transducer (FST) for tokenizing and normalizing natural texts that are input to a large-scale LFG grammar for Wolof. In the early stage of grammar development, a language-independent tokenizer was used to split the input stream into a unique sequence of tokens. is simple transducer took into account general character classes, without using any language-specific information. However, at a later stage of grammar development, uncovered and non-trivial tokenization issues arose, including issues related to multi-word expressions (MWEs), clitics and text normalization. As a consequence, the tokenizer was extended by integrating FST components. is extension was crucial for scaling the hand-written grammar to free text and for enhancing the performance of the parser.

Receive-Noise Analysis of Capacitive Micromachined Ultrasonic Transducers.

This paper presents an analysis of thermal (Johnson) noise received from the radiation medium by otherwise noiseless capacitive micromachined ultrasonic transducer (CMUT) membranes operating in their fundamental resonance mode. Determination of thermal noise received by multiple numbers of transducers or a transducer array requires the assessment of cross-coupling through the radiation medium, as well as the self-radiation impedance of the individual transducer. We show that the total thermal noise received by the cells of a CMUT has insignificant correlation, and is independent of the radiation impedance, but is only determined by the mass of each membrane and the electromechanical transformer ratio. The proof is based on the analytical derivations for a simple transducer with two cells, and extended to transducers with numerous cells using circuit simulators. We used a first-order model, which incorporates the fundamental resonance of the CMUT. Noise power is calculated by integrating over the entire spectrum; hence, the presented figures are an upper bound for the noise. The presented analyses are valid for a transimpedance amplifier in the receive path. We use the analysis results to calculate the minimum detectable pressure of a CMUT. We also provide an analysis based on the experimental data to show that output noise power is limited by and comparable to the theoretical upper limit.

Multi-point fiber-optic refractive index sensor by using coreless fibers

We present a novel multi-point fiber-optic refractive index (RI) sensor based on two different length coreless fibers spliced between single mode fibers (SMFs). The sensing probe operated based on multimode interference. A multi-point interferometer with 25mm and 30mm coreless fiber is fabricated and the measurement of RI is realized by measuring the wavelength shift of resonance dips in the transmission spectrum of the multi-point interferometer. Experimental characterization for a multi-point refractometer is presented. In the RI range of 1.3288–1.3666, the corresponding RI sensitivities are 148.60nm/RIU and 119.27nm/RIU for each point, respectively. We demonstrate that this multi-point fiber optic interferometer can be used as a simple transducer for RI sensing with comparable sensitivity.

Deciding Determinism with Fairness for Simple Transducer Networks

A distributed database system often operates in an asynchronous communication model where messages can be arbitrarily delayed. This communication model causes nondeterministic effects like unpredictable arrival orders of messages. Nonetheless, in general we want the distributed system to be deterministic; the system should produce the same output despite the nondeterministic effects on messages. Previously, two interpretations of determinism have been proposed. The first says that all infinite fair computation traces produce the same output. The second interpretation is a confluence notion, saying that all finite computation traces can still be extended to produce the same output. A decidability result for the confluence notion was previously obtained for so-called simple transducer networks, a model from the field of declarative networking. In the current article, we also present a decidability result for simple transducer networks, but this time for the first interpretation of determinism, with infinite fair computation traces. We also compare the expressivity of simple transducer networks under both interpretations.

Single Layer Gold Hotplate, Printed on Polyimide, with Heater Used as Sensing Current Drain for Metal-oxide Gas Sensor

We report a simple transducer architecture based on two interdigitated inkjet-printed gold electrodes deposited on polymer substrate. The particularity of this transducer is the double functionality of the heater, since it works as heater and sensor electrode simultaneously. This way, a metal-oxide gas sensor can be realized easily using a two-step fabrication process, the printing of the two electrodes and their coating with the sensing film. The transducer was validated by coating it with tungsten oxide nanoneedles (NNs) functionalized with Pt nanoparticles (NPs) via aerosol assisted CVD method (AACVD) and then tested under different concentrations of H2 gas. The proposed flexible printed transducer allows the simple and cost-effective realization of metal oxide gas sensors.

Characterization of a Computational Fluid Dynamics Thermocouple Model Subjected to Stochastic Environmental Forcing Using Moment Based Analysis

With increasing requirements for model validation when comparing computational and experimental results, there is a need to incorporate detailed representations of measurement devices within the computational simulations. Thermocouples are the most common temperature measurement transducers in flames and fire environments. Even for the relatively simple thermocouple transducer, the coupling of heat transfer mechanisms particularly under unsteady flow conditions leads to interesting dynamics. As experimentalists are well aware, the experimentally determined thermocouple values are not the same as the local gas temperatures and corrections are often required. From the computational perspective, it is improper then to assume that the predicted gas temperatures should be the same as the temperatures that an experimentalist might measure since the thermal characteristics of the thermocouple influence the indicated temperature. The thermal characteristics of simulated thermocouples in unsteady flame conditions are investigated. Validation exercises are presented to test the underlying thermocouple model. The thermocouple model problem is examined for a quasi-steady problem in which the gas temperature and surrounding walls are assumed to be random and described by probability density functions (PDFs). Differences are noted between the predicted thermocouple response and expected response. These differences are interpreted from the perspective of what modeling artifacts might drive the differences.

Mechanical and control characteristics of multilayer piezoelectric transducers of nano- and microdisplacements

Mechanical and control characteristics of a multilayer piezoelectric transducer of nanoand microdisplacements in the case of parallel and encoded control are obtained. The static and dynamic characteristics of simple and multilayer piezoelectric transducers of nano- and microscopic displacements are determined for longitudinal and transverse piezoeffects.

A Wearable Technology Revisited for Cardio-Respiratory Functional Exploration

The objective of the present study is to extract new information from complex signals generated by Respiratory Inductive Plethysmography (RIP). This indirect cardio-respiratory (CR) measure is a well-known wearable solution. The authors applied time-scale analysis to estimate cardiac activity from thoracic volume variations, witnesses of CR interactions. Calibrated RIP signals gathered from 4 healthy volunteers in resting conditions are processed by Ensemble Empirical Mode Decomposition to extract cardiac volume signals and estimate stroke volumes. Averaged values of these stroke volumes (SVRIP) are compared with averaged values of stroke volumes determined simultaneously by electrical impedance cardiography (SVICG). There is a satisfactory correlation between SVRIP and SVICG (r=0.76, p&lt;0.001) and the limits of agreement between the 2 types of measurements (±23%) satisfies the required criterion (±30%). The observed under-estimation (-58%) is argued. This validates the use of RIP for following stroke volume variations and suggests that one simple transducer can provide a quantitative exploration of both ventilatory and cardiac volumes.