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Yurikov, Alexey, Nazanin Nourifard, Marina Pervukhina y Maxim Lebedev. "Laboratory ultrasonic measurements: Shear transducers for compressional waves". Leading Edge 38, n.º 5 (mayo de 2019): 392–99. http://dx.doi.org/10.1190/tle38050392.1.
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The ultrasonic measurements technique is well established to measure the elastic properties of rocks in the laboratory for seismic and well-log data interpretation. The key components of every laboratory ultrasonic setup are piezoelectric transducers, which generate and register elastic waves in rock samples. The elastic properties of rocks are determined through the velocities of elastic waves, which are measured by the times of the waves' travel from the source to the receiver transducer. Transducers can be specifically designed to generate P-waves (P-transducers) or S-waves (S-transducers). In limited studies, the measurement of P-wave velocities with S-transducers is mentioned. Such measurement is possible due to specific aspects of the operation of S-transducers. Namely, S-transducers are known to emit parasitic low-energy P-waves, which travel faster than high-energy S-waves and hence can be registered. However, no justification or elaboration of this method of measuring P-wave velocities was reported. To fill this gap, we first compare P-wave velocities measured with S-transducers against P-wave velocities measured with P-transducers in different rocks and materials. We show that the discrepancy between velocities measured with the two methods in homogeneous materials is less than 1% and can be up to 4% for natural rocks. Second, we numerically simulate the operation of S-transducers, show that parasitic P-waves have a dipole structure, and explain how the receiver transducer can register this compressional dipole. Finally, we use laser doppler interferometry to measure the displacement of the free surface of a sample caused by elastic waves emitted by the source S-transducer. We observed the dipole structure of the sample's surface displacement upon P-wave arrival on the surface.
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Catangiu, Adrian, Ileana Nicoleta Popescu, Dan Nicolae Ungureanu y Aurora Anca Poinescu. "Development of Experimental Device with Data Acquisition for Thermomechanical Characterization of Polymers". Scientific Bulletin of Valahia University - Materials and Mechanics 18, n.º 18 (1 de abril de 2022): 26–32. http://dx.doi.org/10.2478/bsmm-2022-0004.
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Abstract The aim of this paper is to present a handmade laboratory device with data acquisition for estimating the thermomechanical characteristics (caused by dimensional changes in height) of polymeric materials. This experimental device is able to perform penetration tests, monitoring the expansion of the samples and based on experimental tests, the thermal expansivity or coefficient of thermal expansion (CTE) can be determined. A data acquisition instrument, which register (i) the deformation of the specimen, by using two displacement transducers (an inductive proximity transducer and an transmission type photoelectric linear encoder) as well as registers (ii) the temperature (at the base of the specimen and in the vicinity of the point of contact with the penetrator) is used. In order to test the device and to highlight its qualities, preliminary tests were carried out on a thermosetting polymeric material in various stages of polymerization.
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Fedynets, Vasyl y Ihor Vasylkivskyi. "Optimization of Thermal Subsystem of Thermo Transducers for Measuring the Temperature of Gas Flows". Energy engineering and control systems 8, n.º 2 (2022): 110–17. http://dx.doi.org/10.23939/jeecs2022.02.110.
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The error of measuring the temperature of gas flows by contact methods consists of two main components: 1) the error that occurs in the process of measuring the physical quantity into which the temperature is converted (the error of the measuring means); 2) errors arising in the process of converting the temperature into a measured physical value using a thermo transducer. This component of the error is completely thermal in nature and is determined by the conditions of the thermal balance between the studied gas flow and the thermo transducer and has the greatest impact on the overall measurement error. It is determined by the combined action of the following factors: heat transfer due to radiation to or from the thermo transducer; heat removal from thermo transducer due to thermal conductivity; by converting part of the kinetic energy of the gas flow into thermal energy in the wall layer surrounding the thermo transducer; by convective transfer of heat from the wall layer to the sensitive element of the thermo transducer. Note also that if the temperature of the gas flow is non-stationary, then due to the thermo transducer's own heat capacity, it does not have time to register the time-varying temperature of the flow. Due to this, a dynamic component of the measurement error arises during the measurement of non-stationary temperatures. The article investigates the component error determined by the conditions of heat exchange between the gas flow and the thermo transducer.
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Pino-Ortega, José, Alejandro Bastida-Castillo, Alejandro Hernández-Belmonte y Carlos D. Gómez-Carmona. "Validity of an inertial device for measuring linear and angular velocity in a leg extension exercise". Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 234, n.º 1 (11 de octubre de 2019): 30–36. http://dx.doi.org/10.1177/1754337119878296.
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Traditionally, linear transducers have been used to evaluate resistance exercise with linear displacement. The current problem is the assessment of exercises with curvilinear displacement. For this reason, new devices should be assessed during training sessions. The purpose was to evaluate (1) the concurrent validity of mean linear velocity and (2) the convergent validity of mean angular velocity measured by an inertial device during a leg extension exercise. Ten elite-level football players completed six series of five repetitions of a leg extension exercise. WIMU PRO™ inertial device and GymAware® linear transducers as criterion measure were used to register data. To assess concurrent validity, the bias of the inertial device measures of velocity was analyzed with Bland–Altman plots with limits of agreement set at 95%. Convergent validity of inertial device measures of velocity was assessed with Pearson’s correlation analysis. Concurrent analysis showed a nearly perfect validity between linear transducers and inertial device in linear ( Bias = –0.011 ± 0.006) and angular velocity (–0.34 ± 2.08). A nearly perfect Pearson’s product–moment correlation coefficient between an inertial device and linear transducers in linear velocity ( r = 0.999) and between an inertial device and linear transducers (calculated) in angular velocity ( r = 0.999) was found. In conclusion, WIMU PRO is valid for measuring linear and angular velocity during two-dimensional linear and rotational motions of exercise equipment. This device can be used as a useful tool to assess movement velocity in resistance training exercises, even in curvilinear movements when linear transducers have obvious limitations.
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Roebuck, Bryan, M. Brooks y M. G. Gee. "Load Cell Ringing in High Rate Compression Tests". Applied Mechanics and Materials 1-2 (septiembre de 2004): 205–10. http://dx.doi.org/10.4028/www.scientific.net/amm.1-2.205.
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Mechanical test machines play an important role in providing simulation data to underpin careful analysis of high rate processes. In many cases elements of the test frame or testpiece can vibrate when subjected to a high rate force. The transducers attached to the machine frequently register this vibration superimposed on the true signal and thus may mask the signal required for analysis [1-4]. At impact all the parts of the test machine oscillate at their natural frequency (dependent on stiffness and mass). Ringing in test machines is determined by the rate at which the testpiece is deformed, the elastic characteristics of test material and resonances in components of load train anvils in compression. In the current work high rate hot compression tests are being developed to underpin best practice measurement guides on test methods for studying the dependence of strength on deformation rate and temperature, [5-7]. At higher rates of deformation ringing is observed in the transducer signals for load and displacement and this measurement note summarises the results of systematic tests to investigate this issue. A purpose built software tool was developed for analysing the time dependence of the transducer signals.
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Malinowski, Pawel, Tomasz Wandowski, Irina Trendafilova y Wiesław M. Ostachowicz. "Multi-Phased Array for Damage Localisation". Key Engineering Materials 347 (septiembre de 2007): 77–82. http://dx.doi.org/10.4028/www.scientific.net/kem.347.77.
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A method for damage localisation has been developed, which is based on the phased array idea. Four arrays of transducers, instead of only one, are used to perform a beam-forming procedure. Each array consists of nine transducers placed along a line, which are able to excite and register elastic waves. The arrays are placed in such a way that the angular difference between them is 45º and the rotation point is the middle transducer, which is common for all the arrays. The idea has been tested on a square aluminium plate modelled by the Spectral Finite Element Method. Two types of damage were considered, namely distributed damage, which was modelled as stiffness reduction, and cracks, modelled as separation of nodes in selected finite elements. The plate is excited by a wave packet (5-cycle sine modulated by the Hanning window). The whole array system is placed in the middle of the plate. Each phase array in the system acts independently and produces maps of a scanned field based on the beam-forming procedure. These maps are made of signals that represent the difference between the damaged plate signals and those from the intact plate. An algorithm was developed to join all four maps. This procedure eliminates the necessity to analyse each map individually and also gives the possibility to extract common features only. It allows to remove ambiguity and helps to localise damage more precisely than in the case of a single map. The problem for damage localisation was investigated and exemplary maps confirming the effectiveness of the system proposed were obtained. The investigation is based exclusively on numerical data.
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Golovachev, Petro, Ivan Korobko y Vitalii Krotevich. "INVESTIGATION OF THE UNCERTAINTY VALUE AT MEASURING THE TEMPERATURE OF THE COOLANT IN THE PIPELINES WITH OUTSIDE SURFACE MOUNTED TEMPERATURE SENSORS". Bulletin of Kyiv Polytechnic Institute. Series Instrument Making, n.º 62(2) (24 de diciembre de 2021): 42–49. http://dx.doi.org/10.20535/1970.62(2).2021.249199.
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During performing technological and production processes and monitoring the modes of their operation, the problem of determining the temperature of various media transported through pipelines is solved without incut temperature sensors (TS) in them, i.e. with using outside surface mounted TS (SMTS). This method is allowing to measure mechanical values at technological processes without structure broken and without influence to physicochemical properties of measured media.
Using of SMTS possible to register heat losses on sections of heating mains, pollution degree of pipelines internal walls, to control serviceability of measurement channels of temperature of the coolant in heat meters, etc.
In the article authors presents results of research the uncertainty values for measuring of the coolant temperature in heating systems pipelines under different modes of its flow. First of all, the uncertainty value of the measurements results was estimated, which was determined by the results of the study for the calculation model and field tests at existing district heating systems.
Emphasis is paid on estimating the difference between the registration of temperature in the middle of the pipeline, determined by mortise transducers and the temperature measured by outside surface mounted temperature transducers, taking into account the temperature gradient across the pipeline and the quality of its insulation.
It is determined that: the temperature measured by temperature transducers on the surface of the pipeline at different points of its perimeter, with proper installation and sufficient thermal insulation does not depend on their location; the average temperature on the surface of the pipeline, measured using the developed method of installation of PT, slightly differs (ΔT ≈- 0.3⁰C) from the average temperature of the coolant in the middle of the flow; temperature transducers have high reproducibility of measurements and small difference in readings between channels at parallel measurements (»0,03⁰С).
It is substantiated that high metrological performances of temperature transducers allow to use them for solving other tasks: measuring the distribution of heat fluxes in heating systems of residential buildings to perform hydraulic balancing of heating systems and increase their efficiency; estimate of contamination of pipelines and heat exchange equipment to determine the need for their washing; determination of thermal resistance of buildings protective structures to assess their energy efficiency; determination of large pumps efficiency by calorimetric method; checking the correct of operation the temperature measuring channels of heat meters and cold meters; in other technology areas where measurements of small temperature differences with high accuracy are required.
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Smirnov, Andrey, Boris Zaitsev, Andrey Teplykh, Ilya Nedospasov, Egor Golovanov, Zheng-hua Qian, Bin Wang y Iren Kuznetsova. "The Experimental Registration of the Evanescent Acoustic Wave in YX LiNbO3 Plate". Sensors 21, n.º 6 (23 de marzo de 2021): 2238. http://dx.doi.org/10.3390/s21062238.
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Evanescent acoustic waves are characterized by purely imaginary or complex wavenumbers. Earlier, in 2019 by using a three dimensional (3D) finite element method (FEM) the possibility of the excitation and registration of such waves in the piezoelectric plates was theoretically shown. In this paper the set of the acoustically isolated interdigital transducers (IDTs) with the different spatial periods for excitation and registration of the evanescent acoustic wave in Y-cut X-propagation direction of lithium niobate (LiNbO3) plate was specifically calculated and produced. As a result, the possibility to excite and register the evanescent acoustic wave in the piezoelectric plates was experimentally proved for the first time. The evanescent nature of the registered wave has been established. The theoretical results turned out to be in a good agreement with the experimental ones. The influence of an infinitely thin layer with arbitrary conductivity placed on a plate surface was also investigated. It has been shown that the frequency region of an evanescent acoustic wave existence is very sensitive to the changes of the electrical boundary conditions. The results obtained may be used for the development of the method of the analysis of thin films electric properties based on the study of evanescent waves.
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Sosa, J., Juan A. Montiel-Nelson, R. Pulido y Jose C. Garcia-Montesdeoca. "Design and Optimization of a Low Power Pressure Sensor for Wireless Biomedical Applications". Journal of Sensors 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/352036.
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A blood pressure sensor suitable for wireless biomedical applications is designed and optimized. State-of-the-art blood pressure sensors based on piezoresistive transducers in a full Wheatstone bridge configuration use low ohmic values because of relatively high sensitivity and low noise approach resulting in high power consumption. In this paper, the piezoresistance values are increased in order to reduce by one order of magnitude the power consumption in comparison with literature approaches. The microelectromechanical system (MEMS) pressure sensor, the mixed signal circuits signal conditioning circuitry, and the successive approximation register (SAR) analog-to-digital converter (ADC) are designed, optimized, and integrated in the same substrate using a commercial 1 μm CMOS technology. As result of the optimization, we obtained a digital sensor with high sensitivity, low noise (0.002 μV/Hz), and low power consumption (358 μW). Finally, the piezoresistance noise does not affect the pressure sensor application since its value is lower than half least significant bit (LSB) of the ADC.
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Kumar Y, L. V. Santosh. "Design and Implementation of SAR-ADC for Medical Electronic Applications". International Journal of Advanced Research in Computer Science and Software Engineering 8, n.º 5 (2 de junio de 2018): 55. http://dx.doi.org/10.23956/ijarcsse.v8i5.665.
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in today’s advance electronic and communication systems the role of high accuracy analog to digital converters are of great importance. Nowadays, a larger percentage of mixed-signal applications requires for health care systems. Also the speed of the chosen ADC design matters a lot as we are connected with the real world signals. SAR based ADC will provides us a better solution for various analog to digital systems. It is an essential device whenever data from the analog world, through sensors or transducers, should be digitally processed or when transmitting data between chips through either long-range wireless links or high-speed transmission between chips on the same printed circuit board. The paper projects up down and ring counter as a logic for successive approximation register (SAR logic for a ADC that is one of the best suited for low power. Here the resolution is of 4-bit and a power consumption of few milli watts. SAR ADC is implemented in 45 nm nano-meter scaling technology CMOS technology with a power supply of 0.5v by maintaining 4:1 w/l ratio.
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Herickhoff, Carl D., Matthew R. Morgan, Joshua S. Broder y Jeremy J. Dahl. "Low-cost Volumetric Ultrasound by Augmentation of 2D Systems: Design and Prototype". Ultrasonic Imaging 40, n.º 1 (8 de julio de 2017): 35–48. http://dx.doi.org/10.1177/0161734617718528.
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Conventional two-dimensional (2D) ultrasound imaging is a powerful diagnostic tool in the hands of an experienced user, yet 2D ultrasound remains clinically underutilized and inherently incomplete, with output being very operator dependent. Volumetric ultrasound systems can more fully capture a three-dimensional (3D) region of interest, but current 3D systems require specialized transducers, are prohibitively expensive for many clinical departments, and do not register image orientation with respect to the patient; these systems are designed to provide improved workflow rather than operator independence. This work investigates whether it is possible to add volumetric 3D imaging capability to existing 2D ultrasound systems at minimal cost, providing a practical means of reducing operator dependence in ultrasound. In this paper, we present a low-cost method to make 2D ultrasound systems capable of quality volumetric image acquisition: we present the general system design and image acquisition method, including the use of a probe-mounted orientation sensor, a simple probe fixture prototype, and an offline volume reconstruction technique. We demonstrate initial results of the method, implemented using a Verasonics Vantage research scanner.
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Galindo-Castillo, Ronaldo, Santos Gabriel Campos-Magaña, Martín Cadena-Zapata, Alejandro Zermeño-González, Juan Antonio López-López y Gilbert Fresh López-López. "Evaluación de un transductor integral para determinar la magnitud del error de medición." REVISTA TERRA LATINOAMERICANA 37, n.º 4 (7 de octubre de 2019): 329. http://dx.doi.org/10.28940/terra.v37i4.466.
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The use of soil reaction force transducers coupled between the tractor and integral tillage implements are in their experimental phase in different parts of the world; however, these developments present measurement errors. The objective of this research was to corroborate the magnitude of error between an Integral Force Sensor (SIF) connected to the tractor three-point hitch and two individual sensors coupled to the work tools to monitor soil reaction forces at the integral implements. SIF was tested under laboratory conditions with calibrated equipment to register force measurements at different lever distances and at different weights, using a data acquisition system DaqBook 2000 (Measurement Computing) and a signal conditioner DBK43A (Iotech Inc.). Obtained results indicated that SIF is sensitive to the load position, equivalent to the tillage depth, in a 2 to 10% range of error. Field evaluations were performed with a chisel plow at different depths for validation, finding errors between 13.07 and 41.72%, where chisel arrangement of 0.30 m depth for front chisels and 0.30 m for the rear chisel, showed the smallest error. Applying the 10% calibration correction obtained in the laboratory for a chisel length of 0.70 to 0.90 m, the obtained error was 3.1%. Comparison of the methods spectral analysis and area under the curve, equivalent to the energy used to obtain the error, showed that there is no significant difference between the two methods.
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Neroev, V. V., T. N. Kiseleva, M. S. Zaytsev, A. V. Baeva, E. K. Eliseeva y A. I. Ushakov. "A comparative analysis of biometric parameters of optic nerves obtained by ultrasonic sensors of varied frequencies". Russian Ophthalmological Journal 16, n.º 4 (29 de diciembre de 2023): 63–68. http://dx.doi.org/10.21516/2072-0076-2023-16-4-63-68.
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Purpose: a comparative analysis of biometric parameters of the optic nerve obtained by different diagnostic ultrasound sensors.Material and methods. We examined 20 healthy volunteers with emmetropia aged 20 to 40 years (40 eyes), average age 30.5 ± 5.4 years, who had no complaints or ophthalmic pathologies. Ultrasound scanning was performed on a multifunctional Voluson E8 (GE) scanner (11–18 MHz linear sensor), ophthalmic ultrasound device Ellex Eyecubed (a conventional 10 MHz transducer) and an ophthalmic scanner Absolu «Quantel Medical» (a 20 MHz transducer). All examinations were carried out by one operator who used the same scanning technique and measured the optic nerve sheath diameter (ONSD) and optic nerve diameter (OND) without sheaths in both eyes. Six consequent measurements of the ONSD and the OND parameters were performed to ascertain the reproducibility of the examinations and evaluate the variation coefficient.Results. The analysis revealed no statistically significant differences in the ONSD and in the OND obtained with 11–18 MHz, 10 MHz and 20 MHz transducers in the B-mode (р > 0.05). The minimum variation coefficient of the optic nerve thickness parameters was registered using a high-frequency 20 MHz transducer on the ophthalmic scanner. The biometry obtained with a high frequency 20 MHz transducer could be considered as the most reproducible.Conclusion. A high frequency 20 MHz transducer can be recommended for optimal visualization and precise evaluation of biometric parameters of the retrobulbar part of the optic nerve. Transducers of multifunctional scanners with the frequency range from 11 to 20 MHz can be used for measurements of the optic nerve sheath diameter.
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Zhitenev, A., I. Kurganov, V. Ignatchik, S. Sarkisov y P. Vinokurov. "Результаты экспериментальных исследований гидравлических ударов, возникающих при работе канализационных насосных станций". Vodosnabzhenie i sanitarnaia tehnika, n.º 11 (15 de noviembre de 2019): 55–59. http://dx.doi.org/10.35776/mnp.2019.11.07.
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Представлены результаты исследований гидравлических ударов, возникающих при работе канализационных насосных станций. Исследования проведены на двух однотипных станциях СанктПетербурга. В настоящее время отсутствуют направленные на снижение интенсивности гидравлических ударов на канализационных насосных станциях практические рекомендации, включающие выбор места установки и типа обратных клапанов, сочетание их совместной работы с плавным пуском и т. п. Поэтому в СанктПетербурге проводится комплекс экспериментальных исследований, направленных на решение этой задачи. При проведении исследований применены пьезорезисторные преобразователи давления и модульный регистр сигналов. Применение обратных клапанов с гидротормозом является более эффективной мерой борьбы с гидравлическими ударами по сравнению с плавным пуском и остановкой насосного агрегата. Гидравлические удары, возникающие при пуске насосных агрегатов при работе в сочетании с обратными клапанами без гидротормоза, могут превышать гидравлические удары, возникающие при их остановке.The results of studies of water hammer arising in the operation of sewage pumping stations are presented. The studies were carried out at two stations of the same type in St. Petersburg. At present, there are no practical recommendations aimed at reducing the strength water hammer at sewage pumping stations including the choice of location, type of check valves, a combination of their joint operation with smooth start, etc. Therefore, a set of experimental studies is conducted in St. Petersburg aimed at the solution to this problem. During the research, piezoresistor pressure transducers and a modular signal register were used. The use of check valves with hydraulic brakes is a more effective measure to combat water hammers compared to the smooth start and halt of the pumping unit. Water hammers that occur at the startup of pumping units while operating in combination with check valves without hydraulic brakes can exceed water hammers that occur when they stop.
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OSADCHUK, Alexsandr, Jaroslav OSADCHUK y Valentin SKOSCHUK. "MULTICHANNEL FREQUENCY METER ON A PROGRAMMABLE LOGICAL INTEGRATED CIRCUIT FOR A RADIOMEASURING SYSTEM WITH FREQUENCY SENSORS". Herald of Khmelnytskyi National University 303, n.º 6 (diciembre de 2021): 186–94. http://dx.doi.org/10.31891/2307-5732-2021-303-6-186-194.
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The paper presents the development of a multi-channel frequency measurement system on FPGA by Altera Cyclone IV, the main task of which is to measure the informative parameter of sensors of physical quantities with frequency output. Based on the analysis of existing multi-channel frequency measurement systems on the FPGA, it is established that it is advisable to use multi-channel frequency meters for simultaneous measurement of several frequencies. Unlike several frequency meters operating simultaneously, multi-channel frequency meters perform measurements in a single time base, which is provided by a common exemplary generator and timer. A multi-channel universal FPGA-based measuring device has been developed, which has 12 measuring channels for frequency output sensors and supports simultaneous operation of 127 digital sensors via I2C interface. Therefore, theoretically, data transmission from the developed device can be carried out wirelessly. The developed device can be connected to a personal computer via a UART-USB converter. As a chip for the implementation of the frequency meter is used FPGA company Altera EP4CE10F17C8 – a chip in the BGA case, which has 179 pins. The parameters, namely the value of the signal propagation delay, determine the maximum measured frequency, in our case about 3 ns (delay of the signal from the input to the internal register), which corresponds theoretically to 333 MHz. Specialized software has been developed to test the efficiency of a multi-channel measuring system for measuring informative parameters obtained from radio measuring transducers, based on the reactive properties of semiconductor structures with negative resistance. For convenience of perception, there is a visualization of the received information from the measuring device.
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Третьяков, Evgeniy Tretyakov, Бритвин, Vladimir Britvin, Вельтищев, Vadim Veltischev, Григорьев et al. "Ship Hull Diagnostics with the Use of Remotely Operated Underwater Vehicle". NDT World 18, n.º 3 (1 de septiembre de 2015): 12–15. http://dx.doi.org/10.12737/12565.
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Introduction. Nowadays ship hull diagnostics is carried out in dry-dock or using divers in the road. The both technologies are time consuming, labour and material resource demanding.
Specialists from Bauman Moscow State Technical University have developed a diagnostics system that allows the ship hull underwater part inspection to be performed without calling at dry-dock and without divers.
The system includes the following main elements: remotely operated vehicle that contains diagnostics tools; hydro acoustic navigation system; software; and diagnostics technology.
Method. The technology is based on an acoustic method of non-destructive testing (NDT). SH-waves with elastic vibrations excitation by non-contact method are used without necessity of thorough surface preparation before testing. SH-waves are also used for flaw detection within damaged areas (areas of different thicknesses). As the research has shown, the mirror-shadow technique with bottom signal attenuation as a criterion for corrosion crack detection is most effective. The minimum detectable deep of the corrosion cracks is 1.5–2 mm. The proposed diagnostics technology uses electromagnetic acoustic transducers (EMAT) with a 5 MHz frequency.
Results. The diagnostics system was successfully tested in the pool. The test results confirmed the system’s ability to perform automatic metal diagnostics with wall thickness measurements and defect detection within areas of corrosion.
Discussions. Nowadays the system is under the process of Russian Maritime Register of Shipping approval. It is planned to develop a system with arc welding tools for underwater objects repair. Prospects of diagnostics system usage for the various underwater steel structures including ones located on the Russian Federation Arctic shelf are under consideration.
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Grzelak, Sławomir, Jarosław Czoków, Marcin Kowalski y Marek Zieliński. "Ultrasonic Flow Measurement with High Resolution". Metrology and Measurement Systems 21, n.º 2 (1 de junio de 2014): 305–16. http://dx.doi.org/10.2478/mms-2014-0026.
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Abstract The ultrasonic flowmeter which is described in this paper, measures the transit of time of an ultrasonic pulse. This device consists of two ultrasonic transducers and a high resolution time interval measurement module. An ultrasonic transducer emits a characteristic wave packet (transmit mode). When the transducer is in receive mode, a characteristic wave packet is formed and it is connected to the time interval measurement module inputs. The time interval measurement module allows registration of transit time differences of a few pulses in the packet. In practice, during a single measuring cycle a few time-stamps are registered. Moreover, the measurement process is also synchronous and, by applying the statistics, the time interval measurement uncertainty improves even in a single measurement. In this article, besides a detailed discussion on the principle of operation of the ultrasonic flowmeter implemented in the FPGA structure, also the test results are presented and discussed
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Pallarés-López, Víctor, Rafael Jesús Real-Calvo, Silvia del Rio Jiménez, Miguel González-Redondo, Isabel Moreno-García y Isabel Santiago. "Monitoring of Energy Data with Seamless Temporal Accuracy Based on the Time-Sensitive Networking Standard and Enhanced µPMUs". Applied Sciences 11, n.º 19 (30 de septiembre de 2021): 9126. http://dx.doi.org/10.3390/app11199126.
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In the energy sector, distributed synchronism and a high degree of stability are necessary for all real-time monitoring and control systems. Instantaneous response to critical situations is essential for the integration of renewable energies. The most widely used standards for clock synchronisation, such as Network Time Protocol (NTP) and Precision Time Protocol (PTP), do not allow for achieving synchronised simultaneous sampling in distributed systems. In this work, a novel distributed synchronism system based on the Time-Sensitive Networking (TSN) standard has been validated for its integration in an architecture oriented towards the high-resolution digitisation of photovoltaic (PV) generation systems. This method guarantees a time stamping with an optimal resolution that allows for the analysis of the influence of fast-evolving atmospheric fluctuations in several plants located in the same geographical area. This paper proposes an enhanced micro-phasor measurement unit (µPMU) that acts as a phasor meter and TSN master controlling the monitoring system synchronism. With this technique, the synchronism would be extended to the remaining measurement systems that would be involved in the installation at distances greater than 100 m. Several analyses were carried out with an on-line topology of four acquisition systems capturing simultaneously. The influence of the Ethernet network and the transducers involved in the acquisition process were studied. Tests were performed with Ethernet cable lengths of 2, 10, 50, and 75 m. The results were validated with 24-bit Sigma-Delta converters and high-precision resistor networks specialised in high-voltage monitoring. It was observed that with an appropriate choice of sensors and TSN synchronism, phase errors of less than ±1 µs can be guaranteed by performing distributed captures up to 50 kS/s. Statistical analysis showed that uncertainties of less than ±100 ns were achieved with 16-bit Successive Approximation Register (SAR) converters at a moderate cost. Finally, the requirements of the IEEE C37.118.1-2011 standard for phasor measurement units (PMU) were also satisfied. This standard establishes an uncertainty of ±3.1 μs for 50 Hz systems. These results demonstrate the feasibility of implementing a simultaneous sampling system for distributed acquisition systems coordinated by a µPMU.
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Malinowski, Pawel, Lukasz Skarbek y Wieslaw Ostachowicz. "Application of Piezo Sensors in EMI and Guided Wave Techniques". Key Engineering Materials 569-570 (julio de 2013): 702–9. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.702.
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In reported research piezoelectric sensors were used for damage identicitaion purposes. Piezoelectric sensor was used for specimen excitation. Two techniques were investigated. The Electromechanical impedance (EMI) technique and guided wave based technique. The principle of EMI technique is based on measurement and analysis of impedance of piezoelectric transducers bonded on or embedded in investigated structure. It is assumed that structural change should influence the impedance characteristics of the transducers. The guided wave based technique is based on the guided elastic wave propagation phenomena. This type of waves can be used in order to obtain information about structure condition and possibly damaged areas. In reported investigation piezoelectric sensor was used to excite guided waves in chosen structural element. Dispersive nature of guided waves results in changes of velocity with the wave frequency, therefore a narrowband signal was used to minimize the dispersion phenomenon. The generated signal was amplified before applying it to the transducer in order to ensure measurable amplitude of excited guided wave. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a points belonging to a defined mesh. This non-contact tool allowed to investigate phenomena related to wave propagation. For both techniques numerical signals processing tools were developed. These numerical tools were designed to extract damage relevant features from EMI measurements and guided wave propagation measurements. The damage index (DI) was introduced on the basis of the extracted features.
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Nedoseka, A. Ya y S. A. Nedoseka. "Effect Of Characteristics Of Ae Transducer On Registered Wave Spectra". Техническая диагностика и неразрушающий контроль 2017, n.º 4 (28 de diciembre de 2017): 3–6. http://dx.doi.org/10.15407/tdnk2017.04.01.
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Wandowski, Tomasz, Pawel Malinowski y Wiesław M. Ostachowicz. "Damage Localisation in Thin Panels Using Elastic Wave Propagation Method". Key Engineering Materials 413-414 (junio de 2009): 87–93. http://dx.doi.org/10.4028/www.scientific.net/kem.413-414.87.
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In this paper algorithm for damage localisation in thin panels made of aluminium alloy has been proposed. Mentioned algorithm uses Lamb wave propagation methods and geometrical approach for damage localisation. Elastic waves are generated and received using piezoelectric transducers. Excited elastic waves propagate and reflect from panel boundary and discontinuities existing in the panel. Wave reflection can be registered through the piezoelectric transducers and used in signal processing algorithm. Processing algorithm consists of two parts: signal filtering and extraction of damage location. The first part is used in order to remove noise from received signals. Second part allows to extract arrival time of waves reflected from discontinuity, very often called Time Of Flight (TOF). Localisation algorithm uses pairs of transducers from a concentrated transducers configuration. Using signals from pair of transducers two times of reflection can be extracted from received signals. Because coordinates of transducers are well known ellipse can be constructed based on extracted times of waves reflections. Damage lies one ellipse but it is not known exactly where. Therefore one ellipse is not enough to localise a discontinuity. In order of proper damage localisation more ellipses must be used. In this purpose signals received by larger number of transducers pairs are used in damage localisation algorithm. Points of ellipses intersections allow to indicate localisation of damage. Described signal processing algorithm has been coded in the MATLAB® environment. In this work experimental results has been presented.
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Knitter-Piątkowska, Anna y Arkadiusz Dobrzycki. "Application of Wavelet Transform to Damage Identification in the Steel Structure Elements". Applied Sciences 10, n.º 22 (19 de noviembre de 2020): 8198. http://dx.doi.org/10.3390/app10228198.
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This work concerns the concept and verification of the experimental possibility of using a wavelet transform to assess a steel structure’s condition. In the research, a developed measuring stand was used. Mechanical waves in the metal plate were excited by the impact. These waves were recorded with an electroacoustic transducer and registered in the form of electrical signals. Both the signals generated by the actuator of the plate and the signals reaching the transducer were recorded. The registered data were decomposed into wavelet coefficients. Laboratory tests have shown the possibility of applying this type of test to identify damage in steel structural elements—the relationship between the details of the wavelet transform and the type of damage was demonstrated.
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Seryeznov, A. N., L. N. Stepanova, S. I. Kabanov, I. S. Kabanov, V. V. Chernova y A. B. Kuznetsov. "ACOUSTIC EMISSION SIGNALS LOCATION IN DURALUMIN AND CARBON FIBER SAMPLES BY OPTICAL FIBER AND PIEZOELECTRIC TRANSDUCER SENSORS ANTENNA". Kontrol'. Diagnostika, n.º 272 (febrero de 2021): 18–29. http://dx.doi.org/10.14489/td.2021.02.pp.018-029.
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The issues are considered of acoustic emission (AE) signals location generated by various simulators (Su–Nielsen, electronic simulator, metal balls of various diameter from 0.5 to 1.5 mm, dropped from different heights). Signals generated by built-in electronic simulator with a frequency of 1 Hz location is analyzed performed by an antenna consisting of two Fabry–Perot fiber-optic sensors (FOS) and two piezoelectric transducers, mounted on samples made of duralumin and T800 carbon fiber. A carbon fiber reinforced plastic sample with the defined above antenna mounted was tested with a VEDS-10 vibration stand. AE signals were registered under the vibration frequency of 20…50 Hz in the acceleration range of 0.3…0.8g. The influence of the time drift recorded by the piezoelectric transducers on the measurement results is determined. It was found that the time drift was not recorded by fiber-optic FOS sensors, but their sensitivity is more than 14 times less than that of piezoelectric transducers.
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Balta, Horia, Catherine Douillard y Alexandru Isar. "On the Equivalence Between Canonical Forms of Recursive Systematic Convolutional Transducers Based on Single Shift Registers". IEEE Access 2 (2014): 381–94. http://dx.doi.org/10.1109/access.2014.2316413.
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Ockenden, Eloise S., Sandrena Ruth Frischer, Huike Cheng, J. Alison Noble y Goylette F. Chami. "The role of point-of-care ultrasound in the assessment of schistosomiasis-induced liver fibrosis: A systematic scoping review". PLOS Neglected Tropical Diseases 18, n.º 3 (20 de marzo de 2024): e0012033. http://dx.doi.org/10.1371/journal.pntd.0012033.
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Background Abdominal ultrasound imaging is an important method for hepatic schistosomiasis diagnosis and staging. Several ultrasound staging systems have been proposed, each attempting to standardise schistosomal periportal fibrosis (PPF) diagnosis. This review aims to establish the role of ultrasound in the diagnosis and staging of schistosomal PPF, and to map the evolution of ultrasound staging systems over time, focusing on internal validation and external reproducibility. Methods A systematic search was undertaken on 21st December 2022 considering the following databases: PubMed/MEDLINE (1946-present), Embase (1974-present), Global Health (1973-present), Global Index Medicus (1901-present), and Web of Science Core Collection–Science Citation Index Expanded (1900-present) and the Cochrane Central Register of Controlled Trials (1996-present). Case reports, systematic reviews and meta-analyses, and studies exclusively using transient or shear-wave elastography were excluded. Variables extracted included study design, study population, schistosomal PPF characteristics, and diagnostic methods. The PRISMA-ScR (2018) guidelines were followed to inform the structure of the scoping analysis. Results The initial search yielded 573 unique articles, of which 168 were removed after screening titles and abstracts, 43 were not retrieved due to full texts not being available online or through inter-library loans, and 170 were excluded during full text review. There were 192 remaining studies eligible for extraction. Of the extracted studies, 61.8% (76/123) of studies that reported study year were conducted after the year 2000. Over half of all extracted studies (59.4%; 114/192) were conducted in Brazil (26.0%; 50/192), China (18.8%; 36/192) or Egypt (14.6%; 28/192). For the species of schistosome considered, 77.6% (149/192) of studies considered S. mansoni and 21.4% (41/192) of studies considered S. japonicum. The ultrasound staging systems used took on three forms: measurement-based, feature-based and image pattern-based. The Niamey protocol, a measurement and image pattern-based system, was the most used among the staging systems (32.8%; 63/192), despite being the most recently proposed in 1996. The second most used was the Cairo protocol (20.8%; 40/192). Of the studies using the Niamey protocol, 77.8% (49/63) only used the image patterns element. Where ultrasound technology was specified, studies after 2000 were more likely to use convex transducers (43.4%; 33/76) than studies conducted before 2000 (32.7%; 16/49). Reporting on ultrasound-based hepatic diagnoses and their association with clinical severity was poor. Just over half of studies (56.2%; 108/192) reported the personnel acquiring the ultrasound images. A small number (9.4%; 18/192) of studies detailed their methods of image quality assurance, and 13.0% (25/192) referenced, discussed or quantified the inter- or intra-observer variation of the staging system that was used. Conclusions The exclusive use of the image patterns in many studies despite lack of specific acquisition guidance, the increasing number of studies over time that conduct ultrasound staging of schistosomal PPF, and the advances in ultrasound technology used since 2000 all indicate a need to consider an update to the Niamey protocol. The protocol update should simplify and prioritise what is to be assessed, advise on who is to conduct the ultrasound examination, and procedures for improved standardisation and external reproducibility.
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Fausto, Robert S., Dirk Van As, Andreas P. Ahlstrøm y Michele Citterio. "Assessing the accuracy of Greenland ice sheet ice ablation measurements by pressure transducer". Journal of Glaciology 58, n.º 212 (2012): 1144–50. http://dx.doi.org/10.3189/2012jog12j075.
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AbstractWe present a method of measuring ice ablation using an absolute pressure transducer as part of an automatic weather station (AWS) system, which we have installed in 17 locations on the Greenland ice sheet. The pressure transducer assembly is drilled into the ice, enclosed in a hose filled with antifreeze liquid. The pressure signal registered by the transducer is that of the vertical column of liquid over the sensor, which can be translated to depth, and ice ablation rate, knowing the density of the liquid. Measuring at sub-daily timescales, this assembly is well suited to monitoring ice ablation in remote regions, with clear advantages over other, well-established methods. The pressure transducer system has the potential to monitor ice ablation for several years without re-drilling, and the system is suitable for high-ablation areas (>5ma-1). A routine to transform raw measurements into ablation values is presented, including a physically based method to remove air-pressure variability from the signal. The pressure transducer time series is compared to that recorded by a sonic ranger for the climatically hostile setting on the Greenland ice sheet.
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Malinowski, Pawel, Tomasz Wandowski y Wieslaw Ostachowicz. "Guided Waves for Aircraft Panel Monitoring". Key Engineering Materials 558 (junio de 2013): 107–15. http://dx.doi.org/10.4028/www.scientific.net/kem.558.107.
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The reported research concerns experimental investigation toward the monitoring of an aircraft panel. Guided wave propagation phenomena were used to obtain information about the state of the monitored structure. A curved aluminium panel with rivets was investigated. Piezoelectric transducer was used to excite guided waves in chosen structural element. The generated signal was amplified before applying it to the transducer in order to ensure measurable amplitude of excited guided waves. Measurement of the wave field was realized using laser scanning vibrometer that registered the velocity responses at a points belonging to a defined mesh. This contactless measurement technique allowed to investigate phenomena related to wave propagation in the aircraft panel. In the first stage, due to high complexity of the element, baseline measurements were taken. Next, a discontinuity (additional mass) was introduced on the panel surface and the measurements were repeated. Signal processing methods for features extraction from signals were proposed. These features were applied in order to detect and localize the presence anomalies in the investigated panel. The signal processing was conducted in MATLAB with the procedures developed by the authors. The used measurement technology (vibrometer) allowed to register whole wavefield of the propagating guided waves. This allowed to visualize the interaction of the waves with rivets. After introducing the discontinuity on the panel surface wave interaction with it was investigated. Two positions of the additional mass were considered. One just before the riveted stiffener and second after the stiffener. Because of this the influence of the stiffener on the damage detection abilities could be investigated. It can be concluded that the guided wave can be used for monitoring of such complex structures. The vibrometer measurements allowed learn about the guided wave propagation phenomena and perform successful damage localization.
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Bryakin, I. V. y I. V. Bochkarev. "Vibration sensor for monitoring systems of construction elements of high-voltage power lines". Power engineering: research, equipment, technology 24, n.º 4 (17 de agosto de 2022): 63–76. http://dx.doi.org/10.30724/1998-9903-2022-24-4-63-76.
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PURPOSE. To develop a differential parametric inductive transducer of vibration values into an electrical signal, which is a vibration displacement sensor (DV) with a new principle of operation. Theoretically substantiate the performance of the proposed DV. To develop a new system for vibroacoustic monitoring of the technical condition of overhead power transmission line (TL) supports using the proposed DV. METHODS. When solving this goal, the theory of parametric transducers and the main provisions of the theory of vibration diagnostics were used. RESULTS. The design feature of the developed DV is the absence of an excitation coil, and its functional elements form a full-fledged measuring bridge, the arms of which include interturn capacitances of the windings of the first and second measuring coils, as well as capacitances formed by a metal cylindrical electrode with a coaxially located inside it ferromagnetic rod and the first lower rows of wire windings of the measuring coils. The bridge circuit operates in a resonant mode, which ensures the high sensitivity of the proposed sensor, and the quadrature conversion of the information signal provides the necessary level of noise immunity. The received signal is a functional dependence of the output voltage of the measuring bridge on the magnitude of external vibrations, the characteristics of the temporary realizations of which reflect the degradation processes occurring in the power transmission line supports. CONCLUSION. The proposed system for monitoring the integrity of power transmission line supports is actually a distributed real-time sensor network that implements PLC technology. The DV of each sensor module registers microvibrations of the structural elements of the corresponding power transmission line support, caused by natural disturbing factors during their operation, and converts them into an electrical information signal, which forms the basis of monitoring information about the current state of the power transmission line support structural elements.
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Rucka, Magdalena. "Monitoring Steel Bolted Joints during a Monotonic Tensile Test Using Linear and Nonlinear Lamb Wave Methods: A Feasibility Study". Metals 8, n.º 9 (31 de agosto de 2018): 683. http://dx.doi.org/10.3390/met8090683.
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The structural integrity of steel bolted joints may be compromised due to excessive loading. Therefore, condition assessment and the detection of potential defects before they cause a failure have become a major issue. The paper is focused on the condition monitoring of a bolted lap joint subjected to progressive degradation in a tensile test. The inspection used Lamb waves propagated through the overlap area. Wave propagation signals were registered automatically by means of piezoelectric transducers. Two damage indices were defined based on linear and nonlinear features of Lamb waves. The use of a network of piezoelectric transducers and the analysis of multiple signals instead of single ones was proved to effectively monitor the state of the bolted joint. The obtained results showed that the method enabled to detect selected stages of the degradation process and to characterize the reduction of the contact area between the plates in the overlap area.
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MARQUET, FABRICE, YAO-SHENG TUNG y ELISA E. KONOFAGOU. "FEASIBILITY STUDY OF A CLINICAL BLOOD–BRAIN BARRIER OPENING ULTRASOUND SYSTEM". Nano LIFE 01, n.º 03n04 (septiembre de 2010): 309–22. http://dx.doi.org/10.1142/s1793984410000286.
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In this paper, we investigate the focalization properties of single-element transducers at intermediate frequencies (500 kHz) through primate and human skulls. The study addresses the transcranial targeting involved in ultrasound-induced blood–brain barrier (BBB) opening with clinically relevant targets such as the hippocampus and the basal ganglia, which are typically affected by early Alzheimer's and Parkinson's disease, respectively. The targeted brain structures were extracted from three-dimensional (3D) brain atlases registered with the skulls and used to virtually position and orient the transducers. The frequency dependence is first investigated and the capability of targeting of different structures is explored. Preliminary in vivo feasibility is investigated in mice at this frequency. A simple, affordable and convenient system is found to be feasible for BBB opening in primates and humans capable of successfully targeting the hippocampus, putamen and substantia nigra and could thus allow for its broader impact and applications.
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Johnson, Laura A., Richard A. Morgan, Mark E. Dudley, Lydie Cassard, James C. Yang, Marybeth S. Hughes, Udai S. Kammula et al. "Gene therapy with human and mouse T-cell receptors mediates cancer regression and targets normal tissues expressing cognate antigen". Blood 114, n.º 3 (16 de julio de 2009): 535–46. http://dx.doi.org/10.1182/blood-2009-03-211714.
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Abstract Gene therapy of human cancer using genetically engineered lymphocytes is dependent on the identification of highly reactive T-cell receptors (TCRs) with antitumor activity. We immunized transgenic mice and also conducted high-throughput screening of human lymphocytes to generate TCRs highly reactive to melanoma/melanocyte antigens. Genes encoding these TCRs were engineered into retroviral vectors and used to transduce autologous peripheral lymphocytes administered to 36 patients with metastatic melanoma. Transduced patient lymphocytes were CD45RA− and CD45RO+ after ex vivo expansion. After infusion, the persisting cells displayed a CD45RA+ and CD45RO− phenotype. Gene-engineered cells persisted at high levels in the blood of all patients 1 month after treatment, responding patients with higher ex vivo antitumor reactivity than nonresponders. Objective cancer regressions were seen in 30% and 19% of patients who received the human or mouse TCR, respectively. However, patients exhibited destruction of normal melanocytes in the skin, eye, and ear, and sometimes required local steroid administration to treat uveitis and hearing loss. Thus, T cells expressing highly reactive TCRs mediate cancer regression in humans and target rare cognate–antigen-containing cells throughout the body, a finding with important implications for the gene therapy of cancer. This trial was registered at www.ClinicalTrials.gov as NCI-07-C-0174 and NCI-07-C-0175.
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Gomes, Matheus K., Willian H. A. da Silva, Antonio Ribas Neto, Julio Fajardo, Eric Rohmer y Eric Fujiwara. "Detection of Hand Poses with a Single-Channel Optical Fiber Force Myography Sensor: A Proof-of-Concept Study". Automation 3, n.º 4 (18 de noviembre de 2022): 622–32. http://dx.doi.org/10.3390/automation3040031.
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Force myography (FMG) detects hand gestures based on muscular contractions, featuring as an alternative to surface electromyography. However, typical FMG systems rely on spatially-distributed arrays of force-sensing resistors to resolve ambiguities. The aim of this proof-of-concept study is to develop a method for identifying hand poses from the static and dynamic components of FMG waveforms based on a compact, single-channel optical fiber sensor. As the user performs a gesture, a micro-bending transducer positioned on the belly of the forearm muscles registers the dynamic optical signals resulting from the exerted forces. A Raspberry Pi 3 minicomputer performs data acquisition and processing. Then, convolutional neural networks correlate the FMG waveforms with the target postures, yielding a classification accuracy of (93.98 ± 1.54)% for eight postures, based on the interrogation of a single fiber transducer.
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Guo, Heng, Weizhi Qi, Ming He, Jian Rong y Lei Xi. "Co-registered photoacoustic and ultrasound imaging for tongue cancer detection". Journal of Innovative Optical Health Sciences 11, n.º 03 (mayo de 2018): 1850008. http://dx.doi.org/10.1142/s1793545818500086.
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Tongue cancer is an increasingly common disease with high morbidity. Besides clinical observation, biomedical imaging techniques have been investigated for early detection of tongue cancer. In this paper, we proposed a co-registered dual-modality photoacoustic (PA) and ultrasound imaging technique to simultaneously map the functional and structural information of human tongue, which has the potential to detect and diagnose tongue cancer in early stage. The imaging probe comprises a 20-MHz side-view focused transducer for ultrasound imaging and PA detection, a light path constructed by a multimode optical fiber, and a prism for PA illumination. Phantom experiments were conducted to evaluate the performance of the system including penetration depth, spatial resolution and signal-to-noise ratio. In vivo imaging of animal tumor and human tongue was carried out to show the feasibility of the proposed technique to detect tumor lesions in human tongue. The results of phantom and in vivo experiments suggest that the proposed technique has the potential to detect the early-stage cancer lesions in human tongue.
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Golinelli, N., A. Spaggiari, D. Castagnetti, L. Fornari, E. Dragoni, G. Gualdi y A. Brunazzi. "Development of a driveshaft torque transducer for low-cost structural health monitoring of off-highway vehicles". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, n.º 4 (22 de septiembre de 2016): 714–20. http://dx.doi.org/10.1177/1464420716669966.
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Mechatronic agricultural machines and equipment are continuously increasing their complexity and cost. In order to ensure their efficiency and reliability and preserve their value, it is important to actively monitor the working loads and register damaging and wear occurring on critical components. This approach needs the introduction of sensors on the machine, which allow continuous monitoring and evaluate the residual life of components. The work presents the development and testing of an innovative low-cost systems for monitoring and diagnostic of off-highway vehicles. The sensor measures the torque of a mechanical power transmissions, and it was designed especially for agricultural machinery. The torque transducer monitors the mechanical power flowing from the tractor into the gearbox and the agricultural implement and is fully integrated with the power take-off driveshaft, thus being generally applicable. The design and development of the transducer was performed following a quality function deployment approach. The system is less expensive considering the typical torque measuring system commercially available and, thanks to its wireless module and integrated power supply, it is reliable and generally applicable to many power take-off to implement combinations.
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Rudenko, Natalia, Ksenia Fursova, Anna Shepelyakovskaya, Anna Karatovskaya y Fedor Brovko. "Antibodies as Biosensors’ Key Components: State-of-the-Art in Russia 2020–2021". Sensors 21, n.º 22 (16 de noviembre de 2021): 7614. http://dx.doi.org/10.3390/s21227614.
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The recognition of biomolecules is crucial in key areas such as the timely diagnosis of somatic and infectious diseases, food quality control, and environmental monitoring. This determines the need to develop highly sensitive display devices based on the achievements of modern science and technology, characterized by high selectivity, high speed, low cost, availability, and small size. Such requirements are met by biosensor systems—devices for reagent-free analysis of compounds that consist of a biologically sensitive element (receptor), a transducer, and a working solution. The diversity of biological material and methods for its immobilization on the surface or in the volume of the transducer and the use of nanotechnologies have led to the appearance of an avalanche-like number of different biosensors, which, depending on the type of biologically sensitive element, can be divided into three groups: enzyme, affinity, and cellular/tissue. Affinity biosensors are one of the rapidly developing areas in immunoassay, where the key point is to register the formation of an antigen–antibody complex. This review analyzes the latest work by Russian researchers concerning the production of molecules used in various immunoassay formats as well as new fundamental scientific data obtained as a result of their use.
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Kochenderfer, James N., Mark E. Dudley, Steven A. Feldman, Wyndham H. Wilson, David E. Spaner, Irina Maric, Maryalice Stetler-Stevenson et al. "B-cell depletion and remissions of malignancy along with cytokine-associated toxicity in a clinical trial of anti-CD19 chimeric-antigen-receptor–transduced T cells". Blood 119, n.º 12 (22 de marzo de 2012): 2709–20. http://dx.doi.org/10.1182/blood-2011-10-384388.
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Abstract We conducted a clinical trial to assess adoptive transfer of T cells genetically modified to express an anti-CD19 chimeric Ag receptor (CAR). Our clinical protocol consisted of chemotherapy followed by an infusion of anti–CD19-CAR–transduced T cells and a course of IL-2. Six of the 8 patients treated on our protocol obtained remissions of their advanced, progressive B-cell malignancies. Four of the 8 patients treated on the protocol had long-term depletion of normal polyclonal CD19+ B-lineage cells. Cells containing the anti-CD19 CAR gene were detected in the blood of all patients. Four of the 8 treated patients had prominent elevations in serum levels of the inflammatory cytokines IFNγ and TNF. The severity of acute toxicities experienced by the patients correlated with serum IFNγ and TNF levels. The infused anti–CD19-CAR–transduced T cells were a possible source of these inflammatory cytokines because we demonstrated peripheral blood T cells that produced TNF and IFNγ ex vivo in a CD19-specific manner after anti–CD19-CAR–transduced T-cell infusions. Anti–CD19-CAR–transduced T cells have great promise to improve the treatment of B-cell malignancies because of a potent ability to eradicate CD19+ cells in vivo; however, reversible cytokine-associated toxicities occurred after CAR–transduced T-cell infusions. This trial was registered with ClinicalTrials.gov as NCT00924326.
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Balasubramaniam, Kaleeswaran, Shirsendu Sikdar, Piotr Fiborek y Pawel H. Malinowski. "Ultrasonic Guided Wave Signal Based Nondestructive Testing of a Bonded Composite Structure Using Piezoelectric Transducers". Signals 2, n.º 1 (15 de enero de 2021): 13–24. http://dx.doi.org/10.3390/signals2010002.
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This paper presents ultrasonic guided wave (UGW) propagation-based nondestructive testing (NDT) of an adhesively bonded composite structure (ACS). In the process, a series of scanning laser Doppler vibrometry (SLDV)-based laboratory experiments and time-domain spectral element method (SEM)-based numerical simulations were carried out on an ACS with barely visible impact damage (BVID) and a hole. A good agreement was observed between the numerical and experimental UGW signals in the cases studied. Finally, a full-field and elliptical signal processing method-based NDT strategy was proposed that uses differential damage features of the registered UGW signals to identify different types of BVIDs in the ACS.
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Zhang, Yuchao, Bin Miao, Guanghua Wang, Hongyu Zhou, Shiqin Zhang, Yimin Hu, Junfeng Wu, Xuechao Yu y Jiadong Li. "ScAlN Film-Based Piezoelectric Micromechanical Ultrasonic Transducers with Dual-Ring Structure for Distance Sensing". Micromachines 14, n.º 3 (23 de febrero de 2023): 516. http://dx.doi.org/10.3390/mi14030516.
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Piezoelectric micromechanical ultrasonic transducers (pMUTs) are new types of distance sensors with great potential for applications in automotive, unmanned aerial vehicle, robotics, and smart homes. However, previously reported pMUTs are limited by a short sensing distance due to lower output sound pressure. In this work, a pMUT with a special dual-ring structure based on scandium-doped aluminum nitride (ScAlN) is proposed. The combination of a dual-ring structure with pinned boundary conditions and a high piezoelectric performance ScAlN film allows the pMUT to achieve a large dynamic displacement of 2.87 μm/V and a high electromechanical coupling coefficient (kt2) of 8.92%. The results of ranging experiments show that a single pMUT achieves a distance sensing of 6 m at a resonant frequency of 91 kHz, the farthest distance sensing registered to date. This pMUT provides surprisingly fertile ground for various distance sensing applications.
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Sikorski, Wojciech. "Active Dielectric Window: A New Concept of Combined Acoustic Emission and Electromagnetic Partial Discharge Detector for Power Transformers". Energies 12, n.º 1 (29 de diciembre de 2018): 115. http://dx.doi.org/10.3390/en12010115.
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The detection and location of partial discharge (PD) is of great significance in evaluating the insulation condition of power transformers. This paper presents an active dielectric window (ADW), which is a new concept of combined acoustic emission (AE) and electromagnetic PD detector intended for assembly in a transformer’s inspection hatch. The novelty of this design lies in the fact that all structural components of an ultrasonic transducer, i.e., the matching and backing layer, an active piezoelectric element with electrodes, and electrical leads, were built into a dielectric window. Due to the fact that its construction was optimized for work in mineral oil, it is characterized by much higher sensitivity of PD detection than a general-purpose AE sensor mounted outside a transformer tank. Laboratory tests showed that the amplitude of the AE pulses generated by creeping discharges, which were registered by the ADW, was around five times higher on average than the pulses registered by a commonly used contact transducer. A possibility of simultaneous detection of acoustic and electromagnetic pulses (with an integrated ultra-high frequency (UHF) antenna) is an important advantage of the ADW. It allows for an increase in the reliability of PD detection, the accuracy of defect location, and the effectiveness of disturbance identification. This paper describes in detail the applied methods of designing and modeling the ADW components, the manufacturing process of the prototype construction, and the results of preliminary laboratory tests, in which the detector’s sensitivity as well as the efficiency of the PD source location were evaluated.
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Łutowicz, Marek y Dominika Cuper-Przybylska. "Influence of the Instantaneous Angular Speed (IAS) of Marine Diesel Engine on its Indication Results". Solid State Phenomena 236 (julio de 2015): 204–11. http://dx.doi.org/10.4028/www.scientific.net/ssp.236.204.
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The paper presents a method of transforming the time axis to the axis of the crank angle rotation based on the pressure measured in time domain and simplified model of the engine dynamics. Indicating is to register the pressure in synchronism with the engine crank angle rotation. Usually in the ad hoc measurements the crankshaft rotation angle transducer is avoided, and the measurements are performed in time domain. For further analysis time axis is transformed for crank angle axis on the base of linear transform. Pressure waveforms obtained during the research were subject of the described transform. During the research instantaneous angular speed (IAS) of the engine crankshaft has been changed by reducing fuel dosage to selected cylinders. Mean indicated pressure (MIP) was calculated. Values o pressure on the begging and the end of compression, opening and closing angles of valves were also determined.
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Ostachowicz, Wiesław M., Arkadiusz Zak, Pawel Malinowski y Tomasz Wandowski. "Control of Properties of Composite Structures with the Use of Multi-Functional Materials". Advances in Science and Technology 56 (septiembre de 2008): 324–33. http://dx.doi.org/10.4028/www.scientific.net/ast.56.324.
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This work is focused on two major applications of multi–functional materials. In the first one the use of piezoelectric transducers have been studied in order to monitor the health of composite plate–like structures. These transducers can act as signal sources and sensors for guided elastic waves in inspected structures. The excited waves propagating in the material can reflect from various discontinuities such like: boundaries, notches, cracks and delamination. In the next step the time responses registered by the sensors, as inputs for a signal processing algorithm, may be processed to correlate the measured arriving waves with the discontinuities in the structures enabling one to indicate the location of the discontinuities. In the second application the use of shape memory alloy (SMA) components integrated with composite structural elements are investigated. SMA elements in the forms of wires, strips, ribbons, beams, tubes, etc. can be bonded to, or integrated within, various structural elements in order to control their mechanical properties, static as well as dynamic behaviour. This can be obtained thanks to unique effects associated with thermal activation of SMAs leading to significant changes in SMA material properties, which next can also be applied for control purposes. The use of such controllable properties of SMA components in active control of static (deflection) and dynamic (natural frequencies, modes of vibrations, amplitudes of forced vibrations) characteristics of laminated composite beams–like structures have been demonstrated.
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Dyankov, Georgi, Petia Genova-Kalou, Tinko Eftimov, Sanaz Shoar Ghaffari, Vihar Mankov, Hristo Kisov, Petar Veselinov, Evdokia Hikova y Nikola Malinowski. "Binding of SARS-CoV-2 Structural Proteins to Hemoglobin and Myoglobin Studied by SPR and DR LPG". Sensors 23, n.º 6 (22 de marzo de 2023): 3346. http://dx.doi.org/10.3390/s23063346.
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One of the first clinical observations related to COVID-19 identified hematological dysfunctions. These were explained by theoretical modeling, which predicted that motifs from SARS-CoV-2 structural proteins could bind to porphyrin. At present, there is very little experimental data that could provide reliable information about possible interactions. The surface plasmon resonance (SPR) method and double resonance long period grating (DR LPG) were used to identify the binding of S/N protein and the receptor bind domain (RBD) to hemoglobin (Hb) and myoglobin (Mb). SPR transducers were functionalized with Hb and Mb, while LPG transducers, were only with Hb. Ligands were deposited by the matrix-assisted laser evaporation (MAPLE) method, which guarantees maximum interaction specificity. The experiments carried out showed S/N protein binding to Hb and Mb and RBD binding to Hb. Apart from that, they demonstrated that chemically-inactivated virus-like particles (VLPs) interact with Hb. The binding activity of S/N- and RBD proteins was assessed. It was found that protein binding fully inhibited heme functionality. The registered N protein binding to Hb/Mb is the first experimental fact that supports theoretical predictions. This fact suggests another function of this protein, not only binding RNA. The lower RBD binding activity reveals that other functional groups of S protein participate in the interaction. The high-affinity binding of these proteins to Hb provides an excellent opportunity for assessing the effectiveness of inhibitors targeting S/N proteins.
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Yamane, Akio, Taketoshi Iyota, Yongwoon Choi, Yuzuru Kubota y Kazuhiro Watanabe. "A Study on Propagation Characteristics of Spread Spectrum Sound Waves Using a Band-Limited Ultrasonic Transducer". Journal of Robotics and Mechatronics 16, n.º 3 (20 de junio de 2004): 333–41. http://dx.doi.org/10.20965/jrm.2004.p0333.
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Propagation characteristics and range experiments of spread spectrum 40kHz ultrasonic waves have been explored under band-limited frequency. Comparative experiments were conducted using two arrangements combining a broadband speaker and a microphone for the broadband case, and an all-purpose receiving transducer and the broadband speaker for the band-limited case. Under the broadband condition, range accuracy measurements and evaluation of signal discrimination in a code division multiple transmission were made demonstrating 0.034% (corresponding to about 7mm in range distance) of range accuracy for a full-scale distance of 21.6m, demonstrating high signal discrimination. The severely band-limited experiment improved accuracy from 0.084% for a distance of 8.4m to 0.063% for a greater distance of 14.4m using a longer M-sequence length by extending shift registers from 10-bit to 15-bit. These experimental results show promise in the intended application of ultrasonic spread spectra to local positioning systems.
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Bartling, C. y J. Schmitz. "Reaction to disturbances of a walking leg during stance". Journal of Experimental Biology 203, n.º 7 (1 de abril de 2000): 1211–23. http://dx.doi.org/10.1242/jeb.203.7.1211.
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The ground reaction forces exerted by the legs of freely walking stick insects, Carausius morosus, were recorded during normal and perturbed locomotion. The animals walked along a path into which a three-dimensional force transducer was integrated. The transducer registered all three components of the forces produced by a single leg when, by chance, it walked on the force platform. The stiffness of the walking surface was found to be a critical variable affecting the forces and the trajectories of leg movements during undisturbed walking. The forces produced by a leg were considerably smaller and the trajectories were closer to the body during walking on soft versus stiff surfaces. Perturbations during stance were generated by moving the platform in various directions within the horizontal plane and at two different rates. Perturbations were applied either immediately after leg contact or after a delay of 300 ms. The reactions to these disturbances were compatible with the hypothesis that the velocity of leg movement is under negative feedback control. This interpretation is also supported by comparison with simulations based upon other control schemes. We propose a model circuit that provides a combination of negative and positive feedback control mechanisms to resolve the apparent discrepancies between our results and those of previous studies.
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Zarcone, Kristen, Charles F. Caskey y Will Grissom. "Palpating particles using the acoustic radiation force: A new approach to magnetic particle imaging". Journal of the Acoustical Society of America 152, n.º 4 (octubre de 2022): A279. http://dx.doi.org/10.1121/10.0016264.
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Magnetic particle imaging (MPI) is a tracer-based imaging technique that does not require radiation or a cyclotron. However, it does require bulky MRI-like hardware and does not produce a background tissue image. We propose a new approach to MPI that uses the acoustic radiation force to dynamically move iron nanoparticles through a magnetic field gradient, thereby changing their magnetic moment and producing a detectable signal in a receiver coil. An image could be formed by electronically steering the ultrasound focus to push particles at different spatial locations, like an ultrasonic palpation. This would enable a device that attaches to an ultrasound imaging transducer for simultaneous MPI and inherently registered ultrasound imaging. To test the feasibility of the technique, a cylindrical agar and graphite phantom was placed between a Maxwell coil pair which generated a linear field gradient across it, and particle signals were detected using a receiver solenoid. 2-ms ultrasound pulses were applied using a 6 MHz transducer to generate displacements along the magnetic field gradient. Signal measurements confirmed a lack of signal when iron nanoparticles were absent from the phantom, but the signal was detected when particles were present, with amplitudes that linearly increased with the gradient coil current.
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Friedrich, Martin G., Ioannes Bougioukas, Peter Wenig, Steffen Vormfelde y Theodor Tirilomis. "New device for intraoperative blood suction avoiding turbulences". BMJ Innovations 4, n.º 2 (1 de febrero de 2018): 91–97. http://dx.doi.org/10.1136/bmjinnov-2017-000201.
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IntroductionBleeding during surgery is common. Increased bleeding may disturb procedure, induces haemodynamic instability and results in need for blood transfusion. Allogenic blood transfusions increase mortality and morbidity, especially risk of infections, pulmonary and renal complications, as well as thromboembolic events. Autotransfusion is in many cases a solution but forced suction may destroy or alter blood cells because of turbulences, shear forces and contact of the blood to extrinsic surfaces. The aim of the study was the analysis of turbulence profile and development of a new suction device reducing (or avoiding) turbulences.MethodsWe registered turbulences with a microphone placed in different positions within the blood suction during surgery and analysed the spectrum. Then, we modified the circuit adding signals from optical sensors and pressure transducer to avoid air mixing and tight suction. Finally, we created the algorithm for the suction circuit regulating individualised suction modes.ResultsWe developed a new suction system based on a roller pump. We used a piezo sensor and registered the acoustic signals. The optimal position for this element was into the suction handle. After filtering the signal and further processing, we used it for regulation of the roller pump. Additionally, an optical sensor minimises air mixing due to further regulation of motor speed. Finally, a negative pressure transducer gives in case of tight suction information to the circuit stopping motor speed and equalising pressure by opening a valve before suctions starts again. The algorithm allows various suction modes in an individualised manner for specific situations in operating field.ConclusionsWe developed a new blood suction device based on a roller pump. The system is turbulence-controlled and its algorithm allows several individualised suction modes. Additional features avoid tight suction and reduce air mixing.
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Andresen, Morten, Marianne Juhler y Ole Cornelius Thomsen. "Electrostatic discharges and their effect on the validity of registered values in intracranial pressure monitors". Journal of Neurosurgery 119, n.º 5 (noviembre de 2013): 1119–24. http://dx.doi.org/10.3171/2013.7.jns13506.
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Object Intracranial pressure (ICP) monitoring is used extensively in clinical practice, and as such, the accuracy of registered ICP values is paramount. Clinical observations of nonphysiological changes in ICP have called into question the accuracy of registered ICP values. Subsequently, the authors have tried to determine if the ICP monitors from major manufacturers were affected by electrostatic discharges (ESDs), if the changes were permanent or transient in nature, and if the changes were modified by the addition of different electrical appliances normally used in the neurointensive care unit environment. Methods The authors established a test setup in the neurointensive care unit using a large container filled with isotonic saline, creating a phantom patient. Intracranial pressure monitors were sequentially lowered into the container and subjected to a predefined test battery of ESDs. Results Five pressure monitors from 4 manufacturers were evaluated. Three monitors containing electrical circuitry at the tip of the transducer were all affected by ESDs. Clinically significant permanent changes in the reported ICP values for 1 pressure monitor were observed, as well as temporary deflections for 2 other monitors. The monitors had different levels of sensitivity to discharges at low voltages. Conclusions These results explain some of the sudden shifts in ICP noted in the clinical setting. However, a clear deflection pattern related to the addition of electrical appliances was not found. The authors recommend instituting policies for reducing the risk of subjecting patients to ESDs in the neurointensive care unit setting.
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Serban, Bogdan-Catalin, Octavian Buiu, Marius Bumbac, Niculae Dumbravescu, Viorel Avramescu, Mihai Brezeanu, Cristiana Radulescu et al. "Ternary Holey Carbon Nanohorns/TiO2/PVP Nanohybrids as Sensing Films for Resistive Humidity Sensors". Coatings 11, n.º 9 (3 de septiembre de 2021): 1065. http://dx.doi.org/10.3390/coatings11091065.
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In this paper, we present the relative humidity (RH) sensing response of a chemiresistive sensor, employing sensing layers based on a ternary nanohybrids comprised of holey carbon nanohorns (CNHox), titanium (IV) oxide, and polyvinylpyrrolidone (PVP) at 1/1/1/(T1), 2/1/1/(T2), and with 3/1/1 (T3) mass ratios. The sensing device is comprised of a silicon-based substrate, a SiO2 layer, and interdigitated transducer (IDT) electrodes. The sensitive layer was deposited via the drop-casting method on the sensing structure, followed by a two-step annealing process. The structure and composition of the sensing films were investigated through scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD). The resistance of the ternary nanohybrid-based sensing layer increases when H increases between 0% and 80%. A different behavior of the sensitive layers is registered when the humidity increases from 80% to 100%. Thus, the resistance of the T1 sensor slightly decreases with increasing humidity, while the resistance of sensors T2 and T3 register an increase in resistance with increasing humidity. The T2 and T3 sensors demonstrate a good linearity for the entire (0–100%) RH range, while for T1, the linear behavior is limited to the 0–80% range. Their overall room temperature response is comparable to a commercial humidity sensor, characterized by a good sensitivity, a rapid response, and fast recovery times. The functional role for each of the components of the ternary CNHox/TiO2/PVP nanohybrid is explained by considering issues such as their electronic properties, affinity for water molecules, and internal pore accessibility. The decreasing number of holes in the carbonaceous component at the interaction with water molecules, with the protonic conduction (Grotthus mechanism), and with swelling were analyzed to evaluate the sensing mechanism. The hard–soft acid-base (HSAB) theory also has proven to be a valuable tool for understanding the complex interaction of the ternary nanohybrid with moisture.
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Buczaj, Marcin y Andrzej Sumorek. "A COMPUTER SYSTEM FOR ACQUISITION AND ANALYSIS OF MEASUREMENT DATA FOR A SKEW ROLLING MILL IN MANUFACTURING STEEL BALLS". Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska 10, n.º 4 (20 de diciembre de 2020): 47–50. http://dx.doi.org/10.35784/iapgos.2396.
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The article presents the concept and capabilities of a computer system for analysing measurement data for a skew rolling mill used to produce steel balls. The computer system for data acquisition and analysis consists of cooperating systems designed to perform control and measurement tasks during the operation of a skew rolling mill. Their main task is to collect and record data related to the measured physical parameters of the batch rolling process. This system registers the current and analyses the radial forces and torque acting on the rolled element by the rolling tool. The process of data acquisition, analysis and archiving is carried out by means of an NI USB 6009 measuring card together with the attached systems of transducers and force and torque sensors and a computer with an installed application. The measurement application was developed in the LabVIEW environment. The application algorithm is based on the state machine architecture and enables the configuration of measurement elements and technical parameters, checking the functioning of the control and measurement system and the acquisition and archiving of measurement data.
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Kochenderfer, James N., Wyndham H. Wilson, John E. Janik, Mark E. Dudley, Maryalice Stetler-Stevenson, Steven A. Feldman, Irina Maric et al. "Eradication of B-lineage cells and regression of lymphoma in a patient treated with autologous T cells genetically engineered to recognize CD19". Blood 116, n.º 20 (18 de noviembre de 2010): 4099–102. http://dx.doi.org/10.1182/blood-2010-04-281931.
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Abstract Adoptive transfer of genetically modified T cells is an attractive approach for generating antitumor immune responses. We treated a patient with advanced follicular lymphoma by administering a preparative chemotherapy regimen followed by autologous T cells genetically engineered to express a chimeric antigen receptor (CAR) that recognized the B-cell antigen CD19. The patient's lymphoma underwent a dramatic regression, and B-cell precursors were selectively eliminated from the patient's bone marrow after infusion of anti–CD19-CAR-transduced T cells. Blood B cells were absent for at least 39 weeks after anti–CD19-CAR-transduced T-cell infusion despite prompt recovery of other blood cell counts. Consistent with eradication of B-lineage cells, serum immunoglobulins decreased to very low levels after treatment. The prolonged and selective elimination of B-lineage cells could not be attributed to the chemotherapy that the patient received and indicated antigen-specific eradication of B-lineage cells. Adoptive transfer of anti–CD19-CAR-expressing T cells is a promising new approach for treating B-cell malignancies. This study is registered at www.clinicaltrials.gov as #NCT00924326.