Zadoff-Chu coded ultrasonic signal for accurate range estimation

KAUST Repository

AlSharif, Mohammed H.; Saad, Mohamed; Siala, Mohamed; Ballal, Tarig; Boujemaa, Hatem; Al-Naffouri, Tareq Y.

2017-01-01

This paper presents a new adaptation of Zadoff-Chu sequences for the purpose of range estimation and movement tracking. The proposed method uses Zadoff-Chu sequences utilizing a wideband ultrasonic signal to estimate the range between two devices with very high accuracy and high update rate. This range estimation method is based on time of flight (TOF) estimation using cyclic cross correlation. The system was experimentally evaluated under different noise levels and multi-user interference scenarios. For a single user, the results show less than 7 mm error for 90% of range estimates in a typical indoor environment. Under the interference from three other users, the 90% error was less than 25 mm. The system provides high estimation update rate allowing accurate tracking of objects moving with high speed.

Development of wide-band, time and energy resolving, optical photon detectors with application to imaging astronomy

International Nuclear Information System (INIS)

Miller, A.J.; Cabrera, B.; Romani, R.W.; Figueroa-Feliciano, E.; Nam, S.W.; Clarke, R.M.

2000-01-01

Superconducting transition edge sensors (TESs) are showing promise for the wide-band spectroscopy of individual photons from the mid-infrared (IR), through the optical, and into the near ultraviolet (UV). Our TES sensors are ∼20 μm square, 40 nm thick tungsten (W) films with a transition temperature of about 80 mK. We typically attain an energy resolution of 0.15 eV FWHM over the optical range with relative timing resolution of 100 ns. Single photon events with sub-microsecond risetimes and few microsecond falltimes have been achieved allowing count rates in excess of 30 kHz per pixel. Additionally, tungsten is approximately 50% absorptive in the optical (dropping to 10% in the IR) giving these devices an intrinsically high quantum efficiency. These combined traits make our detectors attractive for fast spectrophotometers and photon-starved applications such as wide-band, time and energy resolved astronomical observations. We present recent results from our work toward the fabrication and testing of the first TES optical photon imaging arrays

Real-time ultrasonic weld evaluation system

Science.gov (United States)

Katragadda, Gopichand; Nair, Satish; Liu, Harry; Brown, Lawrence M.

1996-11-01

Ultrasonic testing techniques are currently used as an alternative to radiography for detecting, classifying,and sizing weld defects, and for evaluating weld quality. Typically, ultrasonic weld inspections are performed manually, which require significant operator expertise and time. Thus, in recent years, the emphasis is to develop automated methods to aid or replace operators in critical weld inspections where inspection time, reliability, and operator safety are major issues. During this period, significant advances wee made in the areas of weld defect classification and sizing. Very few of these methods, however have found their way into the market, largely due to the lack of an integrated approach enabling real-time implementation. Also, not much research effort was directed in improving weld acceptance criteria. This paper presents an integrated system utilizing state-of-the-art techniques for a complete automation of the weld inspection procedure. The modules discussed include transducer tracking, classification, sizing, and weld acceptance criteria. Transducer tracking was studied by experimentally evaluating sonic and optical position tracking techniques. Details for this evaluation are presented. Classification is obtained using a multi-layer perceptron. Results from different feature extraction schemes, including a new method based on a combination of time and frequency-domain signal representations are given. Algorithms developed to automate defect registration and sizing are discussed. A fuzzy-logic acceptance criteria for weld acceptance is presented describing how this scheme provides improved robustness compared to the traditional flow-diagram standards.

Mode Identification of Guided Ultrasonic Wave using Time- Frequency Algorithm

International Nuclear Information System (INIS)

Yoon, Byung Sik; Yang, Seung Han; Cho, Yong Sang; Kim, Yong Sik; Lee, Hee Jong

2007-01-01

The ultrasonic guided waves are waves whose propagation characteristics depend on structural thickness and shape such as those in plates, tubes, rods, and embedded layers. If the angle of incidence or the frequency of sound is adjusted properly, the reflected and refracted energy within the structure will constructively interfere, thereby launching the guided wave. Because these waves penetrate the entire thickness of the tube and propagate parallel to the surface, a large portion of the material can be examined from a single transducer location. The guided ultrasonic wave has various merits like above. But various kind of modes are propagating through the entire thickness, so we don't know the which mode is received. Most of applications are limited from mode selection and mode identification. So the mode identification is very important process for guided ultrasonic inspection application. In this study, various time-frequency analysis methodologies are developed and compared for mode identification tool of guided ultrasonic signal. For this study, a high power tone-burst ultrasonic system set up for the generation and receive of guided waves. And artificial notches were fabricated on the Aluminum plate for the experiment on the mode identification

Generation of wideband chaos with suppressed time-delay signature by delayed self-interference.

Science.gov (United States)

Wang, Anbang; Yang, Yibiao; Wang, Bingjie; Zhang, Beibei; Li, Lei; Wang, Yuncai

2013-04-08

We demonstrate experimentally and numerically a method using the incoherent delayed self-interference (DSI) of chaotic light from a semiconductor laser with optical feedback to generate wideband chaotic signal. The results show that, the DSI can eliminate the domination of laser relaxation oscillation existing in the chaotic laser light and therefore flatten and widen the power spectrum. Furthermore, the DSI depresses the time-delay signature induced by external cavity modes and improves the symmetry of probability distribution by more than one magnitude. We also experimentally show that this DSI signal is beneficial to the random number generation.

The design of high-efficiency and wide-band ultrasonic transducers for immersion application

International Nuclear Information System (INIS)

Choi, Myung Sun; Kim, Jin Ho; Kang, Eun Kyung

2001-01-01

The optimum design of low-loss and broad-band piezoelectric ultrasonic transducers has been performed for immersion application. In order to obtain the highest efficiency, the piezo plates are backed by air. After determining the matching layers by using the formulas proposed by Desilet et al., inserting both a series inductor and a series or parallel resistor was considerated such that the transducers are electrically matched to the voltage source at the free resonance frequency. By analysing the transfer functions and the time responses of the transducers numerically, it has been shown that the frequency bandwidth becomes broad with increasing the electro-mechanical coupling factor and the number of matching layers, and that the sensitivity becomes best as the motional resistance at the resonance frequency is equal to the voltage source resistance.

Study of a new technique for measuring the travel time of ultrasonic waves using the frequency spectrum

International Nuclear Information System (INIS)

Santos, Allan Xavier dos

2010-01-01

During the operation of a nuclear plant and other industrial plants, the operational time and the exposition to severe working conditions may cause the wear of its components, consequently, compromising the safety and the performance of the installation. The implementation of periodical inspections helps to ensure the safe operation and the best performance of the plant. In this way, the use of ultrasonic techniques for inspection and materials characterization becomes more and more attractive, since they offer quick, precise results and are technically ease to implement. The usual ultrasonic techniques, need to the measure the travelling time of the ultrasonic wave in the material examined in order to extract information useful to characterize it. Thus, the measurement of the travelling time of the ultrasonic wave is the overriding factor in most of the applications made with ultrasound. In this work a new technique was developed for measuring the travelling time of the ultrasonic wave using a Fourier's Fast Transformer (FFT). It will be shown mathematically and experimentally that it is possible to use the ultrasonic signal in the frequency domain to determine the travelling time of the ultrasonic wave. Five experiments were carried out for the experimental validation of this new technique. The materials used were 20 ceramic pastilles with different porosities and 3 aluminum plates of different thicknesses. The obtained results have shown that the new technique proposed in this work was able to determine the travelling time of the ultrasonic wave with the same precision as the conventional technique. It was shown, furthermore, that this new technique is able to measure the travelling time of the ultrasonic wave in situations where the conventional technique cannot be applied greatly expanding the range of application of ultrasonic testing and inspections. (author)

Wideband CMOS receivers

CERN Document Server

Oliveira, Luis

2015-01-01

This book demonstrates how to design a wideband receiver operating in current mode, in which the noise and non-linearity are reduced, implemented in a low cost single chip, using standard CMOS technology.  The authors present a solution to remove the transimpedance amplifier (TIA) block and connect directly the mixer’s output to a passive second-order continuous-time Σ∆ analog to digital converter (ADC), which operates in current-mode. These techniques enable the reduction of area, power consumption, and cost in modern CMOS receivers.

A wideband absorber for television studios

Science.gov (United States)

Baird, M. D. M.

The acoustic treatment in BBC television has taken various forms to date, all of which have been relatively expensive, some of which provide inadequate absorption. An investigation has been conducted into the possibilities of producing a new type of wideband absorber which would be more economic, also taking installation time into account, than earlier designs. This Report describes the absorption coefficient measurements made on various combinations of materials, from which a wideband sound absorber has been developed. The absorber works efficiently between 50 Hz and 10 kHz, is simple and easy to construct using readily available materials, and is fire resistant. The design lends itself, if necessary, to on-site fine tuning, and savings in the region of 50 percent can be achieved in terms of cost and space with respect to previous designs.

Non-linear time reversal ultrasonic pseudo-tomography

Czech Academy of Sciences Publication Activity Database

Převorovský, Zdeněk; Vejvodová, Šárka; Krofta, Josef; Převorovský, David

2011-01-01

Roč. 6, 3/4 (2011), s. 206-213 ISSN 1741-8410. [NDT in Progress. Praha, 05.11.2007-07.11.2007] R&D Projects: GA MPO(CZ) FR-TI1/274 Institutional research plan: CEZ:AV0Z20760514 Keywords : NDT * nonlinear elastic wave spectroscopy * time reversal mirrors * ultrasonic pseudo-tomography Subject RIV: BI - Acoustics http://www.inderscience.com/offer.php?id=43216

Integrated wide-band low-background amplifiers

International Nuclear Information System (INIS)

Il'yushchenko, I.I.

1980-01-01

Ways of increasing stability and reproduction of characteristics of wide-band integral amplifiers that would to the least extent increase their background noises, are discussed. Considered are some certain flowsheets of integral wide-band amplifiers with low background noise of foreign production which differ from one another by construction of inlet cascades as well as by the applied feedback type. The principal flowsheets of the amplifiers and their main performances are presented. The analysis of the data obtained has revealed that microcircuits made of cascades with a common emitter and local combined feedback are most wide-band among all the considered microcircuits [ru

Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

Science.gov (United States)

Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

2014-01-01

Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions. Copyright © 2014 John Wiley & Sons, Ltd.

Introduction to Ultra Wideband for Wireless Communications

DEFF Research Database (Denmark)

Nikookar, Homayoun; Prasad, Ramjee

wireless channels, interference, signal processing as well as applications and standardization activities are addressed. Introduction to Ultra Wideband for Wireless Communications provides easy-to-understand material to (graduate) students and researchers working in the field of commercial UWB wireless......Ultra Wideband (UWB) Technology is the cutting edge technology for wireless communications with a wide range of applications. In Introduction to Ultra Wideband for Wireless Communications UWB principles and technologies for wireless communications are explained clearly. Key issues such as UWB...... communications. Due to tutorial nature of the book it can also be adopted as a textbook on the subject in the Telecommunications Engineering curriculum. Problems at the end of each chapter extend the reader's understanding of the subject. Introduction to Ultra Wideband for Wireless Communications will aslo...

Ultra-Wideband, Short Pulse Electromagnetics 9

CERN Document Server

Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9

2010-01-01

Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...

Maritime wideband communication networks video transmission scheduling

CERN Document Server

Yang, Tingting

2014-01-01

This Springer Brief covers emerging maritime wideband communication networks and how they facilitate applications such as maritime distress, urgency, safety and general communications. It provides valuable insight on the data transmission scheduling and protocol design for the maritime wideband network. This brief begins with an introduction to maritime wideband communication networks including the architecture, framework, operations and a comprehensive survey on current developments. The second part of the brief presents the resource allocation and scheduling for video packet transmission wit

Paper-based inkjet-printed ultra-wideband fractal antennas

KAUST Repository

Maza, Armando Rodriguez; Cook, Benjamin Stassen; Jabbour, Ghassan E.; Shamim, Atif

2012-01-01

For the first time, paper-based inkjet-printed ultra-wideband (UWB) fractal antennas are presented. Two new designs, a miniaturised UWB monopole, which utilises a fractal matching network and is the smallest reported inkjet-printed UWB printed

Ultrasonic Real-Time Quality Monitoring Of Aluminum Spot Weld Process

Science.gov (United States)

Perez Regalado, Waldo Josue

The real-time ultrasonic spot weld monitoring system, introduced by our research group, has been designed for the unsupervised quality characterization of the spot welding process. It comprises the ultrasonic transducer (probe) built into one of the welding electrodes and an electronics hardware unit which gathers information from the transducer, performs real-time weld quality characterization and communicates with the robot programmable logic controller (PLC). The system has been fully developed for the inspection of spot welds manufactured in steel alloys, and has been mainly applied in the automotive industry. In recent years, a variety of materials have been introduced to the automotive industry. These include high strength steels, magnesium alloys, and aluminum alloys. Aluminum alloys have been of particular interest due to their high strength-to-weight ratio. Resistance spot welding requirements for aluminum vary greatly from those of steel. Additionally, the oxide film formed on the aluminum surface increases the heat generation between the copper electrodes and the aluminum plates leading to accelerated electrode deterioration. Preliminary studies showed that the real-time quality inspection system was not able to monitor spot welds manufactured with aluminum. The extensive experimental research, finite element modelling of the aluminum welding process and finite difference modeling of the acoustic wave propagation through the aluminum spot welds presented in this dissertation, revealed that the thermodynamics and hence the acoustic wave propagation through an aluminum and a steel spot weld differ significantly. For this reason, the hardware requirements and the algorithms developed to determine the welds quality from the ultrasonic data used on steel, no longer apply on aluminum spot welds. After updating the system and designing the required algorithms, parameters such as liquid nugget penetration and nugget diameter were available in the ultrasonic data

Apparatus And Method For Wireless Monitoring Using Ultra-wideband Frequencies

KAUST Repository

Sana, Furrukh

2015-04-23

A system for and a method of wirelessly monitoring one or more patients can include transmitting ultra-wideband pulses toward the one or more patients, receiving ultra-wideband signals, and sampling the ultra-wideband signals. Sampling the ultra-wideband pulses can be performed with a sample rate that is less than the Nyquist rate. Impulse response can be estimated and/or recovered by exploiting sparsity of the impulse response.

Two-Step Time of Arrival Estimation for Pulse-Based Ultra-Wideband Systems

Directory of Open Access Journals (Sweden)

H. Vincent Poor

2008-05-01

Full Text Available In cooperative localization systems, wireless nodes need to exchange accurate position-related information such as time-of-arrival (TOA and angle-of-arrival (AOA, in order to obtain accurate location information. One alternative for providing accurate position-related information is to use ultra-wideband (UWB signals. The high time resolution of UWB signals presents a potential for very accurate positioning based on TOA estimation. However, it is challenging to realize very accurate positioning systems in practical scenarios, due to both complexity/cost constraints and adverse channel conditions such as multipath propagation. In this paper, a two-step TOA estimation algorithm is proposed for UWB systems in order to provide accurate TOA estimation under practical constraints. In order to speed up the estimation process, the first step estimates a coarse TOA of the received signal based on received signal energy. Then, in the second step, the arrival time of the first signal path is estimated by considering a hypothesis testing approach. The proposed scheme uses low-rate correlation outputs and is able to perform accurate TOA estimation in reasonable time intervals. The simulation results are presented to analyze the performance of the estimator.

Compact super-wideband optical antenna

Science.gov (United States)

Wang, Wen C.; Forber, Richard; Bui, Kenneth

2009-05-01

We present progress on advanced optical antennas, which are compact, small size-weight-power units capable to receive super wideband radiated RF signals from 30 MHz to over 3 GHz. Based on electro-optical modulation of fiber-coupled guided wave light, these dielectric E-field sensors exhibit dipole-like azimuthal omni directionality, and combine small size (channels, and high EO sensing materials. The antenna system photonic link consists of a 1550 nm PM fiber-pigtailed laser, a specialized optical modulator antenna in channel waveguide format, a wideband photoreceiver, and optical phase stabilizing components. The optical modulator antenna design employs a dielectric (no electrode) Mach-Zehnder interferometer (MZI) arranged so that sensing RF bandwidth is not limited by optical transit time effects, and MZI phase drift is bias stabilized. For a prototype optical antenna system that is < 100 in3, < 10 W, < 5 lbs, we present test data on sensitivity (< 20 mV/m-Hz1/2), RF bandwidth, and antenna directionality, and show good agreement with theoretical predictions.

A Laser-based Ultrasonic Inspection System to Detect Micro Fatigue Cracks

International Nuclear Information System (INIS)

Park, Seung Kyu; Baik, Sung Hoon; Park, Moon Cheol; Lim, Chang Hwan; Cha, Hyung Ki

2005-01-01

Laser-based ultrasonic techniques have been established as a viable non-contact alternative to piezoelectric transducers for generating and receiving ultrasound. Laser-based ultrasonic inspection system provides a number of advantages over the conventional generation by piezoelectric transducers, especially a non-contact generation and detection of ultrasonic waves, high spatial scanning resolution, controllable narrow-band and wide-band spectrum, absolute measurements of the moving distance, use of fiber optics, and an ability to operate on curved and rough surfaces and at hard-to-access locations like a nuclear power plant. Ochiai and Miura used the laser-based ultrasound to detect micro fatigue cracks for the inspection of a material degradation in nuclear power plants. This widely applicable laser-based ultrasonic inspection system is comparatively expensive and provides low signal-to-noise ratio to measure ultrasound by using the laser interferometer. Many studies have been carried out to improve the measuring efficiency of the laser interferometer. One of the widely used laser interferometer types to measure the ultrasound is the Confocal Fabry-Perot Interferometer(CFPI). The measurement gain of the CFPI is slightly and continually varied according to the small change of the cavity length and the fluctuations of the measuring laser beam frequency with time. If we continually adjust the voltage of a PZT which is fixed to one of the interferometer mirrors, the optimum working point of the CFPI can be fixed. Though a static stabilizer can fix the gain of the CFPI where the CW laser beam is targeted at one position, it can not be used when the CW laser beam is scanned like a scanning laser source(SLS) technique. A dynamic stabilizer can be used for the scanning ultrasonic inspection system. A robust dynamic stabilizer is needed for an application to the industrial inspection fields. Kromine showed that the SLS technique is effective to detect small fatigue cracks

Real-time measurement of relative sensor position changes using ultrasonic signal evaluation

Energy Technology Data Exchange (ETDEWEB)

Yastrebova, O.; Bulavinov, A.; Kroening, M. [Fraunhofer Institute Nondestructive Testing IZFP, Saarbruecken (Germany)

2008-07-01

Ultrasonic testing is considered to be one of the most commonly applied nondestructive testing techniques for flaw detection and material characterization. Traditional Nondestructive Testing (NDT) provides detection of material discontinuities that may cause failure within the designed lifetime of a part or component. In addition, Quantitative Nondestructive Testing (QNDT) provides means to obtain required information about type, size and location of deficiencies to the integrity of the inspected structure and further use under specific, given load conditions. The ''Acoustic Mouse'' technique has been developed as a tool for manual ultrasonic inspection to provide test results that can be evaluated quantitatively. The ultrasonic data are processed by real-time variation methods to extract position information from backscattered acoustic noise and geometric scatter signals in the inspection volume. The position and positional changes of the ''Acoustic Mouse'' sensor (transducer) are determined by the sequential analysis of ultrasonic data (highresolution sector-scans), which are acquired and reconstructed using the Sampling Phased Array technique. The results of first experiments conducted with linear scanning and intentional lift-offs demonstrate sufficient accuracy in position measurements. (orig.)

Detection of moving humans in UHF wideband SAR

Science.gov (United States)

Sjögren, Thomas K.; Ulander, Lars M. H.; Frölind, Per-Olov; Gustavsson, Anders; Stenström, Gunnar; Jonsson, Tommy

2014-06-01

In this paper, experimental results for UHF wideband SAR imaging of humans on an open field and inside a forest is presented. The results show ability to detect the humans and suggest possible ways to improve the results. In the experiment, single channel wideband SAR mode of the UHF UWB system LORA developed by Swedish Defence Research Agency (FOI). The wideband SAR mode used in the experiment was from 220 to 450 MHz, thus with a fractional bandwidth of 0.68. Three humans walking and one stationary were available in the scene with one of the walking humans in the forest. The signature of the human in the forest appeared on the field, due to azimuth shift from the positive range speed component. One human on the field and the one in the forest had approximately the same speed and walking direction. The signatures in the SAR image were compared as a function of integration time based on focusing using the average relative speed of these given by GPS logs. A signal processing gain was obtained for the human in forest until approximately 15 s and 35 s for the human on the field. This difference is likely explained by uneven terrain and trees in the way, causing a non-straight walking path.

Real time automatic discriminating of ultrasonic flaws

International Nuclear Information System (INIS)

Suhairy Sani; Mohd Hanif Md Saad; Marzuki Mustafa; Mohd Redzwan Rosli

2009-01-01

This paper is concerned with the real time automatic discriminating of flaws from two categories; i. cracks (planar defect) and ii. Non-cracks (volumetric defect such as cluster porosity and slag) using pulse-echo ultrasound. The raw ultrasonic flaws signal were collected from a computerized robotic plane scanning system over the whole of each reflector as the primary source of data. The signal is then filtered and the analysis in both time and frequency domain were executed to obtain the selected feature. The real time feature analysis techniques measured the number of peaks, maximum index, pulse duration, rise time and fall time. The obtained features could be used to distinguish between quantitatively classified flaws by using various tools in artificial intelligence such as neural networks. The proposed algorithm and complete system were implemented in a computer software developed using Microsoft Visual BASIC 6.0 (author)

Wideband Piezomagnetoelastic Vibration Energy Harvesting

DEFF Research Database (Denmark)

Lei, Anders; Thomsen, Erik Vilain

2014-01-01

This work presents a small-scale wideband piezomagnetoelastic vibration energy harvester (VEH) aimed for operation at frequencies of a few hundred Hz. The VEH consists of a tape-casted PZT cantilever with thin sheets of iron foil attached on each side of the free tip. The wideband operation...... is achieved by placing the cantilever in a magnetic field induced by either one or two magnets located oppositely of the cantilever. The attraction force created by the magnetic field and iron foils introduces a mechanical force in opposite direction of the cantilevers restoring force causing a spring...

Compressed air leak detection based on time delay estimation using a portable multi-sensor ultrasonic detector

International Nuclear Information System (INIS)

Liao, Pingping; Cai, Maolin; Shi, Yan; Fan, Zichuan

2013-01-01

The conventional ultrasonic method for compressed air leak detection utilizes a directivity-based ultrasonic leak detector (DULD) to locate the leak. The location accuracy of this method is low due to the limit of the nominal frequency and the size of the ultrasonic sensor. In order to overcome this deficiency, a method based on time delay estimation (TDE) is proposed. The method utilizes three ultrasonic sensors arranged in an equilateral triangle to simultaneously receive the ultrasound generated by the leak. The leak can be located according to time delays between every two sensor signals. The theoretical accuracy of the method is analyzed, and it is found that the location error increases linearly with delay estimation error and the distance from the leak to the sensor plane, and the location error decreases with the distance between sensors. The average square difference function delay estimator with parabolic fitting is used and two practical techniques are devised to remove the anomalous delay estimates. Experimental results indicate that the location accuracy using the TDE-based ultrasonic leak detector is 6.5–8.3 times as high as that using the DULD. By adopting the proposed method, the leak can be located more accurately and easily, and then the detection efficiency is improved. (paper)

Ultra-Wideband Transceiver for Integrated Communication and Relative Navigation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The goal of this project is to develop an innovative way of using Time Modulated Ultra Wideband (TM-UWB) transceivers (radios) to provide high performance integrated...

Novel ultra-wideband photonic signal generation and transmission featuring digital signal processing bit error rate measurements

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

2009-01-01

We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal.......We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal....

An Analog Correlator for Ultra-Wideband Receivers

Directory of Open Access Journals (Sweden)

Tu Chunjiang

2005-01-01

Full Text Available We present a new analog circuit exhibiting high bandwidth and low distortion, specially designed for signal correlation in an ultra-wideband receiver front end. The ultra-wideband short impulse signals are correlated with a local pulse template by the correlator. A comparator then samples the output for signal detection. A typical Gilbert mixer core is adopted for multiplication of broadband signals up to . As a result of synchronization of the received signal and the local template, the output voltage level after integration and sampling can reach up to , which is sufficient for detection by the comparator. The circuit dissipates about from double voltage supplies of and using SiGe BiCMOS technology. Simulation results are presented to show the feasibility of this circuit design for use in ultra-wideband receivers.

Survey of timing/synchronization of operating wideband digital communications networks

Science.gov (United States)

Mitchell, R. L.

1978-01-01

In order to benefit from experience gained from the synchronization of operational wideband digital networks, a survey was made of three such systems: Data Transmission Company, Western Union Telegraph Company, and the Computer Communications Group of the Trans-Canada Telephone System. The focus of the survey was on deployment and operational experience from a practical (as opposed to theoretical) viewpoint. The objective was to provide a report on the results of deployment how the systems performed, and wherein the performance differed from that predicted or intended in the design. It also attempted to determine how the various system designers would use the benefit of hindsight if they could design those same systems today.

Generalized Wideband Cyclic MUSIC

Directory of Open Access Journals (Sweden)

Zhang-Meng Liu

2009-01-01

Full Text Available The method of Spectral Correlation-Signal Subspace Fitting (SC-SSF fails to separate wideband cyclostationary signals with coherent second-order cyclic statistics (SOCS. Averaged Cyclic MUSIC (ACM method made up for the drawback to some degree via temporally averaging the cyclic cross-correlation of the array output. This paper interprets ACM from another perspective and proposes a new DOA estimation method by generalizing ACM for wideband cyclostationary signals. The proposed method successfully makes up for the aforementioned drawback of SC-SSF and obtains a more satisfying performance than ACM. It is also demonstrated that ACM is a simplified form of the proposed method when only a single spectral frequency is exploited, and the integration of the frequencies within the signal bandwidth helps the new method to outperform ACM.

An Ultra-Wideband Millimeter-Wave Phased Array

Science.gov (United States)

Novak, Markus H.; Miranda, Felix A.; Volakis, John L.

2016-01-01

Wideband millimeter-wave arrays are of increasing importance due to their growing use in high data rate systems, including 5G communication networks. In this paper, we present a new class of ultra-wideband millimeter wave arrays that operate from nearly 20 GHz to 90 GHz. The array is based on tightly coupled dipoles. Feeding designs and fabrication challenges are presented, and a method for suppressing feed resonances is provided.

Spatial Dynamic Wideband Modeling of the MIMO Satellite-to-Earth Channel

Directory of Open Access Journals (Sweden)

Andreas Lehner

2014-01-01

response (CIR time series depending on the movement profile of a land mobile terminal is presented in this paper. Based on high precise wideband measurements in L-band the model reproduces the correlated shadowing and multipath conditions in rich detail. The model includes time and space variant echo signals appearing and disappearing in dependence on the receive antenna position and movement, and the actual azimuths and elevations to the various signal sources. Attenuation and path delays relative to the hypothetical line of sight (LOS ensure usability for ranging purposes. Parameters for car and pedestrian applications in urban and suburban environments are provided. The channel characteristics are determined independently of the transmitted signal. Therefore the usability, for example, for GPS and GALILEO, as well as wideband communication services from hovering platforms, is given.

7th conference on ultra-wideband, short-pulse electromagnetics

CERN Document Server

Schenk, Uwe; Nitsch, Daniel; Sabath, Frank; Ultra-Wideband, Short-Pulse Electromagnetics 7; UWBSP7

2007-01-01

Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-Wideband Short-Pulse Electromagnetics 7 presents selected papers of deep technical content and high scientific quality from the UWB-SP7 Conference, including wide-ranging contributions on electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-res...

Uncertainty analysis of power monitoring transit time ultrasonic flow meters

International Nuclear Information System (INIS)

Orosz, A.; Miller, D. W.; Christensen, R. N.; Arndt, S.

2006-01-01

A general uncertainty analysis is applied to chordal, transit time ultrasonic flow meters that are used in nuclear power plant feedwater loops. This investigation focuses on relationships between the major parameters of the flow measurement. For this study, mass flow rate is divided into three components, profile factor, density, and a form of volumetric flow rate. All system parameters are used to calculate values for these three components. Uncertainty is analyzed using a perturbation method. Sensitivity coefficients for major system parameters are shown, and these coefficients are applicable to a range of ultrasonic flow meters used in similar applications. Also shown is the uncertainty to be expected for density along with its relationship to other system uncertainties. One other conclusion is that pipe diameter sensitivity coefficients may be a function of the calibration technique used. (authors)

A Channelization-Based DOA Estimation Method for Wideband Signals

Directory of Open Access Journals (Sweden)

Rui Guo

2016-07-01

Full Text Available In this paper, we propose a novel direction of arrival (DOA estimation method for wideband signals with sensor arrays. The proposed method splits the wideband array output into multiple frequency sub-channels and estimates the signal parameters using a digital channelization receiver. Based on the output sub-channels, a channelization-based incoherent signal subspace method (Channelization-ISM and a channelization-based test of orthogonality of projected subspaces method (Channelization-TOPS are proposed. Channelization-ISM applies narrowband signal subspace methods on each sub-channel independently. Then the arithmetic mean or geometric mean of the estimated DOAs from each sub-channel gives the final result. Channelization-TOPS measures the orthogonality between the signal and the noise subspaces of the output sub-channels to estimate DOAs. The proposed channelization-based method isolates signals in different bandwidths reasonably and improves the output SNR. It outperforms the conventional ISM and TOPS methods on estimation accuracy and dynamic range, especially in real environments. Besides, the parallel processing architecture makes it easy to implement on hardware. A wideband digital array radar (DAR using direct wideband radio frequency (RF digitization is presented. Experiments carried out in a microwave anechoic chamber with the wideband DAR are presented to demonstrate the performance. The results verify the effectiveness of the proposed method.

Echodentography based on nonlinear time reversal tomography: Ultrasonic nonlinear signature identification

Science.gov (United States)

Santos, Serge Dos; Farova, Zuzana; Kus, Vaclav; Prevorovsky, Zdenek

2012-05-01

This paper examines possibilities of using Nonlinear Elastic Wave Spectroscopy (NEWS) methods in dental investigations. Themain task consisted in imaging cracks or other degradation signatures located in dentin close to the Enamel-Dentine Junction (EDJ). NEWS approach was investigated experimentally with a new bi-modal acousto-optic set-up based on the chirp-coded nonlinear ultrasonic time reversal (TR) concepts. Complex internal structure of the tooth is analyzed by the TR-NEWS procedure adapted to tomography-like imaging of the tooth damages. Ultrasonic instrumentation with 10 MHz bandwidth has been set together including laser vibrometer used to detect responses of the tooth on its excitation carried out by a contact piezoelectric transducer. Bi-modal TR-NEWS images of the tooth were created before and after focusing, which resulted from the time compression. The polar B-scan of the tooth realized with TR-NEWS procedure is suggested to be applied as a new echodentography imaging.

Design of an Ultra-wideband Pseudo Random Coded MIMO Radar Based on Radio Frequency Switches

Directory of Open Access Journals (Sweden)

Su Hai

2017-02-01

Full Text Available A Multiple-Input Multiple-Output (MIMO ultra-wideband radar can detect the range and azimuth information of targets in real time. It is widely used for geological surveys, life rescue, through-wall tracking, and other military or civil fields. This paper presents the design of an ultra-wideband pseudo random coded MIMO radar that is based on Radio Frequency (RF switches and implements a MIMO radar system. RF switches are employed to reduce cost and complexity of the system. As the switch pressure value is limited, the peak power of the transmitting signal is 18 dBm. The ultra-wideband radar echo is obtained by hybrid sampling, and pulse compression is computed by Digital Signal Processors (DSPs embedded in an Field-Programmable Gate Array (FPGA to simplify the signal process. The experiment illustrates that the radar system can detect the range and azimuth information of targets in real time.

8th conference on Ultra-Wideband Short-Pulse Electromagnetics

CERN Document Server

Tyo, J. Scott; Baum, Carl E; Ultra-Wideband Short-Pulse Electromagnetics 8; UWBSP8

2007-01-01

The purpose of the Ultra-Wideband Short-Pulse Electromagnetics Conference series is to focus on advanced technologies for the generation, radiation and detection of ultra-wideband short pulse signals, taking into account their propagation and scattering from and coupling to targets of interest. This Conference series reports on developments in supporting mathematical and numerical methods and presents current and potential future applications of the technology. Ultra-Wideband Short-Pulse Electromagnetics 8 is based on the American Electromagnetics 2006 conference held from June 3-7 in Albuquerque, New Mexico. Topical areas covered in this volume include pulse radiation and measurement, scattering theory, target detection and identification, antennas, signal processing, and communications.

Evaluation of strip-line pick-up system for the SPS wideband transverse feedback system

CERN Document Server

Kotzian, G; Steinhagen, R J; Valuch, D; Wehrle, U

2017-01-01

The proposed SPS Wideband Transverse Feedback sys- tem requires a wide-band pick-up system to be able to de- tect intra-bunch motion within the SPS proton bunches, captured and accelerated in a 200 MHz bucket. We present the electro-magnetic design of transverse beam position pick-up options optimised for installation in the SPS and evaluate their performance reach with respect to direct time domain sampling of the intra-bunch motion. The analy- sis also discusses the achieved subsystem responses of the associated cabling with new low dispersion smooth wall coaxial cables, wide-band generation of intensity and posi- tion signals by means of 180 degree RF hybrids as well as passive techniques to electronically suppress the beam off- set signal, needed to optimise the dynamic range and posi- tion resolution of the planned digital intra-bunch feedback system.

Fast analysis of wide-band scattering from electrically large targets with time-domain parabolic equation method

Science.gov (United States)

He, Zi; Chen, Ru-Shan

2016-03-01

An efficient three-dimensional time domain parabolic equation (TDPE) method is proposed to fast analyze the narrow-angle wideband EM scattering properties of electrically large targets. The finite difference (FD) of Crank-Nicolson (CN) scheme is used as the traditional tool to solve the time-domain parabolic equation. However, a huge computational resource is required when the meshes become dense. Therefore, the alternating direction implicit (ADI) scheme is introduced to discretize the time-domain parabolic equation. In this way, the reduced transient scattered fields can be calculated line by line in each transverse plane for any time step with unconditional stability. As a result, less computational resources are required for the proposed ADI-based TDPE method when compared with both the traditional CN-based TDPE method and the finite-different time-domain (FDTD) method. By employing the rotating TDPE method, the complete bistatic RCS can be obtained with encouraging accuracy for any observed angle. Numerical examples are given to demonstrate the accuracy and efficiency of the proposed method.

The development of PC-based real time ultrasonic metal thickness inspection system

International Nuclear Information System (INIS)

Suhairy Sani; Mohd Hanif Md Saad; Mohamad Pauzi Ismail; Ab Razak Hamzah; Abd Nassir Ibrahim; Amri Amin Abas

2006-01-01

This paper discusses the development of a PC-Based Real Time Ultrasonic Thickness Measurement system (UTMS) for metallic components such as pipes, pressure vessels and metal slabs. Metal thickness measurement for these components is crucial in industrial plants with dangerous environment, such as in oil and gas industry. From the measured metal thickness, a number of deductions could be made, for example the state and the rate of corrosion propagation inside a pipe or pressure vessel, etc. One of the most widely used methods in assessing metal thickness in industry is through the use of Ultrasonic technology. The benefits of using UTMS lies in the flexibility of data analysis, which includes signal processing, feature extraction, visualization capability and intelligent diagnosis. Data can be acquired in real-time and stored for future usage and application. The system was developed as a standalone computer software using Microsoft Visual-BASIC 6. (Author)

A wideband optical monitor for a planetary-rotation coating-system

International Nuclear Information System (INIS)

Campanelli, M.B.; Smith, D.J.

1998-01-01

A substrate-specific, through-planet, wideband optical coating monitor is being developed to increase production yield and the understanding of physical vapor deposition (PVD) coatings fabricated in the Optical Manufacturing Laboratory at the University of Rochester's Laboratory for Laser Energetics. In-situ wideband optical monitoring of planetary rotation systems allows direct monitoring of large, expensive substrates with complex layering schemes. The optical monitor discussed here is under development for coating several large (e.g., 80.7 x 41.7 x 9.0 cm) polarizers for the National Ignition Facility. Wideband optical monitoring of the production substrates is used in concert with an array of crystal monitors for process control, film parameter evaluation, and error detection with associated design reoptimization. The geometry of a planetary rotation system, which produces good uniformity across large substrates, makes optical monitoring more difficult. Triggering and timing techniques for data acquisition become key to the process because the optical coating is available only intermittently for monitoring. Failure to properly consider the effects of the system dynamics during data retrieval and processing may result in significant decreases in the spectral data's reliability. Improved data accuracy allows better determination of film thicknesses, indices, and inhomogeneities and enables in-situ error detection for design reoptimization

Ultrasonic unit for line-by-line ultrasonic scanning of bodies

International Nuclear Information System (INIS)

Soldner, R.

1978-01-01

The ultrasonic unit for medical diagnostics operates by the sectorial scanning principle, which avoids direct coupling of the transducer head to the surface of the body. For this purpose, several transmitter/receiver units (approx. 100) are arranged on a partial ring of a circular arc and the ultrasonic beams, which can be triggered sequentially in time, are directed at a common intersection behind the ultrasonic window of the unit, i.e., outside the unit. A mechanical system is employed to set and adjust the partial ring carrying the transmitter/receiver units. (DG) [de

Wideband feeds for the upgraded GMRT

International Nuclear Information System (INIS)

Bandari, Hanumanth Rao; Sankarasubramanian, G; Kumar, A Praveen

2013-01-01

This paper describes the existing feeds in use at the GMRT Observatory and details the ongoing development of next generation wideband feeds for the upgraded GMRT. The existing feeds include: feed with folded thick dipoles (for 150 MHz), dipole-disc feed (for 325 MHz), dual-band coaxial feed (for 233 MHZ and 610 MHz), and corrugated horn feed (for 1400–1450 MHz). The new broadband feeds covered in this paper are: cone-dipole feeds for 250–500 and 500–1000 MHz, wideband horn feed for 550–900 MHz, and dual ring feed for 130–260 MHz. Design techniques and performance results for these are described.

Graphite Microstructural Characterization Using Time-Domain and Correlation-Based Ultrasonics

Energy Technology Data Exchange (ETDEWEB)

Spicer, James [Johns Hopkins Univ., Baltimore, MD (United States)

2017-12-06

Among techniques that have been used to determine elastic modulus in nuclear graphites, ultrasonic methods have enjoyed wide use and standards using contacting piezoelectric tranducers have been developed to ensure repeatability of these types of measurements. However, the use of couplants and the pressures used to effectively couple transducers to samples can bias measurements and produce results that are not wholly related to the properties of the graphite itself. In this work, we have investigated the use of laser ultrasonic methods for making elastic modulus measurements in nuclear graphites. These methods use laser-based transmitters and receivers to gather data and do not require use of ultrasonic couplants or mechanical contact with the sample. As a result, information directly related to the elastic responses of graphite can be gathered even if the graphite is porous, brittle and compliant. In particular, we have demonstrated the use of laser ultrasonics for the determination of both Young’s modulus and shear modulus in a range of nuclear graphites including those that are being considered for use in future nuclear reactors. These results have been analyzed to assess the contributions of porosity and microcracking to the elastic responses of these graphites. Laser-based methods have also been used to assess the moduli of NBG-18 and IG-110 where samples of each grade were oxidized to produce specific changes in porosity. These data were used to develop new models for the elastic responses of nuclear graphites and these models have been used to infer specific changes in graphite microstructure that occur during oxidation that affect elastic modulus. Specifically, we show how ultrasonic measurements in oxidized graphites are consistent with nano/microscale oxidation processes where basal plane edges react more readily than basal plane surfaces. We have also shown the use of laser-based methods to perform shear-wave birefringence measurements and have shown

Wideband QAMC reflector's antenna for low profile applications

Science.gov (United States)

Grelier, M.; Jousset, M.; Mallégol, S.; Lepage, A. C.; Begaud, X.; LeMener, J. M.

2011-06-01

A wideband reflector's antenna based on quasi-artificial magnetic conductor is proposed. To validate the design, an Archimedean spiral has been backed to this new reflector. In comparison to classical solution using absorbent material, the prototype presents a very low thickness of λ/15 at the lowest operating frequency and an improved gain over a 2.4:1 bandwidth. The whole methodology to design this reflector can be applied to other wideband antennas.

Distributed fiber sparse-wideband vibration sensing by sub-Nyquist additive random sampling

Science.gov (United States)

Zhang, Jingdong; Zheng, Hua; Zhu, Tao; Yin, Guolu; Liu, Min; Bai, Yongzhong; Qu, Dingrong; Qiu, Feng; Huang, Xianbing

2018-05-01

The round trip time of the light pulse limits the maximum detectable vibration frequency response range of phase-sensitive optical time domain reflectometry ({\\phi}-OTDR). Unlike the uniform laser pulse interval in conventional {\\phi}-OTDR, we randomly modulate the pulse interval, so that an equivalent sub-Nyquist additive random sampling (sNARS) is realized for every sensing point of the long interrogation fiber. For an {\\phi}-OTDR system with 10 km sensing length, the sNARS method is optimized by theoretical analysis and Monte Carlo simulation, and the experimental results verify that a wide-band spars signal can be identified and reconstructed. Such a method can broaden the vibration frequency response range of {\\phi}-OTDR, which is of great significance in sparse-wideband-frequency vibration signal detection, such as rail track monitoring and metal defect detection.

Micro-Doppler Ambiguity Resolution for Wideband Terahertz Radar Using Intra-Pulse Interference.

Science.gov (United States)

Yang, Qi; Qin, Yuliang; Deng, Bin; Wang, Hongqiang; You, Peng

2017-04-29

Micro-Doppler, induced by micro-motion of targets, is an important characteristic of target recognition once extracted via parameter estimation methods. However, micro-Doppler is usually too significant to result in ambiguity in the terahertz band because of its relatively high carrier frequency. Thus, a micro-Doppler ambiguity resolution method for wideband terahertz radar using intra-pulse interference is proposed in this paper. The micro-Doppler can be reduced several dozen times its true value to avoid ambiguity through intra-pulse interference processing. The effectiveness of this method is proved by experiments based on a 0.22 THz wideband radar system, and its high estimation precision and excellent noise immunity are verified by Monte Carlo simulation.

Extension of the ITU Channel Models for Wideband (OFDM) Systems

DEFF Research Database (Denmark)

Sørensen, Troels Bundgaard; Frederiksen, Frank

2005-01-01

for the evaluation of wideband system concepts with frequency dependent characteristics, e.g. frequency domain link adaptation and packet scheduling, both of which are likely to be part of future wideband systems such as based on OFDM. With the suggested procedure the frequency correlation can be kept approximately...

Ultrasonic mammography

International Nuclear Information System (INIS)

Hueneke, B.

1982-01-01

608 women are examined by means of ultrasonic mammography during the period of 1 year. 432 patients were examined with the compound method with the U.I. Octoson, a water tank scanner, and 176 patients with the real time method with a directly connected linear-array-scanner. The following results were obtained at the end of the examination period: In the ultrasonic and also in the X-ray mammogram tumour diameters can be determined with an error rate of +- 30%. In the diagnosing of carcinomas, a significant dependence of the exactness on the sice of the tumour is found for the combination of the five methods tested (clinical examination, X-ray mammography, ultrasonic mammography, thermography, cytology). Classifying the individual methods with regard to their exactness, X-ray mammography ranks in front of ultrasonic mammography. Mastopathic changes in the breast can be screened by means of ultrasonic mammography. The structure of the changes can be determined more exactly than with an X-ray picture which is due to the possibility of differentiating solid and cystic structures. In diagnosing fibro-adenomas and establishing diagnoses on young women with dense gland bodies, ultrasonic mammography is superior to radiology both in the ability of screening a finding of a fibro-adenoma (US=88%, X-ray=75%) and in the possibility of classifying it as ''more benign than malignant''. (orig./MG) [de

Five years of testing using the simi-automated ultrasonic time of flight diffraction system

International Nuclear Information System (INIS)

Webber, S.A.

2002-01-01

This paper provides a brief description of the Time of Flight Diffraction (TOFD) test system and also describes a couple of case histories where the system has been successfully applied. The T.O.F.D. system has been contrasted with the conventional manual ultrasonic technique. Whilst the T.O.F.D. system has proven potential, and is without doubt a valuable tool that will continue to gain market share in the inspection industry, conventional manual ultrasonics still has its part to play and will survive for some time to come. One of the outstanding issues facing the T.O.F.D. systems is the question of acceptance testing which is still the predominant convention specified in most standards. Training for a T.O.F.D. system technician is particularly important and the author suggests there are more traps for the unwary than with the conventional manual ultrasonic systems. The overall judgement of the T.O.F.D. system is that it is a most welcome and powerful tool in the hands of the right operator and will do much to boost the prominence of Non-Destructive Testing

Measurement of a 3D Ultrasonic Wavefield Using Pulsed Laser Holographic Microscopy for Ultrasonic Nondestructive Evaluation

Directory of Open Access Journals (Sweden)

Xing Wang

2018-02-01

Full Text Available In ultrasonic array imaging, 3D ultrasonic wavefields are normally recorded by an ultrasonic piezo array transducer. Its performance is limited by the configuration and size of the array transducer. In this paper, a method based on digital holographic interferometry is proposed to record the 3D ultrasonic wavefields instead of the array transducer, and the measurement system consisting of a pulsed laser, ultrasonic excitation, and synchronization and control circuit is designed. A consecutive sequence of holograms of ultrasonic wavefields are recorded by the system. The interferograms are calculated from the recorded holograms at different time sequence. The amplitudes and phases of the transient ultrasonic wavefields are recovered from the interferograms by phase unwrapping. The consecutive sequence of transient ultrasonic wavefields are stacked together to generate 3D ultrasonic wavefields. Simulation and experiments are carried out to verify the proposed technique, and preliminary results are presented.

Efficient Wideband Spectrum Sensing with Maximal Spectral Efficiency for LEO Mobile Satellite Systems

Directory of Open Access Journals (Sweden)

Feilong Li

2017-01-01

Full Text Available The usable satellite spectrum is becoming scarce due to static spectrum allocation policies. Cognitive radio approaches have already demonstrated their potential towards spectral efficiency for providing more spectrum access opportunities to secondary user (SU with sufficient protection to licensed primary user (PU. Hence, recent scientific literature has been focused on the tradeoff between spectrum reuse and PU protection within narrowband spectrum sensing (SS in terrestrial wireless sensing networks. However, those narrowband SS techniques investigated in the context of terrestrial CR may not be applicable for detecting wideband satellite signals. In this paper, we mainly investigate the problem of joint designing sensing time and hard fusion scheme to maximize SU spectral efficiency in the scenario of low earth orbit (LEO mobile satellite services based on wideband spectrum sensing. Compressed detection model is established to prove that there indeed exists one optimal sensing time achieving maximal spectral efficiency. Moreover, we propose novel wideband cooperative spectrum sensing (CSS framework where each SU reporting duration can be utilized for its following SU sensing. The sensing performance benefits from the novel CSS framework because the equivalent sensing time is extended by making full use of reporting slot. Furthermore, in respect of time-varying channel, the spatiotemporal CSS (ST-CSS is presented to attain space and time diversity gain simultaneously under hard decision fusion rule. Computer simulations show that the optimal sensing settings algorithm of joint optimization of sensing time, hard fusion rule and scheduling strategy achieves significant improvement in spectral efficiency. Additionally, the novel ST-CSS scheme performs much higher spectral efficiency than that of general CSS framework.

Computer automation of ultrasonic testing. [inspection of ultrasonic welding

Science.gov (United States)

Yee, B. G. W.; Kerlin, E. E.; Gardner, A. H.; Dunmyer, D.; Wells, T. G.; Robinson, A. R.; Kunselman, J. S.; Walker, T. C.

1974-01-01

Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded.

Inkjet Printing of Paper-Based Wideband and High Gain Antennas

KAUST Repository

Cook, Benjamin

2011-12-07

This thesis represents a major contribution to wideband and high gain inkjet-printed antennas on paper. This work includes the complete characterization of the inkjet printing process for passive microwave devices on paper substrate as well as several ultra-wideband and high gain antenna designs. The characterization work includes the electrical characterization of the permittivity and loss tangent for paper substrate through 10 GHz, ink conductivity data for variable sintering conditions, and minimum feature sizes obtainable by today’s current inkjet processes for metallic nanoparticles. For the first time ever, inkjet-printed antennas are demonstrated that operate over the entire UWB band and demonstrate gains up to 8dB. This work also presents the first fractal-based inkjet-printed antennas with enhanced bandwidth and reduced production costs, and a novel slow wave log periodic dipole array which shows minimizations of 20% in width over conventional log periodic antennas.

Low-sampling-rate ultra-wideband channel estimation using equivalent-time sampling

KAUST Repository

Ballal, Tarig

2014-09-01

In this paper, a low-sampling-rate scheme for ultra-wideband channel estimation is proposed. The scheme exploits multiple observations generated by transmitting multiple pulses. In the proposed scheme, P pulses are transmitted to produce channel impulse response estimates at a desired sampling rate, while the ADC samples at a rate that is P times slower. To avoid loss of fidelity, the number of sampling periods (based on the desired rate) in the inter-pulse interval is restricted to be co-prime with P. This condition is affected when clock drift is present and the transmitted pulse locations change. To handle this case, and to achieve an overall good channel estimation performance, without using prior information, we derive an improved estimator based on the bounded data uncertainty (BDU) model. It is shown that this estimator is related to the Bayesian linear minimum mean squared error (LMMSE) estimator. Channel estimation performance of the proposed sub-sampling scheme combined with the new estimator is assessed in simulation. The results show that high reduction in sampling rate can be achieved. The proposed estimator outperforms the least squares estimator in almost all cases, while in the high SNR regime it also outperforms the LMMSE estimator. In addition to channel estimation, a synchronization method is also proposed that utilizes the same pulse sequence used for channel estimation. © 2014 IEEE.

Ultrasonic Testing

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyeong Jun; Kuk, Jeong Han

2002-02-15

This book introduces ultrasonic testing, which tells of outline of ultrasonic testing, principle of ultrasonic testing, prosperities of ultrasonic waves, radiographic test and ultrasonic test, basic theory on ultrasonic testing, mode conversion, transmission and diffraction, ultrasonic flaw detection and probe, standard test piece and reference test piece, like KS(JIS) ASME and ASTM, classification and properties of ultrasonic testing, straight beam method, angle beam method, ASME SEC.V.Art.5 ASTMA 388 and KS B 0817 Korean industrial standard.

The design of wideband metamaterial absorber at E band based on defect

Science.gov (United States)

Wang, L. S.; Xia, D. Y.; Ding, X. Y.; Wang, Y.

2018-01-01

A kind of wideband metamaterial absorber at E band is designed in this paper; it is composed of round metal cells with defect, dielectric substrate and metal film. The electromagnetic parameters of unit cell are calculated by using the finite element method. The results show that the wideband metamaterial absorber presents nearly perfect absorption above 90% with absorption ranging from 65.38GHz to 67.86GHz; the reason of wideband absorption is the overlap of different absorption frequency which is caused by electromagnetic resonance; the size parameters and position of defect has important effect on its absorption property. It has many advantages, such as simply, easy to preparation and so on. It has potential application on aerospace measurement and control, remote data communication, LTE wideband mobile communication and other fields.

DATA QUALITY EVALUATION AND APPLICATION POTENTIAL ANALYSIS OF TIANGONG-2 WIDE-BAND IMAGING SPECTROMETER

Directory of Open Access Journals (Sweden)

B. Qin

2018-04-01

Full Text Available Tiangong-2 is the first space laboratory in China, which launched in September 15, 2016. Wide-band Imaging Spectrometer is a medium resolution multispectral imager on Tiangong-2. In this paper, the authors introduced the indexes and parameters of Wideband Imaging Spectrometer, and made an objective evaluation about the data quality of Wide-band Imaging Spectrometer in radiation quality, image sharpness and information content, and compared the data quality evaluation results with that of Landsat-8. Although the data quality of Wide-band Imager Spectrometer has a certain disparity with Landsat-8 OLI data in terms of signal to noise ratio, clarity and entropy. Compared with OLI, Wide-band Imager Spectrometer has more bands, narrower bandwidth and wider swath, which make it a useful remote sensing data source in classification and identification of large and medium scale ground objects. In the future, Wide-band Imaging Spectrometer data will be widely applied in land cover classification, ecological environment assessment, marine and coastal zone monitoring, crop identification and classification, and other related areas.

Data Quality Evaluation and Application Potential Analysis of TIANGONG-2 Wide-Band Imaging Spectrometer

Science.gov (United States)

Qin, B.; Li, L.; Li, S.

2018-04-01

Tiangong-2 is the first space laboratory in China, which launched in September 15, 2016. Wide-band Imaging Spectrometer is a medium resolution multispectral imager on Tiangong-2. In this paper, the authors introduced the indexes and parameters of Wideband Imaging Spectrometer, and made an objective evaluation about the data quality of Wide-band Imaging Spectrometer in radiation quality, image sharpness and information content, and compared the data quality evaluation results with that of Landsat-8. Although the data quality of Wide-band Imager Spectrometer has a certain disparity with Landsat-8 OLI data in terms of signal to noise ratio, clarity and entropy. Compared with OLI, Wide-band Imager Spectrometer has more bands, narrower bandwidth and wider swath, which make it a useful remote sensing data source in classification and identification of large and medium scale ground objects. In the future, Wide-band Imaging Spectrometer data will be widely applied in land cover classification, ecological environment assessment, marine and coastal zone monitoring, crop identification and classification, and other related areas.

Development and Application of an Ultrasonic Gas Flowmeter

International Nuclear Information System (INIS)

Hwang, Won Ho; Jeong, Hee Don; Park, Sang Gug; Jhang, Kyung Young

2002-01-01

This paper describes the development and the field application of the ultrasonic gas flowmeter for accurate measurement of the volumetric flow rate of gases in a harsh environmental conditions in iron and steel making company. This ultrasonic flowmeter is especially suited for measuring LDG, COG, BFG gases produced in iron and steel making process. This is a transit time type ultrasonic flowmeter. We have developed the transmitting and receiving algorithm of ultrasonic wave and the ultrasonic signal processing algorithm to develope a transit time type ultrasonic flowmeter. We have evaluated the performance of ultrasonic flowmeter by the calibration system with Venturi type standard flowmeter. We has confirmed its reliability by extensive field tests for a year in POSCO, iron and steel making company. Now we have developed the commercial model of ultrasonic flowmeter and applied to the POSCO gas line

Super wideband characteristics of monopolar patch antenna

Directory of Open Access Journals (Sweden)

Xi Chen

2013-12-01

Full Text Available A simple method of acquiring super wideband characteristics for monopolar patch antenna is proposed. Through adopting a modified cone as feeding and radiating structure, the monopolar patch antenna can reach the impedance bandwidth of more than 1:23.4 for voltage standing wave ratio (VSWR ≤ 2. In the whole operating band, the antenna has the like-monopole omnidirectional radiation patterns and the peak gains of 3.8–8.7 dB. Meanwhile, the height of the antenna is just 0.074λ(c, and the diameter of the radiated body is 0.205λ(c, which is smaller than other ultra-wideband omnidirectional antenna.

Design of a High Linearity Four-Quadrant Analog Multiplier in Wideband Frequency Range

Directory of Open Access Journals (Sweden)

Abdul kareem Mokif Obais

2017-05-01

Full Text Available In this paper, a voltage mode four quadrant analog multiplier in the wideband frequency rangeis designed using a wideband operational amplifier (OPAMP and squaring circuits. The wideband OPAMP is designed using 10 identical NMOS transistorsand operated with supply voltages of ±12V. Two NMOS transistors and two wideband OPAMP are utilized in the design of the proposed squaring circuit. All the NMOS transistors are based on 0.35µm NMOStechnology. The multiplier has input and output voltage ranges of ±10 V, high range of linearity from -10 V to +10 V, and cutoff frequency of about 5 GHz. The proposed multiplier is designed on PSpice in Orcad 16.6

A new metamaterial-based wideband rectangular invisibility cloak

Science.gov (United States)

Islam, S. S.; Hasan, M. M.; Faruque, M. R. I.

2018-02-01

A new metamaterial-based wideband electromagnetic rectangular cloak is being introduced in this study. The metamaterial unit cell shows sharp transmittances in the C- and X-bands and displays wideband negative effective permittivity region there. The metamaterial unit cell was then applied in designing a rectangular-shaped electromagnetic cloak. The scattering reduction technique was adopted for the cloaking operation. The cloak operates in the certain portion of C-and X-bands that covers more than 4 GHz bandwidth region. The experimental results were provided as well for the metamaterial and the cloak.

Iterative equalization for OFDM systems over wideband Multi-Scale Multi-Lag channels

NARCIS (Netherlands)

Xu, T.; Tang, Z.; Remis, R.; Leus, G.

2012-01-01

OFDM suffers from inter-carrier interference (ICI) when the channel is time varying. This article seeks to quantify the amount of interference resulting from wideband OFDM channels, which are assumed to follow the multi-scale multi-lag (MSML) model. The MSML channel model results in full channel

Wideband or Dual-Band Low-Profile Circular Patch Antenna with High Gain and Sidelobe Suppression

DEFF Research Database (Denmark)

Squadrito, Paolo; Zhang, Shuai; Pedersen, Gert F.

2018-01-01

This paper presents a wideband or dual-band circular disk antenna with high gain and sidelobe suppression (SLS). The antenna has a single layer and single-fed configuration. The antenna can operate with the radiation field superposition of TM12 and TM14 modes at one frequency, which provides high...... gain and SLS. A circle of 10 shorting vias with non-identical diameters are loaded inside the antenna cavity in order to excite the field superposition of TM11 and TM13 modes at another frequency. By modifying the radius of the vias, the resonant frequency with the TM11 and TM13 superposition can...... be tuned closer to or further away from the one with the TM12 and TM14 superposition. In this way, a wideband or dual-band behavior can be obtained with high gain and SLS. The proposed antenna achieves the impedance bandwidth of 6.46% for the wideband case, which is over 6 times wider than the previous...

A surface flaw sizing study by time-of-flight ultrasonic technique

International Nuclear Information System (INIS)

Lamy, C.A.

1990-07-01

In this work, sizing of inclined slits and surface cracks in ferritic steel using the ultrasonic time-of-flight technique was studied. The surface cracks were vertical and inclined, nut the slits were only inclined. It was surface Rayleigh wave that was converted to shear wave mode in the material. The specimens with surface crack were submitted to a three four point loading fracture mechanics tests, so that the region of the crack tip became under an increasing tensile stress. Thus, the ultrasonic crack sizing could be compared to the material stress intensity factor (K) of the material for different loadings. Results show that the greater the slope and/or lenght of the slits the greater its subsizing. Vertical cracks int he parent metal are reliably and accuratly sized; in the weld the same remark held if one increases the gain of ultrasonic flaw detector to compensate for the weld attenuation phenomenon. Sizing of inclined cracks in the parent metal shows the same trends of the inclined slits, differing only in slopes over 30 sup(0) where the sizing in surface cracks is no longer reliable. A new appraisal procedure here proposed made reliable these results. The techniques employed in this work lead to reliable and accurate results for sizing of different slits and cracks. It should be noted however that good results are only obtained if a tensile stress state exists in the neighbourhood of the c rack tip. (author)

[Auditory training with wide-band white noise: effects on the recruitment (III)].

Science.gov (United States)

Domínguez Ugidos, L J; Rodríguez Morejón, C; Vallés Varela, H; Iparraguirre Bolinaga, V; Knaster del Olmo, J

2001-05-01

The auditory training with wide-band white noise is a methodology for the qualitative recovery of the hearing loss in people suffering from sensorineural hearing loss. It is based on the application of a wide-band white modified noise. In a prospective study, we have assessed the modifications of the recruitment coefficient in a sample of 48 patients who have followed a program of 15 auditory training with wide-band white noise sessions. The average improvement of the recruitment coefficient expressed in percentage is a 7.7498%, which comes up to 23.5249% in the case of a binaural recruitment coefficient. From our results, it can be deduced that the auditory training with wide-band white noise reduces the recruitment. That is to say, the decrease of the recruitment in high intensities both binaurally and in all ears.

Efficient Time-Domain Ray-Tracing Technique for the Analysis of Ultra-Wideband Indoor Environments including Lossy Materials and Multiple Effects

Directory of Open Access Journals (Sweden)

F. Saez de Adana

2009-01-01

Full Text Available This paper presents an efficient application of the Time-Domain Uniform Theory of Diffraction (TD-UTD for the analysis of Ultra-Wideband (UWB mobile communications for indoor environments. The classical TD-UTD formulation is modified to include the contribution of lossy materials and multiple-ray interactions with the environment. The electromagnetic analysis is combined with a ray-tracing acceleration technique to treat realistic and complex environments. The validity of this method is tested with measurements performed inside the Polytechnic building of the University of Alcala and shows good performance of the model for the analysis of UWB propagation.

Improvement of Ultrasonic Distance Measuring System

Directory of Open Access Journals (Sweden)

Jiang Yu

2018-01-01

Full Text Available This paper mainly introduces a kind of ultrasonic distance measuring system with AT89C51 single chip as the core component. The paper expounds the principle of ultrasonic sensor and ultrasonic ranging, hardware circuit and software program, and the results of experiment and analysis.The hardware circuit based on SCM, the software design adopts the advanced microcontroller programming language.The amplitude of the received signal and the time of ultrasonic propagation are regulated by closed loop control. [1,2]The double closed loop control technology for amplitude and time improves the measuring accuracy of the instrument. The experimental results show that greatly improves the measurement accuracy of the system.

Ultrasonic flow measurements for irrigation process monitoring

Science.gov (United States)

Ziani, Elmostafa; Bennouna, Mustapha; Boissier, Raymond

2004-02-01

This paper presents the state of the art of the general principle of liquid flow measurements by ultrasonic method, and problems of flow measurements. We present an ultrasonic flowmeter designed according to smart sensors concept, for the measurement of irrigation water flowing through pipelines or open channels, using the ultrasonic transit time approach. The new flowmeter works on the principle of measuring time delay differences between sound pulses transmitted upstream and downstream in the flowing liquid. The speed of sound in the flowing medium is eliminated as a variable because the flowrate calculations are based on the reciprocals of the transmission times. The transit time difference is digitally measured by means of a suitable, microprocessor controlled logic. This type of ultrasonic flowmeter will be widely used in industry and water management, it is well studied in this work, followed by some experimental results. For pressurized channels, we use one pair of ultrasonic transducer arranged in proper positions and directions of the pipe, in this case, to determine the liquid velocity, a real time on-line analysis taking account the geometries of the hydraulic system, is applied to the obtained ultrasonic data. In the open channels, we use a single or two pairs of ultrasonic emitter-receiver according to the desired performances. Finally, the goals of this work consist in integrating the smart sensor into irrigation systems monitoring in order to evaluate potential advantages and demonstrate their performance, on the other hand, to understand and use ultrasonic approach for determining flow characteristics and improving flow measurements by reducing errors caused by disturbances of the flow profiles.

10th and 11th conference on Ultra-Wideband Short-Pulse Electromagnetics

CERN Document Server

Mokole, Eric; UWB SP 10; UWB SP 11

2014-01-01

This book presents contributions of deep technical content and high scientific quality in the areas of electromagnetic theory, scattering, UWB antennas, UWB systems, ground penetrating radar (GPR), UWB communications, pulsed-power generation, time-domain computational electromagnetics, UWB compatibility, target detection and discrimination, propagation through dispersive media, and wavelet and multi-resolution techniques. Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Like previous books in this series, Ultra-Wideband Short-Pulse Electrom...

Multichannel Baseband Processor for Wideband CDMA

Science.gov (United States)

Jalloul, Louay M. A.; Lin, Jim

2005-12-01

The system architecture of the cellular base station modem engine (CBME) is described. The CBME is a single-chip multichannel transceiver capable of processing and demodulating signals from multiple users simultaneously. It is optimized to process different classes of code-division multiple-access (CDMA) signals. The paper will show that through key functional system partitioning, tightly coupled small digital signal processing cores, and time-sliced reuse architecture, CBME is able to achieve a high degree of algorithmic flexibility while maintaining efficiency. The paper will also highlight the implementation and verification aspects of the CBME chip design. In this paper, wideband CDMA is used as an example to demonstrate the architecture concept.

GaAs Wideband Low Noise Amplifier Design for Breast Cancer Detection System

DEFF Research Database (Denmark)

Yan, Lei; Krozer, Viktor; Delcourt, Sebastien

2009-01-01

Modern wideband systems require low-noise receivers with bandwidth approaching 10 GHz. This paper presents ultra-wideband stable low-noise amplifier MMIC with cascode and source follower buffer configuration using GaAs technology. Source degeneration, gate and shunt peaking inductors are used...

Method and apparatus to characterize ultrasonically reflective contrast agents

Science.gov (United States)

Pretlow, Robert A., III (Inventor)

1993-01-01

A method and apparatus for characterizing the time and frequency response of an ultrasonically reflective contrast agent is disclosed. An ultrasonically reflective contrast agent is injected, under constant pressure, into a fluid flowing through a pump flow circuit. The fluid and the ultrasonically reflective contrast agent are uniformly mixed in a mixing chamber, and the uniform mixture is passed through a contrast agent chamber. The contrast agent chamber is acoustically and axially interposed between an ultrasonic transducer chamber and an acoustic isolation chamber. A pulse of ultrasonic energy is transmitted into the contrast agent chamber from the ultrasonic transducer chamber. An echo waveform is received from the ultrasonically reflective contrast agent, and it is analyzed to determine the time and frequency response of the ultrasonically reflective contrast agent.

Detection of a surface breaking crack by using the centroid variations of laser ultrasonic spectrums

International Nuclear Information System (INIS)

Park, Seung Kyu; Baik, Sung Hoon; Lim, Chang Hwan; Joo, Young Sang; Jung, Hyun Kyu; Cha, Hyung Ki; Kang, Young June

2006-01-01

A laser ultrasonic system is a non-contact inspection device with a wide-band spectrum and a high spatial resolution. It provides absolute measurements of the moving distance and it can be applied to hard-to-access locations including curved or rough surfaces like in a nuclear power plant. In this paper, we have investigated the detection methods of the depth of a surface-breaking crack by using the surface wave of a laser ultrasound. The filtering function of a surface-breaking crack is a kind of a low-pass filter. The higher frequency components are more highly decreased in proportion to the crack depth. Also, the center frequency value of each ultrasound spectrum is decreased in proportion to the crack depth. We extracted the depth information of a surface-breaking crack by observing the centroid variation of the frequency spectrum. We describe the experimental results to detect the crack depth information by using the peak-to-valley values in the time domain and the center frequency values in the frequency domain.

Wide-band analog frequency modulation of optic signals using indirect techniques

Science.gov (United States)

Fitzmartin, D. J.; Balboni, E. J.; Gels, R. G.

1991-01-01

The wideband frequency modulation (FM) of an optical carrier by a radio frequency (RF) or microwave signal can be accomplished independent of laser type when indirect modulation is employed. Indirect modulators exploit the integral relation of phase to frequency so that phase modulators can be used to impress frequency modulation on an optical carrier. The use of integrated optics phase modulators, which are highly linear, enables the generation of optical wideband FM signals with very low intermodulation distortion. This modulator can be used as part of an optical wideband FM link for RF and microwave signals. Experimental results from the test of an indirect frequency modulator for an optical carrier are discussed.

Spatial Dynamic Wideband Modeling of the MIMO Satellite-to-Earth Channel

OpenAIRE

Lehner, Andreas; Steingass, Alexander

2014-01-01

A novel MIMO (multiple input multiple output) satellite channel model that allows the generation of associated channel impulse response (CIR) time series depending on the movement profile of a land mobile terminal is presented in this paper. Based on high precise wideband measurements in L-band the model reproduces the correlated shadowing and multipath conditions in rich detail. The model includes time and space variant echo signals appearing and disappearing in dependence on the receive ...

A digital, constant-frequency pulsed phase-locked-loop instrument for real-time, absolute ultrasonic phase measurements

Science.gov (United States)

Haldren, H. A.; Perey, D. F.; Yost, W. T.; Cramer, K. E.; Gupta, M. C.

2018-05-01

A digitally controlled instrument for conducting single-frequency and swept-frequency ultrasonic phase measurements has been developed based on a constant-frequency pulsed phase-locked-loop (CFPPLL) design. This instrument uses a pair of direct digital synthesizers to generate an ultrasonically transceived tone-burst and an internal reference wave for phase comparison. Real-time, constant-frequency phase tracking in an interrogated specimen is possible with a resolution of 0.000 38 rad (0.022°), and swept-frequency phase measurements can be obtained. Using phase measurements, an absolute thickness in borosilicate glass is presented to show the instrument's efficacy, and these results are compared to conventional ultrasonic pulse-echo time-of-flight (ToF) measurements. The newly developed instrument predicted the thickness with a mean error of -0.04 μm and a standard deviation of error of 1.35 μm. Additionally, the CFPPLL instrument shows a lower measured phase error in the absence of changing temperature and couplant thickness than high-resolution cross-correlation ToF measurements at a similar signal-to-noise ratio. By showing higher accuracy and precision than conventional pulse-echo ToF measurements and lower phase errors than cross-correlation ToF measurements, the new digitally controlled CFPPLL instrument provides high-resolution absolute ultrasonic velocity or path-length measurements in solids or liquids, as well as tracking of material property changes with high sensitivity. The ability to obtain absolute phase measurements allows for many new applications than possible with previous ultrasonic pulsed phase-locked loop instruments. In addition to improved resolution, swept-frequency phase measurements add useful capability in measuring properties of layered structures, such as bonded joints, or materials which exhibit non-linear frequency-dependent behavior, such as dispersive media.

A low-noise, wideband, integrated CMOS transimpedance preamplifier for photodiode applications

International Nuclear Information System (INIS)

Binkley, D.M.; Paulus, M.J.; Casey, M.E.; Rochelle, J.M.

1992-01-01

In this paper, a low-noise, wideband, integrated CMOS transimpedance preamplifier is presented for silicon avalanche photodiode (APD) applications. The preamplifier, fabricated in a standard 2μ CMOS technology, features a transimpedance gain of 45 kΩ, a risetime of 22 ns, a series noise of 1.6nV/Hz 1/2 , and a wideband equivalent input-noise current of 12 nA for a source capacitance of 12 pF. The measured 22 Na timing resolution of 9.2-ns FWHM and energy resolution of 22.4% FWHM for the RCA C30994 BGO/APD detector module coupled to the preamplifier is comparable to the performance reported using charge-sensitive preamplifiers. This illustrates that transimpedance preamplifiers should be considered for APD applications, especially where APD noise current dominates noise from feedback resistors in the 1--kΩ to 50-kΩ range

Wideband aperture array using RF channelizers and massively parallel digital 2D IIR filterbank

Science.gov (United States)

Sengupta, Arindam; Madanayake, Arjuna; Gómez-García, Roberto; Engeberg, Erik D.

2014-05-01

Wideband receive-mode beamforming applications in wireless location, electronically-scanned antennas for radar, RF sensing, microwave imaging and wireless communications require digital aperture arrays that offer a relatively constant far-field beam over several octaves of bandwidth. Several beamforming schemes including the well-known true time-delay and the phased array beamformers have been realized using either finite impulse response (FIR) or fast Fourier transform (FFT) digital filter-sum based techniques. These beamforming algorithms offer the desired selectivity at the cost of a high computational complexity and frequency-dependant far-field array patterns. A novel approach to receiver beamforming is the use of massively parallel 2-D infinite impulse response (IIR) fan filterbanks for the synthesis of relatively frequency independent RF beams at an order of magnitude lower multiplier complexity compared to FFT or FIR filter based conventional algorithms. The 2-D IIR filterbanks demand fast digital processing that can support several octaves of RF bandwidth, fast analog-to-digital converters (ADCs) for RF-to-bits type direct conversion of wideband antenna element signals. Fast digital implementation platforms that can realize high-precision recursive filter structures necessary for real-time beamforming, at RF radio bandwidths, are also desired. We propose a novel technique that combines a passive RF channelizer, multichannel ADC technology, and single-phase massively parallel 2-D IIR digital fan filterbanks, realized at low complexity using FPGA and/or ASIC technology. There exists native support for a larger bandwidth than the maximum clock frequency of the digital implementation technology. We also strive to achieve More-than-Moore throughput by processing a wideband RF signal having content with N-fold (B = N Fclk/2) bandwidth compared to the maximum clock frequency Fclk Hz of the digital VLSI platform under consideration. Such increase in bandwidth is

Detection and classification of defects in ultrasonic NDE signals using time-frequency representations

Science.gov (United States)

Qidwai, Uvais; Costa, Antonio H.; Chen, C. H.

2000-05-01

The ultrasonic wave, generated by a piezoelectric transducer coupled to the test specimen, propagates through the material and part of its energy is reflected when it encounters an non-homogeneity or discontinuity in its path, while the remainder is reflected by the back surface of the test specimen. Defect echo signals are masked by the characteristics of the measuring instruments, the propagation paths taken by the ultrasonic wave, and are corrupted by additive noise. This leads to difficulties in comparing and analyzing signals, particularly in automated defect identification systems employing different transducers. Further, the multi-component nature of material defects can add to the complexity of the defect identification criteria. With many one-dimensional (1-D) approaches, the multi-component defects can not be detected. Another drawback is that these techniques are not very robust for sharp ultrasonic peaks especially in a very hazardous environment. This paper proposes a technique based on the time-frequency representations (TFRs) of the real defect signals corresponding to artificially produced defects of various geometries in metals. Cohen's class (quadratic) TFRs with Gaussian kernels are then used to represent the signals in the time-frequency (TF) plane. Once the TFR is obtained, various image processing morphological techniques are applied to the TFR (e.g. region of interest masking, edge detection, and profile separation). Based on the results of these operations, a binary image is produced which, in turn, leads to a novel set of features. Using these new features, defects have not only been detected but also classified as flat-cut, angular-cut, and circular-drills. Moreover, with some modifications of the threshold levels of the TFR kernel design, our technique can be used in relatively hostile environments with SNRs as low as 0 dB. Another important characteristic of our approach is the detection of multiple defects. This consists of detection of

Investigation on wide-band scattering of a 2-D target above 1-D randomly rough surface by FDTD method.

Science.gov (United States)

Li, Juan; Guo, Li-Xin; Jiao, Yong-Chang; Li, Ke

2011-01-17

Finite-difference time-domain (FDTD) algorithm with a pulse wave excitation is used to investigate the wide-band composite scattering from a two-dimensional(2-D) infinitely long target with arbitrary cross section located above a one-dimensional(1-D) randomly rough surface. The FDTD calculation is performed with a pulse wave incidence, and the 2-D representative time-domain scattered field in the far zone is obtained directly by extrapolating the currently calculated data on the output boundary. Then the 2-D wide-band scattering result is acquired by transforming the representative time-domain field to the frequency domain with a Fourier transform. Taking the composite scattering of an infinitely long cylinder above rough surface as an example, the wide-band response in the far zone by FDTD with the pulsed excitation is computed and it shows a good agreement with the numerical result by FDTD with the sinusoidal illumination. Finally, the normalized radar cross section (NRCS) from a 2-D target above 1-D rough surface versus the incident frequency, and the representative scattered fields in the far zone versus the time are analyzed in detail.

Study of the ultrasonic technique of elapsed time of notch

International Nuclear Information System (INIS)

Gomes, L.C.F.L.; Rebello, J.M.A.

1989-01-01

The study of the ultrasonic technique of elapsed time in the dimensionment of notch inclined of 15 and 30 degree and of depth of 5 and 10 mm using the superficial Rayleigh wave and the mode conversion, with a headstock transmitter and other receiver. The dimensionment of notch and of the binding of the piece were made with headstock in different positions. Between the various results obtained can be mentioned the increase of the dimensionment, by two techniques, with the increase of the angle and/or of the depth. (V.R.B.)

Full-field ultrasonic inspection for a composite sandwich plate skin-core debonding detection using laser-based ultrasonics

Science.gov (United States)

Chong, See Yenn; Victor, Jared J.; Todd, Michael D.

2017-04-01

In this paper, a full-field ultrasonic guided wave method is proposed to inspect a composite sandwich specimen made for an aircraft engine nacelle. The back skin/core interface of the specimen is built with two fabricated disbond defects (diameters of 12.7 mm and 25.4 mm) by removing areas of the adhesive used to bond the back skin to the core. A laser ultrasonic interrogation system (LUIS) incorporated with a disbond detection algorithm is developed. The system consists of a 1-kHz laser ultrasonic scanning system and a single fixed ultrasonic sensor to interrogate ultrasonic guided waves in the sandwich specimen. The interest area of 400 mm × 400 mm is scanned at a 0.5 mm scan interval. The corresponding full-field ultrasonic data is obtained and generated in the three-dimensional (3-D) space-time domain. Then, the 3-D full-field ultrasonic data is Fourier transformed and the ultrasonic frequency spectra are analyzed to determine the dominant frequency that is sensitive to the disbond defects. Continuous wavelet transform (CWT) based on fast Fourier transform (FFT) is implemented as a single-frequency bandpass filter to filter the full-field ultrasonic data in the 3-D space-time domain at the selected dominant frequency. The LUIS has shown the ability to detect the disbond with diameters of 11 mm and 23 mm which match to the pre-determined disbond sizes well. For future research, a robust signal processing algorithm and a model-based matched filter will be investigated to make the detection process autonomous and improve detectability

Concrete Infill Monitoring in Concrete-Filled FRP Tubes Using a PZT-Based Ultrasonic Time-of-Flight Method.

Science.gov (United States)

Luo, Mingzhang; Li, Weijie; Hei, Chuang; Song, Gangbing

2016-12-07

Concrete-filled fiber-reinforced polymer tubes (CFFTs) have attracted interest for their structural applications in corrosive environments. However, a weak interfacial strength between the fiber-reinforced polymer (FRP) tube and the concrete infill may develop due to concrete shrinkage and inadequate concrete compaction during concrete casting, which will destroy the confinement effect and thereby reduce the load bearing capacity of a CFFT. In this paper, the lead zirconate titanate (PZT)-based ultrasonic time-of-flight (TOF) method was adopted to assess the concrete infill condition of CFFTs. The basic idea of this method is that the velocity of the ultrasonic wave propagation in the FRP material is about half of that in concrete material. Any voids or debonding created along the interface between the FRP tube and the concrete will delay the arrival time between the pairs of PZT transducers. A comparison of the arrival times of the PZT pairs between the intact and the defected CFFT was made to assess the severity of the voids or the debonding. The feasibility of the methodology was analyzed using a finite-difference time-domain-based numerical simulation. Experiments were setup to validate the numerical results, which showed good agreement with the numerical findings. The results showed that the ultrasonic time-of-flight method is able to detect the concrete infill condition of CFFTs.

Concrete Infill Monitoring in Concrete-Filled FRP Tubes Using a PZT-Based Ultrasonic Time-of-Flight Method

Science.gov (United States)

Luo, Mingzhang; Li, Weijie; Hei, Chuang; Song, Gangbing

2016-01-01

Concrete-filled fiber-reinforced polymer tubes (CFFTs) have attracted interest for their structural applications in corrosive environments. However, a weak interfacial strength between the fiber-reinforced polymer (FRP) tube and the concrete infill may develop due to concrete shrinkage and inadequate concrete compaction during concrete casting, which will destroy the confinement effect and thereby reduce the load bearing capacity of a CFFT. In this paper, the lead zirconate titanate (PZT)-based ultrasonic time-of-flight (TOF) method was adopted to assess the concrete infill condition of CFFTs. The basic idea of this method is that the velocity of the ultrasonic wave propagation in the FRP material is about half of that in concrete material. Any voids or debonding created along the interface between the FRP tube and the concrete will delay the arrival time between the pairs of PZT transducers. A comparison of the arrival times of the PZT pairs between the intact and the defected CFFT was made to assess the severity of the voids or the debonding. The feasibility of the methodology was analyzed using a finite-difference time-domain-based numerical simulation. Experiments were setup to validate the numerical results, which showed good agreement with the numerical findings. The results showed that the ultrasonic time-of-flight method is able to detect the concrete infill condition of CFFTs. PMID:27941617

Detection of Fatigue Damage by Using Frequency Attenuation of a Laser Ultrasonic Longitudinal Wave

International Nuclear Information System (INIS)

Park, Seung-Kyu; Baik, Sung-Hoon; Jung, Hyun-Kyu; Joo, Young-Sang; Cha, Hyung-Ki; Kang, Young-June

2006-01-01

The measurement of fatigue damage in nuclear power plant components is very important to prevent a catastrophic accident and the subsequent severe losses. Specifically, it is preferred to detect at an early stage of the fatigue damage. If the fatigue damage that is in danger of growing into a fracture is accurately detected, an appropriate treatment could be carried out to improve the condition. Although most engineers and designers take precautions against fatigue, some breakdowns of nuclear power plant components still occur due to fatigue damage. It is considered that ultrasound testing technique is the most promising method to detect the fatigue damage in many nondestructive testing methods. Ultrasound testing method has a variety of elastic waves, such as a longitudinal wave, a shear wave, a surface wave and a lamb wave. Also we can use various analysis methods, such as a velocity variation and a signal attenuation. Laser ultrasonic testing has attracted attention as a non-contact testing technique. This system consists of a pulse laser to remotely generate ultrasound and a laser interferometer to remotely measure the surface displacement due to the generated ultrasound. This noncontact testing technique has the following advantages over the conventional piezoelectric transducers. Firstly, the inspection system can be remotely operated for a structure in hostile environments, such as in high radioactivity, high temperatures and narrow spaces. Secondly, we can obtain lots of information from the received ultrasonic waveforms because the laser ultrasonic technique does not require fluid couplant which disturbs the ultrasonic waveforms. Thirdly, laser ultrasound has a wideband spectrum and a high spatial resolution. Therefore, the laser ultrasound provides more accurate information for a testing material and has potential for the detection of fatigue damage in various metals composing a nuclear power plant

Ultra-wideband radar sensors and networks

Science.gov (United States)

Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

2013-08-06

Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

Substrate Effects in Wideband SiGe HBT Mixer Circuits

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

2005-01-01

are also applied to predict short distance substrate coupling effects. Simulation results using extracted equivalent circuit models and substrate coupling networks are compared with experimental results obtained on a wideband mixer circuit implemented in a 0.35 μm, 60 GHz ft SiGe HBT BiCMOS process.......In this paper, the influence from substrate effects on the performance of wideband SiGe HBT mixer circuits is investigated. Equivalent circuit models including substrate networks are extracted from on-wafer test structures and compared with electromagnetic simulations. Electromagnetic simulations...

Mutual Coupling Reduction for UWB MIMO Antennas with a Wideband Neutralization Line

DEFF Research Database (Denmark)

Zhang, Shuai; Pedersen, Gert F.

2016-01-01

A wideband neutralization line is proposed to reduce the mutual coupling of a compact ultrawideband (UWB) MIMO antenna. With the introduced decoupling method, the designed UWB MIMO antenna covers the band of 3.1-5 GHz with an isolation of higher than 22 dB. The proposed wideband neutralization line...

Multichannel Baseband Processor for Wideband CDMA

Directory of Open Access Journals (Sweden)

Jim Lin

2005-07-01

Full Text Available The system architecture of the cellular base station modem engine (CBME is described. The CBME is a single-chip multichannel transceiver capable of processing and demodulating signals from multiple users simultaneously. It is optimized to process different classes of code-division multiple-access (CDMA signals. The paper will show that through key functional system partitioning, tightly coupled small digital signal processing cores, and time-sliced reuse architecture, CBME is able to achieve a high degree of algorithmic flexibility while maintaining efficiency. The paper will also highlight the implementation and verification aspects of the CBME chip design. In this paper, wideband CDMA is used as an example to demonstrate the architecture concept.

Wide-band slow-wave systems simulation and applications

CERN Document Server

Staras, Stanislovas

2012-01-01

The field of electromagnetics has seen considerable advances in recent years, based on the wide applications of numerical methods for investigating electromagnetic fields, microwaves, and other devices. Wide-Band Slow-Wave Systems: Simulation and Applications presents new technical solutions and research results for the analysis, synthesis, and design of slow-wave structures for modern electronic devices with super-wide pass-bands. It makes available, for the first time in English, significant research from the past 20 years that was previously published only in Russian and Lithuanian. The aut

Paper-based inkjet-printed ultra-wideband fractal antennas

KAUST Repository

Maza, Armando Rodriguez

2012-01-01

For the first time, paper-based inkjet-printed ultra-wideband (UWB) fractal antennas are presented. Two new designs, a miniaturised UWB monopole, which utilises a fractal matching network and is the smallest reported inkjet-printed UWB printed antenna to date, and a fourth-order Koch Snowflake monopole, which utilises a Sierpinski gasket fractal for ink reduction, are demonstrated. It is shown that fractals prove to be a successful method of reducing fabrication costs in inkjet-printed antennas, while retaining or enhancing printed antenna performance. © 2012 The Institution of Engineering and Technology.

Ultrasonic thermometry for nuclear power plants

International Nuclear Information System (INIS)

Saravana Kumar, S.; Arunraj, A.L.R.; Swaminathan, K.

2013-01-01

Ultrasonic transducer provides a method of measurement of temperature in industrial tanks and boilers containing different liquids with varied salt content. This method is used to measure the average temperature continuously where other traditional methods available do not offer. Traditional methods used for temperature measurement like infrared thermometers, thermocouples, measures temperature at a single location. Numerous thermocouples are to be fixed at various part of the boiler in order to measure the temperature of the entire boiler, which incurs high cost. Reliability of the system decreases, with increasing number of thermocouples. When they fail at a point, the time incurred in finding the faulty part or faulty thermocouple is high. Ultrasonic transducer provides continuous measurement for all different characteristic liquids with higher accuracy and lesser response time. Fault location and clearance time is also less in ultrasonic measurement method, since only a couple of transducers used for the entire boiler structure. Additionally ultrasonic thermometry along support measuring electronic system can be built of low cost. (author)

Fast synthesize ZnO quantum dots via ultrasonic method.

Science.gov (United States)

Yang, Weimin; Zhang, Bing; Ding, Nan; Ding, Wenhao; Wang, Lixi; Yu, Mingxun; Zhang, Qitu

2016-05-01

Green emission ZnO quantum dots were synthesized by an ultrasonic sol-gel method. The ZnO quantum dots were synthesized in various ultrasonic temperature and time. Photoluminescence properties of these ZnO quantum dots were measured. Time-resolved photoluminescence decay spectra were also taken to discover the change of defects amount during the reaction. Both ultrasonic temperature and time could affect the type and amount of defects in ZnO quantum dots. Total defects of ZnO quantum dots decreased with the increasing of ultrasonic temperature and time. The dangling bonds defects disappeared faster than the optical defects. Types of optical defects first changed from oxygen interstitial defects to oxygen vacancy and zinc interstitial defects. Then transformed back to oxygen interstitial defects again. The sizes of ZnO quantum dots would be controlled by both ultrasonic temperature and time as well. That is, with the increasing of ultrasonic temperature and time, the sizes of ZnO quantum dots first decreased then increased. Moreover, concentrated raw materials solution brought larger sizes and more optical defects of ZnO quantum dots. Copyright © 2015 Elsevier B.V. All rights reserved.

Wideband amplifier design

CERN Document Server

Hollister, Allen L

2007-01-01

In this book, the theory needed to understand wideband amplifier design using the simplest models possible will be developed. This theory will be used to develop algebraic equations that describe particular circuits used in high frequency design so that the reader develops a ""gut level"" understanding of the process and circuit. SPICE and Genesys simulations will be performed to show the accuracy of the algebraic models. By looking at differences between the algebraic equations and the simulations, new algebraic models will be developed that include parameters originally left out of the model

An Ultra-wideband and Polarization-independent Metasurface for RCS Reduction.

Science.gov (United States)

Su, Pei; Zhao, Yongjiu; Jia, Shengli; Shi, Wenwen; Wang, Hongli

2016-02-11

In this paper, an ultra-wideband and polarization-independent metasurface for radar cross section (RCS) reduction is proposed. The unit cell of the metasurface operates in a linear cross-polarization scheme in a broad band. The phase and amplitude of cross-polarized reflection can be separately controlled by its geometry and rotation angle. Based on the diffuse reflection theory, a 3-bit coding metasurface is designed to reduce the RCS in an ultra-wide band. The wideband property of the metasurface benefits from the wideband cross polarization conversion and flexible phase modulation. In addition, the polarization-independent feature of the metasurface is achieved by tailoring the rotation angle of each element. Both the simulated and measured results demonstrate that the proposed metasurface can reduce the RCS significantly in an ultra-wide frequency band for both normal and oblique incidences, which makes it promising in the applications such as electromagnetic cloaking.

The effects of ultrasonic solidification on aluminum

OpenAIRE

Đorđević Slavko 1

2003-01-01

The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

The effects of ultrasonic solidification on aluminum

Directory of Open Access Journals (Sweden)

Đorđević Slavko 1

2003-01-01

Full Text Available The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

Ultrasonic neuromodulation

Science.gov (United States)

Naor, Omer; Krupa, Steve; Shoham, Shy

2016-06-01

Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

Uncertainty estimation of ultrasonic thickness measurement

International Nuclear Information System (INIS)

Yassir Yassen, Abdul Razak Daud; Mohammad Pauzi Ismail; Abdul Aziz Jemain

2009-01-01

The most important factor that should be taken into consideration when selecting ultrasonic thickness measurement technique is its reliability. Only when the uncertainty of a measurement results is known, it may be judged if the result is adequate for intended purpose. The objective of this study is to model the ultrasonic thickness measurement function, to identify the most contributing input uncertainty components, and to estimate the uncertainty of the ultrasonic thickness measurement results. We assumed that there are five error sources significantly contribute to the final error, these sources are calibration velocity, transit time, zero offset, measurement repeatability and resolution, by applying the propagation of uncertainty law to the model function, a combined uncertainty of the ultrasonic thickness measurement was obtained. In this study the modeling function of ultrasonic thickness measurement was derived. By using this model the estimation of the uncertainty of the final output result was found to be reliable. It was also found that the most contributing input uncertainty components are calibration velocity, transit time linearity and zero offset. (author)

Wideband two-port beam splitter of a binary fused-silica phase grating.

Science.gov (United States)

Wang, Bo; Zhou, Changhe; Feng, Jijun; Ru, Huayi; Zheng, Jiangjun

2008-08-01

The usual beam splitter of multilayer-coated film with a wideband spectrum is not easy to achieve. We describe the realization of a wideband transmission two-port beam splitter based on a binary fused-silica phase grating. To achieve high efficiency and equality in the diffracted 0th and -1st orders, the grating profile parameters are optimized using rigorous coupled-wave analysis at a wavelength of 1550 nm. Holographic recording and the inductively coupled plasma dry etching technique are used to fabricate the fused-silica beam splitter grating. The measured efficiency of (45% x 2) = 90% diffracted into the both orders can be obtained with the fabricated grating under Littrow mounting. The physical mechanism of such a wideband two-port beam splitter grating can be well explained by the modal method based on two-beam interference of the modes excited by the incident wave. With the high damage threshold, low coefficient of thermal expansion, and wideband high efficiency, the presented beam splitter etched in fused silica should be a useful optical element for a variety of practical applications.

Fourier Collocation Approach With Mesh Refinement Method for Simulating Transit-Time Ultrasonic Flowmeters Under Multiphase Flow Conditions.

Science.gov (United States)

Simurda, Matej; Duggen, Lars; Basse, Nils T; Lassen, Benny

2018-02-01

A numerical model for transit-time ultrasonic flowmeters operating under multiphase flow conditions previously presented by us is extended by mesh refinement and grid point redistribution. The method solves modified first-order stress-velocity equations of elastodynamics with additional terms to account for the effect of the background flow. Spatial derivatives are calculated by a Fourier collocation scheme allowing the use of the fast Fourier transform, while the time integration is realized by the explicit third-order Runge-Kutta finite-difference scheme. The method is compared against analytical solutions and experimental measurements to verify the benefit of using mapped grids. Additionally, a study of clamp-on and in-line ultrasonic flowmeters operating under multiphase flow conditions is carried out.

Effects of operator time pressure and noise on manual ultrasonic testing

International Nuclear Information System (INIS)

Enkvist, J.; Edland, A.; Svenson, O.

2002-01-01

In earlier studies of manual ultrasonic testing, great variations have been found in operator performance, often attributed to operator fatigue. However, no conclusive findings have been reported. In the present study, twenty operators performed manual ultrasonic inspections of six test-pieces with manufactured flaws. The operators performed the inspections under stress (high arousal - time pressure and noise) and no-stress conditions; one condition the first day and the other the second and last day. According to the Yerkes-Dodson Law there is an optimal arousal level where performance is highest. It was hypothesised that the stress condition led to a level of arousal so high that it would affect the results negatively. However, contrary to the hypotheses it was found that the manipulation increased operator performance. Operators with the stress condition day 1 performed better than the other operators (under the no-stress condition). This was interpreted as the 'stress first' (group 1) operators had established efficient performance patterns the first day - affecting also the second day. Operators beginning with stress condition also tended to be more motivated. It was concluded that operator performance is affected by arousal. (author)

Fast optimization method of designing a wideband metasurface without using the Pancharatnam-Berry phase.

Science.gov (United States)

Sui, Sai; Ma, Hua; Lv, Yueguang; Wang, Jiafu; Li, Zhiqiang; Zhang, Jieqiu; Xu, Zhuo; Qu, Shaobo

2018-01-22

Arbitrary control of electromagnetic waves remains a significant challenge although it promises many important applications. Here, we proposed a fast optimization method of designing a wideband metasurface without using the Pancharatnam-Berry (PB) phase, of which the elements are non-absorptive and capable of predicting the wideband and smooth phase-shift. In our design method, the metasurface is composed of low-Q-factor resonant elements without using the PB phase, and is optimized by the genetic algorithm and nonlinear fitting method, having the advantages that the far field scattering patterns can be quickly synthesized by the hybrid array patterns. To validate the design method, a wideband low radar cross section metasurface is demonstrated, showing good feasibility and performance of wideband RCS reduction. This work reveals an opportunity arising from a metasurface in effective manipulation of microwave and flexible fast optimal design method.

Ultrasonic testing

Energy Technology Data Exchange (ETDEWEB)

Song, Sung Jin [Sungkwunkwan Univ., Seoul (Korea, Republic of); Jeong, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of)

2004-02-15

For the proper performance of ultrasonic testing of steel welded joints, and anisotropic material it is necessary to have sound understanding on the underlying physics. To provide such an understanding, it is beneficial to have simulation tools for ultrasonic testing. In order to address such a need, we develop effective approaches to simulate angle beam ultrasonic testing with a personal computer. The simulation is performed using ultrasonic measurement models based on the computationally efficient multi-Gaussian beams. This reach will describe the developed ultrasonic testing models together with the experimental verification of their accuracy.

Ultrasonic divergent-beam scanner for time-of-flight tomography with computer evaluation

Energy Technology Data Exchange (ETDEWEB)

Glover, G H

1978-03-02

The rotatable ultrasonic divergent-beam scanner is designed for time-of-flight tomography with computer evaluation. With it there can be measured parameters that are of importance for the structure of soft tissues, e.g. time as a function of the velocity distribution along a certain path of flight(the method is analogous to the transaxial X-ray tomography). Moreover it permits to perform the quantitative measurement of two-dimensional velocity distributions and may therefore be applied to serial examinations for detecting cancer of the breast. As computers digital memories as well as analog-digital-hybrid systems are suitable.

Semi-blind identification of wideband MIMO channels via stochastic sampling

OpenAIRE

Andrieu, Christophe; Piechocki, Robert J.; McGeehan, Joe P.; Armour, Simon M.

2003-01-01

In this paper we address the problem of wide-band multiple-input multiple-output (MIMO) channel (multidimensional time invariant FIR filter) identification using Markov chains Monte Carlo methods. Towards this end we develop a novel stochastic sampling technique that produces a sequence of multidimensional channel samples. The method is semi-blind in the sense that it uses a very short training sequence. In such a framework the problem is no longer analytically tractable; hence we resort to s...

Numerical Simulation of Ultrasonic Time Reversal Mirror in a Plate with Defect

Czech Academy of Sciences Publication Activity Database

Převorovský, Zdeněk; Krofta, Josef

2008-01-01

Roč. 13, č. 3 (2008), s. 1-5 ISSN 1435-4934. [NDT in Progress. Praha, 05.11.2007-07.11.2007] R&D Projects: GA ČR GA106/07/1393; GA ČR GA103/06/1711 Institutional research plan: CEZ:AV0Z20760514 Keywords : defect detection * nonlinear ultrasonic spectroscopy * time reversal mirror Subject RIV: BI - Acoustics http://www.ndt.net/ search /docs.php3?showForm=off&edit=1&MainSource=53&AuthorID=2812

Method of noncontacting ultrasonic process monitoring

Science.gov (United States)

Garcia, Gabriel V.; Walter, John B.; Telschow, Kenneth L.

1992-01-01

A method of monitoring a material during processing comprising the steps of (a) shining a detection light on the surface of a material; (b) generating ultrasonic waves at the surface of the material to cause a change in frequency of the detection light; (c) detecting a change in the frequency of the detection light at the surface of the material; (d) detecting said ultrasonic waves at the surface point of detection of the material; (e) measuring a change in the time elapsed from generating the ultrasonic waves at the surface of the material and return to the surface point of detection of the material, to determine the transit time; and (f) comparing the transit time to predetermined values to determine properties such as, density and the elastic quality of the material.

Estimating Angle of Arrival (AOA for Wideband Signal by Sensor Delay Line (SDL and Tapped Delay Line (TDL Processors

Directory of Open Access Journals (Sweden)

Bassim Sayed Mohammed

2018-04-01

Full Text Available Angle of arrival (AOA estimation for wideband signal becomes more necessary for modern communication systems like Global System for Mobile (GSM, satellite, military applications and spread spectrum (frequency hopping and direct sequence. Most of the researchers are focusing on how to cancel the effects of signal bandwidth on AOA estimation performance by using a transversal filter (tap delay line (TDL. Most of the researchers were using two elements array antenna to study these effects. In this research, a general case of proposed (M array elements is used. A transversal filter (TDL in phase adaptive array antenna system is used to calculate the optimum number of taps required to compensate these effect. The proposed system uses a phase adaptive array antenna in conjunction with LMS algorithm to work an angle of arrival (AOA estimator for wideband signals rather than interference canceller. An alternative solution to compensate for the effect of signal bandwidth is proposed by using sensor delay line (SDL instead of fixed delay unit since it has variable time sampling in the time domain and not fixed time delay, depending on the angle of arrival of received signals. The proposed system has the ability to estimate two parameters for received signals simultaneously (the output Signal to Noise Ratio (SNR and AOA, unlike others systems which estimate AOA only. The comparison of the simulation results with Multiple Signal Classification (MUSIC technique showed that the proposed system gives good results for estimating AOA and the output SNR for wideband signals. (SDL processor shows better performance result than (TDL processor. MUSIC technique with both (SDL and (TDL processors shows unacceptable results for estimating (AOA for the wideband signal.

Effect of direction on loudness for wideband and reverberant sounds

DEFF Research Database (Denmark)

Sivonen, Ville Pekka; Ellermeier, Wolfgang

2006-01-01

The effect of incidence angle on loudness was investigated for wideband and reverberant sounds. In an adaptive procedure, five listeners matched the loudness of a sound coming from five incidence angles in the horizontal plane to that of the same sound with frontal incidence. The stimuli were...... presented to the listeners via individual binaural synthesis. The results confirm that loudness depends on sound incidence angle, as it does for narrow-band, anechoic sounds. The directional effects, however, were attenuated with the wideband and reverberant stimuli used in the present investigation....

Ultra-wideband RCS reduction using novel configured chessboard metasurface

International Nuclear Information System (INIS)

Zhuang Ya-Qiang; Wang Guang-Ming; Xu He-Xiu

2017-01-01

A novel artificial magnetic conductor (AMC) metasurface is proposed with ultra-wideband 180° phase difference for radar cross section (RCS) reduction. It is composed of two dual-resonant AMC cells, which enable a broadband phase difference of 180°±30° from 7.9 GHz to 19.2 GHz to be achieved. A novel strategy is devised by dividing each rectangular grid in a chessboard configuration into four triangular grids, leading to a further reduction of peak bistatic RCS. Both full-wave simulation and measurement results show that the proposed metasurface presents a good RCS reduction property over an ultra-wideband frequency range. (paper)

First Experimental Impulse-Radio Ultra-Wideband Transmission Under the Russian Spectral Emission Mask

DEFF Research Database (Denmark)

Grakhova, Elizaveta P.; Rommel, Simon; Jurado-Navas, Antonio

2016-01-01

Ultra-wideband impulse-radio wireless transmission under the stringent conditions and complex shape of the Russian spectral emission mask is experimentally demonstrated for the first time. Transmission of 1Gbit/s and 1.25Gbit/s signals over distances of 6m and 3m is achieved with a BER below 3.8×10-3....

Wide-band residual phase-noise measurements on 40-GHz monolithic mode-locked lasers

DEFF Research Database (Denmark)

Larsson, David; Hvam, Jørn Märcher

2005-01-01

We have performed wide-band residual phase-noise measurements on semiconductor 40-GHz mode-locked lasers by employing electrical waveguide components for the radio-frequency circuit. The intrinsic timing jitters of lasers with one, two, and three quantum wells (QW) are compared and our design......-QW laser. There is good agreement between the measured results and existing theory....

Optically addressed ultra-wideband phased antenna array

Science.gov (United States)

Bai, Jian

Demands for high data rate and multifunctional apertures from both civilian and military users have motivated development of ultra-wideband (UWB) electrically steered phased arrays. Meanwhile, the need for large contiguous frequency is pushing operation of radio systems into the millimeter-wave (mm-wave) range. Therefore, modern radio systems require UWB performance from VHF to mm-wave. However, traditional electronic systems suffer many challenges that make achieving these requirements difficult. Several examples includes: voltage controlled oscillators (VCO) cannot provide a tunable range of several octaves, distribution of wideband local oscillator signals undergo high loss and dispersion through RF transmission lines, and antennas have very limited bandwidth or bulky sizes. Recently, RF photonics technology has drawn considerable attention because of its advantages over traditional systems, with the capability of offering extreme power efficiency, information capacity, frequency agility, and spatial beam diversity. A hybrid RF photonic communication system utilizing optical links and an RF transducer at the antenna potentially provides ultra-wideband data transmission, i.e., over 100 GHz. A successful implementation of such an optically addressed phased array requires addressing several key challenges. Photonic generation of an RF source with over a seven-octave bandwidth has been demonstrated in the last few years. However, one challenge which still remains is how to convey phased optical signals to downconversion modules and antennas. Therefore, a feed network with phase sweeping capability and low excessive phase noise needs to be developed. Another key challenge is to develop an ultra-wideband array antenna. Modern frontends require antennas to be compact, planar, and low-profile in addition to possessing broad bandwidth, conforming to stringent space, weight, cost, and power constraints. To address these issues, I will study broadband and miniaturization

Ultra-wideband MMICs for remote sensing applications

DEFF Research Database (Denmark)

Johansen, Tom Keinicke; Vidkjær, Jens; Krozer, Viktor

2003-01-01

This paper presents an overview of the current activity at the Technical University of Denmark in the field of ultra-wideband monolitic microwave integrated circuits (MMICs) for next-generation high-resolution synthetic aperature radar (SAR) systems. The transfer function requirements for MMIC co...

Design and Performance Evaluation on Ultra-Wideband Time-Of-Arrival 3D Tracking System

Science.gov (United States)

Ni, Jianjun; Arndt, Dickey; Ngo, Phong; Dusl, John

2012-01-01

A three-dimensional (3D) Ultra-Wideband (UWB) Time--of-Arrival (TOA) tracking system has been studied at NASA Johnson Space Center (JSC) to provide the tracking capability inside the International Space Station (ISS) modules for various applications. One of applications is to locate and report the location where crew experienced possible high level of carbon-dioxide and felt upset. In order to accurately locate those places in a multipath intensive environment like ISS modules, it requires a robust real-time location system (RTLS) which can provide the required accuracy and update rate. A 3D UWB TOA tracking system with two-way ranging has been proposed and studied. The designed system will be tested in the Wireless Habitat Testbed which simulates the ISS module environment. In this presentation, we discuss the 3D TOA tracking algorithm and the performance evaluation based on different tracking baseline configurations. The simulation results show that two configurations of the tracking baseline are feasible. With 100 picoseconds standard deviation (STD) of TOA estimates, the average tracking error 0.2392 feet (about 7 centimeters) can be achieved for configuration Twisted Rectangle while the average tracking error 0.9183 feet (about 28 centimeters) can be achieved for configuration Slightly-Twisted Top Rectangle . The tracking accuracy can be further improved with the improvement of the STD of TOA estimates. With 10 picoseconds STD of TOA estimates, the average tracking error 0.0239 feet (less than 1 centimeter) can be achieved for configuration "Twisted Rectangle".

Mechanochemical degradation of potato starch paste under ultrasonic irradiation

Institute of Scientific and Technical Information of China (English)

LI Jian-bin; LI Lin; LI Bing; CHEN Ling; GUI Lin

2006-01-01

In the paper, changes in the molecular weight, the intrinsic viscosity and the polydispersity (molecular mass distribution) of treated potato starch paste were studied under different ultrasonic conditions which include irradiation time, ultrasonic intensity, potato starch paste concentration, and distance from probe tip on the degradation of potato starch paste. Intrinsic viscosity of potato starch paste was determined following the ASTM (American Society for Testing and Materials) standard practice for dilute solution viscosity of polymers. Molecular mass and polydispersity of potato starch paste were measured on GPC (Gel Permeation Chromatography). The results showed that the average molecular mass and the intrinsic viscosity of starch strongly depended on irradiation time. Degradation increased with prolonged ultrasonic irradiation time, and the increase of ultrasonic intensity could accelerate the degradation, resulting in a faster degradation rate, a lower limiting value and a higher degradation extent. Starch samples were degraded faster in dilute solutions than in concentrated solutions. The molecular mass and the intrinsic viscosity of starch increased with the increase of distance from probe tip. Our results also showed that the polydispersity decreased with ultrasonic irradiation under all ultrasonic conditions. Ultrasonic degradation of potato starch paste occured based on the mechanism of molecular relaxation of starch paste. In the initial stage, ultrasonic degradation of potato starch paste was a random process, and the molecular mass distribution was broad. After that, ultrasonic degradation of potato starch paste changed to a nonrandom process, and the molecular mass distribution became narrower. Finally, molecular mass distribution tended toward a saturation value.

Up to 35 Gbps Ultra-Wideband Wireless Data Transmission Links

DEFF Research Database (Denmark)

Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

2016-01-01

For the first time Ultra-Wideband record data transmission rates up to 35.1 Gbps and 21.6 Gbps are achieved, compliant with the restrictions on the effective radiated power established by both the United States Federal Communications Commission and the European Electronic Communications Committee......, respectively. To achieve these record bit rates, the multi-band approach of Carrierless Amplitude Phase modulation scheme was employed. Wireless transmissions were achieved with a BER below the 7% FEC threshold of 3.8·10-3 ....

Failed fuel rod detection method by ultrasonic wave

International Nuclear Information System (INIS)

Takamatsu, Masatoshi; Muraoka, Shoichi; Ono, Yukio; Yasojima, Yujiro.

1990-01-01

Ultrasonic wave signals sent from an ultrasonic receiving element are supplied to an evaluation circuit by way of a gate. A table for gate opening and closing timings at the detecting position in each of the fuel rods in a fuel assembly is stored in a memory. A fuel rod is placed between an ultrasonic transmitting element and the receiving element to determine the positions of the transmitting element and the receiving element by positional sensors. The opening and closing timings at the positions corresponding to the result of the detection are read out from the table, and the gates are opened and closed by the timing. This can introduce the ultrasonic wave signals transmitted through a control rod always to the evaluation circuit passing through the gate. Accordingly, the state of failure of the fuel rod can be detected accurately. (I.N.)

Ultra-Wideband Optical Modulation Spectrometer (OMS) Development: Study of the Optical Setup of a Wide-Band Optical Modulation Spectrometer

Science.gov (United States)

Tolls, Volker; Stringfellow, Guy (Technical Monitor)

2001-01-01

The purpose of this study is to advance the design of the optical setup for a wide-band Optical Modulation Spectrometer (OMS) for use with astronomical heterodyne receiver systems. This report describes the progress of this investigation achieved from March until December 2001.

Irradiation Testing of Ultrasonic Transducers

International Nuclear Information System (INIS)

Daw, J.; Rempe, J.; Palmer, J.; Tittmann, B.; Reinhardt, B.; Kohse, G.; Ramuhalli, P.; Montgomery, R.; Chien, H.T.; Villard, J.F.

2013-06-01

Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10 21 n/cm 2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. (authors)

Remote consulting based on ultrasonic digital immages and dynamic ultrasonic sequences

Science.gov (United States)

Margan, Anamarija; Rustemović, Nadan

2006-03-01

Telematic ultrasonic diagnostics is a relatively new tool in providing health care to patients in remote, islolated communities. Our project facility, "The Virtual Polyclinic - A Specialists' Consulting Network for the Islands", is located on the island of Cres in the Adriatic Sea in Croatia and has been extending telemedical services to the archipelago population since 2000. Telemedicine applications include consulting services by specialists at the University Clinical Hospital Center Rebro in Zagreb and at "Magdalena", a leading cardiology clinic in Croatia. After several years of experience with static high resolution ultrasonic digital immages for referral consulting diagnostics purposes, we now also use dynamic ultrasonic sequences in a project with the Department of Emmergency Gastroenterology at Rebro in Zagreb. The aim of the ongoing project is to compare the advantages and shortcomings in transmitting static ultrasonic digital immages and live sequences of ultrasonic examination in telematic diagnostics. Ultrasonic examination is a dynamic process in which the diagnostic accuracy is highly dependent on the dynamic moment of an ultrasound probe and signal. Our first results indicate that in diffuse parenchymal organ pathology the progression and the follow up of a disease is better presented to a remote consulting specialist by dynamic ultrasound sequences. However, the changes that involve only one part of a parenchymal organ can be suitably presented by static ultrasonic digital images alone. Furthermore, we need less time for digital imaging and such tele-consultations overall are more economical. Our previous telemedicine research and practice proved that we can greatly improve the level of medical care in remote healthcare facilities and cut healthcare costs considerably. The experience in the ongoing project points to a conclusion that we can further optimize remote diagnostics benefits by a right choice of telematic application thus reaching a

[Effects of ultrasonic pretreatment on drying characteristics of sewage sludge].

Science.gov (United States)

Li, Run-Dong; Yang, Yu-Ting; Li, Yan-Long; Niu, Hui-Chang; Wei, Li-Hong; Sun, Yang; Ke, Xin

2009-11-01

The high water content of sewage sludge has engendered many inconveniences to its treatment and disposal. While ultrasonic takes on unique advantages on the sludge drying because of its high ultrasonic power, mighty penetrating capability and the ability of causing cavitations. Thus this research studies the characteristics influences of ultrasonic bring to the sludge drying and effects of the exposure time, ultrasonic generator power, temperatures of ultrasonic and drying temperature on the drying characteristics of dewatered sludge. Results indicate that ultrasonic pretreatment could speed up evaporation of the free water in sludge surface and help to end the drying stage with constant speed. In addition, ultrasonic treatment can effectively improve the sludge drying efficiency which could be more evident with the rise of the ultrasonic power (100-250 W), ultrasonic temperature and drying temperature. If dried under low temperature such as 105 degrees C, sludge will have premium drying characteristics when radiated under ultrasound for a shorter time such as 3 min. In the end, the ultrasonic treatment is expected to be an effective way to the low-cost sludge drying and also be an important reference to the optimization of the sludge drying process because of its effects on the increase of sludge drying efficiency.

SHAPE EFFECT OF ANNULAR CONCENTRATOR IN ULTRASONIC SYSTEM ON AMPLIFICATION FACTOR OF VIBRATIONS AMPLITUDE

Directory of Open Access Journals (Sweden)

D. A. Stepanenko

2016-01-01

Full Text Available The paper contains a theoretical underpinning on creation of ultrasonic vibration concentrators based on annular elastic elements with non-circular (ellipse-like eccentric shape of internal contour. Shape of internal contour in polar coordinates is described by Fourier series relative to angular coordinate that consists of a constant term and first and second harmonics. An effect of geometric parameters of the concentrator on amplification factor and natural vibration frequencies has been investigated with the help of a finite element method. The paper reveals the possibility to control an amplification factor of annular concentrators while varying eccentricity of internal contour and mean value of cross-section thickness. The amplification factor satisfies a condition K < N, where N is thickness ratio of amplifier input and output sections, and it is decreasing with increase of vibration mode order. The similar condition has been satisfied for conical bar concentrator with the difference that in the case of bar concentrators an amplification is ensured due to variation of diameter and N will represent ratio of diameters. It has been proved that modification of internal contour shape makes it possible to carry out a wide-band tuning of natural frequencies of concentrator vibrations without alteration of its overall dimensions and substantial change of amplification factor, which is important for frequency matching of the concentrator and ultrasonic vibratory system. Advantages of the proposed concentrators include simplicity of design and manufacturing, small overall dimensions, possibility for natural frequency tuning by means of static load variation. The developed concentrators can find their application in ultrasonic devices and instruments for technological and medical purposes.

Ultrasonic filtration of industrial chemical solutions

Science.gov (United States)

Cosma, T.

1974-01-01

The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

Ultrasonic sectional imaging for crack identification. Part 1. Confirmation test of essential factors for ultrasonic imaging

International Nuclear Information System (INIS)

Sasahara, Toshihiko

2008-01-01

Since the first reports of inter-granular stress corrosion crack (IGSCC) in boiling water reactor (BWR) pipe in the 1970s, nuclear power industry has focused considerable attention on service induced crack detection and sizing using ultrasonic examination. In recent years, phased array systems, those reconstruct high quality flaw images at real time are getting to apply for crack detection and sizing. But because the price of phased array systems are expensive for inspection vendors, field application of phased array systems are limited and reliable ultrasonic imaging systems with reasonable price are expected. This paper will discuss cost effective ultrasonic equipment with sectional image (B-scan) presentation as the simplified imaging system for assisting ultrasonic examination personnel. To develop the simplified B-scan imaging system, the frequency characteristics of IGSCC echoes and neighboring geometry echoes such as base-metal to weld interface and inner surface of a pipe are studied. The experimental study confirmed the reflectors have different frequency characteristics and 2MHz is suitable to visualize IGSCC and 5MHz and higher frequency are suitable to reconstruct geometry images. The other study is the amplifier selection for the imaging system. To reconstruct images of IGSCC and geometry echoes, the ultrasonic imaging instrument with linear amplifier has to adjust gain setting to the target. On the other hand, the ultrasonic imaging instrument with logarithmic amplifier can collect and display wider dynamic range on a screen and this wider dynamic range are effective to visualize IGSCC and geometry echoes on a B-scan presentation at a time. (author)

Rail inspection using noncontact laser ultrasonics

International Nuclear Information System (INIS)

Kim, Nak Hyeon; Sohn, Hoon; Han, Soon Woo

2012-01-01

In this study, a noncontact laser ultrasonic system is proposed for rail defect detection. An Nd Yag pulse laser is used for generation of ultrasonic waves, and the corresponding ultrasonic responses are measured by a laser Doppler vibrometer. For the detection of rail surface damages, the shape of the excitation laser beam is transformed into a line. On the other hand, a point source laser beam is used for the inspection of defects inside a rail head. Then, the interactions of propagating ultrasonic waves with defects are examined using actual rail specimens. Amplitude attenuation was mainly observed for a surface crack, and reflections were most noticeable from an internal damage. Finally, opportunities and challenges associated with real time rail inspection from a high speed train are discussed

Wideband Acoustic Immittance: Normative Study and Test-Retest Reliability of Tympanometric Measurements in Adults

Science.gov (United States)

Sun, Xiao-Ming

2016-01-01

Purpose: The purpose of this study was to present normative data of tympanometric measurements of wideband acoustic immittance and to characterize wideband tympanograms. Method: Data were collected in 84 young adults with strictly defined normal hearing and middle ear status. Energy absorbance (EA) was measured using clicks for 1/12-octave…

Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

Directory of Open Access Journals (Sweden)

Wulandari P.S.

2010-01-01

Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

Wideband propagation measurements at 30.3 GHz through a pecan orchard in Texas

Science.gov (United States)

Papazian, Peter B.; Jones, David L.; Espeland, Richard H.

1992-09-01

Wideband propagation measurements were made in a pecan orchard in Texas during April and August of 1990 to examine the propagation characteristics of millimeter-wave signals through vegetation. Measurements were made on tree obstructed paths with and without leaves. The study presents narrowband attenuation data at 9.6 and 28.8 GHz as well as wideband impulse response measurements at 30.3 GHz. The wideband probe (Violette et al., 1983), provides amplitude and delay of reflected and scattered signals and bit-error rate. This is accomplished using a 500 MBit/sec pseudo-random code to BPSK modulate a 28.8 GHz carrier. The channel impulse response is then extracted by cross correlating the received pseudo-random sequence with a locally generated replica.

Ultrasonic experiment on hydrate formation of a synthesis gas

Energy Technology Data Exchange (ETDEWEB)

Sun, Shicai; Fan, Shuanshi; Liang, Deqing; Zhang, Junshe; Feng, Ziping

2005-07-01

The effect of ultrasonic on the induction time and formation rate of natural gas hydrates was investigated in a stainless steel cell in this study. The results show that the induction time with ultrasonic was about 1/6 of that without ultrasonic and only about 1/10 if rehydration after decomposition in water-gas system. In sodium dodecyl sulfate (SDS) solution-gas system, the critical micellar concentration (CMC) was not identified with ultrasonic. The formation rate and storage capacity of hydrate increased with increasing SDS concentration at a range of 0 to 800ppm. However, the increase was insignificant as the SDS concentration increased from 600 to 800ppm, (Author)

Time-domain ultra-wideband radar, sensor and components theory, analysis and design

CERN Document Server

Nguyen, Cam

2014-01-01

This book presents the theory, analysis, and design of ultra-wideband (UWB) radar and sensor systems (in short, UWB systems) and their components. UWB systems find numerous applications in the military, security, civilian, commercial and medicine fields. This book addresses five main topics of UWB systems: System Analysis, Transmitter Design, Receiver Design, Antenna Design and System Integration and Test. The developments of a practical UWB system and its components using microwave integrated circuits, as well as various measurements, are included in detail to demonstrate the theory, analysis and design technique. Essentially, this book will enable the reader to design their own UWB systems and components. In the System Analysis chapter, the UWB principle of operation as well as the power budget analysis and range resolution analysis are presented. In the UWB Transmitter Design chapter, the design, fabrication and measurement of impulse and monocycle pulse generators are covered. The UWB Receiver Design cha...

Implementation of High Time Delay Accuracy of Ultrasonic Phased Array Based on Interpolation CIC Filter.

Science.gov (United States)

Liu, Peilu; Li, Xinghua; Li, Haopeng; Su, Zhikun; Zhang, Hongxu

2017-10-12

In order to improve the accuracy of ultrasonic phased array focusing time delay, analyzing the original interpolation Cascade-Integrator-Comb (CIC) filter, an 8× interpolation CIC filter parallel algorithm was proposed, so that interpolation and multichannel decomposition can simultaneously process. Moreover, we summarized the general formula of arbitrary multiple interpolation CIC filter parallel algorithm and established an ultrasonic phased array focusing time delay system based on 8× interpolation CIC filter parallel algorithm. Improving the algorithmic structure, 12.5% of addition and 29.2% of multiplication was reduced, meanwhile the speed of computation is still very fast. Considering the existing problems of the CIC filter, we compensated the CIC filter; the compensated CIC filter's pass band is flatter, the transition band becomes steep, and the stop band attenuation increases. Finally, we verified the feasibility of this algorithm on Field Programming Gate Array (FPGA). In the case of system clock is 125 MHz, after 8× interpolation filtering and decomposition, time delay accuracy of the defect echo becomes 1 ns. Simulation and experimental results both show that the algorithm we proposed has strong feasibility. Because of the fast calculation, small computational amount and high resolution, this algorithm is especially suitable for applications with high time delay accuracy and fast detection.

Implementation of High Time Delay Accuracy of Ultrasonic Phased Array Based on Interpolation CIC Filter

Directory of Open Access Journals (Sweden)

Peilu Liu

2017-10-01

Full Text Available In order to improve the accuracy of ultrasonic phased array focusing time delay, analyzing the original interpolation Cascade-Integrator-Comb (CIC filter, an 8× interpolation CIC filter parallel algorithm was proposed, so that interpolation and multichannel decomposition can simultaneously process. Moreover, we summarized the general formula of arbitrary multiple interpolation CIC filter parallel algorithm and established an ultrasonic phased array focusing time delay system based on 8× interpolation CIC filter parallel algorithm. Improving the algorithmic structure, 12.5% of addition and 29.2% of multiplication was reduced, meanwhile the speed of computation is still very fast. Considering the existing problems of the CIC filter, we compensated the CIC filter; the compensated CIC filter’s pass band is flatter, the transition band becomes steep, and the stop band attenuation increases. Finally, we verified the feasibility of this algorithm on Field Programming Gate Array (FPGA. In the case of system clock is 125 MHz, after 8× interpolation filtering and decomposition, time delay accuracy of the defect echo becomes 1 ns. Simulation and experimental results both show that the algorithm we proposed has strong feasibility. Because of the fast calculation, small computational amount and high resolution, this algorithm is especially suitable for applications with high time delay accuracy and fast detection.

Recent progress in online ultrasonic process monitoring

Science.gov (United States)

Wen, Szu-Sheng L.; Chen, Tzu-Fang; Ramos-Franca, Demartonne; Nguyen, Ky T.; Jen, Cheng-Kuei; Ihara, Ikuo; Derdouri, A.; Garcia-Rejon, Andres

1998-03-01

On-line ultrasonic monitoring of polymer co-extrusion and gas-assisted injection molding are presented. During the co- extrusion of high density polyethylene and Santoprene ultrasonic sensors consisting of piezoelectric transducers and clad ultrasonic buffer rods are used to detect the interface between these two polymers and the stability of the extrusion. The same ultrasonic sensor also measures the surface temperature of the extruded polymer. The results indicate that temperature measurements using ultrasound have a faster response time than those obtained by conventional thermocouple. In gas-assisted injection molding the polymer and gas flow front positions are monitored simultaneously. This information may be used to control the plunger movement.

Ultrasonic Cleaning of Nuclear Steam Generator by Micro Bubble

Energy Technology Data Exchange (ETDEWEB)

Jeong, Woo Tae [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of); Kim, Sang Tae; Yoon, Sang Jung [Sae-An Engineering Co., Seoul (Korea, Republic of)

2012-05-15

In this paper, we present ultrasonic cleaning technology for a nuclear steam generator using micro bubble. We could extend the boundary of ultrasonic cleaning by using micro bubbles in water. Ultrasonic energy measured was increased about 5 times after the generation of micro bubbles in water. Furthermore, ultrasound energy was measured to be strong enough to create cavitation even though the ultrasound sensor was about 2 meters away from the ultrasonic transducer

Ultrasonic signature

International Nuclear Information System (INIS)

Borloo, E.; Crutzen, S.

1974-12-01

The unique and tamperproof identification technique developed at Ispra is based on ultrasonic Non-Destructive-Techniques. Reading fingerprints with ultrasonic requires high reproducibility of standard apparatus and transducers. The present report gives an exhaustive description of the ultrasonic technique developed for identification purposes. Different applications of the method are described

Wavelet Analysis of Ultrasonic Echo Waveform and Application to Nondestructive Evaluation

International Nuclear Information System (INIS)

Park, Ik Keun; Park, Un Su; Ahn, Hyung Keun; Kwun, Sook In; Byeon, Jai Won

2000-01-01

Recently, advanced signal analysis which is called 'time-frequency analysis' has been used widely in nondestructive evaluation applications. Wavelet transform(WT) and Wigner Distribution are the most advanced techniques for processing signals with time-varying spectra. Wavelet analysis method is an attractive technique for evaluation of material characterization nondestructively. Wavelet transform is applied to the time-frequency analysis of ultrasonic echo waveform obtained by an ultrasonic pulse-echo technique. In this study, the feasibility of noise suppression of ultrasonic flaw signal and frequency-dependent ultrasonic group velocity and attenuation coefficient using wavelet analysis of ultrasonic echo waveform have been verified experimentally. The Gabor function is adopted the analyzing wavelet. The wavelet analysis shows that the variations of ultrasonic group velocity and attenuation coefficient due to the change of material characterization can be evaluated at each frequency. Furthermore, to assure the enhancement of detectability and new sizing performance, both computer simulated results and experimental measurements using wavelet signal processing are used to demonstrate the effectiveness of the noise suppression of ultrasonic flaw signal obtained from austenitic stainless steel weld including EDM notch

Photonic Ultra-Wideband 781.25-Mb/s Signal Generation and Transmission Incorporating Digital Signal Processing Detection

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

2009-01-01

The generation of photonic ultra-wideband (UWB) impulse signals using an uncooled distributed-feedback laser is proposed. For the first time, we experimentally demonstrate bit-for-bit digital signal processing (DSP) bit-error-rate measurements for transmission of a 781.25-Mb/s photonic UWB signal...

Age effects in the human middle ear: Wideband acoustical measures

Science.gov (United States)

Feeney, M. Patrick; Sanford, Chris A.

2004-12-01

Studies that have examined age effects in the human middle ear using either admittance measures at 220 or 660 Hz or multifrequency tympanometry from 200 to 2000 Hz have had conflicting results. Several studies have suggested an increase in admittance with age, while several others have suggested a decrease in admittance with age. A third group of studies found no significant age effect. This study examined 226 Hz tympanometry and wideband energy reflectance and impedance at ambient pressure in a group of 40 young adults and a group of 30 adults with age >=60 years. The groups did not differ in admittance measures of the middle ear at 226 Hz. However, significant age effects were found in wideband energy reflectance and impedance. In particular, in older adults there was a comparative decrease in reflectance from 800 to 2000 Hz but an increase near 4000 Hz. The results suggest a decrease in middle-ear stiffness with age. The findings of this study hold relevance for understanding the aging process in the auditory system, for the establishment of normative data for wideband energy reflectance, for the possibility of a conductive component to presbycusis, and for the interpretation of otoacoustic emission measurements. .

An inverse method for crack characterization from ultrasonic B-Scan images

International Nuclear Information System (INIS)

Faur, M.; Roy, O.; Benoist, PH.; Morisseau, PH.

1996-01-01

Concern has been expressed about the capabilities of performing non destructive evaluation (NDE) of flaws located near to the outer surface in nuclear pressurized water reactor (PWR) vessels. The ultrasonic examination of PWR is accomplished from the inside with ultrasonic focused transducers working in the pulse echo mode. By recording the echoes as a function of time, the Ascan representation may be obtained. Many ultrasonic flaw detectors used for NDE are based on the simple Ascan concept involving measuring a time interval called 'time of flight'. By combining the Ascan concept synchronized transducer scanning, one can produce Bscan images that are two dimensional descriptions of the flaw interaction with the ultrasonic field. In the following, the flaw is assumed to be an axially oriented crack (the most serious flaw to be found in a pressurized component). In the case of the outer surface cracks (OSC's), analyzing and interpreting ultrasonic Ascan images become difficult because of the various reflections of the ultrasonic beam on the crack and on the outer surface (the so-called corner effect). Methods for automatic interpretation of ultrasonic experimental data are currently under investigation. In this paper, we present an inverse method for determining the geometrical characteristics of OSC's from ultrasonic Bscan images. The direct model used for the inversion procedure predicts synthetic Bscan images of ultrasonic examination of blocks containing planar defects interrogated by focused probes. (authors)

Experimental determination of wellbore diameter and shape (4D imaging of wellbore) by using ultrasonic caliper within different fluids for real-time drilling application

Energy Technology Data Exchange (ETDEWEB)

Elahifar, Behzad; Esmaeili, Abdolali; Thonhauser, Gerhard [Montanuniversitaet Leoben (Austria); Fruhwirth, Rudolf K. [TDE Thonhauser Data Engineering GmbH, Leoben (Austria)

2013-03-15

Drilling programs continue to push into new and more complicated environments. As a result, accurate measurement, interpretation and analysis of drilling data in real time are becoming more critical. One of the key measurement devices for drilling, cementing and formation evaluation is the borehole caliper. An ultrasonic sensor caliper tool is thereby a key measurement device for determining the borehole diameter in MWD or LWD tools. Another use of ultrasonic caliper tools is to offer a method for calculating borehole volumes. Real-time application of ultrasonic caliper tools can also support the early detection of borehole instability. This paper describes the experiments related to the accuracy of the ultrasonic sensor for measuring wellbore diameter by performing the tests in different fluids, comparing the results and determining the weak points of the sensor for detecting echoes. In addition the wellbore profiles were simulated and the simulated results were compared with the recorded data. Different tests related to the position of the caliper tool inside the wellbore were performed as well as the evaluation of the accuracy of the ultrasonic sensor by simulating dog-legs and latches. (orig.)

47 CFR 15.250 - Operation of wideband systems within the band 5925-7250 MHz.

Science.gov (United States)

2010-10-01

... of wideband systems within the band 5925-7250 MHz. (a) The −10 dB bandwidth of a device operating... 47 Telecommunication 1 2010-10-01 2010-10-01 false Operation of wideband systems within the band... variations in temperature and supply voltage. (b) The −10 dB bandwidth of the fundamental emission shall be...

Ultrasonic nondestructive materials characterization

Science.gov (United States)

Green, R. E., Jr.

1986-01-01

A brief review of ultrasonic wave propagation in solid materials is presented with consideration of the altered behavior in anisotropic and nonlinear elastic materials in comparison with isotropic and linear elastic materials. Some experimental results are described in which ultrasonic velocity and attenuation measurements give insight into materials microstructure and associated mechanical properties. Recent developments with laser beam non-contact generation and detection of ultrasound are presented. The results of several years of experimental measurements using high-power ultrasound are discussed, which provide substantial evidence of the inability of presently accepted theories to fully explain the interaction of ultrasound with solid materials. Finally, a special synchrotron X-ray topographic system is described which affords the possibility of observing direct interaction of ultrasonic waves with the microstructural features of real crystalline solid materials for the first time.

Aliasing-free wideband beamforming using sparse signal representation

NARCIS (Netherlands)

Tang, Z.; Blacquière, G.; Leus, G.

2011-01-01

Sparse signal representation (SSR) is considered to be an appealing alternative to classical beamforming for direction-of-arrival (DOA) estimation. For wideband signals, the SSR-based approach constructs steering matrices, referred to as dictionaries in this paper, corresponding to different

Ultrasonic horn design for ultrasonic machining technologies

Directory of Open Access Journals (Sweden)

Naď M.

2010-07-01

Full Text Available Many of industrial applications and production technologies are based on the application of ultrasound. In many cases, the phenomenon of ultrasound is also applied in technological processes of the machining of materials. The main element of equipments that use the effects of ultrasound for machining technology is the ultrasonic horn – so called sonotrode. The performance of ultrasonic equipment, respectively ultrasonic machining technologies depends on properly designed of sonotrode shape. The dynamical properties of different geometrical shapes of ultrasonic horns are presented in this paper. Dependence of fundamental modal properties (natural frequencies, mode shapes of various sonotrode shapes for various geometrical parameters is analyzed. Modal analyses of the models are determined by the numerical simulation using finite element method (FEM design procedures. The mutual comparisons of the comparable parameters of the various sonotrode shapes are presented.

Wideband Impulse Modulation and Receiver Algorithms for Multiuser Power Line Communications

Directory of Open Access Journals (Sweden)

Andrea M. Tonello

2007-01-01

Full Text Available We consider a bit-interleaved coded wideband impulse-modulated system for power line communications. Impulse modulation is combined with direct-sequence code-division multiple access (DS-CDMA to obtain a form of orthogonal modulation and to multiplex the users. We focus on the receiver signal processing algorithms and derive a maximum likelihood frequency-domain detector that takes into account the presence of impulse noise as well as the intercode interference (ICI and the multiple-access interference (MAI that are generated by the frequency-selective power line channel. To reduce complexity, we propose several simplified frequency-domain receiver algorithms with different complexity and performance. We address the problem of the practical estimation of the channel frequency response as well as the estimation of the correlation of the ICI-MAI-plus-noise that is needed in the detection metric. To improve the estimators performance, a simple hard feedback from the channel decoder is also used. Simulation results show that the scheme provides robust performance as a result of spreading the symbol energy both in frequency (through the wideband pulse and in time (through the spreading code and the bit-interleaved convolutional code.

Broadband and High Sensitive Time-of-Flight Diffraction Ultrasonic Transducers Based on PMNT/Epoxy 1–3 Piezoelectric Composite

Directory of Open Access Journals (Sweden)

Dongxu Liu

2015-03-01

Full Text Available 5–6 MHz PMNT/epoxy 1–3 composites were prepared by a modified dice-and-fill method. They exhibit excellent properties for ultrasonic transducer applications, such as ultrahigh thickness electromechanical coupling coefficient kt (85.7%, large piezoelectric coefficient d33 (1209 pC/N, and relatively low acoustic impedance Z (1.82 × 107 kg/(m2·s. Besides, two types of Time-of-Flight Diffraction (TOFD ultrasonic transducers have been designed, fabricated, and characterized, which have different matching layer schemes with the acoustic impedance of 4.8 and 5.7 × 106 kg/(m2·s, respectively. In the detection on a backwall of 12.7 mm polystyrene, the former exhibits higher detectivity, the relative pulse-echo sensitivity and −6 dB relative bandwidth are −21.93 dB and 102.7%, respectively, while the later exhibits broader bandwidth, the relative pulse-echo sensitivity and −6 dB relative bandwidth are −24.08 dB and 117.3%, respectively. These TOFD ultrasonic transducers based on PMNT/epoxy 1–3 composite exhibit considerably improved performance over the commercial PZT/epoxy 1–3 composite TOFD ultrasonic transducer.

Ultrasonic Characterization of Superhard Material: Osmium Diboride

International Nuclear Information System (INIS)

Yadawa, P K

2012-01-01

Higher order elastic constants have been calculated in hexagonal structured superhard material OsB 2 at room temperature following the interaction potential model. The temperature variation of the ultrasonic velocities is evaluated along different angles with unique axis of the crystal using the second order elastic constants. The ultrasonic velocity decreases with the temperature along particular orientation with the unique axis. Temperature variation of the thermal relaxation time and Debye average velocities are also calculated along the same orientation. The temperature dependency of the ultrasonic properties is discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behaviour of ultrasonic attenuation as a function of temperature and the responsible cause of attenuation is phonon-phonon interaction. The mechanical properties of OsB 2 at low temperature are better than at high temperature, because at low temperature it has low ultrasonic velocity and ultrasonic attenuation. Superhard material OsB 2 has many industrial applications, such as abrasives, cutting tools and hard coatings.

Short-time ultrasonication treatment in enzymatic hydrolysis of biomass

Science.gov (United States)

Zengqian Shi; Zhiyong Cai; Siqun Wang; Qixin Zhong; Joseph J. Bozell

2013-01-01

To improve the conversion of enzymatic hydrolysis of biomass in an energy-efficient manner, two shorttime ultrasonication strategies were applied on six types of biomass with different structures and components. The strategies include pre-sonication before the hydrolysis and intermittent sonication during the ongoing hydrolysis. The microstructures of each type of...

A Delay Time Measurement of ULTRAS (Ultra-high Temperature Ultrasonic Response Analysis System) for a High Temperature Experiment

International Nuclear Information System (INIS)

Koo, Kil Mo; Kim, Sang Baik

2010-01-01

The temperature measurement of very high temperature core melt is of importance in a high temperature as the molten pool experiment in which gap formation between core melt and the reactor lower head, and the effect of the gap on thermal behavior are to be measured. The existing temperature measurement techniques have some problems, which the thermocouple, one of the contact methods, is restricted to under 2000 .deg. C, and the infrared thermometry, one of the non-contact methods, is unable to measure an internal temperature and very sensitive to the interference from reacted gases. In order to solve these problems, the delay time technique of ultrasonic wavelets due to high temperature has two sorts of stage. As a first stage, a delay time measurement of ULTRAS (Ultra-high Temperature Ultrasonic Response Analysis System) is suggested. As a second stage, a molten material temperature was measured up to 2300 .deg. C. Also, the optimization design of the UTS (ultrasonic temperature sensor) with persistence at the high temperature was suggested in this paper. And the utilization of the theory suggested in this paper and the efficiency of the developed system are performed by special equipment and some experiments supported by KRISS (Korea Research Institute of Standard and Science)

DOD Use of Commercial Wideband Satellite Communications Systems: How Much is Needed, and How Do We Get It?

National Research Council Canada - National Science Library

Hutchens, Robert

2001-01-01

..., A key enabler to this end is sufficient wideband satellite communications connectivity DoD's organic wideband satellite communications capabilities are inadequate, so commercial services must be used...

Adaptive Space-Time-Spreading-Assisted Wideband CDMA Systems Communicating over Dispersive Nakagami- Fading Channels

Directory of Open Access Journals (Sweden)

Yang Lie-Liang

2005-01-01

Full Text Available In this contribution, the performance of wideband code-division multiple-access (W-CDMA systems using space-time-spreading- (STS- based transmit diversity is investigated, when frequency-selective Nakagami- fading channels, multiuser interference, and background noise are considered. The analysis and numerical results suggest that the achievable diversity order is the product of the frequency-selective diversity order and the transmit diversity order. Furthermore, both the transmit diversity and the frequency-selective diversity have the same order of importance. Since W-CDMA signals are subjected to frequency-selective fading, the number of resolvable paths at the receiver may vary over a wide range depending on the transmission environment encountered. It can be shown that, for wireless channels where the frequency selectivity is sufficiently high, transmit diversity may be not necessitated. Under this case, multiple transmission antennas can be leveraged into an increased bitrate. Therefore, an adaptive STS-based transmission scheme is then proposed for improving the throughput of W-CDMA systems. Our numerical results demonstrate that this adaptive STS-based transmission scheme is capable of significantly improving the effective throughput of W-CDMA systems. Specifically, the studied W-CDMA system's bitrate can be increased by a factor of three at the modest cost of requiring an extra 0.4 dB or 1.2 dB transmitted power in the context of the investigated urban or suburban areas, respectively.

Extrinsic Fabry-Perot ultrasonic detector

Science.gov (United States)

Kidwell, J. J.; Berthold, John W., III

1996-10-01

We characterized the performance of a commercial fiber optic extrinsic Fabry-Perot interferometer for use as an ultrasonic sensor, and compared the performance with a standard lead zirconate titanate (PZT) detector. The interferometer was unstabilized. The results showed that the fiber sensor was about 12 times less sensitive than the PZT detector. Ultrasonic frequency response near 100 kHz was demonstrated. We describe the design of the fiber sensor, the details of the tests performed, and potential applications.

Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium

International Nuclear Information System (INIS)

Kohara, Richard Yuzo Ramida

2015-01-01

This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide

DEFF Research Database (Denmark)

Xiao, Binggang; Li, Sheng-Hua; Xiao, Sanshui

2016-01-01

Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide is proposed. Owing to subwavelength confinement, such a filter has advantage in the structure size without sacrificing the performance. The spoof SPP based notch is introduced to suppress the WLAN and satel......Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide is proposed. Owing to subwavelength confinement, such a filter has advantage in the structure size without sacrificing the performance. The spoof SPP based notch is introduced to suppress the WLAN...

35 Gb/s Ultra-wideband Technology for Advanced Communications

DEFF Research Database (Denmark)

Puerta Ramírez, Rafael; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

be applied, evolving from classic spectral inefficient pulsebased systems to more advanced and flexible modulation schemes. Ultra-wideband technology is suitable for low-power high-speed wireless communication systems over short distances, and is an appealing alternative for next generation networks ranging......The fast development of electronics and portable devices, intended mainly for multimedia applications, is increasing exponentially the data traffic demands per user. To cope with these new data demands in limited bandwidth systems, new technologies must be explored and new transmission schemes must...... from high-speed wireless personal area networks, to the internet of things applications. Its popularity stems from the fact that they can be used as an overlay to existing systems, without interference, operating in parallel to existing wireless systems, which perceive ultra-wideband emissions...

Thermal Studies on the SPS Wideband Transverse Feedback Kicker

CERN Document Server

Roggen, Toon; Hofle, Wolfgang; Montesinos, Eric; CERN. Geneva. ATS Department

2016-01-01

As part of the SPS wideband transverse feedback system in the framework of the LHC Injector Upgrade (LIU) project, a wideband kicker design is being proposed. Vertical beam instabilities due to intensity dependent effects (electron cloud instability (ECI) and transverse mode coupling instability (TMCI)) are potentially suppressed by using a feedback system driving such a kicker system. One of the options for a kicker is a one meter long slotted-coaxial kicker, providing a substantial vertical kick strength (10ˉ5 –10ˉ4 eV.s/m) over a bandwidth ranging from nearly DC to 1 GHz. The necessary kick strength requires a total power of 4 kW. This note describes thermal studies that assisted in the material choice of the feedthroughs of the slotted-coaxial kicker and guided the design choices.

Non-linear ultrasonic time-reversal mirrors in NDT

Czech Academy of Sciences Publication Activity Database

Převorovský, Zdeněk

-, č. 4 (2012), s. 4-4 [World Conference on Nondestructive Testing /18./. 16.4.2012-20.4.2012, Durban] R&D Projects: GA MPO(CZ) FR-TI1/274; GA MPO(CZ) FR-T1/198; GA ČR(CZ) GAP104/10/1430 Institutional research plan: CEZ:AV0Z2076919 Keywords : non-linear ime reversal mirror * ultrasonic techniques * ESAM Subject RIV: BI - Acoustics http://www.academia-ndt.org/Downloads/AcademiaNews4.pdf

Ultrasonic inspection

International Nuclear Information System (INIS)

Satittada, Gannaga

1984-01-01

Ultrasonic inspection is one of the most widely used methods for nondestructive inspection. The beam of high-frequency sound wave, ultrasonic wave, is introduced into the material. It travels through the material with some attendant loss of energy and can be reflected at interfaces. The reflected beam is detected and analyzed. Ultrasonic inspection is used to detect flaws in metal parts as well as in welded, brazed and bonded joints during research work and developing production and service. It is also used to detect and locate porosity, pipe, and flakes. In addition, it can be used for the measurement of metal thickness. Ultrasonic inspection is therefore used for quality control and material inspection in all major industries

Wideband aural acoustic absorbance predicts conductive hearing loss in children.

Science.gov (United States)

Keefe, Douglas H; Sanford, Chris A; Ellison, John C; Fitzpatrick, Denis F; Gorga, Michael P

2012-12-01

This study tested the hypothesis that wideband aural absorbance predicts conductive hearing loss (CHL) in children medically classified as having otitis media with effusion. Absorbance was measured in the ear canal over frequencies from 0.25 to 8 kHz at ambient pressure or as a swept tympanogram. CHL was defined using criterion air-bone gaps of 20, 25, and 30 dB at octaves from 0.25 to 4 kHz. A likelihood-ratio predictor of CHL was constructed across frequency for ambient absorbance, and across frequency and pressure for absorbance tympanometry. Performance was evaluated at individual frequencies and for any frequency at which a CHL was present. Absorbance and conventional 0.226-kHz tympanograms were measured in children of age three to eight years with CHL and with normal hearing. Absorbance was smaller at frequencies above 0.7 kHz in the CHL group than the control group. Based on the area under the receiver operating characteristic curve, wideband absorbance in ambient and tympanometric tests were significantly better predictors of CHL than tympanometric width, the best 0.226-kHz predictor. Accuracies of ambient and tympanometric wideband absorbance did not differ. Absorbance accurately predicted CHL in children and was more accurate than conventional 0.226-kHz tympanometry.

Enhancement of ultrasonic disintegration of sewage sludge by aeration.

Science.gov (United States)

Zhao, He; Zhang, Panyue; Zhang, Guangming; Cheng, Rong

2016-04-01

Sonication is an effective way for sludge disintegration, which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge. But high energy consumption limits the wide application of sonication. In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption, aeration was introduced. Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound. The aeration flow rate, gas bubble size, ultrasonic density and aeration timing had impacts on sludge disintegration efficiency. Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate, small gas bubbles significantly improved ultrasonic disintegration sludge efficiency. At the optimal conditions of 0.4 W/mL ultrasonic irradiation density, 30 mL/min of aeration flow rate, 5 min of aeration in later stage and small gas bubbles, ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved. This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge. Copyright © 2015. Published by Elsevier B.V.

Monostatic ultra-wideband GPR antenna for through wall detection

Directory of Open Access Journals (Sweden)

Ali Jawad

2017-01-01

Full Text Available The aim of this paper is to present a monostatic arc-shaped ultra-wideband (UWB printed monopole antenna system with 3-16 GHz frequency bandwidth suitable for through-wall detection. Ground penetrating radar (GPR technique is used for detection with the gain of 6.2 dB achieved for the proposed antenna using defected ground structure (DGS method. To serve the purpose, a simulation experiment of through-wall detection model is constructed which consists of a monostatic antenna act as transmitter and receiver, concrete wall and human skin model. The time domain reflection of obtained result is then analysed for target detection.

On line ultrasonic integrated backscatter

International Nuclear Information System (INIS)

Landini, L.; Picano, E.; Mazzarisi, A.; Santarelli, F.; Benassi, A.; De Pieri, G.

1988-01-01

A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

Energy-Based Analysis of Ultrasonically Assisted Turning

Directory of Open Access Journals (Sweden)

G.A. Volkov

2011-01-01

Full Text Available The process of ultrasonically-assisted turning (UAT is a superposition of vibration of a cutting tool on its standard movement in conventional turning (CT. The former technique has several advantages compared with the latter, one of the main being a significant decrease in the level of cutting forces. In this paper the effects observed in UAT are analysed employing ideas of dynamic fracture mechanics. The active stage of loading duration depends heavily on ultrasonic frequency and the cutting speed; he application of the fracture criterion based on the notion of incubation time makes it possible to calculate a dependence of this duration on its threshold amplitude. An estimation of energy, necessary to create a threshold pulse in the material, is made by solving the contact Hertz problem. The obtained time dependence of energy has a marked minimum. Thus, the existence of energy-efficient loading duration is demonstrated. This explains the decrease in the cutting force resulting from superimposed ultrasonic vibration. The obtained results are in agreement with experiments on ultrasonic assisted machining of aluminium and Inconel 718 alloy.

Wideband Dual-Polarization Patch Antenna Array With Parallel Strip Line Balun Feeding

DEFF Research Database (Denmark)

Zhang, Jin; Lin, Xianqi; Nie, Liying

2016-01-01

A wideband dual-polarization patch antenna array is proposed in this letter. The array is fed by a parallel strip line balun, which is adopted to generate 180° phase shift in a wide frequency range. In addition, this balun has simple structure, very small phase shift error, and good ports isolati...... is higher than 30 dB. The simulation and measurement turns out to be similar. This antenna array can be used in TD-LTE base stations, and the design methods are also useful to other wideband microstrip antennas....

Development of an ultrasonic process for soil remediation

International Nuclear Information System (INIS)

Wu, J.M.; Huang, H.S.; Livengood, C.D.

1995-01-01

An ultrasonic process for the detoxification of carbon tetrachloride- (CCl 4 - ) contaminated soil was investigated in the laboratory by using a batch irradiation reactor equipped with a 600-W ultrasonic power supply operated at a frequency of 20 kHz. Key parameters studied included soil characteristics, irradiation time, CCl 4 concentration, steady-state operating temperature, applied ultrasonic-wave energy, and the ratio of soil to water in the system. The results of the experiments showed that (1) residual CCl 4 concentrations could be decreased with longer irradiation periods and (2) detoxification efficiency was proportional to steady-state operating temperature and applied ultrasonic-wave energy. The characteristics of the contaminated soil were found to be an important factor in the design of an ultrasonic detoxification system. A soil-phase CCl 4 concentration below 1 ppm (initial concentration of 56 ppm) was achieved through this process, indicating that the application of ultrasonic irradiation is feasible and effective in the detoxification of soil contaminated by organic compounds. On the basis of the experimental results, a schematic of a full-scale ultrasonic soil-detoxification system was developed. Improvements to this novel process are discussed

Wideband radar cross section reduction using two-dimensional phase gradient metasurfaces

Energy Technology Data Exchange (ETDEWEB)

Li, Yongfeng; Qu, Shaobo; Wang, Jiafu; Chen, Hongya [College of Science, Air Force Engineering University, Xi' an, Shaanxi 710051 (China); Zhang, Jieqiu [College of Science, Air Force Engineering University, Xi' an, Shaanxi 710051 (China); Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Xu, Zhuo [Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Zhang, Anxue [School of Electronics and Information Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

2014-06-02

Phase gradient metasurface (PGMs) are artificial surfaces that can provide pre-defined in-plane wave-vectors to manipulate the directions of refracted/reflected waves. In this Letter, we propose to achieve wideband radar cross section (RCS) reduction using two-dimensional (2D) PGMs. A 2D PGM was designed using a square combination of 49 split-ring sub-unit cells. The PGM can provide additional wave-vectors along the two in-plane directions simultaneously, leading to either surface wave conversion, deflected reflection, or diffuse reflection. Both the simulation and experiment results verified the wide-band, polarization-independent, high-efficiency RCS reduction induced by the 2D PGM.

Wideband radar cross section reduction using two-dimensional phase gradient metasurfaces

International Nuclear Information System (INIS)

Li, Yongfeng; Qu, Shaobo; Wang, Jiafu; Chen, Hongya; Zhang, Jieqiu; Xu, Zhuo; Zhang, Anxue

2014-01-01

Phase gradient metasurface (PGMs) are artificial surfaces that can provide pre-defined in-plane wave-vectors to manipulate the directions of refracted/reflected waves. In this Letter, we propose to achieve wideband radar cross section (RCS) reduction using two-dimensional (2D) PGMs. A 2D PGM was designed using a square combination of 49 split-ring sub-unit cells. The PGM can provide additional wave-vectors along the two in-plane directions simultaneously, leading to either surface wave conversion, deflected reflection, or diffuse reflection. Both the simulation and experiment results verified the wide-band, polarization-independent, high-efficiency RCS reduction induced by the 2D PGM.

Numerical shaping of the ultrasonic wavelet

International Nuclear Information System (INIS)

Bonis, M.

1991-01-01

Improving the performance and the quality of ultrasonic testing requires the numerical control of the shape of the driving signal applied to the piezoelectric transducer. This allows precise shaping of the ultrasonic field wavelet and corrections for the physical defects of the transducer, which are mainly due to the damper or the lens. It also does away with the need for an accurate electric matching. It then becomes feasible to characterize, a priori, the ultrasonic wavelet by means of temporal and/or spectral specifications and to use, subsequently, an adaptative algorithm to calculate the corresponding driving wavelet. Moreover, the versatility resulting from the numerical control of this wavelet allows it to be changed in real time during a test

Coding/modulation trade-offs for Shuttle wideband data links

Science.gov (United States)

Batson, B. H.; Huth, G. K.; Trumpis, B. D.

1974-01-01

This paper describes various modulation and coding schemes which are potentially applicable to the Shuttle wideband data relay communications link. This link will be capable of accommodating up to 50 Mbps of scientific data and will be subject to a power constraint which forces the use of channel coding. Although convolutionally encoded coherent binary PSK is the tentative signal design choice for the wideband data relay link, FM techniques are of interest because of the associated hardware simplicity and because an FM system is already planned to be available for transmission of television via relay satellite to the ground. Binary and M-ary FSK are considered as candidate modulation techniques, and both coherent and noncoherent ground station detection schemes are examined. The potential use of convolutional coding is considered in conjunction with each of the candidate modulation techniques.

A Resistive Wideband Space Beam Splitter

OpenAIRE

Mahesh, Nivedita; Subrahmanyan, Ravi; Shankar, N. Udaya; Raghunathan, Agaram

2014-01-01

We present the design, construction and measurements of the electromagnetic performance of a wideband space beam splitter. The beam splitter is designed to power divide the incident radiation into reflected and transmitted components for interferometer measurement of spectral features in the mean cosmic radio background. Analysis of a 2-element interferometer configuration with a vertical beam splitter between a pair of antennas leads to the requirement that the beam splitter be a resistive s...

Ultrasonic actuation for MEMS dormancy-related stiction reduction

Science.gov (United States)

Kaajakari, Ville; Kan, Shyi-Herng; Lin, Li-Jen; Lal, Amit; Rodgers, M. Steven

2000-08-01

The use of ultrasonic pulses incident on surface micromachines has been shown to reduce dormancy-related failure. We applied ultrasonic pulses from the backside of a silicon substrate carrying SUMMiT processed surface micromachined rotors, used earlier as ultrasonic motors. The amplitude of the pulses was less than what is required to actuate the rotor (sub-threshold actuation). By controlling the ultrasonic pulse exposure time it was found that pulsed samples had smaller actuation voltages as compared to non-pulsed samples after twelve-hour dormancy. This result indicates that the micromachine stiction to surfaces during dormant period can be effectively eliminated, resulting in long-term stability of surface micromachines in critical applications.

Ultrasonic physics

CERN Document Server

Richardson, E G

1962-01-01

Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

Ultrasonic testing device having an adjustable water column

Science.gov (United States)

Roach, Dennis P.; Neidigk, Stephen O.; Rackow, Kirk A.; Duvall, Randy L.

2015-09-01

An ultrasonic testing device having a variable fluid column height is disclosed. An operator is able to adjust the fluid column height in real time during an inspection to to produce optimum ultrasonic focus and separate extraneous, unwanted UT signals from those stemming from the area of interest.

Study of plasma-based stable and ultra-wideband electromagnetic wave absorption for stealth application

Science.gov (United States)

Xuyang, CHEN; Fangfang, SHEN; Yanming, LIU; Wei, AI; Xiaoping, LI

2018-06-01

A plasma-based stable, ultra-wideband electromagnetic (EM) wave absorber structure is studied in this paper for stealth applications. The stability is maintained by a multi-layer structure with several plasma layers and dielectric layers distributed alternately. The plasma in each plasma layer is designed to be uniform, whereas it has a discrete nonuniform distribution from the overall view of the structure. The nonuniform distribution of the plasma is the key to obtaining ultra-wideband wave absorption. A discrete Epstein distribution model is put forward to constrain the nonuniform electron density of the plasma layers, by which the wave absorption range is extended to the ultra-wideband. Then, the scattering matrix method (SMM) is employed to analyze the electromagnetic reflection and absorption of the absorber structure. In the simulation, the validation of the proposed structure and model in ultra-wideband EM wave absorption is first illustrated by comparing the nonuniform plasma model with the uniform case. Then, the influence of various parameters on the EM wave reflection of the plasma are simulated and analyzed in detail, verifying the EM wave absorption performance of the absorber. The proposed structure and model are expected to be superior in some realistic applications, such as supersonic aircraft.

Analysis of Ultrasonic Transmitted Signal for Apple using Wavelet Transform

International Nuclear Information System (INIS)

Kim, Ki Bok; Lee, Sang Dae; Choi, Man Yong; Kim, Man Soo

2005-01-01

This study was conducted to analyze the ultrasonic transmitted signal for apple using wavelet transform. Fruit consists of nonlinear visco-elastic properties such as flesh, an ovary and rind and lienee most ultrasonic wave is attenuated and its frequency is shifted during passing the fruit. Thus it is not easy to evaluate the internal quality of the fruit using typical ultrasonic parameters such as wave velocity, attenuation, and frequency spectrum. The discrete wavelet transform was applied to the ultrasonic transmitted signal for apple. The magnitude of the first peak frequency of the wavelet basis from the ultrasonic transmitted signal showed a close correlation to the storage time of apple

A Novel Compact Wideband TSA Array for Near-Surface Ice Sheet Penetrating Radar Applications

Science.gov (United States)

Zhang, Feng; Liu, Xiaojun; Fang, Guangyou

2014-03-01

A novel compact tapered slot antenna (TSA) array for near-surface ice sheet penetrating radar applications is presented. This TSA array is composed of eight compact antenna elements which are etched on two 480mm × 283mm FR4 substrates. Each antenna element is fed by a wideband coplanar waveguide (CPW) to coupled strip-line (CPS) balun. The two antenna substrates are connected together with a metallic baffle. To obtain wideband properties, another two metallic baffles are used along broadsides of the array. This array is fed by a 1 × 8 wideband power divider. The measured S11 of the array is less than -10dB in the band of 500MHz-2GHz, and the measured gain is more than 6dBi in the whole band which agrees well with the simulated results.

Wideband Autonomous Cognitive Radios for Networked Satellites Communications, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Wideband Autonomous Cognitive Radios (WACRs) are advanced radios that have the ability to sense state of the RF spectrum and the network and self-optimize its...

Ultrasonic guided wave for monitoring corrosion of steel bar

Science.gov (United States)

Liu, Xi; Qin, Lei; Huang, Bosheng

2018-01-01

Steel corrosion of reinforced concrete structures has become a serious problem all over the word. In this paper, the work aims at monitoring steel corrosion using ultrasonic guided wave (UGW). Ultrasonic guided wave monitoring is a dynamic and non-destructive testing technology. The advantages of ultrasonic guided wave monitoring for reinforcement corrosion are real-time, online and continuous. In addition, it can judge the different stages of steel bar corrosion, which achieved non-destructive detection.

Ultra-wideband horn antenna with abrupt radiator

Science.gov (United States)

McEwan, Thomas E.

1998-01-01

An ultra-wideband horn antenna transmits and receives impulse waveforms for short-range radars and impulse time-of flight systems. The antenna reduces or eliminates various sources of close-in radar clutter, including pulse dispersion and ringing, sidelobe clutter, and feedline coupling into the antenna. Dispersion is minimized with an abrupt launch point radiator element; sidelobe and feedline coupling are minimized by recessing the radiator into a metallic horn. Low frequency cut-off associated with a horn is extended by configuring the radiator drive impedance to approach a short circuit at low frequencies. A tapered feed plate connects at one end to a feedline, and at the other end to a launcher plate which is mounted to an inside wall of the horn. The launcher plate and feed plate join at an abrupt edge which forms the single launch point of the antenna.

Ultra-wideband ranging precision and accuracy

International Nuclear Information System (INIS)

MacGougan, Glenn; O'Keefe, Kyle; Klukas, Richard

2009-01-01

This paper provides an overview of ultra-wideband (UWB) in the context of ranging applications and assesses the precision and accuracy of UWB ranging from both a theoretical perspective and a practical perspective using real data. The paper begins with a brief history of UWB technology and the most current definition of what constitutes an UWB signal. The potential precision of UWB ranging is assessed using Cramer–Rao lower bound analysis. UWB ranging methods are described and potential error sources are discussed. Two types of commercially available UWB ranging radios are introduced which are used in testing. Actual ranging accuracy is assessed from line-of-sight testing under benign signal conditions by comparison to high-accuracy electronic distance measurements and to ranges derived from GPS real-time kinematic positioning. Range measurements obtained in outdoor testing with line-of-sight obstructions and strong reflection sources are compared to ranges derived from classically surveyed positions. The paper concludes with a discussion of the potential applications for UWB ranging

Ultrasonic applications for the enhancement of turbulence flow by using the PIV measurement

International Nuclear Information System (INIS)

Park, Y. H.; Choi, W. C.; Koo, J. H.; Song, M. G.; Ju, E. S.

2000-01-01

Ultrasonic applications for the enhancement of turbulence flow by using the PIV measurement were carried out according to the angle of the ultrasonic oscillator, materials of the reflector and each section when ultrasonic is reflected several times. Angles of the ultrasonic oscillator such as 30 deg., 45 .deg., 60 .deg., 90 .deg., 120 .deg., 135 .deg. and 150 .deg. were selected, and turbulent intensities were compared at Reynolds No. 2,000 and 4,000. Materials of the reflector such as wood, acryl, iron and glass were selected, and time mean velocity vector and turbulent intensity were compared at Reynolds No. 4,000. The zone which was observed was selected from first section to fourth section when ultrasonic was reflected several times. Every data such as time mean velocity vector and time mean turbulent intensity which was obtained by PIV measurement was examined, compared and discussed at Reynolds No. 2,000 and 4,000 to know the degree of turbulence enhancement in each case

Ultra-wideband WDM VCSEL arrays by lateral heterogeneous integration

Science.gov (United States)

Geske, Jon

Advancements in heterogeneous integration are a driving factor in the development of evermore sophisticated and functional electronic and photonic devices. Such advancements will merge the optical and electronic capabilities of different material systems onto a common integrated device platform. This thesis presents a new lateral heterogeneous integration technology called nonplanar wafer bonding. The technique is capable of integrating multiple dissimilar semiconductor device structures on the surface of a substrate in a single wafer bond step, leaving different integrated device structures adjacent to each other on the wafer surface. Material characterization and numerical simulations confirm that the material quality is not compromised during the process. Nonplanar wafer bonding is used to fabricate ultra-wideband wavelength division multiplexed (WDM) vertical-cavity surface-emitting laser (VCSEL) arrays. The optically-pumped VCSEL arrays span 140 nm from 1470 to 1610 nm, a record wavelength span for devices operating in this wavelength range. The array uses eight wavelength channels to span the 140 nm with all channels separated by precisely 20 nm. All channels in the array operate single mode to at least 65°C with output power uniformity of +/- 1 dB. The ultra-wideband WDM VCSEL arrays are a significant first step toward the development of a single-chip source for optical networks based on coarse WDM (CWDM), a low-cost alternative to traditional dense WDM. The CWDM VCSEL arrays make use of fully-oxidized distributed Bragg reflectors (DBRs) to provide the wideband reflectivity required for optical feedback and lasing across 140 rim. In addition, a novel optically-pumped active region design is presented. It is demonstrated, with an analytical model and experimental results, that the new active-region design significantly improves the carrier uniformity in the quantum wells and results in a 50% lasing threshold reduction and a 20°C improvement in the peak

Multipath ultrasonic gas flow-meter based on multiple reference waves.

Science.gov (United States)

Zhou, Hongliang; Ji, Tao; Wang, Ruichen; Ge, Xiaocheng; Tang, Xiaoyu; Tang, Shizhen

2018-01-01

Several technologies can be used in ultrasonic gas flow-meters, such as transit-time, Doppler, cross-correlation and etc. In applications, the approach based on measuring transit-time has demonstrated its advantages and become more popular. Among those techniques which can be applied to determine time-of-flight (TOF) of ultrasonic waves, including threshold detection, cross correlation algorithm and other digital signal processing algorithms, cross correlation algorithm has more advantages when the received ultrasonic signal is severely disturbed by the noise. However, the reference wave for cross correlation computation has great influence on the precise measurement of TOF. In the applications of the multipath flow-meters, selection of the reference wave becomes even more complicated. Based on the analysis of the impact factors that will introduce noise and waveform distortion of ultrasonic waves, an averaging method is proposed to determine the reference wave in this paper. In the multipath ultrasonic gas flow-meter, the analysis of each path of ultrasound needs its own reference wave. In case study, a six-path ultrasonic gas flow-meter has been designed and tested with air flow through the pipeline. The results demonstrate that the flow rate accuracy and the repeatability of the TOF are significantly improved by using averaging reference wave, compared with that using random reference wave. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamic measurement of liquid film thickness in stratified flow by using ultrasonic echo technique

International Nuclear Information System (INIS)

Serizawa, A.; Nagane, K.; Kamei, T.; Kawara, Z.; Ebisu, T.; Torikoshi, K.

2004-01-01

We developed a technique to measure time-dependent local film thickness in stratified air-water flow over a horizontal plate by using a time of flight of ultrasonic transmission. The ultrasonic echoes reflected at the liquid/air interfaces are detected by a conventional ultrasonic instrumentation, and the signals are analyzed by a personal computer after being digitalized by an A/D converter to give the time of flight for the ultrasonic waves to run over a distance of twice of the film thickness. A 3.8 mm diameter probe type ultrasonic transducer was used in the present work which transmits and receives 10 MHz frequency ultrasonic waves. The estimated spatial resolution with this arrangement is 0.075 mm in film thickness for water. The time resolution, which depends on both the A/D converter and the memory capacity was up to several tens Hz. We also discussed the sensitivity of the method to the inclination angle of the interfaces. (author)

Theoretical analysis and simulation of a code division multiple access system (cdma for secure signal transmission in wideband channels

Directory of Open Access Journals (Sweden)

Stevan M. Berber

2014-06-01

Full Text Available Chaotic spreading sequences can increase secrecy and resistance to interception in signal transmission. Chaos-based CDMA systems have been well investigated in the case of flat fading and noise presence in the channel. However, these systems operating in wideband channels, characterized by the frequency selective fading and white Gaussian noise, have not been investigated to the level of understanding their practical applications. This paper presents a detailed mathematical model of a CDMA system based on chaotic spreading sequences. In a theoretical analysis, all signals are represented in the discrete time domain. Using the theory of discrete time stochastic processes, the probability of error expressions are derived in a closed form for a multi-user chaos based CDMA system. For the sake of comparison, the expressions for the probability of error are derived separately for narrowband and wideband channels. The application of the system interleaving technique is investigated in particular, which showed that this technique can substantially improve probability of error in the system.  The system is simulated and the findings of the simulation confirmed theoretically expected results. Possible improvements in the probability of bit error due to multipath channel nature, with and without interleavers, are quantified depending on the random delay and the number of users in the system. In the analyzed system, a simplified version of the wideband channel model, proposed for modern wideband wireless networks, is used. Introduction Over the past years, the demand for wireless communications has increased substantially due to advancements in mobile communication systems and networks. Following these increasing demands, modern communication systems require the ability to handle a large number of users to process and transmit wideband signals through complex frequency selective channels. One of the techniques for transmission of multi-user signals is the

Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio-Inspired Optimization Techniques

Science.gov (United States)

2017-11-01

on Bio -Inspired Optimization Techniques by Canh Ly, Nghia Tran, and Ozlem Kilic Approved for public release; distribution is...Research Laboratory Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio -Inspired Optimization Techniques by...SUBTITLE Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio -Inspired Optimization Techniques 5a. CONTRACT NUMBER

Ultra-wideband wireless receiver front-end for high-speed indoor applications

Directory of Open Access Journals (Sweden)

Zhe-Yang Huang

2014-12-01

Full Text Available Low-noise, ultra-wideband (UWB wireless receiver front-end circuits were presented in this study. A two-stage common-source low-noise amplifier with wideband input impedance matching network, an active-balun and a double-balanced down-conversion mixer were adopted in the UWB wireless receiver front-end. The proposed wireless receiver front-end circuits were implemented in 0.18 μm radio-frequency-CMOS process. The maximum down-conversion power gain of the front-end is 25.8 dB; minimum single-sideband noise figure of the front-end is 4.9 dB over complete UWB band ranging from 3.1 to 10.6 GHz. Power consumption including buffers is 39.2 mW.

Dual-polarization, wideband microstrip antenna array for airborne C-band SAR

DEFF Research Database (Denmark)

Granholm, Johan; Skou, Niels

2000-01-01

The paper describes the development of a C-band, dual linear polarization wideband antenna array, for use in the next-generation of the Danish airborne polarimetric synthetic aperture radar (SAR) system. The array is made of probe-fed, stacked microstrip patches. The design and performance of the...... of the basic stacked patch element, operating from 4.9 GHz to 5.7 GHz, and a 2×2 element test array of these, are described.......The paper describes the development of a C-band, dual linear polarization wideband antenna array, for use in the next-generation of the Danish airborne polarimetric synthetic aperture radar (SAR) system. The array is made of probe-fed, stacked microstrip patches. The design and performance...

Wideband laser locking to an atomic reference with modulation transfer spectroscopy.

Science.gov (United States)

Negnevitsky, V; Turner, L D

2013-02-11

We demonstrate that conventional modulated spectroscopy apparatus, used for laser frequency stabilization in many atomic physics laboratories, can be enhanced to provide a wideband lock delivering deep suppression of frequency noise across the acoustic range. Using an acousto-optic modulator driven with an agile oscillator, we show that wideband frequency modulation of the pump laser in modulation transfer spectroscopy produces the unique single lock-point spectrum previously demonstrated with electro-optic phase modulation. We achieve a laser lock with 100 kHz feedback bandwidth, limited by our laser control electronics. This bandwidth is sufficient to reduce frequency noise by 30 dB across the acoustic range and narrows the imputed linewidth by a factor of five.

Ultrasonic Welding of Thin Alumina and Aluminum Using Inserts

Science.gov (United States)

Ishikuro, Tomoaki; Matsuoka, Shin-Ichi

This paper describes an experimental study of ultrasonic welding of thin ceramics and metals using inserts. Ultrasonic welding has enable the joining of various thick ceramics, such as Al2O3 and ZrO2, to aluminum at room temperature quickly and easily as compared to other welding methods. However, for thin ceramics, which are brittle, welding is difficult to perform without causing damage. In this study, aluminum anodized oxide with different anodizing time was used as thin alumina ceramic. Vapor deposition of aluminum alloys was used to create an effective binder layer for welding at a low pressure and within a short duration in order to prevent damage to the anodic oxide film formed with a short anodizing time. For example, ultrasonic welding of thin Al2O3/Al was accomplished under the following conditions: ultrasonic horn tip amplitude of 30µm, welding pressure of 5MPa, and required duration of 0.1s. However, since the vapor deposition film tends to exfoliate as observed in the anodic oxide film formed with a long anodizing time, welding was difficult.

Wideband FM Demodulation and Multirate Frequency Transformations

Science.gov (United States)

2016-12-15

Noble identities to extend the proposed approach to larger wideband to narrowband conversion factors and more practical implementations. We further...framework . . . . . . . . . . . . . . . . . . . . . 8 2 Block diagrams of the alternative MFT system for large conversion factors (a) and the Noble Identity ...of both MFT frameworks with conversion factor R = 128 and normalized radian frequency shift wd = 0.1π under the extreme senario with modulation index

Measurement of hydroxyl radical production in ultrasonic aqueous solutions by a novel chemiluminescence method.

Science.gov (United States)

Hu, Yufei; Zhang, Zhujun; Yang, Chunyan

2008-07-01

Measurement methods for ultrasonic fields are important for reasons of safety. The investigation of an ultrasonic field can be performed by detecting the yield of hydroxyl radicals resulting from ultrasonic cavitations. In this paper, a novel method is introduced for detecting hydroxyl radicals by a chemiluminescence (CL) reaction of luminol-hydrogen peroxide (H2O2)-K5[Cu(HIO6)2](DPC). The yield of hydroxyl radicals is calculated directly by the relative CL intensity according to the corresponding concentration of H2O2. This proposed CL method makes it possible to perform an in-line and real-time assay of hydroxyl radicals in an ultrasonic aqueous solution. With flow injection (FI) technology, this novel CL reaction is sensitive enough to detect ultra trace amounts of H2O2 with a limit of detection (3sigma) of 4.1 x 10(-11) mol L(-1). The influences of ultrasonic output power and ultrasonic treatment time on the yield of hydroxyl radicals by an ultrasound generator were also studied. The results indicate that the amount of hydroxyl radicals increases with the increase of ultrasonic output power (< or = 15 W mL(-1)). There is a linear relationship between the time of ultrasonic treatment and the yield of H2O2. The ultrasonic field of an ultrasonic cleaning baths has been measured by calculating the yield of hydroxyl radicals.

Effect of Ultrasonic Frequency on Lactic Acid Fermentation Promotion by Ultrasonic Irradiation

Science.gov (United States)

Shimada, Tadayuki; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi

2004-05-01

The authors have been researching the promotion of lactic acid fermentation by ultrasonic irradiation. In the past research, it was proven that ultrasonic irradiation is effective in the process of fermentation, and the production of yoghurt and kefir was promoted. In this study, the effect of the ultrasonic frequency in this fermentation process was examined. In the frequency range of this study, it was found that the action of fermentation promotion was exponentially proportionate to the irradiated ultrasonic frequency.

Robust Nearfield Wideband Beamforming Design Based on Adaptive-Weighted Convex Optimization

Directory of Open Access Journals (Sweden)

Guo Ye-Cai

2017-01-01

Full Text Available Nearfield wideband beamformers for microphone arrays have wide applications in multichannel speech enhancement. The nearfield wideband beamformer design based on convex optimization is one of the typical representatives of robust approaches. However, in this approach, the coefficient of convex optimization is a constant, which has not used all the freedom provided by the weighting coefficient efficiently. Therefore, it is still necessary to further improve the performance. To solve this problem, we developed a robust nearfield wideband beamformer design approach based on adaptive-weighted convex optimization. The proposed approach defines an adaptive-weighted function by the adaptive array signal processing theory and adjusts its value flexibly, which has improved the beamforming performance. During each process of the adaptive updating of the weighting function, the convex optimization problem can be formulated as a SOCP (Second-Order Cone Program problem, which could be solved efficiently using the well-established interior-point methods. This method is suitable for the case where the sound source is in the nearfield range, can work well in the presence of microphone mismatches, and is applicable to arbitrary array geometries. Several design examples are presented to verify the effectiveness of the proposed approach and the correctness of the theoretical analysis.

Electromagnetic ultrasonic guided waves

CERN Document Server

Huang, Songling; Li, Weibin; Wang, Qing

2016-01-01

This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

Design of ultrasonic probe and evaluation of ultrasonic waves on E.coli in Sour Cherry Juice

Directory of Open Access Journals (Sweden)

B Hosseinzadeh Samani

2015-09-01

Full Text Available Introduction: The common method used for juice pasteurization is the thermal method since thermal methods contribute highly to inactivating microbes. However, applying high temperatures would lead to inefficient effects on nutrition and food value. Such effects may include vitamin loss, nutritional flavor loss, non-enzyme browning, and protein reshaping (Kuldiloke, 2002. In order to decrease the adverse effects of the thermal pasteurization method, other methods capable of inactivation of microorganisms can be applied. In doing so, non-thermal methods including pasteurization using high hydrostatic pressure processing (HPP, electrical fields, and ultrasound waves are of interest (Chen and Tseng, 1996. The reason for diminishing microbial count in the presence of ultrasonic waves could be due to the burst of very tiny bubbles developed by ultrasounds which expand quickly and burst in a short time. Due to this burst, special temperature and pressure conditions are developed which could initiate or intensify several physical and/or chemical reactions. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. Materials and methods: In order to supply uniform ultrasonic waves, a 1000 W electric generator (Model MPI, Switzerland working at 20±1 kHz frequency was used. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. For this purpose, a certain amount of sour cherry fruit was purchased from local markets. First, the fruits were washed, cleaned and cored. The prepared fruits were then dewatered using an electric juicer. In order to separate pulp suspensions and tissue components, the extracted juice was poured into a centrifuge with the speed of 6000 rpm for 20 min. For complete separation of the remaining suspended particles, the transparent portion of the extract was passed through a

A Fourier Collocation Approach for Transit-Time Ultrasonic Flowmeter Under Multi-Phase Flow Conditions

DEFF Research Database (Denmark)

Simurda, Matej; Lassen, Benny; Duggen, Lars

2017-01-01

A numerical model for a clamp-on transit-time ultrasonic flowmeter (TTUF) under multi-phase flow conditions is presented. The method solves equations of linear elasticity for isotropic heterogeneous materials with background flow where acoustic media are modeled by setting shear modulus to zero....... Spatial derivatives are calculated by a Fourier collocation method allowing the use of the fast Fourier transform (FFT) and time derivatives are approximated by a finite difference (FD) scheme. This approach is sometimes referred to as a pseudospectral time-domain method. Perfectly matched layers (PML......) are used to avoid wave-wrapping and staggered grids are implemented to improve stability and efficiency. The method is verified against exact analytical solutions and the effect of the time-staggering and associated lowest number of points per minimum wavelengths value is discussed. The method...

Methanolysis of triolein by low frequency ultrasonic irradiation

Energy Technology Data Exchange (ETDEWEB)

Hanh, Hoang Duc; Starvarache, Carmen; Okitsu, Kenji; Maeda, Yasuaki; Nishimura, Rokuro [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan); Dong, Nguyen The [Institute of Environmental Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi (Viet Nam)

2008-02-15

Methanolysis of triolein was investigated at room temperature by 40 kHz ultrasonic irradiation to make biodiesel fuel as methyl esters. It was found that the yield of methyl esters strongly depended on the amount of KOH and the molar ratio of methanol to triolein (M/T) and was highest at the M/T molar ratio of 6/1, KOH concentration of 1 wt% and irradiation time of 30 min. In addition, the effects of sonication on the methanolysis of triolein were discussed in comparison to the effects of stirring experiments. The optimum condition under stirring experiments showed that the molar ratio of M/T, KOH concentration and reaction time were 6/1, 1.5 wt% and 4 h, respectively. These results clearly indicated that the ultrasonic irradiation method would be a promising one compared to the conventional stirring method. The high yield under the ultrasonic irradiation condition would be due to high speed mixing and mass transfer between the methanol and triolein as well as the formation of a microemulsion resulting from the ultrasonic cavitation phenomenon. (author)

Methanolysis of triolein by low frequency ultrasonic irradiation

Energy Technology Data Exchange (ETDEWEB)

Hoang Duc Hanh [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan)], E-mail: hoangduchanh75@yahoo.com; Nguyen The Dong [Institute of Environmental Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi (Viet Nam); Starvarache, Carmen; Okitsu, Kenji; Maeda, Yasuaki; Nishimura, Rokuro [Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531 (Japan)

2008-02-15

Methanolysis of triolein was investigated at room temperature by 40 kHz ultrasonic irradiation to make biodiesel fuel as methyl esters. It was found that the yield of methyl esters strongly depended on the amount of KOH and the molar ratio of methanol to triolein (M/T) and was highest at the M/T molar ratio of 6/1, KOH concentration of 1 wt% and irradiation time of 30 min. In addition, the effects of sonication on the methanolysis of triolein were discussed in comparison to the effects of stirring experiments. The optimum condition under stirring experiments showed that the molar ratio of M/T, KOH concentration and reaction time were 6/1, 1.5 wt% and 4 h, respectively. These results clearly indicated that the ultrasonic irradiation method would be a promising one compared to the conventional stirring method. The high yield under the ultrasonic irradiation condition would be due to high speed mixing and mass transfer between the methanol and triolein as well as the formation of a microemulsion resulting from the ultrasonic cavitation phenomenon.

Ultrasonic viewing device

International Nuclear Information System (INIS)

Ito, Juro.

1979-01-01

Purpose: To improve the safety of reactor operation by enabling to detect the states and positions of fuel assemblies over a wide range with a set of ultrasonic viewing device comprising a rotatable ultrasonic transmitter-receiver and a reflector mounted with an adjustable angle. Constitution: A driving portion for a ultrasonic viewing device is provided to a rotary plug closing the opening of a reactor vessel and a guide pipe suspending below the coolant level is provided to the driving portion. An ultrasonic transmitter-receiver is provided at the end of the holder tube in the guide pipe. A reflector is provided at the upper position of the reactor core so as to correspond to the ultrasonic transmitter-receiver. The ultrasonic transmitter-receiver, positioned by the driving portion, performs horizontal movement for scanning the entire surface of the top of the reactor core, as well as vertical movement covering the gap between the upper mechanism on the reactor and the reactor core, whereby the confirmation for the separation of the control rod and the detection for the states of the reactor core can be conducted by the reflection waves from the reflector. (Moriyama, K.)

Ultrasonic process for destruction of chlorinated organic compounds in aqueous solution

International Nuclear Information System (INIS)

Wu, Jiann M.; Huang, Hann S.

1993-01-01

Laboratory investigations of the ultrasonic process for destruction of low concentrations of carbon tetrachloride (CCl 4 ) into nonhazardous end products were carried out in a bench-scale batch reactor, equipped with a 600-W ultrasonic power supply. Process parameters studied included irradiation time, concentration, steady-state operating temperature, pH, and the intensity of applied ultrasonic-wave energy. High destruction efficiencies of greater than 99% were achieved through this process, and the irradiation time and the intensity of applied energy were identified to be the most important process parameters. The irradiation time required for a given degree of destruction decreased with increasing intensity of the applied ultrasonic energy. In addition, a detailed chemical reaction mechanism for the destruction of CCl 4 in water was formulated. The agreement between the model and experimental results is generally good

Study of a new technique for measuring the travel time of ultrasonic waves using the frequency spectrum; Estudo de uma nova tecnica de medida do tempo de percurso da onda ultra-sonica usando o espectro de frequencia

Energy Technology Data Exchange (ETDEWEB)

Santos, Allan Xavier dos

2010-07-01

During the operation of a nuclear plant and other industrial plants, the operational time and the exposition to severe working conditions may cause the wear of its components, consequently, compromising the safety and the performance of the installation. The implementation of periodical inspections helps to ensure the safe operation and the best performance of the plant. In this way, the use of ultrasonic techniques for inspection and materials characterization becomes more and more attractive, since they offer quick, precise results and are technically ease to implement. The usual ultrasonic techniques, need to the measure the travelling time of the ultrasonic wave in the material examined in order to extract information useful to characterize it. Thus, the measurement of the travelling time of the ultrasonic wave is the overriding factor in most of the applications made with ultrasound. In this work a new technique was developed for measuring the travelling time of the ultrasonic wave using a Fourier's Fast Transformer (FFT). It will be shown mathematically and experimentally that it is possible to use the ultrasonic signal in the frequency domain to determine the travelling time of the ultrasonic wave. Five experiments were carried out for the experimental validation of this new technique. The materials used were 20 ceramic pastilles with different porosities and 3 aluminum plates of different thicknesses. The obtained results have shown that the new technique proposed in this work was able to determine the travelling time of the ultrasonic wave with the same precision as the conventional technique. It was shown, furthermore, that this new technique is able to measure the travelling time of the ultrasonic wave in situations where the conventional technique cannot be applied greatly expanding the range of application of ultrasonic testing and inspections. (author)

  Ultrasonic monitoring of fish thawing process optimal time of thawing and effect of freezing/thawing.

Science.gov (United States)

El Kadi, Youssef Ait; Moudden, Ali; Faiz, Bouazza; Maze, Gerard; Decultot, Dominique

2013-01-01

Fish quality is traditionally controlled by chemical and microbiological analysis. The non-destructive control presents an enormous professional interest thanks to the technical contribution and precision of the analysis to which it leads. This paper presents the results obtained from a characterisation of fish thaw-ing process by the ultrasonic technique, with monitoring thermal processing from frozen to defrosted states. The study was carried out on fish type red drum and salmon cut into fillets of 15 mm thickness. After being frozen at -20°C, the sample is enclosed in a plexiglas vessel with parallel walls at the ambient temperature 30°C and excited in perpendicular incidence at 0.5 MHz by an ultrasonic pulser-receiver Sofranel 5052PR. the technique of measurement consists to study the signals reflected by fish during its thawing, the specific techniques of signal processing are implemented to deduce informations characterizing the state of fish and its thawing process by examining the evolution of the position echoes reflected by the sample and the viscoelastic parameters of fish during its thawing. The obtained results show a relationship between the thermal state of fish and its acoustic properties, which allowed to deduce the optimal time of the first thawing in order to restrict the growth of microbial flora. For salmon, the results show a decrease of 36% of the time of the second thawing and an increase of 10.88% of the phase velocity, with a decrease of 65.5% of the peak-to-peak voltage of the signal reflected, thus a decrease of the acoustic impedance. This study shows an optimal time and an evolution rate of thawing specific to each type offish and a correlation between the acoustic behavior of fish and its thermal state which approves that this technique of ultrasonic monitoring can substitute the control using the destructive chemical analysis in order to monitor the thawing process and to know whether a fish has suffered an accidental thawing.

Liquid ultrasonic flow meters for crude oil measurement

Energy Technology Data Exchange (ETDEWEB)

Kalivoda, Raymond J.; Lunde, Per

2005-07-01

Liquid ultrasonic flow meters (LUFMs) are gaining popularity for the accurate measurement of petroleum products. In North America the first edition of the API standard ''Measurement of liquid hydrocarbons by ultrasonic flow meters using transit time technology'' was issued in February 2005. It addresses both refined petroleum products and crude oil applications. Its field of application is mainly custody transfer applications but it does provide general guidelines for the installation and operation of LUFM's other applications such as allocation, check meters and leak detection. As with all new technologies performance claims are at times exaggerated or misunderstood and application knowledge is limited. Since ultrasonic meters have no moving parts they appear to have fewer limitations than other liquid flow meters. Liquids ultrasonic flow meters, like turbine meters, are sensitive to fluid properties. It is increasingly more difficult to apply on high viscosity products then on lighter hydrocarbon products. Therefore application data or experience on the measurement of refined or light crude oil may not necessarily be transferred to measuring medium to heavy crude oils. Before better and more quantitative knowledge is available on how LUFMs react on different fluids, the arguments advocating reduced need for in-situ proving and increased dependency on laboratory flow calibration (e.g. using water instead of hydrocarbons) may be questionable. The present paper explores the accurate measurement of crude oil with liquid ultrasonic meters. It defines the unique characteristics of the different API grades of crude oils and how they can affect the accuracy of the liquid ultrasonic measurement. Flow testing results using a new LUFM design are discussed. The paper is intended to provide increased insight into the potentials and limitations of crude oil measurement using ultrasonic flow meters. (author) (tk)

Wideband feedback system prototype validation

CERN Document Server

Li, K; Bjorsvik, E; Fox, J; Hofle, W; Kotzian, G; Rivetta, C; Salvant, B; Turgut, O

2017-01-01

A wideband feedback demonstrator system has been de-veloped in collaboration with US-LARP under the joint lead-ership of CERN and SLAC. The system includes widebandkicker structures and amplifiers along with a fast digital re-configurable system up to 4 GS/s for single bunch and multibunch control. Most of the components have been installedin recent years and have been put into operation to test bothintra-bunch damping and individual bunch control in a multibunch train. In this note we report on the MD program,procedure and key findings that were made with this systemin the past year.

Nondestructive evaluation of a cermet coating using ultrasonic and eddy current techniques

International Nuclear Information System (INIS)

Roge, B.; Fahr, A.; Giguere, J.S.R.; McRae, K.I.

2002-01-01

This paper describes a series of experiments conducted to characterize cermet coatings using conventional ultrasonic and eddy current techniques as well as an ultrasonic leaky surface wave method. The results demonstrate the ability of these techniques to detect the presence of artificial defects on the surface or beneath the surface of the coating. In addition, ultrasonic tests in particular ultrasonic leaky surface waves demonstrate the ability to detect the presence of manufacturing flaws. Ultrasonic time-of-flight and eddy current quadrature measurements also show sensitivity to variations in coating thickness

Digital Receiver Design for Transmitted Reference Ultra-Wideband Systems

NARCIS (Netherlands)

Wang, Y.; Leus, G.; Van der Veen, A.J.

2009-01-01

A complete detection, channel estimation, synchronization, and equalization scheme for a transmitted reference (TR) ultra-wideband (UWB) system is proposed in this paper. The scheme is based on a data model which admits a moderate data rate and takes both the interframe interference (IFI) and the

Radial vibration and ultrasonic field of a long tubular ultrasonic radiator.

Science.gov (United States)

Shuyu, Lin; Zhiqiang, Fu; Xiaoli, Zhang; Yong, Wang; Jing, Hu

2013-09-01

The radial vibration of a metal long circular tube is studied analytically and its electro-mechanical equivalent circuit is obtained. Based on the equivalent circuit, the radial resonance frequency equation is derived. The theoretical relationship between the radial resonance frequency and the geometrical dimensions is studied. Finite element method is used to simulate the radial vibration and the radiated ultrasonic field and the results are compared with those from the analytical method. It is concluded that the radial resonance frequency for a solid metal rod is larger than that for a metal tube with the same outer radius. The radial resonance frequencies from the analytical method are in good agreement with those from the numerical method. Based on the acoustic field analysis, it is concluded that the long metal tube with small wall thickness is superior to that with large wall thickness in producing radial vibration and ultrasonic radiation. Therefore, it is expected to be used as an effective radial ultrasonic radiator in ultrasonic sewage treatment, ultrasonic antiscale and descaling and other ultrasonic liquid handling applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultra-wideband reflective polarization converter based on anisotropic metasurface

International Nuclear Information System (INIS)

Wu Jia-Liang; Lin Bao-Qin; Da Xin-Yu

2016-01-01

In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x - or y -polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. (paper)

Ultrasonic decontamination robot

International Nuclear Information System (INIS)

Patenaude, R.S.

1984-01-01

An ultrasonic decontamination robot removes radioactive contamination from the internal surface of the inlet and outlet headers, divider plate, tube sheet, and lower portions of tubes of a nuclear power plant steam generator. A programmable microprocessor controller guides the movement of a robotic arm mounted in the header manway. An ultrasonic transducer having a solvent delivery subsystem through which ultrasonic action is achieved is moved by the arm over the surfaces. A solvent recovery suction tube is positioned within the header to remove solvent therefrom while avoiding interference with the main robotic arm. The solvent composition, temperature, pressure, viscosity, and purity are controlled to optimize the ultrasonic scrubbing action. The ultrasonic transducer is controlled at a power density, frequency, and on-off mode cycle such as to optimize scrubbing action within the range of transducer-to-surface distance and solvent layer thickness selected for the particular conditions encountered. Both solvent and transducer control actions are optimized by the programmable microprocessor. (author)

Analysis of ultrasonic techniques for the characterization of microfiltration polymeric membranes

International Nuclear Information System (INIS)

Lucas, Carla S.; Baroni, Douglas B.; Costa, Antonio M.L.M.; Bittencourt, Marcelo S.Q.

2009-01-01

The use of polymeric membranes is extremely important in several industries such as nuclear, biotechnology, chemical and pharmaceutical. In the nuclear area, for instance, systems based on membrane separation technologies are currently being used in the treatment of radioactive liquid effluent, and new technologies using membranes are being developed at a great rate. The knowledge of the physical characteristics of these membranes, such as, pore size and the pore size distribution, is very important to the membranes separation processes. Only after these characteristics are known is it possible to determine the type and to choose a particular membrane for a specific application. In this work, two ultrasonic non destructive techniques were used to determine the porosity of membranes: pulse echo and transmission. A 25 MHz immersion transducer was used. Ultrasonic signals were acquired, for both techniques, after the ultrasonic waves passed through a microfiltration polymeric membrane of pore size of 0.45 μm and thickness of 180 μm. After the emitted ultrasonic signal crossed the membrane, the received signal brought several information on the influence of the membrane porosity in the standard signal of the ultrasonic wave. The ultrasonic signals were acquired in the time domain and changed to the frequency domain by application of the Fourier Fast Transform (FFT), thus generating the material frequency spectrum. For the pulse echo technique, the ultrasonic spectrum frequency changed after the ultrasonic wave crossed the membrane. With the transmission technique there was only a displacement of the ultrasonic signal at the time domain. (author)

Identification of the Quality Spot Welding used Non Destructive Test-Ultrasonic Testing: (Effect of Welding Time)

Science.gov (United States)

Sifa, A.; Endramawan, T.; Badruzzaman

2017-03-01

Resistance Spot Welding (RSW) is frequently used as one way of welding is used in the manufacturing process, especially in the automotive industry [4][5][6][7]. Several parameters influence the process of welding points. To determine the quality of a welding job needs to be tested, either by damaging or testing without damage, in this study conducted experimental testing the quality of welding or identify quality of the nugget by using Non-Destructive Test (NDT) -Ultrasonic Testing (UT), in which the identification of the quality of the welding is done with parameter thickness of worksheet after welding using NDT-UT with use same material worksheet and have more thickness of worksheet, the thickness of the worksheet single plate 1mm, with the capability of propagation Ultrasonic Testing (UT) standard limited> 3 mm [1], welding process parameters such as the time difference between 1-10s and the welding current of 8 KV, visually Heat Affected Zone ( HAZ ) have different results due to the length of time of welding. UT uses a probe that is used with a frequency of 4 MHz, diameter 10 mm, range 100 and the couplant used is oil. Identification techniques using drop 6dB, with sound velocity 2267 m / s of Fe, with the result that the effect of the Welding time affect the size of the HAZ, identification with the lowest time 1s show results capable identified joined through NDT - UT.

Ultrasonic testing device

International Nuclear Information System (INIS)

Lawrie, W.E.

1978-01-01

The ultrasonic transmitter made of polarized ferroelectric ceramic material (lead zirconate titanate) is arranged in a strip carrier which allows it to be introduced between the fuel elements of a fuel subassembly in a water cooled nuclear reactor. The ultrasonic transmitter is insulated relative to the carrier. The echo of the ra dal ultrasonic pulse is recorded which changes as faulty water filled fuel elements are detected. (RW) [de

Advanced ultrasonic technology for natural gas measurement

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-11-15

In recent years, due to rising environmental and safety concerns, increasing commodity prices, and operational inefficiencies, a paradigm shift has been taking place with respect to gas measurement. The price of natural gas depends on the location, time of the year, and type of consumer. There is wide uncertainty associated with an orifice meter. This paper presents the use of advanced ultrasonic technology for the measurement of natural gas. For many years, multi-path ultrasonic meters with intelligent sensor technology have been used for gas measurement. This paper gives the various applications of ultrasonic technology along with their advantages and a draws a comparison with orifice meters. From the study it can be concluded that extensive advances in the use of ultrasonic technology for gas measurement have widened the areas of application and that varying frequencies combined with sealed transducer designs make it possible to measure atmospheric and sour gas in custody transfer process control and flaring accurately.

Development of ultrasonic instrument 'UT1000 Series'

International Nuclear Information System (INIS)

Ogura, Yukio; Ikeda, Toshimichi

1984-01-01

The ultrasonic flaw detectors with 'A-scope indication' have been frequently used as the means for confirming the soundness of structures and equipments, but there are problems in their operational, quantifying and recording capabilities. Recently, the digital ultrasonic measuring instrument of touch panel type ''UT 1000 Series'' has been developed, which resolves these problems by a single effort. This measuring instrument is that of portable type, which gives the digital output of measured results in real time only by lightly touching the peak point of an echo on the Brown tube. This instrument contains the rich software for measurement, and can measure the positions and dimensions of defects and the pressure on contact surfaces with high accuracy. 'A-scope indication' is the indication with an oscilloscope taking the intensity of echo and the propagation time of ultrasonic waves on the ordinate and abscissa, respectively. There are three types of the instrument, that is, for detecting defects, for measuring contact surface pressure and for both purposes. The size of the instrument is 240 mm width, 350 mm length and 175 mm height, and the weight is 8.5 kgf. The specification, function and features of the ultrasonic flaw detector, touch panel, gain setter, key board, microcomputer and others are reported. (Kako, I.)

Novel wideband microwave polarization network using a fully-reconfigurable photonic waveguide interleaver with a two-ring resonator-assisted asymmetric Mach-Zehnder structure.

Science.gov (United States)

Zhuang, Leimeng; Beeker, Willem; Leinse, Arne; Heideman, René; van Dijk, Paulus; Roeloffzen, Chris

2013-02-11

We propose and demonstrate a novel wideband microwave photonic polarization network for dual linear-polarized antennas. The polarization network is based on a waveguide-implemented fully-reconfigurable optical interleaver using a two-ring resonator-assisted asymmetric Mach-Zehnder structure. For microwave photonic signal processing, this structure is able to serve as a wideband 2 × 2 RF coupler with reconfigurable complex coefficients, and therefore can be used as a polarization network for wideband antennas. Such a device can equip the antennas with not only the polarization rotation capability for linear-polarization signals but also the capability to operate with and tune between two opposite circular polarizations. Operating together with a particular modulation scheme, the device is also able to serve for simultaneous feeding of dual-polarization signals. These photonic-implemented RF functionalities can be applied to wideband antenna systems to perform agile polarization manipulations and tracking operations. An example of such a interleaver has been realized in TriPleX waveguide technology, which was designed with a free spectral range of 20 GHz and a mask footprint of smaller than 1 × 1 cm. Using the realized device, the reconfigurable complex coefficients of the polarization network were demonstrated with a continuous bandwidth from 2 to 8 GHz and an in-band phase ripple of smaller than 5 degree. The waveguide structure of the device allows it to be further integrated with other functional building blocks of a photonic integrated circuit to realize on-chip, complex microwave photonic processors. Of particular interest, it can be included in an optical beamformer for phased array antennas, so that simultaneous wideband beam and polarization trackings can be achieved photonically. To our knowledge, this is the first-time on-chip demonstration of an integrated microwave photonic polarization network for dual linear-polarized antennas.

Wideband Radar Echo Frequency-domain Simulation and Analysis for High Speed Moving Targets

Directory of Open Access Journals (Sweden)

Ning Chao

2014-04-01

Full Text Available A frequency-domain method is proposed for wideband radar echo simulation of high-speed moving targets. Based on the physical process of electromagnetic waves observing a moving target, a frequency-domain echo model of wideband radar is constructed, and the block diagram of the radar echo simulation in frequency-domain is presented. Then, the impacts of radial velocity and slant range on the matching filtering of LFM radar are analyzed, and some quantitative conclusions on the shift and expansion of the radar profiles are obtained. Simulation results illustrate the correctness and efficiency of the proposed method.

Control of molecular weight distribution in synthesis of poly(2-hydroxyethyl methacrylate) using ultrasonic irradiation.

Science.gov (United States)

Kubo, Masaki; Kondo, Takayuki; Matsui, Hideki; Shibasaki-Kitakawa, Naomi; Yonemoto, Toshikuni

2018-01-01

Poly(2-hydroxyethyl methacrylate) (PHEMA) was synthesized using ultrasonic irradiation without any chemical initiator. The effect of the ultrasonic power intensity on the time course of the conversion to polymer, the number average molecular weight, and the polydispersity were investigated in order to synthesize a polymer with a low molecular weight distribution (i.e., low polydispersity). The conversion to polymer increased with time. A higher ultrasonic power intensity resulted in a faster reaction rate. The number average molecular weight increased during the early stage of the reaction and then gradually decreased with time. A higher ultrasonic intensity resulted in a faster degradation rate of the polymer. The polydispersity decreased with time. This was because the degradation rate of a polymer with a higher molecular weight was faster than that of a polymer with a lower molecular weight. A polydispersity below 1.3 was obtained under ultrasonic irradiation. By changing the ultrasonic power intensity during the reaction, the number average molecular weight can be controlled while maintaining low polydispersity. When the ultrasonic irradiation was halted, the reactions stopped and the number average molecular weight and polydispersity did not change. On the basis of the experimental results, a kinetic model for synthesis of PHEMA under ultrasonic irradiation was constructed considering both polymerization and polymer degradation. The kinetic model was in good agreement with the experimental results for the time courses of the conversion to polymer, the number average molecular weight, and the polydispersity for various ultrasonic power intensities. Copyright © 2017 Elsevier B.V. All rights reserved.

Resilience of LTE networks against smart jamming attacks: Wideband model

KAUST Repository

Aziz, Farhan M.; Shamma, Jeff S.; Stuber, Gordon L.

2015-01-01

communications. We have previously shown that LTE networks are vulnerable to Denial-of-Service (DOS) and loss of service attacks from smart jammers. In this paper, we extend our previous work on resilience of LTE networks to wideband multipath fading channel

High Temperature Ultrasonic Transducer for Real-time Inspection

Science.gov (United States)

Amini, Mohammad Hossein; Sinclair, Anthony N.; Coyle, Thomas W.

A broadband ultrasonic transducer with a novel porous ceramic backing layer is introduced to operate at 700 °C. 36° Y-cut lithium niobate (LiNbO3) single crystal was selected for the piezoelectric element. By appropriate choice of constituent materials, porosity and pore size, the acoustic impedance and attenuation of a zirconia-based backing layer were optimized. An active brazing alloy with high temperature and chemical stability was selected to bond the transducer layers together. Prototype transducers have been tested at temperatures up to 700 °C. The experiments confirmed that transducer integrity was maintained.

Simulation of the Two-Phase Liquid – Gas Flow through Ultrasonic Transceivers Application in Ultrasonic Tomography

Directory of Open Access Journals (Sweden)

Zulkarnay Zakaria

2010-01-01

Full Text Available In this paper, ultrasonic transmission mode tomography was used to visualize the two phase liquid/gas flow in a pipe/vessel. The sensing element consists of 8, 16 and 32 units ultrasonic transceivers were used to cover the pipe cross-section at different time. The motivation of this paper is to analyze the optimum numbers of transceivers which can give the best performance in providing better image of the two phase liquid/gas flow. This paper also details the development of the system including the ultrasonic transduction circuits, the electronic measurement circuits, the data acquisition system and the image reconstruction techniques. Ten conditions of liquid-gas flow have been simulated. The system was found capable of visualizing the internal characteristics and provides the concentration profile for the corresponding liquid and gas phases while the 32 transceivers has provided the best image for the ten conditions applied.

Multiband and wideband monopole antenna for GSM900 and other wireless applications

KAUST Repository

Abutarboush, Hattan; Nasif, H.; Nilavalan, Rajagopal; Cheung, Sing Wai

2012-01-01

In this letter, the design of a compact monopole antenna for multiband and wideband operations is proposed. The antenna has three distinct frequency bands, centered at 0.94, 2.7, and 4.75 GHz. The antenna has a compact size of only 30×40×1.57 mm$ 3 including the ground plane. The multiband and wideband operations are achieved by using an E-shaped slot on the ground plane. The design procedure is also discussed. The frequency bands can be independently controlled by using the parameters of the E-slot. The impedance bandwidth, current distributions, radiation patterns, gain, and efficiency of the antenna are studied by computer simulation and measurements. © 2011 IEEE.

High Performance Wideband CMOS CCI and its Application in Inductance Simulator Design

Directory of Open Access Journals (Sweden)

ARSLAN, E.

2012-08-01

Full Text Available In this paper, a new, differential pair based, low-voltage, high performance and wideband CMOS first generation current conveyor (CCI is proposed. The proposed CCI has high voltage swings on ports X and Y and very low equivalent impedance on port X due to super source follower configuration. It also has high voltage swings (close to supply voltages on input and output ports and wideband current and voltage transfer ratios. Furthermore, two novel grounded inductance simulator circuits are proposed as application examples. Using HSpice, it is shown that the simulation results of the proposed CCI and also of the presented inductance simulators are in very good agreement with the expected ones.

The Large Office Environment - Measurement and Modeling of the Wideband Radio Channel

DEFF Research Database (Denmark)

Andersen, Jørgen Bach; Nielsen, Jesper Ødum; Bauch, Gerhard

2006-01-01

In a future 4G or WLAN wideband application we can imagine multiple users in a large office environment con-sisting of a single room with partitions. Up to now, indoor radio channel measurement and modelling has mainly concentrated on scenarios with several office rooms and corridors. We present...... here measurements at 5.8GHz for 100 MHz bandwidth and a novel modelling approach for the wideband radio channel in a large office room envi-ronment. An acoustic like reverberation theory is pro-posed that allows to specify a tapped delay line model just from the room dimensions and an average...... calculated from the measurements. The pro-posed model can likely also be applied to indoor hot spot scenarios....

Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide

DEFF Research Database (Denmark)

Xiao, Binggang; Li, Sheng-Hua; Xiao, Sanshui

2016-01-01

Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide is proposed. Owing to subwavelength confinement, such a filter has advantage in the structure size without sacrificing the performance. The spoof SPP based notch is introduced to suppress the WLAN and satel...... and satellite communication signals. Due to planar structures proposed here, it is easy to integrate in the microwave integrated systems, which can play an important role in the microwave communication circuit and system.......Spoof surface plasmon polaritons based notch filter for ultra-wideband microwave waveguide is proposed. Owing to subwavelength confinement, such a filter has advantage in the structure size without sacrificing the performance. The spoof SPP based notch is introduced to suppress the WLAN...

Weak wide-band signal detection method based on small-scale periodic state of Duffing oscillator

Science.gov (United States)

Hou, Jian; Yan, Xiao-peng; Li, Ping; Hao, Xin-hong

2018-03-01

The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillatorʼs phase trajectory in a small-scale periodic state are analyzed by introducing the theory of stopping oscillation system. Based on this approach, a novel Duffing oscillator weak wide-band signal detection method is proposed. In this novel method, the reference signal is discarded, and the to-be-detected signal is directly used as a driving force. By calculating the cosine function of a phase space angle, a single Duffing oscillator can be used for weak wide-band signal detection instead of an array of uncoupled Duffing oscillators. Simulation results indicate that, compared with the conventional Duffing oscillator detection method, this approach performs better in frequency detection intervals, and reduces the signal-to-noise ratio detection threshold, while improving the real-time performance of the system. Project supported by the National Natural Science Foundation of China (Grant No. 61673066).

A Dual Stage Linear Prediction Approach Towards Wideband FM Demodulation With Multilevel and Partial Response Signaling

Science.gov (United States)

2018-01-19

attributed to the inherent interpolation process in the MFT demodulation approach, which is more error-sensitive to discontinuous waveforms, such as...Multirate Frequency Transformations In the author’s recent work, frequency transformations enacted via multirate signal processing were used for wideband...FM to narrowband FM conversion to enable a wider range of wideband FM signals [9, 11]. The goal of the multirate processing module is to compress the

Enzyme-catalyzed synthesis and kinetics of ultrasonic-assisted biodiesel production from waste tallow.

Science.gov (United States)

Adewale, Peter; Dumont, Marie-Josée; Ngadi, Michael

2015-11-01

The use of ultrasonic processing was evaluated for its ability to achieve adequate mixing while providing sufficient activation energy for the enzymatic transesterification of waste tallow. The effects of ultrasonic parameters (amplitude, cycle and pulse) and major reaction factors (molar ratio and enzyme concentration) on the reaction kinetics of biodiesel generation from waste tallow bio-catalyzed by immobilized lipase [Candida antarctica lipase B (CALB)] were investigated. Three sets of experiments namely A, B, and C were conducted. In experiment set A, two factors (ultrasonic amplitude and cycle) were investigated at three levels; in experiment set B, two factors (molar ratio and enzyme concentration) were examined at three levels; and in experiment set C, two factors (ultrasonic amplitude and reaction time) were investigated at five levels. A Ping Pong Bi Bi kinetic model approach was employed to study the effect of ultrasonic amplitude on the enzymatic transesterification. Kinetic constants of transesterification reaction were determined at different ultrasonic amplitudes (30%, 35%, 40%, 45%, and 50%) and enzyme concentrations (4, 6, and 8 wt.% of fat) at constant molar ratio (fat:methanol); 1:6, and ultrasonic cycle; 5 Hz. Optimal conditions for ultrasound-assisted biodiesel production from waste tallow were fat:methanol molar ratio, 1:4; catalyst level 6% (w/w of fat); reaction time, 20 min (30 times less than conventional batch processes); ultrasonic amplitude 40% at 5 Hz. The kinetic model results revealed interesting features of ultrasound assisted enzyme-catalyzed transesterification (as compared to conventional system): at ultrasonic amplitude 40%, the reaction activities within the system seemed to be steady after 20 min which means the reaction could proceed with or without ultrasonic mixing. Reversed phase high performance liquid chromatography indicated the biodiesel yield to be 85.6±0.08%. Copyright © 2015 Elsevier B.V. All rights reserved.

Ultrasonic Ranging System With Increased Resolution

Science.gov (United States)

Meyer, William E.; Johnson, William G.

1987-01-01

Master-oscillator frequency increased. Ultrasonic range-measuring system with 0.1-in. resolution provides continuous digital display of four distance readings, each updated four times per second. Four rangefinder modules in system are modified versions of rangefinder used for automatic focusing in commercial series of cameras. Ultrasonic pulses emitted by system innocuous to both people and equipment. Provides economical solutions to such distance-measurement problems as posed by boats approaching docks, truck backing toward loading platform, runway-clearance readout for tail of airplane with high angle attack, or burglar alarm.

Wideband 4-diode sampling circuit

Science.gov (United States)

Wojtulewicz, Andrzej; Radtke, Maciej

2016-09-01

The objective of this work was to develop a wide-band sampling circuit. The device should have the ability to collect samples of a very fast signal applied to its input, strengthen it and prepare for further processing. The study emphasizes the method of sampling pulse shaping. The use of ultrafast pulse generator allows sampling signals with a wide frequency spectrum, reaching several gigahertzes. The device uses a pulse transformer to prepare symmetrical pulses. Their final shape is formed with the help of the step recovery diode, two coplanar strips and Schottky diode. Made device can be used in the sampling oscilloscope, as well as other measurement system.

Wide-band cable systems at SLAC

International Nuclear Information System (INIS)

Struven, W.

1983-01-01

SLAC's first cable TV system was installed in 1979 to remotely monitor a narrow pulse which was generated in the west end of the klystron gallery. When Stanford Linear Collider (SLC) experimental work started at the west end of the accelerator, the original 1979 cable was upgraded to a bidirectional system so that 2 MBaud point-to-point data and several video and 9600 baud channels could be transmitted. The implementation of the SLC requires a complete upgrading of the accelerator control system. The system is based on a distributed processing configuration using a PDP11/780 VAX in the Main Control Center (MCC) and Intel single-board computers in a multibus configuration along the accelerator. The high-speed data linking is supplied by a 1 MBaud Time Division Multiple Access (TDMA) Network. The same cable is used to provide video, low-speed data, voice and high-speed point-to-point data services. The transmission system will utilize a wideband midsplit cable facility to collect and distribute signals to all parts of the network

Wideband MIMO Channel Capacity Analysis in Multiprobe Anechoic Chamber Setups

DEFF Research Database (Denmark)

Fan, Wei; Kyosti, Pekka; Nielsen, Jesper Ødum

2016-01-01

been used to determine the test area size for a limited number of probes. However, it is desirable that the test area size is defined in terms of data rate deviation of the simulated channel in the laboratory from that of the target channel model. This paper reports MIMO capacity analysis results...... for wideband spatio-temporal channel models, with emphasis on the impact of spatial correlation at the transmit (Tx) side, the channel model, and the spatial correlation at the Rx side on the capacity simulation accuracy. Simulation results show that the number of probes is irrelevant to capacity simulation......This paper discusses over the air (OTA) testing for multiple input multiple output (MIMO) capable terminals with emphasis on wideband MIMO channel capacity analysis in a multi-probe anechoic chamber setup. In the literature, the spatial correlation simulation accuracy at the receiver (Rx) side has...

Design of a Compact Wideband Antenna Array for Microwave Imaging Applications

Directory of Open Access Journals (Sweden)

J. Puskely

2013-12-01

Full Text Available In the paper, wideband antenna arrays aimed at microwave imaging applications and SAR applications operating at Ka band were designed. The antenna array feeding network is realized by a low-loss SIW technology. Moreover, we have replaced the large feed network comprised of various T and Y junctions by a simple broadband network of compact size to more reduce losses in the substrate integrated waveguide and also save space on the PCB. The designed power 8-way divider is complemented by a wideband substrate integrated waveguide to a grounded coplanar waveguide transition and directly connected to the antenna elements. The measured results of antenna array are consistent with our simulation. Obtained results of the developed array demonstrated improvement compared to previously developed binary feed networks with microstrip or SIW splitters.

Realization of Miniaturized Multi-/Wideband Microwave Front-Ends

Science.gov (United States)

Al Shamaileh, Khair A.

The ever-growing demand toward designing microwave front-end components with enhanced access to the radio spectrum (e.g., multi-/wideband functionality) and improved physical features (e.g., miniaturized circuitry, ease and cost of fabrication) is becoming more paramount than ever before. This dissertation proposes new design methodologies, simulations, and experimental validations of passive front-ends (i.e., antennas, couplers, dividers) at microwave frequencies. The presented design concepts optimize both electrical and physical characteristics without degrading the intended performance. The developed designs are essential to the upcoming wireless technologies. The first proposed component is a compact ultra-wideband (UWB) Wilkinson power divider (WPD). The design procedure is accomplished by replacing the uniform transmission lines in each arm of the conventional single-frequency divider with impedance-varying profiles governed by a truncated Fourier series. While such non-uniform transmission lines (NTLs) are obtained through the even-mode analysis, three isolation resistors are optimized in the odd-mode circuit to achieve proper isolation and output ports matching over the frequency range of interest. The proposed design methodology is systematic, and results in single-layered and compact structures. For verification purposes, an equal split WPD is designed, simulated, and measured. The obtained results show that the input and output ports matching as well as the isolation between the output ports are below --10 dB; whereas the transmission parameters vary between --3.2 dB and --5 dB across the 3.1--10.6 GHz band. The designed divider is expected to find applications in UWB antenna diversity, multiple-input-multiple-output (MIMO) schemes, and antenna arrays feeding networks. The second proposed component is a wideband multi-way Bagley power divider (BPD). Wideband functionality is achieved by replacing the single-frequency matching uniform microstrip lines in

Linear and nonlinear attributes of ultrasonic time series recorded from experimentally loaded rock samples and total failure prediction

Czech Academy of Sciences Publication Activity Database

Rudajev, Vladimír; Číž, R.

2007-01-01

Roč. 44, č. 3 (2007), s. 457-467 ISSN 1365-1609 R&D Projects: GA ČR GA205/06/0906 Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z30460519 Keywords : ultrasonic emission * microfracturing * time series * autocorrelation * fractal dimensions * neural networks Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.735, year: 2007

Evaluation on damage of pipe using ultrasonic and acoustic emission

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Kyung; Lee, Sang Pill; Lee, Moon Hee [Dongeui Univ., Busan (Korea, Republic of); Lee, Joon Hyun [Pusan National Univ., Busan (Korea, Republic of)

2008-07-01

An elastic waves like ultrasonic and acoustic emission were used to evaluate the propagating properties of the wave in pipe, and study on mode conversion of the elastic wave due to the defects on the pipe was performed. In this study an Acoustic Emission (AE) sensor was used to receive the propagated ultrasonic wave. AE technique has a advantage that it can identify the received ultrasonic wave by the analysis of the AE parameters such as count, energy, frequency, duration time and amplitude. For transmitting and receiving of the wave, an universal angle wedge was manufactured. The optimum angles for transmitting of ultrasonic wave and signal receiving at the attached AE sensor on the pipe were determined. Theoretical dispersion curve was compared with the results of the time-frequency analysis based on the wavelet transformation. The received modes showed a good agreement with theoretical one. The used ultrasonic sensor was 1MHz, and AE sensor was broadband. The artificial cracks were induced in the pipe to measure the propagation characteristics of the elastic wave for the cracks. AE parameters for the received signals were also varied with the crack types in the pipe. AE parameters of amplitude and duration time were more effective factors than the analysis of mode conversion for evaluation of the cracks in the pipe.

Wideband DOA Estimation through Projection Matrix Interpolation

OpenAIRE

Selva, J.

2017-01-01

This paper presents a method to reduce the complexity of the deterministic maximum likelihood (DML) estimator in the wideband direction-of-arrival (WDOA) problem, which is based on interpolating the array projection matrix in the temporal frequency variable. It is shown that an accurate interpolator like Chebyshev's is able to produce DML cost functions comprising just a few narrowband-like summands. Actually, the number of such summands is far smaller (roughly by factor ten in the numerical ...

Underwater detection by using ultrasonic sensor

Science.gov (United States)

Bakar, S. A. A.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

2017-09-01

This paper described the low cost implementation of hardware and software in developing the system of ultrasonic which can visualize the feedback of sound in the form of measured distance through mobile phone and monitoring the frequency of detection by using real time graph of Java application. A single waterproof transducer of JSN-SR04T had been used to determine the distance of an object based on operation of the classic pulse echo detection method underwater. In this experiment, the system was tested by placing the housing which consisted of Arduino UNO, Bluetooth module of HC-06, ultrasonic sensor and LEDs at the top of the box and the transducer was immersed in the water. The system which had been tested for detection in vertical form was found to be capable of reporting through the use of colored LEDs as indicator to the relative proximity of object distance underwater form the sensor. As a conclusion, the system can detect the presence of an object underwater within the range of ultrasonic sensor and display the measured distance onto the mobile phone and the real time graph had been successfully generated.

Piezoelectric Nanotube Array for Broadband High-Frequency Ultrasonic Transducer.

Science.gov (United States)

Liew, Weng Heng; Yao, Kui; Chen, Shuting; Tay, Francis Eng Hock

2018-03-01

Piezoelectric materials are vital in determining ultrasonic transducer and imaging performance as they offer the function for conversion between mechanical and electrical energy. Ultrasonic transducers with high-frequency operation suffer from performance degradation and fabrication difficulty of the demanded piezoelectric materials. Hence, we propose 1-D polymeric piezoelectric nanostructure with controlled nanoscale features to overcome the technical limitations of high-frequency ultrasonic transducers. For the first time, we demonstrate the integration of a well-aligned piezoelectric nanotube array to produce a high-frequency ultrasonic transducer with outstanding performance. We find that nanoconfinement-induced polarization orientation and unique nanotube structure lead to significantly improved piezoelectric and ultrasonic transducing performance over the conventional piezoelectric thin film. A large bandwidth, 126% (-6 dB), is achieved at high center frequency, 108 MHz. Transmission sensitivity of nanotube array is found to be 46% higher than that of the monolithic thin film transducer attributed to the improved electromechanical coupling effectiveness and impedance match. We further demonstrate high-resolution scanning, ultrasonic imaging, and photoacoustic imaging using the obtained nanotube array transducers, which is valuable for biomedical imaging applications in the future.

Doppler Processing with Ultra-Wideband (UWB) Radar Revisited

Science.gov (United States)

2018-01-01

REPORT TYPE Technical Note 3. DATES COVERED (From - To) December 2017 4. TITLE AND SUBTITLE Doppler Processing with Ultra-Wideband (UWB) Radar...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT This technical note revisits previous work performed at the US Army Research Laboratory related to...target considered previously is proportional to a delayed version of the transmitted signal, up to a complex constant factor. We write the received

Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

Directory of Open Access Journals (Sweden)

J. Jilkova

2008-04-01

Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

Ultrasonication aided in-situ transesterification of microbial lipids to biodiesel.

Science.gov (United States)

Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar Dayal; Surampalli, Rao Y; Valéro, Jose R

2014-10-01

In-situ transesterification of microbial lipid to biodiesel has been paid substantial attention due to the fact that the lipid extraction and transesterification can be conducted in one-stage process. To improve the feasibility of in-situ transesterification, ultrasonication was employed to reduce methanol requirement and reaction time. The results showed that the use of ultrasonication could achieve high conversion of lipid to FAMEs (92.1% w lipid conversion/w total lipids) with methanol to lipid molar ratio 60:1 and NaOH addition 1% w/w lipid in 20 min, while methanol to lipid molar ratio 360:1, NaOH addition 1% w/w lipid, and reaction time 12h was required to obtain similar yield in in-situ transesterification without ultrasonication. The compositions of FAMEs obtained in case of ultrasonication aided in-situ transesterification were similar as that of two-stage extraction followed by transesterification processes. Copyright © 2014. Published by Elsevier Ltd.

A study on the repeatability of ultrasonic testing data

International Nuclear Information System (INIS)

Yoshimura, Seiichi; Fukumoto, Hiroshi

1980-01-01

Reliability improvement of ultrasonic testing data is strongly desired in ultrasonic testing working of nuclear power plants. This paper deals with the problems of the testing by the manual and the remote control apparatus, and with the factors which influence the repeatability of ultrasonic testing data. Following results are found in it. (1) In the testing by the manual, working time and posture influence the repeatability of testing data. (2) Glycerin in suitable for the couplant in the respect of the repeatability of testing data. In the case of using machine oil, the pressure to the probe necessitates to be over 0.2 kg/cm 2 . (3) In the testing by the remote control apparatus, working time, working environment and defect position does not influence the repeatability of testing data. (author)

Evaluation of Ultrasonic Nonlinear Characteristics in Heat-Treated Aluminum Alloy (Al-Mg-Si-Cu

Directory of Open Access Journals (Sweden)

JongBeom Kim

2013-01-01

Full Text Available The nonlinear ultrasonic technique has been known to be more sensitive to minute variation of elastic properties in material than the conventional linear ultrasonic method. In this study, the ultrasonic nonlinear characteristics in the heat-treated aluminum alloy (Al-Mg-Si-Cu have been evaluated. For this, the specimens were heat treated for various heating period up to 50 hours at three different heating temperatures: 250°C, 300°C, and 350°C. The ultrasonic nonlinear characteristics of each specimen were evaluated by measuring the ultrasonic nonlinear parameter β from the amplitudes of fundamental and second harmonic frequency components in the transmitted ultrasonic wave. After the ultrasonic test, tensile strengths and elongations were obtained by the tensile test to compare with the parameter β. The heating time showing a peak in the parameter β was identical to that showing critical change in the tensile strength and elongation, and such peak appeared at the earlier heating time in the higher heating temperature. These results suggest that the ultrasonic nonlinear parameter β can be used for monitoring the variations in elastic properties of aluminum alloys according to the heat treatment.

Ultra-wideband reflective polarization converter based on anisotropic metasurface

Science.gov (United States)

Wu, Jia-Liang; Lin, Bao-Qin; Da, Xin-Yu

2016-08-01

In this paper, we propose an ultra-wideband reflective linear cross-polarization converter based on anisotropic metasurface. Its unit cell is composed of a square-shaped resonator with intersectant diagonal and metallic ground sheet separated by dielectric substrate. Simulated results show that the converter can generate resonances at four frequencies under normal incident electromagnetic (EM) wave, leading to the bandwidth expansion of cross-polarization reflection. For verification, the designed polarization converter is fabricated and measured. The measured and simulated results agree well with each other, showing that the fabricated converter can convert x- or y-polarized incident wave into its cross polarized wave in a frequency range from 7.57 GHz to 20.46 GHz with a relative bandwidth of 91.2%, and the polarization conversion efficiency is greater than 90%. The proposed polarization converter has a simple geometry but an ultra wideband compared with the published designs, and hence possesses potential applications in novel polarization-control devices. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471387, 61271250, and 61571460).

Thickness measurement by using cepstrum ultrasonic signal processing

International Nuclear Information System (INIS)

Choi, Young Chul; Yoon, Chan Hoon; Choi, Heui Joo; Park, Jong Sun

2014-01-01

Ultrasonic thickness measurement is a non-destructive method to measure the local thickness of a solid element, based on the time taken for an ultrasound wave to return to the surface. When an element is very thin, it is difficult to measure thickness with the conventional ultrasonic thickness method. This is because the method measures the time delay by using the peak of a pulse, and the pulses overlap. To solve this problem, we propose a method for measuring thickness by using the power cepstrum and the minimum variance cepstrum. Because the cepstrums processing can divides the ultrasound into an impulse train and transfer function, where the period of the impulse train is the traversal time, the thickness can be measured exactly. To verify the proposed method, we performed experiments with steel and, acrylic plates of variable thickness. The conventional method is not able to estimate the thickness, because of the overlapping pulses. However, the cepstrum ultrasonic signal processing that divides a pulse into an impulse and a transfer function can measure the thickness exactly.

Ultrasonic, microwave, and millimeter wave inspection techniques for adhesively bonded stacked open honeycomb core composites

Science.gov (United States)

Thomson, Clint D.; Cox, Ian; Ghasr, Mohammad Tayeb Ahmed; Ying, Kuang P.; Zoughi, Reza

2015-03-01

Honeycomb sandwich composites are used extensively in the aerospace industry to provide stiffness and thickness to lightweight structures. A common fabrication method for thick, curved sandwich structures is to stack and bond multiple honeycomb layers prior to machining core curvatures. Once bonded, each adhesive layer must be inspected for delaminations and the presence of unwanted foreign materials. From a manufacturing and cost standpoint, it can be advantageous to inspect the open core prior to face sheet closeout in order to reduce end-article scrap rates. However, by nature, these honeycomb sandwich composite structures are primarily manufactured from low permittivity and low loss materials making detection of delamination and some of the foreign materials (which also are low permittivity and low loss) quite challenging in the microwave and millimeter wave regime. Likewise, foreign materials such as release film in adhesive layers can be sufficiently thin as to not cause significant attenuation in through-transmission ultrasonic signals, making them difficult to detect. This paper presents a collaborative effort intended to explore the efficacy of different non-contact NDI techniques for detecting flaws in a stacked open fiberglass honeycomb core panel. These techniques primarily included air-coupled through-transmission ultrasonics, single-sided wideband synthetic aperture microwave and millimeter-wave imaging, and lens-focused technique. The goal of this investigation has been to not only evaluate the efficacy of these techniques, but also to determine their unique advantages and limitations for evaluating parameters such as flaw type, flaw size, and flaw depth.

Development and application of the ultrasonic technologies in nuclear engineering

International Nuclear Information System (INIS)

Lebedev, Nikolay; Krasilnikov, Dmitry; Vasiliev, Albert; Dubinin, Gennady; Yurmanov, Viktor

2012-09-01

Efficiency of some traditional chemical technologies in different areas could be significantly increased by adding ultrasonic treatment. For example, ultrasonic treatment was found to improve make-up water systems, decontamination procedures, etc. Improvement of traditional chemical technologies with implementation of ultrasonic treatment has allowed to significantly reducing water waste, including harmful species and radioactive products. The report shows the examples of the recent ultrasonic technology development and application in Russian nuclear engineering. They are as follows: - Preliminary cleaning of surfaces of in-pile parts (e.g. control sensors) prior to their assemblage and welding - Decontamination of grounds and metal surfaces of components with a complex structure -Decrease in sliding friction between fuel rods and grids during VVER reactor fuel assembly manufacturing -Removal of deposits from reactor fuel surfaces in VVER-440s -Increasing the density and strength of pressed sintered items while making fuel pellets and fuel elements, especially mixed-oxide fuel Surface cleanness is very important for the fuel assembly manufacturing, especially prior to welding. An ultrasonic technology for surface cleaning (from graphite and other lubricants, oxides etc.) was developed and implemented. The ultrasonic cleaning is applicable to the parts having both simple shape and different holes. Ultrasonic technology has allowed to improve the surface quality and environmental safety. Ultrasonic treatment appears to be expedient to intensify the chemical decontamination of solid radioactive waste from grounds of different fractions to metallic components. Ultrasonic treatment reduces the decontamination process duration up to 100 times as much. Excellent decontamination factor was received even for the ground fractions below 1 mm. It should be noted that alternative decontamination techniques (e.g. hydraulic separation) are poorly applicable for such ground

Wide-band CMOS low-noise amplifier exploiting thermal noise canceling

NARCIS (Netherlands)

Bruccoleri, F.; Klumperink, Eric A.M.; Nauta, Bram

Known elementary wide-band amplifiers suffer from a fundamental tradeoff between noise figure (NF) and source impedance matching, which limits the NF to values typically above 3 dB. Global negative feedback can be used to break this tradeoff, however, at the price of potential instability. In

Overview of the ultrasonic instrumentation research in the MYRRHA project

Energy Technology Data Exchange (ETDEWEB)

Dierckx, M.; Leysen, W.; Van Dyck, D. [Belgian Nuclear Research Center SCK.CEN (Belgium)

2015-07-01

parameter to assess the performance of ultrasonic systems that are submerged in LBE over longer time periods. In the last part we will briefly present the overall design of the two main ultrasonic systems that will be deployed in MYRRHA: the ultrasonic fuel identification system and the ultrasonic lost fuel localization system. (authors)

Ultrasonic Study of Dislocation Dynamics in Lithium -

Science.gov (United States)

Han, Myeong-Deok

1987-09-01

Experimental studies of dislocation dynamics in LiF single crystals, using ultrasonic techniques combined with dynamic loading, were performed to investigate the time evolution of the plastic deformation process under a short stress pulse at room temperature, and the temperature dependence of the dislocation damping mechanism in the temperature range 25 - 300(DEGREES)K. From the former, the time dependence of the ultrasonic attenuation was understood as resulting from dislocation multiplication followed by the evolution of mobile dislocations to immobile ones under large stress. From the latter, the temperature dependence of the ultrasonic attenuation was interpreted as due to the motion of the dislocation loops overcoming the periodic Peierls potential barrier in a manner analogous to the motion of a thermalized sine-Gordon chain under a small stress. The Peierls stress obtained from the experimental results by application of Seeger's relaxation model with exponential dislocation length distribution was 4.26MPa, which is consistent with the lowest stress for the linear relation between the dislocation velocity and stress observed by Flinn and Tinder.

A wideband Noise-Canceling CMOS LNA exploiting a transformer

NARCIS (Netherlands)

Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, Domine M.W.; Nauta, Bram

2006-01-01

Abstract — A broadband LNA incorporating single-ended to differential conversion, has been successfully implemented using a noise-canceling technique and a single on-chip transformer. The LNA achieves a high voltage gain of 19dB, a wideband input match (2.5–4.0 GHz), and a Noise Figure of 4–5.4 dB,

A wideband Noise-Canceling CMOS LNA exploiting a transformer

NARCIS (Netherlands)

Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, Domine M.W.; Nauta, Bram

2006-01-01

A broadband LNA incorporating single-ended to differential conversion, has been successfully implemented using a noise-canceling technique and a single on-chip transformer. The LNA achieves a high voltage gain of 19dB, a wideband input match (2.5–4.0 GHz), and a Noise Figure of 4–5.4 dB, while

Design and Implementation of Wideband Exciter for an Ultra-high Resolution Airborne SAR System

Directory of Open Access Journals (Sweden)

Jia Ying-xin

2013-03-01

Full Text Available According to an ultra-high resolution airborne SAR system with better than 0.1 m resolution, a wideband Linear Frequency Modulated (LFM pulse compression exciter with 14.8 GHz carrier and 3.2 GHz bandwidth is designed and implemented. The selection of signal generation scheme and some key technique points for wideband LFM waveform is presented in detail. Then, an acute test and analysis of the LFM signal is performed. The final airborne experiments demonstrate the validity of the LFM source which is one of the subsystems in an ultra-high resolution airborne SAR system.

Artificial Intelligence Assists Ultrasonic Inspection

Science.gov (United States)

Schaefer, Lloyd A.; Willenberg, James D.

1992-01-01

Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

Dynamics of Gradient Bioceramic Composite Coating on Surface of Titanium Alloy by Wide-Band Laser Cladding

Institute of Scientific and Technical Information of China (English)

LIU Qi-bin; ZOU Long-jiang; ZHU Wei-dong; LI Hai-tao; DONG Chuang

2004-01-01

The gradient bioceramic coating was prepared on the surface of titanium alloy using wide-band laser cladding. The dynamics of gradient bioceramic composite coating containing hydroxyapatite (HA) prepared with mixture of CaHPO4*2H2O and CaCO3 under the condition of wide-band laser was studied theoretically. The corresponding mathematical model and its numerical solution were presented. The examination experiment showed that HA bioceramic composite coatings can be obtained by appropriately choosing wide-band laser cladding parameters. The microstructure and surface morphology of HA bioceramic coating were observed by SEM and X-ray diffraction. The experimental results showed that the bioceramic coating is composed of HA, β-TCP, CaO, CaTiO3 and TiO2. The surface of bioceramic coating takes coral-shaped structure or short-rod piled structure, which helps osteoblast grow into bioceramic and improves the biocompatibility.

[Destruction of synovial pannus of antigen-induced arthritis by ultrasonic cavitation in rabbits].

Science.gov (United States)

Zhang, Ling-yan; Qiu, Li; Wang, Lei; Lin, Ling; Wen, Xiao-rong

2011-11-01

To optimize the conditions of ultrasonic irradiation and microbubble of ultrasound cavitation on destruction of synovial pannus of antigen-induced arthritis (AIA) in rabbits. Antigen-induced arthritis was successfully induced on bilateral knee joints of 85 rabbits. Each 10 AIA rabbits were divided into two groups to compare various peak negative pressures, different ultrasonic pulse durations, various pulse repetition frequencies, different irradiance duration, different dosages of microbubble contrast agents, different ultrasonic irradiance times. With intravenous infusion of Sonovue to the rabbits, ultrasonic irradiance was performed on the right knee joint using the above condition of ultrasound cavitation. At the day 1 after ultrasonic irradiance, MRI and pathological examination were employed to evaluate the optimal conditions. The optimal parameters and conditions for ultrasonic irradiance included intermittent ultrasonic application (in 6 s intervals), 0.6 mL/kg of microbubble contrast agent, 4.6 MPa of ultrasonic peak negative pressure, 100 cycles of pulse duration, 50 Hz of pulse repetition frequency, 5 min of ultrasonic duration, 0.6 mL/kg of dosages of microbubble contrast agents and multi-sessional ultrasonic irradiance. After the ultrasonic irradiance, the thickness of right knee synovium measured by MRI was thinner than that of left knee and synovial necrosis was confirmed by the pathological finding. Under optimal ultrasonic irradiation and microbubble conditions, ultrasonic cavitation could destroy synovial pannus of AIA in rabbits.

Preparation of ZnO nanocrystals via ultrasonic irradiation

DEFF Research Database (Denmark)

Qian, D.; Jiang, Jianzhong; Hansen, P. L.

2003-01-01

A simple and rapid process has been developed for the preparation of nanometer-sized ZnO crystals via ultrasonic irradiation, by which pure ZnO nanocrystals with an average size of 6 nm and narrow size distribution can be synthesized in a short time and without using any solvents for the precipit......A simple and rapid process has been developed for the preparation of nanometer-sized ZnO crystals via ultrasonic irradiation, by which pure ZnO nanocrystals with an average size of 6 nm and narrow size distribution can be synthesized in a short time and without using any solvents...

Ultrasonic grinding method

International Nuclear Information System (INIS)

Miyahara, Shuji.

1990-01-01

An ultrasonic generator and a liquid supply nozzle are opposed to an object to be ground and a pump is started in this state to supply an organic solvent. Matters to be decontaminated which adheres to the surface of the object to be ground and are difficult to be removed by a mere mechanical removing method can be eliminated previously by the surface active effect of the organic solvent such as ethanol prior to the oscillation of the ultrasonic generator. Subsequently, when the ultrasonic generator is oscillated, scales in the floated state can be removed simply. Further, since the organic solvent can penetrate to provide the surface active effect even in such a narrow portion that the top end of the ultrasonic generator is difficult to the intruded at the surface of the object to be ground, the decontaminating treatment can be applied also to such a narrow portion. (T.M.)

A photonic ultra-wideband pulse generator based on relaxation oscillations of a semiconductor laser

DEFF Research Database (Denmark)

Yu, Xianbin; Gibbon, Timothy Braidwood; Pawlik, Michal

2009-01-01

A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconductor laser is proposed and experimentally demonstrated. We numerically simulate the modulation response of a direct modulation laser (DML) and show that due to the relaxation oscillations of the laser......, the generated signals with complex shape in time domain match the Federal Communications Commission (FCC) mask in the frequency domain. Experimental results using a DML agree well with simulation predictions. Furthermore, we also experimentally demonstrate the generation of FCC compliant UWB signals...

Gas ultrasonic flow rate measurement through genetic-ant colony optimization based on the ultrasonic pulse received signal model

Science.gov (United States)

Hou, Huirang; Zheng, Dandan; Nie, Laixiao

2015-04-01

For gas ultrasonic flowmeters, the signals received by ultrasonic sensors are susceptible to noise interference. If signals are mingled with noise, a large error in flow measurement can be caused by triggering mistakenly using the traditional double-threshold method. To solve this problem, genetic-ant colony optimization (GACO) based on the ultrasonic pulse received signal model is proposed. Furthermore, in consideration of the real-time performance of the flow measurement system, the improvement of processing only the first three cycles of the received signals rather than the whole signal is proposed. Simulation results show that the GACO algorithm has the best estimation accuracy and ant-noise ability compared with the genetic algorithm, ant colony optimization, double-threshold and enveloped zero-crossing. Local convergence doesn’t appear with the GACO algorithm until -10 dB. For the GACO algorithm, the converging accuracy and converging speed and the amount of computation are further improved when using the first three cycles (called GACO-3cycles). Experimental results involving actual received signals show that the accuracy of single-gas ultrasonic flow rate measurement can reach 0.5% with GACO-3 cycles, which is better than with the double-threshold method.

ULTRASONIC ASSEMBLY [REVIEW

Directory of Open Access Journals (Sweden)

PORAV Viorica

2015-05-01

Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

Artificial intelligence and ultrasonic tests in detection of defects

International Nuclear Information System (INIS)

Barrera Cardiel, G.; Fabian Alvarez, M. a.; Velez Martinez, M.; Villasenor, L.

2001-01-01

One of the most serious problems in the quality control of welded unions is the location, identification and classification of defects. As a solution to this problem, a technique for classification, applicable to welded unions done by electric arc welding as well as by friction, is proposed; it is based on ultrasonic signals. The neuronal networks proposed are Kohonen and Multilayer Percept ron, all in a virtual instrument environment. Currently the techniques most used in this field are: radiological analysis (X-rays) and ultrasonic analysis (ultrasonic waves). The X-ray technique in addition to being dangerous requires highly specialized personnel and equipment, therefore its use is restricted. The ultrasonic technique, in spite of being one of the most used for detection of discontinuities, requires personnel with wide experience in the interpretation of ultrasonic signals, this is a time-consuming process which necessarily increases its operation cost. The classification techniques that we propose turn out to be safe, reliable, inexpensive and easy to implement for the solution of this important problem. (Author) 8 refs

Old World frog and bird vocalizations contain prominent ultrasonic harmonics

Science.gov (United States)

Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

2004-02-01

Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

Wideband and UWB Antennas for Wireless Applications: A Comprehensive Review

Directory of Open Access Journals (Sweden)

Renato Cicchetti

2017-01-01

Full Text Available A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible, and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc. and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.

High quantum yield ZnO quantum dots synthesizing via an ultrasonication microreactor method.

Science.gov (United States)

Yang, Weimin; Yang, Huafang; Ding, Wenhao; Zhang, Bing; Zhang, Le; Wang, Lixi; Yu, Mingxun; Zhang, Qitu

2016-11-01

Green emission ZnO quantum dots were synthesized by an ultrasonic microreactor. Ultrasonic radiation brought bubbles through ultrasonic cavitation. These bubbles built microreactor inside the microreactor. The photoluminescence properties of ZnO quantum dots synthesized with different flow rate, ultrasonic power and temperature were discussed. Flow rate, ultrasonic power and temperature would influence the type and quantity of defects in ZnO quantum dots. The sizes of ZnO quantum dots would be controlled by those conditions as well. Flow rate affected the reaction time. With the increasing of flow rate, the sizes of ZnO quantum dots decreased and the quantum yields first increased then decreased. Ultrasonic power changed the ultrasonic cavitation intensity, which affected the reaction energy and the separation of the solution. With the increasing of ultrasonic power, sizes of ZnO quantum dots first decreased then increased, while the quantum yields kept increasing. The effect of ultrasonic temperature on the photoluminescence properties of ZnO quantum dots was influenced by the flow rate. Different flow rate related to opposite changing trend. Moreover, the quantum yields of ZnO QDs synthesized by ultrasonic microreactor could reach 64.7%, which is higher than those synthesized only under ultrasonic radiation or only by microreactor. Copyright © 2016 Elsevier B.V. All rights reserved.

Discrete-Time Mixing Receiver Architecture for RF-Sampling Software-Defined Radio

NARCIS (Netherlands)

Ru, Z.; Klumperink, Eric A.M.; Nauta, Bram

2010-01-01

Abstract—A discrete-time (DT) mixing architecture for RF-sampling receivers is presented. This architecture makes RF sampling more suitable for software-defined radio (SDR) as it achieves wideband quadrature demodulation and wideband harmonic rejection. The paper consists of two parts. In the first

A wideband high-linearity RF receiver front-end in CMOS

NARCIS (Netherlands)

Arkesteijn, V.J.; Klumperink, Eric A.M.; Nauta, Bram

This paper presents a wideband high-linearity RF receiver-front-end, implemented in standard 0.18 μm CMOS technology. The design employs a noise-canceling LNA in combination with two passive mixers, followed by lowpass-filtering and amplification at IF. The achieved bandwidth is >2 GHz, with a noise

Wideband CMOS receivers exploiting simultaneous output balancing and noise/distortion canceling

NARCIS (Netherlands)

Blaakmeer, S.C.; Klumperink, Eric A.M.; Leenaerts, D.M.W.; Nauta, Bram

2008-01-01

Abstract— This paper deals with the problem of realizing wideband receiver front-ends in downscaled CMOSTechnologies, which are highly wanted for multi-standard radio receivers and cognitive radio applications. Instead of using many narrowband inductor based receivers, we prefer the use of one

Ultrasonic aqueous cleaning as a replacement for chlorinated solvent cleaning

International Nuclear Information System (INIS)

Thompson, L.M.; Simandl, R.F.

1992-01-01

The Oak Ridge Y-12 Plant has been involved in the replacement of chlorinated solvents since 1982. One of the most successful replacement efforts has been the substitution of vapor degreasers or soak tanks using chlorinated solvents with ultrasonic cleaning using aqueous detergents. Recently, funding was obtained from the Department of Energy Office (DOE) of Technology Development to demonstrate this technology. A unit has been procured and installed in the vacuum pump shop area to replace the use of a solvent soak tank. Initially, the solvents used in the shop were CFC-113 and a commercial brand cleaner which contained both perchloroethylene and methylene chloride. While the ultrasonic unit was being procured, a terpene-based solvent was used. Generally, parts were soaked overnight in order to soften baked-on vanish. Many times, wire brushing was used to help remove remaining contamination. Initial testing with the ultrasonic cleaner indicated cleaning times of 20 min were as effective as the overnight solvent soaks in removing contamination. Wire brushing was also not required following the ultrasonic cleaning as was sometimes required with the solvent soak

Ultrasonically enhanced disintegration. Polymers, sludge, and contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Groenroos, A.

2010-05-15

on the initial dynamic viscosity. The higher the initial dynamic viscosity, the faster the degradation. This work confirms the general assumption that the shear forces generated by the rapid motion of the solvent following cavitational collapse are responsible for the breakage of the chemical bonds within the polymer. The effect of polymer concentration could be interpreted in terms of the increase in viscosity with concentration, causing the molecules to become less mobile in solution with smaller velocity gradients around collapsing bubbles. Ultrasonic disintegration of sludge increased the amount of soluble chemical oxygen demand (SCOD) and the production of methane. Multivariate data analysis suggested that ultrasonic power, sludge dry solids (DS), sludge temperature, and ultrasonic treatment time significantly affect sludge disintegration. It was also found that high ultrasound power together with a short treatment time is more efficient than low ultrasound power with a long treatment time. When using high ultrasound power, the ultrasound propagation is an important factor both in cavitation erosion prevention and reactor scale-up. Ultrasound efficiency rose linearly with input power in sludge at small distances from the transducer. On the other hand, ultrasound efficiency started even to decrease with input power at long distances from the transducer. When using oxidizing agents together with ultrasonic disintegration there was no increase in SCOD and only a slight increase in total organic carbon (TOC) compared to ultrasonic treatment alone. However, when using oxidizing agents together with ultrasound, no enhancement in methane production was observed. Ultrasound improved the remediation results of both products (sink and float products) in heavy medium separation. This phenomenom was based on the fact that the amount of ultrafine metal fraction was diminished when attrition conditioning was replaced by ultrasound. The remediation process produced float

GARUSO - Version 1.0. Uncertainty model for multipath ultrasonic transit time gas flow meters

Energy Technology Data Exchange (ETDEWEB)

Lunde, Per; Froeysa, Kjell-Eivind; Vestrheim, Magne

1997-09-01

This report describes an uncertainty model for ultrasonic transit time gas flow meters configured with parallel chords, and a PC program, GARUSO Version 1.0, implemented for calculation of the meter`s relative expanded uncertainty. The program, which is based on the theoretical uncertainty model, is used to carry out a simplified and limited uncertainty analysis for a 12`` 4-path meter, where examples of input and output uncertainties are given. The model predicts a relative expanded uncertainty for the meter at a level which further justifies today`s increasing tendency to use this type of instruments for fiscal metering of natural gas. 52 refs., 15 figs., 11 tabs.

Impact of ultrasonication time on elution of super heavy oil and its biomarkers from aging soils using a Triton X-100 micellar solution

International Nuclear Information System (INIS)

Ji Guodong; Zhou Guohui

2010-01-01

An ultrasound-enhanced elution system with Triton X-100 solution was used to remediate aging soils contaminated with super heavy oil. We used GC/MS, SEM, and X-ray diffraction (XRD) to analyze the effect of ultrasonic time (0-1800 s) on the elution of super heavy oil and its three characteristic biomarkers (C 26-34 17α 25-norhopanes, C 26-28 triaromatic steroid [TAS], and C 27-29 methyl triaromatic steroid [MTAS]). The oil and biomarkers remaining in the treated soils followed similar second-order functions with increasing ultrasonication times. Biomarker elution was closely related to carbon numbers in the marker. For C 26-34 17α 25-norhopanes, the smaller molecules were more readily eluted during 0-360 s ultrasound. This trend was reversed upon application of ultrasound during 1080-1800 s, with improved elution of larger molecules and elution followed a similar second-order function. For C 26-28 TAS, smaller molecules were more readily eluted but the elution of larger molecules followed a similar second-order function. For C 27-29 MTAS, elution of larger molecules was close to that of C 26-34 17α 25-norhopanes. Results of SEM and XRD indicated that the mineral and chemical compositions of soils eluted at ultrasonication times of 1080-1800 s closely resembled clean soils.

Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media

Science.gov (United States)

2016-03-04

AFRL-AFOSR-VA-TR-2016-0112 Ultra-Wideband Electromagnetic Pulse Propagation through Causal Media Natalie Cartwright RESEARCH FOUNDATION OF STATE... Electromagnetic Pulse Propagation through Causal Media 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0013 5c.  PROGRAM ELEMENT NUMBER 61102F 6...SUPPLEMENTARY NOTES 14. ABSTRACT When an electromagnetic pulse travels through a dispersive material each frequency of the transmitted pulse changes in both

Ultrasonic level indicator for liquids and its application

International Nuclear Information System (INIS)

Kanngiesser, P.

1976-01-01

Ultrasonic level indicator for liquids where a piezo-element is used to reverse the piezoelectric effect may be applied in a more versatile way if the indicator is provided with a reflector. It becomes less susceptible to faults and may be used for all liquids, including liquid metals. The piezo-element may then be used at the same time as receiver for ultrasonic waves emitted previously and, in that case, echoed back by the refelctor. (UWI) [de

Quadrature demodulation based circuit implementation of pulse stream for ultrasonic signal FRI sparse sampling

International Nuclear Information System (INIS)

Shoupeng, Song; Zhou, Jiang

2017-01-01

Converting ultrasonic signal to ultrasonic pulse stream is the key step of finite rate of innovation (FRI) sparse sampling. At present, ultrasonic pulse-stream-forming techniques are mainly based on digital algorithms. No hardware circuit that can achieve it has been reported. This paper proposes a new quadrature demodulation (QD) based circuit implementation method for forming an ultrasonic pulse stream. Elaborating on FRI sparse sampling theory, the process of ultrasonic signal is explained, followed by a discussion and analysis of ultrasonic pulse-stream-forming methods. In contrast to ultrasonic signal envelope extracting techniques, a quadrature demodulation method (QDM) is proposed. Simulation experiments were performed to determine its performance at various signal-to-noise ratios (SNRs). The circuit was then designed, with mixing module, oscillator, low pass filter (LPF), and root of square sum module. Finally, application experiments were carried out on pipeline sample ultrasonic flaw testing. The experimental results indicate that the QDM can accurately convert ultrasonic signal to ultrasonic pulse stream, and reverse the original signal information, such as pulse width, amplitude, and time of arrival. This technique lays the foundation for ultrasonic signal FRI sparse sampling directly with hardware circuitry. (paper)

Design and Manufacture an Ultrasonic Dispersion System with Automatic Frequency Adjusting Property

Directory of Open Access Journals (Sweden)

Herlina ABDUL RAHIM

2011-03-01

Full Text Available This paper a novel ultrasonic dispersion system for the cleaning application or dispersing of particles which are mixed in liquid has been proposed. The frequency band of designed system is 30 kHz so that the frequency of ultrasonic wave sweeps from 30 kHz to 60 kHz with 100 Hz steps. One of the superiority of manufactured system in compare with the other similar systems which are available in markets is that this system can transfer the maximum and optimum energy of ultrasonic wave inside the liquid tank with the high efficiency in the whole of the usage time of the system. The used ultrasonic transducers in this system as the generator of ultrasonic wave is the type of air coupled ceramic ultrasonic piezoelectric with the nominal maximum power 50 Watt. The frequency characteristic of applied piezoelectric is that it produces the maximum amplitude of ultrasonic wave on the resonance frequency, so this system is designed to work on resonance frequency of piezoelectric, continuously. This is done by the use of control system which is consisted of two major parts, sensing part and controlling part. The manufactured ultrasonic dispersion system is consisted of 9 piezoelectrics so that it can produce 450 watt ultrasonic energy, totally. The main purpose of this project is to produce a safety system especially for fatigue car driver so as to prevent from accidents. The statistic on road fatality shows that human error constitute of 64.84 % road accidents fatality and 17.4 % due to technical factors. These systems encompassed the approach of hand pressure applied on the steering wheel. The steering will be installed with pressure sensors. At the same time these sensors can be used to measure gripping force while driving.

Ultrasonic enhancement of lipase-catalysed transesterification for biodiesel synthesis.

Science.gov (United States)

Bhangu, Sukhvir Kaur; Gupta, Shweta; Ashokkumar, Muthupandian

2017-01-01

The production of biodiesel was carried out from canola oil and methanol catalysed by lipase from Candida rugosa under different ultrasonic experimental conditions using horn (20kHz) and plate (22, 44, 98 and 300kHz) transducers. The effects of experimental conditions such as horn tip diameter, ultrasonic power, ultrasonic frequency and enzyme concentrations on biodiesel yield were investigated. The results showed that the application of ultrasound decreased the reaction time from 22-24h to 1.5h with the use of 3.5cm ultrasonic horn, an applied power of 40W, methanol to oil molar ratio of 5:1 and enzyme concentration of 0.23wt/wt% of oil. Low intensity ultrasound is efficient and a promising tool for the enzyme catalysed biodiesel synthesis as higher intensities tend to inactivate the enzyme and reduce its efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

Chrome tannage using high-intensity ultrasonic field.

Science.gov (United States)

Mäntysalo, E; Marjoniemi, M; Kilpeläinen, M

1997-04-01

The process time in chrome tannage in leather making, using an elastic compression cycle followed by irradiation by high-intensity ultrasound, is quite short lasting only a few minutes, compared with a process time of several hours in modern chrome tannage. After ultrasonic irradiation, samples were basified in 17 h in chrome liquor at a pH of 4.0 and the shrinkage temperature was measured. The determination of the efficiency for the chrome liquor penetrating into the hides can be based on the steepness of the shrinkage temperature-processing time curve. An approximate value of 20 degrees C min(-1) can be evaluated for the initial slope of the curve when elastic compression and high-intensity ultrasonic irradiation is used, and a processing time of 2 min is required in chrome liquor (plus 17 h basification and 24 h storage time) to obtain leather stable to boiling. Usually, hides are kept in chrome liquor for 2 h.

Ultrasonic flow meter

NARCIS (Netherlands)

Lötters, Joost Conrad; Snijders, G.J.; Volker, A.W.F.

2014-01-01

The invention relates to an ultrasonic flow meter comprising a flow tube for the fluid whose flow rate is to be determined. The flow meter comprises a transmitting element for emitting ultrasonic waves, which is provided on the outer jacket of the flow tube. A receiving element, which is provided on

Noise-based frequency offset modulation in wideband frequency-selective fading channels

NARCIS (Netherlands)

Meijerink, Arjan; Cotton, S.L.; Bentum, Marinus Jan; Scanlon, W.G.

2009-01-01

A frequency offset modulation scheme using wideband noise carriers is considered. The main advantage of such a scheme is that it enables fast receiver synchronization without channel adaptation, while providing robustness to multipath fading and in-band interference. This is important for low-power

Ultrasonic Low-Friction Containment Plate for Thermal and Ultrasonic Stir Weld Processes

Science.gov (United States)

Graff, Karl; Short, Matt

2013-01-01

The thermal stir welding (TSW) process is finding applications in fabrication of space vehicles. In this process, workpieces to be joined by TSW are drawn, by heavy forces, between "containment plates," past the TSW tool that then causes joining of the separate plates. It is believed that the TSW process would be significantly improved by reducing the draw force, and that this could be achieved by reducing the friction forces between the workpieces and containment plates. Based on use of high-power ultrasonics in metal forming processes, where friction reduction in drawing dies has been achieved, it is believed that ultrasonic vibrations of the containment plates could achieve similar friction reduction in the TSW process. By applying ultrasonic vibrations to the containment plates in a longitudinal vibration mode, as well as by mounting and holding the containment plates in a specific manner such as to permit the plates to acoustically float, friction between the metal parts and the containment plates is greatly reduced, and so is the drawing force. The concept was to bring in the ultrasonics from the sides of the plates, permitting the ultrasonic hardware to be placed to the side, away from the equipment that contains the thermal stir tooling and that applies clamping forces to the plates. Tests demonstrated that one of the major objectives of applying ultrasonics to the thermal stir system, that of reducing draw force friction, should be achievable on a scaled-up system.

Ultrasonic hydrometer

Science.gov (United States)

Swoboda, Carl A.

1984-01-01

The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time "t" between the initial and returning impulses. Considering the distance "d" between the spaced sonic surfaces and the measured time "t", the sonic velocity "V" is calculated with the equation "V=2d/t". The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0.degree. and 40.degree. C. and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation. The disclosed modified battery has a hollow spacer nub on the battery side wall, the sonic surfaces being on the inside of the nub and the electrolyte filling between the surfaces to the exclusion of intervening structure. An accessible pad exposed on the nub wall opposite one sonic surface allows the reliable placement thereagainst of the transducer.

A wideband software reconfigurable modem

Science.gov (United States)

Turner, J. H., Jr.; Vickers, H.

A wideband modem is described which provides signal processing capability for four Lx-band signals employing QPSK, MSK and PPM waveforms and employs a software reconfigurable architecture for maximum system flexibility and graceful degradation. The current processor uses a 2901 and two 8086 microprocessors per channel and performs acquisition, tracking, and data demodulation for JITDS, GPS, IFF and TACAN systems. The next generation processor will be implemented using a VHSIC chip set employing a programmable complex array vector processor module, a GP computer module, customized gate array modules, and a digital array correlator. This integrated processor has application to a wide number of diverse system waveforms, and will bring the benefits of VHSIC technology insertion into avionic antijam communications systems.

Spectral encoded optical label detection for dynamic routing of impulse radio ultra-wideband signals in metro-access networks

DEFF Research Database (Denmark)

Osadchiy, Alexey Vladimirovich; Yu, Xianbin; Yin, Xiaoli

2010-01-01

In this paper we propose and experimentally demonstrate the principle of coherent label detection for dynamic routing of wavelength division multiplexed impulse radio ultra-wideband signals by using four-tone spectral amplitude coded labels.......In this paper we propose and experimentally demonstrate the principle of coherent label detection for dynamic routing of wavelength division multiplexed impulse radio ultra-wideband signals by using four-tone spectral amplitude coded labels....

Ultra-wideband spectral analysis using S2 technology

International Nuclear Information System (INIS)

Krishna Mohan, R.; Chang, T.; Tian, M.; Bekker, S.; Olson, A.; Ostrander, C.; Khallaayoun, A.; Dollinger, C.; Babbitt, W.R.; Cole, Z.; Reibel, R.R.; Merkel, K.D.; Sun, Y.; Cone, R.; Schlottau, F.; Wagner, K.H.

2007-01-01

This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution (∼25 kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100 μs) and fast update rates (up to 1 kHz). A cryogenically cooled Tm:YAG crystal that operates on microwave signals modulated onto a stabilized optical carrier at 793 nm is used as the core for the spectrum analyzer. Efforts to develop novel component technologies that enhance the performance of the system and meet the application requirements are discussed, including an end-to-end device model for parameter optimization. We discuss the characterization of new ultra-wide bandwidth S2 materials. Detection and post-processing module development including the implementation of a novel spectral recovery algorithm using field programmable gate array technology (FPGA) is also discussed

Ultra-wideband spectral analysis using S2 technology

Energy Technology Data Exchange (ETDEWEB)

Krishna Mohan, R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States)]. E-mail: krishna@spectrum.montana.edu; Chang, T. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Tian, M. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Bekker, S. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Olson, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Ostrander, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Khallaayoun, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Dollinger, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cole, Z. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Reibel, R.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Merkel, K.D. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Sun, Y. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cone, R. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Schlottau, F. [University of Colorado, Boulder, CO 80309 (United States); Wagner, K.H. [University of Colorado, Boulder, CO 80309 (United States)

2007-11-15

This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution ({approx}25 kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100 {mu}s) and fast update rates (up to 1 kHz). A cryogenically cooled Tm:YAG crystal that operates on microwave signals modulated onto a stabilized optical carrier at 793 nm is used as the core for the spectrum analyzer. Efforts to develop novel component technologies that enhance the performance of the system and meet the application requirements are discussed, including an end-to-end device model for parameter optimization. We discuss the characterization of new ultra-wide bandwidth S2 materials. Detection and post-processing module development including the implementation of a novel spectral recovery algorithm using field programmable gate array technology (FPGA) is also discussed.

Ultrasonic inspection of austenitic welds

International Nuclear Information System (INIS)

Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

1976-01-01

The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

Measuring time-of-flight in an ultrasonic LPS system using generalized cross-correlation.

Science.gov (United States)

Villladangos, José Manuel; Ureña, Jesús; García, Juan Jesús; Mazo, Manuel; Hernández, Alvaro; Jiménez, Ana; Ruíz, Daniel; De Marziani, Carlos

2011-01-01

In this article, a time-of-flight detection technique in the frequency domain is described for an ultrasonic local positioning system (LPS) based on encoded beacons. Beacon transmissions have been synchronized and become simultaneous by means of the DS-CDMA (direct-sequence code Division multiple access) technique. Every beacon has been associated to a 255-bit Kasami code. The detection of signal arrival instant at the receiver, from which the distance to each beacon can be obtained, is based on the application of the generalized cross-correlation (GCC), by using the cross-spectral density between the received signal and the sequence to be detected. Prior filtering to enhance the frequency components around the carrier frequency (40 kHz) has improved estimations when obtaining the correlation function maximum, which implies an improvement in distance measurement precision. Positioning has been achieved by using hyperbolic trilateration, based on the time differences of arrival (TDOA) between a reference beacon and the others.

Design and development of Pc-based TOFD ultrasonic scanning system for welds inspection

International Nuclear Information System (INIS)

Suhairy Sani; Mohamad Pauzi Ismai; Muhammad Faiz Mohd Shukri; Amry Amin Abas

2010-01-01

This paper describes the design and development of a portable PC-based ultrasonic scanning system for industrial applications. The system which is called TOFD Ultrasonic Scanning System (TOFUSS) is used to create a gray scale imaging techniques are applied to the RF (AC) signal phase and enables weld integrity to be observed in real time. TOFD consists of a separate ultrasonic transmitter and receiver. The Probes are aimed at the same point in the weld volume. The entire weld is flooded with ultrasound allowing inspection of the weld. With a time of flight path, the ultrasonic velocity and the spatial relationship of the two probes, location and height of the defects can be very accurately calculated. The algorithm and complete system were implemented in a computer software developed using Microsoft Visual BASIC 6.0. (author)

Ultrasonically enhanced extraction of bioactive principles from Quillaja Saponaria Molina.

Science.gov (United States)

Gaete-Garretón, L; Vargas-Hernández, Yolanda; Cares-Pacheco, María G; Sainz, Javier; Alarcón, John

2011-07-01

A study of ultrasonic enhancement in the extraction of bioactive principles from Quillaja Saponaria Molina (Quillay) is presented. The effects influencing the extraction process were studied through a two-level factorial design. The effects considered in the experimental design were: granulometry, extraction time, acoustic Power, raw matter/solvent ratio (concentration) and acoustic impedance. It was found that for aqueous extraction the main factors affecting the ultrasonically-assisted process were: granulometry, raw matter/solvent ratio and extraction time. The extraction ratio was increased by Ultrasonics effect and a reduction in extraction time was verified without any influence in the product quality. In addition the process can be carried out at lower temperatures than the conventional method. As the process developed uses chips from the branches of trees, and not only the bark, this research contributes to make the saponin exploitation process a sustainable industry. Copyright © 2010 Elsevier B.V. All rights reserved.

Ultra wideband coplanar waveguide fed spiral antenna for humanitarian demining

DEFF Research Database (Denmark)

Thaysen, Jesper; Jakobsen, Kaj Bjarne; Appel-Hansen, Jørgen

2000-01-01

to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun covering the frequency range of the antenna was developed. The constructed spiral antenna is very useful in a stepped frequency ground penetrating radar for humanitarian demining due to the very...

Ultrasonic analysis of UO{sub 2} pellets

Energy Technology Data Exchange (ETDEWEB)

Bittencourt, Marcelo de S.Q.; Baroni, Douglas B.; Martorelli, Daniel S., E-mail: bittenc@ien.gov.br, E-mail: douglasbaroni@ien.gov.br, E-mail: daniel@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Ultrassom; Dias, Fabio C.; Silva, Jose W.S. da, E-mail: fabio@ird.gov.br, E-mail: wanderley@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Salvaguardas

2013-07-01

Ceramic materials have been widely used for various purposes in many different industries due to certain characteristics, such as high melting point and high resistance to corrosion. In the nuclear area, ceramics are of great importance due to the process of fabrication of fuel pellets for nuclear reactors. Generally, high accuracy destructive techniques are used to characterize nuclear materials for fuel fabrication. These techniques usually require costly equipment and facilities, as well as experienced personnel. This paper aims at presenting an analysis methodology for UO2 pellets using a non-destructive ultrasonic technique for porosity measurement. This technique differs from traditional ultrasonic techniques in the sense it uses ultrasonic pulses in frequency domain instead of time domain. Therefore, specific characteristics of the analyzed material are associated with the obtained frequency spectrum. In the present work, four fuel grade UO2 pellets were analyzed and the corresponding results evaluated. (author)

Gas ultrasonic flow rate measurement through genetic-ant colony optimization based on the ultrasonic pulse received signal model

International Nuclear Information System (INIS)

Hou, Huirang; Zheng, Dandan; Nie, Laixiao

2015-01-01

For gas ultrasonic flowmeters, the signals received by ultrasonic sensors are susceptible to noise interference. If signals are mingled with noise, a large error in flow measurement can be caused by triggering mistakenly using the traditional double-threshold method. To solve this problem, genetic-ant colony optimization (GACO) based on the ultrasonic pulse received signal model is proposed. Furthermore, in consideration of the real-time performance of the flow measurement system, the improvement of processing only the first three cycles of the received signals rather than the whole signal is proposed. Simulation results show that the GACO algorithm has the best estimation accuracy and ant-noise ability compared with the genetic algorithm, ant colony optimization, double-threshold and enveloped zero-crossing. Local convergence doesn’t appear with the GACO algorithm until –10 dB. For the GACO algorithm, the converging accuracy and converging speed and the amount of computation are further improved when using the first three cycles (called GACO-3cycles). Experimental results involving actual received signals show that the accuracy of single-gas ultrasonic flow rate measurement can reach 0.5% with GACO-3 cycles, which is better than with the double-threshold method. (paper)

Catalase-positive microbial detection by using different ultrasonic parameters

International Nuclear Information System (INIS)

Shukla, S K; Durán, C; Elvira, L

2012-01-01

A method for rapid detection of catalase enzyme activity using ultrasonic parameters is presented in this work. It is based on the detection of the hydrolysis of hydrogen peroxide molecule into water and oxygen induced by the enzyme catalase. A special medium was made to amplify changes produced by catalase enzyme during the hydrolysis process. Enzymatic process can be monitored by means of ultrasonic parameters such as wave amplitude, time of flight (TOF), and backscattering measurements which are sensitive to oxygen bubble production. It is shown that catalase activity of the order of 10 −3 unit/ml can be detected using different ultrasonic parameters. The sensitivity provided by them is discussed.

Wideband impedance measurements and modeling of DC motors for EMI predictions

NARCIS (Netherlands)

Diouf, F.; Leferink, Frank Bernardus Johannes; Duval, Fabrice; Bensetti, Mohamed

2015-01-01

In electromagnetic interference prediction, dc motors are usually modeled as a source and a series impedance. Previous researches only include the impedance of the armature, while neglecting the effect of the motor's rotation. This paper aims at measuring and modeling the wideband impedance of a dc

Compact Wideband and Low-Profile Antenna Mountable on Large Metallic Surfaces

DEFF Research Database (Denmark)

Zhang, Shuai; Pedersen, Gert F.

2017-01-01

This paper proposes a compact wideband and low-profile antenna mountable on large metallic surfaces. Six rows of coupled microstrip resonators with different lengths are printed on a Teflon block. The lengths of the microstrip resonators in different rows are gradually reduced along the end-fire...

Method and apparatus for ultrasonic characterization through the thickness direction of a moving web

Science.gov (United States)

Jackson, Theodore; Hall, Maclin S.

2001-01-01

A method and apparatus for determining the caliper and/or the ultrasonic transit time through the thickness direction of a moving web of material using ultrasonic pulses generated by a rotatable wheel ultrasound apparatus. The apparatus includes a first liquid-filled tire and either a second liquid-filled tire forming a nip or a rotatable cylinder that supports a thin moving web of material such as a moving web of paper and forms a nip with the first liquid-filled tire. The components of ultrasonic transit time through the tires and fluid held within the tires may be resolved and separately employed to determine the separate contributions of the two tire thicknesses and the two fluid paths to the total path length that lies between two ultrasonic transducer surfaces contained within the tires in support of caliper measurements. The present invention provides the benefit of obtaining a transit time and caliper measurement at any point in time as a specimen passes through the nip of rotating tires and eliminates inaccuracies arising from nonuniform tire circumferential thickness by accurately retaining point-to-point specimen transit time and caliper variation information, rather than an average obtained through one or more tire rotations. Morever, ultrasonic transit time through the thickness direction of a moving web may be determined independent of small variations in the wheel axle spacing, tire thickness, and liquid and tire temperatures.

Non-contact feature detection using ultrasonic Lamb waves

Science.gov (United States)

Sinha, Dipen N [Los Alamos, NM

2011-06-28

Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

A study on Computer-controlled Ultrasonic Scanning Device

International Nuclear Information System (INIS)

Huh, H.; Park, C. S.; Hong, S. S.; Park, J. H.

1989-01-01

Since the nuclear power plants in Korea have been operated in 1979, the nondestructive testing (NDT) of pressure vessels and/or piping welds plays an important role for maintaining the safety and integrity of the plants. Ultrasonic method is superior to the other NDT method in the viewpoint of the detectability of small flaw and accuracy to determine the locations, sizes, orientations, and shapes. As the service time of the nuclear power plants is increased, the radiation level from the components is getting higher. In order to get more quantitative and reliable results and secure the inspector from the exposure to high radiation level, automation of the ultrasonic equipment has been one of the important research and development(R and D) subject. In this research, it was attempted to visualize the shape of flaws presented inside the specimen using a Modified C-Scan technique. In order to develop Modified C-Scan technique, an automatic ultrasonic scanner and a module to control the scanner were designed and fabricated. IBM-PC/XT was interfaced to the module to control the scanner. Analog signals from the SONIC MARK II were digitized by Analog-Digital Converter(ADC 0800) for Modified C-Scan display. A computer program has been developed and has capability of automatic data acquisition and processing from the digital data, which consist of maximum amplitudes in each gate range and locations. The data from Modified C-Scan results was compared with shape from artificial defects using the developed system. Focal length of focused transducer was measured. The automatic ultrasonic equipment developed through this study is essential for more accurate, reliable, and repeatable ultrasonic experiments. If the scanner are modified to meet to appropriate purposes, it can be applied to automation of ultrasonic examination of nuclear power plants and helpful to the research on ultrasonic characterization of the materials

Ultrasonic dip seal maintenance system

International Nuclear Information System (INIS)

Poindexter, A.M.; Ricks, H.E.

1978-01-01

Disclosed is a system for removing impurities from the surfaces of liquid dip seals and for wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities

Ultrasonic hyperactivation of cellulase immobilized on magnetic nanoparticles.

Science.gov (United States)

Ladole, Mayur Ramrao; Mevada, Jayesh Sevantilal; Pandit, Aniruddha Bhalchandra

2017-09-01

In the present work, effect of low power, low frequency ultrasound on cellulase immobilized magnetic nanoparticles (cellulase@MNPs) was studied. To gain maximum activity recovery in cellulase@MNPs various parameters viz. ratio of MNPs:cellulase, concentration of glutaraldehyde and cross-linking time were optimized. The influence of ultrasonic power on cellulase@MNPs was studied. Under ultrasonic conditions at 24kHz, 6W power, and 6min of incubation time there was almost 3.6 fold increased in the catalytic activity of immobilized cellulase over the control. Results also indicated that there was improvement in pH and temperature stability of cellulase@MNPs. Furthermore, thermal deactivation energy required was more in cellulase@MNPs than that of the free cellulase. Secondary structural analysis revealed that there were conformational changes in free cellulase and cellulase@MNPs before and after sonication which might be responsible for enhanced activity after ultrasonication. Finally, the influence of ultrasound and cellulase@MNPs for biomass hydrolysis was studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of fundamental and wideband harmonic contrast imaging of liver tumors.

Science.gov (United States)

Forsberg, F; Liu, J B; Chiou, H J; Rawool, N M; Parker, L; Goldberg, B B

2000-03-01

Wideband harmonic imaging (with phase inversion for improved tissue suppression) was compared to fundamental imaging in vivo. Four woodchucks with naturally occurring liver tumors were injected with Imagent (Alliance Pharmaceutical Corp., San Diego, CA). Randomized combinations of dose (0.05, 0.2 and 0.4 ml/kg) and acoustic output power (AO; 5, 25 and 63% or MI Siemens Medical Systems, Issaquah, WA). Tumor vascularity, conspicuity and contrast enhancement were rated by three independent observers. Imagent produced marked tumor enhancement and improved depiction of neovascularity at all dosages and AO settings in both modes. Tumor vascularity and enhancement correlated with mode, dose and AO (P < 0.002). Fundamental imaging produced more enhancement (P < 0.05), but tumor vascularity and conspicuity were best appreciated in harmonic mode (P < 0.05). Under the conditions studied here, the best approach was wideband harmonic imaging with 0.2 ml/kg of Imagent at an AO of 25%.

Proposal of a wide-band mirror polarizer of slow neutrons at a pulsed neutron source

International Nuclear Information System (INIS)

Nikitenko, Yu.V.; Ostanevich, Yu.M.

1992-01-01

The new type wide-band mirror-based neutron polarizer to be operated at a pulsed neutron source is suggested. The idea is to use a movable polarizing mirror system, which, be the incoming beam monochromatized by the time-of-flight, would allow one to tune glancing angles in time so, that the total reflection condition is always fulfilled only for one of the two neutron spin eigenstates. Estimates show, that with the pulsed reactor IBR-2 such polarizer allows one to build a small-angle neutron scattering instrument capable to effectively use the wave-length band from 2 to 15 A. 9 refs.; 1 fig

Ultrasonic sludge disintegration for enhanced methane production in anaerobic digestion: effects of sludge hydrolysis efficiency and hydraulic retention time.

Science.gov (United States)

Kim, Dong-Jin; Lee, Jonghak

2012-01-01

Hydrolysis of waste activated sludge (WAS) has been regarded as the rate limiting step of anaerobic sludge digestion. Therefore, in this study, the effect of ultrasound and hydraulic residence time during sludge hydrolysis was investigated with the goal of enhancing methane production from anaerobic digestion (AD). WAS was ultrasonically disintegrated for hydrolysis, and it was semi-continuously fed to an anaerobic digesters at various hydraulic retention times (HRTs). The results of these experiments showed that the solids and chemical oxygen demand (COD) removal efficiencies when using ultrasonically disintegrated sludge were higher during AD than the control sludge. The longer the HRT, the higher the removal efficiencies of solids and COD, while methane production increased with lower HRT. Sludge with 30% hydrolysis produced 7 × more methane production than the control sludge. The highest methane yields were 0.350 m(3)/kg volatile solids (VS)(add) and 0.301 m(3)/kg COD(con) for 16 and 30% hydrolyzed sludge, respectively. In addition, we found that excess ultrasound irradiation may inhibit AD since the 50% hydrolyzed sludge produced lower methane yields than 16 and 30% hydrolyzed sludge.

Ultrasonic propagation velocity in magnetic and magnetorheological fluids due to an external magnetic field

International Nuclear Information System (INIS)

Bramantya, M A; Sawada, T; Motozawa, M

2010-01-01

Ultrasonic propagation velocity in a magnetic fluid (MF) and magnetorheological fluid (MRF) changes with the application of an external magnetic field. The formation of clustering structures inside the MF and MRF clearly has an influence on the ultrasonic propagation velocity. Therefore, we propose a qualitative analysis of these structures by measuring properties of ultrasonic propagation. Since MF and MRF are opaque, non-contact inspection using the ultrasonic technique can be very useful for analyzing the inner structures of MF and MRF. In this study, we measured ultrasonic propagation velocity in a hydrocarbon-based MF and MRF precisely. Based on these results, the clustering structures of these fluids are analyzed experimentally in terms of elapsed time dependence and the effect of external magnetic field strength. The results reveal hysteresis and anisotropy in the ultrasonic propagation velocity. We also discuss differences of ultrasonic propagation velocity between MF and MRF.

Use of focused ultrasonication in activity-based profiling of deubiquitinating enzymes in tissue.

Science.gov (United States)

Nanduri, Bindu; Shack, Leslie A; Rai, Aswathy N; Epperson, William B; Baumgartner, Wes; Schmidt, Ty B; Edelmann, Mariola J

2016-12-15

To develop a reproducible tissue lysis method that retains enzyme function for activity-based protein profiling, we compared four different methods to obtain protein extracts from bovine lung tissue: focused ultrasonication, standard sonication, mortar & pestle method, and homogenization combined with standard sonication. Focused ultrasonication and mortar & pestle methods were sufficiently effective for activity-based profiling of deubiquitinases in tissue, and focused ultrasonication also had the fastest processing time. We used focused-ultrasonicator for subsequent activity-based proteomic analysis of deubiquitinases to test the compatibility of this method in sample preparation for activity-based chemical proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.

Controls on Magmatic and Hydrothermal Processes at Yellowstone Supervolcano: The Wideband Magnetotelluric Component of an Integrated MT/Seismic Investigation

Science.gov (United States)

Schultz, A.; Bennington, N. L.; Bowles-martinez, E.; Imamura, N.; Cronin, R. A.; Miller, D. J.; Hart, L.; Gurrola, R. M.; Neal, B. A.; Scholz, K.; Fry, B.; Carbonari, R.

2017-12-01

Previous seismic and magnetotelluric (MT) studies beneath Yellowstone (YS) have provided insight into the origin and migration of magmatic fluids within the volcanic system. However, important questions remain concerning the generation of magmatism at YS, the migration and storage of these magmatic fluids, as well as their relationships to hydrothermal expressions. Analysis of regional-scale EarthScope MT data collected previously suggests a relative absence of continuity in crustal partial melt accumulations directly beneath YS. This is in contrast to some seismic interpretations, although such long-period MT data have limited resolving power in the upper-to-mid crustal section. A wideband MT experiment was designed as a component of an integrated MT/seismic project to examine: the origin and location of magmatic fluids at upper mantle/lower crustal depths, the preferred path of migration for these magmatic fluids into the mid- to upper-crust, the resulting distribution of the magma reservoir, the composition of the magma reservoir, and implications for future volcanism at YS. A high-resolution wideband MT survey was carried out in the YS region in the summer of 2017, with more than forty-five wideband stations installed within and immediately surrounding the YS National Park boundary. These data provided nearly six decades of bandwidth ( 10-3 Hz -to- 103 Hz). Extraordinary permitting restrictions prevented us from using conventional installation methods at many of our sites, and an innovative "no-dig" subaerial method of wideband MT was developed and used successfully. Using these new data along with existing MT datasets, we are inverting for the 3D resistivity structure at upper crustal through upper mantle scales at YS. Complementary to this MT work, a joint inversion for the 3D crustal velocity structure is being carried out using both ambient noise and earthquake travel time data. Taken together, these data should better constrain the crustal velocity

Real-time detection of intracellular reactive oxygen species and mitochondrial membrane potential in THP-1 macrophages during ultrasonic irradiation for optimal sonodynamic therapy.

Science.gov (United States)

Sun, Xin; Xu, Haobo; Shen, Jing; Guo, Shuyuan; Shi, Sa; Dan, Juhua; Tian, Fang; Tian, Yanfeng; Tian, Ye

2015-01-01

Reactive oxygen species (ROS) elevation and mitochondrial membrane potential (MMP) loss have been proven recently to be involved in sonodynamic therapy (SDT)-induced macrophage apoptosis and necrosis. This study aims to develop an experimental system to monitor intracellular ROS and MMP in real-time during ultrasonic irradiation in order to achieve optimal effect in SDT. Cultured THP-1 derived macrophages were incubated with 5-aminolevulinic acid (ALA), and then sonicated at different intensities. Intracellular ROS elevation and MMP loss were detected in real-time by fluorospectrophotometer using fluorescence probe DCFH-DA and jc-1, respectively. Ultrasound at low intensities (less than 0.48W/cm(2)) had no influence on ROS and MMP in macrophages, whereas at an intensity of 0.48W/cm(2), ROS elevation and MMP loss were observed during ultrasonic irradiation. These effects were strongly enhanced in the presence of ALA. Quantitative analysis showed that ROS elevation and MMP loss monotonically increased with the rise of ultrasonic intensity between 0.48 and 1.16W/cm(2). SDT at 0.48 and 0.84W/cm(2) induced mainly apoptosis in THP-1 macrophages while SDT at 1.16W/cm(2) mainly cell necrosis. This study supports the validity and potential utility of real-time ROS and MMP detection as a dosimetric tool for the determination of optimal SDT. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparative performance evaluation of conventional and ultrasonic assisted bleaching of cotton fabric

International Nuclear Information System (INIS)

Farooq, A.; Ashraf, M.A.

2013-01-01

Summary: Conventional bleaching process is an important and quality influencing process for textile wet processors. However, the process requires high energy consumption, and is slow and time consuming. In the present research work, cotton woven fabric was bleached with different bleaching agents using conventional and ultrasonic assisted techniques. After bleaching whiteness index, weight loss and tensile strength of samples were measured and compared statistically. The results showed that ultrasonic energy intensifies the diffusion of chemicals and increases the production of hydroxyl radicals which catalyze the bleaching process. Ultrasonic assisted bleaching proved to be a novel technique that can produce better results than conventional bleaching process even at low temperature and in less time. (author)

Ultrasonic colour Doppler imaging

DEFF Research Database (Denmark)

Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

2011-01-01

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

Decrease of Salmonella typhimurium in skim milk and egg by heat and ultrasonic wave treatment

International Nuclear Information System (INIS)

Wrigley, D.M.; Llorca, N.G.

1992-01-01

Ultrasonic waves induce cavitation which is lethal for many bacteria. When Salmonella typhimurium was suspended in skim milk or brain heart infusion broth and placed in an ultrasonicating water bath, the number of bacteria decreased by 2 to 3 log CFU in a time dependent manner. The killing by ultrasonic waves was enhanced if the menstruum was simultaneously maintained at 50 degrees C. Ultrasonic reduction in S. typhimurium numbers in liquid whole egg ranged from 1-3 log CFU at 50 degrees C. The results indicate that indirect ultrasonic wave treatment is effective in killing Salmonella in some foods

Maximum Likelihood DOA Estimation of Multiple Wideband Sources in the Presence of Nonuniform Sensor Noise

Directory of Open Access Journals (Sweden)

K. Yao

2007-12-01

Full Text Available We investigate the maximum likelihood (ML direction-of-arrival (DOA estimation of multiple wideband sources in the presence of unknown nonuniform sensor noise. New closed-form expression for the direction estimation Cramér-Rao-Bound (CRB has been derived. The performance of the conventional wideband uniform ML estimator under nonuniform noise has been studied. In order to mitigate the performance degradation caused by the nonuniformity of the noise, a new deterministic wideband nonuniform ML DOA estimator is derived and two associated processing algorithms are proposed. The first algorithm is based on an iterative procedure which stepwise concentrates the log-likelihood function with respect to the DOAs and the noise nuisance parameters, while the second is a noniterative algorithm that maximizes the derived approximately concentrated log-likelihood function. The performance of the proposed algorithms is tested through extensive computer simulations. Simulation results show the stepwise-concentrated ML algorithm (SC-ML requires only a few iterations to converge and both the SC-ML and the approximately-concentrated ML algorithm (AC-ML attain a solution close to the derived CRB at high signal-to-noise ratio.

Nonlinear Ultrasonic Characterization for Intergranular Corrosion Susceptibility of 304 Austenitic Stainless Steel

Directory of Open Access Journals (Sweden)

HOU Tian-yu

2017-10-01

Full Text Available The variation law of nonlinear ultrasonic parameters for the samples sensitized at 650℃ for 2, 6, 10h was discussed using nonlinear ultrasonic testing technique and XRD pattern as well as microstructure. The results indicate that normalized nonlinear parameters(β/β0 of the samples show a monotonous growth trend with the increase of the sensitized time, and normalized nonlinear parameters(β/β0 of the samples sensitized with 2,6,10h increase to 28%, 32% and 43% respectively compared with that of the base material, meaning that it is feasible to use nonlinear parameter to characterize the sensitivity degree. It is analyzed that the mismatch between the carbide (Cr23C6 precipitated on the grain boundary and the austenitic matrix causes the local strain fields which interfere with the propagation of ultrasonic wave in the solid sample. In addition, the increment of precipitation phase exacerbates further the distortion of the ultrasonic with prolonging of the sensitization time.

Chaotic operation and chaos control of travelling wave ultrasonic motor.

Science.gov (United States)

Shi, Jingzhuo; Zhao, Fujie; Shen, Xiaoxi; Wang, Xiaojie

2013-08-01

The travelling wave ultrasonic motor, which is a nonlinear dynamic system, has complex chaotic phenomenon with some certain choices of system parameters and external inputs, and its chaotic characteristics have not been studied until now. In this paper, the preliminary study of the chaos phenomenon in ultrasonic motor driving system has been done. The experiment of speed closed-loop control is designed to obtain several groups of time sampling data sequence of the amplitude of driving voltage, and phase-space reconstruction is used to analyze the chaos characteristics of these time sequences. The largest Lyapunov index is calculated and the result is positive, which shows that the travelling wave ultrasonic motor has chaotic characteristics in a certain working condition Then, the nonlinear characteristics of travelling wave ultrasonic motor are analyzed which includes Lyapunov exponent map, the bifurcation diagram and the locus of voltage relative to speed based on the nonlinear chaos model of a travelling wave ultrasonic motor. After that, two kinds of adaptive delay feedback controllers are designed in this paper to control and suppress chaos in USM speed control system. Simulation results show that the method can control unstable periodic orbits, suppress chaos in USM control system. Proportion-delayed feedback controller was designed following and arithmetic of fuzzy logic was used to adaptively adjust the delay time online. Simulation results show that this method could fast and effectively change the chaos movement into periodic or fixed-point movement and make the system enter into stable state from chaos state. Finally the chaos behavior was controlled. Copyright © 2013 Elsevier B.V. All rights reserved.

Ultrasonic flowmeters

International Nuclear Information System (INIS)

Wittekind, W.D.

1979-01-01

A prototype ultrasonic flowmeter was assembled and tested. The theoretical basis of this prototype ultrasonic flowmeter is reviewed; the equipment requirements for a portable unit are discussed; the individual electronic modules contained in the prototype are described; the operating procedures and configuration are explained; and the data from preliminary calibrations are presented. The calibration data confirm that the prototype operates according to theoretical predictions and can indeed provide nonintrusive flow measurements to predicted accuracies for pipes larger than two inches, under single phase stable flow conditions

Pulsed ultrasonic stir welding system

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2013-01-01

An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

Enhancement of the automatic ultrasonic signal processing system using digital technology

International Nuclear Information System (INIS)

Koo, In Soo; Park, H. Y.; Suh, Y. S.; Kim, D. Hoon; Huh, S.; Sung, S. H.; Jang, G. S.; Ryoo, S. G.; Choi, J. H.; Kim, Y. H.; Lee, J. C.; Kim, D. Hyun; Park, H. J.; Kim, Y. C.; Lee, J. P.; Park, C. H.; Kim, M. S.

1999-12-01

The objective of this study is to develop the automatic ultrasonic signal processing system which can be used in the inspection equipment to assess the integrity of the reactor vessel by enhancing the performance of the ultrasonic signal processing system. Main activities of this study divided into three categories such as the development of the circuits for generating ultrasonic signal and receiving the signal from the inspection equipment, the development of signal processing algorithm and H/W of the data processing system, and the development of the specification for application programs and system S/W for the analysis and evaluation computer. The results of main activities are as follows 1) the design of the ultrasonic detector and the automatic ultrasonic signal processing system by using the investigation of the state-of-the-art technology in the inside and outside of the country. 2) the development of H/W and S/W of the data processing system based on the results. Especially, the H/W of the data processing system, which have both advantages of digital and analog controls through the real-time digital signal processing, was developed using the DSP which can process the digital signal in the real-time, and was developed not only firmware of the data processing system in order for the peripherals but also the test algorithm of specimen for the calibration. The application programs and the system S/W of the analysis/evaluation computer were developed. Developed equipment was verified by the performance test. Based on developed prototype for the automatic ultrasonic signal processing system, the localization of the overall ultrasonic inspection equipment for nuclear industries would be expected through the further studies of the H/W establishment of real applications, developing the S/W specification of the analysis computer. (author)

Ultrasonic assisted dyeing: dyeing of acrylic fabrics C.I. Astrazon Basic Red 5BL 200%.

Science.gov (United States)

Kamel, M M; Helmy, H M; Mashaly, H M; Kafafy, H H

2010-01-01

The dyeing of acrylic fabrics using C.I. Astrazon Basic Red 5BL 200% has been studied with both conventional and ultrasonic techniques. The effect of dye concentration, dye bath pH, ultrasonic power, dyeing time and temperature were studied and the resulting shades obtained by dyeing with both techniques were compared. Colour strength values obtained were found to be higher with ultrasonic than with conventional heating. The results of fastness properties of the dyed fabrics were studied. X-ray and Scanning Electron Microscope SEM were carried out on dyed samples using both methods of dyeing to find out an explanation for the better dyeability of acrylic fabrics with (US) method. Dyeing kinetics of acrylic fabrics using C.I. Astrazon Basic Red 5BL 200% using conventional and ultrasonic conditions were compared. The time/dye-uptake isotherms are revealing the enhanced dye-uptake in the second phase of dyeing. The values of dyeing rate constant, half-time of dyeing and standard affinity and ultrasonic efficiency have been calculated and discussed.

An Ultrasonic Pattern Recognition Approach to Welding Defect Classification

International Nuclear Information System (INIS)

Song, Sung Jin

1995-01-01

Classification of flaws in weldments from their ultrasonic scattering signals is very important in quantitative nondestructive evaluation. This problem is ideally suited to a modern ultrasonic pattern recognition technique. Here brief discussion on systematic approach to this methodology is presented including ultrasonic feature extraction, feature selection and classification. A stronger emphasis is placed on probabilistic neural networks as efficient classifiers for many practical classification problems. In an example probabilistic neural networks are applied to classify flaws in weldments into 3 classes such as cracks, porosity and slag inclusions. Probabilistic nets are shown to be able to exhibit high performance of other classifiers without any training time overhead. In addition, forward selection scheme for sensitive features is addressed to enhance network performance

Range extension and channel capacity increase in impulse-radio ultra-wideband communications

DEFF Research Database (Denmark)

Rodes Lopez, Roberto; Yu, Xianbin; Caballero Jambrina, Antonio

2010-01-01

We theoretically analyze the channel capacity of a 5th-order Gaussian pulse-based ultra-wideband (UWB) system and experimentally demonstrate 2 Gbit/s UWB-over-fiber transmission systems incorporating wireless transmission. Both electrical and photonic UWB pulse generation methods are employed...

Characterization of Aging Behavior in M250 Grade Maraging Steel Using Ultrasonic Measurements

Science.gov (United States)

Rajkumar, K. V.; Kumar, Anish; Jayakumar, T.; Raj, Baldev; Ray, K. K.

2007-02-01

Ultrasonic measurements have been carried out in M250 grade maraging steel specimens subjected to solution annealing at 1093 K for 1 hour followed by aging at 755 K for various durations in the range of 0.25 to 100 hours. The influence of aging on microstructure, room temperature hardness, and ultrasonic parameters (longitudinal and shear wave velocities and Poisson’s ratio) has been studied in order to derive correlations among these parameters in aged M250 maraging steel. Both hardness and ultrasonic velocities exhibit almost similar behaviors with aging time. They increase with the precipitation of intermetallic phases, Ni3Ti and Fe2Mo, and decrease with the reversion of martensite to austenite. Ultrasonic shear wave velocity is found to be more influenced by the precipitation of intermetallic phases, whereas longitudinal wave velocity is influenced more by the reversion of martensite to austenite. Unlike hardness and ultrasonic velocities, the Poisson’s ratio exhibits a monotonous decrease with aging time and, hence, can be used for unambiguous monitoring of the aging process in M250 maraging steel. Further, none of the parameters, i.e., hardness, ultrasonic velocity, or Poisson’s ratio, alone could identify the initiation of the reversion of austenite at early stage; however, the same could be identified from the correlation between ultrasonic velocity and Poisson’s ratio, indicating the advantage of using the multiparametric approach for comprehensive characterization of complex aging behavior in M250 grade maraging steel.

Ultrasonic stir welding process and apparatus

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2009-01-01

An ultrasonic stir welding device provides a method and apparatus for elevating the temperature of a work piece utilizing at least one ultrasonic heater. Instead of relying on a rotating shoulder to provide heat to a workpiece an ultrasonic heater is utilized to provide ultrasonic energy to the workpiece. A rotating pin driven by a motor assembly performs the weld on the workpiece. A handheld version can be constructed as well as a fixedly mounted embodiment.

Smart ultrasonic flowmeter used for the operation support of water resource management in the agricultural areas

Science.gov (United States)

Elmostafa, Ziani; Mustapha, Bennouna; Boissier, Raymond

2008-10-01

Ultrasonic sensors transmit acoustic waves and receive them later. This is done by ultrasonic transducers, which transform an ultrasonic wave into an electrical signal and vice versa. Often, it is possible to use the same transducer for both transmitting and receiving. The most important parts of any ultrasonic sensor are the transducers. The spectral and spatial radiation characteristics of these components are the prime determinants of sensor performance. Such transducers must have a robust design, stable radiation pattern (high directivity) and good receiving sensitivity. Intelligent ultrasonic sensors have the possibility to extract the information about the variables to be measured, carried by the ultrasonic signals efficiently and with accuracy. To achieve this performance, the signals are processed by dedicated hardware (accurate electronic measuring devices). Ultrasound has the property, that its velocity is strongly affected by the flow velocity of the fluids in which it propagates. The ultrasonic flowmeters have gained a lot of attention over the past few years; they have several advantages over the differential pressure flowmeter, turbine meters, coriolis meters and vortex meters. They are widely used to measure the flow of liquids, first, they are either less intrusive (wetted flowmeter) or non-intrusive (clamp-on flowmeter), depending on the model. Also, they don't have moving parts that are subject to wear over time, and with minimum obstruction of the flow. Ultrasonic flowmeter are not limited to clean liquids (Transit time flowmeter), a special type of ultrasonic flowmeter can also accurately measure the flow of slurries and liquids with many impurities (Doppler flowmeter). This part of paper describes the intelligent ultrasonic sensor. The conception or the realization of intelligent ultrasonic sensor requires the synthesis of several technologies, a knowledge in the fields of sensor, digital ultrasonic signal processing, distributed system and

A new approach involving a multi transducer ultrasonic system for cleaning turbine engines' oil filters under practical conditions.

Science.gov (United States)

Nguyen, Dinh Duc; Ngo, Huu Hao; Yoon, Yong Soo; Chang, Soon Woong; Bui, Hong Ha

2016-09-01

The purpose of this paper is to provide a green technology that can clean turbine engine oil filters effectively in ships using ultrasound, with ultrasonic devices having a frequency of 25kHz and different powers of 300W and 600W, respectively. The effects of temperature, ultrasonic cleaning times, pressure losses through the oil filter, solvent washing, and ultrasonic power devices were investigated. In addition, the cleaning efficiency of three modes (hand washing, preliminary washing and ultrasonic washing) were compared to assess their relative effectiveness. Experimental results revealed that the necessary ultrasonic time varied significantly depending on which solvent was used for washing. For instance, the optimum ultrasonic cleaning time was 50-60min when the oil filter was cleaned in a solvent of kerosene oil (KO) and over 80min when in a solvent of diesel oil (DO) using the same ultrasonic generator device (25kHz, 600W) and experimental conditions. Furthermore, microscopic examination did not reveal any damage or breakdown on or within the structure of the filter after ultrasonic cleaning, even in the filter's surfaces at a constantly low frequency of 25kHz and power specific capacity (100W/gal). Overall, it may be concluded that ultrasound-assisted oil filter washing is effective, requiring a significantly shorter time than manual washing. This ultrasonic method also shows promise as a green technology for washing oil filters in turbine engines in general and Vietnamese navy ships in particular, because of its high cleaning efficiency, operational simplicity and savings. Copyright © 2016 Elsevier B.V. All rights reserved.

Imaging techniques for ultrasonic testing

International Nuclear Information System (INIS)

2013-01-01

These seminar proceedings contain 16 lectures on the following topics: 1. From imaging to quantification - ultrasound methods in medical diagnostics; 2. SAFT, TOFD, Phased Array - classical applications and recent developments in ultrasonic imaging; 3. Innovative ultrasonic imaging methods in research and application; 4. Industrial ultrasonic testing of fibre-reinforced structures of complex geometry; 5. Visualisation of crack tips in the inspection of wheel set shafts with longitudinal boreholes as a means of avoiding unnecessary wheel set changes; 6. Areal analysis of the propagation of Lamb waves on curved, anisotropic structures; 7. High-resolution representation in immersion technique testing; 8. Variants in generating images from phased array measurement data - practical examples involving copper, carbon-fibre reinforced plastic and other materials; 9. GIUM - an unconventional method of microstructure imaging using ultrasonic stimulation and laser vibrometry scanning; 10. Innovative air-ultrasonic testing concepts for improved imaging; 11. Use of imaging methods for improving the quality of test results from nondestructive testing; 12. Modelling and visualisation of EMUS stimulation for transducer optimisation; 13. Use of SAFT in the manufacture of energy conversion machines; 14. Ultrasonic imaging tests for improved defect characterisation during weld seam inspection on longitudinally welded large-diameter pipes; 15. SAFT reconstruction for testing austenitic weld seams and dissimilar metal weld seams for transverse cracks; 16. Imaging-based optimisation method for quantitative ultrasonic testing of anisotropic inhomogeneous austenitic welded joints with determination and utilisation of their elastic properties. One contribution has been abstracted separately. [de

Comparison between conventional and ultrasonic preparation of beef tallow biodiesel

Energy Technology Data Exchange (ETDEWEB)

Teixeira, Leonardo S.G. [Instituto de Quimica - Universidade Federal da Bahia, Campus Universitario de Ondina, 40.170-280 - Salvador, Bahia (Brazil); Assis, Julio C.R.; Santos, Iran T.V.; Guimaraes, Paulo R.B.; Pontes, Luiz A.M. [Universidade Salvador - UNIFACS - Departamento de Engenharia e Arquitetura, - Av. Cardeal da Silva 132, 40.220-141 - Salvador, Bahia (Brazil); Mendonca, Daniel R. [Escola Politecnica - Universidade Federal da Bahia, Av. Aristides Novis 2, 40.210-630, Salvador, Bahia (Brazil); Teixeira, Josanaide S.R. [Instituto Federal de Educacao Ciencia e Tecnologica da Bahia - IFBAHIA - Rua Emidio de Morais S/N, 40.625-650, Salvador - BA (Brazil)

2009-09-15

Tallow is biodiesel feedstock that, due to its highly centralized generation in slaughter/processing facilities and historically low prices, may have energetic, environmental, and economic advantages that could be exploited. Transesterification of fatty acids by means of ultrasonic energy has been used for biodiesel production from different vegetable oils. However, application of ultrasonic irradiation for biodiesel production from beef tallow has received little attention. In this work, the transesterification of beef tallow with methanol was performed in the presence of potassium hydroxide as a catalyst using ultrasound irradiation (400 W, 24 kHz). The reaction time, conversion and biodiesel quality were compared with that seen in conventional transesterification. The results indicated that the reaction conversion and biodiesel quality were similar; however, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative to the conventional method. (author)

Comparison between conventional and ultrasonic preparation of beef tallow biodiesel

International Nuclear Information System (INIS)

Teixeira, Leonardo S.G.; Assis, Julio C.R.; Santos, Iran T.V.; Guimaraes, Paulo R.B.; Pontes, Luiz A.M.; Mendonca, Daniel R.; Teixeira, Josanaide S.R.

2009-01-01

Tallow is biodiesel feedstock that, due to its highly centralized generation in slaughter/processing facilities and historically low prices, may have energetic, environmental, and economic advantages that could be exploited. Transesterification of fatty acids by means of ultrasonic energy has been used for biodiesel production from different vegetable oils. However, application of ultrasonic irradiation for biodiesel production from beef tallow has received little attention. In this work, the transesterification of beef tallow with methanol was performed in the presence of potassium hydroxide as a catalyst using ultrasound irradiation (400 W, 24 kHz). The reaction time, conversion and biodiesel quality were compared with that seen in conventional transesterification. The results indicated that the reaction conversion and biodiesel quality were similar; however, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative to the conventional method. (author)

Design Considerations for Autocalibrations of Wide-Band ΔΣ Fractional-N PLL Synthesizers

Directory of Open Access Journals (Sweden)

Jaewook Shin

2011-01-01

Full Text Available Autocalibration of VCO frequency and loop gain is an essential process in PLL frequency synthesizers. In a wide tuning-range fractional-N PLL frequency synthesizer, high-speed and high-precision automatic calibration is especially important for shortening the lock time and improving the phase noise. This paper reviews the design issues of the PLL auto-calibration and discusses on the limitations of the previous techniques. A very simple and efficient auto-calibration method based on a high-speed frequency-to-digital converter (FDC is proposed and verified through simulations. The proposed method is highly suited for a very wide-band ΔΣ fractional-N PLL.

Correlation between ultrasonic nonlinearity and elastic nonlinearity in heat-treated aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Beom; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

2017-04-15

The nonlinear ultrasonic technique is a potential nondestructive method to evaluate material degradation, in which the ultrasonic nonlinearity parameter is usually measured. The ultrasonic nonlinearity parameter is defined by the elastic nonlinearity coefficients of the nonlinear Hooke’s equation. Therefore, even though the ultrasonic nonlinearity parameter is not equal to the elastic nonlinearity parameter, they have a close relationship. However, there has been no experimental verification of the relationship between the ultrasonic and elastic nonlinearity parameters. In this study, the relationship is experimentally verified for a heat-treated aluminum alloy. Specimens of the aluminum alloy were heat-treated at 300°C for different periods of time (0, 1, 2, 5, 10, 20, and 50 h). The relative ultrasonic nonlinearity parameter of each specimen was then measured, and the elastic nonlinearity parameter was determined by fitting the stress-strain curve obtained from a tensile test to the 5th-order-polynomial nonlinear Hooke’s equation. The results showed that the variations in these parameters were in good agreement with each other.

Preparation of biodiesel with the help of ultrasonic and hydrodynamic cavitation.

Science.gov (United States)

Ji, Jianbing; Wang, Jianli; Li, Yongchao; Yu, Yunliang; Xu, Zhichao

2006-12-22

An alkali-catalyzed biodiesel production method with power ultrasonic (19.7 kHz) has been developed that allows a short reaction time and high yield because of emulsification and cavitation of the liquid-liquid immiscible system. Orthogonality experiments were employed to evaluate the effects of synthesis parameters. Furthermore, hydrodynamic cavitation was used for biodiesel production in comparison to ultrasonic method. Both methods were proved to be efficient, and time and energy saving for the preparation of biodiesel by transesterification of soybean oil.

Ultra-Wideband Transceivers for Cochlear Implants

Directory of Open Access Journals (Sweden)

Reisenzahn Alexander

2005-01-01

Full Text Available Ultra-wideband (UWB radio offers low power consumption, low power spectral density, high immunity against interference, and other benefits, not only for consumer electronics, but also for medical devices. A cochlear implant (CI is an electronic hearing apparatus, requiring a wireless link through human tissue. In this paper we propose an UWB link for a data rate of Mbps and a propagation distance up to 500 mm. Transmitters with step recovery diode and transistor pulse generators are proposed. Two types of antennas and their filter characteristics in the UWB spectrum will be discussed. An ultra-low-power back tunnel diode receiver prototype is described and compared with conventional detector receivers.

A multi-purpose ultrasonic streaming mixer for integrated magnetic bead ELISAs

International Nuclear Information System (INIS)

Brandhoff, Lukas; Lang, Walter; Vellekoop, Michael J; Zirath, Helene; Peham, Johannes; Wiesinger-Mayr, Herbert; Salas, Mariugenia; Haller, Anna; Spittler, Andreas; Schnetz, Guntram

2015-01-01

We present an ultrasonic streaming mixer for disposable and on-chip magnetic bead ELISAs. The ultrasonic transducer is placed at system-level to keep cost per chip as low as possible, and is coupled to the chip by means of a solid ultrasonic horn. The system provides mixing of liquids, as well as dispersion of the superparamagnetic beads in the ELISA. Additionally it can be used clean the chamber surface from nonspecifically bound proteins during the washing steps in the ELISA protocol. Using our system the time for the ELISA protocol has been greatly reduced down to 30 min. (paper)

Effect of Stone Size and Composition on Ultrasonic Propulsion Ex Vivo.

Science.gov (United States)

Janssen, Karmon M; Brand, Timothy C; Bailey, Michael R; Cunitz, Bryan W; Harper, Jonathan D; Sorensen, Mathew D; Dunmire, Barbrina

2018-01-01

To evaluate in more detail the effectiveness of a new designed more efficient ultrasonic propulsion for large stones and specific stone compositions in a tissue phantom model. In the first clinical trial of noninvasive ultrasonic propulsion, urinary stones of unknown compositions and sizes up to 10 mm were successfully repositioned. The study included 8- to 12-mm stones of 4 different primary compositions (calcium oxalate monohydrate, ammonium acid urate, calcium phosphate, and struvite) and a renal calyx phantom consisting of a 12 mm × 30 mm well in a 10-cm block of tissue-mimicking material. Primary outcome was the number of times a stone was expelled over 10 attempts, with ultrasonic propulsion burst duration varying from 0.5 seconds to 5 seconds. Overall success rate at expelling stones was 95%. All calcium oxalate monohydrate and ammonium acid urate stones were expelled 100% of the time. The largest stone (12 mm) became lodged within the 12-mm phantom calyx 25% of the time regardless of the burst duration. With the 0.5-second burst, there was insufficient energy to expel the heaviest stone (0.88 g), but there was sufficient energy at the longer burst durations. With a single burst, ultrasonic propulsion successfully moved most stones at least 3 cm and, regardless of size or composition, expelled them from the calyx. Ultrasonic propulsion is limited to the stones smaller than the calyceal space, and for each burst duration, related to maximum stone mass. Published by Elsevier Inc.

A study for soundness of turbine blade root using ultrasonic and phased array

International Nuclear Information System (INIS)

Gil, Doo Song; Park, Sang Ki; Cho, Yong Sang; Lee, Sang Gug; Huh, Kuang Bum

2003-01-01

Power plant is consisted of many component parts for the generation of the electricity and occasionally, turbine equipment may be caused in break-down because of the damage of the blade root. Phased array ultrasonic testing system has become available for power industry. This research describes the characteristics of phased array ultrasonic testing signal for various type of blade roots in thermal power plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phased array ultrasonic testing signal for power plant component in very simple to understand but to difficult for perform the inspection. This paper is focused on the safety of the turbine equipment by the ultrasonic measurement and phased array analysis. As a result of the test through ultrasonic and phased array method, we have concluded that the main damage in these turbine blade roots parts could be generated by the concentrated stress and centrifugal force.

21 CFR 872.4850 - Ultrasonic scaler.

Science.gov (United States)

2010-04-01

... DEVICES DENTAL DEVICES Surgical Devices § 872.4850 Ultrasonic scaler. (a) Identification. An ultrasonic scaler is a device intended for use during dental cleaning and periodontal (gum) therapy to remove calculus deposits from teeth by application of an ultrasonic vibrating scaler tip to the teeth. (b...

Proposal of a wide-band mirror polarizer of slow neutrons at a pulsed neutron source

International Nuclear Information System (INIS)

Nikitenko, Yu.V.; Ostanevich, Yu.M.

1993-01-01

The new type of wide-band mirror-based neutron polarizer, which is to be operated at a pulsed neutron source, is suggested. The idea is to use a movable polarizing mirror system, which, with the incoming beam monochromatized by the time-of-flight, would allow one to tune glancing angles in time so that the total reflection condition is always fulfilled only for one of the two neutron spin eigenstates. Estimates show that with the pulsed reactor IBR-2 such a polarizer allows one to build a small angle neutron scattering instrument capable of effectively using the wavelength band from 2 A with a rather high luminosity (time-averaged flux at sample position being up to 10 7 n/s/cm -2 ). (orig.)

Performance Analysis of Ultra-Wideband Channel for Short-Range Monopulse Radar at Ka-Band

Directory of Open Access Journals (Sweden)

Naohiko Iwakiri

2012-01-01

Full Text Available High-range resolution is inherently provided with Ka-band ultra-wideband (UWB vehicular radars. The authors have developed a prototype UWB monopulse radar equipped with a two-element receiving antenna array and reported its measurement results. In this paper, a more detailed verification using these measurements is presented. The measurements were analyzed employing matched filtering and eigendecomposition, and then multipath components were extracted to examine the behavior of received UWB monopulse signals. Next, conventional direction finding algorithms based on narrowband assumption were evaluated using the extracted multipath components, resulting in acceptable angle-of-arrival (AOA from the UWB monopulse signal regardless of wideband signals. Performance degradation due to a number of averaging the received monopulses was also examined to design suitable radar's waveforms.

Rodent ultrasonic vocalizations are bound to active sniffing behavior

Directory of Open Access Journals (Sweden)

Yevgeniy B Sirotin

2014-11-01

Full Text Available During rodent active behavior, multiple orofacial sensorimotor behaviors, including sniffing and whisking, display rhythmicity in the theta range (~5-10 Hz. During specific behaviors, these rhythmic patterns interlock, such that execution of individual motor programs becomes dependent on the state of the others. Here we performed simultaneous recordings of the respiratory cycle and ultrasonic vocalization emission by adult rats and mice in social settings. We used automated analysis to examine the relationship between breathing patterns and vocalization over long time periods. Rat ultrasonic vocalizations (USVs, ’50 kHz’ were emitted within stretches of active sniffing (5−10 Hz and were largely absent during periods of passive breathing (1-4 Hz. Because ultrasound was tightly linked to the exhalation phase, the sniffing cycle segmented vocal production into discrete calls and imposed its theta rhythmicity on their timing. In turn, calls briefly prolonged exhalations, causing an immediate drop in sniffing rate. Similar results were obtained in mice. Our results show that ultrasonic vocalizations are an integral part of the rhythmic orofacial behavioral ensemble. This complex behavioral program is thus involved not only in active sensing but also in the temporal structuring of social communication signals. Many other social signals of mammals, including monkey calls and human speech, show structure in the theta range. Our work points to a mechanism for such structuring in rodent ultrasonic vocalizations.

Ruggedizing Printed Circuit Boards Using a Wideband Dynamic Absorber

Directory of Open Access Journals (Sweden)

V.C. Ho

2003-01-01

Full Text Available The existing approaches to ruggedizing inherently fragile and sensitive critical components of electronic equipment such as printed circuit boards (PCB for use in hostile industrial and military environment are either insufficient or expensive. This paper addresses a novel approach towards ruggedizing commercial-off-the-shelf PCBs using a miniature wideband dynamic absorber. The optimisation technique used relies on the experimentally measured vibration spectra and complex receptance of the original PCB.

A Wideband Autonomous Cognitive Radio Development and Prototyping System

Science.gov (United States)

2017-11-14

three infrastructure modules (a Network Spectrum Analyzer, a Vector Signal Generator and a Rapid Printed Circuit Board (PCB) Fabrication Unit) and a...Antennas for Mobile Platforms”, 02/01/17-12/31/17 ($100K), Honeywell FM&T. 3. S. K. Jayaweera (Principal Investigator) and C. G. Christodoulou “Wideband...Signal Generator and a Rapid Printed Circuit Board (PCB) Fabrication Unit) and a Software Defined Radio (SDR) testbed made of several USRP SDR

Ultrasonic RF time series for early assessment of the tumor response to chemotherapy.

Science.gov (United States)

Lin, Qingguang; Wang, Jianwei; Li, Qing; Lin, Chunyi; Guo, Zhixing; Zheng, Wei; Yan, Cuiju; Li, Anhua; Zhou, Jianhua

2018-01-05

Ultrasound radio-frequency (RF) time series have been shown to carry tissue typing information. To evaluate the potential of RF time series for early prediction of tumor response to chemotherapy, 50MCF-7 breast cancer-bearing nude mice were randomized to receive cisplatin and paclitaxel (treatment group; n = 26) or sterile saline (control group; n = 24). Sequential ultrasound imaging was performed on days 0, 3, 6, and 8 of treatment to simultaneously collect B-mode images and RF data. Six RF time series features, slope, intercept, S1, S2, S3 , and S4 , were extracted during RF data analysis and contrasted with microstructural tumor changes on histopathology. Chemotherapy administration reduced tumor growth relative to control on days 6 and 8. Compared with day 0, intercept, S1 , and S2 were increased while slope was decreased on days 3, 6, and 8 in the treatment group. Compared with the control group, intercept, S1, S2, S3 , and S4 were increased, and slope was decreased, on days 3, 6, and 8 in the treatment group. Tumor cell density decreased significantly in the latter on day 3. We conclude that ultrasonic RF time series analysis provides a simple way to noninvasively assess the early tumor response to chemotherapy.

Investigation on cored-eutectic structure in Ni60/WC composite coatings fabricated by wide-band laser cladding

Energy Technology Data Exchange (ETDEWEB)

Ma, Qunshuang, E-mail: maqunshuang@126.com; Li, Yajiang, E-mail: yajli@sdu.edu.cn; Wang, Juan, E-mail: jwang@sdu.edu.cn; Liu, Kun, E-mail: liu_kun@163.com

2015-10-05

Highlights: • Perfect composite coatings were fabricated using wide-band laser cladding. • Special cored-eutectic structure was synthesized in Ni60/WC composite coatings. • Cored-eutectic consists of hard carbide compounds and fine lamellar eutectic of M{sub 23}C{sub 6} carbides and γ-Ni(Fe). • Wear resistance of coating layer was significantly improved due to precipitation of M{sub 23}C{sub 6} carbides. - Abstract: Ni60 composite coatings reinforced with WC particles were fabricated on the surface of Q550 steel using LDF4000-100 fiber laser device. The wide-band laser and circular beam laser used in laser cladding were obtained by optical lens. Microstructure, elemental distribution, phase constitution and wear properties of different composite coatings were investigated. The results showed that WC particles were partly dissolved under the effect of wide-band fiber laser irradiation. A special cored-eutectic structure was synthesized due to dissolution of WC particles. According to EDS and XRD results, the inside cores were confirmed as carbides of M{sub 23}C{sub 6} enriched in Cr, W and Fe. These complex carbides were primarily separated out in the molten metal when solidification started. Eutectic structure composed of M{sub 23}C{sub 6} carbides and γ-Ni(Fe) grew around carbides when cooling. Element content of Cr and W is lower at the bottom of cladding layer. In consequence, the eutectic structure formed in this region did not have inside carbides. The coatings made by circular laser beam were composed of dendritic matrix and interdendritic eutectic carbides, lacking of block carbides. Compared to coatings made by circular laser spot, the cored-eutectic structure formed in wide-band coatings had advantages of well-distribution and tight binding with matrix. The uniform power density and energy distribution and the weak liquid convection in molten pool lead to the unique microstructure evolution in composite coatings made by wide-band laser

Impact of applied ultrasonic power on the low temperature drying of apple.

Science.gov (United States)

Santacatalina, J V; Contreras, M; Simal, S; Cárcel, J A; Garcia-Perez, J V

2016-01-01

Low temperature drying (LTD) allows high-quality dried products to be obtained, preserving the nutritional properties of fresh foods better than conventional drying, but it is a time-consuming operation. Power ultrasound (US) could be used to intensify LTD, but it should be taken into account that process variables, such as the level of applied power, have an influence on the magnitude and extension of the ultrasonic effects. Therefore, the aim of this work was to assess the influence of the level of applied ultrasonic power on the LTD of apple, analyzing the drying kinetics and the quality of the dried product. For that purpose, apple (Malus domestica cv. Granny Smith) cubes (8.8mm side) were dried (2m/s) at two different temperatures (10 and -10°C), without and with (25, 50 and 75 W) US application. In the dried apple, the rehydration kinetics, hardness, total phenolic content, antioxidant capacity and microstructure were analyzed to evaluate the impact of the level of applied ultrasonic power. At both temperatures, 10 and -10°C, the higher the ultrasonic power level, the shorter the drying time; the maximum shortening of the drying time achieved was 80.3% (at -10°C and 75 W). The ultrasonic power level did not significantly (pfruits, like apple, with only a mild impact on the quality of the dried product. Copyright © 2015 Elsevier B.V. All rights reserved.

Analytical reverse time migration: An innovation in imaging of infrastructures using ultrasonic shear waves.

Science.gov (United States)

Asadollahi, Aziz; Khazanovich, Lev

2018-04-11

The emergence of ultrasonic dry point contact (DPC) transducers that emit horizontal shear waves has enabled efficient collection of high-quality data in the context of a nondestructive evaluation of concrete structures. This offers an opportunity to improve the quality of evaluation by adapting advanced imaging techniques. Reverse time migration (RTM) is a simulation-based reconstruction technique that offers advantages over conventional methods, such as the synthetic aperture focusing technique. RTM is capable of imaging boundaries and interfaces with steep slopes and the bottom boundaries of inclusions and defects. However, this imaging technique requires a massive amount of memory and its computation cost is high. In this study, both bottlenecks of the RTM are resolved when shear transducers are used for data acquisition. An analytical approach was developed to obtain the source and receiver wavefields needed for imaging using reverse time migration. It is shown that the proposed analytical approach not only eliminates the high memory demand, but also drastically reduces the computation time from days to minutes. Copyright © 2018 Elsevier B.V. All rights reserved.

Ultrasonic Bat Deterrent Technology

Energy Technology Data Exchange (ETDEWEB)

Kinzie, Kevin; Rominger, Kathryn M.

2017-12-14

The project objective was to advance the development and testing of an Near commercial bat-deterrent system with a goal to increase the current GE deterrent system effectiveness to over 50% with broad species applicability. Additionally, the research supported by this program has provided insights into bat behavior and ultrasonic deterrent design that had not previously been explored. Prior research and development had demonstrated the effectiveness of a commercial-grade, air-powered, ultrasonic bat deterrent to be between 30-50% depending upon the species of bat. However, the previous research provided limited insight into the behavioral responses of bats in the presence of ultrasonic deterrent sound fields that could be utilized to improve effectiveness. A unique bat flight room was utilized to observe the behavioral characteristics of bats in the presence of ultrasonic sound fields. Behavioral testing in the bat flight facility demonstrated that ultrasonic sounds similar to those produced by the GE deterrent influenced the activities and behaviors, primarily those associated with foraging, of the species exposed. The study also indicated that continuous and pulsing ultrasonic signals had a similar effect on the bats, and confirmed that as ultrasonic sounds attenuate, their influence on the bats’ activities and behavior decreases. Ground testing at Wolf Ridge Wind, LLC and Shawnee National Forest assessed both continuous and pulsing deterrent signals emitted from the GE deterrent system and further enhanced the behavioral understanding of bats in the presence of the deterrent. With these data and observations, the existing 4-nozzle continuous, or steady, emission ultrasonic system was redesigned to a 6-nozzle system that could emit a pulsing signal covering a larger air space around a turbine. Twelve GE 1.6-100 turbines were outfitted with the deterrent system and a formal three-month field study was performed using daily carcass searches beneath the 12

Multipurpose discriminator with accurate time coupling

International Nuclear Information System (INIS)

Baldin, B.Yu.; Krumshtejn, Z.V.; Ronzhin, A.I.

1977-01-01

The principle diagram of a multipurpose discriminator is described, designed on the basis of a wide-band differential amplifier. The discriminator has three independent channels: the timing channel, the lower level discriminator and the control channel. The timing channel and the lower level discriminator are connected to a coincidence circuit. Three methods of timing are used: a single threshold, a double threshold with timing on the pulse front, and a constant fraction timing. The lower level discriminator is a wide-band amplifier with an adjustable threshold. The investigation of compensation characteristics of the discriminator has shown that the time shift of the discriminator output in the constant fraction timing regime does not exceed +-75 ns for the input signal range of 1:85. The time resolution was found to be 20 ns in the 20% energy range near the photo-peak maximum of 60 Co γ source

An advanced ultrasonic technique for slow and void fraction measurements of two-phase flow

International Nuclear Information System (INIS)

Faccini, J.L.H.; Su, J.; Harvel, G.D.; Chang, J.S.

2004-01-01

In this paper, we present a hybrid type counterpropagating transmission ultrasonic technique (CPTU) for flow and time averaging ultrasonic transmission intensity void fraction measurements (TATIU) of air-water two-phase flow, which is tested in the new two-phase flow test section mounted recently onto an existing single phase flow rig. The circular pipe test section is made of 51.2 mm stainless steel, followed by a transparent extruded acrylic pipe aimed at flow visualization. The two-phase flow rig operates in several flow regimes: bubbly, smooth stratified, wavy stratified and slug flow. The observed flow patterns are compared with previous experimental and numerical flow regime map for horizontal two phase flows. These flow patterns will be identified by time averaging transmission intensity ultrasonic techniques which have been developed to meet this particular application. A counterpropagating transmission ultrasonic flowmeter is used to measure the flow rate of liquid phase. A pulse-echo TATIU ultrasonic technique used to measure the void fraction of the horizontal test section is presented. We can draw the following conclusions: 1) the ultrasonic system was able to characterize the 2 flow patterns simulated (stratified and plug flow); 2) the results obtained for water volumetric fraction require more experimental work to determine exactly the technique uncertainties but, a priori, they are consistent with earlier work; and 3) the experimental uncertainties can be reduced by improving the data acquisition system, changing the acquisition time interval from seconds to milliseconds

Ultrasonic treatment of Viscozyme Cassava C preparation for improving cellulase activity

Science.gov (United States)

Tra, Tran Thi Thu; Vu, Huynh Minh; Man, Le Van Viet

2017-09-01

In this study, the effects of ultrasonic treatment on the cellulolytic activity of Viscozyme Cassava C preparation were investigated. The biocatalyst was treated with ultrasound at different enzyme concentrations (from 0.02 to 19.50 mg protein/mL), ultrasonic powers (from 0 to 12 W/mL) and times (from 0 to 120 seconds). The highest cellulase activity was achieved when the enzyme preparation was ultrasonicated at 7.3 W/mL for 40 sec, under which the cellulase activity increased by 18.1% over the control. The optimal pH and temperature of the sonicated and unsonicated biocatalysts were statistically similar. However, the half-life value of the sonicated preparation at 4 °C was 24.5% higher than that of the unsonicated preparation. This result indicated that ultrasonic treatment of the enzyme preparation could reduce its amount used in biocatalysis.

MOSFET-based high voltage short pulse generator for ultrasonic transducer excitation

Science.gov (United States)

Hidayat, Darmawan; Setianto, Syafei, Nendi Suhendi; Wibawa, Bambang Mukti

2018-02-01

This paper presents the generation of a high-voltage short pulse for the excitation of high frequency ultrasonic transducers. This is highly required in the purpose of various ultrasonic-based evaluations, particularly when high resolution measurement is necessary. A high voltage (+760 V) DC voltage source was pulsated by an ultrafast switching MOSFET which was driven by a pulse generator circuit consisting of an astable multivibrator, a one-shot multivibrator with Schmitt trigger input and a high current MOSFET driver. The generated pulses excited a 200-kHz and a 1-MHz ultrasonic transducers and tested in the transmission mode propagation to evaluate the performances of the generated pulse. The test results showed the generator were able to produce negative spike pulses up to -760 V voltage with the shortest time-width of 107.1 nanosecond. The transmission-received ultrasonic waves show frequency oscillation at 200 and 961 kHz and their amplitudes varied with the voltage of excitation pulse. These results conclude that the developed pulse generator is applicable to excite transducer for the generation of high frequency ultrasonic waves.

Quality control of disinfection in ultrasonic baths

Energy Technology Data Exchange (ETDEWEB)

Schoene, H. [Technical University Dresden (Germany). Faculty of Mechanical Engineering; Jatzwauk, L. [University Hospital of the Technical University Dresden (Germany). Abt. Krankenhaushygiene

2002-07-01

Numerous investigations under laboratory conditions confirmed the microbicidal efficacy of ultrasonication. Morphological destruction was shown on bacteria and fungi as well as on different virus species. Ultrasonic treatment seems to increase the effect of different antibiotics and disinfectants. Reasons for this synergism are largely unknown and uninvestigated, but the active principle seems to bee the dispersing effect of ultrasonication in combination with the destruction of cell wall or cell membrane. Unfortunately no validation of test conditions exists for most of these investigations, regarding intensity and frequency of ultrasonic waves, temperature of liquid medium and measurement of cavitation which is an essential part of physical and chemical effects in ultrasonic baths. In contrast to most laboratory experiments sound density of ultrasound for treatment of medical instruments is below 1 W/cm{sup 2} because instruments will be destroyed under stronger ultrasonic conditions. The frequency is below 50 KHz. This paper describes bactericidal and fungicidal effects of low- intensity-ultrasonication and its synergistical support to chemical disinfection. (orig.)

Metasurface base on uneven layered fractal elements for ultra-wideband RCS reduction

Science.gov (United States)

Su, Jianxun; Cui, Yueyang; Li, Zengrui; Yang, Yaoqing Lamar; Che, Yongxing; Yin, Hongcheng

2018-03-01

A novel metasurface based on uneven layered fractal elements is designed and fabricated for ultra-wideband radar cross section (RCS) reduction in this paper. The proposed metasurface consists of two fractal subwavelength elements with different layer thickness. The reflection phase difference of 180° (±37°) between two unit cells covers an ultra-wide frequency range. Ultra-wideband RCS reduction results from the phase cancellation between two local waves produced by these two unit cells. The diffuse scattering of electromagnetic (EM) waves is caused by the randomized phase distribution, leading to a low monostatic and bistatic RCS simultaneously. This metasurface can achieve -10dB RCS reduction in an ultra-wide frequency range from 6.6 to 23.9 GHz with a ratio bandwidth (fH/fL) of 3.62:1 under normal incidences for both x- and y-polarized waves. Both the simulation and the measurement results are consistent to verify this excellent RCS reduction performance of the proposed metasurface.

Ultrasonic Tomography Imaging for Liquid-Gas Flow Measurement

Directory of Open Access Journals (Sweden)

Muhammad Jaysuman PUSPPANATHAN

2013-01-01

Full Text Available This research was carried out to measure two-phase liquid – gas flow regime by using a dual functionality ultrasonic transducer. Comparing to the common separated transmitter–receiver ultrasonic pairs transducer, the dual functionality ultrasonic transceiver is capable to produce the same measurable results hence further improvises and contributes to the hardware design improvement and system accuracy. Due to the disadvantages and the limitations of the separated ultrasonic transmitter–receiver pair, this paper presents a non-invasive ultrasonic tomography system using ultrasonic transceivers as an alternative approach. Implementation of ultrasonic transceivers, electronic measurement circuits, data acquisition system and suitable image reconstruction algorithms, the measurement of a liquid/gas flow was realized.

Hardware Development of Ultrasonic Tomography for Composition Determination of Water and Oil Flow

Directory of Open Access Journals (Sweden)

Ruzairi Abdul Rahim

2007-01-01

Full Text Available A monitoring system for water and oil flow using ultrasonic Tomography is implemented. Information such as the type of flow, the composition of the water and oil can be obtained from the system. The composition of the flow is determined based on the propagation time of the ultrasonic waves. The ultrasonic Tomography system includes the sensors fixture design, signal conditioning circuits and image reconstruction software. The image reconstruction algorithm that used is the Linear Back Projection (LBP algorithm.

Self-Calibrating Ultrasonic Methods for In-Situ Monitoring of Fatigue Crack Progression

International Nuclear Information System (INIS)

Michaels, J.E.; Mi, B.; Cobb, A.C.; Michaels, T.E.; Stobbe, D.M.

2005-01-01

Ultrasonic sensors permanently affixed to aluminum coupons are used to monitor progression of damage during fatigue testing with the long term goal of structural health monitoring for diagnostics and prognostics. Necessary for success are proper design of the ultrasonic testing methods, robust transducer mounting techniques, and real-time signal processing for determining the state of the structure. It is also highly desirable for the overall system to be self-calibrating with built-in diagnostics in order to detect and compensate for sensor degradation or failure. Self-calibrating ultrasonic techniques are applied for monitoring of cracks initiating and propagating from the inaccessible inner diameters of rivet holes where the transducers are mounted on the accessible specimen surface. Angle beam ultrasonic methods are utilized that are suitable for detecting small defects in critical local regions of high stress. Results are presented for aluminum coupons subjected to low cycle fatigue and demonstrate ultrasonic tracking of crack growth

Response surface methodology for the optimization of sludge solubilization by ultrasonic pre-treatment

Science.gov (United States)

Zheng, Mingyue; Zhang, Xiaohui; Lu, Peng; Cao, Qiguang; Yuan, Yuan; Yue, Mingxing; Fu, Yiwei; Wu, Libin

2018-02-01

The present study examines the optimization of the ultrasonic pre-treatment conditions with response surface experimental design in terms of sludge disintegration efficiency (solubilisation of organic components). Ultrasonic pre-treatment for the maximum solubilization with residual sludge enhanced the SCOD release. Optimization of the ultrasonic pre-treatment was conducted through a Box-Behnken design (three variables, a total of 17 experiments) to determine the effects of three independent variables (power, residence time and TS) on COD solubilization of sludge. The optimal COD was obtained at 17349.4mg/L, when the power was 534.67W, the time was 10.77, and TS was 2%, while the SE of this condition was 28792J/kg TS.

Ultrasonic Stir Welding

Science.gov (United States)

Nabors, Sammy

2015-01-01

NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

Contribution of dynamic focusing to ultrasonic defect characterization

International Nuclear Information System (INIS)

Mahaut, S.

1997-01-01

Non destructive testing of vessels of pressurized water reactors uses ultrasonic focused transducers, with spherically shaped emitting surface or requiring an acoustic lens. But a mechanically focused transducer has to be used for a given inspection zone and for a fixed control configuration. The aim of this thesis is to improve ultrasonic defect characterization using adaptive dynamic focusing. Such a technique makes use of a ultrasonic defect characterization using adaptive dynamic focusing. Such a technique makes use of an ultrasonic transducer split into an array of individually controlled elements, allowing to apply delay and amplitude laws, calculated from modeling or experimentally deduced. Acoustical characteristics of the ultrasonic beam in the inspected specimen this can be electronically controlled; refraction angle, depth focusing, beam width. We briefly describe in the first chapter a theoretical modeling of the ultrasonic field radiated through a fluid/solid interface, extended to phase array transducers. This model is based on the integral formulation of Rayleigh, modified to take into account transmission through a fluid/solid (homogeneous and isotropic), of planar or cylindrical shape. In the second chapter an experimental study of this technique, with delay and amplitude laws given from the model, is presented, showing the efficiency of this method to adjust the acoustic performances. In he third chapter, experimental delay laws, extracted from the time distribution of signals received by the array (issued from a preliminary detected reflector), are used to provide an optimal imaging of the defect. This self-focusing procedure shows to adapt to a defect without using theoretical delays. The last chapter is dedicated to different applications devoted to improved defect characterization. The first application uses amplitude distribution received by the array, pointing out geometric characteristics of the reflector, while the second application

Development of coaxial ultrasonic probe for fatty liver diagnostic system using ultrasonic velocity change

Science.gov (United States)

Hori, Makoto; Yokota, Daiki; Aotani, Yuhei; Kumagai, Yuta; Wada, Kenji; Matsunaka, Toshiyuki; Morikawa, Hiroyasu; Horinaka, Hiromichi

2017-07-01

A diagnostic system for fatty liver at an early stage is needed because fatty liver is linked to metabolic syndrome. We have already proposed a fatty liver diagnosis method based on the temperature coefficient of ultrasonic velocity. In this study, we fabricated a coaxial ultrasonic probe by integrating two kinds of transducers for warming and signal detection. The diagnosis system equipped with the coaxial probe was applied to tissue-mimicking phantoms including the fat area. The fat content rates corresponding to the set rates of the phantoms were estimated by the ultrasonic velocity-change method.

Novel wideband MIMO antennas that can cover the whole LTE spectrum in handsets and portable computers.

Science.gov (United States)

Sanad, Mohamed; Hassan, Noha

2014-01-01

A dual resonant antenna configuration is developed for multistandard multifunction mobile handsets and portable computers. Only two wideband resonant antennas can cover most of the LTE spectrums in portable communication equipment. The bandwidth that can be covered by each antenna exceeds 70% without using any matching or tuning circuits, with efficiencies that reach 80%. Thus, a dual configuration of them is capable of covering up to 39 LTE (4G) bands besides the existing 2G and 3G bands. 2×2 MIMO configurations have been also developed for the two wideband antennas with a maximum isolation and a minimum correlation coefficient between the primary and the diversity antennas.

Pitch-catch only ultrasonic fluid densitometer

Science.gov (United States)

Greenwood, M.S.; Harris, R.V.

1999-03-23

The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

S – C – L triple wavelength superluminescent source based on an ultra-wideband SOA and FBGs

Energy Technology Data Exchange (ETDEWEB)

Ahmad, H; Zulkifli, M Z; Hassan, N A; Muhammad, F D; Harun, S W [Photonics Research Center (Department of Physics), University of Malaya, 50603 Kuala Lumpur (Malaysia)

2013-10-31

We propose and demonstrate a wide-band semiconductor optical amplifier (SOA) based triple-wavelength superluminescent source with the output in the S-, C- and L-band regions. The proposed systems uses an ultra-wideband SOA with an amplification range from 1440 to 1620 nm as the linear gain medium. Three fibre Bragg gratings (FBGs) with centre wavelengths of 1500, 1540 and 1580 nm are used to generate the lasing wavelengths in the S-, Cand L-bands respectively, while a variable optical attenuator is used to finely balance the optical powers of the lasing wavelengths. The ultra-wideband SOA generates an amplified spontaneous emission (ASE) spectrum with a peak power of -33 dBm at the highest SOA drive current, and also demonstrates a down-shift in the centre wavelength of the generated spectrum due to the spatial distribution of the carrier densities. The S-band wavelength is the dominant wavelength at high drive currents, with an output power of -6 dBm as compared to the C- and L-bands, which only have powers of -11 and -10 dBm, respectively. All wavelengths have a high average signal-to-noise ratio more than 60 dB at the highest drive current of 390 mA, and the system also shows a high degree of stability, with power fluctuations of less than 3 dB within 70 min. The proposed system can find many applications where a wide-band and stable laser source is crucial, such as in communications and sensing. (control of laser radiation parameters)

S – C – L triple wavelength superluminescent source based on an ultra-wideband SOA and FBGs

International Nuclear Information System (INIS)

Ahmad, H; Zulkifli, M Z; Hassan, N A; Muhammad, F D; Harun, S W

2013-01-01

We propose and demonstrate a wide-band semiconductor optical amplifier (SOA) based triple-wavelength superluminescent source with the output in the S-, C- and L-band regions. The proposed systems uses an ultra-wideband SOA with an amplification range from 1440 to 1620 nm as the linear gain medium. Three fibre Bragg gratings (FBGs) with centre wavelengths of 1500, 1540 and 1580 nm are used to generate the lasing wavelengths in the S-, Cand L-bands respectively, while a variable optical attenuator is used to finely balance the optical powers of the lasing wavelengths. The ultra-wideband SOA generates an amplified spontaneous emission (ASE) spectrum with a peak power of -33 dBm at the highest SOA drive current, and also demonstrates a down-shift in the centre wavelength of the generated spectrum due to the spatial distribution of the carrier densities. The S-band wavelength is the dominant wavelength at high drive currents, with an output power of -6 dBm as compared to the C- and L-bands, which only have powers of -11 and -10 dBm, respectively. All wavelengths have a high average signal-to-noise ratio more than 60 dB at the highest drive current of 390 mA, and the system also shows a high degree of stability, with power fluctuations of less than 3 dB within 70 min. The proposed system can find many applications where a wide-band and stable laser source is crucial, such as in communications and sensing. (control of laser radiation parameters)

Ultrasonic degradation of butadiene, styrene and their copolymers.

Science.gov (United States)

Sathiskumar, P S; Madras, Giridhar

2012-05-01

Ultrasonic degradation of commercially important polymers, styrene-butadiene (SBR) rubber, acrylonitrile-butadiene (NBR) rubber, styrene-acrylonitrile (SAN), polybutadiene rubber and polystyrene were investigated. The molecular weight distributions were measured using gel permeation chromatography (GPC). A model based on continuous distribution kinetics approach was used to study the time evolution of molecular weight distribution for these polymers during degradation. The effect of solvent properties and ultrasound intensity on the degradation of SBR rubber was investigated using different pure solvents and mixed solvents of varying volatility and different ultrasonic intensities. Copyright © 2011 Elsevier B.V. All rights reserved.

Digital Receiver Design for Transmitted Reference Ultra-Wideband Systems

Directory of Open Access Journals (Sweden)

Wang Yiyin

2009-01-01

Full Text Available Abstract A complete detection, channel estimation, synchronization, and equalization scheme for a transmitted reference (TR ultra-wideband (UWB system is proposed in this paper. The scheme is based on a data model which admits a moderate data rate and takes both the interframe interference (IFI and the intersymbol interference (ISI into consideration. Moreover, the bias caused by the interpulse interference (IPI in one frame is also taken into account. Based on the analysis of the stochastic properties of the received signals, several detectors are studied and evaluated. Furthermore, a data-aided two-stage synchronization strategy is proposed, which obtains sample-level timing in the range of one symbol at the first stage and then pursues symbol-level synchronization by looking for the header at the second stage. Three channel estimators are derived to achieve joint channel and timing estimates for the first stage, namely, the linear minimum mean square error (LMMSE estimator, the least squares (LS estimator, and the matched filter (MF. We check the performance of different combinations of channel estimation and equalization schemes and try to find the best combination, that is, the one providing a good tradeoff between complexity and performance.

Digital Receiver Design for Transmitted Reference Ultra-Wideband Systems

Directory of Open Access Journals (Sweden)

Yiyin Wang

2009-01-01

Full Text Available A complete detection, channel estimation, synchronization, and equalization scheme for a transmitted reference (TR ultra-wideband (UWB system is proposed in this paper. The scheme is based on a data model which admits a moderate data rate and takes both the interframe interference (IFI and the intersymbol interference (ISI into consideration. Moreover, the bias caused by the interpulse interference (IPI in one frame is also taken into account. Based on the analysis of the stochastic properties of the received signals, several detectors are studied and evaluated. Furthermore, a data-aided two-stage synchronization strategy is proposed, which obtains sample-level timing in the range of one symbol at the first stage and then pursues symbol-level synchronization by looking for the header at the second stage. Three channel estimators are derived to achieve joint channel and timing estimates for the first stage, namely, the linear minimum mean square error (LMMSE estimator, the least squares (LS estimator, and the matched filter (MF. We check the performance of different combinations of channel estimation and equalization schemes and try to find the best combination, that is, the one providing a good tradeoff between complexity and performance.

Proposed new ultrasonic test bed

International Nuclear Information System (INIS)

Maxfield, B.W.

1978-01-01

Within the last four or five years, a great deal of progress has been made both here and in a number of other laboratories in developing techniques that will enable considerably more information to be obtained from the ultrasonic examination of an object. Some of these recent developments relate to information contained within the diffracted beam which does not return along the incident path. An ultrasonic examination based upon an evaluation of diffracted energy must use at least two transducers, one for transmission and the other for reception. Current indications are that even more reliable test results will be achieved using a receiving transducer that can scan a significant portion of the diffracted field including that portion which is back-reflected. In general, this scan can be interpreted most accurately if it follows a path related to the surface shape. If more than one region within the object is to be interrogated, then the transmitting transducer must also be scanned, again along a path related to the surface shape. The large quantity of information obtained as the result of such an examination must be subjected to sophisticated computer analysis in order to be displayed in a meaningful and intelligible manner. Although one motivation for building such an instrument is to explore new ultrasonic test procedures that are evolving from current laboratory research, this is neither the sole motivation nor the only use for this instrument. Such a mechanical and electronic device would permit conventional ultrasonic tests to be performed on parts of complex geometry without the expensive and time-consuming special fixturing that is currently required. May possible test geometries could be explored in practice prior to the construction of a specialized test apparatus. Hence, it would be necessary to design much, if any, flexibility into the special test apparatus

Ultrasonic attenuation as a function of heat treatment and grain size in 79Ni--6Mo--15Fe alloy

International Nuclear Information System (INIS)

Gieske, J.H.

1978-03-01

A pulse echo ultrasonic technique was used to measure the attenuation coefficient for 79Ni-6Mo-15Fe alloy specimens. The attenuation coefficient was determined using a 25 MHz ultrasonic transducer for specimens which had undergone different time-temperature heat treatments. The ultrasonic attenuation data versus heat treat time was used to assess grain size growth in the specimens

Ultrasonic dissection versus electrocautery in mastectomy for breast cancer - a meta-analysis.

Science.gov (United States)

Currie, A; Chong, K; Davies, G L; Cummins, R S

2012-10-01

Electrocautery has advanced the practice of mastectomy but significant morbidity, such as seroma and blood loss, remains a concern. This has led to newer forms of dissection being introduced including the ultrasonic dissection devices, which are thought to reduce tissue damage. The aim of this systematic review was to compare the outcomes after mastectomy using novel ultrasonic dissection or standard electrocautery in published trials. Medline, Embase, trial registries, conference proceedings and reference lists were searched for comparative trials of ultrasonic dissection versus electrocautery for mastectomy. The primary outcomes were total postoperative drainage, seroma development and intra-operative blood loss. Secondary outcomes were operative time and wound complications. Odds ratios were calculated for categorical outcomes and standardised mean differences for continuous outcomes. Six trials were included in the analysis of 287 mastectomies. There was no effect in total postoperative drainage (pooled analysis weight mean difference: -0.21 (95% CI: -0.70-0.29); p = 0.41) or seroma development (pooled analysis odds ratio: 0.77 (95% CIs 0.43-1.37); p = 0.37). Intra-operative blood was slightly less for ultrasonic dissection compared to standard electrocautery (pooled analysis weight mean difference: -1.04 (95% CI: -2.00 to -0.08); p = 0.03). Ultrasonic dissection and standard electrocautery had similar outcomes with regard to operative time and wound complications. Ultrasonic dissection and standard electrocautery appear to deliver similar results in the mastectomy setting. Further cost-effectiveness analysis may guide surgeon selection in the use of new technologies for mastectomy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Advanced ultrasonic inspections

International Nuclear Information System (INIS)

Ghia, S.

1990-08-01

Acoustic Emission (AE) continuous monitoring and periodical inspections by advanced ultrasonic have been applied to evaluate defect evolution within a PWR reduced scale (1:5) pressure vessel subjected to cyclic mechanical fatigue test. This experimental activity has been carried out in the frame of the Primary Circuit Component Life Prediction programme. In the time period covered by this report actions were performed as following: (1) Ultrasonic examination by multifrequency acoustic holography to evaluate defect evolution subsequently repair and heat treatment of the R2 vessel carried out in March 1988. For the purpose, measurements were performed both at 0 and 200 bar of internal pressure. As uniformity of the procedures adopted, for calibration and testing, made the results comparable with the previous ones no evidence for significant growing of the examined defects has been found. (2) Acoustic emission monitoring has then been carried out during fatigue test from 416000 to 565000 fatigue cycles. Analysis of a large amount of data has been performed paying particular attention to the distinction between friction phenomena and crack growth in order to obtain a correct diagnosis of flaw evolution. The signal duration distribution and the correlation of AE appearance time versus load cycle phase were considered to characterise stick-slip processes. A general intensification of AE activity has been recorded during this last period of monitoring and previous known AE sources were confirmed together with the appearance of new AE sources some of them correlable with real defects

Development of an intelligent system for ultrasonic flaw classification in weldments

International Nuclear Information System (INIS)

Song, Sung-Jin; Kim, Hak-Joon; Cho, Hyeon

2002-01-01

Even though ultrasonic pattern recognition is considered as the most effective and promising approach to flaw classification in weldments, its application to the realistic field inspection is still very limited due to the crucial barriers in cost, time and reliability. To reduce such barriers, previously we have proposed an intelligent system approach that consisted of the following four ingredients: (1) a PC-based ultrasonic testing (PC-UT) system; (2) an effective invariant ultrasonic flaw classification algorithm; (3) an intelligent flaw classification software; and (4) a database with abundant experimental flaw signals. In the present work, for performing the ultrasonic flaw classification in weldments in a real-time fashion in many real word situations, we develop an intelligent system, which is called the 'Intelligent Ultrasonic Evaluation System (IUES)' by the integration of the above four ingredients into a single, unified system. In addition, for the improvement of classification accuracy of flaws, especially slag inclusions, we expand the feature set by adding new informative features, and demonstrate the enhanced performance of the IUES with flaw signals in the database constructed previously. And then, to take care of the increased redundancy in the feature set due to the addition of features, we also propose two efficient schemes for feature selection: the forward selection with trial and error, and the forward selection with criteria of the error probability and the linear correlation coefficients of individual features

Design of signal reception and processing system of embedded ultrasonic endoscope

Science.gov (United States)

Li, Ming; Yu, Feng; Zhang, Ruiqiang; Li, Yan; Chen, Xiaodong; Yu, Daoyin

2009-11-01

Embedded Ultrasonic Endoscope, based on embedded microprocessor and embedded real-time operating system, sends a micro ultrasonic probe into coelom through the biopsy channel of the Electronic Endoscope to get the fault histology features of digestive organs by rotary scanning, and acquires the pictures of the alimentary canal mucosal surface. At the same time, ultrasonic signals are processed by signal reception and processing system, forming images of the full histology of the digestive organs. Signal Reception and Processing System is an important component of Embedded Ultrasonic Endoscope. However, the traditional design, using multi-level amplifiers and special digital processing circuits to implement signal reception and processing, is no longer satisfying the standards of high-performance, miniaturization and low power requirements that embedded system requires, and as a result of the high noise that multi-level amplifier brought, the extraction of small signal becomes hard. Therefore, this paper presents a method of signal reception and processing based on double variable gain amplifier and FPGA, increasing the flexibility and dynamic range of the Signal Reception and Processing System, improving system noise level, and reducing power consumption. Finally, we set up the embedded experiment system, using a transducer with the center frequency of 8MHz to scan membrane samples, and display the image of ultrasonic echo reflected by each layer of membrane, with a frame rate of 5Hz, verifying the correctness of the system.

Numeric ultrasonic image processing method: application to non-destructive testing of stainless austenitic steel welds

International Nuclear Information System (INIS)

Corneloup, G.

1988-09-01

A bibliographic research on the means used to improve the ultrasonic inspection of heterogeneous materials such as stainless austenitic steel welds has shown, taking into account the first analysis, a signal assembly in the form of an image (space, time) which carries an original solution to fault detection in highly noisy environments. A numeric grey-level ultrasonic image processing detection method is proposed based on the research of a certain determinism, in the way which the ultrasonic image evolves in space and time in the presence of a defect: the first criterion studies the horizontal stability of the gradients in the image and the second takes into account the time-transient nature of the defect echo. A very important rise in the signal-to-noise ratio obtained in welding inspections evidencing defects (real and artificial) is shown with the help of a computerized ultrasonic image processing/management system, developed for this application [fr

Wideband pulse amplifiers for the NECTAr chip

International Nuclear Information System (INIS)

Sanuy, A.; Delagnes, E.; Gascon, D.; Sieiro, X.; Bolmont, J.; Corona, P.; Feinstein, F.; Glicenstein, J-F.; Naumann, C.L.; Nayman, P.; Ribó, M.

2012-01-01

The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1–3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

Wideband pulse amplifiers for the NECTAr chip

Science.gov (United States)

Sanuy, A.; Delagnes, E.; Gascon, D.; Sieiro, X.; Bolmont, J.; Corona, P.; Feinstein, F.; Glicenstein, J.-F.; Naumann, C. L.; Nayman, P.; Ribó, M.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

2012-12-01

The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

Under sodium ultrasonic imaging system for PFBR

International Nuclear Information System (INIS)

Patankar, V.H.; Lalwani, S.K.; Agashe, A.A.

2014-01-01

Under Sodium UltraSonic Scanner (USUSS) has been developed to detect the growth and protrusion of fuel sub-assemblies of PFBR, submerged in liquid sodium by using the ultrasonic imaging technique during reactor shut-down when liquid sodium is at 180 ℃. The imaging is carried out prior to every Fuel handling operation. Electronics Division, BARC has designed and developed an 8-Channel Ultrasonic Imaging System (UIS) which consists of 4 downward viewing and 4 side viewing ultrasonic transducers alongwith pulser-receiver, signal processing electronics hardware and software. An automated mechanical scanner developed by IGCAR houses sodium immersible transducers to image the fuel sub assemblies. The system has been successfully tested with dummy protruding and grown FSAs, submerged under liquid sodium. Such ultrasonic imaging systems are not available to India from international market. The USUSS developed indigenously has all the features available in similar systems developed by other countries. After every imaging campaign, the mechanical scanner containing ultrasonic transducers is stored in the Argon filled storage-pit. Before every campaign of USUSS, it is necessary to check the healthiness of the sodium immersible and contaminated ultrasonic transducers, as the under-sodium scanner is decontaminated once in five years. For this purpose, a novel Non Contact Ultrasonic Inspection System (NCUIS) has been designed and developed by Electronics Division, BARC to check the functionality of the high-temperature and contaminated transducers of USUSS, using air-coupled ultrasonic technique. (author)

A study for soundness of turbine blade root using ultrasonic and phased array

International Nuclear Information System (INIS)

Gil, Doo Song; Park, Sang Ki; Cho, Yong Sang; Lee, Sang Gug; Huh, Kuang Bum

2003-01-01

Power plant is consisted of many component parts for the generation of the electricity, and occasionally, turbine equipment may be caused in break-down because of the damage of the blade root. Phased array ultrasonic testing system has become available for practical application in complicated geometry such as turbine blade root, tenon, disc in power industry. This research describes the characteristics of phased array ultrasonic testing signal for various type of blade roots in thermal Power Plant turbines. This application of Phased array ultrasonic testing system has been promoted mainly to save inspection time and labor cost of turbine inspection. The characteristic of phased array ultrasonic testing signal for power plant component in very simple to understand but to difficult for perform the inspection. This paper is focused on the safety of the turbine equipment by the ultrasonic measurement and phased array analysis. As a result of the test through ultrasonic and phased array method, we have concluded that the main damage in these turbine blade root parts could be generated by the concentrated stress and centrifugal force.

Ultrasonic Linear Motor with Two Independent Vibrations

Science.gov (United States)

Muneishi, Takeshi; Tomikawa, Yoshiro

2004-09-01

We propose a new structure of an ultrasonic linear motor in order to solve the problems of high-power ultrasonic linear motors that drive the XY-stage for electron beam equipment and to expand the application fields of the motor. We pay special attention to the following three points: (1) the vibration in two directions of the ultrasonic linear motor should not influence mutually each other, (2) the vibration in two directions should be divided into the stage traveling direction and the pressing direction of the ultrasonic linear motor, and (3) the rigidity of the stage traveling direction of the ultrasonic linear motor should be increased. As a result, the supporting method of ultrasonic linear motors is simplified. The efficiency of the motor is improved and temperature rise is reduced. The stage position drift is also improved.

Mechanisms of microstructure formation under the influence of ultrasonic vibrations

Science.gov (United States)

Rakita, Milan

Positive effects of ultrasound on crystallization have been known for almost 90 years. Application of ultrasound has been very successful in many industries, most notably in chemistry, creating a new branch of science - sonochemistry. However, ultrasonication has not found wide commercial application in the solidification processing. The reason for that is the complexity of underlying phenomena and the lack of predicting models which correlate processing parameters with the properties of a product. The purpose of this study is to give some contribution toward better understanding of mechanisms that lead to changes in the solidifying microstructure. It has been found that, under experimental conditions used in this work, cavitation-induced nucleation is the major contributor to the grain refinement. Ultrasonication at minimal supercoolings is expected to give maximal grain refinement. Dendrite fragmentation has not shown to be a significant contributor to the grain refinement. Dendrite fragmentation is maximal if done by bubbles that come in contact with the solidifying phase, or that are created there. Alloys/solutions with long solidification interval, or wide mushy zone, are expected to exhibit more dendrite fragmentation. Bubbles are recognized as a crucial feature in ultrasonication. Their size distribution in the liquid phase prior to ultrasonication dictates the cavitation threshold and intensity of cavitation. For the first time, radiation pressure has been recognized as potentially significant factor in grain refinement. In the experimental setup used in this study, acoustic pressure at the main (driving) frequency is not substantial to cause significant fragmentation, and only dendrites close to the sonotrode were fragmented. However, application of ultrasound with frequencies that are several times higher than the current industrial practice could substantially increase dendrite fragmentation. Appearance of fractional harmonics has also been recognized

The STADUS ultrasonic data acquisition and processing system

International Nuclear Information System (INIS)

Frappier, J.C.; Birac, A.M.; Saglio, R.

1983-01-01

The use of the PRODUS software for real-time system management results in definitely improved date acquisition, although signal arrival is, of course, a random process. As regards data processing and display; the STADUS-PRODUS combination provides the operator with a high degree of flexibility in changing the parameters from which the three standard A-SCAN, B-SCAN, and C-SCAN displays are generated. STADUS effectivity has been demonstrated in the field through the many reactor vessel inspections performed to date. The system has been a key element in the success of underclad cracking detection and evaluation methods. The STADUS equipment, designed and built by CEA, has the advantage of being capable of acquiring a large number of ultrasonic date simultaneously generated by several transducers (up to sixteen), and to immediately process the date for creating pictures of the zone under examination, as required by the operator. Through these improvements in ultrasonic data acquisition and interpretation, the STADUS system helps enhance the quality of automatic ultrasonic examinations

Pulsed ultrasonic stir welding method

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2013-01-01

A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

Ultrasonic tests. Pt. 2

International Nuclear Information System (INIS)

Goebbels, K.

1980-01-01

After a basic treatment of ultrasonic wave propagation, of the state-of-the-art methods and the technical background in the preceeding part, advanced ultrasonic NDT techniques are presented here. The discussion of new development includes - manipulation systems, - automation of ultrasonic testing methods, documentation and evaluation. In the middle of this part the main problem areas will be discussed: - detection of defects (e.g. in coarse grained structures and welds), - classification of defects (e.g. discrimination between crack-like and volumetric faults), - sizing of defects. Research in the field of acoustical holography, development of probes and phased arrays, electromagnetic acoustic transducers and signal enhancement are the main contributing parts to the report. (orig./RW)

WISM - A Wideband Instrument for Snow Measurement: Past Accomplishments, Current Status, and Path Forward

Science.gov (United States)

Bonds, Quenton; Racette, Paul; Durham, Tim (Principal Investigator)

2016-01-01

Presented are the prior accomplishments, current status and path forward for GSFC's Wideband Instrument for Snow Measurement (WISM). This work is a high level overview of the project, presented via Webinar to the IEEE young professionals.

Detailed simulation of ultrasonic inspections

International Nuclear Information System (INIS)

Chaplin, K.R.; Douglas, S.R.; Dunford, D.

1997-01-01

Simulation of ultrasonic inspection of engineering components have been performed at the Chalk River Laboratories of AECL for over 10 years. The computer model, called EWE for Elastic Wave Equations, solves the Elastic Wave Equations using a novel finite difference scheme. It simulates the propagation of an ultrasonic wave from the transducer to a flaw, the scatter of waves from the flaw, and measurement of signals at a receive transducer. Regions of different materials, water and steel for example, can be simulated. In addition, regions with slightly different material properties from the parent material can be investigated. The two major types of output are displays of the ultrasonic waves inside the component and the corresponding A-scans. EPRI and other organizations have used ultrasonic models for: defining acceptable ultrasonic inspection procedures, designing and evaluating inspection techniques, and for quantifying inspection reliability. The EWE model has been applied to the inspection of large pipes in a nuclear plant, gas pipeline welds and steam generator tubes. Most recent work has dealt with the ultrasonic inspection of pressure tubes in CANDU reactors. Pressure tube inspections can reliably detect and size defects; however, there are improvements that can be made. For example, knowing the sharpness of a flaw-tip is crucial for fitness for service assessments. Computer modelling of the ultrasonic inspection of flaws with different root radius has suggested inspection techniques that provide flaw tip radius information. A preliminary investigation of these methods has been made in the laboratory. The basis for the model will be reviewed at the presentation. Then the results of computer simulations will be displayed on a PC using an interactive program that analyzes simulated A-scans. This software tool gives inspection staff direct access to the results of computer simulations. (author)

Analysis of ultrasonic techniques for monitoring milk coagulation during cheesemaking

International Nuclear Information System (INIS)

Budelli, E; Lema, P; Pérez, N; Negreira, C

2012-01-01

Experimental determination of time of flight and attenuation has been proposed in the literature as alternatives to monitoring the evolution of milk coagulation during cheese manufacturing. However, only laboratory scale procedures have been described. In this work, the use of ultrasonic time of flight and attenuation to determine cutting time and its feasibility to be applied at industrial scale were analyzed. Limitations to implement these techniques at industrial scale are shown experimentally. The main limitation of the use of time of flight is its strong dependence with temperature. Attenuation monitoring is affected by a thin layer of milk skin covering the transducer, which modifies the signal in a non-repetitive way. The results of this work can be used to develop alternative ultrasonic systems suitable for application in the dairy industry.

A high-speed Schottky detector for ultra-wideband communications

DEFF Research Database (Denmark)

Valdecasa, Guillermo Silva; Cimoli, Bruno; Blanco Granja, Ángel

2017-01-01

This letter reviews the design procedure of a high‐speed Schottky video detector for high‐data‐rate communications within the ultra‐wideband (UWB) frequencies. The classic design approach for video detectors is extended with a mixer‐like analysis, which results in a more detailed assessment of th....... Using 0 dBm carrier power, the lowest measured conversion loss is 10 dB for a video frequency of 1.1 GHz and better than 13 dB up to 1.8 GHz....

Case studies in ultrasonic testing

International Nuclear Information System (INIS)

Prasad, V.; Satheesh, C.; Varde, P.V.

2015-01-01

Ultrasonic testing is widely used Non Destructive Testing (NDT) method and forms the essential part of In-service inspection programme of nuclear reactors. Main application of ultrasonic testing is for volumetric scanning of weld joints followed by thickness gauging of pipelines and pressure vessels. Research reactor Dhruva has completed the first In Service Inspection programme in which about 325 weld joints have been volumetrically scanned, in addition to thickness gauging of 300 meters of pipe lines of various sizes and about 24 nos of pressure vessels. Ultrasonic testing is also used for level measurements, distance measurements and cleaning and decontamination of tools. Two case studies are brought out in this paper in which ultrasonic testing is used successfully for identification of butterfly valve opening status and extent of choking in pipe lines in Dhruva reactor systems

Internal ultrasonic inspection of flexible pipe

Energy Technology Data Exchange (ETDEWEB)

Baltzersen, O. (IKU Petroleumsforskning A/S, Trondheim (Norway) Norwegian Inst. of Tech., Trondheim (Norway). Div. of Petroleum Engineering and Applied Geophysics); Waag, T.I. (IKU Petroleumsforskning A/S, Trondheim (Norway))

1993-10-01

Methods for internal ultrasonic inspection of flexible pipe have been investigated through experiments with a short sample of Coflexip pipe. Ultrasonic backscatter methods using normal and non-normal incidence have been used for qualitative high contrast ultrasonic imaging of the inner surface of the pipe. Analysis of the internal cross-section has been performed based on the use of a non-contact ultrasonic caliper, and processing procedures which enable calculation of, and compensation for, eccentricity of the tool in the pipe. The methods developed can be used to quantitatively estimate the thickness of the internal carcass, and perform high resolution topographic mapping of the inner surface. (Author)

Stresses in ultrasonically assisted bone cutting

International Nuclear Information System (INIS)

Alam, K; Mitrofanov, A V; Silberschmidt, V V; Baeker, M

2009-01-01

Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

Ultrasonic determination of thermodynamic threshold parameters for irreversible cutaneous burns

Science.gov (United States)

Cantrell, J. H., Jr.

1982-01-01

In vivo ultrasonic measurements of the depth of conductive cutaneous burns experimentally induced in anesthetized Yorkshire pigs are reported as a function of burn time for the case in which the skin surface temperature is maintained at 100 C. The data are used in the solution of the one-dimensional heat diffusion equation with time-dependent boundary conditions to obtain the threshold temperature and the energy of transformation per unit mass associated with the transition of the tissue from the state of viability to the state of necrosis. The simplicity of the mathematical model and the expediency of the ultrasonic measurements in studies of thermal injury are emphasized.

Simulation of ultrasonic and EMAT arrays using FEM and FDTD.

Science.gov (United States)

Xie, Yuedong; Yin, Wuliang; Liu, Zenghua; Peyton, Anthony

2016-03-01

This paper presents a method which combines electromagnetic simulation and ultrasonic simulation to build EMAT array models. For a specific sensor configuration, Lorentz forces are calculated using the finite element method (FEM), which then can feed through to ultrasonic simulations. The propagation of ultrasound waves is numerically simulated using finite-difference time-domain (FDTD) method to describe their propagation within homogenous medium and their scattering phenomenon by cracks. Radiation pattern obtained with Hilbert transform on time domain waveforms is proposed to characterise the sensor in terms of its beam directivity and field distribution along the steering angle. Copyright © 2015 Elsevier B.V. All rights reserved.

Ultrasonic imaging of projected components of PFBR

Energy Technology Data Exchange (ETDEWEB)

Sylvia, J.I., E-mail: sylvia@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Jeyan, M.R.; Anbucheliyan, M.; Asokane, C.; Babu, V. Rajan; Babu, B.; Rajan, K.K.; Velusamy, K.; Jayakumar, T. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

2013-05-15

Highlights: ► Under sodium ultrasonic scanner in PFBR is for detecting protruding objects. ► Feasibility study for detecting Absorber rods and its drive mechanisms. ► Developed in-house PC based ultrasonic imaging system. ► Different case studies were carried out on simulated ARDM's. ► Implemented the experimental results to PFBR application. -- Abstract: The 500 MWe, sodium cooled, Prototype Fast Breeder Reactor (PFBR) is under advanced stage of construction at Kalpakkam in India. Opacity of sodium restricts visual inspection of components immersed in sodium by optical means. Ultrasonic wave passes through sodium hence ultrasonic techniques using under sodium ultrasonic scanners are developed to obtain under sodium images. The main objective of such an Under Sodium Ultrasonic Scanner (USUSS) for Prototype Fast Breeder Reactor (PFBR) is to detect and ensure that no core Sub Assembly (SA) or Absorber Rod or its Drive Mechanism is protruded in the above core plenum before starting the fuel handling operation. Hence, it is necessary to detect and locate the object, if it is protruding the above core plenum. To study the feasibility of detecting the absorber rods and their drive mechanisms using direct ultrasonic imaging technique, experiments were carried out for different orientations and profiles of the projected components in a 5 m diameter water tank. The in-house developed PC based ultrasonic scanning system is used for acquisition and analysis of data. The pseudo three dimensional color images obtained are discussed and the results are applicable for PFBR. This paper gives the details of the features of the absorber rods and their drive mechanisms, their orientation in the reactor core, experimental setup, PC based ultrasonic scanning system, ultrasonic images and the discussion on the results.

Development of fuel number reader by ultrasonic imaging techniques

International Nuclear Information System (INIS)

Omote, T.; Yoshida, T.

1991-01-01

This paper reports on a spent fuel ID number reader using ultrasonic imaging techniques that has been developed to realize efficient and automatic verification of fuel numbers, thereby to reduce mental load and radiation exposure for operators engaged in the verification task. The ultrasonic imaging techniques for automatic fuel number recognition are described. High-speed and high reliability imaging of the spent fuel ID number are obtained by using linear array type ultrasonic probe. The ultrasonic wave is scanned by switching array probe in vertical direction, and scanned mechanically in horizontal direction. Time for imaging of spent fuel ID number on assembly was confirmed less than three seconds by these techniques. And it can recognize spent fuel ID number even if spent fuel ID number can not be visualized by an optical method because of depositing fuel number regions by soft card. In order to recognize spent fuel ID number more rapidly and more reliably, coded fuel number expressed by plural separate recesses form is developed. Every coded fuel number consists of six small holes (about 1 mm dia.) and can be marked adjacent to the existing fuel number expressed by letters and numbers

Analytical ultrasonics for characterization of metallurgical microstructures and transformations

Science.gov (United States)

Rosen, M.

1986-01-01

The application of contact (piezoelectric) and noncontact (laser generation and detection) ultrasonic techniques for dynamic investigation of precipitation hardening processes in aluminum alloys, as well as crystallization and phase transformation in rapidly solidified amorphous and microcrystalline alloys is discussed. From the variations of the sound velocity and attenuation the precipitation mechanism and kinetics were determined. In addition, a correlation was established between the observed changes in the velocity and attenuation and the mechanical properties of age-hardenable aluminum alloys. The behavior of the elastic moduli, determined ultrasonically, were found to be sensitive to relaxation, crystallization and phase decomposition phenomena in rapidly solidified metallic glasses. Analytical ultrasonics enables determination of the activation energies and growth parameters of the reactions. Therefrom theoretical models can be constructed to explain the changes in mechanical and physical properties upon heat treatment of glassy alloys. The composition dependence of the elastic moduli in amorphous Cu-Zr alloys was found to be related to the glass transition temperature, and consequently to the glass forming ability of these alloys. Dynamic ultrasonic analysis was found to be feasible for on-line, real-time, monitoring of metallurgical processes.

Fundamentals of ultrasonic phased arrays

CERN Document Server

Schmerr, Lester W

2014-01-01

This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

Ultrasonic pretreatment of woodchips for the conversion of cellulose to glucose for bioethanol production

International Nuclear Information System (INIS)

Tutun Nugraha; Rettyana Ayuputri; Mohammad Ihsan

2010-01-01

In this study, lignocellulosic biomass i.e. the woodchips of Albacia tree (Paraserianthes falcataria) were given different pretreatment methods, i.e. chemical (acid) and physical (ultrasonic). The pretreatment was given in order to convert the cellulose to glucose for the production of bioethanol. 1 % H_2SO_4 was applied for the acid pretreatment. Ultrasound pretreatment was carried out at varied time (10, 20 and 30 minutes) at 600 W, 20 khz before or after the acid pretreatment. Enzymatic attack of the pretreated sample was also applied to enhance the saccharification process of cellulose. The objective of the research was to determine the most effective ultrasonic duration and the best combination of method for enzymatic hydrolysis of the woodchips. The data showed that the highest yield of glucose was achieved at 20 minutes ultrasonic time. It was also found that substantial amount of hydrolysis of cellulose to glucose occur during the ultrasonic stage even without the presence of acid or cellulose enzyme. It is likely that the highly energetic ultrasonic process alone could assist in enhancing rate of hydrolysis of lignocellulosic cellulose into glucose. (author)

Statistical ultrasonics: the influence of Robert F. Wagner

Science.gov (United States)

Insana, Michael F.

2009-02-01

An important ongoing question for higher education is how to successfully mentor the next generation of scientists and engineers. It has been my privilege to have been mentored by one of the best, Dr Robert F. Wagner and his colleagues at the CDRH/FDA during the mid 1980s. Bob introduced many of us in medical ultrasonics to statistical imaging techniques. These ideas continue to broadly influence studies on adaptive aperture management (beamforming, speckle suppression, compounding), tissue characterization (texture features, Rayleigh/Rician statistics, scatterer size and number density estimators), and fundamental questions about how limitations of the human eye-brain system for extracting information from textured images can motivate image processing. He adapted the classical techniques of signal detection theory to coherent imaging systems that, for the first time in ultrasonics, related common engineering metrics for image quality to task-based clinical performance. This talk summarizes my wonderfully-exciting three years with Bob as I watched him explore topics in statistical image analysis that formed a rational basis for many of the signal processing techniques used in commercial systems today. It is a story of an exciting time in medical ultrasonics, and of how a sparkling personality guided and motivated the development of junior scientists who flocked around him in admiration and amazement.

Acoustic propagation in viscous fluid with uniform flow and a novel design methodology for ultrasonic flow meter.

Science.gov (United States)

Chen, Yong; Huang, Yiyong; Chen, Xiaoqian

2013-02-01

Ultrasonic flow meter with non-invasive no-moving-parts construction has good prospective application for space on-orbit fluid gauging. In traditional pulse transit time flow meter, inconsistency of ultrasonic transducers leads to measurement error and plane wave theory, bases of transit time flow meter, is valuable only for low-frequency wave propagation in inviscid fluid and will lose feasibility when fluid viscosity is considered. In this paper, based on the hydrodynamics of viscous fluid, wave propagation with uniform flow profile is mathematically formulated and a novel solution for viscous fluid using potential theory is firstly presented. Then a novel design methodology of continuous ultrasonic flow meter is proposed, where high measurement rangeability and accuracy are guaranteed individually by solving the integral ambiguity using multi-tone wide laning strategy and the fractional phase shift using phase lock loop tracking method. A comparison with transit time ultrasonic flow meter shows the advantage of proposed methodology. In the end, parametric analysis of viscosity on wave propagation and ultrasonic flow meter is compressively investigated. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Inkjet printing of novel wideband and high gain antennas on low-cost paper substrate

KAUST Repository

Cook, Benjamin Stassen

2012-09-01

A complete characterization of the inkjet printing process using metallic nanoparticle inks on a paper substrate for microwave frequencies up to 12.5 GHz as well as its application to low-cost, high gain and wideband antenna design are demonstrated in this work. Laser and heat sintering of metallic nanoparticles are compared on paper substrate for the first time which demonstrate immense cost and time benefits of laser sintering. The antennas fabricated using the characterized process include a Vivaldi for the UWB band which exhibits a significantly higher gain of up to 8 dBi as compared to the currently published inkjet printed antennas, and a novel slow-wave log periodic dipole array which employs a new miniaturization technique to show 20% width reduction. © 1963-2012 IEEE.

Dynamic Mode Tuning of Ultrasonic Guided Wave Using an Array Transducer

International Nuclear Information System (INIS)

Kim, Young H.; Song, Sung J.; Park, Joon S.; Kim, Jae H.; Eom, Heung S.

2005-01-01

Ultrasonic guided waves have been widely employed for long range inspection of structures such as plates, rods and pipes. There are numerous modes with different wave velocities, and the appropriate mode selection is one of key techniques in the application of guided waves. In the present work, phase tuning by an array transducer was applied to generate ultrasonic guided waves. For this purpose, 8-channel ultrasonic pulser/receiver and their controller which enables sequential activation of each channels with given time delay were developed. Eight transducers were fabricated in order to generate guided waves by using an array transducer. The selective tuning of wave mode can be achieved by changing the interval between elements of an array transducer

Reduction of aerosols produced by ultrasonic scalers.

Science.gov (United States)

Harrel, S K; Barnes, J B; Rivera-Hidalgo, F

1996-01-01

There is concern with decreased air quality and potential aerosol contamination in the dental operatory. This problem has been addressed by the Centers for Disease Control and Prevention, which recommends that all sources of blood-contaminated splatter and aerosols be minimized. One of the major sources of potential aerosol contamination in the dental setting is the ultrasonic scaler. This study looks at the use of a high volume evacuator attachment for the ultrasonic scaler handpiece. Artificial teeth were mock-scaled for 1 minute with and without the evacuator attachment. The mock scaling was performed within a plastic enclosure that had a 1 cm grid laid out on 4 sides. Scaling was performed 10 times each by 2 operators. An erythrosin solution was used for the ultrasonic scaler coolant with a coolant volume of 17.5 ml/min. The number of squares containing a red erythrosin spot were counted and considered to represent aerosol contamination. The high volume evacuator attachment produced a 93% reduction in the number of contaminated squares (chi squared significant at P < 0.05). There was no increase in heat transfer to a tooth analogue when the high volume evacuator attachment was used with the ultrasonic scaler as compared to the scaler without the evacuator attachment. It is felt that the high volume evacuator attachment is capable of significantly reducing the amount of aerosol contamination produced within the test system without increased heat transfer to the tooth.

An ultra-wideband pattern reconfigurable antenna based on graphene coating

Science.gov (United States)

Jiang, YanNan; Yuan, Rui; Gao, Xi; Wang, Jiao; Li, SiMin; Lin, Yi-Yu

2016-11-01

An ultra-wideband pattern reconfigurable antenna is proposed. The antenna is a dielectric coaxial hollow monopole with a cylindrical graphene-based impedance surface coating. It consists of a graphene sheet coated onto the inner surface of a cylindrical substrate and a set of independent polysilicon DC gating pads mounted on the outside of the cylindrical substrate. By changing the DC bias voltages to the different gating pads, the surface impedance of the graphene coating can be freely controlled. Due to the tunability of graphene's surface impedance, the radiation pattern of the proposed antenna can be reconfigured. A transmission line method is used to illustrate the physical mechanism of the proposed antenna. The results show that the proposed antenna can reconfigure its radiation pattern in the omnidirectional mode with the relative bandwidth of 58.5% and the directional mode over the entire azimuth plane with the relative bandwidth of 67%. Project supported by the National Natural Science Foundation of China (Grant Nos. 61661012, 61461016, and 61361005), the Natural Science Foundation of Guangxi, China (Grant Nos. 2015GXNSFBB139003 and 2014GXNSFAA118283), Program for Innovation Research Team of Guilin University of Electromagnetic Technology, China, and the Dean Project of Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing, China.

Novel Wideband MIMO Antennas That Can Cover the Whole LTE Spectrum in Handsets and Portable Computers

Directory of Open Access Journals (Sweden)

Mohamed Sanad

2014-01-01

Full Text Available A dual resonant antenna configuration is developed for multistandard multifunction mobile handsets and portable computers. Only two wideband resonant antennas can cover most of the LTE spectrums in portable communication equipment. The bandwidth that can be covered by each antenna exceeds 70% without using any matching or tuning circuits, with efficiencies that reach 80%. Thus, a dual configuration of them is capable of covering up to 39 LTE (4G bands besides the existing 2G and 3G bands. 2×2 MIMO configurations have been also developed for the two wideband antennas with a maximum isolation and a minimum correlation coefficient between the primary and the diversity antennas.

Effects of Compound K-Distributed Sea Clutter on Angle Measurement of Wideband Monopulse Radar

Directory of Open Access Journals (Sweden)

Hong Zhu

2017-01-01

Full Text Available The effects of compound K-distributed sea clutter on angle measurement of wideband monopulse radar are investigated in this paper. We apply the conditional probability density function (pdf of monopulse ratio (MR error to analyze these effects. Based on the angle measurement procedure of the wideband monopulse radar, this conditional pdf is first deduced in detail for the case of compound K-distributed sea clutter plus noise. Herein, the spatial correlation of the texture components for each channel clutter and the correlation of the texture components between the sum and difference channel clutters are considered, and two extreme situations for each of them are tackled. Referring to the measured sea clutter data, angle measurement performances in various K-distributed sea clutter plus noise circumstances are simulated, and the effects of compound K-distributed sea clutter on angle measurement are discussed.

Ultrasonic hydrometer. [Specific gravity of electrolyte

Science.gov (United States)

Swoboda, C.A.

1982-03-09

The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.

Custom ultrasonic instrumentation for flow measurement and real-time binary gas analysis in the CERN ATLAS experiment

Science.gov (United States)

Alhroob, M.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Boyd, G.; Crespo-Lopez, O.; Degeorge, C.; Deterre, C.; Di Girolamo, B.; Doubek, M.; Favre, G.; Hallewell, G.; Katunin, S.; Lombard, D.; Madsen, A.; McMahon, S.; Nagai, K.; O'Rourke, A.; Pearson, B.; Robinson, D.; Rossi, C.; Rozanov, A.; Stanecka, E.; Strauss, M.; Vacek, V.; Vaglio, R.; Young, J.; Zwalinski, L.

2017-01-01

The development of custom ultrasonic instrumentation was motivated by the need for continuous real-time monitoring of possible leaks and mass flow measurement in the evaporative cooling systems of the ATLAS silicon trackers. The instruments use pairs of ultrasonic transducers transmitting sound bursts and measuring transit times in opposite directions. The gas flow rate is calculated from the difference in transit times, while the sound velocity is deduced from their average. The gas composition is then evaluated by comparison with a molar composition vs. sound velocity database, based on the direct dependence between sound velocity and component molar concentration in a gas mixture at a known temperature and pressure. The instrumentation has been developed in several geometries, with five instruments now integrated and in continuous operation within the ATLAS Detector Control System (DCS) and its finite state machine. One instrument monitors C3F8 coolant leaks into the Pixel detector N2 envelope with a molar resolution better than 2ṡ 10-5, and has indicated a level of 0.14 % when all the cooling loops of the recently re-installed Pixel detector are operational. Another instrument monitors air ingress into the C3F8 condenser of the new C3F8 thermosiphon coolant recirculator, with sub-percent precision. The recent effect of the introduction of a small quantity of N2 volume into the 9.5 m3 total volume of the thermosiphon system was clearly seen with this instrument. Custom microcontroller-based readout has been developed for the instruments, allowing readout into the ATLAS DCS via Modbus TCP/IP on Ethernet. The instrumentation has many potential applications where continuous binary gas composition is required, including in hydrocarbon and anaesthetic gas mixtures.

Nuclear Radiation Tolerance of Single Crystal Aluminum Nitride Ultrasonic Transducer

Science.gov (United States)

Reinhard, Brian; Tittmann, Bernhard R.; Suprock, Andrew

Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models, (Rempe et al., 2011; Kazys et al., 2005). These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The irradiation is also supported by a multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET ASI) program. The results from this irradiation, which started in February 2014, offer the potential to enable the development of novel radiation tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. Hence, results from this irradiation offer the potential to bridge the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the

Ultrasonic characterization of pork meat salting

International Nuclear Information System (INIS)

García-Pérez, J V; De Prados, M; Pérez-Muelas, N; Cárcel, J A; Benedito, J

2012-01-01

Salting process plays a key role in the preservation and quality of dry-cured meat products. Therefore, an adequate monitoring of salt content during salting is necessary to reach high quality products. Thus, the main objective of this work was to test the ability of low intensity ultrasound to monitor the salting process of pork meat. Cylindrical samples (diameter 36 mm, height 60±10 mm) of Biceps femoris were salted (brine 20% NaCl, w/w) at 2 °C for 1, 2, 4 and 7 days. During salting and at each experimental time, three cylinders were taken in order to measure the ultrasonic velocity at 2 °C. Afterwards, the cylinders were split in three sections (height 20 mm), measuring again the ultrasonic velocity and determining the salt and the moisture content by AOAC standards. In the whole cylinders, moisture content was reduced from 763 (g/kg sample) in fresh samples to 723 (g/kg sample) in samples salted for 7 days, while the maximum salt gain was 37.3 (g/kg sample). Although, moisture and salt contents up to 673 and 118 (g/kg sample) were reached in the sections of meat cylinders, respectively. During salting, the ultrasonic velocity increased due to salt gain and water loss. Thus, significant (p 2 = 0.975) and moisture (R 2 = 0.863) contents. In addition, the change of the ultrasonic velocity with the increase of the salt content showed a good agreement with the Kinsler equation. Therefore, low intensity ultrasound emerges as a potential technique to monitor, in a non destructive way, the meat salting processes carried out in the food industry.

Finite element modeling of ultrasonic inspection of weldments

International Nuclear Information System (INIS)

Dewey, B.R.; Adler, L.; Oliver, B.F.; Pickard, C.A.

1983-01-01

High performance weldments for critical service applications require 100% inspection. Balanced against the adaptability of the ultrasonic method for automated inspection are the difficulties encountered with nonhomogeneous and anisotropic materials. This research utilizes crystals and bicrystals of nickel to model austenitic weld metal, where the anisotropy produces scattering and mode conversion, making detection and measurement of actual defects difficult. Well characterized samples of Ni are produced in a levitation zone melting facility. Crystals in excess of 25 mm diameter and length are large enough to permit ultrasonic measurements of attenuation, wave speed, and spectral content. At the same time, the experiments are duplicated as finite element models for comparison purposes

Interaction of Sound with Sound by Novel Mechanisms: Ultrasonic Four-Wave Mixing Mediated by a Suspension and Ultrasonic Three-Wave Mixing at a Free Surface

Science.gov (United States)

Simpson, Harry Jay

Two mechanisms of sound interacting with sound are experimentally and theoretically investigated. Ultrasonic four-wave mixing in a dilute particle suspension, analogous to optical four-wave mixing in photorefractive materials, involves the interaction of three ultrasonic wavefields that produces a fourth scattered wavefield. The experimental configuration consists of two ultrasonic (800 kHz) pump waves that are used to produce a grating in a suspension of 25 μm diameter polymer particles in salt water. The pump waves are counter-propagating, which form a standing wavefield in the suspension and the less compressible particles are attracted to the pressure nodes in response to the time averaged radiation pressure. A higher frequency (2-10 MHz) ultrasonic wavefield is used to probe the resulting grating. The ultrasonic Bragg scattering is then measured. The scattering depends strongly on the response to the pump wave and is an unusual class of acoustical nonlinearity. Investigation of very small amplitude gratings are done by studying the temporal response of the Bragg scattering to a sudden turn on of a moderate amplitude pump wavefield in a previously homogeneous particle suspension. The Bragg scattering has been verified experimentally and is modeled for early-time grating formations using a sinusoidal grating. The larger amplitude gratings are studied in equilibrium and are modeled using an Epstein layer approximation. Ultrasonic three-wave mixing at a free surface involves the interaction of a high amplitude 400 kHz plane wavefield incident at 33^circ on a water-air interface with a normally incident high frequency (4.6 MHz) focused wavefield. The 400 kHz "pump" wavefield reflects from the surface and produces an oscillating surface displacement that forms a local traveling phase grating. Simultaneously the 4.6 MHz "probe" wavefield is reflected from the free surface. The grating scatters the focused probe wavefield and produces (or contributes to) spatially

OPTIMATION OF 48 KHZ ULTRASONIC WAVE DOSE FOR THE INACTIVATION OF SALMONELLA TYPHI

Directory of Open Access Journals (Sweden)

Dwi May Lestari

2015-01-01

Full Text Available This study was aimed to determine the effect of ultrasonic dose exposure which could decrease the viability of Salmonella typhi by using the variation of exposure time (15, 20, 25, and 30 minutes and volume of bacterial suspension (2, 4, 6, and 8 ml at constant power. The sample used was Salmonella typhi. Ultrasonic wave transmitter was a piezoelectric tweeter with 0,191 watts of power and 48 kHz frequency generated by the signal generator. Piezoelectric tweeter was a kind of transducer which converted electrical energy into ultrasonic energy. This research was an experimental laboratory with a completely randomized design. The decrease of bacterial percentage was calculated by using TPC (Total Plate Count. Data were analyzed by using One Way Anova. The results showed that the variation of exposure time and volume of bacterial suspension gave significant effect on the percentage of Salmonella typhi kill. The most optimal of ultrasonic dose exposure to kill Salmonella typhi was 281.87 J/ml with 100% bacterial kill.

An inductorless wideband LNA with a new noise canceling technique

OpenAIRE

MOGHADAM, POURIA PAZHOUHESH; ABRISHAMIFAR, ADIB

2017-01-01

An inductorless wideband low-noise amplifier (LNA) employing a new noise canceling technique for multistandard applications is presented. The main amplifier has a cascode common gate structure, which provides good input impedance matching and isolation. The proposed noise canceling technique not only improves the noise figure and power gain but also embeds a g$_{m}$-boosting technique in itself, which reduces the power consumption of the main amplifier. Using current-steering and ...

Wide-band CMOS low-noise amplifier exploiting thermal noise canceling

OpenAIRE

Bruccoleri, F.; Klumperink, Eric A.M.; Nauta, Bram

2004-01-01

Known elementary wide-band amplifiers suffer from a fundamental tradeoff between noise figure (NF) and source impedance matching, which limits the NF to values typically above 3 dB. Global negative feedback can be used to break this tradeoff, however, at the price of potential instability. In contrast, this paper presents a feedforward noise-canceling technique, which allows for simultaneous noise and impedance matching, while canceling the noise and distortion contributions of the matching d...

Bullet Ultrasonic Obstruction Detection & Distance Measurement Using AVR Microcontroller

Directory of Open Access Journals (Sweden)

Satish Pandey

2008-08-01

Full Text Available This paper describes the practical implementation of a short range ultrasonic obstruction detection and distance measurement device. By employing an ultrasonic transducer pair for producing ultrasonic sounds and sensing the reflected sound waves, the obstructions are detected. The hardware interface uses an Atmel ATmega8 AVR microcontroller to facilitate the generation of 40 kHz signal burst which is used in the transmitter circuit, and also to process the received signal for measuring the time of flight of reflected waves and exact distance of the obstruction. The program for this device is developed in WinAVR, and the code generated is dumped into microcontroller using AVR Studio. Educational aspects of this project include the mastery of a programming language and corresponding tools, the design of a functional and intuitive embedded application, and the development of appropriate hardware to build the device.

Enhanced bit rate-distance product impulse radio ultra-wideband over fiber link

DEFF Research Database (Denmark)

Rodes Lopez, Roberto; Jensen, Jesper Bevensee; Caballero Jambrina, Antonio

2010-01-01

We report on a record distance and bit rate-wireless impulse radio (IR) ultra-wideband (UWB) link with combined transmission over a 20 km long fiber link. We are able to improve the compliance with the regulated frequency emission mask and achieve bit rate-distance products as high as 16 Gbit/s·m....

Ultrasonic tests on materials with protective coatings

International Nuclear Information System (INIS)

Whaley, H.L.

1977-01-01

Protective coatings are applied to some nuclear components such as reactor vessels to inhibit surface corrosion. Since in-service ultrasonic inspection is required for such components, a study was performed to determine whether the use of protective coatings can affect ultrasonic tests. Two 2 in. thick steel plates were uniformly machined, sandblasted, and used as bases for two types of protective coatings. The type and thickness of the coating and the presence of contamination, such as fingerprints or mild oxidation under the paint, were the independent variables associated with the coating. Tests were run to determine the effects of the protective coatings on ultrasonic tests conducted on the steel plates. Significant variations in ultrasonic test sensitivity occurred as a function of the type and thickness of protective coating, couplant (material that conducts the ultrasound from the transducer into the test part, normally water or some type of oil), transducer wear plate, and ultrasonic test frequency. Ultrasonic tests can be strongly affected by a protective coating on the component to be inspected. As compared to the test sensitivity for an uncoated reference sample, the sensitivity may be dramatically shifted up or down on the coated surface. In certain coating thickness ranges, the sensitivity can fluctuate widely with small changes in coating thickness. If a coating is chosen properly, however, components with protective coatings can be tested ultrasonically with valid results. These results are for the case of ultrasonic input on the coated surface. It is not expected that an ultrasonic test conducted from the front surface would be appreciably affected by a coating on the rear surface

Real-time ultrasonic imaging of the ovary and uterus of the dog.

Science.gov (United States)

England, G C; Allen, W E

1989-01-01

The reproductive tracts of 50 bitches were ultrasonically imaged to evaluate the appearance of the uterus and ovaries at different stages of the oestrous cycle. Ovarian follicular growth was observed throughout the oestrous period. Follicles increased in size slowly until 7 days after the onset of pro-oestrus. Thereafter there was a rapid increase in diameter, indicating impending ovulation. The maximum recorded follicular diameter was 13 mm. It was not possible to observe ovulation since in the bitch follicles do not collapse as rapidly as in other species. During the post-ovulatory period there was a gradual loss of follicle shape and an increase in wall thickness. It was not possible to image the uterus of prepubertal bitches or young nulliparous bitches in anoestrus. During pro-oestrus and oestrus the uterus became increasingly hypoechoic with central regions of hyperechogenicity, which may represent uterine oedema. Uterine involution was observed in 5 bitches, and a rapid change in uterine diameter occurred over the first 3 days post partum. The ultrasonographic appearance was characteristic at this time.

Statistical Modeling, Simulation, and Experimental Verification of Wideband Indoor Mobile Radio Channels

Directory of Open Access Journals (Sweden)

Yuanyuan Ma

2018-01-01

Full Text Available This paper focuses on the modeling, simulation, and experimental verification of wideband single-input single-output (SISO mobile fading channels for indoor propagation environments. The indoor reference channel model is derived from a geometrical rectangle scattering model, which consists of an infinite number of scatterers. It is assumed that the scatterers are exponentially distributed over the two-dimensional (2D horizontal plane of a rectangular room. Analytical expressions are derived for the probability density function (PDF of the angle of arrival (AOA, the PDF of the propagation path length, the power delay profile (PDP, and the frequency correlation function (FCF. An efficient sum-of-cisoids (SOC channel simulator is derived from the nonrealizable reference model by employing the SOC principle. It is shown that the SOC channel simulator approximates closely the reference model with respect to the FCF. The SOC channel simulator enables the performance evaluation of wideband indoor wireless communication systems with reduced realization expenditure. Moreover, the rationality and usefulness of the derived indoor channel model is confirmed by various measurements at 2.4, 5, and 60 GHz.

The Analysis of a Wideband Strip-Helical Antenna with 1.1 Turns

Directory of Open Access Journals (Sweden)

Xihui Tang

2016-01-01

Full Text Available A wideband strip-helical antenna with 1.1 turns is analyzed numerically and experimentally. By replacing the traditional wire helix with wide metallic strip, the forward traveling current on the strip helix with about one turn smoothly decays to the minimum value at the open end of the helix. Therefore, the strip helix can excite a wideband circular polarization (CP wave with 50-ohm impedance matching. The proposed antenna is printed on a hollow-cylinder with a substrate relative permittivity of εr=2.2 and a thickness of h=0.5 mm. A 50 Ω coaxial cable is directly connected to excite the strip-helical antenna without any additional impedance matching section. The ground plane is placed below the antenna in order to provide a directional radiation pattern. To demonstrate this method, a prototype of 1.1-turn strip-helical antenna is tested. The test shows that the proposed antenna can reach an overlapped bandwidth of 46% with height of 0.52λ0, where λ0 is the wavelength in free space at the center operation frequency.

Ultra-wideband and 60 GHz communications for biomedical applications

CERN Document Server

Yuce, Mehmet R

2013-01-01

This book investigates the design of devices, systems, and circuits for medical applications using the two recently established frequency bands: ultra-wideband (3.1-10.6 GHz) and 60 GHz ISM band. These two bands provide the largest bandwidths available for communication technologies and present many attractive opportunities for medical applications. The applications of these bands in healthcare are wireless body area network (WBAN), medical imaging, biomedical sensing, wearable and implantable devices, fast medical device connectivity, video data transmission, and vital signs monitoring. The r

Coded ultrasonic remote control without batteries

International Nuclear Information System (INIS)

Gerhardy, C; Burlage, K; Schomburg, W K

2009-01-01

A concept for battery-less remote controls has been developed based on mechanically actuated beams and micro whistles generating ultrasound signals. These signals need to be frequency or time coded to increase the number of signals which can be distinguished from each other and environmental ultrasound. Several designs for generating coded ultrasonic signals have been investigated

An online real time ultrasonic NDT system for the quality control of spot welding in the automotive industry

International Nuclear Information System (INIS)

Athi, N; Wylie, S R; Cullen, J D; Al-Jader, M; Al-Shamma'a, A I; Shaw, A

2009-01-01

Resistance spot welding is the main joining technique used for the fabrication of body-in-white structures in the automotive industry. The quality of the welds depends on the profile of the spot welding electrode cap. The increased use of zinc coated steel in the industry increases wear rate of the caps, making quality control more difficult. This paper presents a novel online real time ultrasonic NDE system for resistance spot welding which evaluates every weld as it is formed. SEM results are presented to show the alloying of the electrode caps.

An online real time ultrasonic NDT system for the quality control of spot welding in the automotive industry

Science.gov (United States)

Athi, N.; Wylie, S. R.; Cullen, J. D.; Al-Jader, M.; Al-Shamma'a, A. I.; Shaw, A.

2009-07-01

Resistance spot welding is the main joining technique used for the fabrication of body-in-white structures in the automotive industry. The quality of the welds depends on the profile of the spot welding electrode cap. The increased use of zinc coated steel in the industry increases wear rate of the caps, making quality control more difficult. This paper presents a novel online real time ultrasonic NDE system for resistance spot welding which evaluates every weld as it is formed. SEM results are presented to show the alloying of the electrode caps.

Wideband pulse amplifiers for the NECTAr chip

Energy Technology Data Exchange (ETDEWEB)

Sanuy, A., E-mail: asanuy@ecm.ub.es [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Delagnes, E. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Gascon, D. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Sieiro, X. [Departament d' Electronica, Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, CC072, bat. 13, place Eugene Bataillon, 34095 Montpellier (France); Glicenstein, J-F. [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Barre 12-22, 1er etage, 4 place Jussieu, 75252 Paris (France); Ribo, M. [Dept. AM i Dept. ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona. Marti i Franques 1, E08028, Barcelona (Spain); and others

2012-12-11

The NECTAr collaboration's FE option for the camera of the CTA is a 16 bits and 1-3 GS/s sampling chip based on analog memories including most of the readout functions. This works describes the input amplifiers of the NECTAr ASIC. A fully differential wideband amplifier, with voltage gain up to 20 V/V and a BW of 400 MHz. As it is impossible to design a fully differential OpAmp with an 8 GHz GBW product in a 0.35 CMOS technology, an alternative implementation based on HF linearized transconductors is explored. The output buffer is a class AB miller operational amplifier, with special non-linear current boost.

A GPU-Based Wide-Band Radio Spectrometer

Science.gov (United States)

Chennamangalam, Jayanth; Scott, Simon; Jones, Glenn; Chen, Hong; Ford, John; Kepley, Amanda; Lorimer, D. R.; Nie, Jun; Prestage, Richard; Roshi, D. Anish; Wagner, Mark; Werthimer, Dan

2014-12-01

The graphics processing unit has become an integral part of astronomical instrumentation, enabling high-performance online data reduction and accelerated online signal processing. In this paper, we describe a wide-band reconfigurable spectrometer built using an off-the-shelf graphics processing unit card. This spectrometer, when configured as a polyphase filter bank, supports a dual-polarisation bandwidth of up to 1.1 GHz (or a single-polarisation bandwidth of up to 2.2 GHz) on the latest generation of graphics processing units. On the other hand, when configured as a direct fast Fourier transform, the spectrometer supports a dual-polarisation bandwidth of up to 1.4 GHz (or a single-polarisation bandwidth of up to 2.8 GHz).

Process monitoring using optical ultrasonic wave detection

International Nuclear Information System (INIS)

Telschow, K.L.; Walter, J.B.; Garcia, G.V.; Kunerth, D.C.

1989-01-01

Optical ultrasonic wave detection techniques are being developed for process monitoring. An important limitation on optical techniques is that the material surface, in materials processing applications, is usually not a specular reflector and in many cases is totally diffusely reflecting. This severely degrades the light collected by the detection optics, greatly reducing the intensity and randomly scattering the phase of the reflected light. A confocal Fabry-Perot interferometer, which is sensitive to the Doppler frequency shift resulting from the surface motion and not to the phase of the collected light, is well suited to detecting ultrasonic waves in diffusely reflecting materials. This paper describes the application of this detector to the real-time monitoring of the sintering of ceramic materials. 8 refs., 5 figs

Ultrasonic propulsion of kidney stones.

Science.gov (United States)

May, Philip C; Bailey, Michael R; Harper, Jonathan D

2016-05-01

Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the ureteropelvic junction with relief of pain, and differentiating large stones from a collection of small fragments. Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing ureteropelvic junction stones into the kidney to alleviate acute renal colic.

Ultrasonic density detector for vessel and reactor core two-phase flow measurements

International Nuclear Information System (INIS)

Arave, A.E.

1979-01-01

A local ultrasonic density (LUD) detector has been developed by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory for the Loss-of-Fluid Test (LOFT) reactor vessel and core two-phase flow density measurements. The principle of operating the sensor is the change in propagation time of a torsional ultrasonic wave in a metal transmission line as a function of the density of the surrounding media. A theoretical physics model is presented which represents the total propagation time as a function of the sensor modulus of elasticity and polar moment of inertia

Application of laser ultrasonic method for on-line monitoring of friction stir spot welding process.

Science.gov (United States)

Zhang, Kuanshuang; Zhou, Zhenggan; Zhou, Jianghua

2015-09-01

Application of a laser ultrasonic method is developed for on-line monitoring of the friction stir spot welding (FSSW) process. Based on the technology of FSSW, laser-generated ultrasonic waves in a good weld and nonweld area are simulated by a finite element method. The reflected and transmitted waves are analyzed to disclose the properties of the welded interface. The noncontact-laser ultrasonic-inspection system was established to verify the numerical results. The reflected waves in the good-weld and nonweld area can be distinguished by time-of-flight. The transmitted waves evidently attenuate in the nonweld area in contrast to signal amplitude in the good weld area because of interfacial impedance difference. Laser ultrasonic C-scan images can sufficiently evaluate the intrinsic character of the weld area in comparison with traditional water-immersion ultrasonic testing results. The research results confirm that laser ultrasonics would be an effective method to realize the characterization of FSSW defects.

Dispersion curve estimation via a spatial covariance method with ultrasonic wavefield imaging.

Science.gov (United States)

Chong, See Yenn; Todd, Michael D

2018-05-01

Numerous Lamb wave dispersion curve estimation methods have been developed to support damage detection and localization strategies in non-destructive evaluation/structural health monitoring (NDE/SHM) applications. In this paper, the covariance matrix is used to extract features from an ultrasonic wavefield imaging (UWI) scan in order to estimate the phase and group velocities of S0 and A0 modes. A laser ultrasonic interrogation method based on a Q-switched laser scanning system was used to interrogate full-field ultrasonic signals in a 2-mm aluminum plate at five different frequencies. These full-field ultrasonic signals were processed in three-dimensional space-time domain. Then, the time-dependent covariance matrices of the UWI were obtained based on the vector variables in Cartesian and polar coordinate spaces for all time samples. A spatial covariance map was constructed to show spatial correlations within the full wavefield. It was observed that the variances may be used as a feature for S0 and A0 mode properties. The phase velocity and the group velocity were found using a variance map and an enveloped variance map, respectively, at five different frequencies. This facilitated the estimation of Lamb wave dispersion curves. The estimated dispersion curves of the S0 and A0 modes showed good agreement with the theoretical dispersion curves. Copyright © 2018 Elsevier B.V. All rights reserved.

Networks systems and operations. [wideband communication techniques for data links with satellites

Science.gov (United States)

1975-01-01

The application of wideband communication techniques for data links with satellites is discussed. A diagram of the demand assigned voice communications system is provided. The development of prototype integrated spacecraft paramps at S- and C-bands is described and the performance of space-qualified paramps is tabulated. The characteristics of a dual parabolic cylinder monopulse zoom antenna for use with the tracking and data relay satellite system (TDRSS) are analyzed. The development of a universally applicable transponder at S-band is reported. A block diagram of the major subassemblies of the S-band transponder is included. The technology aspects of network timing and synchronization of communication systems are to show the use of the Omega navigation system. The telemetry data compression system used during the Skylab program is evaluated.

Comparison of three flaw-location methods for automated ultrasonic testing

International Nuclear Information System (INIS)

Seiger, H.

1982-01-01

Two well-known methods for locating flaws by measurement of the transit time of ultrasonic pulses are examined theoretically. It is shown that neither is sufficiently reliable for use in automated ultrasonic testing. A third method, which takes into account the shape of the sound field from the probe and the uncertainty in measurement of probe-flaw distance and probe position, is introduced. An experimental comparison of the three methods indicates that use of the advanced method results in more accurate location of flaws. (author)

Study on electrical impedance matching for broadband ultrasonic transducer

Energy Technology Data Exchange (ETDEWEB)

Kim, Geon Woo [University of Science and Technology, Daejeon (Korea, Republic of); Kim, Ki Bok [Korea Research Institute of Standards and Science, Center for Safety Measurement, Daejeon (Korea, Republic of); Baek, Kwang Sae [Elache Co., Busan (Korea, Republic of)

2017-02-15

Ultrasonic transducers with high resolution and resonant frequency are required to detect small defects (less than hundreds of μm) by ultrasonic testing. The resonance frequency and resolution of an ultrasonic transducer are closely related to the thickness of piezo-electric materials, backing materials, and the electric impedance matching technique. Among these factors, electrical impedance matching plays an important role because it can reduce the loss and reflection of ultrasonic energy differences in electrical impedance between an ultrasonic transducer and an ultrasonic defects detecting system. An LC matching circuit is the most frequently used electric matching method. It is necessary for the electrical impedance of an ultrasonic transducer to correspond to approximately 50 Ω to compensate the difference in electrical impedance between both connections. In this study, a 15 MHz immersion ultrasonic transducer was fabricated and an LC electrical impedance circuit was applied to that for having broad-band frequency characteristic.

Ultrasonic inspection of austenitic welds

International Nuclear Information System (INIS)

Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

1976-01-01

Optical and X-ray metallography combined with ultrasonic testing by compression waves was used for inspection of stainless steel weld metal produced by three different welding techniques. X-ray diffraction showed that each weld possessed a characteristic fibre textured structure which was shown by optical microscopy to be parallel to columnar grain boundaries. Metallographic evidence suggested that the development of fibre texture is due to the mechanism of competitive growth. From observations made as a result of optical metallographic examination the orientation of the fibre axis could be predicted if the weld geometry and welding procedure were known. Ultrasonic velocity and attenuation measurements as a continuous function of grain orientation, made on cylinders machined from weld samples, showed that attenuation was strongly orientation dependent. It was concluded that the sensitivity of ultrasonic inspection to small defects is unlikely to be as high for austenitic welds as for ferritic even when transmission is improved by modifying the welding procedure to improve the ultrasonic transmission. (U.K.)

A Comprehensive Evaluation of Indoor Ranging Using Ultra-Wideband Technology

Directory of Open Access Journals (Sweden)

Camillo Gentile

2007-04-01

Full Text Available Ultra-wideband technology shows promise for precision ranging due to its fine time resolution to resolve multipath fading and the presence of lower frequencies in the baseband to penetrate walls. While a concerted effort has been conducted in the extensive modeling of the indoor UWB channel in recent years, to our knowledge only two papers have reported ranging performance, but for limited range and fixed bandwidth and center frequency. In principle, boosting power can guarantee connectivity between transmitter and receiver, but not precision due to the distorting effects of walls and other objects in the direct path. In order to gauge the limits of UWB ranging, we carry out 5000 measurements up to an unprecedented 45 m in non-line-of-sight conditions in four separate buildings with dominant wall material varying from sheet rock to steel. In addition, we report performance for varying bandwidth and center frequency of the system.

A Comprehensive Evaluation of Indoor Ranging Using Ultra-Wideband Technology

Directory of Open Access Journals (Sweden)

Gentile Camillo

2007-01-01

Full Text Available Ultra-wideband technology shows promise for precision ranging due to its fine time resolution to resolve multipath fading and the presence of lower frequencies in the baseband to penetrate walls. While a concerted effort has been conducted in the extensive modeling of the indoor UWB channel in recent years, to our knowledge only two papers have reported ranging performance, but for limited range and fixed bandwidth and center frequency. In principle, boosting power can guarantee connectivity between transmitter and receiver, but not precision due to the distorting effects of walls and other objects in the direct path. In order to gauge the limits of UWB ranging, we carry out 5000 measurements up to an unprecedented 45 m in non-line-of-sight conditions in four separate buildings with dominant wall material varying from sheet rock to steel. In addition, we report performance for varying bandwidth and center frequency of the system.

Multiple temperature sensors embedded in an ultrasonic “spiral-like” waveguide

Directory of Open Access Journals (Sweden)

Suresh Periyannan

2017-03-01

Full Text Available This paper studies the propagation of ultrasound in spiral waveguides, towards distributed temperature measurements on a plane. Finite Element (FE approach was used for understanding the velocity behaviour and consequently designing the spiral waveguide. Temperature measurements were experimentally carried out on planar surface inside a hot chamber. Transduction was performed using a piezo-electric crystal that is attached to one end of the waveguide. Lower order axisymmetric guided ultrasonic modes L(0,1 and T(0,1 were employed. Notches were introduced along the waveguide to obtain ultrasonic wave reflections. Time of fight (TOF differences between the pre-defined reflectors (notches located on the waveguides were used to infer local temperatures. The ultrasonic temperature measurements were compared with commercially available thermocouples.

P-scan, a new system for ultrasonic weld inspection

International Nuclear Information System (INIS)

Lund, S.A.; Iversen, S.E.; Holst, H.

1978-01-01

The P-scan method is explained. It is described how the new P-scan system improves the ultrasonic method by adding means for visualization, data storage and documentation. Three different scanners are described: One designed for manual operation, another for automatic operation and a third for semiautomatic operation. The p'scan image of an ultrasonically examined test plate is presented and discussed. The variable Display Level (i.e. the inspection sensitivity) facility is described. The main advantage of this facility is the fact that the level can be varied at any time after the inspection. (orig.) [de

Wideband Channel Modeling for mm-Wave inside Trains for 5G-Related Applications

Directory of Open Access Journals (Sweden)

Juan Moreno García-Loygorri

2018-01-01

Full Text Available Passenger trains and especially metro trains have been identified as one of the key scenarios for 5G deployments. The wireless channel inside a train car is reported in the frequency range between 26.5 GHz and 40 GHz. These bands have received a lot of interest for high-density scenarios with a high-traffic demand, two of the most relevant aspects of a 5G network. In this paper we provide a full description of the wideband channel estimating Power-Delay Profiles (PDP, Saleh-Valenzuela model parameters, time-of-arrival (TOA ranging, and path-loss results. Moreover, the performance of an automatic clustering algorithm is evaluated. The results show a remarkable degree of coherence and general conclusions are obtained.

Low-complexity Wireless Monitoring of Respiratory Movements Using Ultra-wideband Impulse Response Estimation

KAUST Repository

Sana, Furrukh

2014-03-01

In this paper; we present a comprehensive scheme for wireless monitoring of the respiratory movements in humans. Our scheme overcomes the challenges low signal-to-noise ratio, background clutter and high sampling rates. It is based on the estimation of the ultra-wideband channel impulse response. We suggest techniques for dealing with background clutter in situations when it might be time variant. We also present a novel methodology for reducing the required sampling rate of the system significantly while achieving the accuracy offered by the Nyquist rate. Performance results from simulations conducted with pre-recorded respiratory signals demonstrate the robustness of our scheme for tackling the above challenges and providing a low-complexity solution for the monitoring of respiratory movements.

Ultrasonic-assisted extraction and in vitro antioxidant activity of polysaccharides from Agaricus bisporus.

Science.gov (United States)

Qiao, De-Liang; Zhao, Feng; Huang, Hai-Zhong; Fan, Chun-Chun; Han, Lei

2012-08-01

To optimize ultrasonic-assisted extraction parameters of polysaccharides from Agaricus bisporus and evaluate antioxidant activities of A. bisporus polysaccharides. Polysaccharides from A. bisporus was extracted by using methods of ultrasonic-assisted hot water lixiviation, ethanol precipitation, Sevag's deproteination and ethanol precipitation again. Extraction temperature, extraction time, ratio of water to raw material and ultrasonic power were selected in single-factor tests. Based on the single-factor tests, parameters combination for the ultrasonic-assisted extraction of A. bisporus polysaccharides was optimized by using four-factor-three-level orthogonal test. Antioxidant activities (reductive potential, superoxide anion scavenging activity and H2O2 scavenging activity) of A. bisporus polysaccharides were evaluated in vitro. Optimum conditions for the extracting of A. bisporus polysaccharides were extracting temperature 65 degrees C, extracting time 40 min, ratio of water to raw material 30 mL/g and ultrasonic power 170 w. Practicing this optimal condition, extraction yield of polysaccharides from A. bisporus was 5.6 014%. In crude polysaccharides of A. bisporus, carbohydrates content, determined by applying the phenol-sulfuric acid method, was 75.48%. Polysaccharides of A. bisporus could reduce ferric ion, scavenge superoxide anion and hydrogen peroxide in a dose-dependent manner. Utrasonic-assisted extraction could be used in the extracting of A. bisporus polysaccharides. Polysaccharides of A. bisporus, had direct and potent antioxidant activities, might be developed and utilized as natural antioxidant.

Ultrasonic characterization of yogurt fermentation process

OpenAIRE

IZBAIM , DRIS; FAIZ , BOUAZZA; MOUDDEN , ALI; MALAININE , MOHAMED; ABOUDAOUD , Idriss

2012-01-01

International audience; The objective of this work is to characterize the fermentation of yogurt based on an ultrasonic technique. Conventionally, the acidity of the yogurt is measured by a pH meter to determine the progress of fermentation. However, the pH meter should be cleaned and calibrated for each measurement and, therefore, this method is not practical. In this regard, ultrasonic techniques are fast, non-invasive and inexpensive. The measurement of ultrasonic parameters such as amplit...

Numerical Analysis of Ultrasonic Beam Profile Due to the Change of the Number of Piezoelectric Elements for Phased Array Transducer

International Nuclear Information System (INIS)

Choi, Sang Woo; Lee, Joon Hyun

1999-01-01

A phased array is a multi-element piezoelectric device whose elements are individually excited by electric pulses at programmed delay time. One of the advantages of using phased array in nondestructive evaluation (NDE) application over conventional ultrasonic transducers is their great maneuverability of ultrasonic beam. There are some parameters such as the number and the size of the piezoelectric elements and the inter-element spacing of the elements to design phased array transducer. In this study, the characteristic of ultrasonic beam for phased array transducer due to the variation of the number of elements has been simulated for ultrasonic SH-wave on the basis of Huygen's principle. Ultrasonic beam directivity and focusing due to the change of time delay of each element were discussed due to the change of the number of piezoelectric elements. It was found that ultrasonic beam was much more spreaded and hence its sound pressure was decreased as steering angle of ultrasonic beam was increased. In addition, the ability of ultrasonic bean focusing decreased gradually with the increase of focal length at the same piezoelectric elements. However, the ability of beam focusing was improved as the number of consisting elements was increased

Effect of ultrasonic treatment on reduction of Esherichia coli ATCC 25922 and egg quality parameters in experimentally contaminated hens' shell eggs.

Science.gov (United States)

Sert, Durmus; Aygun, Ali; Torlak, Emrah; Mercan, Emin

2013-09-01

In this study, hen eggs which were experimentally contaminated with Esherichia coli ATCC 25922 were used. Contaminated eggs were washed statically (S5 to S30; 0 kHz) and by ultrasonic waves (U5 to U30; 35 kHz) for given applications of time (5, 15 and 30 min), then the eggs were stored at 22°C for 14 days. Depending on the time of ultrasonic application, a significant increase in egg shell strength (P eggs which were washed by ultrasonic waves. Yolk width values of ultrasonic washed eggs diminished. E. coli was completely removed by 30 min of ultrasonic application. During storage E. coli growth was not detected on the eggs which were washed by ultrasonic waves except the eggs in U5 group (2.04 log CFU eggshell⁻¹) on the first day of storage. Depending on the time of ultrasonic application a significant increase in egg quality parameters (shell strength, albumen height, Haugh units, and yolk height) were observed. The application of ultrasound led to a significant reduction in E. coli numbers on egg shells. © 2013 Society of Chemical Industry.

Closely Mounted Compact Wideband Diversity Antenna for Mobile Phone Applications

Directory of Open Access Journals (Sweden)

Bunggil Yu

2012-01-01

Full Text Available Here a compact wideband diversity antenna covering the PCS/UMTS/WiMAX bands with high isolation and low enveloped correlation coefficient (ECC is proposed. To widen the bandwidth, the proposed antenna uses a structure with a gap-coupled feed and an inductively shorted line that has capacitive compensation between the radiator and the ground plane. Also, a suspended line with a parasitic element is used to enhance the isolation between the two antennas.

Studies on Section XI ultrasonic repeatability

International Nuclear Information System (INIS)

Jamison, T.D.; McDearman, W.R.

1981-05-01

A block representative of a nuclear component has been welded containing intentional defects. Acoustic emission data taken during the welding correlate well with ultrasonic data. Repetitive ultrasonic examinations have been performed by skilled operators using a procedure based on that desribed in ASME Section XI. These examinations were performed by different examination teams using different ultrasonic equipment in such a manner that the effects on the repeatability of the ultrasonic test method caused by the operator and by the use of different equipment could be estimated. It was tentatively concluded that when considering a large number of inspections: (1) there is no significant difference in indication sizing between operators, and (2) there is a significant difference in amplitude and defect sizing when instruments having different, Code acceptable operating characteristics are used. It was determined that the Section XI sizing parameters follow a bivariate normal distribution. Data derived from ultrasonically and physically sizing indications in nuclear components during farication show that the Section XI technique tends to overestimate the size of the reflectors

Experimental investigation of ultrasonic velocity anisotropy in ...

Indian Academy of Sciences (India)

Permanent link: https://www.ias.ac.in/article/fulltext/pram/077/02/0345-0355. Keywords. Magnetic fluids; ultrasonic wave; sound velocity; anisotropy. Abstract. Magnetic field-induced dispersion of ultrasonic velocity in a Mn0.7Zn0.3Fe2O4 fluid (applied magnetic field is perpendicular to the ultrasonic propagation vector) is ...

Ultrasonic osteotome: A cutting edge technology, our experience in 96 patients

Directory of Open Access Journals (Sweden)

V Velho

2014-01-01

Full Text Available Background: The ultrasonic osteotome is a tissue-specific device that allows the surgeon to make precise osteotomies while protecting collateral or adjacent soft tissue structures. The recurring impacts pulverize the noncompliant crystalline structure resulting in a precise cut. The more compliant adjacent soft tissue is not affected by the ultrasonic oscillation. Objective: The purpose of this study is to present our experience of using this technology in osteotomies. Materials and Methods: We reviewed 96 patients, both male and female; of different ages in which ultrasonic osteotome was used to perform an osteotomy of different manners (Craniotomy, laminotomy, facetectomy, etc.. Patients with head injury, spine injury, degenerative spine diseases, and brain tumors were included in this study. Results: In all these patients, the bone cut was even with minimal surrounding bone loss. The time required for the osteotomy was reduced to half. There was no damage to underlying dura, cord or nerve structures. Conclusions: Ultrasonic osteotome is a safe and effective ultrasonic bone cutting device that can be used to facilitate osteotomies in various types of cranial and spinal surgeries. This device allows precision bone cutting with minimal surrounding bone loss and obviates the risk associated with the use of high-speed burrs and oscillating saws.

Improved biohydrogen production and treatment of pulp and paper mill effluent through ultrasonication pretreatment of wastewater

International Nuclear Information System (INIS)

Hay, Jacqueline Xiao Wen; Wu, Ta Yeong; Juan, Joon Ching; Md Jahim, Jamaliah

2015-01-01

Highlights: • Ultrasonication facilitated the reuse of PPME in biohydrogen production. • Ultrasonication at an amplitude of 60% for 45 min produced the highest biohydrogen. • Ultrasonication increased the solubilization of PPME. • Higher net savings were obtained in pretreated PPME compared to raw PPME. - Abstract: Pulp and paper mill effluent (PPME), a rich cellulosic material, was found to have great potential for biohydrogen production through a photofermentation process. However, pretreatments were needed for degrading the complex structure of PPME before biohydrogen production. The aim of this study was to gain further insight into the effect of an ultrasonication process on PPME as a pretreatment method and on photofermentative biohydrogen production using Rhodobacter sphaeroides NCIMB. The ultrasonication amplitudes and times were varied between 30–90% and 15–60 min, respectively, and no dilution or nutrient supplementation was introduced during the biohydrogen production process. A higher biohydrogen yield, rate, light efficiency and COD removal efficiency were attained in conditions using ultrasonicated PPME. Among these different pretreatment conditions, PPME with ultrasonication pretreatment employing an amplitude of 60% and time of 45 min (A60:T45) gave the highest yield and rate of 5.77 mL H_2/mL medium and 0.077 mL H_2/mL h, respectively, while the raw PPME without ultrasonication showed a significantly lower yield and rate of 1.10 mL H_2/mL medium and 0.015 mL H_2/mL h, respectively. The results of this study demonstrated the potential of using ultrasonication as a pretreatment for PPME because the yield and rate of biohydrogen production were highly enhanced compared to the raw PPME. Economic analysis was also performed in this study, and in comparison with raw PPME, the highest net saving was $0.2132 for A60:T45.

Updated Results of Ultrasonic Transducer Irradiation Test

Energy Technology Data Exchange (ETDEWEB)

Daw, Joshua; Palmer, Joe [Idaho National Laboratory, P.O. Box 1625, MS 4112, Idaho Falls, ID, 38415-3840 (United States); Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert [Pacific Northwest National Laboratory, 902 Battelle Blvd. Richland, WA, 99354 (United States); Chien, Hual-Te [Argonne National Laboratory, 9700 S. Cass Avenue Argonne, IL, 60439 (United States); Tittmann, Bernhard; Reinhardt, Brian [Pennsylvania State University, 212 Earth and Engr. Sciences Building, University Park, PA, 16802 (United States); Kohse, Gordon [Massachusetts Institute of Technology, 77 Massachusetts Ave. Cambridge, MA 02139 (United States); Rempe, Joy [Rempe and Associates, LLC, 360 Stillwater, Idaho Falls, ID 83404 (United States); Villard, J.F. [Commissariat a l' energie atomique et aux energies alternatives, Centre d' etudes de Cadarache, 13108 Saint-Paul-lez-Durance (France)

2015-07-01

Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10{sup 21} n/cm{sup 2}. A multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET-ASI) program also provided initial support for this effort. This irradiation, which started in February 2014, is an instrumented lead test and real-time transducer performance data are collected along with temperature and neutron and gamma flux data. The irradiation is ongoing and will continue to approximately mid-2015. To date, very encouraging results have been attained as several transducers continue to operate under irradiation. (authors)

Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

NARCIS (Netherlands)

Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

1998-01-01

At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

NARCIS (Netherlands)

Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

1999-01-01

At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

Wideband energy harvesting based on mixed connection of piezoelectric oscillators

Science.gov (United States)

Wu, P. H.; Chen, Y. J.; Li, B. Y.; Shu, Y. C.

2017-09-01

An approach for wideband energy harvesting together with power enhancement is proposed by integrating multiple piezoelectric oscillators with mixed parallel-series connection. This gives rise to the feasibility of shifting the operation frequency band to the dominant frequency domain of ambient excitations. There are two types of connection patterns discussed here: the p-type (s-type) is the parallel (series) connection of all sets of oscillators where some of them may be connected in series (parallel). In addition, the standard interface circuit used for electric rectification is adopted here. The analytic estimates of output power are derived and explicitly expressed in terms of different matrix formulations for these two connection patterns. They are subsequently validated and are found in good agreement with numerical simulations and experimental observations. Finally, the experimental results from the mixed connection of 4 piezoelectric oscillators show that the peak power of each array is about 3.4 times higher than that generated by a single piezoelectric oscillator. In addition, the bandwidth of the array capable of switching connection patterns is around 2.8 times wider than that based on a single array configuration. Hence, the effective bandwidth is enlarged without the loss of peak power.

Ultrasonic level, temperature, and density sensor

International Nuclear Information System (INIS)

Rogers, S.C.; Miller, G.N.

1982-01-01

A sensor has been developed to measure simultaneously the level, temperature, and density of the fluid in which it is immersed. The sensor is a thin, rectangular stainless steel ribbon which acts as a waveguide and is housed in a perforated tube. The waveguide is coupled to a section of magnetostrictive magnetic-coil transducers. These tranducers are excited in an alternating sequence to interrogate the sensor with both torsional ultrasonic waves, utilizing the Wiedemann effect, and extensional ultrasonic waves, using the Joule effect. The measured torsional wave transit time is a function of the density, level, and temperature of the fluid surrounding the waveguide. The measured extensional wave transit time is a function of the temperature of the waveguide only. The sensor is divided into zones by the introduction of reflecting surfaces at measured intervals along its length. Consequently, the transit times from each reflecting surface can be analyzed to yield a temperature profile and a density profile along the length of the sensor. Improvements in acoustic wave dampener and pressure seal designs enhance the compatibility of the probe with high-temperature, high-radiation, water-steam environments and increase the likelihood of survival in such environments. Utilization of a microcomputer to automate data sampling and processing has resulted in improved resolution of the sensor