Thermal and ultrasonic influence in the formation of nanometer scale hydroxyapatite bio-ceramic

PubMed Central

Poinern, GJE; Brundavanam, R; Le, X Thi; Djordjevic, S; Prokic, M; Fawcett, D

2011-01-01

Hydroxyapatite (HAP) is a widely used biocompatible ceramic in many biomedical applications and devices. Currently nanometer-scale forms of HAP are being intensely investigated due to their close similarity to the inorganic mineral component of the natural bone matrix. In this study nano-HAP was prepared via a wet precipitation method using Ca(NO3)2 and KH2PO4 as the main reactants and NH4OH as the precipitator under ultrasonic irradiation. The Ca/P ratio was set at 1.67 and the pH was maintained at 9 during the synthesis process. The influence of the thermal treatment was investigated by using two thermal treatment processes to produce ultrafine nano-HAP powders. In the first heat treatment, a conventional radiant tube furnace was used to produce nano-particles with an average size of approximately 30 nm in diameter, while the second thermal treatment used a microwave-based technique to produce particles with an average diameter of 36 nm. The crystalline structure and morphology of all nanoparticle powders produced were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). Both thermal techniques effectively produced ultrafine powders with similar crystalline structure, morphology and particle sizes. PMID:22114473

Characteristics of Turbulent Airflow Deduced from Rapid Surface Thermal Fluctuations: An Infrared Surface Anemometer

NASA Astrophysics Data System (ADS)

Aminzadeh, Milad; Breitenstein, Daniel; Or, Dani

2017-12-01

The intermittent nature of turbulent airflow interacting with the surface is readily observable in fluctuations of the surface temperature resulting from the thermal imprints of eddies sweeping the surface. Rapid infrared thermography has recently been used to quantify characteristics of the near-surface turbulent airflow interacting with the evaporating surfaces. We aim to extend this technique by using single-point rapid infrared measurements to quantify properties of a turbulent flow, including surface exchange processes, with a view towards the development of an infrared surface anemometer. The parameters for the surface-eddy renewal (α and β ) are inferred from infrared measurements of a single-point on the surface of a heat plate placed in a wind tunnel with prescribed wind speeds and constant mean temperatures of the surface. Thermally-deduced parameters are in agreement with values obtained from standard three-dimensional ultrasonic anemometer measurements close to the plate surface (e.g., α = 3 and β = 1/26 (ms)^{-1} for the infrared, and α = 3 and β = 1/19 (ms)^{-1} for the sonic-anemometer measurements). The infrared-based turbulence parameters provide new insights into the role of surface temperature and buoyancy on the inherent characteristics of interacting eddies. The link between the eddy-spectrum shape parameter α and the infrared window size representing the infrared field of view is investigated. The results resemble the effect of the sampling height above the ground in sonic anemometer measurements, which enables the detection of larger eddies with higher values of α . The physical basis and tests of the proposed method support the potential for remote quantification of the near-surface momentum field, as well as scalar-flux measurements in the immediate vicinity of the surface.

Effect of ultrasonication in synthesis of gold nano fluid for thermal applications

NASA Astrophysics Data System (ADS)

Nath, G.; Giri, R.

2018-02-01

Ultrasonically synthesized nanofluids are efficient coolant and heat exchanger material has demonstrated its potential in various fields and thermal engineering. The computation of different acoustical parameter using the ultrasonic velocity data of gold nanofluids are taken in estimation of thermal conductivity. The computational and experimental measured values of thermal conductivity are well agrees. The results execute ultrasonically synthesized gold nanofluids is an economic and efficient technology for explaining the increase of thermal conductivity of nanofluids in suitable optimum conditions.

Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components.

PubMed

Ciampa, Francesco; Mahmoodi, Pooya; Pinto, Fulvio; Meo, Michele

2018-02-16

Active infrared thermography is a fast and accurate non-destructive evaluation technique that is of particular relevance to the aerospace industry for the inspection of aircraft and helicopters' primary and secondary structures, aero-engine parts, spacecraft components and its subsystems. This review provides an exhaustive summary of most recent active thermographic methods used for aerospace applications according to their physical principle and thermal excitation sources. Besides traditional optically stimulated thermography, which uses external optical radiation such as flashes, heaters and laser systems, novel hybrid thermographic techniques are also investigated. These include ultrasonic stimulated thermography, which uses ultrasonic waves and the local damage resonance effect to enhance the reliability and sensitivity to micro-cracks, eddy current stimulated thermography, which uses cost-effective eddy current excitation to generate induction heating, and microwave thermography, which uses electromagnetic radiation at the microwave frequency bands to provide rapid detection of cracks and delamination. All these techniques are here analysed and numerous examples are provided for different damage scenarios and aerospace components in order to identify the strength and limitations of each thermographic technique. Moreover, alternative strategies to current external thermal excitation sources, here named as material-based thermography methods, are examined in this paper. These novel thermographic techniques rely on thermoresistive internal heating and offer a fast, low power, accurate and reliable assessment of damage in aerospace composites.

Recent Advances in Active Infrared Thermography for Non-Destructive Testing of Aerospace Components

PubMed Central

Mahmoodi, Pooya; Pinto, Fulvio; Meo, Michele

2018-01-01

Active infrared thermography is a fast and accurate non-destructive evaluation technique that is of particular relevance to the aerospace industry for the inspection of aircraft and helicopters’ primary and secondary structures, aero-engine parts, spacecraft components and its subsystems. This review provides an exhaustive summary of most recent active thermographic methods used for aerospace applications according to their physical principle and thermal excitation sources. Besides traditional optically stimulated thermography, which uses external optical radiation such as flashes, heaters and laser systems, novel hybrid thermographic techniques are also investigated. These include ultrasonic stimulated thermography, which uses ultrasonic waves and the local damage resonance effect to enhance the reliability and sensitivity to micro-cracks, eddy current stimulated thermography, which uses cost-effective eddy current excitation to generate induction heating, and microwave thermography, which uses electromagnetic radiation at the microwave frequency bands to provide rapid detection of cracks and delamination. All these techniques are here analysed and numerous examples are provided for different damage scenarios and aerospace components in order to identify the strength and limitations of each thermographic technique. Moreover, alternative strategies to current external thermal excitation sources, here named as material-based thermography methods, are examined in this paper. These novel thermographic techniques rely on thermoresistive internal heating and offer a fast, low power, accurate and reliable assessment of damage in aerospace composites. PMID:29462953

Experimental evidence for the lattice instability of Bi-based superconducting systems

NASA Astrophysics Data System (ADS)

Yusheng, He; Jiong, Xiang; Hsin, Wang; Aisheng, He; Jincang, Zhang; Fanggao, Chang

1989-11-01

Ultrasonic measurements, specific heat and thermal analysis experiments, X-ray diffraction study and infrared investigation revealed that there are anomalous structural changes or lattice instabilities near 200 K in single 2212 or 2223 phase samples of Bi(Pb)-Sr-Ca-Cu-O system. Detailed study showed that anomalous changes or lattice instabilities are isothermal-like processes and have the characteristics of a structural phase transition, accompanying with increases in lattice constants. Possible mechanism for this lattice instability is discussed.

Mid-infrared pulsed laser ultrasonic testing for carbon fiber reinforced plastics.

PubMed

Kusano, Masahiro; Hatano, Hideki; Watanabe, Makoto; Takekawa, Shunji; Yamawaki, Hisashi; Oguchi, Kanae; Enoki, Manabu

2018-03-01

Laser ultrasonic testing (LUT) can realize contactless and instantaneous non-destructive testing, but its signal-to-noise ratio must be improved in order to measure carbon fiber reinforced plastics (CFRPs). We have developed a mid-infrared (mid-IR) laser source optimal for generating ultrasonic waves in CFRPs by using a wavelength conversion device based on an optical parametric oscillator. This paper reports a comparison of the ultrasonic generation behavior between the mid-IR laser and the Nd:YAG laser. The mid-IR laser generated a significantly larger ultrasonic amplitude in CFRP laminates than a conventional Nd:YAG laser. In addition, our study revealed that the surface epoxy matrix of CFRPs plays an important role in laser ultrasonic generation. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method

NASA Astrophysics Data System (ADS)

Gopi, D.; Indira, J.; Kavitha, L.; Sekar, M.; Mudali, U. Kamachi

Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology.

Effect of acoustic softening on the thermal-mechanical process of ultrasonic welding.

PubMed

Chen, Kunkun; Zhang, Yansong; Wang, Hongze

2017-03-01

Application of ultrasonic energy can reduce the static stress necessary for plastic deformation of metallic materials to reduce forming load and energy, namely acoustic softening effect (ASE). Ultrasonic welding (USW) is a rapid joining process utilizing ultrasonic energy to form a solid state joint between two or more pieces of metals. Quantitative characterization of ASE and its influence on specimen deformation and heat generation is essential to clarify the thermal-mechanical process of ultrasonic welding. In the present work, experiments were set up to found out mechanical behavior of copper and aluminum under combined effect of compression force and ultrasonic energy. Constitutive model was proposed and numerical implemented in finite element model of ultrasonic welding. Thermal-mechanical analysis was put forward to explore the effect of ultrasonic energy on the welding process quantitatively. Conclusions can be drawn that ASE increases structural deformation significantly, which is beneficial for joint formation. Meanwhile, heat generation from both frictional work and plastic deformation is slightly influenced by ASE. Based on the proposed model, relationship between ultrasonic energy and thermal-mechanical behavior of structure during ultrasonic welding was constructed. Copyright © 2016 Elsevier B.V. All rights reserved.

NASA Tech Briefs, September 2009

NASA Technical Reports Server (NTRS)

2009-01-01

opics covered include: Filtering Water by Use of Ultrasonically Vibrated Nanotubes; Computer Code for Nanostructure Simulation; Functionalizing CNTs for Making Epoxy/CNT Composites; Improvements in Production of Single-Walled Carbon Nanotubes; Progress Toward Sequestering Carbon Nanotubes in PmPV; Two-Stage Variable Sample-Rate Conversion System; Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas; Board Saver for Use with Developmental FPGAs; Circuit for Driving Piezoelectric Transducers; Digital Synchronizer without Metastability; Compact, Low-Overhead, MIL-STD-1553B Controller; Parallel-Processing CMOS Circuitry for M-QAM and 8PSK TCM; Differential InP HEMT MMIC Amplifiers Embedded in Waveguides; Improved Aerogel Vacuum Thermal Insulation; Fluoroester Co-Solvents for Low-Temperature Li+ Cells; Using Volcanic Ash to Remove Dissolved Uranium and Lead; High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell; Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays; Micro-Horn Arrays for Ultrasonic Impedance Matching; Improved Controller for a Three-Axis Piezoelectric Stage; Nano-Pervaporation Membrane with Heat Exchanger Generates Medical-Grade Water; Micro-Organ Devices; Nonlinear Thermal Compensators for WGM Resonators; Dynamic Self-Locking of an OEO Containing a VCSEL; Internal Water Vapor Photoacoustic Calibration; Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings; Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays; Improved Scanners for Microscopic Hyperspectral Imaging; Rate-Compatible LDPC Codes with Linear Minimum Distance; PrimeSupplier Cross-Program Impact Analysis and Supplier Stability Indicator Simulation Model; Integrated Planning for Telepresence With Time Delays; Minimizing Input-to-Output Latency in Virtual Environment; Battery Cell Voltage Sensing and Balancing Using Addressable Transformers; Gaussian and Lognormal Models of Hurricane Gust Factors; Simulation of Attitude and Trajectory Dynamics and Control of Multiple Spacecraft; Integrated Modeling of Spacecraft Touch-and-Go Sampling; Spacecraft Station-Keeping Trajectory and Mission Design Tools; Efficient Model-Based Diagnosis Engine; and DSN Simulator.

Processing of ultra-high molecular weight polyethylene/graphite composites by ultrasonic injection moulding: Taguchi optimization.

PubMed

Sánchez-Sánchez, Xavier; Elias-Zuñiga, Alex; Hernández-Avila, Marcelo

2018-06-01

Ultrasonic injection moulding was confirmed as an efficient processing technique for manufacturing ultra-high molecular weight polyethylene (UHMWPE)/graphite composites. Graphite contents of 1 wt%, 5 wt%, and 7 wt% were mechanically pre-mixed with UHMWPE powder, and each mixture was pressed at 135 °C. A precise quantity of the pre-composites mixtures cut into irregularly shaped small pieces were subjected to ultrasonic injection moulding to fabricate small tensile specimens. The Taguchi method was applied to achieve the optimal level of ultrasonic moulding parameters and to maximize the tensile strength of the composites; the results showed that mould temperature was the most significant parameter, followed by the graphite content and the plunger profile. The observed improvement in tensile strength in the specimen with 1 wt% graphite was of 8.8% and all composites showed an increase in the tensile modulus. Even though the presence of graphite produced a decrease in the crystallinity of all the samples, their thermal stability was considerably higher than that of pure UHMWPE. X-ray diffraction and scanning electron microscopy confirmed the exfoliation and dispersion of the graphite as a function of the ultrasonic processing. Fourier transform infrared spectra showed that the addition of graphite did not influence the molecular structure of the polymer matrix. Further, the ultrasonic energy led oxidative degradation and chain scission in the polymer. Copyright © 2018 Elsevier B.V. All rights reserved.

Optical temperature sensing of NaYbF4: Tm3+@SiO2 core-shell micro-particles induced by infrared excitation.

PubMed

Wang, Xiangfu; Zheng, Jin; Xuan, Yan; Yan, Xiaohong

2013-09-09

NaYbF(4):Tm3+@SiO(2) core-shell micro-particles were synthesized by a hydrothermal method and subsequent ultrasonic coating process. Optical temperature sensing has been observed in NaYbF4: Tm(3+)@SiO(2)core-shell micro-particles with a 980 nm infrared laser as excitation source.The fluorescence intensity ratios, optical temperature sensitivity, and temperature dependent population re-distribution ability from the thermally coupled (1)D(2)/(1)G(4) and (3)F(2) /(3)H(4) levels of the Tm(3+) ion have been analyzed as a function of temperature in the range of 100~700 K in order to check its availability as a optical temperature sensor. A better behavior as a lowtemperature sensor has been obtained with a minimum sensitivity of 5.4 × 10(-4) K(-1) at 430 K. It exhibits temperature induced population re-distribution from (1)D(2) /(1)G(4) thermally coupled levels at higher temperature range.

Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method.

PubMed

Gopi, D; Indira, J; Kavitha, L; Sekar, M; Mudali, U Kamachi

2012-07-01

Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology. Copyright © 2012 Elsevier B.V. All rights reserved.

Detection of multiple thin surface cracks using vibrothermography with low-power piezoceramic-based ultrasonic actuator—a numerical study with experimental verification

NASA Astrophysics Data System (ADS)

Parvasi, Seyed Mohammad; Xu, Changhang; Kong, Qingzhao; Song, Gangbing

2016-05-01

Ultrasonic vibrations in cracked structures generate heat at the location of defects mainly due to frictional rubbing and viscoelastic losses at the defects. Vibrothermography is an effective nondestructive evaluation method which uses infrared imaging (IR) techniques to locate defects such as cracks and delaminations by detecting the heat generated at the defects. In this paper a coupled thermo-electro-mechanical analysis with the use of implicit finite element method was used to simulate a low power (10 W) piezoceramic-based ultrasonic actuator and the corresponding heat generation in a metallic plate with multiple surface cracks. Numerical results show that the finite element software Abaqus can be used to simultaneously model the electrical properties of the actuator, the ultrasonic waves propagating within the plate, as well as the thermal properties of the plate. Obtained numerical results demonstrate the ability of these low power transducers in detecting multiple cracks in the simulated aluminum plate. The validity of the numerical simulations was verified through experimental studies on a physical aluminum plate with multiple surface cracks while the same low power piezoceramic stack actuator was used to excite the plate and generate heat at the cracks. An excellent qualitative agreement exists between the experimental results and the numerical simulation’s results.

Development of Fe3O4/ZrO2 Composite Powered by Nanographene Platelets (NGP) for Degradation of Water Pollutants via Photo- and Sonocatalysis

NASA Astrophysics Data System (ADS)

Kristianto, Yogi; Taufik, Ardiansyah; Saleh, Rosari

2017-03-01

In this study, a series of Fe3O4/ZrO2/nanographene platelets (NGP) composite, with various weight percent (wt%) of NGP (5%, 10% and 15%), were prepared successfully using ultrasonic-assisted followed by simple hydrothermal method. Their physicochemical properties were fairly characterized by X-ray diffraction, fourier transform infrared and thermal gravimetric analysis. Furthermore, their catalytic activities were investigated toward anionic congo red (CR) and cationic methylene blue (MB) as models of organic pollutant under ultraviolet (UV) and ultrasonic (US) irradiation, respectively. The experimental results showed that the incorporation of NGP in Fe3O4/ZrO2 composite improved its efficiency in degrading CR and MB and became maximum at 10wt% of NGP. In addition, the role of active radicals involved in catalytic activities were discussed.

Methods of measurement for semiconductor materials, process control, and devices

NASA Technical Reports Server (NTRS)

Bullis, W. M. (Editor)

1972-01-01

Significant accomplishments include development of a procedure to correct for the substantial differences of transistor delay time as measured with different instruments or with the same instrument at different frequencies; association of infrared response spectra of poor quality germanium gamma ray detectors with spectra of detectors fabricated from portions of a good crystal that had been degraded in known ways; and confirmation of the excellent quality and cosmetic appearance of ultrasonic bonds made with aluminum ribbon wire. Work is continuing on measurement of resistivity of semiconductor crystals; study of gold-doped silicon, development of the infrared response technique; evaluation of wire bonds and die attachment; and measurement of thermal properties of semiconductor devices, delay time and related carrier transport properties in junction devices, and noise properties of microwave diodes.

Embedded spacecraft thermal control using ultrasonic consolidation

NASA Astrophysics Data System (ADS)

Clements, Jared W.

Research has been completed in order to rapidly manufacture spacecraft thermal control technologies embedded in spacecraft structural panels using ultrasonic consolidation. This rapid manufacturing process enables custom thermal control designs in the time frame necessary for responsive space. Successfully embedded components include temperature sensors, heaters, wire harnessing, pre-manufactured heat pipes, and custom integral heat pipes. High conductivity inserts and custom integral pulsating heat pipes were unsuccessfully attempted. This research shows the viability of rapid manufacturing of spacecraft structures with embedded thermal control using ultrasonic consolidation.

Investigation of thermal conductivity of metal materials on view of influence of ultrasonic waves

NASA Astrophysics Data System (ADS)

Lepeshkin, A. R.; Shcherbakov, P. P.

2017-11-01

A devices and methods were developed to determine characteristics of thermal cunductivity in metals materials on view of influence of ultrasonic waves at frequencies of 20 kHz and 2.6 MHz. A thermograph was used for investigation of the nonstationary thermal state of a conical rod and contactless measurements of its surface temperatures. The curves of heating of the tip of the conical rod and the time of heat transfer from the electric heater to the tip of the rod in experiments with an ultrasonic radiator and without it were carried out. According to the results of the research it was obtained that the thermal conductivity of a metal rod is increased by 2 times at a frequency of 20 kHz with an intensity of 50 W. The measure technique and the experimental data on the thermal conductivity of AISI-304 stainless steel in the ultrasonic wave field 2.6 MHz are given. A stationary comparative method for determining the thermal conductivity is used. As a result of the experiments it was established that the thermal conductivity of the rod increases by 2 times in the temperature range 20-100 °C in the field of ultrasonic wave. The obtained results confirm that in the alloys under the influence of ultrasonic waves on electrons and nodes of the crystal structure the contribution of the electron and lattice components of the thermal conductivity increases.

Infrared laser thermal fusion of blood vessels: preliminary ex vivo tissue studies.

PubMed

Cilip, Christopher M; Rosenbury, Sarah B; Giglio, Nicholas; Hutchens, Thomas C; Schweinsberger, Gino R; Kerr, Duane; Latimer, Cassandra; Nau, William H; Fried, Nathaniel M

2013-05-01

Suture ligation of blood vessels during surgery can be time-consuming and skill-intensive. Energy-based, electrosurgical, and ultrasonic devices have recently replaced the use of sutures and mechanical clips (which leave foreign objects in the body) for many surgical procedures, providing rapid hemostasis during surgery. However, these devices have the potential to create an undesirably large collateral zone of thermal damage and tissue necrosis. We explore an alternative energy-based technology, infrared lasers, for rapid and precise thermal coagulation and fusion of the blood vessel walls. Seven near-infrared lasers (808, 980, 1075, 1470, 1550, 1850 to 1880, and 1908 nm) were tested during preliminary tissue studies. Studies were performed using fresh porcine renal vessels, ex vivo, with native diameters of 1 to 6 mm, and vessel walls flattened to a total thickness of 0.4 mm. A linear beam profile was applied normal to the vessel for narrow, full-width thermal coagulation. The laser irradiation time was 5 s. Vessel burst pressure measurements were used to determine seal strength. The 1470 nm laser wavelength demonstrated the capability of sealing a wide range of blood vessels from 1 to 6 mm diameter with burst strengths of 578 ± 154, 530 ± 171, and 426 ± 174  mmHg for small, medium, and large vessel diameters, respectively. Lateral thermal coagulation zones (including the seal) measured 1.0 ± 0.4  mm on vessels sealed at this wavelength. Other laser wavelengths (1550, 1850 to 1880, and 1908 nm) were also capable of sealing vessels, but were limited by lower vessel seal pressures, excessive charring, and/or limited power output preventing treatment of large vessels (>4  mm outer diameter).

Ultrasonic Characterization of Superhard Material: Osmium Diboride

NASA Astrophysics Data System (ADS)

Yadawa, P. K.

2012-12-01

Higher order elastic constants have been calculated in hexagonal structured superhard material OsB2 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 OsB2 at low temperature are better than at high temperature, because at low temperature it has low ultrasonic velocity and ultrasonic attenuation. Superhard material OsB2 has many industrial applications, such as abrasives, cutting tools and hard coatings.

Thermally Stable, Piezoelectric and Pyroelectric Polymeric Substrates and Method Relating Thereto

NASA Technical Reports Server (NTRS)

Simpson, Joycelyn O. (Inventor); St.Claire, Terry L. (Inventor)

2002-01-01

A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared, This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers, acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors. in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches. adjustable fresnel lenses, speakers, tactile sensors, weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 100 C; depositing a metal electrode material onto the polymer film; attaching a plurality of electrical leads to the metal electrode coated polymeric substrates; heating the metal electrode coated polymeric substrate in a low dielectric medium; applying a voltage to the heated metal electrode coated polymeric substrate to induce polarization; and cooling the polarized metal electrode coated polymeric electrode while maintaining a constant voltage.

Thermally Stable, Piezoelectric and Pyroelectric Polymeric Substrates

NASA Technical Reports Server (NTRS)

Simpson, Joycely O. (Inventor); St.Clair, Terry L. (Inventor)

1999-01-01

A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers. acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors, in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches, adjustable fresnel lenses, speakers, tactile sensors. weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 1000 C; depositing a metal electrode material onto the polymer film; attaching a plurality of electrical leads to the metal electrode coated polymeric substrate; heating the metal electrode coated polymeric substrate in a low dielectric medium; applying a voltage to the heated metal electrode coated polymeric substrate to induce polarization; and cooling the polarized metal electrode coated polymeric electrode while maintaining a constant voltage.

Method of Making Thermally Stable, Piezoelectric and Proelectric Polymeric Substrates

NASA Technical Reports Server (NTRS)

Simpson, Joycelyn O. (Inventor); St.Clair, Terry L. (Inventor)

1999-01-01

A thermally stable, piezoelectric and pyroelectric polymeric substrate was prepared. This thermally stable, piezoelectric and pyroelectric polymeric substrate may be used to prepare electromechanical transducers, thermomechanical transducers, accelerometers, acoustic sensors, infrared sensors, pressure sensors, vibration sensors, impact sensors. in-situ temperature sensors, in-situ stress/strain sensors, micro actuators, switches, adjustable fresnel lenses, speakers, tactile sensors, weather sensors, micro positioners, ultrasonic devices, power generators, tunable reflectors, microphones, and hydrophones. The process for preparing these polymeric substrates includes: providing a polymeric substrate having a softening temperature greater than 100 C; depositing a metal electrode material onto the polymer film; attaching a plurality of electrical leads to the metal electrode coated polymeric substrate; heating the metal electrode coated polymeric substrate in a low dielectric medium: applying a voltage to the heated metal electrode coated polymeric substrate to induce polarization; and cooling the polarized metal electrode coated polymeric electrode while maintaining a constant voltage.

Ultrasonic Technology in Duress Alarms.

ERIC Educational Resources Information Center

Lee, Martha A.

2000-01-01

Provides the pros and cons of the most commonly used technologies in personal duress alarm systems in the school environment. Discussed are radio frequency devices, infrared systems, and ultrasonic technology. (GR)

Profiling defect depth in composite materials using thermal imaging NDE

NASA Astrophysics Data System (ADS)

Obeidat, Omar; Yu, Qiuye; Han, Xiaoyan

2018-04-01

Sonic Infrared (IR) NDE, is a relatively new NDE technology; it has been demonstrated as a reliable and sensitive method to detect defects. SIR uses ultrasonic excitation with IR imaging to detect defects and flaws in the structures being inspected. An IR camera captures infrared radiation from the target for a period of time covering the ultrasound pulse. This period of time may be much longer than the pulse depending on the defect depth and the thermal properties of the materials. With the increasing deployment of composites in modern aerospace and automobile structures, fast, wide-area and reliable NDE methods are necessary. Impact damage is one of the major concerns in modern composites. Damage can occur at a certain depth without any visual indication on the surface. Defect depth information can influence maintenance decisions. Depth profiling relies on the time delays in the captured image sequence. We'll present our work on the defect depth profiling by using the temporal information of IR images. An analytical model is introduced to describe heat diffusion from subsurface defects in composite materials. Depth profiling using peak time is introduced as well.

Ultrasonic and micromechanical study of damage and elastic properties of SiC/RBSN ceramic composites. [Reaction Bonded Silicon Nitride

NASA Technical Reports Server (NTRS)

Chu, Y. C.; Hefetz, M.; Rokhlin, S. I.; Baaklini, G. Y.

1992-01-01

Ultrasonic techniques are employed to develop methods for nondestructive evaluation of elastic properties and damage in SiC/RBSN composites. To incorporate imperfect boundary conditions between fibers and matrix into a micromechanical model, a model of fibers having effective anisotropic properties is introduced. By inverting Hashin's (1979) microstructural model for a composite material with microscopic constituents the effective fiber properties were found from ultrasonic measurements. Ultrasonic measurements indicate that damage due to thermal shock is located near the surface, so the surface wave is most appropriate for estimation of the ultimate strength reduction and critical temperature of thermal shock. It is concluded that bonding between laminates of SiC/RBSN composites is severely weakened by thermal oxidation. Generally, nondestructive evaluation of thermal oxidation effects and thermal shock shows good correlation with measurements previously performed by destructive methods.

Advanced NDE techniques for quantitative characterization of aircraft

NASA Technical Reports Server (NTRS)

Heyman, Joseph S.; Winfree, William P.

1990-01-01

Recent advances in nondestructive evaluation (NDE) at NASA Langley Research Center and their applications that have resulted in quantitative assessment of material properties based on thermal and ultrasonic measurements are reviewed. Specific applications include ultrasonic determination of bolt tension, ultrasonic and thermal characterization of bonded layered structures, characterization of composite materials, and disbonds in aircraft skins.

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

NASA Technical Reports Server (NTRS)

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.

Boiler Tube Corrosion Characterization with a Scanning Thermal Line

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Jacobstein, Ronald; Reilly, Thomas

2001-01-01

Wall thinning due to corrosion in utility boiler water wall tubing is a significant operational concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. Unfortunately, ultrasonic inspection is very manpower intense and slow. Therefore, thickness measurements are typically taken over a relatively small percentage of the total boiler wall and statistical analysis is used to determine the overall condition of the boiler tubing. Other inspection techniques, such as electromagnetic acoustic transducer (EMAT), have recently been evaluated, however they provide only a qualitative evaluation - identifying areas or spots where corrosion has significantly reduced the wall thickness. NASA Langley Research Center, in cooperation with ThermTech Services, has developed a thermal NDE technique designed to quantitatively measure the wall thickness and thus determine the amount of material thinning present in steel boiler tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source coupled with the analysis technique represents a significant improvement in the inspection speed and accuracy for large structures such as boiler water walls. A theoretical basis for the technique will be presented to establish the quantitative nature of the technique. Further, a dynamic calibration system will be presented for the technique that allows the extraction of thickness information from the temperature data. Additionally, the results of the application of this technology to actual water wall tubing samples and in-situ inspections will be presented.

Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubey, P. K., E-mail: premkdubey@gmail.com; Kumar, Yudhisther; Gupta, Reeta

2014-05-15

The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occursmore » at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.« less

Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

NASA Astrophysics Data System (ADS)

Dubey, P. K.; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

2014-05-01

The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO2 adsorption performance

NASA Astrophysics Data System (ADS)

Sargazi, Ghasem; Afzali, Daryoush; Mostafavi, Ali; Ebrahimipour, S. Yousef

2017-06-01

This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2k-1 factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m2/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO2 adsorption.

High temperature ultrasonic immersion measurements using a BS-PT based piezoelectric transducer without a delay line

NASA Astrophysics Data System (ADS)

Bilgunde, Prathamesh N.; Bond, Leonard J.

2018-04-01

Ultrasonic imaging is a key enabling technology required for in-service inspection of advanced sodium fast reactors at the hot stand-by operating mode (˜250C). Current work presents development of a single element, 2.4MHz, planar, ultrasonic immersion transducer for a potential application in ranging, inspection and imaging of the reactor components. The prototype immersion transducer is first tested in water for three thermal cycles up to 92C. The transducer is further evaluated for four thermal cycles in silicone oil, with total seven thermal cycles that exceeded operation period of 21 hours. Moreover, the preliminary data acquired for speed of sound in silicone oil indicates 24% reduction from 22C to 142C. Sensitivity of the ultrasonic transducer is also measured as a function of temperature and demonstrates the effect of multiple thermal cycles on the transducer components.

Ozonolysis combined with ultrasound as a pretreatment of sugarcane bagasse: Effect on the enzymatic saccharification and the physical and chemical characteristics of the substrate.

PubMed

Perrone, Olavo Micali; Colombari, Felippe Mariano; Rossi, Jessika Souza; Moretti, Marcia Maria Souza; Bordignon, Sidnei Emilio; Nunes, Christiane da Costa Carreira; Gomes, Eleni; Boscolo, Mauricio; Da-Silva, Roberto

2016-10-01

Sugarcane bagasse (SCB) was treated in three stages using ozone oxidation (O), washing in an alkaline medium (B) and ultrasonic irradiation (U). The impact of each pretreatment stage on the physical structure of the SCB was evaluated by its chemical composition, using an infrared technique (FTIR-ATR), and using thermogravimetric analysis (TGA/DTG). The pretreatment sequence O, B, U provided a significant reduction of lignin and hemicellulose, which was confirmed by changes in the absorption bands corresponding to these compounds, when observed using infrared. Thermogravimetric analysis confirmed an increased thermal stability in the treated sample due to the removal of hemicellulose and extractives during the pretreatment. This pretreatment released 391mg glucose/g from treated SCB after the enzymatic hydrolysis, corresponding to a yield of 94% of the cellulose available. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experimental Design for the Evaluation of Detection Techniques of Hidden Corrosion Beneath the Thermal Protective System of the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

Kemmerer, Catherine C.; Jacoby, Joseph A.; Lomness, Janice K.; Hintze, Paul E.; Russell, Richard W.

2007-01-01

The detection of corrosion beneath Space Shuttle Orbiter thermal protective system is traditionally accomplished by removing the Reusable Surface Insulation tiles and performing a visual inspection of the aluminum substrate and corrosion protection system. This process is time consuming and has the potential to damage high cost tiles. To evaluate non-intrusive NDE methods, a Proof of Concept (PoC) experiment was designed and test panels were manufactured. The objective of the test plan was three-fold: establish the ability to detect corrosion hidden from view by tiles; determine the key factor affecting detectability; roughly quantify the detection threshold. The plan consisted of artificially inducing dimensionally controlled corrosion spots in two panels and rebonding tile over the spots to model the thermal protective system of the orbiter. The corrosion spot diameter ranged from 0.100" to 0.600" inches and the depth ranged from 0.003" to 0.020". One panel consisted of a complete factorial array of corrosion spots with and without tile coverage. The second panel consisted of randomized factorial points replicated and hidden by tile. Conventional methods such as ultrasonics, infrared, eddy current and microwave methods have shortcomings. Ultrasonics and IR cannot sufficiently penetrate the tiles, while eddy current and microwaves have inadequate resolution. As such, the panels were interrogated using Backscatter Radiography and Terahertz Imaging. The terahertz system successfully detected artificially induced corrosion spots under orbiter tile and functional testing is in-work in preparation for implementation.

Assessment of damage in ceramics and ceramic matrix composites using ultrasonic techniques

NASA Technical Reports Server (NTRS)

Chu, Y. C.; Baaklini, G. Y.; Rokhlin, S.I.

1993-01-01

This paper addresses the application of ultrasonic sensing to damage assessment in ceramics and ceramic matrix composites. It focuses on damage caused by thermal shock or oxidation at elevated temperatures, which often results in elastic anisotropy. This damaged-induced anisotropy is determined by measuring the velocities of ultrasonic waves in different propagation directions. Thermal shock damage is assessed in ceramic samples of reaction bonded silicon nitride (RBSN). Thermal shock treatment from different temperatures up to 1000 C is applied to produce the microcracks. Results indicate that most microcracks produced by thermal shock are located near sample surfaces. Ultrasonic measurements using the surface wave method are found to correlate well with measurements of degradation of mechanical properties obtained independently by other authors using destructive methods. Oxidation damage is assessed in silicon carbide fiber/reaction bonded silicon nitride matrix (SCS-6/RBSN) composites. The oxidation is done by exposing the samples in a flowing oxygen environment at elevated temperatures, up to 1400 C, for 100 hr. The Youngs' modulus in the fiber direction as obtained from ultrasonic measurements decreases significantly at 600 C but retains its original value at temperatures above 1200 C. This agrees well with the results of destructive tests by other authors. On the other hand, the transverse moduli obtained from ultrasonic measurements decrease continually until 1200 C. Measurements on the shear stiffnesses show behavior similar to the transverse moduli. The results of this work show that the damage-induced anisotropy in both ceramics and ceramic matrix composites can be determined successfully by ultrasonic methods. This suggests the possibility of assessing damage severity using ultrasonic techniques.

Proposal of ultrasonic-assisted mid-infrared spectroscopy for incorporating into daily life like smart-toilet and non-invasive blood glucose sensor

NASA Astrophysics Data System (ADS)

Kitazaki, Tomoya; Mori, Keita; Yamamoto, Naoyuki; Wang, Congtao; Kawashima, Natsumi; Ishimaru, Ichiro

2017-07-01

We proposed the extremely compact beans-size snap-shot mid-infrared spectroscopy that will be able to be built in smartphones. And also the easy preparation method of thin-film samples generated by ultrasonic standing wave is proposed. Mid-infrared spectroscopy is able to identify material components and estimate component concentrations quantitatively from absorption spectra. But conventional spectral instruments were very large-size and too expensive to incorporate into daily life. And preparations of thin-film sample were very troublesome task. Because water absorption in mid-infrared lights is very strong, moisture-containing-sample thickness should be less than 100[μm]. Thus, midinfrared spectroscopy has been utilized only by analytical experts in their laboratories. Because ultrasonic standing wave is compressional wave, we can generate periodical refractive-index distributions inside of samples. A high refractiveindex plane is correspond to a reflection boundary. When we use a several MHz ultrasonic transducer, the distance between sample surface and generated first node become to be several ten μm. Thus, the double path of this distance is correspond to sample thickness. By combining these two proposed methods, as for liquid samples, urinary albumin and glucose concentrations will be able to be measured inside of toilet. And as for solid samples, by attaching these apparatus to earlobes, the enhancement of reflection lights from near skin surface will create a new path to realize the non-invasive blood glucose sensor. Using the small ultrasonic-transducer whose diameter was 10[mm] and applied voltage 8[V], we detected the internal reflection lights from colored water as liquid sample and acrylic board as solid sample.

Environmentally friendly ultrosound synthesis and antibacterial activity of cellulose/Ag/AgCl hybrids.

PubMed

Dong, Yan-Yan; Deng, Fu; Zhao, Jin-Jin; He, Jing; Ma, Ming-Guo; Xu, Feng; Sun, Run-Cang

2014-01-01

This study aims to investigate the fabrication and property of cellulose/Ag/AgCl hybrids. In this article, preparation of cellulose/Ag/AgCl hybrids was reported using the cellulose solution, AgNO₃, AlCl₃·6H₂O with ultrasound agitation method. The cellulose solution was synthesized by the dissolution of the microcrystalline cellulose in NaOH/urea aqueous solution. Influences of the experimental parameters of ultrasound treatment time and ultrasonic intermittent on the hybrids were investigated. The phase, microstructure, thermal stability, and morphology of the hybrids were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). Results showed the successful synthesis of cellulose/Ag/AgCl hybrids with good thermal stability. Moreover, the hybrids displayed desirable antimicrobial activities. Compared with other conventional methods, the rapid, green, and environmentally friendly ultrasound agitation method opens a new window to the high value-added applications of biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

Feasibility of Using Ultrasonic Nakagami Imaging for Monitoring Microwave-Induced Thermal Lesion in Ex Vivo Porcine Liver.

PubMed

Zhang, Siyuan; Han, Yuqiang; Zhu, Xingguang; Shang, Shaoqiang; Huang, Guojing; Zhang, Lei; Niu, Gang; Wang, Supin; He, Xijing; Wan, Mingxi

2017-02-01

The feasibility of using ultrasonic Nakagami imaging to evaluate thermal lesions induced by microwave ablation (MWA) in ex vivo porcine liver was explored. Dynamic changes in echo amplitudes and Nakagami parameters in the region of the MWA-induced thermal lesion, as well as the contrast-to-noise ratio (CNR) between the MWA-induced thermal lesion and the surrounding normal tissue, were calculated simultaneously during the MWA procedure. After MWA exposure, a bright hyper-echoic region appeared in ultrasonic B-mode and Nakagami parameter images as an indicator of the thermal lesion. Mean values of the Nakagami parameter in the thermal lesion region increased to 0.58, 0.71 and 0.91 after 1, 3 and 5 min of MVA. There were no significant differences in envelope amplitudes in the thermal lesion region among ultrasonic B-mode images obtained after different durations of MWA. Unlike ultrasonic B-mode images, Nakagami images were less affected by the shadow effect in monitoring of MWA exposure, and a fairly complete hyper-echoic region was observed in the Nakagami image. The mean value of the Nakagami parameter increased from approximately 0.47 to 0.82 during MWA exposure. At the end of the postablation stage, the mean value of the Nakagami parameter decreased to 0.55 and was higher than that before MWA exposure. CNR values calculated for Nakagami parameter images increased from 0.13 to approximately 0.61 during MWA and then decreased to 0.26 at the end of the post-ablation stage. The corresponding CNR values calculated for ultrasonic B-mode images were 0.24, 0.42 and 0.17. This preliminary study on ex vivo porcine liver suggested that Nakagami imaging have potential use in evaluating the formation of MWA-induced thermal lesions. Further in vivo studies are needed to evaluate the potential application. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Application thinking on Bian-stone of the acousto-optic effect in the treatment of primary dysmenorrhea

NASA Astrophysics Data System (ADS)

Ge, Shu; Chen, Gui-Zhen; Liu, Song-Hao

2009-08-01

In order to identify the relations between the Si-Bin Bian-stone of the mineral composition characteristics and Bian-stone of the good infrared emission features. A detailed study of the Sibin Bian-stone samples was conducted by using the laser Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM). The study is to provide theoretical physical support for Bian-stone in the treatment of primary dysmenorrhea. And Thermal tomography technology (TTM) is intended to be carried out to assess the effects of Bian-stone. The Raman spectroscopic study confirmed the existence of fine-grained pyrite, anatase, calcitepyrite and graphite. It is believed that the combination of good thermal properties of the above 4 minerals make the Sibin Bian-stone as a useful material with very good physiotherapical functions. The ultrasonic has a resonance with the body's biological molecules so that it can improve meridians microcirculation. Hence, the Sibin Bian-stones can be used to make acupuncture tools for stimulating the circulation of the blood in vessels and relieving pains of human beings by utilizing its infrared thermal radiation property. TTM which accepts the heat produced by the metabolism process of life can reflect the energy status information, TTM will be introduced to evaluate effect at the overall level of the abdomen from the thermal image and analyze to derive a comprehensive diagnosis. In sum, this experiment is explored to provide a new idea for the modernization of traditional Chinese medicine.

Production of polyimide ceria nanocomposites by development of molecular hook technology in nano-sonochemistry.

PubMed

Hatami, Mehdi

2018-06-01

Poly(amic acid), the precursor of polyimide (PI), was used for the preparation of PI/CeO 2 nanocomposites (NC)s by ultrasonic assisted technique via insertion of the surface modified CeO 2 nanoparticles (NP)s into PI matrix. In the preparation stages, in the first, the modifications of CeO 2 NPs by using hexadecyltrimethoxysilane (HDTMS) as a binder were targeted using ultrasonic waves. In the second step, newly designed PI structure was formed from the sonochemical imidization process as a molecular hook. In this step two different reactions were occurred. The acetic acid elimination reaction in the main chain of macromolecule, and the acetylation reaction in the side chains of poly(amic acid) were accomplished. By acetylation process the hook structure was created for trapping of the modified nanoparticles. In the final step the preparation of PI NCs were achieved by sonochemical process. The structural and thermal properties of pure PI and PI/CeO 2 NCs were studied by several techniques such as fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and thermal analyses. FT-IR and 1 H NMR spectra confirmed the success in preparation of PI matrix. The FE-SEM, TEM, and AFM analyses showed the uniform distribution of CeO 2 NPs in PI matrix. The XRD patterns of NCs show the presence of crystalline CeO 2 NPs in amorphous PI matrix. The thermal analysis results reveal that, with increases in the content of CeO 2 NPs in PI matrix, the thermally stability factors of samples were improved. Copyright © 2018 Elsevier B.V. All rights reserved.

Passive ultrasonics using sub-Nyquist sampling of high-frequency thermal-mechanical noise.

PubMed

Sabra, Karim G; Romberg, Justin; Lani, Shane; Degertekin, F Levent

2014-06-01

Monolithic integration of capacitive micromachined ultrasonic transducer arrays with low noise complementary metal oxide semiconductor electronics minimizes interconnect parasitics thus allowing the measurement of thermal-mechanical (TM) noise. This enables passive ultrasonics based on cross-correlations of diffuse TM noise to extract coherent ultrasonic waves propagating between receivers. However, synchronous recording of high-frequency TM noise puts stringent requirements on the analog to digital converter's sampling rate. To alleviate this restriction, high-frequency TM noise cross-correlations (12-25 MHz) were estimated instead using compressed measurements of TM noise which could be digitized at a sampling frequency lower than the Nyquist frequency.

Ultrasound—biophysics mechanisms†

PubMed Central

O'Brien, William D.

2007-01-01

Ultrasonic biophysics is the study of mechanisms responsible for how ultrasound and biological materials interact. Ultrasound-induced bioeffect or risk studies focus on issues related to the effects of ultrasound on biological materials. On the other hand, when biological materials affect the ultrasonic wave, this can be viewed as the basis for diagnostic ultrasound. Thus, an understanding of the interaction of ultrasound with tissue provides the scientific basis for image production and risk assessment. Relative to the bioeffect or risk studies, that is, the biophysical mechanisms by which ultrasound affects biological materials, ultrasound-induced bioeffects are generally separated into thermal and nonthermal mechanisms. Ultrasonic dosimetry is concerned with the quantitative determination of ultrasonic energy interaction with biological materials. Whenever ultrasonic energy is propagated into an attenuating material such as tissue, the amplitude of the wave decreases with distance. This attenuation is due to either absorption or scattering. Absorption is a mechanism that represents that portion of ultrasonic wave that is converted into heat, and scattering can be thought of as that portion of the wave, which changes direction. Because the medium can absorb energy to produce heat, a temperature rise may occur as long as the rate of heat production is greater than the rate of heat removal. Current interest with thermally mediated ultrasound-induced bioeffects has focused on the thermal isoeffect concept. The non-thermal mechanism that has received the most attention is acoustically generated cavitation wherein ultrasonic energy by cavitation bubbles is concentrated. Acoustic cavitation, in a broad sense, refers to ultrasonically induced bubble activity occurring in a biological material that contains pre-existing gaseous inclusions. Cavitation-related mechanisms include radiation force, microstreaming, shock waves, free radicals, microjets and strain. It is more challenging to deduce the causes of mechanical effects in tissues that do not contain gas bodies. These ultrasonic biophysics mechanisms will be discussed in the context of diagnostic ultrasound exposure risk concerns. PMID:16934858

Characterization of sonicated natural zeolite/ferric chloride hexahydrate by infrared spectroscopy

NASA Astrophysics Data System (ADS)

Prasetyo, T. A. B.; Soegijono, B.

2018-03-01

The characteristics of sonicated Bayah natural zeolite with and without ferric chloride hexahydrate solution using infrared method has been studied. High intensity ultrasonic waves were exposed to the samples for 40 min, 80 min and 120 min. Infra red spectra analysis was conducted to evaluate zeolite vibrational spectrum contributions, namely, the vibrations from the framework of the zeolite, from the charge-balancing cations, and from the relatively isolated groups, such as the surface OH groups and their behavior after sonication process. An addition of FeCl3.6H2O and sonication process on natural zeolite improved secondary building units link by forming oxygen bridges and also close relationship with duration of applied high intensity ultrasonic process. Longer ultrasonic process resulted in more increment of O-H absorbance.

Rapid bonding enhancement by auxiliary ultrasonic actuation for the fabrication of cyclic olefin copolymer (COC) microfluidic devices

NASA Astrophysics Data System (ADS)

Yu, H.; Tor, S. B.; Loh, N. H.

2014-11-01

Thermal compression bonding is a straightforward, inexpensive and widely used method for enclosing open microchannels in thermoplastic microfluidic devices. It is advantageous over adhesive, solvent and grafting bonding methods in retaining material homogeneity. However, the trade-off between high bond strength and low microchannel deformation is always a crucial consideration in thermal compression bonding. In this study, an effective method for improving bond strength while retaining the microchannel integrity with negligible distortion is proposed and analyzed. Longitudinal ultrasonic actuation was applied to the preheated cyclic olefin copolymer (COC) substrates to achieve accelerated and enhanced bonding with an ultrasonic welding system. Intimate contact between the bonding surfaces before the ultrasonic actuation was found to be an important prior condition. With improper contact, several bonding defects would occur, such as voids, localized spot melting and edge melting. Under auxiliary ultrasonic vibration, within 10 s, the bond strength developed at the bonding interface could be dramatically improved compared with those achieved without ultrasonic actuation. The enhanced bond strength obtained at a preheating temperature of 20 °C lower than its Tg could be comparable to the strength for pure thermal compression at 5 °C higher than its Tg. It is believed that the ultrasonic energy introduced could elevate the interfacial temperature and facilitate the interdiffusion of molecular chain segments at the interface, consequently resulting in rapidly enhanced bonding. Also, the microchannel distortion after ultrasonic actuation was found to be satisfactory—another important requirement. From dynamic mechanical analysis, the glass transition temperature of COC was found to increase with increasing frequency, and the temperature of the bulk polymer under ultrasonic actuation was still well under Tg; therefore the deformation is minor under ultrasonic actuation.

Synthesis and characterization of polyaniline/MnWO4 nanocomposites as electrodes for pseudocapacitors

NASA Astrophysics Data System (ADS)

Saranya, S.; Selvan, R. Kalai; Priyadharsini, N.

2012-03-01

Polyaniline (PAni)/MnWO4 nanocomposite was successfully synthesized by in situ polymerization method under ultrasonication and the MnWO4 was prepared by surfactant assisted ultrasonication method. The thermal stability of PAni was determined by TG/DTA (Thermo Gravimetric/ Differential thermal analysis). The structural and morphological features of PAni, MnWO4 and PAni/MnWO4 composite was analyzed using Fourier transform infrared spectrometry, X-ray diffraction (XRD), scanning electron microscope (SEM) and Transmission electron microscope (TEM) images. The electro-chemical properties of PAni, MnWO4 and its composites with different weight percentage of MnWO4 loading were studied through cyclic voltammetry (CV) for the application of supercapacitors as active electrode materials. From the cyclic voltammogram, 50% of MnWO4 impregnated PAni showed a high specific capacitance (SC) of 481 F/g than their individual counterparts of PAni (396 F/g) and MnWO4 (18 F/g). The galvanostatic charge-discharge studies indicate the in situ polymerized composite shows greater specific capacitance (475 F/g) than the physical mixture (346 F/g) at a constant discharge current of 1 mA/cm2 with reasonable cycling stability. The charge transfer resistance (Rct) of PAni/MnWO4 composite (22 ohm) was calculated using electrochemical impedance spectroscopy (EIS) and compared with its physical mixture (58 ohm).

Ultrasonically-assisted Polymer Molding: An Evaluation

NASA Astrophysics Data System (ADS)

Moles, Matthew; Roy, Anish; Silberschmidt, Vadim

Energy reduction in extrusion and injection molding processes can be achieved by the introduction of ultrasonic energy. Polymer flow can be enhanced on application of ultrasonic vibration, which can reduce the thermal and pressure input requirements to produce the same molding; higher productivity may also be achieved. In this paper, a design of an ultrasound-assisted injection mold machine is explored. An extrusion-die design was augmented with a commercial 1.5 kW ultrasonic transducer and sonotrode designed to resonate close to 20 kHz with up to 100 μm vibration amplitude. The design was evaluated with modal and thermal analysis using finite-element analysis software. The use of numerical techniques, including computational fluid dynamics, fluid-structure interaction and coupled Lagrangian-Eulerian method, to predict the effect of ultrasound on polymer flow was considered. A sonotrode design utilizing ceramic to enhance thermal isolation was also explored.

Modeling of Ultrasonic and Terahertz Radiations in Defective Tiles for Condition Monitoring of Thermal Protection Systems

DTIC Science & Technology

2013-04-01

different ultrasonic and electromagnetic field modeling problems for NDE (nondestructive evaluation) applications [5- 14]. 2d . Use of the...transient ultrasonic wave propagation using the Distributed Point Source Method”, IEEE Transactions on Ultrasonics, Ferroelectric and Frequency Control...Cavity”, IEEE Transactions on Ultrasonics, Ferroelectric and Frequency Control, Vol. 57(6), pp. 1396-1404, 2010. [10] A. Shelke, S. Das and T. Kundu

Infrared laser sealing of porcine vascular tissues using a 1,470 nm diode laser: Preliminary in vivo studies.

PubMed

Cilip, Christopher M; Kerr, Duane; Latimer, Cassandra A; Rosenbury, Sarah B; Giglio, Nicholas C; Hutchens, Thomas C; Nau, William H; Fried, Nathaniel M

2017-04-01

Infrared (IR) lasers are being explored as an alternative to radiofrequency (RF) and ultrasonic (US) devices for rapid hemostasis with minimal collateral zones of thermal damage and tissue necrosis. Previously, a 1,470 nm IR laser sealed and cut ex vivo porcine renal arteries of 1-8 mm diameter in 2 seconds, yielding burst pressures greater than 1,200 mmHg and thermal coagulation zones less than 3 mm. This preliminary study describes in vivo testing of a handheld laser probe in a porcine model. A handheld prototype with vessel/tissue clasping mechanism was tested on 73 blood vessels less than 6 mm diameter using 1,470 nm laser power of 35 W for 1-5 seconds. Device power settings, irradiation time, tissue type, vessel diameter, and histology sample number were recorded for each procedure. The probe was evaluated for hemostasis after sealing isolated and bundled arteriole/venous (A/V) vasculature of porcine abdomen and hind leg. Sealed vessel samples were collected for histological analysis of lateral thermal damage. Hemostasis was achieved in 57 of 73 seals (78%). The probe consistently sealed vasculature in small bowel mesentery, mesometrium, and gastrosplenic and epiploic regions. Seal performance was less consistent on hind leg vasculature including saphenous arteries/bundles and femoral and iliac arteries. Collagen denaturation averaged 1.6 ± 0.9 mm in eight samples excised for histologic examination. A handheld laser probe sealed porcine vessels, in vivo. Further probe development and laser parameter optimization is necessary before infrared lasers may be evaluated as an alternative to RF and US vessel sealing devices. Lasers Surg. Med. 49:366-371, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Infrared thermography for inspecting of pipeline specimen

NASA Astrophysics Data System (ADS)

Chen, Dapeng; Li, Xiaoli; Sun, Zuoming; Zhang, Xiaolong

2018-02-01

Infrared thermography is a fast and effective non-destructive testing method, which has an increasing application in the field of Aeronautics, Astronautic, architecture and medical, et al. Most of the reports about the application of this technology are focus on the specimens of planar, pulse light is often used as the heat stimulation and a plane heat source is generated on the surface of the specimen by the using of a lampshade, however, this method is not suitable for the specimen of non-planar, such as the pipeline. Therefore, in this paper, according the NDT problem of a steel and composite pipeline specimen, ultrasonic and hot water are applied as the heat source respectively, and an IR camera is used to record the temperature varies of the surface of the specimen, defects are revealed by the thermal images sequence processing. Furthermore, the results of light pulse thermography are also shown as comparison, it is indicated that choose the right stimulation method, can get a more effective NDT results for the pipeline specimen.

Local defect resonance for sensitive non-destructive testing

NASA Astrophysics Data System (ADS)

Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

2016-02-01

Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

The Hit and Away technique: optimal usage of the ultrasonic scalpel in laparoscopic gastrectomy.

PubMed

Irino, Tomoyuki; Hiki, Naoki; Ohashi, Manabu; Nunobe, Souya; Sano, Takeshi; Yamaguchi, Toshiharu

2016-01-01

Thermal injury and unexpected bleeding caused by ultrasonic scalpels can lead to fatal complications in laparoscopic gastrectomy (LG), such as postoperative pancreatic fistulas (POPF). In this study, we developed the "Hit and Away" protocol for optimal usage of the ultrasonic scalpel, which in essence involves dividing tissues and vessels in batches using the tip of the scalpel to control tissue temperature. To assess the effectiveness of the technique, the surface temperature of the mesocolon of female swine after ultrasonic scalpel activations was measured, and tissue samples were collected to evaluate microscopic thermal injury to the pancreas. In parallel, we retrospectively surveyed 216 patients who had undergone LG before or after the introduction of this technique and assessed the ability of this technique to reduce POPF. The tissue temperature of the swine mesocolon reached 43 °C, a temperature at which adipose tissue melted but fibrous tissue, including vessels, remained intact. The temperature returned to baseline within 3 s of turning off the ultrasonic scalpel, demonstrating the advantage of using ultrasonic scalpel in a pulsatile manner. Tissue samples from the pancreas demonstrated that the extent of thermal injury post-procedure was limited to the capsule of the pancreas. Moreover, with respect to the clinical outcomes before and after the introduction of this technique, POPF incidence decreased significantly from 7.8 to 1.0% (p = 0.021). The "Hit and Away" technique can reduce blood loss and thermal injury to the pancreas and help to ensure the safety of lymph node dissection in LG.

Evaluation of Ultrasonic and Thermal Nondestructive Evaluation for the Characterization of Aging Degradation in Braided Composite Materials

NASA Technical Reports Server (NTRS)

Martin, Richard E.

2010-01-01

This paper examines the ability of traditional nondestructive evaluation (NDE) techniques to measure the degradation of braided polymer composite materials subjected to thermal-humidity cycling to simulate aging. A series of braided composite coupons were examined using immersion ultrasonic and pulsed thermography techniques in the as received condition. These same specimens were then examined following extended thermal-humidity cycling. Results of this examination did not show a significant change in the resulting (NDE) signals.

Nondestructive characterization of thermal barrier coating by noncontact laser ultrasonic technique

NASA Astrophysics Data System (ADS)

Zhao, Yang; Chen, Jianwei; Zhang, Zhenzhen

2015-09-01

We present the application of a laser ultrasonic technique in nondestructive characterization of the bonding layer (BL) in a thermal barrier coating (TBC). A physical mode of a multilayered medium is established to describe the propagation of a longitudinal wave generated by a laser in a TBC system. Furthermore, the theoretical analysis on the ultrasonic transmission in TBC is carried out in order to derive the expression of the BL transmission coefficient spectrum (TCS) which is used to determine the velocity of the longitudinal wave in the BL. We employ the inversion method combined with TCS to ascertain the attenuation coefficient of the BL. The experimental validations are performed with TBC specimens produced by an electron-beam physical vapor deposition method. In those experiments, a pulsed laser with a width of 10 ns is used to generate an ultrasonic signal while a two-wave mixing interferometer is created to receive the ultrasonic signals. By introducing the wavelet soft-threshold method that improves the signal-to-noise ratio, the laser ultrasonic testing results of TBC with an oxidation of 1 cycle, 10 cycles, and 100 cycles show that the attenuation coefficients of the BL become larger with an increase in the oxidation time, which is evident for the scanning electron microscopy observations, in which the thickness of the thermally grown oxide increases with oxidation time.

Electromagnetic stimulation of the ultrasonic signal for nondestructive detection of the ferromagnetic inclusions and flaws

NASA Astrophysics Data System (ADS)

Finkel, Peter

2007-03-01

It was recently shown that thermal or optical stimulation can be used to increase sensitivity of the conventional nondestructive ultrasonic detection of the small crack, flaws and inclusions in a ferromagnetic thin-walled parts. We proposed another method based on electromagnetic modulation of the ultrasonic scattered signal from the inclusions or defects. The electromagnetically induced high density current pulse produces stresses which alter the ultrasonic waves scanning the part with the defect and modulate ultrasonic signal. The excited electromagnetic field can produces crack-opening due to Lorentz forces that increase the ultrasonic reflection. The Joule heating associated with the high density current, and consequent thermal stresses may cause both crack-closure, as well as crack-opening, depending on various factors. Experimental data is presented here for the case of a small cracks near small holes in thin-walled structures. The measurements were taken at 2-10 MHz with a Lamb wave wedge transducer. It is shown that electromagnetic transient modulation of the ultrasonic echo pulse tone-burst suggest that this method could be used to enhance detection of small cracks and ferromagnetic inclusions in thin walled metallic structures.

Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO{sub 2} adsorption performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sargazi, Ghasem, E-mail: g.sargazi@gmail.com; Young Researchers Society, Shahid Bahonar University of Kerman, Kerman, Iran; Afzali, Daryoush, E-mail: daryoush_afzali@yahoo.com

2017-06-15

This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2{sup k-1} factorial design experiments, and the response surfacemore » optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m{sup 2}/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO{sub 2} adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.« less

Quantitative evaluation of hidden defects in cast iron components using ultrasound activated lock-in vibrothermography.

PubMed

Montanini, R; Freni, F; Rossi, G L

2012-09-01

This paper reports one of the first experimental results on the application of ultrasound activated lock-in vibrothermography for quantitative assessment of buried flaws in complex cast parts. The use of amplitude modulated ultrasonic heat generation allowed selective response of defective areas within the part, as the defect itself is turned into a local thermal wave emitter. Quantitative evaluation of hidden damages was accomplished by estimating independently both the area and the depth extension of the buried flaws, while x-ray 3D computed tomography was used as reference for sizing accuracy assessment. To retrieve flaw's area, a simple yet effective histogram-based phase image segmentation algorithm with automatic pixels classification has been developed. A clear correlation was found between the thermal (phase) signature measured by the infrared camera on the target surface and the actual mean cross-section area of the flaw. Due to the very fast cycle time (<30 s/part), the method could potentially be applied for 100% quality control of casting components.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montanini, R.; Freni, F.; Rossi, G. L.

This paper reports one of the first experimental results on the application of ultrasound activated lock-in vibrothermography for quantitative assessment of buried flaws in complex cast parts. The use of amplitude modulated ultrasonic heat generation allowed selective response of defective areas within the part, as the defect itself is turned into a local thermal wave emitter. Quantitative evaluation of hidden damages was accomplished by estimating independently both the area and the depth extension of the buried flaws, while x-ray 3D computed tomography was used as reference for sizing accuracy assessment. To retrieve flaw's area, a simple yet effective histogram-based phasemore » image segmentation algorithm with automatic pixels classification has been developed. A clear correlation was found between the thermal (phase) signature measured by the infrared camera on the target surface and the actual mean cross-section area of the flaw. Due to the very fast cycle time (<30 s/part), the method could potentially be applied for 100% quality control of casting components.« less

LASERUT® Technology Development Programs for the Ultrasonic Inspection of Composites in the Aerospace Industry

NASA Astrophysics Data System (ADS)

Dubois, Marc; Drake, Thomas; Osterkamp, Mark; Yawn, Ken; Kaiser, David; Do, Tho; Maestas, Jeff; Thomas, Michael

2008-02-01

A laser-ultrasonic technique developed at Lockheed Martin Aeronautics called LaserUT® is used for the ultrasonic inspection of composite parts in the aeronautic industry and has demonstrated significant reduction in inspection labor and capital expenditure over approximately 20,000 parts so far. Development of new technologies will further increase LaserUT savings: structured-light mapping, improved CO2 laser, mid-infrared generation laser, and new robotic approach. Those different technologies are described and their status relatively to their introduction to production is discussed.

Mechanical and Thermal Properties of Praseodymium Monopnictides: AN Ultrasonic Study

NASA Astrophysics Data System (ADS)

Bhalla, Vyoma; Kumar, Raj; Tripathy, Chinmayee; Singh, Devraj

2013-09-01

We have computed ultrasonic attenuation, acoustic coupling constants and ultrasonic velocities of praseodymium monopnictides PrX(X: N, P, As, Sb and Bi) along the <100>, <110>, <111> in the temperature range 100-500 K using higher order elastic constants. The higher order elastic constants are evaluated using Coulomb and Born-Mayer potential with two basic parameters viz. nearest-neighbor distance and hardness parameter in the temperature range of 0-500 K. Several other mechanical and thermal parameters like bulk modulus, shear modulus, Young's modulus, Poisson ratio, anisotropic ratio, tetragonal moduli, Breazeale's nonlinearity parameter and Debye temperature are also calculated. In the present study, the fracture/toughness (B/G) ratio is less than 1.75 which implies that PrX compounds are brittle in nature at room temperature. The chosen material fulfilled Born criterion of mechanical stability. We also found the deviation of Cauchy's relation at higher temperatures. PrN is most stable material as it has highest valued higher order elastic constants as well as the ultrasonic velocity. Further, the lattice thermal conductivity using modified approach of Slack and Berman is determined at room temperature. The ultrasonic attenuation due to phonon-phonon interaction and thermoelastic relaxation mechanisms have been computed using modified Mason's approach. The results with other well-known physical properties are useful for industrial applications.

Thermal and ultrasonic evaluation of porosity in composite laminates

NASA Technical Reports Server (NTRS)

Johnston, Patrick H.; Winfree, William P.; Long, Edward R., Jr.; Kullerd, Susan M.; Nathan, N.; Partos, Richard D.

1992-01-01

The effects of porosity on damage incurred by low-velocity impact are investigated. Specimens of graphite/epoxy composite were fabricated with various volume fractions of voids. The void fraction was independently determined using optical examination and acid resin digestion methods. Thermal diffusivity and ultrasonic attenuation were measured, and these results were related to the void volume fraction. The relationship between diffusivity and fiber volume fraction was also considered. The slope of the ultrasonic attenuation coefficient was found to increase linearly with void content, and the diffusivity decreased linearly with void volume fraction, after compensation for an approximately linear dependence on the fiber volume fraction.

Ultrasonic emissions during ice nucleation and propagation in plant xylem.

PubMed

Charrier, Guillaume; Pramsohler, Manuel; Charra-Vaskou, Katline; Saudreau, Marc; Améglio, Thierry; Neuner, Gilbert; Mayr, Stefan

2015-08-01

Ultrasonic acoustic emission analysis enables nondestructive monitoring of damage in dehydrating or freezing plant xylem. We studied acoustic emissions (AE) in freezing stems during ice nucleation and propagation, by combining acoustic and infrared thermography techniques and controlling the ice nucleation point. Ultrasonic activity in freezing samples of Picea abies showed two distinct phases: the first on ice nucleation and propagation (up to 50 AE s(-1) ; reversely proportional to the distance to ice nucleation point), and the second (up to 2.5 AE s(-1) ) after dissipation of the exothermal heat. Identical patterns were observed in other conifer and angiosperm species. The complex AE patterns are explained by the low water potential of ice at the ice-liquid interface, which induced numerous and strong signals. Ice propagation velocities were estimated via AE (during the first phase) and infrared thermography. Acoustic activity ceased before the second phase probably because the exothermal heating and the volume expansion of ice caused decreasing tensions. Results indicate cavitation events at the ice front leading to AE. Ultrasonic emission analysis enabled new insights into the complex process of xylem freezing and might be used to monitor ice propagation in natura. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Muscle Strength Endurance Testing Development Based Photo Transistor with Motion Sensor Ultrasonic

NASA Astrophysics Data System (ADS)

Rusdiana, A.

2017-03-01

The endurance of upper-body muscles is one of the most important physical fitness components. As technology develops, the process of test and assessment is now getting digital; for instance, there are a sensor stuck to the shoe (Foot Pod, Polar, and Sunto), Global Positioning System (GPS) and Differential Global Positioning System (DGPS), radar, photo finish, kinematic analysis, and photocells. Those devices aim to analyze the performances and fitness of athletes particularly the endurance of arm, chest, and shoulder muscles. In relation to that, this study attempt to create a software and a hardware for pull-ups through phototransistor with ultrasonic motion sensor. Components needed to develop this device consist of microcontroller MCS-51, photo transistor, light emitting diode, buzzer, ultrasonic sensor, and infrared sensor. The infrared sensor is put under the buffer while the ultrasonic sensor is stuck on the upper pole. The components are integrated with an LED or a laptop made using Visual Basic 12 software. The results show that pull-ups test using digital device (mean; 9.4 rep) is lower than using manual calculation (mean; 11.3 rep). This is due to the fact that digital test requires the test-takers to do pull-ups perfectly.

Ultrasonically assisted solvothermal synthesis of novel Ni/Al layered double hydroxide for capturing of Cd(II) from contaminated water

NASA Astrophysics Data System (ADS)

Rahmanian, Omid; Maleki, Mohammad Hassan; Dinari, Mohammad

2017-11-01

A novel adsorbent of nickel aluminum layered double hydroxide (Ni/Al-LDH) was prepared through the precipitation of metal nitrates by ultrasonically assisted solvothermal method. The surface morphology, chemical structure and thermal properties of this compound were examined by X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) techniques. The XRD, TEM and FE-SEM results established that the synthesized LDH have a well-ordered layer structure with good crystalline nature. Then it was applied to remove excessive Cd(II) ions from water and the effects of contact time, pH and adsorbent dose were examined at initial Cd(II) concentration of 10 mg/L. Results show that the time required to reach equilibrium was fast (40 min) and working pH solution was neutral (pH 7). Langmuir and Freundlich model of adsorption isotherms were explored; the results show that the Freundlich model was better fitted than that Langmuir model. This results predicting a multilayer adsorption of Cd(II) on LDH. The equilibrium kinetic adsorption data were fixed to the pseudo-second order kinetic equation.

Ultrasonic-assisted synthesis of ZrO2 nanoparticles and their application to improve the chemical stability of Nafion membrane in proton exchange membrane (PEM) fuel cells.

PubMed

Taghizadeh, Mohammad Taghi; Vatanparast, Morteza

2016-12-01

Zirconium dioxide (ZrO2) nanoparticles were fabricated successfully via ultrasonic-assisted method using ZrO(NO3)2·H2O, ethylenediamine and hydrazine as precursors in aqueous solution. Morphology, structure and composition of the obtained products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR) and diffuse reflectance spectroscopy (DRS). Then, the synthesized nanoparticles were used to prepare Nafion/ZrO2 nanocomposite membranes. The properties of the membranes were studied by ion exchange capacity (IEC) proton conductivity (σ), thermal stability and water uptake measurements. The ex-situ Fenton's test was used to investigate the chemical stability of the membranes. From our results, compared with Nafion membrane, the nanocomposite membrane exhibited lower fluoride release and weight loss. Therefore, it can concluded that Nafion/ZrO2 nanocomposite exhibit more chemical stability than the pure Nafion membrane. ATR-FTIR spectra and SEM surface images of membranes also confirm these results. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrasonic Sensor Signals and Optimum Path Forest Classifier for the Microstructural Characterization of Thermally-Aged Inconel 625 Alloy

PubMed Central

de Albuquerque, Victor Hugo C.; Barbosa, Cleisson V.; Silva, Cleiton C.; Moura, Elineudo P.; Rebouças Filho, Pedro P.; Papa, João P.; Tavares, João Manuel R. S.

2015-01-01

Secondary phases, such as laves and carbides, are formed during the final solidification stages of nickel-based superalloy coatings deposited during the gas tungsten arc welding cold wire process. However, when aged at high temperatures, other phases can precipitate in the microstructure, like the γ” and δ phases. This work presents an evaluation of the powerful optimum path forest (OPF) classifier configured with six distance functions to classify background echo and backscattered ultrasonic signals from samples of the inconel 625 superalloy thermally aged at 650 and 950 °C for 10, 100 and 200 h. The background echo and backscattered ultrasonic signals were acquired using transducers with frequencies of 4 and 5 MHz. The potentiality of ultrasonic sensor signals combined with the OPF to characterize the microstructures of an inconel 625 thermally aged and in the as-welded condition were confirmed by the results. The experimental results revealed that the OPF classifier is sufficiently fast (classification total time of 0.316 ms) and accurate (accuracy of 88.75% and harmonic mean of 89.52) for the application proposed. PMID:26024416

Ultrasonic sensor signals and optimum path forest classifier for the microstructural characterization of thermally-aged inconel 625 alloy.

PubMed

de Albuquerque, Victor Hugo C; Barbosa, Cleisson V; Silva, Cleiton C; Moura, Elineudo P; Filho, Pedro P Rebouças; Papa, João P; Tavares, João Manuel R S

2015-05-27

Secondary phases, such as laves and carbides, are formed during the final solidification stages of nickel-based superalloy coatings deposited during the gas tungsten arc welding cold wire process. However, when aged at high temperatures, other phases can precipitate in the microstructure, like the γ'' and δ phases. This work presents an evaluation of the powerful optimum path forest (OPF) classifier configured with six distance functions to classify background echo and backscattered ultrasonic signals from samples of the inconel 625 superalloy thermally aged at 650 and 950 °C for 10, 100 and 200 h. The background echo and backscattered ultrasonic signals were acquired using transducers with frequencies of 4 and 5 MHz. The potentiality of ultrasonic sensor signals combined with the OPF to characterize the microstructures of an inconel 625 thermally aged and in the as-welded condition were confirmed by the results. The experimental results revealed that the OPF classifier is sufficiently fast (classification total time of 0.316 ms) and accurate (accuracy of 88.75%" and harmonic mean of 89.52) for the application proposed.

Synthesis and characterization of polyurethane/CdS-SiO 2 nanocomposites via ultrasonic process

NASA Astrophysics Data System (ADS)

Chen, Jing; Zhou, Yu-Ming; Nan, Qiu-Li; Ye, Xiao-Yun; Sun, Yan-Qing; Wang, Zhi-Qiang; Zhang, Shi-Ming

2008-12-01

In this study, the high-intensity ultrasound was applied in the preparation of chiral polyurethane/CdS-SiO 2 nanocomposites. The polyurethane/CdS-SiO 2 nanocomposites were analyzed by powder X-ray diffraction, thermogravimetric analysis (TGA), TEM and SEM. The results indicated that the heat stability of the nanocomposites was improved in the presence of CdS-SiO 2 core-shell nanoparticles. The infrared emissivity (8-14 μm) study revealed that the nanocomposites possessed much lower infrared values compared with those of the neat polymers and nanoparticles, respectively. A possible mechanism of ultrasonic induced composite reaction was proposed based on the experimental results.

Interactions at the planar Ag3Sn/liquid Sn interface under ultrasonic irradiation.

PubMed

Shao, Huakai; Wu, Aiping; Bao, Yudian; Zhao, Yue; Liu, Lei; Zou, Guisheng

2017-11-01

The interactions at the interface between planar Ag 3 Sn and liquid Sn under ultrasonic irradiation were investigated. An intensive thermal grooving process occurred at Ag 3 Sn grain boundaries due to ultrasonic effects. Without ultrasonic application, planar shape of Ag 3 Sn layer gradually evolved into scalloped morphology after the solid-state Sn melting, due to a preferential dissolution of the intermetallic compounds from the regions at grain boundaries, which left behind the grooves embedding in the Ag 3 Sn layer. Under the effect of ultrasonic, stable grooves could be rapidly generated within an extremely short time (<10s) that was far less than the traditional soldering process (>10min). In addition, the deepened grooves leaded to the formation of necks at the roots of Ag 3 Sn grains, and further resulted in the strong detachment of intermetallic grains from the substrate. The intensive thermal grooving could promote the growth of Ag 3 Sn grains in the vertical direction but restrain their coarsening in the horizontal direction, consequently, an elongated morphology was presented. All these phenomena could be attributed to the acoustic cavitation and streaming effects of ultrasonic vibration. Copyright © 2017 Elsevier B.V. All rights reserved.

Mn-Doped CaBi4Ti4O15/Pb(Zr,Ti)O3 Ultrasonic Transducers for Continuous Monitoring at Elevated Temperatures

PubMed Central

Kibe, Taiga; Nagata, Hajime

2017-01-01

Continuous ultrasonic in-situ monitoring for industrial applications is difficult owing to the high operating temperatures in industrial fields. It is expected that ultrasonic transducers consisting of a CaBi4Ti4O15(CBT)/Pb(Zr,Ti)O3(PZT) sol-gel composite could be one solution for ultrasonic nondestructive testing (NDT) above 500 °C because no couplant is required and CBT has a high Curie temperature. To verify the high temperature durability, CBT/PZT sol-gel composite films were fabricated on titanium substrates by spray coating, and the CBT/PZT samples were tested in a furnace at various temperatures. Reflected echoes with a high signal-to-noise ratio were observed up to 600 °C. A thermal cycle test was conducted from room temperature to 600 °C, and no significant deterioration was found after the second thermal cycle. To investigate the long-term high-temperature durability, a CBT/PZT ultrasonic transducer was tested in the furnace at 600 °C for 36 h. Ultrasonic responses were recorded every 3 h, and the sensitivity and signal-to-noise ratio were stable throughout the experiment. PMID:29186910

Ultrasonic determination of recrystallization

NASA Technical Reports Server (NTRS)

Generazio, E. R.

1986-01-01

Ultrasonic attenuation was measured for cold worked Nickel 200 samples annealed at increasing temperatures. Localized dislocation density variations, crystalline order and colume percent of recrystallized phase were determined over the anneal temperature range using transmission electron microscopy, X-ray diffraction, and metallurgy. The exponent of the frequency dependence of the attenuation was found to be a key variable relating ultrasonic attenuation to the thermal kinetics of the recrystallization process. Identification of this key variable allows for the ultrasonic determination of onset, degree, and completion of recrystallization.

Ultrasonic versus monopolar energy-based surgical devices in terms of surgical smoke and lateral thermal damage (ULMOST): a randomized controlled trial.

PubMed

Choi, Chahien; Do, In-Gu; Song, Taejong

2018-04-09

The purpose of this study was to compare the degree of surgical smoke or vapor and lateral thermal damage caused by two different energy-based surgical devices (ESDs) used in colpotomy during total laparoscopic hysterectomy. Patients undergoing laparoscopic hysterectomy were randomly assigned to an ultrasonic ESD group (n = 20) or monopolar ESD group (n = 20). Colpotomy was performed using the assigned ESD. The degree of surgical smoke or vapor obstructing the laparoscopic view was assessed by two independent reviewers using a 5-point Likert scale, in which a higher score indicates worse visibility. The degree of the lateral thermal damage was measured as the width from the point of instrument application to the margins of the unchanged nearby tissue using a light microscope. The baseline characteristics did not statistically differ between the two groups. The degree of surgical smoke or vapor obstructing vision was 1.2 ± 0.8 points in the ultrasonic group and 3.9 ± 0.7 points in the monopolar groups (p < 0.001). The lateral thermal damage was significantly increased in the monopolar group compared to in the ultrasound group (1500 µm [1200-2500 µm] vs. 950 µm [650-1725 µm], p = 0.037). Ultrasonic ESD had better laparoscopic visibility and caused less lateral thermal damage during colpotomy compared to monopolar device.

Thermal Nondestructive Characterization of Corrosion in Boiler Tubes by Application fo a Moving Line Heat Source

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Winfree, William P.

2000-01-01

Wall thinning in utility boiler waterwall tubing is a significant inspection concern for boiler operators. Historically, conventional ultrasonics has been used lor inspection of these tubes. This technique has proved to be very labor intensive and slow. This has resulted in a "spot check" approach to inspections, making thickness measurements over a relatively small percentage of the total boiler wall area. NASA Langley Research Center has developed a thermal NDE technique designed to image and quantitatively characterize the amount of material thinning present in steel tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source, coupled with this analysis technique, represents a significant improvement in the inspection speed for large structures such as boiler waterwalls while still providing high-resolution thickness measurements. A theoretical basis for the technique will be presented thus demonstrating the quantitative nature of the technique. Further, results of laboratory experiments on flat Panel specimens with fabricated material loss regions will be presented.

Basic investigation on acoustic velocity change imaging method for quantitative assessment of fat content in human liver

NASA Astrophysics Data System (ADS)

Mano, Kazune; Tanigawa, Shohei; Hori, Makoto; Yokota, Daiki; Wada, Kenji; Matsunaka, Toshiyuki; Morikawa, Hiroyasu; Horinaka, Hiromichi

2016-07-01

Fatty liver is a disease caused by the excess accumulation of fat in the human liver. The early diagnosis of fatty liver is very important, because fatty liver is the major marker linked to metabolic syndrome. We already proposed the ultrasonic velocity change imaging method to diagnose fatty liver by using the fact that the temperature dependence of ultrasonic velocity is different in water and in fat. For the diagonosis of a fatty liver stage, we attempted a feasibility study of the quantitative assessment of the fat content in the human liver using our ultrasonic velocity change imaging method. Experimental results showed that the fat content in the tissue mimic phantom containing lard was determined by its ultrasonic velocity change in the flat temperature region formed by a circular warming ultrasonic transducer with an acoustic lens having an appropriate focal length. By considering the results of our simulation using a thermal diffusion equation, we determined whether this method could be applied to fatty liver assessment under the condition that the tissue had the thermal relaxation effect caused by blood flow.

Time reversal for ultrasonic transcranial surgery and echographic imaging

NASA Astrophysics Data System (ADS)

Tanter, Mickael; Aubry, Jean-Francois; Vignon, Francois; Fink, Mathias

2005-09-01

High-intensity focused ultrasound (HIFU) is able to induce non-invasively controlled and selective destruction of tissues by focusing ultrasonic beams within organs, analogous to a magnifying glass that concentrates enough sunlight to burn a hole in paper. The brain is an attractive organ in which to perform ultrasonic tissue ablation, but such an application has been hampered by the strong defocusing effect of the skull bone. Our group has been involved in this topic for several years, providing proofs of concept and proposing technological solutions to this problem. Thanks to a high-power time-reversal mirror, presented here are in vivo thermal lesions induced through the skull of 12 sheep. Thermal lesions were confirmed by T2-weighted magnetic resonance post-treatment images and histological examination. These results provide striking evidence that noninvasive ultrasound brain surgery is feasible. A recent approach for high-resolution brain ultrasonic imaging will also be discussed with a skull aberration correction technique based on twin arrays technology. The correction of transcranial ultrasonic images is implemented on a new generation of time-reversal mirrors relying on a fully programmable transmit and receive beamformer.

Surface modified SiO2 nanoparticles by thiamine and ultrasonication synthesis of PCL/SiO2-VB1 NCs: Morphology, thermal, mechanical and bioactivity investigations.

PubMed

Mallakpour, Shadpour; Khani, Zahra

2018-03-01

The influence of silica (SiO 2 ) nanoparticles (NPs) on the properties of polycaprolactone (PCL) was investigated. Due to the intense tendency of SiO 2 NPs to aggregation and their high surface energy, the surface of SiO 2 NPs was treatment via Vitamin B 1 (VB 1 ) as a biosafe coupling agent. Novel PCL/SiO 2 -VB 1 nanocomposites (NC) films by variety of percentage of SiO 2 -VB 1 NPs were prepared under ultrasonic irradiation as an eco-friendly and fast procedure following by casting method. Fourier transform infrared spectroscopy and energy dispersive X-ray analysis exposed the presence of SiO 2 NPs into the polymer matrix. A good distribution of the silica into the polymer matrix was detected by microscopic observations and EDX testing. According to the UV-Vis spectra, the absorption of prepared NCs was improved via increasing the amount of SiO 2 NPs. PCL/SiO 2 -VB 1 NCs showed more thermal stability compared to the pure polymer. The tensile test was investigated and good arrangement among the experimental data and the predicted flexibility of NCs was obtained. Moreover, PCL/SiO 2 -VB 1 6wt% had noticeable increase values for tensile strength. Finally, in vitro bioactivity investigation designated that by rising SiO 2 contents in the NCs, the amount of the hydroxyapatite formed was increased and NC films are bioactive and have a potential to be utilized in bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

Detecting water in aviation honeycomb structures by using transient infrared thermographic NDT

NASA Astrophysics Data System (ADS)

Vavilov, Vladimir P.; Klimov, Alexey G.; Nesteruk, Dmitry; Shiryaev, Vladimir V.

2003-04-01

A lot of structural key elements of many modern civilian and military airplanes, such as flaps, keel, etc., are made of honeycomb structures. Honeycombs involve a combination of some materials including aluminum, Nomex, glass and graphite epoxy composites. During exploitation, atmosphere water could penetrate these structures due to possible imperfections in various junctions, and, thus, deteriorate airplane durability. In Russia, water in honeycombs is typically detected by using the X ray and ultrasonic technique. However, the X ray equipment is hardly accepted by commercial airlines because of the safety reason, and the point-by-point ultrasonic inspection is low-productive. Since 2002, we develop the IR thermographic method of detecting water by thermally stimulating aviation panels under test. Unlike the technique accepted by Airbus Industry, Inc., that uses 'a warm blanket', we use a powerful optical heater assembled with an IR camera into a single set. The first stage of research included modeling the detection process and optimizing the experimental procedure. As a result, we have demonstrated that, due to the high heat capacity of water, a temperature signal over moist areas evolves in time during a relatively long period that relaxes the requirements to the test protocol. Thus, even aluminum panels can be thermally stimulated during few seconds with a delay time being also in a few second range. A similar protocol can be applied to the inspection of composite honeycombs where the image quality resembles that obtained by X rays. The paper will describe all stages of the research starting from modeling and finishing with the preliminary experimental results obtained in situ on civilian airplanes.

Experimental Investigation on Thermal Effects in Ultrasonic Joining of Thin Poly(ethylene terephthalate) Films Using Torsional Vibrations

NASA Astrophysics Data System (ADS)

Adachi, Kazunari; Uchiyama, Kenta; Kuriyama, Takashi; Miyata, Ken; Hisamatsu, Tokuro

2009-11-01

The authors previously determined that thermal effects are not a dominant factor in the ultrasonic joining of very low density polyethylene (VLDPE) films using torsional vibration. Now, to confirm that the plastic materials are not “melted” by mechanically generated heat in the joining, they have conducted joining experiments for thin poly(ethylene terephthalate) (PET) films. The temperature at the interface of two PET films of 0.1 mm thickness only increased to approximately 100 °C, and no trace of liquidation of the material was observed at the interface under a polarizing microscope. Investigation using a differential scanning calorimeter (DSC) revealed that the “melting point” of PET is about 260 °C, and an ultrasonically joined specimen showed no significant difference in thermal characteristics compared with an intact PET film. It was also determined that the PET films cannot be joined even after being pressed together for a period of 30 min or longer at approximately 150 °C. From the results obtained using the microscope and the DSC, the authors conclude that melting of the materials plays essentially no role in ultrasonic plastic joining.

Effect of Heat Generation of Ultrasound Transducer on Ultrasonic Power Measured by Calorimetric Method

NASA Astrophysics Data System (ADS)

Uchida, Takeyoshi; Kikuchi, Tsuneo

2013-07-01

Ultrasonic power is one of the key quantities closely related to the safety of medical ultrasonic equipment. An ultrasonic power standard is required for establishment of safety. Generally, an ultrasonic power standard below approximately 20 W is established by the radiation force balance (RFB) method as the most accurate measurement method. However, RFB is not suitable for high ultrasonic power because of thermal damage to the absorbing target. Consequently, an alternative method to RFB is required. We have been developing a measurement technique for high ultrasonic power by the calorimetric method. In this study, we examined the effect of heat generation of an ultrasound transducer on ultrasonic power measured by the calorimetric method. As a result, an excessively high ultrasonic power was measured owing to the effect of heat generation from internal loss in the transducer. A reference ultrasound transducer with low heat generation is required for a high ultrasonic power standard established by the calorimetric method.

Physics of direct-contact ultrasonic cloth drying process

DOE PAGES

Peng, Chang; Ravi, Saitej; Patel, Viral K.; ...

2017-02-27

Existing methods of drying fabrics involve energy-intensive thermal evaporation of moisture from clothes. Drying fabrics using high-frequency vibrations of piezoelectric transducers can substantially reduce drying time and energy consumption. In this method, vibrational energy generates instability on the liquid-air interface and mechanically ejects water from a wet fabric. For the first time, the physics of the ultrasonic fabric drying process in direct-contact mode is studied. The kinematic and thermal responses of water droplets and fabrics on piezoelectric crystal transducers and metal mesh–based transducers are studied. The results suggest that on piezoelectric crystal transducers, the response of a droplet subjected tomore » ultrasonic excitation is dictated by the relative magnitude of the surface tension and the ultrasonic excitation forces. The drying process for a fabric on the studied transducers consists of two regimes—vibrational and thermal. When the water content is high, the vibrational forces can eject bulk water rapidly. But the more strongly bound water within the smaller fabric pores evaporates by the thermal energy generated as a result of the viscous losses. Our study finds that a metal mesh–based transducer is more suitable for dewatering fabrics, as it facilitates the ejection of water from the fabric–transducer interface to the opposite side of the mesh. A demonstration unit developed consumes 10–20% of the water latent heat energy at water contents greater than 20%.« less

Physics of direct-contact ultrasonic cloth drying process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Chang; Ravi, Saitej; Patel, Viral K.

Existing methods of drying fabrics involve energy-intensive thermal evaporation of moisture from clothes. Drying fabrics using high-frequency vibrations of piezoelectric transducers can substantially reduce drying time and energy consumption. In this method, vibrational energy generates instability on the liquid-air interface and mechanically ejects water from a wet fabric. For the first time, the physics of the ultrasonic fabric drying process in direct-contact mode is studied. The kinematic and thermal responses of water droplets and fabrics on piezoelectric crystal transducers and metal mesh–based transducers are studied. The results suggest that on piezoelectric crystal transducers, the response of a droplet subjected tomore » ultrasonic excitation is dictated by the relative magnitude of the surface tension and the ultrasonic excitation forces. The drying process for a fabric on the studied transducers consists of two regimes—vibrational and thermal. When the water content is high, the vibrational forces can eject bulk water rapidly. But the more strongly bound water within the smaller fabric pores evaporates by the thermal energy generated as a result of the viscous losses. Our study finds that a metal mesh–based transducer is more suitable for dewatering fabrics, as it facilitates the ejection of water from the fabric–transducer interface to the opposite side of the mesh. A demonstration unit developed consumes 10–20% of the water latent heat energy at water contents greater than 20%.« less

Effect of dissolved oxygen level of water on ultrasonic power measured using calorimetry

NASA Astrophysics Data System (ADS)

Uchida, Takeyoshi; Yoshioka, Masahiro; Horiuchi, Ryuzo

2018-07-01

Ultrasonic therapeutic equipment, which exposes the human body to high-power ultrasound, is used in clinical practice to treat cancer. However, the safety of high-power ultrasound has been questioned because the equipment affects not only cancer cells but also normal cells. To evaluate the safety of ultrasound, it is necessary to accurately measure the ultrasonic power of the equipment. This is because ultrasonic power is a key quantity related to the thermal hazard of ultrasound. However, precise techniques for measuring ultrasonic power in excess of 15 W are yet to be established. We have been studying calorimetry as a precise measurement technique. In this study, we investigated the effect of the dissolved oxygen (DO) level of water on ultrasonic power by calorimetry. The results show that the measured ultrasonic power differed significantly between water samples of different DO levels. This difference in ultrasonic power arose from acoustic cavitation.

Ultrasonic attenuation measurements determine onset, degree, and completion of recrystallization

NASA Technical Reports Server (NTRS)

Generazio, E. R.

1988-01-01

Ultrasonic attenuation was measured for cold worked Nickel 200 samples annealed at increasing temperatures. Localized dislocation density variations, crystalline order and volume percent of recrystallized phase were determined over the anneal temperature range using transmission electron microscopy, X-ray diffraction, and metallurgy. The exponent of the frequency dependence of the attenuation was found to be a key variable relating ultrasonic attenuation to the thermal kinetics of the recrystallization process. Identification of this key variable allows for the ultrasonic determination of onset, degree, and completion of recrystallization.

Synthesis and Thermal Characterization of Hydroxyapatite Powders Obtained by Sol-Gel Technique

NASA Astrophysics Data System (ADS)

Jiménez-Flores, Y.; Camacho, N.; Rojas-Trigos, J. B.; Suárez, M.

The development of bioactive materials presents an interesting and an extremely relevant problem to solve, in the development of customized cranial and maxillofacial prosthesis, bioactive coating, and cements, for example. In such areas, one of the more employed materials is the synthetic hydroxyapatite, due to its proved biocompatibility with the human body; however, there are few studies about the thermal affinity with the biological surroundings, and most of them are centered in the thermal stability of the hydroxyapatite instead of its transient thermal response. In the present paper, the synthesis and physical-chemical characterization of hydroxyapatite samples, obtained by the sol-gel technique employing ultrasonic mixing, are reported. Employing X-ray diffraction patterns, XEDS and FTIR spectra, the crystal symmetry, chemical elements, and the present functional groups of the studied samples were determined and found to correspond to those reported in the literature, with a stoichiometry close to the ideal for biological applications. Additionally, by means of the photoacoustic detection and infrared photothermal radiometry (IPTR) techniques, the thermal response of the samples was obtained. Analyzing the photoacoustic data, the synthetized samples show photoacoustic opaqueness, responding in the thermally thick regime in the measurement range, and their thermal effusivity was also determined, having values of 1.47 folds the thermal effusivity of the mandibular human bone. Finally, from the IPTR measurements, the thermal diffusivity and thermal conductivity of the samples were also determined, having good agreement with the reported values for synthetic hydroxyapatite. The structural and thermophysical properties of the here reported samples show that the synthesized samples have good thermal affinity with the mandibular human bone tissue, and are suitable for biomedical applications.

Ultrasonically Encoded Photoacoustic Flowgraphy in Biological Tissue

NASA Astrophysics Data System (ADS)

Wang, Lidai; Xia, Jun; Yao, Junjie; Maslov, Konstantin I.; Wang, Lihong V.

2013-11-01

Blood flow speed is an important functional parameter. Doppler ultrasound flowmetry lacks sufficient sensitivity to slow blood flow (several to tens of millimeters per second) in deep tissue. To address this challenge, we developed ultrasonically encoded photoacoustic flowgraphy combining ultrasonic thermal tagging with photoacoustic imaging. Focused ultrasound generates a confined heat source in acoustically absorptive fluid. Thermal waves propagate with the flow and are directly visualized in pseudo color using photoacoustic computed tomography. The Doppler shift is employed to calculate the flow speed. This method requires only acoustic and optical absorption, and thus is applicable to continuous fluid. A blood flow speed as low as 0.24mm·s-1 was successfully measured. Deep blood flow imaging was experimentally demonstrated under 5-mm-thick chicken breast tissue.

The effects of crystal proximity and crystal-binder adhesion on the thermal responses of ultrasonically-excited composite energetic materials

NASA Astrophysics Data System (ADS)

Roberts, Z. A.; Casey, A. D.; Gunduz, I. E.; Rhoads, J. F.; Son, S. F.

2017-12-01

Composite energetic materials have been shown to generate heat under certain ultrasonic excitations, enough to drive rapid reactions in some cases. In an attempt to isolate the proposed heat generation mechanisms of frictional and viscoelastic heating at crystal-crystal and crystal-binder interfaces, a systematic study was conducted with cyclotetramethylene-tetranitramine crystals arranged as discrete inclusions within Sylgard 184 binder. Groups of three embedded crystals, or "triads," were arranged in two geometries with the crystals either in contact or slightly separated. Additionally, samples with good crystal-binder adhesion as well as ones mechanically debonded using compression were considered. The samples were excited ultrasonically with a contact piezoelectric transducer, and the top surface of each sample was monitored via infrared thermography. The contacting triads showed evidence of an intense localized heat source conducting to the polymer surface above the crystal locations in contrast to the separated triads. The debonded samples of both types reached higher maximum surface temperatures, on average. The results of both two-way and nested analysis of variance indicate a statistically significant difference for both adhesion and separation distance on temperature rise. We conclude that friction between crystal contact points and a debonded, moving binder at the crystal interface (also a mode of friction) play a significant role in localized heat generation, while viscoelastic/viscoplastic heating appears comparatively minor for these specific excitation conditions. The significance of frictional heat generation over viscoelastic heating in these systems may influence future design considerations related to the selection of binder materials for composite energetic materials.

Novel characterization method for fibrous materials using non-contact acoustics: material properties revealed by ultrasonic perturbations.

PubMed

Periyaswamy, Thamizhisai; Balasubramanian, Karthikeyan; Pastore, Christopher

2015-02-01

Fibrous materials are unique hierarchical complex structures exhibiting a range of mechanical, thermal, optical and electrical properties. The inherent discontinuity at micro and macro levels, heterogeneity and multi-scale porosity differentiates fibrous materials from other engineering materials that are typically continuum in nature. These structural complexities greatly influence the techniques and modalities that can be applied to characterize fibrous materials. Typically, the material response to an applied external force is measured and used as a characteristic number of the specimen. In general, a range of equipment is in use to obtain these numbers to signify the material properties. Nevertheless, obtaining these numbers for materials like fiber ensembles is often time consuming, destructive, and requires multiple modalities. It is hypothesized that the material response to an applied acoustic frequency would provide a robust alternative characterization mode for rapid and non-destructive material analysis. This research proposes applying air-coupled ultrasonic acoustics to characterize fibrous materials. Ultrasonic frequency waves transmitted through fibrous assemblies were feature extracted to understand the correlation between the applied frequency and the material properties. Mechanical and thermal characteristics were analyzed using ultrasonic features such as time of flight, signal velocity, power and the rate of attenuation of signal amplitude. Subsequently, these temporal and spectral characteristics were mapped with the standard low-stress mechanical and thermal properties via an empirical artificial intelligence engine. A high correlation of >0.92 (S.D. 0.06) was observed between the ultrasonic features and the standard measurements. The proposed ultrasonic technique can be used toward rapid characterization of dynamic behavior of flexible fibrous assemblies. Copyright © 2014 Elsevier B.V. All rights reserved.

High Thermal Dissipation of Al Heat Sink When Inserting Ceramic Powders by Ultrasonic Mechanical Coating and Armoring

PubMed Central

Tsai, Wei-Yu; Huang, Guan-Rong; Wang, Kuang-Kuo; Chen, Chin-Fu; Huang, J. C.

2017-01-01

Aluminum alloys, which serve as heat sink in light-emitting diode (LED) lighting, are often inherent with a high thermal conductivity, but poor thermal total emissivity. Thus, high emissive coatings on the Al substrate can enhance the thermal dissipation efficiency of radiation. In this study, the ultrasonic mechanical coating and armoring (UMCA) technique was used to insert various ceramic combinations, such as Al2O3, SiO2, or graphite, to enhance thermal dissipation. Analytic models have been established to couple the thermal radiation and convection on the sample surface through heat flow equations. A promising match has been reached between the theoretical predictions and experimental measurements. With the adequate insertion of ceramic powders, the temperature of the Al heat sinks can be lowered by 5–11 °C, which is highly favorable for applications requiring cooling components. PMID:28772814

High Thermal Dissipation of Al Heat Sink When Inserting Ceramic Powders by Ultrasonic Mechanical Coating and Armoring.

PubMed

Tsai, Wei-Yu; Huang, Guan-Rong; Wang, Kuang-Kuo; Chen, Chin-Fu; Huang, J C

2017-04-26

Aluminum alloys, which serve as heat sink in light-emitting diode (LED) lighting, are often inherent with a high thermal conductivity, but poor thermal total emissivity. Thus, high emissive coatings on the Al substrate can enhance the thermal dissipation efficiency of radiation. In this study, the ultrasonic mechanical coating and armoring (UMCA) technique was used to insert various ceramic combinations, such as Al₂O₃, SiO₂, or graphite, to enhance thermal dissipation. Analytic models have been established to couple the thermal radiation and convection on the sample surface through heat flow equations. A promising match has been reached between the theoretical predictions and experimental measurements. With the adequate insertion of ceramic powders, the temperature of the Al heat sinks can be lowered by 5-11 °C, which is highly favorable for applications requiring cooling components.

Nanocomposite materials based on poly(vinyl chloride) and bovine serum albumin modified ZnO through ultrasonic irradiation as a green technique: Optical, thermal, mechanical and morphological properties.

PubMed

Mallakpour, Shadpour; Darvishzadeh, Marzieh

2018-03-01

In this project, physicochemical properties of poly(vinyl chloride) (PVC) reinforced by ZnO nanoparticles (NPs) were studied. Firstly, ZnO NPs were modified with bovine serum albumin (BSA) as an organo-modifier and biocompatible substance through ultrasound irradiation as environmental friendly, low cost and rapid means. Nanocomposite (NC) films were prepared by loadings of various ratios of ZnO/BSA NPs (3, 6 and 9wt%) inside the PVC. Structural morphology and physical properties of the ZnO-BSA NPs and NC films were investigated via Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis (TGA), transmission electron microscopy and field emission scanning electron microscopy. According to the obtained information from the TGA, an increase in the thermal stability can be clearly observed. Also the results of contact angle analysis indicated with increasing percent of ZnO/BSA NPs into PVC the hydrophilic behaviors of NCs were increased. Copyright © 2017 Elsevier B.V. All rights reserved.

A comparative scanning electron microscopy study between hand instrument, ultrasonic scaling and erbium doped:Yttirum aluminum garnet laser on root surface: A morphological and thermal analysis

PubMed Central

Mishra, Mitul Kumar; Prakash, Shobha

2013-01-01

Background and Objectives: Scaling and root planing is one of the most commonly used procedures for the treatment of periodontal diseases. Removal of calculus using conventional hand instruments is incomplete and rather time consuming. In search of more efficient and less difficult instrumentation, investigators have proposed lasers as an alternative or as adjuncts to scaling and root planing. Hence, the purpose of the present study was to evaluate the effectiveness of erbium doped: Yttirum aluminum garnet (Er:YAG) laser scaling and root planing alone or as an adjunct to hand and ultrasonic instrumentation. Subjects and Methods: A total of 75 freshly extracted periodontally involved single rooted teeth were collected. Teeth were randomly divided into five treatment groups having 15 teeth each: Hand scaling only, ultrasonic scaling only, Er:YAG laser scaling only, hand scaling + Er:YAG laser scaling and ultrasonic scaling + Er:YAG laser scaling. Specimens were subjected to scanning electron microscopy and photographs were evaluated by three examiners who were blinded to the study. Parameters included were remaining calculus index, loss of tooth substance index, roughness loss of tooth substance index, presence or absence of smear layer, thermal damage and any other morphological damage. Results: Er:YAG laser treated specimens showed similar effectiveness in calculus removal to the other test groups whereas tooth substance loss and tooth surface roughness was more on comparison with other groups. Ultrasonic treated specimens showed better results as compared to other groups with different parameters. However, smear layer presence was seen more with hand and ultrasonic groups. Very few laser treated specimens showed thermal damage and morphological change. Interpretation and Conclusion: In our study, ultrasonic scaling specimen have shown root surface clean and practically unaltered. On the other hand, hand instrument have produced a plane surface, but removed more tooth structure. The laser treated specimens showed rough surfaces without much residual deposit or any other sign of morphological change. PMID:24015009

Methods of measurement for semiconductor materials, process control, and devices

NASA Technical Reports Server (NTRS)

Bullis, W. M. (Editor)

1972-01-01

Activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices are described. Accomplishments include the determination of the reasons for differences in measurements of transistor delay time, identification of an energy level model for gold-doped silicon, and the finding of evidence that it does not appear to be necessary for an ultrasonic bonding tool to grip the wire and move it across the substrate metallization to make the bond. Work is continuing on measurement of resistivity of semiconductor crystals; study of gold-doped silicon; development of the infrared response technique; evaluation of wire bonds and die attachment; measurement of thermal properties of semiconductor devices, delay time, and related carrier transport properties in junction devices, and noise properties of microwave diodes; and characterization of silicon nuclear radiation detectors.

Safety assessment of the use of ultrasonic energy in the proximity of the recurrent laryngeal nerve in a porcine model.

PubMed

Chávez, Karla V; Barajas, Elpidio M; Soroa, Francisco; Gamboa-Dominguez, Armando; Ordóñez, Samuel; Pantoja, Juan P; Sierra, Mauricio; Velázquez-Fernández, David; Herrera, Miguel F

2018-01-01

Advanced bipolar and ultrasonic energy have demonstrated reduction of operating time and blood loss in thyroidectomy. However, these devices generate heat and thermal dispersion that may damage adjacent structures such as the recurrent laryngeal nerve (RLN). This study was designed to evaluate the safety profile of the Harmonic Focus+ ® (HF+) device through the evaluation of thermal injury to the RLN using different algorithms of distance and time with state of the art technology. 25 Vietnamese pigs underwent activation of HF+ in the proximity of their RLN. They were divided into 4 groups according to activation distance (3 mm, 2 mm, 1 mm and on the RLN). Time of activation, time between tones of the ultrasonic generator, changes in the electromyographic signal using continuous nerve neuromonitoring, vocal fold mobility assessed by direct laryngoscopy and histological thermal damaged were evaluated. None of the pigs had loss of signal in the electromyography during the procedure; only one pig had isolated transient decrease in amplitude and one increase in latency. One pig had transient vocal fold paresis in the group with activation on the nerve. Evaluation of the nerves by histology and immunohistochemistry did not show significant changes attributed to thermal injury. The use of ultrasonic energy close to the RLN is safe, provided that activation time does not exceed the necessary time to safely transect the tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

Apparatus and method for transient thermal infrared spectrometry of flowable enclosed materials

DOEpatents

McClelland, John F.; Jones, Roger W.

1993-03-02

A method and apparatus for enabling analysis of a flowable material enclosed in a transport system having an infrared transparent wall portion. A temperature differential is transiently generated between a thin surface layer portion of the material and a lower or deeper portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material, and the altered thermal infrared emission spectrum is detected through the infrared transparent portion of the transport system while the altered thermal infrared emission spectrum is sufficiently free of self-absorption by the material of emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower or deeper portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation. By such detection, the detected altered thermal infrared emission spectrum is indicative of characteristics relating to molecular composition of the material.

Effects of thermal treatment and sonication on quality attributes of Chokanan mango (Mangifera indica L.) juice.

PubMed

Santhirasegaram, Vicknesha; Razali, Zuliana; Somasundram, Chandran

2013-09-01

Ultrasonic treatment is an emerging food processing technology that has growing interest among health-conscious consumers. Freshly squeezed Chokanan mango juice was thermally treated (at 90 °C for 30 and 60s) and sonicated (for 15, 30 and 60 min at 25 °C, 40 kHz frequency, 130 W) to compare the effect on microbial inactivation, physicochemical properties, antioxidant activities and other quality parameters. After sonication and thermal treatment, no significant changes occurred in pH, total soluble solids and titratable acidity. Sonication for 15 and 30 min showed significant improvement in selected quality parameters except color and ascorbic acid content, when compared to freshly squeezed juice (control). A significant increase in extractability of carotenoids (4-9%) and polyphenols (30-35%) was observed for juice subjected to ultrasonic treatment for 15 and 30 min, when compared to the control. In addition, enhancement of radical scavenging activity and reducing power was observed in all sonicated juice samples regardless of treatment time. Thermal and ultrasonic treatment exhibited significant reduction in microbial count of the juice. The results obtained support the use of sonication to improve the quality of Chokanan mango juice along with safety standard as an alternative to thermal treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

The comparison of thermal tissue injuries caused by ultrasonic scalpel and electrocautery use in rabbit tongue tissue

PubMed Central

Beriat, Guclu Kaan; Akmansu, Sefik Halit; Ezerarslan, Hande; Dogan, Cem; Han, Unsal; Saglam, Mehmet; Senel, Oytun Okan; Kocaturk, Sinan

2012-01-01

The aim of this study compares to the increase in tissue temperature and the thermal histological effects of ultrasonic scalpel, bipolar and unipolar electrosurgery incisions in the tongue tissue of rabbits. This study evaluates the histopathological changes related to thermal change and the maximum temperature values in the peripheral tissue brought about by the incisions carried out by the three methods in a comparative way. To assess thermal tissue damage induced by the three instruments, maximum tissue temperatures were measured during the surgical procedure and tongue tissue samples were examined histopathologically following the surgery. The mean maximum temperature values of the groups were 93.93±2.76 C° for the unipolar electrocautery group, whereas 85.07±5.95 C° for the bipolar electrocautery group, and 108.23±7.64 C° for the ultrasonic scalpel group. There was a statistically significant relationship between the increase in maximum temperature values and the separation among tissue layers, edema, congestion, necrosis, hemorrhage, destruction in blood vessel walls and fibrin accumulation, and between the existence of fibrin thrombus and tissue damage depth (p<0.05). It was concluded that the bipolar electrocautery use gives way to less temperature increase in the tissues and less thermal tissue damage in comparison to the other methods. PMID:22938541

Synthesis of porous Cu-BTC with ultrasonic treatment: Effects of ultrasonic power and solvent condition.

PubMed

Israr, Farrukh; Kim, Duk Kyung; Kim, Yeongmin; Oh, Seung Jin; Ng, Kim Choon; Chun, Wongee

2016-03-01

Cu-BTC (BTC=1,3,5-benzenetricarboxylate) metal organic framework (MOF) was synthesized using different solvent conditions with ultrasonic treatment. Solvent mixtures of water/N,N-dimethylformamide (DMF), water/ethanol were used for the reactions with or without a variety of bases under 20 kHz ultrasonically treated conditions. Prepared crystals were purified through 30 min of sonication to remove unreacted chemicals. Treatment time and ultrasonic power effects were compared to get optimum synthetic condition. The characterization of MOF powders was performed by scanning electron microscopy, X-ray powder diffraction, infrared-spectroscopy, thermo-gravimetric analysis and specific surface determination using the BET method. Isolated crystal yields varied with different solvent and applied ultrasonic power conditions. A high isolated crystal yield of 86% was obtained from water/ethanol/DMF solvent system after 120 min of ultrasonic treatment at 40% power of 750 W. Different solvent conditions led to the formation of Cu-BTC with different surface area, and an extremely high surface area of 1430 m(2)/g was obtained from the crystals taken with the solvent condition of water:DMF=70:30. Copyright © 2015 Elsevier B.V. All rights reserved.

Hot spots in energetic materials generated by infrared and ultrasound, detected by thermal imaging microscopy.

PubMed

Chen, Ming-Wei; You, Sizhu; Suslick, Kenneth S; Dlott, Dana D

2014-02-01

We have observed and characterized hot spot formation and hot-spot ignition of energetic materials (EM), where hot spots were created by ultrasonic or long-wavelength infrared (LWIR) exposure, and were detected by high-speed thermal microscopy. The microscope had 15-20 μm spatial resolution and 8.3 ms temporal resolution. LWIR was generated by a CO2 laser (tunable near 10.6 μm or 28.3 THz) and ultrasound by a 20 kHz acoustic horn. Both methods of energy input created spatially homogeneous energy fields, allowing hot spots to develop spontaneously due to the microstructure of the sample materials. We observed formation of hot spots which grew and caused the EM to ignite. The EM studied here consisted of composite solids with 1,3,5-trinitroperhydro-1,3,5-triazine crystals and polymer binders. EM simulants based on sucrose crystals in binders were also examined. The mechanisms of hot spot generation were different with LWIR and ultrasound. With LWIR, hot spots were most efficiently generated within the EM crystals at LWIR wavelengths having longer absorption depths of ∼25 μm, suggesting that hot spot generation mechanisms involved localized absorbing defects within the crystals, LWIR focusing in the crystals or LWIR interference in the crystals. With ultrasound, hot spots were primarily generated in regions of the polymer binder immediately adjacent to crystal surfaces, rather than inside the EM crystals.

Kinetics and mechanism of nickel ferrite formation under high temperature ultrasonic treatment.

PubMed

Baranchikov, Alexander Ye; Ivanov, Vladimir K; Tretyakov, Yuri D

2007-02-01

The effect of simultaneous ultrasonic and thermal treatment on kinetics and mechanism of nickel ferrite formation was studied. It was established that sonication leads to notable increase of the mean rate of this reaction and decrease of effective activation energy from 190+/-5 to 125+/-7 kJ/mol. XRD data show that ultrasonic treatment significantly affects the microstructure of both initial reagent (Fe(2)O(3)) and reaction product (NiFe(2)O(4)) thus promoting formation of well developed reaction zone. A general model of ferrite formation mechanism under high temperature ultrasonic treatment was proposed.

Structural study of some divalent aluminoborate glasses using ultrasonic and positron annihilation techniques

NASA Astrophysics Data System (ADS)

Saddeek, Yasser B.; Mohamed, Hamdy F. M.; Azooz, Moenis A.

2004-07-01

Positron annihilation lifetime (PAL), ultrasonic techniques, and differential thermal analysis (DTA) were performed to study the structure of some aluminoborate glasses. The basic compositions of these glasses are 50 B2O3 + 10 Al2O3 + 40 RO (wt%), where RO is the divalent oxide (MgO, CaO, SrO, and CdO). The ultrasonic data show that the rigidity increases from MgO to CaO then decrease at SrO and again increases at CdO. The glass transition temperature (determined from DTA) decreases from MgO to SrO then increases at CdO. The trend of the thermal properties was attributed to thermal stability. The experimental data are correlated with the internal glass structure and its connectivity. The PAL data show that an inversely correlation between the relative fractional of the open hole volume and the density of the samples. Also, there is a good correlation between the ortho-positronium (o-Ps) lifetime (open hole volume size) and the bulk modulus of the samples (determined from ultrasonic technique). The open volume hole size distribution for the samples shows that the open volume holes expand in size for CaO, SrO, MgO, and CdO, respectively with their distribution function moving to higher volume size.

Effects of ultrasonication and conventional mechanical homogenization processes on the structures and dielectric properties of BaTiO3 ceramics.

PubMed

Akbas, Hatice Zehra; Aydin, Zeki; Yilmaz, Onur; Turgut, Selvin

2017-01-01

The effects of the homogenization process on the structures and dielectric properties of pure and Nb-doped BaTiO 3 ceramics have been investigated using an ultrasonic homogenization and conventional mechanical methods. The reagents were homogenized using an ultrasonic processor with high-intensity ultrasonic waves and using a compact mixer-shaker. The components and crystal types of the powders were determined by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. The complex permittivity (ε ' , ε″) and AC conductivity (σ') of the samples were analyzed in a wide frequency range of 20Hz to 2MHz at room temperature. The structures and dielectric properties of pure and Nb-doped BaTiO 3 ceramics strongly depend on the homogenization process in a solid-state reaction method. Using an ultrasonic processor with high-intensity ultrasonic waves based on acoustic cavitation phenomena can make a significant improvement in producing high-purity BaTiO 3 ceramics without carbonate impurities with a small dielectric loss. Copyright © 2016 Elsevier B.V. All rights reserved.

Tracking Polymer Cure Via Embedded Optical Fibers

NASA Technical Reports Server (NTRS)

Dean, David L.; Davidson, T. Fred

1993-01-01

Fourier-transform infrared spectroscopy applied in interior of specimen of material by bringing infrared light through specimen in optical fiber. Light interacts with material via evanescent-wave effect. Spectra obtained in this way at various times during curing process also combined with data from ultrasonic, thermographic, and dielectric-impedance monitoring, and other measurement techniques to obtain more complete characterization of progress of curing process.

Apparatus and method for transient thermal infrared spectrometry

DOEpatents

McClelland, John F.; Jones, Roger W.

1991-12-03

A method and apparatus for enabling analysis of a material (16, 42) by applying a cooling medium (20, 54) to cool a thin surface layer portion of the material and to transiently generate a temperature differential between the thin surface layer portion and the lower portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material. The altered thermal infrared emission spectrum of the material is detected by a spectrometer/detector (28, 50) while the altered thermal infrared emission spectrum is sufficiently free of self-absorption by the material of the emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation, so that the detected altered thermal infrared emission spectrum is indicative of the characteristics relating to the molecular composition of the material.

Synthesis and structural characteristics of high surface area TiO2 aerogels by ultrasonic-assisted sol-gel method

NASA Astrophysics Data System (ADS)

Qingge, Feng; Huidong, Cai; Haiying, Lin; Siying, Qin; Zheng, Liu; Dachao, Ma; Yuyang, Ye

2018-02-01

TiO2 aerogel is a unique three-dimensional porous nano-particle material with the characteristics of high specific surface area and good light transmittance. In this paper, a novel method involving ultrasonic-assisted sol-gel, solvent exchange, and vacuum drying was successfully developed to synthesis the TiO2 aerogel. The morphology and properties of the prepared TiO2 aerogels were characterized by the Brunauer-Emmett-Teller theory (BET), x-ray diffraction, field-emission scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis-differential thermal analysis, Fourier transform infrared spectroscopy, and Raman spectroscopy. The adsorption and photocatalytic activity of TiO2 aerogels was evaluated by monitoring the degradation of Rhodamine B solution. Our results indicated that: (1) with an optimum ratio of Ti:H2O = 8:1 the BET surface area, average pore diameter, and total pore volume of TiO2 aerogel are enhanced to 563.6 m2 g-1, 3.01 nm, and 0.42 cm3 g-1, respectively; (2) the TiO2 aerogels possessed controllable crystal form depending on the thermal treatments conditions. The crystal face (101) of anatase, complete anatase, mixed state of anatase and rutile, and rutile were obtained by increasing the temperature from 200 °C-300 °C, from 400 °C-500 °C, 600 °C, and from 700 °C-1000 °C, respectively; and (3) the excellent catalytic activity of the as-prepared TiO2 aerogels for the ultraviolet photolytic degradation of Rhodamine B had attributed to the synergistic effect of adsorption and photoactivity.

Experimental and DFT simulation study of a novel felodipine cocrystal: Characterization, dissolving properties and thermal decomposition kinetics.

PubMed

Yang, Caiqin; Guo, Wei; Lin, Yulong; Lin, Qianqian; Wang, Jiaojiao; Wang, Jing; Zeng, Yanli

2018-05-30

In this study, a new cocrystal of felodipine (Fel) and glutaric acid (Glu) with a high dissolution rate was developed using the solvent ultrasonic method. The prepared cocrystal was characterized using X-ray powder diffraction, differential scanning calorimetry, thermogravimetric (TG) analysis, and infrared (IR) spectroscopy. To provide basic information about the optimization of pharmaceutical preparations of Fel-based cocrystals, this work investigated the thermal decomposition kinetics of the Fel-Glu cocrystal through non-isothermal thermogravimetry. Density functional theory (DFT) simulations were also performed on the Fel monomer and the trimolecular cocrystal compound for exploring the mechanisms underlying hydrogen bonding formation and thermal decomposition. Combined results of IR spectroscopy and DFT simulation verified that the Fel-Glu cocrystal formed via the NH⋯OC and CO⋯HO hydrogen bonds between Fel and Glu at the ratio of 1:2. The TG/derivative TG curves indicated that the thermal decomposition of the Fel-Glu cocrystal underwent a two-step process. The apparent activation energy (E a ) and pre-exponential factor (A) of the thermal decomposition for the first stage were 84.90 kJ mol -1 and 7.03 × 10 7  min -1 , respectively. The mechanism underlying thermal decomposition possibly involved nucleation and growth, with the integral mechanism function G(α) of α 3/2 . DFT calculation revealed that the hydrogen bonding between Fel and Glu weakened the terminal methoxyl, methyl, and ethyl groups in the Fel molecule. As a result, these groups were lost along with the Glu molecule in the first thermal decomposition. In conclusion, the formed cocrystal exhibited different thermal decomposition kinetics and showed different E a , A, and shelf life from the intact active pharmaceutical ingredient. Copyright © 2018 Elsevier B.V. All rights reserved.

Using Ultrasonic Lamb Waves To Measure Moduli Of Composites

NASA Technical Reports Server (NTRS)

Kautz, Harold E.

1995-01-01

Measurements of broad-band ultrasonic Lamb waves in plate specimens of ceramic-matrix/fiber and metal-matrix/fiber composite materials used to determine moduli of elasticity of materials. In one class of potential applications of concept, Lamb-wave responses of specimens measured and analyzed at various stages of thermal and/or mechanical processing to determine effects of processing, without having to dissect specimens. In another class, structural components having shapes supporting propagation of Lamb waves monitored ultrasonically to identify signs of deterioration and impending failure.

Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover

PubMed Central

Tian, Shuang-Qi; Wang, Zhen-Yu; Fan, Zi-Luan; Zuo, Li-Li

2012-01-01

To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment. PMID:22605970

Comparison of ultrasonic and CO₂laser pretreatment methods on enzyme digestibility of corn stover.

PubMed

Tian, Shuang-Qi; Wang, Zhen-Yu; Fan, Zi-Luan; Zuo, Li-Li

2012-01-01

To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO(2) laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO(2) laser irradiation. The present work demonstrated that the CO(2) laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO(2) laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO(2) laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

Achieving Real-Time Tracking Mobile Wireless Sensors Using SE-KFA

NASA Astrophysics Data System (ADS)

Kadhim Hoomod, Haider, Dr.; Al-Chalabi, Sadeem Marouf M.

2018-05-01

Nowadays, Real-Time Achievement is very important in different fields, like: Auto transport control, some medical applications, celestial body tracking, controlling agent movements, detections and monitoring, etc. This can be tested by different kinds of detection devices, which named "sensors" as such as: infrared sensors, ultrasonic sensor, radars in general, laser light sensor, and so like. Ultrasonic Sensor is the most fundamental one and it has great impact and challenges comparing with others especially when navigating (as an agent). In this paper, concerning to the ultrasonic sensor, sensor(s) detecting and delimitation by themselves then navigate inside a limited area to estimating Real-Time using Speed Equation with Kalman Filter Algorithm as an intelligent estimation algorithm. Then trying to calculate the error comparing to the factual rate of tracking. This paper used Ultrasonic Sensor HC-SR04 with Arduino-UNO as Microcontroller.

Quantitative Mapping of Pore Fraction Variations in Silicon Nitride Using an Ultrasonic Contact Scan Technique

NASA Technical Reports Server (NTRS)

Roth, Don J.; Kiser, James D.; Swickard, Suzanne M.; Szatmary, Steven A.; Kerwin, David P.

1993-01-01

An ultrasonic scan procedure using the pulse-echo contact configuration was employed to obtain maps of pore fraction variations in sintered silicon nitride samples in terms of ultrasonic material properties. Ultrasonic velocity, attenuation coefficient, and reflection coefficient images were obtained simultaneously over a broad band of frequencies (e.g., 30 to 110 MHz) by using spectroscopic analysis. Liquid and membrane (dry) coupling techniques and longitudinal and shear-wave energies were used. The major results include the following: Ultrasonic velocity (longitudinal and shear wave) images revealed and correlated with the extent of average through-thickness pore fraction variations in the silicon nitride disks. Attenuation coefficient images revealed pore fraction nonuniformity due to the scattering that occurred at boundaries between regions of high and low pore fraction. Velocity and attenuation coefficient images were each nearly identical for machined and polished disks, making the method readily applicable to machined materials. Velocity images were similar for wet and membrane coupling. Maps of apparent Poisson's ratio constructed from longitudinal and shear-wave velocities quantified Poisson's ratio variations across a silicon nitride disk. Thermal wave images of a disk indicated transient thermal behavior variations that correlated with observed variations in pore fraction and velocity and attenuation coefficients.

Modeling and experimental investigation of thermal-mechanical-electric coupling dynamics in a standing wave ultrasonic motor

NASA Astrophysics Data System (ADS)

Li, Xiang; Yao, Zhiyuan; He, Yigang; Dai, Shichao

2017-09-01

Ultrasonic motor operation relies on high-frequency vibration of a piezoelectric vibrator and interface friction between the stator and rotor/slider, which can cause temperature rise of the motor under continuous operation, and can affect motor parameters and performance in turn. In this paper, an integral model is developed to study the thermal-mechanical-electric coupling dynamics in a typical standing wave ultrasonic motor. Stick-slip motion at the contact interface and the temperature dependence of material parameters of the stator are taken into account in this model. The elastic, piezoelectric and dielectric material coefficients of the piezoelectric ceramic, as a function of temperature, are determined experimentally using a resonance method. The critical parameters in the model are identified via measured results. The resulting model can be used to evaluate the variation in output characteristics of the motor caused by the thermal-mechanical-electric coupling effects. Furthermore, the dynamic temperature rise of the motor can be accurately predicted under different input parameters using the developed model, which will contribute to improving the reliable life of a motor for long-term running.

Effects of Ultrasonic Parameters on the Crystallization Behavior of Virgin Coconut Oil.

PubMed

Wu, Linhe; Cao, Jun; Bai, Xinpeng; Chen, Haiming; Zhang, Yuxiang; Wu, Qian

2016-12-01

Crystallization behavior of virgin coconut oil (VCO) in the absence and presence of ultrasonic treatment under a temperature gradient field was investigated. The effects of ultrasonic parameters on the crystallization behavior of VCO were studied by differential scanning calorimetry, ultraviolet/visible spectrophotometry and polarized light microscopy. The thermal effect of the ultrasonic treatment was also increased at higher power levels. Therefore, the optimal power level was determined at approximately 36 W. Induction time reduced evidently and the crystallization rate was accelerated under ultrasonic treatment at crystallization temperature (T c ) above 15°C. However, no significant difference in induction time was noted at 13°C. The result of morphological studies showed that the growth mechanism of crystals was significantly changed. Meanwhile, smaller and uniform crystals were produced by the ultrasonic treatment. This study shows a novel technique to accelerate the crystallization rate and alter the growth mechanism of VCO crystals.

Enhancement of ultraweak photon emission with 3 MHz ultrasonic irradiation on transplanted tumor tissues of mice.

PubMed

Kim, Hongbae; Ahn, Saeyoung; Kim, Jungdae; Soh, Kwang-Sup

2008-07-01

We investigated photon emissions of various bio-samples which were induced by ultrasonic stimulation. It has been reported that ultrasonic stimulations induced the thermal excitation of the bio-tissues. After ultrasonic stimulation, any measurement of photon radiation in the visible spectral range has not been carried out yet. The instruments consisted of electronic devices for an ultrasonic generator of the frequency 3 MHz and a photomultiplier tube (PMT) system counting photons from bio-tissues. The transplanted tumor tissues of mice were prepared for the experiments and their liver and spleen tissues were also used for the controls. It was found that the continuous ultrasonic stimulations with the electrical power 2300 mW induced ultraweak photon emissions from the tumor tissues. The number of induced photon was dependent of the type of the tissues and the stimulation time intervals. The level of photon emission was increased from the mouse tumor exposed to the ultrasonic stimulations, and the changes were discriminated from those of the spleens and livers.

Fuzzy Logic Based Autonomous Parallel Parking System with Kalman Filtering

NASA Astrophysics Data System (ADS)

Panomruttanarug, Benjamas; Higuchi, Kohji

This paper presents an emulation of fuzzy logic control schemes for an autonomous parallel parking system in a backward maneuver. There are four infrared sensors sending the distance data to a microcontroller for generating an obstacle-free parking path. Two of them mounted on the front and rear wheels on the parking side are used as the inputs to the fuzzy rules to calculate a proper steering angle while backing. The other two attached to the front and rear ends serve for avoiding collision with other cars along the parking space. At the end of parking processes, the vehicle will be in line with other parked cars and positioned in the middle of the free space. Fuzzy rules are designed based upon a wall following process. Performance of the infrared sensors is improved using Kalman filtering. The design method needs extra information from ultrasonic sensors. Starting from modeling the ultrasonic sensor in 1-D state space forms, one makes use of the infrared sensor as a measurement to update the predicted values. Experimental results demonstrate the effectiveness of sensor improvement.

Ultrasonic degradation of aqueous phenolsulfonphthalein (PSP) in the presence of nano-Fe/H2O2.

PubMed

Ayanda, Olushola S; Nelana, Simphiwe M; Naidoo, Eliazer B

2018-10-01

In this study, nano iron (nano-Fe) was successfully synthesized by sodium borohydride reduction of ferric chloride solution to enhance the ultrasonic degradation of phenolsulfonphthalein (PSP). The nano-Fe was characterized by scanning electron microscopy - energy dispersive spectroscopy (SEM-EDX), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), attenuated total reflection - Fourier transform infrared spectroscopy (ATR-FTIR), and Brunauer, Emmett and Teller (BET) surface area determination. Experimental results demonstrated that a combined ultrasonic/nano-Fe/H 2 O 2 system was more effective for PSP removal in combination than they were individually and there was a significant difference between the combined and single processes. The ultrasonic/nano-Fe/H 2 O 2 degradation follows the Langmuir-Hinshelwood (L-H) kinetic model. The addition of nano-Fe and H 2 O 2 to the ultrasonic reactor greatly accelerated the degradation of PSP (25 mg/L) from 12.5% up to 96.5%. These findings indicated that ultrasonic degradation in the presence of nano-Fe and H 2 O 2 is a promising and efficient technique for the elimination of emerging micropollutants from aqueous solution. Copyright © 2018 Elsevier B.V. All rights reserved.

Survey of Non-Destructive Tire Inspection Techniques

DOT National Transportation Integrated Search

1971-07-01

The status of several promising methods for non-destructive tire inspection is surveyed with the conclusion that radiographic, infrared, holographic and ultrasonic techniques warrant further evaluation. A program plan is outlined to correlate non-des...

Acoustic microscopy analyses to determine good vs. failed tissue engineered oral mucosa under normal or thermally stressed culture conditions.

PubMed

Winterroth, Frank; Lee, Junho; Kuo, Shiuhyang; Fowlkes, J Brian; Feinberg, Stephen E; Hollister, Scott J; Hollman, Kyle W

2011-01-01

This study uses scanning acoustic microscopy (SAM) ultrasonic profilometry to determine acceptable vs. failed tissue engineered oral mucosa. Specifically, ex vivo-produced oral mucosal equivalents (EVPOMEs) under normal or thermally stressed culture conditions were scanned with the SAM operator blinded to the culture conditions. As seeded cells proliferate, they fill in and smooth out the surface irregularities; they then stratify and produce a keratinized protective upper layer. Some of these transformations could alter backscatter of ultrasonic signals and in the case of the thermally stressed cells, produce backscatter similar to an unseeded device. If non-invasive ultrasonic monitoring could be developed, then tissue cultivation could be adjusted to measure biological variations in the stratified surface. To create an EVPOME device, oral mucosa keratinocytes were seeded onto acellular cadaveric dermis. Two sets of EVPOMEs were cultured: one at physiological temperature 37 °C and the other at 43 °C. The specimens were imaged with SAM consisting of a single-element transducer: 61 MHz center frequency, 32 MHz bandwidth, 1.52 f#. Profilometry for the stressed and unseeded specimens showed higher surface irregularities compared to unstressed specimens. Elevated thermal stress retards cellular differentiation, increasing root mean square values; these results show that SAM can potentially monitor cell/tissue development.

Research of Adhesion Bonds Between Gas-Thermal Coating and Pre-Modified Base

NASA Astrophysics Data System (ADS)

Kovalevskaya, Z.; Zaitsev, K.; Klimenov, V.

2016-08-01

Nature of adhesive bonds between gas-thermal nickel alloy coating and carbon steel base was examined using laser profilometry, optical metallography, transmission and scanning electron microscopy. The steel surface was plastically pre-deformed by an ultrasonic tool. Proved that ultrasound pre-treatment modifies the steel surface. Increase of dislocation density and formation of sub micro-structure are base elements of surface modification. While using high-speed gas-flame, plasma and detonation modes of coatings, surface activation occurs and durable adhesion is formed. Ultrasonic pre-treatment of base material is effective when sprayed particles and base material interact through physical-chemical bond formation. Before applying high-speed gas flame and plasma sprayed coatings, authors recommend ultrasonic pretreatment, which creates periodic wavy topography with a stroke of 250 microns on the steel surface. Before applying detonation sprayed coatings, authors recommend ultrasound pretreatment that create modified surface with a uniform micro-topography.

Nanostructural reorganization of bacterial cellulose by ultrasonic treatment.

PubMed

Tischer, Paula C S Faria; Sierakowski, Maria Rita; Westfahl, Harry; Tischer, Cesar Augusto

2010-05-10

In this work, bacterial cellulose was subjected to a high-power ultrasonic treatment for different time intervals. The morphological analysis, scanning electron microscopy, and atomic force microscopy revealed that this treatment changed the width and height of the microfibrillar ribbons and roughness of their surface, originating films with new nanostructures. Differential thermal analysis showed a higher thermal stability for ultrasonicated samples with a pyrolysis onset temperature of 208 degrees C for native bacterial cellulose and 250 and 268 degrees C for the modified samples. The small-angle X-ray scattering experiments demonstrated that the treatment with ultrasound increased the thickness of the ribbons, while wide-angle X-ray scattering experiments demonstrated that the average crystallite dimension and the degree of crystallinity also increased. A model is proposed where the thicker ribbons and crystallites result from the fusion of neighboring ribbons due to cavitation effects.

Photoacoustic Tomography

NASA Astrophysics Data System (ADS)

Wang, Lihong V.

Photoacoustic tomography (PAT) refers to imaging that is based on the photoacoustic effect. Although the photoacoustic effect as a physical phenomenon was first reported on by Alexander Graham Bell in 1880 [1], PAT as an imaging technology was developed only after the advent of ultrasonic transducers, computers, and lasers [2-31]. A review on biomedical photoacoustics is available [32]. The motivation for PAT is to combine optical-absorption contrast with ultrasonic spatial resolution for deep imaging in the optical quasi-diffusive or diffusive regime. In PAT, the tissue is irradiated by usually a short-pulsed laser beam to achieve a thermal and acoustic impulse response (Fig. 19.1). Locally absorbed light is converted into heat, which is further converted to a pressure rise via thermo-elastic expansion. The initial pressure rise - determined by the local optical absorption coefficient (μ â ), fluence (ψ) and other thermal and mechanical properties - propagates as an ultrasonic wave, which is referred to as a photoacoustic wave.

Maintaining functional properties of shell eggs by ultrasound treatment.

PubMed

Caner, Cengiz; Yuceer, Muhammed

2015-11-01

Ultrasonic treatment is an emerging technique that could be an alternative to existing thermal processing techniques in foods. Ultrasonic treatments may also be used to extend the shelf life of egg during storage period in ambient temperature. The effectiveness of ultrasound treatment with different power levels (200 W, 300 W, 450 W) and treatment times (2 min and 5 min) was evaluated for enhancing the functional properties of eggs during storage at 24 ° C for 6 weeks. Ultrasound treatment power and treatment time had significant effects on Haugh unit, yolk index, albumen pH, dry matter, relative whipping capacity, and albumen viscosity resulting in extended shelf life. Attributes such as yolk index, Haugh unit, pH, whipping capacity, dry matter for 300 W and 450 W treatments were better than control and 200 W treatments. Longer treatment time and power showed a significant influence on functional properties. Power levels of 300 W and 450 W of ultrasound treatments had improved internal quality of fresh eggs during storage, but negative effect on shell strength. The study showed that ultrasound treatment could be an alternative and effective technique for maintaining the internal qualities of fresh eggs during long-term storage while Fourier transform near infrared spectroscopy could be used as a new tool for the assessment of freshness. © 2014 Society of Chemical Industry.

A combined system for measuring animal motion activities.

PubMed

Young, M S; Young, C W; Li, Y C

2000-01-31

In this study, we have developed a combined animal motion activity measurement system that combines an infrared light matrix subsystem with an ultrasonic phase shift subsystem for animal activity measurement. Accordingly, in conjunction with an IBM PC/AT compatible personal computer, the combined system has the advantages of both infrared and ultrasonic subsystems. That is, it can at once measure and directly analyze detailed changes in animal activity ranging from locomotion to tremor. The main advantages of this combined system are that it features real time data acquisition with the option of animated real time or recorded display/playback of the animal's motion. Additionally, under the multi-task operating condition of IBM PC, it can acquire and process behavior using both IR and ultrasound systems simultaneously. Traditional systems have had to make separate runs for gross and fine movement recording. This combined system can be profitably employed for normative behavioral activity studies and for neurological and pharmacological research.

MR-guided noninvasive thermal coagulation of in-vivo liver tissue using ultrasonic phased array

NASA Astrophysics Data System (ADS)

Daum, Douglas R.; Smith, Nadine; McDannold, Nathan; Hynynen, Kullervo H.

1999-05-01

Magnetic resonance (MR) imaging was used to guide and monitor the thermal tissue coagulation of in vivo porcine tissue using a 256 element ultrasonic phased array. The array could coagulate tissue volumes greater than 2 cm3 in liver and 0.5 cm3 in kidney using a single 20 second sonication. This sonication used multiple focus fields which were temporally cycled to heat large tissue volumes simultaneously. Estimates of the coagulated tissue using a thermal dose threshold compare well with T2-weighted images of post sonication lesions. The overlapping large focal volumes could aid in the treatment of large tumor volumes which require multiple overlapping sonications. The ability of MR to detect the presence and undesirable thermal increases at acoustic obstacle such as cartilaginous and bony ribs is demonstrated. This could have a significant impact on the ability to monitor thermal treatments of the liver and other organs which are acoustically blocked.

Ultrasonic-assisted conversion of limestone into needle-like hydroxyapatite nanoparticles.

PubMed

Klinkaewnarong, Jutharatana; Utara, Songkot

2018-09-01

Needle-like hydroxyapatite nanoparticles were successfully synthesized via a reaction between calcium oxide (CaO) that was obtained from calcined limestone and orthophosphoric acid (H 3 PO 4 ) under ultrasonic irradiation at 25 °C. The reaction systems were exposed to ultrasonic waves of 20 kHz for various times ranging from 0 to 4 h. The initial and final pH values of the mixtures of CaO and H 3 PO 4 solution were continuously observed (pH < 4.0) after ultrasonic irradiation. The powder was then dried at 60 °C and calcined at 300 °C for 3 h (3 °C/min). The products were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The results showed that the formation of needle-like hydroxyapatite (HAp) nanoparticles was substantially accelerated compared with the reaction without ultrasonic irradiation. The HAp phase was increasingly visible with longer ultrasonic irradiation time compared with the monetite phase (CaHPO 4 ). This suggests that ultrasonic waved induced a phase transition from the monetite to HAp phase. A smaller needle-like structure of HAp (diameter ∼ 7.4 nm) with a lower contamination of monetite phase was obtained following sonication for 3 h. This study shows that Thai limestone can used as a starting material for synthesizing needle-like HAp nanoparticles with the aid of ultrasonic methods. Copyright © 2018 Elsevier B.V. All rights reserved.

A preliminary investigation of acousto-ultrasonic NDE of metal matrix composite test specimens

NASA Technical Reports Server (NTRS)

Kautz, Harold E.; Lerch, Brad A.

1991-01-01

Acousto-ultrasonic (AU) measurements were performed on a series of tensile specimens composed of 8 laminated layers of continuous, SiC fiber reinforced Ti-15-3 matrix. The following subject areas are covered: AU signal analysis; tensile behavior; AU and interrupted tensile tests; AU and thermally cycled specimens; AU and stiffness; and AU and specimen geometry.

Thermal injury through intraradicular heat transfer using ultrasonic devices: precautions and practical preventive strategies.

PubMed

Gluskin, Alan H; Ruddle, Clifford J; Zinman, Edwin J

2005-09-01

The use of ultrasonic energy is a highly efficient method of removing obstructions and cements within the root canal space when re-treatment or rehabilitation of that ultrasonic energy dislodges and removes cemented objects from the bonded interface of the canal wall. When using this method, there is less potential for structural loss or root damage and significantly less operator stress than when using other methods. There is little evidence in published research of the considerable heat transfer that occurs during use of ultrasonic devices to remove posts, pastes and separated instruments in teeth. The authors present three cases of patients who experienced serious burn injuries during application of ultrasonic energy for restorative dentistry. The authors also offer techniques and strategies for safe and effective use of ultrasonic devices. On the basis of the best available evidence, the authors recommend strategies to provide safe and effective therapy while using ultrasonic devices in intraradicular obstruction removal. The intent of the suggested protocols is to provide advanced and sophisticated therapies in a safe and regulated manner with patient safety as an overriding priority.

Ultrasonic Detection of Delamination and Material Characterization of Thermal Barrier Coatings

NASA Astrophysics Data System (ADS)

Chen, Hung-Liang Roger; Zhang, Binwei; Alvin, Mary Anne; Lin, Yun

2012-12-01

This article describes ultrasonic nondestructive evaluation (NDE) to detect the changes of material properties and provide early warning of delamination in thermal barrier coating (TBC) systems. NDE tests were performed on single-crystal René N5 superalloy coupons that were coated with a commercially available MCrAlY bond coat and an air plasma sprayed 7% yttria-stabilized zirconia (YSZ) top coat deposited by Air Plasma Spray method, as well as Haynes 230 superalloy coupons coated with MCrA1Y bond coat, and an electron beam physical vapor deposit of 7% YSZ top coat. The TBC coupons were subjected to either cyclic or isothermal exposure for various lengths of time at temperatures ranging from 900 to 1100 °C. The ultrasonic measurements performed on the coupons had provided an early warning of delamination along the top coat/TGO interface before exposure time, when delamination occurred. The material's property (Young's modulus) of the top coat was estimated using the measured wave speeds. Finite element analysis (FEA) of the ultrasonic wave propagation was conducted on a simplified TBC system to verify experimental observations. The technique developed was also demonstrated on an as-manufactured turbine blade to estimate normalized top coat thickness measurements.

Ultrasonic Investigations on Polonides of Ba, Ca, and Pb

NASA Astrophysics Data System (ADS)

Singh, Devraj; Bhalla, Vyoma; Bala, Jyoti; Wadhwa, Shikha

2017-10-01

The temperature-dependent mechanical and ultrasonic properties of barium, calcium, and lead polonides (BaPo, CaPo, and PbPo) were investigated in the temperature range 100-300 K. The second- and third-order elastic constants (SOECs and TOECs) were computed using Coulomb and Born-Mayer potential and these in turn have been used to estimate other secondary elastic properties such as strength, anisotropy, microhardness, etc. The theoretical approach followed the prediction that BaPo, CaPo, and PbPo are brittle in nature. PbPo is found to be the hardest amongst the chosen compounds. Further the SOECs and TOECs are applied to determine ultrasonic velocities, Debye temperature, and acoustic coupling constants along <100>, <110>, and <111> orientations at room temperature. Additionally thermal conductivity has been computed using Morelli and Slack's approach along different crystallographic directions at room temperature. Finally ultrasonic attenuation due to phonon-phonon interaction and thermoelastic relaxation mechanisms has been computed for BaPo, CaPo, and PbPo. The behaviour of these compounds is similar to that of semi-metals with thermal relaxation time of the order 10-11 s. The present computation study is reasonably in agreement with the available theoretical data for the similar type of materials.

Electromagnetic modulation of the ultrasonic signal for nondestructive detection of small defects and ferromagnetic inclusions in thin wall structures

NASA Astrophysics Data System (ADS)

Finkel, Peter

2008-03-01

We report on new nondestructive evaluation technique based on electromagnetic modulation of ultrasonic signal for detection of the small crack, flaws and inclusions in thin-walled parts. The electromagnetically induced high density current pulse produces stresses which alter the ultrasonic waves scanning the part with the defect and modulate ultrasonic signal. The excited electromagnetic field can produces crack-opening due to Lorentz forces that increase the ultrasonic reflection. The Joule heating associated with the high density current, and consequent thermal stresses may cause both crack-closure, as well as crack-opening, depending on various factors. Experimental data is presented here for the case of a small crack near holes in thin-walled structures. The measurements were taken at 2-10 MHz with a Lamb wave wedge transducer. It is shown that electromagnetic transient modulation of the ultrasonic echo pulse tone-burst suggest that this method could be used to enhance detection of small cracks and ferromagnetic inclusions in thin walled metallic structures.

Ultrasonic Emission from Nanocrystalline Porous Silicon

NASA Astrophysics Data System (ADS)

Shinoda, Hiroyuki; Koshida, Nobuyoshi

A simple layer structure composed of a metal thin film and a porous silicon layer on a silicon substrate generates intense and wide-band airborne ultrasounds. The large-bandwidth and the fidelity of the sound reproduction are leveraged in applications varying from sound-based measurement to a scientific study of animal ecology. This chapter describes the basic principle of the ultrasound generation. The macroscopic properties of the low thermal conductivity and the small heat capacity of nanocrystalline porous silicon thermally induce ultrasonic emission. The state-of-the-art of the achievable sound pressure and sound signal properties is introduced, with the technological and scientific applications of the devices.

Nondestructive Evaluation of Adhesive Bonds via Ultrasonic Phase Measurements

NASA Technical Reports Server (NTRS)

Haldren, Harold A.; Perey, Daniel F.; Yost, William T.; Cramer, K. Elliott; Gupta, Mool C.

2016-01-01

The use of advanced composites utilizing adhesively bonded structures offers advantages in weight and cost for both the aerospace and automotive industries. Conventional nondestructive evaluation (NDE) has proved unable to reliably detect weak bonds or bond deterioration during service life conditions. A new nondestructive technique for quantitatively measuring adhesive bond strength is demonstrated. In this paper, an ultrasonic technique employing constant frequency pulsed phased-locked loop (CFPPLL) circuitry to monitor the phase response of a bonded structure from change in thermal stress is discussed. Theoretical research suggests that the thermal response of a bonded interface relates well with the quality of the adhesive bond. In particular, the effective stiffness of the adhesive-adherent interface may be extracted from the thermal phase response of the structure. The sensitivity of the CFPPLL instrument allows detection of bond pathologies that have been previously difficult-to-detect. Theoretical results with this ultrasonic technique on single epoxy lap joint (SLJ) specimens are presented and discussed. This technique has the potential to advance the use of adhesive bonds - and by association, advanced composite structures - by providing a reliable method to measure adhesive bond strength, thus permitting more complex, lightweight, and safe designs.

Physicochemical changes and microbial inactivation after high-intensity ultrasound processing of prebiotic whey beverage applying different ultrasonic power levels.

PubMed

Guimarães, Jonas T; Silva, Eric Keven; Alvarenga, Verônica O; Costa, Ana Letícia R; Cunha, Rosiane L; Sant'Ana, Anderson S; Freitas, Monica Q; Meireles, M Angela A; Cruz, Adriano G

2018-06-01

In this work, we investigated the effects of the ultrasonic power (0, 200, 400 and 600 W) on non-thermal processing of an inulin-enriched whey beverage. We studied the effects of high-intensity ultrasound (HIUS) on microbial inactivation (aerobic mesophilic heterotrophic bacteria (AMHB), total and thermotolerant coliforms and yeasts and molds), zeta potential, microstructure (optical microscopy, particle size distribution), rheology, kinetic stability and color. The non-thermal processing applying 600 W of ultrasonic power was comparable to high-temperature short-time (HTST) treatment (75 °C for 15 s) concerning the inactivation of AMHB and yeasts and molds (2 vs 2 log and 0.2 vs 0.4 log, respectively), although HIUS has reached a lower output temperature (53 ± 3 °C). The HIUS was better than HTST to improve beverage kinetic stability, avoiding phase separation, which was mainly attributed to the decrease of particles size, denaturation of whey proteins and gelation of polysaccharides (inulin and gellan gum). Thus, non-thermal processing by HIUS seems to be an interesting technology for prebiotic dairy beverages production. Copyright © 2018 Elsevier B.V. All rights reserved.

Rotary ultrasonic drilling on bone: A novel technique to put an end to thermal injury to bone.

PubMed

Gupta, Vishal; Pandey, Pulak M; Gupta, Ravi K; Mridha, Asit R

2017-03-01

Bone drilling is common in orthopedic procedures and the heat produced during conventional experimental drilling often exceeds critical temperature of 47 °C and induces thermal osteonecrosis. The osteonecrosis may be the reason for impaired healing, early loosening and implant failure. This study was undertaken to control the temperature rise by interrupted cutting and reduced friction effects at the interface of drill tool and the bone surface. In this work, rotary ultrasonic drilling technique with diamond abrasive particles coated on the hollow drill tool without any internal or external cooling assistance was used. Experiments were performed at room temperature on the mid-diaphysis sections of fresh pig bones, which were harvested immediately after sacrifice of the animal. Both rotary ultrasonic drilling on bone and conventional surgical drilling on bone were performed in a five set of experiments on each process using identical constant process parameters. The maximum temperature of each trial was recorded by K-type thermocouple device. Ethylenediaminetetraacetic acid decalcification was done for microscopic examination of bone. In this comparative procedure, rotary ultrasonic drilling on bone produced much lower temperature, that is, 40.2 °C ± 0.4 °C and 40.3 °C ± 0.2 °C as compared to that of conventional surgical drilling on bone, that is, 74.9 °C ± 0.8 °C and 74.9 °C ± 0.6 °C with respect to thermocouples fixed at first and second position, respectively. The conventional surgical drilling on bone specimens revealed gross tissue burn, microscopic evidence of thermal osteonecrosis and tissue injury in the form of cracks due to the generated force during drilling. But our novel technique showed no such features. Rotary ultrasonic drilling on bone technique is robust and superior to other methods for drilling as it induces no thermal osteonecrosis and does not damage the bone by generating undue forces during drilling.

Ultrasonically-assisted Thermal Stir Welding System

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey (Inventor)

2014-01-01

A welding head assembly has a work piece disposed between its containment plates' opposing surfaces with the work piece being maintained in a plastic state thereof at least in a vicinity of the welding head assembly's stir rod as the rod is rotated about its longitudinal axis. The welding head assembly and the work piece experience relative movement there between in a direction perpendicular to the rod's longitudinal axis as the work piece is subjected to a compressive force applied by the containment plates. A first source coupled to the first containment plate applies a first ultrasonic wave thereto such that the first ultrasonic wave propagates parallel to the direction of relative movement. A second source coupled to the second containment plate applies a second ultrasonic wave thereto such that the second ultrasonic wave propagates parallel to the direction of relative movement.propagates parallel to the direction of relative movement.

Thermal-depth matching in dynamic scene based on affine projection and feature registration

NASA Astrophysics Data System (ADS)

Wang, Hongyu; Jia, Tong; Wu, Chengdong; Li, Yongqiang

2018-03-01

This paper aims to study the construction of 3D temperature distribution reconstruction system based on depth and thermal infrared information. Initially, a traditional calibration method cannot be directly used, because the depth and thermal infrared camera is not sensitive to the color calibration board. Therefore, this paper aims to design a depth and thermal infrared camera calibration board to complete the calibration of the depth and thermal infrared camera. Meanwhile a local feature descriptors in thermal and depth images is proposed. The belief propagation matching algorithm is also investigated based on the space affine transformation matching and local feature matching. The 3D temperature distribution model is built based on the matching of 3D point cloud and 2D thermal infrared information. Experimental results show that the method can accurately construct the 3D temperature distribution model, and has strong robustness.

Relationship between tissue tension and thermal diffusion to peripheral tissue using an energy device.

PubMed

Kondo, Akihiro; Nishizawa, Yuji; Ito, Masaaki; Saito, Norio; Fujii, Satoshi; Akamoto, Shintaro; Fujiwara, Masao; Okano, Keiichi; Suzuki, Yasuyuki

2016-08-01

The aim of the study was to assess the relationship between tissue tension and thermal diffusion to peripheral tissues using an electric scalpel, ultrasonically activated device, or a bipolar sealing system. The mesentery of pigs was excised with each energy device (ED) at three tissue tensions (0, 300, 600 g). The excision time and thermal diffusion area were monitored with thermography, measured for each ED, and then histologically examined. Correlations between tissue tension and thermal diffusion area were examined. The excision time was inversely correlated with tissue tension for all ED (electric scalpel, r = 0.718; ultrasonically activated device, r = 0.949; bipolar sealing system, r = 0.843), and tissue tension was inversely correlated with the thermal diffusion area with the electric scalpel (r = 0.718) and bipolar sealing system (r = 0.869). Histopathologically, limited deep thermal denaturation occurred at a tension of 600 g with all ED. We conclude that thermal damage can be avoided with adequate tissue tension when any ED is used. © 2016 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Modeling of ultrasonic and terahertz radiations in defective tiles for condition monitoring of thermal protection systems

NASA Astrophysics Data System (ADS)

Kabiri Rahani, Ehsan

Condition based monitoring of Thermal Protection Systems (TPS) is necessary for safe operations of space shuttles when quick turn-around time is desired. In the current research Terahertz radiation (T-ray) has been used to detect mechanical and heat induced damages in TPS tiles. Voids and cracks inside the foam tile are denoted as mechanical damage while property changes due to long and short term exposures of tiles to high heat are denoted as heat induced damage. Ultrasonic waves cannot detect cracks and voids inside the tile because the tile material (silica foam) has high attenuation for ultrasonic energy. Instead, electromagnetic terahertz radiation can easily penetrate into the foam material and detect the internal voids although this electromagnetic radiation finds it difficult to detect delaminations between the foam tile and the substrate plate. Thus these two technologies are complementary to each other for TPS inspection. Ultrasonic and T-ray field modeling in free and mounted tiles with different types of mechanical and thermal damages has been the focus of this research. Shortcomings and limitations of FEM method in modeling 3D problems especially at high-frequencies has been discussed and a newly developed semi-analytical technique called Distributed Point Source Method (DPSM) has been used for this purpose. A FORTRAN code called DPSM3D has been developed to model both ultrasonic and electromagnetic problems using the conventional DPSM method. This code is designed in a general form capable of modeling a variety of geometries. DPSM has been extended from ultrasonic applications to electromagnetic to model THz Gaussian beams, multilayered dielectrics and Gaussian beam-scatterer interaction problems. Since the conventional DPSM has some drawbacks, to overcome it two modification methods called G-DPSM and ESM have been proposed. The conventional DPSM in the past was only capable of solving time harmonic (frequency domain) problems. Time history was obtained by FFT (Fast Fourier Transform) algorithm. In this research DPSM has been extended to model DPSM transient problems without using FFT. This modified technique has been denoted as t-DPSM. Using DPSM, scattering of focused ultrasonic fields by single and multiple cavities in fluid & solid media is studied. It is investigated when two cavities in close proximity can be distinguished and when it is not possible. A comparison between the radiation forces generated by the ultrasonic energies reflected from two small cavities versus a single big cavity is also carried out.

Ultrasonic Non Linearity Characterization of the Stainless Steel Wire Reinforced Aluminium Composite

NASA Astrophysics Data System (ADS)

Kim, C. S.; Park, T. S.; Park, I. K.; Hyun, C. Y.

2009-03-01

The effectiveness of the ultrasonic nonlinearity measurement for nearly closed cracks was demonstrated for hot pressing and extrusion of stainless steel 304 short wire reinforced aluminum composite. Aluminum based composites show considerable potential in the aerospace industry and the automotive industry due to their high specific strength and low thermal expansion coefficient. The ultrasonic nonlinearity (β/β0) increased with the volume fraction of SSF and aging heat treatment because of the generation of microvoids resulted from localized SSF and matrix precipitation. This study demonstrates the potential for characterization of reinforced composite materials fabricated by the powder metallurgy technique.

Target Detection over the Diurnal Cycle Using a Multispectral Infrared Sensor.

PubMed

Zhao, Huijie; Ji, Zheng; Li, Na; Gu, Jianrong; Li, Yansong

2016-12-29

When detecting a target over the diurnal cycle, a conventional infrared thermal sensor might lose the target due to the thermal crossover, which could happen at any time throughout the day when the infrared image contrast between target and background in a scene is indistinguishable due to the temperature variation. In this paper, the benefits of using a multispectral-based infrared sensor over the diurnal cycle have been shown. Firstly, a brief theoretical analysis on how the thermal crossover influences a conventional thermal sensor, within the conditions where the thermal crossover would happen and why the mid-infrared (3~5 μm) multispectral technology is effective, is presented. Furthermore, the effectiveness of this technology is also described and we describe how the prototype design and multispectral technology is employed to help solve the thermal crossover detection problem. Thirdly, several targets are set up outside and imaged in the field experiment over a 24-h period. The experimental results show that the multispectral infrared imaging system can enhance the contrast of the detected images and effectively solve the failure of the conventional infrared sensor during the diurnal cycle, which is of great significance for infrared surveillance applications.

Target Detection over the Diurnal Cycle Using a Multispectral Infrared Sensor

PubMed Central

Zhao, Huijie; Ji, Zheng; Li, Na; Gu, Jianrong; Li, Yansong

2016-01-01

When detecting a target over the diurnal cycle, a conventional infrared thermal sensor might lose the target due to the thermal crossover, which could happen at any time throughout the day when the infrared image contrast between target and background in a scene is indistinguishable due to the temperature variation. In this paper, the benefits of using a multispectral-based infrared sensor over the diurnal cycle have been shown. Firstly, a brief theoretical analysis on how the thermal crossover influences a conventional thermal sensor, within the conditions where the thermal crossover would happen and why the mid-infrared (3~5 μm) multispectral technology is effective, is presented. Furthermore, the effectiveness of this technology is also described and we describe how the prototype design and multispectral technology is employed to help solve the thermal crossover detection problem. Thirdly, several targets are set up outside and imaged in the field experiment over a 24-h period. The experimental results show that the multispectral infrared imaging system can enhance the contrast of the detected images and effectively solve the failure of the conventional infrared sensor during the diurnal cycle, which is of great significance for infrared surveillance applications. PMID:28036073

Rapid sealing and cutting of porcine blood vessels, ex vivo, using a high-power, 1470-nm diode laser.

PubMed

Giglio, Nicholas C; Hutchens, Thomas C; Perkins, William C; Latimer, Cassandra; Ward, Arlen; Nau, William H; Fried, Nathaniel M

2014-03-01

Suture ligation with subsequent cutting of blood vessels to maintain hemostasis during surgery is time consuming and skill intensive. Energy-based electrosurgical and ultrasonic devices are often used to replace sutures and mechanical clips to provide rapid hemostasis and decrease surgery time. Some of these devices may create undesirably large collateral zones of thermal damage and tissue necrosis, or require separate mechanical blades for cutting. Infrared lasers are currently being explored as alternative energy sources for vessel sealing applications. In a previous study, a 1470-nm laser was used to seal vessels 1 to 6 mm in diameter in 5 s, yielding burst pressures of ∼500  mmHg. The purpose of this study was to provide vessel sealing times comparable with current energy-based devices, incorporate transection of sealed vessels, and demonstrate high vessel burst pressures to provide a safety margin for future clinical use. A 110-W, 1470-nm laser beam was transmitted through a fiber and beam shaping optics, producing a 90-W linear beam 3.0 by 9.5 mm for sealing (400  W/cm2), and 1.1 by 9.6 mm for cutting (1080  W/cm2). A two-step process sealed and then transected ex vivo porcine renal vessels (1.5 to 8.5 mm diameter) in a bench top setup. Seal and cut times were 1.0 s each. A burst pressure system measured seal strength, and histologic measurements of lateral thermal spread were also recorded. All blood vessels tested (n=55 seal samples) were sealed and cut, with total irradiation times of 2.0 s and mean burst pressures of 1305±783  mmHg. Additional unburst vessels were processed for histological analysis, showing a lateral thermal spread of 0.94±0.48  mm (n=14 seal samples). This study demonstrated that an optical-based system is capable of precisely sealing and cutting a wide range of porcine renal vessel sizes and, with further development, may provide an alternative to radiofrequency- and ultrasonic-based vessel sealing devices.

Physical property measurements of doped cesium iodide crystals

NASA Technical Reports Server (NTRS)

Synder, R. S.; Clotfelter, W. N.

1974-01-01

Mechanical and thermal property values are reported for crystalline cesium iodide doped with sodium and thallium. Young's modulus, bulk modulus, shear modulus, and Poisson's ratio were obtained from ultrasonic measurements. Young's modulus and the samples' elastic and plastic behavior were also measured under tension and compression. Thermal expansion and thermal conductivity were the temperature dependent measurements that were made.

New Frontiers for Applications of Thermal Infrared Imaging Devices: Computational Psychopshysiology in the Neurosciences

PubMed Central

Cardone, Daniela; Merla, Arcangelo

2017-01-01

Thermal infrared imaging has been proposed, and is now used, as a tool for the non-contact and non-invasive computational assessment of human autonomic nervous activity and psychophysiological states. Thanks to a new generation of high sensitivity infrared thermal detectors and the development of computational models of the autonomic control of the facial cutaneous temperature, several autonomic variables can be computed through thermal infrared imaging, including localized blood perfusion rate, cardiac pulse rate, breath rate, sudomotor and stress responses. In fact, all of these parameters impact on the control of the cutaneous temperature. The physiological information obtained through this approach, could then be used to infer about a variety of psychophysiological or emotional states, as proved by the increasing number of psychophysiology or neurosciences studies that use thermal infrared imaging. This paper presents a review of the principal achievements of thermal infrared imaging in computational psychophysiology, focusing on the capability of the technique for providing ubiquitous and unwired monitoring of psychophysiological activity and affective states. It also presents a summary on the modern, up-to-date infrared sensors technology. PMID:28475155

New Frontiers for Applications of Thermal Infrared Imaging Devices: Computational Psychopshysiology in the Neurosciences.

PubMed

Cardone, Daniela; Merla, Arcangelo

2017-05-05

Thermal infrared imaging has been proposed, and is now used, as a tool for the non-contact and non-invasive computational assessment of human autonomic nervous activity and psychophysiological states. Thanks to a new generation of high sensitivity infrared thermal detectors and the development of computational models of the autonomic control of the facial cutaneous temperature, several autonomic variables can be computed through thermal infrared imaging, including localized blood perfusion rate, cardiac pulse rate, breath rate, sudomotor and stress responses. In fact, all of these parameters impact on the control of the cutaneous temperature. The physiological information obtained through this approach, could then be used to infer about a variety of psychophysiological or emotional states, as proved by the increasing number of psychophysiology or neurosciences studies that use thermal infrared imaging. This paper presents a review of the principal achievements of thermal infrared imaging in computational psychophysiology, focusing on the capability of the technique for providing ubiquitous and unwired monitoring of psychophysiological activity and affective states. It also presents a summary on the modern, up-to-date infrared sensors technology.

OBSERVED ASTEROID SURFACE AREA IN THE THERMAL INFRARED

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nugent, C. R.; Mainzer, A.; Masiero, J.

The rapid accumulation of thermal infrared observations and shape models of asteroids has led to increased interest in thermophysical modeling. Most of these infrared observations are unresolved. We consider what fraction of an asteroid’s surface area contributes the bulk of the emitted thermal flux for two model asteroids of different shapes over a range of thermal parameters. The resulting observed surface in the infrared is generally more fragmented than the area observed in visible wavelengths, indicating high sensitivity to shape. For objects with low values of the thermal parameter, small fractions of the surface contribute the majority of thermally emittedmore » flux. Calculating observed areas could enable the production of spatially resolved thermal inertia maps from non-resolved observations of asteroids.« less

Rapid infrared laser sealing and cutting of porcine renal vessels, ex vivo

NASA Astrophysics Data System (ADS)

Giglio, Nicholas C.; Hutchens, Thomas C.; Perkins, William C.; Latimer, Cassandra; Ward, Arlen; Nau, William H.; Fried, Nathaniel M.

2014-03-01

Suture ligation with subsequent cutting of blood vessels to maintain hemostasis during surgery is time consuming and skill intensive. Energy-based, electrosurgical and ultrasonic devices are often used to replace sutures and mechanical clips to provide rapid hemostasis, and decrease surgical time. Some of these devices may create undesirably large collateral zones of thermal damage and tissue necrosis, or require separate mechanical blades for cutting. Infrared lasers are currently being explored as alternative energy sources for vessel sealing applications. In a previous study, a 1470-nm laser was used to seal vessels of 1-6 mm in diameter in 5 s, yielding burst pressures of ~ 500 mmHg. The purpose of this study was to provide faster sealing, incorporate transection of the sealed vessels, and increase the burst pressure. A 110-Watt, 1470-nm laser beam was transmitted through a fiber and beam shaping optics, producing a linear beam 3.0 mm by 9.5 mm for sealing, and 1.1 mm by 9.6 mm for cutting (FWHM). A twostep process sealed then transected ex vivo porcine renal vessels (1-8.5 mm diameter) in a bench top setup. Seal and cut times were 1.0 s each. A standard burst pressure system measured resulting seal strength, and gross and histologic thermal damage measurements were also recorded. All blood vessels tested (n = 30) were sealed and cut, with total irradiation times of 2.0 s, mean burst pressures > 1000 mmHg (compared to normal systolic blood pressure of 120 mmHg), and combined seal/collateral thermal coagulation zones of 2-3 mm. The results of this study demonstrated that an optical-based system is capable of precisely sealing and cutting a wide range of porcine renal vessel sizes, and with further development, may provide an alternative to radiofrequency and ultrasound-based vessel sealing devices.

Acoustic Emission Characteristics of Nanocrystalline Porous Silicon Device Driven as an Ultrasonic Speaker

NASA Astrophysics Data System (ADS)

Tsubaki, Kenji; Komoda, Takuya; Koshida, Nobuyoshi

2006-04-01

It is shown that the dc-superimposed driving mode is more useful for the efficient operation of a novel thermally induced ultrasonic emitter based on nanocrystalline porous silicon (nc-PS) than the conventional simple ac-voltage driving mode. The nc-PS device is composed of a patterned heater electrode, an nc-PS layer and a single crystalline silicon (c-Si) substrate. The almost complete thermally insulating property of nc-PS as a quantum-sized system makes it possible to apply the nc-PS device as an ultrasonic generator by efficient thermo acoustic conversion without any mechanical vibrations. In the dc-superimposed driving mode, the output frequency is the same as the input frequency and a stationary temperature rise is kept constant independent of input peak-to-peak voltage. In addition, power efficiency is significantly increases compared with that in the ac-voltage driving mode without affecting on the temperature rise. The present results suggest the further possibility of the nc-PS device being used as a functional speaker.

Surgical Efficacy Among Laparoscopic Ultrasonic Dissectors: Are We Advancing Safely? A Review of Literature.

PubMed

Devassy, Rajesh; Gopalakrishnan, Sreelatha; De Wilde, Rudy Leon

2015-10-01

The specialty of laparoscopy has evolved with the advent of new technologies over the last few years. Energy-based devices and Ultrasonic dissectors are used with a lot of factors in play-including ergonomics and economics during surgery. Here an attempt is based to review the surgical efficacy and safety of these dissectors with importance to plume production and lateral thermal damage. The factors contributing to adversities to the dissectors are also to be noted. The strategy adopted was aimed at finding relevant studies from PubMed from 1995 to 2014. The basic principle of plume production and thermal damage are studied in this review. Factors contributing to the same that can lead to adversities during laparoscopic surgeries are identified. Summarizing key points that increase lateral thermal damage and plume production amongst different ultrasonic shears and suggesting a technique to identify the right balance between the existing dissectors was possible. The RF Device and USS are both useful and widely used and are more safer than monopolar devices. RF Device is considerably slower than USS, as it cannot achieve coagulation and cutting at the same time. Although USS definitely improvises dissection and has less thermal injury than RF Device, the clinical implications in balancing dissection efficacy with hemostasis need to be investigated further. The ideal haemostatic energy-based shear device would be one with excellent hemostatic results and visual acuity while allowing none or minimal thermal energy escape at the point of application. In our current setting, a combined use of both RF and USS device usage as applied in the particular situations has potential.

Applications of thermal infrared imagery for energy conservation and environmental surveys

NASA Technical Reports Server (NTRS)

Carney, J. R.; Vogel, T. C.; Howard, G. E., Jr.; Love, E. R.

1977-01-01

The survey procedures, developed during the winter and summer of 1976, employ color and color infrared aerial photography, thermal infrared imagery, and a handheld infrared imaging device. The resulting imagery was used to detect building heat losses, deteriorated insulation in built-up type building roofs, and defective underground steam lines. The handheld thermal infrared device, used in conjunction with the aerial thermal infrared imagery, provided a method for detecting and locating those roof areas that were underlain with wet insulation. In addition, the handheld infrared device was employed to conduct a survey of a U.S. Army installation's electrical distribution system under full operating loads. This survey proved to be cost effective procedure for detecting faulty electrical insulators and connections that if allowed to persist could have resulted in both safety hazards and loss in production.

Reproduction of mouse-pup ultrasonic vocalizations by nanocrystalline silicon thermoacoustic emitter

NASA Astrophysics Data System (ADS)

Kihara, Takashi; Harada, Toshihiro; Kato, Masahiro; Nakano, Kiyoshi; Murakami, Osamu; Kikusui, Takefumi; Koshida, Nobuyoshi

2006-01-01

As one of the functional properties of ultrasound generator based on efficient thermal transfer at the nanocrystalline silicon (nc-Si) layer surface, its potential as an ultrasonic simulator of vocalization signals is demonstrated by using the acoustic data of mouse-pup calls. The device composed of a surface-heating thin-film electrode, an nc-Si layer, and a single-crystalline silicon (c-Si) wafer, exhibits an almost completely flat frequency response over a wide range without any mechanical surface vibration systems. It is shown that the fabricated emitter can reproduce digitally recorded ultrasonic mouse-pups vocalizations very accurately in terms of the call duration, frequency dispersion, and sound pressure level. The thermoacoustic nc-Si device provides a powerful physical means for the understanding of ultrasonic communication mechanisms in various living animals.

Ultrasonically treated multi-walled carbon nanotubes (MWCNTs) as PtRu catalyst supports for methanol electrooxidation

NASA Astrophysics Data System (ADS)

Yang, Chunwei; Hu, Xinguo; Wang, Dianlong; Dai, Changsong; Zhang, Liang; Jin, Haibo; Agathopoulos, Simeon

In the quest of fabricating supported catalysts, experimental results of transmission electron microscopy, Raman and infrared spectroscopy indicate that ultrasonic treatment effectively functionalizes multi-walled carbon nanotubes (MWCNTs), endowing them with groups that can act as nucleation sites which can favor well-dispersed depositions of PtRu clusters on their surface. Ultrasonic treatment seems to be superior than functionalization via regular refluxing. This is confirmed by the determination of the electrochemistry active surface area (ECA) and the CO-tolerance performance of the PtRu catalysts, measured by adsorbed CO-stripping voltammetry in 0.5 M sulfuric acid solution, and the real surface area of the PtRu catalysts, evaluated by Brunauer-Emmett-Teller (BET) measurements. Finally, the effectiveness for methanol oxidation is assessed by cyclic voltammetry (CV) in a sulfuric acid and methanol electrolyte.

Precision Cleaning Verification of Nonvolatile Residues by Using Water, Ultrasonics, and Turbidity Analyses

NASA Technical Reports Server (NTRS)

Skinner, S. Ballou

1991-01-01

Chlorofluorocarbons (CFC's) in the atmosphere are believed to present a major environmental problem because they are able to interact with and deplete the ozone layer. NASA has been mandated to replace chlorinated solvents in precision cleaning, cleanliness verification, and degreasing of aerospace fluid systems hardware and ground support equipment. KSC has a CFC phase-out plan which provides for the elimination of over 90 percent of the CFC and halon use by 1995. The Materials Science Laboratory and KSC is evaluating four analytical methods for the determination of nonvolatile residues removal by water: (1) infrared analyses using an attenuated total reflectance; (2) surface tension analyses, (3) total organic content analyses, and (4) turbidity analyses. This research project examined the ultrasonic-turbidity responses for 22 hydrocarbons in an effect to determine: (1) if ultrasonics in heated water (70 C) will clean hydrocarbons (oils, greases, gels, and fluids) from aerospace hardware; (2) if the cleaning process by ultrasonics will simultaneously emulsify the removed hydrocarbons in the water; and (3) if a turbidimeter can be used successfully as an analytical instrument for quantifying the removal of hydrocarbons. Sixteen of the 22 hydrocarbons tested showed that ultrasonics would remove it at least 90 percent of the contaminated hydrocarbon from the hardware in 10 minutes or less giving a good ultrasonic-turbidity response. Six hydrocarbons had a lower percentage removal, a slower removal rate, and a marginal ultrasonic-turbidity response.

Face recognition in the thermal infrared domain

NASA Astrophysics Data System (ADS)

Kowalski, M.; Grudzień, A.; Palka, N.; Szustakowski, M.

2017-10-01

Biometrics refers to unique human characteristics. Each unique characteristic may be used to label and describe individuals and for automatic recognition of a person based on physiological or behavioural properties. One of the most natural and the most popular biometric trait is a face. The most common research methods on face recognition are based on visible light. State-of-the-art face recognition systems operating in the visible light spectrum achieve very high level of recognition accuracy under controlled environmental conditions. Thermal infrared imagery seems to be a promising alternative or complement to visible range imaging due to its relatively high resistance to illumination changes. A thermal infrared image of the human face presents its unique heat-signature and can be used for recognition. The characteristics of thermal images maintain advantages over visible light images, and can be used to improve algorithms of human face recognition in several aspects. Mid-wavelength or far-wavelength infrared also referred to as thermal infrared seems to be promising alternatives. We present the study on 1:1 recognition in thermal infrared domain. The two approaches we are considering are stand-off face verification of non-moving person as well as stop-less face verification on-the-move. The paper presents methodology of our studies and challenges for face recognition systems in the thermal infrared domain.

Ultrasonic monitoring of Iberian fat crystallization during cold storage

NASA Astrophysics Data System (ADS)

Corona, E.; García-Pérez, J. V.; Santacatalina, J. V.; Peña, R.; Benedito, J.

2012-12-01

The aim of this work was to evaluate the use of ultrasonic measurements to characterize the crystallization process and to assess the textural changes of Iberian fat and Iberian ham during cold storage. The ultrasonic velocity was measured in two types of Iberian fats (Montanera and Cebo) during cold storage (0, 2, 5, 7 and 10 °C) and in vacuum packaged Iberian ham stored at 6°C for 120 days. The fatty acid profile, thermal behaviour and textural properties of fat were determined. The ultrasonic velocity and textural measurements showed a two step increase during cold storage, which was related with the separate crystallization of two fractions of triglycerides. It was observed that the harder the fat, the higher the ultrasonic velocity. Likewise, Cebo fat resulted harder than Montanera due to a higher content of saturated triglycerides. The ultrasonic velocity in Iberian ham showed an average increase of 55 m/s after 120 days of cold storage due to fat crystallization. Thus, non-destructive ultrasonic technique could be a reliable method to follow the crystallization of fats and to monitor the changes in the textural properties of Iberian ham during cold storage.

Solar panel thermal cycling testing by solar simulation and infrared radiation methods

NASA Technical Reports Server (NTRS)

Nuss, H. E.

1980-01-01

For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound

PubMed Central

Lopez-Haro, S. A.; Leija, L.

2016-01-01

Objectives. To present a quantitative comparison of thermal patterns produced by the piston-in-a-baffle approach with those generated by a physiotherapy ultrasonic device and to show the dependency among thermal patterns and acoustic intensity distributions. Methods. The finite element (FE) method was used to model an ideal acoustic field and the produced thermal pattern to be compared with the experimental acoustic and temperature distributions produced by a real ultrasonic applicator. A thermal model using the measured acoustic profile as input is also presented for comparison. Temperature measurements were carried out with thermocouples inserted in muscle phantom. The insertion place of thermocouples was monitored with ultrasound imaging. Results. Modeled and measured thermal profiles were compared within the first 10 cm of depth. The ideal acoustic field did not adequately represent the measured field having different temperature profiles (errors 10% to 20%). Experimental field was concentrated near the transducer producing a region with higher temperatures, while the modeled ideal temperature was linearly distributed along the depth. The error was reduced to 7% when introducing the measured acoustic field as the input variable in the FE temperature modeling. Conclusions. Temperature distributions are strongly related to the acoustic field distributions. PMID:27999801

Analysis and research on thermal infrared properties and adaptability of the camouflage net

NASA Astrophysics Data System (ADS)

Cui, Guangzhen; Hu, Jianghua; Jian, Chaochao; Yang, Juntang

2016-10-01

As camouflage equipment, camouflage net which covers or obstruct the enemy reconnaissance and attack, have the compatibility such as optics, infrared, radar wave band performance. To improve the adaptive between the camouflage net with background in infrared wavelengths, the heat shield and heat integration requirements on the surface of the camouflage net was analyzed. The condition that satisfied the heat shield was when the average thermal infrared transmittance was less than 25.38% on camouflage screen surface. Studies have shown that camouflage nets and the background field fused together when infrared radiation temperature difference control is within the scope of ± 4K . Experiment on temperature contrast was tested in situ background, thermal camouflage spots and camouflage net with sponge material, the infrared heat maps was recorded in the period of experiment through the thermal imager. Results showed that the thermal inertia of camouflage net was markedly lower than the background and the exposed signs were obvious. It was difficult to reach camouflage thermal infrared fusion requirements by relying on camouflage spot emissivity, but sponge which mix with polymer resin can reduce target significance in the context of mottled and realize the fusion effect.

Inconspicuous echolocation in hoary bats (Lasiurus cinereus)

Treesearch

Aaron J. Corcoran; Theodore J. Weller

2018-01-01

Echolocation allows bats to occupy diverse nocturnal niches. Bats almost always use echolocation, even when other sensory stimuli are available to guide navigation. Here, using arrays of calibrated infrared cameras and ultrasonic microphones, we demonstrate that hoary bats (Lasiurus cinereus) use previously unknown echolocation behaviours that...

Choosing a Motion Detector.

ERIC Educational Resources Information Center

Ballard, David M.

1990-01-01

Examines the characteristics of three types of motion detectors: Doppler radar, infrared, and ultrasonic wave, and how they are used on school buses to prevent students from being killed by their own school bus. Other safety devices cited are bus crossing arms and a camera monitor system. (MLF)

In situ assessment of structural timber elements of a historic building by infrared thermography and ultrasonic velocity

NASA Astrophysics Data System (ADS)

Kandemir-Yucel, A.; Tavukcuoglu, A.; Caner-Saltik, E. N.

2007-01-01

The infrared thermography (IRT) and the ultrasonic velocity measurements (UVM) promise to be particularly important to assess the state of deterioration and the adequacy of the boundary and microclimatic conditions for timber elements. These non-destructive methods supported by laboratory analyses of timber samples were conducted on a 13th century monument, Aslanhane Mosque in Ankara, Turkey. The combined interpretation of the results was done to assess the condition of structural timber elements in terms of their state of preservation, the dampness problems and the recent incompatible repairs affecting them. Results indicated that moist areas in the structure were associated with roof drainage problems and the repairs undertaken with cement-based mortars and plasters and oil-based paints. Juxtaposition of the IRT and UVM together with laboratory analyses was found to be useful to assess the soundness of timber, enhanced the accuracy and effectiveness of the survey and facilitated to build up the urgent and long-term conservation programs.

Image Processing Occupancy Sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

The Image Processing Occupancy Sensor, or IPOS, is a novel sensor technology developed at the National Renewable Energy Laboratory (NREL). The sensor is based on low-cost embedded microprocessors widely used by the smartphone industry and leverages mature open-source computer vision software libraries. Compared to traditional passive infrared and ultrasonic-based motion sensors currently used for occupancy detection, IPOS has shown the potential for improved accuracy and a richer set of feedback signals for occupant-optimized lighting, daylighting, temperature setback, ventilation control, and other occupancy and location-based uses. Unlike traditional passive infrared (PIR) or ultrasonic occupancy sensors, which infer occupancy based only onmore » motion, IPOS uses digital image-based analysis to detect and classify various aspects of occupancy, including the presence of occupants regardless of motion, their number, location, and activity levels of occupants, as well as the illuminance properties of the monitored space. The IPOS software leverages the recent availability of low-cost embedded computing platforms, computer vision software libraries, and camera elements.« less

Infrared non-destructive evaluation method and apparatus

DOEpatents

Baleine, Erwan; Erwan, James F; Lee, Ching-Pang; Stinelli, Stephanie

2014-10-21

A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

Thermal Infrared and Visible to Near-Infrared Spectral Analysis of Chert and Amorphous Silica

NASA Astrophysics Data System (ADS)

McDowell, M. L.; Hamilton, V. E.; Cady, S. L.; Knauth, P.

2009-03-01

We look in detail at the thermal infrared and visible to near-infrared spectra of various forms of chert and amorphous silica and compare the spectral variations between samples with variations in physical and chemical characteristics.

Thermographic Imaging of Material Loss in Boiler Water-Wall Tubing by Application of Scanning Line Source

NASA Technical Reports Server (NTRS)

Cramer, K. Elliott; Winfree, William P.

2000-01-01

Localized wall thinning due to corrosion in utility boiler water-wall tubing is a significant inspection concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. This technique has proven to be very manpower and time intensive. This has resulted in a spot check approach to inspections, documenting thickness measurements over a relatively small percentage of the total boiler wall area. NASA Langley Research Center has developed a thermal NDE technique designed to image and quantitatively characterize the amount of material thinning present in steel tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source coupled with the analysis technique represents a significant improvement in the inspection speed for large structures such as boiler water-walls. A theoretical basis for the technique will be presented which explains the quantitative nature of the technique. Further, a dynamic calibration system will be presented for the technique that allows the extraction of thickness information from the temperature data. Additionally, the results of applying this technology to actual water-wall tubing samples and in situ inspections will be presented.

The effect of thermal and ultrasonic treatment on amino acid composition, radical scavenging and reducing potential of hydrolysates obtained from simulated gastrointestinal digestion of cowpea proteins.

PubMed

Quansah, Joycelyn K; Udenigwe, Chibuike C; Saalia, Firibu K; Yada, Rickey Y

2013-03-01

The effect of thermal and ultrasonic treatment of cowpea proteins (CP) on amino acid composition, radical scavenging and reducing potential of hydrolysates (CPH) obtained from in vitro simulated gastrointestinal digestion of CP was evaluated. Hydrolysis of native and treated CP with gastrointestinal pepsin and pancreatin yielded CPH that displayed antioxidant activities based on oxygen radical scavenging capacity (ORAC), ferric reducing antioxidant power (FRAP) and superoxide radical scavenging activity (SRSA). CPH derived from the treated CP yielded higher ORAC values than CPH from untreated proteins. However, lower significant FRAP and SRSA values were observed for these samples compared to untreated CPH (p < 0.05). Amino acid analysis indicated that CP processing decreased total sulphur-containing amino acids in the hydrolysates, particularly cysteine. The amount of cysteine appeared to be positively related to FRAP and SRSA values of CPH samples, but not ORAC. The results indicated that thermal and ultrasonic processing of CP can reduce the radical scavenging and reducing potential of the enzymatic hydrolysates possibly due to the decreased amounts of cysteine. Since the hydrolysates were generated with gastrointestinal enzymes, it is possible that the resulting compounds are produced to exert some health functions during normal consumption of cowpea.

Photo-, sono- and sonophotocatalytic degradation of methylene blue using Fe3O4/ZrO2 composites catalysts

NASA Astrophysics Data System (ADS)

Kristianto, Y.; Taufik, A.; Saleh, R.

2017-07-01

In the present work, magnetite material Fe3O4/ZrO2 with various molar ratios was prepared by the two-step method (sol-gel followed by the ultrasonic-assisted method). The as-prepared samples were fairly characterized by various characterization methods, such as X-ray Diffraction (XRD), Vibrating Sample Magnetometer (VSM), Fourier Transform Infrared (FT-IR) and Thermal Gravimetric Analysis (TGA). The catalytic performance of the as-prepared samples was evaluated based on the degradation of methylene blue under UV light, ultrasound and combination of UV and ultrasound irradiation. The results revealed that the sample with Fe3O4:ZrO2 molar ratio of 0.5:1 showed the best catalytic performance under UV, ultrasound and UV + ultrasound irradiation. The degradation of methylene blue follows the order: sonophotocatalytic > sonocatalytic > photocatalytic. In addition, the effect of various scavengers has also been studied. Furthermore, all prepared samples could be used as a convenient recyclable catalyst.

Preparation of nanostructured and nanosheets of MoS2 oxide using oxidation method.

PubMed

Amini, Majed; Ramazani S A, Ahmad; Faghihi, Morteza; Fattahpour, Seyyedfaridoddin

2017-11-01

Molybdenum disulfide (MoS 2 ), a two-dimensional transition metal has a 2D layered structure and has recently attracted attention due to its novel catalytic properties. In this study, MoS 2 has been successfully intercalated using chemical and physical intercalation techniques, while enhancing its surface properties. The final intercalated MoS 2 is of many interests because of its low-dimensional and potential properties in in-situ catalysis. In this research, we report different methods to intercalate the layers of MoS 2 successfully using acid-treatment, ultrasonication, oxidation and thermal shocking. The other goal of this study is to form SO bonds mainly because of expected enhanced in-situ catalytic operations. The intercalated MoS 2 is further characterized using analyses such as Fourier Transform Infrared Spectroscopy (FTIR), Raman, Contact Angle, X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-Ray Microanalysis (EDAX), Transmission electron microscopy (TEM), and BET. Copyright © 2017. Published by Elsevier B.V.

Ultrasonic determination of thermodynamic threshold parameters for irreversible cutaneous burns

NASA Technical Reports Server (NTRS)

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.

PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON NONDESTRUCTIVE TESTING, [HELD AT MONTREAL, CANADA, MAY 21--26, 1967].

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1969-07-01

The Fifth International Conference on Nondestructive Testing was held in Montreal, Canada, for the purpose of promoting international collaboration in all matters related to the development and use of nondestructive test methods. A total of 82 papers were selected for presentation. Session titles included: evaluation of material quality; ultrasonics - identification and measurements; thermal methods; testing of welds; visual aids in nondestructive testing; measurements of stress and elastic properties; magnetic and eddy-current methods; surface methods and neutron radiography; standardization - general; ultrasonics at elevated temperatures; applications; x-ray techniques; radiography; ultrasonic standardization; training and qualification; and, correlation of weld defects.

A primary study on finding hot groundwater using infrared remote sensing

NASA Astrophysics Data System (ADS)

Qiao, Y.; Wu, Q.

Hot groundwater is a kind of valuable natural resources to be explored utilized. Shanxi Province, located in the eastern Loess Plateau of China, is rich in geothermal resources, most of which was found in irrigation well drilling or geological survey. Basic study is weak. Now new developed Remote Sensing technique provides geothermal study with an advanced way. Air-RS information of thermal infrared and dada from thermal channel of Meteorological Landset AVHRR has been used widely. A thermal infrared channel (TM6) was installed in the U. S. second Landset, Its resolving power of space is as high as 120 m, 10 times more t an one ofh AVHRR. A Landset earth recourses launched by China and Brazil (CBERS-1) in 1999, including a spectrum of thermal infrared. It is paid a great interested and attention to survey geothermal resources using thermal infrared. This article is a brief introduction of finding hot groundwater with on the bases of differences of thermal radiation of objects reflected by thermal infrared in the Landset, and treated with HIS colors changes. This study provides an advanced way widely used to exploit hot groundwater and to promote the development of tourism and geothermal medical in China.

An improved contrast enhancement algorithm for infrared images based on adaptive double plateaus histogram equalization

NASA Astrophysics Data System (ADS)

Li, Shuo; Jin, Weiqi; Li, Li; Li, Yiyang

2018-05-01

Infrared thermal images can reflect the thermal-radiation distribution of a particular scene. However, the contrast of the infrared images is usually low. Hence, it is generally necessary to enhance the contrast of infrared images in advance to facilitate subsequent recognition and analysis. Based on the adaptive double plateaus histogram equalization, this paper presents an improved contrast enhancement algorithm for infrared thermal images. In the proposed algorithm, the normalized coefficient of variation of the histogram, which characterizes the level of contrast enhancement, is introduced as feedback information to adjust the upper and lower plateau thresholds. The experiments on actual infrared images show that compared to the three typical contrast-enhancement algorithms, the proposed algorithm has better scene adaptability and yields better contrast-enhancement results for infrared images with more dark areas or a higher dynamic range. Hence, it has high application value in contrast enhancement, dynamic range compression, and digital detail enhancement for infrared thermal images.

Nonlinear ultrasonic stimulated thermography for damage assessment in isotropic fatigued structures

NASA Astrophysics Data System (ADS)

Fierro, Gian Piero Malfense; Calla', Danielle; Ginzburg, Dmitri; Ciampa, Francesco; Meo, Michele

2017-09-01

Traditional non-destructive evaluation (NDE) and structural health monitoring (SHM) systems are used to analyse that a structure is free of any harmful damage. However, these techniques still lack sensitivity to detect the presence of material micro-flaws in the form of fatigue damage and often require time-consuming procedures and expensive equipment. This research work presents a novel "nonlinear ultrasonic stimulated thermography" (NUST) method able to overcome some of the limitations of traditional linear ultrasonic/thermography NDE-SHM systems and to provide a reliable, rapid and cost effective estimation of fatigue damage in isotropic materials. Such a hybrid imaging approach combines the high sensitivity of nonlinear acoustic/ultrasonic techniques to detect micro-damage, with local defect frequency selection and infrared imaging. When exciting structures with an optimised frequency, nonlinear elastic waves are observed and higher frictional work at the fatigue damaged area is generated due to clapping and rubbing of the crack faces. This results in heat at cracked location that can be measured using an infrared camera. A Laser Vibrometer (LV) was used to evaluate the extent that individual frequency components contribute to the heating of the damage region by quantifying the out-of-plane velocity associated with the fundamental and second order harmonic responses. It was experimentally demonstrated the relationship between a nonlinear ultrasound parameter (βratio) of the material nonlinear response to the actual temperature rises near the crack. These results demonstrated that heat generation at damaged regions could be amplified by exciting at frequencies that provide nonlinear responses, thus improving the imaging of material damage and the reliability of NUST in a quick and reproducible manner.

Detection and modeling of subsurface coal oxidation

USGS Publications Warehouse

Leonhart, Leo S.; Rasmussen, William O.; Barringer, Anthony R.

1980-01-01

The oxidation and sustained ignition of coal and coaly wastes within surface coal mine spoils in the southwestern U.S. have hampered the success of reclamation efforts at these locations. To assess better the magnitude, depth, geometry, and dynamics of the oxidation process thermal infrared remote sensing data have been used. Digital thermal imagery was found to be useful for this purpose and was integrated with finite different heat transfer models to yield predictions of several characteristics of the thermal source. In addition to thermal infrared imagery, aerial color and false color infrared imagery were found to provide useful information for the interpretation of oxidation phenomena by means of variations in surface vegetation, color of the surface material, subsidence, etc. The combined use of thermal infrared imagery and thermal modeling techniques are well suited for use in exploration and interpretation of other thermal targets.

Ultrasonic Studies of Composites Undergoing Thermal and Fatigue Loading

NASA Technical Reports Server (NTRS)

Madaras, Eric I.; Winfree, William P.; Johnston, Patrick H.

1997-01-01

New composite materials possess attractive properties for use in advanced aircraft. A necessary requirement for their introduction into aeronautic use is an accurate understanding of their long term aging processes so that proper design criteria can be established. In order to understand those properties, these composites must be exposed to thermal and load cycles that are characteristic of flight conditions. Additionally, airline companies will require nondestructive evaluation (NDE) methods that can be used in the field to assess the condition of these new materials as they age. As part of an effort to obtain the required information about new composites for aviation use, we are performing ultrasonic measurements both in the NDE laboratory and in the materials testing laboratory at NASA. The materials testing laboratory is equipped with environmental chambers mounted on load frames so that composite samples can be exposed to thermal and loading cycles representative of flight protocols. Applying both temperature and load simultaneously will help to highlight temperature and load interactions during the aging of these composite materials. This study reports on our initial ultrasonic attenuation results from thermoset and thermoplastic composite samples. Ultrasonic attenuation measurements have been used reliably to assess the effects of material degradation. For example, recently, researchers have shown that by using frequencies of ultrasound on the order of 24 MHz, they could obtain adequate contrast in the evaluation of thermal degradation in these composites. This paper will present data that shows results at a lower frequency range. In addition, we report results on the frequency dependence of attenuation as the slope of attenuation with respect to frequency, beta = delta alpha (f) / delta f. The slope of attenuation is an attractive parameter since it is quantitative, yet does not require interface corrections like conventional quantitative attenuation measurements. This is a consequence of the assumption that interface correction terms are frequently independent. Uncertainty in those corrections terms compromises the value of conventional quantitative attenuation data.

Thermal Infrared Anomalies of Several Strong Earthquakes

PubMed Central

Wei, Congxin; Guo, Xiao; Qin, Manzhong

2013-01-01

In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of “time-frequency relative power spectrum.” (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting. PMID:24222728

Thermal infrared anomalies of several strong earthquakes.

PubMed

Wei, Congxin; Zhang, Yuansheng; Guo, Xiao; Hui, Shaoxing; Qin, Manzhong; Zhang, Ying

2013-01-01

In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of "time-frequency relative power spectrum." (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting.

Thermal Infrared Imaging-Based Computational Psychophysiology for Psychometrics.

PubMed

Cardone, Daniela; Pinti, Paola; Merla, Arcangelo

2015-01-01

Thermal infrared imaging has been proposed as a potential system for the computational assessment of human autonomic nervous activity and psychophysiological states in a contactless and noninvasive way. Through bioheat modeling of facial thermal imagery, several vital signs can be extracted, including localized blood perfusion, cardiac pulse, breath rate, and sudomotor response, since all these parameters impact the cutaneous temperature. The obtained physiological information could then be used to draw inferences about a variety of psychophysiological or affective states, as proved by the increasing number of psychophysiological studies using thermal infrared imaging. This paper presents therefore a review of the principal achievements of thermal infrared imaging in computational physiology with regard to its capability of monitoring psychophysiological activity.

Infrared thermography: A non-invasive window into thermal physiology.

PubMed

Tattersall, Glenn J

2016-12-01

Infrared thermography is a non-invasive technique that measures mid to long-wave infrared radiation emanating from all objects and converts this to temperature. As an imaging technique, the value of modern infrared thermography is its ability to produce a digitized image or high speed video rendering a thermal map of the scene in false colour. Since temperature is an important environmental parameter influencing animal physiology and metabolic heat production an energetically expensive process, measuring temperature and energy exchange in animals is critical to understanding physiology, especially under field conditions. As a non-contact approach, infrared thermography provides a non-invasive complement to physiological data gathering. One caveat, however, is that only surface temperatures are measured, which guides much research to those thermal events occurring at the skin and insulating regions of the body. As an imaging technique, infrared thermal imaging is also subject to certain uncertainties that require physical modelling, which is typically done via built-in software approaches. Infrared thermal imaging has enabled different insights into the comparative physiology of phenomena ranging from thermogenesis, peripheral blood flow adjustments, evaporative cooling, and to respiratory physiology. In this review, I provide background and guidelines for the use of thermal imaging, primarily aimed at field physiologists and biologists interested in thermal biology. I also discuss some of the better known approaches and discoveries revealed from using thermal imaging with the objective of encouraging more quantitative assessment. Copyright © 2016 Elsevier Inc. All rights reserved.

[Nondestructive Evaluation (NDE) Capabilities

NASA Technical Reports Server (NTRS)

Born, Martin

2010-01-01

These poster boards display the United Space Alliance's (USA) systems and equipment used for Nondestructive Evaluation. These include: (1) the Robotic Inspection Facility, (2) CAT-Scan and Laminography, (3) Laser Surface Profilometry, (4) Remote Eddy Current, (5) Ultrasonic Phased Array, (7) Infrared Flash Thermography, and (8) Backscatter X-Ray (BSX)

10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... occupancy sensor means a device which uses passive infrared, ultrasonic, or other motion-sensing technology..., frozen, combination chilled and frozen, or variable temperature; (4) Displays or stores merchandise and... doors; (6) Is designed for pull-down temperature applications or holding temperature applications; and...

Damage detection in composites using nonlinear ultrasonically modulated thermography

NASA Astrophysics Data System (ADS)

Malfense Fierro, G.-P.; Dionysopoulos, D.; Meo, M.; Ciampa, F.

2018-03-01

This paper proposes a novel nonlinear ultrasonically stimulated thermography technique for a quick and reliable assessment of material damage in carbon fibre reinforced plastic (CFRP) composite materials. The proposed nondestructive evaluation (NDE) method requires narrow sweep ultrasonic excitation using contact piezoelectric transducers in order to identify dual excitation frequencies associated with the damage resonance. High-amplitude signals and higher harmonic generation are necessary conditions for an accurate identification of these two input frequencies. Dual periodic excitation using high- and low-frequency input signals was then performed in order to generate frictional heating at the crack location that was measured by an infrared (IR) camera. To validate this concept, an impact damaged CFRP composite panel was tested and the experimental results were compared with traditional flash thermography. A laser vibrometer was used to investigate the response of the material with dual frequency excitation. The proposed nonlinear ultrasonically modulated thermography successfully detected barely visible impact damage in CFRP composites. Hence, it can be considered as an alternative to traditional flash thermography and thermosonics by allowing repeatable detection of damage in composites.

Ultrasonic Stir Welding

NASA Technical Reports Server (NTRS)

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.

Spectrum Tunable Quantum Dot-In-A-Well Infrared Detector Arrays for Thermal Imaging

DTIC Science & Technology

2008-09-01

Spectrum tunable quantum dot-in-a- well infrared detector arrays for thermal imaging Jonathan R. Andrews1, Sergio R. Restaino1, Scott W. Teare2...Materials at the University of New Mexico has been investigating quantum dot and quantum well detectors for thermal infrared imaging applications...SEP 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Spectrum tunable quantum dot-in-a- well infrared

The edge detection method of the infrared imagery of the laser spot

NASA Astrophysics Data System (ADS)

Che, Jinxi; Zhang, Jinchun; Li, Zhongmin

2016-01-01

In the jamming effectiveness experiments, in which the thermal infrared imager was interfered by the CO2 Laser, in order to evaluate the jamming effect of the thermal infrared imager by the CO2 Laser, it was needed to analyses the obtained infrared imagery of laser spot. Because the laser spot pictures obtained from the thermal infrared imager are irregular, the edge detection is an important process. The image edge is one of the most basic characteristics of the image, and it contains most of the information of the image. Generally, because of the thermal balance effect, the partly temperature of objective is no quite difference; therefore the infrared imagery's ability of reflecting the local detail of object is obvious week. At the same time, when the information of heat distribution of the thermal imagery was combined with the basic information of target, such as the object size, the relative position of field of view, shape and outline, and so on, the information just has more value. Hence, it is an important step for making image processing to extract the objective edge of the infrared imagery. Meanwhile it is an important part of image processing procedure and it is the premise of many subsequent processing. So as to extract outline information of the target from the original thermal imagery, and overcome the disadvantage, such as the low image contrast of the image and serious noise interference, and so on, the edge of thermal imagery needs detecting and processing. The principles of the Roberts, Sobel, Prewitt and Canny operator were analyzed, and then they were used to making edge detection on the thermal imageries of laser spot, which were obtained from the jamming effect experiments of CO2 laser jamming the thermal infrared imager. On the basis of the detection result, their performances were compared. At the end, the characteristics of the operators were summarized, which provide reference for the choice of edge detection operators in thermal imagery processing in future.

Distance correction system for localization based on linear regression and smoothing in ambient intelligence display.

PubMed

Kim, Dae-Hee; Choi, Jae-Hun; Lim, Myung-Eun; Park, Soo-Jun

2008-01-01

This paper suggests the method of correcting distance between an ambient intelligence display and a user based on linear regression and smoothing method, by which distance information of a user who approaches to the display can he accurately output even in an unanticipated condition using a passive infrared VIR) sensor and an ultrasonic device. The developed system consists of an ambient intelligence display and an ultrasonic transmitter, and a sensor gateway. Each module communicates with each other through RF (Radio frequency) communication. The ambient intelligence display includes an ultrasonic receiver and a PIR sensor for motion detection. In particular, this system selects and processes algorithms such as smoothing or linear regression for current input data processing dynamically through judgment process that is determined using the previous reliable data stored in a queue. In addition, we implemented GUI software with JAVA for real time location tracking and an ambient intelligence display.

Estimation of human emotions using thermal facial information

NASA Astrophysics Data System (ADS)

Nguyen, Hung; Kotani, Kazunori; Chen, Fan; Le, Bac

2014-01-01

In recent years, research on human emotion estimation using thermal infrared (IR) imagery has appealed to many researchers due to its invariance to visible illumination changes. Although infrared imagery is superior to visible imagery in its invariance to illumination changes and appearance differences, it has difficulties in handling transparent glasses in the thermal infrared spectrum. As a result, when using infrared imagery for the analysis of human facial information, the regions of eyeglasses are dark and eyes' thermal information is not given. We propose a temperature space method to correct eyeglasses' effect using the thermal facial information in the neighboring facial regions, and then use Principal Component Analysis (PCA), Eigen-space Method based on class-features (EMC), and PCA-EMC method to classify human emotions from the corrected thermal images. We collected the Kotani Thermal Facial Emotion (KTFE) database and performed the experiments, which show the improved accuracy rate in estimating human emotions.

Detection of tissue coagulation by decorrelation of ultrasonic echo signals in cavitation-enhanced high-intensity focused ultrasound treatment.

PubMed

Yoshizawa, Shin; Matsuura, Keiko; Takagi, Ryo; Yamamoto, Mariko; Umemura, Shin-Ichiro

2016-01-01

A noninvasive technique to monitor thermal lesion formation is necessary to ensure the accuracy and safety of high-intensity focused ultrasound (HIFU) treatment. The purpose of this study is to ultrasonically detect the tissue change due to thermal coagulation in the HIFU treatment enhanced by cavitation microbubbles. An ultrasound imaging probe transmitted plane waves at a center frequency of 4.5 MHz. Ultrasonic radio-frequency (RF) echo signals during HIFU exposure at a frequency of 1.2 MHz were acquired. Cross-correlation coefficients were calculated between in-phase and quadrature (IQ) data of two B-mode images with an interval time of 50 and 500 ms for the estimation of the region of cavitation and coagulation, respectively. Pathological examination of the coagulated tissue was also performed to compare with the corresponding ultrasonically detected coagulation region. The distribution of minimum hold cross-correlation coefficient between two sets of IQ data with 50-ms intervals was compared with a pulse inversion (PI) image. The regions with low cross-correlation coefficients approximately corresponded to those with high brightness in the PI image. The regions with low cross-correlation coefficients in 500-ms intervals showed a good agreement with those with significant change in histology. The results show that the regions of coagulation and cavitation could be ultrasonically detected as those with low cross-correlation coefficients between RF frames with certain intervals. This method will contribute to improve the safety and accuracy of the HIFU treatment enhanced by cavitation microbubbles.

Infrared cameras are potential traceable "fixed points" for future thermometry studies.

PubMed

Yap Kannan, R; Keresztes, K; Hussain, S; Coats, T J; Bown, M J

2015-01-01

The National physical laboratory (NPL) requires "fixed points" whose temperatures have been established by the International Temperature Scale of 1990 (ITS 90) be used for device calibration. In practice, "near" blackbody radiators together with the standard platinum resistance thermometer is accepted as a standard. The aim of this study was to report the correlation and limits of agreement (LOA) of the thermal infrared camera and non-contact infrared temporal thermometer against each other and the "near" blackbody radiator. Temperature readings from an infrared thermography camera (FLIR T650sc) and a non-contact infrared temporal thermometer (Hubdic FS-700) were compared to a near blackbody (Hyperion R blackbody model 982) at 0.5 °C increments between 20-40 °C. At each increment, blackbody cavity temperature was confirmed with the platinum resistance thermometer. Measurements were taken initially with the thermal infrared camera followed by the infrared thermometer, with each device mounted in turn on a stand at a fixed distance of 20 cm and 5 cm from the blackbody aperture, respectively. The platinum thermometer under-estimated the blackbody temperature by 0.015 °C (95% LOA: -0.08 °C to 0.05 °C), in contrast to the thermal infrared camera and infrared thermometer which over-estimated the blackbody temperature by 0.16 °C (95% LOA: 0.03 °C to 0.28 °C) and 0.75 °C (95% LOA: -0.30 °C to 1.79 °C), respectively. Infrared thermometer over-estimates thermal infrared camera measurements by 0.6 °C (95% LOA: -0.46 °C to 1.65 °C). In conclusion, the thermal infrared camera is a potential temperature reference "fixed point" that could substitute mercury thermometers. However, further repeatability and reproducibility studies will be required with different models of thermal infrared cameras.

Additive Manufacturing of Thermoplastic Matrix Composites Using Ultrasonics

NASA Astrophysics Data System (ADS)

Olson, Meghan

Advanced composite materials have great potential for facilitating energy efficient product design and their manufacture if improvements are made to current composite manufacturing processes. This thesis focuses on the development of a novel manufacturing process for thermoplastic composite structures entitled Laser-Ultrasonic Additive Manufacturing ('LUAM'), which is intended to combine the benefits of laser processing technology, developed by Automated Dynamics Inc., with ultrasonic bonding technology that is used commercially for unreinforced polymers. These technologies used together have the potential to significantly reduce the energy consumption and void content of thermoplastic composites made using Automated Fiber Placement (AFP). To develop LUAM in a methodical manner with minimal risk, a staged approach was devised whereby coupon-level mechanical testing and prototyping utilizing existing equipment was accomplished. Four key tasks have been identified for this effort: Benchmarking, Ultrasonic Compaction, Laser Assisted Ultrasonic Compaction, and Demonstration and Characterization of LUAM. This thesis specifically addresses Tasks 1 and 2, i.e. Benchmarking and Ultrasonic Compaction, respectively. Task 1, fabricating test specimens using two traditional processes (autoclave and thermal press) and testing structural performance and dimensional accuracy, provide results of a benchmarking study by which the performance of all future phases will be gauged. Task 2, fabricating test specimens using a non-traditional process (ultrasonic conpaction) and evaluating in a similar fashion, explores the the role of ultrasonic processing parameters using three different thermoplastic composite materials. Further development of LUAM, although beyond the scope of this thesis, will combine laser and ultrasonic technology and eventually demonstrate a working system.

Thermal Infrared Imaging-Based Computational Psychophysiology for Psychometrics

PubMed Central

Cardone, Daniela; Pinti, Paola; Merla, Arcangelo

2015-01-01

Thermal infrared imaging has been proposed as a potential system for the computational assessment of human autonomic nervous activity and psychophysiological states in a contactless and noninvasive way. Through bioheat modeling of facial thermal imagery, several vital signs can be extracted, including localized blood perfusion, cardiac pulse, breath rate, and sudomotor response, since all these parameters impact the cutaneous temperature. The obtained physiological information could then be used to draw inferences about a variety of psychophysiological or affective states, as proved by the increasing number of psychophysiological studies using thermal infrared imaging. This paper presents therefore a review of the principal achievements of thermal infrared imaging in computational physiology with regard to its capability of monitoring psychophysiological activity. PMID:26339284

Permeability recovery of damaged water sensitive core using ultrasonic waves.

PubMed

Khan, Nasir; Pu, Chunsheng; Li, Xu; He, Yanlong; Zhang, Lei; Jing, Cheng

2017-09-01

It is imperative to recover the well productivity lose due to formation damage nearby wellbore during variant well operations. Some indispensable issues in conventional techniques make ultrasonic technology more attractive due to simple, reliable, favorable, cost-effective, and environment friendly nature. This study proposes the independent and combined use of ultrasonic waves and chemical agents for the treatment of already damaged core samples caused by exposure to distilled water. Results elucidate that ultrasonic waves with optimum (20kHz, 1000W) instead of maximum frequency and power worked well in the recovery owing to peristaltic transport caused by matching of natural frequency with acoustic waves frequency. In addition, hundred minutes was investigated as optimum irradiation time which provided ample time span to detach fine loosely suspended particles. However, further irradiation adversely affected the damaged permeability recovery. Moreover, permeability improvement attributes to cavitation due to ultrasonic waves propagation through fluid contained in porous medium and thermal energy generated by three different ways. Eventually, experimental outcomes indicated that maximum (25.3%) damaged permeability recovery was witnessed by applying ultrasonic waves with transducer #2 (20kHz and 1000W) and optimum irradiation timeframe (100min). This recovery was further increased to 45.8% by applying chemical agent and optimum ultrasonic waves simultaneously. Copyright © 2017 Elsevier B.V. All rights reserved.

Isolation and characterization of cellulose nanofibers from culinary banana peel using high-intensity ultrasonication combined with chemical treatment.

PubMed

Khawas, Prerna; Deka, Sankar C

2016-02-10

In the present study, culinary banana peel was explored as a source of raw material for production of cellulose nanofibers (CNFs). For isolation of CNFs, first the peel flour was subjected to different chemical treatments to eliminate non-cellulosic compounds. The obtained chemically treated cellulose fibers were then mechanically tailored and separated into nanofibers using high-intensity ultrasonication at different output power ranging from 0 to 1000 W. The presences of nanofibers in all samples were confirmed by TEM. Increasing output power of ultrasonication reduced size of CNFs and generated more thinner and needle-like structure. SEM, FT-IR and XRD results indicated chemical treatment employed was effective in removing compounds other than cellulose fibers. Thermal analyses evinced the developed CNFs enhanced thermal properties which serve the purpose as an effective reinforcing material to be used as bionanocomposites. Hence, the production of CNFs from this underutilized agro-waste has potential application in commercial field that can add high value to culinary banana. Copyright © 2015 Elsevier Ltd. All rights reserved.

Flight-vehicle materials, structures, and dynamics - Assessment and future directions. Vol. 4 - Tribological materials and NDE

NASA Technical Reports Server (NTRS)

Fusaro, Robert L. (Editor); Achenbach, J. D. (Editor)

1993-01-01

The present volume on tribological materials and NDE discusses liquid lubricants for advanced aircraft engines, a liquid lubricant for space applications, solid lubricants for aeronautics, and thin solid-lubricant films in space. Attention is given to the science and technology of NDE, tools for an NDE engineering base, experimental techniques in ultrasonics for NDE and material characterization, and laser ultrasonics. Topics addressed include thermal methods of NDE and quality control, digital radiography in the aerospace industry, materials characterization by ultrasonic methods, and NDE of ceramics and ceramic composites. Also discussed are smart materials and structures, intelligent processing of materials, implementation of NDE technology on flight structures, and solid-state weld evaluation.

Laser-Generated Ultrasonic Source for a Real-Time Dry-Contact Imaging System

NASA Astrophysics Data System (ADS)

Petculescu, G.; Zhou, Y.; Komsky, I.; Krishnaswamy, S.

2006-03-01

A laser-generated ultrasonic source, to be used with a real-time imaging device, was developed. The ultrasound is generated in the thermoelastic regime, in a composite layer composed of absorbing particles (carbon) and silicone rubber. The composite layer plays three roles: of absorption, constriction and dry-coupling. The central frequency of the generated pulse was controlled by varying the absorption depth of the generation layer. The maximum peak frequency obtained was 4MHz. When additional constriction was provided to the composite layer, the amplitude of the generated signal increased further, due to the large thermal expansion coefficient of the silicone. Images using the laser-generated ultrasonic source were taken.

Adaptive Process Controls and Ultrasonics for High Temperature PEM MEA Manufacture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walczyk, Daniel F.

2015-08-26

The purpose of this 5-year DOE-sponsored project was to address major process bottlenecks associated with fuel cell manufacturing. New technologies were developed to significantly reduce pressing cycle time for high temperature PEM membrane electrode assembly (MEA) through the use of novel, robust ultrasonic (U/S) bonding processes along with low temperature (<100°C) PEM MEAs. In addition, greater manufacturing uniformity and performance was achieved through (a) an investigation into the causes of excessive variation in ultrasonically and thermally bonded MEAs using more diagnostics applied during the entire fabrication and cell build process, and (b) development of rapid, yet simple quality control measurementmore » techniques for use by industry.« less

77 FR 57596 - Government-Owned Inventions, Available for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-18

...; NASA Case No.: MFS-32940-1: Weld Nugget Temperature Control in Thermal Stir Welding; NASA Case No.: MFS-31559-2-DIV: Thermal Stir Welding Process; NASA Case No.: MFS-32611-1: Mass Gauging Demonstrator for Any....: MFS-32859-1: Pulsed Ultrasonic Stir Welding System; NASA Case No.: MFS-32655-1: Aerospace Laser...

Apparatus and method for transient thermal infrared emission spectrometry

DOEpatents

McClelland, John F.; Jones, Roger W.

1991-12-24

A method and apparatus for enabling analysis of a solid material (16, 42) by applying energy from an energy source (20, 70) top a surface region of the solid material sufficient to cause transient heating in a thin surface layer portion of the solid material (16, 42) so as to enable transient thermal emission of infrared radiation from the thin surface layer portion, and by detecting with a spectrometer/detector (28, 58) substantially only the transient thermal emission of infrared radiation from the thin surface layer portion of the solid material. The detected transient thermal emission of infrared radiation is sufficiently free of self-absorption by the solid material of emitted infrared radiation, so as to be indicative of characteristics relating to molecular composition of the solid material.

Method and apparatus for implementing material thermal property measurement by flash thermal imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Jiangang

A method and apparatus are provided for implementing measurement of material thermal properties including measurement of thermal effusivity of a coating and/or film or a bulk material of uniform property. The test apparatus includes an infrared camera, a data acquisition and processing computer coupled to the infrared camera for acquiring and processing thermal image data, a flash lamp providing an input of heat onto the surface of a two-layer sample with an enhanced optical filter covering the flash lamp attenuating an entire infrared wavelength range with a series of thermal images is taken of the surface of the two-layer sample.

Enhanced ultrasonically assisted turning of a β-titanium alloy.

PubMed

Maurotto, Agostino; Muhammad, Riaz; Roy, Anish; Silberschmidt, Vadim V

2013-09-01

Although titanium alloys have outstanding mechanical properties such as high hot hardness, a good strength-to-weight ratio and high corrosion resistance; their low thermal conductivity, high chemical affinity to tool materials severely impair their machinability. Ultrasonically assisted machining (UAM) is an advanced machining technique, which has been shown to improve machinability of a β-titanium alloy, namely, Ti-15-3-3-3, when compared to conventional turning processes. Copyright © 2013 Elsevier B.V. All rights reserved.

Role of Friction on the Thermal Development in Ultrasonically Consolidated Aluminum Foils and Composites

DTIC Science & Technology

2011-01-01

amplitude, . The third input parameter, weld speed, s, is inversely proportional to N, the num- ber of cycles as shown in Eq. (3). In summary, F is...though, an extensive body of work on mechanical testing of ultrasonically consolidated thin foils has been performed at Loughborough University. In...comprehensive textbook on tribology presents a preliminary derivation for plastic contact of ductile metals which suggests ≤ 1/5; this is much lower

Thermal-Independent Properties of PIN-PMN-PT Single-Crystal Linear-Array Ultrasonic Transducers

PubMed Central

Chen, Ruimin; Wu, Jinchuan; Lam, Kwok Ho; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K. Kirk

2013-01-01

In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 (PIN-PMN-PT) and binary Pb(Mg1/3Nb2/3)–PbTiO3 (PMN-PT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a −6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

Magnetic nanoparticles for enhancing the effectiveness of ultrasonic hyperthermia

NASA Astrophysics Data System (ADS)

Józefczak, A.; Kaczmarek, K.; Hornowski, T.; Kubovčíková, M.; Rozynek, Z.; Timko, M.; Skumiel, A.

2016-06-01

Ultrasonic hyperthermia is a method of cancer treatment in which tumors are exposed to an elevated cytotoxic temperature using ultrasound (US). In conventional ultrasonic hyperthermia, the ultrasound-induced heating in the tumor is achieved through the absorption of wave energy. However, to obtain appropriate temperature in reasonable time, high US intensities, which can have a negative impact on healthy tissues, are required. The effectiveness of US for medical purposes can be significantly improved by using the so-called sonosensitizers, which can enhance the thermal effect of US on the tissue by increasing US absorption. One possible candidate for such sonosensitizers is magnetic nanoparticles with mean sizes of 10-300 nm, which can be efficiently heated because of additional attenuation and scattering of US. Additionally, magnetic nanoparticles are able to produce heat in the alternating magnetic field (magnetic hyperthermia). The synergetic application of ultrasonic and magnetic hyperthermia can lead to a promising treatment modality.

Thermographic Imaging of Defects in Anisotropic Composites

NASA Technical Reports Server (NTRS)

Plotnikov, Y. A.; Winfree, W. P.

2000-01-01

Composite materials are of increasing interest to the aerospace industry as a result of their weight versus performance characteristics. One of the disadvantages of composites is the high cost of fabrication and post inspection with conventional ultrasonic scanning systems. The high cost of inspection is driven by the need for scanning systems which can follow large curve surfaces. Additionally, either large water tanks or water squirters are required to couple the ultrasonics into the part. Thermographic techniques offer significant advantages over conventional ultrasonics by not requiring physical coupling between the part and sensor. The thermographic system can easily inspect large curved surface without requiring a surface following scanner. However, implementation of Thermal Nondestructive Evaluations (TNDE) for flaw detection in composite materials and structures requires determining its limit. Advanced algorithms have been developed to enable locating and sizing defects in carbon fiber reinforced plastic (CFRP). Thermal Tomography is a very promising method for visualizing the size and location of defects in materials such as CFRP. However, further investigations are required to determine its capabilities for inspection of thick composites. In present work we have studied influence of the anisotropy on the reconstructed image of a defect generated by an inversion technique. The composite material is considered as homogeneous with macro properties: thermal conductivity K, specific heat c, and density rho. The simulation process involves two sequential steps: solving the three dimensional transient heat diffusion equation for a sample with a defect, then estimating the defect location and size from the surface spatial and temporal thermal distributions (inverse problem), calculated from the simulations.

A Fracture Mechanics Approach to Thermal Shock Investigation in Alumina-Based Refractory

NASA Astrophysics Data System (ADS)

Volkov-Husović, T.; Heinemann, R. Jančić; Mitraković, D.

2008-02-01

The thermal shock behavior of large grain size, alumina-based refractories was investigated experimentally using a standard water quench test. A mathematical model was employed to simulate the thermal stability behavior. Behavior of the samples under repeated thermal shock was monitored using ultrasonic measurements of dynamic Young's modulus. Image analysis was used to observe the extent of surface degradation. Analysis of the obtained results for the behavior of large grain size samples under conditions of rapid temperature changes is given.

Infrared thermal imaging figures of merit

NASA Technical Reports Server (NTRS)

Kaplan, Herbert

1989-01-01

Commercially available types of infrared thermal imaging instruments, both viewers (qualitative) and imagers (quantitative) are discussed. The various scanning methods by which thermal images (thermograms) are generated will be reviewed. The performance parameters (figures of merit) that define the quality of performance of infrared radiation thermometers will be introduced. A discussion of how these parameters are extended and adapted to define the performance of thermal imaging instruments will be provided. Finally, the significance of each of the key performance parameters of thermal imaging instruments will be reviewed and procedures currently used for testing to verify performance will be outlined.

Ultrasonic-assisted preparation of graphene oxide carboxylic acid polyvinyl alcohol polymer film and studies of thermal stability and surface resistivity.

PubMed

Li, Yongshen; Li, Jihui; Li, Yuehai; Li, Yali; Song, Yunan; Niu, Shuai; Li, Ning

2018-01-01

In this paper, flake graphite, nitric acid and acetic anhydride are used to prepare graphene oxide carboxylic acid (GO-COOH) via an ultrasonic-assisted method, and GO-COOH and polyvinyl alcohol polymer (PVA) are used to synthesize graphene oxide carboxylic acid polyvinyl alcohol polymer (GO-COOPVA) via the ultrasonic-assisted method, and GO-COOPVA is used to manufacture graphene oxide carboxylic acid polyvinyl alcohol polymer film (GO-COOPVA film) via a solidification method, and the structure and morphology of GO-COOH, GO-COOPVA and GO-COOPVA film are characterized, and the thermal stability and surface resistivity are measured in the case of the different amount of GO-COOH. Based on the characterization and measurement, it has been successively confirmed and attested that carboxyl groups implant on 2D lattice of GO to form GO-COOH, and GO-COOH and PVA have the esterification reaction to produce GO-COOPVA, and GO-COOPVA consists of 2D lattice of GO-COOH and the chain of PVA connected in the form of carboxylic ester, and GO-COOPVA film is composed of GO-COOPVA, and the thermal stability of GO-COOPVA film obviously improves in comparison with PVA film, and the surface resistivity of GO-COOPVA film clearly decreases. Copyright © 2017 Elsevier B.V. All rights reserved.

Tree Canopy Characterization for EO-1 Reflective and Thermal Infrared Validation Studies: Rochester, New York

NASA Technical Reports Server (NTRS)

Ballard, Jerrell R., Jr.; Smith, James A.

2002-01-01

The tree canopy characterization presented herein provided ground and tree canopy data for different types of tree canopies in support of EO-1 reflective and thermal infrared validation studies. These characterization efforts during August and September of 2001 included stem and trunk location surveys, tree structure geometry measurements, meteorology, and leaf area index (LAI) measurements. Measurements were also collected on thermal and reflective spectral properties of leaves, tree bark, leaf litter, soil, and grass. The data presented in this report were used to generate synthetic reflective and thermal infrared scenes and images that were used for the EO-1 Validation Program. The data also were used to evaluate whether the EO-1 ALI reflective channels can be combined with the Landsat-7 ETM+ thermal infrared channel to estimate canopy temperature, and also test the effects of separating the thermal and reflective measurements in time resulting from satellite formation flying.

The Visualization of Infrared Radiation Using Thermal Sensitive Foils

ERIC Educational Resources Information Center

Bochnícek, Zdenek

2013-01-01

This paper describes a set of demonstration school experiments where infrared radiation is detected using thermal sensitive foils. The possibility of using standard glass lenses for infrared imaging is discussed in detail. It is shown that with optic components made from glass, infrared radiation up to 2.5 µm of wavelength can be detected. The…

Characterization of Land Surfaces with Satellite-borne Sensor

NASA Astrophysics Data System (ADS)

Qiao, Y.

Hot groundwater is a kind of valuable natural resources to be explored utilized. Shanxi Province, located in the eastern Loess Plateau of China, is rich in geothermal resources, most of which was found in irrigation well drilling or geological survey. Basic study is weak. Now new developed Remote Sensing technique provides geothermal study with an advanced way. Air-RS information of thermal infrared and dada from thermal channel of Meteorological Landset AVHRR has been used widely. A thermal infrared channel (TM6) was installed in the U.S. second Landset, Its resolving power of space is as high as 120m, 10 times more than one of AVHRR. A Landset earth recourses launched by China and Brazil (CBERS-1) in 1999, including a spectrum of thermal infrared. It is paid a great interested and attention to survey geothermal resources using thermal infrared. This article is a brief introduction of finding hot groundwater with on the bases of differences of thermal radiation of objects reflected by thermal infrared in the Landset, and treated with HIS colors changes. This study provides an advanced way widely used to exploit hot groundwater and to promote the development of tourism and geothermal medical in China.

Frequency and amplitude dependences of molding accuracy in ultrasonic nanoimprint technology

NASA Astrophysics Data System (ADS)

Mekaru, Harutaka; Takahashi, Masaharu

2009-12-01

We use neither a heater nor ultraviolet lights, and are researching and developing an ultrasonic nanoimprint as a new nano-patterning technology. In our ultrasonic nanoimprint technology, ultrasonic vibration is not used as a heat generator instead of the heater. A mold is connected with an ultrasonic generator, and mold patterns are pushed down and pulled up at a high speed into a thermoplastic. Frictional heat is generated by ultrasonic vibration between mold patterns and thermoplastic patterns formed by an initial contact force. However, because frictional heat occurs locally, the whole mold is not heated. Therefore, a molding material can be comprehensively processed at room temperature. A magnetostriction actuator was built into our ultrasonic nanoimprint system as an ultrasonic generator, and the frequency and amplitude can be changed between dc-10 kHz and 0-4 µm, respectively. First, the ultrasonic nanoimprint was experimented by using this system on polyethylene terephthalate (PET, Tg = 69 °C), whose the glass transition temperature (Tg) is comparatively low in engineering plastics, and it was ascertained that the most suitable elastic material for this technique was an ethyl urethane rubber. In addition, we used a changeable frequency of the magnetostriction actuator, and nano-patterns in an electroformed-Ni mold were transferred to a 0.5 mm thick sheet of PET, polymethylmethacrylate (PMMA) and polycarbonate (PC), which are typical engineering plastics, under variable molding conditions. The frequency and amplitude dependence of ultrasonic vibration to the molding accuracy were investigated by measuring depth and width of imprinted patterns. As a result, regardless of the molding material, the imprinted depth was changed drastically when the frequency exceeded 5 kHz. On the other hand, when the amplitude of ultrasonic vibration grew, the imprinted depth gradually deepened. Influence of the frequency and amplitude of ultrasonic vibration was not observed on the width of imprinted patterns. Moreover, the imprinted depth deepened as the Tg of the molding material lowered, and a progressive change according to conditions of ultrasonic vibration also became remarkable. Therefore, it seems that impressing ultrasonic vibration with a high frequency and large amplitude promotes thermal deformation and improves the molding accuracy in the ultrasonic nanoimprint technology.

Thermal targets for satellite calibration

NASA Astrophysics Data System (ADS)

Villa-Aleman, Eliel; Garrett, Alfred J.; Kurzeja, Robert J.; O'Steen, Byron L.; Pendergast, Malcolm M.

2001-03-01

The Savannah River Technology Center (SRTC) is currently calibrating the Multispectral Thermal Imager (MTI) satellite sponsored by the Department of Energy. The MTI imager is a research and development project with 15 wavebands in the visible, near-infrared, short-wave infrared, mid-wave infrared and long-wave infrared spectral regions. A plethora of targets with known temperatures such as power plant heated lakes, volcano lava vents, desert playas and aluminized Mylar tarps are being used in the validation of the five thermal bands of the MTI satellite. SRTC efforts in the production of cold targets with aluminized Mylar tarps will be described. Visible and thermal imagery and wavelength dependent radiance measurements of the calibration targets will be presented.

Real-time simulation of thermal shadows with EMIT

NASA Astrophysics Data System (ADS)

Klein, Andreas; Oberhofer, Stefan; Schätz, Peter; Nischwitz, Alfred; Obermeier, Paul

2016-05-01

Modern missile systems use infrared imaging for tracking or target detection algorithms. The development and validation processes of these missile systems need high fidelity simulations capable of stimulating the sensors in real-time with infrared image sequences from a synthetic 3D environment. The Extensible Multispectral Image Generation Toolset (EMIT) is a modular software library developed at MBDA Germany for the generation of physics-based infrared images in real-time. EMIT is able to render radiance images in full 32-bit floating point precision using state of the art computer graphics cards and advanced shader programs. An important functionality of an infrared image generation toolset is the simulation of thermal shadows as these may cause matching errors in tracking algorithms. However, for real-time simulations, such as hardware in the loop simulations (HWIL) of infrared seekers, thermal shadows are often neglected or precomputed as they require a thermal balance calculation in four-dimensions (3D geometry in one-dimensional time up to several hours in the past). In this paper we will show the novel real-time thermal simulation of EMIT. Our thermal simulation is capable of simulating thermal effects in real-time environments, such as thermal shadows resulting from the occlusion of direct and indirect irradiance. We conclude our paper with the practical use of EMIT in a missile HWIL simulation.

Observations of Jupiter thermal emission made by the Infrared Telescope Facility and the Galileo NIMS instrument

NASA Image and Video Library

1998-03-26

These observations of Jupiter equator in thermal heat emission were made by NASA Infrared Telescope Facility top panel within hours of the Near-Infrared Mapping Spectrometer NIMS instrument image middle inset and the spectra bottom.

Preparation of well-adhered γ-Al 2O 3 washcoat on metallic wire mesh monoliths by electrophoretic deposition

NASA Astrophysics Data System (ADS)

Sun, Hong; Quan, Xie; Chen, Shuo; Zhao, Huimin; Zhao, Yazhi

2007-01-01

Washcoat deposited on metallic wire mesh monoliths was prepared using γ-alumina powders by electrophoretic deposition under a relatively low electric voltage. The microstructure, phase structure and adhesion of washcoat were investigated by SEM, XRD, ultrasonic vibration and thermal shock. The results showed that the loading and adhesion of washcoat were affected obviously by the properties of suspension, such as the zeta potential and the amount of adding binders. A small quantity of aluminum isopropoxide could promote the cohesive affinity of washcoat in thermal shock. The adhesion of washcoat in ultrasonic vibration could be reinforced by increasing calcined temperature and adding a certain aluminum particles. It was also found that the washcoat immersed metal nitrate has excellent vibration-resistant ability.

Recognizing Bedside Events Using Thermal and Ultrasonic Readings

PubMed Central

Asbjørn, Danielsen; Jim, Torresen

2017-01-01

Falls in homes of the elderly, in residential care facilities and in hospitals commonly occur in close proximity to the bed. Most approaches for recognizing falls use cameras, which challenge privacy, or sensor devices attached to the bed or the body to recognize bedside events and bedside falls. We use data collected from a ceiling mounted 80 × 60 thermal array combined with an ultrasonic sensor device. This approach makes it possible to monitor activity while preserving privacy in a non-intrusive manner. We evaluate three different approaches towards recognizing location and posture of an individual. Bedside events are recognized using a 10-second floating image rule/filter-based approach, recognizing bedside falls with 98.62% accuracy. Bed-entry and exit events are recognized with 98.66% and 96.73% accuracy, respectively. PMID:28598394

Landsat and Thermal Infrared Imaging

NASA Technical Reports Server (NTRS)

Arvidson, Terry; Barsi, Julia; Jhabvala, Murzy; Reuter, Dennis

2012-01-01

The purpose of this chapter is to describe the collection of thermal images by Landsat sensors already on orbit and to introduce the new thermal sensor to be launched in 2013. The chapter describes the thematic mapper (TM) and enhanced thematic mapper plus (ETM+) sensors, the calibration of their thermal bands, and the design and prelaunch calibration of the new thermal infrared sensor (TIRS).

Provisional maps of thermal areas in Yellowstone National Park, based on satellite thermal infrared imaging and field observations

USGS Publications Warehouse

Vaughan, R. Greg; Heasler, Henry; Jaworowski, Cheryl; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.

2014-01-01

Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park infrastructure, preservation and protection of park resources, and ensuring visitor safety. Because of the challenges associated with field-based monitoring of a large, complex geothermal system that is spread out over a large and remote area, satellite-based thermal infrared images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to map the location and spatial extent of active thermal areas, to generate thermal anomaly maps, and to quantify the radiative component of the total geothermal heat flux. ASTER thermal infrared data acquired during winter nights were used to minimize the contribution of solar heating of the surface. The ASTER thermal infrared mapping results were compared to maps of thermal areas based on field investigations and high-resolution aerial photos. Field validation of the ASTER thermal mapping is an ongoing task. The purpose of this report is to make available ASTER-based maps of Yellowstone’s thermal areas. We include an appendix containing the names and characteristics of Yellowstone’s thermal areas, georeferenced TIFF files containing ASTER thermal imagery, and several spatial data sets in Esri shapefile format.

Mineral Information Extraction Based on GAOFEN-5'S Thermal Infrared Data

NASA Astrophysics Data System (ADS)

Liu, L.; Shang, K.

2018-04-01

Gaofen-5 carries six instruments aimed at various land and atmosphere applications, and it's an important unit of China High-resolution Earth Observation System. As Gaofen-5's thermal infrared payload is similar to that of ASTER, which is widely used in mineral exploration, application of Gaofen-5's thermal infrared data is discussed regarding its capability in mineral classification and silica content estimation. First, spectra of silicate, carbonate, sulfate minerals from a spectral library are used to conduct spectral feature analysis on Gaofen-5's thermal infrared emissivities. Spectral indices of band emissivities are proposed, and by setting thresholds of these spectral indices, it can classify three types of minerals mentioned above. This classification method is tested on a simulated Gaofen-5 emissivity image. With samples acquired from the study area, this method is proven to be feasible. Second, with band emissivities of silicate and their silica content from the same spectral library, correlation models have been tried to be built for silica content inversion. However, the highest correlation coefficient is merely 0.592, which is much lower than that of correlation model built on ASTER thermal infrared emissivity. It can be concluded that GF-5's thermal infrared data can be utilized in mineral classification but not in silica content inversion.

Carbon nanotube-polymer nanocomposite infrared sensor.

PubMed

Pradhan, Basudev; Setyowati, Kristina; Liu, Haiying; Waldeck, David H; Chen, Jian

2008-04-01

The infrared photoresponse in the electrical conductivity of single-walled carbon nanotubes (SWNTs) is dramatically enhanced by embedding SWNTs in an electrically and thermally insulating polymer matrix. The conductivity change in a 5 wt % SWNT-polycarbonate nanocomposite is significant (4.26%) and sharp upon infrared illumination in the air at room temperature. While the thermal effect predominates in the infrared photoresponse of a pure SWNT film, the photoeffect predominates in the infrared photoresponse of SWNT-polycarbonate nanocomposites.

Energy Efficiency Technology Demonstration Project for Florida Educational Facilities: Occupancy Sensors.

ERIC Educational Resources Information Center

Floyd, David B.; Parker, Danny S.; McIlvaine, Janet E. R.; Sherwin, John R.

A Florida study replaced conventional light switches with passive infrared or ultrasonic sensing systems to control classroom lighting in an elementary school to determine the performance of such controls in saving energy. A before-and-after monitoring protocol was used for 33 classrooms and 7 offices in which electrical demand data were…

Integration of ground-penetrating radar, ultrasonic tests and infrared thermography for the analysis of a precious medieval rose window

NASA Astrophysics Data System (ADS)

Nuzzo, L.; Calia, A.; Liberatore, D.; Masini, N.; Rizzo, E.

2010-04-01

The integration of high-resolution, non-invasive geophysical techniques (such as ground-penetrating radar or GPR) with emerging sensing techniques (acoustics, thermography) can complement limited destructive tests to provide a suitable methodology for a multi-scale assessment of the state of preservation, material and construction components of monuments. This paper presents the results of the application of GPR, infrared thermography (IRT) and ultrasonic tests to the 13th century rose window of Troia Cathedral (Apulia, Italy), affected by widespread decay and instability problems caused by the 1731 earthquake and reactivated by recent seismic activity. This integrated approach provided a wide amount of complementary information at different scales, ranging from the sub-centimetre size of the metallic joints between the various architectural elements, narrow fractures and thin mortar fillings, up to the sub-metre scale of the internal masonry structure of the circular ashlar curb linking the rose window to the façade, which was essential to understand the original building technique and to design an effective restoration strategy.

Laparoscopic prototype for optical sealing of renal blood vessels

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

2017-02-01

Energy-based, radiofrequency and ultrasonic devices provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternative for vessel sealing with less collateral thermal damage. Previous studies demonstrated vessel sealing in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices in surgical use was developed, and tests were conducted on porcine renal blood vessels. The 5-mm-OD prototype featured a traditional Maryland jaw configuration. Laser energy was delivered through a 550-μm-core fiber and side-delivery from the lower jaw, with beam dimensions of 18-mm-length x 1.2-mm-width. The 1470-nm diode laser delivered 68 W with 3 s activation time. A total of 69 porcine renal vessels with mean diameter of 3.3 +/- 1.7 mm were tested, ex vivo. Vessels smaller than 5 mm were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038 +/- 474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174 +/- 221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7 +/- 0.8, 3.4 +/- 0.7, and 1.0 +/- 0.4 mm. A novel optical laparoscopic prototype with 5-mm- OD shaft integrated within a standard Maryland jaw design consistently sealed vessels less than 5 mm with minimal thermal spread. Further in vivo studies are planned to test performance across a variety of vessels and tissues.

Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells.

PubMed

Ji, Ran; Zheng, Ding; Zhou, Chang; Cheng, Jiang; Yu, Junsheng; Li, Lu

2017-07-18

Tungsten oxide (WO₃) is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL) for organic solar cells (OSCs). The properties of the WO₃ transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO₃ ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO₃, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO₃ ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO₃, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication.

Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells

PubMed Central

Ji, Ran; Zheng, Ding; Zhou, Chang; Cheng, Jiang; Yu, Junsheng; Li, Lu

2017-01-01

Tungsten oxide (WO3) is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL) for organic solar cells (OSCs). The properties of the WO3 transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO3 ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO3, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO3 ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO3, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication. PMID:28773177

Residual heat of laparoscopic energy devices: how long must the surgeon wait to touch additional tissue?

PubMed

Govekar, Henry R; Robinson, Thomas N; Stiegmann, Greg V; McGreevy, Francis T

2011-11-01

Energy devices are essential laparoscopic tools. Residual heat is defined as the increased instrument temperature after energy activation is completed. This study aimed to determine the length of time a surgeon needs to wait before touching other tissue using four common laparoscopic energy sources. Thermal imaging quantified instrument and tissue temperature ex vivo using monopolar coagulation, argon beam coagulation, ultrasonic dissection, and bipolar tissue fusion devices. To simulate realistic operative usage, each instrument was activated for 5 s four consecutive times with 5 s pauses between fires. Thermal conductivity to bovine liver tissue was measured 2.5, 5, 10, and 20 s after final activation. The maximum increase in instrument tip temperature was 172 ± 63°C for the ultrasonic dissection, 81 ± 18°C for the monopolar coagulation, 46 ± 19°C for the bipolar tissue fusion, and 1 ± 1°C for the argon beam coagulation (P < 0.05 for all comparisons). Touching the instrument tip to tissue at four intervals after the final activation (2.5, 5, 10, and 20 s) found that ultrasonic energy raised the tissue temperature higher (maximum change, 58°C) than the other three energy devices at all four time points (P < 0.05). Ultrasonic energy instruments have greater residual heat than monopolar electrosurgery, bipolar tissue fusion, and argon beam. The ultrasonic energy instrument tips heated tissue more than 20°C from baseline even 20 s after activation; whereas all the other energy sources raised the tissue temperature less than 20°C by 5 s. These practical findings may alter a surgeon's usage of these common energy devices.

Ring-based ultrasonic virtual point detector with applications to photoacoustic tomography

NASA Astrophysics Data System (ADS)

Yang, Xinmai; Li, Meng-Lin; Wang, Lihong V.

2007-06-01

An ultrasonic virtual point detector is constructed using the center of a ring transducer. The virtual point detector provides ideal omnidirectional detection free of any aperture effect. Compared with a real point detector, the virtual one has lower thermal noise and can be scanned with its center inside a physically inaccessible medium. When applied to photoacoustic tomography, the virtual point detector provides both high spatial resolution and high signal-to-noise ratio. It can also be potentially applied to other ultrasound-related technologies.

Lock-in thermographic inspection of squats on rail steel head

NASA Astrophysics Data System (ADS)

Peng, D.; Jones, R.

2013-03-01

The development of squat defects has become a major concern in numerous railway systems throughout the world. Infrared thermography is a relatively new non-destructive inspection technique used for a wide range of applications. However, it has not been used for rail squat detection. Lock-in thermography is a non-destructive inspection technique that utilizes an infrared camera to detect the thermal waves. A thermal image is produced, which displays the local thermal wave variation in phase or amplitude. In inhomogeneous materials, the amplitude and phase of the thermal wave carries information related to both the local thermal properties and the nature of the structure being inspected. By examining the infrared thermal signature of squat damage on the head of steel rails, it was possible to generate a relationship matching squat depth to thermal image phase angle, using appropriate experimental/numerical calibration. The results showed that with the additional data sets obtained from further experimental tests, the clarity of this relationship will be greatly improved to a level whereby infrared thermal contours can be directly translated into the precise subsurface behaviour of a squat.

Ground truth spectrometry and imagery of eruption clouds to maximize utility of satellite imagery

NASA Technical Reports Server (NTRS)

Rose, William I.

1993-01-01

Field experiments with thermal imaging infrared radiometers were performed and a laboratory system was designed for controlled study of simulated ash clouds. Using AVHRR (Advanced Very High Resolution Radiometer) thermal infrared bands 4 and 5, a radiative transfer method was developed to retrieve particle sizes, optical depth and particle mass involcanic clouds. A model was developed for measuring the same parameters using TIMS (Thermal Infrared Multispectral Scanner), MODIS (Moderate Resolution Imaging Spectrometer), and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer). Related publications are attached.

Thin Semiconductor/Metal Films For Infrared Devices

NASA Technical Reports Server (NTRS)

Lamb, James L.; Nagendra, Channamallappa L.

1995-01-01

Spectral responses of absorbers and reflectors tailored. Thin cermet films composites of metals and semiconductors undergoing development for use as broadband infrared reflectors and absorbers. Development extends concepts of semiconductor and dielectric films used as interference filters for infrared light and visible light. Composite films offer advantages over semiconductor films. Addition of metal particles contributes additional thermal conductivity, reducing thermal gradients and associated thermal stresses, with resultant enhancements of thermal stability. Because values of n in composite films made large, same optical effects achieved with lesser thicknesses. By decreasing thicknesses of films, one not only decreases weights but also contributes further to reductions of thermal stresses.

Ultrasonic-assisted extraction, structure and antitumor activity of polysaccharide from Polygonum multiflorum.

PubMed

Zhu, Weili; Xue, Xiaoping; Zhang, Zhanjun

2016-10-01

Polygonum multiflorum is a popular Chinese herbal medicine with various pharmacological functions. In this study, the ultrasonic-assisted extraction condition, structural characterization and antitumor activity of a polysaccharide from roots of P. multiflorum were investigated. The ultrasonic-assisted extraction condition was optimized by single-factor experiments and response surface methodology. Results showed that the maximum extraction yield (5.49%) was obtained at ultrasonic power 158W, extraction temperature 62°C, extraction time 80min and ratio of water to material 20mL/g. The obtained crude polysaccharides were further purified to afford a neutral and an acidic fraction. The structure of the main neutral polysaccharide (named PPS with molecular weight of 3.26×10(5)Da) was characterized as a linear (1→6)-α-d-glucan by gas chromatography, Fourier transform-infrared spectroscopy, methylation analysis, 1D and 2D nuclear magnetic resonance. At the concentration of 400μg/mL, the inhibitory ratios of PPS on HepG-2 and BGC-823 cells were 53.35% and 38.58%, respectively. Results suggested this polysaccharide could be a potential natural antitumor agent. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabrication of Carbon Nanofibers/A356 Nanocomposites by High-Intensity Ultrasonic Processing

NASA Astrophysics Data System (ADS)

Wu, Qing-Jie; Yan, Hong

2018-03-01

A356 alloy reinforced with carbon nanofibers (CNFs) was fabricated by high-intensity ultrasonic vibration processing. The microstructure and mechanical properties were investigated. The distribution of CNFs became more and more uniform with the increase of ultrasonic power, and the mechanical properties of nanocomposites were significantly enhanced accordingly. The yield strength (YS), ultimate tensile strength (UTS), and microhardness of the nanocomposite increased by 38.3, 21.9, and 43.2 pct, respectively, at a CNF content of 0.9 wt pct compared with the matrix without CNF addition. The improvement in mechanical properties was the effect of CNFs on the thermal expansion mismatch strengthening of the nanocomposite, the grain refinement of the nanocomposite, and the load transfer from the matrix to the nanofibers.

Fabrication of Carbon Nanofibers/A356 Nanocomposites by High-Intensity Ultrasonic Processing

NASA Astrophysics Data System (ADS)

Wu, Qing-Jie; Yan, Hong

2018-06-01

A356 alloy reinforced with carbon nanofibers (CNFs) was fabricated by high-intensity ultrasonic vibration processing. The microstructure and mechanical properties were investigated. The distribution of CNFs became more and more uniform with the increase of ultrasonic power, and the mechanical properties of nanocomposites were significantly enhanced accordingly. The yield strength (YS), ultimate tensile strength (UTS), and microhardness of the nanocomposite increased by 38.3, 21.9, and 43.2 pct, respectively, at a CNF content of 0.9 wt pct compared with the matrix without CNF addition. The improvement in mechanical properties was the effect of CNFs on the thermal expansion mismatch strengthening of the nanocomposite, the grain refinement of the nanocomposite, and the load transfer from the matrix to the nanofibers.

Effect of rutile titania dioxide nanoparticles on the mechanical property, thermal stability, weathering resistance and antibacterial property of styrene acrylic polyurethane coating

NASA Astrophysics Data System (ADS)

Vuong Nguyen, Thien; Nguyen, Tuan Anh; Dao, Phi Hung; Phuc Mac, Van; Hiep Nguyen, Anh; Thanh Do, Minh; Nguyen, The Huu

2016-12-01

This study aims to enhance the mechanical properties, thermal stability, weathering resistance and antibacterial property of a styrene acrylic polyurethane coating by adding rutile titania dioxide (R-TiO2) nanoparticles in coating formulation. The styrene acrylic polyurethane/R-TiO2 nanocomposite had been prepared by using ultrasonication. The effects of nanoparticles on the mechanical properties, thermal stability and weathering resistance of as-prepared coatings were investigated by using the adhesion strength and ball impact tests, the Fourier transform infrared and UV-vis analyses, thermogravimetric analysis (TGA), and UV/condensation weathering chamber equipped with UVA-340 fluorescent lamps, respectively. The disperse quality of nanoparticles in the coating was examined by using the field emission scanning electron microscope (FESEM). The mechanical test results showed that suitable content of R-TiO2 nanoparticles in the nanocomposite coating was 2 wt%. The FESEM images indicated that the nanoparticles were dispersed homogeneously into the entire volume of the coating. For the nanocomposite prepared by 3 h of ultrasonication, the average size of nanoparticles was in range of 40-50 nm. The ball impact and adhesion tests showed that the incorporation of nanoparticles into the coating significantly enhanced the impact strength from 120 to 145 kg cm and increased the adhesion from level 1 to level 0. The TGA test illustrated that in presence of nanoparticles, the decomposition temperature of coating increased from 146.9 °C to 154.21 °C. For the temperature at 50% loss in mass (T 50%), it was found that the T 50% of the neat coating is 351.86 °C. Adding the 2 wt% R-TiO2 nanoparticles into coating increased the T 50% value to 360.06 °C. After UV/condensation accelerated weathering test (30 cycles), the significant improvement in weight loss, impact strength and adhesion of the neat coating was observed with the presence of nanoparticles. The antibacterial test showed that in the nanocomposite coating, R-TiO2 nanoparticles exhibited their photocatalytic effect in the inhibition against E. coli bacterial growth. Incorporating 2 wt% of R-TiO2 nanoparticles into the coating reduced the bacterial concentration by 6.1% after 60 min of culture.

Infrared thermal imaging in medicine.

PubMed

Ring, E F J; Ammer, K

2012-03-01

This review describes the features of modern infrared imaging technology and the standardization protocols for thermal imaging in medicine. The technique essentially uses naturally emitted infrared radiation from the skin surface. Recent studies have investigated the influence of equipment and the methods of image recording. The credibility and acceptance of thermal imaging in medicine is subject to critical use of the technology and proper understanding of thermal physiology. Finally, we review established and evolving medical applications for thermal imaging, including inflammatory diseases, complex regional pain syndrome and Raynaud's phenomenon. Recent interest in the potential applications for fever screening is described, and some other areas of medicine where some research papers have included thermal imaging as an assessment modality. In certain applications thermal imaging is shown to provide objective measurement of temperature changes that are clinically significant.

Design, fabrication, and testing of an ultrasonic de-icing system for helicopter rotor blades

NASA Astrophysics Data System (ADS)

Palacios, Jose Luis

A low-power, non-thermal ultrasonic de-icing system is introduced as a possible substitute for current electro-thermal systems. The system generates delaminating ultrasonic transverse shear stresses at the interface of accreted ice. A PZT-4 disk driven at 28.5 KHz (radial resonance of the disk) instantaneously de-bonds 2 mm thick freezer ice layers. The ice layers are accreted to a 0.7 mm thick, 30.4 cm x 30.4 cm steel plate at an environment temperature of -20°C. A power input of 50 Watts is applied to the actuator (50 V, 19.6 KV/m), which translates to a de-icing power of 0.07 W/cm2. A finite element model of the actuator bonded to the isotropic plate is used to guide the design of the system, and predicts the transverse shear stresses at the ice interface. Wind tunnel icing tests were conducted to demonstrate the potential use of the proposed system under impact icing conditions. Both glaze ice and rime ice were generated on steel and composite plates by changing the cloud conditions of the wind tunnel. Continuous ultrasonic vibration prevented impact ice formation around the actuator location at an input power not exceeding 0.18 W/cm 2 (1.2 W/in2). As ice thickness reached a critical thickness of approximately 1.2 mm, shedding occurred on those locations where ultrasonic transverse shear stresses exceeded the shear adhesion strength of the ice. Finite element transverse shear stress predictions correlate with observed experimental impact ice de-bonding behavior. To increase the traveling distance of propagating ultrasonic waves, ultrasonic shear horizontal wave modes are studied. Wave modes providing large modal interface transverse shear stress concentration coefficients (ISCC) between the host structure (0.7 mm thick steel plate) and accreted ice (2.5 mm thick ice layer) are identified and investigated for a potential increase in the wave propagation distance. Ultrasonic actuators able to trigger these optimum wave modes are designed and fabricated. Despite exciting wave modes with high ISCC values, instantaneous ice de-bonding is not observed at input powers under 100 Watts. The two triggered ultrasonic wave modes of the structure occur at high excitation frequencies, 202 KHz and 500 KHz respectively. At these frequencies, the ultrasonic actuators do not provide large enough transverse shear stresses to exceed the shear adhesion strength of the ice layer. Neither the actuator exciting the SH1 mode (202 KHz), nor the actuator triggering the SH2 mode (500 KHz) instantaneously de-bonds ice layers with an input power under 100 Watts.

Research and applications of infrared thermal imaging systems suitable for developing countries

NASA Astrophysics Data System (ADS)

Weili, Zhang; Danyu, Cai

1986-01-01

It is a common situation in most developing countries that the utilization ratio of the sources of energy is low, the reliability service of equipment is poor, the cost of installation maintenance is high, the loss due to conflagration is heavy, and so on. Therefore, they are in urgent need of using infrared thermal imaging technique to improve their energy saving, equipment diagnosis as well as fire searching. But the infrared thermal imaging systems in the world market so far are not suitable for their use. This paper summarizes the research on two dimensional real time infrared thermal imaging systems on the basis of electron beam scanning and pyroelectric detection, as well as their applications in industry in China.

Effective and efficient agricultural drainage pipe mapping with UAS thermal infrared imagery: a case study

USDA-ARS?s Scientific Manuscript database

Effective and efficient methods are needed to map agricultural subsurface drainage systems. Visible (VIS), near infrared (NIR), and/or thermal infrared (TIR) imagery obtained by unmanned aircraft systems (UAS) may provide a means for determining drainage pipe locations. Preliminary UAS surveys wit...

40 CFR 60.613 - Monitoring of emissions and operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., photoionization, or thermal conductivity, each equipped with a continuous recorder. (2) Where a condenser is the... detection principle such as infra-red, photoionization, or thermal conductivity, each equipped with a... based on a detection principle such as infra-red, photoionization, or thermal conductivity, each...

Generating high temporal and spatial resolution thermal band imagery using robust sharpening approach

USDA-ARS?s Scientific Manuscript database

Thermal infrared band imagery provides key information for detecting wild fires, mapping land surface energy fluxes and evapotranspiration, monitoring urban heat fluxes and drought monitoring. Thermal infrared (TIR) imagery at fine resolution is required for field scale applications. However, therma...

Advanced Welding Concepts

NASA Technical Reports Server (NTRS)

Ding, Robert J.

2010-01-01

Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

Bulk mineralogy of the NE Syrtis and Jezero crater regions of Mars derived through thermal infrared spectral analyses

NASA Astrophysics Data System (ADS)

Salvatore, M. R.; Goudge, T. A.; Bramble, M. S.; Edwards, C. S.; Bandfield, J. L.; Amador, E. S.; Mustard, J. F.; Christensen, P. R.

2018-02-01

We investigated the area to the northwest of the Isidis impact basin (hereby referred to as "NW Isidis") using thermal infrared emission datasets to characterize and quantify bulk surface mineralogy throughout this region. This area is home to Jezero crater and the watershed associated with its two deltaic deposits in addition to NE Syrtis and the strong and diverse visible/near-infrared spectral signatures observed in well-exposed stratigraphic sections. The spectral signatures throughout this region show a diversity of primary and secondary surface mineralogies, including olivine, pyroxene, smectite clays, sulfates, and carbonates. While previous thermal infrared investigations have sought to characterize individual mineral groups within this region, none have systematically assessed bulk surface mineralogy and related these observations to visible/near-infrared studies. We utilize an iterative spectral unmixing method to statistically evaluate our linear thermal infrared spectral unmixing models to derive surface mineralogy. All relevant primary and secondary phases identified in visible/near-infrared studies are included in the unmixing models and their modeled spectral contributions are discussed in detail. While the stratigraphy and compositional diversity observed in visible/near-infrared spectra are much better exposed and more diverse than most other regions of Mars, our thermal infrared analyses suggest the dominance of basaltic compositions with less observed variability in the amount and diversity of alteration phases. These results help to constrain the mineralogical context of these previously reported visible/near-infrared spectral identifications. The results are also discussed in the context of future in situ investigations, as the NW Isidis region has long been promoted as a region of paleoenvironmental interest on Mars.

Local defect resonance (LDR): A route to highly efficient thermosonic and nonlinear ultrasonic NDT

NASA Astrophysics Data System (ADS)

Solodov, Igor

2014-02-01

The concept of LDR is based on the fact that inclusion of a defect leads to a local drop of rigidity for a certain mass of the material that should manifest in a particular characteristic frequency of the defect. A frequency match between the driving ultrasonic wave and this characteristic frequency provides an efficient energy pumping from the wave directly into the defect. For simulated and realistic defects in various materials the LDR-induced local resonance increase in the vibration amplitude averages up to ˜ (20-40 dB). Due to a strong resonance amplification of the local vibrations, the LDR-driven defects manifest a profound nonlinearity even at moderate ultrasonic excitation level. The nonlinearity combined with resonance results in efficient generation of the higher harmonics and is also used as a filter/amplifier in the frequency mixing mode of nonlinear NDT. The LDR high-Q thermal response enables to realize a frequency-selective imaging with an opportunity to distinguish between different defects by changing the driving frequency. The LDR-thermosonics requires much lower acoustic power to activate defects that makes it possible to avoid high-power ultrasonic instrumentation and proceed to a noncontact ultrasonic thermography by using air-coupled ultrasonic excitation.

Preparation and characterization of CNTs/UHMWPE nanocomposites via a novel mixer under synergy of ultrasonic wave and extensional deformation.

PubMed

Yin, Xiaochun; Li, Sai; He, Guangjian; Feng, Yanhong; Wen, Jingsong

2018-05-01

In this work, design and development of a new melt mixing method and corresponding mixer for polymer materials were reported. Effects of ultrasonic power and sonication time on the carbon nanotubes (CNTs) filled ultra high molecular weight polyethylene (UHMWPE) nanocomposites were experimentally studied. Transmission Electron Microscopy images showed that homogeneous dispersion of CNTs in intractable UHMWPE matrix is successfully realized due to the synergetic effect of ultrasonic wave and extensional deformation without any aid of other additives or solvents. Differential scanning calorimetry results revealed an increase in crystallinity and crystallization rate due to the finer dispersion of the CNTs in the matrix which act as nucleating point. Composites' complex viscosity and storage modulus decreased sharply at first and then leveled off with the increase of sonication time or the ultrasonic power. The thermal stability and the tensile strength of the CNTs/UHMWPE nanocomposites improved by using this novel mixing method. This is the first method that combined the ultrasonic wave and the extensional deformation in which the elongation rate, sonication time and ultrasonic power can be adjusted simultaneously during mixing. The novel mixer offers several advantages such as environment-friendly, high mixing efficiency, self-cleaning and wide adaptability to materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Heterodyne Spectroscopy in the Thermal Infrared Region: A Window on Physics and Chemistry

NASA Technical Reports Server (NTRS)

Kostiuk, Theodor

2004-01-01

The thermal infrared region contains molecular bands of many of the most important species in gaseous astronomical sources. True shapes and frequencies of emission and absorption spectral lines from these constituents of planetary and stellar atmospheres contain unique information on local temperature and abundance distribution, non-thermal effects, composition, local dynamics and winds. Heterodyne spectroscopy in the thermal infrared can remotely measure true line shapes in relatively cool and thin regions and enable the retrieval of detailed information about local physics and chemistry. The concept and techniques for heterodyne detection will be discussed including examples of thermal infrared photomixers and instrumentation used in studies of several astronomical sources. Use of heterodyne detection to study non-LTE phenomena, planetary aurora, minor planetary species and gas velocities (winds) will be discussed. A discussion of future technological developments and relation to space flight missions will be addressed.

Ultrasonic-assisted chemical reduction synthesis and structural characterization of copper nanoparticles

NASA Astrophysics Data System (ADS)

Anh-Nga, Nguyen T.; Tuan-Anh, Nguyen; Thanh-Quoc, Nguyen; Ha, Do Tuong

2018-04-01

Copper nanoparticles, due to their special properties, small dimensions and low-cost preparation, have many potential applications such as in optical, electronics, catalysis, sensors, antibacterial agents. In this study, copper nanoparticles were synthesized by chemical reduction method with different conditions in order to investigate the optimum conditions which gave the smallest (particle diameter) dimensions. The synthesis step used copper (II) acetate salt as precursor, ascorbic acid as reducing agent, glycerin and polyvinylpyrrolidone (PVP) as protector and stabilizer. The assistance of ultrasonic was were considered as the significant factor affecting the size of the synthesized particles. The results showed that the copper nanoparticles have been successfully synthesized with the diameter as small as 20-40 nm and the conditions of ultrasonic waves were 48 kHz of frequency, 20 minutes of treated time and 65-70 °C of temperature. The synthesized copper nanoparticles were characterized by optical absorption spectrum, scanning electron microscopy (SEM), and Fourier Transform Infrared Spectrometry.

Development of chitosan/β-glycerophosphate/glycerol hydrogel as a thermosensitive coupling agent.

PubMed

Huang, Chih-Ling; Chen, Yu-Bin; Lo, Yu-Lung; Lin, Yi-Hsiang

2016-08-20

This work develops a dual-function thermosensitive hydrogel to prevent overheating, a side effect of focused ultrasound therapy. The proposed hydrogel has the components of chitosan, β-glycerophosphate, and glycerol. Its thermosensitive sol-to-gel transition gives an instant signal of overheating without the need of any awkward sensing device. Impacts of varying component concentrations on the sol-to-gel temperature, rate, and degree of transparency are also investigated. Chemical structures and ultrasonic coefficients after heating are obtained with a Fourier transform infrared spectroscopy and ultrasonic measurement, respectively. Optimized formula of the proposed hydrogel is 0.5% chitosan, 5% β-glycerophosphate, and 25% glycerol. This hydrogel has a high acoustic impedance (Z=1.8 Mrayl) close to that of human skin, high ultrasonic transmission (T=99%, which is normalized to water) from 25 to 55°C, and low attenuation coefficient (α=4.0Np/m). These properties assure the success of dual functions of the hydrogel developed in this work. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrasound assisted, thermally activated persulfate oxidation of coal tar DNAPLs.

PubMed

Peng, Libin; Wang, Li; Hu, Xingting; Wu, Peihui; Wang, Xueqing; Huang, Chumei; Wang, Xiangyang; Deng, Dayi

2016-11-15

The feasibility of ultrasound assisted, thermally activated persulfate for effective oxidation of twenty 2-6 ringed coal tar PAHs in a biphasic tar/water system and a triphasic tar/soil/water system were investigated and established. The results indicate that ultrasonic assistance, persulfate and elevated reaction temperature are all required to achieve effective oxidation of coal tar PAHs, while the heating needed can be provided by ultrasonic induced heating as well. Further kinetic analysis reveals that the oxidation of individual PAH in the biphasic tar/water system follows the first-order kinetics, and individual PAH oxidation rate is primary determined by the mass transfer coefficients, tar/water interfacial areas, the aqueous solubility of individual PAH and its concentration in coal tar. Based on the kinetic analysis and experimental results, the contributions of ultrasound, persulfate and elevated reaction temperature to PAHs oxidation were characterized, and the effects of ultrasonic intensity and oxidant dosage on PAHs oxidation efficiency were investigated. In addition, the results indicate that individual PAH degradability is closely related to its reactivity as well, and the high reactivity of 4-6 ringed PAHs substantially improves their degradability. Copyright © 2016 Elsevier B.V. All rights reserved.

Opto-acoustic transducer for medical applications

DOEpatents

Benett, William; Celliers, Peter; Da Silva, Luiz; Glinsky, Michael; London, Richard; Maitland, Duncan; Matthews, Dennis; Krulevich, Peter; Lee, Abraham

2002-01-01

This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

Opto-acoustic transducer for medical applications

DOEpatents

Benett, William; Celliers, Peter; Da Silva, Luiz; Glinsky, Michael; London, Richard; Maitland, Duncan; Matthews, Dennis; Krulevich, Peter; Lee, Abraham

1999-01-01

This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

Opto-acoustic transducer for medical applications

DOEpatents

Benett, W.; Celliers, P.; Da Silva, L.; Glinsky, M.; London, R.; Maitland, D.; Matthews, D.; Krulevich, P.; Lee, A.

1999-08-31

This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control. 7 figs.

Techniques for noise removal and registration of TIMS data

USGS Publications Warehouse

Hummer-Miller, S.

1990-01-01

Extracting subtle differences from highly correlated thermal infrared aircraft data is possible with appropriate noise filters, constructed and applied in the spatial frequency domain. This paper discusses a heuristic approach to designing noise filters for removing high- and low-spatial frequency striping and banding. Techniques for registering thermal infrared aircraft data to a topographic base using Thematic Mapper data are presented. The noise removal and registration techniques are applied to TIMS thermal infrared aircraft data. -Author

Thermal Infrared Multispectral Scanner (TIMS): An investigator's guide to TIMS data

NASA Technical Reports Server (NTRS)

Palluconi, F. D.; Meeks, G. R.

1985-01-01

The Thermal Infrared Multispectral Scanner (TIMS) is a NASA aircraft scanner providing six channel spectral capability in the thermal infrared region of the electromagnetic spectrum. Operating in the atmospheric window region (8 to 12 micrometers) with a channel sensitivity of approximately 0.1 C, TIMS may be used whenever an accurate measure of the Earth's surface is needed. A description of this scanner is provided as well as a discussion of data acquisition and reduction.

Microstructure and Mechanical Properties of Ultrafine-Grained Al-6061 Prepared Using Intermittent Ultrasonic-Assisted Equal-Channel Angular Pressing

NASA Astrophysics Data System (ADS)

Lu, Jianxun; Wu, Xiaoyu; Wu, Zhaozhi; Liu, Zhiyuan; Guo, Dengji; Lou, Yan; Ruan, Shuangchen

2017-10-01

Equal-channel angular pressing (ECAP) is an efficient technique to achieve grain refinement in a wide range of materials. However, the extrusion process requires an excessive extrusion force, the microstructure of ECAPed specimens scatters heterogeneously because of considerable fragmentation of the structure and strain heterogeneity, and the resultant ultrafine grains exhibit poor thermal stability. The intermittent ultrasonic-assisted ECAP (IU-ECAP) approach was proposed to address these issues. In this work, ECAP and IU-ECAP were applied to produce ultrafine-grained Al-6061 alloys, and the differences in their mechanical properties, microstructural characteristics, and thermal stability were investigated. Mechanical testing demonstrated that the necessary extrusion force for IU-ECAP was significantly reduced; even more, the microhardness and ultimate tensile strength were strengthened. In addition, the IU-ECAPed Al alloy exhibited a smaller grain size with a more homogeneous microstructure. X-ray diffraction analysis indicated that the intensities of the textures were weakened using IU-ECAP, and a more homogeneous microstructure and larger dislocation densities were obtained. Investigation of the thermal stability revealed that the ultrafine-grained materials produced using IU-ECAP recrystallized at higher temperature or after longer time; the materials thus exhibited improved thermal stability.

Infrared Surveys of Hawaiian Volcanoes: Aerial surveys with infrared imaging radiometer depict volcanic thermal patterns and structural features.

PubMed

Fisher, W A; Moxham, R M; Polcyn, F; Landis, G H

1964-11-06

Aerial infrared-sensor surveys of Kilauea volcano have depicted the areal extent and the relative intensity of abnormal thermal features in the caldera area of the volcano and along its associated rift zones. Many of these anomalies show correlation with visible steaming and reflect convective transfer of heat to the surface from subterranean sources. Structural details of the volcano, some not evident from surface observation, are also delineated by their thermal abnormalities. Several changes were observed in the patterns of infrared emission during the period of study; two such changes show correlation in location with subsequent eruptions, but the cause-and-effect relationship is uncertain. Thermal anomalies were also observed on the southwest flank of Mauna Loa; images of other volcanoes on the island of Hawaii, and of Haleakala on the island of Maui, revealed no thermal abnormalities. Approximately 25 large springs issuing into the ocean around the periphery of Hawaii have been detected. Infrared emission varies widely with surface texture and composition, suggesting that similar observations may have value for estimating surface conditions on the moon or planets.

From iron coordination compounds to metal oxide nanoparticles.

PubMed

Iacob, Mihail; Racles, Carmen; Tugui, Codrin; Stiubianu, George; Bele, Adrian; Sacarescu, Liviu; Timpu, Daniel; Cazacu, Maria

2016-01-01

Various types, shapes and sizes of iron oxide nanoparticles were obtained depending on the nature of the precursor, preparation method and reaction conditions. The mixed valence trinuclear iron acetate, [Fe 2 III Fe II O(CH 3 COO) 6 (H 2 O) 3 ]·2H 2 O (FeAc1), μ 3 -oxo trinuclear iron(III) acetate, [Fe 3 O(CH 3 COO) 6 (H 2 O) 3 ]NO 3 ∙4H 2 O (FeAc2), iron furoate, [Fe 3 O(C 4 H 3 OCOO) 6 (CH 3 OH) 3 ]NO 3 ∙2CH 3 OH (FeF), iron chromium furoate, FeCr 2 O(C 4 H 3 OCOO) 6 (CH 3 OH) 3 ]NO 3 ∙2CH 3 OH (FeCrF), and an iron complex with an original macromolecular ligand (FePAZ) were used as precursors for the corresponding oxide nanoparticles. Five series of nanoparticle samples were prepared employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination) or using a nonconventional energy source (i.e., microwave or ultrasonic treatment) to convert precursors into iron oxides. The resulting materials were structurally characterized by wide-angle X-ray diffraction and Fourier transform infrared, Raman, energy-dispersive X-ray, and X-ray fluorescence spectroscopies, as well as thermogravimetric analysis. The morphology was characterized by transmission electron microscopy, atomic force microscopy and dynamic light scattering. The parameters were varied within each route to fine tune the size and shape of the formed nanoparticles.

From iron coordination compounds to metal oxide nanoparticles

PubMed Central

Iacob, Mihail; Racles, Carmen; Tugui, Codrin; Stiubianu, George; Bele, Adrian; Sacarescu, Liviu; Timpu, Daniel

2016-01-01

Various types, shapes and sizes of iron oxide nanoparticles were obtained depending on the nature of the precursor, preparation method and reaction conditions. The mixed valence trinuclear iron acetate, [Fe2 IIIFeIIO(CH3COO)6(H2O)3]·2H2O (FeAc1), μ3-oxo trinuclear iron(III) acetate, [Fe3O(CH3COO)6(H2O)3]NO3∙4H2O (FeAc2), iron furoate, [Fe3O(C4H3OCOO)6(CH3OH)3]NO3∙2CH3OH (FeF), iron chromium furoate, FeCr2O(C4H3OCOO)6(CH3OH)3]NO3∙2CH3OH (FeCrF), and an iron complex with an original macromolecular ligand (FePAZ) were used as precursors for the corresponding oxide nanoparticles. Five series of nanoparticle samples were prepared employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination) or using a nonconventional energy source (i.e., microwave or ultrasonic treatment) to convert precursors into iron oxides. The resulting materials were structurally characterized by wide-angle X-ray diffraction and Fourier transform infrared, Raman, energy-dispersive X-ray, and X-ray fluorescence spectroscopies, as well as thermogravimetric analysis. The morphology was characterized by transmission electron microscopy, atomic force microscopy and dynamic light scattering. The parameters were varied within each route to fine tune the size and shape of the formed nanoparticles. PMID:28144555

A novel technique to monitor thermal discharges using thermal infrared imaging.

PubMed

Muthulakshmi, A L; Natesan, Usha; Ferrer, Vincent A; Deepthi, K; Venugopalan, V P; Narasimhan, S V

2013-09-01

Coastal temperature is an important indicator of water quality, particularly in regions where delicate ecosystems sensitive to water temperature are present. Remote sensing methods are highly reliable for assessing the thermal dispersion. The plume dispersion from the thermal outfall of the nuclear power plant at Kalpakkam, on the southeast coast of India, was investigated from March to December 2011 using thermal infrared images along with field measurements. The absolute temperature as provided by the thermal infrared (TIR) images is used in the Arc GIS environment for generating a spatial pattern of the plume movement. Good correlation of the temperature measured by the TIR camera with the field data (r(2) = 0.89) make it a reliable method for the thermal monitoring of the power plant effluents. The study portrays that the remote sensing technique provides an effective means of monitoring the thermal distribution pattern in coastal waters.

Short infrared laser pulses increase cell membrane fluidity

NASA Astrophysics Data System (ADS)

Walsh, Alex J.; Cantu, Jody C.; Ibey, Bennett L.; Beier, Hope T.

2017-02-01

Short infrared laser pulses induce a variety of effects in cells and tissues, including neural stimulation and inhibition. However, the mechanism behind these physiological effects is poorly understood. It is known that the fast thermal gradient induced by the infrared light is necessary for these biological effects. Therefore, this study tests the hypothesis that the fast thermal gradient induced in a cell by infrared light exposure causes a change in the membrane fluidity. To test this hypothesis, we used the membrane fluidity dye, di-4-ANEPPDHQ, to investigate membrane fluidity changes following infrared light exposure. Di-4-ANEPPDHQ fluorescence was imaged on a wide-field fluorescence imaging system with dual channel emission detection. The dual channel imaging allowed imaging of emitted fluorescence at wavelengths longer and shorter than 647 nm for ratiometric assessment and computation of a membrane generalized polarization (GP) value. Results in CHO cells show increased membrane fluidity with infrared light pulse exposure and this increased fluidity scales with infrared irradiance. Full recovery of pre-infrared exposure membrane fluidity was observed. Altogether, these results demonstrate that infrared light induces a thermal gradient in cells that changes membrane fluidity.

Infrared Detector System with Controlled Thermal Conductance

NASA Technical Reports Server (NTRS)

Cunningham, Thomas J. (Inventor)

2000-01-01

A thermal infrared detector system includes a heat sink, a support member, a connection support member connecting the support member to the heat sink and including a heater unit is reviewed. An infrared detector element is mounted on the support member and a temperature signal representative of the infrared energy contacting the support member can then be derived by comparing the temperature of the support member and the heat sink. The temperature signal from a support member and a temperature signal from the connection support member can then be used to drive a heater unit mounted on the connection support member to thereby control the thermal conductance of the support member. Thus, the thermal conductance can be controlled so that it can be actively increased or decreased as desired.

Method to analyze remotely sensed spectral data

DOEpatents

Stork, Christopher L [Albuquerque, NM; Van Benthem, Mark H [Middletown, DE

2009-02-17

A fast and rigorous multivariate curve resolution (MCR) algorithm is applied to remotely sensed spectral data. The algorithm is applicable in the solar-reflective spectral region, comprising the visible to the shortwave infrared (ranging from approximately 0.4 to 2.5 .mu.m), midwave infrared, and thermal emission spectral region, comprising the thermal infrared (ranging from approximately 8 to 15 .mu.m). For example, employing minimal a priori knowledge, notably non-negativity constraints on the extracted endmember profiles and a constant abundance constraint for the atmospheric upwelling component, MCR can be used to successfully compensate thermal infrared hyperspectral images for atmospheric upwelling and, thereby, transmittance effects. Further, MCR can accurately estimate the relative spectral absorption coefficients and thermal contrast distribution of a gas plume component near the minimum detectable quantity.

Applications of infrared thermography for nondestructive testing of fatigue cracks in steel bridges

NASA Astrophysics Data System (ADS)

Sakagami, Takahide; Izumi, Yui; Kobayashi, Yoshihiro; Mizokami, Yoshiaki; Kawabata, Sunao

2014-05-01

In recent years, fatigue crack propagations in aged steel bridge which may lead to catastrophic structural failures have become a serious problem. For large-scale steel structures such as orthotropic steel decks in highway bridges, nondestructive inspection of deteriorations and fatigue damages are indispensable for securing their safety and for estimating their remaining strength. As conventional NDT techniques for steel bridges, visual testing, magnetic particle testing and ultrasonic testing have been commonly employed. However, these techniques are time- and labor- consuming techniques, because special equipment is required for inspection, such as scaffolding or a truck mount aerial work platform. In this paper, a new thermography NDT technique, which is based on temperature gap appeared on the surface of structural members due to thermal insulation effect of the crack, is developed for detection of fatigue cracks. The practicability of the developed technique is demonstrated by the field experiments for highway steel bridges in service. Detectable crack size and factors such as measurement time, season or spatial resolution which influence crack detectability are investigated.

Method and apparatus for measuring surface contour on parts with elevated temperatures

DOEpatents

Horvath, Mark S.; Nance, Roy A.; Cohen, George H.; Fodor, George

1991-01-01

The invention is directed to a method and apparatus for measuring the surface contour of a test piece, such as the bow of a radioactive fuel rod, which is completely immersed in water. The invention utilizes ultrasonic technology and is capable of measuring surface contours of test pieces which are at a higher temperature than the surrounding water. The presence of a test piece at a higher temperature adversely affects the distance measurements by causing thermal variations in the water near the surface of the test piece. The contour measurements depend upon a constant temperature of the water in the path of the ultrasonic wave to provide a constant acoustical velocity (the measurement is made by the time of flight measurement for an ultrasonic wave). Therefore, any variations of water temperature near the surface will introduce errors degrading the measurement. The present invention overcomes these problems by assuring that the supply of water through which the ultrasonic waves travel is at a predetermined and constant temperature.

Ultrasonic Study of Dislocation Dynamics in Lithium -

NASA Astrophysics Data System (ADS)

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.

Ultrasonic hyperactivation of cellulase immobilized on magnetic nanoparticles.

PubMed

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.

Mid-Infrared Lifetime Imaging for Viability Evaluation of Lettuce Seeds Based on Time-Dependent Thermal Decay Characterization

PubMed Central

Kim, Ghiseok; Kim, Geon Hee; Ahn, Chi-Kook; Yoo, Yoonkyu; Cho, Byoung-Kwan

2013-01-01

An infrared lifetime thermal imaging technique for the measurement of lettuce seed viability was evaluated. Thermal emission signals from mid-infrared images of healthy seeds and seeds aged for 24, 48, and 72 h were obtained and reconstructed using regression analysis. The emission signals were fitted with a two-term exponential model that had two amplitudes and two time variables as lifetime parameters. The lifetime thermal decay parameters were significantly different for seeds with different aging times. Single-seed viability was visualized using thermal lifetime images constructed from the calculated lifetime parameter values. The time-dependent thermal signal decay characteristics, along with the decay amplitude and delay time images, can be used to distinguish aged lettuce seeds from normal seeds. PMID:23529120

Infrared Thermal Imaging as a Tool in University Physics Education

ERIC Educational Resources Information Center

Mollmann, Klaus-Peter; Vollmer, Michael

2007-01-01

Infrared thermal imaging is a valuable tool in physics education at the university level. It can help to visualize and thereby enhance understanding of physical phenomena from mechanics, thermal physics, electromagnetism, optics and radiation physics, qualitatively as well as quantitatively. We report on its use as lecture demonstrations, student…

The surface roughness of (433) Eros as measured by thermal-infrared beaming

NASA Astrophysics Data System (ADS)

Rozitis, B.

2017-01-01

In planetary science, surface roughness is regarded to be a measure of surface irregularity at small spatial scales, and causes the thermal-infrared beaming effect (I.e. re-radiation of absorbed sunlight back towards to the Sun). Typically, surface roughness exhibits a degeneracy with thermal inertia when thermophysical models are fitted to disc-integrated thermal-infrared observations of asteroids because of this effect. In this work, it is demonstrated how surface roughness can be constrained for near-Earth asteroid (433) Eros (I.e. the target of NASA's NEAR Shoemaker mission) when using the Advanced Thermophysical Model with thermal-infrared observations taken during an `almost pole-on' illumination and viewing geometry. It is found that the surface roughness of (433) Eros is characterized by an rms slope of 38 ± 8° at the 0.5-cm spatial scale associated with its thermal-infrared beaming effect. This is slightly greater than the rms slope of 25 ± 5° implied by the NEAR Shoemaker laser ranging results when extrapolated to this spatial scale, and indicates that other surface shaping processes might operate, in addition to collisions and gravity, at spatial scales under one metre in order to make asteroid surfaces rougher. For other high-obliquity asteroids observed during `pole-on' illumination conditions, the thermal-infrared beaming effect allows surface roughness to be constrained when the sub-solar latitude is greater than 60°, and if the asteroids are observed at phase angles of less than 40°. They will likely exhibit near-Earth asteroid thermal model beaming parameters that are lower than expected for a typical asteroid at all phase angles up to 100°.

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

PubMed

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.

The Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes

NASA Astrophysics Data System (ADS)

Wong, Elizabeth Wing-See

There is much evidence that the ocean is heating as a result of an increase in concentrations of greenhouse gases (GHGs) in the atmosphere from human activities. GHGs absorb infrared radiation and re-emit infrared radiation back to the ocean's surface which is subsequently absorbed. However, the incoming infrared radiation is absorbed within the top micrometers of the ocean's surface which is where the thermal skin layer exists. Thus the incident infrared radiation does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of infrared radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that since heat lost through the air-sea interface is controlled by the thermal skin layer, which is directly influenced by the absorption and emission of infrared radiation, the heat flow through the thermal skin layer adjusts to maintain the surface heat loss, assuming the surface heat loss does not vary, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in incoming longwave radiation and analyzing retrieved thermal skin layer vertical temperature profiles from a shipboard infrared spectrometer from two research cruises. The data are limited to night-time, no precipitation and low winds of less than 2 m/s to remove effects of solar radiation, wind-driven shear and possibilities of thermal skin layer disruption. The results show independence of the turbulent fluxes and emitted radiation on the incident radiative fluxes which rules out the immediate release of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation and increase infrared emission. Furthermore, independence was confirmed between the incoming and outgoing radiative flux which implies the heat sink for upward flowing heat at the air-sea interface is more-or-less fixed. The surplus energy, from absorbing increasing levels of infrared radiation, is found to adjust the curvature of the thermal skin layer such that there is a smaller gradient at the interface between the thermal skin layer and the mixed layer beneath. The vertical conduction of heat from the mixed layer to the surface is therefore hindered while the additional energy within the thermal skin layer is supporting the gradient changes of the skin layer's temperature profile. This results in heat beneath the thermal skin layer, which is a product of the absorption of solar radiation during the day, to be retained and cause an increase in upper ocean heat content. The accuracy of four published skin layer models were evaluated by comparison with the field results. The results show a need to include radiative effects, which are currently absent, in such models as they do not replicate the findings from the field data and do not elucidate the effects of the absorption of infrared radiation.

Application of ultrasound in periodontics: Part I

PubMed Central

Bains, Vive K.; Mohan, Ranjana; Bains, Rhythm

2008-01-01

Ultrasonic is a branch of acoustics concerned with sound vibrations in frequency ranges above audible level. Ultrasound uses the transmission and reflection of acoustic energy. A pulse is propagated and its reflection is received, both by the transducer. For clinical purposes ultrasound is generated by transducers, which converts electrical energy into ultrasonic waves. This is usually achieved by magnetostriction or piezoelectricity. Primary effects of ultrasound are thermal, mechanical (cavitation and microstreaming), and chemical (sonochemicals). Knowledge of the basic and other secondary effects of ultrasound is essential for the development of techniques of application. PMID:20142941

Chemical coloring on stainless steel by ultrasonic irradiation.

PubMed

Cheng, Zuohui; Xue, Yongqiang; Ju, Hongbin

2018-01-01

To solve the problems of high temperature and non-uniformity of coloring on stainless steel, a new chemical coloring process, applying ultrasonic irradiation to the traditional chemical coloring process, was developed in this paper. The effects of ultrasonic frequency and power density (sound intensity) on chemical coloring on stainless steel were studied. The uniformity of morphology and colors was observed with the help of polarizing microscope and scanning electron microscopy (SEM), and the surface compositions were characterized by X-ray photoelectric spectroscopy (XPS), meanwhile, the wear resistance and the corrosion resistance were investigated, and the effect mechanism of ultrasonic irradiation on chemical coloring was discussed. These results show that in the process of chemical coloring on stainless steel by ultrasonic irradiation, the film composition is the same as the traditional chemical coloring, and this method can significantly enhance the uniformity, the wear and corrosion resistances of the color film and accelerate the coloring rate which makes the coloring temperature reduced to 40°C. The effects of ultrasonic irradiation on the chemical coloring can be attributed to the coloring rate accelerated and the coloring temperature reduced by thermal-effect, the uniformity of coloring film improved by dispersion-effect, and the wear and corrosion resistances of coloring film enhanced by cavitation-effect. Ultrasonic irradiation not only has an extensive application prospect for chemical coloring on stainless steel but also provides an valuable reference for other chemical coloring. Copyright © 2017 Elsevier B.V. All rights reserved.

Feasibility on Ultrasonic Velocity using Contact and Non-Contact Nondestructive Techniques for Carbon/Carbon Composites

NASA Astrophysics Data System (ADS)

Im, K. H.; Chang, M.; Hsu, D. K.; Song, S. J.; Cho, H.; Park, J. W.; Kweon, Y. S.; Sim, J. K.; Yang, I. Y.

2007-03-01

Advanced materials are to be required to have specific functions associated with extremely environments. One of them is carbon/carbon(C/C) composite material, which has obvious advantages over conventional materials. The C/Cs have become to be utilized as parts of aerospace applications and its low density, high thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal material for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. In this work, a C/C composite material was characterized with non-contact and contact ultrasonic methods using a scanner with automatic-data acquisition function. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake were compared and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude of the ultrasonic pulse was used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the dry-coupling ultrasonic UT system and through transmission method in immersion. Finally, feasibility has been found to measure and compare ultrasonic velocities of C/C composites with using the contact/noncontact peak-delay measurement method based on the pulse overlap method.

Interfacial Dynamics of Condensing Vapor Bubbles in an Ultrasonic Acoustic Field

NASA Astrophysics Data System (ADS)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2016-11-01

Enhancement of vapor condensation in quiescent subcooled liquid using ultrasonic actuation is investigated experimentally. The vapor bubbles are formed by direct injection from a pressurized steam reservoir through nozzles of varying characteristic diameters, and are advected within an acoustic field of programmable intensity. While kHz-range acoustic actuation typically couples to capillary instability of the vapor-liquid interface, ultrasonic (MHz-range) actuation leads to the formation of a liquid spout that penetrates into the vapor bubble and significantly increases its surface area and therefore condensation rate. Focusing of the ultrasonic beam along the spout leads to ejection of small-scale droplets from that are propelled towards the vapor liquid interface and result in localized acceleration of the condensation. High-speed video of Schlieren images is used to investigate the effects of the ultrasonic actuation on the thermal boundary layer on the liquid side of the vapor-liquid interface and its effect on the condensation rate, and the liquid motion during condensation is investigated using high-magnification PIV measurements. High-speed image processing is used to assess the effect of the actuation on the dynamics and temporal variation in characteristic scale (and condensation rate) of the vapor bubbles.

Evaluation of Die-Attach Bonding Using High-Frequency Ultrasonic Energy for High-Temperature Application

NASA Astrophysics Data System (ADS)

Lee, Jong-Bum; Aw, Jie-Li; Rhee, Min-Woo

2014-09-01

Room-temperature die-attach bonding using ultrasonic energy was evaluated on Cu/In and Cu/Sn-3Ag metal stacks. The In and Sn-3Ag layers have much lower melting temperatures than the base material (Cu) and can be melted through the heat generated during ultrasonic bonding, forming intermetallic compounds (IMCs). Samples were bonded using different ultrasonic powers, bonding times, and forces and subsequently aged at 300°C for 500 h. After aging, die shear testing was performed and the fracture surfaces were inspected by scanning electron microscopy. Results showed that the shear strength of Cu/In joints reached an upper plateau after 100 h of thermal aging and remained stable with aging time, whereas that of the Cu/Sn-3Ag joints decreased with increasing aging time. η-Cu7In4 and (Cu,Au)11In9 IMCs were observed at the Cu/In joint, while Cu3Sn and (Ag,Cu)3Sn IMCs were found at the Cu/Sn-3Ag joint after reliability testing. As Cu-based IMCs have high melting temperatures, they are highly suitable for use in high-temperature electronics, but can be formed at room temperature using an ultrasonic approach.

Ultrasonic-assisted solution combustion synthesis of porous Na3V2(PO4)3/C: formation mechanism and sodium storage performance

NASA Astrophysics Data System (ADS)

Chen, Qiuyun; Liu, Qing; Chu, Xiangcheng; Zhang, Yiling; Yan, Youwei; Xue, Lihong; Zhang, Wuxing

2017-04-01

Solution combustion synthesis (SCS) is an effective and rapid method for synthesizing nanocrystalline materials. However, the control over size, morphology, and microstructure are rather limited in SCS. Here, we develop a novel ultrasonic-assisted solution combustion route to synthesize the porous and nano-sized Na3V2(PO4)3/C composites, and reveal the effects of ultrasound on the structural evolution of NVP/C. Due to the cavitation effects generated from ultrasonic irradiation, the ultrasonic-assisted SCS can produce honeycomb precursor, which can be further transformed into porous Na3V2(PO4)3/C with reticular and hollow structures after thermal treatment. When used as cathode material for Na-ion batteries, the porous Na3V2(PO4)3/C delivers an initial discharge capacity of 118 mAh g-1 at 0.1 C and an initial coulombic efficiency of 85%. It can retain 93.8% of the initial capacity after 120 cycles at 0.2 C. The results demonstrate that ultrasonic-assisted SCS can be a new strategy to design crystalline nanomaterials with tunable microstructures.

A novel ultrasonication method in the preparation of zirconium impregnated cellulose for effective fluoride adsorption.

PubMed

Barathi, M; Kumar, A Santhana Krishna; Rajesh, N

2014-05-01

In the present work, we propose for the first time a novel ultrasound assisted methodology involving the impregnation of zirconium in a cellulose matrix. Fluoride from aqueous solution interacts with the cellulose hydroxyl groups and the cationic zirconium hydroxide. Ultrasonication ensures a green and quick alternative to the conventional time intensive method of preparation. The effectiveness of this process was confirmed by comprehensive characterization of zirconium impregnated cellulose (ZrIC) adsorbent using Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectrometry (EDX) and X-ray diffraction (XRD) studies. The study of various adsorption isotherm models, kinetics and thermodynamics of the interaction validated the method. Copyright © 2013 Elsevier B.V. All rights reserved.

Client-centred development of an infrared thermal access switch for a young adult with severe spastic quadriplegic cerebral palsy.

PubMed

Memarian, Negar; Venetsanopoulos, Anastasios N; Chau, Tom

2011-01-01

This study reports a client-centred development of a non-contact access switch based on an infrared thermal imaging of mouth opening-closing activity of an individual with severe spastic quadriplegic cerebral palsy. Over a 6-month period, the client participated in five test sessions to inform the development of an infrared thermal switch. The client completed eight stimulus-response trials (switch test) and eight word-matching trials (scan test) using the infrared thermal switch and provided subjective feedback throughout. For the switch test, the client achieved an average correct activation rate of 90% and average response time of 2.4 s. His mean correct activation rate on the scan test improved from 65 to 80% over the course of system development, with an average response time of 11.7 s. An infrared thermography switch tuned to a client's extant orofacial gestures is a practical non-invasive access solution and warrants further research in clients with severe physical disability.

Representation of thermal infrared imaging data in the DICOM using XML configuration files.

PubMed

Ruminski, Jacek

2007-01-01

The DICOM standard has become a widely accepted and implemented format for the exchange and storage of medical imaging data. Different imaging modalities are supported however there is not a dedicated solution for thermal infrared imaging in medicine. In this article we propose new ideas and improvements to final proposal of the new DICOM Thermal Infrared Imaging structures and services. Additionally, we designed, implemented and tested software packages for universal conversion of existing thermal imaging files to the DICOM format using XML configuration files. The proposed solution works fast and requires minimal number of user interactions. The XML configuration file enables to compose a set of attributes for any source file format of thermal imaging camera.

Effect of boron on enhancing infrared emissivity of Ni-Cr system coating

NASA Astrophysics Data System (ADS)

Li, Yongjia; Ouyang, Taoyuan; Wang, Xiaohuan; Li, Shuhao; Mao, Jiawei; Cheng, Xudong

2018-03-01

High infrared emissivity coating possesses great value in practical application, whether in the military or civilian areas. In this study, B-NiCr precursor powder containing NiO, Cr2O3 and ZrB2 was calcined at 1300 °C and then used to prepare a high infrared emissivity B-NiCr coating via atmospheric plasma spraying. A large number of test methods were employed to analyze the powder and coating, including TG-DSC, XRD, FE-SEM, infrared spectrometer and so on. The result of infrared emissivity measurement indicates that the coating possesses maximum infrared emissivity of 0.908 at 1000 °C while the infrared emissivity is 0.901 after thermal shock test. Comparing with NiCr coating, Ni2CrO2(BO3) formed during calcination may be the main factor to improve the infrared emissivity of B-NiCr coating. The B-NiCr coating possesses good thermal shock resistance and can withstand 50 times thermal shock at least without falling off, from 800 °C to room temperature.

Application and possible mechanisms of combining LLLT (low level laser therapy), infrared hyperthermia and ionizing radiation in the treatment of cancer

NASA Astrophysics Data System (ADS)

Abraham, Edward H.; Woo, Van H.; Harlin-Jones, Cheryl; Heselich, Anja; Frohns, Florian

2014-02-01

Benefit of concomitant infrared hyperthermia and low level laser therapy and ionizing radiation is evaluated in this study. The purpose/objectives: presentation with locally advanced bulky superficial tumors is clinically challenging. To enhance the efficacy of chemotherapy and IMRT (intensity-modulated radiation therapy) and/or electron beam therapy we have developed an inexpensive and clinically effective infrared hyperthermia approach that combines black-body infrared radiation with halogen spectrum radiation and discrete wave length infrared clinical lasers LLLT. The goal is to produce a composite spectrum extending from the far infrared to near infrared and portions of the visible spectrum with discrete penetrating wavelengths generated by the clinical infrared lasers with frequencies of 810 nm and/or 830 nm. The composite spectrum from these sources is applied before and after radiation therapy. We monitor the surface and in some cases deeper temperatures with thermal probes, but use an array of surface probes as the limiting safe thermal constraint in patient treatment while at the same time maximizing infrared entry to deeper tissue layers. Fever-grade infrared hyperthermia is produced in the first centimeters while non-thermal infrared effects act at deeper tissue layers. The combination of these effects with ionizing radiation leads to improved tumor control in many cancers.

Broadband near-field infrared spectromicroscopy using photothermal probes and synchrotron radiation.

PubMed

Donaldson, Paul M; Kelley, Chris S; Frogley, Mark D; Filik, Jacob; Wehbe, Katia; Cinque, Gianfelice

2016-02-08

In this paper, we experimentally demonstrate the use of infrared synchrotron radiation (IR-SR) as a broadband source for photothermal near-field infrared spectroscopy. We assess two methods of signal transduction; cantilever resonant thermal expansion and scanning thermal microscopy. By means of rapid mechanical chopping (50-150 kHz), we modulate the IR-SR at rates matching the contact resonance frequencies of atomic force microscope (AFM) cantilevers, allowing us to record interferograms yielding Fourier transform infrared (FT-IR) photothermal absorption spectra of polystyrene and cyanoacrylate films. Complementary offline measurements using a mechanically chopped CW IR laser confirmed that the resonant thermal expansion IR-SR measurements were below the diffraction limit, with a spatial resolution better than 500 nm achieved at a wavelength of 6 μm, i.e. λ/12 for the samples studied. Despite achieving the highest signal to noise so far for a scanning thermal microscopy measurement under conditions approaching near-field (dictated by thermal diffusion), the IR-SR resonant photothermal expansion FT-IR spectra measured were significantly higher in signal to noise in comparison with the scanning thermal data.

Monitoring of HIFU thermal damage using integrated photoacoustic imaging and high intensity focused ultrasound technique

NASA Astrophysics Data System (ADS)

Cui, Huizhong; Yang, Xinmai

2011-03-01

In this study, we applied an integrated photoacoustic imaging (PAI) and high intensity focused ultrasound (HIFU) system to noninvasively monitor the thermal damage due to HIFU ablation in vivo. A single-element, spherically focused ultrasonic transducer, with a central frequency of 5MHz, was used to generate a HIFU area in soft tissue. Photoacoustic signals were detected by the same ultrasonic transducer before and after HIFU treatments using different wavelengths. The feasibility of combined contrast imaging and treatment of solid tumor in vivo by the integrated PAI and HIFU system was also studied. Gold nanorods were used to enhance PAI during the imaging of a CT26 tumor, which was subcutaneously inoculated on the hip of a BALB/c mouse. Subsequently, the CT26 tumor was ablated by HIFU with the guidance of photoacoustic images. Our results suggested that the tumor was clearly visible on photoacoustic images after the injection of gold nanorods and was ablated by HIFU. In conclusion, PAI may potentially be used for monitoring HIFU thermal lesions with possible diagnosis and treatment of solid tumors.

Thermal Emission Spectrometer Results: Mars Atmospheric Thermal Structure and Aerosol Distribution

NASA Technical Reports Server (NTRS)

Smith, Michael D.; Pearl, John C.; Conrath, Barney J.; Christensen, Philip R.; Vondrak, Richard R. (Technical Monitor)

2001-01-01

Infrared spectra returned by the Thermal Emission Spectrometer (TES) are well suited for retrieval of the thermal structure and the distribution of aerosols in the Martian atmosphere. Combined nadir- and limb-viewing spectra allow global monitoring of the atmosphere up to 0.01 mbar (65 km). We report here on the atmospheric thermal structure and the distribution of aerosols as observed thus far during the mapping phase of the Mars Global Surveyor mission. Zonal and temporal mean cross sections are used to examine the seasonal evolution of atmospheric temperatures and zonal winds during a period extending from northern hemisphere mid-summer through vernal equinox (L(sub s) = 104-360 deg). Temperature maps at selected pressure levels provide a characterization of planetary-scale waves. Retrieved atmospheric infrared dust opacity maps show the formation and evolution of regional dust storms during southern hemisphere summer. Response of the atmospheric thermal structure to the changing dust loading is observed. Maps of water-ice clouds as viewed in the thermal infrared are presented along with seasonal trends of infrared water-ice opacity. Uses of these observations for diagnostic studies of the dynamics of the atmosphere are discussed.

The Infrared Automatic Mass Screening (IRAMS) System For Printed Circuit Board Fault Detection

NASA Astrophysics Data System (ADS)

Hugo, Perry W.

1987-05-01

Office of the Program Manager for TMDE (OPM TMDE) has initiated a program to develop techniques for evaluating the performance of printed circuit boards (PCB's) using infrared thermal imaging. It is OPM TMDE's expectation that the standard thermal profile (STP) will become the basis for the future rapid automatic detection and isolation of gross failure mechanisms on units under test (UUT's). To accomplish this OPM TMDE has purchased two Infrared Automatic Mass Screening ( I RAMS) systems which are scheduled for delivery in 1987. The IRAMS system combines a high resolution infrared thermal imager with a test bench and diagnostic computer hardware and software. Its purpose is to rapidly and automatically compare the thermal profiles of a UUT with the STP of that unit, recalled from memory, in order to detect thermally responsive failure mechanisms in PCB's. This paper will review the IRAMS performance requirements, outline the plan for implementing the two systems and report on progress to date.

Reduced isothermal feature set for long wave infrared (LWIR) face recognition

NASA Astrophysics Data System (ADS)

Donoso, Ramiro; San Martín, Cesar; Hermosilla, Gabriel

2017-06-01

In this paper, we introduce a new concept in the thermal face recognition area: isothermal features. This consists of a feature vector built from a thermal signature that depends on the emission of the skin of the person and its temperature. A thermal signature is the appearance of the face to infrared sensors and is unique to each person. The infrared face is decomposed into isothermal regions that present the thermal features of the face. Each isothermal region is modeled as circles within a center representing the pixel of the image, and the feature vector is composed of a maximum radius of the circles at the isothermal region. This feature vector corresponds to the thermal signature of a person. The face recognition process is built using a modification of the Expectation Maximization (EM) algorithm in conjunction with a proposed probabilistic index to the classification process. Results obtained using an infrared database are compared with typical state-of-the-art techniques showing better performance, especially in uncontrolled acquisition conditions scenarios.

Infrared thermal facial image sequence registration analysis and verification

NASA Astrophysics Data System (ADS)

Chen, Chieh-Li; Jian, Bo-Lin

2015-03-01

To study the emotional responses of subjects to the International Affective Picture System (IAPS), infrared thermal facial image sequence is preprocessed for registration before further analysis such that the variance caused by minor and irregular subject movements is reduced. Without affecting the comfort level and inducing minimal harm, this study proposes an infrared thermal facial image sequence registration process that will reduce the deviations caused by the unconscious head shaking of the subjects. A fixed image for registration is produced through the localization of the centroid of the eye region as well as image translation and rotation processes. Thermal image sequencing will then be automatically registered using the two-stage genetic algorithm proposed. The deviation before and after image registration will be demonstrated by image quality indices. The results show that the infrared thermal image sequence registration process proposed in this study is effective in localizing facial images accurately, which will be beneficial to the correlation analysis of psychological information related to the facial area.

Early Results from the Odyssey THEMIS Investigation

NASA Technical Reports Server (NTRS)

Christensen, Philip R.; Bandfield, Joshua L.; Bell, James F., III; Hamilton, Victoria E.; Ivanov, Anton; Jakosky, Bruce M.; Kieffer, Hugh H.; Lane, Melissa D.; Malin, Michael C.; McConnochie, Timothy

2003-01-01

The Thermal Emission Imaging System (THEMIS) began studying the surface and atmosphere of Mars in February, 2002 using thermal infrared (IR) multi-spectral imaging between 6.5 and 15 m, and visible/near-IR images from 450 to 850 nm. The infrared observations continue a long series of spacecraft observations of Mars, including the Mariner 6/7 Infrared Spectrometer, the Mariner 9 Infrared Interferometer Spectrometer (IRIS), the Viking Infrared Thermal Mapper (IRTM) investigations, the Phobos Termoscan, and the Mars Global Surveyor Thermal Emission Spectrometer (MGS TES). The THEMIS investigation's specific objectives are to: (1) determine the mineralogy of localized deposits associated with hydrothermal or sub-aqueous environments, and to identify future landing sites likely to represent these environments; (2) search for thermal anomalies associated with active sub-surface hydrothermal systems; (3) study small-scale geologic processes and landing site characteristics using morphologic and thermophysical properties; (4) investigate polar cap processes at all seasons; and (5) provide a high spatial resolution link to the global hyperspectral mineral mapping from the TES investigation. THEMIS provides substantially higher spatial resolution IR multi-spectral images to complement TES hyperspectral (143-band) global mapping, and regional visible imaging at scales intermediate between the Viking and MGS cameras.

Thermal infrared imaging of the temporal variability in stomatal conductance for fruit trees

NASA Astrophysics Data System (ADS)

Struthers, Raymond; Ivanova, Anna; Tits, Laurent; Swennen, Rony; Coppin, Pol

2015-07-01

Repeated measurements using thermal infrared remote sensing were used to characterize the change in canopy temperature over time and factors that influenced this change on 'Conference' pear trees (Pyrus communis L.). Three different types of sensors were used, a leaf porometer to measure leaf stomatal conductance, a thermal infrared camera to measure the canopy temperature and a meteorological sensor to measure weather variables. Stomatal conductance of water stressed pear was significantly lower than in the control group 9 days after stress began. This decrease in stomatal conductance reduced transpiration, reducing evaporative cooling that increased canopy temperature. Using thermal infrared imaging with wavelengths between 7.5 and13 μm, the first significant difference was measured 18 days after stress began. A second order derivative described the average rate of change of the difference between the stress treatment and control group. The average rate of change for stomatal conductance was 0.06 (mmol m-2 s-1) and for canopy temperature was -0.04 (°C) with respect to days. Thermal infrared remote sensing and data analysis presented in this study demonstrated that the differences in canopy temperatures between the water stress and control treatment due to stomata regulation can be validated.

Jupiter's atmospheric composition from the Cassini thermal infrared spectroscopy experiment

NASA Technical Reports Server (NTRS)

Kunde, V. G.; Flasar, F. M.; Jennings, D. E.; Bezard, B.; Strobel, D. F.; Conrath, B. J.; Nixon, C. A.; Bjoraker, G. L.; Romani, P. N.; Achterberg, R. K.;

Porous tooling process for manufacture of graphite/polyimide composites

NASA Technical Reports Server (NTRS)

Smiser, L. W.; Orr, K. K.; Araujo, S. M.

1981-01-01

A porous tooling system was selected for the processing of Graphite/PMR-15 Polyimide laminates in thickness up to 3.2 mm. (0.125 inch). This tool system must have a reasonable strength, permeability dimensional stability, and thermal conductivity to accomplish curing at 600 F and 200 psi and 200 psi autoclave temperature and pressure. A permeability measuring apparatus was constructed and permeability vs. casting water level determined to produce tools at three different permeability levels. On these tools, laminates of 5, 11, and 22 plies (.027, .060, and 0.121 inch) were produced and evaluated by ultrasonic, mechanical, and thermal tests to determine the effect of the tool permeability on the cured laminates. All tools produced acceptable laminates at 5 and 11 plies but only the highest permeability produced acceptable clear ultrasonic C-Scans. Recommendations are made for future investigations of design geometry, and strengthening techniques for porous ceramic tooling.

Assessment of precipitation in alloy steel using nonlinear Rayleigh surface waves

NASA Astrophysics Data System (ADS)

Thiele, Sebastian; Matlack, Kathryn H.; Kim, Jin-Yeon; Qu, Jianmin; Wall, James J.; Jacobs, Laurence J.

2014-02-01

Nonlinear ultrasonic waves have shown to be sensitive to various microstructural changes in metals including coherent precipitates; these precipitates introduce a strain field in the lattice structure. The thermal aging of certain alloy steels leads to the formation of coherent precipitates, which pin dislocations and contribute to the generation of a second harmonic component. A precipitate hardenable material namely 17-4 PH stainless steel is thermally treated in this research to obtain different precipitation stages, and then the influence of precipitates on the acoustic nonlinearity parameter is assessed. Conclusions about the microstrucutural changes in the material are drawn based on the results from a nonlinear Rayleigh surface wave measurement and complementary thermo-electric power, hardness and ultrasonic velocity measurements. The results show that the nonlinear parameter is sensitive to coherent precipitates in the material and moreover that precipitation characteristics can be characterized based on the obtained experimental data.

Detection of leaks in buried rural water pipelines using thermal infrared images

USGS Publications Warehouse

Eidenshink, Jeffery C.

1985-01-01

Leakage is a major problem in many pipelines. Minor leaks called 'seeper leaks', which generally range from 2 to 10 m3 per day, are common and are difficult to detect using conventional ground surveys. The objective of this research was to determine whether airborne thermal-infrared remote sensing could be used in detecting leaks and monitoring rural water pipelines. This study indicates that such leaks can be detected using low-altitude 8.7- to 11.5. micrometer wavelength, thermal infrared images collected under proper conditions.

Probabilistic thermal-shock strength testing using infrared imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wereszczak, A.A.; Scheidt, R.A.; Ferber, M.K.

1999-12-01

A thermal-shock strength-testing technique has been developed that uses a high-resolution, high-temperature infrared camera to capture a specimen's surface temperature distribution at fracture. Aluminum nitride (AlN) substrates are thermally shocked to fracture to demonstrate the technique. The surface temperature distribution for each test and AlN's thermal expansion are used as input in a finite-element model to determine the thermal-shock strength for each specimen. An uncensored thermal-shock strength Weibull distribution is then determined. The test and analysis algorithm show promise as a means to characterize thermal shock strength of ceramic materials.

Non-thermal cytocidal effect of infrared irradiation on cultured cancer cells using specialized device.

PubMed

Tanaka, Yohei; Matsuo, Kiyoshi; Yuzuriha, Shunsuke; Yan, Huimin; Nakayama, Jun

2010-06-01

As infrared penetrates the skin, thermal effects of infrared irradiation on cancer cells have been investigated in the field of hyperthermia. We evaluated non-thermal effects of infrared irradiation using a specialized device (1100-18000 nm with filtering of wavelengths between 1400 and 1500 nm and contact cooling) on cancer cells. In in vitro study, five kinds of cultured cancer cell lines (MCF7 breast cancer, HeLa uterine cervical cancer, NUGC-4 gastric cancer, B16F0 melanoma, and MDA-MB435 melanoma) were irradiated using the infrared device, and then the cell proliferation activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Proliferation of all the cancer cell lines was significantly suppressed by infrared irradiation. Total infrared output appeared to be correlated with cell survival. Increased temperature during infrared irradiation appeared not to play a role in cell survival. The maximum temperature elevation in the wells after each shot in the 20 and 40 J/cm(2) culture was 3.8 degrees C and 6.9 degrees C, respectively. In addition, we have shown that infrared irradiation significantly inhibited the tumor growth of MCF7 breast cancer transplanted in severe combined immunodeficiency mice and MDA-MB435 melanoma transplanted in nude mice in vivo. Significant differences between control and irradiated groups were observed in tumor volume and frequencies of TUNEL-positive and Ki-67-positive cells. These results indicate that infrared, independent of thermal energy, can induce cell killing of cancer cells. As this infrared irradiation schedule reduces discomfort and side effects, reaches the deep subcutaneous tissues, and facilitates repeated irradiations, it may have potential as an application for treating various forms of cancer.

Skylab S191 visible-infrared spectrometer. [in Earth Resources Experiment Package

NASA Technical Reports Server (NTRS)

Barnett, T. L.; Juday, R. D.

1977-01-01

The paper describes the S191 visible-infrared spectrometer of the Skylab Earth Resources Experiment Package - a manually pointed two-channel instrument operating in the reflective (0.4-2.5 micron) and thermal emissive (6-15 micron) regions. A sensor description is provided and attention is given to data quality in the short wavelength and thermal infrared regions.

Preparation and characterization of novel polyimide/functionalized ZnO bionanocomposite for gas separation and study of their antibacterial activity

NASA Astrophysics Data System (ADS)

Esmaielzadeh, Sheida; Ahmadizadegan, Hashem

2018-04-01

In the present investigation novel Polyimide/functionalized ZnO (PI/ZnO) bionanocomposites containing amino acid (Methionine) and benzimidazole pendent groups with different amounts of modified ZnO nanoparticles (ZnO NPs) were successfully prepared through ultrasonic irradiation technique. Due to the high surface energy and tendency for agglomeration, the surface ZnO NPs was modified by a coupling agent as 3- methacryloxypropyl-trimethoxysilane (MPS) to form MPS-ZnO nanoparticles. The ultrasonic irradiation effectively changes the rheology and the glass transition temperature and the crystallinity of the composite polymer. PI/ZnO nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). TEM analysis showed that the modified ZnO nanoparticles were homogeneously dispersed in polymer matrix. The TGA results of PI/ZnO nanocomposites showed that the thermal stability is obviously improved the presence of MPS-ZnO NPs in comparison with the pure PI and that this increase is higher when the NP content increases. The permeabilities of pure H2, CH4, O2, and N2 gases through prepared membranes were determined at room temperature (25 °C) and 20 bar feed pressure. The membranes having 20% ZnO showed higher values of H2 permeability, and H2/CH4 and H2/N2 ideal selectivities (the ratio of pair gas permeabilities) compared with other membranes. The antibacterial activity of bionanocomposite films was tested against gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Further, it was observed that antibacterial activity of the resulting hybrid biofilms showed somewhat higher for gram-positive bacteria compared to gram-negative bacteria.

Study on thermal, mechanical and adsorption properties of amine-functionalized MCM-41/PMMA and MCM-41/PS nanocomposites prepared by ultrasonic irradiation.

PubMed

Mohammadnezhad, Gholamhossein; Abad, Saeed; Soltani, Roozbeh; Dinari, Mohammad

2017-11-01

In this study, two common industrial polymers, poly(methyl methacrylate) (PMMA) and polystyrene (PS), were incorporated into amine-functionalized MCM-41 mesoporous silica as reinforcement agents via an ultrasonic assisted method as a facile, fast, eco-friendly, and versatile synthetic tool. Amino functionalization of MCM-41 were performed by 3-aminopropyl triethoxysilane as a coupling agent and it is denoted as APTS-MCM-41. The obtained nanocomposites (NCs), APTS-MCM-41/PMMA and APTS-MCM-41/PS, were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), and thermogravimetric analysis (TGA). Their mechanical properties were also probed via stress-strain curves and improved tensile properties were observed in the NCs relative to the neat polymers. Additionally, APTS-MCM-41/PMMA exhibited better mechanical properties than APTS-MCM-41/PS. Sorption studies were carried out on the two NCs and the effect of different process parameters, namely, pH, contact time, and initial Cd(II) concentration investigated in batch mode. Pseudo-second order and intraparticle diffusion models explain the Cd(II) kinetics more effectively for APTS-MCM-41/PMMA and APTS-MCM-41/PS, respectively. The adsorption isotherm data fitted well to Langmuir isotherm for both NCs and the maximum monolayer adsorption capacities were found to be 24.75mg/g and 10.42mg/g for APTS-MCM-41/PMMA and APTS-MCM-41/PS, respectively. The results demonstrate that the NCs show potential for use in adsorption of heavy metal ion such as Cd(II) from aqueous media. Copyright © 2017 Elsevier B.V. All rights reserved.

Combined theory of reflectance and emittance spectroscopy

NASA Technical Reports Server (NTRS)

Hapke, Bruce

1995-01-01

The theory in which either or both reflected sunlight and thermally emitted radiation contribute to the power received by a detector viewing a particulate medium, such as a powder in the laboratory or a planetary regolith, is considered theoretically. This theory is of considerable interest for the interpretation of data from field or spacecraft instruments that are sensitive to the near-infrared region of the spectrum, such as NIMS (near-infrared mapping spectrometer) and VIMS (visual and infrared mapping spectrometer), as well as thermal infrared detectors.

Space Weathering in the Thermal Infrared: Lessons from LRO Diviner and Next Steps

NASA Astrophysics Data System (ADS)

Greenhagen, B. T.; Lucey, P. G.; Glotch, T. D.; Arnold, J. A.; Bowles, N. E.; Donaldson Hanna, K. L.; Shirley, K. A.

2018-04-01

Global data from the LRO Diviner show that the thermal infrared is affected by space weathering. We will present and discuss hypotheses for the unanticipated space weathering dependence and next steps.

Application of infrared camera to bituminous concrete pavements: measuring vehicle

NASA Astrophysics Data System (ADS)

Janků, Michal; Stryk, Josef

2017-09-01

Infrared thermography (IR) has been used for decades in certain fields. However, the technological level of advancement of measuring devices has not been sufficient for some applications. Over the recent years, good quality thermal cameras with high resolution and very high thermal sensitivity have started to appear on the market. The development in the field of measuring technologies allowed the use of infrared thermography in new fields and for larger number of users. This article describes the research in progress in Transport Research Centre with a focus on the use of infrared thermography for diagnostics of bituminous road pavements. A measuring vehicle, equipped with a thermal camera, digital camera and GPS sensor, was designed for the diagnostics of pavements. New, highly sensitive, thermal cameras allow to measure very small temperature differences from the moving vehicle. This study shows the potential of a high-speed inspection without lane closures while using IR thermography.

Compositional and textural information from the dual inversion of visible, near and thermal infrared remotely sensed data

NASA Technical Reports Server (NTRS)

Brackett, Robert A.; Arvidson, Raymond E.

1993-01-01

A technique is presented that allows extraction of compositional and textural information from visible, near and thermal infrared remotely sensed data. Using a library of both emissivity and reflectance spectra, endmember abundances and endmember thermal inertias are extracted from AVIRIS (Airborne Visible and Infrared Imaging Spectrometer) and TIMS (Thermal Infrared Mapping Spectrometer) data over Lunar Crater Volcanic Field, Nevada, using a dual inversion. The inversion technique is motivated by upcoming Mars Observer data and the need for separation of composition and texture parameters from sub pixel mixtures of bedrock and dust. The model employed offers the opportunity to extract compositional and textural information for a variety of endmembers within a given pixel. Geologic inferences concerning grain size, abundance, and source of endmembers can be made directly from the inverted data. These parameters are of direct relevance to Mars exploration, both for Mars Observer and for follow-on missions.

Development of infrared thermal imager for dry eye diagnosis

NASA Astrophysics Data System (ADS)

Chiang, Huihua Kenny; Chen, Chih Yen; Cheng, Hung You; Chen, Ko-Hua; Chang, David O.

2006-08-01

This study aims at the development of non-contact dry eye diagnosis based on an infrared thermal imager system, which was used to measure the cooling of the ocular surface temperature of normal and dry eye patients. A total of 108 subjects were measured, including 26 normal and 82 dry eye patients. We have observed that the dry eye patients have a fast cooling of the ocular surface temperature than the normal control group. We have developed a simplified algorithm for calculating the temperature decay constant of the ocular surface for discriminating between normal and dry eye. This study shows the diagnostic of dry eye syndrome by the infrared thermal imager system has reached a sensitivity of 79.3%, a specificity of 75%, and the area under the ROC curve 0.841. The infrared thermal imager system has a great potential to be developed for dry eye screening with the advantages of non-contact, fast, and convenient implementation.

A simple method for the sonochemical synthesis of PVA/ZrO2-vitamin B1 nanocomposites: Morphology, mechanical, thermal and wettability investigations.

PubMed

Mallakpour, Shadpour; Shafiee, Elaheh

2018-01-01

Poly(vinyl alcohol) (PVA) based nanocomposites (NCs) filled by various weight percent of modified ZrO 2 nanoparticles (NPs) with vitamin B 1 (VB 1 ) up to 7wt% were fabricated via ultrasonication method then was cast to thin films. The ultrasonication was applied for the preparation and modification process asan easy, safe and fast method. Ultrasonic was responsible for great homogeneities of NPs into PVA matrix, which could not be achieved by mechanical or magnetically stirring. The creation of polymer NCs and changes in the structural properties were examined by X-ray diffraction. FT-IR spectroscopy indicated the possible interactions of the ZrO 2 -VB 1 NPs with the PVA backbones and also, existence of absorption bands related to PVA and ZrO 2 NPs in the NC structures. The distribution of nano-fillers and uniform morphology of the NCs showed that the ZrO 2 -VB 1 NPs were homogeneously dispersed in the polymer matrix in the nanosized scale. UV-Vis analysis shown that the the optical absorption were improved by evolution of ZrO 2 -VB 1 NPs content. The tensile strength of PVA film was increased significantly with increasing the ZrO 2 -VB 1 NPs content. Thermal gravimetric analysis confirmed that NCs displayed higher thermal stability than the pristine PVA. Also, water contact angle analysis indicated that the hydrophilicity of NC films was enhanced with increasing the concentration of ZrO 2 NPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Numerical modeling of ultrasonic cavitation in ionic liquids

NASA Astrophysics Data System (ADS)

Calvisi, Michael L.; Elder, Ross M.

2017-11-01

Ionic liquids have favorable properties for sonochemistry applications in which the high temperatures and pressures achieved by cavitation bubbles are important drivers of chemical processes. Two different numerical models are presented to simulate ultrasonic cavitation in ionic liquids, each with different capabilities and physical assumptions. A model based on a compressible form of the Rayleigh-Plesset equation (RPE) simulates ultrasonic cavitation of a spherical bubble with a homogeneous interior, incorporating evaporation and condensation at the bubble surface, and temperature-varying thermodynamic properties in the interior. A second, more computationally intensive model of a spherical bubble uses the finite element method (FEM) and accounts for spatial variations in pressure and temperature throughout the flow domain. This model provides insight into heat transfer across the bubble surface and throughout the bubble interior and exterior. Parametric studies are presented for sonochemistry applications involving ionic liquids as a solvent, examining a range of realistic ionic liquid properties and initial conditions to determine their effect on temperature and pressure. Results from the two models are presented for parametric variations including viscosity, thermal conductivity, water content of the ionic liquid solvent, acoustic frequency, and initial bubble pressure. An additional study performed with the FEM model examines thermal penetration into the surrounding ionic liquid during bubble oscillation. The results suggest the prospect of tuning ionic liquid properties for specific applications.

Thermal microphotonic sensor and sensor array

DOEpatents

Watts, Michael R [Albuquerque, NM; Shaw, Michael J [Tijeras, NM; Nielson, Gregory N [Albuquerque, NM; Lentine, Anthony L [Albuquerque, NM

2010-02-23

A thermal microphotonic sensor is disclosed for detecting infrared radiation using heat generated by the infrared radiation to shift the resonant frequency of an optical resonator (e.g. a ring resonator) to which the heat is coupled. The shift in the resonant frequency can be determined from light in an optical waveguide which is evanescently coupled to the optical resonator. An infrared absorber can be provided on the optical waveguide either as a coating or as a plate to aid in absorption of the infrared radiation. In some cases, a vertical resonant cavity can be formed about the infrared absorber to further increase the absorption of the infrared radiation. The sensor can be formed as a single device, or as an array for imaging the infrared radiation.

[Using infrared thermal asymmetry analysis for objective assessment of the lesion of facial nerve function].

PubMed

Liu, Xu-long; Hong, Wen-xue; Song, Jia-lin; Wu, Zhen-ying

2012-03-01

The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Some lesions of facial nerve function are associated with an alteration of the thermal distribution of the human body. Since the dissipation of heat through the skin occurs for the most part in the form of infrared radiation, infrared thermography is the method of choice to capture the alteration of the infrared thermal distribution. This paper presents a new method of analysis of the thermal asymmetry named effective thermal area ratio, which is a product of two variables. The first variable is mean temperature difference between the specific facial region and its contralateral region. The second variable is a ratio, which is equal to the area of the abnormal region divided by the total area. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell's palsy respectively. The results show: that the mean specificity and sensitivity of this method are 0.90 and 0.87 respectively, improved by 7% and 26% compared with conventional methods. Spearman correlation coefficient between effective thermal area ratio and the degree of facial nerve function is an average of 0.664. Hence, concerning the diagnosis and assessment of facial nerve function, infrared thermography is a powerful tool; while the effective ther mal area ratio is an efficient clinical indicator.

Thermophysical Properties of Matter - The TPRC Data Series. Volume 3. Thermal Conductivity - Nonmetallic Liquids and Gases

DTIC Science & Technology

1970-01-01

design and experimentation. I. The Shock- Tube Method Smiley [546] introduced the use of shock waves...one of the greatest disadvantages of this technique. Both the unique adaptability of the shock tube method for high -temperature measurement of...Line-Source Flow Method H. The Hot-Wire Thermal Diffusion Column Method I. The Shock- Tube Method J. The Arc Method K. The Ultrasonic Method .

Effects of varying environmental conditions on emissivity spectra of bulk lunar soils: Application to Diviner thermal infrared observations of the Moon

NASA Astrophysics Data System (ADS)

Donaldson Hanna, K. L.; Greenhagen, B. T.; Patterson, W. R.; Pieters, C. M.; Mustard, J. F.; Bowles, N. E.; Paige, D. A.; Glotch, T. D.; Thompson, C.

2017-02-01

Currently, few thermal infrared measurements exist of fine particulate (<63 μm) analogue samples (e.g. minerals, mineral mixtures, rocks, meteorites, and lunar soils) measured under simulated lunar conditions. Such measurements are fundamental for interpreting thermal infrared (TIR) observations by the Diviner Lunar Radiometer Experiment (Diviner) onboard NASA's Lunar Reconnaissance Orbiter as well as future TIR observations of the Moon and other airless bodies. In this work, we present thermal infrared emissivity measurements of a suite of well-characterized Apollo lunar soils and a fine particulate (<25 μm) San Carlos olivine sample as we systematically vary parameters that control the near-surface environment in our vacuum chamber (atmospheric pressure, incident solar-like radiation, and sample cup temperature). The atmospheric pressure is varied between ambient (1000 mbar) and vacuum (<10-3 mbar) pressures, the incident solar-like radiation is varied between 52 and 146 mW/cm2, and the sample cup temperature is varied between 325 and 405 K. Spectral changes are characterized as each parameter is varied, which highlight the sensitivity of thermal infrared emissivity spectra to the atmospheric pressure and the incident solar-like radiation. Finally spectral measurements of Apollo 15 and 16 bulk lunar soils are compared with Diviner thermal infrared observations of the Apollo 15 and 16 sampling sites. This comparison allows us to constrain the temperature and pressure conditions that best simulate the near-surface environment of the Moon for future laboratory measurements and to better interpret lunar surface compositions as observed by Diviner.

Phase Retrieval on Undersampled Data from the Thermal Infrared Sensor (TIRS)

NASA Technical Reports Server (NTRS)

Bolcar, Matthew R.; Mentzell, Eric

2011-01-01

Phase retrieval was applied to under-sampled data from a thermal infrared imaging system to estimate defocus across the field of view (FOV). We compare phase retrieval estimated values to those obtained using an independent technique.

Wide-Field Infrared Survey Telescope (WFIRST) Integrated Modeling

NASA Technical Reports Server (NTRS)

Liu, Kuo-Chia; Blaurock, Carl

2017-01-01

Contents: introduction to WFIRST (Wide-Field Infrared Survey Telescope) and integrated modeling; WFIRST stability requirement summary; instability mitigation strategies; dynamic jitter results; STOP (structural-thermal-optical performance) (thermal distortion) results; STOP and jitter capability limitations; model validation philosophy.

Key issues in the thermal design of spaceborne cryogenic infrared instruments

NASA Astrophysics Data System (ADS)

Schember, Helene R.; Rapp, Donald

1992-12-01

Thermal design and analysis play an integral role in the development of spaceborne cryogenic infrared (IR) instruments. From conceptual sketches to final testing, both direct and derived thermal requirements place significant constraints on the instrument design. Although in practice these thermal requirements are interdependent, the sources of most thermal constraints may be grouped into six distinct categories. These are: (1) Detector temperatures, (2) Optics temperatures, (3) Pointing or alignment stability, (4) Mission lifetime, (5) Orbit, and (6) Test and Integration. In this paper, we discuss these six sources of thermal requirements with particular regard to development of instrument packages for low background infrared astronomical observatories. In the end, the thermal performance of these instruments must meet a set of thermal requirements. The development of these requirements is typically an ongoing and interactive process, however, and the thermal design must maintain flexibility and robustness throughout the process. The thermal (or cryogenic) engineer must understand the constraints imposed by the science requirements, the specific hardware, the observing environment, the mission design, and the testing program. By balancing these often competing factors, the system-oriented thermal engineer can work together with the experiment team to produce an effective overall design of the instrument.

High throughput integrated thermal characterization with non-contact optical calorimetry

NASA Astrophysics Data System (ADS)

Hou, Sichao; Huo, Ruiqing; Su, Ming

2017-10-01

Commonly used thermal analysis tools such as calorimeter and thermal conductivity meter are separated instruments and limited by low throughput, where only one sample is examined each time. This work reports an infrared based optical calorimetry with its theoretical foundation, which is able to provide an integrated solution to characterize thermal properties of materials with high throughput. By taking time domain temperature information of spatially distributed samples, this method allows a single device (infrared camera) to determine the thermal properties of both phase change systems (melting temperature and latent heat of fusion) and non-phase change systems (thermal conductivity and heat capacity). This method further allows these thermal properties of multiple samples to be determined rapidly, remotely, and simultaneously. In this proof-of-concept experiment, the thermal properties of a panel of 16 samples including melting temperatures, latent heats of fusion, heat capacities, and thermal conductivities have been determined in 2 min with high accuracy. Given the high thermal, spatial, and temporal resolutions of the advanced infrared camera, this method has the potential to revolutionize the thermal characterization of materials by providing an integrated solution with high throughput, high sensitivity, and short analysis time.

Ultrasonically assisted synthesis of lead oxide nanoflowers using ball milling

NASA Astrophysics Data System (ADS)

Bangi, Uzma K. H.; Park, Hyung-Ho; Han, Wooje; Prakshale, Vipul M.; Deshmukh, Lalasaheb P.

2017-05-01

The experimental results on the ultrasonically assisted synthesis of lead oxide nanoflowers using ball milling have been reported in the present work. Lead oxide nanoflowers were prepared employing mixed ligands by subjecting the formed precipitate to ultrasonication and grinding/ball milling. The effect of ball milling as well as fine grinding in agate mortar on the microstructure and surface morphology of the lead oxide was studied. The characteristics of synthesized PbO were studied using X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and field emission scanning electron microscopy techniques. XRD results demonstrated the tetragonal phase of PbO with crystallite size of around 25 nm and strain of 3.6 × 10-3 calculated from Williamson-Hall plot. FESEM images manifested the formation of nanodiscs and nanoflowers with a diameter of around 300 nm and thickness of 50 nm. XPS spectra revealed the formation of PbO with photoelectron peak of Pb 4f and O 1 s lied at 137.68 and 529.96 eV. Moreover, FTIR spectrum exhibited Pb-O bond peak in the range of 400-530 cm-1.

Ultrasonically-enhanced preparation, characterization of CaFe-layered double hydroxides with various interlayer halide, azide and oxo anions (CO32-, NO3-, ClO4-).

PubMed

Szabados, Márton; Varga, Gábor; Kónya, Zoltán; Kukovecz, Ákos; Carlson, Stefan; Sipos, Pál; Pálinkó, István

2018-01-01

An ultrasonically-enhanced mechanochemical method was developed to synthesize CaFe-layered double hydroxides (LDHs) with various interlayer anions (CO 3 2- , NO 3 - , ClO 4 - , N 3 - , F - , Cl - , Br - and I - ). The duration of pre-milling and ultrasonic irradiation and the variation of synthesis temperature in the wet chemical step were investigated to obtain the optimal parameters of preparation. The main method to characterize the products was X-ray diffractometry, but infrared and synchrotron-based X-ray absorption spectroscopies as well as thermogravimetric measurements were also used to learn about fine structural details. The synthesis method afforded successful intercalation of the anions, among others the azide anion, a rarely used counter ion providing a system, which enables safe handling the otherwise highly reactive anion. The X-ray absorption spectroscopic measurements revealed that the quality of the interlayered anions could modulate the spatial arrangement of the calcium ions around the iron(III) ions, but only in the second coordination sphere. Copyright © 2017 Elsevier B.V. All rights reserved.

High-speed time-reversed ultrasonically encoded (TRUE) optical focusing inside dynamic scattering media at 793 nm

NASA Astrophysics Data System (ADS)

Liu, Yan; Lai, Puxiang; Ma, Cheng; Xu, Xiao; Suzuki, Yuta; Grabar, Alexander A.; Wang, Lihong V.

2014-03-01

Time-reversed ultrasonically encoded (TRUE) optical focusing is an emerging technique that focuses light deep into scattering media by phase-conjugating ultrasonically encoded diffuse light. In previous work, the speed of TRUE focusing was limited to no faster than 1 Hz by the response time of the photorefractive phase conjugate mirror, or the data acquisition and streaming speed of the digital camera; photorefractive-crystal-based TRUE focusing was also limited to the visible spectral range. These time-consuming schemes prevent this technique from being applied in vivo, since living biological tissue has a speckle decorrelation time on the order of a millisecond. In this work, using a Tedoped Sn2P2S6 photorefractive crystal at a near-infrared wavelength of 793 nm, we achieved TRUE focusing inside dynamic scattering media having a speckle decorrelation time as short as 7.7 ms. As the achieved speed approaches the tissue decorrelation rate, this work is an important step forward toward in vivo applications of TRUE focusing in deep tissue imaging, photodynamic therapy, and optical manipulation.

A debugging method of the Quadrotor UAV based on infrared thermal imaging

NASA Astrophysics Data System (ADS)

Cui, Guangjie; Hao, Qian; Yang, Jianguo; Chen, Lizhi; Hu, Hongkang; Zhang, Lijun

2018-01-01

High-performance UAV has been popular and in great need in recent years. The paper introduces a new method in debugging Quadrotor UAVs. Based on the infrared thermal technology and heat transfer theory, a UAV is under debugging above a hot-wire grid which is composed of 14 heated nichrome wires. And the air flow propelled by the rotating rotors has an influence on the temperature distribution of the hot-wire grid. An infrared thermal imager below observes the distribution and gets thermal images of the hot-wire grid. With the assistance of mathematic model and some experiments, the paper discusses the relationship between thermal images and the speed of rotors. By means of getting debugged UAVs into test, the standard information and thermal images can be acquired. The paper demonstrates that comparing to the standard thermal images, a UAV being debugging in the same test can draw some critical data directly or after interpolation. The results are shown in the paper and the advantages are discussed.

Testing and Evaluation of Low-Light Sensors to Enhance Intelligence, Surveillance, and Reconnaissance (ISR) and Real-Time Situational Awareness

DTIC Science & Technology

2009-03-01

infrared, thermal , or night vision applications. Understanding the true capabilities and limitations of the ALAN camera and its applicability to a...an option to more expensive infrared, thermal , or night vision applications. Ultimately, it will be clear whether the configuration of the Kestrel...45  A.  THERMAL CAMERAS................................................................................45  1

Relationship among eye temperature measured using digital infrared thermal imaging and vaginal and rectal temperatures in hair sheep and cattle

USDA-ARS?s Scientific Manuscript database

Digital infrared thermal imaging (DITI) using a thermal camera has potential to be a useful tool for the production animal industry. Thermography has been used in both humans and a wide range of animal species to measure body temperature as a method to detect injury or inflammation. The objective of...

Conformational changes in matrix-isolated 6-methoxyindole: Effects of the thermal and infrared light excitations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopes Jesus, A. J.; CQC, Faculty of Pharmacy, University of Coimbra, 3004-295 Coimbra; Reva, I., E-mail: reva@qui.uc.pt

2016-03-28

Conformational changes induced thermally or upon infrared excitation of matrix-isolated 6-methoxyindole were investigated. Narrowband near-infrared excitation of the first overtone of the N–H stretching vibration of each one of the two identified conformers is found to induce a selective large-scale conversion of the pumped conformer into the other one. This easily controllable bidirectional process consists in the intramolecular reorientation of the methoxy group and allowed a full assignment of the infrared spectra of the two conformers. Matrices with different conformational compositions prepared by narrow-band irradiations were subsequently used to investigate the effects of both thermal and broadband infrared excitations onmore » the conformational mixtures. Particular attention is given to the influence of the matrix medium (Ar vs. Xe) and conformational effects of exposition of the sample to the spectrometer light source during the measurements.« less

[Evaluation of the thermal effects of the plasma microtorch by infrared thermography].

PubMed

Lhuisset, F; Zeboulon, S; Bouchier, G

1991-01-01

This study presents a detailed example of the examination of the tooth treated by thermal therapy, by infrared thermography and the different manners to show the results of the examination. The results of the work shows: the thermal diffusion into the tooth is similar to the thermal diffusion into an isotropic environment, the fusion heat of the dentine is reached without any damage to the pulp. The study of the tooth treated by the thermal action of the MICRO PLASMA SYSTEM confirms the thérapeutical effects of the thermal treatment without any damage to the pulp.

Inorganic plugs removal using ultrasonic waves

NASA Astrophysics Data System (ADS)

Khan, Nasir; Pu, Chunsheng; Xu, Li; Lei, Zhang

2017-03-01

It is essential to recover the lost productivity caused by formation damage in the proximity of the wellbore during different well operations. In comparison to conventionally used methods, the efficiency, reliability, environment friendly, and simple and convenient technique of ultrasonic waves make it more attractive in petroleum industries. In current study, ultrasonic waves were applied to mitigate the formation damage caused by deposition of calcium carbonate (CaCO3) nearby well bore. Results showed that 100 minutes exposure time could efficiently recover 38.1% of original productivity but further increase in irradiation time (120mins) would decrease the recovery to 37.1%. This aberration can be attributed to the particle-bridge formation formed by larger particles at later stages and tendency of acoustic wave to push back the fluid flow. Moreover, ultrasonic waves transducer#2 (Frequency 20KHz and Power 1000W) could recovery maximum recovery of 36.3%, however, high frequency transducer was not effective in this recovery. This inorganic removal can be attributed to the cavitation and thermal energy produced through three different ways including cavitation, boundary friction and transformation upon hitting the medium.

In-situ laser ultrasonic measurement of the hcp to bcc transformation in commercially pure titanium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinbine, A., E-mail: alyssa.shinbine@gmail.com; Garcin, T.; Sinclair, C.

2016-07-15

Using a novel in-situ laser ultrasonic technique, the evolution of longitudinal velocity was used to measure the α − β transformation during cyclic heating and cooling in commercially pure titanium. In order to quantify the transformation kinetics, it is shown that changes in texture can not be ignored. This is particularly important in the case of titanium where significant grain growth occurs in the β-phase leading to the ultrasonic wave sampling a decreasing number of grains on each thermal treatment cycle. Electron backscatter diffraction measurements made postmortem in the region where the ultrasonic pulse traveled were used to obtain anmore » estimate of such local texture and grain size changes. An analysis technique for including the anisotropy of wave velocity depending on local texture is presented and shown to give self consistent results for the transformation kinetics. - Highlights: • Laser ultrasound and EBSD interpret the hcp/bcc phase transformation in cp-Ti. • Grain growth and texture produced variation in velocity during similar treatments. • Texture was deconvoluted from phase addition to obtain transformation kinetics.« less

Theory and application of laser ultrasonic shear wave birefringence measurements to the determination of microstructure orientation in transversely isotropic, polycrystalline graphite materials

DOE PAGES

Zeng, Fan W.; Contescu, Cristian I.; Gallego, Nidia C.; ...

2016-12-18

Laser ultrasonic line source methods have been used to study elastic anisotropy in nuclear graphites by measuring shear wave birefringence. Depending on the manufacturing processes used during production, nuclear graphites can exhibit various degrees of material anisotropy related to preferred crystallite orientation and to microcracking. In this paper, laser ultrasonic line source measurements of shear wave birefringence on NBG-25 have been performed to assess elastic anisotropy. Laser line sources allow specific polarizations for shear waves to be transmitted – the corresponding wavespeeds can be used to compute bulk, elastic moduli that serve to quantify anisotropy. These modulus values can bemore » interpreted using physical property models based on orientation distribution coefficients and microcrack-modified, single crystal moduli to represent the combined effects of crystallite orientation and microcracking on material anisotropy. Finally, ultrasonic results are compared to and contrasted with measurements of anisotropy based on the coefficient of thermal expansion to show the relationship of results from these techniques.« less

Diamond fly cutting of aluminum thermal infrared flat mirrors for the OSIRIS-REx Thermal Emission Spectrometer (OTES) instrument

NASA Astrophysics Data System (ADS)

Groppi, Christopher E.; Underhill, Matthew; Farkas, Zoltan; Pelham, Daniel

2016-07-01

We present the fabrication and measurement of monolithic aluminum flat mirrors designed to operate in the thermal infrared for the OSIRIS-Rex Thermal Emission Spectrometer (OTES) space instrument. The mirrors were cut using a conventional fly cutter with a large radius diamond cutting tool on a high precision Kern Evo 3-axis CNC milling machine. The mirrors were measured to have less than 150 angstroms RMS surface error.

Comparison of ultrasonic energy, bipolar thermal energy, and vascular clips for the hemostasis of small-, medium-, and large-sized arteries.

PubMed

Harold, K L; Pollinger, H; Matthews, B D; Kercher, K W; Sing, R F; Heniford, B T

2003-08-01

Advanced laparoscopic procedures have necessitated the development of new technology for vascular control. Suture ligation can be time-consuming and cumbersome during laparoscopic dissection. Titanium clips have been used for hemostasis, and recently plastic clips and energy sources such as ultrasonic coagulating shears and bipolar thermal energy devices have become popular. The purpose of this study was to compare the bursting pressure of arteries sealed with ultrasonic coagulating shears (UCS), electrothermal bipolar vessel sealer (EBVS), titanium laparoscopic clips (LCs), and plastic laparoscopic clips (PCs). In addition, the spread of thermal injury from the UCS and the EBVS was compared. Arteries in three size groups (2-3, 4-5 and 6-7 mm) were harvested from freshly euthanized pigs. Each of the four devices was used to seal 16 specimens from each size group for burst testing. A 5-Fr catheter was placed into the open end of the specimen and secured with a purse-string suture. The catheter was connected to a pressure monitor and saline was infused until there was leakage from the sealed end. This defined the bursting pressure in mmHg. The ultrasonic shears and bipolar thermal device were used to seal an additional 8 vessels in each size group, which were sent for histologic examination. These were examined with hematoxylin and eosin stains, and the extent of thermal injury, defined by coagulation necrosis, was measured in millimeters. Analysis of variance was performed and, where appropriate, a Tukey's test was also performed. The EBVS's mean burst pressure was statistically higher than that of the UCS at 4 or 5 mm (601 vs 205 mmHg) and 6 or 7 mm (442 vs 175 mmHg). EBVS had higher burst pressures for the 4 or 5-mm group (601 mmHg) and 6 or 7-mm group (442 mmHg) compared with its pressure at 2 or 3 mm (128 mmHg) ( p = 0.0001). The burst pressures of the UCS and EBVS at 2 or 3 mm were not significantly different. Both clips were statistically stronger than the thermal devices except at 4 or 5 mm, in which case the EBVS was as strong as the LC (601 vs 593 mmHg). The PC and LC were similar except at 4 or 5 mm, where the PC was superior (854 vs 593 mmHg). The PC burst pressure for 4 or 5 mm (854 mmHg) was statistically higher than that for vessels 2 or 3 mm (737 mmHg) but not different from the 6 or 7 mm pressure (767 mmHg). Thermal spread was not statistically different when comparing EBVS and UCS at any size (EBVS mean = 2.57 mm vs UCS mean = 2.18 mm). Both the PC and LC secured all vessel sizes to well above physiologic levels. The EBVS can be used confidently in vessels up to 7 mm. There is no difference in the thermal spread of the LigaSure vessel sealer and the UCS.

Robotics research projects report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsia, T.C.

The research results of the Robotics Research Laboratory are summarized. Areas of research include robotic control, a stand-alone vision system for industrial robots, and sensors other than vision that would be useful for image ranging, including ultrasonic and infra-red devices. One particular project involves RHINO, a 6-axis robotic arm that can be manipulated by serial transmission of ASCII command strings to its interfaced controller. (LEW)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, N.S.V.

The classical Nadaraya-Watson estimator is shown to solve a generic sensor fusion problem where the underlying sensor error densities are not known but a sample is available. By employing Haar kernels this estimator is shown to yield finite sample guarantees and also to be efficiently computable. Two simulation examples, and a robotics example involving the detection of a door using arrays of ultrasonic and infrared sensors, are presented to illustrate the performance.

Detection of Humans and Light Vehicles Using Acoustic-to-Seismic Coupling

DTIC Science & Technology

2009-08-31

microphones, video cameras (regular and infrared), magnetic sensors, and active Doppler radar and sonar systems. These sensors could be located at... sonar systems due to dramatic absorption/reflection of electromagnetic/ultrasonic waves [8,9]. 6...engine was turned off, and the car continued moving. This eliminated the engine sound. A PCB microphone, 377B41, with preamplifier , 426A30, and with

Harvesting renewable energy from Earth's mid-infrared emissions.

PubMed

Byrnes, Steven J; Blanchard, Romain; Capasso, Federico

2014-03-18

It is possible to harvest energy from Earth's thermal infrared emission into outer space. We calculate the thermodynamic limit for the amount of power available, and as a case study, we plot how this limit varies daily and seasonally in a location in Oklahoma. We discuss two possible ways to make such an emissive energy harvester (EEH): A thermal EEH (analogous to solar thermal power generation) and an optoelectronic EEH (analogous to photovoltaic power generation). For the latter, we propose using an infrared-frequency rectifying antenna, and we discuss its operating principles, efficiency limits, system design considerations, and possible technological implementations.

The thermal structure of Saturn: Inferences from ground-based and airborne infrared observations

NASA Technical Reports Server (NTRS)

Tokunaga, A.

1978-01-01

Spectroscopic and photometric infrared observations of Saturn are reviewed and compared to the expected flux from thermal structure models. Large uncertainties exist in the far-infrared measurements, but the available data indicate that the effective temperature of the disk of Saturn is 90 + or - 5 K. The thermal structure models proposed by Tokunaga and Cess and by Gautier et al. (model 'N') agree best with the observations. North-South limb scans of Saturn at 10 and 20 micrometers show that the temperature inversion is much stronger at the South polar region than at the equator.

Estimating top-of-atmosphere thermal infrared radiance using MERRA-2 atmospheric data

NASA Astrophysics Data System (ADS)

Kleynhans, Tania; Montanaro, Matthew; Gerace, Aaron; Kanan, Christopher

2017-05-01

Thermal infrared satellite images have been widely used in environmental studies. However, satellites have limited temporal resolution, e.g., 16 day Landsat or 1 to 2 day Terra MODIS. This paper investigates the use of the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis data product, produced by NASA's Global Modeling and Assimilation Office (GMAO) to predict global topof-atmosphere (TOA) thermal infrared radiance. The high temporal resolution of the MERRA-2 data product presents opportunities for novel research and applications. Various methods were applied to estimate TOA radiance from MERRA-2 variables namely (1) a parameterized physics based method, (2) Linear regression models and (3) non-linear Support Vector Regression. Model prediction accuracy was evaluated using temporally and spatially coincident Moderate Resolution Imaging Spectroradiometer (MODIS) thermal infrared data as reference data. This research found that Support Vector Regression with a radial basis function kernel produced the lowest error rates. Sources of errors are discussed and defined. Further research is currently being conducted to train deep learning models to predict TOA thermal radiance

Spacewatch Survey for Asteroids and Comets

DTIC Science & Technology

2005-11-01

radar images. Relationship of Spacewatch to the WISE spacecraft mission: E. L. Wright of the UCLA Astronomy Dept. is the PI of the Wide-field Infrared ...Survey Explorer (WISE) MIDEX spacecraft mission. WISE will map the whole sky at thermal infrared wavelengths with 500 times more sensitivity than the...elongations. WISE=s detections in the thermal infrared will also provide a size-limited sample of asteroids instead of the brightness-limited surveys

Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities.

PubMed

Hafsa, Jawhar; Chaouch, Mohamed Aymen; Charfeddine, Bassem; Rihouey, Christophe; Limem, Khalifa; Le Cerf, Didier; Rouatbi, Sonia; Majdoub, Hatem

2017-12-01

Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements. In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities. Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed. The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090-181 kDa) and intrinsic viscosity (1550-473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC 50 value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA. The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.

Effect of perspiration on skin temperature measurements by infrared thermography and contact thermometry during aerobic cycling

NASA Astrophysics Data System (ADS)

Priego Quesada, Jose Ignacio; Martínez Guillamón, Natividad; Cibrián Ortiz de Anda, Rosa M.^a.; Psikuta, Agnes; Annaheim, Simon; Rossi, René Michel; Corberán Salvador, José Miguel; Pérez-Soriano, Pedro; Salvador Palmer, Rosario

2015-09-01

The aim of the present study was to compare infrared thermography and thermal contact sensors for measuring skin temperature during cycling in a moderate environment. Fourteen cyclists performed a 45-min cycling test at 50% of peak power output. Skin temperatures were simultaneously recorded by infrared thermography and thermal contact sensors before and immediately after cycling activity as well as after 10 min cooling-down, representing different skin wetness and blood perfusion states. Additionally, surface temperature during well controlled dry and wet heat exchange (avoiding thermoregulatory responses) using a hot plate system was assessed by infrared thermography and thermal contact sensors. In human trials, the inter-method correlation coefficient was high when measured before cycling (r = 0.92) whereas it was reduced immediately after the cycling (r = 0.82) and after the cooling-down phase (r = 0.59). Immediately after cycling, infrared thermography provided lower temperature values than thermal contact sensors whereas it presented higher temperatures after the cooling-down phase. Comparable results as in human trials were observed for hot plate tests in dry and wet states. Results support the application of infrared thermography for measuring skin temperature in exercise scenarios where perspiration does not form a water film.

Nondestructive inspection of graphite-epoxy laminates for heat damage using DRIFT and LPF spectroscopies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powell, G.L.; Smyrl, N.R.; Janke, C.J.

The effect of heat damage on polymer matrix composites (PMC) used in aircraft structures presents a unique problem for nondestructive testing (ND) in that damage may result as a combination of thermally cycling the PMC above the glass transition temperature of the polymer and oxidative degradation of the polymer or the polymer-fiber interface. The usual techniques for the detection of voids and flaws by radiographic, ultrasonic, and thermal imaging techniques play an important role in this ND problem. However, heat damage may result in loss of strength in these materials without producing physical flaws (cracks and delaminations) big enough tomore » be detected. Diffuse reflectance Fourier transform infrared (DRIFT) and laser pumped fluorescence (LPF) measurements previously obtained on IM6/3501-6 laminate panels were re-evaluated to improve these techniques for the nondestructive inspection of aircraft. A more robust algorithm for relating flexural strength to changes in DRIFT spectra related to oxidation is presented and used to interpret previously reported evacuable cell DRIFT measurements. Recent advances in DRIFT technology are described which include an evacuable cell with a hemispherical window for oxidation kinetics studies, and the development of a portable DRIFT spectrometer that was used to make measurements on an aircraft. The use of a 633-nm helium-neon laser for LPF is reported as a means for rapidly relating both fluorescence intensity and spectral distribution to flexural strength.« less

Ultrasonic Attenuation Results of Thermoplastic Resin Composites Undergoing Thermal and Fatigue Loading

NASA Technical Reports Server (NTRS)

Madaras, Eric I.

1998-01-01

As part of an effort to obtain the required information about new composites for aviation use, materials and NDE researchers at NASA are jointly performing mechanical and NDE measurements on new composite materials. The materials testing laboratory at NASA is equipped with environmental chambers mounted on load frames that can expose composite materials to thermal and loading cycles representative of flight protocols. Applying both temperature and load simultaneously will help to highlight temperature and load interactions during the aging of these composite materials. This report highlights our initial ultrasonic attenuation results from thermoplastic composite samples that have undergone over 4000 flight cycles to date. Ultrasonic attenuation measurements are a standard method used to assess the effects of material degradation. Recently, researchers have shown that they could obtain adequate contrast in the evaluation of thermal degradation in thermoplastic composites by using frequencies of ultrasound on the order of 24 MHz. In this study, we address the relationship of attenuation measured at lower frequencies in thermoplastic composites undergoing both thermal and mechanical loading. We also compare these thermoplastic results with some data from thermoset composites undergoing similar protocols. The composite s attenuation is reported as the slope of attenuation with respect to frequency, defined as b = Da(f)/Df. The slope of attenuation is an attractive parameter since it is quantitative, yet does not require interface corrections like conventional quantitative attenuation measurements. This latter feature is a consequence of the assumption that interface correction terms are frequency independent. Uncertainty in those correction terms can compromise the value of conventional quantitative attenuation data. Furthermore, the slope of the attenuation more directly utilizes the bandwidth information and in addition, the bandwidth can be adjusted in the post processing stage to compensate for the loss of dynamic range of the signal as the composites age.

Thermographic imaging for high-temperature composite materials: A defect detection study

NASA Technical Reports Server (NTRS)

Roth, Don J.; Bodis, James R.; Bishop, Chip

1995-01-01

The ability of a thermographic imaging technique for detecting flat-bottom hole defects of various diameters and depths was evaluated in four composite systems (two types of ceramic matrix composites, one metal matrix composite, and one polymer matrix composite) of interest as high-temperature structural materials. The holes ranged from 1 to 13 mm in diameter and 0.1 to 2.5 mm in depth in samples approximately 2-3 mm thick. The thermographic imaging system utilized a scanning mirror optical system and infrared (IR) focusing lens in conjunction with a mercury cadmium telluride infrared detector element to obtain high resolution infrared images. High intensity flash lamps located on the same side as the infrared camera were used to heat the samples. After heating, up to 30 images were sequentially acquired at 70-150 msec intervals. Limits of detectability based on depth and diameter of the flat-bottom holes were defined for each composite material. Ultrasonic and radiographic images of the samples were obtained and compared with the thermographic images.

The ultrasonic machining of silicon carbide / alumina composites

NASA Astrophysics Data System (ADS)

Nicholson, Garth Martyn John

Silicon carbide fibre reinforced alumina is a ceramic composite which was developed in conjunction with the Rolls-Royce Aerospace Group. The material is intended for use in the latest generation of jet engines, specifically for high temperature applications such as flame holders, combustor barrel segments and turbine blade tip seals. The material in question has properties which have been engineered by optimizing fibre volume fractions, weaves and fibre interface materials to meet the following main requirements : high thermal resistance, high thermal shock resistance and low density.Components intended for manufacture using this material will use the "direct metal oxidation" (DIMOX) method. This process involves manufacturing a near net shape component from the woven fibre matting, and infiltrating the matting with the alumina matrix material. Some of the components outlined require high tolerance features to be included in their design. The combustor barrel segments for example require slots to be formed within them for sealing purposes, the dimensions of these features preclude their formation using DIMOX, and therefore require a secondary process to be performed. Conventional machining techniques such as drilling, turning and milling cannot be used because of the brittle nature of the material. Electrodischarge machining (E.D.M.) cannot be used since the material is an insulator. Electrochemical machining (E.C.M.) cannot be used since the material is chemically inert. One machining method which could be used is ultrasonic machining (U.S.M.).The research programme investigated the feasibility of using ultrasonic machining as a manufacturing method for this new fibre reinforced composite. Two variations of ultrasonic machining were used : ultrasonic drilling and ultrasonic milling. Factors such as dimensional accuracy, surface roughness and delamination effects were examined. Previously performed ultrasonic machining experimental programmes were reviewed, as well as process models which have been developed. The process models were found to contain empirical constants which usually require specific material data for their calculation.Since a limited amount of the composite was available, and ultrasonic machining has many process variables, a Taguchi factorial experiment was conducted in order to ascertain the most relevant factors in machining. A full factorial experiment was then performed using the relevant factors. Techniques used in the research included both optical and scanning electron microscopy, surface roughness analysis, x-ray analysis and finite element stress analysis. A full set of machining data was obtained including relationships between the factors examined and both material removal rates, and surface roughness values. An attempt was made to explain these findings by examining established brittle fracture mechanisms. These established mechanisms did not seem to apply entirely to this material, an alternative method of material removal is therefore proposed. It is hoped that the data obtained from this research programme may contribute to the development of a more realistic mathematical model.

Engineering Analysis of Thermal-Load Components in the Process of Heating of Pet Preforms

NASA Astrophysics Data System (ADS)

Sidorov, D. É.; Kolosov, A. E.; Kazak, I. A.; Pogorelyi, A. V.

2018-05-01

The influence of thermal-load components (convection, collimated and uncollimated components of infrared radiation) in the process of production of PET packaging on the heating of PET preforms has been assessed. It has been established that the collimated component of infrared radiation ensures most (up to 70%) of the thermal energy in the process of heating of a PET preform.

Spectral reflectance and emissivity features of broad leaf plants: Prospects for remote sensing in the thermal infrared (8.0-14.0 μm)

USGS Publications Warehouse

Ribeiro da Luz, Beatriz; Crowley, James K.

2007-01-01

In contrast to visible and short-wave infrared data, thermal infrared spectra of broad leaf plants show considerable spectral diversity, suggesting that such data eventually could be utilized to map vegetation composition. However, remotely measuring the subtle emissivity features of leaves still presents major challenges. To be successful, sensors operating in the 8–14 μm atmospheric window must have high signal-to-noise and a small enough instantaneous field of view to allow measurements of only a few leaf surfaces. Methods for atmospheric compensation, temperature–emissivity separation, and spectral feature analysis also will need to be refined to allow the recognition, and perhaps, exploitation of leaf thermal infrared spectral properties.

Thermal-infrared spectral observations of geologic materials in emission

NASA Technical Reports Server (NTRS)

Christensen, Philip R.; Luth, Sharon J.

1987-01-01

The thermal-infrared spectra of geologic materials in emission were studied using the prototype Thermal Emission Spectrometer (TES). A variety of of processes and surface modifications that may influence or alter the spectra of primary rock materials were studied. It was confirmed that thermal emission spectra contain the same absorption features as those observed in transmission and reflection spectra. It was confirmed that the TES instrument can be used to obtain relevant spectra for analysis of rock and mineral composition.

Non-destructive investigations at the Dionisiac Frieze in the Villa of Mysteries, Pompeii

NASA Astrophysics Data System (ADS)

Cristiano, Luigia; Erkul, Ercan; Jepsen, Kalle; Meier, Thomas; Vanacore, Stefano; Stefani, Grete

2014-05-01

The Villa of Mysteries with its Dionisiac Frieze is one of the well-known buildings of ancient Pompeii. It has been excavated in the early 20th century. Since then many initiatives have been taken for its preservation. Currently, the Frieze is investigated in detail and tests have been made to clean the wall paintings. Non-destructive investigations as infrared thermography (IR), Ground penetrating radar (GPR), and ultrasonic measurements have been performed in order to test if these methods are well suited to reveal the walls' and paintings' structure and to identify the detachments or cracks. IR, GPR and ultrasonic measurements have different penetration capabilities and resolution in depths. So, using these three methods simultaneously can improve the knowledge of the investigated structures at several depths from millimetres and centimetres to metres. It has been tested if detachments of the paintings, cracks, or alterations of the paintings can be detected by passive and active IR measurements. 6 passive and 3 active measurements have been conducted on the Dionisiac Frieze. Lateral temperature differences present at the Frieze are mapped by passive measurements. Here, we show that temperature differences up to about 0.3°C are present and detectable. These small changes in temperature may be related to detachments, cracks, or wet areas. By active IR measurements the paintings are artificially heated by about 1°C and the cooling to normal temperature is observed and analyzed. Lateral differences in the heating and cooling behavior are related to variability in the heat absorption properties and in thermal conductivity. It is shown that detachments as well as restorative treatments are associated with changes in the thermal behavior. In order to image the construction and the condition of the investigated walls, Ground Penetrating Radar (GPR) was measured with a 2 GHz antenna. Each profile was 1.2 m long, the spacing cross-line was 3 cm and in-line 1 mm. The vertical sections contain reflection horizons of the plaster layer, the second wall layer and the back wall. Additional diffractions of objects with high differences in electrical properties i.e. bricks, cavities, cracks enables to estimate the travelling velocity of electromagnetic waves and the deep penetration. In addition, calculated time slices show areas with concentrated high and low reflection energy of different depth layers of the wall inside structure, which can related to changes in the composition and the water saturation. Ultrasonic experiments with frequencies between about 5 kHz and 500 kHz may be applied to non-destructive testing of structures made of natural stone for example facades, engineering structures, Usually, traveltimes of first-arriving P-waves are measured in ultrasonic transmission experiments. The resolution for changes of uppermost structures in transmission configuration is however limited. Therefore, we firstly perform surface measurements and secondly the full waveform is investigated. That means source and receiver are coupled to nearly plane parts of the object's surface and the receiver is moved along profiles with lengths between about 10 cm to 30 cm. These measurements are simple to perform because the object under consideration has to be accessible only from one side and the source and receiver configuration is easier to control. In this configuration, P-waves show generally very low signal-to-noise ratios but surface waves propagating along the free surface - here Rayleigh waves - show large amplitudes and are well suited for the investigation of superficial layering. Furthermore, surface wave dispersion is sensitive also to gradual changes of the structure with depth as usually present in real structures. This is another advantage of ultrasonic surface wave studies as body waves are not reflected by gradual internal changes in the structure and methods based on reflected body waves may not be applied in these cases. Here, we show examples for ultrasonic surface measurements that are generally of high quality. Forward modelling and inversion of ultrasonic waveforms reveal strong changes of the material properties with depth: in the upper millimetres, high shear-wave velocities are observed while the plaster below is characterized by much lower shear-wave velocities. The paintings form a layer of about 3 mm to 6 mm thickness with larger strength than the underlying plaster. Furthermore, a pronounced lateral changes in the properties of the paintings are detected by the strong variability of the ultrasonic surface measurements. They are caused by changes in the structure of the paintings as well as by alterations as detachments or cracks.

Exploring the Use of Thermal Infrared Imaging in Human Stress Research

PubMed Central

Grant, Joshua A.; Cardone, Daniela; Tusche, Anita; Singer, Tania

2014-01-01

High resolution thermal infrared imaging is a pioneering method giving indices of sympathetic activity via the contact-free recording of facial tissues (thermal imprints). Compared to established stress markers, the great advantage of this method is its non-invasiveness. The goal of our study was to pilot the use of thermal infrared imaging in the classical setting of human stress research. Thermal imprints were compared to established stress markers (heart rate, heart rate variability, finger temperature, alpha-amylase and cortisol) in 15 participants undergoing anticipation, stress and recovery phases of two laboratory stress tests, the Cold Pressor Test and the Trier Social Stress Test. The majority of the thermal imprints proved to be change-sensitive in both tests. While correlations between the thermal imprints and established stress markers were mostly non-significant, the thermal imprints (but not the established stress makers) did correlate with stress-induced mood changes. Multivariate pattern analysis revealed that in contrast to the established stress markers the thermal imprints could not disambiguate anticipation, stress and recovery phases of both tests. Overall, these results suggest that thermal infrared imaging is a valuable method for the estimation of sympathetic activity in the stress laboratory setting. The use of this non-invasive method may be particularly beneficial for covert recordings, in the study of special populations showing difficulties in complying with the standard instruments of data collection and in the domain of psychophysiological covariance research. Meanwhile, the established stress markers seem to be superior when it comes to the characterization of complex physiological states during the different phases of the stress cycle. PMID:24675709

Exploring the use of thermal infrared imaging in human stress research.

PubMed

Engert, Veronika; Merla, Arcangelo; Grant, Joshua A; Cardone, Daniela; Tusche, Anita; Singer, Tania

2014-01-01

High resolution thermal infrared imaging is a pioneering method giving indices of sympathetic activity via the contact-free recording of facial tissues (thermal imprints). Compared to established stress markers, the great advantage of this method is its non-invasiveness. The goal of our study was to pilot the use of thermal infrared imaging in the classical setting of human stress research. Thermal imprints were compared to established stress markers (heart rate, heart rate variability, finger temperature, alpha-amylase and cortisol) in 15 participants undergoing anticipation, stress and recovery phases of two laboratory stress tests, the Cold Pressor Test and the Trier Social Stress Test. The majority of the thermal imprints proved to be change-sensitive in both tests. While correlations between the thermal imprints and established stress markers were mostly non-significant, the thermal imprints (but not the established stress makers) did correlate with stress-induced mood changes. Multivariate pattern analysis revealed that in contrast to the established stress markers the thermal imprints could not disambiguate anticipation, stress and recovery phases of both tests. Overall, these results suggest that thermal infrared imaging is a valuable method for the estimation of sympathetic activity in the stress laboratory setting. The use of this non-invasive method may be particularly beneficial for covert recordings, in the study of special populations showing difficulties in complying with the standard instruments of data collection and in the domain of psychophysiological covariance research. Meanwhile, the established stress markers seem to be superior when it comes to the characterization of complex physiological states during the different phases of the stress cycle.

The Effect of Ultrasonic Peening on Service Life of the Butt-Welded High-Temperature Steel Pipes

NASA Astrophysics Data System (ADS)

Daavari, Morteza; Vanini, Seyed Ali Sadough

2015-09-01

Residual stresses introduced by manufacturing processes such as casting, forming, machining, and welding have harmful effects on the mechanical behavior of the structures. In addition to the residual stresses, weld toe stress concentration can play a determining effect. There are several methods to improve the mechanical properties such as fatigue behavior of the welded structures. In this paper, the effects of ultrasonic peening on the fatigue life of the high-temperature seamless steel pipes, used in the petrochemical environment, have been investigated. These welded pipes are fatigued due to thermal and mechanical loads caused by the cycle of cooling, heating, and internal pressure fluctuations. Residual stress measurements, weld geometry estimation, electrochemical evaluations, and metallography investigations were done as supplementary examinations. Results showed that application of ultrasonic impact treatment has led to increased fatigue life, fatigue strength, and corrosion resistance of A106-B welded steel pipes in petrochemical corrosive environment.

Hot topics in biomedical ultrasound: ultrasound therapy and its integration with ultrasonic imaging

NASA Astrophysics Data System (ADS)

Everbach, E. Carr

2005-09-01

Since the development of biomedical ultrasound imaging from sonar after WWII, there has been a clear divide between ultrasonic imaging and ultrasound therapy. While imaging techniques are designed to cause as little change as possible in the tissues through which ultrasound propagates, ultrasound therapy typically relies upon heating or acoustic cavitation to produce a desirable therapeutic effect. Concerns over the increasingly high acoustic outputs of diagnostic ultrasound scanners prompted the adoption of the Mechanical Index (MI) and Thermal Index (TI) in the early 1990s. Therapeutic applications of ultrasound, meanwhile, have evolved from deep tissue heating in sports medicine to include targeted drug delivery, tumor and plaque ablation, cauterization via high intensity focused ultrasound (HIFU), and accelerated dissolution of blood clots. The integration of ultrasonic imaging and therapy in one device is just beginning, but the promise of improved patient outcomes is balanced by regulatory and practical impediments.

Wave speed propagation measurements on highly attenuative heated materials

DOE PAGES

Moore, David G.; Ober, Curtis C.; Rodacy, Phil J.; ...

2015-09-19

Ultrasonic wave propagation decreases as a material is heated. Two factors that can characterize material properties are changes in wave speed and energy loss from interactions within the media. Relatively small variations in velocity and attenuation can detect significant differences in microstructures. This paper discusses an overview of experimental techniques that document the changes within a highly attenuative material as it is either being heated or cooled from 25°C to 90°C. The experimental set-up utilizes ultrasonic probes in a through-transmission configuration. The waveforms are recorded and analyzed during thermal experiments. To complement the ultrasonic data, a Discontinuous-Galerkin Model (DGM) wasmore » also created which uses unstructured meshes and documents how waves travel in these anisotropic media. This numerical method solves particle motion travel using partial differential equations and outputs a wave trace per unit time. As a result, both experimental and analytical data are compared and presented.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeng, Fan W.; Contescu, Cristian I.; Gallego, Nidia C.

Laser ultrasonic line source methods have been used to study elastic anisotropy in nuclear graphites by measuring shear wave birefringence. Depending on the manufacturing processes used during production, nuclear graphites can exhibit various degrees of material anisotropy related to preferred crystallite orientation and to microcracking. In this paper, laser ultrasonic line source measurements of shear wave birefringence on NBG-25 have been performed to assess elastic anisotropy. Laser line sources allow specific polarizations for shear waves to be transmitted – the corresponding wavespeeds can be used to compute bulk, elastic moduli that serve to quantify anisotropy. These modulus values can bemore » interpreted using physical property models based on orientation distribution coefficients and microcrack-modified, single crystal moduli to represent the combined effects of crystallite orientation and microcracking on material anisotropy. Finally, ultrasonic results are compared to and contrasted with measurements of anisotropy based on the coefficient of thermal expansion to show the relationship of results from these techniques.« less

Potential impact of thermal effects during ultrasonic neurostimulation: retrospective numerical estimation of temperature elevation in seven rodent setups

NASA Astrophysics Data System (ADS)

Constans, Charlotte; Mateo, Philippe; Tanter, Mickaël; Aubry, Jean-François

2018-01-01

In the past decade, a handful but growing number of groups have reported worldwide successful low intensity focused ultrasound induced neurostimulation trials on rodents. Its effects range from movement elicitations to reduction of anesthesia time or reduction of the duration of drug induced seizures. The mechanisms underlying ultrasonic neuromodulation are still not fully understood. Given the low intensities used in most of the studies, a mechanical effect is more likely to be responsible for the neuromodulation effect, but a clear description of the thermal and mechanical effects is necessary to optimize clinical applications. Based on five studies settings, we calculated the temperature rise and thermal doses in order to evaluate its implication in the neuromodulation phenomenon. Our retrospective analysis shows thermal rise ranging from 0.002 °C to 0.8 °C in the brain for all setups, except for one setup for which the temperature increase is estimated to be as high as 7 °C. We estimate that in the latter case, temperature rise cannot be neglected as a possible cause of neuromodulation. Simulations results were supported by temperature measurements on a mouse with two different sets of parameters. Although the calculated temperature is compatible with the absence of visible thermal lesions on the skin, it is high enough to impact brain circuits. Our study highlights the usefulness of performing thermal simulations prior to experiment in order to fully take into account not only the impact of the peak intensity but also pulse duration and pulse repetition.

Detection of Thermal Water Vapor Emission from W Hydrae

NASA Technical Reports Server (NTRS)

Neufeld, David A.; Chen, Wesley; Melnick, Gary J.; DeGraauw, Thijs; Feuchtgruber, Helmut; Harwitt, Martin

1997-01-01

We have detected four far-infrared emission lines of water vapor toward the evolved star W Hydrae, using the Short Wavelength Spectrometer (SWS) of the Infrared Space Observatory (ISO). This is the first detection of thermal water vapor emission from a circumstellar outflow.

Infrared emission of a freestanding plasmonic membrane

NASA Astrophysics Data System (ADS)

Monshat, Hosein; Liu, Longju; McClelland, John; Biswas, Rana; Lu, Meng

2018-01-01

This paper reports a free-standing plasmonic membrane as a thermal emitter in the near- and mid-infrared regions. The plasmonic membrane consists of an ultrathin gold film perforated with a two-dimensional array of holes. The device was fabricated using an imprint and transfer process and fixed on a low-emissivity metal grid. The thermal radiation characteristics of the plasmonic membrane can be engineered by controlling the array period and the thickness of the gold membrane. Plasmonic membranes with two different periods were designed using electromagnetic simulation and then characterized for their transmission and infrared radiation properties. The free-standing membranes exhibit extraordinary optical transmissions with the resonant transmission coefficient as high as 76.8%. After integration with a customized heater, the membranes demonstrate narrowband thermal emission in the wavelength range of 2.5 μm to 5.5 μm. The emission signatures, including peak emission wavelength and bandwidth, are associated with the membrane geometry. The ultrathin membrane infrared emitter can be adopted in applications, such as chemical analysis and thermal imaging.

Correlating ultrasonic impulse and addition of ZnO promoter with CO2 conversion and methanol selectivity of CuO/ZrO2 catalysts.

PubMed

Ezeh, Collins I; Yang, Xiaogang; He, Jun; Snape, Colin; Cheng, Xiao Min

2018-04-01

The thermal characteristics of Cu-based catalysts for CO 2 utilization towards the synthesis of methanol were analysed and discussed in this study. The preparation process were varied by adopting ultrasonic irradiation at various impulses for the co-precipitation route and also, by introducing ZnO promoters using the solid-state reaction route. Prepared catalysts were characterised using XRD, TPR, TPD, SEM, BET and TG-DTA-DSC. In addition, the CO 2 conversion and CH 3 OH selectivity of these samples were assessed. Calcination of the catalysts facilitated the interaction of the Cu catalyst with the respective support bolstering the thermal stability of the catalysts. The characterisation analysis clearly reveals that the thermal performance of the catalysts was directly related to the sonication impulse and heating rate. Surface morphology and chemistry was enhanced with the aid of sonication and introduction of promoters. However, the impact of the promoter outweighs that of the sonication process. CO 2 conversion and methanol selectivity showed a significant improvement with a 270% increase in methanol yield. Copyright © 2017 Elsevier B.V. All rights reserved.

Multivariable control of a rapid thermal processor using ultrasonic sensors

NASA Astrophysics Data System (ADS)

Dankoski, Paul C. P.

The semiconductor manufacturing industry faces the need for tighter control of thermal budget and process variations as circuit feature sizes decrease. Strategies to meet this need include supervisory control, run-to-run control, and real-time feedback control. Typically, the level of control chosen depends upon the actuation and sensing available. Rapid Thermal Processing (RTP) is one step of the manufacturing cycle requiring precise temperature control and hence real-time feedback control. At the outset of this research, the primary ingredient lacking from in-situ RTP temperature control was a suitable sensor. This research looks at an alternative to the traditional approach of pyrometry, which is limited by the unknown and possibly time-varying wafer emissivity. The technique is based upon the temperature dependence of the propagation time of an acoustic wave in the wafer. The aim of this thesis is to evaluate the ultrasonic sensors as a potentially viable sensor for control in RTP. To do this, an experimental implementation was developed at the Center for Integrated Systems. Because of the difficulty in applying a known temperature standard in an RTP environment, calibration to absolute temperature is nontrivial. Given reference propagation delays, multivariable model-based feedback control is applied to the system. The modelling and implementation details are described. The control techniques have been applied to a number of research processes including rapid thermal annealing and rapid thermal crystallization of thin silicon films on quartz/glass substrates.

Non-invasive Measurement of Thermal Diffusivity Using High-Intensity Focused Ultrasound and Through-Transmission Ultrasonic Imaging.

PubMed

Yeshurun, Lilach; Azhari, Haim

2016-01-01

Thermal diffusivity at the site ablated by high-intensity focused ultrasound (HIFU) plays an important role in the final therapeutic outcome, as it influences the temperature's spatial and temporal distribution. Moreover, as tissue thermal diffusivity is different in tumors as compared with normal tissue, it could also potentially be used as a new source of imaging contrast. The aim of this study was to examine the feasibility of combining through-transmission ultrasonic imaging and HIFU to estimate thermal diffusivity non-invasively. The concept was initially evaluated using a computer simulation. Then it was experimentally tested on phantoms made of agar and ex vivo porcine fat. A computerized imaging system combined with a HIFU system was used to heat the phantoms to temperatures below 42°C to avoid irreversible damage. Through-transmission scanning provided the time-of-flight values in a region of interest during its cooling process. The time-of-flight values were consequently converted into mean values of speed of sound. Using the speed-of-sound profiles along with the developed model, we estimated the changes in temperature profiles over time. These changes in temperature profiles were then used to calculate the corresponding thermal diffusivity of the studied specimen. Thermal diffusivity for porcine fat was found to be lower by one order of magnitude than that obtained for agar (0.313×10(-7)m(2)/s vs. 4.83×10(-7)m(2)/s, respectively, p < 0.041). The fact that there is a substantial difference between agar and fat implies that non-invasive all-ultrasound thermal diffusivity mapping is feasible. The suggested method may particularly be suitable for breast scanning. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Thermal infrared near-field spectroscopy.

PubMed

Jones, Andrew C; Raschke, Markus B

2012-03-14

Despite the seminal contributions of Kirchhoff and Planck describing far-field thermal emission, fundamentally distinct spectral characteristics of the electromagnetic thermal near-field have been predicted. However, due to their evanescent nature their direct experimental characterization has remained elusive. Combining scattering scanning near-field optical microscopy with Fourier-transform spectroscopy using a heated atomic force microscope tip as both a local thermal source and scattering probe, we spectroscopically characterize the thermal near-field in the mid-infrared. We observe the spectrally distinct and orders of magnitude enhanced resonant spectral near-field energy density associated with vibrational, phonon, and phonon-polariton modes. We describe this behavior and the associated distinct on- and off-resonance nanoscale field localization with model calculations of the near-field electromagnetic local density of states. Our results provide a basis for intrinsic and extrinsic resonant manipulation of optical forces, control of nanoscale radiative heat transfer with optical antennas, and use of this new technique of thermal infrared near-field spectroscopy for broadband chemical nanospectroscopy. © 2012 American Chemical Society

An ultrasonic technique for measuring stress in fasteners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, K. J.; Day, P.; Byron, D.

1999-12-02

High temperature bolting alloys are extensively used in the thermal power generation industry as for example, reheat ESV and Governor valve studs. Remnant life assessment methodologies and plant maintenance procedures require the monitoring of the operational stress levels in these fasteners. Some conventional ultrasonic techniques require longitudinal wave measurements to be undertaken when the nut on the bolt is loosened and then re-tightened. Other techniques use a combination of shear waves and longitudinal waves. In this paper, the problems and pitfalls associated with various ultrasonic techniques for measuring stress in bolts, is discussed. An ultrasonic technique developed for measuring themore » stress in Durehete 1055 bolts is presented. Material from a textured rolled bar has been used as a test bed in the development work. The technique uses shear wave birefringence and compression waves at several frequencies to measure texture, fastener length and the average stress. The technique was developed by making ultrasonic measurements on bolts tensioned in universal testing machines and a hydraulic nut. The ultrasonic measurements of residual stress have been checked against strain gauge measurements. The Durehete bolts have a hollow cylinder geometry of restricted dimensions, which significantly alters compression and shear wave velocities from bulk values and introduces hoop stresses which can be measured by rotating the polarization of the shear wave probe. Modelling of the experimental results has been undertaken using theories for the elastic wave propagation through waveguides. The dispersion equations allow the velocity and length of the fastener to be measured ultrasonically in some situations where the length of the fastener can not be measured directly with a vernier caliper or micrometer and/or where it is undesirable to loosen nuts to take calibration readings of the shear and compression wave velocities.« less

Rapid sealing of porcine renal blood vessels, ex vivo, using a high power, 1470-nm laser, and laparoscopic prototype

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

2017-05-01

Energy-based, radiofrequency (RF) and ultrasonic (US) devices currently provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternate energy modality for vessel sealing, capable of generating less collateral thermal damage. Previous studies demonstrated feasibility of sealing vessels in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for testing in open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices currently in surgical use was developed, and performance tests were conducted on porcine renal blood vessels, ex vivo. The 5-mm outer-diameter laparoscopic prototype featured a traditional Maryland jaw configuration that enables tissue manipulation and blunt dissection. Laser energy was delivered through a 550-μm-core-diameter optical fiber with side-delivery from the lower jaw and beam dimensions of 18-mm length×1.2-mm width. The 1470-nm diode laser delivered 68 W with 3-s activation time, consistent with vessel seal times associated with RF and US-based devices. A total of 69 fresh porcine renal vessels with mean diameter of 3.3±1.7 mm were tested, ex vivo. Vessels smaller than 5-mm diameter were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038±474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174±221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7±0.8, 3.4±0.7, and 1.0±0.4 mm, respectively. Results demonstrated that the 5-mm optical laparoscopic prototype consistently sealed vessels less than 5-mm diameter with low thermal spread. Further in vivo studies are planned to test the performance across a variety of vessels and tissues.

Infrared broadband metasurface absorber for reducing the thermal mass of a microbolometer.

PubMed

Jung, Joo-Yun; Song, Kyungjun; Choi, Jun-Hyuk; Lee, Jihye; Choi, Dae-Geun; Jeong, Jun-Ho; Neikirk, Dean P

2017-03-27

We demonstrate an infrared broadband metasurface absorber that is suitable for increasing the response speed of a microbolometer by reducing its thermal mass. A large fraction of holes are made in a periodic pattern on a thin lossy metal layer characterised with a non-dispersive effective surface impedance. This can be used as a non-resonant metasurface that can be integrated with a Salisbury screen absorber to construct an absorbing membrane for a microbolometer that can significantly reduce the thermal mass while maintaining high infrared broadband absorption in the long wavelength infrared (LWIR) band. The non-dispersive effective surface impedance can be matched to the free space by optimising the surface resistance of the thin lossy metal layer depending on the size of the patterned holes by using a dc approximation method. In experiments a high broadband absorption was maintained even when the fill factor of the absorbing area was reduced to 28% (hole area: 72%), and it was theoretically maintained even when the fill factor of the absorbing area was reduced to 19% (hole area: 81%). Therefore, a metasurface with a non-dispersive effective surface impedance is a promising solution for reducing the thermal mass of infrared microbolometer pixels.

Optimized mid-infrared thermal emitters for applications in aircraft countermeasures

NASA Astrophysics Data System (ADS)

Lorenzo, Simón G.; You, Chenglong; Granier, Christopher H.; Veronis, Georgios; Dowling, Jonathan P.

2017-12-01

We introduce an optimized aperiodic multilayer structure capable of broad angle and high temperature thermal emission over the 3 μm to 5 μm atmospheric transmission band. This aperiodic multilayer structure composed of alternating layers of silicon carbide and graphite on top of a tungsten substrate exhibits near maximal emittance in a 2 μm wavelength range centered in the mid-wavelength infrared band traditionally utilized for atmospheric transmission. We optimize the layer thicknesses using a hybrid optimization algorithm coupled to a transfer matrix code to maximize the power emitted in this mid-infrared range normal to the structure's surface. We investigate possible applications for these structures in mimicking 800-1000 K aircraft engine thermal emission signatures and in improving countermeasure effectiveness against hyperspectral imagers. We find these structures capable of matching the Planck blackbody curve in the selected infrared range with relatively sharp cutoffs on either side, leading to increased overall efficiency of the structures. Appropriately optimized multilayer structures with this design could lead to matching a variety of mid-infrared thermal emissions. For aircraft countermeasure applications, this method could yield a flare design capable of mimicking engine spectra and breaking the lock of hyperspectral imaging systems.

The Far-Infrared Spectral Energy Distributions of Quasars

NASA Technical Reports Server (NTRS)

Wilkes, Belinda J.; West, Donald K. (Technical Monitor)

2001-01-01

The origin of the infrared emission in Active Galactic Nuclei (AGN), whose strength is comparable to the optical/ultraviolet (OUV) emission, is generally thought to be a combination of thermal emission from dust and non-thermal, synchrotron emission. Although data are sparse, particularly in the far-infrared, the broad wavelength range of this emission suggests a wide range of temperatures and a combination of AGN and starburst heating mechanisms. The strength of the non-thermal emission is expected to be related to the radio emission. While this scenario is well-established, basic questions, such as the spatial and temperature distribution of the dust, the relative importance of AGN and starburst heating, and the significance of the non-thermal contribution remain largely undetermined. The wide wavelength range of the Infrared Space Observatory (ISO) combined with its arcmin spatial resolution and increased sensitivity facilitated the observation of a larger subset of the AGN population than previously covered, allowing these questions to be investigated in more detail. This paper will review the spectral energy distributions (SED) of AGN with particular emphasis on the infrared emission and on ISO's contributions to our knowledge. Preliminary results from ISO observations of X-ray selected and high-redshift AGN will be described.

Surface contamination detection by means of near-infrared stimulation of thermal luminescence

NASA Astrophysics Data System (ADS)

Carrieri, Arthur H.; Roese, Erik S.

2006-02-01

A method for remotely detecting liquid chemical contamination on terrestrial surfaces is presented. Concurrent to irradiation by an absorbing near-infrared beam, the subject soil medium liberates radiance called thermal luminescence (TL) comprising middle-infrared energies (numir) that is scanned interferometrically in beam duration tau. Cyclic states of absorption and emission by the contaminant surrogate are rendered from a sequential differential-spectrum measurement [deltaS(numir,tau)] of the scanned TL. Detection of chemical warfare agent simulant wetting soil is performed in this manner, for example, through pattern recognition of its unique, thermally dynamic, molecular vibration resonance bands on display in the deltaS(numir,tau) metric.

Use of thermal infrared and colour infrared imagery to detect crop moisture stress. [Alberta, Canada

NASA Technical Reports Server (NTRS)

Mckenzie, R. C.; Clark, N. F.; Cihlar, J. (Principal Investigator)

1979-01-01

The author has identified the following significant results. In the presence of variable plant cover (primarily percent cover) and variable available water content, the remotely sensed apparent temperatures correlate closely with plant cover and poorly with soil water. To the extent that plant cover is not systematically related to available soil water, available water in the root zone values may not be reliably predicted from the thermal infrared data. On the other hand, if plant cover is uniform and the soil surface is shown in a minor way, the thermal data indicate plant stress and consequently available water in the soil profile.

Harvesting renewable energy from Earth’s mid-infrared emissions

PubMed Central

Byrnes, Steven J.; Blanchard, Romain; Capasso, Federico

2014-01-01

It is possible to harvest energy from Earth's thermal infrared emission into outer space. We calculate the thermodynamic limit for the amount of power available, and as a case study, we plot how this limit varies daily and seasonally in a location in Oklahoma. We discuss two possible ways to make such an emissive energy harvester (EEH): A thermal EEH (analogous to solar thermal power generation) and an optoelectronic EEH (analogous to photovoltaic power generation). For the latter, we propose using an infrared-frequency rectifying antenna, and we discuss its operating principles, efficiency limits, system design considerations, and possible technological implementations. PMID:24591604

Implications of high-spatial-resolution thermal infrared (Termoskan) data for Mars landing site selection

NASA Technical Reports Server (NTRS)

Betts, Bruce H.

1994-01-01

Thermal infrared observations of Mars from spacecraft provide physical information about the upper thermal skin depth of the surface, which is on the order of a few centimeters in depth and thus very significant for lander site selection. The Termoskan instrument onboard the Soviet Phobos '88 spacecraft acquired the highest spatial-resolution thermal infrared data obtained for Mars, ranging in resolution from 300 m to 3 km per pixel. It simultaneously obtained broadband reflected solar flux data. Although the 6 deg N - 30 deg S Termoskan coverage only slightly overlaps the nominal Mars Pathfinder target range, the implications of Termoskan data for that overlap region and the extrapolations that can be made to other regions give important clues for optimal landing site selection.

Chemical, Biological, Radiological, Nuclear, and High-Yield Explosives Consequences Management

DTIC Science & Technology

2006-10-02

cause three types of injuries: blast, thermal and radiation, as well as electromagnetic pulse (EMP) effects described further in a later section. (1...occur with conventional explosives and are further described in the next section. (2) Thermal injuries present as flash burns (burns from direct...exposure to the thermal radiation pulse, typically ultraviolet, visible, and infrared waves) or flame burns (burns from materials set afire by the infrared

Thermal Physical Property-Based Fusion of Geostationary Meteorological Satellite Visible and Infrared Channel Images

PubMed Central

Han, Lei; Shi, Lu; Yang, Yiling; Song, Dalei

2014-01-01

Geostationary meteorological satellite infrared (IR) channel data contain important spectral information for meteorological research and applications, but their spatial resolution is relatively low. The objective of this study is to obtain higher-resolution IR images. One common method of increasing resolution fuses the IR data with high-resolution visible (VIS) channel data. However, most existing image fusion methods focus only on visual performance, and often fail to take into account the thermal physical properties of the IR images. As a result, spectral distortion occurs frequently. To tackle this problem, we propose a thermal physical properties-based correction method for fusing geostationary meteorological satellite IR and VIS images. In our two-step process, the high-resolution structural features of the VIS image are first extracted and incorporated into the IR image using regular multi-resolution fusion approach, such as the multiwavelet analysis. This step significantly increases the visual details in the IR image, but fake thermal information may be included. Next, the Stefan-Boltzmann Law is applied to correct the distortion, to retain or recover the thermal infrared nature of the fused image. The results of both the qualitative and quantitative evaluation demonstrate that the proposed physical correction method both improves the spatial resolution and preserves the infrared thermal properties. PMID:24919017

Thermal physical property-based fusion of geostationary meteorological satellite visible and infrared channel images.

PubMed

Han, Lei; Shi, Lu; Yang, Yiling; Song, Dalei

2014-06-10

Geostationary meteorological satellite infrared (IR) channel data contain important spectral information for meteorological research and applications, but their spatial resolution is relatively low. The objective of this study is to obtain higher-resolution IR images. One common method of increasing resolution fuses the IR data with high-resolution visible (VIS) channel data. However, most existing image fusion methods focus only on visual performance, and often fail to take into account the thermal physical properties of the IR images. As a result, spectral distortion occurs frequently. To tackle this problem, we propose a thermal physical properties-based correction method for fusing geostationary meteorological satellite IR and VIS images. In our two-step process, the high-resolution structural features of the VIS image are first extracted and incorporated into the IR image using regular multi-resolution fusion approach, such as the multiwavelet analysis. This step significantly increases the visual details in the IR image, but fake thermal information may be included. Next, the Stefan-Boltzmann Law is applied to correct the distortion, to retain or recover the thermal infrared nature of the fused image. The results of both the qualitative and quantitative evaluation demonstrate that the proposed physical correction method both improves the spatial resolution and preserves the infrared thermal properties.

Thermal Infrared Spectroscopy of Experimentally Shocked Anorthosite and Pyroxenite

NASA Technical Reports Server (NTRS)

Johnson, J. R.; Hoerz, F.; Christensen, P.; Lucey, P. G.

2001-01-01

We performed shock recovery experiments at JSC (17-63 GPa) on samples of Stillwater pyroxenite and anorthosite and acquired their thermal infrared spectra (3-50 micron) to investigate the degradation of spectral features at high pressures. Additional information is contained in the original extended abstract.

RF Bearing Estimation in Wireless Sensor Networks

DTIC Science & Technology

2010-01-01

are the main design drivers. Techniques based on ultrasonic and infrared signal modalities have short range and require line-of-sight. Clearly, RF...generating a Doppler shifted RF signal . The small frequency change can be measured even on low cost resource constrained nodes using a radio...is already included in the power budget and RF range is superior to most other signals . Radio signal strength (RSS) based approaches are the most

Thermal removal from near-infrared imaging spectroscopy data of the Moon

USGS Publications Warehouse

Clark, R.N.; Pieters, C.M.; Green, R.O.; Boardman, J.W.; Petro, N.E.

2011-01-01

In the near-infrared from about 2 ??m to beyond 3 ??m, the light from the Moon is a combination of reflected sunlight and emitted thermal emission. There are multiple complexities in separating the two signals, including knowledge of the local solar incidence angle due to topography, phase angle dependencies, emissivity, and instrument calibration. Thermal emission adds to apparent reflectance, and because the emission's contribution increases over the reflected sunlight with increasing wavelength, absorption bands in the lunar reflectance spectra can be modified. In particular, the shape of the 2 ??m pyroxene band can be distorted by thermal emission, changing spectrally determined pyroxene composition and abundance. Because of the thermal emission contribution, water and hydroxyl absorptions are reduced in strength, lowering apparent abundances. It is important to quantify and remove the thermal emission for these reasons. We developed a method for deriving the temperature and emissivity from spectra of the lunar surface and removing the thermal emission in the near infrared. The method is fast enough that it can be applied to imaging spectroscopy data on the Moon. Copyright ?? 2011 by the American Geophysical Union.

Thermal removal from near-infrared imaging spectroscopy data of the Moon

USGS Publications Warehouse

Clark, Roger N.; Pieters, Carle M.; Green, Robert O.; Boardman, J.W.; Petro, Noah E.

2011-01-01

In the near-infrared from about 2 μm to beyond 3 μm, the light from the Moon is a combination of reflected sunlight and emitted thermal emission. There are multiple complexities in separating the two signals, including knowledge of the local solar incidence angle due to topography, phase angle dependencies, emissivity, and instrument calibration. Thermal emission adds to apparent reflectance, and because the emission's contribution increases over the reflected sunlight with increasing wavelength, absorption bands in the lunar reflectance spectra can be modified. In particular, the shape of the 2 μm pyroxene band can be distorted by thermal emission, changing spectrally determined pyroxene composition and abundance. Because of the thermal emission contribution, water and hydroxyl absorptions are reduced in strength, lowering apparent abundances. It is important to quantify and remove the thermal emission for these reasons. We developed a method for deriving the temperature and emissivity from spectra of the lunar surface and removing the thermal emission in the near infrared. The method is fast enough that it can be applied to imaging spectroscopy data on the Moon.

Life cycle monitoring of lithium-ion polymer batteries using cost-effective thermal infrared sensors with applications for lifetime prediction

NASA Astrophysics Data System (ADS)

Zhou, Xunfei; Malik, Anav; Hsieh, Sheng-Jen

2017-05-01

Lithium-ion batteries have become indispensable parts of our lives for their high-energy density and long lifespan. However, failure due to from abusive usage conditions, flawed manufacturing processes, and aging and adversely affect battery performance and even endanger people and property. Therefore, battery cells that are failing or reaching their end-of-life need to be replaced. Traditionally, battery lifetime prediction is achieved by analyzing data from current, voltage and impedance sensors. However, such a prognostic system is expensive to implement and requires direct contact. In this study, low-cost thermal infrared sensors were used to acquire thermographic images throughout the entire lifetime of small scale lithium-ion polymer batteries (410 cycles). The infrared system (non-destructive) took temperature readings from multiple batteries during charging and discharging cycles of 1C. Thermal characteristics of the batteries were derived from the thermographic images. A time-dependent and spatially resolved temperature mapping was obtained and quantitatively analyzed. The developed model can predict cycle number using the first 10 minutes of surface temperature data acquired through infrared imaging at the beginning of the cycle, with an average error rate of less than 10%. This approach can be used to correlate thermal characteristics of the batteries with life cycles, and to propose cost-effective thermal infrared imaging applications in battery prognostic systems.

New technology of functional infrared imaging and its clinical applications

NASA Astrophysics Data System (ADS)

Yang, Hongqin; Xie, Shusen; Lu, Zukang; Liu, Zhongqi

2006-01-01

With improvements in infrared camera technology, the promise of reduced costs and noninvasive character, infrared thermal imaging resurges in medicine. The paper introduces a new technology of functional infrared imaging, thermal texture maps (TTM), which is not only an apparatus for thermal radiation imaging but also a new method for revealing the relationship between the temperature distribution of the skin surface and the emission field inside body. The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Any disease in the body is associated with an alteration of the thermal distribution of human body. Infrared thermography is noninvasive, so it is the best choice for studying the physiology of thermoregulation and the thermal dysfunction associated with diseases. Reading and extracting information from the thermograms is a complex and subjective task that can be greatly facilitated by computerized techniques. Through image processing and measurement technology, surface or internal radiation sources can be non-invasively distinguished through extrapolation. We discuss the principle, the evaluation procedure and the effectiveness of TTM technology in the clinical detection and diagnosis of cancers, especially in their early stages and other diseases by comparing with other imaging technologies, such as ultrasound. Several study cases are given to show the effectiveness of this method. At last, we point out the applications of TTM technology in the research field of traditional medicine.

Grain engineering by ultrasonic substrate vibration post-treatment of wet perovskite films for annealing-free, high performance, and stable perovskite solar cells.

PubMed

Xiong, Hao; Zabihi, Fatemeh; Wang, Hongzhi; Zhang, Qinghong; Eslamian, Morteza

2018-05-10

Perovskite solar cells (PSCs) have gained great interest, owing to a fast increase in their power conversion efficiency (PCE), within a few years. However, their wide application and scale-up are hampered due to multiple obstacles, such as chemical instability, which leads to a short lifetime, and their complicated reaction and crystallization, which requires thermal annealing. Here, we address these issues using the ultrasonic substrate vibration post treatment (SVPT) applied on the as-spun perovskite wet films, so as to achieve a uniform, microscale and stable mixed-halide and mixed-cation perovskite layer, (FAPbI3)0.85(MAPbBr3)0.15, without the need for a conventional thermal annealing step. This is achieved by the creation of fluid micromixing and in situ annealing within the solution, caused by the ultrasonic excitation of the wet film. The optoelectronic properties of the perovskite films subjected to the SVPT, including photoemission, carrier lifetime and band gap, are remarkably improved compared to the conventionally annealed films. When incorporated into a planar PSC, a maximum PCE of 18.55% was achieved, compared to 15.17% for the control device, with high reproducibility and no hysteresis, and the device retained 80% of its initial PCE, over a period of 20 days of storage under ambient conditions.

Thermal Imaging with Novel Infrared Focal Plane Arrays and Quantitative Analysis of Thermal Imagery

NASA Technical Reports Server (NTRS)

Gunapala, S. D.; Rafol, S. B.; Bandara, S. V.; Liu, J. K.; Mumolo, J. M.; Soibel, A.; Ting, D. Z.; Tidrow, Meimei

2012-01-01

We have developed a single long-wavelength infrared (LWIR) quantum well infrared photodetector (QWIP) camera for thermography. This camera has been used to measure the temperature profile of patients. A pixel coregistered simultaneously reading mid-wavelength infrared (MWIR)/LWIR dual-band QWIP camera was developed to improve the accuracy of temperature measurements especially with objects with unknown emissivity. Even the dualband measurement can provide inaccurate results due to the fact that emissivity is a function of wavelength. Thus we have been developing a four-band QWIP camera for accurate temperature measurement of remote object.

Physical properties of asteroids derived from a novel approach to modeling of optical lightcurves and WISE thermalinfrared data

NASA Astrophysics Data System (ADS)

Durech, Josef; Hanus, Josef; Delbo, Marco; Ali-Lagoa, Victor; Carry, Benoit

2014-11-01

Convex shape models and spin vectors of asteroids are now routinely derived from their disk-integrated lightcurves by the lightcurve inversion method of Kaasalainen et al. (2001, Icarus 153, 37). These shape models can be then used in combination with thermal infrared data and a thermophysical model to derive other physical parameters - size, albedo, macroscopic roughness and thermal inertia of the surface. In this classical two-step approach, the shape and spin parameters are kept fixed during the thermophysical modeling when the emitted thermal flux is computed from the surface temperature, which is computed by solving a 1-D heat diffusion equation in sub-surface layers. A novel method of simultaneous inversion of optical and infrared data was presented by Durech et al. (2012, LPI Contribution No. 1667, id.6118). The new algorithm uses the same convex shape representation as the lightcurve inversion but optimizes all relevant physical parameters simultaneously (including the shape, size, rotation vector, thermal inertia, albedo, surface roughness, etc.), which leads to a better fit to the thermal data and a reliable estimation of model uncertainties. We applied this method to selected asteroids using their optical lightcurves from archives and thermal infrared data observed by the Wide-field Infrared Survey Explorer (WISE) satellite. We will (i) show several examples of how well our model fits both optical and infrared data, (ii) discuss the uncertainty of derived parameters (namely the thermal inertia), (iii) compare results obtained with the two-step approach with those obtained by our method, (iv) discuss the advantages of this simultaneous approach with respect to the classical two-step approach, and (v) advertise the possibility to use this approach to tens of thousands asteroids for which enough WISE and optical data exist.

A novel electron tunneling infrared detector

NASA Technical Reports Server (NTRS)

Kenny, T. W.; Waltman, S. B.; Reynolds, J. K.; Kaiser, W. J.

1990-01-01

The pneumatic infrared detector, originally developed by Golay in the late 1940s, uses the thermal expansion of one cm(exp 3) of xenon at room temperature to detect the heat deposited by infrared radiation. This detector was limited by thermal fluctuations within a 10 Hz bandwidth, but suffered from long thermal time constants and a fragile structure. Nevertheless, it represents the most sensitive room temperature detector currently available in the long wavelength infrared (LWIR). Fabrication of this type of detector on smaller scales has been limited by the lack of a suitably sensitive transducer. Researchers designed a detector based on this principle, but which is constructed entirely from micromachined silicon, and uses a vacuum tunneling transducer to detect the expansion of the trapped gas. Because this detector is fabricated using micromachining techniques, miniaturization and integration into one and two-dimensional arrays is feasible. The extreme sensitivity of vacuum tunneling to changes in electrode separation will allow a prototype of this detector to operate in the limit of thermal fluctuations over a 10 kHz bandwidth. A calculation of the predicted response and noise of the prototype is presented with the general formalism of thermal detectors. At present, most of the components of the prototype have been fabricated and tested independently. In particular, a characterization of the micromachined electron tunneling transducer has been carried out. The measured noise in the tunnel current is within a decade of the limit imposed by shot noise, and well below the requirements for the operation of an infrared detector with the predicted sensitivity. Assembly and characterization of the prototype infrared detector will be carried out promptly.

High-efficiency electroluminescence and amplified spontaneous emission from a thermally activated delayed fluorescent near-infrared emitter

NASA Astrophysics Data System (ADS)

Kim, Dae-Hyeon; D'Aléo, Anthony; Chen, Xian-Kai; Sandanayaka, Atula D. S.; Yao, Dandan; Zhao, Li; Komino, Takeshi; Zaborova, Elena; Canard, Gabriel; Tsuchiya, Youichi; Choi, Eunyoung; Wu, Jeong Weon; Fages, Frédéric; Brédas, Jean-Luc; Ribierre, Jean-Charles; Adachi, Chihaya

2018-02-01

Near-infrared organic light-emitting diodes and semiconductor lasers could benefit a variety of applications including night-vision displays, sensors and information-secured displays. Organic dyes can generate electroluminescence efficiently at visible wavelengths, but organic light-emitting diodes are still underperforming in the near-infrared region. Here, we report thermally activated delayed fluorescent organic light-emitting diodes that operate at near-infrared wavelengths with a maximum external quantum efficiency of nearly 10% using a boron difluoride curcuminoid derivative. As well as an effective upconversion from triplet to singlet excited states due to the non-adiabatic coupling effect, this donor-acceptor-donor compound also exhibits efficient amplified spontaneous emission. By controlling the polarity of the active medium, the maximum emission wavelength of the electroluminescence spectrum can be tuned from 700 to 780 nm. This study represents an important advance in near-infrared organic light-emitting diodes and the design of alternative molecular architectures for photonic applications based on thermally activated delayed fluorescence.

Propagation characteristics of ultrasonic guided waves in continuously welded rail

NASA Astrophysics Data System (ADS)

Yao, Wenqing; Sheng, Fuwei; Wei, Xiaoyuan; Zhang, Lei; Yang, Yuan

2017-07-01

Rail defects cause numerous railway accidents. Trains are derailed and serious consequences often occur. Compared to traditional bulk wave testing, ultrasonic guided waves (UGWs) can provide larger monitoring ranges and complete coverage of the waveguide cross-section. These advantages are of significant importance for the non-destructive testing (NDT) of the continuously welded rail, and the technique is therefore widely used in high-speed railways. UGWs in continuous welded rail (CWR) and their propagation characteristics have been discussed in this paper. Finite element methods (FEMs) were used to accomplish a vibration modal analysis, which is extended by a subsequent dispersion analysis. Wave structure features were illustrated by displacement profiles. It was concluded that guided waves have the ability to detect defects in the rail via choice of proper mode and frequency. Additionally, thermal conduction that is caused by temperature variation in the rail is added into modeling and simulation. The results indicated that unbalanced thermal distribution may lead to the attenuation of UGWs in the rail.

Ultrasound assisted combustion synthesis of TiC in Al-Ti-C system.

PubMed

Liu, Zhiwei; Rakita, Milan; Xu, Wilson; Wang, Xiaoming; Han, Qingyou

2015-11-01

This research investigated the effects of high-intensity ultrasound on the combustion synthesis of TiC particles in Al-Ti-C system. The process involved that high-intensity ultrasound was applied on the surface of a compacted Al-Ti-C pellet directly through a Nb probe during the thermal explosion reaction. By comparing with the sample without ultrasonic treatment, it was found that the thermal explosion reaction for synthesizing TiC phase could take place thoroughly in the ultrasonically treated sample. During the process of synthesizing TiC phase, the dissolution of solid graphite particles into the Al-Ti melt, as well as the nucleation and growth of TiC particles could be promoted effectively due to the effects of ultrasound, leading to an enhancement of the formation of TiC particles. Ultrasound assisted combustion synthesis as a simple and effective approach was proposed for synthesizing materials in this research. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of various pretreatments on biological sulfate reduction with waste activated sludge as electron donor and waste activated sludge diminution under biosulfidogenic condition.

PubMed

Sheng, Yuxing; Cao, Hongbin; Li, Yuping; Zhang, Yi

2010-07-15

The current study focused on the influences of various pretreatments, including alkaline, ultrasonic and thermal pretreatments on biological sulfate reduction with waste activated sludge (WAS) as sole electron donor. Our results showed that thermal and ultrasonic pretreatments increased the sulfate reduction percentage by 14.8% and 7.1%, respectively, compared with experiment with raw WAS, while alkaline pretreatment decreased the sulfate reduction percentage by 46%. By analyzing the WAS structure, particle size distribution, organic component, and enzyme activity after different pretreatments, we studied the effects of these pretreatments on WAS as well as on the mechanisms of how biological sulfate reduction was affected. The reduction of WAS and variation of WAS structure in the process of sulfate reduction were investigated. Our results showed that biosulfidogenesis was an efficient method of diminishing WAS, and various pretreatments could enhance the reduction efficiency of volatile solid in the WAS. 2010 Elsevier B.V. All rights reserved.

Framework for 2D-3D image fusion of infrared thermography with preoperative MRI.

PubMed

Hoffmann, Nico; Weidner, Florian; Urban, Peter; Meyer, Tobias; Schnabel, Christian; Radev, Yordan; Schackert, Gabriele; Petersohn, Uwe; Koch, Edmund; Gumhold, Stefan; Steiner, Gerald; Kirsch, Matthias

2017-11-27

Multimodal medical image fusion combines information of one or more images in order to improve the diagnostic value. While previous applications mainly focus on merging images from computed tomography, magnetic resonance imaging (MRI), ultrasonic and single-photon emission computed tomography, we propose a novel approach for the registration and fusion of preoperative 3D MRI with intraoperative 2D infrared thermography. Image-guided neurosurgeries are based on neuronavigation systems, which further allow us track the position and orientation of arbitrary cameras. Hereby, we are able to relate the 2D coordinate system of the infrared camera with the 3D MRI coordinate system. The registered image data are now combined by calibration-based image fusion in order to map our intraoperative 2D thermographic images onto the respective brain surface recovered from preoperative MRI. In extensive accuracy measurements, we found that the proposed framework achieves a mean accuracy of 2.46 mm.

Infrared Thermal Imaging System on a Mobile Phone

PubMed Central

Lee, Fu-Feng; Chen, Feng; Liu, Jing

2015-01-01

A novel concept towards pervasively available low-cost infrared thermal imaging system lunched on a mobile phone (MTIS) was proposed and demonstrated in this article. Through digestion on the evolutional development of milestone technologies in the area, it can be found that the portable and low-cost design would become the main stream of thermal imager for civilian purposes. As a representative trial towards this important goal, a MTIS consisting of a thermal infrared module (TIM) and mobile phone with embedded exclusive software (IRAPP) was presented. The basic strategy for the TIM construction is illustrated, including sensor adoption and optical specification. The user-oriented software was developed in the Android environment by considering its popularity and expandability. Computational algorithms with non-uniformity correction and scene-change detection are established to optimize the imaging quality and efficiency of TIM. The performance experiments and analysis indicated that the currently available detective distance for the MTIS is about 29 m. Furthermore, some family-targeted utilization enabled by MTIS was also outlined, such as sudden infant death syndrome (SIDS) prevention, etc. This work suggests a ubiquitous way of significantly extending thermal infrared image into rather wide areas especially health care in the coming time. PMID:25942639

Carbon nanotube/paraffin/montmorillonite composite phase change material for thermal energy storage.

PubMed

Li, Min; Guo, Qiangang; Nutt, Steven

2017-04-01

A composite phase change material (PCM) comprised of organic montmorillonite (OMMT)/paraffin/grafted multi-walled nanotube (MWNT) is synthesized via ultrasonic dispersion and liquid intercalation. The microstructure of the composite PCM has been characterized to determine the phase distribution, and thermal properties (latent heat and thermal conductivity) have been measured by differential scanning calorimetry (DSC) and a thermal constant analyzer. The results show that paraffin molecules are intercalated in the montmorillonite layers and the grafted MWNTs are dispersed in the montmorillonite layers. The latent heat is 47.1 J/g, and the thermal conductivity of the OMMT/paraffin/grafted MWNT composites is 34% higher than that of the OMMT/paraffin composites and 65% higher than that of paraffin.

Ultrasonication effect on thermophysical properties of Al2O3 nanofluids

NASA Astrophysics Data System (ADS)

Shah, Janki; Ranjan, Mukesh; Gupta, Sanjeev K.; Sonvane, Yogesh

2018-04-01

In this work, we studied the thermal conductivity and viscosity of alumina nanofluids for their excellent thermophysical properties. Here we considered the bath sonication time effects on thermal conductivity, viscosity and zeta potential of alumina nanofluid with different concentration (0.2, 0.3, 0.4, 0.5 Vol.%). We observed that the thermal conductivity of the nanofluids increased nonlinearly with an increased sonication time/energy as well as viscosity decreased. An enhancement of the thermal conductivity and viscosity at higher particle concentration is also observed. The results indicate that thermal properties of Al2O3 nanofluid enhances as the sonication time increases and prove Al2O3 nanofluid is one of the best thermostable heat transfer fluids compared to conventional cooling fluids.

Mapping Acid Sulfate Alteration of Basaltic Andesite with Thermal Infrared Data

NASA Technical Reports Server (NTRS)

Vaughan, R. G.; Calvin, W. M.; Hook, S. J.; Taranik, J. V.

2002-01-01

Airborne thermal infrared multi- and hyperspectral data sets are used to map sulfate alteration of basaltic andesites near Reno, NV. Alteration includes quartz-alunite, jarosite and a number of clay minerals such as kaolinite and montmorillonite. Additional information is contained in the original extended abstract.

Thermal infrared sensors for postharvest deficit irrigation of peach

USDA-ARS?s Scientific Manuscript database

California has been in a historic drought and the lack of water has been a major problem for agriculture especially for crops that depend on irrigation. A multi-year field study was carried out to demonstrate the feasibility of applying thermal infrared sensors for managing deficit irrigation in an ...

Interpretation of Thermal Infrared Imagery for Irrigation Water Resource Management.

ERIC Educational Resources Information Center

Nellis, M. Duane

1985-01-01

Water resources play a major role in the character of agricultural development in the arid western United States. This case study shows how thermal infrared imagery, which is sensitive to radiant or heat energy, can be used to interpret crop moisture content and associated stress in irrigated areas. (RM)

Students' Framing of Laboratory Exercises Using Infrared Cameras

ERIC Educational Resources Information Center

Haglund, Jesper; Jeppsson, Fredrik; Hedberg, David; Schönborn, Konrad J.

2015-01-01

Thermal science is challenging for students due to its largely imperceptible nature. Handheld infrared cameras offer a pedagogical opportunity for students to see otherwise invisible thermal phenomena. In the present study, a class of upper secondary technology students (N = 30) partook in four IR-camera laboratory activities, designed around the…

Remote sensing-a geophysical perspective.

USGS Publications Warehouse

Watson, K.

1985-01-01

In this review of developments in the field of remote sensing from a geophysical perspective, the subject is limited to the electromagnetic spectrum from 0.4 mu m to 25cm. Three broad energy categories are covered: solar reflected, thermal infrared, and microwave.-from Authorremote sensing electromagnetic spectrum solar reflected thermal infrared microwave geophysics

Evaluation of thermal remote sensing indices to estimate crop evapotranspiration coefficients

USDA-ARS?s Scientific Manuscript database

Remotely sensed data such as spectral reflectance and infrared canopy temperature can be used to quantify crop canopy cover and/or crop water stress, often through the use of vegetation indices calculated from the near-infrared and red bands, and stress indices calculated from the thermal wavelength...

Calibration of ultra-low infrared power at NIST

NASA Astrophysics Data System (ADS)

Woods, Solomon I.; Carr, Stephen M.; Carter, Adriaan C.; Jung, Timothy M.; Datla, Raju U.

2010-07-01

The Low Background Infrared (LBIR) facility has developed and tested the components of a new detector for calibration of infrared greater than 1 pW, with 0.1 % uncertainty. Calibration of such low powers could be valuable for the quantitative study of weak astronomical sources in the infrared. The pW-ACR is an absolute cryogenic radiometer (ACR) employing a high resolution transition edge sensor (TES) thermometer, ultra-weak thermal link and miniaturized receiver to achieve a noise level of around 1 fW at a temperature of 2 K. The novel thermometer employs the superconducting transition of a tin (Sn) core and has demonstrated a temperature noise floor less than 3 nK/Hz1/2. Using an applied magnetic field from an integrated solenoid to suppress the Sn transition temperature, the operating temperature of the thermometer can be tuned to any temperature below 3.6 K. The conical receiver is coated on the inside with infrared-absorbing paint and has a demonstrated absorptivity of 99.94 % at 10.6 μm. The thermal link is made from a thin-walled polyimide tube and has exhibited very low thermal conductance near 2x10-7 W/K. In tests with a heater mounted on the receiver, the receiver/thermal-link assembly demonstrated a thermal time constant of about 15 s. Based on these experimental results, it is estimated that an ACR containing these components can achieve noise levels below 1 fW, and the design of a radiometer merging the new thermometer, receiver and thermal link will be discussed.

A Multi-Wavelength Thermal Infrared and Reflectance Scene Simulation Model

NASA Technical Reports Server (NTRS)

Ballard, J. R., Jr.; Smith, J. A.; Smith, David E. (Technical Monitor)

2002-01-01

Several theoretical calculations are presented and our approach discussed for simulating overall composite scene thermal infrared exitance and canopy bidirectional reflectance of a forest canopy. Calculations are performed for selected wavelength bands of the DOE Multispectral Thermal Imagery and comparisons with atmospherically corrected MTI imagery are underway. NASA EO-1 Hyperion observations also are available and the favorable comparison of our reflective model results with these data are reported elsewhere.

A novel high-temperature furnace for combined in situ synchrotron X-ray diffraction and infrared thermal imaging to investigate the effects of thermal gradients upon the structure of ceramic materials

PubMed Central

Robinson, James B.; Brown, Leon D.; Jervis, Rhodri; Taiwo, Oluwadamilola O.; Millichamp, Jason; Mason, Thomas J.; Neville, Tobias P.; Eastwood, David S.; Reinhard, Christina; Lee, Peter D.; Brett, Daniel J. L.; Shearing, Paul R.

2014-01-01

A new technique combining in situ X-ray diffraction using synchrotron radiation and infrared thermal imaging is reported. The technique enables the application, generation and measurement of significant thermal gradients, and furthermore allows the direct spatial correlation of thermal and crystallographic measurements. The design and implementation of a novel furnace enabling the simultaneous thermal and X-ray measurements is described. The technique is expected to have wide applicability in material science and engineering; here it has been applied to the study of solid oxide fuel cells at high temperature. PMID:25178003

Photoresponse of an electrically tunable ambipolar graphene infrared thermocouple.

PubMed

Herring, Patrick K; Hsu, Allen L; Gabor, Nathaniel M; Shin, Yong Cheol; Kong, Jing; Palacios, Tomás; Jarillo-Herrero, Pablo

2014-02-12

We explore the photoresponse of an ambipolar graphene infrared thermocouple at photon energies close to or below monolayer graphene's optical phonon energy and electrostatically accessible Fermi energy levels. The ambipolar graphene infrared thermocouple consists of monolayer graphene supported by an infrared absorbing material, controlled by two independent electrostatic gates embedded below the absorber. Using a scanning infrared laser microscope, we characterize these devices as a function of carrier type and carrier density difference controlled at the junction between the two electrostatic gates. On the basis of these measurements, conducted at both mid- and near-infrared wavelengths, the primary detection mechanism can be modeled as a thermoelectric response. By studying the effect of different infrared absorbers, we determine that the optical absorption and thermal conduction of the substrate play the dominant role in the measured photoresponse of our devices. These experiments indicate a path toward hybrid graphene thermal detectors for sensing applications such as thermography and chemical spectroscopy.

Color Infrared, Terra Sirenum

NASA Image and Video Library

2002-03-01

This is the first high-resolution color infrared image taken of Mars. The image was constructed using three of the ten infrared filters on the thermal emission imaging system of NASA Mars Odyssey spacecraft.

Peeling mechanism of tomato under infrared heating

USDA-ARS?s Scientific Manuscript database

Critical behaviors of peeling tomatoes using infrared heat are thermally induced peel loosening and subsequent cracking. However, the mechanism of peel loosening and cracking due to infrared heating remains unclear. This study aimed at investigating the mechanism of peeling tomatoes under infrared h...

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

PubMed

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 (p<0.05) affect the quality parameters analyzed. Therefore, US could be considered a non-thermal method of intensifying the LTD of fruits, like apple, with only a mild impact on the quality of the dried product. Copyright © 2015 Elsevier B.V. All rights reserved.

Low cost infrared and near infrared sensors for UAVs

NASA Astrophysics Data System (ADS)

Aden, S. T.; Bialas, J. P.; Champion, Z.; Levin, E.; McCarty, J. L.

2014-11-01

Thermal remote sensing has a wide range of applications, though the extent of its use is inhibited by cost. Robotic and computer components are now widely available to consumers on a scale that makes thermal data a readily accessible resource. In this project, thermal imagery collected via a lightweight remote sensing Unmanned Aerial Vehicle (UAV) was used to create a surface temperature map for the purpose of providing wildland firefighting crews with a cost-effective and time-saving resource. The UAV system proved to be flexible, allowing for customized sensor packages to be designed that could include visible or infrared cameras, GPS, temperature sensors, and rangefinders, in addition to many data management options. Altogether, such a UAV system could be used to rapidly collect thermal and aerial data, with a geographic accuracy of less than one meter.

Ex-Situ Synthesis of Polyvinyl alcohol(PVA)-coated Fe3O4 Nanoparticles by Coprecipitation-Ultrasonication Method

NASA Astrophysics Data System (ADS)

Riva'i, Imam; Oktavia Wulandari, Ika; Sulistyarti, Hermin; Sabarudin, Akhmad

2018-01-01

In this study, the synthesis of Fe3O4 nanoparticles was done with surface modification using PVA with coprecipitation-ultrasonication method. Time variations and PVA concentrations were added to determine the effect on crystallite size and lattice parameters on the synthesis of Fe3O4-PVA nanoparticles. Fe3O4 characterization was done using X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) instruments. FTIR was employed to determine PVA coating on the surface of Fe3O4 nanoparticles. The crystallite size and lattice parameters were analyzed using XRD. From the FTIR data, it is known that the interaction between PVA and Fe3O4 nanoparticles is characterized by Fe-O-C group at 1100 cm-1 region which is characteristic of Fe3O4-PVA nanoparticles, C-H groups of PVA in the range of 2950 cm-1 wave number, C-C of PVA regions of wave number 1405 cm-1, Fe3O4 and Fe3O4-PVA samples are in the range of 565 cm-1. In addition, the variation of ultrasonication time and the addition of PVA concentration have an effect on the crystallite size change and the lattice parameter observed from the XRD data. The use of ultrasonication time will affect the size of the crystallite become smaller and the grating lattice parameters obtained are wider. The effect of addition of PVA showed that higher concentration of PVA resulted in smaller crystallite size and larger lattice parameters. These results indicated that ultrasonication time and addition of PVA concentration greatly affect the characteristics of nanoparticles.

Use of an ultrasonic osteotome device in spine surgery: experience from the first 128 patients.

PubMed

Hu, Xiaobang; Ohnmeiss, Donna D; Lieberman, Isador H

2013-12-01

The ultrasonic BoneScalpel is a tissue-specific device that allows the surgeon to make precise osteotomies while protecting collateral or adjacent soft tissue structures. The device is comprised of a blunt ultrasonic blade that oscillates at over 22,500 cycles/s with an imperceptible microscopic amplitude. 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. The purpose of this study is to report the experience and safety of using this ultrasonic osteotome device in a variety of spine surgeries. Data were retrospectively collected from medical charts and surgical reports for each surgery in which the ultrasonic scalpel was used to perform any type of osteotomy (facetectomy, laminotomy, laminectomy, en bloc resection, Smith Petersen osteotomy, pedicle subtraction osteotomy, etc.). The majority of patients had spinal stenosis, degenerative or adolescent scoliosis, pseudoarthrosis, adjacent segment degeneration, and spondylolisthesis et al. Intra-operative complications were also recorded. A total of 128 consecutive patients (73 female, 55 male) beginning with our first case experience were included in this study. The mean age of the patients was 58 years (range 12-85 years). Eighty patients (62.5 %) had previous spine surgery and/or spinal deformity. The ultrasonic scalpel was used at all levels of the spine and the average levels operated on each patient were 5. The mean operation time (skin to skin) was 4.3 h and the mean blood loss was 425.4 ml. In all cases, the ultrasonic scalpel was used to create the needed osteotomies to facilitate the surgical procedure without any percussion on the spinal column or injury to the underlying nerves. There was a noticeable absence of bleeding from the cut end of the bone consistent with the ultrasonic application. There were 11 instances of dural injuries (8.6 %) and two of which were directly associated with the use of ultrasonic device. In no procedure was the use of the ultrasonic scalpel abandoned for use of another instrument due to difficulty in using the device or failure to achieve the desired osteotomy. Overall, the ultrasonic scalpel was safe and performed as desired when used as a bone cutting device to facilitate osteotomies in a variety of spine surgeries. However, caution should be taken to avoid potential thermal injury and dural tear. If used properly, this device may decrease the risk of soft tissue injury associated with the use of high speed burrs and oscillating saws during spine surgery.

Optimization of Ultrasonic-Microwave Synergistic Extraction of Ricinine from Castor Cake by Response Surface Methodology.

PubMed

Xu, Wei; Yan, Xiuhua; Shao, Rong; Chen, Ligen; Ke, Zengguang

Castor cake is the residue in castor oil production in which many active components exist and the major one among them is ricinine. In this study, optimization of extraction of ricinine from castor cake using ultrasonic-microwave synergistic extraction (UMSE) was investigated to obtain high yield and purity by Box-Behnken design (BBD) response surface design. The optimal conditions of extraction were: ultrasound power 342 W, extracting time 5 min, microwave power 395 W, and non-significant factor of liquid/solid ratio 1:10. The crude extraction was recrystallized from ethanol. As a result, the maximum yield of ricinine was approximately 67.52%. The purity of ricinine was 99.39% which was determined by high performance liquid chromatography (HPLC). Additionally, the structure of purified ricinine was identified by fourier transforms infrared (FTIR) and liquid chromatography-mass spectrometry (LC-MS). Scanning electron microscope (SEM) was used to characterize the prismatic crystals morphology of ricinine. Results demonstrated that the present method combined the advantages of ultrasonic extraction and microwave extraction, which is time-saving with high extraction yield. Our results offer a suitable method for large-scale isolation of ricinine.

Uses of infrared thermography in the low-cost solar array program

NASA Technical Reports Server (NTRS)

Glazer, S. D.

1982-01-01

The Jet Propulsion Laboratory has used infrared thermography extensively in the Low-Cost Solar Array (LSA) photovoltaics program. A two-dimensional scanning infrared radiometer has been used to make field inspections of large free-standing photovoltaic arrays and smaller demonstration sites consisting of integrally mounted rooftop systems. These field inspections have proven especially valuable in the research and early development phases of the program, since certain types of module design flaws and environmental degradation manifest themselves in unique thermal patterns. The infrared camera was also used extensively in a series of laboratory tests on photovoltaic cells to obtain peak cell temperatures and thermal patterns during off-design operating conditions. The infrared field inspections and the laboratory experiments are discussed, and sample results are presented.

Hybrid-mode read-in integrated circuit for infrared scene projectors

NASA Astrophysics Data System (ADS)

Cho, Min Ji; Shin, Uisub; Lee, Hee Chul

2017-05-01

The infrared scene projector (IRSP) is a tool for evaluating infrared sensors by producing infrared images. Because sensor testing with IRSPs is safer than field testing, the usefulness of IRSPs is widely recognized at present. The important performance characteristics of IRSPs are the thermal resolution and the thermal dynamic range. However, due to an existing trade-off between these requirements, it is often difficult to find a workable balance between them. The conventional read-in integrated circuit (RIIC) can be classified into two types: voltage-mode and current-mode types. An IR emitter driven by a voltage-mode RIIC offers a fine thermal resolution. On the other hand, an emitter driven by the current-mode RIIC has the advantage of a wide thermal dynamic range. In order to provide various scenes, i.e., from highresolution scenes to high-temperature scenes, both of the aforementioned advantages are required. In this paper, a hybridmode RIIC which is selectively operated in two modes is proposed. The mode-selective characteristic of the proposed RIIC allows users to generate high-fidelity scenes regardless of the scene content. A prototype of the hybrid-mode RIIC was fabricated using a 0.18-μm 1-poly 6-metal CMOS process. The thermal range and the thermal resolution of the IR emitter driven by the proposed circuit were calculated based on measured data. The estimated thermal dynamic range of the current mode was from 261K to 790K, and the estimated thermal resolution of the voltage mode at 300K was 23 mK with a 12-bit gray-scale resolution.

Combined use of visible, reflected infrared, and thermal infrared images for mapping Hawaiian lava flows

NASA Technical Reports Server (NTRS)

Abrams, Michael; Abbott, Elsa; Kahle, Anne

1991-01-01

The weathering of Hawaiian basalts is accompanied by chemical and physical changes of the surfaces. These changes have been mapped using remote sensing data from the visible and reflected infrared and thermal infrared wavelength regions. They are related to the physical breakdown of surface chill coats, the development and erosion of silica coatings, the oxidation of mafic minerals, and the development of vegetation cover. These effects show systematic behavior with age and can be mapped using the image data and related to relative ages of pahoehoe and aa flows. The thermal data are sensitive to silica rind development and fine structure of the scene; the reflectance data show the degree of oxidation and differentiate vegetation from aa and cinders. Together, data from the two wavelength regions show more than either separately. The combined data potentially provide a powerful tool for mapping basalt flows in arid to semiarid volcanic environments.

Broadband infrared vibrational nano-spectroscopy using thermal blackbody radiation

DOE PAGES

O’Callahan, Brian T.; Lewis, William E.; Möbius, Silke; ...

2015-12-03

Infrared vibrational nano-spectroscopy based on scattering scanning near-field optical microscopy (s-SNOM) provides intrinsic chemical specificity with nanometer spatial resolution. Here we use incoherent infrared radiation from a 1400 K thermal blackbody emitter for broadband infrared (IR) nano-spectroscopy.With optimized interferometric heterodyne signal amplification we achieve few-monolayer sensitivity in phonon polariton spectroscopy and attomolar molecular vibrational spectroscopy. Near-field localization and nanoscale spatial resolution is demonstrated in imaging flakes of hexagonal boron nitride (hBN) and determination of its phonon polariton dispersion relation. The signal-to-noise ratio calculations and analysis for different samples and illumination sources provide a reference for irradiance requirements and the attainablemore » near-field signal levels in s-SNOM in general. As a result, the use of a thermal emitter as an IR source thus opens s-SNOM for routine chemical FTIR nano-spectroscopy.« less

Infrared Imaging Sharpens View in Critical Situations

NASA Technical Reports Server (NTRS)

2007-01-01

Innovative Engineering and Consulting (IEC) Infrared Systems, a leading developer of thermal imaging systems and night vision equipment, received a Glenn Alliance for Technology Exchange (GATE) award, half of which was in the form of additional NASA assistance for new product development. IEC Infrared Systems worked with electrical and optical engineers from Glenn's Diagnostics and Data Systems Branch to develop a commercial infrared imaging system that could differentiate the intensity of heat sources better than other commercial systems. The research resulted in two major thermal imaging solutions: NightStalkIR and IntrudIR Alert. These systems are being used in the United States and abroad to help locate personnel stranded in emergency situations, defend soldiers on the battlefield abroad, and protect high-value facilities and operations. The company is also applying its advanced thermal imaging techniques to medical and pharmaceutical product development with a Cleveland-based pharmaceutical company.

Interpretation of multispectral and infrared thermal surveys of the Suez Canal Zone, Egypt

NASA Technical Reports Server (NTRS)

Elshazly, E. M.; Hady, M. A. A. H.; Hafez, M. A. A.; Salman, A. B.; Morsy, M. A.; Elrakaiby, M. M.; Alaassy, I. E. E.; Kamel, A. F.

1977-01-01

Remote sensing airborne surveys were conducted, as part of the plan of rehabilitation, of the Suez Canal Zone using I2S multispectral camera and Bendix LN-3 infrared passive scanner. The multispectral camera gives four separate photographs for the same scene in the blue, green, red, and near infrared bands. The scanner was operated in the microwave bands of 8 to 14 microns and the thermal surveying was carried out both at night and in the day time. The surveys, coupled with intensive ground investigations, were utilized in the construction of new geological, structural lineation and drainage maps for the Suez Canal Zone on a scale of approximately 1:20,000, which are superior to the maps made by normal aerial photography. A considerable number of anomalies belonging to various types were revealed through the interpretation of the executed multispectral and infrared thermal surveys.

Broadband infrared vibrational nano-spectroscopy using thermal blackbody radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

O’Callahan, Brian T.; Lewis, William E.; Möbius, Silke

Infrared vibrational nano-spectroscopy based on scattering scanning near-field optical microscopy (s-SNOM) provides intrinsic chemical specificity with nanometer spatial resolution. Here we use incoherent infrared radiation from a 1400 K thermal blackbody emitter for broadband infrared (IR) nano-spectroscopy.With optimized interferometric heterodyne signal amplification we achieve few-monolayer sensitivity in phonon polariton spectroscopy and attomolar molecular vibrational spectroscopy. Near-field localization and nanoscale spatial resolution is demonstrated in imaging flakes of hexagonal boron nitride (hBN) and determination of its phonon polariton dispersion relation. The signal-to-noise ratio calculations and analysis for different samples and illumination sources provide a reference for irradiance requirements and the attainablemore » near-field signal levels in s-SNOM in general. As a result, the use of a thermal emitter as an IR source thus opens s-SNOM for routine chemical FTIR nano-spectroscopy.« less

Prediction and Characterization of NaGaS2, A High Thermal Conductivity Mid-Infrared Nonlinear Optical Material for High-Power Laser Frequency Conversion.

PubMed

Hou, Dianwei; Nissimagoudar, Arun S; Bian, Qiang; Wu, Kui; Pan, Shilie; Li, Wu; Yang, Zhihua

2018-06-15

Infrared nonlinear optical (IR NLO) crystals are the major materials to widen the output range of solid-state lasers to mid- or far-infrared regions. The IR NLO crystals used in the middle IR region are still inadequate for high-power laser applications because of deleterious thermal effects (lensing and expansion), low laser-induced damage threshold, and two-photon absorption. Herein, the unbiased global minimum search method was used for the first time to search for IR NLO optical materials and ultimately found a new IR NLO material NaGaS 2 . It meets the stringent demands for IR NLO materials pumped by high-power laser with the highest thermal conductivity among common IR NLO materials able to avoid two-photon absorption, a classic nonlinear coefficient, and wide infrared transparency.

Passive Infrared Thermographic Imaging for Mobile Robot Object Identification

NASA Astrophysics Data System (ADS)

Hinders, M. K.; Fehlman, W. L.

2010-02-01

The usefulness of thermal infrared imaging as a mobile robot sensing modality is explored, and a set of thermal-physical features used to characterize passive thermal objects in outdoor environments is described. Objects that extend laterally beyond the thermal camera's field of view, such as brick walls, hedges, picket fences, and wood walls as well as compact objects that are laterally within the thermal camera's field of view, such as metal poles and tree trunks, are considered. Classification of passive thermal objects is a subtle process since they are not a source for their own emission of thermal energy. A detailed analysis is included of the acquisition and preprocessing of thermal images, as well as the generation and selection of thermal-physical features from these objects within thermal images. Classification performance using these features is discussed, as a precursor to the design of a physics-based model to automatically classify these objects.

Thermal Infrared Spectroscopy of Saturn and Titan from Cassini

NASA Technical Reports Server (NTRS)

Jennings, Donald E.; Brasunas, J. C.; Carlson, R. C.; Flasar, F. M.; Kunde, V. G.; Mamoutkine, A. A.; Nixon, A.; Pearl, J. C.; Romani, P. N.; Simon-Miller, A. A.;

Flight vehicle thermal testing with infrared lamps

NASA Technical Reports Server (NTRS)

Fields, Roger A.

1992-01-01

The verification and certification of new structural material concepts for advanced high speed flight vehicles relies greatly on thermal testing with infrared quartz lamps. The basic quartz heater system characteristics and design considerations are presented. Specific applications are illustrated with tests that were conducted for the X-15, the Space Shuttle, and YF-12 flight programs.

Objective assessment of biomagnetic devices and alternative clinical therapies using infrared thermal imaging

NASA Astrophysics Data System (ADS)

Rockley, Graham J.

2001-03-01

The overwhelming introduction of magnetic devices and other alternative therapies into the health care market prompts the need for objective evaluation of these techniques through the use of infrared thermal imaging. Many of these therapies are reported to promote the stimulation of blood flow or the relief of pain conditions. Infrared imaging is an efficient tool to assess such changes in the physiological state. Therefore, a thermal imager can help document and substantiate whether these therapies are in fact providing an effective change to the local circulation. Thermal images may also indicate whether the change is temporary or sustained. As a specific case example, preliminary findings will be presented concerning the use of magnets and the effect they have on peripheral circulation. This will include a discussion of the recommended protocols for this type of infrared testing. This test model can be applied to the evaluation of other devices and therapeutic procedures which are reputed to affect circulation such as electro acupuncture, orthopedic footwear and topical ointments designed to relieve pain or inflammation.

Infrared surveys of Hawaiian volcanoes

USGS Publications Warehouse

Fischer, W. A.; Moxham, R.M.; Polcyn, F.; Landis, G.H.

1964-01-01

Aerial infrared-sensor surveys of Kilauea volcano have depicted the areal extent and the relative intensity of abnormal thermal features in the caldera area of the volcano and along its associated rift zones. Many of these anomalies show correlation with visible steaming and reflect convective transfer of heat to the surface from subterranean sources. Structural details of the volcano, some not evident from surface observation, are also delineated by their thermal abnormalities. Several changes were observed in the patterns of infrared emission during the period of study; two such changes show correlation in location with subsequent eruptions, but the cause-and-effect relationship is uncertain.Thermal anomalies were also observed on the southwest flank of Mauna Loa; images of other volcanoes on the island of Hawaii, and of Haleakala on the island of Maui, revealed no thermal abnormalities.Approximately 25 large springs issuing into the ocean around the periphery of Hawaii have been detected.Infrared emission varies widely with surface texture and composition, suggesting that similar observations may have value for estimating surface conditions on the moon or planets.

Ceramic Gas Turbine Engine Demonstration Program

DTIC Science & Technology

1982-05-01

of Radiographs 124 5.2.3 Ultrasonic NDE 127 5.2.4 Scanning Laser Acoustic Microscopy 132 5.2.5 Microwave NDE 134 5.2.6 Neutron Radiography 134 5.2.7...microwaves, and scanning loser acoustic microscopy (SLAM) were evaluated using the standards containing known defects. Component shape standards...mounted in a carousel and rotated in the high velocity combustor gases. The temperature is measured by an infrared pyrometer 95 TABLE 4-3. SUMMARY OF

Infrared characterization of thermal gradients on disc brakes

NASA Astrophysics Data System (ADS)

Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

2003-04-01

The heat generated in frictional organs like brakes and clutches induces thermal distortions which may lead to localized contact areas and hot spots developments. Hot spots are high thermal gradients on the rubbing surface. They count among the most dangerous phenomena in frictional organs leading to damage, early failure and unacceptable braking performances such as brake fade or undesirable low frequency vibrations called hot judder. In this paper, an experimental study of hot spots occurrence in railway disc brakes is reported on. The aim of this study was to better classify and to explain the thermal gradients appearance on the surface of the disc. Thermograph measurements with an infrared camera have been carried out on the rubbing surface of brake discs on a full-scale test bench. The infrared system was set to take temperature readings in snap shot mode precisely synchronized with the rotation of the disc. Very short integration time allows reducing drastically haziness of thermal images. Based on thermographs, a classification of hot-spots observed in disc brakes is proposed. A detailed investigation of the most damaging thermal gradients, called macroscopic hot spots (MHS) is given. From these experimental researches, a scenario of hot spots occurrence is suggested step by step. Thanks to infrared measurements at high frequency with high resolution, observations give new highlights on the conditions of hot spots appearance. Comparison of the experimental observations with the theoretical approaches is finally discussed.

Advanced Flaw Manufacturing and Crack Growth Control

NASA Astrophysics Data System (ADS)

Kemppainen, M.; Pitkänen, J.; Virkkunen, I.; Hänninen, H.

2004-02-01

Advanced artificial flaw manufacturing method has become available. The method produces true fatigue cracks, which are representative of most service-induced cracks. These cracks can be used to simulate behaviour of realistic cracks under service conditions. This paper introduces studies of the effects of different thermal loading cycles to crack opening and residual stress state as seen at the surface of the sample and in the ultrasonic signal. In-situ measurements were performed under dynamic thermal fatigue loading of a 20 mm long artificial crack.

Thermal surveillance of volcanoes

NASA Technical Reports Server (NTRS)

Friedman, J. D. (Principal Investigator)

1972-01-01

The author has identified the following significant results. A systematic aircraft program to monitor changes in the thermal emission from volcanoes of the Cascade Range has been initiated and is being carried out in conjunction with ERTS-1 thermal surveillance experiments. Night overflights by aircraft equipped with thermal infrared scanners sensitive to terrestrial emission in the 4-5.5 and 8-14 micron bands are currently being carried out at intervals of a few months. Preliminary results confirm that Mount Rainier, Mount Baker, Mount Saint Helens, Mount Shasta, and the Lassen area continue to be thermally active, although with the exception of Lassen which erupted between 1914 and 1917, and Mount Saint Helens which had a series of eruptions between 1831 and 1834, there has been no recent eruptive activity. Excellent quality infrared images recorded over Mount Rainier, as recently as April, 1972, show similar thermal patterns to those reported in 1964-1966. Infrared images of Mount Baker recorded in November 1970 and again in April 1972 revealed a distinct array of anomalies 1000 feet below the crater rim and associated with fumaroles or structures permitting convective heat transfer to the surface.

Structure of the Saint Francois Mountains and surrounding lead belt, S.E. Missouri: Inference from thermal IR and other data sets

NASA Technical Reports Server (NTRS)

Arvidson, R. E. (Principal Investigator)

1982-01-01

Progress in the preparation of manuscripts on the discovery of a Precambrian rift running NW-SE through Missouri as seen in free air and Bouguer gravity anomalies and in HCMM data, and on digital image processing of potential field and topographic data on the rift is reported. Copies of the papers are attached. Contrast-enhanced HCMM images that have been transformed to Mercator projections are presented. Shaded relief map overlays of thermal and apparent thermal inertia images used as part of a masers thesis examining correlations between HCMM data products, linears, and geologic units are presented. Progress in examination of the difference in information content of daytime infrared, night time infrared, albedo, and thermal inertia images and their application to he identification of linears not directly controlled by topography is reported. Thermal infrared and albedo data were coded as hue, saturation and brightness values to generate a color display, which is included.

Thermal effects of an ICL-based mid-infrared CH 4 sensor within a wide atmospheric temperature range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.

Here, thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH 4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ~ 25°C was measured for 5 hours and its Allan deviation was ~ 2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to control such effects. An environmental test chamber was employed to investigate thermal effects that occur in the sensor system with variation of the test chambermore » temperature between 10 and 30°C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH 4 standard gas sample. indoor/outdoor CH 4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.« less

Thermal effects of an ICL-based mid-infrared CH4 sensor within a wide atmospheric temperature range

NASA Astrophysics Data System (ADS)

Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; Girija, Aswathy V.; He, Qixin; Zheng, Huadan; Griffin, Robert J.; Tittel, Frank K.

2018-03-01

The thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ∼25 °C was measured for 5 h and its Allan deviation was ∼2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to minimize these effects. An environmental test chamber was employed to investigate the thermal effects that occur in the sensor system with variation of the test chamber temperature between 10 and 30 °C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH4 standard gas sample. Indoor/outdoor CH4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.

Thermal effects of an ICL-based mid-infrared CH 4 sensor within a wide atmospheric temperature range

DOE PAGES

Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; ...

2018-01-31

Here, thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH 4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ~ 25°C was measured for 5 hours and its Allan deviation was ~ 2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to control such effects. An environmental test chamber was employed to investigate thermal effects that occur in the sensor system with variation of the test chambermore » temperature between 10 and 30°C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH 4 standard gas sample. indoor/outdoor CH 4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.« less

A comparison of thermocouple and infrared thermographic analysis of temperature rise on the root surface during the continuous wave of condensation technique.

PubMed

Mc Cullagh, J J; Setchell, D J; Gulabivala, K; Hussey, D L; Biagioni, P; Lamey, P J; Bailey, G

2000-07-01

This study was designed to use two methods of temperature measurement to analyse and quantify the in vitro root surface temperature changes during the initial stage of the continuous wave technique of obturation of 17 single-rooted premolar teeth with standard canal preparations. A model was designed to allow simultaneous temperature measurement with both thermocouples and an infrared thermal imaging system. Two thermocouples were placed on the root surface, one coronally and the other near the root apex. A series of thermal images were recorded by an infrared thermal imaging camera during the downpack procedure. The mean temperature rises on the root surface, as measured by the two thermocouples, averaged 13.9 degrees C over the period of study, whilst the infrared thermal imaging system measured an average rise of 28.4 degrees C at the same sites. Temperatures at the more apical point were higher than those measured coronally. After the first wave of condensation, the second activation of the plugger in the canal prior to its removal always resulted in a secondary rise in temperature. The thermal imaging system detected areas of greater temperature change distant from the two selected thermocouple sites. The continuous wave technique of obturation may result in high temperatures on the external root surface. Infrared thermography is a useful device for mapping patterns of temperature change over a large area.

[The progress in retrieving land surface temperature based on thermal infrared and microwave remote sensing technologies].

PubMed

Zhang, Jia-Hua; Li, Xin; Yao, Feng-Mei; Li, Xian-Hua

2009-08-01

Land surface temperature (LST) is an important parameter in the study on the exchange of substance and energy between land surface and air for the land surface physics process at regional and global scales. Many applications of satellites remotely sensed data must provide exact and quantificational LST, such as drought, high temperature, forest fire, earthquake, hydrology and the vegetation monitor, and the models of global circulation and regional climate also need LST as input parameter. Therefore, the retrieval of LST using remote sensing technology becomes one of the key tasks in quantificational remote sensing study. Normally, in the spectrum bands, the thermal infrared (TIR, 3-15 microm) and microwave bands (1 mm-1 m) are important for retrieval of the LST. In the present paper, firstly, several methods for estimating the LST on the basis of thermal infrared (TIR) remote sensing were synthetically reviewed, i. e., the LST measured with an ground-base infrared thermometer, the LST retrieval from mono-window algorithm (MWA), single-channel algorithm (SCA), split-window techniques (SWT) and multi-channels algorithm(MCA), single-channel & multi-angle algorithm and multi-channels algorithm & multi-angle algorithm, and retrieval method of land surface component temperature using thermal infrared remotely sensed satellite observation. Secondly, the study status of land surface emissivity (epsilon) was presented. Thirdly, in order to retrieve LST for all weather conditions, microwave remotely sensed data, instead of thermal infrared data, have been developed recently, and the LST retrieval method from passive microwave remotely sensed data was also introduced. Finally, the main merits and shortcomings of different kinds of LST retrieval methods were discussed, respectively.

The effect of lunarlike satellites on the orbital infrared light curves of Earth-analog planets.

PubMed

Moskovitz, Nicholas A; Gaidos, Eric; Williams, Darren M

2009-04-01

We have investigated the influence of lunarlike satellites on the infrared orbital light curves of Earth-analog extrasolar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet and determine its orbit. We used an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon, and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of Earth, while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g., via spectroscopy or visible-wavelength detection of specular glint from a surface ocean), only the largest (approximately Mars-sized) lunarlike satellites can be detected by light curve data from a TPF-like instrument (i.e., one that achieves a photometric signal-to-noise ratio of 10 to 20 at infrared wavelengths). Nondetection of a lunarlike satellite can obfuscate the interpretation of a given system's infrared light curve so that it may resemble a single planet with high obliquity, different orbital longitude of vernal equinox relative to inferior conjunction, and in some cases drastically different thermal characteristics. If the thermal properties of the planet are not independently established, then the presence of a lunarlike satellite cannot be inferred from infrared data, which would thus demonstrate that photometric light curves alone can only be used for preliminary study, and the addition of spectroscopic data will be necessary.

Effectiveness of digital infrared thermal imaging in detecting lower extremity deep venous thrombosis.

PubMed

Deng, Fangge; Tang, Qing; Zeng, Guangqiao; Wu, Hua; Zhang, Nuofu; Zhong, Nanshan

2015-05-01

The authors aimed to determine the effectiveness of infrared thermal imaging (IRTI) as a novel, noninvasive technique in adjunctive diagnostic screening for lower limb deep venous thrombosis (DVT). The authors used an infrared thermal imaging sensor to examine the lower limbs of 64 DVT patients and 64 healthy volunteers. The DVT patients had been definitively diagnosed with either Doppler vascular compression ultrasonography or angiography. The mean area temperature (T_area) and mean linear temperature (T_line) in the region of interest were determined with infrared thermal imaging. Images were evaluated with qualitative pseudocolor analysis to verify specific color-temperature responses and with quantitative temperature analysis. Differences in T_area and T_line between the DVT limb and the nonaffected limb in each DVT patient and temperature differences (TDs) in T_area (TDarea) and T_line (TDline) between DVT patients and non-DVT volunteers were compared. Qualitative pseudocolor analysis revealed visible asymmetry between the DVT side and non-DVT side in the presentation and distribution characteristics (PDCs) of infrared thermal images. The DVT limbs had areas of abnormally high temperature, indicating the presence of DVT. Of the 64 confirmed DVT patients, 62 (96.88%) were positive by IRTI detection. Among these 62 IRTI-positive cases, 53 (82.81%) showed PDCs that agreed with the DVT regions detected by Doppler vascular compression ultrasonography or angiography. In nine patients (14.06%), IRTI PDCs did not definitively agree with the DVT regions established with other testing methods, but still correctly indicated the DVT-affected limb. There was a highly significant difference between DVT and non-DVT sides in DVT patients (P < 0.01). The TDarea and TDline in non-DVT volunteers ranged from 0.19 ± 0.15 °C to 0.21 °C ± 0.17 °C; those in DVT patients ranged from 0.86 °C ± 0.71 °C to 1.03 °C ± 0.79 °C (P < 0.01). Infrared thermal imaging can be effectively used in DVT detection and adjunctive diagnostic screening because of its specific infrared PDCs and TDs values.

Ultrasonication effects on thermal and rheological properties of carbon nanotube suspensions

PubMed Central

2012-01-01

The preparation of nanofluids is very important to their thermophysical properties. Nanofluids with the same nanoparticles and base fluids can behave differently due to different nanofluid preparation methods. The agglomerate sizes in nanofluids can significantly impact the thermal conductivity and viscosity of nanofluids and lead to a different heat transfer performance. Ultrasonication is a common way to break up agglomerates and promote dispersion of nanoparticles into base fluids. However, research reports of sonication effects on nanofluid properties are limited in the open literature. In this work, sonication effects on thermal conductivity and viscosity of carbon nanotubes (0.5 wt%) in an ethylene glycol-based nanofluid are investigated. The corresponding effects on the agglomerate sizes and the carbon nanotube lengths are observed. It is found that with an increased sonication time/energy, the thermal conductivity of the nanofluids increases nonlinearly, with the maximum enhancement of 23% at sonication time of 1,355 min. However, the viscosity of nanofluids increases to the maximum at sonication time of 40 min, then decreases, finally approaching the viscosity of the pure base fluid at a sonication time of 1,355 min. It is also observed that the sonication process not only reduces the agglomerate sizes but also decreases the length of carbon nanotubes. Over the current experimental range, the reduction in agglomerate size is more significant than the reduction of the carbon nanotube length. Hence, the maximum thermal conductivity enhancement and minimum viscosity increase are obtained using a lengthy sonication, which may have implications on application. PMID:22333487

Correlation of Predicted and Observed Optical Properties of Multilayer Thermal Control Coatings

NASA Technical Reports Server (NTRS)

Jaworske, Donald A.

1998-01-01

Thermal control coatings on spacecraft will be increasingly important, as spacecraft grow smaller and more compact. New thermal control coatings will be needed to meet the demanding requirements of next generation spacecraft. Computer programs are now available to design optical coatings and one such program was used to design several thermal control coatings consisting of alternating layers of WO3 and SiO2. The coatings were subsequently manufactured with electron beam evaporation and characterized with both optical and thermal techniques. Optical data were collected in both the visible region of the spectrum and the infrared. Predictions of solar absorptance and infrared emittance were successfully correlated to the observed thermal control properties. Functional performance of the coatings was verified in a bench top thermal vacuum chamber.

Thermal Performance of an Annealed Pyrolytic Graphite Solar Collector

NASA Technical Reports Server (NTRS)

Jaworske, Donald A.; Hornacek, Jennifer

2002-01-01

A solar collector having the combined properties of high solar absorptance, low infrared emittance, and high thermal conductivity is needed for applications where solar energy is to be absorbed and transported for use in minisatellites. Such a solar collector may be used with a low temperature differential heat engine to provide power or with a thermal bus for thermal switching applications. One concept being considered for the solar collector is an Al2O3 cermet coating applied to a thermal conductivity enhanced polished aluminum substrate. The cermet coating provides high solar absorptance and the polished aluminum provides low infrared emittance. Annealed pyrolytic graphite embedded in the aluminum substrate provides enhanced thermal conductivity. The as-measured thermal performance of an annealed pyrolytic graphite thermal conductivity enhanced polished aluminum solar collector, coated with a cermet coating, will be presented.

The Potential of Sonic IR to Inspect Aircraft Components Traditionally Inspected with Fluorescent Penetrant and or Magnetic Particle Inspection

NASA Astrophysics Data System (ADS)

DiMambro, J.; Ashbaugh, D. M.; Han, X.; Favro, L. D.; Lu, J.; Zeng, Z.; Li, W.; Newaz, G. M.; Thomas, R. L.

2006-03-01

Sandia National Laboratories Airworthiness Assurance Nondestructive Inspection Validation Center (AANC) provides independent and quantitative evaluations of new and enhanced inspection, to developers, users, and regulators of aircraft. Wayne State University (WSU) has developed and patented an inspection technique using high-power ultrasonic excitation and infrared technology to detect defects in a variety of materials. AANC and WSU are working together as part of the FAA Sonic Infrared Technology Transfer Program. The ultimate goal of the program is to implement Sonic IR in the aviation field where appropriate. The capability of Sonic IR imaging to detect cracks in components commonly inspected with magnetic particle or liquid penetrant inspection in the field is of interest to industry.

High pressure elasticity and thermal properties of depleted uranium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobsen, M. K., E-mail: mjacobsen@lanl.gov; Velisavljevic, N., E-mail: nenad@lanl.gov

2016-04-28

Studies of the phase diagram of uranium have revealed a wealth of high pressure and temperature phases. Under ambient conditions the crystal structure is well defined up to 100 gigapascals (GPa), but very little information on thermal conduction or elasticity is available over this same range. This work has applied ultrasonic interferometry to determine the elasticity, mechanical, and thermal properties of depleted uranium to 4.5 GPa. Results show general strengthening with applied load, including an overall increase in acoustic thermal conductivity. Further implications are discussed within. This work presents the first high pressure studies of the elasticity and thermal properties ofmore » depleted uranium metal and the first real-world application of a previously developed containment system for making such measurements.« less

Night vision imaging system design, integration and verification in spacecraft vacuum thermal test

NASA Astrophysics Data System (ADS)

Shang, Yonghong; Wang, Jing; Gong, Zhe; Li, Xiyuan; Pei, Yifei; Bai, Tingzhu; Zhen, Haijing

2015-08-01

The purposes of spacecraft vacuum thermal test are to characterize the thermal control systems of the spacecraft and its component in its cruise configuration and to allow for early retirement of risks associated with mission-specific and novel thermal designs. The orbit heat flux is simulating by infrared lamp, infrared cage or electric heater. As infrared cage and electric heater do not emit visible light, or infrared lamp just emits limited visible light test, ordinary camera could not operate due to low luminous density in test. Moreover, some special instruments such as satellite-borne infrared sensors are sensitive to visible light and it couldn't compensate light during test. For improving the ability of fine monitoring on spacecraft and exhibition of test progress in condition of ultra-low luminous density, night vision imaging system is designed and integrated by BISEE. System is consist of high-gain image intensifier ICCD camera, assistant luminance system, glare protect system, thermal control system and computer control system. The multi-frame accumulation target detect technology is adopted for high quality image recognition in captive test. Optical system, mechanical system and electrical system are designed and integrated highly adaptable to vacuum environment. Molybdenum/Polyimide thin film electrical heater controls the temperature of ICCD camera. The results of performance validation test shown that system could operate under vacuum thermal environment of 1.33×10-3Pa vacuum degree and 100K shroud temperature in the space environment simulator, and its working temperature is maintains at 5° during two-day test. The night vision imaging system could obtain video quality of 60lp/mm resolving power.

Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings

NASA Technical Reports Server (NTRS)

Edlridge, Jeffrey I.; Martin, Richard E.

2009-01-01

An apparatus for mid-infrared reflectance imaging has been developed as means of inspecting for subsurface damage in thermal-barrier coatings (TBCs). The apparatus is designed, more specifically, for imaging the progression of buried delamination cracks in plasma-sprayed yttria-stabilized zirconia coatings on turbine-engine components. Progression of TBC delamination occurs by the formation of buried cracks that grow and then link together to produce eventual TBC spallation. The mid-infrared reflectance imaging system described here makes it possible to see delamination progression that is invisible to the unaided eye, and therefore give sufficiently advanced warning before delamination progression adversely affects engine performance and safety. The apparatus (see figure) includes a commercial mid-infrared camera that contains a liquid-nitrogen-cooled focal plane indium antimonide photodetector array, and imaging is restricted by a narrow bandpass centered at wavelength of 4 microns. This narrow wavelength range centered at 4 microns was chosen because (1) it enables avoidance of interfering absorptions by atmospheric OH and CO2 at 3 and 4.25 microns, respectively; and (2) the coating material exhibits maximum transparency in this wavelength range. Delamination contrast is produced in the midinfrared reflectance images because the introduction of cracks into the TBC creates an internal TBC/air-gap interface with a high diffuse reflectivity of 0.81, resulting in substantially higher reflectance of mid-infrared radiation in regions that contain buried delamination cracks. The camera is positioned a short distance (.12 cm) from the specimen. The mid-infrared illumination is generated by a 50-watt silicon carbide source positioned to the side of the mid-infrared camera, and the illumination is collimated and reflected onto the specimen by a 6.35-cm-diameter off-axis paraboloidal mirror. Because the collected images are of a steady-state reflected intensity (in contrast to the transient thermal response observed in infrared thermography), collection times can be lengthened to whatever extent needed to achieve desired signal-to-noise ratios. Each image is digitized, and the resulting data are processed in several steps to obtain a true mid-infrared reflectance image. The raw image includes thermal radiation emitted by the specimen in addition to the desired reflected radiation. The thermal-radiation contribution is eliminated by subtracting the image obtained with the illumination off from the image obtained with the illumination on. A flat-field correction is then made to remove the effects of non-uniformities in the illumination level and pixel-to-pixel variations in sensitivity. This correction is performed by normalizing to an image of a standard object that has a known reflectance at a wavelength of 4 microns. After correction, each pixel value is proportional to the reflectance (at a wavelength of 4-microns) at the corresponding location on the specimen. Mid-infrared reflectance imaging of specimens that were thermally cyc led for different numbers of cycles was performed and demonstrated t hat mid-infrared reflectance imaging was able to monitor the gradual delamination progression that occurs with continued thermal cycling . Reproducible values were obtained for the reflectance associated w ith an attached and fully delaminated TBC, so that intermediate refle ctance values could be interpreted to successfully predict the numbe r of thermal cycles to failure.

Calculated photonic structures for infrared emittance control

NASA Astrophysics Data System (ADS)

Rung, Andreas; Ribbing, Carl G.

2002-06-01

Using an available program package based on the transfer-matrix method, we calculated the photonic band structure for two different structures: a quasi-three-dimensional crystal of square air rods in a high-index matrix and an opal structure of high-index spheres in a matrix of low index, epsilon = 1.5. The high index used is representative of gallium arsenide in the thermal infrared range. The geometric parameters of the rod dimension, sphere radius, and lattice constants were chosen to give total reflectance for normal incidence, i.e., minimum thermal emittance, in either one of the two infrared atmospheric windows. For these four photonic crystals, the bulk reflectance spectra and the wavelength-averaged thermal emittance as a function of crystal thickness were calculated. The results reveal that potentially useful thermal signature suppression is obtained for crystals as thin as 20-50 mum, i.e., comparable with that of a paint layer.

Photoacoustic tomography of foreign bodies in soft biological tissue.

PubMed

Cai, Xin; Kim, Chulhong; Pramanik, Manojit; Wang, Lihong V

2011-04-01

In detecting small foreign bodies in soft biological tissue, ultrasound imaging suffers from poor sensitivity (52.6%) and specificity (47.2%). Hence, alternative imaging methods are needed. Photoacoustic (PA) imaging takes advantage of strong optical absorption contrast and high ultrasonic resolution. A PA imaging system is employed to detect foreign bodies in biological tissues. To achieve deep penetration, we use near-infrared light ranging from 750 to 800 nm and a 5-MHz spherically focused ultrasonic transducer. PA images were obtained from various targets including glass, wood, cloth, plastic, and metal embedded more than 1 cm deep in chicken tissue. The locations and sizes of the targets from the PA images agreed well with those of the actual samples. Spectroscopic PA imaging was also performed on the objects. These results suggest that PA imaging can potentially be a useful intraoperative imaging tool to identify foreign bodies.

Sulfonated reduced graphene oxide as a highly efficient catalyst for direct amidation of carboxylic acids with amines using ultrasonic irradiation.

PubMed

Mirza-Aghayan, Maryam; Tavana, Mahdieh Molaee; Boukherroub, Rabah

2016-03-01

Sulfonated reduced graphene oxide nanosheets (rGO-SO3H) were prepared by grafting sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide (rGO) under sonochemical conditions. rGO-SO3H catalyst was characterized by Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). rGO-SO3H catalyst was successfully applied as a reusable solid acid catalyst for the direct amidation of carboxylic acids with amines into the corresponding amides under ultrasonic irradiation. The direct sonochemical amidation of carboxylic acid takes place under mild conditions affording in good to high yields (56-95%) the corresponding amides in short reaction times. Copyright © 2015 Elsevier B.V. All rights reserved.

Receive-Noise Analysis of Capacitive Micromachined Ultrasonic Transducers.

PubMed

Bozkurt, Ayhan; Yaralioglu, G Goksenin

2016-11-01

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

From carbon nanotubes and silicate layers to graphene platelets for polymer nanocomposites.

PubMed

Zaman, Izzuddin; Kuan, Hsu-Chiang; Dai, Jingfei; Kawashima, Nobuyuki; Michelmore, Andrew; Sovi, Alex; Dong, Songyi; Luong, Lee; Ma, Jun

2012-08-07

In spite of extensive studies conducted on carbon nanotubes and silicate layers for their polymer-based nanocomposites, the rise of graphene now provides a more promising candidate due to its exceptionally high mechanical performance and electrical and thermal conductivities. The present study developed a facile approach to fabricate epoxy-graphene nanocomposites by thermally expanding a commercial product followed by ultrasonication and solution-compounding with epoxy, and investigated their morphologies, mechanical properties, electrical conductivity and thermal mechanical behaviour. Graphene platelets (GnPs) of 3.57 ± 0.50 nm in thickness were created after the expanded product was dispersed in tetrahydrofuran using 60 min ultrasonication. Since epoxy resins cured by various hardeners are widely used in industries, we chose two common hardeners: polyoxypropylene (J230) and 4,4'-diaminodiphenylsulfone (DDS). DDS-cured nanocomposites showed a better dispersion and exfoliation of GnPs, a higher improvement (573%) in fracture energy release rate and a lower percolation threshold (0.612 vol%) for electrical conductivity, because DDS contains benzene groups which create π-π interactions with GnPs promoting a higher degree of dispersion and exfoliation of GnPs during curing. This research pointed out a potential trend where GnPs would replace carbon nanotubes and silicate layers for many applications of polymer nanocomposites.

2060 Chiron - Visual and thermal infrared observations

NASA Technical Reports Server (NTRS)

Lebofsky, L. A.; Tholen, D. J.; Rieke, G. H.; Lebofsky, M. J.

1984-01-01

Five-color (wavelength = 0.36-0.85 microns) and thermal infrared (wavelength = 22.5 microns) photometric observations of the unusual asteroid 2060 Chiron were made. Between 0.36 and 0.85 microns, Chiron's reflectance spectrum is similar to those of C-class asteroids as well as Saturn's satellite Phoebe. However, the thermal IR measurements imply an albedo greater than 0.05 (i.e., a diameter of less than 250 km at the 2-sigma level) that is probably higher than those of C-class asteroids or Phoebe.

Mechanized scaling with ultrasonics: Perils and proactive measures

PubMed Central

Paramashivaiah, Rashmi; Prabhuji, M. L. V

2013-01-01

Mechanized scaling for plaque removal is a routine procedure in the practice of periodontics. Though it appears innocuous by itself, there are retinues of hazards associated with it on various organ systems in the body. Some of these unwanted effects and measures to avoid or ameliorate the same are elaborated here. Exposure to ultrasonic scaling is inevitable before any other treatment procedure. Aerosol contamination, vibrational hazards, thermal effects on the dental pulp, altered vascular dynamics, disruption in electromagnetic device, diminished hearing and dental unit waterline contamination are some of the probable off-shoots a patient has to bear. Uses of barrier devices, proper attention to usage of equipment, protection for ear and water treatment are few of solutions for the same. Though documented evidence for the existence of all effects is lacking, it is never the less significant for the overall safety of the patient. A conscientious clinician should therefore inculcate the available steps to overcome the hazards of ultrasonic scaling. PMID:24174718

Enhanced Energy Localization in Hyperthermia Treatment Based on Hybrid Electromagnetic and Ultrasonic System: Proof of Concept with Numerical Simulations.

PubMed

Nizam-Uddin, N; Elshafiey, Ibrahim

2017-01-01

This paper proposes a hybrid hyperthermia treatment system, utilizing two noninvasive modalities for treating brain tumors. The proposed system depends on focusing electromagnetic (EM) and ultrasound (US) energies. The EM hyperthermia subsystem enhances energy localization by incorporating a multichannel wideband setting and coherent-phased-array technique. A genetic algorithm based optimization tool is developed to enhance the specific absorption rate (SAR) distribution by reducing hotspots and maximizing energy deposition at tumor regions. The treatment performance is also enhanced by augmenting an ultrasonic subsystem to allow focused energy deposition into deep tumors. The therapeutic faculty of ultrasonic energy is assessed by examining the control of mechanical alignment of transducer array elements. A time reversal (TR) approach is then investigated to address challenges in energy focus in both subsystems. Simulation results of the synergetic effect of both modalities assuming a simplified model of human head phantom demonstrate the feasibility of the proposed hybrid technique as a noninvasive tool for thermal treatment of brain tumors.

Ultrasonic-assisted Aqueous Extraction and Physicochemical Characterization of Oil from Clanis bilineata.

PubMed

Sun, Mingmei; Xu, Xiao; Zhang, Qiuqin; Rui, Xin; Wu, Junjun; Dong, Mingsheng

2018-02-01

Ultrasound-assisted aqueous extraction (UAAE) was used to extract oil from Clanis bilineata (CB), a traditional edible insect that can be reared on a large scale in China, and the physicochemical property and antioxidant capacity of the UAAE-derived oil (UAAEO) were investigated for the first time. UAAE conditions of CB oil was optimized using response surface methodology (RSM) and the highest oil yield (19.47%) was obtained under optimal conditions for ultrasonic power, extraction temperature, extraction time, and ultrasonic interval time at 400 W, 40°C, 50 min, and 2 s, respectively. Compared with Soxhlet extraction-derived oil (SEO), UAAEO had lower acid (AV), peroxide (PV) and p-anisidine values (PAV) as well as higher polyunsaturated fatty acids contents and thermal stability. Furthermore, UAAEO showed stronger antioxidant activities than those of SEO, according to DPPH radical scavenging and β-carotene bleaching tests. Therefore, UAAE is a promising process for the large-scale production of CB oil and CB has a developing potential as functional oil resource.

Enhanced Energy Localization in Hyperthermia Treatment Based on Hybrid Electromagnetic and Ultrasonic System: Proof of Concept with Numerical Simulations

PubMed Central

Elshafiey, Ibrahim

2017-01-01

This paper proposes a hybrid hyperthermia treatment system, utilizing two noninvasive modalities for treating brain tumors. The proposed system depends on focusing electromagnetic (EM) and ultrasound (US) energies. The EM hyperthermia subsystem enhances energy localization by incorporating a multichannel wideband setting and coherent-phased-array technique. A genetic algorithm based optimization tool is developed to enhance the specific absorption rate (SAR) distribution by reducing hotspots and maximizing energy deposition at tumor regions. The treatment performance is also enhanced by augmenting an ultrasonic subsystem to allow focused energy deposition into deep tumors. The therapeutic faculty of ultrasonic energy is assessed by examining the control of mechanical alignment of transducer array elements. A time reversal (TR) approach is then investigated to address challenges in energy focus in both subsystems. Simulation results of the synergetic effect of both modalities assuming a simplified model of human head phantom demonstrate the feasibility of the proposed hybrid technique as a noninvasive tool for thermal treatment of brain tumors. PMID:28840125

Combined investigation of Eddy current and ultrasonic techniques for composite materials NDE

NASA Technical Reports Server (NTRS)

Davis, C. W.; Nath, S.; Fulton, J. P.; Namkung, M.

1993-01-01

Advanced composites are not without trade-offs. Their increased designability brings an increase in the complexity of their internal geometry and, as a result, an increase in the number of failure modes associated with a defect. When two or more isotropic materials are combined in a composite, the isotropic material failure modes may also combine. In a laminate, matrix delamination, cracking and crazing, and voids and porosity, will often combine with fiber breakage, shattering, waviness, and separation to bring about ultimate structural failure. This combining of failure modes can result in defect boundaries of different sizes, corresponding to the failure of each structural component. This paper discusses a dual-technology NDE (Non Destructive Evaluation) (eddy current (EC) and ultrasonics (UT)) study of graphite/epoxy (gr/ep) laminate samples. Eddy current and ultrasonic raster (Cscan) imaging were used together to characterize the effects of mechanical impact damage, high temperature thermal damage and various types of inserts in gr/ep laminate samples of various stacking sequences.

Isolation and characterization of cellulose nanofibers from bamboo using microwave liquefaction combined with chemical treatment and ultrasonication.

PubMed

Xie, Jiulong; Hse, Chung-Yun; De Hoop, Cornelis F; Hu, Tingxing; Qi, Jinqiu; Shupe, Todd F

2016-10-20

Cellulose nanofibers were successfully isolated from bamboo using microwave liquefaction combined with chemical treatment and ultrasonic nanofibrillation processes. The microwave liquefaction could eliminate almost all the lignin in bamboo, resulting in high cellulose content residues within 7min, and the cellulose enriched residues could be readily purified by subsequent chemical treatments with lower chemical charging and quickly. The results of wet chemistry analyses, SEM images, and FTIR and X-ray spectra indicated the combination of microwave liquefaction and chemical treatment was significantly efficient in removing non-cellulosic compounds. Ultrasonication was used to separate the nanofibrils from the purified residues to extract nanofibers. The TEM images confirmed the presence of elementary fibrils, nano-sized fibril bundles, and aggregated fibril bundles. As evidenced by the TGA analysis, cellulose nanofibers isolated by this novel technique had high thermal stability indicating that the isolated nanofibers could possibly be applied as reinforcing elements in biomaterials. Copyright © 2016 Elsevier Ltd. All rights reserved.

University Physics Students' Ideas of Thermal Radiation Expressed in Open Laboratory Activities Using Infrared Cameras

ERIC Educational Resources Information Center

Haglund, Jesper; Melander, Emil; Weiszflog, Matthias; Andersson, Staffan

2017-01-01

Background: University physics students were engaged in open-ended thermodynamics laboratory activities with a focus on understanding a chosen phenomenon or the principle of laboratory apparatus, such as thermal radiation and a heat pump. Students had access to handheld infrared (IR) cameras for their investigations. Purpose: The purpose of the…

Tracking thermal-induced amorphization of a zeolitic imidazolate framework via synchrotron in situ far-infrared spectroscopy.

PubMed

Ryder, Matthew R; Bennett, Thomas D; Kelley, Chris S; Frogley, Mark D; Cinque, Gianfelice; Tan, Jin-Chong

2017-06-27

We present the first use of in situ far-infrared spectroscopy to analyze the thermal amorphization of a zeolitic imidazolate framework material. We explain the nature of vibrational motion changes during the amorphization process and reveal new insights into the effect that temperature has on the Zn-N tetrahedra.

Critical Technology Events in the Development of the Abrams Tank: Project Hindsight Revisited

DTIC Science & Technology

2005-12-01

recognizes the problems posed by an external APU and while awaiting an under - armor APU has added batteries to the M1A2 SEP to run the vehicle’s electronics...as the externally mounted Far Infrared Thermal Indicator and the first under - armor thermal viewer device (named the Far Infrared Periscope), were

Measuring fire spread rates from repeat pass airborne thermal infrared imagery

Treesearch

Douglas A. Stow; Philip J. Riggan; Emanual A. Storey; Lloyd L. Coulter

2014-01-01

The objective is to evaluate procedures for direct measurement of fire spread rates (FSRs) based on archived repeat pass airborne thermal infrared (ATIR) imagery and to identify requirements for more refined measurements of FSR and environmental factors that influence FSR. Flaming front positions are delineated on sequential FireMapper ATIR images captured at...

Retrieval of an available water-based soil moisture proxy from thermal infrared remote sensing. Part I: Methodology and validation

USDA-ARS?s Scientific Manuscript database

A retrieval of soil moisture is proposed using surface flux estimates from satellite-based thermal infrared (TIR) imagery and the Atmosphere-Land-Exchange-Inversion (ALEXI) model. The ability of ALEXI to provide valuable information about the partitioning of the surface energy budget, which can be l...

A facile sol-gel synthesis of impurity-free nanocrystalline titania.

PubMed

Vinogradov, Alexandr V; Ermakova, Al'ena V; Butman, Mikhail F; Hey-Hawkins, Evamarie; Vinogradov, Vladimir V

2014-06-14

This paper reports an original technique that provides a highly pure crystalline sol of titania with controllable particle size by ultrasonic activation of the hydrolysis products of titanium isopropoxide in an aqueous medium at a near-neutral pH, which is potentially promising in impurity-sensitive electronics and biochemical engineering. Optimal conditions (H2O/TIP ratio, sonication time, etc.) for preparation of stable nanocrystalline titania sol were adopted. A new mechanism of regulation of aggregation and polycondensation under ultrasonic irradiation is proposed. Entrapment of human serum albumin (HSA) in the formed porous titania matrix results in high thermal stability of the protein dopants: the denaturation temperature of HSA is shifted by 31 °C.

Infrared Imaging; A casebook in clinical medicine

NASA Astrophysics Data System (ADS)

Ring, Francis

2015-09-01

Infrared thermal imaging is a rapid and non-invasive procedure for mapping skin temperature distribution of the human body. Advanced software and high-resolution infrared detectors has allowed for a renaissance in the use of infrared thermal imaging or thermography in medical research and practice. After a review of theory, technology and methodology of medical infrared imaging, the remainder of the book consists of a collection of clinical case studies demonstrating the wide variety of applications of thermography in modern medicine. The combined expertise from a number of centres is used to create this database of images and cases that will be invaluable for medical researchers and practitioners in making diagnoses and measuring treatment efficacy. This book is recommended reading for practising and training radiographers, medical physicists and clinicians.

Thermography Inspection for Early Detection of Composite Damage in Structures During Fatigue Loading

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Burke, Eric R.; Parker, F. Raymond; Seebo, Jeffrey P.; Wright, Christopher W.; Bly, James B.

2012-01-01

Advanced composite structures are commonly tested under controlled loading. Understanding the initiation and progression of composite damage under load is critical for validating design concepts and structural analysis tools. Thermal nondestructive evaluation (NDE) is used to detect and characterize damage in composite structures during fatigue loading. A difference image processing algorithm is demonstrated to enhance damage detection and characterization by removing thermal variations not associated with defects. In addition, a one-dimensional multilayered thermal model is used to characterize damage. Lastly, the thermography results are compared to other inspections such as non-immersion ultrasonic inspections and computed tomography X-ray.

Employment of ultrasonic irradiation for production of poly(vinyl pyrrolidone)/modified alpha manganese dioxide nanocomposites: Morphology, thermal and optical characterization.

PubMed

Mallakpour, Shadpour; Abdolmaleki, Amir; Tabebordbar, Hashem

2018-03-01

This work explains the production, morphology, and features of novel nanocomposite (NC) established on poly(vinyl pyrrolidone) (PVP) as polymer background and modified alpha manganese dioxide (α-MnO 2 ) nanorod (NR) asan efficient filler. At first, one-dimensional α-MnO 2 nanorods (NRs) were produced by a hydrothermal technique and then they were amended with stearic acid (SA) by a solvothermal process. In following, the NCs were made by adding different volumes of α-MnO 2 -SA NR (1, 3 and 5wt%) in the PVP matrix through ultrasonic irradiation as a green, low-cost, fast, and useful technique. Structural and morphological descriptions confirm crystallinity of α-MnO 2 -SA NRs and showed that NRs have been separately dispersed in PVP matrix with rod-like morphology and diameter of about 40-60nm. The use of modifier and ultrasonic waves is accountable for good homogeneities of NRs. Thermogravimetric analysis revealed that thermal permanency of the obtained NCs has grown with increasing the α-MnO 2 -SA content. Also, the UV-vis absorption of NCs was enhanced with the incorporation of the modified α-MnO 2 NR in PVP matrix. The substantial perfections in NCs properties are associated to compatible intermolecular relations between the surface modifying groups of the α-MnO 2 -SA and PVP chain. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal infrared remote sensing of surface features for renewable resource applications

NASA Technical Reports Server (NTRS)

Welker, J. E.

1981-01-01

The subjects of infrared remote sensing of surface features for renewable resource applications is reviewed with respect to the basic physical concepts involved at the Earth's surface and up through the atmosphere, as well as the historical development of satellite systems which produce such data at increasingly greater spatial resolution. With this general background in hand, the growth of a variety of specific renewable resource applications using the developing thermal infrared technology are discussed, including data from HCMM investigators. Recommendations are made for continued growth in this field of applications.

Applications of TIMS data in agricultural areas and related atmospheric considerations

NASA Technical Reports Server (NTRS)

Pelletier, R. E.; Ochoa, M. C.

1986-01-01

While much of traditional remote sensing in agricultural research was limited to the visible and reflective infrared, advances in thermal infrared remote sensing technology are adding a dimension to digital image analysis of agricultural areas. The Thermal Infrared Multispectral Scanner (TIMS) an airborne sensor having six bands over the nominal 8.2 to 12.2 m range, offers the ability to calculate land surface emissivities unlike most previous singular broadband sensors. Preliminary findings on the utility of the TIMS for several agricultural applications and related atmospheric considerations are discussed.

Ocean properties

NASA Technical Reports Server (NTRS)

Korb, C. L.; Potter, J. F. (Principal Investigator)

1976-01-01

The author has identified the following significant results. Results of testing the CP program indicate that the best results can be obtained in the near infrared water bands. The absorption due to water vapor and carbon dioxide in the thermal infrared band appeared to be less reliable in comparison to spacecraft-acquired data and band models. Comparisons of laboratory carbon dioxide transmission in the thermal infrared band show good agreement except in regions where lines are known to be missing. The comparison of ozone transmission at a wavelength of 9.6 micrometers to laboratory data showed unexceptedly large differences.

Detection and mapping of volcanic rock assemblages and associated hydrothermal alteration with Thermal Infrared Multiband Scanner (TIMS) data Comstock Lode Mining District, Virginia City, Nevada

NASA Technical Reports Server (NTRS)

Taranik, James V.; Hutsinpiller, Amy; Borengasser, Marcus

1986-01-01

Thermal Infrared Multispectral Scanner (TIMS) data were acquired over the Virginia City area on September 12, 1984. The data were acquired at approximately 1130 hours local time (1723 IRIG). The TIMS data were analyzed using both photointerpretation and digital processing techniques. Karhuen-Loeve transformations were utilized to display variations in radiant spectral emittance. The TIMS image data were compared with color infrared metric camera photography, LANDSAT Thematic Mapper (TM) data, and key areas were photographed in the field.

Infrared Technology Trends and Implications to Home and Building Energy Use Efficiency

NASA Astrophysics Data System (ADS)

Woolaway, James T.

2008-09-01

It has long been realized that infrared technology would have applicability in improving the energy efficiency of homes and buildings. Walls that are missing or are poorly insulated can be quickly evaluated by looking at the thermal images of these surfaces. Similarly, air infiltration leaks under doors and around windows leave a telltale thermal signature easily seen in the infrared. The ability to view, evaluate and quickly respond to these images has immediate benefits in addressing and correcting situations where these types of losses are occurring. The principle issue that has been limiting the use of infrared technology in these applications has been the lack of availability and accessibility of infrared technology at a cost point suited to this market. The emergence of low cost microbolometer based infrared cameras, not needing sensor cooling, will greatly increase the accessibility and use of infrared technology for House Doctor inspections. The technology cost for this use is projected to be less than 1 per inspection.

A study of thermographic diagnosis system and imaging algorithm by distributed thermal data using single infrared sensor.

PubMed

Yoon, Se Jin; Noh, Si Cheol; Choi, Heung Ho

2007-01-01

The infrared diagnosis device provides two-dimensional images and patient-oriented results that can be easily understood by the inspection target by using infrared cameras; however, it has disadvantages such as large size, high price, and inconvenient maintenance. In this regard, this study has proposed small-sized diagnosis device for body heat using a single infrared sensor and implemented an infrared detection system using a single infrared sensor and an algorithm that represents thermography using the obtained data on the temperature of the point source. The developed systems had the temperature resolution of 0.1 degree and the reproducibility of +/-0.1 degree. The accuracy was 90.39% at the error bound of +/-0 degree and 99.98% at that of +/-0.1 degree. In order to evaluate the proposed algorithm and system, the infrared images of camera method was compared. The thermal images that have clinical meaning were obtained from a patient who has lesion to verify its clinical applicability.

Infrared and infrared emission spectroscopic study of typical Chinese kaolinite and halloysite.

PubMed

Cheng, Hongfei; Frost, Ray L; Yang, Jing; Liu, Qinfu; He, Junkai

2010-12-01

The structure and thermal stability between typical Chinese kaolinite and halloysite were analysed by X-ray diffraction (XRD), infrared spectroscopy, infrared emission spectroscopy (IES) and Raman spectroscopy. Infrared emission spectroscopy over the temperature range of 300-700°C has been used to characterise the thermal decomposition of both kaolinite and halloysite. Halloysite is characterised by two bands in the water bending region at 1629 and 1648 cm(-1), attributed to structural water and coordinated water in the interlayer. Well defined hydroxyl stretching bands at around 3695, 3679, 3652 and 3625 cm(-1) are observed for both kaolinite and halloysite. The 550°C infrared emission spectrum of halloysite is similar to that of kaolinite in 650-1350 cm(-1) spectral region. The infrared emission spectra of halloysite were found to be considerably different to that of kaolinite at lower temperatures. These differences are attributed to the fundamental difference in the structure of the two minerals. Copyright © 2010 Elsevier B.V. All rights reserved.

Analysis of temperature rise and the use of coolants in the dissipation of ultrasonic heat buildup during post removal.

PubMed

Davis, Stephen; Gluskin, Alan H; Livingood, Philip M; Chambers, David W

2010-11-01

This study was designed to calculate probabilities for tissue injury and to measure effectiveness of various coolant strategies in countering heat buildup produced by dry ultrasonic vibration during post removal. A simulated biological model was used to evaluate the cooling efficacy of a common refrigerant spray, water spray, and air spray in the recovery of post temperatures deep within the root canal space. The data set consisted of cervical and apical measures of temperature increase at 1-second intervals from baseline during continuous ultrasonic instrumentation until a 10 °C increase in temperature at the cervical site was registered, wherein instrumentation ceased, and the teeth were allowed to cool under ambient conditions or with the assistance of 4 coolant methods. Data were analyzed with analysis of variance by using the independent variables of time of ultrasonic application (10, 15, 20 seconds) and cooling method. In addition to the customary means, standard deviations, and analysis of variance tests, analyses were conducted to determine probabilities that procedures would reach or exceed the 10 °C threshold. Both instrumentation time and cooling agent effects were significant at P <.0001. Under the conditions of this study, it was shown that injurious heat transfer occurs in less than 1 minute during dry ultrasonic instrumentation of metallic posts. Cycles of short instrumentation times with active coolants were effective in reducing the probability of tissue damage when teeth were instrumented dry. With as little as 20 seconds of continuous dry ultrasonic instrumentation, the consequences of thermal buildup to an individual tooth might contribute to an injurious clinical outcome. Copyright © 2010 American Association of Endodontists. All rights reserved.

Cold Pad-Batch dyeing method for cotton fabric dyeing with reactive dyes using ultrasonic energy.

PubMed

Khatri, Zeeshan; Memon, Muhammad Hanif; Khatri, Awais; Tanwari, Anwaruddin

2011-11-01

Reactive dyes are vastly used in dyeing and printing of cotton fibre. These dyes have a distinctive reactive nature due to active groups which form covalent bonds with -OH groups of cotton through substitution and/or addition mechanism. Among many methods used for dyeing cotton with reactive dyes, the Cold Pad Batch (CPB) method is relatively more environment friendly due to high dye fixation and non requirement of thermal energy. The dyed fabric production rate is low due to requirement of at least twelve hours batching time for dye fixation. The proposed CPB method for dyeing cotton involves ultrasonic energy resulting into a one third decrease in batching time. The dyeing of cotton fibre was carried out with CI reactive red 195 and CI reactive black 5 by conventional and ultrasonic (US) method. The study showed that the use of ultrasonic energy not only shortens the batching time but the alkalis concentrations can considerably be reduced. In this case, the colour strength (K/S) and dye fixation (%F) also enhances without any adverse effect on colour fastness of the dyed fabric. The appearance of dyed fibre surface using scanning electron microscope (SEM) showed relative straightening of fibre convolutions and significant swelling of the fibre upon ultrasonic application. The total colour difference values ΔE (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample. Copyright © 2011 Elsevier B.V. All rights reserved.

Characterization of drinking water treatment sludge after ultrasound treatment.

PubMed

Zhou, Zhiwei; Yang, Yanling; Li, Xing; Zhang, Yang; Guo, Xuan

2015-05-01

Ultrasonic technology alone or the combination of ultrasound with alkaline or thermal hydrolysis as pretreatment for anaerobic digestion of activated sludge has been extensively documented. However, there are few reports on ultrasound as pretreatment of drinking water treatment sludge (DWTS), and thereby the characteristic variability of sonicated DWTS has not been fully examined. This research presents a lab-scale study on physical, chemical and biological characteristics of a DWTS sample collected from a water plant after ultrasonic treatment via a bath/probe sonoreactor. By doing this work, we provide implications for using ultrasound as pretreatment of enhanced coagulation of recycling sludge, and for the conditioning of water and wastewater mixed sludge by ultrasound combined with polymers. Our results indicate that the most vigorous DWTS disintegration quantified by particles' size reduction and organic solubilization is achieved with 5 W/ml for 30 min ultra-sonication (specific energy of 1590 kWh/kg TS). The Brunauer, Emmett and Teller (BET) specific surface area of sonicated DWTS flocs increase as ultra-sonication prolongs at lower energy densities (0.03 and 1 W/ml), while decrease as ultra-sonication prolongs at higher energy densities (3 and 5 W/ml). Additionally, the pH and zeta potential of sonicated DWTS slightly varies under all conditions observed. A shorter sonication with higher energy density plays a more effective role in restraining microbial activity than longer sonication with lower energy density. Copyright © 2015. Published by Elsevier B.V.

NEAR-INFRARED THERMAL EMISSION DETECTIONS OF A NUMBER OF HOT JUPITERS AND THE SYSTEMATICS OF GROUND-BASED NEAR-INFRARED PHOTOMETRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croll, Bryce; Albert, Loic; Lafreniere, David

We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K {sub CONT}-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so asmore » to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations.« less

Feasibility of Inspection of Fungicidal Finishes on Textiles by X-Ray, Infrared and Ultrasonic Methods

DTIC Science & Technology

1989-08-01

spectrum computed as a function of wavelength . 25 This particular sample is calculated at an anode voltage of 43 kv, wifci a beam take-off of 20...distribution between different types of specimens indicates that a partial treatment will be easily detected , as long as the distribution within a type...inspection requirements under reasonable assumptions. In a production system meant to detect and measure not only misfeasance, but clever and

Multi-Sensory Features for Personnel Detection at Border Crossings

DTIC Science & Technology

2011-07-08

challenging problem. Video sensors consume high amounts of power and require a large volume for storage. Hence, it is preferable to use non- imaging sensors...temporal distribution of gait beats [5]. At border crossings, animals such as mules, horses, or donkeys are often known to carry loads. Animal hoof...field, passive ultrasonic, sonar, and both infrared and visi- ble video sensors. Each sensor suite is placed along the path with a spacing of 40 to

Evaluation of thermal data for geologic applications

NASA Technical Reports Server (NTRS)

Kahle, A. B.; Palluconi, F. D.; Levine, C. J.; Abrams, M. J.; Nash, D. B.; Alley, R. E.; Schieldge, J. P.

1982-01-01

Sensitivity studies using thermal models indicated sources of errors in the determination of thermal inertia from HCMM data. Apparent thermal inertia, with only simple atmospheric radiance corrections to the measured surface temperature, would be sufficient for most operational requirements for surface thermal inertia. Thermal data does have additional information about the nature of surface material that is not available in visible and near infrared reflectance data. Color composites of daytime temperature, nighttime temperature, and albedo were often more useful than thermal inertia images alone for discrimination of lithologic boundaries. A modeling study, using the annual heating cycle, indicated the feasibility of looking for geologic features buried under as much as a meter of alluvial material. The spatial resolution of HCMM data is a major limiting factor in the usefulness of the data for geologic applications. Future thermal infrared satellite sensors should provide spatial resolution comparable to that of the LANDSAT data.

Emirates Mars Infrared Spectrometer (EMIRS) Overview from the Emirates Mars Mission

NASA Astrophysics Data System (ADS)

Altunaiji, Eman; Edwards, Christopher; Smith, Michael; Christensen, Philip; AlMheiri, Suhail; Reed, Heather

2017-04-01

Emirates Mars Infrared Spectrometer (EMIRS) instrument is one of three scientific instruments aboard the Emirate Mars Mission (EMM), with the name of "Hope". EMM is United Arab Emirates' (UAE) mission to be launched in 2020, with the aim of exploring the dynamics of the atmosphere of Mars on a global scale with sampling on a diurnal and sub-seasonal time-scales. EMM has three scientific instruments selected to provide an improved understanding of circulation and weather in the Martian lower atmosphere as well as the thermosphere and exosphere. The EMIRS instrument is an interferometric thermal infrared spectrometer that is jointly developed by Arizona State University (ASU) and Mohammed Bin Rashid Space Centre (MBRSC), Dubai, UAE. It builds on a long heritage of thermal infrared spectrometers designed, built, and managed, by ASU's Mars Space Flight Facility, including the Thermal Emission Spectrometer (TES), Miniature Thermal Emission Spectrometer (Mini-TES), and the OSIRIS-REx Thermal Emission Spectrometer (OTES). EMIRS operates in the 6-40+ μm range with 5 cm-1 spectral sampling, enabled by a Chemical Vapor-Deposited (CVD) diamond beam splitter and state of the art electronics. This instrument utilizes a 3×3 line array detector and a scan mirror to make high-precision infrared radiance measurements over most of the Martian hemisphere. The EMIRS instrument is optimized to capture the integrated, lower-middle atmosphere dynamics over a Martian hemisphere, using a scan-mirror to make 60 global images per week ( 20 images per orbit) at a resolution of 100-300 km/pixel while requiring no special spacecraft maneuvers.

A highly efficient CMOS nanoplasmonic crystal enhanced slow-wave thermal emitter improves infrared gas-sensing devices

PubMed Central

Pusch, Andreas; De Luca, Andrea; Oh, Sang S.; Wuestner, Sebastian; Roschuk, Tyler; Chen, Yiguo; Boual, Sophie; Ali, Zeeshan; Phillips, Chris C.; Hong, Minghui; Maier, Stefan A.; Udrea, Florin; Hopper, Richard H.; Hess, Ortwin

2015-01-01

The application of plasmonics to thermal emitters is generally assisted by absorptive losses in the metal because Kirchhoff’s law prescribes that only good absorbers make good thermal emitters. Based on a designed plasmonic crystal and exploiting a slow-wave lattice resonance and spontaneous thermal plasmon emission, we engineer a tungsten-based thermal emitter, fabricated in an industrial CMOS process, and demonstrate its markedly improved practical use in a prototype non-dispersive infrared (NDIR) gas-sensing device. We show that the emission intensity of the thermal emitter at the CO2 absorption wavelength is enhanced almost 4-fold compared to a standard non-plasmonic emitter, which enables a proportionate increase in the signal-to-noise ratio of the CO2 gas sensor. PMID:26639902

Mapping TES Aerobreaking Data of The Martian Polar Caps

NASA Astrophysics Data System (ADS)

Altunaiji, E. S.; Edwards, C. S.; Smith, M. D.; AlShamsi, M. R.; AlJanaahi, A. A.

2016-12-01

The purpose of this paper is to create maps of the north and south Mars polar caps using Thermal Emission Spectrometer (TES) aerobreaking surface temperature data in south and north as well as Lambert albedo data in the south. TES is an instrument on board the Mars Global Surveyor (MGS) spacecraft. It has six detectors arranged in a 2x3 array with a nominal spot size of 3 × 6 km; however, given the elliptical nature of the orbit during aerobreaking the footprint can be significantly larger (10s of km), especially over the southern hemisphere. TES is a Fourier transform infrared spectrometer designed to study the Martian surface and atmosphere using thermal infrared emission spectroscopy. It is composed of 2 separate channels, a broadband visible/near-infrared bolometer and hyperspectral thermal infrared spectrometer with a broadband thermal infrared bolometer. TES aerobraking spectra were taken between Mars Year 23, Ls=180° and Mars Year 24, Ls=30°. To determine the footprint location on the surface, geometry is calculated using the Spacecraft Planet Instrument Camera Matrix and Event (SPICE) Toolkit. These data were then binned and mapped to surface in polar stereographic projection. While some early studies focused on these data, we have expanded upon the ranges, generated time-/seasonally-binned data, and re-examined this largely underutilized set of data from TES ultimately extending the record of polar science on Mars.

Soil moisture inferences from thermal infrared measurements of vegetation temperatures

NASA Technical Reports Server (NTRS)

Jackson, R. D. (Principal Investigator)

1981-01-01

Thermal infrared measurements of wheat (Triticum durum) canopy temperatures were used in a crop water stress index to infer root zone soil moisture. Results indicated that one time plant temperature measurement cannot produce precise estimates of root zone soil moisture due to complicating plant factors. Plant temperature measurements do yield useful qualitative information concerning soil moisture and plant condition.

Impact of atmospheric water vapor on the thermal infrared remote sensing of volcanic sufur dioxide emmisions: A case study from Pu'u 'O'o vent of Kilauea volcano, Hawaii

NASA Technical Reports Server (NTRS)

Realmuto, V. J.; Worden, H. M.

2000-01-01

The December 18, 1999, launch of NASA's Terra satellite put two multispectral thermal infrared imaging instruments into Earth orbit. Experiments with airborne instruments have demonstrated that the data from such instruments can be used to detect volcanic SO2 plumes and clouds.

Multispectral Thermal Infrared Mapping of Sulfur Dioxide Plumes: A Case Study from the East Rift Zone of Kilauea Volcano, Hawaii

NASA Technical Reports Server (NTRS)

Realmuto, V. J.; Sutton, A. J.; Elias, T.

1996-01-01

The synoptic perspective and rapid mode of data acquisition provided by remote sensing are well-suited for the study of volcanic SO2 plumes. In this paper we describe a plume-mapping procedure that is based on image data acquired with NASA's airborne Thermal Infrared Multispectral Scanner (TIMS).

Infra-red lamp panel study and assessment application to thermal vacuum testing of sigma telescope

NASA Technical Reports Server (NTRS)

Mauduyt, Jacques; Merlet, Joseph; Poux, Christiane

1986-01-01

A research and development program of the Infra-Red Test has been conducted by the French Space Agency (CNES). A choice, after characterization, among several possibilities has been made on the type of methods and facilities for the I.R. test. An application to the Thermal Vacuum Test of the SIGMA Telescope is described.

Carbon nanotube composites prepared by ultrasonically assisted twin screw extrusion

NASA Astrophysics Data System (ADS)

Lewis, Todd

Two ultrasonic twin screw extrusion systems were designed and manufactured for the ultrasonic dispersion of multi-walled carbon nanotubes in viscous polymer matrices at residence times of the order of seconds in the ultrasonic treatment zones. The first design consisted of an ultrasonic slit die attachment in which nanocomposites were treated. A second design incorporated an ultrasonic treatment section into the barrel of the extruder to utilize the shearing of the polymer during extrusion while simultaneously applying treatment. High performance, high temperature thermoset phenylethynyl terminate imide oligomer (PETI-330) and two different polyetherether ketones (PEEK) were evaluated at CNT loadings up to 10 wt%. The effects of CNT loading and ultrasonic amplitude on the processing characteristics and rheological, mechanical, electrical, thermal and morphological properties of nanocomposites were investigated. PETI and PEEK nanocomposites showed a decrease in resistivity, an increase in modulus and strength and a decrease in strain at break and toughness with increased CNT loading. Ultrasonically treated samples showed a decrease in die pressure and extruder torque with increasing ultrasonic treatment and an increase in complex viscosity and storage modulus at certain ultrasonic treatment levels. Optical microscopy showed enhanced dispersion of the CNT bundles in ultrasonically treated samples. However, no significant improvement of mechanical properties was observed with ultrasonic treatment due to lack of adhesion between the CNT and matrix in the solid state. A curing model for PETI-330 was proposed that includes the induction and curing stages to predict the degree of cure of PETI-330 under non-isothermal conditions. Induction time parameters, rate constant and reaction order of the model were obtained based on differential scanning calorimetry (DSC) data. The model correctly predicted experimentally measured degrees of cure of compression molded plaques cured to various degrees. An apparatus for high temperature resin transfer molding (HT-RTM) was designed and built to produce PETI-8 and PETI-330/carbon fabric composite panels. Performance of the panels was tested at various temperatures. The produced panels exhibited low void content in wetted areas and had higher short beam shear properties in comparison with vacuum assisted resin transfer moldings. To investigate the environmental aspects of nanomaterials, a testing apparatus was designed and manufactured to study the effectiveness of particulate respirators at filtering CNTs. Three different grades of respirators were evaluated for their effectiveness to prevent the inhalation of CNTs. Dust masks, commonly used in a processing environment, were found to be highly ineffective at preventing the inhalation of CNTs. However, respirators with a National Institute for Occupational Safety and Health (NIOSH) rating of P95 or greater were shown to prevent the inhalation of CNTs under normal breathing conditions.

Poly(vinyl alcohol) films reinforced with nanofibrillated cellulose (NFC) isolated from corn husk by high intensity ultrasonication.

PubMed

Xiao, Shaoliang; Gao, Runan; Gao, LiKun; Li, Jian

2016-01-20

This work was aimed at fabricating and characterizing poly(vinyl alcohol) films that were reinforced by nanofibrillated corn husk celluloses using a combination of chemical pretreatments and ultrasonication. The obtained nanofibrillated celluloses (NFCs) possessed a narrow width ranging from 50 to 250 nm and a high aspect ratio (394). The crystalline type of NFC was cellulose I type. Compared with the original corn husks, the NCF crystallinity and thermal stability increased due to the removal of the hemicelluloses and lignin. PVA films containing different NFC concentrations (0.5%, 1%, 3%, 5%, 7% and 9%, w/w, dry basis) were examined. The 1% PVA/NFC reinforced films exhibited a highly visible light transmittance of 80%, and its tensile strength and the tensile strain at break were increased by 1.47 and 1.80 times compared to that of the pure PVA film, respectively. The NFC with high aspect ratio and high crystallinity is beneficial to the improvement of the mechanical strength and thermal stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Piezoelectric Sol-Gel Composite Film Fabrication by Stencil Printing.

PubMed

Kaneko, Tsukasa; Iwata, Kazuki; Kobayashi, Makiko

2015-09-01

Piezoelectric films using sol-gel composites could be useful as ultrasonic transducers in various industrial fields. For sol-gel composite film fabrication, the spray coating technique has been used often because of its adaptability for various substrates. However, the spray technique requires multiple spray coating processes and heating processes and this is an issue of concern, especially for on-site fabrication in controlled areas. Stencil printing has been developed to solve this issue because this method can be used to fabricate thick sol-gel composite films with one coating process. In this study, PbTiO3 (PT)/Pb(Zr,Ti)O3 (PZT) films, PZT/PZT films, and Bi4Ti3O12 (BiT)/PZT films were fabricated by stencil printing, and PT/ PZT films were also fabricated using the spray technique. After fabrication, a thermal cycle test was performed for the samples to compare their ultrasonic performance. The sensitivity and signal-to-noise-ratio (SNR) of the ultrasonic response of PT/PZT fabricated by stencil printing were equivalent to those of PT/PZT fabricated by the spray technique, and better than those of other samples between room temperature and 300°C. Therefore, PT/PZT films fabricated by stencil printing could be a good candidate for nondestructive testing (NDT) ultrasonic transducers from room temperature to 300°C.

Thermal Conductivity on the Nanofluid of Graphene and Silver Nanoparticles Composite Material.

PubMed

Myekhlai, Munkhshur; Lee, Taejin; Baatar, Battsengel; Chung, Hanshik; Jeong, Hyomin

2016-02-01

The composite material consisted of graphene (GN) and silver nanoparticles (AgNPs) has been essential topic in science and industry due to its unique thermal, electrical and antibacterial proper- ties. However, there are scarcity studies based on their thermal properties of nanofluids. Therefore, GN-AgNPs composite material was synthesized using facile and environment friendly method and further nanofluids were prepared by ultrasonication in this study. The morphological and structural investigations were carried out using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) as well as ultra violet (UV)-visible spectroscopy. Furthermore, thermal conductivity measurements were performed for as-prepared nanofluids. As a result of thermal conductivity study, GN-AgNPs composite material was considerably enhanced the thermal conductivity of base fluid (water) by to 6.59% for the nanofluid (0.2 wt% GN and 0.4 wt% AgNPs).