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Existing research on pavement interlayer bonding has mainly focused on bonding materials and external factors, neglecting the upper and lower interlayer surface characteristics. This study aims to analyze the contact conditions between these surfaces, developing a numerical model to reveal their properties. Five double-layered asphalt systems, including dense-graded asphalt concrete (AC), open-graded friction course (OGFC), and stone mastic asphalt (SMA) mixes, were examined using a nondestructive interlayer separation method and 3D laser scanning. Three indices were proposed to assess interlayer surface characteristics in both 2D and 3D domains. Shear strength tests at room temperature were also conducted, revealing that AC-only systems had lower surface mismatch at the layer interface compared to SMA or OGFC mixes. The study concludes that surface mismatch decreases with greater differences in aggregate coarseness, and systems with significant mismatch gaps have lower shear strength. These findings provide valuable insights for designing durable pavement structures. [ABSTRACT FROM AUTHOR]

The physical principles motivating the Z-scanning laser photoreflectance technique are discussed. The technique is shown to provide a powerful non-contact means to unambiguously characterize electronic transport properties in semiconductors. The technique does not require modeling of charge transport in the sample or a detailed theoretical model for the sample physics. Rather, the measurement protocol follows directly from the simple relation describing the radial diffusion of carriers injected by a laser source. The use of a probe laser beam permits an analytic parametrization for the Z dependence of the photoreflectance signal which depends solely on the focal parameters and the carrier diffusion length. This allows electronic transport properties to be determined with high precision using a nonlinear least squares fit procedure. The practical use of the technique is illustrated by the characterization of carrier transport properties in semiconducting p-n junctions. [ABSTRACT FROM AUTHOR]

Two geometries of acoustic loop filters side-loaded onto waveguides are explored using audio-frequency impulse response measurements. Finite element modeling is used to elucidate the interference mechanisms in each loop filter configuration. These simulations also yield transmission amplitude results, which are in good agreement with those determined experimentally. The ability to create broad forbidden transmission regions is demonstrated by the use of a sub-wavelength spaced series of slightly detuned filters. Finally, the phase information from the impulse response measurements is analyzed to show that regions of negative bulk modulus exist at frequencies in the vicinity of the loop interference minima. [ABSTRACT FROM AUTHOR]

A thick Cu column based double-bump flip chip structure is one of the promising alternatives for fine pitch flip chip applications. In this study, the thermal cycling (T/C) reliability of Cu/SnAg double-bump flip chip assemblies was investigated, and the failure mechanism was analyzed through the correlation of T/C test and the finite element analysis (FEA) results. After 1000 thermal cycles, T/C failures occurred at some Cu/SnAg bumps located at the edge and corner of chips. Scanning acoustic microscope analysis and scanning electron microscope observations indicated that the failure site was the Cu column/Si chip interface. It was identified by a FEA where the maximum stress concentration was located during T/C. During T/C, the Al pad between the Si chip and a Cu column bump was displaced due to thermomechanical stress. Based on the low cycle fatigue model, the accumulation of equivalent plastic strain resulted in thermal fatigue deformation of the Cu column bumps and ultimately reduced the thermal cycling lifetime. The maximum equivalent plastic strains of some bumps at the chip edge increased with an increased number of thermal cycles. However, equivalent plastic strains of the inner bumps did not increase regardless of the number of thermal cycles. In addition, the z-directional normal plastic strain [variant_greek_epsilon]22 was determined to be compressive and was a dominant component causing the plastic deformation of Cu/SnAg double bumps. As the number of thermal cycles increased, normal plastic strains in the perpendicular direction to the Si chip and shear strains were accumulated on the Cu column bumps at the chip edge at low temperature region. Thus it was found that the Al pad at the Si chip/Cu column interface underwent thermal fatigue deformation by compressive normal strain and the contact loss by displacement failure of the Al pad, the main T/C failure mode of the Cu/SnAg flip chip assembly, then occurred at the Si chip/Cu column interface shear strain deformation during T/C. [ABSTRACT FROM AUTHOR]

We present a near-eye augmented reality display with resolution and focal depth dynamically driven by gaze tracking. The display combines a traveling microdisplay relayed off a concave half-mirror magnifier for the high-resolution foveal region, with a wide field-of-view peripheral display using a projector-based Maxwellian-view display whose nodal point is translated to follow the viewer's pupil during eye movements using a traveling holographic optical element. The same optics relay an image of the eye to an infrared camera used for gaze tracking, which in turn drives the foveal display location and peripheral nodal point. Our display supports accommodation cues by varying the focal depth of the microdisplay in the foveal region, and by rendering simulated defocus on the "always in focus" scanning laser projector used for peripheral display. The resulting family of displays significantly improves on the field-of-view, resolution, and form-factor tradeoff present in previous augmented reality designs. We show prototypes supporting 30, 40 and 60 cpd foveal resolution at a net 85° × 78° field of view per eye. [ABSTRACT FROM AUTHOR]

Abstract A direct microscopic time-lapse method, using appropriate staining for cell viability in a confocal scanning laser microscope, was used for the direct assessment of Salmonella Agona individual cell inactivation in small two-dimensional colonies exposed to osmotic stress. Individual cell inactivation times were fitted to a variety of continuous distributions using @Risk software. The best fitted distribution (LogLogistic) was further used to predict the inactivation of Salmonella populations of various initial levels using Monte Carlo simulation. The simulation results showed that the variability in inactivation kinetics is negligible for concentrations down to 100 cells and the population behavior can be described with a deterministic model. As the concentration decreases below 100 cells, however, the variability increases significantly indicating that the traditional D -value used in deterministic first order kinetic models is not valid. At a second stage, single cell behavior was monitored in larger three dimensional colonies. The results showed that colony size can affect the inactivation pattern. The effect of colony size on microbial inactivation was confirmed with validation experiments which showed a higher inactivation rate for populations consisting of single cells or small colonies compared to those consisting of cells organized in larger colonies. Highlights • Salmonella single cells inactivation time was studied using time-lapse microscopy. • Single cell inactivation time is highly heterogeneous. • Single cell death time constitutes a source of biological variability in inactivation. • Colony size can affect the inactivation pattern and the distribution of death times. [ABSTRACT FROM AUTHOR]

Abstract: The problem of the development of an adjustable video-spectrometer unit based on an acousto-optic tunable filter has been considered. This unit is embedded into an optical system of microscopes for hyperspectral analysis of microscopic objects. For this purpose, light-energy conjugation of the filter with microscopes is performed. We have calculated the conjugating optical system, which yields an equality of field of view for a wideband and spectral channel. The experimental model of the developed device has been described. Examples of detection for test objects and histological sections along with the calculation results of the spectral parameters for various skin tissues are given. The developed video-spectrometer unit considerably extends the functionality of microscopes and can be widely used to solve various problems of biomedical diagnostics. [ABSTRACT FROM AUTHOR]

Presents a study which constructed a micron wavelength acoustic microscope for the observation of third-order nonlinear products. Information on how the micron wavelength acoustic microscope works; Instrument characteristics; Results of observations.

Presents information on a study which described strain-imaging observation of a lead-zirconate-titanate film using a tunneling acoustic microscope. Methodology of the study; Results and discussion; Conclusion.

Presents an acoustic microscope using pressurized superfluid [sup4]He. Description of the experiment apparatus; Performance of the Z positioner; Information on the nonlinear behavior of received signals.

Presents a study that described the measurement of the velocity and power flow angle of surface waves using a scanning laser acoustic microscope. Measurement of saw slowness curves; Data processing; Results and discussion.

The article explores the application of gigahertz-scanning acoustic microscopy (GHz-SAM) in electronic failure analysis. It discusses three case studies that includes the use of GHz-SAM for detecting sub-micron voids on thin power metal lines, inspecting wire bond interfaces, and forming electrical interconnections by direct routing through the silicon material by through-silicon vias (TSV).

A new measurement procedure is proposed to assess the airborne sound insulation of a partition under diffuse sound field excitation using mobility measurements combined with a numerical procedure. The advantage of this hybrid approach is that the diffuse acoustic field does not need to be physically created, thus avoiding problems related to the generation of such fields at low frequencies. Furthermore, the acoustic properties of both the source and receiving rooms will not affect the determination of the sound reduction index R . The proposed method is especially suited for frequencies below the so called Schroeder frequency of the room, and is complementary to the standardized measurement approaches as described in ISO 10140-2:2010. The measurement part of the proposed procedure involves the measurement of the mobility by forcing the partition along a grid of excitation points (e.g. by means of a shaker) and measuring its response along a grid of response points (e.g. by means of a scanning laser Doppler vibrometer). Using the resulting matrix of mobility transfer functions, the vibrational response of the partition excited by a diffuse acoustic field is numerically calculated, from which the radiated sound power is computed using the Rayleigh integral. Thus the reliance on source and receiving rooms used in standard sound insulation testing is removed entirely. The proposed method provides an estimate that only depends on the properties of the partition. The method was tested in an acoustic laboratory on a single layer glass plate of 1.35 × 1.54 m 2 , as well as on a funicular shell structure with dimensions of 3 × 3 m 2 . Comparisons with analytical models and standardized ISO10140-2:2010 measurements confirm the validity of the results. [ABSTRACT FROM AUTHOR]

Mechanical testing in environmental chambers is typically limited to 450°C. Some specialty chambers have been designed but at a high cost. Furthermore, accurate extensometers in environmental chambers are rare and expensive to operate. A unique solution investigated in this manuscript is the mating of a confocal laser scanning microscope with a sealed environmental chamber fitted with loading clevises for mechanical testing. Such a setup allows the researcher to measure strain data at elevated temperatures in controlled environments. Utilizing a laser light source avoids problems with blackbody radiation at elevated temperatures. Setup and accuracy of the microscope are discussed concerning tensile loading. P91 boiler steel was selected for this work because of the long history of the alloy in the fossil energy industry. Optical strain uncertainty was measured between 1.6% and 3.5%. Other tensile parameters were satisfactorily measured within the experimental error of larger standard specimens. [ABSTRACT FROM AUTHOR]

Featured Application: This paper presents a method to identify the location and depth of surface cracks in cylindrical components based on scanning laser line source (SLLS) techniques. The research results are conducive to improving the accuracy and efficiency of laser ultrasonic testing for complex structures such as curved surface structures. Cylindrical structures play an important role in industrial fields. The surface crack is a typical defect in the cylindrical structures. Non-destructive surface crack detection of these structures is critical to the safe operation of the equipment. In this study, the signal enhancement of the scanning laser line source (SLLS) method is investigated by a numerical simulation method to identify the location and depth of the surface crack in the aluminum cylinder. A fully coupled explicit finite element model is established to study the signal enhancement of cylindrical surface waves on the aluminum cylinder. The simulation results indicate that the signal enhancement of the SLLS is more sensitive to the surface crack of a cylinder than that of the scanning laser detection (SLD) because of the wider span and higher peak. Due to the phase shift characteristics of surface waves on the cylinder, the maximum peak-to-peak amplitude of signal enhancement in the SLLS method (the SLLS peak) is affected by the detection position and diameter of the cylinder. Therefore, an optimization approach for detection position in SLLS is proposed for the location of surface crack on the cylinder. The locations of the surface crack on the solid cylinders with different diameters are investigated using simulated laser ultrasonic field data. Moreover, we find that the SLLS peak for signal enhancement can effectively respond to the crack depth within a limited scope which is dependent on the directivity pattern of the longitudinal waves. [ABSTRACT FROM AUTHOR]

Machine learning is widely used in industrial diagnosis and can be used to obtain accurate results automatically and online. The flip chip is a useful technology for microelectronic packaging. As flip chip technology trends towards high density and fine pitch, with the introduction of materials of low dielectric constant and lead-free materials, intelligent non-destructive inspection of solder bumps for defects becomes more difficult. Machine learning is a method for realising online inspection and overcoming the effects resulting from human factors such as eye fatigue. In this paper, the authors propose an intelligent diagnosis method for the inspection of flip chip solder bumps for defects. A scanning acoustic microscope with a high-frequency transducer obtains ultrasonic images of the flip chips. A vertical projection method is proposed to segment the flip chip ultrasonic images into solder bump images. Eight features are extracted from each solder bump image, including five geometric features and three frequency domain features. A machine learning method using a naive Bayes classifier is introduced for classification and recognition. The results demonstrate a high rate of accurate classification. Thus, this approach has strong potential for the intelligent diagnosis of flip chip solder bumps online. [ABSTRACT FROM AUTHOR]

Objective: this study proposes and evaluates a technique for in vivo deep-tissue superresolution imaging in the light-scattering mouse brain at up to a 3.5 Hz 2-D imaging rate with a 21×21 μm2 field of view. Methods: we combine the deep-tissue penetration and high imaging speed of resonant laser scanning two-photon (2P) microscopy with the superresolution ability of patterned excitation microscopy. Using high-frequency intensity modulation of the scanned two-photon excitation beam, we generate patterned illumination at the imaging plane. Using the principles of structured illumination, the high-frequency components in the collected images are then used to reconstruct images with an approximate twofold increase in optical resolution. Results: using our technique, resonant 2P superresolution patterned excitation reconstruction microscopy, we demonstrate our ability to investigate nanoscopic neuronal architecture in the cerebral cortex of the mouse brain at a depth of 120 μm in vivo and 210 μm ex vivo with a resolution of 119 nm. This technique optimizes the combination of speed and depth for improved in vivo imaging in the rodent neocortex. Conclusion: this study demonstrates a potentially useful technique for superresolution in vivo investigations in the rodent brain in deep tissue, creating a platform for investigating nanoscopic neuronal dynamics. Significance : this technique optimizes the combination of speed and depth for improved superresolution in vivo imaging in the rodent neocortex. [ABSTRACT FROM PUBLISHER]

This paper presents a method for measuring the thickness and velocities of body waves and the density of an isotropic layer by a pulse scanning acoustic microscope. The method is based on recording the microscope signal as a function of the displacement magnitude of the focused ultrasonic transducer along its axis perpendicular to the sample surface and on the decomposition of the recorded 2D spatiotemporal signal into the spectrum of plane pulse waves. The velocities of the longitudinal and transverse waves and the layer's thickness are calculated from the relative delays of the components of the spectrum of plane waves reflected from the surfaces of the layer and the density is computed by the amplitudes of these components. An experimental investigation of a test sample in the form of a glass plate carried out in the 50-MHz range shows that the error in measuring the thickness and velocities of body waves does not exceed 1% and the density measurement error does not exceed 10%. [ABSTRACT FROM AUTHOR]

An acoustic microscope with a cylindrical lens and ultrasound transducer have been considered, as well as the method based on it for the measuring of longitudinal and transverse wave velocities, the thickness and density of the investigated layer. A theoretical model of the microscope has been constructed, and the relation between the spatiotemporal output signal of the transducer and the angular dependence of the sample reflection coefficient has been found. It has been shown that the velocities of body waves and the thickness can be determined by the delays of ultrasound responses reflected from the layer boundaries measured by the transducer elements, and the density, by the amplitudes of these responses. The method was tested experimentally using a 20-element transducer with a central frequency of 15 MHz and a period of 0.8 mm. The example of a duralumin plate has shown that the error in measuring the thickness and velocity of longitudinal waves error does not exceed 1%; the velocity of transverse waves, 2%; and the density can be estimated with an accuracy of about 5%. [ABSTRACT FROM AUTHOR]

Specimens of Selectively Laser Melted (SLM) CM247LC powder have been characterised using analytical scanning and transmission electron microscopy. In specimens from the bulk, it has been found that longitudinal sections consist mainly of columnar γ grains, containing virtually identically oriented cells, approximately 700 nm in width and length up to hundreds of microns. These cells are separated from adjacent cells and from adjacent grains by γ′/γ eutectic, by high densities of Hf/Ti/Ta/W-rich precipitates and high densities of dislocations. The eutectic γ′ is up to about 50 nm in diameter but up to 10 nm within the cells. The microstructure in the top layer is similar to that taken from the bulk, but single-track samples are heterogeneous along the track length. The microstructures are interpreted in terms of the precipitation sequence, the volume fraction of eutectic and partitioning of the solute elements during solidification and the influence of subsequent laser-tracks. The cooling rate during solidification, calculated from the observed cell diameters is about 10 6 K/s, but the value obtained from the size of γ′ within the bulk is about 10 4 K/s. It is suggested that the discrepancy is due to the limited accuracy of this approach. Tensile tests on as-fabricated samples show that the yield strength is comparable with that of cast samples after standard heat treatments. The high strength of the as-fabricated samples is interpreted in terms the high densities of precipitates and dislocations in cell boundaries, the fine cell structure and the γ′ within cells. [ABSTRACT FROM AUTHOR]

Objective: This paper describes development of a novel 500-MHz scanning acoustic microscope (SAM) for assessing the mechanical properties of ocular tissues at fine resolution. The mechanical properties of some ocular tissues, such as lamina cribrosa (LC) in the optic nerve head, are believed to play a pivotal role in eye pathogenesis. Methods: A novel etching technology was used to fabricate silicon-based lens for a 500-MHz transducer. The transducer was tested in a custom-designed scanning system on human eyes. Two-dimensional (2-D) maps of bulk modulus (K) and mass density (ρ) were derived using improved versions of current state-of-the-art signal processing approaches. Results: The transducer employed a lens radius of 125 μm and had a center frequency of 479 MHz with a –6-dB bandwidth of 264 MHz and a lateral resolution of 4 μm. The LC, Bruch's membrane (BM) at the interface of the retina and choroid, and Bowman's layer (BL) at the interface of the corneal epithelium and stroma, were successfully imaged and resolved. Analysis of the 2-D parameter maps revealed average values of LC, BM, and BL with \rmKLC = 2.81 \pm 0.17; GPa, \rmKBM = 2.89 \pm 0.18; GPa, \rmKBL = 2.6 \pm 0.09 ; GPa, ρ \rmLC = 0.96 \pm 0.03 g/cm3; ρ \rmBM = 0.97 \pm 0.04 g/cm3; ρ \rmBL = 0.98 \pm 0.04 g/cm3. Significance: This novel SAM was shown to be capable of measuring mechanical properties of soft biological tissues at microscopic resolution; it is currently the only system that allows simultaneous measurement of K, ρ, and attenuation in large lateral scales (field area >9 mm2) and at fine resolutions. [ABSTRACT FROM AUTHOR]

A scanning laser Doppler vibrometer (SLDV) has been widely used in non-contact vibration measurement. This paper presents a novel investigation of three-dimensional (3D) vibration measurement by a single SLDV sequentially placed at three different positions, where 3D vibration is defined as three vibration components along axes of a specified measurement coordinate system (MCS), which can give more precise knowledge of structural dynamic characteristics. A geometric model of the SLDV is proposed and a vibrometer coordinate system (VCS) based on the geometric model is defined and fixed on the SLDV. The pose of a SLDV with respect to a MCS is expressed in the form of a translation vector and a direction cosine matrix from the VCS to the MCS, which can be calculated by four or more target points with known coordinates in both the MCS and the VCS. An improved method based on the least squares method and singular value decomposition is proposed to obtain the pose of the SLDV. Compared with an inverse method, the proposed method can yield an orthogonal direction cosine matrix and be applicable to a two-dimensional structure. Effects of the number of target points on the accuracy and stability of the proposed method are investigated. With three direction cosine matrices of three different positions obtained by the proposed method, measured vibration velocities along laser line-of-sight directions can be transformed to vibration components along axes of the MCS. An experiment was conducted to measure 3D vibration of a target point on a beam under sinusoidal excitation by a single SLDV sequentially placed at three different positions. Vibration components along axes of the MCS obtained by the single SLDV were in good agreement with those from a commercial Polytec 3D scanning laser vibrometer PSV-500-3D. [ABSTRACT FROM AUTHOR]

This study presented the principle of defect imaging technique from a remote location and its experimental results. The experimental system consists of a fiber laser for generating narrow band burst waves and a laser Doppler vibrometer for detecting flexural vibration in a plate-like structure. Because a defect image can be obtained at an extremely high speed using the system, we call this Ecamera. The experimental results showed that defect images for aluminum alloy plate and pipe with complex geometries can be obtained in the measurements from the distances about 2.3 meters and 6.0 meters. [ABSTRACT FROM AUTHOR]

Investigates the local piezoelectric activity of thin vinylidene fluoride trifluoroethylene copolymer films using the scanning nearfield acoustic microscope. Surface topography for metallized and uncovered polymers; Change of the piezoactivity during the poling process; Description of a semicrystalline structure.

Street trees interlaced with other objects in cluttered point clouds of urban scenes inhibit the automatic extraction of individual trees. This paper proposes a method for the automatic extraction of individual trees from mobile laser scanning data, according to the general constitution of trees. Two components of each individual tree – a trunk and a crown can be extracted by the dual growing method. This method consists of coarse classification, through which most of artifacts are removed; the automatic selection of appropriate seeds for individual trees, by which the common manual initial setting is avoided; a dual growing process that separates one tree from others by circumscribing a trunk in an adaptive growing radius and segmenting a crown in constrained growing regions; and a refining process that draws a singular trunk from the interlaced other objects. The method is verified by two datasets with over 98% completeness and over 96% correctness. The low mean absolute percentage errors in capturing the morphological parameters of individual trees indicate that this method can output individual trees with high precision. [ABSTRACT FROM AUTHOR]

Scanning acoustic microscopy (SAM) is used as a routine non-destructive test tool for different diagnostic examinations: detection of defects such as microcracks, delamination, disbonding, inclusions, subsurface features in materials such as pores and cracks. SAM can be operated in a wide frequency range from Megahertz to Gigahertz. SAM measurement spatial resolution is diffraction limited by the wavelength of the acoustic wave in particular medium and also depends on individual transducers geometry. Actual SAM spatial resolution can be determined by measuring calibrated lithographically formed microstructures in high acoustic impedance materials. Numerical acoustic signal simulation method, based on the diffraction approach, was employed for the selection of the calibration block pattern geometry and linear dimensions of the elements. Universal calibration block for SAM operating in a 20-230 MHz frequency range was micromachined in high acoustic impedance ceramic substrates. Differently spaced (from 18 to 185 μm) lines of the same width and different widths (from 17 to 113 μm) but similar spacing lines were imposed in alumina ceramics employing one step lithography process, i.e. femtosecond laser ablation. Proposed SAM calibration pattern linear dimensions were characterized employing optical and scanning electron microscopy. Finally the samples were measured with SAM employing different frequency transducers and results were compared with the numerical simulations. It was obtained that resolution of SAM operating with 230 MHz transducer is not worse than 40 μm. [ABSTRACT FROM AUTHOR]

The thermal effect is one of the most important factors that influence the accuracy of nanoscale measurement and the surface topography of samples in scanning probe microscopes (SPMs). We propose a method called correlation-steered scanning, which is capable of overcoming three-dimensional thermal drifts in real time for ultra-long time scanned images. The image is scanned band by band with overlapping parts between adjacent bands. The vertical drift can be considered as linear and can thus be eliminated together with the tilt of the sample by applying the flattening method. Each band is artificially divided into several blocks for conveniently calculating lateral drifts on the basis of the overlapping area of adjacent bands through digital image correlation. The calculated lateral drifts are compensated to steer the scanning of the subsequent blocks, thus ensuring that all bands are parallel to one another. Experimental results proved that images scanned by the proposed method exhibited less distortions than those obtained from the traditional raster scanning method. The nanoscale measurement results based on the image obtained by the proposed method also showed high accuracy, with an error of less than 1.5%. By scanning as many bands as needed, the correlation-steered scanning method can obtain a highly precise SPM image of an ultra-large area. [ABSTRACT FROM AUTHOR]

A series of transition metal M (Fe, Co, Ni, Cu, Zn) modified Ce–Al 2 O 3 bimetal catalysts with a certain amount of M (3.0%) were prepared using the incipient-wetness impregnation method, and the as-prepared catalysts were characterized by using automatic adsorption instrument, X-ray diffraction (XRD), Infrared spectroscopy (IR), Temperature programmed reduction (H 2 -TPR) and Scanning electron microscope-Energy dispersive spectrometer (SEM-EDS). Steam reforming of n-decane over such M/Ce–Al 2 O 3 catalysts was investigated in a fixed bed reactor under high temperature. Significantly, the catalytic reforming activities over series M/Ce–Al 2 O 3 bimetal catalysts were evidently heightened compared with the corresponding Ce–Al 2 O 3 catalyst. Meanwhile, the bimetal catalysts exhibited different hydrogen selectivity and anti-carbon deposition ability which were greatly depending on the modified metal M. Ni/Ce–Al 2 O 3 performed better catalytic reforming activity, which was in accordance with the synergy between Ni and Ce–Al 2 O 3 , also the larger surface area. The valuable information indicated in this work is that based on the special characters of Ni/Ce–Al 2 O 3 , bimetal particles can be supported on Al 2 O 3 , which should be an effective approach to maintain both catalytic activities and thermal stability. [ABSTRACT FROM AUTHOR]

A lens acoustic microscope is proposed in which a two-dimensional high-frequency ultrasound array is used instead of a single converter. In this microscope, electronic scanning of the region of naturally occurring focus of the acoustic lens can be performed and the focus can be held electronically at different distances, including inside solid objects. It was demonstrated that the multielement microscope has potentially higher performance compared with a single-element scanning microscope and is not inferior in resolution power. [ABSTRACT FROM AUTHOR]

We present a seminumerical simulation method called SIRFEM, which enables the efficient prediction of high-frequency transducer outputs. In particular, this is important for acoustic microscopy where the specimen under investigation is immersed in a coupling fluid. Conventional finite-element (FE) simulations for such applications would consume too much computational power due to the required spatial and temporal discretization, especially for the coupling fluid between ultrasonic transducer and specimen. However, FE simulations are in most cases essential to consider the mode conversion at and inside the solid specimen as well as the wave propagation in its interior. SIRFEM reduces the computational effort of pure FE simulations by treating only the solid specimen and a small part of the fluid layer with FE. The propagation in the coupling fluid from transducer to specimen and back is processed by the so-called spatial impulse response (SIR). Through this hybrid approach, the number of elements as well as the number of time steps for the FE simulation can be reduced significantly, as it is presented for an axis-symmetric setup. Three B-mode images of a plane 2-D setup—computed at a transducer center frequency of 20 MHz—show that SIRFEM is, furthermore, able to predict reflections at inner structures as well as multiple reflections between those structures and the specimen’s surface. For the purpose of a pure 2-D setup, the SIR of a curved-line transducer is derived and compared to the response function of a cylindrically focused aperture of negligible extend in the third spatial dimension. [ABSTRACT FROM PUBLISHER]

Copyright of Archives of Mining Sciences is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The possibility of detecting subsurface flaws in solids using the scanning high-frequency acoustic-microscopy method was investigated. The influence of a distortion of the focal region and aberrations, which appear during focusing to a subsurface region in a solid, on the formation of the output signal of a microscope is estimated via mathematical simulation of the refraction of focused acoustic beams in a solid and during experiments on a laboratory scanning acoustic microscope at a 400-MHz frequency of probing acoustic waves. [ABSTRACT FROM AUTHOR]

This paper integrates the theory of inventive problem solving and cluster analysis to develop effective rework processes for underfilled electronic components. First, the function analysis is used to clarify the functional disadvantages such as underfill material attaching to the component, the printed circuit board (PCB), and the solder joints during the rework process. The cause–effect contradiction chain analysis then helps to identify engineering contradictions. Second, this research proposes clustered contradiction matrix. The optimal number of clusters for the inventive principles is determined by Ward’s method of hierarchical approach. The $K$ -means method is then used to allocate the engineering parameters to the appropriate cluster to achieve superior clustering performance. The priority of inventive principles considered as solution triggers is based on their corresponding frequency of appearances. Three solutions focused laser beam to remove electronics component, dispensable component bracket, and interchangeable PCB are proposed to rework the underfilled electronics components. Finally, the idealities of solutions are assessed and the most ideal solution interchangeable PCB is nominated for the U.S. patent. [ABSTRACT FROM AUTHOR]

We report on the development of a new type of scanning acoustic microscope. We use a femtosecond light pulse to generate a short sound pulse, and then focus this sound onto the sample by means of a specially designed and microfabricated acoustic lens of radius a few microns. The sound travels to the sample through a thin layer of water. The sound reflected from the sample is collected by the lens and then passes through a monolithically integrated optical resonant cavity. The induced change in the properties of this cavity are measured using a time-delayed probe light pulse. We describe some of the challenges involved in the construction and operation of this high-precision metrology apparatus and present some preliminary results. [ABSTRACT FROM AUTHOR]

The stereo light microscope (SLM) plays an important role in the measurement of three-dimensional geometry on the microscopic scale. We propose a fast and precise affine calibration algorithm based on the invariable extrinsic parameters for the SLM. This calibration algorithm with a free planar reference consists of three steps: first, derive the extrinsic parameters based on their invariable definition in the pinhole and affine models; second, calculate the intrinsic parameters through homography matrix; finally, refine all the model parameters by global optimization with the previous closed-form solutions as the initial values. The effectiveness of assuming a noncoaxial optical system as an affine camera is also verified to affinely model all types of SLMs. The calibration experiments show that the affine calibration is preferable for multicriteria including running time, relative positioning precision, and absolute positioning precision. With PlanApo S 1.5x and a total magnification of 3.024x, the proposed affine calibration algorithm achieves a distance error of 0.423 µm and a positioning error of 0.195 mm within 10.6 s. [ABSTRACT FROM AUTHOR]

This paper focuses on the design of the optimal scanning mode for the family of scanning probe microscopes. Based on different values of the maximum acceleration (deceleration) rate and maximum speed of X- and Y- axes of the mechanical scanner encountered in practice due to different mechanical design and loads, the design procedure of the optimal fast scanning mode is presented, which is found to be sensitive to the specific parameters of the scanning motion. By utilizing the simultaneous motion of the two axes, the fast raster scanning mode proposed can improve the scanning efficiency by 29% when comparing with the conventional raster (CR) scanning mode, if the scanning speeds of both axes are identical. In addition, the optimal fast mode provided by us has no effects on the image accuracy such as image degradation, image distortion when the efficiency is evaluated. No further difficulties are introduced to the control of the mechanical scanner and the data acquisition process. This optimal scanning mode is useful when the response time of the probe is very fast (such as ultrasonic probe in scanning acoustic microscope (SAM)), and the main limitations are due to the mechanical scanner. By applying different loads for both axes, the experiments with different scanning areas and scanning modes are conducted in a self-developed SAM. Experimental results coincide with the theoretical analysis and confirm the validation of our proposed optimal fast scanning mode and its superiority over the CR scanning mode. SCANNING 36:185-193, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Bitumen, the residue of oil distillation and applied e.g. as binder in asphalt pavements displays a rich microstructure at the bitumen surface-to-air surface with several clearly distinguishable phases. However, uncertainty still remains whether this micro-structure is just present at free surfaces or a similar structure exists in the bulk of the material. Two new experimental techniques in bitumen research (i) one based on Atomic Force Microscopy (AFM) on a freeze–fracture surface and (ii) one technique employing a Scanning Acoustic Microscope (SAM) offer the required spatial resolution and show the presence of two phases in the bulk showing similarities with the known surface structures in bitumen. [Copyright &y& Elsevier]

Purpose: A scanning acoustic microscope (SAM) uses an ultrasound to image an object by plotting the speed-of-sound (SOS) through tissues on screen. Because hard tissues result in great SOS, SAM can provide data on the tissue elasticity. This paper investigated the utility of SAM in evaluating thyroid lesions. Methods: Formalin-fixed, paraffin sections were scanned with a 120 MHz transducer. SOS through each area was calculated and plotted on the screen to provide histological images, and SOS of each lesion was compared and statistically analyzed. Results: High-concentrated colloids, red blood cells, and collagen fibers showed great SOS, while low-concentrated colloids, parathyroids, lymph follicles, and epithelial tissues including carcinomas demonstrated lower SOS. SAM clearly discriminated structure of thyroid components corresponding to low magnification of light microscopy. Thyroid tumors were classified into three groups by average SOS: the fast group consisted of follicular adenomas/carcinomas and malignant lymphomas; the slow group contained poorly differentiated/undifferentiated carcinomas; and the intermediate group comprised papillary/medullary carcinomas. Fragmented colloids, irregular-shaped follicles, and desmoplastic reactions were observed in the invasive area of surrounding carcinomas. Conclusion: The SAM imaging method had the following benefits: 1) precise images were acquired in a few minutes without special staining; 2) structural irregularity and desmoplastic reactions, which indicated malignancy, were detected; 3) images reflected tissue elasticity, which was statistically comparable among lesions by SOS; 4) follicular functional activity was predictable by converting colloid concentration to SOS; and 5) tumor classification was predictable by SOS because more poorly differentiated carcinomas had a tendency to show lower SOS. [ABSTRACT FROM AUTHOR]

The residua] stress caused by polymerization shrinkage and thermal contraction of a heat-curing resin containing 4-META on a metal-resin structure was measured by a scanning acoustic microscope. The tensile residual stress in the resin occurred within 70 um of the adhesion interface with a flat plate specimen. The maximum tensile stress was about 58 MPa at. the interface. On a metal plate specimen with retention holes, ring-like cracks in the resin occurred around the retention holes with the adhesive specimen and many linear cracks occurred in the resin vertical to the longitudinal direction of the metal frame with the non-adhesive specimens. There was tensile residual stress on the resin surface at the center of the retention holes of the adhesion specimen, indicating that the stress in the specimen with surface treatment for adhesion was higher than in that without surface treatment. [ABSTRACT FROM AUTHOR]