Non-destructive Mapping Research Articles

多维标度法在可视化卷烟感官评价结果中的应用

卷烟感官评价是一种多指标评价，以便较全面表征卷烟的各方面感官特征。但由于评价结果为多维，不易于直接比较多种不同卷烟之间的不相似度。为此，对全国54个代表性卷烟样品的评价结果，比较研究了多种多元统计作图技术的表现。结果表明：1) 统计脸谱图、星形图、平行坐标图等无损作图法仅适合少数样品的可视化比较；2) 无损作图法中，采用主成分分析法时，前几个主成分解释的方差比例比较小，需要至少在十维空间才能保持原始数据的信息不会有严重损失。因此，采用主成分分析在二维空间中进行可视化会严重失真；采用多维标度法在四维空间就能较好保留原始空间中两两样品的不相似度，因此，多维标度法更适合对卷烟感官评价结果进行可视化。 Cigarette sensory evaluation is a multi index evaluation, so that the various aspects of cigarette sensory can be characterized comprehensively. However, the evaluation results are multi-dimen- sional, and it is not easy to compare the differences of different cigarettes directly. For the national evaluation results of 54 representative samples of cigarettes, there is a comparative study of var-ious multivariate statistical mapping techniques. The results showed that: 1) Some lossless graphing methods such as Facebook statistics chart, star chart, parallel coordinate plots so on are only suitable for visual comparison in a small number of samples; 2) In the nondestructive mapping method, when using principal component analysis, the variance proportion of the first few principal components explained is relatively small. It means that we need at least ten dimensions space, in order to keep the original data as more information as possible. Therefore, the use of principal component analysis to visualize severely distorted in two-dimensional space; using mul-tidimensional scaling method will be able to better preserve the original space dissimilarity between two samples in four-dimensional space. In conclusion, multidimensional scaling method is more suitable for visualization of cigarette sensory evaluation results.

The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials.

The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented.

Digital direct electron imaging of energy-filtered electron backscatter diffraction patterns

Electron backscatter diffraction is a scanning electron microscopy technique used to obtain crystallographic information on materials. It allows the nondestructive mapping of crystal structure, texture, and strain with a lateral and depth resolution on the order of tens of nanometers. Electron backscatter diffraction patterns (EBSPs) are presently acquired using a detector comprising a scintillator coupled to a digital camera, and the crystallographic information obtainable is limited by the conversion of electrons to photons and then back to electrons again. In this article we will report the direct acquisition of energy-filtered EBSPs using a digital complementary metal-oxide-semiconductor hybrid pixel detector, Timepix. We show results from a range of samples with different mass and density, namely diamond, silicon, and GaN. Direct electron detection allows the acquisition of EBSPs at lower (≤5 keV) electron beam energies. This results in a reduction in the depth and lateral extension of the volume of the specimen contributing to the pattern and will lead to a significant improvement in lateral and depth resolution. Direct electron detection together with energy filtering (electrons having energy below a specific value are excluded) also leads to an improvement in spatial resolution but in addition provides an unprecedented increase in the detail in the acquired EBSPs. An increase in contrast and higher-order diffraction features are observed. In addition, excess-deficiency effects appear to be suppressed on energy filtering. This allows the fundamental physics of pattern formation to be interrogated and will enable a change in the use of electron backscatter diffraction (EBSD) for crystal phase identification and the mapping of strain. The enhancement in the contrast in high-pass energy-filtered EBSD patterns is found to be stronger for lighter, less dense materials. The improved contrast for such materials will enable the application of the EBSD technique to be expanded to materials for which conventional EBSD analysis is not presently practicable.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy.

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through ‘4D’ in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance.

Three-dimensional mass density mapping of cellular ultrastructure by ptychographic X-ray nanotomography.

We demonstrate absolute quantitative mass density mapping in three dimensions of frozen-hydrated biological matter with an isotropic resolution of 180 nm. As model for a biological system we use Chlamydomonas cells in buffer solution confined in a microcapillary. We use ptychographic X-ray computed tomography to image the entire specimen, including the 18 μm-diameter capillary, thereby providing directly an absolute mass density measurement of biological matter with an uncertainty of about 6%. The resulting maps have sufficient contrast to distinguish cells from the surrounding ice and several organelles of different densities inside the cells. Organelles are identified by comparison with a stained, resin-embedded specimen, which can be compared with established transmission electron microscopy results. For some identified organelles, the knowledge of their elemental composition reduces the uncertainty of their mass density measurement down to 1% with values consistent with previous measurements of dry weight concentrations in thin cellular sections by scanning transmission electron microscopy. With prospects of improving the spatial resolution in the near future, we expect that the capability of non-destructive three-dimensional mapping of mass density in biological samples close to their native state becomes a valuable method for measuring the packing of organic matter on the nanoscale.

Ultra-high-resolution 3D digitalized imaging of the cerebral angioarchitecture in rats using synchrotron radiation.

The angioarchitecture is a fundamental aspect of brain development and physiology. However, available imaging tools are unsuited for non-destructive cerebral mapping of the functionally important three-dimensional (3D) vascular microstructures. To address this issue, we developed an ultra-high resolution 3D digitalized angioarchitectural map for rat brain, based on synchrotron radiation phase contrast imaging (SR-PCI) with pixel size of 5.92 μm. This approach provides a systematic and detailed view of the cerebrovascular anatomy at the micrometer level without any need for contrast agents. From qualitative and quantitative perspectives, the present 3D data provide a considerable insight into the spatial vascular network for whole rodent brain, particularly for functionally important regions of interest, such as the hippocampus, pre-frontal cerebral cortex and the corpus striatum. We extended these results to synchrotron-based virtual micro-endoscopy, thus revealing the trajectory of targeted vessels in 3D. The SR-PCI method for systematic visualization of cerebral microvasculature holds considerable promise for wider application in life sciences, including 3D micro-imaging in experimental models of neurodevelopmental and vascular disorders.

Non-destructive 3-dimensional mapping of microcapsules in polymeric coatings by confocal Raman spectroscopy

Abstract Nowadays, the properties of polymeric coatings are enhanced by various additives mixed into the resin. Recently, embedding of polymeric microcapsules into the coating matrix has been investigated to provide special on-demand features to the coating. The detection and characterization of such microcapsules in a polymeric coating are of major importance but difficult, because both are built up by similar molecules with similar densities. Current analysis methods require complex sample preparation to allow reliable measurements. In contrast, confocal Raman spectroscopy allows fast and non-destructive differentiation between characteristic molecular bonds at a spatial resolution below one micrometer. Hence, the objective of this research was to apply this technique on microcapsules embedded in a coating and provide answers to the following questions: Can one detect microcapsules embedded in a coating and clearly identify them? Can one differentiate between full and empty microcapsules and the coating matrix? Can one determine the exact location of the capsules and their distribution in the coating? Therefore, several two-dimensional confocal Raman spectroscopy mappings recorded at different depths allowed a three-dimensional reconstruction of the polymeric coating with the polymeric microcapsules in it. Thereby, the distribution of the capsules within the coating could be determined with micrometer resolution. As a result Raman tomography provides a more detailed insight into the distribution of microcapsules through the possibility of three-dimensional reconstruction.

Non-Destructive High-Resolution Conductivity Mapping of Thin-Film Battery Electrodes

Accurately determining electronic conductivity of thin-film battery electrodes is not trivial, especially with the metallic current conductor still attached. A fast and reliable method would be of use for quality control and optimization purposes in battery manufacture, and would provide insight into the effects of changes in the fabrication process on the electrode structure. We report a four-line probe that has been used to make high-resolution maps of local electrode conductivity on the micron scale. A computer-controlled apparatus allows precise control of pressure on the sample and positioning of the probe. A significant part of the work was developing a novel hybrid numerical-analytical model to invert the experiment, allowing a separate determination of film conductivity and contact resistance at the current collector in real time on a desktop computer. We will discuss the amount of local conductivity variation within representative electrode films. This work was supported by the U.S. Department of Energy through the BMR program. Figure 1

Non-destructive mapping of doping and structural composition of MOVPE-grown high current density resonant tunnelling diodes through photoluminescence spectroscopy

We report on photoluminescence (PL) characterisation of metal-organic vapour phase epitaxy (MOVPE) grown high current density (~700kA/cm2) InGaAs/AlAs/InP based resonant tunnelling diodes (RTDs) for terahertz emission. The PL mapping we describe allows important information about doping level and uniformity, ternary alloy composition and uniformity, and uniformity of quantum well thickness to be deduced. PL as a function of doping concentration is studied for InGaAs test layers at low temperatures and correlated to secondary-ion mass spectroscopy (SIMS) and electrochemical capacitance–voltage (eCV) profiling to provide non-destructive mapping of doping over the wafer. For the RTD structures, we utilise eCV as a selective etch tool to identify the origin of low temperature PL emission from the quantum well (QW) and the highly doped contact layers. PL mapping of the RTD wafer at low temperatures is shown to allow the assessment of variations in InGaAs alloy composition and QW thickness. Details of the growth process are discussed and confirmed using high resolution X-ray diffraction (HRXRD) crystallography. The rapid non-destructive characterisation and wafer mapping of these structures promises a route to future growth optimisation of such structures.

NON-DESTRUCTIVE GPR ANALYSIS OF THREATENED ANGKORIAN CERAMIC KILNS AT BANGKONG, SIEM REAP, CAMBODIA

Pedestrian surveys have identified a large number of 9th century ceramic kilns to the north of the early Angkorian centre of Hariharalaya. Recent development in this area has put this archaeological site under threat. With a large number of kilns already destroyed before analysis, it was necessary to identify the sites for protection from further damage.Since the defined areas showed little evidence on the surface, GPR surveys were conducted to find out what additional subsurface features could be used for classification. Using a 250MHz antenna system, the surveys were conducted over four kilns in varying state of preservation. The analysis included one definite and partly exposed kiln, and three potential kilns. Of the latter, one had been completely bulldozed, one partly destroyed and another one had remained undisturbed. The geophysical surveys shows the possibilities to better define the extent of the kiln mound. 3D visualization of the data displays depth and extent of the fire box and ware chamber of this type of Khmer kiln, providing the opportunity to better outline the area to be protected. The survey serves as a successful sample case for the systematic non-destructive mapping of known and newly discovered kiln sites.

Evaluation of an X-ray-excited optical microscope for chemical imaging of metal and other surfaces.

The application of a modular system for the nondestructive chemical imaging of metal and other surfaces is described using heritage metals as an example. The custom-built X-ray-excited optical luminescence (XEOL) microscope, XEOM 1, images the chemical state and short-range atomic order of the top 200 nm of both amorphous and crystalline surfaces. A broad X-ray beam is used to illuminate large areas (up to 4 mm(2)) of the sample, and the resulting XEOL emission is collected simultaneously for each pixel by a charge-coupled device sensor to form an image. The input X-ray energy is incremented across a range typical for the X-ray absorption near-edge structure (XANES) and an image collected for each increment. The use of large-footprint beams combined with parallel detection allows the power density to be kept low and facilitates complete nondestructive XANES mapping on a reasonable time scale. In this study the microscope was evaluated by imaging copper surfaces with well-defined patterns of different corrosion products (cuprite Cu2O and nantokite CuCl). The images obtained show chemical contrast, and filtering the XEOL light allowed different corrosion products to be imaged separately. Absorption spectra extracted from software-selected regions of interest exhibit characteristic XANES fingerprints for the compounds present. Moreover, when the X-ray absorption edge positions were extracted from each spectrum, an oxidation state map of the sample could be compiled. The results show that this method allows one to obtain nondestructive and noninvasive information at the micrometer scale while using full-field imaging.

3D cross-correlative matrix temperature detection and non-invasive thermal mapping based on a molecular probe

Cryogenic temperature detection underlies the understanding of important physical phenomena and is crucial for material science and space exploration. Simple, facile, and accurate assessment of temperature, especially for surface or body thermal mapping, is one of the challenges that must be addressed when developing new materials or technologies for thermometers. Here, we introduce a temperature detection strategy based on a 3D cross-correlative matrix derived from fluorescence response patterns of an organic probe in three solvation envelopes. The intermolecular interactions, such as excimer or exciplex formation, intramolecular charge transfer and solvent relaxation processes, between the probe and molecule surroundings, are attributed to the unique temperature-dependent optical behaviors in different solutions. The precise temperature detection originated from apparent variations in fluorescence intensity and wavelength upon temperature change in these solvents. This enabled the construction of a comprehensive temperature sensor array, which gives a unique visible color pattern of signals as a read-output discernible by the naked eye. Furthermore, as a proof-of-concept, a new strategy for facile and non-destructive thermal mapping of a crystal surface is presented.

Nondestructive quantitative mapping of impurities and point defects in thin films: Ga and VZn in ZnO:Ga

Ga-doped ZnO (GZO) films grown by pulsed-laser deposition on quartz and other lattice-mismatched substrates can routinely attain resistivities of 2 × 10−4 Ω·cm and thus compete with Sn-doped In2O3 (ITO) in large-area transparent-electrode applications. Nondestructive, high-resolution (1-mm) maps of thickness d, concentration n, and mobility μ on such films can be obtained automatically from commercial spectroscopic ellipsometers. From n and μ, degenerate-electron scattering theory yields donor ND and acceptor NA concentrations at each point. Finally, ND and NA can be identified as [Ga] and [VZn], respectively, demonstrating high-density mapping of impurities and point defects in a semiconductor thin film.

RICH TOMOGRAPHY TECHNIQUES FOR THE ANALYSIS OF MICROSTRUCTURE AND DEFORMATION

Until very recently, the three-dimensionality of the material world presented numerous challenges in terms of characterization, data handling, visualization, and modeling. For this reason, 2D representation of sections, projections, or surfaces remained the mainstay of most popular imaging techniques, such as optical and electron microscopy and X-ray radiography. However, the advent of faster computers with greater memory capacity ensured that large 3D matrices can now not only be stored and manipulated efficiently, but also that advanced algorithms such as algebraic reconstruction techniques (ART) can be used to interpret redundant datasets containing multiple projections or averages across the object obtained by some suitable analytical measurement technique. These tools open up unprecedented opportunities for numerical simulation. Model formulation can be accomplished semi-automatically on the basis of microstructurally-informed 3D imaging, while model validation can be achieved by direct comparison of 3D maps of complex quantities, such as displacement vectors or strain tensor components. In this paper, we review several modalities of what can be referred to as "rich" tomography: strain tomography in the bulk of a load bearing structural component; Laue orientation tomography for nondestructive mapping of grain orientation within a polycrystal, and the use of sequences of tomographic reconstructions for digital volume correlation (DVC) analysis of in situ deformation.

Short-wavelength infrared defect emission as a probe of degradation processes in 980 nm single-mode diode lasers

Infrared emission from 980-nm single-mode high power diode lasers is recorded and analyzed in the wavelength range from 0.8 to 8.0 μm. A pronounced short-wavelength infrared (SWIR) emission band with a maximum at 1.3 μm originates from defect states located in the waveguide of the devices. The SWIR intensity is a measure of the non-equilibrium carrier concentration in the waveguide, allowing for a non-destructive waveguide mapping in spatially resolved detection schemes. The potential of this approach is demonstrated by measuring spatially resolved profiles of SWIR emission and correlating them with mid-wavelength infrared (MWIR) thermal emission along the cavity of devices undergoing repeated catastrophic optical damage. The enhancement of SWIR emission in the damaged parts of the cavity is due to a locally enhanced carrier density in the waveguide and allows for an analysis of the spatial damage patterns. The figure shows a side view of a diode laser during catastrophic degradation as recorded by a thermocamera within 5 successive current pulses. The geometry of the device is given in grayscale. The position of the laser chip is indicated by the dotted line. The thermal signatures of the internal degradation of the diode laser are overlaid in color. The bi-directional spread of the damage along the laser cavity is clearly visible.

Photoluminescence characterization of KH₂PO₄ crystal: application to three-dimensional growth-sector identification.

In this work, rapidly grown KH2PO4 (KDP) crystals extracted from the prismatic and the pyramidal growth sectors of crystal boules were analyzed using photoluminescence measurements. From the spectra, we deduced a robust criterion to discriminate between both growth sectors in an unknown KDP plate. Moreover, spatially resolved photoluminescence was shown to enable a local probing of different planes in the bulk of the material leading to accurate and nondestructive three-dimensional mapping of the sector boundary, which is often the weakest point in terms of laser-damage resistance in rapidly grown KDP crystals.

3D Mapping of Crystallographic Phase Distribution using Energy‐Selective Neutron Tomography

Nondestructive 3D mapping of crystallographic phases is introduced providing distribution of phase fractions within the bulk (centimeter range) of samples with micrometer-scale resolution. The novel neutron tomography based technique overcomes critical limitations of existing techniques and offers a wide range of potential applications. It is demonstrated for steel samples exhibiting phase transformation after being subjected to tensile and torsional deformation.

Fast nanomechanical spectroscopy of soft matter

A method that combines high spatial resolution, quantitative and non-destructive mapping of surfaces and interfaces is a long standing goal in nanoscale microscopy. The method would facilitate the development of hybrid devices and materials made up of nanostructures of different properties. Here we develop a multifrequency force microscopy method that enables simultaneous mapping of nanomechanical spectra of soft matter surfaces with nanoscale spatial resolution. The properties include the Young's modulus and the viscous or damping coefficients. In addition, it provides the peak force and the indentation. The method does not limit the data acquisition speed nor the spatial resolution of the force microscope. It is non-invasive and minimizes the influence of the tip radius on the measurements. The same tip is used to measure in air heterogeneous interfaces with near four orders of magnitude variations in the elastic modulus, from 1 MPa to 3 GPa.

Non-destructive laboratory-based X-ray diffraction mapping of warpage in Si die embedded in IC packages

Reliability issues as a consequence of thermal/mechanical stresses created during packaging processes have been the main obstacle towards the realisation of high volume 3D Integrated Circuit (IC) integration technology for future microelectronics. However, there is no compelling laboratory-based metrology that can non-destructively measure or image stress/strain or warpage inside packaged chips, System-on-Chip (SoC) or System-in-Package (SiP), which is identified as a requirement by the International Technology Roadmap for Semiconductors (ITRS). In the work presented here, a triple-axis Jordan Valley Bede D1 X-ray diffractometer is used to develop a novel lab-based technique called X-ray diffraction 3-dimensional surface modelling (XRD/3DSM) for non-destructive analysis of manufacturing process-induced stress/warpage inside completely encapsulated packaged chips. The technique is demonstrated at room temperature and at elevated temperatures up to 115°C by in situ XRD annealing experiments. The feasibility of this technique is confirmed through the characterisation of die stress inside encapsulated commercially available ultra-thin Quad Flat Non-lead (QFN) packages, as well as die stress in embedded QFN packages at various stages of the chip manufacturing process.

Three-dimensional distribution of polymorphs and magnesium in a calcified underwater attachment system by diffraction tomography.

Biological materials display complicated three-dimensional hierarchical structures. Determining these structures is essential in understanding the link between material design and properties. Herein, we show how diffraction tomography can be used to determine the relative placement of the calcium carbonate polymorphs calcite and aragonite in the highly mineralized holdfast system of the bivalve Anomia simplex. In addition to high fidelity and non-destructive mapping of polymorphs, we use detailed analysis of X-ray diffraction peak positions in reconstructed powder diffraction data to determine the local degree of Mg substitution in the calcite phase. These data show how diffraction tomography can provide detailed multi-length scale information on complex materials in general and of biomineralized tissues in particular.