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Purpose Surface imaging (SI) offers a nonionizing, near real time alternative to radiographic imaging for intrafraction radiosurgery localization. In this work, we systematically compared a commercial SI system vs a commercial room mounted x‐ray localization system in phantom. Methods An anthropomorphic head phantom with fiducial markers was imaged with linear accelerator on‐board x‐ray imaging, SI, and room mounted x‐ray imaging (RM) at ±45° and ±90° couch angles for three different head tilts and six different isocenters (72 total positions). The shifts generated by the three systems were compared as functions of couch angle, head tilt, and isocenter position with the on‐board imaging shifts used as ground truth. Two sample Kolmogorov–Smirnov tests were used to evaluate equivalence of the groups. Results The magnitude of the displacement vectors for RM minus on‐board imaging and SI minus on‐board imaging over all 72 phantom positions were 0.7 ± 0.3 mm for both cases. The RM and SI showed no significant difference based on couch angle or isocenter position. Both systems showed decreasing accuracy with increasing couch angle, but both systems agreed with ground truth to

There always exist contrast reduction and details degradation when the infrared imaging system works on water surface because of fog and water mist. An image enhancement method is proposed based on radiative transfer theory. Firstly, the infrared enhancement model is built according to radiative transfer theory, with which we construct an optimization frame. Secondly, edge matrix is designed for weight analysis, which is particularly important for next estimation of fine transmissivity and optical path radiation. Finally, enhancement is achieved with edge matrix. The main contribution and novelty includes the derivation of enhancement based on radiative transfer theory, design of edge matrix, and estimation of fine transmissivity and optical path radiation. The experimental comparisons show the proposed method can generate results with a good visual effect, which is proved by both subjective and objective assessment. The experiments also indicate that the proposed algorithm runs fast to apply in real system.

Fundamental chemistry in heterogeneous catalysis is increasingly explored using operando techniques in order to address the pressure gap between ultrahigh vacuum studies and practical operating pressures. Because most operando experiments focus on the surface and surface-bound species, there is a knowledge gap of the near-surface gas phase and the fundamental information the properties of this region convey about catalytic mechanisms. We demonstrate in situ visualization and measurement of gas-phase species and temperature distributions in operando catalysis experiments using complementary near-surface optical and mass spectrometry techniques. The partial oxidation of methanol over a silver catalyst demonstrates the value of these diagnostic techniques at 600 Torr (800 mbar) pressure and temperatures from 150 to 410 °C. Planar laser-induced fluorescence provides two-dimensional images of the formaldehyde product distribution that show the development of the boundary layer above the catalyst under different flow conditions. Raman scattering imaging provides measurements of a wide range of major species, such as methanol, oxygen, nitrogen, formaldehyde, and water vapor. Near-surface molecular beam mass spectrometry enables simultaneous detection of all species using a gas sampling probe. Detection of gas-phase free radicals, such as CH3 and CH3O, and of minor products, such as acetaldehyde, dimethyl ether, and methyl formate, provides insights into catalytic mechanisms of the partial oxidation of methanol. The combination of these techniques provides a detailed picture of the coupling between the gas phase and surface in heterogeneous catalysis and enables parametric studies under different operating conditions, which will enhance our ability to constrain microkinetic models of heterogeneous catalysis. (Less)

Optical coherence tomography (OCT) is an imaging technique which can provide sub-surface evaluation of defects in optically compliant components such as those manufactured by polymeric selective laser sintering. In OCT systems, achieving lateral imaging resolutions of

International audience; Alsingle bondSi coated boron steels have been of interest for many years because of their superior mechanical properties and their excellent oxidation resistance. These high strength steels are particularly used in hot stamping processes during which the Alsingle bondSi coating undergoes multiple microstructural transformations. In this study, morphology and structure transformations are investigated using an original approach. Most of the time, the coating evolution is studied in cross section, by ex situ characterization of its different layers after heat treatment. In this work, the evolution of the surface is explored for the first time using in situ high-temperature Environmental Scanning Electron Microscopy (HT-ESEM). The austenitization step reproduced in the ESEM chamber allows a precise description of several surface changes occurring, depending on the temperature range. Among them, the main change in morphology is occurring between 650 and 800 °C and is linked to different reactions between aluminium and bi- and ternary Fe-Al-Si phases. The heating rate is also pointed out as a key parameter that affects the surface morphology. In fact, with low heating rates the surface is mostly composed of hexagonal and rectangular elements coming from τ5 (Fe2Al8Si) structuration, while needle-shaped FeAl3 structures are found for higher heating rates. In addition, it is observed that the heating rate also affects the surface roughness depending on the surface morphology. Finally, the origin of the presence of micrometrics pores appearing between 800 and 900 °C at the coating surface is discussed. Our hypothesis supported by ex situ characterization is that they result from formation of a crystallized oxide layer, probably close to α-Al2O3 structure.

We highlight the impact of Ultrahigh Vacuum (UHV)-born surface science on modern electrocatalysis. The microscopic, atomic level picture of surface adsorption and reaction, which was developed in the surface science community in decades of systematic research on single crystals in UHV, has meanwhile become state-of-the-art also in electrochemistry. For the example of CO on Pt(111) single crystals, which has been extensively studied at the solid/gas and the solid/liquid interface using atomic resolution scanning tunnelling microscopy (STM), we highlight how both interfaces may have even more in common than often assumed. We then illustrate how planar model surfaces such as mono- and bimetallic single crystals and surface alloys, prepared and thoroughly analysed in UHV, enabled a systematic search for improved electrocatalysts. Surface alloys, thermodynamically more stable than foreign metal islands, are a particularly important sub-group of model surfaces, which so far have only been fabricated in UHV. We also flag that model surfaces may not always assume the structure anticipated for the respective experiment, regardless of their preparation in UHV or by electrochemical methods. “Accidental” surface alloying may be more common than often assumed, leading to misinterpretations of the structure-property relationships targeted in many model studies. We highlight that controlled surface alloy formation should be a key step in any model study looking at bimetallic systems in order to get an idea what the effect of unintended alloying could possibly be, and to cross-check whether alloyed surfaces may potentially be the better electrocatalysts in the first place.

A novel type of microwave probes based on the loaded aperture geometry has been proposed and experimentally evaluated for dielectrics characterisation and high-resolution near-field imaging. Experimental results demonstrate the possibility of very accurate microwave spectroscopic characterisation of thin lossy dielectric samples and biological materials containing water. High-resolution images of the subwavelength lossy dielectric strips and wet and dry leaves have been obtained with amplitude contrast around 10-20 dB and spatial resolution better than one-tenth of a wavelength in the near-field zone. A microwave imaging scenario for the early-stage skin cancer identification based on the artificial dielectric model has also been explored. This model study shows that the typical resolution of an artificial malignant tumour with a characteristic size of one-tenth of a wavelength can be discriminated with at least 6 dB amplitude and 50° phase contrast from the artificial healthy skin and with more than 3 dB contrast from a benign lesion of the same size. It has also been demonstrated that the proposed device can efficiently deliver microwave energy to very small, subwavelength, focal areas which is highly sought in the microwave hyperthermia applications.

Exquisite control of the electrodeposition of metal films and coatings is critical to a number of high technology and manufacturing industries, delivering functionality as\ud diverse as anti-corrosion and anti-wear coatings, electronic device interconnects and energy storage. The frequent involvement of more than one metal motivates the\ud capability to control, maintain and monitor spatial disposition of the component metals, whether as multilayers, alloys or composites. Here we investigate the deposition, evolution and dissolution of single and two-component metal layers involving Ag, Cu, and Sn on Au substrates immersed in the deep eutectic solvent (DES) Ethaline. During galvanostatically controlled stripping of the metals from two-component systems the potential signature in simultaneous thickness electrochemical potential (STEP) measurements provides identification of the dissolving metal; coulometric assay of deposition efficiency is an additional outcome. When combined with quartz crystal microbalance (QCM) frequency responses, the mass change : charge ratio provides oxidation state data; this is significant for Cu in the high chloride environment provided by Ethaline. The spatial distribution (solvent penetration and external roughness) of multiple components in bilayer systems is provided by specular neutron reflectivity (NR). Significantly, the use of the recently established event mode capability shortens the\ud observational timescale of the NR measurements by an order of magnitude, permitting dynamic in situ observations on practically useful timescales. Ag,Cu bilayers of both\ud spatial configurations give identical STEP signatures indicating that, despite theextremely low layer porosity, thermodynamic constraints (rather than spatial accessibility) dictate reactivity; thus, surprisingly, Cu dissolves first in both instances. Sn penetrates the Au electrode on the timescale of deposition; this can be prevented by interposing a layer of either Ag or Cu.

Both approaches have strengths and weaknesses. The SEM's strength is to quickly generate images with a large range of magnifications, making it easy to locate the area of interest. However, it doesn't yield 3D information, e.g. "invisible" contamination layers. The AFM's main advantage is its ability to obtain 3D information, the downsides are that it is hard to find the target area and image generation is slow. Combining these two tools into one setup putting an AFM inside an SEM gives quick access to a more complete data set. Additionally, FIB-milled or FIB-deposited structures can be characterized using this combination of tools in a FIB/SEM system.

In the laundry industry, colorimetry is a common way to evaluate the stain removal efficiency of detergents and cleaning products. For ease of visualization, the soiling agent is treated with a dye before measurement. However, it effectively measures the dye removal rather than stain removal, and it cannot provide depth-resolved information of the sample. In this study, we show that full-field (FF) optical coherence tomography (OCT) technique is capable of measuring the cleaning effect on cotton fabric by imaging the sub-surface features of fabric samples. We used a broadband light-emitting diode (LED) source to power the FF-OCT system that achieves the resolution of 1 µm axially and 1.6 µm laterally. This allows the micron-sized cotton fibres/fibrils at different depth positions to be resolved. The clean, the soiled, and the washed samples can be differentiated from their cross-sectional images using OCT, where the cleaning effect can be correlated with the sub-surface fibre volume. The experimental results of the proposed method were found to be in good agreement with those of the standard colorimetry method. The proposed technique therefore offers an alternative way for measuring the stain removal from fabric substrate to assess the effectiveness of laundry detergent products.

Lithium ions in LiMn2O4 crystals have been shown observable by using an aberration corrected electron microscope (R005) which has achieved a sub-50 pm resolution. Based on the annular bright-field image of the observed image, surface imaging of a LiMn2O4 crystal is discussed through simulation. The present simulation showed that ABF images with large convergence angles are sensitive to the top surface profile. A vacancy locating at the top surface of the lithium or manganese atomic columns can be observable with contrast reduced by 10-25% from the columns without vacancy. [DOI: 10.1380/ejssnt.2012.454]

Synthetic aperture imaging methods have been employed widely in recent research in non-destructive testing (NDT), but uptake has been more limited in medical ultrasound imaging. Typically offering superior focussing power over more traditional phased array methods, these techniques have been employed in NDT applications to locate and characterise small defects within large samples, but have rarely been used to image surfaces. A desire to ultimately employ ultrasonic surface imaging for bone surface geometry measurement prior to surgical intervention motivates this research, and results are presented for initial laboratory trials of a surface reconstruction technique based on global thresholding of ultrasonic 3D point cloud data. In this study, representative geometry artefacts were imaged in the laboratory using two synthetic aperture techniques; the Total Focusing Method (TFM) and the Synthetic Aperture Focusing Technique (SAFT) employing full and narrow synthetic apertures, respectively. Three high precision metallic samples of known geometries (cuboid, sphere and cylinder) which featured a range of elementary surface primitives were imaged using a 5 MHz, 128 element 1D phased array employing both SAFT and TFM approaches. The array was manipulated around the samples using a precision robotic positioning system, allowing for repeatable ultrasound derived 3D surface point clouds to be created. A global thresholding technique was then developed that allowed the extraction of the surface profiles, and these were compared with the known geometry samples to provide a quantitative measure of error of 3D surface reconstruction. The mean errors achieved with optimised SAFT imaging for the cuboidal, spherical and cylindrical samples were 1.3 mm, 2.9 mm and 2.0 mm respectively, while those for TFM imaging were 3.7 mm, 3.0 mm and 3.1 mm, respectively. These results were contrary to expectations given the higher information content associated with the TFM images. However, it was established that the reduced error associated with the SAFT technique was associated with significant reductions in side lobe levels of approximately 24 dB in comparison to TFM imaging, although this came at the expense of reduced resolution and coverage.

Terahertz sub-surface imaging offers an effective solution for surface and 3D imaging because of minimal sample preparation requirements and its ability to “see” below the surface. Another important property is the ability to inspect on a layer-by layer basis via a non-contact route, non-destructive route. Terahertz 3D imager designed at Applied Research and Photonics (Harrisburg, PA) has been used to demonstrate reconstructive imaging with a resolution of less than a nanometer. Gridding with inverse distance to power equations has been described for 3D image formation. A continuous wave terahertz source derived from dendrimer dipole excitation has been used for reflection mode scanning in the three orthogonal directions. Both 2D and 3D images are generated for the analysis of silver iodide quantum dots’ size parameter. Layer by layer image analysis has been outlined. Graphical analysis was used for particle size and layer thickness determinations. The demonstrated results of quantum dot particle size checks well with those determined by TEM micrograph and powder X-ray diffraction analysis. The reported non-contact measurement system is expected to be useful for characterizing 2D and 3D naomaterials as well as for process development and/or quality inspection at the production line.

Here we derived analytical solutions to diffuse light transport in biological tissue based on spectral deformation of diffused near-infrared measurements. These solutions provide a closed-form mathematical expression which predicts that the depth of a fluorescent molecule distribution is linearly related to the logarithm of the ratio of fluorescence at two different wavelengths. The slope and intercept values of the equation depend on the intrinsic values of absorption and reduced scattering of tissue. This linear behavior occurs if the following two conditions are satisfied: the depth is beyond a few millimeters, and the tissue is relatively homogenous. We present experimental measurements acquired with a broad-beam non-contact multi-spectral fluorescence imaging system using a hemoglobin-containing diffusive phantom. Preliminary results confirm that a significant correlation exists between the predicted depth of a distribution of protoporphyrin IX (PpIX) molecules and the measured ratio of fluorescence at two different wavelengths. These results suggest that depth assessment of fluorescence contrast can be achieved in fluorescence-guided surgery to allow improved intra-operative delineation of tumor margins.

The present study introduces a new three-dimensional (3D) surface image analysis technique in which white light illumination from different incident angles is used to create 3D surfaces with a photometric approach. The three-dimensional features of the surface images created are then used in the characterization of particle size distributions of granules. This surface image analysis method is compared to sieve analysis and a particle sizing method based on spatial filtering technique with nearly 30 granule batches. The aim is also to evaluate the technique in flowability screening of granular materials. Overall, the new 3D imaging approach allows a rapid analysis of large amounts of sample and gives valuable visual information on the granule surfaces in terms of surface roughness and particle shape.

Novel high-resolution near field imaging technique based on microwave resonance reflectometry is presented. Two types of microwave resonance probes are considered - a small helix antenna and a resonantly loaded aperture in conductive screen. It is shown that these probes possess the electromagnetic (EM) characteristics essential for high-resolution near field imaging device: (i) they enable very tight near field collimation with full width at half maximum less than λ/10, λ is a wavelength of radiation; (ii) the probes near field coupling to the imaged samples is based on the high-quality resonance energy transmission which allows their operation at very low excitation power level with high receive signal-tonoise ratio. Additionally, the resonance nature of these probes enables accurate microwave spectroscopic characterization of a wide range of dielectric materials. To the best of the authors' knowledge resonance microwave probes of considered types have never been applied to near field imaging before.

The optimal imaging conditions for 3D brain surface imaging by magnetic resonance imaging (MRI) and multi-slice CT were investigated. Visualization of the sulci, gyri, and veins on the brain's surface was also compared between 3D surface images acquired using multi-slice CT and conventional single-slice CT and MRI. Various imaging parameters, including slice thickness, dose, and matrix size, were evaluated using our original brain surface phantom and longitudinal direction evaluation phantom as well as images obtained from healthy volunteers. Subjects of the clinical study were patients with arteriovenous malformations and brain tumors who underwent CT-angiography at the same time as MR-angiography. The quality of 3D images of the brain surface is most strongly influenced by partial volume effects related to slice thickness. In multi-slice CT, a slice thickness of 0.5 mm can be employed to minimize the partial volume effect, providing results that are far superior to those that can be achieved by conventional single-slice 3D-CT. In addition, the excellent S/N of multi-slice CT permits the veins on the brain's surface to be clearly visualized without the use of contrast medium. With regard to visualization of the sulci and gyri, although some problems remain to be overcome, multi-slice CT was found to be equivalent to 3D surface imaging using MRI.

Molecular imaging is very promising technique used for surgical guidance, which requires advancements related to properties of imaging agents and subsequent data retrieval methods from measured multispectral images. In this article, an upconversion material is introduced for subsurface near-infrared imaging and for the depth recovery of the material embedded below the biological tissue. The results confirm significant correlation between the analytical depth estimate of the material under the tissue and the measured ratio of emitted light from the material at two different wavelengths. Experiments with biological tissue samples demonstrate depth resolved imaging using the rare earth doped multifunctional phosphors. In vitro tests reveal no significant toxicity, whereas the magnetic measurements of the phosphors show that the particles are suitable as magnetic resonance imaging agents. The confocal imaging of fibroblast cells with these phosphors reveals their potential for in vivo imaging. The depth-resolved imaging technique with such phosphors has broad implications for real-time intraoperative surgical guidance.

Application of atop-surface imaging(TSI) process by silylation to ArF lithography is desirable for ULSI production with minimum feature size for sub-120nm. We evaluated lithographic performances of non-chemically amplified positive TSI photoresist and chemically amplified negative TSI photoresist, both based on phenolic polymer. When off-axis illumination was used, 120nm and 110nm L/S patterns were obtained with non-chemically amplified resist(non-CAR) and chemically amplified resist(CAR) respectively. 100nm L/S patterns of CAR were obtained with strong off-axis illumination using binary intensity mask. CAR was superior to non-CAR in terms of lithographic performances, but inferior to non-CAR in terms of resist pattern collapse. Line edge roughness(LER) of CAR was sufficiently minimized by optimizing silylation bake temperature and it was comparable to that of single layer resist. For the prevention of resist pattern collapse in dry development process, the property of adhesion and resist rigidity is impor ant. This results can help the design of matrix resin of TSI resist for sub-100nm lithography.

A new approach to image microscopic surface properties is introduced. Information about surface properties such as topography is obtained by repeated acquisition of an optical signal from a large number of microscopic, self-propelled probes moving on random paths across a surface. These self-propelled probes sample the surface in a statistical process in contrast to the deterministic, linear sampling performed by a scanning probe microscope. This method is experimentally demonstrated using microtubules as probes, which are moved by the motor protein kinesin.

The use of extreme ultraviolet radiation (13.4nm) for microlithography requires a thin layer imaging resist technology due to the strongly absorbing nature of 13.4nm radiation. In any thin layer imaging technique, the aerial image from the exposure system is transferred into a top imaging layer of photoresist and is used to form an in-situ mask for pattern transfering the image through the remaining resist thickness to the device layer in a separate etch development step. The work presented here takes advantage of a new aminodisilane silylation reagent to make improvements in the thin layer imaging process known as top surface imaging. This silylation process is capable of 100nm resolution using extreme ultraviolet exposure at 13.4 nm and the new aminodisilane reagent.

Near-infrared (NIR) optical imaging is a noninvasive and nonionizing modality that is emerging as a diagnostic tool for breast cancer. The handheld optical devices developed to date using the NIR technology are predominantly developed for spectroscopic applications. A novel handheld probe-based optical imaging device has been recently developed toward area imaging and tomography applications. The three-dimensional (3D) tomographic imaging capabilities of the device have been demonstrated from previous fluorescence studies on tissue phantoms. In the current work, fluorescence imaging studies are performed on tissue phantoms, in vitro, and in vivo tissue models to demonstrate the fast two-dimensional (2D) surface imaging capabilities of this flexible handheld-based optical imaging device, toward clinical breast imaging studies. Preliminary experiments were performed using target(s) of varying volume (0.23 and 0.45 cm(3)) and depth (1-2 cm), using indocyanine green as the fluorescence contrast agent in liquid phantom, in vitro, and in vivo tissue models. The feasibility of fast 2D surface imaging ( approximately 5 seconds) over large surface areas of 36 cm(2) was demonstrated from various tissue models. The surface images could differentiate the target(s) from the background, allowing a rough estimate of the target's location before extensive 3D tomographic analysis (future studies).

The surface imaging processes using germylating agents are investigated. The removability of the resist is expected to be improved by using germylation instead of silylation. The reactivity of several germylating agents with phenolic OH group is evaluated. And germylamine compounds are found to exhibit the highest reactivity among them. Three different types of surface imaging processes are demonstrated and submicron patterns are obtained with each process. Bis(triethylgermyl)amine (BGA) as the germylating agent and PLASMASK 200G-C are used for these processes. The reactivity of BGA is higher than that of HMDS.In the deep UV exposure process, the differences between the germylation and the silylation are investigated on the oxygen dry etching characteristics and the diffusion depth of the reaction. The process using the germylation by BGA is found to have higher oxygen dry etching resistance and lower swelling which corresponds to the diffusion depth in germylated area as compared with the silylation by HMDS. From these results the surface imaging process is expected to have high controllability for linewidth by using the germylation.

We report the use of a high-refractive-index aplanatic solid immersion lens (ASIL) in total internal reflection fluorescence (TIRF) microscopy. This new solid immersion total internal reflection fluorescence (SITIRF) microscopy allows highly confined surface imaging with a significantly reduced imaging depth compared with conventional TIRF microscopy. We explore the application of a high refractive index, low optical dispersion material zirconium dioxide in the SITIRF microscope and also introduce a novel system design which enables the SITIRF microscope to work either in the epi-fluorescence or TIRF modes with variable illumination angles. We use both synthetic and biological samples to demonstrate that the imaging depth in the SITIRF microscope can be confined to a few tens of nanometers. SITIRF microscopy has the advantages of performing highly selective imaging and high-resolution high-contrast imaging. Potential applications in biological imaging and future developments of SITIRF microscopy are proposed.

The paper describes a new technique for measuring surface slopes at the air–water interface. A microlens array is employed to optically sample the fluid surface at a large number of measurement points in parallel. The focal plane image of the lenslet array is recorded by a standard video camera, generating a data set of typically 4000 candidate samples for each video frame. The displacement of the focal spots is analyzed using a cross-correlation technique augmented by a topological identification algorithm which makes use of the hexagonal structure of the lenslet array. Surface height profiles are computed by integrating the surface slope field.

At present one of the most promising production-worthy 193nm resist approaches is a single layer, dry developed, surface imaging, silylation process. An evaluation of commercially available developmental resists shows excellent process versatility and lithographic performance. An evaluation of silylation conditions shows more versatility than previously demonstrated. No flow is seen in silylated features, leading to excellent dimensional control and edge profiles. Preliminary results indicate better than 0.18μm resolution and linearity to 0.20μm without the use of phase shift masks. Geometries of 0.1μm have been demonstrated in a resist process which is available for evaluation of 0.20μm devices processes as well as 256MB DRAM circuits.

Poly(p-vinylbenzoic acid) and its ester are opaque below 300nm and therefore useful in deep UV top surface imaging (TSI), which is a viable technique to overcome the shallow depth of focus and topography effects. In this paper are described two TSI systems utilizing the benzoic acid derivatives in the chemical amplification scheme. The first system is a single-layer negative TSI based on gas-phase silylation of poly(t-butyl p-vinylbenzoate) resist. The second case is the use of poly(p-vinylbenzoic acid) as a strippable bottom layer in conjunction with a thermally-developable, oxygen RIE barrier resist, which comprises an all-dry bilayer, positive TSI system.

This chapter presents an overview of Atomic Force Microscopy (AFM) principles followed by details on AFM instrumentation. In particular, the frequency modulation method of the non-contact AFM (NC-AFM) used in ultra-high vacuum conditions is explained in detail. Then, applications of NC-AFM for an atomic-scale range characterization of semiconductor and isolator surfaces as well as supported nanostructures are introduced.