bluuebunny/crossref_metadata_2025_split huggingface dataset:
Richardson Plots for Fractal Dimension Characterization of Bound Aries of Digitized Grains and Particles
Authors: Bright DS 
Published: July 2020

Abstract
Fractal dimension is useful for characterizing objects with tortuous boundaries, providing an additional measurement to characterize shape beyond the commonly used area, perimeter, caliper diameter and their combinations. The fractal dimension of the boundary describes the increase of the measured value of the perimeter of an object resulting from increasing measurement resolution, i.e., decreasing step size. We desire to characterize and classify shapes such as soot particles, as shown in the TEM micrograph in Fig. 1a, and crystalline grains of metal alloys, as shown in the SEM micrograph of Raney nickel in Fig. 4.
This investigation involves evaluation of the Minkowski-sausage or dilation technique (Fig. 1) using the histogram of the Euclidean distance map of the perimeter of the object. The distance map gives bands of various widths that follow the perimeter - greater widths lose detail. Perimeter length is sausage (band) area divided by sausage width, w.
Detailed Calculations of Thermal Diffuse Scattering
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Müller DA , Edwards B , Kirkland EJ , Silcox J 
Published: July 2020

Abstract
Convergent beam electron diffraction (CBED) produces a diffraction pattern from a single point on the specimen using a focused probe in the scanning transmission electron microscope (STEM). Because the incident wavefunction is a focused probe, each diffraction spot is enlarged to a disk the size of the objective aperture. Thermal vibration in the specimen reduces the intensity of the diffraction disks and introduces scattering in between the disk. This normally forbidden scattering between the diffraction disks is referred to as thermal diffuse scattering (TDS). The effects are most pronounced at large scattering angles, where TDS scattering can greatly reduce the intensity of the higher order Laue zone (HOLZ) lines. Previous work on modeling the TDS intensity involved the so-called frozen phonon method and the Einstein model of lattice vibration. The Einstein model assumes that each atom in the specimen vibrates independently of every other atom in the specimen and possible correlations among adjacent atoms are ignored.
Ultimate Resolution Limits - Nanotips and Atom Lenses
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Spence JCH 
Published: July 2020

Abstract
The most useful classical definition of resolution is a property of an instrument alone, independent of the sample. Because of this it is not possible to define resolution simply for HREM or for most of the new microscopies. For weak phase objects, the best current HREM machines offer a point resolution very close to 0.lnm. For the first time, recent off-axis electron holography has extended resolution beyond the point resolution limit, in fulfillment of Gabor’s original aim. Other recent approaches to super-resolution have used through-focus series under highly coherent conditions, sums of images obtained under different illumination angles, dark-field STEM imaging with high-angle detectors,thin annular detectors in STEM, or the use of coherent nanodiffraction patterns. Aberration correction by electron optical means has undergone a recent revival, and the effects of third-order astigmatism are under study. If third-order spherical aberration is corrected, the projected charge density approximation may be more useful than the weak-phase object approximation, since the Scherzer focus then no longer applies.
Resolution in Light Microscopy
Authors: Tandler H , Schreiber L , Simon U , Keller H E 
Published: July 2020

Abstract
The resolution in conventional light microscopy was defined by Abbe as: Wavelength (λ) and Numerical Aperture (NA) have a direct influence while the factor (c) is dependent upon the geometry of the illumination and observation beam paths. Some typical examples are:
High illumination apertures in darkfield or oblique illumination or specific ratios between illumination and observation aperture can substantially improve resolution. Various shapes of the illumination aperture, annular, point, centered or off axis at different azimuths directly influence numerical aperture and coherence and with this resolution, contrast and depth.
In mirror objectives low apertures become vignetted, the resolution is enhanced at the expense of contrast. In studies of Hopkins and Barham the factor “c” can range from 0.5 to 0.8. For the practically attainable condition, where illumination and observation aperture are identical, “c” becomes 0.61 and we have partial coherence.
Exceeding the observation aperture on the illumination side reduces “c” further but diffraction significantly reduces contrast.
What Do we Really See? Resolution in Near-Field Optical Microscopy
Authors: Isaacson MS 
Published: July 2020

Abstract
Six years ago there was a symposium held at the 1991 EMS A meeting to discuss the issue of “Resolution in the Microscope”.1 In this paper, we will look at resolution in near-field imaging, a blossoming field, and see whether any of our concepts have changed.
It has been only within the last decade that the concept of super-resolution microscopy in the near field has been vigorously pursued and experimentally demonstrated. (For reviews on the subject, the reader is referred to the proceedings of the second and third international conferences on near field optics.) However, as in most areas of microscopy, the idea is not new, but rather rediscovered after decades of dormancy.
The idea of optical resolution unhindered by far-field diffraction limitations was conceived more than a half-century ago by E.H. Synge4 in a paper entitled “A Suggested Method for Extending Microscopy Resolution into the Ultra-Microscope Regime”.
The Limits of Resolution in X-Ray Microscopy
Authors: Maser J , Jacobsen C , Spector S 
Published: July 2020

Abstract
In far-field microscopes, the spatial resolution is ultimately limited by the wavelength of the radiation used. While near-field and related microscopes can improve upon this, they can only do so with thin specimen regions. Thin specimens can also be studied at atomic resolution using electron microscopes. To achieve improved resolution on micrometer-thick specimens, another alternative is to use significantly shorter photon wavelengths. We discuss here the use of soft x-rays for microscopy and their resolution limits.
Image formation requires resolution and contrast. by using soft x-rays with a photon energy between the K absorption edges of carbon and oxygen, one is able to image hydrated biological specimens with high contrast. The contrast is such that no addi-tional staining is required, while efforts are also underway to utilize gold and luminescent probes for selective labeling. In addition, x-ray sources have high spectral resolution and good signal-to-background relative to electron microscopes which allows for elemental and chemical state mapping of major constituents.
Transport of Secondary Electrons Through a Film of Condensed Water; Implications for Imaging Wet Samples
Authors: Bache I C , Thiel B L , Stelmashenko N , Donald A M 
Published: July 2020

Abstract
We have performed a theoretical and experimental study of the the effect that a surface layer of condensed water has on the emission of secondary electrons from the surface. This is an issue of considerable interest to users of the Environmental SEM (ESEM) when imaging wet samples. Previous work has been performed to investigate the effect of a layer of water on back scattered electrons (BSE), but secondary electron (SE) imaging is more commonly used in ESEM, so an understanding of the interactions of SE with water is important. The aim of this work is to quantify the thickness of water through which imaging is possible, by considering both the interactions of secondary electrons with the water, and the interactions of the water layer with the sample, which may affect the secondary electron emission coefficient, δ.
The effects that a surface layer of water may have on electron emission from a sample surface can be split into three regimes.
Characterization of Contamination Effects on Polyimide Film Fracture Using Environmental Scanning Electron Microscope
Authors: Li M J , Taylor M E 
Published: July 2020

Abstract
Polyimide films have been used in many applications for their excellent mechanical, thermal mechanical, electrical, and chemical properties. In microelectronic industries, for example, polyimide films are utilized as dielectric materials in high density interconnects, passivation layers for semiconductor devices, and substrates for flexible printed circuits. One of the major concerns in these applications is the degradation due to deficient environments in fields. The change of environmental conditions, such as temperature, relative humidity, and containmination, may affect mechanical or electrical performance of the films. Cracking, warpage and delamination have been reported in recent years. Temperature and humidity effects have been investigated in previous studies. In this work, containmination effects on polyimide film cracking and fracture are investigated using an environmental scanning electron microscope (ESEM) with a tensile substage and a low-magnification device.
The ESEM (ElectroScan) enables examining non-conductive materials without conductive coating which maintains the materials in its natural state.
Variations in the Probe Beam Broadening with Operating Conditions in ESEM: Monte-Carlo Simulations and Edx Measurements
Authors: C. Bache I , Kitching S , Thiel B L , Donald A M 
Published: July 2020

Abstract
An understanding of the scattering of an electron beam as it passes through a volume of low pressure gas is of critical importance for users of Low Vacuum and Environmental Scanning Electron Microscopes (LV-SEM & ESEM respectively) The ‘skirting’ of the primary beam as a result of scattering is of particular importance in X-ray microanalysis where scattered electrons, falling onto the sample away from the probe beam, can adversely affect the spatial resolution of the X-ray signal. A number of studies have attempted to quantify the width of the probe beam experimentally and hence determine optimum microscope operating parameters. Theoretical and computational work modelling the interactions of the beam with the gas have suggested that the shape of the probe beam can be modelled by some form of Gaussian. Experimental measurements, however, suggest that the probe has a skirted form rather than a Gaussian one.
Sensitivity of SEM/EDX to Detect Small Particles on Substrates.
Authors: Thornton. MF 
Published: July 2020

Abstract
The characterization of microscopic particles on substrates is of interest in numerous scientific fields. One example is semiconductor device defect review, where the characterization of particles or defects on a device is an essential aid in tracing sources of contamination in the production process. With the ever decreasing component separation on the integrated circuits the sensitivity of SEM/EDX to detect small particles on substrates is an important issue. The minimum size of particles causing defects in semiconductor device manufacture is predicted to decrease from 0.12µm today to 0.02µm by the year 2010. The question of interest is how long the SEM/EDX analysis tool can continue to be used to identify elements present in “killer” defect particles of ever decreasing size? This paper attempts to address this question.
It has already been shown that films as thin as a monolayer can be detected with WDX provided high beam currents are available.
Use of Low Voltage High Resolution SEM (LVHRSEM) to Reveal Architectural Organization of Bone Mineral
Authors: Benezra V , Spector M , Hobbs LW 
Published: July 2020

Abstract
Load-bearing tissues in different organ systems display a wide variety of mechanical properties, yet are composed of only a few different molecules, with collagen as the principal structural protein. In bone, a mineral phase comprising carbonate-apatite crystallites confers compressive and torsional strength. The arrangement of collagen and apatite into three-dimensional hierarchical composite structures enables the tissue to bear high loads while maintaining flexibility. Moreover, bone serves as the body’s chemical storehouse for non-collagenous proteins and smaller molecular weight anions and cations such as calcium.
An understanding of the three-dimensional structure of the apatite phase at the nanometer and micrometer levels can provide insights into the properties of bone, and serve as the guide for the development of bone substitute materials. Transmission electron microscopy (TEM) has been valuable in revealing certain ultrastructural features of the mineral. However, it has not yet been possible to obtain three-dimensional reconstructions of the morphology and distribution of the apatite phase of bone using this method.
Chromium Coating for High Resolution SEM
Authors: Chen Ya , Wokosin David 
Published: July 2020

Abstract
High quality imaging of the macromolecular structure of biological samples can be obtained when combining high resolution SEM with advanced thin metal film coating techniques. A thin layer of fine grain metal film is often necessary to enrich the secondary electron (SE) signal generation and to enhance the contrast of features of interest, because the yield of SE signal from biological samples is low. Secondary electron signals, types SE-I and SE-II, are generated by primary beam at the impact point or by backscattered electrons (BSE) dislocated from the impact point, respectively (Peters, 1982; Joy, 1984). The SE-II signal yield depends on the amount of BSE signal and the collection ratio of SE-I/SE-II components regulates the surface topographic contrast. Therefore, the low atomic number metals with low backscattering coefficients should be considered for high resolution SEM coating. Chromium, which has both the features of low atomic number (Z=24) and sufficient SE signal yield, is an appropriate choice and was first used by Peters (1982) for high resolution SEM imaging.
Effect of Staining on Latex Particle Size Examined by Electron Microscopy
Authors: Ming Y , Doumaux H , Scriven L E , Davis H T 
Published: July 2020

Abstract
Electron microscopy has been an invaluble tool to the study of polymer morphology, especially latex particles, microphase-separated block copolymers, and polymer blends. However, in order to examine these materials in an electron microscope, the sample often needs to be stained to heighten contrast between locales of different composition in the specimen. Staining usually has the following advantages: heightened contrast; higher polymer glass transition temperature Tg; lowered charging; and reduced radiation damage. However, staining can also introduce artifact. It is reported that the latex particle size is raised and the polybutadiene “sphere” in block copolymers is lowered after staining. This indicates that the staining process may be complex.
Recently, low voltage field emission scanning electron microscopy (LVFESEM), especially high-resolution backscattered electron imaging produced with staining, has been used to study latex film formation, latex particle deformation and adhesion on substrates, latex particle deformation, distribution and binding in paper coatings.
Characterization of Ceramic-Based Dual Ultramicroelectrodes by Microscopic and Electrochemical Methods
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Bums F M , Giolando D M , Kirchhoff J R 
Published: July 2020

Abstract
Recent trends directed toward the miniaturization of electrodes have produced ultramicroelectrode (UME) devices. Interest in UMEs is due to the considerable improvement in the quality of the electrochemical information that is obtained as the dimensions of the electroactive surface decreases. UMEs exhibit increased sensitivity to analytes, decreased response time, and enhanced single-to-noise. In addition, solution resistance has a decreased influence on the signal. Finally, the reduced size of UMEs allows electroanalysis in small sampling environments. As a result, UMEs have been used in applications for intracellular electroanalysis, as detectors in capillary separation methods and gas chromatography, and as electrochemical probes in scanning electrochemical microscopy.
While UMEs have been investigated since the early 1980s, single probe dual UMEs are a recent development. Dual UMEs have two independent UMEs in close proximity, which allows much flexibility in the design of electrochemical-based sensor devices.
Clostridium Spore Attachment to Human Cells
Authors: Panessa-Warren B , Tortora G , Warren J 
Published: July 2020

Abstract
This paper uses high resolution scanning electron microscopy (SEM) with a LaB6 gun and the newest commercial field emission guns, to obtain high magnification images of intact clostridial spores throughout the activation/germination/outgrowth process. by high resolution SEM, the clostridial exosporial membrane can be seen to produce numerous delicate projections (following activation), that extend from the exosporial surface to a nutritive substrate (agar), or cell surface when anaerobically incubated in the presence of human cells (embryonic fibroblasts and colon carcinoma cells). Magnifications of 20,000 to 200,000Xs at accelerating voltages low enough to minimize or eliminate specimen damage (1-5 kV) have permitted the entire surface of C.sporogenes and C.difficile endospores to be examined during all stages of germination. The relationships between the spore and the agar or human cell surface were also clearly visible.
Clostridium sporogenes ATCC 3584 and C.difficile ATCC 43594 and 9689 were grown in cooked meat media, filtered and cleaned.
Surface Characters of Interfaces and Twin Domains: TEM and AFM Study of a Feldspar Crystal
Authors: xu Huifang 
Published: July 2020

Abstract
Alkali feldspar, a framework silicate (K, Na)(Si3Al)04, is a common component in ceramic materials. The feldspar crystals commonly display exsolution lamellae, twins, and modulated structures. The boundaries between neighboring domains may cause stain energy. The domain structures cause heterogeneities both inside crystals and on crystal surfaces in aspects of structure, composition, and surface microtopography. Reactivity at domain boundary positions is different from the neighboring areas. More and more studies show the effects of microtopography on the surface reactivity. It is important to reveal the surface characters or microtopography of domain structures in crystals, and their effects on local reactivity.
Results from transmission electron microscopy (TEM) characterization show it contains exsolution lamellae (both K-rich and Na-rich lamellae) and twin domains in the Na-rich lamellae (Fig. 1A). Its SAED pattern shows reflections from both K-rich and Na-rich lamellae (Fig. B). Splitted reflections result from the Na-rich lamellae wiht twin domains related by (010) mirror plane, i.e., albite twin law.
Micromechanical Behavior of Silicate Glass Films on Alumina Substrates
Authors: Zagrebelny A V , Carter C B 
Published: July 2020

Abstract
In polycrystalline liquid-phase sintered (LPS) alumina ceramics, intergranular phases have proved to have a profound effect on mechanical properties such as strength, toughness, plastic deformation, and high-temperature creep. The presence of such intergranular phases, can also influence the kinetics of many processes including sintering, grain growth, and phase transformations. As a result, the key to optimizing the performance of a ceramic material is frequently related to optimizing the properties of these grain boundary regions. In order to understand the interactions between the glass layer and the crystalline grains at a fundamental level, the amorphous material must be placed in contact with the crystalline ceramic as a thin film in a controlled manner. Preparation of such a glass phase in the thin-film geometry has also prompted the use of nontraditional mechanicaltesting techniques.
In the present study, interfaces between silicate glass and single-crystal α-Al2O3 have been studied using AFM and nanoindentation.
Slip Band Analysis by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM)
Authors: Okerstrom S , Geng W , Kramer D , Gerberich W 
Published: July 2020

Abstract
Fatigue is a common cause of failure in components subjected to cyclic stresses. Repeated loads much smaller than the yield stress of the material can cause a fatigue failure. One such component subject to cyclic stresses is a titanium heart valve housing. The valve is subjected to a low level of stress with each heart beat as a disc pivots and closes against the housing. Interest in the initiation of fatigue in such components was an impetus to examine surface plasticity and accumulated damage which could lead to fatigue initiation. Grade 4 titanium used in heart valves and pure titanium have been studied.
The three phases of fatigue are initiation of a crack, propagation, and catastrophic failure. Minimum defect size for crack propagation and failure are fairly well understood by scientists and engineers. However, the initiation portion of fatigue as a function of accumulated surface microplasticty is less well defined. SEM and AFM have been be used to evaluate microplasticity on the surface of titanium and correlate damage accumulation to the initiation of a crack.
Fully reverse loaded four point bend testing was conducted on a an electropolished pure titanium sample 15 mm by 5 mm by 1 mm thick. The sample was oxidized at 300°C for one hour prior to fatigue testing. The sample was fatigued for 25,000 cycles using a ±45N load.
Phase Contrast Imaging in Atomic Force Microscopy
Authors: Magonov Sergei 
Published: July 2020

Abstract
Phase detection in TappingMode™ enhances capabilities of Atomic Force Microscopy (AFM) for soft samples (polymers and biological materials). Changes of amplitude and phase changes of a fast oscillating probe are caused by tip-sample force interactions. Height images reflect the amplitude changes, and in most cases they present a sample topography. Phase images show local differences between phases of free-oscillating probe and of probe interacting with a sample surface. These differences are related to the change of the resonance frequency of the probe either by attractive or repulsive tip-sample forces. Therefore phase detection helps to choose attractive or repulsive force regime for surface imaging and to minimize tip-sample force. For heterogeneous materials the phase imaging allows to distinguish individual components and to visualize their distribution due to differences in phase contrast. This is typically achieved in moderate tapping, when set-point amplitude, Asp, is about half of the amplitude of free-oscillating cantilever, Ao. In contrast, light tapping with Asp close to Ao is best suited for recording a true topography of the topmost surface layer of soft samples. Examples of phase imaging of polymers obtained with a scanning probe microscope Nanoscope® IIIa (Digital Instruments). Si probes (225 μk long, resonance frequencies 150-200 kHz) were used.