bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digital photogrammetric quantification of surface area and volume on scanning electron micrographs of frozen hydrated lung tissue
Authors: Poinar H. N. , Strohman R. D. , Lee C. Y. , Bastacky S. J. 
Published: June 2010

AbstractA digital video plotter (DVP, Leica), the personal computer equivalent of an analytical plotter, was used to measure the coordinates of points chosen from stereo pair images of the surface of frozen hydrated lung imaged at magnifications of 2000 and 5000x with a low‐temperature scanning electron microscope (SEM). Rat lung tissue was frozen in vivo with a liquid nitrogen cryoprobe under carefully controlled physiologic conditions. At slow freezing rates, water in the aqueous layer at the surface of the lung segregates into ice crystals (dendrites) which branch in the plane of the surface. Coordinates of points on dendrite surfaces were measured by the DVP and passed to TERRAMODEL (Plus III Software, a land modeling program) where they were used to generate a three‐dimensional model, from which surface area and planimetric area of the lung surface were calculated. Additional measurements were made at the top and bottom of the ice structures and a Basic language program was written to calculate the volume of ice on the lung surface. Digital photogrammetry coupled with low‐temperature SEM of frozen samples allows measurement of water and water‐containing microstructures ubiquitous in biology.
The role of the environmental scanning electron microscope in the investigation of cement‐based materials
Authors: Neubauer C. M. , Jennings H. M. 
Published: June 2010

AbstractThe role of the environmental scanning electron microscope (ESEM) in the study of cement‐based materials is reviewed. Since water is an intrinsic part of the microstructure of cement paste, techniques that facilitate the study of wet specimens are necessary. The evolution of techniques is traced from standard microscopic methods to the use of the ESEM for in situ analysis. The importance of past and current work is discussed, including novel analytical methods designed for the study of cement pastes. Directions for future work are also discussed.
Applications of the environmental scanning electron microscope to the analysis of pharmaceutical formulations
Authors: Emanuele Antony D. , Gilpin Christopher 
Published: June 2010

AbstractElectron microscopy has been used for several years as a routine tool for the study of pharmaceutical formulations. However, it is usually desirable to obtain information on these systems in the wet state, and there are concerns regarding the interpretation of information provided by conventional electron microscopy where samples are subjected to preparation techniques which may include freezing, drying, fracturing, and coating. The environmental scanning electron microscope (ESEM) has been used to analyse a number of pharmaceutical samples in their natural state. Results obtained from these samples, including biodegradable matrices, microparticulate systems (both degradable and non‐biodegradable), and bioadhesive matrices, will be discussed and the merits and limitations of the ESEM will be highlighted.
Image sharpness measurement in scanning electron microscopy—part I
Authors: Chae Postek M. L. T. , Vladár András E. 
Published: June 2010

AbstractThis study introduces the idea of the sharpness concept in relationship to the determination of scanning electron microscope (SEM) performance. Scanning electron microscopes are routinely used in many manufacturing environments. Fully automated or semiautomated SEMs as metrology instruments are used in semiconductor production and other forms of manufacturing where the ability to measure small features with the smallest possible errors is essential. It is felt that these automated instruments must be routinely capable of 5 nm (or better) resolution at or below 1 kV accelerating voltage for the measurement of nominal 0.18–0.35 μm size parts of the integrated circuits. Testing and proving on a day‐by‐day basis that an instrument is performing well is not easy, but, understandably, is an industry need and concern. Furthermore, with the introduction of fully automated inspection and metrology instrumentation, not only does an appropriate, easy to obtain or manufacture sharpness measurement sample have to exist but also an objective and automated algorithm must be developed for its analysis. Both of these have been the object of a study at the National Institute of Standards and Technology (NIST), and the fundamentals are discussed in this paper and the computer‐based automated analysis in a companion paper (Part II; Vladáret al. 1998). The method described in these papers is based on the analysis of the frequency domain representation of the SEM image and can also be used to check and optimize two basic parameters—focus and astigmatism—of the primary electron beam as related to a measure of image sharpness. The application of this technique to check regularly the resolution of the SEM in quantitative form will also be discussed.
Mean atomic number and backscattered electron coefficient calculations for some materials with low mean atomic number
Authors: Howell P. G. T. , Davy K. M. W. , Boyde A. 
Published: June 2010

AbstractIn modelling electron backscattering from solids using Monte Carlo simulations, knowledge of mean atomic number, mean atomic weight, and density of the bulk material are required. We studied four different ways in common useforthe calculation of mean atomic number. An alternative and improved approach is to calculate the mean backscattered electron (BSE) coefficient, η, from a knowledge of the elemental composition and values of η for the elements. Again, we studied a number of formulae suggested for this averaging process. As it is not possible to measure η directly for a number of elements, the method used to interpolate between elements with known η was also examined. In addition, we obtained experimental backscattering relationships for topography‐free samples of poly (methylmethacrylate) (PMMA), carbon, aluminium, and a series of novel halogenated resins, all solids with relatively low mean atomic numbers, and calcified tissues. None of the methods for determining mean atomic number placed the materials of interest in the correct sequence of their experimentally determined BSE peaks: the data differed widely between the individual methods. The averaged BSE coefficient calculated by the Castaing formula gave the best agreement with the experimentally derived data.
Three‐dimensional reconstruction and modeling of microstructures and microchemistry in geological materials
Authors: Marschallinger Robert 
Published: June 2010

AbstractComputer‐aided three‐dimensional (3‐D) reconstruction of minerals and rock fabrics enables quantification, spatial analysis, and state of the art communication of the complex spatial relations typically encountered in geological materials. An efficient and versatile combination of sample preparation, data acquisition, and processing methods has been established which renders the 3‐D reconstruction of microstructures in geological materials applicable on a routine basis: rock samples are subject to a cycle of precision serial lapping and subsequent image acquisition by an electron probe microanalyzer. The yielded backscattered electron images and x‐ray maps depict mineral phase distribution and chemical variation; backscattered electron images are stacked in a voxel array to be interpolated by binary processing. X‐ray map data are interpolated by geostatistical methods, and the results are forwarded to one voxel array per chemical element of interest. Merging the voxel arrays by boolean and image algebraic methods enables the integrated analysis and visualization of mineral morphology and associated chemical variation in geological materials.
Toward a standard for remote microscope control systems
Authors: Morgan Christopher , Pardoe Don , Smith Nancy 
Published: June 2010

AbstractRemote access to scientific instruments provides a way to share a variety of valuable resources with a worldwide audience. By pooling these resources and providing a common network and user interfaces to these resources, science researchers and educators will have capabilities that no one institution could afford. The Microscope And Graphic Imaging Center (MAGIC) at California State University, Hayward (CSU Hayward) is developing a model for such a system. We are developing model software for interactive remote‐shared access to an unmodified Philips XL 40 scanning electron microscope (SEM). Located within the Department of Biological Sciences, MAGIC provides facilities and expertise in specimen preparation as well as providing remote access to researchers and educators over the Internet. We have used a wide range of networking technologies, including modem, ISDN, Ethernet, T1, and ATM to control the SEM, and a wide range of image transmission technologies, including closed circuit TV, compressed video over ATM, and digital imaging (Smith et al. 1996a,b,c). We have taken a modular approach to software control which allows us to arrange key pieces in a variety of ways on a number of different platforms. Results indicate that under the correct conditions, access to expensive and sensitive commercially available scientific equipment can be shared by large research, educational, and industrial communities. However, care must be taken to address issues of security, robustness, and performance. Plans are to incorporate remote access into university, community college, and high school use starting in 1998. Based upon this experience, we propose a framework for standardizing remote access to visual scientific equipment. This framework consists of three layers: (1) clients, (2) servers, and (3) instruments. This approach will allow a wide variety of equipment to be shared in a flexible and uniform manner.
A low‐temperature scanning tunneling microscopy investigation of single electron effects
Authors: Drechsler T. , Chi L. F. , Fuchs H. 
Published: June 2010

AbstractThe design and the performance of a low‐temperature scanning tunneling microscope (STM) operating in ultrahigh vacuum (UHV) is described. The sample and the STM are cooled by means of a helium bath cryostate. The STM consists of a “beetle”‐type microscope, which is mounted on a spring suspension stage that can be operated between room temperature and 30 K. We present the results of tunneling spectroscopy on ligand‐stabilized Au55‐clusters on a thiol‐covered gold substrate. I(V)‐curves taken at 100 K clearly show coulomb staircase structures, which agree well with theoretical predictions for these structures.
Microstructure of the processing of black beans (Phaseolus vulgaris L.) from purée to drum‐dried flakes
Authors: Wood Delilah. F. , De J. Berrios Joseé , Venet Cecile 
Published: June 2010

AbstractBlack bean purée and drum‐dried flake microstructures were studied and compared with raw bean by light and scanning electron microscopies. Results illustrate the value of microscopy as a tool for evaluating physical and chemical changes in bean components due to processing. Microscopy was employed to follow the microstructural changes during the processing of black beans by looking at the intermediate product (the purée) and the end product (the flake). The consequences of processing on storage components such as starch, proteins, lipids, and cell walls were elucidated. The bean purée contained starch granules within intact cells and seed coat fragments throughout the product. The drum‐dried flakes had a rough exterior, and starch granules were also found within intact cells. Both starch granules and seed coat fragments were found in the drum‐dried flake matrices. Protein bodies, occurring in the raw bean, were present (but less obvious than in the raw bean) in both the bean purée and the drum‐dried flake. Cell contents that no longer occurred in intact cells consisted of fused protein bodies in both products. The seed coat did not change significantly during processing, and pieces of seed coat were easily differentiated throughout the bean purée and the drum‐dried flakes. The endosperm, which is closely adherent to the inner portion of the seed coat in the intact bean, was no longer evident in the processed samples, presumably because the endosperm tissue had completely solubilized following the addition of water. Lipids occurred as small droplets and were located throughout both the bean purée and the drum‐dried flakes. The bean purée consisted mostly of clumps of intact cotyledon cells with very few broken cells. The cotyledon cells contained intact starch granules with no evidence of starch gelatinization [i.e., the irreversible breakdown of the granule structure (Dengate 1984)]. Free starch granules in the purée, resulting from broken cells, were slightly swollen and had begun to gelatinize. Protein bodies were still evident in the purée, but no longer stained as in the raw, mature bean. The drum‐dried flakes contained intact and broken cotyledon cells. Intact cells contained protein bodies that were difficult to detect and appeared to be a rather continuous protein matrix. The cotyledon cells also contained partially gelatinized starch granules that remained mostly distinct but were beginning to fuse. Starch granules interspersed between intact cells were fused and completely gelatinized. The drum‐dried flake matrix consisted of a continuous mixture of protein, starch, and cell wall material.
Computer‐aided design helps design what may be world's smallest scanning tunneling microscope
Authors: Fasanella Kenn 
Published: June 2010

AbstractComputer‐aided design (CAD) played a crucial role in designing what is believed to be the world's smallest scanning tunneling microscope. Conventional scanning tunneling microscopes (STMs) are 2) to 6) in diameter. NEC researchers needed an STM only 1) in diameter to study objects in a high magnetic field at very low temperature within a tank of liquid helium. NEC engineers built the microscope in‐house and at a local machine shop using a combination of commercial components and others that they built themselves. Computer‐aided design was crucial in the fitting of all the required components within the very tight envelope requirement. An inexpensive Macintosh and PC‐based CAD program, Vellumfrom Ashlar, Inc., San Jose, California, was used to evaluate a wide range of possible configurations in minimal time.
Sintering of Sio2‐Tio2 obtained by the sol‐gel process from chelated Ti precursors
Authors: Méndez‐vivar J. , Mendoza‐Serna R. 
Published: June 2010

AbstractTwo experimental procedures were used to obtain SiO2‐TiO2. In one case, the Si precursor was prehydrolyzed before reacting with Ti to equalize the chemical reactivity of both reagents. In the other case, H2O was produced in situ to avoid precipitation of TiO2. Two chelating agents were also used separately to control the polymerization process. It was found that the type of chelating agent leads to differences in the particle size.
Mechanical properties of L929 cells measured by atomic force microscopy: Effects of anticytoskeletal drugs and membrane crosslinking
Authors: Wu H. W. , Kuhn T. , Moy V. T. 
Published: June 2010

AbstractTo shed light on the architecture of the cytoskeleton, we used the atomic force microscope (AFM) to measure the elasticity, viscoelasticity, and plasticity of L929 cells. The initial elastic response (Young's modulus ∼ 4,000 Pa) of the cells to an applied force was followed by a slow compression of the cytoskeleton (τ1/2 ≈ 10 s). When force application was terminated, the cytoskeleton underwent a sudden partial decompression and a subsequent slow, incomplete recovery. The role of the cytoskeletal elements in cell mechanics was accessed in AFM measurements carried out on cells treated with cytochalasin D, nocodazole, or col‐cemid. Cytochalasin D treatment reduced both elasticity (∼45%) and cytoplasmic viscosity (∼65%), whereas cells treated with nocodazole or colcemid exhibited a marked increase in elasticity (∼100%) and a slight increase in viscosity (∼15%). The AFM force measurements also provided evidence that the cell membrane and the cytoskeleton are mechanically coupled. Tightly adherent cells were stiffer than cells that were loosely attached. Moreover, cells crosslinked with either glutaraldehyde, 3,3 ‘‐dithiobis’sul‐fosuccinimidylpropionate] (DTSSP), or Concanavalin A were more rigid than untreated cells. It is of interest that cells crosslinked with Concanavalin A, but not DTSSP, displayed plastic behaviors that may reflect the induction of cytoskeletal reorganization by Concanavalin A.
Quantitative secondary ion mass spectrometry imaging of self‐assembled monolayer films for electron beam dose mapping in the environmental scanning electron microscope
Authors: Gillen Greg , Wight Scott , Bright David , Herne Tonya 
Published: June 2010

AbstractFluorinated alkanethiol self‐assembled monolayers (SAM) films immobilized on gold substrates have been used as electron‐sensitive resists to map quantitatively the spatial distribution of the primary electronbeam scattering in an environmental scanning electron microscope (ESEM). In this procedure, a series of electron dose standards are prepared by exposing a SAM film to electron bombardment in well‐defined regions at different levels of electron dose. Microbeam secondary ion mass spectrometry (SIMS) using Cs+ bombardment is then used to image the F‐ secondary ion signal from these areas. From the reduction in F‐ intensity as a function of increasing electron dose, a calibration curve is generated that allows conversion of secondary ion signal to electron dose on a pixel‐by‐pixel basis. Using this calibration, electron dose images can be prepared that quantitatively map the electron scattering distribution in the ESEM with micrometer spatial resolution. The SIMS imaging technique may also be used to explore other aspects of electron‐surface interactions in the ESEM.
Study of luminescent centers annealing in wide bandgap semiconductors: Color cathodoluminescence‐scanning electron microscopy
Authors: Mokhov E. N. , Roenkov A. D. , Saparin G. V. , Obyden S. K. 
Published: June 2010

AbstractA color cathodoluminescence‐scanning electron microscopy (CCL‐SEM) technique was used to study the annealing of luminescent centers in wide bandgap semiconductors (mainly silicon carbide), due to native defects, induced during the growth process or to radiation by high‐energy particles. The significant role of dislocations in the crystals was revealed. These dislocations are created by the mechanical failure of crystals and play the role of getters for unstable defects and assist in quenching the luminescence at fairly low annealing temperatures. During the electron beam annealing of the samples, the resolved CL fine structure of luminescence images was measured around failure regions which look like a rosette of strength* at temperatures of 1300–1350°C.
Transmission line probes for scanning photon‐tunneling microscopy
Authors: McCutchen C. W. 
Published: June 2010

AbstractBecause metalized light probes for scanning photon‐tunneling microscopy are tapered waveguides beyond cutoff, tapered coaxial transmission lines have been tried instead. It is shown here that insertion losses in such a line can be reduced by asymmetrically phase‐apodizing the illuminating lens. Alternatively, a strip rather than a coaxial line can be used.
High‐resolution photon scanning tunneling microscopic investigations of NaCl crystal surfaces
Authors: Brückl H. , Pagnia H. , Sotnik N. 
Published: June 2010

AbstractCleaved NaCl crystal surfaces were investigated with a photon scanning tunneling microscope. Steps 4 nm high and 3 nm wide could be resolved. The lateral resolution is coupled to the step height by the steepest measured slopes of about 50°. The measured stepwidth at shallow steps is noise‐and slope‐limited to 3 nm. The mapping of the decay coefficient of the evanescent field shows spatial inhomogeneities often coupled to the crystalline structure.
The influence of elastic and ionization cross‐section approximations on the result of Monte Carlo calculations
Authors: Bakaleinikov L. A. , Tretyakov V. V. 
Published: June 2010

AbstractA Monte Carlo program has been developed on the basis of a Mott cross‐section and knock‐on model. The use of this program for the set of the film‐substrate type systems shows that there is some difference between the calculated and experimental x‐ray depth distribution. To clear up the reasons for the discrepancies, the Monte Carlo model is investigated by calculating the various physical quantities associated with the electron distribution in homogeneous bulk and film specimens and by comparing them with the known experimental data. The influence of the elastic and ionization cross‐section approximation on the electron distribution in target is studied.
Low‐energy electron/atom elastic scattering cross sections from 0.1–30 keV
Authors: Browning R. , Li T. Z. , Chui B. , Ye Jun , Pease R. F. W. , Czyzewski Z. , Joy D. C. 
Published: June 2010

AbstractEmpirical forms for electron/atom scattering cross sections predict backscattering factors that compare well with those calculated using tabulated Mott data from 0.1 to 30 keV. The form of the empirical total cross section is similar to the screened Rutherford cross section. The fit to the tabulated differential Mott cross sections is decomposed into two parts, one part being of the same mathematical form as the screened Rutherford cross section (σR), and the second part being an isotropic distribution (σI). The ratio of the total cross sections (σR/σI) between the screened Rutherford part of the differential scattering cross section and the isotropic part of the distribution is fitted to give the same ratio of forward to backscattered currents as the tabulated Mott differential cross sections. The three equations, one for the total elastic cross section and two describing the differential cross section—one for the Rutherford screening parameter and one for the ratio σR/σI—give backscattering results covering all the major trends with energy and atomic number compared with the backscattering coefficients calculated using tabulated Mott cross sections. However, agreement with experiment is poor for some well‐researched examples such as Au. Monte Carlo calculations using the empirical cross sections show that surface effects may be critical in interpreting experimental results.
Properties and structures of Co‐based metallic glasses
Authors: Habib K. , Caceres P. 
Published: June 2010

AbstractA fundamental study on Co‐based metallic glasses has been conducted. The study focused on understanding the changes of the properties and structures of an Fe‐B‐Si glass as a function of Co, Co‐Ni, Co‐Mn, and Co‐Ni‐Mo additions. The separate addition of Co, Co‐Ni, Co‐Mn, and Co‐Ni‐Mo elements was successful in such a way that four new metallic glasses were produced. The compositions of the new glasses are Fe66Co18B15Si1, Co66Fe4B14Si15, Co76Fe2Mn4B12Si6, and Co69Fe4Mo2B12Si12. Consequently, an evaluation of the physical and magnetic properties was determined. Furthermore, the internal and surface structures of the glasses have been characterized by a transmission electron microscope (TEM), and a scanning tunneling microscope (STM), respectively. A comparison between the internal and surface structures of the glasses was carried out on both amorphous and crystalline forms. As a result, a correlation between the properties and structures of the glasses is established.