bluuebunny/crossref_metadata_2025_split huggingface dataset:
The release of asbestos fibers from vinyl-asbestos floor tiles
Authors: MacDonald H.S. , Kushnaryov V. M. , Kolinski S. , Gallun M. 
Published: June 2020

There have been extensive studies of the release of asbestos fibers from friable materials used for construction. To date very little is known about the release of asbestos fibers from materials we assume to be non-friable. Since one of the major uses of asbestos was in the manufacture of floor tiles, and flooring is scoured prior to applying sealants, we have studied the release of asbestos from tiles treated in ways which model the processes tiles would be subjected to over their time of use.Vinyl-asbestos tiles were gathered and assayed for their asbestos content by TEM and polarized light microscopy (PLM). Containments were set up and the following experiments performed: 1. 9 inch square tiles were drilled 10 times with a 3/4 inch drill 2. tiles were drilled once with the drill bit above 3. tiles were boken into 1 1/2 inch pieces 4. tiles were broken into 4 pieces 5. tiles were stripped, and then coated with sealants prior to further scrubbing.
On-line high resolution image analysis
Authors: Huang F. , Zhang J. P. , Buckett M. I. , Marks L. D. 
Published: June 2020

A persistent practical problem in high resolution electron microscopy has been the diffulty to obtain careful, statistical comparisons between experimental and theoretical images. As a rule, practical applications of image simulation have involved either a direct comparison of calculated and experimental images, or a comparison of digitized images from a microdensitometer. Both of these pose substantial impediments to the final goal of HREM, namely R-factor measurements of the agreement between experimental and theoretical images.As a step beyond these approaches, we have recently finished bus-interfacing a framestore device to an Apollo 3000 workstation. The full set-up is shown in Figure 1. The framestore device, an IMAGING 151 set of boards, can perform all the standard video rate processes such as recursive filtering, as well as accumulating a 16 bit image. This device is fully integrated into the Apollo mini-computer, and is set up so that images can be directly transferred to disk within the SEMPER software system.
Boersch's electron optical bench updated
Authors: Geiger J. , Schmoranzer H. , Jakobs H. , Katterwe H. , Schröder B. 
Published: June 2020

The electron optical module system designed by Boersch /l/ has proved a success in various laboratories. The system offers in principle the advantage of being highly versatile and flexible, and is applicable to perform various experiments involving electron optics by assembling standard types of modules.The original electron optical bench does no longer meet the requirements of modern experiments. Therefore we have maintained on one hand the concept of simplicity and fast handling, e.g. in braking the vacuum and modifying the set-up. On the other hand we have improved the design in order to fullfill the following specifications:In order to avoid contamination at surfaces which are exposed to electron bombardment the vacuum was improved up to 10-7 Torr. This was achieved by tolerating viton O-rings for static sealings only. Dynamic feedthroughs such as rotary or linear motion drives are sealed by stainless steel bellows. The diffusion pump uses silicon-free oil and is equipped with a machine cooled trap.
Coadsorption of lanthanum and boron on tungsten by field emission and field ion microscope
Authors: Inoue T. , Nakada M. , Okuno K. 
Published: June 2020

The electron bean which has the sectional diameter of angstrom order and the high brightness is necessary to obtain an ultrahigh resolution in the field of electron microscopy, electron spectroscopy and other electron beam technology, and the field emitter called tip is suitable for this purpose. We have already published that we can make small protrusions near (100) planes on the tungsten tip apex by field evaporation at about 600 K.Concerning the treatment of the tip called remolding we reported with my coworker, august 1974 at the eighth international congress on electron microscopy in Canberra Australia. The LaB6 field emitter has recently received considerable attention as an electron beam source of higher brightness as well as longer life time than conventional tungsten field emitter. LaB6 cathode has been used as such a cathode because of high thermal stability and stable for poisoning gas. However, the surface state of this cathode at high temperatures during operation has been scarcely known, because there has not been effective method to analyse the surface materials or to observe the surface condition.
The development of a combined deformation/heating stage with acoustic emission rate measurement for scanning electron microscopy
Authors: Wetzig Klaus , Edelmann Johannes 
Published: June 2020

A novel in situ deformation and heating stage was constructed for use in the scanning electron microscope JSM - S1 /1/. It possesses the following technical features:— tension loading up to 100 kp during electron optical observation, either with a constant tension load or with different, constant feed velocities from 1.10-3mm/min to 0,2mm/min;— sample heating from r.t. up to 800°C under loading and imaging conditions;— electrical measuring of tension and elongation respectively and plotting of σ-ε - curves;— selective exchange of the tension support to a bending strain support, also with electrical registration of bending and load;— selective connection with piezoelectric ceramics for acoustic emission rate measurements under loading and imaging conditions.Figure 1 gives a schematic section through the tensile stage. The sample 1 is fixed in two chucks 2;3, which can move symmetrically against each other by the guiding rods 4; 5.
In-situ electrical-resistivity measurements in the high-voltage electron microscope
Authors: King W. E. 
Published: June 2020

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).
New detector system for cathodoluminescence SEM
Authors: Roschger P. , Hörl E.M. 
Published: June 2020

The basic idea leading to the construction of our new detector system has been the realisation of maximum efficiency in collecting and detecting of the photons emitted by the specimen. A maximum of efficiency is necessary in many investigations, especially in biological ones where one has to deal with extrem low light levels. In many cases electron beam damage causes a rapid decrease of the light intensity, especially at high magnifications. In these cases a high sensitivity of the detector system is also very important.Fig. 1 shows the principle of the design of our new system, consisting essentially of two ellipsoidal mirrors in contrast to one ellipsoidal mirror in our previous system. The left hand focus (F2) of mirror 1 is identical with the right hand focus of mirror 2. In this way a large fraction of the light emitted by the specimen is again focused in the left hand focus (F3) of mirror 2.
A new technique for measuring the local nitrogen concentration in Gap by means of the scanning electron microscope
Authors: Golubev Yu.A. , Evstropov V.V. , Kalinin B.N. , Lejnin V.P. , Petrov V.I. 
Published: June 2020

The nuclear reaction and optical absorption techniques have been developed to determine the absolute nitrogen doping concentration in GaP crystals/1/.In both cases the data measured are averaged over the doped layer and these methods do not permit to obtain the nitrogen doping profile across the layer.In this work the measurement of the nitrogen concentration in GaP LED structures is carried out with high spatial resolution by using the local cathodoluminescence (CL) data obtained in the scanning electron microscope (SEM).The method is based on determining in CL spectra the degree of the A-line self-absorption by substitutional nitrogen in GaP crystal.lt has been shown recently /2/ that in the temperature range of 77°K - 130°K without self-absorption the peak intensities ratio of A-line and its phonon replication side bands A-LO and A-2L0 in luminescence spectra of GaP should correspond to 1,00 : 0,36 : 0,065.
Dislocation core studies using high resolution electron microscopy
Authors: Cockayne D.J.H. , Anstis G.R. 
Published: June 2020

The interpretation of high resolution (0.5nm) image detail to study dislocation cores relies upon image calculations for its justification. The scattering equations used to calculate these images make use of various approximations, and their validity at this level of resolution has been in doubt. Because of this, a detailed study has been made of the various methods of image calculation, and the reliability of image interpretation for a number of experimental situations has been determined.Images of dislocations of arbitrary resolution can be calculated by an extension of the approach considered by Howie and Basinski. Given an expansion of the potential V(r) = Σgvg(r) exp (2Πig.r) and wavefunctionsthen, for a given incident wavefunction, the wavefunction ψ(r) = Σgϕg(r) exp (2Πig.r) is the unique solution to the form of Schroedinger's equation in which backscattering is neglected, irrespective of the extent of lattice distortion.
The dynamical theory of a double crystal electron interferometer
Authors: Buxton B.F. , Rackham G.M. , Steeds J.W. 
Published: June 2020

Recently, Rackham et al.(1977) reported the observation of fine fringes in convergent beam patterns obtained from double crystal interferometers consisting of two perfectly aligned crystals separated by a gap D of about 1 μm (Fig. 1). If we assume for simplicity that the reciprocal lattice vectors G of the operating reflections are parallel to the crystals, the many-beam wavefunction Ψ(R,t1) on the exit surface of crystal I due to an incident plane wave eix.r. (Fig. 2), given by(1)can be matched onto plane waves propagating in directions K+G between the crystals. In the gap therefore, the wavefunction is(2)where(3)since x ≫ |K+G| for all reflections of interest. The wavefunction (2) is diffracted by the second crystal, from which emerge waves in directions K+H with amplitudes.
The atomic string approximation in high energy electron diffraction
Authors: Tremewan P.T. , Buxton B. F. 
Published: June 2020

It is often useful to study dispersion surfaces in order to understand the complicated diffraction effects which are observed in transmission electron micrographs. To obtain these dispersion surfaces accurately from the many-beam equations in cross-grating high energy electron diffraction it is necessary to diagonalise matrices at least of the order 60×60 even for the simplest structures. Such a method cannot easily be used to relate the form of the dispersion surface to the projected potential U(R) seen by the fast electrons. It is possible, however, to solve an equivalent two-dimensional band structure problem for the fast electrons in the crystal. The KKR method, which exploits the near cylindrical symmetry of the projected potential within each atomic string in order to expand the Bloch waves in terms of angular momentum basis functions eiℓθ, enables such an approach to be made and requires the solution of small secular determinants.Defining the transverse energy S to be zero at the maxima of the atomic string potentials, the atomic string approximation(ASA) reduces the KKR equations for one string per unit cell of the projected potential to the formwhere the eigenvector components C are simply related to the coefficients in the angular momentum expansion of the Bloch waves and the structure constants Mℓℓ'(K) only depend on the arrangement of the atomic strings and the orientation K.
A method to measure pores and fissures in geologic materials under S.E.M. by digital image processing
Authors: Montoto L. , Montoto M. , Bel-Lan A. 
Published: June 2020

INTRODUCTION.- The physical properties of rock masses are greatly influenced by their internal discontinuities, like pores and fissures. So, these need to be measured as a basis for interpretation. To avoid the basic difficulties of measurement under optical microscopy and analogic image systems, the authors use S.E.M. and multiband digital image processing. In S.E.M., analog signal processing has been used to further image enhancement (1), but automatic information extraction can be achieved by simple digital processing of S.E.M. images (2). The use of multiband image would overcome difficulties such as artifacts introduced by the relative positions of sample and detector or the typicals encountered in optical microscopy.DIGITAL IMAGE PROCESSING.- The studied rock specimens were in the form of flat deformation-free surfaces observed under a Phillips SEM model 500. The SEM detector output signal was recorded in picture form in b&w negatives and digitized using a Perkin Elmer 1010 MP flat microdensitometer.
Correlation analysis of radiation damage
Authors: Hegerl R. , Feltynowski A. , Grill B. 
Published: June 2020

Till now correlation functions have been used in electron microscopy for two purposes: a) to find the common origin of two micrographs representing the same object, b) to check the optical parameters e. g. the focus. There is a third possibility of application, if all optical parameters are constant during a series of exposures. In this case all differences between the micrographs can only be caused by different noise distributions and by modifications of the object induced by radiation.Because of the electron noise, a discrete bright field image can be considered as a stochastic series Pm,where i denotes the number of the image and m (m = 1,.., M) the image element. Assuming a stable object, the expectation value of Pmwould be Ηmfor all images. The electron noise can be introduced by addition of stationary, mutual independent random variables nmwith zero expectation and the variance. It is possible to treat the modifications of the object as a noise, too.
3-D reconstruction from conically tilted projections
Authors: Radermacher M. , Hoppe W. 
Published: June 2020

As shown earlier, reconstruction from conically tilted projections has the advantage of delivering a smoother background around the elongated image point than reconstruction from single axis tilted projections, because of the smaller blind region in Fourier space. In this paper a weighted backprojection for conical tilting is presented. In contrast to the iterative techniques of the ART-type the shape of the image point and its clutter are defined and predictable.Let S with x, y, z be the coordinate system fixed to the object, and S'j with x'j, y'j, z'j be the system with the x'j, y'j -plane on the j-th projection. Let ϑ be the polar angle and φj be the azimuthal angle between S and S'j. The j-th projection then is
Off-axis electron holography by field emission electron microscope
Authors: Tonomura A. , Matsuda T. , Komoda T. 
Published: June 2020

Although the feasibility of electron holography has been verified by several authors, it has not yet been put to practical use. This is because of the lack of a coherent electron source, such as optical laser. In practice, the number of interference fringes produced with a biprism is 200 at most, the exception being one dimensional cases. Off-axis holography requires 5,000∼100,000 interference fringes. Therefore, the useful application of electron holography in higher resolution and phase contrast electron microscopy hinges on development of a coherent electron source capable of producing 5,000 fringes or more.To realize a coherent electron source, a 100 kV field emission electron gun was developed and attached to an electron microscope. In designing the microscope,special care was taken in the column and electric supply. This was done to minimize movement of the small beam spot, which is easily disturbed from outside, so as to maintain the field emission electron beam.
High resolution phase contrast electron microscopy:imaging of single atoms and “amorphous state”
Authors: Iijima Sumio 
Published: June 2020

Using very thin films of graphite crystals as support films, we demonstrated some bright-field CTEM images of single tungsten atoms and surface structures of the graphite films. Theoretical calculation on these objects using phase object approximation supported the validity of our interpretation of the images.We made a further investigation on the similar phase objects by utilizing a JEOL-UHP objective pole-piece (Cs= 0.7mm) installed in a JEM-100B microscope. This lens gives an “interpretable resolution”,, of 2.6Å. Practically, however, the attainable resolution is restricted by chromatic aberration and illumination angle, barring operational faults. These parameters modify the ideal image transfer functions in the higher frequency region and thus become important for discussing the high resolution details. The resolution measured for the new lens from the optical diffractograms was around 3.2Å, which is slightly better than the value 3.8Å for our old lens (BLG-pole-piece, Cs= 2.0mm).
Imaging of the crystal structure of a new WO3, phase by high-resolution electron microscopy
Authors: Gerand B. , Figlarz M. 
Published: June 2020

A new hydrate of tungsten trioxide with the formula WO3,1/3 H2O was found by hydrothermal treatment in an autoclave either of crystalline WO3,2 H2O or of a tungstic acid gel. By dehydration of this hydrate in the air and by subsequent reductions a set of new compounds of tungsten were obtained : a polymorph of WO3 and two other oxides, all unknown. Their structures have in general a higher symmetry than the compounds already known. The detailed procedure for preparing these phases, their analysis, their structures and properties will be reported elsewhere (1).In the present paper, we examine the structure of the new polymorph of WO3. This compound is white. A study by powder X-ray diffraction shows that this compound is hexagonal with the space group P6/mmm and the lattice parameters a = 7.296 and c = 3.899 A°. The structure, which can be imagined by analogy with the hexagonal bronze structures (2), is shown in figure 1.
The observation of edge dislocation loops by high resolution lattice imaging
Authors: Howitt D.G. , Mitchell T.E. 
Published: June 2020

IntroductionThe characterization of small defects by diffraction contrast methods in the electron microscope becomes uncertain when the image widths approach the dimensions of the defect. In the case of small defect aggretates, it becomes difficult not only to distinguish between interstitial and vacancy character but also between volume and planar defects.These small defect aggregates, or rather the disturbances that they produce, can also be investigated by lattice imaging where the interference of two or more beams, whose phases have been disturbed by the defect, produces an image. The images obtained in this way, although not a one-to-one mapping of the atomic arrangement, do bear an unique relationship to it; however, this uniqueness is lost in an electron micrograph since the phase relationships are not recorded. The image interpretation therefore relies upon the effect that the phase relationships have on the image intensity being sufficient to distinguish between likely candidates for the atomic distribution, since the image intensities from this type of microscopy are not in general straightforward to predict.
Electron lattice image interpretation of V2O3 wedge shaped crystal
Authors: Tanaka M. , Rocher A. , Ayroles R. , Jouffrey B. 
Published: June 2020

The thickness dependence of a two dimensional lattice image with small lattice spacings (< 5 Å) has been discussed in the theoretical aspect by some authors(1) (2),(3) in the case of zone axis orientation. Our intention is to compare the experimental image with the theoretical one for a vanadium sesquioxide (V2O3) crystal not in the zone axis orientation but in more general orientations. This crystal, one of those which show the metal-insulator transition, is metallic and belongs to the space group at room temperature. The unit cell dimensions in the hexagonal system are a = 4.951 Å and c = 14.003 Å (4). The electron microscope used is a JEM-100C equipped with the fixed specimen stage and operated at 100 kV (Cs = 1.4 mm).Figure 1 shows a lattice image from a wedge shaped crystal. Especially remarkable is the recurrence of similar contrast in three thicknesses regions : < 50 Å,∽ 250Å,and ∽ 450Å.
Transmission electron microscopy of SI-AL-O-N alloys
Authors: Kirn M. , Rühle M. , Schmid H. , Gauckler L.J. 
Published: June 2020

It is expected that Si-Al-O-N alloys are important high temperature construction materials. The phase diagrams for Si-Al-O-N alloys were studied systematically mainly by X-ray diffraction work (for a summary see). Different stable phases were found. For the understanding of the physical and mechanical properties it is of great interest to know for the different stable phases the microstructure and the morphology, which can be obtained by TEM observations. Results of some TEM studies are reported here utilizing not only the conventional TEM but also the lattice fringe imaging technique.Specimens of the different phases were produced as described in They were prepared for TEM observations. For high resolution work a Siemens ELMISKOP 102 (operating voltage 125 kV) was used fitted with a double tilting stage (± 45°), for conventional TEM studies the specimens were examined in an AEI EM7 high voltage EM operated at 1 MeV.
Simulation of electron displacement damage in the high voltage electron microscopy
Authors: Ono S. , Kanaya K. 
Published: June 2020

By applying the fundamental theory of the neutron cooling to the conservation law of energy and momentum, the average transferred energy Ea of an atom caused by high energy electrons is given by Ea=Em/2.72, where Emis the maximum energy transferred in a head-on collision.The threshold energy ETHof the incident electron for the displaced atom is obtained from, where Ed is the average displacement energy of an atom with mass M, Essublimation energy instead of the binding energy by Cosslett, m electron rest mass and c light velocity (Fig.1).When the energy of the incident electron exceeds the threshold energy ETHof displacements the concentration Cdof displaced atoms produced can be given by Cd=σDΦN, where σDis the cross section for the knock-on process, Φ the electron dose, and the total number N of displaced atoms summing over all collisions giving by Keywell as