scholarly journals INFLUENCE OF CHISEL SHARE FOR THE DESTRUCTION OF CONCRETE

2003 ◽  
Vol 9 (4) ◽  
pp. 260-265
Author(s):  
Friedel Peldschus ◽  
Jens-Thorsten Wild
Keyword(s):  
Energy Loss ◽  
Cutting Edge ◽  
Experimental Conditions ◽  
Friction Forces

The energy shares occurring in the chiselling process were investigated in order to increase the productivity of the manual destruction of concrete. Apart from the influences of notch energy and cleaving energy, the energy loss due to friction forces was considered. As a result two new chisel forms were developed as a combination of sharp cutting edge and steep wedge. The effectiveness of these chisels was tested under experimental conditions as well as under reality conditions. It was found that the application of lateral tips at the chisel leads to an improved processing performance.

scholarly journals Energy-loss magnetic chiral dichroism (EMCD): Magnetic chiral dichroism in the electron microscope

2008 ◽  
Vol 23 (10) ◽  
pp. 2582-2590 ◽  
Author(s):  
S. Rubino ◽  
P. Schattschneider ◽  
M. Stöger-Pollach ◽  
C. Hébert ◽  
J. Rusz ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Electron Microscope ◽  
Energy Loss ◽  
Magnetic Circular Dichroism ◽  
Magnetic Moments ◽  
Sample Collection ◽  
Experimental Conditions ◽  
Advantages And Disadvantages ◽  
A New Technique ◽  
Circular Dichroïsm

A new technique called energy-loss magnetic chiral dichroism (EMCD) has recently been developed [P. Schattschneider, et al. Nature441, 486 (2006)] to measure magnetic circular dichroism in the transmission electron microscope (TEM) with a spatial resolution of 10 nm. This novel technique is the TEM counterpart of x-ray magnetic circular dichroism, which is widely used for the characterization of magnetic materials with synchrotron radiation. In this paper we describe several experimental methods that can be used to measure the EMCD signal [P. Schattschneider, et al. Nature441, 486 (2006); C. Hébert, et al. Ultramicroscopy108(3), 277 (2008); B. Warot-Fonrose, et al. Ultramicroscopy108(5), 393 (2008); L. Calmels, et al. Phys. Rev. B76, 060409 (2007); P. van Aken, et al. Microsc. Microanal.13(3), 426 (2007)] and give a review of the recent improvements of this new investigation tool. The dependence of the EMCD on several experimental conditions (such as thickness, relative orientation of beam and sample, collection and convergence angle) is investigated in the transition metals iron, cobalt, and nickel. Different scattering geometries are illustrated; their advantages and disadvantages are detailed, together with current limitations. The next realistic perspectives of this technique consist of measuring atomic specific magnetic moments, using suitable spin and orbital sum rules, [L. Calmels, et al. Phys. Rev. B76, 060409 (2007); J. Rusz, et al. Phys. Rev. B76, 060408 (2007)] with a resolution down to 2 to 3 nm.

Desktop Generation and Analysis of Spectra

1990 ◽  
Vol 48 (2) ◽  
pp. 108-109
Author(s):  
C.R. Swyt ◽  
C.E. Fiori
Keyword(s):  
Energy Loss ◽  
Spectral Data ◽  
Electron Energy ◽  
Personal Computer ◽  
Physical Processes ◽  
Experimental Conditions ◽  
Joint Project ◽  
X Ray ◽  
Computer Environment ◽  
Electron Energy Loss

The computer environment which allows the analyst to interact with a program by means of windows, dialogs, pull-down menus and check boxes is probably the most comfortable to the largest number of users. This environment is becoming available to both x-ray and electron energy loss analysts in commercial products and in programs written by analysts in the field. One such program for a personal computer has been under developement by the authors as a joint project at the NIH and the NIST. This program not only enables the analyst to process and display spectral data from electron column instruments but also provides the analyst the additional powerful capability to model the physical processes involved in the generation of an x-ray spectrum. The procedure to emulate the experimental environment and specimen to generate a series of spectra reflecting the relevant physics and statistics was previously described in some detail in terms of the application to estimating detection limits under proposed experimental conditions [1].

Synthesis of Electron Energy Loss Spectra for the Quantification of Detection Limits

2002 ◽  
Vol 8 (3) ◽  
pp. 203-215 ◽  
Author(s):  
Nanda K. Menon ◽  
Ondrej L. Krivanek
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Materials Science ◽  
Detection Limits ◽  
Single Atom ◽  
Experimental Conditions ◽  
Empirical Observation ◽  
Thin Carbon ◽  
Atom Detection ◽  
Electron Energy Loss

We describe a method for predicting detection limits of minority elements in electron energy loss spectroscopy (EELS), and its implementation as a software package that gives quantitative predictions for user-specified materials and experimental conditions. The method is based on modeling entire energy loss spectra, including shot noise as well as instrumental noise, and taking into account all the relevant experimental parameters. We describe the steps involved in modeling the entire spectrum, from the zero loss up to inner shell edges, and pay particular attention to the contributions to the pre-edge background. The predicted spectra are used to evaluate the signal-to-noise ratios (SNRs) for inner shell edges from user-specified minority elements. The software also predicts the minimum detectable mass (MDM) and minimum mass fraction (MMF). It can be used to ascertain whether an element present at a particular concentration should be detectable for given experimental conditions, and also to quickly and quantitatively explore ways of optimizing the experimental conditions for a particular EELS analytical task. We demonstrate the usefulness of the software by confirming the recent empirical observation of single atom detection using EELS of phosphorus in thin carbon films, and show the effect on the SNR of varying the acquisition parameters. The case of delta-doped semiconductors is also considered as an important example from materials science where low detection limits and high spatial resolution are essential, and the feasibility of such characterization using EELS is assessed.

Probing the Chemical Structure in Diamond-Based Materials Using Combined Low-Loss and Core-Loss Electron Energy-Loss spectroscopy

2014 ◽  
Vol 20 (3) ◽  
pp. 779-783 ◽  
Author(s):  
Paolo Longo ◽  
Ray D. Twesten ◽  
Jaco Olivier
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Core Loss ◽  
Amorphous Region ◽  
Low Loss ◽  
Plasmon Energy ◽  
Carbon Structure ◽  
Experimental Conditions ◽  
Electron Energy Loss

AbstractWe report the analysis of the changes in local carbon structure and chemistry caused by the self-implantation of carbon into diamond via electron energy-loss spectroscopy (EELS) plasmon energy shifts and core-edge fine structure fingerprinting. These two very different EELS energy and intensity ranges of the spectrum can be acquired under identical experimental conditions and nearly simultaneously using specially designed deflectors and energy offset devices known as “DualEELS.” In this way, it is possible to take full advantage of the unique and complementary information that is present in the low- and core-loss regions of the EELS spectrum. We find that self-implanted carbon under the implantation conditions used for the material investigated in this paper creates an amorphous region with significant sp2 content that varies across the interface.

Removal and tribological behaviors of waxy deposition layer in cleaning process

2017 ◽  
Vol 69 (4) ◽  
pp. 566-573
Author(s):  
Yanbao Guo ◽  
Shuhai Liu ◽  
Guibin Tan ◽  
Liu Yang ◽  
Deguo Wang
Keyword(s):  
Rake Angle ◽  
Depth Of Cut ◽  
Curvature Radius ◽  
Cleaning Process ◽  
Wax Deposition ◽  
Experimental Conditions ◽  
Friction Forces ◽  
Content Type ◽  
Oil Transportation ◽  
Cleaning Machine

Purpose The wax deposition in oil wells and pipelines is very viciously negative to the petroleum extraction and crude oil transportation, and it even causes severe blockage accident. This study aims to describe cleaning experiments performed on wax deposition of different deposition layer and experimental conditions to investigate the removal and tribological properties and chip formation. Design/methodology/approach An optical arrangement was used to visually record the cleaning process, whereas the friction forces were measured by a custom-built tribometer. Various measurements were performed with tool rake angles of 45° and −30° and cleaning depths from 1 to 5 mm. Findings Results from experiments and modeling suggest that the transition of chip was dependent on rake angle, wax performance and cleaning depth. While the cleaning depth increased, the friction and cleaning resistant force also increased. With the increase of cleaning depth, the wax layer cleaning quantity increased and the chip strengthened; hence, the curvature radius of chip was enhanced to form platy chip. The chip of wax–oil mixture was discontinuous units, and it was easy to adhere on the rake face with the increasing depth of cut. With an increase in cleaning depth, the friction and cleaning-resistant force also increased. Originality/value It is concluded that for effectively cleaning and stabilizing of pipeline cleaning machine, different cleaning parameters should be applied to accommodate wax layer or wax–oil mixture.

scholarly journals Elemental Mapping of Labeled Biological Specimens at Intermediate Energy Loss in an Energy-Filtered TEM acquired using a Direct Detection Device

2020 ◽  
Author(s):  
Ranjan Ramachandra ◽  
Mason R. Mackey ◽  
Junru Hu ◽  
Steven T. Peltier ◽  
Nguyen-Huu Xuong ◽  
...  
Keyword(s):  
Energy Loss ◽  
Lower Energy ◽  
Direct Detection ◽  
Core Loss ◽  
Intermediate Energy ◽  
High Signal ◽  
Experimental Conditions ◽  
High Loss ◽  
The Core ◽  
Elemental Maps

ABSTRACTThe multi-color or single-color EM that was developed previously, by the pseudo-colored overlay of the core-loss or high-loss EFTEM elemental map/s of the lanthanide onto the conventional image, the lanthanide chelates conjugated to diaminobenzidine being sequentially deposited as a result of selective oxidization by orthogonal photosensitizers / peroxidases. The synthesis of the new second generation lanthanide DABs, which contains 4 times more lanthanide per DAB, gives significant signal amplification and enabling collection of elemental maps at much lower energy-loss regions more favorable. Under the same experimental conditions, acquiring EFTEM elemental maps for the lanthanides at the lower energy-loss of N4,5 edge instead of the core-loss M4,5 edge, provides ~4x increase in signal-to-noise and ~2x increase in resolution. The higher signal at the N4,5 edge, also allows for more sophisticated technique of EFTEM spectrum Image for the acquisition of elemental maps with very high signal fidelity.

scholarly journals Methods for the construction of lowered structures and pile foundations

2021 ◽  
Vol 258 ◽  
pp. 09036
Author(s):  
Vladimir Kocherzhenko ◽  
Lyudmila Suleymanova
Keyword(s):  
Bearing Capacity ◽  
Lateral Surface ◽  
Cutting Edge ◽  
Pile Foundations ◽  
Driven Piles ◽  
Friction Forces ◽  
Rational Use ◽  
Antifriction Coatings ◽  
Frictional Forces

The paper discusses the methods of erecting sunk wells and pile foundations, which consist in regulating the frictional forces of soils: lowering along the lateral surface when sinking wells and increasing when erecting pile foundations. The developed method of sinking wells provides for the application of two types of effective antifriction coatings along the lateral surface: along the cutting edge of the structure and above the cutting ledge. At the same time, the coefficients of reducing the friction forces by these coatings for various types of soils have been established, and a method for calculating sunk wells for lowering is proposed, taking into account the use of the developed submerging method. To increase the friction forces on the lateral surface of the driven piles and to increase their bearing capacity, modular piles with a developed lateral surface of the T-section have been developed and introduced. The areas of rational use of these piles are established depending on the types of soils (clay and sandy) and the depth of their penetration.

An examination of centrifugal barrier effects in iodine pentafluoride by inner shell electron energy loss spectroscopy

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1093-1100
Author(s):  
Glyn Cooper ◽  
Wenzhu Zhang ◽  
C. E. Brion
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Shape Resonance ◽  
High Electron ◽  
Excitation Spectra ◽  
Experimental Conditions ◽  
Barrier Effects ◽  
Shell Electron ◽  
Electron Energy Loss

Electron energy loss spectroscopy was used to study the core (I 4d, I 3d, and F Is) level electronic excitation spectra of IF5. The spectra were collected under experimental conditions such that dipole transitions were dominant (high electron impact energy (3 keV) and 0° scattering angle). The spectra were assigned using term value arguments, and by analogy with those of the isoelectronic molecules TeF6 and XeF4. In common with the spectra of TeF6 and XeF4, the spectra of IF5 show features that are consistent with a centrifugal potential-barrier model. In particular, transitions to virtual valence orbitals and to above-edge shape resonance channels are relatively intense, whereas transitions to Rydberg orbitals are, in comparison, very weak or absent. As in the case of TeF6, it was necessary to include atomic 4f orbitals in the molecular orbital basis to adequately account for the continuum resonance features observed in the IF5 spectra. The valence shell electron energy loss spectrum of IF5 from 5 to 35 eV was also obtained.

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