Analysis of Lubricant Additive Elements by X-Ray Fluorescence and Supporting Methods

2009 ◽  
pp. 118-118-10 ◽  
Author(s):  
JR Sieber ◽  
SG Salmon ◽  
MC Williams
Keyword(s):  
Lubricant Additive ◽  
X Ray

Preparation, Characterization and Tribological Evaluation of Calcium Borate Nanoparticles as Lubricant Additives

2010 ◽  
Vol 148-149 ◽  
pp. 1047-1056 ◽  
Author(s):  
Jiu Sheng Li ◽  
Li Feng Hao ◽  
Xiao Hong Xu ◽  
Li Zhang ◽  
Tian Hui Ren
Keyword(s):  
Oleic Acid ◽  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Lubricant Additive ◽  
Calcium Borate ◽  
Action Mechanism ◽  
Friction Process ◽  
X Ray ◽  
Transmission Electron ◽  
Worn Surface

To develop a potential substitute for conventional lubricant additive, pure calcium borate nanoparticles (PCBN) and calcium borate nanoparticles modified with oleic acid (MCBN) were prepared. The microstructures of the as-obtained samples were characterized using X-ray power diffraction (XRD), transmission electron microscope (TEM) and infrared spectra (IR), and the dispersing stability of oil containing nanoparticles was also evaluated. Tribological properties of MCBN used as lubricating additive were evaluated using four-ball tribometer and compared with that of PCBN. The results indicate that MCBN show better antiwear and friction-reducing property than PCBN. The worn surface of the steel ball lubricated with MCBN was investigated by Polarized microscope (PM) and X-ray photoelectron spectroscopy (XPS), and the action mechanism of MCBN during friction process was preliminarily discussed.

Conductive capacity and tribological properties of several carbon materials in conductive greases

2016 ◽  
Vol 68 (5) ◽  
pp. 577-585 ◽  
Author(s):  
Zhengfeng Cao ◽  
Yanqiu Xia ◽  
Xiangyu Ge
Keyword(s):  
Electron Microscope ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Volume Resistivity ◽  
Lubricant Additive ◽  
Step Method ◽  
Content Type ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Complex Lithium

Purpose The purpose of this paper is to synthesize a new kind of conductive grease which possesses a prominent conductive capacity and good tribological properties. Design/methodology/approach A two-step method was used to prepare complex lithium-based grease. Ketjen black (KB), acetylene black (AB) and carbon black (CB) were characterized by transmission electron microscope and used as lubricant additives to prepare conductive greases. Conductive capacity was evaluated by a conductivity meter, a surface volume resistivity meter and a circuit resistance meter. Tribological properties were investigated by a reciprocating friction and wear tester (MFT-R4000). The worn surfaces were analyzed by a scanning electron microscope, Raman spectroscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscope. Findings The conductive grease prepared with KB has a prominent conductive capacity at room temperature, 100°C and 150°C. Further, this conductive grease also possesses better tribological properties than AB and KB greases. When the concentration of KB is 1.8 Wt.%, the coefficient of friction and wear width reduced by 11 and 14 per cent, respectively. Originality/value This work is a new application of nanometer KB as a lubricant additive in grease, which provides a direction for preparing conductive grease. The conductivity and tribology experiments have been carried out though the variation of experiment conductions.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

Axial Observation of X-Ray Spectra from a Beam-Foil Source

1988 ◽  
Vol 102 ◽  
pp. 339-342
Author(s):  
J.M. Laming ◽  
J.D. Silver ◽  
R. Barnsley ◽  
J. Dunn ◽  
K.D. Evans ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Axis ◽  
Doppler Broadening ◽  
X Ray ◽  
Beam Foil

AbstractNew observations of x-ray spectra from foil-excited heavy ion beams are reported. By observing the target in a direction along the beam axis, an improvement in spectral resolution, δλ/λ, by about a factor of two is achieved, due to the reduced Doppler broadening in this geometry.

Observed and Theoretical Spectra in the 10–100Å Interval

1988 ◽  
Vol 102 ◽  
pp. 259-261
Author(s):  
W.A. Brown ◽  
M.E. Bruner ◽  
L.W. Acton
Keyword(s):  
Sounding Rocket ◽  
Full Spectrum ◽  
X Ray

AbstractThe soft x-ray spectra recorded in two sounding rocket flights in 1982 and 1985 are compared with with predicted spectra. The poster presents the processed densitometer trace of the full spectrum together with the new spectrum from the 1985 experiment. This note compares the intensities of the lines with predictions.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

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