Tribological characteristics and load-sharing of point-contact interface in three-body mixed lubrication

2021 ◽  
pp. 1-44
Author(s):  
Jeng-haur Horng ◽  
Chia-Chun Yu ◽  
Yang-Yuan Chen
Keyword(s):  
Particle Size ◽  
Particle Density ◽  
Full Range ◽  
Point Contact ◽  
Mixed Lubrication ◽  
Real Contact Area ◽  
Body Contact ◽  
The Third ◽  
Conventional Film ◽  
Film Parameter

Abstract The third particle occurred at the interface of contacting surfaces is common situations in relative motion part. This study involved developing an analysis framework to investigate the contact characteristics in the full range of 3-body mixed lubrication. Conventional 2-body mixed lubrication is a special case of 3-body mixed lubrication analysis with particle size of zero. This study revealed that the values of real contact area, film thickness, contact mode, and the solid contact load in 3-body contact were larger than those in ideal 2-body contact in mixed lubrication, and they increased with an increasing particle size or density under the study conditions. The initial stages and transition processes of four types of 3-body contact modes under mixed lubrication were significantly different for different particle sizes and densities. The size of the third particle increased the values of both minimum and maximum values, λmin and λmax, of film parameter in the mixed lubrication regime. The particle density did not have a significant effect on the λmax value in mixed lubrication. Higher particle density led to a larger λmin value in mixed lubrication. The conventional film parameter, λ, was not a sufficient indicator of the different lubrication regimes in 3-body contact.

scholarly journals CHARACTERISTICS AND ADSORPTION PERFORMANCE OF FORMULATED TRIKOTAC FILTER AIDS

2019 ◽  
Vol 81 (3) ◽  
Author(s):  
N. Masdiana ◽  
M. Rashid ◽  
S. Hajar ◽  
M. R. Ammar
Keyword(s):  
Particle Size ◽  
Activated Carbon ◽  
Particle Density ◽  
Adsorption Properties ◽  
The Other ◽  
Bet Surface Area ◽  
Adsorption Performance ◽  
Filtration System ◽  
Filter Aids ◽  
The Relationship

TrikotAC filter aids is a combination of a pre-coating material PreKot™ with two adsorbents; activated carbon and lime and their characteristics were investigated in this study. TrikotAC was formulated into three different weight ratios of 5:1:94, 10:1:89 and 10:5:85, respectively. The relationship between adsorption properties and characteristics of the formulated materials particle size distribution, particle density, bulk density, and BET surface area were investigated. The results showed that the adsorption capacity for TrikotAC 10:5:85 (11.88 mg/g) was higher than for the other formulated filter aids samples, and the formulated filter aids material TrikotAC showed promising characteristic as a filter aids and adsorbent for organic compound in fabric filtration system.

Improvement in Precision, Accuracy, and Efficiency in Standardizing the Characterization of Granular Materials

2013 ◽  
Author(s):  
J. R. Tucker ◽  
L. J. Shadle ◽  
S. Benyahia ◽  
J. Mei ◽  
C. Guenther ◽  
...  
Keyword(s):  
Particle Size ◽  
Distribution Density ◽  
Particle Density ◽  
Solid Particles ◽  
Minimum Fluidization Velocity ◽  
Void Fractions ◽  
Multiphase Systems ◽  
Precision And Accuracy ◽  
Accuracy And Repeatability

Useful prediction of the kinematics, dynamics, and chemistry of a system relies on precision and accuracy in the quantification of component properties, operating mechanisms, and collected data. In an attempt to emphasize, rather than gloss over, the benefit of proper characterization to fundamental investigations of multiphase systems incorporating solid particles, a set of procedures were developed and implemented for the purpose of providing a revised methodology having the desirable attributes of reduced uncertainty, expanded relevance and detail, and higher throughput. Better, faster, cheaper characterization of multiphase systems result. Methodologies are presented to characterize particle size, shape, size distribution, density (particle, skeletal and bulk), minimum fluidization velocity, void fraction, particle porosity, and assignment within the Geldart Classification. A novel form of the Ergun equation was used to determine the bulk void fractions and particle density. Accuracy of properties-characterization methodology was validated on materials of known properties prior to testing materials of unknown properties. Several of the standard present-day techniques were scrutinized and improved upon where appropriate. Validity, accuracy, and repeatability were assessed for the procedures presented and deemed higher than present-day techniques. A database of over seventy materials has been developed to assist in model validation efforts and future designs.

Gastric emptying of nondigestible solids in dogs: a hydrodynamic correlation

1990 ◽  
Vol 258 (1) ◽  
pp. G65-G72 ◽  
Author(s):  
P. J. Sirois ◽  
G. L. Amidon ◽  
J. H. Meyer ◽  
J. Doty ◽  
J. B. Dressman
Keyword(s):  
Particle Size ◽  
Gastric Emptying ◽  
Gravitational Constant ◽  
Particle Density ◽  
Particle Diameter ◽  
High Viscosity ◽  
Fluid Viscosity ◽  
Fluid Flow Rate ◽  
Hydrodynamic Correlation ◽  
Viscosity Polymer

The influence of particle size, particle density, fluid viscosity, and fluid flow rate on the gastric emptying of nondigestible solids was investigated in five dogs with chronically placed fistulas. Six hundred and fifty particles of 13 different size and density combinations were administered simultaneously with 500 ml of either normal saline or low-, medium-, or high-viscosity polymer solutions. The canine stomach was found to discriminate between these solids on the basis of size and density at all levels of viscosity above saline. The observed patterns of emptying are consistent with the hypothesis that gastric emptying of nondigestible solids is governed in part by hydrodynamics and correlate well with the gastric-emptying coefficient (GEC), a dimensionless grouping of variables that takes the form GEC = (Dpy/Dp) [g(rho f - rho p)Dp2]/[eta (nu)] where [g(rho f - rho p)] is particle buoyancy consisting of fluid (rho f) and particle (rho p) densities and g, the gravitational constant; (Dp) is the particle diameter, (Dpy) the estimated pyloric diameter, eta the fluid viscosity, and (nu) the average linear velocity of fluid exiting the stomach.

scholarly journals Spatial relationship of photosystem I, photosystem II, and the light-harvesting complex in chloroplast membranes.

1977 ◽  
Vol 73 (2) ◽  
pp. 400-418 ◽  
Author(s):  
P A Armond ◽  
L A Staehelin ◽  
C J Arntzen
Keyword(s):  
Particle Size ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Light Harvesting ◽  
Particle Density ◽  
Unit Size ◽  
Fracture Face ◽  
Photosynthetic Unit ◽  
Light Harvesting Complex ◽  
Chloroplast Membrane

We have previously demonstrated (Armond, P. A., C. J. Arntzen, J.-M. Briantais, and C. Vernotte. 1976. Arch. Biochem. Biophys. 175:54-63; and Davis, D. J., P. A. Armond, E. L. Gross, and C. J. Arntzen. 1976. Arch. Biochem. Biophys. 175:64-70) that pea seedlings which were exposed to intermittent illumination contained incompletely developed chloroplasts. These plastids were photosynthetically competent, but did not contain grana. We now demonstrate that the incompletely developed plastids have a smaller photosynthetic unit size; this is primarily due to the absence of a major light-harvesting pigment-protein complex which is present in the mature membranes. Upon exposure of intermittent-light seedlings to continuous white light for periods up to 48 h, a ligh-harvesting chlorophyll-protein complex was inserted into the chloroplast membrane with a concomitant appearance of grana stacks and an increase in photosynthetic unit size. Plastid membranes from plants grown under intermediate light were examined by freeze-fracture electron microscopy. The membrane particles on both the outer (PF) and inner (EF) leaflets of the thylakoid membrane were found to be randomly distributed. The particle density of the PF fracture face was approx. four times that of the EF fracture face. While only small changes in particle density were observed during the greening process under continuous light, major changes in particle size were noted, particularly in the EF particles of stacked regions (EFs) of the chloroplast membrane. Both the changes in particle size and an observed aggregation of the EF particles into the newly stacked regions of the membrane were correlated with the insertion of light-harvesting pigment-protein into the membrane. Evidence is presented for identification of the EF particles as the morphological equivalent of a "complete" photosystem II complex, consisting of a phosochemically active "core" complex surrounded by discrete aggregates of the light-harvesting pigment protein. A model demonstrating the spatial relationships of photosystem I, photosystem II, and the light-harvesting complex in the chloroplast membrane is presented.

A Novel Three-Dimensional Finite Element Model to Simulate Third Body Effects on Fretting Wear of Hertzian Point Contact in Partial Slip

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Arman Ahmadi ◽  
Farshid Sadeghi
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Point Contact ◽  
Fretting Wear ◽  
Partial Slip ◽  
Wear Particles ◽  
Third Body ◽  
Stick Slip ◽  
The Third

Abstract In this investigation, a finite element (FE) model was developed to study the third body effects on the fretting wear of Hertzian contacts in the partial slip regime. An FE three-dimensional Hertzian point contact model operating in the presence of spherical third bodies was developed. Both first bodies and third bodies were modeled as elastic–plastic materials. The effect of the third body particles on contact stresses and stick-slip behavior was investigated. The influence of the number of third body particles and material properties including modulus of elasticity, hardening modulus, and yield strength were analyzed. Fretting loops in the presence and absence of wear particles were compared, and the relation between the number of cycles and the hardening process was evaluated. The results indicated that by increasing the number of particles in contact, more load was carried by the wear particles which affect the wear-rate of the material. In addition, due to the high plastic deformation of the debris, the wear particles deformed and took a platelet shape. Local stick-slip behavior over the third body particles was also observed. The results of having wear debris with different material properties than the first bodies indicated that harder wear particles have a higher contact pressure and lower slip at the location of particles which affects the wear-rate.

scholarly journals New frontiers in biologging science

2009 ◽  
Vol 5 (3) ◽  
pp. 289-292 ◽  
Author(s):  
Christian Rutz ◽  
Graeme C. Hays
Keyword(s):  
Decision Making ◽  
Full Range ◽  
Level Of Detail ◽  
Biological Research ◽  
Future Research ◽  
The Third ◽  
Ecological Scales ◽  
Free Ranging ◽  
Dynamics Of Populations

The term ‘biologging’ refers to the use of miniaturized animal-attached tags for logging and/or relaying of data about an animal's movements, behaviour, physiology and/or environment. Biologging technology substantially extends our abilities to observe, and take measurements from, free-ranging, undisturbed subjects, providing much scope for advancing both basic and applied biological research. Here, we review highlights from the third international conference on biologging science, which was held in California, USA, from 1 to 5 September 2008. Over the last few years, considerable progress has been made with a range of recording technologies as well as with the management, visualization, integration and analysis of increasingly large and complex biologging datasets. Researchers use these techniques to study animal biology with an unprecedented level of detail and across the full range of ecological scales—from the split-second decision making of individuals to the long-term dynamics of populations, and even entire communities. We conclude our report by suggesting some directions for future research.

Analysis of Use Wear on Ceramic Potter's Tools

1992 ◽  
Vol 267 ◽  
Author(s):  
Robert C. Henrickson
Keyword(s):  
Full Range ◽  
Western Iran ◽  
The Third ◽  
Use Wear ◽  
Third Millennium

ABSTRACTAnalyses of the distribution and nature of abrasion on ceramic rings from the third millennium B.C. portion of the Godin III pottery assemblage in western Iran (2600-1400 B.C.) indicate that it represents use wear. Residual scars on pottery vessels and reconstruction of vessel forming sequences support identification of these rings as potter's tools. They provide interconnections among varied sizes of Buff Common ware vessels made using different forming and finishing methods. This strengthens the inference of workshop production by specialist potters who make the full range of Buff Common ware vessels.

ROLE OF MOLYBDENUM TRIOXIDE ON THERMAL STABILITY OF POLYANILINE NANOCOMPOSITE

2012 ◽  
Vol 11 (03) ◽  
pp. 1250025
Author(s):  
P. SUJA PREMA RAJINI ◽  
R. MURUGESAN ◽  
S. PERUMAL
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Particle Size ◽  
Metal Oxide ◽  
Molybdenum Trioxide ◽  
Spectral Studies ◽  
Average Particle ◽  
Weight Loss Step ◽  
The Third ◽  
Thermal Stability Of

Molybdenum trioxide (MoO3) grains were coated with conducting organic polymer of polyaniline. The as-prepared nanocomposite samples were characterized by Fourier transformed infrared (FTIR) spectra, X-ray diffraction (XRD) and Thermogravimetry (TGA). The XRD curves shows that, [Formula: see text] have high crystallinity due to the presence of large number of sharp peaks. From the XRD pattern the particle size is evaluated by using Debye-Scherrer's formula and the average particle size of [Formula: see text] and [Formula: see text] nanocomposites are found to be 46 and 32 nm, respectively. This is clearly observed that the condensed particle size of nanocomposite materials is due to the insertion of metal oxide of molybdenum. The incorporation of metal oxide of MoO3 in polyaniline (Pani) is confirmed by FTIR spectral studies. After de-doping, the characteristic peaks of Pani for all the Pani materials are almost same. This is due to the leaching of metal oxide of MoO3 from Pani. From these observations it is noted that doping–dedoping can also take place in inorganic metal oxides. The thermogram showed a three-step degradation process. The first weight loss step was due to the removal of physisorbed water molecules and moisture. The second minor weight loss step was associated with the removal of dopant from Pani backbone and the slight degradation of benzenoid structure of Pani and their thermal stability is enhanced. The third weight loss step was ascribed to the degradation of quinoid form of Pani. This confirmed the thermal stability of [Formula: see text] nanocomposite system. After degradation above 1000°C, the Pani with MoO3 showed a remaining weight of 8%. This confirmed that incorporation of metal oxide in the Pani nanocomposites is 8%. The enhancement of thermal stability is due to the intercalation of Pani chains into MoO3 in first two step degradation, which is further supported by FTIR and XRD reports. The third step degradation of Pani with MoO3 nanocomposite is loosely bound in organic and inorganic part. Therefore, the organic part is easily decomposed.

Gear-Cutting Method of Parallel Depth Hypoid Gears

2003 ◽  
Author(s):  
Akira Homma ◽  
Sumio Hirokawa ◽  
Akira Yamamoto
Keyword(s):  
Angular Velocity ◽  
Velocity Ratio ◽  
Point Contact ◽  
Constant Angular Velocity ◽  
Tooth Surface ◽  
Cutting Method ◽  
Hypoid Gears ◽  
The Third ◽  
Gear Cutting ◽  
Red Lead

The purpose of this study is to develop a gear-cutting method of hypoid gears to achieve a good tooth bearing and good performance for practical use. In this report, the authors propose a new cutting method of parallel depth hypoid gears, which mesh with each other at one point keeping a constant angular velocity ratio, and describe the theory for the gear-cutting method. Next, the theory of the trace of the point contact mark is shown. One of the features of this method is that the designer can control the trace of the point contact mark on the tooth surface as desired. The third, the theory of the ellipse of tooth bearing is shown minutely. In order to confirm the validity of the method, some hypoid gears were designed and manufactured, and ellipse of tooth bearing on red lead corresponded to those of the theory.

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