Tribology (Engineering)

A planetary trains for multi-speed is mainly used for automation in industries of automobile. A planetary
gear train is represented by a graph. It is identified by (i) number of vertices and their connectivity (ii) number of edges and their types and values (iii) fundamental circuits, their size and adjancy. Connectivity of individual link is a property characteristic of kinematic chain. It is possible to identify a planetary gear,therefore of using sets of labele (decimal numbers representing connectivity ) of individual link. The
connectivity of vertices , edges values and circuit values, related to design invariants which in turn indicates the possible behavior of the gear train ( for example capacity of power transmission, speed ratio and power carculation). For a specified degree – of – freedom a number of planetary gear kinematic chain (PGKCs) are selected and hence planetary gear trains (PGTs) can be formed with a given number of links
and joints so that designer must be able to select to select the best train from the view point of say velocity ratio and capacity of power transmission, space requirements etc. Synthesis of planetary gear kinematic chain and planetary gear trains has been studied(1-9). Almost all reported work deals with only
identification of distinct chains. Besides providing an atlus of chains, this in itself does not provide any help to designer in the selection of best possible gear train. In the present paper a simple method based of circuit property ( based on link-link shortest path distance and degree of links) is presented to determine the topology values of power transmission efficiency and topology power transmission capacity of five-links PGKCs and their distinct inversions

The fretting corrosion behaviour of tin plated copper alloy contacts at 3, 10 and 20 Hz and at two different track lengths (fretting amplitude) of ± 5 and ± 25 μm is studied. The change in contact resistance as a function of fretting cycles, surface profile of the contact zone, extent of fretting damage, extent of oxidation and elemental distribution across the contact zone were used to assess the fretting corrosion behaviour. The time to reach a threshold value of contact resistance of 0.1 Ω is found to be early for the track length of ± 5 μm compared to that of ± 25 μm, at all the three frequencies. For a given track length, this threshold value reaches early at 20 Hz. The roughness and the nature of surface profile suggest considerable amount of oxidation have occurred at the track length of ± 25 μm compared to that of ± 5 μm. The surface morphology of the fretted zone reveals severe damage of the contact zone for samples with a track length of ± 25 μm at all the three frequencies. A pictorial model is proposed to describe the evolution of change in area of the contact zone. Based on the length and width of the contact zone, the fretted area is calculated. The change is fretted area as a function fretting frequency and track length is analyzed. Delamination wear is found to be operative at both track lengths and at all three frequencies. EDX line scanning also indicates higher levels of oxidation at the track length of ± 25 μm compared to that of ± 5 μm. The variation in the atomic ratios of tin, copper and oxygen of the oxide debris present at the centre and edges of the fretted zone is plotted as an area plot as a function of experimental conditions. The debris is predominantly oxides of copper for the track length of ± 25 μm whereas they are mostly oxides of tin for the track length of ± 5 μm at all the three frequencies. The narrow and deep surface profile, lower Ra values, overlapping of the tin and copper lines in the EDX line scan and the predominance of oxides of tin support the view that the chances of accumulation of wear debris at the contact zone is very high at the track length of ± 5 μm. The study concludes that tin plated contacts could encounter an early failure even at shorter track lengths of ± 5 μm, if there is sufficient accumulation of the wear debris at the contact zone.

The mechanism that is discussed in this study is cardan shaft. The main objective of the proposed and completed research within the presented work was diagnostic of bearing assembly at joints of cardan shafts, which was performed in order to define the overall reliability of shafts. Presented reliability model of cardan shafts is based on an examination of diagnostic size of the bearing assembly on cardan joints. This document presents a difference between reliability of cardan shafts investigated in pure laboratory conditions and those cardan shafts investigated in clean exploitation conditions.

Prediction of frictional losses in elastohydrodynamic lubricated contacts is of particular importance from the viewpoint of energy efficiency, thus reduced levels of emissions. There are increasingly stringent government regulations. Thus, the industry strives to identify potential losses and improve energy efficiency. Most losses occur in a large number of load bearing conjunctions in all forms of mechanisms and machines. These losses are affected by the operating conditions, such as applied load, contact kinematics and generated temperature. Prediction of prevailing conditions, such as generated pressures, film thickness is the prelude to evaluation of frictional power losses. Many contact conjunctions in vehicular drivetrains are subjected to elastohydrodynamic conditions, the fundamental aspects of which are still evolving. In particular, effective prediction of performance of elastohydrodynamic lubricated (EHL) contacts is subject to inclusion of realistic contact conditions, particularly with respect to inlet and outlet boundary conditions as well as kinematics of contact. This paper demonstrates the importance of boundary conditions on predictions of prevailing situations.

A new reciprocating testing machine was designed and constructed to perform wear tests
under constant and fluctuating loading conditions at a constant sliding speed for most of its
stroke. The tribometer has the facility of changing the amplitude, mean load and the
frequency of loading cycle. The wear tests can, also, be conducted under dry or wet
conditions. The influence of loading mode on the wear behavior of Nylon 66 sliding against
stainless steel in dry conditions was investigated on this test rig. The polymer was tested
under constant and fluctuating loading conditions at two different loads and at three
frequencies. Results suggested that under cyclic loading condition the polymer shows a
significant increase in wear factor than those found under constant loads. The frequency of
load cycle, also, has a pronounced influence on the wear behavior under cyclic load.

This paper refers to testing of timing belt drives. Timing belt drives are relatively young drives that
originate from 1950’s. Considering the larger and larger use of timing belts and their limited lifetime, their
testing is justified. A large number of factors have influence on timing belt drive’s lifetime: wear, amount of
transmitted power, operating environment, coaxiality of shafts and belt pulleys, handling before and during
assembly and others. Failure most frequently occurs because of damage of belt’s and belt pulley’s teeth or
damage of tractive element due to wear. The paper presents the results of experimental testing of wear and
failure of timing belt drives originating from change in their geometrical dimensions. Gained experimental
results fully coincide with theoretical assumptions and similar tests around the world.

This paper refers to testing of timing belt drives. Timing belt drives are relatively young drives that
originate from 1950’s. Considering the larger and larger use of timing belts and their limited lifetime, their
testing is justified. A large number of factors have influence on timing belt drive’s lifetime: wear, amount of
transmitted power, operating environment, coaxiality of shafts and belt pulleys, handling before and during
assembly and others. Failure most frequently occurs because of damage of belt’s and belt pulley’s teeth or
damage of tractive element due to wear. The paper presents the results of experimental testing of wear and
failure of timing belt drives originating from change in their geometrical dimensions. Gained experimental
results fully coincide with theoretical assumptions and similar tests around the world.

The increasing capacity of current hard-disk drives places a great importance on reliability, as tens of gigabytes of data can be lost in an instant due to a single tribological failure event. To improve the reliability of the head-disk interface there is a need to predict, measure and monitor any interactions during manufacture.

The usual tribomechanical systems that are used in the process of development design are presented in this paper. Complex processes of friction and wear at contact surfaces are done within those tribomechanical systems.
The basic tribological characteristics of tribomechanical systems are friction and wear that are the main causes of system structure alteration, energy and material losses. As natural processes, friction and wear depend on large number of factors such as: system structure, exploitative conditions (speed and load), mechanical and chemical properties of material, lubrication characteristics, environment aggressiveness, temperature, topography of surfaces in contacts, mechanical
processing (pre- and post-processing) an so on.
The number of influential factors and complexity of their interactions in which variation of one parameter caused chain alterations of different parameters complicate the quantification of theirs influences. Those are the reasons for present
insufficiency of systematic information about tribological characteristics of tribomechanical systems.

Wear of contact surfaces is one of the most common causes of gear failure. In addition to physical and chemical processes that occur in the contact zone, ki-nematic meshing parameters have a great effect on the wear process. This paper analyses the influence of geometric and kinematic parameters of the gear profile on the instantaneous friction coefficient of the trochoidal gearing in the gerоtor pump. The friction coefficient is not a constant value and it varies during the teeth meshing as a result of a constant change in the lubrication regime. There are many empirical expressions for calculation of the instantaneous friction coefficient, but due to numerous limitations, many of these expressions can be applied only to certain operating conditions and loads. The analysis of the friction coefficient was performed through two contact periods defined by the change in direction of the rolling velocity of the meshing profiles contact point. The obtained results enable identification of dominant factors that influence the instantaneous friction coefficient and show possibilities for further development of analytical models of mechanical losses in the gerоtor pump. There is a wide range of pumps used in modern industrial practice. One of the simplest is a gerоtor pump. Gerоtor (trochoidal) pumps are rotary pumps with in

Cycloid drives are a relatively new group of planetary power transmissions. These transmissions have numerous favorable characteristics, such as a wide range of transmission ratios, very compact design, high reliability in dynamic exploitation conditions, high efficiency, etc. As they are part of a newer generation of transmissions , the possibility of using other materials other than steel in their production is not yet fully investigated. For the purposes of this investigation a single stage cycloid reducer was designed and manufactured out of mainly plastic components. The theoretical efficiency was determined and experimentally tested. Their comparative analysis is given through the discussion. The paper concludes with suggestions for further research on this type of cycloid reducers.

Dynamic behaviour of automotive dry clutches depends on the frictional characteristics of the contact between the friction lining material, the flywheel and the pressure plate during the clutch engagement process. During engagement due to high interfacial slip and relatively high contact pressures, generated friction gives rise to contact heat, which affects the material behaviour and the associated frictional characteristics. In practice excess interfacial slipping and generated heat during torque transmission can result in wear of the lining, thermal distortion of the friction disc and reduced useful life of the clutch.
This paper provides measurement of friction lining characteristics for dry clutches for new and worn state under representative operating conditions pertaining to interfacial slipping during clutch engagement, applied contact pressures and generated temperatures. An analytical thermal partitioning network model of the clutch assembly, incorporating the flywheel, friction lining and the pressure plate is presented, based upon the principle of conservation of energy. The results of the analysis show a higher coefficient of friction for the new lining material which reduces the extent of interfacial slipping during clutch engagement, thus reducing the frictional power loss and generated interfacial heating. The
generated heat is removed less efficiently from worn lining. This might be affected by different factors observed such as the reduced lining thickness and the reduction of density of the material but mainly due to poorer thermal conductivity due to the depletion of copper particles in its microstructure as the result of wear.
The study integrates frictional characteristics, microstructural composition, mechanisms of heat generation, effect of lining wear and heat transfer in a fundamental manner, an approach not hitherto reported in literature.

In this paper are presented the power losses and sources of their occurrence in worm gear boxes. These are the losses that occur in the coupling of worm teeth and worm gear, losses in bearings, seals and oil churning power losses in the transmission. When the operation of worm gearing is characterized by line contact of coupled elements which is accompanied by significant sliding, the highest value have the power losses in the worm and worm gear coupling compared to other losses in gearing. Among other things, in the paper also presents the expressions that are used for calculation of individual power losses and efficiency of the gearing. The size of the losses primarily depends on the type of coupled material and geometry of worm pair, circumferential velocity (input rotational speed), the type and viscosity of lubricating oil, load, worm shape, and temperature and so on. The paper also deals with the influence of different factors on power losses and efficiency. As the efficiency of the worm pair is significantly lower compared to other types of gear pairs, the appropriate combination of geometric parameters and materials of worm and worm gear, lubrication and working conditions can significantly affect its increase.

Because of their nanometric dimensions, thin films have a very high specific, a very high reactivity and exceptional mechanical, optical and electronic properties. The application of this technology in the internal combustion engine industry reduces losses of friction and wear with a low loss of material, which directly influences on the cost, whether during production phase or during the service.

Se construyó un sistema basado en computadora que permitió centralizar la instrumentación de diferentes sensores y ejecutar simultáneamente dos controles de lazo cerrado (posición y temperatura). El equipo, mediante la manipulación de un microscopio digital, genera automáticamente reportes con los datos de la instrumentación e imágenes con sus medidas dimensionales.

International Journal of Recent Advances in Mechanical Engineering (IJMECH) is a peer-reviewed, open access journal that addresses the impacts and challenges of Mechanical Engineering. The journal documents practical and theoretical results which make a fundamental contribution for the development of Mechanical Engineering

A B S T R A C T Textured surfaces have been shown to provide enhanced tribological performance in a variety of contacts. Numerical analysis and optimisation methods are combined for application-oriented texture optimisation. However, an analytical approach is advantageous in providing more generic in-depth understanding of the nature of the relationships between texture parameters and objective functions, such as enhanced load carrying capacity and reduced friction. The paper outlines such an approach to obtain a set of global optimum design parameters for partially textured surfaces. The optimised results are expressed in dimensionless form, which enables their use for a variety of applications. The performance of optimised partially textured sliding surfaces is compared with the other conventional bearing geometries in their optimum state.

The combined cycle gas turbine integrates the Brayton cycle as topping cycle and the steam turbine Rankine cycle as bottoming cycle in order to achieve higher thermal efficiency and proper utilization of energy by minimizing the energy loss to a minimum. In this work, the effect of various operating parameters such as maximum temperature and pressure of Rankine cycle, turbine inlet temperature and pressure ratio of Brayton cycle on the net output work and thermal efficiency of the combine cycle are investigated. The outcome of this work can be utilized in order to facilitate the design of a combined cycle with higher efficiency and output work. A MATLAB simulation has been carried out to study the effects and influences of the above mentioned parameters on the efficiency and work output.

The tribological phenomena that occur in brake systems are interesting even in other respects than just
the braking action.One important issue,that is gaining increasing importance over the last years,
concerns the environmental impact of wear debris produced by the braking action.In this context, the
present study is focussed on the tribological behaviour of acommercial friction pad material dry sliding
against a cast iron disc.Pin-on-disc tests were conducted at room temperature under mild wear
conditions, as concerns load and rotating speed.The effect of some components of pad material,
in particular of copper,on the dynamic of formation of tribological layer and wear debris is presented.
The results obtained so,although referring to quite a simpler system that real brake systems,still may
provide interesting indications,for instance in view of the development of novel brake pad materials and
braking control systems.

A review of high temperature tribocorrosion is presented focusing attention on those contributions that illustrate the general principles, modeling, and scientific theories of the processes of high temperature wear. A significant aspect of this chapter is the inclusion of new information on glaze formation, generated at the sub-microscopic and nano-scale level.

Timing belt tooth goes into contact with a drive pulley, stretched to the maximum, because of the previous tension. When the contact begins the peak of the belt tooth makes the contact with the outer surface of the pulley teeth. The process of the teeth entering into the contact zone is accompanied with the relative sliding of their side surfaces and appropriate friction force. The normal force value is changing with the parabolic function, which also leads to the changes of the friction force. The biggest value of the normal force and of the friction force ...

Space mechanisms use preloaded ball bearings in order to withstand the severe vibrations during launch. The launch strength requires the calculation of the bearing stiffness, but this calculation is complex. Nowadays, there is no analytical expression that gives the stiffness of a bearing. Stiffness is computed using an iterative algorithm such as Newton-Raphson, to solve the nonlinear system of equations. This paper aims at offering a simplified analytical approach, based on the assumption that the contact angle is constant. This approach gives analytical formulas of the stiffness of preloaded ball bearing. Notations a Semimajor axis of contact ellipse b Semiminor axis of contact ellipse B = f e + f i – 1Total curvature of the bearing D Ball diameter d m Bearing pitch diameter E Modulus of elasticity e Axial deflection due to preload f f e = r e /D Dimensionless parameter F(κ) Elliptic integral of the first kind K n Ball stiffness k a Axial stiffness of paired bearing k r Radial stiffness of paired bearing p H Hertzian pressure P Bearing preload Q Ball normal load r i r e Raceway groove curvature radius R x R y Equivalent curvature radius S(κ) Elliptic integral of the second kind Z Ball complement α Contact angle δa Axial deflection δn Normal approach along the line of contact δr Radial deflection ε = 0,5 [1+ (δa/δr) tanα] γ = D cosα /d m Dimensionless parameter Γ Curvature difference κ = a /b Elongation of elliptic contact area ν Poisson's ratio ρ = R x / R y

Summary: This dispatch covers Ekwensu and its relation to Yeshua. Other mythological and metaphorical figures and forces mentioned at least briefly includeMoses, Aganju, Khebioso, Inyonyi-Yezulu, Esu, Khonsu, Osiris, Egbesu, Bast. These figures were invented by related cultures with differing political agendas but derive from related linguistic roots and concepts, namely the -s- sound which means in general, to gush out, to shoot forth, to cause, to create, to begin”. In the interest of time and expediency many citations were left out by the author but they are not difficult to find using internet resources such as Google Books. Political-religious researchers and research committees may request the author for specific sources. At the same time they are encouraged to verify the information and proliferate the information.

The study of textured surface performance is one of the highly researched topics in recent times. This is mainly due to the advantages that such surfaces can potentially provide in practice, in mitigating adverse tribological conditions, such as friction and wear. However, considering the complexities found in practice, a methodological analysis and evaluation procedure is essential in order to gain an understanding of the benefits from utilising such features in a given contact. The current study provides a combined analytical and experimental approach towards an enhanced understanding of the behaviour of textured surfaces relative to their untextured counterparts. The developed analytical models are invaluable in providing an insight into the relationship between the many parameters involved in defining even simple surface texture feature geometry and the expected outcomes in practice, when corroborated with experimental results. The current study reports on such an endeavour. With the studied texture configuration, the results have shown the possibility of reducing friction by as much as 25%.

The vehicle is one of the most common machines in use today, and it is no exaggeration to state that it is crucial to the economic success of all the developing and developed nations of the world and to the quality of life of their citizens. The vehicle itself consists of thousands of component parts, many of which rely on the interaction of their surfaces to function. There are many hundreds of tribological components, from bearings, pistons, transmissions, clutches, gears, to wiper blades, tires, and electrical contacts. The application of tribological principles is essential for the reliability of the vehicle, and mass production of the vehicle has led to enormous advances in the field of tribology. For example, many of the developments in lubrication and bearing surface technology have been driven by requirements for increased capacity and durability in the vehicle industry. For the purpose of classifying the tribological components, one can divide the motor vehicle into engine, transmission, drive line, and ancillaries such as tires, brakes, and windshield wipers. In the following sections, each automotive component is discussed in detail. Lubricants used with these automotive tribological components are described in the last section of this study. The reciprocating internal combustion engine as shown in Fig. 1 is the prime mover in the motor vehicle, as well as in many other modes of ground and sea transport, including motorcycles, scooters, mopeds, vans, trucks, buses, agricultural vehicles, construction vehicles, trains, boats, and ships. Further applications can be found in the field of electrical power generation, where the internal combustion engine is used for primary and standby electricity generation and for combined heat and power plants. The popularity of the reciprocating internal combustion engine is testament to its performance, reliability, and versatility. However, there are also some major drawbacks. Thermal and mechanical efficiencies are relatively low, with much of the energy of the fuel dissipated as heat loss and friction. The internal combustion engine is also a significant contributor to atmospheric pollution through hydrocarbon, particulate, and NO x (nitrogen oxides) emissions and to the greenhouse effect via carbon dioxide (CO 2) emissions. A viable alternative with the required portfolio of attributes including cost, however, has yet to be found and, hence, the reciprocating internal combustion engine is set to dominate the road vehicle market for the foreseeable future. Fig. 1 Main engine components in a reciprocating internal combustion engine A. Importance of Engine Tribology To reduce friction and wear, the engine tribologist is required to achieve effective lubrication of all moving engine components, with minimum adverse impact on the environment. This task is particularly difficult given the wide range of operating conditions of load, speed, temperature, and chemical reactivity experienced in an engine. Improvements in the tribological performance of engines can yield:

The friction between two sliding surfaces is probably one of the oldest problems in mechanics. Frictional losses in any I.C. engine vary between 17% and 19% of the total indicated horse power. The performance of internal combustion engines in terms of frictional power loss, fuel consumption, oil consumption, and harmful exhaust emissions is closely related to the friction force and wear between moving parts of the engine
such as piston assembly, valve train, and bearings. To solve this problem, most modern research in the area of Nanotribology (Nanolubricants)
aims to improve surface properties, reduce frictional power losses, increase engine efficiency, and reduce consumed fuel and cost of maintenance. Nanolubricants contain different nanoparticles such as Cu, CuO, TiO2, Ag, Al2O3, diamond, and graphene oxide. This paper demonstrates the effect of nanoparticles on the tribological behavior of the engine oil. The main objective of this review is to present recent progress and, consequently, develop an exhaustive understanding
about the tribological behavior of engine oils mixed with nanoparticles.

Metal matrix composites (MMCs) are an important class of engineering materials that are increasingly replacing a number of conventional materials in the automotive, aerospace, marine, and sports industries due to their lightweight and superior mechanical properties. In MMCs, nonmetallic materials are embedded into the metals or the alloys as reinforcements to obtain a novel material with attractive engineering properties, such as improved ultimate tensile strength, ductility, toughness, and tribological behavior. In this chapter, an attempt has been made to summarize the tribological performance of various MMCs as a function of several relevant parameters. These parameters include material parameters (size, shape, volume fraction, and type of the reinforcements), mechanical parameters (normal load and sliding speed), and physical parameters (temperature and the environment). In general, it was shown that the wear resistance and friction coefficient of MMCs are improved by increasing the volume fraction of the reinforcements. As the normal load and sliding speed increase, the wear rate of the composites increases and the friction coefficient of the composites decreases. The wear rate and friction coefficient decrease with increasing temperature up to a critical temperature, and thereafter both wear rate and friction coefficient increase with increasing temperature. The nano-composites showed best friction and wear performance when compared to micro-composites.

A systematic approach is required in order to determine the frictional characteristics of a contacting pair in the presence of a tribofilm. Despite the clear benefits in functionality and in reducing wear, the generation of ZDDP-based tribofilms often lead to increased frictional losses. Such an increase is also observed in the tribometric tests reported here, as well as in open literature. This paper investigates the underlying mechanics for the rise in friction using an integrated methodology, based upon Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). The use of an analytical contact mechanics model demonstrates that the pressure coefficient of boundary shear strength, measured using lateral force microscopy, provides an explanation for the observed increase in measured friction at micro-scale.

This paper evaluates the design selection of a hydrostatic bearing pad for automotive application. The purpose of hydrostatic bearing is to eliminate high frequency vibration from gear mesh-frequency, example from heavy truck. Pugh controlled convergence method was used to obtain the optimum design shape for selection. The setting up parameter criteria verses the concept pad shape between applications of hydrostatic journal and hydrostatic thrust bearings were varied. Comparison of design engineering criteria was made with number of leading concepts in hydrostatic bearing for ultimate qualitative optimization, and the parameter design criteria was customized for automotive heavy truck vehicle. Fourteen (14) selection considerations were used as, manufacturing ease, safety of the design, cost development, accuracy in output, reliability in life span, simplicity in degree of design, load capacity, stiffness, damping, suppress temperature rise, pumping power, mounting space for fitting, oil circulation without leakage and finally displacement of the controlled plunger. From this convergence method, 'Circular recess pocket plunger' with spring loaded (CRPP) conceptually selected. It was model from qualitative optimization by combining 'squeeze film damper' (SFD) of a journal bearing without journal rotation and Cooper's squeeze film coil spring test apparatus.

The damage caused by the combination of corrosion and wear processes on the materials that machine elements are produced causes huge losses in several industries such as mineral processing, chemical, petrochemical and power generation. Some devices that operate in harsh environments, such as centrifugal pumps for transportation of caustic liquor used in the industries of production of aluminum, undergo a rapid deterioration of their materials by the coexistence of corrosion and erosion at temperatures around 75°C. The aim of this work is to study new ways for the corrosive-erosive problems confronted by the aluminum and nickel
industries. Several coating materials in powder or wire form applied by GMA welding and HVOF thermal spray techniques are compared in erosion and erosion-corrosion tests.
Corrosion tests were performed for comparison. A solution of 1M NaOH was used as corrosive medium to get the polarization curves The temperature of the electrolyte was 25°C.
For pure erosion test, the slurry erosive agent was 4 liters of water and an erosive particle concentration of 400 g/l. Particles of ferric oxide, HRC = 40-50 and average diameter of 600
um, were used as erosive agent. The impact angle of 90° was tested, with impact velocity of the abrasive particles of 31 m / s. Tests were performed for each condition at a time of 2 hours
at intervals of 20 minutes. The results show that the best performance was that of the mixed stainless steel and Cobalt alloys welded coating even though the general resistance to erosive corrosive wear significantly favors cermets in relation to the other welded deposits.

Tribofilms are activated using precision sliding strip microscale tribometry with a base and a fully formulated lubricant with a ZDDP anti-wear additive. The employed tribometry uses combined pressure, shear and temperature activation. The chemical compositions of the formed tribofilms are ascertained through use of Photo-electron X-ray Spectroscopy (XPS). Nanoscale frictional measurements of the tribofilms are reported using fluid cell lateral force microscopy (LFM). The measured coefficient of interfacial boundary shear strength is used with analytical contact mechanics to relate the in-situ conditions to the activation energy components of the Eyring potential cage model. The paper shows that combined LFM and the Eyring model can explain the variations in the frictional characteristics of formed tribofilms.

Abstract:
This is more of the research notes I compiled, on the original Black Aboriginal meaning of "Ekwensu" also known as "Egwo Nsi" and "Ekwe Nsi".

Ekwe Nsu - drum (healing song) for loss (violence, of senses ie senility, stammering, antisocial behavior); medicine drum for trauma. Ekwensu is the embodiment and procedure for dealing with traumatic events, war, protection from violent retaliation, protection and incitement of violence/war-mongering, and a procedure for dealing with all forms of post traumatic stress disorder and loss of senses .
Egwo Nsi - concoction/tribute herbs for charms (poisons?) - this term is clearly related to Agwu Nsi.

Also I reason other terms in nearby languages like Ogun, Ogbu, Ogwu, Egbesu are related based on similar procedures and concepts.

This paper deals with the tribological performance of carbon nanoparticles dispersed in polyalphaolefin PAO6 oil. Stribeck curves are obtained under various operating conditions, using a fully instrumented pin-on-disc tribometer under controlled conditions. A detailed multi-physics thermal fluid flow model with Lagrangian low concentration discrete solid phase and Eulerian multi-phase fluid with cavitation represented by modified Rayleigh-Plesset and vapour transport equation is presented. The numerical predictions under identical conditions to the experiments show good conformance with the measurements, and provide a fundamental understanding of the role of nanoparticles. Results show improved heat transfer from the contact with the presence of nanoparticles even at low levels of concentration. The analysis shows that this leads to higher lubricant viscosity, load carrying capacity and reduced friction. Furthermore, a resulting small region of cavitation at low volume fraction does not unduly affect the enhanced heat transfer of nanoparticles. This combined experimentation and detailed numerical analysis has not hitherto been reported in literature.