Synthetic friction force algorithms provide simulated static friction forces as well as dynamic friction forces. On either side of a hand-control element reference position a small static friction zone is established. As long as the hand-control element is within this static friction zone, the reference position remains constant and the control element drive motor generates a centering force proportional to the distance of the hand-control element from the reference position; a force urging the hand-control element toward the reference position. When the relative position of the hand-control element reaches or exceeds an edge of the static friction zone, it enters the dynamic friction zone. The motor applies a constant dynamic friction force, urging the hand-control element toward the reference position and the reference position is translated so that the edge of the static friction zone is translated to the current hand-control element position.
In question number 69 of six minute for geotechnical, for PE exam study, it tells us to calculate the skin friction based on Beta Method, and uses cohesion of the soil. no angle of friction between pile and soil is given, the question doesnt talk about it. so it uses tha beta method and calculates the skin friction. we didnt add the capacity from skin friction because it was not given correct? and in reality there is always a skin friction? and all the layers of soil in question have
We present an investigation of the temperature-dependent friction behavior of PTFE, MoS 2, and PTFE-on- MoS 2. Friction behavior was measured while continuously varying contact temperature in the range -150 to 175°C while sliding in dry nitrogen, as well as for self-mated PTFE immersed in liquid nitrogen. These results contrast with previous reports of monotonic inverse temperature dependent friction behavior, as well as reported high-friction transitions and plateaus at temperatures below about -20°C that were not observed, providing new insights about the molecular mechanisms of macro-scale friction. The temperature-dependent friction behavior characteristic of self-mated PTFE was found also on the PTFE-on-MoS 2 sliding contact, suggesting that PTFE friction was defined by sub-surface deformation mechanisms and internal friction even when sliding against a lamellar lubricant with extremely low friction coefficient (μ ~ 0.02). The various relaxation temperatures of PTFE were found in the ...
TY - JOUR. T1 - Molecular dynamics simulation of atomic-scale frictional behavior of corrugated nano-structured surfaces. AU - Kim, Hyun Joon. AU - Kim, Dae Eun. PY - 2012/7/7. Y1 - 2012/7/7. N2 - Surface morphology is one of the critical parameters that affect the frictional behavior of two contacting bodies in relative motion. It is important because the real contact area as well as the contact stiffness is dictated by the micro- and nano-scale geometry of the surface. In this regard, the frictional behavior may be controlled by varying the surface morphology through nano-structuring. In this study, molecular dynamics simulations were conducted to investigate the effects of contact area and structural stiffness of corrugated nano-structures on the fundamental frictional behavior at the atomic-scale. The nano-structured surface was modeled as an array of corrugated carbon atoms with a given periodicity. It was found that the friction coefficient of the nano-structured surface was lower than ...
The data is summarized (Table 2) by means and standard deviations. Friction was evaluated and compared in grams-force (gF) under traction with a round 0.020-in stainless steel wire. The findings suggest lower friction means for the self-ligating groups compared with conventional brackets tied with elastomeric ligatures. A more effective frictional control was achieved in the passive self-ligating system when these brackets were tested with no angulation. Under a 2.5° angulation, the frictional force increased in the self-ligating and conventional groups (p , 0.01).. ANOVA revealed associations between frictional forces and self-ligating systems. The p value (p , 0.01) found using the Bonferroni multiple comparisons test indicated differences between groups (Table 2).. DISCUSSION. Surface friction generated by sliding an orthodontic archwire inside a bracket slot opposes the tendency of tooth movement intended when delivering orthodontic forces. A greater friction effect can be observed in ...
The friction reducing capability of engine oils in the piston ring/cylinder bore contact was investigated under fully-flooded and starved lubrication conditions at 100° C using a laboratory piston ring/cylinder bore friction rig. The rig is designed to acquire instantaneous transient measurements of applied loads and friction forces at the ring/bore interface in reciprocating motion over a 50.8 mm stroke. The effects of increasing load and speed on the friction coefficient have been compared with new and used engine oils of different viscosity that were formulated with and without friction modifying additives. Test results with fully formulated engine oils containing molybdenum dithiocarbamate (MoDTC) show that friction is always lower than that obtained with non-friction modified oils but in regions of persistent starvation the coefficient of friction can increase significantly, approaching levels equivalent to fully-flooded non-friction modified formulations. The laboratory rig was able to ...
The aim of this thesis is to interconnect human tactile perception with various physical properties of materials. Tactile perception necessitates contact and relative motion between the skin and the surfaces of interest. This implies that properties such as friction and surface roughness ought to be important physical properties for tactile sensing. In this work, a method to measure friction between human fingers and surfaces is presented. This method is believed to best represent friction in tactile perception.. This study is focused on the tactile perception of printing papers. However, the methodology of finger friction measurements, as well as the methodology to link physical properties with human perception data, can be applied to almost whichever material or surfaces.. This thesis is based on three articles.. In Article I, one participant performed finger friction measurements, using a piezoelectric force sensor, on 21 printing papers of different paper grades and grammage (weight of the ...
Best Friction Dust Dealers. Find the list of best Friction Dust suppliers & Manufacturers. Yellow Pages Directory of Friction Dust, Friction Dust manufacturers, Traders, and Friction Dust, Friction Dust Suppliers & Dealers in India.
TY - JOUR. T1 - Frictional response of articular cartilage containing crystals. AU - Clift, Sally E. AU - Harris, B. AU - Dieppe, P A. AU - Hayes, A. PY - 1989. Y1 - 1989. N2 - Many joint diseases are associated with the deposition of crystals in articular cartilage. Three main types are commonly found: calcium pyrophosphate, calcium hydroxyapatite and monosodium urate. The effects of these articular crystals on the frictional properties and the surface condition of the articular cartilage were studied. A total of 43 cartilage specimens cut from 19 post-mortem knee joints have been tested in purpose-designed apparatus. The results show that a high friction coefficient and a high level of crystal deposition tend to occur with a worsening of the surface quality of the articular cartilage. AB - Many joint diseases are associated with the deposition of crystals in articular cartilage. Three main types are commonly found: calcium pyrophosphate, calcium hydroxyapatite and monosodium urate. The effects ...
A series of ball-disk contact friction tests were carried out using a microtribometer to study the tribological characteristics of steel/steel rubbing pairs immersed in 47 different organic compounds as lubricant base oils. The structures and their friction data were included in a back-propagation neural network (BPNN) quantitative structure tribo-ability relationship (QSTR) model. Following leave-one-out (LOO) cross-validation, the BPNN model shows good predictability and accuracy for the friction parameter (R2 = 0.994, R2(LOO) = 0.849, and q2 = 0.935). Connectivity indices (CHI) show the large positive contribution to friction, which imply that friction performance has a strong correlation with molecular structure. The BPNN-QSTR models can flexibly and easily estimate the friction properties of lubricant base oils.. ...
A novel microtribometer is developed to characterize microelectromechanical systems (MEMS) sidewall friction with high resolution. The design is based on a rotational grating displacement sensing mechanism, with which 1.2-nm sensing sensitivity can be achieved. Employing it, the adhesion force (1.85 N) and the coefficients of static (0.801) and kinetic (0.363) frictions on the sidewall of an as-fabricated MEMS device have been measured. Besides these, the whole process of stick-slip associated with the movement under friction, including the transition between static and kinetic frictional states, has also been clearly revealed. To reduce friction, a localized lubrication method is developed, with which liquid lubricant can be applied directly onto the desired region without affecting other components on the same device. From the experimental results, reduced values in adhesion force (1.23 N) and coefficients of friction (0.262 for static and 0.183 for kinetic) are obtained in the same MEMS ...
The report provides a unique tool for evaluating the Market, highlighting opportunities, and supporting strategic and tactical decision-making. This report recognizes that in this rapidly-evolving and competitive environment, up-to-date marketing information is essential to monitor performance and make critical decisions for growth and profitability. It provides information on trends and developments, and focuses on markets capacities and on the changing structure of the Linear Friction Welding Machines. Avail a sample copy before purchase : http://www.e-marketresearch.com/request-sample-21296.html. Key Segment of Linear Friction Welding Machines Market Report:. 1) Major Key Players of Linear Friction Welding Machines Market: Branson, Thompson, MTI, Bielomatik, Forward Technology, Dukane, KLN, Daeyoung Ultrasonic, Chango. 2) Global Linear Friction Welding Machines Market, by Type : Linear Vibration Welding, Linear Friction Welding. 3) Global Linear Friction Welding Machines Market, by ...
Deep friction massage is one of several physiotherapy interventions suggested for the management of tendinopathy. The objective of this study was to determine the prevalence of deep friction massage use in clinical practice, to characterize the application parameters used by physiotherapists, and to identify empirical model-based patterns of deep friction massage application in degenerative tendinopathy.. 478 physiotherapists were selected through snow-ball sampling method. The participants completed an online questionnaire about personal and professional characteristics as well as specific questions regarding the use of deep friction massage. Characterization of deep friction massage parameters used by physiotherapists were presented as counts and proportions. Latent class analysis was used to identify the empirical model-based patterns. Crude and adjusted odds ratios and 95% confidence intervals were computed.. The use of deep friction massage was reported by 88.1% of the participants; ...
friction - MedHelps friction Center for Information, Symptoms, Resources, Treatments and Tools for friction. Find friction information, treatments for friction and friction symptoms.
... providing at least 30% less friction than corresponding standard SKF bearings. Because friction loss is energy loss, Low friction tapered roller bearings help deliver lower energy consumption ...
... providing at least 30% less friction than corresponding standard SKF bearings. Because friction loss is energy loss, Low friction tapered roller bearings help deliver lower energy consumption ...
View Notes - mechanics-static-lec6 from ME mechanics- at École Normale Supérieure. Lecture 6 Friction Tangential forces generated between contacting surfaces are called friction forces and occur to
According to the HK model of dislocation-assisted frictional slip processes, the sliding mechanisms of single-asperity friction can be classified into three categories, i.e. concurrent slip, single-dislocation-assisted (SDA) slip and MDC slip, depending on the contact size. These three regions are shown in figure 7. The boundary between the concurrent- and SDA-slip regions is depicted as line l1. The other boundary between SDA- and MDC-slip regions is represented by line i1. In figure 7, the scale dependence of the friction stress in SDA-slip region can be described by a series of dashed lines depending on the Rice-Thomson parameter η (see Hurtado & Kim 1999a,b; for details). The AFM friction data measured by Carpick et al. (1996a) lie inside the concurrent-slip region. In this range, the friction stress is independent of the contact size, as shown in figure 7 by two sets of up triangles connected by a line. However, as mentioned earlier, the friction stress drifted from 910 down to 270 MPa, as ...
A coin is placed on a record that is rotating at 33.3 rpm. If the coefficient of static friction between the coin and the record is 0.2, how far from the center of the record can the coin be placed without having it slip off ...
Aim Surface tribological properties of a tendon in terms of coefficient of friction and lubrication mechanism are expected to change with the progression of surface tears which can affect the optimal function of the tendon. This study investigated whether coefficient of friction proportionally increases with the progression of a surface tear in a bovine tendon model. Methods The study was performed using a pin-on-glass tribometer and bovine tendon samples (n = 16) divided into 4 groups. One group of tendons had no surface tears and thus served as a control, whilst the other 3 groups comprised tendons with increasing severity of artificially-induced surface tears. The coefficient of friction and the lubrication mechanism of the four groups of samples were investigated, calculated and compared. Results Statistical analysis showed significant change in coefficient of friction between the control group and the group with minimal tear (p , 0.05) while no difference noted between the groups of ...
Large selection of Indasa sandpaper and Nortons Sandpaper Packs allow you to purchase only what you need for your specific job. Purchase sandpaper rolls wet or dry at Eastwood to save your money. Visit us on-line today.
Large selection of Indasa sandpaper and Nortons Sandpaper Packs allow you to purchase only what you need for your specific job. Purchase sandpaper rolls wet or dry at Eastwood to save your money. Visit us on-line today.
Sliding friction experiments were conducted with various iron-base alloys (alloying elements were Ti, Cr, Mn, Ni, Rh, and W) in contact with a single-crystal silicon carbide (0001) surface in vacuum. Results indicate atomic size misfit and concentration of alloying elements play a dominant role in controlling adhesion, friction, and wear properties of iron-base binary alloys. The controlling mechanism of the alloy properties is as an intrinsic effect involving the resistance to shear fracture of cohesive bonding in the alloy. The coefficient of friction generally increases with an increase in solute concentration. The coefficient of friction increases as the solute-to-iron atomic radius ratio increases or decreases from unity. Alloys having higher solute concentration produce more transfer to silicon carbide than do alloys having low solute concentrations. The chemical activity of the alloying element is also an important parameter in controlling adhesion and friction of alloys.. ...
Transmission Friction Plates, Wholesale Various High Quality Transmission Friction Plates Products from Global Transmission Friction Plates Suppliers and Transmission Friction Plates Factory,Importer,Exporter at Alibaba.com.
The Greeks, including Aristotle, Vitruvius, and Pliny the Elder, were interested in the cause and mitigation of friction.[8] They were aware of differences between static and kinetic friction with Themistius stating in 350 A.D. that "it is easier to further the motion of a moving body than to move a body at rest".[8][9][10][11]. The classic laws of sliding friction were discovered by Leonardo da Vinci in 1493, a pioneer in tribology, but the laws documented in his notebooks, were not published and remained unknown.[12][13][14][15][16][17] These laws were rediscovered by Guillaume Amontons in 1699[18] and became known as Amontons three laws of dry friction (below). Amontons presented the nature of friction in terms of surface irregularities and the force required to raise the weight pressing the surfaces together. This view was further elaborated by Bernard Forest de Bélidor[19] and Leonhard Euler (1750), who derived the angle of repose of a weight on an inclined plane and first distinguished ...
We develop a framework for nonparametrically identifying optimization frictions and structural elasticities using notches-discontinuities in the choice sets of agents-introduced by tax and transfer policies. Notches create excess bunching on the low-tax side and missing mass on the high-tax side of a cutoff, and they are often associated with a region of strictly dominated choice that would have zero mass in a frictionless world. By combining excess bunching (observed response attenuated by frictions) with missing mass in the dominated region (frictions), it is possible to uncover the structural elasticity that would govern behavior in the absence of frictions and arguably capture long-run behavior. We apply our framework to tax notches in Pakistan using rich administrative data. While observed bunching is large and sharp, optimization frictions are also very large as the majority of taxpayers in dominated ranges are unresponsive to tax incentives. The combination of large observed bunching and ...
Friction Animal Toy Car, Wholesale Various High Quality Friction Animal Toy Car Products from Global Friction Animal Toy Car Suppliers and Friction Animal Toy Car Factory,Importer,Exporter at Alibaba.com.
Fcuk Friction Cologne on sale. Fcuk Friction by French Connection as low as $15.29 at fragranceX.com, FREE Shipping on orders over $35. Fcuk Friction, Fcuk Friction Cologne by French Connection, This enchanting fragrance was released in 2012. Fcuk friction is warm and fruity with aquactic notes. The scent is blended with amber, geranium, green fruits, cardamom, lavender, leather, mandarin, marine notes, musk, and patchouli. It also has a splash of rum accord and black coconut. All products are original, authentic name brands. We do not sell knockoffs or imitations.
As was shown in part II, the Gorter-Mellink mutual friction force in a heat current is probably associated with turbulence in the superfluid. Following Feynman, it is suggested that this turbulence takes the form of a tangled mass of quantized vortex lines, so that the mutual friction probably arises from collisions between thermal excitations and these vortex lines. From the observed properties of the mutual friction it is deduced that the walls of the channel carrying the heat current play no essential role in the generation, maintenance or decay of the turbulence, but merely introduce a number of incidental complications; the present paper ignores these complications and deals therefore with the idealized case of a homogeneous heat current in an unbounded volume of helium. The turbulence in this idealized case must be homogeneous, and it is shown from experimental evidence that it is probably also isotropic. Values of the force exerted on unit length of a vortex line, which have been derived ...
A vehicles response is predominately defined by the tire characteristics as they constitute the only contact between the vehicle and the road; and the surface friction condition is the primary attribute that determines these characteristics. The friction coefficient is not directly measurable through any sensor attachments in production-line vehicles. Therefore, current chassis control systems make use of various estimation methods to approximate a value. However a significant challenge is that these schemes require a certain level of perturbation (i.e. excitation by means of braking or traction) from the initial conditions to converge to the expected values; which might not be the case all the time during a regular drive. This study proposes an observer scheme that utilizes an instrumented tire (i.e. smart tire) as an additional sensor input and develops a sliding-mode observer based on tire force feedback to provide the estimated friction coefficient irrespective of the available excitation. ...
Types Of Frictional Force: solid & liquid frictional force : solid friction occurs between two solid surfaces. e.g an inclined plane liquid friction occurs between layers of liquid molecules which is known as Viscosity or Liquid Friction and surface tension
This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, ...
Solid state Friction stir welding (FSW) is of major interest in the welding of aluminium since it improves the joint properties. Many applications where Al-alloys are used are subject to varying load conditions, making fatigue failure a critical issue. In the scope of this thesis, the fatigue performance of friction stir welded AlMgSi-alloy 6082 has been investigated. Static and dynamic properties of different joint configurations and welds produced with varying process parameters have been determined. Microstructures of fractured surfaces have been studied to evaluate the effect of weld discontinuities on fatigue. The mechanical strength of the friction stir welds was set in relation to that of conventional fusion welds, and that of other FS welded Al-alloys.. The friction stir process produced aluminium butt welds with high and consistent fatigue strengths, which exceeded the strengths of similar fusion welded samples. A smooth weld geometry showed to be of great importance for the fatigue ...
Performance under pressure. Performance Frictions brake system technology provides unique solutions for modern tactical military wheeled vehicles. PFC has provided OEM pads for the HMMWV as well as engineered a disk brake system for numerous other armored vehicles.. Military applications require high flexibility in friction material selection because of the wide range of performance requirements. PFCs innovative use of materials, advanced process technology, and patented Zero Drag technology, delivers unrivalled braking performance with high reliability.. For applications ranging from motorcycles and light reconnaissance vehicles to tactical vehicles such as the HMMWV, JLTV, M-ATV, and heavier, the best solution is Performance Friction. No other company has the ability to provide lightweight, high performance brake systems for these vehicles while maintaining OEM TS 16949 quality standards. All products are engineered and manufactured in the USA.. Test-proven. Over 5,000 friction materials ...
We numerically investigated the effects of friction drag reduction and energy gain by traveling wave-like blowing using plasma actuators arrayed on channel walls. Wall-normal flow is induced by opposed arrangement of plasma actuators. We used Shyy et al.s model [1] to compute the body force of plasma actuators, which is added to the Navier-Stokes equation. With this model, the body force distribution is simplified as compared to the actual one, which is quite complicated. We perform direct numerical simulation under several parameter sets: the wavenumber, the amplitude, and the phasespeed of body forces. The obtained maximum friction drag reduction rate is 37% as compared to the uncontrolled case. Under the same phase speed and amplitude of body force, the friction drag is found to be reduced more with larger wavenumber. Under the same phase speed and wavenumber, the friction drag reduction is found to be larger with stronger body force. In the drag reducing cases, formation of spanwise ...
We are frition plate manufacturer from Hangzhou, China. The friction plate Dia. we can provide range from 117mm to 1164mm. The friction plate formula including copper, iron, paper and carbon graphite, etc.
The tractor friction disc we can provide including MF, FORD,JOHN DEERE,etc.The tractor friction plate dimension range from 128mm to 368mm.
[113 Pages Report] Check for Discount on Global Low Friction Ring Sales Market Report 2017 report by QYResearch Group. In this report, the global Low Friction Ring market is...
In this article, the influence of contact conditions (sliding velocity) on the tribological behavior of uncoated tungsten carbide tool against OFHC copper work material was investigated. Series of tribology tests combined with numerical simulations of the contact process were performed under different sliding speeds and contact pressures, in order to identify the friction coefficient and the heat partition between OFHC copper and tungsten carbide. The friction coefficient in function of the sliding velocity was then integrated into a FE model of the orthogonal cutting of OFHC copper and applied to surface integrity prediction ...
This paper investigates the influence of the material parameter, buoyancy parameter and Prandtl number on the skin friction coefficient and the heat transfer rate at the surface on a steady, two dimensional flow of an incompressible micropolar fluid near the stagnation point on a vertical plate with prescribed surface heat flux in presence of a magnetic filed. The free stream velocity and the surface heat flux are assumed to be proportional to the distance from the stagnation point. Similarly transformation is employed to transform the governing partial differential equations to a set of ordinary differential equations. The effects of the material parameter, buoyancy parameter and Prandtl number on the skin friction coefficient and the heat transfer rate at the surface are discussed and the corresponding velocity, temperature and microrotation profiles are shown graphically. Both assisting and opposing flows are considered and it is found that dual solutions exist for both cases
President Donald Trump on Sunday denied that his trade war with China is causing friction at the G7 summit, but indicated he will hold off from a threatened...
The minimum force required to move an object on a surface depends on the angle at which the force applied to pull the object. If it is not stated that the force is applied horizontally then the answer will be different. The component of the force applied in vertical direction will change the normal reaction and hence the limiting friction force ...
To envision how axial oscillation works, imagine a cell phone setting on an incline. When the phone is not vibrating, it stays stationary. Once a call comes in and the phone begins to vibrate, it slides down the slope. The movement breaks the friction between the phone and the surface it is resting on, allowing the force of gravity to overcome the friction forces. The same principle works on a drill string resting on the bottom side of a borehole in an extended-reach operation.. Incorporating the Agitator system into the BHA has enabled operators around the world to reduce friction and drilling time, saving operating costs. In Egypt, an operator experienced torque and drag challenges when drilling in complex wells. Using a 6¾-in. Agitator system improved WOB and allowed the operator to drill an entire 8½-in. section in one run. Compared to offset wells without the Agitator system, the drill string with the Agitator system saved half a dozen trips, increased average ROP by 31%, and reduced cost ...
An effective method has been developed for analysis of the multiharmonic forced response of large-scale finite element models of bladed discs with contact interfaces at blade roots. Area contact elements are developed to model nonlinear forces acting at the contact surfaces. The elements allow for unilateral normal and tangential friction contact forces. The friction model includes effects of the variable normal load and variation of the contact area. Numerical investigations of the forced response for realistic finite element models of bladed discs with root damping are performed for the first time. ...
A string carrying two weights is hung over a low friction bearing mounted pulley. The weights have slightly different masses, causing a uniform acceleration. When the time it takes the weights to move 1 meter is timed, we can calculate the acceleration of the system due to gravity. Because of the low amount of friction in the system, this value is very close to the theoretical value.. Read more about the Atwood Machine. ...
Amontons law defines a material-dependent constant, the friction coefficient, as the ratio between friction force and normal force. Amontons law is commonly explained with the two non-trivial assumptions that both the frictional and normal force depend linearly on the real contact area between the two sliding surfaces. Most surfaces are rough and experimental testing of frictional contact models has proven difficult, because few in-situ experiments are able to resolve this real contact area. Here, we present a new contact detection method with molecular-level sensitivity, and independently probe the two relations that form the microscopic origin of Amontons law. While the friction force is proportional to the real contact area, we find that this real contact area does not increase linearly with normal force. Contact simulations performed on the identical surface show that the breaking of Amontons law is due to both elastic interactions between asperities on the surface and contact plasticity of ...
Munich, Germany , Posted on May 16th, 2013. Friction is an omnipresent but often annoying physical ph nomenon: It causes wear and energy loss in machines as well as in our joints. In search of low-friction components for ever smaller components, a team of physicists led by the professors Thorsten Hugel and Alexander Holleitner now discovered a previously unknown type of friction that they call "desorption stick ...
2.8)where U(x) is the van der Waals potential energy; γ the interlayer cohesive energy density for a single MWNT layer; C the circumference of the active nanotube bearing cylinder; and x the length of the overlap between the core section and the outer layer. It is interesting to note that the interlayer force is independent of the overlap length. For the nanotube in figure 10, the van der Waals force was estimated to be 9 nN. Based on the observation that complete retraction occurred between two frames of the video recording (Δt=33 ms), Cumings & Zettl estimated limits on the static friction force fs,23 fN per atom and the dynamic friction force fd,15 fN per atom.. As these limits were based on estimates, it was however unclear at this point what the magnitude of interlayer force and friction would be, if the interlayer friction would scale with the length of the moving segment, and how it would evolve during prolonged actuation and damage to the nanotube. The magnitude of the surface energy ...
Aqueous biocompatible tribosystems are desirable for a variety of tissue-contacting medical devices. L-3,4-dihydroxyphenylalanine (DOPA) and lysine (K) peptide mimics of mussel adhesive proteins strongly interact with surfaces and may be useful for surface attachment of lubricating polymers in tribosystems. Here, we describe a significant improvement in lubrication properties of poly (dimethylsiloxane) (PDMS) surfaces when modified with PEG-DOPA-K. Surfaces were characterized by optical and atomic force microscopy, contact angle, PM-IRRAS, and X-ray photoelectron spectroscopy. Such surfaces, tested over the course of 200 rotations (∼8 m in length), maintained an extremely low friction coefficient (μ) (0.03 ± 0.00) compared to bare PDMS (0.98 ± 0.02). These results indicate the potential applications of PEG-DOPA-K for the modification of device surfaces. Extremely low μ values were maintained over relatively long length scales and a range of sliding speeds without the need for substrate ...
Indasa RHYNOSTICK PSA sandpaper Made in Portugal Grits available 80, 120, 220, 320, 400, 600* and 800 grit All grits are European P-Scale* White colored sanding surface except for *600 grit which is red 5 feet (1.52m) length 2 3/4 (70mm) width Convenient peel and stick liner Please pick the grit from above optionIndasa brand of sandpaper is one of the best available. Features both a high initial cutting action and clog resistance coating that is safe for use with water based finishes. The protective release paper backing (ie. peel and stick) keep the adhesive surface free of sanding grit until you are ready to use. This is better then other brands(ie. 3m gold) where the adhesive layer is stuck to the abrasive layer. This also allows us to sell the sandpaper in both full rolls and in 5.