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Effect of Tire Inflation Pressure on Rolling Resistance, Contact Patch Area and Braking Distance

Effect of Tire Inflation Pressure on Rolling Resistance, Contact Patch Area and Braking Distance

As the inflation pressure reduces, it results in more contact of tire with pavement. This results in increase in adhesion [1] and hysteresis [2] between tire and road. This entire factor contributes to the increase in resistive forces experienced by vehicle in motion. Fuel economy [3] also reduces with reduction in tire inflation pressure but reduction in inflation pressure increases the rolling resistance [4] which contributes to the reduction in braking distance.

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Rolling resistance contribution to a road pavement life cycle carbon footprint analysis

Rolling resistance contribution to a road pavement life cycle carbon footprint analysis

The main aim of this paper was to investigate if current models of the impact of pavement surface properties on rolling resistance can be implemented in road pavement LCA. Considering the significant impact that the pavement surface properties can have during the life cycle of a road, it is necessary that any model used to estimate this component leads to results that can be used with confidence in the decision-making process. Taking into account the results ob- tained in the selected case study, the use of the UCPRC and VTI models in the UK should be treated with caution because they produce significantly different results. Further and differ- ent case studies are needed before it can be decided where they can be used. The different weight that the models give to the different pavement condition variables means the relative re- sults from the two models are very sensitive to both level of pavement condition and its deterioration rate. This will have an impact both on stand-alone and comparative LCA studies. For UK roads, there is currently insufficient information available to predict the deterioration of roughness and texture depth over time depending on maintenance treatments, traffic volume, surface properties and materials. This must be corrected before pavement LCA studies can be extended to the use phase. Traffic growth and the emission factors/fuel efficiency predictions, combined to predict future vehicle emissions, have a relatively small effect because they cancel out to a large extent. Changes in predicted future traffic levels or emission factors could change this result and should be kept under review.

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Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation

Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation

simulations to the rolling–machining process, thereby incorporating more preliminary information for the tooling design and determining the optimum processing conditions. Wu et al. [6] studied the effect of the roller tooth’s taper angle, imprint depth, and imprint temperature on the properties of single-crystalline gold and observed that imprint force and adhesion increase with increasing imprint depth and decreasing taper angle. Lin et al. [7] used a MD simulation with the embedded atom method (EAM) to study the deformation process of pure copper nanorods in the nanoforming process; they reported that the pure copper nanorods undergo plastic deformation because of structural defects owing to higher energies in the material, wherein the higher energies are induced by large compressive loadings and high temp- eratures. Furthermore, the rolling process is similar to the milling, polishing, grinding, and cutting processes performed with a machining center. On the basis of MD simulations, Yang et al. [8] proposed a single-crystalline copper structure for ultra-precision polishing with the self- rotation of a diamond abrasive. They observed that an increase in abrasive rotation velocity decreased the tangen- tial force, resulting in diminished material machine quality.

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Design and Working of Adjustable Manually Push Operated Pesticide Spraying Machine 

Design and Working of Adjustable Manually Push Operated Pesticide Spraying Machine 

For calculation of demand drive force/ Total tractive force (TTE) of machine it is important to calculate a) force required to overcome rolling resistance of whole machine (RR), b) force to overcome gradient resistance of machine (GR), c) force to accelerate equipment to gain its maximum velocity for operation (FA), d) force to overcome resistance due to power generating fifth wheel (FB).

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Parametric study on colluvium volume evaluation by simple model of distinct element method

Parametric study on colluvium volume evaluation by simple model of distinct element method

Table 5 shows the calculation results in the simulation where the maximum amount of collapsed soil is 26,009 m 3 with a rolling resistance coefficient of 0.05 using J Company's code, but is 22,114 m 3 with a rolling resistance coefficient of 0.0 using I Company's code. Although the trends differ between the two codes, they both produced maximum values that exceed the actual value in the collapsed site. A method to perform a parametric study within an appropriate range is realistic to obtain a maximum value because generally all information is unavailable for the target site (layers, properties, groundwater level, etc.) or cannot be obtained in case of an emergency.

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Energy and transportation

Energy and transportation

4 . 1. Rolling resistance and drag for bicycles. – Let us consider cycling on a horizontal road, so we do not need to fight gravity. The bike itself offers very little mechanical resistance, provided it is in good condition. The ball bearings cause a loss of about 1% only, a well-oiled chain about 1.5%, the gears (derailleur ) 5% at most [4]. Once we reach cruising speed, the real forces that we have to compensate for are rolling resistance and air resistance. It is the same as for a car (see fig. 1). But with a bicycle, we are obviously working with different figures.

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Modeling And Analysis Of Non-Pneumatic Tyre By Using Ansys

Modeling And Analysis Of Non-Pneumatic Tyre By Using Ansys

Rolling resistance of the tire is depends on the vehicle fuel consumption and it also increases the temperature in the tire. In the current scenario of automotive fleet, tires have a short lever on (i) fuel economy; roughly 10% decrease in rolling resistance and 1% better fuel economy. (ii) Rolling resistance is influenced by a number of factors which are the i. load, ii. tire geometry, iii. speed, iv. temperature, and v. contact pressure.

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The physical and mechanical properties of potato Solanum tuberosum L.) tubers as related to the automatic separation from clods and stones

The physical and mechanical properties of potato Solanum tuberosum L.) tubers as related to the automatic separation from clods and stones

The mean values of the static coefficient of fric- tion and the rolling resistance of the two potato tuber varieties and the five abrasion surfaces are given in Table 3. As seen in Table 3, the coefficient of static friction in the second and third classes on the wood surface was the highest for both varieties. According to the results, after the wood, the high- est static coefficient of friction values was followed by the rubber, the glass and the aluminium sheet, respectively, and it was the lowest on the galva- nized iron sheet. Dalvand (2011) found out which coefficient of sliding friction, whether on glass, galvanized iron and wood surfaces for the peeled potato tubers, was greater than the corresponding values for the unpeeled potatoes.

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Design and testing of inertia dynamometer for prototype fuel cell electric vehicle

Design and testing of inertia dynamometer for prototype fuel cell electric vehicle

Therefore, this numerical technique for determining the test bench rolling resistance is not accurate. So, we measured the car load and calibrated the test bench by putting the load down one by one until the reading of the test bench showed the true power of the car. Figure 7 shows an experimental result of load variation versus power consumed by motor. This experiment was done by ensuring both tire pressures were 3 bars.

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Modeling and Analysis of Non-Pneumatic Tyre by Using Ansys

Modeling and Analysis of Non-Pneumatic Tyre by Using Ansys

In the pres work focuses on modeling and design with reference to vertical stiffness properties, contact pressure and energy loss due to rolling. The finite element analysis using Ansys software is used to study parametrically the vertical stiffness effect and the contact pressure influence with the rolling resistance response by considering the three design variables such as 1. Spokes thickness, 2. Thickness of shear band and 3. Shear modulus.

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REDUCING ENERGY CONSUMPTION BY PASSENGER CAR WITH USING 		OF NON-ELECTRICAL HYBRID DRIVE TECHNOLOGY

REDUCING ENERGY CONSUMPTION BY PASSENGER CAR WITH USING OF NON-ELECTRICAL HYBRID DRIVE TECHNOLOGY

The parameters needed to calculate the ki- netic energy of Citroën C3 Hybrid Air vehicle are the same. The only difference is in the weight and size of the tire. In the calculation the same val- ues of parameters except of the weight and roll- ing resistance coefficient were considered. The weight of the Hybrid Air system is about 100 kg higher than the common Citroën C3 and tires size is 165/50 R 18. They have a smaller value of the rolling resistance coefficient, with an estimation of about 0,008 [3, 4, 7, 9].

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Influence of soil and tire parameters on traction

Influence of soil and tire parameters on traction

Abstract: The drawbar pull, travel reduction (slip), and rolling resistance are the main criteria to describe the traction behaviour of off road vehicles. Besides the engine performance, the drawbar pull is influenced by the traction conditions such as soil and the tire parameters. These traction conditions have to be described by a limited number of parameters which can be easily determined. Empirical equations were used to analyse roughly 850 traction curves measured and published by Steinkampf. As a result, the important parameters to describe the traction conditions are three tire pa- rameters (radius, width, inflation pressure) and five soil parameters (soil cover, upper soil strength, lower soil strength, clay content, moisture content). These parameters with relative values between 0 and 100% are used to establish the equations for the traction prediction. Main steps to achieve this goal are the extension of the traction slip equation by a linear term of slip, and the description of this curve by 4 meaningful characteristic coefficients: the x- and y-coordinates of the κ -maximum ( σ κmax , κ max ), the y-axis intercept ρ e , and the gradient of κ at zero slip ( κ ’(0)).

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Finite element simulation of a rolling process of aluminium

Finite element simulation of a rolling process of aluminium

Rolling in metal forming process is the process of reducing the thickness or changing the cross section of a long work piece by compressive forces applied through a set of rolls. Outcome of the rolling process don’t always turn out as they should be. It is important that the rolling process is simulated so that the outcome of the material can be examined so that time and cost can be optimized. There are two sets of results obtained in this study, static finite element analysis and dynamic finite element analysis of rolling process. For the static analysis, it is observed that the stress distribution along the arc of contact between roll and material (roll bite) is not uniform and increases from the entry to the exit of the roll bite. The strain that is produced by the force used in the static analysis is not as expected, because the force that moves and deforms the material is a combination of forces that acts with each other. For the dynamic analysis, it is observed that the exit thickness is not exactly as desired due to elastic relaxation of the material. Maximum stress occurs in the roll bite, and some stress is on the material after it has exited the roll bite. The strain in the material increases as it enters the roll bite and then decreases to a certain point as it exits the material. The velocity of the rolling process does not affect the deformation of the material because the stress and strain remains the same after a few trials in the analysis using different roll speeds. Careful application of stress and strain is important in the rolling process so that the outcome can be controlled to save time and cost during the rolling process and finite element analysis can be used to predict the behavior of material during the rolling process.

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Simulation of Flat Rolling and Analyzing of Rolling Pressure Profile

Simulation of Flat Rolling and Analyzing of Rolling Pressure Profile

The author of this paper had a project for computer simulation of flat rolling and he makes software by using theoretical aspect of metal forming, experimental data and experience in industrial rolling technology. Analysis of pressure profile on rolls and other useful information and computation of flat rolling process which are

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Cold Rolling Effect on the Microstructure and Pitting Resistance of the NBR ISO 5832-1 Austenitic Stainless Steel

Cold Rolling Effect on the Microstructure and Pitting Resistance of the NBR ISO 5832-1 Austenitic Stainless Steel

The polarization curves show that the material with the highest degree of deformation (70%) presented the highest resistance to passive film breakdown. This result was supported also by the EIS one. This could be explained by the obstruction of the defects generated due to fragmentation of the inclusions by the matrix material which has been displaced into the defects, filling the voids during cold deformation, as Figure 5 shows. This phenomenon leads to a surface of higher corrosion resistance by protecting/covering the sites where aggressive species could accumulate and lead to localized corrosion with the passive film breakdown. On the other hand, the surface with the lowest resistance to film breakdown was the surface with 50% of deformation. This result is also supported by the EIS data and it is easily explained by the effect of deformation on the silicon containing inclusions causing their fragmentation and formation of voids/crevices at the interface between the matrix and the inclusions.

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Vibration Analysis For Diagnostic Of local Faults In Rolling Element Bearing

Vibration Analysis For Diagnostic Of local Faults In Rolling Element Bearing

there are several methods that can be used which are overall vibrations, FFT spectrum, Acceleration Enveloping, phase, SEE Technology (Acoustic Emissions) and high frequency detection (HFD). Machines have complex mechanical structure that oscillate and this result in a machines related frequency spectrum that characterizes healthy machines behaviors. The frequency component in the spectrum will change when a mechanical part such as rolling element bearing either wear or break up. In fact, each fault in a rolling element bearing produces vibration with distinctive characteristics that can be measured and compared with reference ones in order to perform the faults detection and diagnosis.

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Transit time of leukocytes rolling through venules controls cytokine induced inflammatory cell recruitment in vivo

Transit time of leukocytes rolling through venules controls cytokine induced inflammatory cell recruitment in vivo

In a model of inflammation induced by intrascrotal in- jection of TNF- a in mice, E- and P-selectin expression are induced on the surface of the venular endothelium in the cremaster muscle (8). This expression coincides with the in- duction of leukocyte rolling in these microvessels (3, 9–11). Al- though mice deficient in P-selectin demonstrate a deficit in trauma-induced leukocyte rolling primarily during the first hour after exteriorization (9, 12), the number of rolling leuko- cytes after treatment with TNF- a is close to normal in P-selec- tin–deficient mice (9) and elevated in E-selectin–deficient mice (10). E-selectin preferentially mediates slow leukocyte rolling ( , 5 m m/s), while P-selectin mediates more rapid leu- kocyte rolling (20–50 m m/s) (10, 11). Based on the absence of rolling and the severe inflammatory defect seen in E- and P-selectin double-deficient mice (4, 5), rolling is thought to be required for firm adhesion. However, it is not known why roll- ing is required for firm adhesion to occur. Current hypotheses include that rolling may be necessary to physically slow down leukocytes because the integrins may have forward reaction rates (on-rates) insufficient to promote leukocyte binding from flow (13). Second, a close geometric proximity may be neces- sary between the rolling leukocyte and the endothelial surface to allow leukocyte activation by inflammatory chemoattrac- tants such as platelet-activating factor (PAF) 1 and IL-8 pre-

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Influence of Hot Band Annealing and Cold Rolling on Texture and Ridging of 430 Stainless Steel Containing Aluminum

Influence of Hot Band Annealing and Cold Rolling on Texture and Ridging of 430 Stainless Steel Containing Aluminum

An approach to optimize the processing parameters to get superior ridging resistance and mechanical properties in commercial production of 430 ferritic stainless steel has been studied. Attention was also paid to improve productivity and energy saving without hampering the surface and mechanical property aspects of the material. Hot rolled coils an- nealed by slow cooling under insulated cover exhibit better ridging resistance than bell annealing treatment with a mi- nor decrease in ductility. Soaking temperature prior to hot rolling has a significant effect on ridging resistance.

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An Impedimetric Sensor for Real-Time Detection of Antibiotic Resistance Genes Employing Rolling Circle Amplification

An Impedimetric Sensor for Real-Time Detection of Antibiotic Resistance Genes Employing Rolling Circle Amplification

In this paper, we present a method for the detection of antibiotic resistance genes belonging to the diverse group of β-lactamases based on real-time monitoring of a rolling-circle amplification (RCA), and a simple electrochemical sensor for capacitatively coupled contactless conductivity (C 4 ) measurements. Impedance spectra are presented to describe the underlying principles of the sensor and to find optimum operating conditions. Conductivity changes induced by the formation of amplification products were monitored. By comparing the time responses we were able to distinguish amplification reactions starting with DNA target concentrations as low as 0.42 nM from negative controls containing no target DNA.

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Temperature Resistance of the Boundary Lubrication Layers Under Rolling with Slippage Condition

Temperature Resistance of the Boundary Lubrication Layers Under Rolling with Slippage Condition

Abstract: The influence of slip velocity at rolling with slippage on the intensity of heat release in the local contact at different modes of lubricating action was examined. Efficiency of using different procedures for calculating a temperature increase in the friction contact under conditions of dominating elastohydrodynamic and boundary modes of lubricating action was shown. The interrelation between the processes of heat release intensity in tribotechnical contact and wear of friction pairs was established. It was analyzed that the locality of the increased wear in the central section of the contact line is determined by a change in the stress–strained surface condition at friction and by the occurrence of stress concentrator center.

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