Effects of Bionic Geometric Structure Press Rollers on Reducing Rolling Resistance and Adhesion against Soil

2013 ◽  
Vol 461 ◽  
pp. 63-72 ◽  
Author(s):  
Jin Tong ◽  
Qing Zhu Zhang ◽  
Dong Hui Chen ◽  
Yuan Chang ◽  
Hong Chang Wang
Keyword(s):  
Geometric Structure ◽  
Rolling Resistance ◽  
Ventral Surface ◽  
Diameter Ratio ◽  
Testing Conditions ◽  
Ridge Height ◽  
Dimensionless Ratio ◽  
Tillage Operation ◽  
Ultra High Molecular Weight ◽  
Press Roller

Press roller is a commonly used tool for compacting soil to a suitable compactness. An ideal press roller should be able to ensure a low adhesion and rolling resistance in a suitable compaction. However, in tillage operation, the phenomenon of soil adhesion occurred widely when press roller worked. In this research, the ventral surface of dung beetles was taken as the bionic prototype and bionic ridged geometric structure press rollers were designed using ultra high molecular weight polyethylene material. Under the same testing conditions, press rollers with different geometrical details were conducted to examine the effect of ridge section diameter, ridge height to diameter ratio and the number of ridges along the circumference of the rollers on rolling resistance and soil adhesion. The results showed that the all bionic rollers exhibited lower adhesion than a conventional roller. While, only ridged bionic roller with suitable size could reduce rolling resistance. The bionic roller with the ridge diameter of 40 mm, dimensionless ratio of height to diameter of 0.5, the number of 12 indicated the lowest resistance in this work, 25 % lower than conventional roller.

A Laboratory Method to Comprehensively Evaluate Abrasion, Traction and Rolling Resistance of Tire Tread Compounds

2007 ◽  
Vol 80 (4) ◽  
pp. 580-607 ◽  
Author(s):  
M. Heinz ◽  
K. A. Grosch
Keyword(s):  
Friction Coefficient ◽  
Laboratory Test ◽  
Rolling Resistance ◽  
Limited Range ◽  
Slip Angle ◽  
Testing Conditions ◽  
Side Force ◽  
The Road ◽  
Wide Range ◽  
On The Road

Abstract A laboratory test method has been developed which allows the evaluation of diverse properties of tire tread compounds on the same sample. The laboratory test instrument consists of a rotating abrasive disk against which a rubber sample wheel runs under a given load, slip angle and speed. All three force components acting on the wheel during the tests are recorded. By changing the variable values over a wide range practically all severities encountered in tire wear are covered. The well-known fact that compound ratings depend on the road testing conditions is verified. Most compounds are only significantly distinguishable against a control over a limited range of testing conditions. Using a road test simulation computer program based on the laboratory data shows that not only ratings correspond to practical experience but also calculated absolute tire life times do. Tests on surfaces of different coarseness and sharpness indicate that sharp coarse surfaces give the best results with road tests, which of necessity are mostly carried out on public roads of differing constitution. The abrasive surface can be wetted with water at different temperatures and hence either the friction force at a locked wheel or the side force at a slipping wheel can be measured over a wide range of temperatures and speeds. At small slip angles the side force is dominated by dynamic cornering stiffness of the compound, at large slip angles by the friction coefficient. In this case, too, good correlations to road experience exist over a limited range of testing conditions. Low water temperatures and low slip speed settings in the laboratory produce side force ratings, which correlate closely with ABS braking on the road High and higher slip speeds give ratings in close agreement with locked wheel braking on the road. A heatable/coolable disk enables traction measurements on ice and newly abrasion measurements on surfaces at elevated surface temperature. Ice surface temperatures between −5 °C and −25 °C are possible. Friction measurements show that the difference in compound rating between summer and winter compounds is maintained over the whole temperature range. New investigations show not only a differentiation between different winter tire treads qualities but also an excellent correlation between tire and laboratory results. As a new topic side force measurements on dry surfaces highlight the correlation to dry handling of tires. The tire tread compound contributes to this performance through its shear stiffness and its friction coefficient. The shear stiffness contributes to the response of the tire in directional changes. The friction coefficient determines the maximum force, which can be transmitted. A simple operation possibility for evaluation of determined side forces is demonstrated. In addition to antecedent investigations the rolling resistance of the rubber wheel can be measured over a range of loads and speeds with the slip angle set at zero. Again for these new results good correlations are achieved with practical experience. In particular, the dependence of the rolling resistance on the velocity and loads are pointed out. Ultimately a good correlation between tire test and laboratory test results was demonstrated.

Effects of Biomimetic Press Roller Type, Material, Velocity, and Packing Force on Soil Compaction Characteristics

2021 ◽  
Vol 64 (6) ◽  
pp. 1929-1941
Author(s):  
Qingzhu Zhang ◽  
Bing Li ◽  
Yunjie Xu ◽  
Jinbo Zhang ◽  
Mo Li ◽  
...  
Keyword(s):  
Soil Compaction ◽  
Enamel Coating ◽  
Field Experiments ◽  
Rolling Resistance ◽  
Type Material ◽  
List Type ◽  
Plant Spacing ◽  
Compaction Characteristics ◽  
The Third ◽  
Press Roller

HighlightsThe performance of biomimetic rollers was better than that of a conventional roller.The biomimetically ridged roller had better soil compaction performance.The resistance order of rollers with different materials was: Fe360A steel > UHMWPE > enamel coating.Packing force was the most significant factor.Abstract. To reduce soil adhesion and rolling resistance during seeding and improve the uniformity of plant spacing, a biomimetically ridged press roller (BRPR) and a biomimetically polyhedral press roller (BPPR) were designed. Moreover, hydrophobic materials, i.e., ultra-high molecular weight polyethylene (UHMWPE) and enamel coating, were applied and compared with uncoated Fe360A steel. Field experiments were conducted to test the effects of the biomimetic press roller type, material, velocity, and packing force on soil compaction characteristics. A conventional press roller (CPR) was used as a reference. Traction resistance (TR), soil bulk density (SBD), soil moisture content (SMC), emergence rate (ER), and percent change of plant spacing (PCPS) were measured. The packing force was the most significant factor affecting each index. For all rollers, the TR, SBD, ER, and PCPS increased with increasing packing force, while the loss of SMC decreased. The TR and SBD decreased with increasing velocity. All rollers achieved proper SBD for corn seeds. The biomimetic press rollers had a significant effect on TR, PCPS, and SMC on the third day after sowing. The BRPR had lower PCPS and TR than the BPPR and higher SMC than the BPPR on the third day after sowing. Compared with the CPR, the PCPS for all biomimetic rollers decreased, and the ER and SMC increased. The BPPR with Fe360A steel had a slightly higher TR than the CPR, but the other biomimetic rollers had a lower TR than the CPR. The BRPR decreased the TR by 2.13% to 22.30%, while the BPPR decreased the TR by 0.35% to 18.59%. Moreover, both types of biomimetic press rollers had the highest TR values when using Fe360A steel, followed by UHMWPE, and the enamel coating had the lowest TR values. The BRPR decreased the PCPS by 19.46% to 48.34%, while the BPPR decreased the PCPS by 9.69% to 36.99%. The biomimetic rollers increased the ER by 2.17% to 11.36%. On the 18th day after sowing, the SMC was 4.21% to 7.75% higher for the biomimetic press rollers compared to the CPR when the packing force was 700 N. This study can provide a reference for the biomimetic design, material, and force selection of press rollers. Keywords: Biomimetics, Compaction characteristics, Enamel coating, Press roller, UHMWPE.

Effect of Testing Conditions on Rolling Resistance of Automobile Tires

1984 ◽  
Author(s):  
Darrell L. Fuller ◽  
George L. Hall ◽  
Floyd S. Conant
Keyword(s):  
Rolling Resistance ◽  
Testing Conditions ◽  
Automobile Tires

Effect of Wear on Kinematics of a TKR: A Simulator Comparison of Molded and Machined UHMWPE Tibial Plateaus

1999 ◽  
Author(s):  
Lisa C. Benson ◽  
John D. DesJardins ◽  
David W. Schroeder ◽  
Martine LaBerge
Keyword(s):  
Molecular Weight ◽  
Surface Roughness ◽  
Knee Joint ◽  
Total Knee Replacement ◽  
Mechanical Performance ◽  
Direct Compression ◽  
Testing Conditions ◽  
Total Knee ◽  
Implant Alignment ◽  
Ultra High Molecular Weight

Abstract The wear and mechanical performance of identically designed total knee replacement (TKR) tibial bearing surfaces, which differed only in manufacturing process, were evaluated using a Stanmore KC Four Station Knee Joint Simulator. The first group utilized Co-Cr-Mo alloy femoral components with ultra-high molecular weight polyethylene (UHMWPE) tibial bearings processed by direct compression molding. The second group was identical to the first, except that the UHMWPE components were machined from a compression molded sheet. The implant alignment and testing conditions were identical for both series, with a 1 Hz standardized force-controlled walking cycle being employed for a duration of 3 million cycles. Gravimetric wear and surface roughness of the UHMWPE components were quantified every 1 million cycles. Measures of implant mechanics and kinematics were quantified every 0.1 million cycles. Results show that molded UHMWPE exhibited less wear (12 mg/million cycles) and no changes in kinematics. Moreover, the higher rate of wear (18 mg/million cycles) in the machined components was correlated with a statistically significant change in implant kinematics.

Scanning electron microscopy of the integument of schistosoma rodhaini

1986 ◽  
Vol 44 ◽  
pp. 132-133
Author(s):  
P. Evers ◽  
C. Schutte ◽  
C. D. Dettman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Oral Sucker ◽  
Adult Male ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Sensory Receptors ◽  
East African ◽  
Dorsal Midline ◽  
Scanning Electron

S.rodhaini (Brumpt 1931) is a parasite of East African rodents which may possibly hybridize with the human schistosome S. mansoni. The adult male at maturity measures approximately 3mm long and possesses both oral and ventral suckers and a marked gynaecophoric canal. The oral sucker is surrounded by a ring of sensory receptors with a large number of inwardly-pointing spines set into deep sockets occupying the bulk of the ventral surface of the sucker. Numbers of scattered sensory receptors are found on both dorsal and ventral surfaces of the head (Fig. 1) together with two conspicuous rows of receptors situated symmetrically on each side of the midline. One row extends along the dorsal surface of the head midway between the dorsal midline and the lateral margin.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

The geometric structure and optical response of gaseous endohedral magnesium-fullerenes

2003 ◽  
Vol 50 (15-17) ◽  
pp. 2691-2704 ◽  
Author(s):  
M. Aichinger ◽  
S. A. Chin ◽  
E. Krotscheck ◽  
H. A. Schuessler
Keyword(s):  
Geometric Structure ◽  
Optical Response

Improvement in the Fock test for determining the reactivity of dissolving pulp

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 21-26 ◽  
Author(s):  
CHAO TIAN ◽  
LINQIANG ZHENG ◽  
QINGXIAN MIAO ◽  
CHRIS NASH ◽  
CHUNYU CAO ◽  
...  
Keyword(s):  
Moisture Content ◽  
Sodium Hydroxide ◽  
Constant Temperature ◽  
Carbon Disulfide ◽  
Testing Procedure ◽  
Dissolving Pulp ◽  
Water Bath ◽  
Testing Conditions ◽  
Pulp Sample ◽  
Fock Reactivity

The Fock test is widely used for assessing the reactivity of dissolving pulp. The objective of this study was to modify the method to improve the repeatability of the test. Various parameters that affect the repeatability of the Fock test were investigated. The results showed that Fock reactivity is dependent on testing conditions affecting the xanthation between cellulose and carbon disulfide, such as the moisture content of the pulp sample, sodium hydroxide (NaOH) concentration, xanthation temperature, carbon disulfide dosage, and xanthation time. The repeatability of the test was significantly improved using the following modified testing procedure: air dried sample in the constant temperature/humidity room, xanthation temperature of 66°F (19°C) in a water bath, xanthation time of 3 h, NaOH concentration of 9% (w/w), and 1.3 mL carbon disulfide.

Ortho-k lenses fitting in patients with “non-typical” corneas

The Eye ◽  
2020 ◽  
Vol 22 (129) ◽  
pp. 22-29
Author(s):  
Svetlana Kravchuk ◽  
Olga Zhabina
Keyword(s):  
Correction Method ◽  
Diameter Ratio ◽  
Corneal Curvature ◽  
Individual Approach ◽  
Fitting In ◽  
Corneal Diameter ◽  
Clinical Cases

We described two clinical cases of ortho-k lenses fitting in patients with “non-typical” corneal curvature/diameter ratio. The main goal was to acknowledge effective and safe use of this myopia correction method in patients with corneal diameter greater than 11 mm. Individual approach to each patient is the key to a successful and safe ortho-k lenses fitting.

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