Apparent Coefficient of Friction of Wheat on Denim

2017 ◽  
Vol 23 (3) ◽  
pp. 175-181 ◽  
Author(s):  
Charles V. Schwab
Keyword(s):  
Standard Deviation ◽  
Moisture Content ◽  
Bulk Density ◽  
Coefficient Of Friction ◽  
Current Understanding ◽  
Farm Safety ◽  
The Coefficient Of Friction ◽  
Denim Fabric ◽  
Apparent Coefficient Of Friction

Abstract. Calculation of the extraction force for a grain entrapment victim requires a coefficient of friction between the grain and the surface of the victim. Because denim is a common fabric for the work clothes that cover entrapment victims, the coefficient of friction between grain and denim becomes necessary. The purpose of this research was to calculate the apparent coefficient of friction of wheat on denim fabric using a proven procedure. The expectation is to improve the current understanding of conditions that influence extraction forces for victims buried in wheat. The apparent coefficient of friction of wheat on denim fabric was calculated to be 0.167 with a standard deviation of ±0.013. The wheat had a moisture content of 10.7% (w.b.) and bulk density of 778.5 kg m-3. The apparent coefficient of friction of wheat on denim was not significantly affected by pull speeds of 0.004, 0.008, and 0.021 mm s-1 nor normal grain pressures of 3.2, 4.8, 6.3, 7.9, and 11.1 kPa. This is a beginning of understanding the conditions that influence the extraction forces for grain entrapment victims. Keywords: Farm safety, Grain entrapment, Grain rescue, Grain extraction.

Friction of a Rubber Wedge Sliding on Glass

1991 ◽  
Vol 64 (1) ◽  
pp. 108-117 ◽  
Author(s):  
C. W. Extrand ◽  
A. N. Gent ◽  
S. Y. Kaang
Keyword(s):  
Coefficient Of Friction ◽  
Applied Load ◽  
Unit Length ◽  
Sliding Speed ◽  
Normal Loading ◽  
Contact Width ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Apparent Coefficient Of Friction ◽  
Pressure Independent

Abstract The contact width, and hence contact area, for an elastic wedge pressed against a rigid flat surface appears to be proportional to the applied load per unit length. For a particular rubber sample, the reciprocal of the constant of proportionality, i.e., the mean normal pressure, was 130 kPa, i.e., about 7% of the tensile modulus E of the material. It was also independent of sliding speed over the range examined. Thus, a sharp wedge gave a relatively high loading pressure, independent of the applied load. As a result, the coefficient of friction was also independent of applied load over a wide range. The coefficient of friction was measured for a wedge of an unfilled natural rubber vulcanizate over wide ranges of sliding speed (50 µm/s to 100 mm/s) and test temperature (3°C to 63°C). It was found to increase with sliding speed and decrease with temperature over these ranges. The results at different temperatures were superposable using the WLF rate-temperature equivalence to create a master curve of friction vs. reduced sliding speed, rising from a value of about 1.5 at high temperatures and low speeds to about 5 at low temperatures and high speeds. Chlorination of a thin surface region reduced the coefficient of friction and its dependence on speed and temperature. It then became similar to that typically found for thermoplastics, 0.4 to 0.7. The geometry of sliding a flexible strip against a rigid curved surface caused high values of the apparent coefficient of friction to be obtained at relatively small departures from normal loading. In an extreme case, frictional seizure was observed when a high-friction sample contacted the glass surface at an angle of about 15° to the direction of loading. The apparent coefficient of friction then became indefinitely large. This same phenomenon of abnormally large frictional effects would be expected to occur in the case of conventional windshield-wiper blades, sliding over curved glass windshields.

Some Physical Properties of Azarbayejani Hazelnut and Its Kernel

2013 ◽  
Vol 9 (1) ◽  
pp. 135-140
Author(s):  
Gisoo Maleki ◽  
Jafar Milani ◽  
Ali Motamedzadegan
Keyword(s):  
Friction Coefficient ◽  
Moisture Content ◽  
Physical Properties ◽  
Bulk Density ◽  
Coefficient Of Friction ◽  
Commercial Variety ◽  
True Density ◽  
Four Levels ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

AbstractIn this study, some physical properties such as bulk density, true density, porosity and static coefficient of friction in four levels of moisture content (against four structural surfaces) of an Iranian commercial variety of hazelnut (Azarbayejani Hazelnut) and its kernel was determined. Bulk density increased from 409.7 to 491.4 kg m−3 and from 415.4 to 477.9 kg m−3 for whole nut and its kernel respectively. True density increased from 954.8 to 1079.4 kg m−3 for whole nut and from 886.9 to 965.8 kg m−3 for its kernel, porosity decreased from 57.11 to 54.47 kg m−3 and from 53.52 to 52.51 kg m−3 for whole nut and its kernel. The static coefficient of friction of both nuts and kernels on all four test surfaces increased with increasing the moisture content. The average friction coefficient (both nut and kernel) was the highest on MDF and the lowest on galvanized iron sheet.

scholarly journals Physical properties of shelled and kernel walnuts as affected by the moisture content

2010 ◽  
Vol 28 (No. 6) ◽  
pp. 547-556 ◽  
Author(s):  
E. Altuntas ◽  
M. Erkol
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Bulk Density ◽  
Coefficient Of Friction ◽  
Terminal Velocity ◽  
Unit Mass ◽  
True Density ◽  
Projected Area ◽  
Dynamic Coefficients ◽  
Volume Coefficient

The variations in physical properties such as the size dimensions, unit mass, sphericity, projected area, bulk density, true density, volume, coefficient of friction on various surfaces, and terminal velocity of shelled and kernel walnuts as a function of the moisture content were determined. With an increase in the moisture content, the sphericity, projected area, bulk density, volume, and porosity of shelled and kernel walnuts increased, whereas the true density linearly decreased. Studies on rewetted walnuts showed that the terminal velocity increased from 14.17 m/s to 15.50 m/s, and from 12.60 m/s to 14.35 m/s, for shelled and kernel walnuts, respectively. The static and dynamic coefficients of friction of shelled and kernel walnuts on chipboard and plywood surfaces also increased linearly with an increase in the moisture content.

Physical Properties of Whole Rye Seed (Secale cereal)

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Mohammad Jouki ◽  
Zahra Emam-Djomeh ◽  
Naimeh Khazaei
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Physical Properties ◽  
Bulk Density ◽  
Coefficient Of Friction ◽  
Average Length ◽  
Angle Of Internal Friction ◽  
Length Width ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

Abstract Certain physical properties of rye – density, true density, angle of internal friction, porosity and static coefficient of friction – are necessary for the design of transport, storage and processing equipment. . These properties were evaluated as a function of moisture content of grain. The grain was tested for bulk density, density, porosity, angle of internal friction and coefficient of friction with various materials at 9% and 13% moisture content (dry basis, db). The average length, width and thickness of the rye grains were 7.11mm, 4.65mm and 3.18mm. It was observed that bulk density decreased linearly from 598.41 to 580.76 kg/m3, as moisture content increased, while density increased linearly from 922.43 to 991.56 kg/m3. The porosity and angle of internal friction increased as moisture increased. The porosity increased linearly from 37.00% to 40.50%, and the angle of internal friction increased from 21.500 to 25.000. The static coefficient of friction increased from 0.283 to 0.412, 0.345 to 0.438, and 0.380 to 0.461 for glass, galvanized iron and wood surfaces respectively.

Experimental Investigation of aluminum doping crumb rubber/epoxy composite in reciprocating motion

2015 ◽  
Vol 3 ◽  
pp. 1
Author(s):  
Goutam Chandra Karar ◽  
Nipu Modak
Keyword(s):  
Experimental Investigation ◽  
Coefficient Of Friction ◽  
Epoxy Composite ◽  
Normal Load ◽  
Crumb Rubber ◽  
The Other ◽  
Reciprocating Motion ◽  
Molding Process ◽  
Friction Tester ◽  
The Coefficient Of Friction

The experimental investigation of reciprocating motion between the aluminum doped crumb rubber /epoxy composite and the steel ball has been carried out under Reciprocating Friction Tester, TR-282 to study the wear and coefficient of frictions using different normal loads (0.4Kg, 0.7Kgand1Kg), differentfrequencies (10Hz, 25Hz and 40Hz).The wear is a function of normal load, reciprocating frequency, reciprocating duration and the composition of the material. The percentage of aluminum presents in the composite changesbut the other components remain the same.The four types of composites are fabricated by compression molding process having 0%, 10%, 20% and 30% Al. The effect of different parameters such as normal load, reciprocating frequency and percentage of aluminum has been studied. It is observed that the wear and coefficient of friction is influenced by the parameters. The tendency of wear goes on decreasing with the increase of normal load and it is minimum for a composite having 10%aluminum at a normal load of 0.7Kg and then goes on increasing at higher loads for all types of composite due to the adhesive nature of the composite. The coefficient of friction goes on decreasing with increasing normal loads due to the formation of thin film as an effect of heat generation with normal load.

scholarly journals Comparative Study of the Properties of Wood Flour and Wood Pellets Manufactured from Secondary Processing Mill Residues

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2487
Author(s):  
Geeta Pokhrel ◽  
Yousoo Han ◽  
Douglas J. Gardner
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Raw Materials ◽  
Wood Flour ◽  
The United States ◽  
Red Maple ◽  
Wood Pellets ◽  
Secondary Processing ◽  
Material Costs ◽  
Mill Residues

The generation of secondary processing mill residues from wood processing facilities is extensive in the United States. Wood flour can be manufactured utilizing these residues and an important application of wood flour is as a filler in the wood–plastic composites (WPCs). Scientific research on wood flour production from mill residues is limited. One of the greatest costs involved in the supply chain of WPCs manufacturing is the transportation cost. Wood flour, constrained by low bulk densities, is commonly transported by truck trailers without attaining allowable weight limits. Because of this, shipping costs often exceed the material costs, consequently increasing raw material costs for WPC manufacturers and the price of finished products. A bulk density study of wood flour (190–220 kg/m3) and wood pellets (700–750 kg/m3) shows that a tractor-trailer can carry more than three times the weight of pellets compared to flour. Thus, this study focuses on exploring the utilization of mill residues from four wood species in Maine to produce raw materials for manufacturing WPCs. Two types of raw materials for the manufacture of WPCs, i.e., wood flour and wood pellets, were produced and a study of their properties was performed. At the species level, red maple 40-mesh wood flour had the highest bulk density and lowest moisture content. Spruce-fir wood flour particles were the finest (dgw of 0.18 mm). For all species, the 18–40 wood flour mesh size possessed the highest aspect ratio. Similarly, on average, wood pellets manufactured from 40-mesh particles had a lower moisture content, higher bulk density, and better durability than the pellets from unsieved wood flour. Red maple pellets had the lowest moisture content (0.12%) and the highest bulk density (738 kg/m3). The results concluded that the processing of residues into wood flour and then into pellets reduced the moisture content by 76.8% and increased the bulk density by 747%. These material property parameters are an important attempt to provide information that can facilitate the more cost-efficient transport of wood residue feedstocks over longer distances.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

scholarly journals Parameters of Trucks and Loads in the Transport of Scots Pine Wood Biomass Depending on the Season and Moisture Content of the Load

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 223
Author(s):  
Grzegorz Trzciński ◽  
Łukasz Tymendorf ◽  
Paweł Kozakiewicz
Keyword(s):  
Moisture Content ◽  
Bulk Density ◽  
Load Capacity ◽  
Wood Chips ◽  
Total Weight ◽  
Wood Biomass ◽  
Four Seasons ◽  
Gross Vehicle Weight ◽  
Bulk Volume ◽  
Average Quantity

Transport of wood biomass is one of the key operations in forestry and in the wood industry. An important part is the transport of shredded wood, where the most common forms are chips and sawdust. The aim of the research was to present the variability of the total weight of trucks (gross vehicle weight, GVW), the weight of the empty trucks (tare), and loads of chips and sawdust in different periods of the year. Changes in specific parameters were analyzed: GVW; tare weight; trailer capacity; use of the trailer load capacity; bulk volume and bulk density of wood biomass loads; solid cubic meter (m3) and weight of 1m3 of the load; and load weight depending on the season, with simultaneous measurements of wood chips and sawdust moisture. More than 250 transports from four seasons of the year were analyzed in the research. It was found that the total weight of trucks (GVW) was at a comparable level, on average from 39.42 to 39.64 Mg with slight differences (with SD 0.29 and 0.39). The weight of empty trucks was 16.15 Mg for chip-bearing trucks and 15.93 Mg for sawdust-bearing trucks (with SD 0.604 and 0.526). The type of wood material has an influence on the transported volume. The average quantity of load in the bulk cubic meter was 64.783 m3 for wood chips (SD 3.127) and 70.465 m3 (SD 2.516) for sawdust. Over 30% differences in the volume of transported wood chips and approximately 18% for sawdust were observed. The use of the loading capacity of the trailer was on average 72.58% (SD 5.567) for the transport of wood chips and 77.42% (SD 3.019) for the transport of sawdust. The sawdust bulk density was from 0.3050 to 0.4265 Mg⋅m−3 for wood chips and 0.3200 to 0.3556 Mg⋅m−3 for sawdust. This parameter is significantly dependent on moisture content, and the determined correlation functions can be used for estimating and predicting bulk density. The abovementioned absolute moisture content of chips and sawdust also depends on the season, which also affects the selected parameters of wood biomass loads.

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