Paper. Printing and business paper. Determination of the coefficient of static friction

2015 ◽  
Keyword(s):  
Static Friction

scholarly journals Boundary lubrication.—The temperature coefficient

1922 ◽  
Vol 101 (713) ◽  
pp. 487-492 ◽  
Keyword(s):  
Experimental Method ◽  
Temperature Coefficient ◽  
Boundary Lubrication ◽  
Static Friction ◽  
Effect Of Temperature ◽  
Dry Air ◽  
Electric Grids ◽  
Continuous Sheet ◽  
A Current

The experimental method employed was that described in earlier papers. A slider having a spherical face is made to slide over a plate in an atmosphere of rigorously clean and dry air. The friction measured is static friction and the object of the experiments the determination of the effect of temperature. This has now been studied over a range of 15°C. to 110°C., and it may be said at once that the relations discovered are of a totally unexpected character. More than one attempt to study the effect of temperature was defeated by the fact that lubricating vapours were given off from the walls of the chamber in which the plate and slider were enclosed. This difficulty was completely removed by using a chamber with double walls, the inner wall being a continuous sheet of nickel. Between the walls were placed the electric grids for heating the chamber. The stream of dry air with which the chamber was flooded was also heated by being passed through a tube of silica, which was maintained at the required temperature by a coil of wire through which a current was passing. The temperature of the stream of air and the temperature of the chamber were recorded electrically.

scholarly journals Static and kinetic friction of rapeseed

2008 ◽  
Vol 53 (No. 1) ◽  
pp. 14-19 ◽  
Author(s):  
R. Rusinek ◽  
M. Molenda
Keyword(s):  
Moisture Content ◽  
Coefficient Of Friction ◽  
Direct Shear Test ◽  
Shear Test ◽  
Kinetic Coefficient ◽  
Static Friction ◽  
Galvanized Steel ◽  
Direct Shear ◽  
Kinetic Friction

he present paper examines the static and kinetic coefficient of friction of rapeseed. The project utilized two methods of determination of coefficient of friction of rapeseed: according Eurocode 1 (kinetic) in direct shear test and (static) in model silo. Samples of rapeseed in a range of moisture content from 6 to 15% w.b. were used and the tests were performed for galvanized steel, stainless steel and concrete B 30. Coefficient of friction for both steel types approached stable value for all levels of moisture content w.b. in a range from 0.11 to 0.18, for concrete B 30 it was found in a range from 0.25 to 0.43. The coefficient of static friction found in model silo decreased with an increase in vertical pressure from 0.3 to 0.2 for first loading, while in subsequent loading cycles decreased from 0.2 to 0.1.

scholarly journals Determination of physical, mechanical, and structural seed properties of pepper cultivars

2015 ◽  
Vol 29 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Ilknur Alibas ◽  
Nezihe Koksal
Keyword(s):  
Stainless Steel ◽  
Aspect Ratio ◽  
Moisture Content ◽  
Structural Characteristics ◽  
Initial Moisture Content ◽  
Static Friction ◽  
Friction Angle ◽  
Terminal Velocity

Abstract The aim of the present study was to determine various physical, mechanical, and structural characteristics of seed of pepper cultivars Yağlık Kapya, Demre Sivri, Yalova Carliston, Kandil Dolma, and Cin Sus Yediveren, which are grown extensively in Turkey, with initial moisture content ranging between 7.03 and 7.21% (w.b.). Width, length, and thickness were found to be in the range of 3.00-3.72, 3.43-4.40, and 0.66-0.82 mm, respectively. It was revealed that sphericity of the seeds of Yağlık Kapya, Demre Sivri, Yalova Carliston, Kandil Dolma, and Cin Sus Yediveren were 51, 57, 56, 51 and 57%, respectively. In terms of the roundness which ranges between 76 and 85% depending on pepper cultivars. The aspect ratio of Yağlık Kapya, Demre Sivri, Yalova Carliston, Kandil Dolma, and Cin Sus Yediveren were determined to be 84.60, 88.04, 94.43, 85.55, and 87.67%, respectively. It was also noted that the porosity of the pepper seeds was in the range of 44.94-49.61%. Besides, we found that as the weight of pepper seeds increased, their terminal velocity increased accordingly, and thus terminal velocities were found to be 2.87-4.66 m s-1. In the current study, the static friction angle and coefficients of the cultivars were determined by means of six different plates including aluminium, stainless steel, galvanized iron, rubber, glass, and plywood. The plywood plate was found to be the least slippery; consequently, the static friction angle and coefficient were determined to be the highest for the plywood plate.

scholarly journals Technological Properties of Radish

2019 ◽  
pp. 265-278
Author(s):  
Andrey A. Ashitko ◽  
Evgeny A. Gavrish ◽  
Andrey Yu. Nesmiyan ◽  
Ruslan Yu. Kolesnik
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Static Friction ◽  
Average Diameter ◽  
Small Scale ◽  
North Caucasus ◽  
Plant Materials ◽  
Radish Root ◽  
Federal Districts

Introduction. When cultivating root crops, harvesting is one of the most important operations. In industrial production, the technique for harvesting beets, carrots, black radishes, chicory, etc. is widely known, except for radishes, which differ significantly in the sowing scheme, maturation periods, and in physical and mechanical properties of the plants. In the study dealing with the development of small-scale mechanization for harvesting radishes, the authors made a determination of basic physical and mechanical properties of this plant. Materials and Methods. The study was conducted for the two radish varieties (Celeste and Belokrayka), typical for the Southern and North Caucasus federal districts of Russia. In doing so, the known methods were used to determine the size, mass and frictional characteristics of radishes. Results. It was established that the Celeste radishe was 1.2–2.1 times larger than the Belokrayka radish and 1.8–2.8 times heavier. The weight of the radish roots (10...28 g.) in the total mass of the plant was 52–90 %, and the weight was 0.5–0.6 %. The average diameter of the radish roots was 26.7–34 mm, with a coefficient of variation (V) about 13–14 %, radish root height was 29–45 mm (at V ≈ 18–20 %). A direct correlation between all the dimensions considered was found. The coefficient of the static friction of radish roots with unpainted steel was 0.63–0.66, the movement was 0.44–0.58. Frictional characteristics of the stems of the radish leaves were 1.25 times higher on the average. The diameter of the bundle of stems at the proposed cut end was 9–12 mm. Discussion and Conclusion. In general, the physical and mechanical characteristics of radishes depend significantly on their variety, maturity, freshness and other factors, so the results of the study vary significantly. Nevertheless, they can be used as primary information for designing radish harvesting machines.

Determination of the coefficient of static friction from circular motion using a smartphone’s sensors

2019 ◽  
Vol 54 (5) ◽  
pp. 053007 ◽  
Author(s):  
Chokchai Puttharugsa ◽  
Supitch Khemmani ◽  
Surawut Wicharn ◽  
Suwan Plaipichit
Keyword(s):  
Static Friction ◽  
Circular Motion

Determination of the static friction coefficient from circular motion

2014 ◽  
Vol 49 (4) ◽  
pp. 400-405 ◽  
Author(s):  
J A Molina-Bolívar ◽  
M A Cabrerizo-Vílchez
Keyword(s):  
Friction Coefficient ◽  
Static Friction ◽  
Circular Motion ◽  
Static Friction Coefficient

scholarly journals PENGEMBANGAN PETUNJUK PRAKTIKUM GAYA GESEK DI BIDANG MIRING BERBASIS VIDEO TRACKING UNTUK MENINGKATKAN MINAT MAHASISWA

2021 ◽  
Vol 7 (2) ◽  
pp. 335
Author(s):  
Richardo Barry Astro ◽  
Hamsa Doa ◽  
Konstantinus Denny Pareira Meke
Keyword(s):  
Research And Development ◽  
Static Friction ◽  
Video Tracking ◽  
Ease Of Use ◽  
Average Score ◽  
Student Interest ◽  
Kinetic Friction ◽  
Inclined Plane ◽  
Expert Validation

ABSTRAKPenelitian ini bertujuan menghasilkan petunjuk praktikum berbasis video tracking yang valid, praktis, dan efektif, serta mampu meningkatkan minat mahasiswa pada materi gaya gesek di bidang miring. Metode yang digunakan adalah Research and Development (R&D) dengan mengacu pada model pengembangan 4D (Define, Design, Develop dan Disseminate). Secara umum petunjuk praktikum yang dikembangkan meliputi dua topik kegiatan yakni penentuan koefisien gesek statis dengan memanipulasi kemiringan bidang serta koefisien gesek kinetis dengan menganalisis gerak benda di bidang miring. Petunjuk praktikum dalam rancangan menggunakan model praktikum/percobaan tertutup. Hasil validasi ahli yang mencakup aspek kelayakan isi, penyajian, komponen kebahasaan, dan keterlaksanaan menunjukkan petunjuk praktikum hasil pengembangan dinilai valid dengan perolehan skor rata-rata 4,03 dan layak digunakan. Hasil uji kepraktisan yang terdiri dari komponen kemenarikan, kemudahan penggunaan, dan manfaat petunjuk praktikum yang dikembangkan juga dinilai praktis dengan perolehan nilai rata-rata 3,93. Hasil uji efektifitas terhadap petunjuk praktikum menunjukkan bahwa produk pengembangan ini dinilai efektif untuk meningkatkan minat mahasiswa (kategori tinggi). Dengan demikian dapat disimpulkan bahwa produk petunjuk praktikum berbasis video tracking ini valid, praktis, efektif untuk digunakan sebagai penuntun praktikum serta mampu meningkatkan minat mahasiswa. Kata kunci: Petunjuk praktikum; video tracking; minat mahasiswa. ABSTRACTThis study is conducted to produce practical video tracking-based instructions that are valid, effective, and can increase student interest in the frictional force material on an inclined plane. The method used in this study was Research and Development (R&D) concerning the 4D development model (Define, Design, Develop and Disseminate). In general, the developed practicum instructions had covered two topics of activity, namely the determination of the coefficient of static friction by manipulating the slope of the plane and the coefficient of kinetic friction by analyzing the motion of objects on an inclined plane. Practical instructions in the design adopted a closed practicum/experimental model. The results of expert validation which include aspects of the feasibility of content, presentation, linguistic components, and implementation indicated that the practicum instructions developed were estimated valid with an average score of 4.03 and were suitable for use. On the other hand, the results of the practicality test consisting of components of attractiveness, ease of use, and the benefits of the developed practicum instructions were also considered practical with an average score of 3.93. Moreover, the results of the effectiveness test on the practicum instructions showed that this development product was considered effective for increasing student interest (high category). Thus, it can be concluded that this video tracking-based practicum guide product is valid, practical, effective to be used as a practicum guide, and is able to increase student interest. Keywords: Practical Instructions; video tracking; student interest.

scholarly journals Static Friction in Oil Lubricated Cold Forming Processes

2022 ◽  
Vol 70 (1) ◽  
Author(s):  
Wilhelm Schmidt ◽  
Philipp Heck ◽  
Christoph Gaedigk ◽  
Peter Groche
Keyword(s):  
Metal Forming ◽  
Sliding Friction ◽  
Static Friction ◽  
Test Stand ◽  
Forming Process ◽  
Cold Forming ◽  
The Past

Abstract Friction is one of the variables that have a far-reaching influence on forming processes. In the past, less attention was paid to static friction than to sliding friction in forming processes. In this paper, a test stand for the determination of static friction under load in metal forming is presented. The results are discussed using the example of an oscillating cold forming process. It could be shown that the expected influence of static friction is low in this application. Graphical abstract

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