Search

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Twin wire arc spray (TWAS) is a type of thermal spray coating technology that has been extensively researched to improve the service life and overcome wear, cavitation and corrosion in pump impellers. This study aims to investigate the effect of post-heat treatment on the properties of FeCrBMnSi coatings fabricated by the Twin Wire Arc Spray (TWAS) method on 304 stainless steel substrates with varying stand-off distances. NiAl and FeCrBMnSi were employed as bond coats and top coats in this study. The substrate material was sandblasted before the coating process to achieve a surface roughness of 75-100 µm. The TAFA 9000 Electrical Wire-Arc Spraying machine's voltage (V), current (A), and compressed air pressure (Bar) were set to 28.4; 150; and 5, respectively. The coating operation was performed at 100, 200, and 300 mm stand-off distances. The specimens were then post-heated for 3 hours at 500°C and 700°C in a Thermolyne F6010 Furnace Chamber. The quality of the coating produced in this study was evaluated using thickness, hardness, wear, bond strength, micrography, and SEM (Scanning Electron Microscope) testing. According to the findings of this study, specimens with a stand-off distance of 100 mm and a post-heat treatment temperature of 700oC produce the best coating qualities when compared to other specimens. This specimen resulted in a percentage of porosity and unmelted material, thickness, hardness, adhesive strength, and total wear rate of 7.1%, 5.53 x 10-1 mm, 1460 HV, 24.86 MPa, and 3.8 x10-4 mm3/s, respectively. [ABSTRACT FROM AUTHOR]

This research aims to analyse the California Bearing Ratio (CBR) and Unconfined Compressive Strength Test (UCS) values as road foundation layers using local materials, namely Kinang Jingkion. The study's soil and Kinang Jingkion materials were taken from the Apalapsili quarry in Yalimo Regency. Additionally, the additive or soil stabiliser used was Matos, which was obtained from testing soil characteristics, including sieve analysis or gradation, Standard Proctor Test for light density, and liquid limit test. After testing, it was found that the soil from the Apalapsili quarry is granular and can be categorised as A-1-a according to SNI 03-6797-2002. According to SNI 6887-2012, the compressive strength value after seven days of immersion should be within 25-35 Kg/Cm², while other Mix Designs met the criteria of SNI 6887-2012. CBR testing also utilised the same Mix Designs, and the highest CBR result was obtained from the Mix Design with compositions of Kinang Jingkion, soil, and cement at 8% and Matos at 2%, with a CBR value of 112%. According to the 2018 Revised General Specifications, a CBR value of 112% indicates a Class A Foundation Layer. [ABSTRACT FROM AUTHOR]

This study aims to analyze the nature of chemical content, analyze abrasion value and optimum asphalt content using local Kinang Jingkion as road pavement material. In this study, XRF and XRD testing methods were used to determine the chemical content of Kinang Jingkion local material, then testing the characteristics of rough aggregate to determine the abrasion value, testing fine aggregate characteristics, and testing asphalt pen 60/70 and marshall test to determine the optimum asphalt content (KAO). The tests obtained the results of comparative data analysis between laboratory tests and literature standards that meet the eligibility requirements. The results showed that: First, the results of XRF and XRD analysis on Wilihingke samples, 0.15 mm granules, 2.36 mm granules, and Kinang Holuwon found that all chemical elements contained in the four samples were solid metal inorganic chemical elements. The results of this analysis prove that the four samples, which are fine aggregates and coarse aggregates, do not contain organic substances. Where the results of this analysis are by the requirements of aggregates which are one of the components in the concrete mixture, where the aggregates used must meet certain conditions, one of which must not contain excess organic matter because it can undergo decay by bacteria using dissolved oxygen; Second, from the test results obtained, the aggregate wear value (abrasion) was 32.69%; Third, based on the test results, the value of the Marshall parameter with Optimum Asphalt Content (KAO) obtained a value of 6.125%. [ABSTRACT FROM AUTHOR]