scholarly journals Surface Analysis of Chain Joint Components after Tribological Load and Usage of Antiwear Additives

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
D. Sappok ◽  
R. Merz ◽  
B. Sauer ◽  
M. Kopnarski

Wear in chain joints leads to an increased clearance and thus an elongation of the entire chain which determines the lifetime of the chain. This particularly applies for chains that are used in timing chain drives. The aim of this study was to investigate especially the influences of lubricant additives and a contamination with carbon black on the tribological behavior of chain joint components and to correlate these influences to observable changes in topographical and chemical surface properties. A precisely defined contact and load situation is essential for generating a comparable series of samples for surface analyses. To meet this requirement, chain joint component samples from tests on a linear reciprocating model tribometer were used for the following analyses. But to connect the results to the realistic situation regarding the typical wear rates of the subjected chain types, suited experimental parameters were selected. Topographical, structural, and chemical characterization of the worn surface regions of the components were performed after the tribological loading. The results show the influence of the lubricant, the additive, and the contamination with carbon black especially on the chemical properties of the component surfaces.

2010 ◽  
Vol 16 (2) ◽  
pp. 169-178 ◽  
Author(s):  
G. Osthoff ◽  
A. Hugo ◽  
P. van Wyk ◽  
M. de Wit ◽  
S. Meyer

Physical characterization of a soymilk powder was carried out by electron microscopy. Chemical characterization was analyzed by proximate analysis, mineral composition by atomic absorption spectrometry, fatty acid composition by gas chromatography and protein composition by electrophoresis. The powder consists of large granules of 60—80 μm, which may be hollow, with smaller granules of 10—20 μm attached to them. Powder particles are covered by a layer of fat. During storage at 25 °C fat is spreading over the surface, while at —12 °C the fat is contracting. This change affected chemical stability, resulting in high level of fat oxidation when stored at 4 °C or 25 °C as well as a decrease in unsaturated fatty acids. Storage also affected the chemical properties of the re-constituted soymilk; the pH of a 12% soy powder suspension increased from 6.68±0.05 to 7.06±0.08 after 12 months of storage. Storage temperature did not affect the pH of the suspension and this change could also not be ascribed to protein aggregation.


Author(s):  
A. N. Campbell ◽  
D. M. Tanner ◽  
J. M. Soden ◽  
D. K. Stewart ◽  
A. Doyle ◽  
...  

Abstract The electrical and chemical properties of insulators produced by codeposition of siloxane compounds or TEOS with oxygen in a focused ion beam (FIB) system were investigated. Metal-insulator-metal capacitor structures were fabricated and tested. Specifically, leakage current and breakdown voltage were measured and used to calculate the effective resistance and breakdown field. Capacitance measurements were performed on a subset of the structures. It was found that the siloxanebased FIB-insulators had superior electrical properties to those based on TEOS. Microbeam Rutherford backscattering spectrometry analysis and Fourier transform infrared spectroscopy were used to characterize the films and to help understand the differences in electrical behavior as a function of gas chemistry and deposition conditions. Finally, a comparison is made between the results presented here, previous results for FIB-deposited insulators, and typical thermally-grown gate oxides and interlevel dielectric Si02 insulators.


2019 ◽  
Vol 107 (9-11) ◽  
pp. 803-819
Author(s):  
Yuichiro Nagame

Abstract Recent progress in the production of heavy nuclei far from stability and in the studies of nuclear and chemical properties of heavy actinides is briefly reviewed. Exotic nuclear decay properties including nuclear fission of heavy nuclei, measurements of first ionization potentials of heavy actinides, and redox studies of heavy actinides are described. Brief history of discovery of the transuranium elements is also presented.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shijiao Zhao ◽  
Jingtao Ma ◽  
Rui Xu ◽  
Xuping Lin ◽  
Xing Cheng ◽  
...  

AbstractZirconium compounds has been widely attention over the last decades due to its excellent physical and chemical properties. Zirconium nitride nanopowders were synthesized via a simple direct carbothermic nitridation process of internal gel derived zirconia in the presence of nano-sized carbon black. The effects of reaction temperature, dwell time and molar ratio of carbon black to Zr (C/Zr) on the phase composition, grain size and crystal parameters of products were studied. Based upon the analysis of crystallite phase evolution and microstructure characterization, it was found that zirconium oxynitride is intermediate product and then O atoms in oxynitride were extracted by oxygen getter, carbon black. Anion sites were directly replaced by N atoms to form rock-salt type nitride in carbothermic nitridation process.


Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2103
Author(s):  
Saša Prđun ◽  
Lidija Svečnjak ◽  
Mato Valentić ◽  
Zvonimir Marijanović ◽  
Igor Jerković

Chemical characterization of bee pollen is of great importance for its quality estimation. Multifloral and unifloral bee pollen samples collected from continental, mountain and Adriatic regions of Croatia were analyzed by means of physico-chemical, chromatographic (GC-MS), and spectroscopic (FTIR-ATR) analytical tools, aiming to conduct a comprehensive characterization of bee pollen. The most distinctive unifloral bee pollen with regard to nutritional value was Aesculus hippocastanum (27.26% of proteins), Quercus spp. (52.58% of total sugars), Taraxacumofficinale (19.04% of total lipids), and Prunusavium (3.81% of ash). No statistically significant differences between multifloral and unifloral bee pollen from different regions were found for most of the physico-chemical measurement data, with an exception of melezitose (p = 0.04). Remarkable differences were found among the bee pollen HS VOCs. The major ones were lower aliphatic compounds, monoterpenes (mainly linalool derivatives, especially in Prunusmahaleb and P.avium bee pollen), and benzene derivatives (mainly benzaldehyde in T.officinale and Salix spp.). Aldehydes C9 to C17 were present in almost all samples. FTIR-ATR analysis revealed unique spectral profiles of analyzed bee pollen exhibiting its overall chemical composition arising from molecular vibrations related to major macromolecules—proteins, lipids, and carbohydrates (sugars).


2014 ◽  
Vol 971-973 ◽  
pp. 131-134
Author(s):  
Xian Jun Meng ◽  
Li Yan Gong ◽  
Guo Hui Huang ◽  
Nai Qiao Liu ◽  
Jin Feng Bi ◽  
...  

Physical and chemical properties of 6 apple varieties were measured to gain the variations. The qualities of apples are important for the consumer. These quality attributes can be described by colour, texture and physical attributes such as size and shape. Individual sugars, organic acids, and vitamin C were quantified in six apple cultivars with same soil, climatic conditions and altitudes. The results showed physical and chemical characterization existed different variance in apple varieties, the variance ranged from 6.1% to 109.05%. Fructose was the most dominant sugar in the different apple cultivars, followed by glucose and sucrose, while malic acid was the principal organic acid.


2013 ◽  
Vol 807-809 ◽  
pp. 1954-1959
Author(s):  
Li Yan Gong ◽  
Bin Li ◽  
Jin Feng Bi ◽  
Sha Sha Bai ◽  
Xian Jun Meng

Physical and chemical characterization of 6 apple varieties (Early Golden Delicious, Jonagold, Hanfu, Ralls, Rainier and Fuji) from China was performed using pattern recognition tools. Measurements were taken on 12 parameters including weigh, colour, fruit firmness, crude fiber, total soluble solids, titration acid, water, Vitamin C, edible rate and juice yield .The results showed that physical and chemical properties existed different variance in apple varieties. The coefficient of variance of 12 properties was from 2.15% to 69.04%. The different apple varieties were investigated by principal component analysis (PCA) and hierarchical cluster analysis (HCA). PCA revealed that the first four components represented 95.13% of the total variability in properties and different apple groups. HCA classified samples into three groups on the basis of the physical and chemical properties.


Química Nova ◽  
2020 ◽  
Author(s):  
Natália Carvalho ◽  
João Barros ◽  
Diego Silva ◽  
Gabriela Nakashima ◽  
Fábio Yamaji

PHYSICAL AND CHEMICAL CHARACTERIZATION OF BIOMASS USED AS SOLID FUEL IN A BOILER. Biomass is a renewable energy source most used in the world, however, depending on the chemical properties and origin of the material used as biofuel, the amount of ash generated during combustion can be high, harming the energetic harnessing. The objective of this study was to characterize chemically and physically biomass: bark, sawdust, and urban pruning; used for energy generation. Also, part of the study was the physical characterization of briquettes produced from these materials. The analyzes performed to characterize the biomass were: moisture determination, higher heating value, proximate analysis and chemical composition - extractives, lignin and holocellulose contents. Subsequently, the biomass was briquetted and the mechanical properties of the briquettes were tested. The results showed that all biomass (bark, sawdust, and urban pruning) has the energy potential to be used in the industry. T1 briquettes (100% bark) showed the highest mechanical resistance. However, the formation of blends should be sought to minimize the ash content in the boiler. Thus, blends T2 and T3 can be considered as the best alternatives for the company.


2020 ◽  
Vol 2 (3) ◽  
pp. 68-82
Author(s):  
Jhuliana Xiomara Valverde -Rodríguez ◽  

This research evaluated the chemical composition of the wood of Juglans neotropica D ie ls (Walnut) and its relationship with the chemical properties of the soil, ina humid forest ecosystem of the Valladolid parish in southern Ecuador. For this purp os e , w o od s a m ple s were taken from five walnut trees and soil samples around each individual within a ra d iu s of two meters. Later, in the laboratory, the chemical characterization of the woodwas carried out, as well as the edaphic analysis. For statistical analysis between variables, we used the non-parametric test of Kruskal-Wallis and Spearman. The results showed th a t th e wood of Walnut has greater percentage of holocellulose (78.91%), followed by lignin (13.39%), and in smaller proportions of extractive (5.76%) and ashes (1.94%). The soil presented an average pH of 5.21 (acid), high levels of nitrogen (159.39 ppm) and phosphorus (57.33 ppm). It was evidenced that among the variables of soiland wood th e re are two significant negative relationships (nitrogen-holocellulose and phosphorus-extractants), and a positive relationship (nitrogen-lynogen). However, the p H a n d th e a s h did not present any relation with the components and properties analyzed.Key word:Extractives, ash, lignin, holocellulose, pH.


2016 ◽  
Vol 13 (2) ◽  
pp. 197-206
Author(s):  
PR Sheel ◽  
MAH Chowdhury ◽  
M Ali ◽  
MA Mahamud

The soil physico-chemical properties have been disturbed due to long continued intensive agricultural practices. Under this situation we are approaching rapidly to a very strong future challenge in sustaining the quality of our soil. This study was conducted to evaluate the physico-chemical properties of the selected soil series. The area covered Mymensingh and Jamalpur districts of Bangladesh. Soil samples were collected randomly from different profiles of Lokdeo, Tarakanda, Silmondi and Melandah soil series during March-May, 2014 and analysed. All soils were acidic and textural classes were sandy loam, silt loam, loam, and clay loam. Organic matter and total N contents low to very low. Available S content in the upper layers of most soils were medium to optimum and in the deeper layer low to medium. The exchangeable K, Ca and Na contents were also low. The upper layers of all the locations contained higher amounts of available Zn. The available Cu and Fe contents of most soils were very high. The soils of all locations contained very high amount of available Mn except the deeper layers (45-75 cm) of Melandah which contained optimum amount of available Mn. Soil pH showed negative correlation with total N and available S. Total N showed positive correlation with soil OM, available Cu and available S. There was positive correlation between available S and available Mn.J. Bangladesh Agril. Univ. 13(2): 197-206, December 2015


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