scholarly journals Influence of Roughness on Quality Molybdenum Deposit Layer by Thermal Spraying

Author(s):  
Marián Bujna ◽  
Miroslav Prístavka ◽  
Petr Dostál ◽  
Maroš Korenko ◽  
Milan Kadnár

In this paper we deal with the impact of roughness on the quality of molybdenum layer. Insufficient cleaning may result in a poor quality of the sprayed layer. Our aim is to analyze the influence of surface roughness on the quality of molybdenum layer thickness applied by thermal spraying. Thermal spraying influence several physical and chemical properties of the coating surface. The most important ones include: hardness, density, porosity, corrosion resistance and adhesion. This technology of surface treatment of material is often used for its high degree of hardness. Hardness and erosion resistance are the parameters that need to be achieved particularly in working conditions where there is excessive depreciation of a component.

2013 ◽  
Vol 801 ◽  
pp. 35-40
Author(s):  
Marián Bujna ◽  
Miroslav Prístavka ◽  
Pavol Kaplík

Thermal spraying influences several physical and chemical properties of the coating surface. The most important of them are hardness, density, porosity, corrosion resistance and adhesion. This technology of surface treatment of material is often used for its high degree of hardness. Hardness and erosion resistance are the parameters that need to be achieved particularly in working conditions where there is excessive component wear. In this paper, we deal with the impact of purifying on the quality of molybdenum layer. Insufficient cleaning may result in a poor quality of the sprayed layer. Our aim is to measure and analyse the quality of molybdenum layer thickness applied by thermal spraying after insufficient cleaning.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hao Liu ◽  
Bing Xie ◽  
Yue-lin Qin

The physical and chemical properties such as particle size, montmorillonite content, swelling degree, water absorption, and blue absorption of A, B, and C bentonites were studied under laboratory conditions. The effects of adding different quality and different proportion of bentonite on falling strength, compression strength, and shock temperature of green pellet were investigated. The experimental results show that the montmorillonite content, water absorption, and methylene blue absorption of bentonite-B are the highest. And the quality of bentonite-B is the best, followed by bentonite-C and bentonite-A poor quality. When the amount of bentonite-B reduced from 1.5% to 1.0%, the strength of green pellets and the shock temperature both decrease. As the same proportion of A, B, and C bentonites, the green-ball strength and shock temperature are as follows: bentonite-A > bentonite-B > bentonite-C.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Hrishikesh Khodade

Soil plays an important role for sustainable agricultural development which is a widely accepted fact. The composition of soil makes perfect recipe for proper growth and development of growing plants. Mainly the texture and contains of the soil give an idea about overall productivity of any type of soil. The present case study was conducted on the physical and chemical properties of soil at Rajgurunagar (Khed) Tehsil, Pune District (Maharashtra) state of India. The study has been conducted in 5 different localities of different directions for better understanding of nature and composition of soil. Rajgurunagar(Khed) is well known for upcoming developing region due to accumulation of various industrial companies such as SEZ, MIDC and many more. The effect of industrialisation on hydrosphere, atmosphere and lithosphere is noticeable in this Tehsil as an effect is seen on plant growth and development and is affecting on abundance, density of many plant as well as animal species. The total land area is unmanageable for agricultural development purpose. The impact of environmental factors on the soil attributes such as soil particle size which are the product of high degree of soil pollutants, organic matter content which show variability at different localities and other chemical constituents which indicate high degree of salt presence. The control measures are also indicated in a given study to overcome challenging and problem associated conditions.


2021 ◽  
pp. 10-24
Author(s):  
C. R. Abah ◽  
C. N. Ishiwu ◽  
J. E. Obiegbuna ◽  
E. F. Okpalanma ◽  
C. S. Anarado

Quality cassava(Manihotesculentus, Crantz) flour is often influenced by process variables such as slice weight and soaking time which may affect its nutritional quality. In this study, the effect of process variables (slice weight and soaking time) on quality of cassava flour was carried out. Cassava root was peeled, washed and cut into varied sizes (25.86 - 54.14 g) and soaked at varied time (7.03 - 40.97 h). The proximate composition, physical and chemical properties of the flour were carried out using standard methods. The result in our findings showed that slice weight and soaking time had significant increase (p<0.05) on the proximate and physico-chemical properties of the flour.The amylose and amylopectin content of the flour increased with increasing soaking time while the hydrogen cyanide content decreased with increase in soaking time. Overall, the quality cassava flour displayed desirable properties for its incorporation into baked goods.


Galaxies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Christian Henkel ◽  
Leslie K. Hunt ◽  
Yuri I. Izotov

Dwarf galaxies are by far the most numerous galaxies in the Universe, showing properties that are quite different from those of their larger and more luminous cousins. This review focuses on the physical and chemical properties of the interstellar medium of those dwarfs that are known to host significant amounts of gas and dust. The neutral and ionized gas components and the impact of the dust will be discussed, as well as first indications for the existence of active nuclei in these sources. Cosmological implications are also addressed, considering the primordial helium abundance and the similarity of local Green Pea galaxies with young, sometimes protogalactic sources in the early Universe.


2004 ◽  
pp. 79-90
Author(s):  
Vesna Vratusa

Efficient nursery production of woody plants, as well as the level of their successful application in urban green spaces, greatly depends upon properties of substrates in which these individuals grow, develop and endure. Furthermore, quality of substrate does not only affect the quality of future product (plant individual or green space), but distinctly determines its price. This element, extremely significant for all countries in transition, thus Serbia as well, commands finding ways of making qualitative, but least expensive substrate. The most logical solution is to use mixtures/substrates of precisely defined properties, composed of domestic components. Results presented in this paper imply that it is possible to create precisely such standard mixtures from domestic resources at relatively low cost, adjusted to needs of particular species, which would ultimately lead to successful, non-expensive nursery production and application of produced stock, both on domestic and foreign markets.


Environments ◽  
2018 ◽  
Vol 5 (9) ◽  
pp. 104 ◽  
Author(s):  
Elizabeth Pillar-Little ◽  
Marcelo Guzman

Due to the adverse effect of atmospheric aerosols on public health and their ability to affect climate, extensive research has been undertaken in recent decades to understand their sources and sinks, as well as to study their physical and chemical properties. Atmospheric aerosols are important players in the Earth’s radiative budget, affecting incoming and outgoing solar radiation through absorption and scattering by direct and indirect means. While the cooling properties of pure inorganic aerosols are relatively well understood, the impact of organic aerosols on the radiative budget is unclear. Additionally, organic aerosols are transformed through chemical reactions during atmospheric transport. The resulting complex mixture of organic aerosol has variable physical and chemical properties that contribute further to the uncertainty of these species modifying the radiative budget. Correlations between oxidative processing and increased absorptivity, hygroscopicity, and cloud condensation nuclei activity have been observed, but the mechanisms behind these phenomena have remained unexplored. Herein, we review environmentally relevant heterogeneous mechanisms occurring on interfaces that contribute to the processing of aerosols. Recent laboratory studies exploring processes at the aerosol–air interface are highlighted as capable of generating the complexity observed in the environment. Furthermore, a variety of laboratory methods developed specifically to study these processes under environmentally relevant conditions are introduced. Remarkably, the heterogeneous mechanisms presented might neither be feasible in the gas phase nor in the bulk particle phase of aerosols at the fast rates enabled on interfaces. In conclusion, these surface mechanisms are important to better understand how organic aerosols are transformed in the atmosphere affecting the environment.


Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1297 ◽  
Author(s):  
Cristian Gómez-Rodríguez ◽  
Daniel Fernández-González ◽  
Linda Viviana García-Quiñonez ◽  
Guadalupe Alan Castillo-Rodríguez ◽  
Josué Amilcar Aguilar-Martínez ◽  
...  

The chemical environment and the internal conditions of the furnaces and ladles are extremely aggressive for the refractories, so metallurgical industries demand refractory linings with greater durability and resistance to avoid unforeseen stoppages and to reduce the changes of the furnace lining. Therefore, the current work aims to evaluate the impact of the additions of ZrO2-nanoparticles (1, 3, and 5 wt. %) in magnesia-based bricks. A comparative study of the physical and chemical properties in bricks obtained using two cold pressing techniques (uniaxial and isostatic pressing) and two sintering temperatures (1550 and 1650 °C) was carried out. The microstructure and crystalline phase characteristics obtained after the heat treatments and the slag corrosion test was studied using scanning electron microscopy/electron dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD). The results reveal that the sample with 5 wt. % of ZrO2 nanoparticles (obtained by cold isostatic pressing and sintering at 1650 °C) has the lowest porosity and greatest resistance to penetration of blast furnace slag.


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