scholarly journals Evaluation of UV radiation influence on abrasivity of protective-decorative coatings for car bodies

2019 ◽  
Vol 24 (6) ◽  
pp. 192-197
Author(s):  
Danuta Kotnarowska ◽  
Dariusz Stanisławek
Keyword(s):  
Surface Roughness ◽  
Mass Loss ◽  
Uv Radiation ◽  
Ageing Time ◽  
Chemical Properties ◽  
Roughness Parameters ◽  
Surface Layers ◽  
Progressive Decline ◽  
Time Flow ◽  
Physico Chemical

The paper presents investigations concerning physico-chemical properties as well as a resistance to abrasion (abrasivity) of three-layer acrylic-polyester (renovation) coating systems after ageing with ultraviolet (UV) radiation. Generated by UV radiation photodestruction and photodegradation of examined coatings surface layers caused their chipping. This had an impact on progressive decline of the coatings thickness and hardness with the ageing time flow. UV ageing caused also almost twofold increase in surface roughness parameters Ra and Rz values. Surface roughness of the aged coatings increasing with the ageing time flow as well as their decreasing hardness contributed to their resistance to abrasion decrease, measured with the mass loss of abraded (using T-07 apparatus) coating material.

scholarly journals Destruction of protective-decorative coatings for car bodies under the influence of solar radiation

2018 ◽  
Vol 19 (12) ◽  
pp. 474-479
Author(s):  
Danuta Kotnarowska ◽  
Dariusz Stanisławek
Keyword(s):  
Surface Roughness ◽  
Surface Layer ◽  
Solar Radiation ◽  
Uv Radiation ◽  
Ageing Time ◽  
Colour Change ◽  
Acrylic Resin ◽  
Time Flow ◽  
Acrylic Coatings

It was stated on the basis of carried out accelerated investigations that UV radiation influence had a significant impact on destruction of acrylic coatings surface layer. The brittleness of surface layer increased with ageing time flow. As a result fillers and pigments particles, losing adhesion to the acrylic resin, issued from the coatings superficial layers which led to coatings thickness as well as gloss decrease. It caused also substantial increase of coatings surface roughness, evaluated on the basis of Ra, Rz and Rt parameters. A deterioration of coatings decorative properties was observed too due to their colour change and local discolorations.

Nano Structure and Properties of Beta–D-Poly-Glucopyranose

2010 ◽  
Vol 123-125 ◽  
pp. 739-742
Author(s):  
Oleg Figovsky ◽  
Michael Ioelovich
Keyword(s):  
Phase Transformation ◽  
Structural Characteristics ◽  
Chemical Properties ◽  
Supermolecular Structure ◽  
Structure And Properties ◽  
Surface Layers ◽  
Nano Structure ◽  
Nano Scale ◽  
Physico Chemical ◽  
Multi Level

Beta–D-poly-glucopyranose is widespread class of the natural semi-crystalline polysaccharide known as cellulose. This polymer has complicated multi-level supermolecular structure. It is built from elementary nano-fibrils and their aggregates; moreover, each nano-fibril contains ordered nanocrystallites and low-ordered amorphous nano-domains. Therefore cellulose can be a pronounced and eminent representative of nano-structured matters. Such nano matter has peculiar physico-chemical properties depending on specific surface of nano-scale constituents. In this paper, physico-chemistry of the nano-structured cellulose is discussed. In particular, the ability of nano-scale crystallites to co-crystallization and aggregation, as well as their ability to phase transformation through dissolution, alkalization and chemical modification was a subject of the investigation. Structural characteristics of paracrystalline surface layers of nano-crystallites and their effect on physico-chemical properties of the polysaccharide have been discussed.

scholarly journals Modified Ethylsilicates as Efficient Innovative Consolidants for Sedimentary Rock

Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
Monika Remzova ◽  
Luis Carrascosa ◽  
María Mosquera ◽  
Jiri Rathousky
Keyword(s):  
Size Distribution ◽  
Chemical Properties ◽  
Water Vapor Permeability ◽  
Test Material ◽  
Vapor Permeability ◽  
Surface Layers ◽  
Significant Deterioration ◽  
Stone Monuments ◽  
Physico Chemical ◽  
Natural Characteristics

Although silicon alkoxides (especially ethylsilicates) have long been used as consolidants of weathered stone monuments, their physical properties are not ideal. In this study, an innovative procedure for the consolidation of sedimentary rocks was developed that combines the use of organometallic and alkylamine catalysts with the addition of well-defined nanoparticles exhibiting a narrow size distribution centered at ca. 10 nm. As a suitable test material, Pietra di Lecce limestone was selected because of its color and problematic physico-chemical properties, such as rather low hardness. Using the developed procedure, the mechanical and surface properties of the limestone were improved without the unwanted over-consolidation of the surface layers of the stone, and any significant deterioration in the pore size distribution, water vapor permeability, or the stone’s appearance. The developed modified ethylsilicates penetrated deeper into the pore structure of the stone than the unmodified ones and increased the hardness of the treated material. The formed xerogels within the stone pores did not crack. Importantly, they did not significantly alter the natural characteristics of the stone.

scholarly journals Electrospun Combination of Peppermint Oil and Copper Sulphate with Conducive Physico-Chemical properties for Wound Dressing Applications

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 586 ◽  
Author(s):  
Saravana Jaganathan ◽  
Mohan Mani ◽  
Ahmad Khudzari
Keyword(s):  
Surface Roughness ◽  
Copper Sulphate ◽  
Wound Dressing ◽  
Fiber Diameter ◽  
Blood Compatibility ◽  
Chemical Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Physico Chemical ◽  
Afm Analysis

The ultimate goal in tissue engineering is to fabricate a scaffold which could mimic the native tissue structure. In this work, the physicochemical and biocompatibility properties of electrospun composites based on polyurethane (PU) with added pepper mint (PM) oil and copper sulphate (CuSO4) were investigated. Field Emission Electron microscope (FESEM) study depicted the increase in mean fiber diameter for PU/PM and decrease in fiber diameter for PU/PM/CuSO4 compared to the pristine PU. Fourier transform infrared spectroscopy (FTIR) analysis revealed the formation of a hydrogen bond for the fabricated composites as identified by an alteration in PU peak intensity. Contact angle analysis presented the hydrophobic nature of pristine PU and PU/PM while the PU/PM/CuSO4 showed hydrophilic behavior. Atomic force microscopy (AFM) analysis revealed the increase in the surface roughness for the PU/PM while PU/PM/CuSO4 showed a decrease in surface roughness compared to the pristine PU. Blood compatibility studies showed improved blood clotting time and less toxic behavior for the developed composites than the pristine PU. Finally, the cell viability of the fabricated composite was higher than the pristine PU as indicated in the MTS assay. Hence, the fabricated wound dressing composite based on PU with added PM and CuSO4 rendered a better physicochemical and biocompatible nature, making it suitable for wound healing applications.

Variability of enzymatic activity in forest Cambisols and Brunic Arenosols of Polish lowland areas

2013 ◽  
Vol 64 (2) ◽  
pp. 54-59 ◽  
Author(s):  
Ewa Błońska ◽  
Jarosław Lasota ◽  
Kazimierz Januszek
Keyword(s):  
Enzymatic Activity ◽  
National Parks ◽  
Chemical Properties ◽  
Soil Surface ◽  
Surface Layers ◽  
Physico Chemical ◽  
Lowland Area ◽  
The Relationship ◽  
Properties Of Soil ◽  
Humus Horizons

Abstract The aim of this study was to determine the enzymatic activity (dehydrogenase and urease) in trophically diverse Brunic Arenosols and Cambisols. Efforts to establish the relationship between enzymatic activity and physico-chemical properties of various subtypes of Brunic Arenosols and Cambisols were attempted. Another aim was to determine the effect of vegetation on the properties of soil surface levels. The study was conducted on 94 plots located in nature reserves and national parks in the Polish lowland area. Dehydrogenase activity and urease showed large variations in the subtypes of the distinguished Brunic Arenosols and Cambisols. Dehydrogenases and urease activity in surface layers of fresh humus of Cambisols and Brunic Arenosols was strongly associated with the plants. This is confirmed by the relationship between the enzymatic activity and the type of accumulated humus substances, the ratio of carbon to nitrogen and humus horizons reaction.

scholarly journals Modified Ethylsilicates as Efficient Innovative Consolidants for Sedimentary Rock

2018 ◽  
Author(s):  
Monika Remzova ◽  
Luis Antonio Martinez Carrascosa ◽  
Maria Jesus Mosquera ◽  
Jiri Rathousky
Keyword(s):  
Size Distribution ◽  
Chemical Properties ◽  
Water Vapor Permeability ◽  
Test Material ◽  
Vapor Permeability ◽  
Surface Layers ◽  
Significant Deterioration ◽  
Stone Monuments ◽  
Physico Chemical ◽  
Natural Characteristics

Even if silicon alkoxides (especially ethylsilicates) have long been used as consolidants of weathered stone monuments, their physical properties are not ideal. In this study, an innovative procedure for the consolidation of sedimentary rocks was developed that combines the use of organometallic and alkylamine catalysts with the addition of well-defined nanoparticles exhibiting a narrow size distribution centered at ca 10 nm. As a suitable test material, the Pietra di Lecce limestone was selected because of its color and problematic physico-chemical properties, such as rather low hardness. Using the developed procedure, the mechanical and surface properties of the limestone were improved without the unwanted over-consolidation of the surface layers of the stone, and any significant deterioration in the pore size distribution, water vapor permeability or the stone’s appearance. The developed modified ethylsilicates penetrated deeper into the pore structure of the stone than the unmodified ones and increased the hardness of the treated material. The formed xerogels within the stone pores did not crack. Importantly, they did not significantly alter the natural characteristics of the stone.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

PHYSICO CHEMICAL PROPERTIES OF NICKEL OXIDE AT HIGH TEMPERATURE

1976 ◽  
Vol 37 (C7) ◽  
pp. C7-438-C7-442 ◽  
Author(s):  
R. FARHI ◽  
G. PETOT-ERVAS
Keyword(s):  
High Temperature ◽  
Nickel Oxide ◽  
Chemical Properties ◽  
Physico Chemical

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Physico-chemical properties of the rare-earth metals, scandium, and yttrium

1963 ◽  
Vol 79 (2) ◽  
pp. 263-293 ◽  
Author(s):  
E.M. Savitskii ◽  
V.F. Terekhova ◽  
O.P. Naumkin
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Chemical Properties ◽  
Physico Chemical ◽  
The Rare Earth
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