scholarly journals Assessment of Stone Protective Coatings with a Novel Eco-Friendly Encapsulated Biocide

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1109
Author(s):  
Martina Zuena ◽  
Ludovica Ruggiero ◽  
Giulia Caneva ◽  
Flavia Bartoli ◽  
Giancarlo Della Ventura ◽  
...  
Keyword(s):  
Protective Coatings ◽  
Environmental Issues ◽  
Capillary Water ◽  
Hydrophobic Properties ◽  
Water Absorption Coefficient ◽  
Stone Monuments ◽  
Static Contact ◽  
Different Types ◽  
Relevant Role ◽  
Natural Stones

The conservation of stone monuments is a constant concern due to their continuous weathering, in which biofouling plays a relevant role. To enhance the effectiveness of biocidal treatments and to avoid environmental issues related to their possible toxicity, this research aims at formulating and characterizing a coating charged with an eco-friendly biocide and showing hydrophobic properties. For this purpose, zosteric sodium salt—a natural biocide product—has been encapsulated into two silica nanocontainers and dispersed into a tetraethoxysilane-based (TEOS) coating also containing TiO2 nanoparticles. The coatings were applied on four different types of stone: brick, mortar, travertine, and Carrara marble. The effectiveness of the coating formulations and their compatibility concerning the properties of coated stones were assessed. The results showed that all coatings conferred a hydrophobic character to the substrate, as demonstrated by the increase of the static contact angle and the reduction in the capillary water absorption coefficient. The transmission of water vapor of the natural stones was preserved as well as their natural aspect. Furthermore, the coatings were homogeneously distributed on the surface and crack-free. Therefore, the protective capability of the coatings was successfully demonstrated.

Electrokinetic Characterization of Nanocomposites Applied on Natural Stones by Streaming Current Measurements

2018 ◽  
Author(s):  
Marco Roveri ◽  
Simona Raneri ◽  
Sabrina Bianchi ◽  
Francesca Gherardi ◽  
Valter Castelvetro ◽  
...  
Keyword(s):  
Protective Coatings ◽  
Structural Complexity ◽  
Complex Task ◽  
Capillary Water ◽  
Stone Surface ◽  
Physical Behaviour ◽  
Streaming Current ◽  
Natural Stones ◽  
Electrokinetic Characterization

The characterization of protective coatings applied on natural stones is often a complex task due to the difficulty of identifying and quantifying the various factors contributing to the overall behaviour of the coating-stone system. In particular, linking information about the coating-stone interaction to macroscopic effects in terms of physical behaviour of treated stones can be especially arduous owing to the inherent structural complexity of stone substrates. Electrokinetic analysis based on streaming current measurements, having already proved the ability to sense even minor changes in the chemical composition of different materials surfaces upon treatment, may provide useful insights in view of better understanding the extent of stone surface modification. In particular, involving the interaction of stones with a water-based solution, the streaming current technique could extend the characterization of stone surface to the outermost part of the pore network, which is part of every treatment-induced modification of surface properties. In this work, the effectiveness of streaming current measurements as analytical tool for the characterization of coatings applied on natural stones is assessed by considering different lithotypes and coatings and trying to correlate the results of electrokinetic analysis with the physical behaviour of treated stones, with specific regard to wettability and capillary water absorption.

scholarly journals Diffuse Water Pollution from Agriculture: A Review of Nature-Based Solutions for Nitrogen Removal and Recovery

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1893
Author(s):  
Giuseppe Mancuso ◽  
Grazia Federica Bencresciuto ◽  
Stevo Lavrnić ◽  
Attilio Toscano
Keyword(s):  
Water Pollution ◽  
Nitrogen Removal ◽  
Plant Uptake ◽  
Environmental Issues ◽  
Polluted Water ◽  
Health Issues ◽  
Agricultural Wastewater ◽  
Research Activities ◽  
Wide Range ◽  
Different Types

The implementation of nature-based solutions (NBSs) can be a suitable and sustainable approach to coping with environmental issues related to diffuse water pollution from agriculture. NBSs exploit natural mitigation processes that can promote the removal of different contaminants from agricultural wastewater, and they can also enable the recovery of otherwise lost resources (i.e., nutrients). Among these, nitrogen impacts different ecosystems, resulting in serious environmental and human health issues. Recent research activities have investigated the capability of NBS to remove nitrogen from polluted water. However, the regulating mechanisms for nitrogen removal can be complex, since a wide range of decontamination pathways, such as plant uptake, microbial degradation, substrate adsorption and filtration, precipitation, sedimentation, and volatilization, can be involved. Investigating these processes is beneficial for the enhancement of the performance of NBSs. The present study provides a comprehensive review of factors that can influence nitrogen removal in different types of NBSs, and the possible strategies for nitrogen recovery that have been reported in the literature.

scholarly journals Protection of Stone Monuments Using a Brushing Treatment with Ammonium Oxalate

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 379
Author(s):  
Domagoj Mudronja ◽  
Frederik Vanmeert ◽  
Stjepko Fazinic ◽  
Koen Janssens ◽  
Darko Tibljas ◽  
...  
Keyword(s):  
Chemical Weathering ◽  
Treatment Time ◽  
Protective Coatings ◽  
Ammonium Oxalate ◽  
Protective Layer ◽  
Thick Layer ◽  
Calcite Dissolution ◽  
X Ray ◽  
Stone Monuments ◽  
Surface Corrosion

Stone monuments and buildings are susceptible to weathering. Carbonate-based stones are especially vulnerable in acidic environments, whereas magmatic acidic stones are more susceptible to chemical weathering in basic environments. To slow down surface corrosion of limestone and marble artworks/buildings, protective coatings which inhibit calcite dissolution have been proposed. In this work, samples from two stone types with different porosity were treated with ammonium oxalate (AmOx) to create a protective layer of calcium oxalate (CaOx) using the previously developed brushing method. Two different synchrotron microscopy experiments were performed to determine its protective capability. X-ray powder diffraction (SR-μ-XRPD) in transmission geometry allowed visualization of the distributions of calcium carbonate and oxalates along the sample depths. In a second step, X-ray fluorescence (SR-μ-XRF) was used to check the efficiency/integrity of the protective surface coating layer. This was done by measuring the sulfur distribution on the stone surface after exposing the protected stones to sulfuric acid. XRPD showed the formation of a protective oxalate layer with a thickness of 5–15 µm on the less porous stone, while a 20–30 µm thick layer formed on the more porous stone. The XRF study showed that the optimal treatment time depends on the stone porosity. Increasing the treatment time from 1 to 3 h resulted in a decreased efficiency of the protective layer for the low porosity stone. We assume that this is due to the formation of vertical channels (cracks) in the protective layer.

scholarly journals The effect of electrolysis conditions during microarc oxidation on the phase-structural state, hardness and corrosion resistance of magnesium alloys

2020 ◽  
Vol 21 (3) ◽  
pp. 545-551
Author(s):  
V.V. Subbotina ◽  
V.V. Belozerov
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Magnesium Alloys ◽  
Protective Coatings ◽  
Microarc Oxidation ◽  
High Hardness ◽  
Ceramic Coatings ◽  
Functional Layer ◽  
Different Types ◽  
Spinel Mgal2o4

By the method of microarc oxidation for different types of electrolytes (which include KOH, Na2SiO3, Н2О2, NaOH, NaAlO2, Na5P3O10, NaF) and electrolysis conditions, multifunctional ceramic coatings on a magnesium alloy were obtained. The phase composition of the coating includes magnesium oxide (MgO), spinel MgAl2O4, Mg2SiO4 and Мg3(РО4)2 compounds. The phase composition of the coatings is determined by the composition of the electrolyte. The obtained MAO coatings provide high hardness, which is 1500 to 7300 MPa, as well as high corrosion resistance. The results obtained make it possible to recommend MAO coatings on magnesium alloys both as an external (functional) layer and for the formation of an underlayer for the subsequent application of protective coatings (varnishes, polymers, polytetrafluoroethylene, in particular).

scholarly journals IMPACT OF AUTOMOTIVE AND MOTORCYCLE SPORT ON THE ENVIRONMENT

2019 ◽  
Vol 17 (Suppl.1) ◽  
pp. 860-863
Author(s):  
Boyan Doytchev
Keyword(s):  
Future Development ◽  
Environmental Conditions ◽  
Environmental Sustainability ◽  
Internal Combustion Engines ◽  
Age Groups ◽  
Environmental Issues ◽  
Combustion Engines ◽  
Electric Motors ◽  
Different Types ◽  
Motor Sports

Automotive and motorcycle sports are motor sports in which various vehicles (serial and modified cars, motorcycles, buggies, jeeps, trucks, prototypes, etc.) compete with engines of different types (electric motors, hybrid and mostly thermal internal combustion engines - piston and partly rotary). Interest in the discuss sport are progressively increases in the years from people of different age groups. The article comments on environmental issues related to these sports and environmental recommendations for their application. The combined efforts of various institutions are needed to increase the popularity and awareness of sport that can be realized under optimal environmental conditions and does not impair its environmental sustainability. This requires an actual environmental policy and education aimed at future development in this direction.

scholarly journals The Effect of a High Amount of Micro-Fillers on the Long-Term Properties of Concrete

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3421 ◽  
Author(s):  
Sičáková ◽  
Špak
Keyword(s):  
Glass Powder ◽  
Capillary Water ◽  
Ecological Benefits ◽  
Water Absorption Coefficient ◽  
Capillary Water Absorption ◽  
Brick Powder ◽  
The Impact ◽  
Intended Use ◽  
Micro Fillers

Concretes in which a large portion of fine natural aggregate is replaced with inert mineral powders would offer both economic and ecological benefits for the concrete industry, and they represent eco-friendly materials. Moreover, using the powders having potential pozzolanic effect could have positive extra effect on the properties of concrete. This paper analyses the impact of a high dosage of three kinds of micro-fillers (brick, concrete and glass powders) on the properties of concrete over a three-year period. Microfillers were applied as 40% replacement of 0/4 aggregate by volume. Samples having high dosage of micro-fillers and thus a higher binder volume achieved excellent values of both compressive (from 31 to 48 MPa in 28 days, and from 67 to 93 MPa in three years) and flexural strength (from 6.3 to 8.4 MPa in 28 days, and from 7.1 to 11.1 MPa in three years). Both samples with brick powder and concrete powder achieved the biggest strength values; however, due to better performance in durability parameters (capillary water absorption coefficient and density), sample prepared with glass powder can be identified as having the biggest potential for intended use.

scholarly journals Modification of water transport properties of porous building stones caused by polymerization of silicon-based consolidation products

2017 ◽  
Vol 89 (11) ◽  
pp. 1673-1684 ◽  
Author(s):  
Ioannis Karatasios ◽  
Anastasia Michalopoulou ◽  
Maria Amenta ◽  
Vassilis Kilikoglou
Keyword(s):  
Surface Tension ◽  
Transport Properties ◽  
Water Transport ◽  
Amorphous Material ◽  
Polymerization Process ◽  
Water Absorption Coefficient ◽  
Wetting Properties ◽  
Natural Stones ◽  
Silicon Based ◽  
Water Transport Properties

AbstractThis work studies the polymerization process of four different commercially available silicon-based polymers and their consequent effect on surface tension and water transport properties of natural stones used in architectural monuments, essential for modeling and predicting the durability of natural stones against weathering action of aqueous solutions. The four products studied consisted of two ethyl-silicate based materials, an alkyl-alkoxy siloxane oligomer with hydrophobic agents and finally, a silane/siloxane emulsion. In all cases, the morphology of the amorphous material deposited into the pore network of stones was examined by electron microscopy (SEM). The polymerization process was studied by infrared spectroscopy (FTIR) on both inert surface and porous stone substrate. The treated stone specimens were further tested after polymerization in terms of determination and comparison of water absorption coefficient, open porosity, pore size distribution (mercury intrusion porosimetry) and surface tension (contact angle measurements) properties. According to the analysis, the modification of the wetting properties of the stone surface should be related rather with the chemistry than the microstructure of the xerogels alone.

scholarly journals A Review of Solar Photovoltaic Concentrators

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Mehrdad Khamooshi ◽  
Hana Salati ◽  
Fuat Egelioglu ◽  
Ali Hooshyar Faghiri ◽  
Judy Tarabishi ◽  
...  
Keyword(s):  
Cooling System ◽  
Environmental Issues ◽  
Solar Photovoltaic ◽  
Acceptance Angle ◽  
Cooling Systems ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Additional Costs ◽  
The Cost ◽  
Photovoltaic Solar Cells

Throughout the recent centuries, the limits of using energy resources due to the cost and environmental issues became one of the scientists’ concerns. Because of the huge amount of energy received by the Earth from the sun, the application of photovoltaic solar cells has become popular in the world. The photovoltaic (PV) efficiency can be increased by several factors; concentrating photovoltaic (CPV) system is one of the important tools for efficiency improvement and enables for a reduction in the cell area requirement. The limits of the PV area can reduce the amount of absorbing irradiation; CPV systems can concentrate a large amount of sunlight into a smaller one by applying lenses or curved and flat mirrors. However, the additional costs on concentrating optics and cooling systems made CPV less common than nonconcentrated photovoltaic. This paper reviews the different types of PV concentrators, their performance with advantages and disadvantages, concentration ratio, acceptance angle, brief comparison between their efficiencies, and appropriate cooling system.

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