Topic Review
Pearlescent Pigments
Pigments are substances used to modify the colour of a material, which, unlike dyes, are insoluble both in common solvents and binders. Pigments can be either organic or inorganic, though the latest type is the most used and widespread for industry applications.
  • 8.3K
  • 01 Nov 2020
Topic Review Peer Reviewed
Porcelain Enamel Coatings
Porcelain enamel is an inorganic-type coating, which is applied to metals or glass for both decorative and functional purposes. This coating is a silica-based solidified glass mass obtained by high-temperature firing (temperature can range between 450 and 1200 °C depending on the substrate). Porcelain enamel coatings differ from ceramic coatings mainly by their glass structure and dilatation coefficient, and from organic paints mainly by the inorganic nature of the matrix and the chemical bond that exists between the coating and the substrate. 
  • 5.6K
  • 18 Apr 2022
Topic Review
Prehistoric Paintings in Magura Cave
The paintings are made of bat guano applied over limestone, therefore two sets of laboratory specimens were considered: stone specimens and stone specimens covered with a layer of sterilized bat guano. The two investigated treatments were a commercial product based on ethyl silicate (“ES”) and a solution of diammonium hydrogen phosphate (“DAP”), aimed at forming calcium phosphates. The results of the study indicate that both treatments were able to increase mechanical properties of stone, the increase being higher for “DAP”. Both consolidants caused acceptable color changes, but the “ES” treatment significantly decreased stone wettability, water absorption and water vapor permeability, while the “DAP” treatment slightly affected those properties. In the stone+guano specimens, the presence of the guano layer affected the penetration of the consolidants, thus partly reducing their effectiveness. Compared to the stone samples, the guano layer experienced a more intense color change, alongside visible cracking. However, the adopted methodology to replicate the cave paintings was not completely successful, as the so-deposited guano layer was very prone to detachment when dry, unlike cave paintings. Future work will be dedicated to assess the consolidant performance onto samples that resemble even more closely the conditions of the cave paintings, by improving the methodology for the guano layer deposition and by contaminating specimens with soluble salts before consolidant application.
  • 5.5K
  • 02 Nov 2020
Topic Review
Lipid Membrane
The biological lipid membrane is the key element for the maintenance of cell architecture and physiology. Lipid membranes act as a barrier separating the inner cellular space from the outer environment and further helping in the transmission of signals across the cell boundary. The correct composition and structure of cell membranes define key pathophysiological aspects of cells.
  • 5.1K
  • 23 Dec 2020
Topic Review
Ti Nitrides and Ti Silicides
The diffusion of nitrogen into TiSi2 films of low electrical resistivity, deposited on complementary metal oxyde semiconductor (CMOS) and Schottky diodes components increases their performances. TiN acts as a good diffusion barrier, gate material, Schottky barrier contact...Both TiSi2 and TiN are synthesized in Ti films coated on Si wafers and processed in an expanding microwave plasma producing nitrogen species such as NHx...This process promotes the chemical reactions at the surface of the metal. The growth of both compounds give rise to two competing processes which are thermodynamically and kinetically controlled. Ti films, 250 nm thick, processed at 600°C for  30 min, only consist of TiSi2 crystallites and TiN of amorphous structure. TiN crystallizes at 800°C and grows at the expense of TiSi2 according to thermodynamic data. 
  • 4.5K
  • 30 Oct 2020
Topic Review
Lotus-Leaf-Inspired Biomimetic Coatings
A universal infrastructural issue is wetting of surfaces; millions of dollars are invested annually for rehabilitation and maintenance of infrastructures including roadways and buildings to fix the damages caused by moisture and frost. The biomimicry of the lotus leaf can provide superhydrophobic surfaces that can repel water droplets, thus reducing the penetration of moisture, which is linked with many deterioration mechanisms in infrastructures, such as steel corrosion, sulfate attack, alkali-aggregate reactions, and freezing and thawing. In cold-region countries, the extent of frost damage due to freezing of moisture in many components of infrastructures will be decreased significantly if water penetration can be minimized. Consequently, it will greatly reduce the maintenance and rehabilitation costs of infrastructures.
  • 3.6K
  • 11 Jun 2022
Topic Review
Niobium Oxides
Niobium oxides (NbO, NbO2, Nb2O5), being a versatile material has achieved tremendous popularity to be used in a number of applications because of its outstanding electrical, mechanical, chemical, and magnetic properties. NbxOy films possess a direct band gap within the ranges of 3.2–4.0 eV, with these films having utility in different applications which include; optical systems, stainless steel, ceramics, solar cells, electrochromic devices, capacitor dielectrics, catalysts, sensors, and architectural requirements. With the purpose of fulfilling the requirements of a vast variety of the named applications, thin films having comprehensive properties span described by film composition, morphology, structural properties, and thickness are needed.
  • 3.4K
  • 06 Jan 2021
Topic Review
Water Droplet Erosion
The term erosion is originally derived from the Latin word “rodere”, which means “to gnaw”, and used to indicate a form of materials wear (i.e. loss of material) that is caused by the impact of solid or liquid particles with sufficiently high speed. Liquid erosion can be divided into two types; cavitation erosion and liquid impingement erosion (LIE). The term Water droplet erosion (WDE) is commonly used to indicate liquid impingement erosion (LIE), where a progressive material loss is caused by the repetitive impact of high speed water droplets. WDE constitutes a major concern in many industries including aerospace and aviation, power generation industries particularly in gas turbines and steam turbines, nuclear power plants, and wind energy. Hence, WDE has become an important topic of research.
  • 3.0K
  • 23 Oct 2020
Topic Review Peer Reviewed
Active Edible Packaging
Active edible packaging is a food packaging made of comestible bioproducts and active compounds that interacts with the food. The bioproducts, usually biopolymers, must be recognized as safe and with characteristics to be consumed by humans—comestible—and not toxic and capable of carrying an active compound, like anti-browning agents, colorants, flavors, nutrients, antimicrobial and/or antioxidant compounds, in order to extend the product shelf-life, reduce contamination and maintain or even enhance the nutritional value.
  • 2.5K
  • 13 Apr 2022
Topic Review
2D Nanomaterials
Materials can be rightly characterized as 2D material or nanosheet if only one of its dimensions is in nano-size, they usually resemble a large sheet with one or few atomic thickness layers (more like a sheet of paper). This explains the fundamental characteristic of 2D materials and their unique properties that made them very attractive in tribological applications. Also, the method of preparation of the materials are highlighted.
  • 2.5K
  • 11 Nov 2021
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