Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
2D-MoS2
Two-dimensional (2D) materials are generally defined as crystalline substances with a few atoms thickness.Two-dimensional transition metal dichalcogenide (2D-TMDs) semiconducting (SC) materials have exhibited unique optical and electrical properties. The layered configuration of the 2D-TMDs materials is at the origin of their strong interaction with light and the relatively high mobility of their charge carriers, which in turn prompted their use in many optoelectronic applications, such as ultra-thin field-effect transistors, photo-detectors, light emitting diode, and solar-cells. Generally, 2D-TMDs form a family of graphite-like layered thin semiconducting structures with the chemical formula of MX2, where M refers to a transition metal atom (Mo, W, etc.) and X is a chalcogen atom (Se, S, etc.). The layered nature of this class of 2D materials induces a strong anisotropy in their electrical, chemical, mechanical, and thermal properties. In particular, molybdenum disulfide (MoS2) is the most studied layered 2D-TMD.
  • 4.5K
  • 28 Sep 2021
Topic Review
Cationic Surfactants
Cationic surfactants are a class of surfactant molecules that contain a positively charged head group and a long hydrophobic tail. They have a wide range of properties that make them useful in various applications, including solubility in water and organic solvents, high surface activity, emulsification, antimicrobial activity, conditioning properties, and fabric softening. However, some cationic surfactants can be toxic to aquatic life, so they should be used with caution in applications where they may come into contact with the environment. Overall, cationic surfactants are important molecules that play a crucial role in various industrial, personal care, and household applications. Cationic surfactants are a type of surfactant that have a positively charged hydrophilic (water-loving) head and a hydrophobic (water-hating) tail. The positive charge on the head of the surfactant makes it attracted to negatively charged surfaces, such as cell membranes and proteins. Due to their positive charge, cationic surfactants are often used in personal care and household cleaning products, as well as in the textile and paper industries. They are effective in removing dirt, oil, and other contaminants from surfaces, as they can bind to these substances and help to lift them away from the surface. Cationic surfactants can also have antimicrobial properties, as they can disrupt the cell membranes of bacteria and other microorganisms. This makes them useful in disinfectants, as well as in personal care products such as shampoos and body washes.
  • 4.2K
  • 24 Mar 2023
Topic Review
History, Preparation, Characterization and Applications of Moisturizers
Moisturizers are one of the most widely used preparations in cosmetics and have been extensively used to soften the skin for consumers. Cosmetically, moisturizers make the skin smooth by the mechanism of increasing the water content in the stratum corneum, hence exerting its most vital action, which is moisturizing action and maintaining a normal skin pH.
  • 4.2K
  • 13 Jul 2022
Topic Review
Design Challenges and Limitations of Injectable Hydrogels
Injectable hydrogels (IHs) are smart biomaterials and are the most widely investigated and versatile technologies, which can be either implanted or inserted into living bodies with minimal invasion. Their unique features, tunable structure and stimuli-responsive biodegradation properties make these IHs promising in many biomedical applications, including tissue engineering, regenerative medicines, implants, drug/protein/gene delivery, cancer treatment, aesthetic corrections and spinal fusions. Regarding their current prospective and ongoing research, hydrogel formulations have some limitations in their applications, clinical practices and sustainability. Many hydrogel systems (natural/synthetic), such as thermosensitive hydrogels, are free-flowing sols at a low temperature, while upon raising to body temperature (physiological temperature), they are converted to a stable visco-elastic gel phase, such as poly (phosphazene), pluronic and poly (N-isopropyl acrylamide). 
  • 3.2K
  • 08 Apr 2022
Topic Review
Polycrystalline Materials
Polycrystalline materials can be defined as the counterpart of single crystals. These latter  arise from solution crystallization by transfer of a solute from the liquid phase to the crystalline phase. Crystallization from melt originates instead crystallites or grains, that is regular crystalline regions  randomly oriented and separated one anoher by borders with geometric shapes, Polycrystalline materials are the result of a multiple nucleation process, whereas monocrystals are ideally obtainable by dipping a seed crystal into a supercooled melt.  Polycrystalline materials often consist of spherulites, i.e. crystalline aggregates growing with a rounded shape up to impingment with adjacent spherulites. The borders amongst spherulites and the size and the final shape of spherulites affect considerably the properties of polycrystalline materials.
  • 3.0K
  • 12 May 2021
Topic Review
Dimensionality of materials
As generally known dimensionality of materials is a crucial factor to determine functions and properties of the materials. In addition to zero-dimensional, one-dimensional, three-dimensional, and further integrated functional materials, various two-dimensional materials have been paid special attention. Two-dimensional materials have their unique electronic propertiesand play important roles in interfacial sciences.
  • 2.4K
  • 12 Aug 2021
Topic Review
Methanol to Gasoline (MTG)
The MTG (Methanol to Gasoline) process allows us to transform methanol into hydrocarbons within the range of gasoline boiling points.
  • 2.2K
  • 04 Mar 2022
Topic Review
GeSn Alloys for Photonic and Electronic Applications
GeSn materials have attracted considerable attention for their tunable band structures and high carrier mobilities, which serve well for future photonic and electronic applications.
  • 1.9K
  • 28 Mar 2022
Topic Review
Clinoptilolite Characterization and EDS Analysis
Zeolites are materials of biomedical interest, in particular owing to their ability to remove metabolic products such as uremic toxins (i.e., urea, uric acid, creatinine, p-cresol, and indoxul sulfate); they are used for the regeneration of dialysis solutions and as in vivo membranes for artificial kidney. Zeolites have further important applications in the biomedical field, in fact they are used as hemostats (due to their ability to absorb water), antiseptics (when modified with silver or zinc ions), carriers for drugs and genes (adjuvant in vaccines), glucose absorbers, etc. Here, EDS microanalysis in the study of a sample of natural clinoptilolite is reported. 
  • 1.8K
  • 28 Sep 2021
Topic Review
Available Sampling Methods for Plastic Waste
Given the rapid development of plastics recycling in recent years, the need for guidelines for sampling and material characterization is steadily emerging. However, there still exists a considerable scarcity of methods that enable proper material data acquisition. It was found that neither the literature nor the standards provide a comprehensive practice that considers the distinctive characteristics of plastic waste and applies it to different situations along the value chain. Two variants of the proposed plan were evaluated based on the flake size distribution and the apparent density of four different pretreated polyolefin (PO) waste materials. Combining stratified random sampling with composite sampling yields a good sampling technique for rigid PO waste. Moreover, the analysis of a composite sample adequately conveys the true material properties of a sublot or lot.
  • 1.5K
  • 31 Aug 2022
Topic Review
Mechanism of Cotton Combustion
As a cellulose-based polymer, the combustion of cotton is an exothermic oxidation process that takes place upon heating, consuming flammable gases, liquids, and solid residues produced during the pyrolysis of the textile material, thus generating heat.
  • 1.5K
  • 27 Jul 2023
Topic Review
Gold and Silver Nanoparticle-Based Colorimetric Sensors
Gold and Silver nanoparticles (AuNPs and AgNPs) are perfect platforms for developing sensing colorimetric devices thanks to their high surface to volume ratio and distinctive optical properties, particularly sensitive to changes in the surrounding environment. These characteristics ensure high sensitivity in colorimetric devices. Au and Ag nanoparticles can be capped with suitable molecules that can act as specific analyte receptors, so highly selective sensors can be obtained.
  • 1.4K
  • 23 Nov 2021
Topic Review
Steel for Nuclear Pressure Vessels
The nuclear reactor pressure vessel is an important component of a nuclear power plant. It has been used in harsh environments such as high temperature, high pressure, neutron irradiation, thermal aging, corrosion and fatigue for a long time, which puts forward higher standards for the performance requirements for nuclear pressure vessel steel.
  • 1.4K
  • 22 Dec 2022
Topic Review
Raw Materials for Geopolymer Production
Due to the high generation of industrial waste by-products, disposal concerns, less utilization, and hazardous nature, the research on its valorization as a precursor for geopolymer production is potentially environmentally viable.
  • 1.4K
  • 18 Oct 2022
Topic Review
Nanomaterials for Industrial Wastewater Treatment
Industrial wastewater originating from various industries contributes as a major source of water pollution. This pollutant poses a severe threat to the environment. Recent years saw nanomaterials as a potential candidate for pollutants removal. Nowadays, a range of cost-effective nanomaterials is available with unique properties.
  • 1.3K
  • 22 Jul 2021
Topic Review
Catalytic Mechanism of Photocatalysts Based on GCN Heterogeneous
In the current world situation, population and industrial growth have become major problems for energy and environmental concerns. Extremely noxious pollutants such as heavy metal ions, dyes, antibiotics, phenols, and pesticides in water are the main causes behind deprived water quality leading to inadequate access to clean water. In this connection, graphite carbon nitride (GCN or g-C3N4) a nonmetallic polymeric material has been utilized extensively as a visible-light-responsive photocatalyst for a variety of environmental applications.
  • 1.3K
  • 16 Jun 2022
Topic Review
High Temperature Tribology
High temperature tribology is considered to begin from a minimum temperature of 300–350 °C, where organic base oils and polymers begin to decompose, until a temperature of 1000 °C. In this field of tribology, tests are typically run under dry or solid-state friction, unless a solid lubricant is used, since most lubricants will oxidize or break down when exposed to these extreme temperatures. Therefore, this form of tribotesting is useful to determine the friction, wear, and other tribological characteristics of coatings, ceramics, alloys, cermets, and similar materials.
  • 1.2K
  • 30 Apr 2021
Topic Review
Metal-Organic Frameworks in CO2 Cycloaddition with Epoxides
The level of carbon dioxide in the atmosphere is growing rapidly due to fossil fuel combustion processes, heavy oil, coal, oil shelter, and exhausts from automobiles for energy generation, which lead to depletion of the ozone layer and consequently result in global warming. The realization of a carbon-neutral environment is the main focus of science and academic researchers of today. Several processes were employed to minimize carbon dioxide in the air, some of which include the utilization of non-fossil sources of energy like solar, nuclear, and biomass-based fuels. Consequently, these sources were reported to have a relatively high cost of production and maintenance. The applications of both homogeneous and heterogeneous processes in carbon capture and storage were investigated in recent years and the focus now is on the conversion of CO2 into useful chemicals and compounds. It was established that CO2 can undergo cycloaddition reaction with epoxides under the influence of special catalysts to give cyclic carbonates, which can be used as value-added chemicals at a different level of pharmaceutical and industrial applications. Among the various catalysts studied for this reaction, metal-organic frameworks are now on the frontline as a potential catalyst due to their special features and easy synthesis. Several metal-organic framework (MOF)-based catalysts were studied for their application in transforming CO2 to organic carbonates using epoxides. Here, we report some recent studies of porous MOF materials and an in-depth discussion of two repeatedly used metal-organic frameworks as a catalyst in the conversion of CO2 to organic carbonates
  • 1.2K
  • 25 Nov 2021
Topic Review
Particle-Bound Mercury Characterization
Particulate Bound Hg (PBM) consists of all airborne particulate containing Hg, including both stable condensed and gaseous forms adsorbed on atmospheric particulate matter (PM); it is operationally sampled and quantified by pulling air through a glass fiber or a quartz filter. PBM usually includes all those particles with a diameter <2.5 μm, even if its characterization depends on the pore size of the filter used for its collection. The accurate dimensional characterization is then essential to estimate the dry deposition of PBM, as well as any other particulate pollutant; the particles diameters directly influence gravitational sedimentation and the PBM residence time in the atmosphere. In addition, PBM chemical speciation, as well as for the other Hg forms, is fundamental to understand PBM bioavailability and therefore the effects on human .
  • 1.2K
  • 05 Jul 2021
Topic Review Peer Reviewed
Conductive Heat Transfer in Thermal Bridges
A thermal bridge is a component of a building that is characterized by a higher thermal loss compared with its surroundings. Their accurate modeling is a key step in energy performance analysis due to the increased awareness of the importance of sustainable design. Thermal modeling in architecture and engineering is often not carried out volumetrically, thereby sacrificing accuracy for complex geometries, whereas numerical textbooks often give the finite element method in much higher generality than required, or only treat the case of uniform materials. Despite thermal modeling traditionally belonging exclusively to the engineer’s toolbox, computational and parametric design can often benefit from understanding the key steps of finite element thermal modeling, in order to inform a real-time design feedback loop. In this entry, these gaps are filled and the reader is introduced to all relevant physical and computational notions and methods necessary to understand and compute the stationary energy dissipation and thermal conductance of thermal bridges composed of materials in complex geometries. The overview is a self-contained and coherent expository, and both physically and mathematically as correct as possible, but intuitive and accessible to all audiences. Details for a typical example of an insulated I-beam thermal bridge are provided.
  • 1.1K
  • 26 May 2022
  • Page
  • of
  • 6
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback