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Topic Review

Metal Current Collector for LMBs

Lithium Metal Anode (LMA) has been considered as the promising candidate, owing to their high theoretical gravimetric capacity, low electrochemical potential, and low density, to replace the conventional carbon based anode materials of lithium-ion batteries (LIBs). Unfortunately, the inherent hyperactive and volume expansion issues of Lithium (Li) leads to the formation of notorious Li dendrite growth and unstable solid-electrolyte-interphase (SEI), eventually hindering the practical application of lithium metal batteries (LMBs). To resolve this issue, one of the effective approach is to engineer three dimensional (3D) porous metal based Li host owing to their chemical and mechanical stability, high electronic conductivity and low cost. In this review, the challenges and strategies to suppress the Li dendrite growth are presented. Then the design principles and effectiveness of different kinds of metal based Li host to accommodate and buffer the volume expansion of Li for guiding the uniform Li deposition are summarized. Then the special attention is paid to the lithiophilic coating or decoration which can further control the initial Li deposition and lowers the nucleation and voltage overpotential in 3D porous metal framework during Li plating/stripping cycles. Finally, the conclusion and perspective are given on the current status, challenges and future research pathway toward advancement of LMA for dendrite-free and improved battery performance.

2.3K
28 Oct 2020

Topic Review

Aromatic Water Pollutants

In recent years, the intensification of human activities including rapid urbanization, industrialization, population, and economic growth, led to an increase in waste production and energy demand. Most importantly such activities pose concerns for health, energy security and climate changes. Hazardous volatile organic compounds, VOC, and aromatic organic compounds, AOC, are being generated from the activities of many vital industries like mining and petrochemicals. They are instrumental in the economic growth of many countries and their products are regarded as privileges to modern communities. Nevertheless, they are toxic and carcinogenic thus, these wastes have been classified as “hazardous”. The simultaneous treatment of organic pollutants and energy recovery is an attractive solution to reduce pollution in water, air, and soil as well as provide alternative clean energy sources. Hydrogen could be generated from organic pollutants in water through photocatalysis. Photocatalysis refers to the oxidation and reduction, redox, reactions on semiconductor surfaces, mediated by the valence band holes and conduction band electrons, which are generated by the absorption of ultraviolet or visible light radiation. Compared to traditional oxidation processes, photocatalytic redox reaction operates at ambient conditions without a high temperature or high pressure, and many recalcitrant organic contaminants can be degraded without the addition of chemical oxidants, hence it is fully green process. Among the various photocatalysts, TiO2, as the most widely employed “golden” photocatalyst, has been largely used in photocatalysis, due to its chemical stability, nontoxicity, and low cost. In the last two decades, TiO2 photocatalysis has expanded very quickly, having undergone various development‐related energy issues and environmental issues, such as direct solar H2O splitting into H2 and the decomposition of pollutants in air and H2O at low concentrations. Although great progress has been made in TiO2 photocatalysis, much remains unknown, which raises an interesting challenge not only for engineers but also for basic scientists. a typical photocatalytic reaction in TiO2 photocatalysis contains many fundamental processes, including charge carrier formation, separation, relaxation, trapping, transfer, recombination, and transportation.

2.3K
24 May 2021

Topic Review

Surfactants in Corrosion Inhibitors

Surfactants are commonly used as corrosion inhibitors due to their ability to adsorb onto metal surfaces and form a protective barrier. When surfactants are added to a solution, they can reduce the surface tension and promote the wetting of the metal surface by the solution. This allows the surfactant molecules to be attracted to the metal surface, where they can adsorb and form a protective layer. Surfactants can also help to inhibit corrosion by reducing the electrochemical activity of the metal surface. This can be achieved by either reducing the rate of anodic or cathodic reactions, or by reducing the rate of ion transport across the metal-solution interface. By inhibiting these electrochemical processes, the surfactant can slow down the rate of corrosion and prevent further degradation of the metal surface. In addition to their inhibitive properties, surfactants can also improve the performance of other corrosion inhibitors. For example, surfactants can enhance the adsorption of organic inhibitors onto metal surfaces, which can increase their effectiveness. Surfactants can also improve the solubility and stability of inorganic inhibitors, which can improve their dispersibility in a solution.

2.3K
24 Mar 2023

Topic Review

Seaweed Polysaccharide Based Products/Materials

Among the various natural polymers, polysaccharides are one of the oldest biopolymers present on the earth. They play a very crucial role in the survival of both animals and plants. Due to the presence of hydroxyl functional groups in most of the polysaccharides, it is easy to prepare their chemical derivatives. Several polysaccharide derivatives are widely used in a number of industrial applications. The polysaccharides such as cellulose, starch, chitosan, etc. have several industrial applications but due to some distinguished characteristic properties, seaweed polysaccharides are preferred in a number of applications.

2.2K
17 Sep 2021

Topic Review

Phosphorus Compounds of Natural Origin

Natural phosphorus compounds are essential for modern biological systems, and their diverse biological properties testify to their importance in the world of living organisms. They provide stable ligation necessary for fixing information in RNA and DNA, contribute to cellular structure in phospholipids, serve as the main source of biochemical energy (eg, ATP, phosphoenolpyruvate, creatinephosphate), and are present in a large number of metabolites. Сentral place that phosphates retain in biological systems allows us to conclude that they played an important role in the emergence of life on Earth. In recent years, a large number of natural phosphorus compounds have been isolated from living organisms and significant advances have been made in understanding the effect of phosphates on prebiotic chemistry.

2.2K
23 Jun 2021

Topic Review

Organic Binders in Archaeological Wall Paintings

Binding media are complex materials, employed to allow pigment grains to adhere to each other and to the surface of the support, through the formation of a coherent and homogeneous film. The function of the binder consists, therefore, in keeping the pigment particles firmly together and at the same time adhering them in the form of a coherent thin film to the surface of the support. The binder must obviously be in the fluid state, in order to form with the pigments a stable, homogeneous, stretchy, and viscous dough. For the realization of wall paintings and, in later times, for their preservation, different materials with functions of binders, adhesives, paints, protective and consolidating were and are still necessary. There is a very large class of products which can have both constitutive functions but also a function of conservation and restoration.

2.2K
21 Oct 2021

Topic Review

Visible-Light-Promoted Carbonylation Reactions

The abundant and inexpensive carbon monoxide (CO) is widely exploited as a C1 source for the synthesis of both fine and bulk chemicals. In this context, photochemical carbonylation reactions have emerged as a powerful tool for the sustainable synthesis of carbonyl-containing compounds (esters, amides, ketones, etc.).

2.1K
11 Aug 2021

Topic Review

Electrodermal Activity Data Collection

The electrodermal activity (EDA) signal is an electrical manifestation of the sympathetic innervation of the sweat glands. EDA has a history in psychophysiological (including emotional or cognitive stress) research since 1879, but it was not until recent years that researchers began using EDA for pathophysiological applications like the assessment of fatigue, pain, sleepiness, exercise recovery, diagnosis of epilepsy, neuropathies, depression, and so forth. The advent of new devices and applications for EDA has increased the development of novel signal processing techniques, creating a growing pool of measures derived mathematically from the EDA. For many years, simply computing the mean of EDA values over a period was used to assess arousal. Much later, researchers found that EDA contains information not only in the slow changes (tonic component) that the mean value represents, but also in the rapid or phasic changes of the signal. The techniques that have ensued have intended to provide a more sophisticated analysis of EDA, beyond the traditional tonic/phasic decomposition of the signal. With many researchers from the social sciences, engineering, medicine, and other areas recently working with EDA, it is timely to summarize and review the recent developments and provide an updated and synthesized framework for all researchers interested in incorporating EDA into their research.

2.1K
30 Oct 2020

Topic Review

Phytochemicals Used for Hair Dyeing

Natural dyes have been used since ancient times, when they were used not only for hair coloration, but also for medicinal, decoration and religious purposes. Many organic compounds have been identified as the principal coloring matters in hair dye plants and investigated for dyeing performance under experimental conditions. Natural colorants can be classified based on dye source, application method and chemical structure.

2.0K
23 Nov 2022

Topic Review

Biosensors for Malaria Biomarkers

This entry discusses recent advances in the development of biosensors for the purposes of malaria diagnostics. It underscore relevant challenges that have defined the gap between biosensor development and their successful utilization in routine clinical practice within resource-limitted settings. It proposes a way to think about developing biosensors that are suitable for biomedical diagnostics applications.

2.0K
30 Oct 2020

Topic Review

Direct Synthesis of Silicon Compounds

The development of industrial organosilicon chemistry, and thus the development of silicon chemistry, is partly related to the discovery of the direct process of organosilanes synthesis in the 1940s, which allowed the production of organosilanes and silicone polymers on a large scale, and resulted in the development of new technologies to produce organosilicon monomers and polymers. The direct synthesis process, also known as the Müller–Rochow process, is one of the best-known industrial processes for obtaining organosilicon compounds, and has been the basis of the silicone industry.

2.0K
08 Mar 2023

Topic Review

Bioethanol Production Using Seawater

Bioethanol has many environmental and practical benefits as a transportation fuel. It is one of the best alternatives to replace fossil fuels due to its liquid nature, which is similar to the gasoline and diesel fuels traditionally used in transportation. In addition, bioethanol production technology has the capacity for negative carbon emissions, which is vital for solving the current global warming dilemma. However, conventional bioethanol production takes place based on an inland site and relies on freshwater and edible crops (or land suitable for edible crop production) for production, which has led to the food vs. fuel debate. Establishing a coastal marine biorefinery (CMB) system for bioethanol production that is based on coastal sites and relies on marine resources (seawater, marine biomass and marine yeast) could be the ultimate solution. In this paper, we aim to evaluate the environmental impact of using seawater for bioethanol production at coastal locations as a step toward the evaluation of a CMB system. Hence, a life cycle assessment for bioethanol production was conducted using the proposed scenario, named Coastal Seawater, and compared to the conventional scenario, named Inland Freshwater (IF). The impact of each scenario in relation to climate change, water depletion, land use and fossil depletion was studied for comparison. The Coastal Seawater scenario demonstrated an improvement upon the conventional scenario in all the selected impact categories. In particular, the use of seawater in the process had a significant effect on water depletion, showing an impact reduction of 31.2%. Furthermore, reductions were demonstrated in natural land transformation, climate change and fossil depletion of 5.5%, 3.5% and 4.2%, respectively. This indicates the positive impact of using seawater and coastal locations for bioethanol production and encourages research to investigate the CMB system.

2.0K
21 Aug 2021

Topic Review

Hydrophobic Solid Catalysts Synthesis

The preparation methods of hydrophobic materials such as zeolites, modified silicas and polymers has been reviewed. Particular attention has been paid to the characterization methods classified according to the surface and bulk composition, on one hand, and to the measure of interactions with water or organic solvents, on the other. Some selected applications are analyzed in order to understand the relevance of the reactants/products adsorption to address activity and selectivity of the reaction. Thus, absorption of a non-polar reactant or desorption of a hydrophilic product are much easier on a hydrophobic surface and can effectively boost the catalytic activity.

1.9K
30 Nov 2020

Topic Review

Perezhivanie and Its Application

Perezhivanie is a concept that was originally defined by Vygotsky, but it did not become a part of educational theory until recently. Today the concept has been revived, and it is now used as a way to include emotional aspects into education and educational research. The concept also provides a rationale for describing and forming personalised learning.

1.9K
17 Jan 2022

Topic Review

Polyphenols comprise a number of natural substances, such as flavonoids, that show interesting biological effects. Among these substances is naringin, a naturally occurring flavanone glycoside found in citrus fruits and Chinese medicinal herbs. Several studies have shown that naringin has numerous biological properties, including cardioprotective, cholesterol-lowering, anti-Alzheimer’s, nephroprotective, antiageing, antihyperglycemic, antiosteoporotic and gastroprotective, anti-inflammatory, antioxidant, antiapoptotic, anticancer and antiulcer effects. Despite its multiple benefits, the clinical application of naringin is severely restricted due to its susceptibility to oxidation, poor water solubility, and dissolution rate.

1.9K
24 Mar 2023

Topic Review

σ-hole is a region of depleted electronic density located on the outer side of a covalently-bonded atom, situated roughly along an extension of the bond axis

1.8K
24 May 2021

Topic Review

Reaction Mechanism of Olefins

Light olefins (C2-C4) are important C-building blocks which are currently used to produce a variety of chemicals, such as elastomers, medicines, cosmetics, detergents, solvents, etc. They can be produced by steam cracking, fluid catalytic cracking of naphtha, direct/indirect conversion of synthesis gas (CO + H2) or by hydrogenation of CO2 using H2 from renovable energy sources. However, the catalytic production of light olefins from CO2 is difficult due to the chemical inactivity of CO2 molecule, the high C-C coupling barrier and the necesity to limit the formation of C-C bond and methane. Therefore, the catalysts required for this reaction must to be multifunctional and have an optimized amount of active sites.

1.8K
29 Nov 2021

Topic Review

Pyrido[2,3-d], [3,2-d], [3,4-d] and [4,3-d]pyrimidine Derivatives

The structures composed of a pyridopyrimidine moiety which have shown a therapeutic interest or have already been approved for use as therapeutics, including pyrido[2,3-d]pyrimidines, pyrido[3,4-d]pyrimidines, pyrido[4,3-d]pyrimidines and pyrido[3,2-d]pyrimidines.

1.8K
06 Apr 2022

Topic Review

Gamma-Aminobutyric Acid

Gamma-Aminobutyric acid, or γ-aminobutyric acid /ˈɡæmə əˈmiːnoʊbjuːˈtɪrɪk ˈæsɪd/, or GABA /ˈɡæbə/, is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GABA is sold as a dietary supplement in many countries. It has been traditionally thought that exogenous GABA (i.e. taken as a supplement) doesn't cross the blood-brain barrier, however data obtained from more current research indicates that it may be possible.

1.8K
01 Dec 2022

Topic Review

The Versatility in the Applications of Dithiocarbamates

Dithiocarbamate ligands have the ability to form stable complexes with transition metals, and this chelating ability has been utilized in numerous applications. The complexes have also been used to synthesize other useful compounds.

1.8K
10 Mar 2022

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