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Topic Review
Ergot Alkaloids Mycotoxins in Cereals
Mycotoxins are secondary metabolites synthesized by an array of fungal genera, usually Fusarium, Penicillium and Aspergillus.
  • 1.1K
  • 24 May 2021
Topic Review
Extraction of Metal Ions with Metal–Organic Frameworks
Metal–organic frameworks (MOFs) are crystalline porous materials composed of metal ions or clusters coordinated with organic linkers. Due to their extraordinary properties such as high porosity with homogeneous and tunable in size pores/cages, as well as high thermal and chemical stability, MOFs have gained attention in diverse analytical applications. 
  • 1.1K
  • 23 Dec 2021
Topic Review
Metallophthalocyanines
Since the serendipitous discovery of phthalocyanines (Pcs), at the beginning of the 20th century, growing attention has been devoted to the ubiquitous catalytic properties and applications of Pcs and Pcs coordinated with metal ions, Metallophthalocyanines (MPcs). In fact, these old synthetic dyes have been very attractive in the view of academic research, but mainly for catalytic industrial purposes as these dyes are easily accessible on a large scale, are robust under harsh reaction conditions, show high activity, and can be recovered and recycled. The success and diversity of MPcs as catalysts over different substrates are mostly attributed to their high structural flexibility in terms of metals and electronic properties of the phthalocyanine ligands.
  • 1.1K
  • 20 Feb 2021
Topic Review
Coatings for Milling
This entry talks a little about the development and application of PVD and CVD coatings on machining tools.
  • 1.1K
  • 05 Nov 2020
Topic Review
Applications of Magnetic Hydrogels
Magnetic hydrogels (MHGs) are a special class of hydrogel that contain at least one magnetic component in their composition. Generally, MNPs are dispersed in a polymer gel matrix to form MHGs. These hydrogels are special because they are prone to show fluctuations in their physical properties in the presence of an externally applied magnetic field.
  • 1.1K
  • 08 Dec 2021
Topic Review
Processes for Obtaining Syngas and Hydrogen
The growing demand for high-quality chemical products has already stimulated an increased interest in the conversion of hydrocarbon gases (natural gas, methane, biogas) into motor fuels and high value-added chemical products, as well as into hydrogen, which is increasingly in demand on the market. The conversion of natural gas into hydrogen and syngas is still the most complex and costly stage of modern gas chemical processes, the low efficiency of which hinders the development of modern gas chemistry. 
  • 1.1K
  • 14 Apr 2023
Topic Review
Steady State
In chemistry, a steady state is a situation in which all state variables are constant in spite of ongoing processes that strive to change them. For an entire system to be at steady state, i.e. for all state variables of a system to be constant, there must be a flow through the system (compare mass balance). A simple example of such a system is the case of a bathtub with the tap running but with the drain unplugged: after a certain time, the water flows in and out at the same rate, so the water level (the state variable Volume) stabilizes and the system is in a steady state. The steady state concept is different from chemical equilibrium. Although both may create a situation where a concentration does not change, in a system at chemical equilibrium, the net reaction rate is zero (products transform into reactants at the same rate as reactants transform into products), while no such limitation exists in the steady state concept. Indeed, there does not have to be a reaction at all for a steady state to develop. The term steady state is also used to describe a situation where some, but not all, of the state variables of a system are constant. For such a steady state to develop, the system does not have to be a flow system. Therefore, such a steady state can develop in a closed system where a series of chemical reactions take place. Literature in chemical kinetics usually refers to this case, calling it steady state approximation. In simple systems the steady state is approached by state variables gradually decreasing or increasing until they reach their steady state value. In more complex systems state variable might fluctuate around the theoretical steady state either forever (a limit cycle) or gradually coming closer and closer. It theoretically takes an infinite time to reach steady state, just as it takes an infinite time to reach chemical equilibrium. Both concepts are, however, frequently used approximations because of the substantial mathematical simplifications these concepts offer. Whether or not these concepts can be used depends on the error the underlying assumptions introduce. So, even though a steady state, from a theoretical point of view, requires constant drivers (e.g. constant inflow rate and constant concentrations in the inflow), the error introduced by assuming steady state for a system with non-constant drivers may be negligible if the steady state is approached fast enough (relatively speaking).
  • 1.1K
  • 14 Oct 2022
Topic Review
Near- and Mird-Infrared Spectroscopy
Given the exquisite capability of direct, non-destructive label-free sensing of molecular transitions, IR spectroscopy has become a ubiquitous and versatile analytical tool. IR application scenarios range from industrial manufacturing processes, surveillance tasks and environmental monitoring to elaborate evaluation of (bio)medical samples. Given recent developments in associated fields, IR spectroscopic devices increasingly evolve into reliable and robust tools for quality control purposes, for rapid analysis within at-line, in-line or on-line processes, and even for bed-side monitoring of patient health indicators. 
  • 1.1K
  • 03 Aug 2022
Topic Review
Applications of g-C3N4-Based Photocatalysts
The assembly of g-C3N4 with metal oxides is an effective strategy which can not only improve electron–hole separation efficiency by forming a polymer–inorganic heterojunction, but also compensate for the redox capabilities of g-C3N4 owing to the varied oxidation states of metal ions, enhancing its photocatalytic performance. Applications of g-C3N4-based materials in photocatalysis are discussed, including water splitting to generate H2 and O2, the degradation of pollutants, CO2 reduction and bacterial disinfection.
  • 1.1K
  • 29 Nov 2022
Topic Review
Production of Refractory Materials with Silicon Dioxide
Organization of environmentally-friendly production of refractory materials based on the principles of cost-effective use of energy and material resources through use of energy-saving technologies and replacement of natural raw materials with industrial and agricultural waste is gaining relevance. Scientists are increasingly interested in creating high-temperature materials using silica of plant origin. Its source is rice husk, a multi-tonnage waste from rice production. Organo-mineral in its nature, rice husk determines the uniqueness of the structure and properties of the materials obtained from it. Use of this waste allows to produce porous, high-strength silicon carbide refractories with properties corresponding to classical analogs, while benefiting from environmental, economic and technological aspects.
  • 1.1K
  • 05 Sep 2022
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