Topic Review
Black Soldier Fly
The black soldier fly (BSF), Hermetia illucens Linnaeus, is a large Stratiomyidae fly (13-20 mm size) found worldwide, but it is believed to have originated in the Americas. It is frequently found in the tropics and temperate regions throughout the world. Although adapted primarily to these regions, it can tolerate wide extremes of temperature except when ovipositing. They are generally considered a beneficial insect and non-pest. The adult fly does not have mouthparts, stingers, or digestive organs; thus, they do not bite or sting and do not feed during its short lifespan. They feed only as larvae and are, therefore, not associated with disease transmission. BSF larvae (BSFL) are voracious eaters of a wide range of organic wastes, decomposing and returning nutrients to the soil. Additionally, BSFL is an alternative protein source for aquaculture, pet food, livestock feed, and human nutrition.
  • 15031
  • 24 Dec 2022
Topic Review
Electronic Circular Dichroism
This entry provides an introduction to the basic concepts of Electronic Circular Dichroism (ECD) spectroscopy. It describes the fundamental principles, instrumentation, and different approaches for interpreting and predicting ECD spectra. It surveys the most popular modern applications of ECD for the structural analysis of organic compounds.
  • 14117
  • 24 May 2022
Topic Review
Geopolymer Concrete
Geopolymer concrete is a type of concrete that is made by reacting aluminate and silicate bearing materials with a caustic activator, such as fly ash or slag from iron and metal production. It can be a suitable substitute for ordinary Portland cement (OPC). 
  • 12606
  • 18 Feb 2022
Topic Review
Two-Dimensional Materials
Two-dimensional (2D) materials are defined as crystalline materials consisting of single- or few-layer atoms, in which the in-plane interatomic interactions are much stronger than those along the stacking direction. Since the success of monolayer graphene exfoliation, 2D materials have been extensively studied due to their unique structures and unprecedented properties. Among these fascinating studies, the most predominant focus has been on their atomic structures, defects, and mechanical behaviors and properties, which serve as the basis for the practical applications of 2D materials.
  • 8038
  • 07 Jan 2022
Topic Review
Synthetic Dyes
Synthetic dyes are commonly used in food products like soft drinks, vegetable sauces, jellies, etc. Most artificial dyes can cause cancer, therefore it is very important to develop sensors to detect them in food samples.
  • 7633
  • 09 Jun 2021
Topic Review
Extraction Techniques in Sample Preparation
Sample preparation is the most crucial step in the analytical procedure designed for implementation in any analytical application (food analysis, bionalysis, forensics, toxicology, environmental monitoring etc). It is the limiting factor in chemical analysis since it is time consuming and it can potentially introduce errors. No one can doubt that the best approach would be the direct introduction of the sample to the instrument, however this is rarely feasible. Efficient sample pretreatment is inevitably required as the instrument technology has produced highly sophisticated and sensitive analytical equipment. Hence, the analytical scientists have to develop and apply a suitable sample preparation protocol that ensures that the composition of the sample remains unchanged, no impurities are introduced during handling, all interferences have been left back, the analytes’ concentration is not only at detectable levels, but it can also be quantified precisely and accurately and that the matrix of the sample is compatible with the analytical technique. Extraction techniques are the most powerful tool in hands of the analytical chemists and lab practitioners. Either sorbent based or solvent based, extraction techniques provide the necessary tool that can be used to handle the sample in a way that all information in it can be revealed, all advantages in instrumentation have been exploited to the fullest and the lifetime of the instrument is prolonged in a seamless operation mode.
  • 7398
  • 28 Oct 2020
Topic Review
Tautomerism Detected by NMR
Tautomerism is typically the relocation of a light atom, often hydrogen, at the same time as a rearrangement of the electronic structure.  Typical examples are acetylacetone and acetone. This entry gives a short introduction to how to detect and describe a tautomeric equilibrium using Nuclear Magnetic Resonance (NMR). Typical parameters used are chemical shifts (1H,13C,15N,19F and 17O) one-bond coupling constants and isotope effects on chemical shifts.
  • 5924
  • 29 Oct 2020
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.
  • 5497
  • 01 Nov 2020
Topic Review
Food Colorants Analysis in Foods
Color additives are used extensively in several food products, as to enhance their appearance, and their nutritional properties. They can be defined as “any substance that its intentional addition of which to a food aiming for a technological (including organoleptic) purpose in the manufacture, processing, preparation treatment, packing, packaging, transport or holding of such food results, or may be reasonably expected to result, in it or its by-products becoming a component of the food or otherwise affecting the characteristics of such foods”. Thus, hereby they are presented all the late advancements related to existing analytical methods and sample preparation methodologies, for their determination and quantification in food matrices.Furthermore, all these advancements are connected to general information about the existing natural or synthetic food colorants, along with legislative information and toxicological aspects, in order to support the importance and the need of appropriate analytical methodologies.
  • 4870
  • 12 Jan 2021
Topic Review
Hydraulic Actuators
Hydraulic actuators are elements converting the energy of the working fluid into mechanical energy related to the reciprocating motion. The most frequently applied materials used in power hydraulics are described, and various surface modifications of the discussed elements, which are aimed at improving the operating parameters of actuators, are presented. The most frequently used materials for actuators elements are iron alloys. However, due to rising ecological requirements, there is a tendency to looking for modern replacements to obtain the same or even better mechanical or tribological parameters. Sealing systems are manufactured mainly from thermoplastic or elastomeric polymers, which are characterized by low friction and ensure the best possible interaction of seals with the cooperating element. In the field of surface modification, among others, the issue of chromium plating of piston rods has been discussed, which, due, to the toxicity of hexavalent chromium, should be replaced by other methods of improving surface properties.
  • 4624
  • 23 Mar 2021
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