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:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Laser-Induced Breakdown Spectroscopy
Laser-Induced Breakdown Spectroscopy (LIBS) has been firstly introduced and proposed for analytical applications almost immediately after the invention of the laser in 1960. Since then, it has been proposed and today is widely used as an alternative analytical method for numerous applications. The operating principle of LIBS is quite simple and is based on the interaction of a powerful enough laser beam, focused usually on or in a sample, inducing a dielectric breakdown of the material, thus resulting in plasma formation consisting of excited and non-excited atoms and molecules, fragments of molecular species, electrons and ions, and emitting characteristic radiations, whose spectroscopic analysis can in principle provide the elemental composition fingerprint of the material. The required instrumentation consisting basically of a laser source, and a spectrometer/monochromator equipped with the appropriate light detector (nowadays being almost exclusively some CCD or ICCD type detector) is relatively simple and economically affordable, while significant progresses have been achieved to small size and/or portable equipment, facilitating largely the in situ operation.
  • 1.8K
  • 31 Aug 2021
Topic Review
Reaction of CO2 with Epoxides
Coupling of CO2 with epoxides is a green emerging alternative for the synthesis of cyclic organic carbonates (COC) and aliphatic polycarbonates (APC). The scope of this work is to provide a comprehensive overview of metal complexes having sulfur-containing ligands as homogeneous catalytic systems able to efficiently promote this transformation with a concise discussion of the most significant results. The crucial role of sulfur as the hemilabile ligand and its influence on the catalytic activity are highlighted as well.
  • 1.8K
  • 22 Jan 2021
Topic Review
Extraction Functional Ingredients from Jackfruit
Various studies in the literature showed the effect of conventional and non-conventional extraction methods to obtain jackfruit functional ingredients; among the non-conventional methods, some use emerging technologies to extract or as a pre-treatment. Among the studies using conventional extraction, applying solvents such as methanoland oxalic acidstands out, as well as the extraction with hot water. Regarding extraction by emerging technologies, radio frequency-assistedand supercritical fluid (SFE) with CO2extractions have attracted attention owing to their less negative impact on the environment and safety of the final product obtained in comparison with other methods using non-conventional technologies.
  • 1.8K
  • 26 Aug 2021
Topic Review
Carbon Nanomaterials
Being a member of nanofamily, carbon nanomaterials exhibit specific properties that mostly arise from their small size. They have proved as very promising for the application in the technical and biomedical fields. A wide spectrum of use implies the inevitable presence of carbon nanomaterials in the environment, thus potentially endangering the whole nature. Although scientists worldwide have conducted researches investigating the impact of these materials, it is evident that there are still significant gaps concerning the knowledge of their mechanisms, as well as prolonged and chronic exposure and effects. Thinking small can greatly help us improve our lives, but also obliges us to deeply and comprehensively investigate all the possible consequences that could arise from our pure-hearted scientific ambitions and work.
  • 1.8K
  • 07 Aug 2020
Topic Review
Synthesis and Properties of Pyrazoles
Pyrazole derivatives are a special class of N-heterocyclic compounds (NHCps) bearing a heteroaromatic five-membered ring with two adjacent nitrogen atoms in the annular structure, one pyrrole-type (proton donor) and one pyridine-type (proton acceptor). Pyrazoles can act as weak bases or acids, with possible strength highly dependent on the nature of their substituent groups. The other three positions in the ring permit structural variants starting from the appropriate precursors or using post-functionalization reactions once the pyrazole ring is formed; these variations give the pyrazoles diverse and valuable synthetical, biological, and photophysical properties; indeed, more complex structures with various relevant examples can be formed from them.
  • 1.8K
  • 09 Sep 2022
Topic Review
LGD Theory for Nanoscale Ferroelectrics
This is a entry of the Landau-Ginzburg-Devonshire (LGD) Theory applied for description of nanoscale ferroelectrics. The polarization switching kinetics of nanosized ferroelectric crystals and the transition between homogeneous and domain switching in the nanoscale ferroelectric films are considered. Homogeneous switching according to the Ginzburg-Landau-Devonshire (LGD) theory is possible only in two-dimensional (2D) ferroelectrics. The main condition for the applicability of the LGD theory in such systems is its homogeneity along the polarization switching direction. A review is given of the experimental results for two-dimensional (2D) films of a ferroelectric polymer, nanosized barium titanate nanofilms, and hafnium oxide-based films. For ultrathin 2D ferroelectric polymer films, the results are confirmed by first-principle calculations. Fitting of the transition region from homogeneous to domain switching by sigmoidal Boltzmann functions was carried out. Boltzmann function fitting data enabled us to estimate correctly the region sizes of the homogeneous switching in which the LGD theory is valid. These sizes contain several lattice constants or monolayers of a nanosized ferroelectrics.
  • 1.8K
  • 14 Jan 2021
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.
  • 1.8K
  • 30 Oct 2020
Topic Review
Taxol Biosynthetic Pathway
Taxol is one of the most effective anticancer drugs in the world that is widely used in the treatment of several cancers. The elucidation of the taxol biosynthetic pathway is the key to solve the problem of taxol supply. So far, the taxol biosynthetic pathway has been reported to require an estimated 20 steps of enzymatic reactions, and most of enzymes involved have been well characterized. In details, the source and formation of the taxane core and the process of the downstream synthetic pathway have been basically depicted, while the modification of the core taxane skeleton has not been fully reported, mainly concerning the developments from diol intermediates to 2-debenzoyltaxane. 
  • 1.7K
  • 01 Jun 2021
Topic Review
Dielectric Materials
Owing to their insulating properties, dielectric materials are known as electrically insulating materials. According to the different dielectric materials, traditional dielectric capacitors can be divided into three categories. Firstly, there are polymer-based dielectric capacitors. The dielectric materials of this type of capacitors are mainly polymer materials. Second, there are ceramic-based dielectric capacitors. The dielectric materials of such capacitors include multi-phase ceramics, glass ceramics, ceramic films, etc. Third is the polymer ceramic composite dielectric capacitors, using a variety of polymer and ceramic composite materials as storage medium.
  • 1.7K
  • 19 Feb 2021
Topic Review
Green Extraction Techniques for Active Ingredients in Tea
The so-called “Green Extraction”—which is based on the design of different extraction processes for the reduction in energy consumption, as well as the usage of alternative solvents and renewable natural materials —was developed.
  • 1.7K
  • 17 Feb 2023
  • Page
  • of
  • 467
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
Video Production Service
Feedback