You're using an outdated browser. Please upgrade to a modern browser for the best experience.
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 by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Aragonite and Unusual Pigments Identification
Aragonite is a mineralogical form of calcium carbonate, mainly of biogenic origin. Historical sources report its use in Roman times as an aggregate in mortars, and in the literature it has only been shown in Roman wall paintings. Thus, its use in 16thcentury wall paintings of the church of Santo Stefano in Selva (Cerignale, Apennines of central Italy) is surprising.
  • 1.3K
  • 01 Nov 2021
Topic Review
Fluorescent Chemosensors Based on Polyamine Ligands
Polyamine ligands are water-soluble receptors that are able to coordinate, depending on their protonation degree, either metal ions, anionic, or neutral species. Furthermore, the presence of fluorescent signaling units allows an immediate visual response/signal. For these reasons, they can find applications in a wide variety of fields, mainly those where aqueous media is necessary, such as biological studies, wastewater analysis, soil contamination, etc.
  • 1.3K
  • 29 Dec 2021
Topic Review
Raman Spectroscopy in Biosensing
The effect of Raman scattering is a result of inelastic light scattering processes, which lead to the emission of scattered light with a different frequency associated with molecular vibrations of the identified molecule. Spontaneous Raman scattering is usually weak, resulting in complexities with the separation of weak inelastically scattered light and intense Rayleigh scattering. These limitations have led to the development of various techniques for enhancing Raman scattering, including resonance Raman spectroscopy (RRS) and nonlinear Raman spectroscopy (coherent anti-Stokes Raman spectroscopy and stimulated Raman spectroscopy). Furthermore, the discovery of the phenomenon of enhanced Raman scattering near metallic nanostructures gave impetus to the development of the surface-enhanced Raman spectroscopy (SERS) as well as its combination with resonance Raman spectroscopy and nonlinear Raman spectroscopic techniques. The combination of nonlinear and resonant optical effects with metal substrates or nanoparticles can be used to increase speed, spatial resolution, and signal amplification in Raman spectroscopy, making these techniques promising for the analysis and characterization of biological samples.
  • 1.2K
  • 07 Jan 2022
Topic Review
Asymmetric Recognition by Chiral Porphyrinoids
Over the years, chiral discrimination of chiral molecules such as amino acids, alcohols, amines, hydroxy-carboxylic acids, etc. has aroused the interest of the scientific community. Thus, numerous studies have reported the possibility to discriminate several organic guests by using both symmetric and asymmetric porphyrin derivatives. Nevertheless, this entry exclusively focuses on chiral porphyrinoids as probes for asymmetric recognition and sensing, illustrating the main aspects concerning the chiral recognition phenomena of a multitude of chiral organic guests through several chiral mono- and bis-porphyrins via different spectroscopic techniques.
  • 1.2K
  • 17 Nov 2021
Topic Review
Practical Aspects of Nuclear Magnetic Resonance Application
Nuclear magnetic resonance (NMR) is a primary method of measurement according to metrology standards. It has been proven to have good reproducibility. NMR spectra are evaluated numerically, including chemical shifts, coupling constants, and signal integrals, which lead to quantitative results.
  • 1.1K
  • 13 Dec 2023
Topic Review
NIRS in Wild Rodents’ Research
The near-infrared spectroscopy (NIRS) method proved to be a useful tool to determine the amount of a particular food ingredient in the diet from faeces or chyme and to estimate the food quality.
  • 989
  • 17 Jan 2022
Topic Review
Quaternary Ammonium Gemini Surfactant 12-6-12
Gemini surfactants are a modern variety of surfactants with unique properties and a very wide range of potential applications. Hexamethylene-1,6-bis(N-dodecyl-N,N-dimethylammonium bromide) is one such representative compound that is a better alternative to a single analogue. It shows excellent surface, antimicrobial, and anticorrosion properties. With a highly efficient synthetic method and a good ecological profile, it is a potential candidate for numerous applications, including biomedical applications.
  • 930
  • 14 Sep 2023
Topic Review
Energy Calibration for a Sectional Scan
For a sectional scan, the spectral energies within each scan need to be re-distributed point by point with a linear function of the accumulated time scanned rather than be scaled with a universal constant as in a traditional energy calibration.
  • 914
  • 06 Dec 2022
Topic Review
Random Laser Properties
In a random laser (RL), optical feedback arises from multiple scattering instead of conventional mirrors. RLs generate a laser-like emission, and meanwhile take advantage of a simpler and more flexible laser configuration. The applicability of RLs as light sources and optical sensors has been proved. 
  • 910
  • 13 Jan 2023
Topic Review
Near-Infrared Hyperspectral Imaging Techniques for Non-Destructive Quality Assessment
Hyperspectral imaging (HSI) is one of the most often used techniques for rapid quality evaluation for various applications. It is a non-destructive technique that effectively evaluates the quality attributes of root and tuber crops, including yam and cassava, and their food products. Hyperspectral imaging technology, which combines spectroscopy and imaging principles, has an advantage over conventional spectroscopy due to its ability to simultaneously evaluate the physical characteristics and chemical components of various food products and specify their spatial distributions. HSI has demonstrated significant potential for obtaining quick information regarding the chemical composition of the root and tuber, such as starch, protein, dry matter, amylose, and soluble sugars, as well as physical characteristics such as textural properties and water binding capacity.
  • 821
  • 25 Apr 2023
Topic Review
Vibrational Biospectroscopy for Endometrial Cancer Diagnosis and Screening
Endometrial cancer (EC) is the sixth most common cancer and the fourth leading cause of death among women worldwide. Early detection and treatment are associated with a favourable prognosis and reduction in mortality. Unlike other common cancers, however, screening strategies lack the required sensitivity, specificity and accuracy to be successfully implemented in clinical practice and current diagnostic approaches are invasive, costly and time consuming. Such limitations highlight the unmet need to develop diagnostic and screening alternatives for EC, which should be accurate, rapid, minimally invasive and cost-effective. Vibrational spectroscopic techniques, Mid-Infrared Absorption Spectroscopy and Raman, exploit the atomic vibrational absorption induced by interaction of light and a biological sample, to generate a unique spectral response: a “biochemical fingerprint”. These are non-destructive techniques and, combined with multivariate statistical analysis, have been shown over the last decade to provide discrimination between cancerous and healthy samples, demonstrating a promising role in both cancer screening and diagnosis. 
  • 763
  • 18 May 2022
Topic Review
Infrared Spectroscopy in Quantification of Food Bioactive Compounds
Infrared spectroscopy (wavelengths ranging from 750–25,000 nm) offers a rapid means of assessing the chemical composition of a wide range of sample types, both for qualitative and quantitative analyses. Its use in the food industry has increased significantly and it is now an accepted analytical technique for the routine analysis of certain analytes. Furthermore, it is commonly used for routine screening and quality control purposes in numerous industry settings, albeit not typically for the analysis of bioactive compounds. 
  • 718
  • 06 May 2023
Topic Review
T-MIR Spectroscopy Applications in Coffee and Cocoa
Nowadays, coffee and cocoa have broad applications in the food and pharmaceutical industries due to their organoleptic and nutraceutical properties, which have turned them into products of great commercial demand. Consequently, these products are susceptible to fraud and adulteration, especially those sold at high prices, such as saffron, vanilla, and turmeric. This situation represents a major problem for industries and consumers’ health. Implementing analytical techniques, i.e., Fourier transform mid-infrared (FT-MIR) spectroscopy coupled with multivariate analysis, can ensure the authenticity and quality of these products since these provide unique information on food matrices.
  • 696
  • 01 Mar 2022
Topic Review
Isocyanoaminoanthracene
Isocyanoaminoarenes (ICAAr-s) are a novel and versatile group of solvatochromic fluorophores. Despite their versatile applicability, such as antifungals, cancer drugs and analytical probes, they still represent a mostly unchartered territory among intramolecular charge-transfer (ICT) dyes.
  • 688
  • 28 Feb 2022
Topic Review
CO Molecules Detection on Metal Surfaces
Detection of intermediates during the catalytic process by infrared techniques has been widely implemented for many important reactions. For the reduction of CO2 into hydrocarbons on metal surfaces, CO molecule is one of the most important transient species to be followed due to its involvement in several products’ pathways, and its distinct vibrational features. 
  • 684
  • 28 Jan 2022
Topic Review
Signal-Amplifying Substrates for Surface-Enhanced Raman Scattering-Based Bioassays
Surface-enhanced Raman spectroscopy (SERS) has become a powerful detection scheme for many applications, particularly bioassays, due to its unique strengths, such as its ultrasensitive performance. Due to the development of various SERS substrates, more SERS-based bioassays with improved sensitivity and reproducibility have been designed and manufactured. 
  • 616
  • 24 Aug 2023
Topic Review
Spectroscopy in Plant-Based Foods and Beverages
Near-infrared (NIR) spectroscopy and machine vision systems, such as hyperspectral imaging (HSI), are among the most successful technologies applied for the quality evaluation and safety inspection of several commodities.
  • 580
  • 28 Dec 2023
Topic Review
Raman Spectroscopy for Monitoring of Photopolymerization Systems
Raman spectroscopy provides the flexibility and resolution needed for in-situ and real-time monitoring of a wide variety of photopolymerization systems, as well as characterization of polymers resulting from these inherently fast and energy-efficient reactions.
  • 563
  • 27 Sep 2023
Topic Review Peer Reviewed
The Logarithmic Derivative in Scientific Data Analysis
The logarithmic derivative has been shown to be a useful tool for data analysis in applied sciences because of either simplifying mathematical procedures or enabling an improved understanding and visualization of structural relationships and dynamic processes. In particular, spatial and temporal variations in signal amplitudes can be described independently of their sign by one and the same compact quantity, the inverse logarithmic derivative. In the special case of a single exponential decay function, this quantity becomes directly identical to the decay time constant. When generalized, the logarithmic derivative enables local gradients of system parameters to be flexibly described by using exponential behavior as a meaningful reference. It can be applied to complex maps of data containing multiple superimposed and alternating ramping or decay functions. Selected examples of experimental and simulated data from time-resolved plasma spectroscopy, multiphoton excitation, and spectroscopy are analyzed in detail, together with reminiscences of early activities in the field. The results demonstrate the capability of the approach to extract specific information on physical processes. Further emerging applications are addressed.
  • 396
  • 14 Apr 2025
  • Page
  • of
  • 2
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback