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... A detector 4. Optical system of mirrors Schematics of a two-beam absorption spectrometer are shown in. Fig. ...
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... infrared radiation from the source by reflecting to a flat mirror passes through the sample and reference monochromator then through the sample. The beams are reflected on a rotating mirror, which alternates passing the sample and reference beams to the dispersing element and finally to detector to give the spectrum (see Fig 4). As the beams alternate the mirror rotates slowly and different frequencies of infrared radiation pass to detector. The modern spectrometers [7] came with the development of the high performance Fourier Transform Infrared Spectroscopy (FT-IR) with the application of a Michelson Interferometer [10]. Both IR spectrometers classical and modern give the same information the main difference is the use of Michelson interferometer, which allows all the frequencies to reach the detector at once and not one at the time/ In the 1870’s A.A. Michelson [11] was measuring light and its speed with great precision(3) and reported the speed of light with the greatest precision to be 299,940 km/s and for this he was awarded the Nobel Prize in 1907. However, even though the experiments in interferometry by Michelson and Morley [12] were performed in 1887 the interferograms obtained with this spectrometer were very complex and could not be analyzed at that time because the mathematical formulae of Jean Baptiste Fourier series in 1882 could not be solved [13]. We had to wait until the invention of Lasers and the high performance of electronic computers in order to solve the mathematical formulae of Fourier to transform a number of points into waves and finally into the spectra [14] The addition, of the lasers to the Michelson interferometer provided an accurate method (see Figs. 5A & 5B) of monitoring displacements of a moving mirror in the interferometer with a high performance computer, which allowed the complex interferogram to be analyzed and to be converted via Fourier transform to give ...
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Our primary interest in this book lies in the study of dynamical properties of reaction-diffusion equations perturbed by Lévy noise of intensity \(\varepsilon\) in the small noise limit \(\varepsilon \rightarrow 0\).
Introduction to the book.
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... As infrared spectrophotometry (IR) is a non-destructive technique, it is ideal for analysing the secondary structure of complex substances such as biological molecules, proteins, DNA, and membranes. In the last decade, IR has been employed in medical sciences to characterise healthy and unhealthy human tissues [19]. ...
This review focuses on monosodium glutamate which proclaims the fifth taste as “Umami”. Monosodium glutamate imparts a deep, meaty, umami flavour to foods. Asian cuisine frequently uses this flavouring, just as in the processed items produced across the United States and Europe. This article dealt with a detailed discussion of physicochemical features, pharmacological actions, and different reported analytical methodologies for the estimation of monosodium glutamate. Monosodium glutamate is analyzed using a variety of techniques, including spectroscopy, chromatography, electrochemistry, electrophoresis, chemometrics, flow injection analysis, and biosensors. According to results of comparative research of analytical methodologies, high performance liquid chromatography (HPLC) is most widely used method for analyzing monosodium glutamate which surpasses the gas chromatographic (GC) approach. All of the reported methods are accurate, precise, cost-effective, and sensitive. The European Union defined monosodium glutamate as a food additive that is permitted in some foods, but is subject to quantitative limits. Consequently, this study provides the analyst with an accessible path to quantifying monosodium glutamate's content for use in the food and pharmaceutical industries.
... Vol.: (0123456789) interaction between matter and electromagnetic radiation is studied and the resultant electromagnetic spectra yield useful information regarding the matter. The information related to the spectroscopic parameters for transitions between different energy levels in different molecules based on their interaction with radiations is necessary for deciphering and modelling the interaction of radiation (light) for different media (Theophanides 2012). HITRAN (High-Resolution Transmission) is a database compilation of different molecular spectroscopic parameters, generally used to analyse and simulate the transmission of optical rays through gaseous media and assessing planetary atmospheres and gases (HITRAN website: https:// hitran. ...
Environmental contamination especially air pollution is an exponentially growing menace requiring immediate attention, as it lingers on with the associated risks of health, economic and ecological crisis. The special focus of this study is on the advances in Air Quality (AQ) monitoring using modern sensors, integrated monitoring systems, remote sensing and the usage of Machine Learning (ML), Deep Learning (DL) algorithms, artificial neural networks, recent computational techniques, hybridizing techniques and different platforms available for AQ modelling. The modern world is data-driven, where critical decisions are taken based on the available and accessible data. Today’s data analytics is a consequence of the information explosion we have reached. The current research also tends to re-evaluate its scope with data analytics. The emergence of artificial intelligence and machine learning in the research scenario has radically changed the methodologies and approaches of modern research. The aim of this review is to assess the impact of data analytics such as ML/DL frameworks, data integration techniques, advanced statistical modelling, cloud computing platforms and constantly improving optimization algorithms on AQ research. The usage of remote sensing in AQ monitoring along with providing enormous datasets is constantly filling the spatial gaps of ground stations, as the long-term air pollutant dynamics is best captured by the panoramic view of satellites. Remote sensing coupled with the techniques of ML/DL has the most impact in shaping the modern trends in AQ research. Current standing of research in this field, emerging trends and future scope are also discussed.
... Nonlinear regression is also used in chemometrics with stepwise regression, ridge regression, elastic net, and LASSO regression among the more commonly used examples (37). These methods are helpful when there is multicollinearity present in the data (38 IR spectroscopy measures bond vibrations in molecules caused by a change in dipole at specific frequencies (39). Nearinfrared and mid-infrared are the two most commonly used IR spectroscopic techniques in the dairy sector. ...
Increasing consumer awareness, scale of manufacture, and demand to ensure safety, quality and sustainability have accelerated the need for rapid, reliable, and accurate analytical techniques for food products. Spectroscopy, coupled with Artificial Intelligence-enabled sensors and chemometric techniques, has led to the fusion of data sources for dairy analytical applications. This article provides an overview of the current spectroscopic technologies used in the dairy industry, with an introduction to data fusion and the associated methodologies used in spectroscopy-based data fusion. The relevance of data fusion in the dairy industry is considered, focusing on its potential to improve predictions for processing traits by chemometric techniques, such as principal component analysis (PCA), partial least squares regression (PLS), and other machine learning algorithms.
... FTIR spectra of ADA show the characteristic aldehyde peak at 1729 cm − 1 . The C-H band of aldehyde, which generally appears around 1390 cm − 1 is not seen in ADA spectra and may be hidden under the 1408 cm − 1 band of alginate [37]. The spectrum of gelatin shows the characteristic absorption bands of its protein structure, e.g., at 1630 cm − 1 , 1530 cm − 1 and 1240 cm − 1 are assigned to the N-H stretching vibration peaks for amide I, amide II, and amide III, respectively. ...
Research on bio-active materials of natural origin and their applications in medicine is of great interest lately. Many hydrogel systems have been developed by incorporating phenolic phytochemicals into polymers. Ferulic acid (FA) is a dietary phenolic compound known for its wound healing activity due to its anti-oxidant and anti-microbial properties. In this work, a FA incorporated hydrogel was prepared from self-crosslinking alginate dialdehyde (ADA) and gelatin (G) and evaluated for its anti-microbial properties and wound healing activity in-vitro. FTIR spectroscopy revealed that FA forms hydrogen bonds with amino groups of gelatin through its hydroxyl group in ADAGFA hydrogel. FA incorporation imparted anti-microbial activity to the hydrogel. The properties of the hydrogel such as water absorption (345 ± 20%), water vapor transmission rate (1170 ± 78 g/m²/day), mechanical properties (52.80 ± 6.02 MPa (dry film)), and the anti-microbial activity indicated that the FA incorporated hydrogel film has characteristics appropriate for moderately exudating wounds. In vitro scratch wound assay gives evidence that the FA released from ADAGFA enhanced the migration rate of the human dermal fibroblast cells. The ADAGFA also promotes collagen deposition from fibroblast cells which is additional evidence of the suitability of the material as a wound care biomaterial.
... We decided to try to use IR spectroscopy to solve this problem. IR spectroscopy is a technology used to identify substances [3,14,16] and, according to our opinion, it will be possible to use it to identify the braking trace at the scene of a road accident. Preliminary studies have been performed. ...
Detailed analysis of literature showed that there is no method that can be used in order to investigate skid marks left by vehicles equipped with ABS. Authors decided to identify braking trace by using IR spectroscopy. Preliminary studies have been performed and results were promising. Due to that fact authors decided to conduct detailed research where the influence of various factors on the possibility of revealing breaking traces would be taken into account. This article is the first in a series of articles taking into account the influence of various factors on the possibility of revealing breaking marks using IR spectroscopy. In this article the influence of the type of asphalt was studied. Authors conducted tests with the most popular types of asphalts used for the wearing course. 100 samples from 5 different types of asphalt were prepared. Each sample was measured 3 times to create its spectrum. The results were analyzed thoroughly using the dedicated SpectraGryph software. The analysis showed that for 4 out of 5 types of tested asphalt, the braking traces were visible at a wavelength of approximately 11 500 nm. Only for the rubberized asphalt there weren't possibility to reveal skid mark.
... Chemical bonds may form between particle surfaces as van der Waals forces, which are always present. Additionally, the magnetic dipole forces can potentially participate in internal particle forces [46] [47]. The average grain size for all seven samples under investigation is in the (22.87-29.05nm) ...
Doping magnesium oxide nanoparticles (MgO-NPs) forms a good material for magnetisation applications. The Room Temperature Ferromagnetic (RTFM) of Pb ²⁺ -doped ions MgO-NPs synthesised by a modified Pechini method are discussed in the present paper. The structural, morphological and magnetic properties of the samples were characterised by X-ray diffraction (XRD), Field Emission scanning electron microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS) and vibrating sample magnetometer (VSM).
The XRD results showed that the synthesised materials have a single set of peaks in the XRD patterns, corresponding to the cubic phase of MgO-NPs. As the Pb content increased in the host MgO-NPs leading to an increase in the lattice parameter, the interplanar spacing and the crystallite size; however, the intensity decreased.
Small spherical nanoparticles (22.87–29.05nm) were observed in the Pb ²⁺ -doped ions MgO samples by (FE-SEM). The purity of the samples was confirmed using EDS spectroscopy.
The pure MgO and doped samples exhibiting RTFM may be attributed to vacancy defects, which caused local magnetisation. The saturation magnetism (Ms) was found to be varied as a function of doping concentration. The maximum (Ms) was found at x=0.015 of Mg 0.985 Pb 0.015 O sample. The obtained results suggest that both Pb doping and oxygen vacancies play an important role in the development of room-temperature ferromagnetism.
... IRS is an analytical technique for the characterization of a wide range of materials and is commonly used in research and production for quality control purposes (Theophanides 2012). This technique involves the interaction between infrared radiation (IR) and matter and is mostly used to identify and quantify various organic compounds present in a material, via their selective IR absorption. ...
... The history of IRS dates back to the 19 th century, and the first spectrometer was built in 1835. By the beginning of the 20 th century, IRS had become a valuable tool for identifying and characterizing chemical compounds and materials (Theophanides 2012). Thereafter, it was applied to more complicated molecules such as proteins (Elliot and Ambrose 1950) and later, DNA (Colthup et al. 1990). ...
Near-infrared spectroscopy (NIRS) is a suitable technique for characterizing many materials, including wood, and has been used to predict several wood properties. However, existing reports on this use of NIRS have paid little attention to the effect of wood surface condition and grain orientation. This study therefore used NIRS to assess wood density, modulus of elasticity, modulus of rupture, grain angle, and annual ring width, studying whether and how surface condition and grain orientation affected the measurement of these properties.
The research focused on using NIRS coupled with partial least squares regression (PLS-R) to predict the properties of two softwoods (Western hemlock and Douglas-fir). PLS-R models were calibrated and validated using the test-set validation method. The predictive accuracies based on grain orientation (quarter-sawn and flat-sawn) and wood surface condition (rough and smooth) were compared. Models developed using reduced wavelengths also showed the possibility of predicting these properties using a narrow spectral range.
The results of this study showed that calibrations based on mixed sets, which included both cross-sections, were inferior to those based on these cross-sections separately. Promising predictive models were obtained for density (Rp2 = 0.66), modulus of elasticity (Rp2 = 0.78), and modulus of rupture (Rp2 = 0.82), with poor correlations for grain angle and annual ring width (Rp2 ≤ 0.50). Further, the rough surface predictions outperformed those from the smooth surface for all properties. The quarter-sawn sections also showed better predictive ability than the flat-sawn sections for both surface conditions. The only exception was for modulus of rupture, where the trend was reversed. The results therefore show the potential for using NIRS as a non-destructive technique to predict the properties of wood.
... The first series of research was aimed at comparing samples of clean asphalt with asphalt with skid mark. In this study IR spectroscopy was used as a method of identifying substances [3,19]. Corresponding results were compared to create differential spectra. ...
This paper presents the possible use for IR spectroscopy to reveal skid marks left by cars equipped with Anti-lock Braking System. Detailed analysis of literature showed that there is no method that can be used in order to investigate this kind of tire marks. Up till now only two techniques have been devised. The first one is Method of Image Refinement which consists of transforming the image from the scene of the accident using dedicated graphics software. Second method includes analysis of traces using a thermal imaging camera. This study presents an innovative approach to the problem. Numerous analyses using IR spectroscopy were conducted to check the suitability of this method. The research was conducted on a Thermo Scientific FTIR Nicolet iS50 Spectrophotometer with an ATR attachment. 40 samples from 10 different types of asphalt were prepared. Each sample was measured 3 times to create its spectrum. The results were analyzed thoroughly using the dedicated SpectraGryph software. The analysis show that the wavelength which makes the braking marks visible is found within the mid-infrared range. Finally, the wavelength in which skid marks should be visible was found. This range is located in the mid-infrared.
... A possibilidade de captar essa radiaçãoé o princípio de funcionamento dos detectores de infravermelho, amplamente empregados nasáreas militares e de segurança, bem como,é a ferramenta de sobrevivência de alguns animais com atividades noturnas[6].A espectroscopia de NIRé o estudo da interação de ondas eletromagnéticas, na faixa do infravermelho próximo, com a matéria. Técnicas espectroscópicas baseadas na interação entre luz e matéria têm sido utilizadas para estudar materiais in vivo, ex vivo ou in vitro[10]. O funcionamento básico de um espectroscópio, consiste em passar um feixe de luz através de uma solução/amostra e medir a quantidade de energia radiante que foi absorvida ou refletida. O feixe de luz infravermelha produzido pela fonteé dividido em dois, sendo que um passa pela amostra a ser analisada e o outro por uma amostra de referência. ...
... A radiação incidente sobre a amostra terá uma parcela absorvida e o restante será refletido sobre uma grade de difração que os direcionará sobre o detector, fazendo com que os sinais sejam convertidos para o formato digital, possibilitando o processamento por sistemas computacionais. Os espectros resultantes fornecem um conjunto de característica que compõe uma assinaturaúnica com importantes informações bioquímicas da amostra[6],[10]. A Figura 2 ilustra o esquema de funcionamento básico de um espectrômetro.Figura 2: Representação básica do espectrômetro.4 ...
The identification of a species of tree becomes complex when it has available only your wood, which requires further analysis for their characterization. Using near infrared spectrometry is possible to obtain spectra with unique informations about the chemical composition of a sample timber. However, the interpretation of data obtained by the spectrometer is complex, making it difficult to identify characteristics specific to a particular species. In this paper, in order to speed up the identification process, we used a system based in Artificial Neural Networks for classification of four species of trees by analyzing the spectra of their timber. Three tests were performed to demonstrate the efficiency of recognition capability, the results obtained were encouraging since the neural net has proved to be flexible to noise and distortions, without requiring that the spectra were submit to prior statistical treatment or that were separated by groups relative to types of timber cut.
