chemical measurements
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2021 ◽  
Vol 19 (11) ◽  
pp. 84-94
Author(s):  
Aymen Abdul Rasool Jawad ◽  
Dr. Nagham Mahmood Aljamali

The last decades of this century witnessed a wide interest in three heterogeneous compounds, especially nitrogen atoms, which were represented by triazole rings and their derivatives, whose effects were studied in the widest medical and pharmaceutical journals and as anti-cancer agents and other groups that are characterized by the presence of electronic pairs, which have given greater importance for this reason. In order to increase the effectiveness of any compound, it must include in its composition active groups, donor groups, or electron pairs, and this has been proven by researchers in biochemistry, coordination research, reagent chemistry, reagents, analytical chemistry, estimation of elements and ions in river water and environmental models. Extensive studies have been conducted for the reagents under study to determine their chemical structures through microscopic technical examinations, spectroscopic techniques (Uv-Vis, FT.IR, H.NMR, Mass)–spectra, also Analytical studies like: {Thermal study, TLC–Technique, Scanning Electron Microscopy (FESEM)} and other physico-chemical measurements.


2021 ◽  
Vol 15 ◽  
Author(s):  
Nicholas LeBow ◽  
Bodo Rueckauer ◽  
Pengfei Sun ◽  
Meritxell Rovira ◽  
Cecilia Jiménez-Jorquera ◽  
...  

Liquid analysis is key to track conformity with the strict process quality standards of sectors like food, beverage, and chemical manufacturing. In order to analyse product qualities online and at the very point of interest, automated monitoring systems must satisfy strong requirements in terms of miniaturization, energy autonomy, and real time operation. Toward this goal, we present the first implementation of artificial taste running on neuromorphic hardware for continuous edge monitoring applications. We used a solid-state electrochemical microsensor array to acquire multivariate, time-varying chemical measurements, employed temporal filtering to enhance sensor readout dynamics, and deployed a rate-based, deep convolutional spiking neural network to efficiently fuse the electrochemical sensor data. To evaluate performance we created MicroBeTa (Microsensor Beverage Tasting), a new dataset for beverage classification incorporating 7 h of temporal recordings performed over 3 days, including sensor drifts and sensor replacements. Our implementation of artificial taste is 15× more energy efficient on inference tasks than similar convolutional architectures running on other commercial, low power edge-AI inference devices, achieving over 178× lower latencies than the sampling period of the sensor readout, and high accuracy (97%) on a single Intel Loihi neuromorphic research processor included in a USB stick form factor.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abd El-Aziz S. Fouda ◽  
Abdelmonem H. El-Askalany ◽  
Ahmed F. S. Molouk ◽  
Niveen S. Elsheikh ◽  
Ashraf S. Abousalem

AbstractThe present work aims to study 6-amino-4-aryl-2-oxo-1-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives namely: 6-Amino-2-oxo-1,4-diphenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-H), 6-Amino-2-oxo-1-phenyl-4-(p-tolyl)-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-Me) and 6-Amino-4-(4-hydroxyphenyl)-2-oxo-1-phenyl-1,2-dihydropyridine-3,5-dicarbonitrile (PdC-OH) as corrosion inhibitors to provide protection for carbon steel in a molar hydrochloric acid medium. Chemical measurements such as (weight loss) and electrochemical techniques such as (Potentiodynamic polarization, electrochemical impedance spectroscopy, and Electron frequency modulation) were applied to characterize the inhibitory properties of the synthesized derivatives. The adsorption of these derivatives on the carbon steel surface was confirmed by Attenuated Total Refraction Infrared (ATR-IR), Atomic Force Microscope (AFM), and X-ray Photoelectron Spectroscopy (XPS). Our findings revealed that the tested derivatives have corrosion inhibition power, which increased significantly from 75.7 to 91.67% on the addition of KI (PdC-OH:KI = 1:1) to inhibited test solution with PdC-OH derivative at 25 °C. The adsorption process on the metal surface follows the Langmuir adsorption model. XPS analysis showed that the inhibitor layer consists of an iron oxide/hydroxide mixture in which the inhibitor molecules are incorporated. Computational chemical theories such as DFT calculations and Mont Carlo simulation have been performed to correlate the molecular properties of the investigated inhibitors with experimental efficiency. The theoretical speculation by Dmol3 corroborates with the results from the experimental findings.


2021 ◽  
Vol 17 (3) ◽  
pp. 45-61
Author(s):  
E. V. Shabanova ◽  
I. E. Vasil’eva ◽  
D. S. Tausenev ◽  
S. Scherbarth ◽  
U. Pierau

Four multielement reference materials compile the «Plants» cluster in the developed by IGC SB RAS collection. These are part of terrestrial plants (birch leaf, pine needles, mown meadow grass) and the aquatic plant Elodea canadensis (roots, stems, leaves and flowers). Plants that are sensitive indicators of the state of the environment are collected from unpolluted territories of Eastern Siberia (near and on Lake Baikal). The paper discusses differences in methods of selection and preparation of the material. Such features of these reference materials as granulometric composition (shape, size, particle size distribution), homogeneity and minimum representative mass of the sample, stability ofpowders under conditions of natural aging were studied in accordance with Russian and international requirements with the use of modern devices and methods of chemical analysis. The elemental compositions of matrix plant samples were evaluated according to the method of interlaboratory certification and are represented by the contents of more than 60 elements, of which 23 to 41 are certified. The participation of 20 to 38 accredited Russian and foreign laboratories and the use of more than ten different methods of analysis ensured the traceability of the results. The comparison of the developed and Chinese certified matrix plant reference samples demonstrated their consistency. Based on the results of the discussion of the characteristic properties offour plant PM, they are recommended for performing chemical measurements during the validation of existing and development of new analytical methods, quality control and evaluation of the traceability of the results of determining a wide range of elements in plant materials, as well as professional testing of laboratories of geo-ecological, pharmaceutical and agricultural organisations.


2021 ◽  
Vol 93 (36) ◽  
pp. 12147-12155
Author(s):  
Richard J. C. Brown ◽  
Paul J. Brewer ◽  
Axel Pramann ◽  
Olaf Rienitz ◽  
Bernd Güttler

2021 ◽  
Vol 17 (2) ◽  
pp. 33-47
Author(s):  
I. E. Vasil’eva ◽  
E. V. Shabanova

The population needs reliable information on the chemical composition of plants and products made from them in order to preserve the environment and its safety. With the increase in cross-border trade, there is a growing demand for traceable results of determining the content of chemical elements in plants and not only proteins, fats, carbohydrates, pesticides, moisture, vitamins, etc., which can affect the quality of human life. An urgent but difficult analytical task is to obtain reliable measurements of the elemental composition of agricultural and wild plants and various products made from them. Reference materials (RMs) are a widely recognized tool for ensuring the uniformity of chemical measurements. They are designed for certification (validation) of existing and new methods (techniques) of chemical analysis, certification studies in the development of reference materials, and professional testing of laboratories. The article lists the reputable manufacturers of plant RMs in which the content of chemical elements is certified. The ratio of certified, reference, and quality control samples of plant-matrix has been assessed. The classification of certified reference materials according to the type of plant material used for their food application is provided. The contribution of different countries to the development of plant CRMs is hown. The selection of plants for the development of new RMs is discussed from two points of view, namely food composition databases (AOAC INTERNATIONAL) and the ‘Reference Plant’ chemical fingerprinting (B. Markert). Based on the consolidation of studies devoted to the development and appliance of plant-matrix reference materials, a list of the most important requirements has been compiled for reference materials that ensure the reliability and comparability of the results of chemical analysis in the fields of biology, geochemistry, ecology, agriculture, medicine, and interdisciplinary research.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2664
Author(s):  
Isabella Lancellotti ◽  
Federica Piccolo ◽  
Hoang Nguyen ◽  
Mohammad Mastali ◽  
Mohammad Alzeer ◽  
...  

Alternative cementitious binders, based on industrial side streams, characterized by a low carbon footprint, are profitably proposed to partially replace Portland cement. Among these alternatives, alkali-activated materials have attracted attention as a promising cementitious binder. In this paper, the chemical stability of the matrix, in fiber-reinforced slag-based alkali-activated composites, was studied, in order to assess any possible effect of the presence of the reinforcement on the chemistry of polycondensation. For this purpose, organic fiber, cellulose, and an inorganic fiber, basalt, were chosen, showing a different behavior in the alkaline media that was used to activate the slag fine powders. The novelty of the paper is the study of consolidation by means of chemical measurements, more than from the mechanical point of view. The evaluation of the chemical behavior of the starting slag in NaOH, indeed, was preparatory to the understanding of the consolidation degree in the alkali-activated composites. The reactivity of alkali-activated composites was studied in water (integrity test, normed leaching test, pH and ionic conductivity), and acids (leaching in acetic acid and HCl attack). The presence of fibers does not favor nor hinder the geopolymerization process, even if an increase in the ionic conductivity in samples containing fibers leads to the hypothesis that samples with fibers are less consolidated, or that fiber dissolution contributes to the conductivity values. The amorphous fraction was enriched in silicon after HCl attack, but the structure was not completely dissolved, and the presence of an amorphous phase is confirmed (C–S–H gel). Basalt fibers partly dissolved in the alkaline environment, leading to the formation of a C–N–A–S–H gel surrounding the fibers. In contrast, cellulose fiber remained stable in both acidic and alkaline conditions.


2021 ◽  
Vol 14 (5) ◽  
pp. 3631-3655
Author(s):  
Hongyu Guo ◽  
Pedro Campuzano-Jost ◽  
Benjamin A. Nault ◽  
Douglas A. Day ◽  
Jason C. Schroder ◽  
...  

Abstract. Aerosol intercomparisons are inherently complex as they convolve instrument-dependent detection efficiencies vs. size (which often change with pressure, temperature, or humidity) and variations in the sampled aerosol population, in addition to differences in chemical detection principles (e.g., inorganic-only nitrate vs. inorganic plus organic nitrate for two instruments). The NASA Atmospheric Tomography Mission (ATom) spanned four separate aircraft deployments which sampled the remote marine troposphere from 86∘ S to 82∘ N over different seasons with a wide range of aerosol concentrations and compositions. Aerosols were quantified with a set of carefully characterized and calibrated instruments, some based on particle sizing and some on composition measurements. This study aims to provide a critical evaluation of inlet transmissions impacting aerosol intercomparisons, and of aerosol quantification during ATom, with a focus on the aerosol mass spectrometer (AMS). The volume determined from physical sizing instruments (aerosol microphysical properties, AMP, 2.7 nm to 4.8 µm optical diameter) is compared in detail with that derived from the chemical measurements of the AMS and the single particle soot photometer (SP2). Special attention was paid to characterize the upper end of the AMS size-dependent transmission with in-field calibrations, which we show to be critical for accurate comparisons across instruments with inevitably different size cuts. Observed differences between campaigns emphasize the importance of characterizing AMS transmission for each instrument and field study for meaningful interpretation of instrument comparisons. Good agreement (regression slope =0.949 and 1.083 for ATom-1 and ATom-2, respectively; SD =0.003) was found between the composition-based volume (including AMS-quantified sea salt) and that derived from AMP after applying the AMS inlet transmission. The AMS captured, on average, 95±15 % of the standard PM1 volume (referred to as the URG Corp. standard cut 1 µm cyclone operated at its nominal efficiency). These results support the absence of significant unknown biases and the appropriateness of the accuracy estimates for AMS total mass and volume for the mostly aged air masses encountered in ATom. The particle size ranges (and their altitude dependence) that are sampled by the AMS and complementary composition instruments (such as soluble acidic gases and aerosol, SAGA, and particle analysis by laser mass spectrometry, PALMS) are investigated to inform their use in future studies.


2021 ◽  
Vol 252 ◽  
pp. 118338
Author(s):  
Atinderpal Singh ◽  
Neeraj Rastogi ◽  
Varun Kumar ◽  
Jay G. Slowik ◽  
R. Satish ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 457
Author(s):  
Piotr Fabijańczyk ◽  
Jarosław Zawadzki

The purpose of this study was to use fast geophysical measurements of soil magnetic susceptibility (κ) as supplementary data for chemical measurements of selected light rare earth elements (REEs) in soil. In order to ensure diversity in soil conditions, anthropogenic conditions and types of land use, seven areas were selected, all located in regions subjected to past or present industrial pollution. Magnetometric parameters were measured using a selected magnetic sensor that was specially designed for measurements of soil cores and were used to classify collected soil cores into six distinctive types. The analysis of REEs concentrations in soil was carried out taking into account the grouping of collected soil samples based on the type of study area (open, forested and mountain), and additionally on the measured magnetometric parameters of collected soil cores. A use of magnetometric measurements provided different, but complementary to chemical measurements information, which allowed to obtain deeper insight on REEs concentrations in soils in studied areas.


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