A reference installation based on thermo-gravimetric analysis with mass-spectrometric detection as a part of the state primary standard GET 173

2018 ◽  
Vol 84 (6) ◽  
pp. 63-70 ◽  
Author(s):  
M. Yu. Medvedevskikh ◽  
M. P. Krasheninina ◽  
A. S. Sergeeva ◽  
O. S. Shokhina
Keyword(s):  
Mass Fraction ◽  
Water Mass ◽  
Primary Standard ◽  
Thermo Gravimetric Analysis ◽  
The State ◽  
State Primary Standard ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Reference Installation

The issue of assuring the traceability of the results of water determination in solid and liquid substances and materials is discussed. The stages of development and improvement, as well as composition of the State primary measurement standard of mass fraction and mass (molar) concentration of water in liquid and solid substances and materials (GET 173) are considered. The problems of the limited applicability of GET 173 in case of separation of water with different binding energies and impossibility of conducting qualitative analysis of non-water volatile compounds during heating of substances and materials are revealed. The results regarding upgrading of GET 173 due to incorporation of additional reference installation which implements the methods of thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and mass-spectrometry (MS) are presented. The composition and operating principle of the new reference unit are described. An algorithm for estimating the uncertainty of reproducing a unit mass fraction of water using this reference facility is presented and sources of the uncertainty are identified. The results of the experiment on determination of the lower limit of the reproduction range for a unit water mass fraction are presented. We also present the results of comparisons regarding determination of the water mass fraction in crystalline hydrates obtained using the improved State primary standard and high-precision installations of the metrological and leading sectorial research institutes of the European countries. The results of developing a certified reference material of water mass fraction in sodium molybdate dihydrate (Na2MoO4· 2H2O CRM UNIIM 10911–2017 intended for metrological support of measurement instruments and measurement procedures based on thermo-gravimetric method are presented. Additional possibilities which result from the introduction of a new reference installation into the state primary standard of GET 173 are disclosed: identification and the quantification of non-water volatile components, adjustment of drying regimes both in laboratory and process conditions, determination of water content as one of the main impurities in estimating mass fraction of the main component of high-purity substances.

Synthesis and Evaluation Methacrylate-Based Monolithic Materials Mixed with Carbon Nanotubes

2014 ◽  
Vol 900 ◽  
pp. 378-381
Author(s):  
Rui Feng
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
Thermo Gravimetric Analysis ◽  
Reversed Phase ◽  
Gravimetric Analysis ◽  
Reversed Phase Liquid Chromatography ◽  
Hydrophobic Properties ◽  
Thermo Gravimetric ◽  
Mercury Intrusion ◽  
Phase Liquid

An effective approach to synthesize methacrylate-based hybrid monoliths was carried out by photopolymerization and the properties of the obtained monoliths mixed with mult-wall carbon nanotube (MWNT) were studied in this paper. The prepared hybrid materials with MWNT in the range of 0-5% total weight of monomers were characterized by Fourier transform infrared spectra, thermo-gravimetric analysis (TGA), and mercury intrusion porosimetry, respectively. Moreover, their porosities were evaluated by the determination of flow rate for different prepared monolithic capillaries. The results showed that the monoliths with more MWNT (1-5%) possessed larger pore sizes between 1-10 μm. The hybrid monoliths have the potential advantages including stronger hydrophobic properties and less resistance for the application of reversed phase liquid chromatography in the micro-column separation.

Determination of Composition of Cellulose and Lignin Mixtures Using Thermo Gravimetric Analysis (TGA)

2007 ◽  
Author(s):  
Kaushlendra Singh ◽  
Mark Risse ◽  
K. C. Das ◽  
John Worley
Keyword(s):  
Lignin Content ◽  
Preliminary Investigation ◽  
Linear Equations ◽  
Thermo Gravimetric Analysis ◽  
Rate Of Change ◽  
Unit Weight ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Bio Oil

The proportional composition of cellulose, hemicellulose, lignin and minerals in a biomass plays a significant role in the proportion of pyrolysis products (bio-oil, char, and gases). Traditionally, the composition of biomass is chemically determined, which is a time consuming process. This paper presents the results of a preliminary investigation of a method using thermo-gravimetric analysis for predicting the fraction of cellulose and lignin in lignin-cellulose mixtures. The concept is based on a newly developed theory of Pyrolytic Unit Thermographs (PUT). The Pyrolytic Unit Thermograph (PUT) is a thermograph showing rate of change of biomass weight with respect to temperature for a unit weight loss. These PUTs were used as input for two predictive mathematical procedures that minimize noise to predict the fractional composition in unknown lignin-cellulose mixtures. The first model used linear correlations between cellulose/lignin content and peak decomposition rate while the second method used a system of linear equations. Results showed that both models predicted the composition of lignin-cellulose mixture within 7 to 18% of measured value. The promising results of this preliminary study will certainly motivate further refinement of this method through advanced research.

Research on expanding the range of reproduction of magnetic flux density of the DC field of the state primary standard GET12-2011

2020 ◽  
pp. 3-7
Author(s):  
Vladlen Ya. Shifrin ◽  
Denis I. Belyakov ◽  
Alexander E. Shilov ◽  
Denis D. Kosenko
Keyword(s):  
Magnetic Flux ◽  
Magnetic Induction ◽  
Frequency Conversion ◽  
Magnetic Measurements ◽  
Primary Standard ◽  
Uncertainty Budget ◽  
The State ◽  
State Primary Standard ◽  
Magnetic Flux Density ◽  
Constant Field

The results of works aimed at increasing the level of uniformity of measurements of the magnetic induction of a constant field – the basic value in the field of magnetic measurements. A set of equipment for reproducing a unit of magnetic induction of a constant field in the range of 1–25 mT was created and described. The inclusion of this complex in the State primary standard of units of magnetic induction, magnetic flux, magnetic moment and magnetic induction gradient GET 12-2011 will ensure the reproduction and direct transmission of the unit of permanent magnetic induction in the ranges of not only weak (10–3–1 mT), but medium (1–25 mT) and strong (0.025–1 T) magnetic fields. A quantum cesium magnetometer based on the resolved structure of cesium atoms was created to transmit the unit of magnetic induction to the region of medium fields. The procedure for calculating the frequency conversion coefficients to magnetic induction of the created quantum cesium magnetometer is described. The uncertainty budget for reproducing a unit of magnetic induction of a constant field using the created complex is estimated.

Coordination Compounds of Some 3d-Transition Metal Ions with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)- thiosemicarbazide

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu
Keyword(s):  
Coordination Compounds ◽  
Magnetic Moments ◽  
Thermo Gravimetric Analysis ◽  
Electronic Spectroscopy ◽  
Transition Metal Ions ◽  
Synthesis And Characterization ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
New Compounds

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.

scholarly journals Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  
Keyword(s):  
Food Packaging ◽  
Thermo Gravimetric Analysis ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Total Phenolic ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Phenolic And Flavonoid ◽  
Thermal Stability Of

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

The state primary standard for the unit of mean laser power

2007 ◽  
Vol 50 (7) ◽  
pp. 695-699 ◽  
Author(s):  
V. S. Ivanov ◽  
A. F. Kotyuk ◽  
A. A. Liberman ◽  
S. A. Moskalyuk ◽  
M. V. Ulanovskii
Keyword(s):  
Laser Power ◽  
Primary Standard ◽  
The State ◽  
State Primary Standard
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