Structure and chemical composition of exopolysaccharides of frost-damaged sugar beet

2020 ◽  
pp. 34-39
Author(s):  
Aneta Antczak-Chrobot ◽  
Maciej Wojtczak

In this research paper, development of a procedure of isolation of exopolysaccharides from frost-damaged beet and an analysis of structural and chemical composition of polymers isolated from sugar beet of different origin are presented. Total acid hydrolysis degradation integrated with HPAEC-ED analysis has been utilized to confirm the monomeric composition of the separated polysaccharides. The implementation of NMR spectral analysis and SEC chromatography of the structure of exopolysaccharides has been investigated. The results demonstrate that the chemical composition and structure of exopolysaccharides depend on their origin. Typical exopolysaccharides from Central European beet roots consist mainly of glucose monomers – and they have low branched structure – about 90% of α-1,6 linkage which is typical for dextran. The exopolysaccharides isolated from Swedish beet are characterized by 50–60% fructose monomers. They contain only about 65% α-1,6 linkages. Exopolysaccharides extracted from various origin beet differ in average molecular mass. The molecular distribution is not normal.

2016 ◽  
Vol 10 (4s) ◽  
pp. 595-600 ◽  
Author(s):  
Witold Brostow ◽  
◽  
Haley E. Hagg Lobland ◽  

The property of brittleness for polymers and polymer-based materials (PBMs) is an important factor in determining the potential uses of a material. Brittleness of polymers may also impact the ease and modes of polymer processing, thereby affecting economy of production. Brittleness of PBMs can be correlated with certain other properties and features of polymers; to name a few, connections to free volume, impact strength, and scratch recovery have been explored. A common thread among all such properties is their relationship to chemical composition and morphology. Through a survey of existing literature on polymer brittleness specifically combined with relevant reports that connect additional materials and properties to that of brittleness, it is possible to identify chemical features of PBMs that are connected with observable brittle behavior. Relations so identified between chemical composition and structure of PBMs and brittleness are described herein, advancing knowledge and improving the capacity to design new and to choose among existing polymers in order to obtain materials with particular property profiles.


2019 ◽  
Vol 85 (2) ◽  
pp. 17-22
Author(s):  
M. I. Khamdeev ◽  
E. A. Erin

Physical parameters of electric arc plasma as well as their time dependences are calculated when analyzing phosphate precipitates of the fission products of irradiated nuclear fuel. Phosphate concentrates of the fission products are known for their complex chemical composition and high thermal and chemical stability. Hence, direct atomic emission spectral analysis of phosphate powders without transferring them into solutions is advisable. Different conditions of sample preparation and synthesis of the reference materials determine the different chemical forms of the elements to be determined. This, in turn, affects the kinetics of their evaporation in the electrode crate and excitation processes in the plasma. The known mechanisms of those processes cannot always be transferred to specific conditions of the given method of analysis thus entailing the necessity of studying the effect of the samples chemical composition on the results of determination, proper choice of spectroscopic carriers, detailed study of spectra excitation processes in spectral analysis, and analysis of the physical parameters of the electric arc plasma. We used the lines Zn I 307.206 nm and Zn I 307.589 nm to measure the effective temperature of the central hot sections of the arc in a range of4500 - 6500 K. NaCl, BaCl2 and NaCl + T1C1 were studied to reduce the effect of the sample elemental composition on excitation conditions of the spectra and their stabilization as a spectroscopic carrier. In control experiments we used carrier-free samples. The coincidence of the values of the plasma physical parameters within the measurement error not exceeding 20%, as well as the identity of the nature of the kinetic curves for samples of phosphate precipitates and synthetic reference materials prove their correctness. The result of the study substantiate correctness of the direct atomic-emission spectral procedure in analysis of phosphate concentrates of fission when using synthetic reference materials.


Sugar Tech ◽  
2021 ◽  
Author(s):  
Arkadiusz Artyszak ◽  
Małgorzata Kondracka ◽  
Dariusz Gozdowski ◽  
Alicja Siuda ◽  
Magda Litwińczuk-Bis

AbstractThe effect of marine calcite, a mixture of ortho- and polysilicic acid as well as orthosilicic acid applied as a foliar spray on the chemical composition of sugar beet leaves in the critical phase of nutrient supply (beginning of July) but also leaves and roots during harvest time in 2015–2016, was studied. The content of silicon in the leaves ranged from 1.24 to 2.36 g kg−1 d.m. at the beginning of July, 3.85–5.34 g kg−1 d.m. during harvest and 2.91–4.20 g kg−1 d.m. in the roots. The foliar application of silicon caused a significant increase in the content of magnesium and calcium in leaves (in July) as compared to the control. The sugar beet consumes approx. 75 kg Si ha−1, which is almost 3.5 times more than P and 20% more than Mg thus proving its importance for its species. About 70% of the silicon taken up by sugar beet is stored in roots and 30% in leaves. The pure sugar yield is most favorably influenced by two- and threefold foliar application of the product containing silicon in the form of orthosilicic acid stabilized with choline, and a threefold mixture of ortho- and polysilicic acid. The increase in the pure sugar yield is not the result of a change in the chemical composition of sugar beet plants, but their more efficient functioning after foliar application of silicon under stress conditions caused by water shortage.


2021 ◽  
pp. 51-56
Author(s):  
Yu. B. Sazonov ◽  
D. Yu. Ozherelkov ◽  
R. Sh. Latypov ◽  
E. E. Gorshkov

Possibility of determination of the fragments and articles made of different grades of steel aluminium and copper alloys and their affiliation to the common melt was examined via the methods of photoelectric spectral analysis based on composition of micro-impurities. Chemical elements with micro-impurities were revealed; they allow to determine affiliation of metal fragments to one melt. Ultimately possible deviations of micro-impurities within one melt were obtained. The technique allowing to establish affiliation of fragments to the common melt based on their elementary composition of micro-impurities with minimal amount of measurements was suggested based on the obtained results. The minimal geometric size of a sample available for analysis was determined; it allows to classify the examined fragments to one melt based on the results of investigation of expanded elementary composition of micro-impurities. Practical opportunities of this technique were displayed on the example of the alloys with different chemical composition.


2003 ◽  
Vol 107 (3) ◽  
pp. 678-684 ◽  
Author(s):  
Onno L. J. Gijzeman ◽  
Ad J. M. Mens ◽  
Joop H. van Lenthe ◽  
Wifried J. Mortier ◽  
Bert M. Weckhuysen

2000 ◽  
Vol 95 ◽  
pp. 207-217 ◽  
Author(s):  
Helen Mangou ◽  
Panayiotis V. Ioannou

Seven bun type, one slab type, and 44 oxhide type Late Bronze Age ingots found in the Aegean region, Crete and Mainland Greece have been analysed for their chemical content (twelve elements) by atomic absorption spectroscopy. The results show that the ingots contain variable amounts of oxygen as copper(I) oxide. The oxhide ingots are made of purer copper, the bun type are of relatively pure copper and bronze, while the slab type is bronze. The oxhide ingots from Crete may have a different origin from those found in the Aegean and in Mainland Greece because they have a different chemical composition. The metallographic examination of twenty ingots, three of bun and seventeen of oxhide type, revealed that they have been cast in open moulds, followed by slow cooling. Microanalyses of inclusions in fifteen ingots revealed the presence of copper(I) sulphide, copper(I) oxide, copper-iron and copper-iron-sulphur and their origin is discussed. Hardness measurements on fourteen ingots of various types revealed that they are somewhat harder for a cast object than control alloys and likely explanations are given.


2011 ◽  
Vol 347-353 ◽  
pp. 2656-2660
Author(s):  
Xiu Chen ◽  
Yin Nan Yuan ◽  
Yong Bin Lai

Thermogravimetry (TG) has been employed to yield information on the thermal volatilization of the fuels since the volatility influences the ignition quality of the fuels in a compression ignition engine. The chemical composition of -10 petrodiesel (-10PD) and waste oil biodiesel (WME) was analyzed by gas chromatography-mass spectrometry. The thermal volatilization of biodiesel and its blends was investigated by TG and liquid volatile theory. Volatile index was put forward for describing biodiesel/petrodisel volatility. A good correlation model was proposed for calculate the biodiesel/petrodiesel volatility by biodiesel blending ratio. The study showed that -10PD and WME had similar chemical composition and structure. -10PD was mainly composed of long chain alkanes: C8–C26. WME was mainly composed of long chain fatty acid methyl esters: C14:0–C22:0, C16:1–C22:1, C18:2 and C18:3. The volatile indexes of WME and -10PD were 1.47E-04 and 3.64E-05, respectively. The biodiesel was considerably more volatile in comparison to the petrodiesel. The WME/-10PD volatility was better with increasing the biodiesel blending ratio.


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