Thermoplastics pipes for industrial applications under pressure. Determination of the chemical resistance factor and of the basic stress

2015 ◽  
Keyword(s):  
Chemical Resistance ◽  
Industrial Applications ◽  
Resistance Factor

Oxa-Michael polyaddition of vinylsulfonylethanol for aliphatic polyethersulfones

2021 ◽  
Author(s):  
Nicole Ziegenbalg ◽  
Ruth Lohwasser ◽  
Giovanni D’Andola ◽  
Torben Adermann ◽  
Johannes Christopher Brendel
Keyword(s):  
Refractive Index ◽  
High Temperature ◽  
Flame Retardant ◽  
Chemical Resistance ◽  
High Refractive Index ◽  
Industrial Applications ◽  
Interesting Class ◽  
The Common ◽  
Flame Retardant Properties

Polyethersulfones are an interesting class of polymers for industrial applications due to their unusual properties such as a high refractive index, flame-retardant properties, high temperature and chemical resistance. The common...

Consecutive determination of softwood kraft lignin structure and molar mass from NMR measurements

Holzforschung ◽  
2017 ◽  
Vol 71 (7-8) ◽  
pp. 563-570 ◽  
Author(s):  
Jerk Rönnols ◽  
Anna Jacobs ◽  
Fredrik Aldaeus
Keyword(s):  
Molar Mass ◽  
Industrial Applications ◽  
Size Exclusion ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Exclusion Chromatography ◽  
Pfg Nmr ◽  
Softwood Kraft Lignin ◽  
Good Agreement

Abstract The general molecular properties and in particular, the molar mass of lignin are of central importance for industrial applications, as these data govern important thermal and mechanical characteristics. The focus of the present paper is pulsed field gradient-nuclear magnetic resonance (PFG-NMR), which is suitable for determination of lignins’ weight-average molar mass, based on diffusion constants. The method is calibrated by lignin fractions characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). It could be demonstrated on a set of softwood kraft lignins that the PFG-NMR approach gives results in very good agreement with those obtained using conventional size exclusion chromatography (SEC).

Determination of Optimum Sensor Positions for Defect Detection on Revolving Machines by a Finite Element Vibration Analysis

2000 ◽  
Author(s):  
F. Bogard ◽  
K. Debray ◽  
Y. Q. Guo ◽  
A. Pavan
Keyword(s):  
Finite Element ◽  
Spectral Analysis ◽  
Element Model ◽  
Industrial Applications ◽  
Vibration Monitoring ◽  
Tangent Stiffness Matrix ◽  
Main Research ◽  
Optimum Sensor ◽  
Sensor Positions

Abstract The vibration monitoring is largely used to detect the defects in the revolving machines. The determination of the best sensor positions is one of main research goals in the domain of the conditional maintenance. This paper proposes a numerical methodology based on a finite element model and a spectral analysis in order to find optimum sensor positions. The bearing is considered as a key component in vibration propagation from the moving parts to static ones. In this paper, we use an analytical bearing model and its numerical implementation in a FE code. The tangent stiffness matrix of the bearing element is calculated by the Newton-Raphson method and then introduced into the modal and spectral analysis. The technique of “Mode Shape Summation Plot” (MSSP) is adopted to find the most sensitive zones to usual defects. The proposed numerical approach gives good agreements with the experimental results. A real grinder modeling shows its interesting industrial applications.

scholarly journals Fucoidan Characterization: Determination of Purity and Physicochemical and Chemical Properties

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 571
Author(s):  
Ahmed Zayed ◽  
Mona El-Aasr ◽  
Abdel-Rahim S. Ibrahim ◽  
Roland Ulber
Keyword(s):  
Structural Characteristics ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Chemical Structures ◽  
Seasonal Factors ◽  
Molecular Masses ◽  
Current Article ◽  
Downstream Processes

Fucoidans are marine sulfated biopolysaccharides that have heterogenous and complicated chemical structures. Various sugar monomers, glycosidic linkages, molecular masses, branching sites, and sulfate ester pattern and content are involved within their backbones. Additionally, sources, downstream processes, and geographical and seasonal factors show potential effects on fucoidan structural characteristics. These characteristics are documented to be highly related to fucoidan potential activities. Therefore, numerous chemical qualitative and quantitative determinations and structural elucidation methods are conducted to characterize fucoidans regarding their physicochemical and chemical features. Characterization of fucoidan polymers is considered a bottleneck for further biological and industrial applications. Consequently, the obtained results may be related to different activities, which could be improved afterward by further functional modifications. The current article highlights the different spectrometric and nonspectrometric methods applied for the characterization of native fucoidans, including degree of purity, sugar monomeric composition, sulfation pattern and content, molecular mass, and glycosidic linkages.

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