A method for the determination of the levels of asbestos fibres in ophiolitic rocks used in construction and industrial applications

2014 ◽  
Author(s):  
I. Rigopoulos ◽  
B. Tsikouras ◽  
K. Hatzipanagiotou
Keyword(s):  
Industrial Applications ◽  
Ophiolitic Rocks

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.

Determination of Morphological Textures of the Fibres in Composite Materials Made from Textiles of Carbon Fibres

2005 ◽  
Vol 495-497 ◽  
pp. 1675-1680
Author(s):  
G. Langelaan ◽  
S. Deprez ◽  
Ignaas Verpoest ◽  
Paul van Houtte
Keyword(s):  
Composite Materials ◽  
Reference Material ◽  
Polymer Matrix ◽  
Crystallographic Texture ◽  
Orientation Distribution ◽  
Industrial Applications ◽  
Woven Fabrics ◽  
Carbon Fibres ◽  
Made In

The orientation distribution of fibres (morphological texture) in a composite is very important in determining the properties of the material. Therefore, methods which can provide quantitative descriptions of the morphological texture are essential. One approach to determining the morphological texture function (MTF) is to measure the orientation distribution of the crystals in the fibres. Since many types of reinforcing fibres are crystalline and textured (i.e. carbon fibres, whiskers, etc.) this approach may be interesting for commercial/industrial applications. For this technique to be applied, the crystallographic texture intrinsic to the fibres must be determined and subsequently measurements of the crystallographic texture should be made in the composite. The morphological texture can then be calculated by a deconvolution of the composite texture with the fibre’s intrinsic texture. In this paper, morphological textures are determined in woven fabrics made from carbon fibres embedded in a polymer matrix. Straight fibres removed from the fabric serve as the reference material for the deconvolution. It is demonstrated that this technique is applicable and can resolve the orientation distribution to an accuracy greater than is needed for determining the elastic properties.

scholarly journals Qualitative and Quantitative Determination of Phytochemical Contents of Indigenous Nigerian Softwoods

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Chukwuma S. Ezeonu ◽  
Chigozie M. Ejikeme
Keyword(s):  
Alternative Medicine ◽  
Moringa Oleifera ◽  
Industrial Applications ◽  
Qualitative And Quantitative Analysis ◽  
Dichrostachys Cinerea ◽  
Qualitative And Quantitative ◽  
Kaempferia Galanga ◽  
Anogeissus Leiocarpus ◽  
Phytochemical Contents

The phytochemical contents of some milled Nigerian softwood chips were carried out in a quest to evaluate their potentials as sources of alternative medicine as well as uses in other industrial applications. The qualitative and quantitative analysis were ascertained. Tannin was found in all the Nigerian softwoods examined with the highest quantities obtained in Sterculia oblonga (1240 mg/100 g) and Barteria nigritiana (1230 mg/100 g). Highest quantities of alkaloid were obtained in Cordia millenii (11.2%) and Sterculia oblonga (10.4%). Barteria nigritiana (14.2%) and Moringa oleifera (12.2%) recorded more flavonoid content than other individual softwoods. Saponin was more in Anogeissus leiocarpus (12.5%) and Dichrostachys cinerea (9.8%). Oxalate was found to be higher in Combretodendron macrocarpum (5.84 g/100 g) and Glyphaea brevis (3.55 g/100 g). Pentaclethra macrophylla (890 mg/100 g) and Moringa oleifera (880 mg/100 g) contained more cyanogenic glycosides. Sacoglottis gabonensis (4.68 mg/g) and Pentaclethra macrophylla (4.04 mg/g) showed the highest contents of phenol, while more lipids (8% and 7.2%) were found in Anogeissus leiocarpus and Kaempferia galanga, respectively. The results showed that these Nigerian softwoods grains could be a source for the exploitation of these phytochemicals beneficial in the pharmaceutical and alternative medicine industries.

Noncontact thermophysical property measurement of liquid cerium by electrostatic levitation

2009 ◽  
Vol 24 (7) ◽  
pp. 2449-2452 ◽  
Author(s):  
Jianqiang Li ◽  
Takehiko Ishikawa ◽  
Junpei T. Okada ◽  
Yuki Watanabe ◽  
Jianding Yu ◽  
...  
Keyword(s):  
Thermophysical Properties ◽  
Sessile Drop ◽  
Industrial Applications ◽  
High Reactivity ◽  
Electrostatic Levitation ◽  
Gaseous Environment ◽  
Density Surface ◽  
Property Measurement ◽  
Metallurgical Processes

The knowledge of thermophysical properties of active metals is critical to understand their metallurgical processes and further industrial applications. However, due to high reactivity and melt contamination from a crucible and gaseous environment, accurate values of the properties are hard to obtain using conventional methods such as the sessile-drop method. In the present study, a vacuum electrostatic levitator was used to circumvent these difficulties and enabled the noncontact determination of thermophysical properties of liquid cerium even in an undercooled state. The data of density, surface tension, and viscosity of molten cerium were reported, as well as their temperature dependence.

Modal analysis of pyroclastic rocks by combined Rietveld and RIR methods

1996 ◽  
Vol 11 (2) ◽  
pp. 97-106 ◽  
Author(s):  
A. Gualtieri
Keyword(s):  
Modal Analysis ◽  
Bulk Material ◽  
Rietveld Method ◽  
Internal Standard ◽  
Industrial Applications ◽  
Incoherent Scattering ◽  
Glass Content ◽  
Volume Calculation ◽  
Zeolite Content

The modal analysis of samples belonging to the zeolite-rich pyroclastic formation named “Neapolitan yellow tuff” (Central and Southern Italy) has been determined by full-profile refinement of X-ray powder diffraction (XRPD) data using a combined Rietveld–RIR method. The quantitative analysis and especially the zeolite content is a profitable source for geo-petrographic and genetic considerations and as well an essential source to assess the physical and chemical properties of the bulk material for a feasible use in industrial applications. Albeit a wealth of methods are used for the quantitative determination of zeolite content in pyroclastites they all fail for lack of accuracy as far as concerns the absolute standard deviation of the quantitative data. The outstanding outcomes achievable by using the Rietveld method make it as the most promising technique to fulfill this lack. The glass content in each sample is calculated by a combined Rietveld–RIR method in which a known amount of an internal standard is added to the mixture to rescale the Rietveld refined weight fractions into absolute values. Then, it is reasonable to designate this method as an external method according to the definition given by Hill and Howard (1987). Its counterpart is the internal method developed by Riello etal. (1995a,b). Other techniques such as the addition method and the background scattering volume calculation are developed to accomplish a further determination of the glass content. The results are compared to the values obtained from the Rietveld–RIR analysis. These experimental methods yield an over-estimation of the amorphous phase because the incoherent scattering contribution (air, absorption, sample holder, Compton scattering) is accounted for as the amorphous fraction itself. The glass content of each sample acquired from the Rietveld–RIR refinement on the “raw data” is compared to that accomplished from the refinement of incoherent scattering subtracted data. In addition, some largely used XRPD quantitative techniques such as the external standard and RIR (reference intensity ratio) and the influence of the sample loading method are accounted for in an internally consistent comparison among different procedures of analysis.

scholarly journals COMPARATIVE STUDY OF THE CESIUM UPTAKE ABILITY BETWEEN HEU-TYPE (CLINOPTILOLITE-HEULANDITE) ZEOLITIC TUFF AND PURE HEULANDITE

2020 ◽  
Vol 56 (1) ◽  
pp. 56
Author(s):  
Christina Mytiglaki ◽  
Nikolaos Kantiranis ◽  
Panagiotis Misaelides ◽  
Fotini Noli ◽  
Anestis Filippidis
Keyword(s):  
Mineral Chemistry ◽  
Solution Concentration ◽  
Industrial Applications ◽  
Radioactive Cesium ◽  
X Ray Diffraction ◽  
Zeolitic Tuff ◽  
Suitable Material ◽  
Type Zeolite ◽  
Cesium Uptake

Specific continuous layers of zeolitic tuff in Ntrista stream location of Petrota area of Evros region (NA11) and pure natural crystals of heulandite (HEU1) from the collection of the Department of Mineralogy-Petrology-Economic Geology, School of Geology, Aristotle University of Thessaloniki, have been investigated. The X-Ray Diffraction analyses showed that the sample NA11 consists of 86 wt% HEU-type zeolite, 4 wt% micas+ clay-minerals, 4 wt% quartz, 2 wt% christobalite and 4 wt% feldspars, while the sample HEU1 is pure heulandite crystal. The mineral-chemistry was determined by SEM-EDS microanalyses. The zeolite of the NA11 sample is Ca-rich clinoptilolite and its chemical formulae is Ca1.8K1.0Mg0.7Na0.5Al6.4 Si29.5O72·21H2O, while the zeolite of the sample HEU1 is heulandite and its chemical formulae is Ca3.6Na1.0Κ0.2Sr0.2Ba0.1Al8.1Si27.6O72·21H2O. The uptake ability of the samples was measured by the AMAS method (Ammonium Acetate Saturation). The two examined materials show high uptake ability. The measured value for the zeolitic tuff NA11 is 231 meq/100g, while for the heulandite crystal (HEU1) is 296 meq/100g. For the determination of the cesium sorption a CsNO3 solution (concentration 500 mg/L), labelled with small activity of 137Cs, and pH 2-12 was used. The sorption of the cesium by the two materials, was determined by measuring the gamma radiation emitted by the 137Cs tracer. The zeolitic tuff presents higher uptake ability of radioactive cesium than the pure heulandite crystal, whereas the sorption of radioactive cesium is not significantly affected by the pH values of the initial solutions in the range pH 2-12.The clinoptilolitic zeolitic tuff NA11 is suitable material for various environmental, agricultural and industrial applications.

scholarly journals A jssp solution for production planning optimization combining industrial engineering and evolutionary algorithms

2020 ◽  
pp. 58-58
Author(s):  
Saso Srsen ◽  
Marjan Mernik
Keyword(s):  
Completion Time ◽  
Job Shop ◽  
Job Shop Scheduling ◽  
Research Work ◽  
Industrial Applications ◽  
Industrial Engineering ◽  
Job Shop Scheduling Problem ◽  
Shop Scheduling ◽  
Planning Optimization

A Job Shop Scheduling Problem (JSSP), where p processes and n jobs should be processed on m machines so that the total completion time is minimal, is a well-known problem with many industrial applications. Many researchers focus on the JSSP classification and algorithms that address the different JSSP classes. In this research work, the production times, a very well-known theme covered in Industrial Engineering (IE), are integrated into an Evolutionary Algorithm (EA) to solve real-world JSSP problems. Since a drawback of classical IE is a manual determination of the technological times, an Internet of Things (IoT) architecture is proposed as a possible solution.

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