scholarly journals Application of the method of differential scanning calorimetry in the study of the properties of oilseeds

2021 ◽  
Vol 83 (2) ◽  
pp. 208-216
Author(s):  
I. A. Saranov ◽  
O. B. Rudakov ◽  
K. K. Polansky ◽  
A. S. Ramazanov ◽  
S. A. Balaeva ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Milk Thistle ◽  
Scanning Calorimetry ◽  
Peak Separation ◽  
Melting Curves ◽  
Geographic Origins ◽  
Overlapping Peaks ◽  
Dsc Method ◽  
Oxidized Triacylglycerols ◽  
Dsc Curves

The method of differential scanning calorimetry (DSC) is used to characterize the thermophysical properties during melting of samples of milk thistle oil of various geographic origins, seeds and meal. The world experience in applying the DSC method on the study of milk thistle oils is generalized. The temperature measurement program is described. It is shown that, despite the general similarity of the curve profiles of the melting DSC, there are differences in the profiles due to genotypic and phenotypic factors - variety and growing location. The DSC curves of freshly squeezed oil distinguish from the DSC curves after 6 months storage of the oil due to oxidative deterioration and the formation of more refractory partially oxidized triacylglycerols. This fact is relevant to determining the capabilities of the DSC method in controlling the freshness of vegetable oils. The peaks amplitudes in the DSC curves of fresh oil are higher than those of oils that has been stored at room temperature for six months. Double differentiation of the melting curves makes it possible to reveal the temperatures of phase transitions in the case of overlapping endothermic peaks, the establishment of which is difficult without double differentiation. Using the «Netzsch Peak Separation» software to divide the peaks in the melting curves allows at once to estimate the areas of overlapping peaks and increase the informativeness of the DSC data. Thermal analysis of milk thistle seeds and meal reveals that the meal contains a residual amount of oil, in which the proportion of triunsaturated fats is overestimated in comparison to seeds, indicating that triunsaturated fats are more difficult to extract from oil by cold pressing.

scholarly journals A STUDY OF PARAMETERS RELATED TO ANALYSIS OF TRANSITION TEMPERATURES AND ENTHALPIES OF POLYPROPYLENE BY DIFFERENTIAL SCANNING CALORIMETRY (DSC)

2002 ◽  
Vol 10 (11) ◽  
pp. 73-78
Author(s):  
Carlos R. Wolf ◽  
Emir Grave
Keyword(s):  
Differential Scanning Calorimetry ◽  
Material Characterization ◽  
Transition Temperatures ◽  
Nitrogen Flow ◽  
Thermoplastic Polymer ◽  
Scanning Calorimetry ◽  
Know How ◽  
Heating And Cooling ◽  
Polypropylene Material ◽  
Dsc Method

Polypropylene is a thermoplastic polymer, widely employed by converter industries to produce different plastic objects. In order to control and optimize the final properties of the polypropylene material, the evaluation of transition temperatures and enthalpies by Differential Scanning Calorimetry (DSC) has a very important role. Therefore, it is fundamental to know how the analytical conditions influence the results. In this study heating and cooling rates, 10°C/min and 20°C/min, and two different rates of nitrogen flow, 20mL/min and 50mL/min were investigated. It was concluded that thermal properties are influenced by rates of heating and rates of nitrogen flow. The best precision was obtained with the low heating rate, 10°C/min, and high flow rate, 50mL/min. These conditions are being used with the DSC method for polyolefin quality control and material characterization.

scholarly journals Application of DSC Method in Studies on Phase Transitions of Ni Superalloys

2017 ◽  
Vol 17 (4) ◽  
pp. 133-136 ◽  
Author(s):  
R. Przeliorz ◽  
J. Piątkowski
Keyword(s):  
Phase Transitions ◽  
Specific Heat ◽  
Protective Atmosphere ◽  
Scanning Calorimetry ◽  
Heating And Cooling ◽  
Complete Melting ◽  
Calorimetric Studies ◽  
Dsc Method ◽  
Dsc Curves

Abstract The paper presents results of calorimetric studies of foundry nickel superalloys: IN100, IN713C, Mar-M247 and ŻS6U. Particular attention was paid to determination of phase transitions temperatures during heating and cooling. The samples were heated to a temperature of 1500°C with a rate of 10°C⋅min-1 and then held at this temperature for 5 min. After a complete melting, the samples were cooled with the same rate. Argon with a purity of 99.99% constituted the protective atmosphere. The sample was placed in an alundum crucible with a capacity of 0.45 cm3. Temperature and heat calibration was carried out based on the melting point of high-purity Ni. The tests were carried out by the differential scanning calorimetry (DSC) using a Multi HTC high-temperature calorimeter from Setaram. Based on the DSC curves, the following temperatures were determined: solidus and liquidus, dissolution and precipitation of the γ’ phase, MC carbides and melting of the γ’/γ eutectic. In the temperature range of 100-1100°C, specific heat capacity of the investigated superalloys was determined. It was found that the IN713C and IN100 alloys exhibit a higher specific heat while compared to the Mar-M247 and ŻS6U alloys.

Positron Lifetimes and Crystallinity of γ-Irradiated Polypropylenes

2012 ◽  
Vol 733 ◽  
pp. 163-166
Author(s):  
Zhe Chen ◽  
Wei Huang ◽  
Peng Fei Fang ◽  
Wen Yu ◽  
Shao Jie Wang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Irradiation Dose ◽  
Gamma Ray ◽  
Positron Lifetime ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Γ Ray ◽  
Positron Lifetimes ◽  
Dsc Method ◽  
Low Irradiation

The microstructure of the polypropylenes (PP) irradiated by gamma ray was studied by positron lifetime technique and differential scanning calorimetry (DSC). Lifetime measurement shows o-Ps intensity decreases with increasing γ irradiation dose. The crystallinity of irradiated samples was detected by DSC method. The correlation between o-Ps intensity and crystallinity indicates γ-ray can induce higher crystallinity in the polypropylene at low irradiation dose.

A theoretical method for resolving overlapping peaks in differential scanning calorimetry

1994 ◽  
Vol 18 (5-6) ◽  
pp. 280-285 ◽  
Author(s):  
C. Wagner ◽  
J. Vázquez ◽  
P. Villares ◽  
R. Jiménez-Garay
Keyword(s):  
Differential Scanning Calorimetry ◽  
Theoretical Method ◽  
Scanning Calorimetry ◽  
Overlapping Peaks

Differential Scanning Calorimetry as a Method for Controlling the Authenticity of Wild Milk Thistle Oil

2021 ◽  
Vol 76 (12) ◽  
pp. 1468-1475
Author(s):  
O. B. Rudakov ◽  
I. A. Saranov ◽  
Sh. A. Balaeva ◽  
A. Sh. Ramazanov ◽  
Ya. O. Rudakov
Keyword(s):  
Differential Scanning Calorimetry ◽  
Milk Thistle ◽  
Scanning Calorimetry

Characterization of Main-Chain Liquid Crystal Elastomers by Using Differential Scanning Calorimetry (DSC) Method

2015 ◽  
Vol 1123 ◽  
pp. 69-72 ◽  
Author(s):  
Supardi ◽  
Y. Yusuf ◽  
Harsoyo
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Basic Principle ◽  
Main Chain ◽  
Scanning Calorimetry ◽  
Mechanical Effects ◽  
Liquid Crystal Elastomers ◽  
Dsc Method

We performed an experiment to characterize the four samples of main chain liquid crystal elastomers (MCLCEs) by using differential scanning calorimetry (DSC) method. Basic principle of this method is that difference in the amount of heat required to increase the temperature of the sample and reference is measured as a function of temperature. The temperature between the sample and reference is maintained nearly the same throughout the experiment. There were four samples with different concentrations of crosslinker we have taken, namely 8%, 12%, 14%, and 16%. The results showed that the phase transition from nematic to isotropic obtained by this method had correlation with their thermo-mechanical effects.

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