The study of bitumen by differential scanning calorimetry: The interpretation of thermal effects

2019 ◽  
Vol 37 (4) ◽  
pp. 417-424 ◽  
Author(s):  
Igor N. Frolov ◽  
Ekaterina S. Okhotnikova ◽  
Marat A. Ziganshin ◽  
Tatyana N. Yusupova ◽  
Alexey A. Firsin
2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.


2018 ◽  
Vol 45 (3) ◽  
pp. 79-86 ◽  
Author(s):  
V.A. Zhorin ◽  
M.R. Kiselev

Mixtures of polyethylene and 80% germanium dioxide, magnesium, magnesium oxide, and sodium chloride were subjected to plastic deformation under a pressure of 0.5–4.0 GPa, and were then investigated by differential scanning calorimetry. The enthalpy of melting of the polymer in certain mixtures reached 300 J/g. On thermograms of deformed mixtures, exothermic processes were observed. The observed thermal effects are possibly due to interphase interaction at the phase boundary.


2018 ◽  
Vol 58 (8) ◽  
pp. 593-598 ◽  
Author(s):  
I. N. Frolov ◽  
T. N. Yusupova ◽  
M. A. Ziganshin ◽  
E. S. Okhotnikova ◽  
A. A. Firsin

2020 ◽  
pp. 157-164
Author(s):  
Igor' Aleksandrovich Saranov ◽  
Oleg Borisovich Rudakov ◽  
Konstantin Konstantinovich Polyansky ◽  
Natal'ya Leonidovna Kleymenova ◽  
Aleksey Valer'yevich Vetrov

The thermophysical properties of vegetable oils were studied by differential scanning calorimetry method was used to study the fatty acid composition of vegetable oils liquid at room temperature, such as amaranth (Amaránthus), corn (Zea mays), flax (Línum usitatíssimum), sunflower (Helianthus), rape (Brusss napor), milk thistle (Sílybum mariánum), saffron milk cap (Camelina sativa) and pumpkin (Cucurbita pepo). The temperatures of the endothermic peak maxima and their area on the DSC thermograms of these oils were established as characteristic thermal effects. The interconnection between thermal effects and fatty acid composition are revealed. On the melting curves of liquid vegetable oils, up to 5 endothermic peaks of different intensities were selected in the ranges -80÷-55 °C, -40÷-15 °C, -25÷-8 °C, -19÷+6 °C and -10÷+4 °C. The coordinates of the maxima of these peaks (Ti) and their area (Si) significantly correlate with the content (Wi,%) in the oils, primarily oleic, linoleic and linolenic acids, the total proportion of which in oils is from 75 to 92%. Using the DSC thermograms of rapeseed oil as an example, it is shown that the program separation of DSC peaks allows a multiple increase in the number of analytical signals, an increase in the reliability of identification of the fat phase, and identification of the main fractions of triglycerides. DSC as a method for identifying vegetable oils using modern thermal analysis instruments is simple to sample, has good reproducibility and can be an independent method for identifying and controlling the quality of vegetable oils.


2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>


Author(s):  
Hariyanti Hariyanti ◽  
Sophi Damayanti ◽  
Sasanti Tarini

Sinkonin praktis tidak larut dalam air, sedikit larut dalam kloroform dan alkohol. Hal ini berdampak pada rendahnya penetrasi transfollicular sinkonin, karena hanya bahan aktif hidrofilik yang mampu melewati hair follicle. Dengan demikian dibutuhkan satu sistem penghantaran yang mampu menurunkan hidrofobisitas sinkonin untuk meningkatkan penetrasi sinkonin ke follicle. Niosom merupakan vesikel ampifilik dengan struktur lapisan rangkap yang terbentuk dari hidrasi kombinasi surfaktan nonionik dan kolesterol yang mampu menurunkan hidrofobisitas sinkonin. Penelitian ini bertujuan untuk menentukan proses pembuatan niosom sinkonin yang optimum. Pembuatan niosom sinkonin diawali dengan menentukan temperatur gelasi (Tg) dari span 60 dengan Differential Scanning Calorimetry (DSC), kemudian dilanjutkan dengan optimasi proses meliputi: optimasi kecepatan rotavapor pembentukan film lapis tipis, temperatur hidrasi, kecepatan rotavapor hidrasi, waktu hidrasi, dan waktu sonikasi. Karakteristik vesikel niosom yang optimal meliputi: ukuran partikel dan indeks polidispersitas dengan menggunakan Particle Size Analized (PSA) serta efisiensi penjeratan sinkonin dengan menggunakan KCKT. Temperatur gelasi (Tg) span 60 45±2 oC, kecepatan rotavapor pembentukan film lapis tipis niosom 210 rpm, temperatur hidrasi 55±2 oC, kecepatan rotavapor hidrasi 210 rpm, waktu hidrasi 20 menit, waktu sonikasi suspensi niosom 1 menit. Ukuran vesikel yang diperoleh adalah 100–200 nm, indeks polidispersitas 0,2–0,4 dan efisiensi penjeratan niosom sinkonin 84,49±0,0025%. Proses pembuatan niosom sinkonin memiliki pengaruh besar terhadap hasil ukuran vesikel dan efisiensi penjeratan niosom sinkonin.


Author(s):  
Sheila Liza B. Dal

Abstract The choice of epoxy mold compound (EMC) for an electronic package is based mostly on how much protection it provides to the active components in the package. But the choice is not a straightforward process. Rather it is mostly trial and error using different assembly parameters to find the most robust material while assembly defects are monitored. One such defect associated to EMC processing is wire sweep, and many studies have shown that it is mainly caused by viscosity changes in the EMC. In this study, samples of EMC in various stages of shelf life and staging times were analyzed for degree of cure using a method called differential scanning calorimetry (DSC). Samples are then processed at assembly for wire sweep measurement. It was found out that degree of cure increases with staging time at different rates for each shelf life. It was also found out that wire sweep did not only increase with degree of cure but it was also found to be predictable with respect to the latter. Using this information, the age and staging limit for each material was identified that would not cause wire sweep issues.


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