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41.
The study of mica–epoxy-based composite has a great role in high voltage machines industry. Beside electric properties, this
composite should present compatible mechanical and chemical, in this case thermal characteristics to insulate properly the
conductor strand, avoiding short-circuits, and leading electrical current with minimal losses. Improvement of the quality
is possible through the knowledge of raw materials and system. This study aims to list a complete thermal characterization
of mica composite, its components, epoxy resin, anhydride methylhexahydrophtalic, mica tape and zinc naphthenate, and thermoanalytical
interactions between them. These data shows intrinsic properties of the system, which is so relevant to its great electrical
and thermal performance. Thermal analysis allows the detailed study of curing process and thermal decomposition, predicting
and suggesting mechanisms, beside future and possible optimization to the system. Composite system glass transition (T
g) was obtained through an important and very respected methodology, presenting the value of T
g = 138 ± 2 °C, finally characterizing the material. 相似文献
42.
43.
M. Agostinha R. Matos Margarida S. Miranda Victor M. F. Morais Joel F. Liebman 《Molecular physics》2013,111(2-3):221-228
The standard molar enthalpies of combustion, sublimation, and formation in the crystalline and gaseous phase at a temperature of 298.15?K have been experimentally determined for saccharin and for benzenesulfonamide. These compounds were also studied theoretically using density functional theory, the B3LYP functional and extended basis sets. 相似文献
44.
Israel Quiros Ricardo García-Salcedo Tonatiuh Matos Claudia Moreno 《Physics letters. [Part B]》2009,670(4-5):259-265
We apply the dynamical systems tools to study the linear dynamics of a self-interacting scalar field trapped on a DGP brane. The simplest kinds of self-interaction potentials are investigated: (a) constant potential, and (b) exponential potential. It is shown that the dynamics of DGP models can be very rich and complex. One of the most interesting results of this study shows that dynamical screening of the scalar field self-interaction potential, occurring within the Minkowski cosmological phase of the DGP model and that mimics 4D phantom behaviour, is an attractor solution for a constant self-interaction potential but not for the exponential one. In the latter case gravitational screening is not even a critical point of the corresponding autonomous system of ordinary differential equations. 相似文献
45.
46.
Robson Miranda da Gama Tatiana Santana Balogh Simone França Tânia Cristina Sá Dias Valcinir Bedin André Rolim Baby Jivaldo do Rosário Matos Maria Valéria Robles Velasco 《Journal of Thermal Analysis and Calorimetry》2011,106(2):399-405
This research aimed the effect on Caucasian hair tresses treated with oxidative hair dye, either incorporated or not with
conditioners agents, analyzed by Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TG). The formulations
of hair dyes were emulsions oil-in-water with light blond color containing or not the conditioners agents: silanetriol and
panthenol; PEG-12 dimethicone; hydrolyzed silk, hydrolyzed milk protein, and lactose. Each dye (1.5 g) was applied in the
hair tress (2.0 g/20.0 cm of length of Caucasian light-brown), previously treated, more 1.5 g of hydrogen peroxide 20 vol
during 40 min. Evaluation of mass loss of the different hair sample demonstrates that these chemical hair treatments impair
the hair fibers, reduced their moisture content with respect to the untreated hair. The incorporation of conditioners agents
(silanetriol and panthenol; PEG-12 dimethicone; hydrolyzed silk, hydrolyzed milk protein, and lactose) in oxidative hair dyes
types did not decrease the damage caused on the tresses by the coloring process quantified by TG/DTG. However, the DSC curves
demonstrated those conditioners agents (silanetriol and panthenol; PEG-12 dimethicone) dislocated the beginning of the third
event in 20 °C and they inhibited the presence of the fourth event, having characterized thermal protection to the hair. 相似文献
47.
48.
Reis Thaiene A. Matos Breno N. Lima Eliana M. Chaker Juliano A. Gratieri Tais Cunha-Filho Marcílio S. S. Gelfuso Guilherme M. 《Journal of Thermal Analysis and Calorimetry》2017,128(3):1671-1682
Journal of Thermal Analysis and Calorimetry - The objectives of this study were to verify the viability of the photoinitiating system using curcumin as a photoinitiator and glycerol as a... 相似文献
49.
50.
Campos E Cordeiro R Santos AC Matos C Gil MH 《Colloids and surfaces. B, Biointerfaces》2011,88(1):477-482
Bi-soft segmented poly(ester urethane urea) microparticles were prepared and characterized aiming a biomedical application. Two different formulations were developed, using poly(propylene glycol), tolylene 2,4-diisocyanate terminated pre-polymer (TDI) and poly(propylene oxide)-based tri-isocyanated terminated pre-polymer (TI). A second soft segment was included due to poly(?-caprolactone) diol (PCL). Infrared spectroscopy, used to study the polymeric structure, namely its H-bonding properties, revealed a slightly higher degree of phase separation in TDI-microparticles. TI-microparticles presented slower rate of hydrolytic degradation, and, accordingly, fairly low toxic effect against macrophages. These new formulations are good candidates as non-biodegradable biomedical systems. 相似文献