Track topics on Twitter Track topics that are important to you
The effects of thermal history on the enthalpy relaxation in polystyrene are studied by differential scanning calorimetry. The temperature dependence of the specific heat in the liquid and the glassy states, that of relaxation time, and the exponent of the Kohlrausch-Williams-Watts function are determined by measurements of the thermal response against sinusoidal temperature variation. A phenomenological model equation previously proposed to interpret the memory effect in the frozen state is applied to the enthalpy relaxation and the evolution of entropy under a given thermal history is calculated. The annealing below the glass transition temperature produces two effects on enthalpy relaxation: the decay of excess entropy with annealing time in the early stage of annealing and the increase in relaxation time due to physical aging in the later stage. The crossover of these effects is reflected in the variation of temperature of the maximum specific heat observed in the heating process after annealing and cooling.
Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan.
This article was published in the following journal.
Name: Physical review. E, Statistical, nonlinear, and soft matter physics
Random L-isomer rich copolymers of poly (lactic acid) containing up to 4 % D-isomer co-units have been cooled from the molten state such to obtain glasses free of crystals and homogenous crystal nucle...
A novel method was previously reported for detecting the glass transition of thin polystyrene (PS) films by correlating the relationships between the temperature-dependent viscoelasticity of the PS fi...
A short account of the developments and perspectives of IKR (iso-kinetic relation) and EEC (enthalpy (H) - entropy (S) compensation) has been presented. The IKR and EEC are known to be extra thermodyn...
We report a study on directed self-assembly (DSA) with solvent annealing to induce the formation of non-bulk block copolymer microdomains on chemical patterns. Ultrathin films of symmetric polystyrene...
Heat effects for the addition of Co in bulk and nanosized forms into the liquid Sn-3.8Ag-0.7Cu alloy were studied using drop calorimetry at four temperatures between 673 and 1173 K. Significant differ...
OBJECTIVES: I. Establish the sodium and potassium intake that will maintain a normovolemic state in a patient with pseudohypoaldosteronism. II. Determine the effect of extracellular flu...
The goal of this study is to determine if relaxation therapy improves patient satisfaction with Mohs micrographic surgery.
Advances in treatment has turned HIV/AIDS into a chronic illness. Relaxation response is a state in which individuals evoke a bodily calm, effecting physiological changes that are shown t...
The purpose is threefold: Assess the anxiety reduction, the mood positive effect and the rise of quality of life when using methods of relaxation combined with virtual reality with patient...
Stress contributes to health and behavioral issues in students, but will not be integrated into schools without evidence of benefit. This study was conducted to determine if a 6-week relax...
An effect usually, but not necessarily, beneficial that is attributable to an expectation that the regimen will have an effect, i.e., the effect is due to the power of suggestion.
A colorless, toxic liquid with a strong aromatic odor. It is used to make rubbers, polymers and copolymers, and polystyrene plastics.
A quaternary skeletal muscle relaxant usually used in the form of its bromide, chloride, or iodide. It is a depolarizing relaxant, acting in about 30 seconds and with a duration of effect averaging three to five minutes. Succinylcholine is used in surgical, anesthetic, and other procedures in which a brief period of muscle relaxation is called for.
A synthetic PGE2 analog that has an inhibitory effect on gastric acid secretion, a mucoprotective effect, and a postprandial lowering effect on gastrin. It has been shown to be efficient and safe in the treatment of gastroduodenal ulcers.
A strongly basic anion exchange resin whose main constituent is polystyrene trimethylbenzylammonium Cl(-) anion.