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
The origin of two maxima in specific heat observed at the higher and the lower temperatures in the glass-transition region in the heating process has been studied for polymethyl methacrylate and polyv...
We explore the correlation between a boson peak and structural relaxation in a typical metallic glass. Consistent with enthalpy recovery, a boson peak shows a memory effect in an aging-and-scan proced...
Anisotropic polymer particles such as Janus particles have attracted significant attention in recent years because of their unique properties and unusual self-assembly behavior. Most anisotropic polym...
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...
The response of polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS) thin films to UV exposure during solvent vapor annealing is described, in order to improve their applicability in nanolithography a...
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.