Temperature independence of the heat capacity of liquid water at atmospheric pressure

Abstract

Debye temperature and Frenkel temperature of liquid water at atmospheric pressure are estimated from the modified phonon-polariton model. Moreover, the decrease in the Debye temperature and the increase in the Frenkel temperature as rising temperature are pointed out. The heat capacity of liquid water is given by the phonon theory reported in 2012, covering both classical to quantum regimes for both the motion of phonon polariton and the di˙usion motion of particles. Because the ratio between temperature and the Debye temperature varies from 0.8 to 1.5, leading to the temperature independence of the heat capacity of liquid water at atmospheric pressure, in agreement with experimental work.

High-frequency Collective Ionic Dynamics in Liquid Metals

“…Due to the coexistence of strong ion-ion interaction and the strong diffusions of ions, it is difficult to develop a unified theory of liquid metals. Considering liquids as systems in a mixed dynamical state [1][2][3][4]13] combining behaviors of both solid and gas phases is an effective theoretical approach to probe their dynamics at high frequencies. Despite continuous progress in the development of theoretical schemes, it remains many unanswered questions towards the understanding of the collective ionic dynamics, for example, the origin of the two collective ionic excitation modes in liquid metals.…”

“…It means that liquid still conserves itself several dynamic behaviors at solid phase. Therefore, theoretical model based on a phonon theory has been used to investigate the properties in thermodynamics of liquids [2,3,14].…”

“…Thus, the transverse collective vibrations (phonons) could be emerged in metallic liquids and propagate along the local dimers confined in icosahedral or cage until they scatter. The existence of phonons in liquid water at ambient temperatures has ever been confirmed [3,14]. Indeed, the terms "collective modes" and "phonons" have been used interchangeably as investigating liquid thermodynamics at high frequencies [1].…”

“…Yet, the contribution of these modes to the energy and heat capacity is inconsiderable. It demonstrated that the energy of metallic liquids as well as nonmetallic liquids is mostly governed by two types of collective excitations at terahertz frequencies [1][2][3][4]. The first mode is transverse collective oscillations whose speed is smaller, a bit, than the speed of the common sound waves.…”

Searching for Suitable Cultivation System of Swiss Chard (Beta vulgaris subsp. cicla (L.) W.D.J.Koch) in the Tropical Lowland

“…Swiss chard plants are most often cultivated at lower air temperatures, ranging from 13 to 21 °C (Rana & Rani 2017). The existence of liquid water is known to lower the temperature of the air above the surface of the water because water has a high heat capacity (Nhan & Tuan 2020).…”