scholarly journals Environmentally friendly and highly productive bi-component melt spinning of thermoregulated smart polymer fibres with high latent heat capacity

2018 ◽  
Vol 12 (3) ◽  
pp. 203-214 ◽  
Author(s):  
Ch. Cherif ◽  
N. H. A. Tran ◽  
M. Kirsten ◽  
H. Bruenig ◽  
R. Vogel
Keyword(s):  
Heat Capacity ◽  
Latent Heat ◽  
Melt Spinning ◽  
Environmentally Friendly ◽  
Smart Polymer ◽  
Latent Heat Capacity ◽  
High Latent Heat

The Effects of Nucleating Agents on Phase Transition of a Salt Hydrate Phase-Change Material for Thermal Energy Storage Heat Exchangers

2019 ◽  
Author(s):  
Sarath Kannan ◽  
M. A. Jog ◽  
Raj M. Manglik
Keyword(s):  
Phase Transition ◽  
Heat Capacity ◽  
Phase Change ◽  
Latent Heat ◽  
Superheated Liquid ◽  
Stable Phase ◽  
Lithium Nitrate ◽  
Nitrate Hexahydrate ◽  
Salt Hydrate ◽  
Latent Heat Capacity

Abstract Salt hydrate based Phase-Change Materials (PCM) typically store and discharge large quantities of heat during their phase transition process. However, the repeated use of these PCM, especially when they are completely dehydrated and superheated in a cyclic process, is impeded by certain irreversible behavior. These include (1) phase segregation: where the PCM degrades to forms a lower hydrate during phase transition while losing its storage capacity, and (2) subcooling: when crystallization and rehydration from the liquid PCM state occurs at a temperature lower than their phase transition point. Higher degrees of subcooling (ΔTs), which is how much the PCM has to be super cooled below its phase transition temperature for crystallization to begin, adversely affects its performance and in some cases renders it ineffective. Lithium Nitrate Trihydrate [(LNT) LiNO3.3H2O] is one of the more promising candidate among these inorganic salt hydrate PCMs because of its rather stable phase change behavior and relatively very high latent heat capacity (282kJ/kg). Nevertheless, when completely in superheated liquid phase, it requires a high degree of subcooling (ΔTs > 20°C), which limits its utility. This study reports a novel nucleating agent — Zinc Nitrate Hexahydrate (ZNH) that reduces the subcooling to below 5°C (1000 Cycles). However, the latent heat capacity reduced to half the initial value after the cycling.

scholarly journals Calorimetric analysis of ice onset temperature during cryoablation: a model approach to identify early predictors of effective applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elena Campagnoli ◽  
Andrea Ballatore ◽  
Valter Giaretto ◽  
Matteo Anselmino
Keyword(s):  
Cooling Rate ◽  
Latent Heat ◽  
Bovine Liver ◽  
Onset Temperature ◽  
Ice Formation ◽  
Scanning Calorimetry ◽  
Calorimetric Analysis ◽  
Early Predictors ◽  
Latent Heat Capacity ◽  
Model Approach

AbstractAim of the present study is to analyze thermal events occurring during cryoablation. Different bovine liver samples underwent freezing cycles at different cooling rate (from 0.0075 to 25 K/min). Ice onset temperature and specific latent heat capacity of the ice formation process were measured according to differential scanning calorimetry signals. A computational model of the thermal events occurring during cryoablation was compiled using Neumann’s analytical solution. Latent heat (#1 = 139.8 ± 7.4 J/g, #2 = 147.8 ± 7.9 J/g, #3 = 159.0 ± 4.1 J/g) of all liver samples was independent of the ice onset temperature, but linearly dependent on the water content. Ice onset temperature was proportional to the logarithm of the cooling rate in the range 5 ÷ 25 K/min (#3a = − 12.2 °C, #3b = − 16.2 °C, #3c = − 6.6 °C at 5K/min; #3a = − 16.5 °C, #3b = − 19.3 °C, #3c = − 11.6 °C at 25 K/min). Ice onset temperature was associated with both the way in which the heat involved into the phase transition was delivered and with the thermal gradient inside the tissue. Ice onset temperature should be evaluated in the early phase of the ablation to tailor cryoenergy delivery. In order to obtain low ice trigger temperatures and consequent low ablation temperatures a high cooling rate is necessary.

Temperature regulating fibers of high latent heat and strength: Mass production, characterization and applications

2021 ◽  
Vol 42 ◽  
pp. 103030
Author(s):  
Guoqing Zhang ◽  
Shixiang Xu ◽  
Mengyu Du ◽  
Guojin Liu ◽  
Lan Zhou
Keyword(s):  
Latent Heat ◽  
Mass Production ◽  
High Latent Heat

Change in inter-atomic communication character in the formation of solid and liquid solutions. Relationship of vibrational and configuration entropy and their physical interpretation

2021 ◽  
pp. 28-40
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Heat Capacity ◽  
Heat Release ◽  
Latent Heat ◽  
Physical Interpretation ◽  
Latent Heat Release ◽  
Statistical Entropy ◽  
Average Heat ◽  
Configuration Entropy ◽  
Liquid Solutions ◽  
Relationship Of

The purpose of this work is to show that during mixing, two hidden (latent) processes proceed simultaneously and compensate each other: the first initiates an increase in the average heat capacity, equal in magnitude to the entropy of mixing, which requires energy absorption to ensure a constant temperature, the second initiates simultaneous latent heat release by strengthening interatomic bonds. The passage of these two processes during mixing shows the identity of the vibrational and configurational (statistical) entropy.

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