Following an earlier study, we reexamined the latent heat of fusion during freezing at 5 K/min of twelve different pre-nucleated solute-laden aqueous solutions using a Differential Scanning Calorimeter (DSC) and correlated it with the amount of initially dissolved solids or solutes in the solution. In general, a decrease in DSC-measured heat release (in comparison to that of pure water, 335 mJ/mg) was observed with an increasing fraction of dissolved solids or solutes, as observed in the earlier study. In addition, the kinetics of ice crystallization was also obtained in three representative biological media by performing additional experiments at 1, 5 and 20 K/min. A model of ice crystallization based on the phase diagram of a water-NaCl binary solution and a modified Avrami-like model of kinetics was then developed and fit to the experimental data. Concurrently, a heat and mass transfer model of the freezing of a salt solution in a small container is also presented to account for the effect of the cooling rate as well as the solute concentration on the measured latent of freezing. This diffusion-based model of heat and mass transfer was non-dimensionalized, solved using a numerical scheme and compared with experimental results. The simulation results show that the heat and mass transfer model can predict (± 10%) the experimental results.
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http://dx.doi.org/10.3390/bioengineering9100540 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China.
A carbon nanotube (CNT) composite is an effective method to improve the thermoelectricity of materials. However, the depletion layer between the CNT and thermoelectric (TE) material always decreases the contribution of CNT to the conductivity of the TE material. It is important to eliminate the depletion layer for improving the TE properties.
View Article and Find Full Text PDFSmall Methods
January 2025
School of Mechanical and Aerospace Engineering, Gyeongsang National University, Jinju, 52828, South Korea.
In various applications, the pore structure of a porous medium must be controlled to facilitate heat and mass transfer, which considerably influence the system performance. Freeze-casting is a versatile technique for creating aligned pores; However, because of the complexity of the associated equipment and the energy inefficiency of liquid-nitrogen-based cooling in a room-temperature environment, limits scalability for industrial applications. This study is aimed at establishing a novel freeze-casting strategy with a simple mold design combining heat-conductive and insulating materials for long-range pore alignment via directional ice growth under deep-freezing conditions, rendering it feasible for large-scale production.
View Article and Find Full Text PDFIntroduction: It has been reported that even with the same body mass index (BMI), there are subjects with metabolically healthy or unhealthy phenotype. The main determinants of the unhealthy phenotype are the type and distribution of fat, ectopic fat accumulation, genetics, and lifestyle factors. Uncoupling proteins (UCPs) disengage mitochondrial respiration from ATP synthesis and result in heat production, which in turn is related to energy expenditure and, thus, to fat mass accumulation.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
January 2025
Department of Biology, Colgate University, Hamilton, New York, USA.
An animal's body mass is said to be indirectly related to its rate of heat loss; that is, smaller animals with higher surface area to volume tend to lose heat faster than larger animals. Thus, thermoregulation should be related to body size, however, generalizable patterns are still unclear. Domestic dogs are a diverse species of endothermic mammals, including a 44-fold difference in body size.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Mechanical Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Background: The development of heat transfer devices used for heat conversion and recovery in several industrial and residential applications has long focused on improving heat transfer between two parallel plates. Numerous articles have examined the relevance of enhancing thermal performance for the system's performance and economics. Heat transport is improved by increasing the Reynolds number as the turbulent effects grow.
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