Local Temperature and Heat Flux in the Aqueous Solution of Antifreeze Protein Near Ice Surfaces in a Narrow Space

2010 ◽  
Author(s):  
Yoshimichi Hagiwara ◽  
Daichi Yamamoto ◽  
Yosuke Ohnishi
Keyword(s):  
Aqueous Solution ◽  
Heat Flux ◽  
Near Infrared ◽  
Pure Water ◽  
Infrared Camera ◽  
Interface Velocity ◽  
Antifreeze Protein ◽  
Heat Of Fusion ◽  
Protein Solution ◽  
The Difference

Experiments have been conducted into the unidirectional freezing of an aqueous solution of winter flounder antifreeze protein 0.02mm thick. It is confirmed that the instantaneous temperature field can be measured with a near-infrared camera. It is found that the difference between the conduction heat flux of pure water near the interface and that of ice is approximately equal to the heat flux for solidification, which is the product of ice density, interface velocity and the latent heat of fusion. The sum of the conduction heat flux of protein solution near the front edge of the serrated interface and the heat flux for solidification is approximately equal to the conduction heat flux of ice. On the other hand, the sum of the conduction heat flux of protein solution near the bottom edge of the serrated interface and the heat flux for solidification is much higher than the conduction heat flux of ice.

scholarly journals Ice Growth Suppression in the Solution Flows of Antifreeze Protein and Sodium Chloride in a Mini-Channel

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 306
Author(s):  
Kazuya Taira ◽  
Tomonori Waku ◽  
Yoshimichi Hagiwara
Keyword(s):  
Sodium Chloride ◽  
Synergistic Effects ◽  
Pure Water ◽  
Interface Velocity ◽  
Antifreeze Protein ◽  
Layer Growth ◽  
Mixed Solution ◽  
Solution Flow ◽  
Ice Growth ◽  
Cold Energy

The control of ice growth inside channels of aqueous solution flows is important in numerous fields, including (a) cold-energy transportation plants and (b) the preservation of supercooled human organs for transplantation. A promising method for this control is to add a substance that influences ice growth in the flows. However, limited results have been reported on the effects of such additives. Using a microscope, we measured the growth of ice from one sidewall toward the opposite sidewall of a mini-channel, where aqueous solutions of sodium chloride and antifreeze protein flowed. Our aim was to considerably suppress ice growth by mixing the two solutes. Inclined interfaces, the overlapping of serrated interfaces, and interfaces with sharp and flat tips were observed in the cases of the protein-solution, salt-solution, and mixed-solution flows, respectively. In addition, it was found that the average interface velocity in the case of the mixed-solution flow was the lowest and decreased by 64% compared with that of pure water. This significant suppression of the ice-layer growth can be attributed to the synergistic effects of the ions and antifreeze protein on the diffusion of protein.

Inhibition of Blockage by Ice Crystal in Water in a Micro-Channel by Using Antifreeze Protein

2010 ◽  
Author(s):  
Yoshimichi Hagiwara ◽  
Yosuke Ohnishi ◽  
Daichi Yamamoto
Keyword(s):  
Flow Rate ◽  
Pure Water ◽  
Antifreeze Protein ◽  
The Other ◽  
Micro Channel ◽  
Ice Crystal ◽  
Protein Solution ◽  
Local Cooling ◽  
Solution Flow ◽  
Temperature Changes

Experiments have been conducted into the freezing of water flow and the aqueous solution flow of winter flounder antifreeze protein in a micro-channel of 0.15mm in height, 1.2mm in width and 21mm in length. The local temperature is measured with a sheathed thermocouple of 0.1mm in diameter. Nearly flat interfaces, parallel to the cooling sidewall of the channel, are observed in the case of pure water regardless of flow rate. On the other hand, serrated interfaces are observed in the case of protein solution flow regardless of flow rate. The decreasing rate of the temperature changes when the interface reaches the thermocouple. Around this instant, a slight increase in the temperature is observed due to supercooling release. In the case of local cooling, the interface becomes more serrated as the flow rate increases. This is because the interaction between the interface and the protein continuously approaching the interface due to the flow occurs more frequently with an increase in the flow rate.

Critical Heat Flux of Butanol Aqueous Solution

2008 ◽  
Author(s):  
Shotaro Nishiguchi ◽  
Naoki Ono ◽  
Masahiro Shoji
Keyword(s):  
Heat Transfer ◽  
Aqueous Solution ◽  
Surface Tension ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Heated Surface ◽  
Pure Water ◽  
Liquid Temperature ◽  
Heat Transfer Characteristics ◽  
Heated Wire

Aqueous solutions of some alcohols such as butanol show peculiar temperature dependence of surface tension. Contrary to ordinary liquids or solutions, the surface tension increases with temperature at the range of high liquid temperature. So at the triple-phase point on a heated surface, the thermo-capillary force acts for the liquid to wet the heated surface, so the solutions are sometimes called as “self-wetting liquids”. Self-wetting liquids may prohibit the dry-out of a heated surface so that the heat transfer performance would be enhanced. For this reason, applications of self-wetting liquids to heat transfer devices such as heat pipes are actively studied in recent years. However, the heat transfer characteristics of boiling of self-wetting liquids are not fully understood. In the present research, a boiling experiment of butanol aqueous solution was performed on a heated fine wire in order to make clear the fundamental heat transfer characteristics. A heated wire configuration is easy to observe the phenomena and easy to address the fundamental issues of boiling. In the present experiment, nucleate boiling heat transfer were investigated with special attention to critical heat flux (CHF), by changing solution concentration and temperature. Bubbling aspects were observed by high-speed video camera. It is found from the experiment that CHF is generally enhanced 20 to 50% when compared to the case of pure water. It is also found that at a certain concentration and at a certain liquid temperature, peculiar boiling takes place where very small bubbles are emitted from the heated wire and CHF enhancement becomes very large from 2 to 3 times higher than CHF of pure water. The temperature when the peculiar boiling takes place is close to boiling temperature of the solution. These results suggest the possibility of application of aqueous solution to high-performance cooling devices utilizing micro-scaled channels because generating bubbles are small enough so that the pressure loss of the flow passage is small and heat transfer rate is very large.

Fluid Motion and Heat Transfer of Boiling With Impinging Flow in a Mini-Tube With Nonlinear Thermocapillary Solutions

2010 ◽  
Author(s):  
Naoki Ono ◽  
Atsushi Hamaoka ◽  
Yuta Otsubo
Keyword(s):  
Heat Transfer ◽  
Aqueous Solution ◽  
Surface Tension ◽  
Heat Flux ◽  
Liquid Layer ◽  
Heated Surface ◽  
Pure Water ◽  
Heated Area ◽  
Impinging Flow ◽  
Butanol Solution

Boiling heat transfer with impinging flow can be an effective way for cooling a small heated area such as CPUs and laser emitting devices. In the phenomena the movement of liquid layer on the heated surface strongly affects the detachment of boiling bubbles and the heat flux. In this study, nonlinear thermocapillary solutions such as button aqueous solutions were applied to this type of boiling with impinging flow aiming to promote heat transfer. These solutions have special characteristics that the surface tension increases as the temperature is raised over some temperature. It is expected that this tendency about the surface tension will promote the wetting of the heated surface and the detachment of boiling bubbles. In the experiment, T-shaped mini tubes were built with quartz tubes and used for flow boiling. The inner diameter of the tube was 2 mm and the outer diameter was 4 mm. The liquid flow impinged at the junction point where small area was heated by using a conducting thin film coated at the outer surface of the tube. The test fluids were butanol aqueous solution and pure water. The flow rate of the liquid was the order of 1 ml/min, the concentration of the butanol aqueous solution was 7.15 wt %. The liquid motion was observed by CCD video camera system. It was found from the experiment that the motion of the liquid layer of the butanol solution at the impinging area was very different from that of pure water. The layer of the butanol solution tended to extend to the hotter part of the heated area. In another experiment for precisely fixing the imposed heat flux value, T-shaped mini channel with small copper surface installed for heating the fluid was prepared. The cross section of the channel was rectangular shape of 3 mm × 3 mm, and the entire channel was made of insulating polymer material. It was found that the heat transfer of the boiling with impinging flow in using butanol solution was more promoted than that in using pure water.

Understanding the Interaction Between Oligopeptide and Water in Aqueous Solution Using Temperature-Dependent Near-Infrared Spectroscopy

2018 ◽  
Vol 72 (9) ◽  
pp. 1354-1361 ◽  
Author(s):  
Dan Cheng ◽  
Wensheng Cai ◽  
Xueguang Shao
Keyword(s):  
Aqueous Solution ◽  
Independent Component Analysis ◽  
Near Infrared ◽  
Pure Water ◽  
Component Analysis ◽  
Independent Component ◽  
Spectral Intensity ◽  
Spectral Information ◽  
Temperature Dependent ◽  
Water Species

Investigating the interaction between oligopeptide and water is essential for understanding the structure, dynamics and function of proteins. Temperature-dependent near-infrared (NIR) spectroscopy and independent component analysis (ICA) were employed to study the interaction between oligopeptide and water in aqueous solution. The NIR spectra of two homo-oligopeptides, penta-aspartic acid (D5) and penta-lysine (K5), in aqueous solution of different concentration were measured at different temperature (30–90 ℃). Independent component analysis was performed to extract the spectral information that changes with temperature. The independent components (ICs) representing the spectral information of NH and CH2 groups were obtained. Compared with D5, the two groups in K5 change significantly at higher temperature. The result may suggest that K5 has stronger interaction with water than D5. Moreover, three ICs that contain the spectral information of the water species with no (S0), one (S1), and two (S2) hydrogen-bonds were obtained. It was shown that the spectral intensity of S0 and S1 increases while that of S2 decreases with the temperature, and the changes of oligopeptide solutions are weaker than those of pure water. The results indicate that water structure is sensitive to temperature and the oligopeptide in aqueous solution improves the thermal stability of the water species. When oligopeptide is added, the spectral intensity of S0 and S2 decreases and that of S1 increases for D5 solution, but the intensity of all the three species decreases for K5 solution. Furthermore, the concentration effect of K5 was found to be stronger than D5. The result may reveal that D5 combines with water molecule through forming one hydrogen bond but K5 interacts with water through a different way.

scholarly journals Search for giant planets around seven white dwarfs in the Hyades cluster with the Hubble Space Telescope

2020 ◽  
Vol 500 (3) ◽  
pp. 3920-3925
Author(s):  
Wolfgang Brandner ◽  
Hans Zinnecker ◽  
Taisiya Kopytova
Keyword(s):  
White Dwarfs ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
Infrared Camera ◽  
Detection Limits ◽  
Giant Planets ◽  
High Angular Resolution ◽  
Mass Detection ◽  
Space Telescope ◽  
Hyades Cluster

ABSTRACT Only a small number of exoplanets have been identified in stellar cluster environments. We initiated a high angular resolution direct imaging search using the Hubble Space Telescope (HST) and its Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument for self-luminous giant planets in orbit around seven white dwarfs in the 625 Myr old nearby (≈45 pc) Hyades cluster. The observations were obtained with Near-Infrared Camera 1 (NIC1) in the F110W and F160W filters, and encompass two HST roll angles to facilitate angular differential imaging. The difference images were searched for companion candidates, and radially averaged contrast curves were computed. Though we achieve the lowest mass detection limits yet for angular separations ≥0.5 arcsec, no planetary mass companion to any of the seven white dwarfs, whose initial main-sequence masses were >2.8 M⊙, was found. Comparison with evolutionary models yields detection limits of ≈5–7 Jupiter masses (MJup) according to one model, and between 9 and ≈12 MJup according to another model, at physical separations corresponding to initial semimajor axis of ≥5–8 au (i.e. before the mass-loss events associated with the red and asymptotic giant branch phase of the host star). The study provides further evidence that initially dense cluster environments, which included O- and B-type stars, might not be highly conducive to the formation of massive circumstellar discs, and their transformation into giant planets (with m ≥ 6 MJup and a ≥6 au). This is in agreement with radial velocity surveys for exoplanets around G- and K-type giants, which did not find any planets around stars more massive than ≈3 M⊙.

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