Mechanism of fume suppression and performance on asphalt of expanded graphite for pavement under high temperature condition

Background: Orthosiphon stamineus is a traditional medicinal plant in Southeast Asia countries with various well-known pharmacological activities such as antidiabetic, diuretics and antitumor activities. Transketolase is one of the proteins identified in the leaves of the plant and transketolase is believed able to lower blood sugar level in human through non-pancreatic mechanism. In order to understand the protein behavioral properties, 3D model of transketolase and analysis of protein structure are of obvious interest. Methods: In the present study, 3D model of transketolase was constructed and its atomic characteristics revealed. Besides, molecular dynamic simulation of the protein at 310 K and 368 K deciphered transketolase may be a thermophilic protein as the structure does not distort even at elevated temperature. This study also used the protein at 310 K and 368 K resimulated back at 310 K environment. Results: The results revealed that the protein is stable at all condition which suggest that it has high capacity to adapt at different environment not only at high temperature but also from high temperature condition to low temperature where the structure remains unchanged while retaining protein function. Conclusion: The thermostability properties of transketolase is beneficial for pharmaceutical industries as most of the drug making processes are at high temperature condition.

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Laboratory-Scale Processing and Performance Assessment of Ti–Ta High-Temperature Shape Memory Spring Actuators

Shape Memory and Superelasticity ◽

10.1007/s40830-021-00334-1 ◽

2021 ◽

Author(s):

A. Paulsen ◽

H. Dumlu ◽

D. Piorunek ◽

D. Langenkämper ◽

J. Frenzel ◽

...

Keyword(s):

High Temperature ◽

Shape Memory ◽

Detrimental Effect ◽

Wire Drawing ◽

Fast Heating ◽

Heating And Cooling ◽

Arc Melting ◽

Ω Phase ◽

And Performance

AbstractTi75Ta25 high-temperature shape memory alloys exhibit a number of features which make it difficult to use them as spring actuators. These include the high melting point of Ta (close to 3000 °C), the affinity of Ti to oxygen which leads to the formation of brittle α-case layers and the tendency to precipitate the ω-phase, which suppresses the martensitic transformation. The present work represents a case study which shows how one can overcome these issues and manufacture high quality Ti75Ta25 tensile spring actuators. The work focusses on processing (arc melting, arc welding, wire drawing, surface treatments and actuator spring geometry setting) and on cyclic actuator testing. It is shown how one can minimize the detrimental effect of ω-phase formation and ensure stable high-temperature actuation by fast heating and cooling and by intermediate rejuvenation anneals. The results are discussed on the basis of fundamental Ti–Ta metallurgy and in the light of Ni–Ti spring actuator performance.

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The impact of flow field plate misalignment on the gas diffusion layer intrusion and performance of a high-temperature polymer electrolyte fuel cell

Journal of Power Sources ◽

10.1016/j.jpowsour.2021.230036 ◽

2021 ◽

Vol 501 ◽

pp. 230036

Author(s):

Eugen Hoppe ◽

Holger Janßen ◽

Martin Müller ◽

Werner Lehnert

Keyword(s):

High Temperature ◽

Fuel Cell ◽

Flow Field ◽

Polymer Electrolyte ◽

Diffusion Layer ◽

Gas Diffusion ◽

Polymer Electrolyte Fuel Cell ◽

Field Plate ◽

And Performance ◽

The Impact

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Investigation Into Thermal Stress Characteristics of Pipe-in-Pipe Under High Temperature Condition

Volume 3A: Design and Analysis ◽

10.1115/pvp2018-84578 ◽

2018 ◽

Author(s):

Si-Hwa Jeong ◽

Min-Gu Won ◽

Nam-Su Huh ◽

Yun-Jae Kim ◽

Young-Jin Oh ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Stress ◽

High Temperature ◽

Temperature Distribution ◽

Heat Transfer Analysis ◽

Piping System ◽

Curved Pipe ◽

High Temperature Condition ◽

Single Pipe ◽

Radiation Conditions

In this paper, the thermal stress characteristics of the pipe-in-pipe (PIP) system under high temperature condition are analyzed. The PIP is a type of pipe applied in sodium-cooled faster reactor (SFR) and has a different geometry from a single pipe. In particular, under the high temperature condition of the SFR, the high thermal stress is generated due to the temperature gradient occurring between the inner pipe and outer pipe. To investigate the thermal stress characteristics, three cases are considered according to geometry of the support. The fully constrained support and intermediate support are considered for case 1 and 2, respectively. For case 3, both supports are applied to the actual curved pipe. The finite element (FE) analyses are performed in two steps for each case. Firstly, the heat transfer analysis is carried out considering the thermal conduction, convection and radiation conditions. From the heat transfer analysis, the temperature distribution results in the piping system are obtained. Secondly, the structural analysis is performed considering the temperature distribution results and boundary conditions. Finally, the effects of the geometric characteristics on the thermal stress in the PIP system are analyzed.

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Effect of Expanded Temperature on Microstructure of Carbon Nanotubes/Expanded Graphite Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.716.373 ◽

2013 ◽

Vol 716 ◽

pp. 373-378

Author(s):

Qian Zhang ◽

Xin Bao Gao ◽

Tian Peng Li

Keyword(s):

Carbon Nanotubes ◽

Composite Material ◽

High Temperature ◽

Carbon Nanotube ◽

Physical Adsorption ◽

Expanded Graphite ◽

Graphite Flake ◽

Graphite Composite ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Carbon nanotube/expanded graphite composite material was prepared by expanding the mixture of multi-walled carbon nanotubes and expansible graphite under the condition of high temperature. The microstructure and composition was studied by using SEM and XRD. The study shows that the tubular structure of carbon nanotubes in the composite material is changed by high temperature expanding process, and the microstructure is different with different expanding temperature. When the expanding temperature was 900°C, carbon nanotubes transformed, then attached to the surface of expanded graphite flake, so carbon nanotubes and expanding graphite combined strongly; globular carbon nanotubes attached to the surface of expanded graphite flake at the temperature of 700°C, both were combined much more strongly; carbon nanotubes retained the tube structure at the temperature of 500°C, combination was looser due to the simple physical adsorption. The result shows that the choice of expanding temperature has an important effect on microstructure of carbon nanotube/expanded graphite composite material.

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