HEAT PROCESSING OF BEEF. PART VI. THERMAL DIFFUSIVITY AND "SLOPES" OF HEATING AND COOLING CURVES FOR THE HIGH-TEMPERATURE PROCESS

AbstractA microwave generator and a closed-circuit wind tunnel were used to measure the thermal diffusivity of tobacco (Nicotianatabacum L.) stems in vivo by the unsteady-state method. A simple mathematical model for heat flow, based on Fourier's heat-conduction equation and Newton's law of cooling, was used in this study. The microwave method was found to be relatively rapid as both heating and cooling of a cylindrical stem in an air stream could be completed in approximately 30 minutes for thermal-diffusivity determinations. Thermal-diffusivity value of the tobacco stems, containing 94 % moisture and a mean stem temperature of 30°C, was found to be (1.38 ± 0.06) × 10-7 m2 s-1. The coefficient of variation for the measurements did not exceed 1.4 % as determined through the analysis of cooling curves for five different air-flow rates over the stems. This study showed that the microwave technique could be effectively used to determine both accurately and reliably the thermal diffusivity of tobacco stems in vivo.

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POTOMAC

Alloy Digest ◽

10.31399/asm.ad.ts0290 ◽

1975 ◽

Vol 24 (8) ◽

Keyword(s):

Fracture Toughness ◽

High Temperature ◽

Heat Treating ◽

General Purpose ◽

Low Carbon ◽

Repeated Heating ◽

Temperature Changes ◽

Heating And Cooling ◽

Temperature Performance ◽

Heat Checking

Abstract POTOMAC is a general-purpose, low-carbon, chromium-molybdenum-tungsten hot-work steel. It has excellent resistance to shock and heat checking after repeated heating and cooling. Potomac is suitable for hot-work applications involving severe conditions of shock and sudden temperature changes. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-290. Producer or source: Allegheny Ludlum Corporation.

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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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Integrated high temperature heat pumps and thermal storage tanks for combined heating and cooling in the industry

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2021.116731 ◽

2021 ◽

Vol 189 ◽

pp. 116731

Author(s):

Marcel Ulrich Ahrens ◽

Sverre Stefanussen Foslie ◽

Ole Marius Moen ◽

Michael Bantle ◽

Trygve Magne Eikevik

Keyword(s):

High Temperature ◽

Thermal Storage ◽

Heat Pumps ◽

Storage Tanks ◽

Heating And Cooling ◽

Temperature Heat

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Catalyzed Deuterium-Deuterium and Deuterium-Tritium Fusion Blankets for High Temperature Process Heat Production

Nuclear Technology - Fusion ◽

10.13182/fst82-a20734 ◽

1982 ◽

Vol 2 (1) ◽

pp. 55-72 ◽

Cited By ~ 6

Author(s):

Magdi M. H. Ragheb ◽

Behzad Salimi

Keyword(s):

High Temperature ◽

Heat Production ◽

High Temperature Process ◽

Process Heat ◽

Fusion Blankets

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Review on Relationships of Temperature History, Fatigue Damage and Microstructure Evolution Mechanism of Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.584-586.944 ◽

2014 ◽

Vol 584-586 ◽

pp. 944-950 ◽

Cited By ~ 1

Author(s):

Dong Fu Zhao ◽

Mei Liu ◽

Shi Ji Zhang

Keyword(s):

High Temperature ◽

Fatigue Damage ◽

Microstructure Evolution ◽

Research Direction ◽

Concrete Research ◽

Temperature History ◽

Evolution Mechanism ◽

Main Research ◽

High Temperature Process ◽

Application Prospects

The domestic and overseas research progresses of microstructure of the concrete and fatigue damage after treated by high temperature are reviewed. The main research direction and current shortage on the high temperature process, fatigue damage and the microstructure evolution mechanism of concrete are discussed. A view of the application prospects of concrete research on the high temperature process, fatigue damage and the microstructure evolution mechanism of concrete is forecast.

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