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  • thermal conductivity  (52)
  • thermal diffusivity  (27)
  • phylogeny
  • Springer  (79)
  • Blackwell Publishing Ltd
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  • 1
    Electronic Resource
    Electronic Resource
    A high-temperature system based on the laser flash method to measure the thermal diffusivity of melts (1996)
    Springer
    International journal of thermophysics 17 (1996), S. 253-261 
    Details
    ISSN: 1572-9567
    Keywords: flash method ; melts ; radiation correction ; slags ; three-layer analysis ; thermal conductivity ; thermal diffusivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A high-temperature measuring system has been developed to undertake measurements of thennal difusivity and specific heat up to 1900 K. The overall design allows measurements on solids to be undertaken using the accepted standard techniques and analytical procedures. The specific design for molten materials and especially slags is based on the differential threelayer technique utilizing a special cell which can be accomodated in the system. In this method, the liquid specimen is sandwiched between an upper inner platinum crucible and a lower outer platinum crucible, to provide a three-layered sandwich. A laser pulse irradiates the surface of the upper platinum crucible and the temperature response of the surface of the lower platinum crucible is observed. For the purpose of accurate measurement of specimen thickness at the measuring temperature, two runs are performed in which the thicknesses arel andl+°Dl, wherel is unknown butΔl can be set accurately with a built-in micrometer. The thermal difusivity is obtained through a curve-fitting method by a personal computer using a three-layer analysis with a correction for the radiative component based on the transparent body assumption. Following verification of the basic performance, using solids of known properties and water and ethanol, a continuous casting mixture has been evaluated. The initial results on the fluids are in good agreement with those in the literature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01448227
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  • 2
    Electronic Resource
    Electronic Resource
    Measurement of Thermal Diffusivity of Thermal Control Coatings by the Flash Method Using Two-Layer Composite Sample1 (2000)
    Springer
    International journal of thermophysics 21 (2000), S. 535-542 
    Details
    ISSN: 1572-9567
    Keywords: flash method ; thermal contact resistance ; thermal control coatings ; thermal diffusivity ; two-layer composite sample
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The thermal diffusivity of brittle coatings cannot be measured by the flash method directly because of the difficulty of preparing free-standing samples. Adopting the flash method using a two-layer composite sample, it is possible to measure thermal diffusivity if the radiant pulse is well defined and good thermal contact on the interface of the composite sample can be ensured. Using an equilateral trapezoidal pulse of an Nd-glass laser measuring the dimensionless temperature history of the rear face of the sample, we determined the thermal diffusivity of thermal control coatings in the temperature range of 80 to 200°C. The results for different thicknesses of substrate showed that the thermal contact resistance of the interface can be neglected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006660318958
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal Diffusivity Measurement of Diamond Films1 (2000)
    Springer
    International journal of thermophysics 21 (2000), S. 479-485 
    Details
    ISSN: 1572-9567
    Keywords: diamond ; film ; flash method ; thermal diffusivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This paper discusses the short-pulse-flash method developed for thermal diffusivity measurements on thin films. Two kinds of CVD diamond film have been prepared, and their thermal diffusivity in the perpendicular direction has been measured with this method. The measurement errors caused by the surface coating are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006648016232
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  • 4
    Electronic Resource
    Electronic Resource
    Measurements and correlation of the thermal conductivity of liquid n-paraffin hydrocarbons and their binary and ternary mixtures (1985)
    Springer
    International journal of thermophysics 6 (1985), S. 251-265 
    Details
    ISSN: 1572-9567
    Keywords: alkanes ; hydrocarbons ; liquids ; mixing rule ; thermal conductivity ; transient hot-wire method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The thermal conductivity of four pure normal paraffin hydrocarbons (C11, C14, C15, C16) and binary and ternary mixtures of three n-paraffin hydrocarbons (C7, C11, C16) have been measured in the temperature range from about 20 to 90°C at atmospheric pressure. Measurements have been performed with the aid of a fully automated transient hot-wire instrument. The accuracy of the reported data is estimated to be ±1.0 to ±1.5%. A new simple and practical equation, which can calculate the thermal conductivity of pure n-paraffin hydrocarbons (4≤n≤ 16) with the uncertainty of ±1%, has been correlated in terms of temperature and number of carbon atoms based on the present results including some other reliable data. Also, a mixing rule for the mixtures of n-paraffin hydrocarbons was proposed and was adequately confirmed by the present results within the experimental error.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00522147
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  • 5
    Electronic Resource
    Electronic Resource
    Thermal conductivity of gaseous fluorocarbon refrigerants R 12, R 13, R 22, and R 23, under pressure (1981)
    Springer
    International journal of thermophysics 2 (1981), S. 249-268 
    Details
    ISSN: 1572-9567
    Keywords: chorotrifluoromethane (R 13) ; chlorodifluoromethane (R 22) ; dichlorodifluoromethane (R 12) ; fluorocarbon ; pressure effect on thermal conductivity ; thermal conductivity ; trifluoromethane (R 23)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The thermal conductivity of four gaseous fluorocarbon refrigerants has been measured by a vertical coaxial cylinder apparatus on a relative basis. The fluorocarbon refrigerants used and the ranges of temperature and pressure covered are as follows: R 12 (Dichlorodifluoromethane CCl2F2): 298.15–393.15 K, 0.1–4.28 MPa R 13 (Chlorotrifluoromethane CClF3): 283.15–373.15 K, 0.1–6.96 MPa R 22 (Chlorodifluoromethane CHClF2): 298.15–393.15 K, 0.1–5.76 MPa R 23 (Trifluoromethane CHF3): 283.15–373.15 K, 0.1–6.96 MPa The apparatus was calibrated using Ar, N2, and CO2 as the standard gases. The uncertainty of the experimental data is estimated to be within 2%, except in the critical region. The behavior of the thermal conductivity for these fluorocarbons is quite similar; thermal conductivity increases with increasing pressure. The temperature coefficient of thermal conductivity at constant pressure, (∂λ/∂T) p , is positive at low pressures and becomes negative at high pressures. Therefore, the thermal conductivity isotherms of each refrigerant intersect each other in a specific range of pressure. A steep enhancement of thermal conductivity is observed near the critical point. The experimental results are statistically analyzed and the thermal conductivities are expressed as functions of temperature and pressure and of temperature and density.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00504188
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  • 6
    Electronic Resource
    Electronic Resource
    Thermal conductivity of five normal alkanes in the temperature range 283–373 k at pressures up to 250 MPa (1988)
    Springer
    International journal of thermophysics 9 (1988), S. 331-350 
    Details
    ISSN: 1572-9567
    Keywords: alkane ; correlation ; decane ; dodecane ; heptane ; hexane ; octane ; thermal conductivity ; transient hot-wire method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Experimental data on the thermal conductivity of five liquid n-alkanes-hexane, heptane, octane, decane, and dodecane-are presented in the temperature range from 283 to 373 K at pressures up to 250 MPa or the freezing pressures. The measurements were performed on an absolute basis by an automated transient hot-wire apparatus. The uncertainty of the reported data is estimated to be within ±1%. The thermal conductivity of each alkane decreases almost linearly with rising temperature at a constant pressure and increases with increasing pressure at a constant temperature. Both the temperature coefficient of the thermal conductivity ¦(∂λ/∂T) p¦ and the pressure coefficient (∂λ/∂P) T decrease with increasing carbon number of alkanes. The experimental results were correlated with temperature and pressure by a similar expression to the Tait equation. It is also found that both the dense hard-sphere model presented by Menashe et al. and the modified significant structure theory proposed by Prabhuram and Saksena provide good representations of the present experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00513075
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  • 7
    Electronic Resource
    Electronic Resource
    Rapid measurement of the thermal diffusivity of flowing polymer melts (1993)
    Springer
    International journal of thermophysics 14 (1993), S. 585-592 
    Details
    ISSN: 1572-9567
    Keywords: anisotropy ; forced Rayleigh scattering method ; polymer melt ; polystyrene ; thermal diffusivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Use of polymer materials for precision parts in advanced technology requires precise control of production processes such as melting, casting, and cooling processes. To achieve this, a reliable knowledge of thermophysical properties is essential. In the present study, submillisecond measurement of the thermal diffusivity of a flowing polymer melt was performed. Laminar flow of polymer melt through a narrow gap between two parallel plates creates a shear stress in the flow layer which then results in molecular orientation of polymer molecules. Once this orientation takes place, anisotropy of the thermal diffusivity is expected to occur. The method used in the present study was that of the so-called forced Rayleigh scattering method, a high-speed optical method. Nagasaka and Nagashima have recently improved the method significantly and applied it to the measurements on various difficult materials including molten salts. Measurement of thermal diffusivity anisotropy of molten polystyrene was successfully performed. Dependence of the thermal diffusivity and its anisotropy on shear force in flowing polymer melt was studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00566055
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  • 8
    Electronic Resource
    Electronic Resource
    Development of a database system for the thermophysical properties of 340 pure fluids (1983)
    Springer
    International journal of thermophysics 4 (1983), S. 283-294 
    Details
    ISSN: 1572-9567
    Keywords: compressibility factor ; database system: density ; dielectric constant ; refractive index ; retrieval program ; specific enthalpy ; specific entropy ; specific heat capacity ; specific volume ; surface tension ; thermal conductivity ; vapor pressure ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new database system was designed and constructed in order to provide the newest and most reliable numerical data on thermophysical properties of fluids to the scientific and technical community as quickly as possible. The database is concerned with 12 kinds of property data: density, specific volume, compressibility factor, vapor pressure, specific heat, specific enthalpy, specific entropy, viscosity, thermal conductivity, surface tension, refractive index, and dielectric constant of 340 pure fluids under all conditions of seven convenient physical states. Only the most probable data, which were critically evaluated in advance, are compiled as functions of temperature and pressure in the form of either numerical data tables or correlation formulas. Property values at desired grid points of temperature and pressure can be obtained in SI units directly or by interpolations with some supplementary information, such as the grade of reliability, source bibliography, and fundamental physical constants of the fluid. The database is usable as conversational processing by TSS, the tabulation of property data in a batch processing, and one of the subroutine libraries in the computation of a user's program. Ten kinds of application programs are prepared for multipurpose retrievals so that anyone can use the database without any special knowledge of the structure or machine languages of this system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01178780
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  • 9
    Electronic Resource
    Electronic Resource
    Development of non-reproductive castes in the neotropical termite generaCornitermes, Embiratermes andRhynchotermes (Isoptera, Nasutitermitinae) (1992)
    Springer
    Insectes sociaux 39 (1992), S. 313-324 
    Details
    ISSN: 1420-9098
    Keywords: Isoptera ; Termitidae ; Nasutitermitinae ; caste differentiation ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental pattern of the neuter castes was studied in the mandibulate nasute generaCornitermes, Embiratermes andRhynchotermes. InCornitermes walkeri, all the workers and soldiers are male. There are two larval and a single worker instar. Workers can molt into presoldiers. InEmbiratermes chagresi andRhynchotermes perarmatus, both sexes are present among the neuters. A slight sexual dimorphism (males 〉 females) is discernible among both larval instars and among workers ofE. chagresi; female workers can molt into presoldiers. InR. perarmatus, the sexual dimorphism is conspicuous from the first larval instar on. Male larvae go through two instars, then give rise to workers, which do not molt. InR. perarmatus, there is no worker stage in females, but a third larval instar, preceding the presoldier. Hypotheses are proposed as to the evolution of these caste patterns, attempting to conciliate present knowledge of Nasutitermitinae phylogeny and known evolutionary trends affecting termite caste patterns, according to the species' ecology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01323951
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  • 10
    Electronic Resource
    Electronic Resource
    Castes in humivorous and litter-dwelling neotropical nasute termites (Isoptera, Termitidae) (1996)
    Springer
    Insectes sociaux 43 (1996), S. 375-389 
    Details
    ISSN: 1420-9098
    Keywords: Nasutitermitinae ; Subulitermes ; Coatitermes ; Velocitermes ; evolution ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental pathways of the neuter castes were studied in three species of Nasutitermitinae from central Panama. The humivorousSubulitermes denisae andCoatitermes clevelandi display several primitive traits: absence of sex dimorphism, representation of both sexes among workers and soldiers, and occurrence of successive worker instars. The litter-dwellingVelocitermes barrocoloradensis has a more complex caste system: female larvae are larger than males and give rise to the large workers, which constitute the bulk of the work force; male larvae proceed to soldiers through a small worker or a special larval instar. The resulting soldier caste is polymorphic. These results support previously formulated hypotheses regarding a link between humivorous diet and reduced polymorphism on the one hand, and between forest-floor foraging and large continuous size variation among soldiers on the other. Whereas the caste systems ofSubulitermes andCoatitermes probably represent a primitive condition,Velocitermes shares derived traits withNasutitermes and the other fully nasute genera previously studied. I therefore hypothesize that ancestors with these advanced features may have spread from the neotropics and be at the origin of most nasute genera, including humivorous taxa, present in other regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01258410
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