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  • 1
    Electronic Resource
    Electronic Resource
    Growth, sex differentiation and gonad and plasma levels of sex steroids in male- and female-dominant populations of Dicentrarchus labrax obtained through repeated size grading (2005)
    Oxford, UK; Malden, USA : Blackwell Science Ltd
    Journal of fish biology 66 (2005), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Starting from 66 days post hatching (dph), European sea bass Dicentrarchus labrax were graded successively to create a fast growing (L-extreme) and a slow growing (S-extreme) population. The L-extreme population grew significantly larger (ANOVA, n = 89–101, P 〈 0·01) attaining twice the wet mass of the S-extreme population at 300 dph (130·9 ± 1·8 v. 66·7 ± 0·9 g, mean ± s.e.). When the two populations were sexed, the L-extreme consisted of 96·5% and the S-extreme of 30·2% females, while the ungraded control had 59·2% females. Sex differentiation began first in females at a total length (LT) of 97 ± 4 mm and wet mass of 9·4 ± 1·2 g (150 dph), and was completed when fish reached 166 ± 6 mm and 53·4 ± 6·4 g (250 dph) in both sexes. Precocious maturation in males was positively correlated to growth. Gonad oestradiol (E2) was significantly higher in the female-dominant population at the onset of ovarian differentiation (ANOVA, n = 10, P 〈 0·05) and in the plasma after the appearance of the first primary oocytes (P 〈 0·01). Gonad testosterone (T) increased in both populations after sex differentiation (ANOVA, n = 10, P 〈 0·05), while plasma levels were significantly higher in the male-dominant population (P 〈 0·001). Both gonad and plasma 11-keto testosterone (11-KT) were significantly higher in the male-dominant population (ANOVA, n = 10, P 〈 0·01) reaching maximal values at spermiation. The results suggest that E2 is closely related with ovarian differentiation and the onset of oogenesis, while T and 11-KT is more related to spermatogenesis and precocious maturation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.0022-1112.2005.00639.x
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  • 2
    Electronic Resource
    Electronic Resource
    An experimental comparison of secret-based user authentication technologies (2002)
    Bradford : Emerald
    Information management & computer security 10 (2002), S. 100-108 
    Details
    ISSN: 0968-5227
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Computer Science
    Notes: The paper presents a comparative study of software-based user authentication techniques, contrasting the use of traditional password and personal identifier numbers (PIN) against alternative methods involving question and answer responses and graphical representation. All methods share the common basis of some secret knowledge and rely upon the user's ability to recall it in order to achieve authentication. An experimental trial is described, along with the results based upon 27 participants. The alternative methods are assessed in terms of practical effectiveness (in this context relating to the participant's ability to authenticate themselves a significant time after initial use of the methods), as well as the perceived levels of user friendliness and security that they provide. The investigation concludes that while passwords and PIN approaches garner good ratings on the basis of their existing familiarity to the participants, other methods based upon image recall and cognitive questions also achieved sufficiently positive results to suggest them as viable alternatives in certain contexts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/09685220210431854
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  • 3
    Electronic Resource
    Electronic Resource
    An absolute vibrating-wire viscometer for liquids at high pressures (1991)
    Springer
    International journal of thermophysics 12 (1991), S. 231-244 
    Details
    ISSN: 1572-9567
    Keywords: high pressure ; n-hexane ; vibrating wire ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The design and operation of a new vibrating-wire viscometer for the measurement of the viscosity of liquids at pressures up to 100 MPa are described. The design of the instrument is based on a complete theory so that it is possible to make absolute measurements with an associated error of only a few parts in one thousand. Absolute measurements of the viscosity of n-hexane are reported at 298.15 K at pressures up to 80 MPa. The overall uncertainty in the reported viscosity data is estimated to be ±0.5%, an estimate confirmed by the comparison of values of viscosity of slightly inferior accuracy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500749
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  • 4
    Electronic Resource
    Electronic Resource
    Measurements of the viscosity of benzene, toluene, and m-xylene at pressure up to 80 MPa (1991)
    Springer
    International journal of thermophysics 12 (1991), S. 449-457 
    Details
    ISSN: 1572-9567
    Keywords: benzene ; high pressure ; toluene ; viscosity ; vibrating wire ; m-xylene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New absolute measurements of the viscosity of benzene, toluene, and m-xylene are presented. The measurements were performed in a recently developed vibrating-wire instrument, at temperatures of 303.15 and 323.15 K and pressures up to 80 MPa. The overall uncertainty in the reported viscosity data is estimated to be ±0.5%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502361
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  • 5
    Electronic Resource
    Electronic Resource
    Measurements of the viscosity of n-heptane, n-nonane, and n-undecane at pressures up to 70 MPa (1991)
    Springer
    International journal of thermophysics 12 (1991), S. 801-810 
    Details
    ISSN: 1572-9567
    Keywords: high pressure ; n-heptane ; n-nonane ; n-undecane ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New absolute measurements of the viscosity of n-heptane, n-nonane, and n-undecane are presented. The measurements were performed with a vibrating-wire instrument at temperatures of 303.15 and 323.15 K and pressures up to 70 MPa. The overall uncertainty in the reported viscosity data is estimated to be ±0.5%. A recently developed semiempirical scheme for the correlation and prediction of the thermal conductivity, viscosity, and self-diffusion coefficients of n-alkanes is applied to the prediction of the viscosity of n-heptane, n-nonane, and n-undecane. The comparison of these predicted values with the present high-pressure measurements demonstrates the predictive power of this scheme.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502407
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  • 6
    Electronic Resource
    Electronic Resource
    Measurements of the viscosity of n-heptane + n-undecane mixtures at pressures up to 75 MPa (1991)
    Springer
    International journal of thermophysics 12 (1991), S. 811-820 
    Details
    ISSN: 1572-9567
    Keywords: high pressures ; mixtures ; n-heptane ; n-undecane ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New absolute measurements of the viscosity of binary mixtures of n-heptane and n-undecane are presented. The measurements, performed in a vibrating-wire instrument, cover the temperature range 295–335 K and pressures up to 75 MPa. The concentrations studied were 40 and 70%, by weight, of n-heptane. The overall uncertainty in the reported viscosity data is estimated to be ±0.5%. A recently extended semiempirical scheme for the prediction of the thermal conductivity of mixtures from the pure components is used to predict successfully both the thermal conductivity and the viscosity of these mixtures, as a function of composition, temperature, and pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502408
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  • 7
    Electronic Resource
    Electronic Resource
    The thermal conductivity of some alkyl ethers and alkanones (1991)
    Springer
    International journal of thermophysics 12 (1991), S. 937-942 
    Details
    ISSN: 1572-9567
    Keywords: alkanones ; alkyl ethers ; thermal conductivity ; transient hot wire
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New absolute measurements, by the transient hot-wire technique, of the thermal conductivity of some alkyl ethers and alkanones are presented. The alkyl ethers studied are tert-butyl methyl ether, di-iso-propyl ether and di-butyl ether, while the alkanones studied are 2-butanone, 4-methyl pentan-2-one, and 2-octanone. The temperature range examined was 295–350 K, and the pressure atmospheric. The overall uncertainty in the reported thermal conductivity data is estimated to be better than ±1%, an estimate confirmed by the measurement of the thermal conductivity of water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00502417
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  • 8
    Electronic Resource
    Electronic Resource
    Viscosity and thermal conductivity of binary n-heptane + n-alkane mixtures (1992)
    Springer
    International journal of thermophysics 13 (1992), S. 237-249 
    Details
    ISSN: 1572-9567
    Keywords: n-heptane ; n-hexane ; n-nonane ; prediction ; thermal conductivity ; vibrating wire ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New absolute measurements of the viscosity of binary mixtures of n-heptane with n-hexane and n-nonane are presented. The measurements, performed in a vibrating-wire instrument, cover a temperature range 290–335 K and pressures up to 75 MPa. The concentrations studied are 40 and 70% by weight of n-heptane. The accuracy of the reported viscosity data is estimated to be ±0.5%. The present measurements, together with other n-heptane + n-alkane viscosity and thermal-conductivity measurements, are used to develop a consistent semiempirical scheme for the correlation and prediction of these mixture properties from those of the pure components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00504434
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  • 9
    Electronic Resource
    Electronic Resource
    Correlation and prediction of dense fluid transport coefficients. I. n-alkanes (1992)
    Springer
    International journal of thermophysics 13 (1992), S. 269-281 
    Details
    ISSN: 1572-9567
    Keywords: diffusion ; hard-sphere theory ; n-alkanes ; thermal conductivity ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Recent accurate measurements of the self-diffusion coefficient for n-hexadecane and n-octane and of the viscosity coefficient for n-heptane, n-nonane, and n-undecane over wide pressure ranges have been used to provide a critical test of a previously described method, based on consideration of hard-sphere theory, for the correlation of transport coefficient data. It is found that changes are required to the universal curve for the reduced viscosity coefficient as a function of reduced volume and, also, to the parameters R D, R η , and R λ which were introduced to account for effects of nonspherical molecular shape. The scheme now accounts most satisfactorily for the self-diffusion, viscosity, and thermal conductivity coefficient data for all n-alkanes from methane to hexadecane at densities greater than the critical density.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00504436
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  • 10
    Electronic Resource
    Electronic Resource
    Vibrating-wire viscometers for liquids at high pressures (1992)
    Springer
    International journal of thermophysics 13 (1992), S. 593-615 
    Details
    ISSN: 1572-9567
    Keywords: high pressure ; vibrating wire ; viscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The design and operation of two independent vibrating-wire viscometers are described. The instruments are intended for operation in the liquid phase at pressures up to 300 MPa and have been designed specifically for this purpose using the detailed theory of the device. Extensive evidence is adduced to demonstrate that the operation of the viscometers is consistent with the theory. Although the instruments attain a precision in viscosity measurements of ±0.1%, when used in an absolute mode the accuracy that can be achieved is no better than ±3%. However, if the instrument is calibrated for two welldefined instrumental parameters, the uncertainty in the reported viscosity is improved to +0.5%. The results of measurements of the viscosity of normal heptane in the temperature range 303 to 348 K at pressures up to 250 MPa made with one of the viscometers are reported. The results are shown to be totally consistent with measurements reported earlier using the instrument designed for lower pressures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501943
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