Stefan, Josef

Stahre, Ludvig (1843-1909), 313 Staszic, Stardslaw (1755-1826), 238 Steen, Caroline (1854-1935), 230 Steenberg, Niels Georg (1839-1915), 79 Steenbuch, Erik Christian Verlaufif (1850-1910), 79 Stefan, Josef (1835-1893), 3 Stein, SigfiedFrederik Edvard Valdemar (1836-1905), 79, 80 Stevenson, Sir Thomas (1838-1908),... 

Two crucial pieces of experimental information about black-body radiation were discovered in the late nineteenth century. In 1879, Josef Stefan investigated the increasing brightness of a black body as it is heated and discovered that the total intensity of radiation emitted over all wavelengths increases as the fourth... 

Ludwig Boltzmann was bom into the family of a Viennese tax collector and educated at his parent s home by private tutor until high school. After completing his PhD (on the kinetic theory of gases, with Josef Stefan) at Vienna, he became full Professor of Mathematical... 

Blinc, R., Lahajnar, Nukl. Inst. Josef Stefan Rept. 530 (1968). 

Stanislaw Biniecki, Stanislaw Chachula, Helena Jozwiak, Zbigniew Ludwicki, Stefan Labedzki, Wiktor Fietrzak, Stanislaw Pieta, Stanislaw Paradowski, Josef Izdebski, Alicja Maria Izdebska, Barbara Anieszka Izdebska US Patent No. 3,591,588 July 6, 1971 As... 

Josef Stefan Institute, Jamova 39,1000 Ljubljana, Slovenia E-mail robert.blinc ijs.si... 

We also can predict the total energy a blackbody emits. According to the Stefan-Boltzmann radiation law formulated in 1879 by Austrian physicist Josef Stefan and derived in 1889 by Austrian physicist Ludwig Boltzmann, the amount of energy emitted is proportional to the fourth power of the temperature of the object. A star that is the same size and four times as hot as our Sun radiates 44 or 256 times more energy than the Sun. A spherical blackbody (like a star) will produce a luminosity, I, that depends on the star s surface area times the fourth power of its temperature. We ll discuss this further in chapter 5. We ll also discuss in more detail how the chemical composition of the stellar atmosphere can affect the appearance of certain giant stars. 

Equation 6.18a can be derived from quantum-physical considerations developed by Max Planck in 1900 (see Footnote 7), but it was first proposed in the late 19th century. In 1879, Josef Stefan empirically determined that the maximum radiation was proportional to the fourth power of the absolute temperature in 1884, Ludwig Boltzmann interpreted this in terms of classical physics. The coefficient of proportionality [Pg.311]

The authors are grateful to the U. S. Energy Research and Development Authority and the Committee on Research of the University of California at Berkeley for the support of this work and to the Boris Kidric Foundation for a fellowship to B.Z. who was on leave from the Institut Josef Stefan Ljubljana, Yugoslavia. 

Josef Stefan (1835-1893) became Professor of Physics at the University of Vienna in 1863. He was an excellent researcher and published numerous papers on heat conduction and diffusion in fluids, ice formation, and the connection between surface tension and evaporation. He suggested the T4-law after careful evaluation of lots of earlier experiments on the emission of heat from hot bodies. 

These are the Maxy ell-Stefan diffusion equations for multicomponent systems. These equations are named after the Scottish physicist James Clerk Maxwell and the Austrian scientist Josef Stefan who were primarily responsible for their development (Maxwell, 1866, 1952 Stefan, 1871). These equations appeared, in more or less the complete form of Eq. 2.1.15, in an early edition of the Encyclopedia Britannica (incomplete forms had been published earlier) in a general article on diffusion by Maxwell (see Maxwell, 1952). In addition to his major contributions to electrodynamics and kinetic theory. Maxwell wrote several articles for the encyclopedia. Stefan s 1871 paper is a particularly perceptive one and anticipated several of the multicomponent interaction effects to be discussed later in this book. 

M.l The fathers of multicomponent diffusion are James Clerk Maxwell and Josef Stefan. It is remarkable how several of the multicomponent diffusional interaction phenomena introduced in Chapter 5 were anticipated by these two scientists. Study the classic contributions of Maxwell (1866, 1868) (see his collected papers Maxwell, 1952) and Stefan (1871) and draw your own conclusions as to how much (or how little) extra insight has been gained in the last century. 

Boltzmann was born in Vienna, Anstria, and graduated from high school in Linz. He entered the University of Vienna in 1863, and he received his doctorate in physics three years later. Then, for two years, he served as assistant professor at the university, where he was strongly influenced by the atomistic thinking of physicists Josef Loschmidt and Josef Stefan. 

These are the Maxwell-Stefan diffusion equations for multicomponent systems. They are named after the Scottish physicist James Clerk Maxwell and the Austrian scientist Josef Stefan, who were primarily reponsible for their development around 1870. It is important to point out that only n - 1 of the Maxwell-Stefan equations are independent because the d(- must sum to zero. Also, for a multicomponent ideal gas mixture a more elaborate analysis than that of Example 1.4 is needed to show that (Taylor and Krishna, 1993)... 

Kosta, L. et al., Uptake of Mercury by Living Organisms and Its Distribution as a Result of Contamination of the Biosphere in Characteristic Areas with Special Reference to Forage and Food, Annual Research Progress Report Inst. Josef Stefan, Ljubljana, Yugoslavia, 1971. 

Byme, A. R., personal communication (Inst. Josef Stefan, Ljubljana, Yugoslavia), 1972. 

Ludwig Boltzmann (1844-1906), the Austrian physicist, is famous for his outstanding contributions to heat transfer, thermodynamics, statistical mechanics, and kinetic theory of gases. Boltzmann was a student of Josef Stefan and received his doctoral degree in 1866 under his supervision. The Stefan-Boltzmann law (1884) for black body radiation is the result of the associated work of Josef Stefan and Boltzmann in the field of heat transfer. Boltzmann s most significant works were in kinetic theory of gases in the form of Maxwell-Boltzmann distribution and Maxwell-Boltzmann statistics in classical statistical mechanics. 

In 1868, 12 years after Tick s definitive publication of his theory, James Clerk Maxwell published a paper on a different approach to studying the diffusivity of gases, hi 1871 Josef Stefan extended Maxwell s theory and anticipated multiconponent effects (Cussler. 2009). Although the Maxwell-Stefan theory has had many strong adherents in the more than 140 years since its development, it always seems to be playing catch-up to the earlier Fickian theory. Three perceived difficulties have prevented wider acceptance of the Maxwell-Stefan theory. First, the Fickian model is well-entrenched in textbooks and diffusivity data collections, and it works well for many binary systems. Second, the Maxwell-Stefan theory gives one fewer flux N than is needed to conpletely solve the problem. However, this is really no different than choosing a reference velocity for Tick s law, and, as will be shown later, for most... 

In 1869 the Chemisch-Physikalische Gesellschaft (CPG, Chemical-Physical Society) was founded by the chemist Heinrich Hlasiwetz and the physicists Josef Loschmidt, Josef Petzval and Josef Stefan. Aims of the association were to further the development of chemistry and physics and to disseminate chemical and physical knowledge. This was to be achieved by ... 

If we measured the intensity of blackbody radiation versus the wavelength emitted at different temperatures, we would obtain a series of curves similar to the ones shown in Figure 1.7. Experiments at the end of the nineteenth century by Josef Stefan and Wilhelm Wien led to two important empirical laws of blackbody radiation, now named the Stefan-Bc 1 and Wien s law. (An empirical law is one that is formira fl onfflw is... 

Josef Stefan (1835-1893). Austrian physicist. In addition to his quantitative experiments on blackbody radiation, he made important contributions to the kinetic theory of heat and to the theory of heat conduction in fluids. 

It has long been observed that heat can pass from one body to another in the form of radiation with no material contact between the two bodies. This was called heat radiation. When it was discovered that motion of charges produced electromagnetic radiation, the idea that heat radiation was a form of electromagnetic radiation was taken up, especially in the works of Gustav Kirchhoff (1824-1887), Ludwig Boltzmann (1844-1906), Josef Stefan (1835-1893) and Wilhelm Wien (1864-1928) and its thermodynamic consequences were investigated [1]. 

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