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It is now recognized that the contact methods to measure a thermal conductivity of metals and carbides in liquid/solid phase transition are facing some difficulties. On the other side, the normal spectral emissivity for these materials at melting/freezing points can be measured with high degree of accuracy. Therefore, it is of considerable interest to develop a method that makes it possible to determine the thermal conductivity through the measured value of the normal spectral emissivity. A new optical non-contact method to determine the thermal conductivity of metals and carbides at their melting/freezing points is proposed. This method is based on the use of the Drude model, the Hagen–Rubens relation, and the Wiedemann–Franz law. To define the thermal conductivity of materials at melting/freezing points, the experimental measurements of the normal spectral emissivity in a specific far-infrared range are needed. The proposed method does not require to model the power balance of heat transport for calculating the thermal conductivity. The applicability of the proposed method was demonstrated on cobalt, nickel, and zirconium carbide. A good agreement with experimental data published in the literature is obtained. The gap between the thermal conductivity of the materials under study in the solid and liquid phases at their melting/freezing temperatures is calculated. The temperature dependence of the thermal conductivity of the “ideal” solar power emitter is obtained.

An optimal bandwidth interval is proposed for increasing the optical temporal coherence of thermal light. The choice of this most intensely emitted frequency interval is based on solving the problem of optimizing the emission spectrum of a black body. The calculated frequency interval is also the narrowest band for the coherence filter for a given value of the total transmitted energy. As a result, the interval found can be used to achieve the highest possible coherent properties at a given level of total energy that has passed. The achieved coherence length values for such optimized bandpass filters are calculated analytically. Some practical applications of the obtained results are discussed.

We present weighty evidence of specific transformations during thermal motion in bulk water in the physiological temperature range. The vicinity of the temperature point of 315 K (42 °C) is the maximum value for death for many warm-blooded organisms under physiological conditions and at the same time is the upper limit of the temperature range in which the crystal-like behavior of thermal motion in water turns into argon-like (the so-called dynamic phase transition). This temperature is also a threshold point in the temperature dependences of the Zeta potential for the main plasma proteins, such as albumin and fibrinogen, in aqueous solutions. The limitation of the physiological temperature range from the lower temperature limit of 303 K is naturally explained by the clustering of water molecules, which increases strongly with decreasing temperature.

The Sunyaev-Zel’dovich (SZ) effect represents a small spectral distortion to the cosmic microwave background (CMB) radiation, caused by the Compton scattering of CMB photons by the hot gas of galaxy clusters. In an early stage of universe, the SZ effect generates $\mu$ -type of distortions for the CMB spectrum. A $\mu$ -type distortion is created between the double Compton scattering decoupling ( $z \sim 10^{6}$ ) and the thermalization decoupling by the Compton scattering ( $z \sim 10^{5}$ ). In this case, to describe the small spectral distortion of the CMB spectrum, we use the Bose-Einstein ( $\mu$ -type) distribution with a non-zero chemical potential. At present, it is interesting to investigate the effect of this spectral distortion on the integral characteristics of the Bose-Einstein ( $\mu$ -type) spectrum. The thermal radiative and thermodynamic functions are such integral characteristics. These functions are as follows: a) the total radiation power per unit area; b) total energy density; c) number density of photons; d) grand potential density; e) Helmholtz free energy density; f) entropy density; g) heat capacity at constant volume; h) enthalpy density; and i) pressure. Precise analytical expressions are obtained for the temperature dependences of these functions. Using the observational data obtained by the COBE FIRAS, PIXIE, PRISM, and Planck missions, the thermal radiative and thermodynamic functions are calculated. A comparative analysis of the results obtained with the results for the same functions of the CMB spectrum at $T = 2.72548~\mbox{K}$ is carried out. Very small distortions are observed for the thermal radiative and thermodynamic functions. In the redshift range $10^{5} < z < 3 \times10^{6}$ , these functions are calculated. The expressions are obtained for new astrophysical parameters, such as the entropy density/Boltzmann constant and number density, created by the Bose-Einstein ( $\mu$ -type) spectrum.

Using the three-component spectral model describing the FIRAS average continuum spectra, the exact analytical expressions for thermodynamic and radiative functions of Galactic far-infrared radiation are obtained. The COBE FIRAS instrument data in the 0.15 – 2.88 THz frequency interval at the mean temperatures of T 1 = 17.72 K, T 2 = 14 K and T 3 = 6.73 K are used for calculating the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, total emissivity, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume and pressure for the warm, intermediate temperature and very cold components of the Galactic continuum spectra. The generalized Stefan-Boltzmann law for warm, intermediate-temperature and very cold components is constructed. The temperature dependence of each component is determined by the formula I S−B ( T ) = σ′ T 6 . This result is important when we construct the cosmological models of radiative transfer that can be applied inside the Galaxy. Within the framework of the three-component spectral model, the total number of photons in our Galaxy and the total radiation power (total luminosity) emitted from a surface of the Galaxy are calculated. Their values are N Gtotal = 1.3780 × 10 68 and I Gtotal ( T ) = 1.0482 × 10 36 W. Other radiative and thermodynamic properties of the Galactic far-infrared radiation (photon gas) of the Galaxy are calculated. The expressions for astrophysical parameters, such as the entropy density/Boltzmann constant and number density of the Galactic far-infrared photons are obtained. We assume that the obtained analytical expressions for thermodynamic and radiative functions may be useful for describing the continuum spectra of the far-infrared radiation for other galaxies.

Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v 1≤v≤v 2 are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60–600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.

Using formula to describe the average spectrum of the extragalactic far infrared background (FIRB) radiation measured by the COBE FIRAS instrument in the 0.15–2.4 THz frequency interval at mean temperature T=18.5 K, the radiative and thermodynamic properties, such as the total emissivity, total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure are calculated. The value for the total intensity received in the 0.15–2.4 THz frequency interval is equal to 13.6 nW m−2 sr−1. This value is about 19.4 % of the total intensity expected from the energy released by stellar nucleosynthesis over cosmic history. The radiative and thermodynamic functions of the extragalactic far infrared background (FIRB) radiation are calculated at redshift z=1.5.

The devices which are dealing with the thermal radiation (such as emitters [1–4], receivers [5–8], filters [9–12], transformers [13–15], etc.) are mainly working in a finite range of frequencies. Such devices are frequently need to be optimized for getting the best possible value for the specific thermal radiative or thermodynamic characteristics that can be reached in the given spectral range. For example, the devices can be optimized for obtaining the maximal possible amount of the emitted (or received) total radiation energy, or, alternatively, the maximal number of the emitted (or received) number of photons. Potentially, the devices can be also optimized for some other thermal radiative or thermodynamic parameters.

For multiple applications, such as photography, television, color printing, etc., it is interesting to analyze the chromatic properties of the black-body sources of thermal radiation in the visible part of spectrum (380–780 nm). This topic was partially investigated in [1], where the relative chromaticity coordinates for the black-body radiation spectrum were calculated at various temperatures.

The knowledge of thermal radiative and thermodynamic properties of uranium and plutonium carbides under extreme conditions is essential for designing a new metallic fuel materials for next generation of a nuclear reactor. The present work is devoted to the study of the thermal radiative and thermodynamic properties of liquid and solid uranium and plutonium carbides at their melting/freezing temperatures. The Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, pressure, and normal total emissivity are calculated using experimental data for the frequency dependence of the normal spectral emissivity of liquid and solid uranium and plutonium carbides in the visible-near infrared range. It is shown that the thermal radiative and thermodynamic functions of uranium carbide have a slight difference during liquid-to-solid transition. Unlike UC, such a difference between these functions have not been established for plutonium carbide. The calculated values for the normal total emissivity of uranium and plutonium carbides at their melting temperatures is in good agreement with experimental data. The obtained results allow to calculate the thermal radiative and thermodynamic properties of liquid and solid uranium and plutonium carbides for any size of samples. Based on the model of Hagen-Rubens and the Wiedemann-Franz law, a new method to determine the thermal conductivity of metals and carbides at the melting points is proposed., Comment: 17 pages, 2 Tables

In this chapter the tables of black-body radiative, thermodynamic, and chromatic functions are presented. The constants for the calculation of black-body radiative, thermodynamic, and chromatic functions have been selected as follows

In almost all areas of physics and astrophysics related to the measurement of spectral and integral properties of the emitted systems, a small interval of the electromagnetic spectrum has the practical interest [1]. Therefore, extensive numbers of tables of the Planck functions, Planck integrals, and their fractional values have been constructed in the finite spectral ranges [1–12]. In this chapter, the analytical expressions for the thermal radiative functions and a number density of photons over an arbitrary spectral range are presented. Using these exact analytical expressions the values of these functions are calculated for various ranges of the electromagnetic spectrum at different temperatures. Their values are presented in Tables 6.1–6.3.

Let us consider several examples of using the Tables 6.1–6.3 for calculating the thermal radiative and thermodynamic functions of black-body radiation in the finite spectral range.

The true temperatures of the thermal radiation of stoichiometric hafnium, titanium, and zirconium carbides are defined from the generalized Wien displacement law. It is shown that Wien’s displacement law for the investigated stoichiometric carbides decreases linearly with increasing temperature. The uncertainties in the determination of the true temperature are no greater than 1 %. For determining the true temperature of stoichiometric carbides, the experimental values of the position of the maximum of the spectral density power are needed. By extrapolating the generalized Wien displacement laws in the ultra-high-temperature region, the positions of the maximum of the normal energy density of hafnium, titanium, and zirconium carbides at melting temperatures are obtained. Thermodynamics of thermal radiation of stoichiometric carbides is constructed by using the temperature dependences of the generalized Stefan–Boltzmann law. The calculated values of the normal total emissivity for the investigated carbides at different temperatures are in good agreement with experimental data. For determining the true temperatures of the thermal radiation of stoichiometric carbides, experimental values of either the normal total emissivity or the normal total energy density are needed. The temperature dependences of the Helmholtz free energy, entropy, heat capacity at constant volume, pressure, enthalpy, and internal energy of the thermal radiation of stoichiometric carbides at high temperature are obtained. It is shown that thermodynamic function values increase with increasing temperature as a power law.

The true temperature of thermal radiation of molybdenum and luminous flames is defined from the temperature dependences of generalized Wien’s displacement and Stefan–Boltzmann’s laws. For determining the true temperature of molybdenum, experimental values of either the position of the maximum of the spectral emitted density or the total emitted density are needed. It is shown that the thermal radiation of molybdenum belongs to the same universality class as that of tantalum, tungsten, and zirconium and titanium carbides. The thermodynamic functions of thermal radiation of molybdenum and luminous flames are constructed.

In this work, attention is mainly focused on those properties of water which are essentially changed in the physiological temperature range of warm-blooded organisms. Studying in detail the half-width of the diffusion peak in the quasi-elastic incoherent neutron scattering, the behavior of the entropy and the kinematic shear viscosity, it is shown that the character of the translational and rotational thermal motions in water radically change near T(H) ~ 315 K, which can be interpreted as the temperature of the smeared dynamic phase transition. These results for bulk pure water are completed by the analysis of the isothermic compressibility and the NMR-spectra for water-glycerol solutions. It was noted that the non-monotone temperature dependence of the isothermic compressibility (beta(T)) takes also place for the water-glycerol solutions until the concentration of glycerol does not exceed 30 mol%. At that, the minimum of beta(T) shifts at left when the concentration increases. All these facts give us some reasons to assume that the properties of the intracellular and extracellular fluids are close to ones for pure water. Namely therefore, we suppose that the upper temperature limit for the life of warm-blooded organisms [T(D) = (315 +/- 3) K] is tightly connected with the temperature of the dynamic phase transition in water. This supposition is equivalent to the assertion that the denaturation of proteins at Tor = T(H) is mainly provoked by the rebuilding of the H-bond network in the intracellular and extracellular fluids, which takes place at Tor = T(H). A question why the heavy water cannot be a matrix for the intracellular and extracellular fluids is considered. The lower physiological pH limit for the life of warm-blooded organisms is discussed.

This work is devoted to the study of the properties of water in the physiological temperature range for warm-blooded organisms. Special attention is paid to the nature of thermal motion in bulk water. Through the analysis of data from incoherent neutron scattering in water, it is shown that the crystal-like thermal motion in water takes place only in its supercooled and normal states, the temperature of which does not exceed T H = (310 ± 5) K. A quite similar temperature, T ν = (308 ± 5) K, is also characteristic of the temperature dependence of the kinematic shear viscosity of water. It is shown that the average number of H-bonds per molecule near T H is about 2.1–2.3 because the spatially ordered H-bond network in bulk water becomes unstable. The interpretation of T H as the temperature of the dynamic phase transition from the crystal-like to argon-like character of thermal motion is discussed in detail. It is assumed that the nature of thermal motion in the “cellular water solution” changes analogously at temperatures close to T H . As a result, the problem of protein and DNA denaturation and the death of living organisms is connected with the dynamic phase transition in intracellular water.

Like [A.I. Fisenko, N.P. Malomuzh, A.V. Oleynik, Chem. Phys. Lett. 450 (2008) 297.], the key role in our consideration belongs to the principle of corresponding states and the Hilbert’s principle. In accordance with the first of them, ν is represented as the sum of the argon-like contribution and that νH, which is caused by H-bonds. The using of the Hilbert’s principle allows us to connect νH with the main characteristics of the H-bond network – the number of H-bonds per molecule. It is shown that the exponential behavior of ν takes place only for T

A new view on the role of H-bonds in water, arising from the principle of corresponding states and Hilbert’s principle is presented. It is shown that the relative values of the H-bond contributions to the fraction volume and the heat of evaporation per molecule do not exceed 5%, although H-bonds are responsible for the non-monotone behavior of the fraction volume. It is established that the average number of H-bonds per molecule everywhere on the vapor–liquid coexistence curve is given by the formula n H ( T ) ≈ 4(1 − 0.83 t ), where t = T / T c ( w ) and T c ( w ) is the critical temperature of water.

The general analytical expressions for the thermal radiative and thermodynamic properties of a real-body are obtained in a finite range of frequencies at different temperatures. The frequency dependence of the spectral emissivity is represented as a power series. The Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, pressure, and total emissivity are expressed in terms of the polylogarithm functions. The general expressions for the thermal radiative and thermodynamic functions are applied for the study of thermal radiation of liquid and solid zirconium carbide. These functions are calculated using experimental data for the frequency dependence of the normal spectral emissivity in the visible-near infrared range at the melting (freezing) point. The gaps between the thermal radiative and thermodynamic functions of liquid and solid zirconium carbide are observed. The general analytical expressions obtained can easily be presented in wavenumber domain., Comment: 21 pages, 2 tables

A new long-term approach to the cleaning-up of streams directly on site is proposed. This approach is based on the natural capacity of rivers to purify themselves through the discovered froth formation process. One of the important processes in stream self-purification is the decomposition of total organics by fungi, bacteria and other microorganisms. While the decomposition takes place, the entire water as well as the benthic soil is periodically enriched with biological surfactants and the generated dissolved biogases. Further, this system also contains dissolved air and all kinds of polluting particles, including man-made surfactants. Therefore, the next step in river self-purification–the generating of biogas and air bubbles, and the attaching of the polluting particles to the bubbles in the presence of surfactants should be considered. For the latter, the proper level of turbulence must exist. Water cascading over weirs, waterfalls and other obstacles, creating the shallow-turbulent character of water current, is the suitable condition. The particle–bubble aggregates will rise to the water surface and concentrate in the froth. The resulting froth comprises a high concentration of polluting agents–organic and inorganic, including pathogens. By testing a large number of the froth and the water samples, we proved our hypothesis that rivers possess their own environmental capacity to purify themselves from pollutants through the natural froth formation process. As a result, we can, without adding any chemicals, intervene directly on site in the clean-up of the stream that is heavily polluted from all kinds of polluting sources, including the non-point ones.

Using polylogarithm functions the exact analytical expressions for the radiative and thermodynamic properties of blackbody radiation, such as the Wien displacement law, Stefan-Boltzmann law, total energy density, number density of photons, Helmholtz free energy density, internal energy density, enthalpy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies are constructed. The obtained expressions allow us to tabulate these functions in various finite frequency bands at different temperatures for practical applications. As an example, the radiative and thermodynamic functions using experimental data for the monopole spectrum of the Cosmic Microwave Background (CMB) radiation measured by the COBE FIRAS instrument in the 60 - 600 GHz frequency interval at the temperature T = 2.725 K are calculated. The expressions obtained for the radiative and thermodynamic functions can be easily presented in wavelength and wavenumber domains., Comment: 20 pages, 2 tables

The work is devoted to the description of the integral intensity of molecular light scattering by the surface of glasses. The main attention is focused on the manifestations of the quasi-static distortions of the glass surface.

The contamination of fiber optics connectors has recently been recognized as an industry wide problem. The contamination has resulted in degradation of optical signal performance, which creates false fails during the manufacturing process. These contaminated fiber optics connectors require additional manufacturing operations such as inspection of incoming components, cleaning process and re-inspection. The cleanliness of test connectors is also very important to ensure good product quality. The dirty connectors in the test environment create false functional failures at the board level, resulting in unnecessary and costly rework. All precautions have to be taken to identify the critical steps in the manufacturing process that cause the contamination to the component, assembly or board levels. The potential sources of contamination and the mechanisms of the transferring contamination have been analyzed.