The present work considers the impact of hydrogen fuel on the environment within the cycles of its generation and combustion. Hydrogen has been portrayed by the media as a fuel that is environmentally clean because its combustion results in the formation of harmless water. However, hydrogen first must be generated. The effect of hydrogen generation on the environment depends on the production process and the related byproducts. Hydrogen available on the market at present is mainly generated by using steam reforming of natural gas, which is a fossil fuel. Its byproduct is CO2, which is a greenhouse gas and its emission results in global warming and climate change. Therefore, hydrogen generated from fossil fuels is contributing to global warming to the similar extent as direct combustion of the fossil fuels. On the other hand hydrogen obtained from renewable energy, such solar energy, is environmentally clean during the cycles of its generation and combustion. Consequently, the introduction of hydrogen economy must be accompanied by the development of hydrogen that is environmentally friendly. The present work considers several aspects related to the generation and utilisation of hydrogen obtained by steam reforming and solar energy conversion (solar-hydrogen).

The paper discusses the possibility of obtaining liquid and gaseous fuels from different types of biomass (BM) and combustible solid waste (CSW) of various origins. The available world reserves of traditional types of fuel are analyzed and a number of environmental shortcomings that created during their use are indicated. The tables present the data on the conditional calorific value (CCV) of the main traditional and alternative types of solid, liquid and gaseous fuels which compared with CCV of various types of BM and CSW. Possible methods for utilization of BM and CSW are analyzed, as well as the methods for converting them into alternative types of fuel, especially into combustible gases.
Reliable information is given on the available oil and gas reserves in Azerbaijan. As a result of the research, it was revealed that the currently available oil reserves of Azerbaijan can completely dry out after 33.5 years, and gas reserves–after 117 years, without taking into account the growth rates of the exported part of these fuels to European countries. In order to fix this situation, first of all it is necessary to use as much as possible alternative and renewable energy sources, especially wind power plants (WPP) and solar photovoltaic energy sources (SFES) in the energy sector of the republic. Azerbaijan has large reserves of solar and wind energy. In addition, all regions of the country have large reserves of BM, and in the big cities, especially in industrial ones, there are CSW from which through pyrolysis and gasification is possible to obtain a high-quality combustible gas mixture, comprising: H2 + CO + CH4, with the least amount of harmful waste. The remains of the reaction of thermochemical decomposition of BM and CSW to combustible gases can also be used as mineral fertilizers in agriculture. The available and projected resources of Azerbaijan for the BM and the CSW are given, as well as their assumed energy intensity in the energy sector of the republic.
Given the high energy intensity of the pyrolysis and gasification of the BM and CSW, at the present time for carrying out these reactions, the high-temperature solar installations with limited power are used as energy sources, and further preference is given to the use of WPP and SFES on industrial scale.

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to the
initiation of a low-temperature glow quasi-stationary plasma discharge.
A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.

Hydrogen sulphide, an acid gas, is generally considered an environmental pollutant. As an industrial byproduct, it is produced mostly during fuel processing. Hydrogen sulphide occurs naturally in many gas wells and also in gas hydrates and gas-saturated sediments especially at the bottom of the Black Sea where 90% of the sea water is anaerobic.
The anoxic conditions exist in the deepest parts of the basin since nearly 7300 years, caused by the density stratification following the significant influx of the Mediterranean water through the Bosphorous nearly 9000 years ago. Here, H2S is believed to be produced by sulphur reducing bacteria at an approximate rate of 10 000 tons per day, and it poses a serious threat since it keeps reducing the life in the Black Sea. An oxygen–hydrogen sulphide interface is established at 150–200 m below the surface after which H2S concentration starts increasing regularly until 1000 m, and finally reaches a nearly constant value of 9.5 mg/l around 1500 m depth.
Hydrogen sulphide potentially has economic value if both sulphur and hydrogen can be recovered. Several methods are studied for H2S decomposition, including thermal, thermochemical, electrochemical, photochemical and plasmochemical methods.
In the present work, H2S potential in the Black Sea is investigated as a source of hydrogen, an evaluation of the developing prominent techniques for hydrogen production from H2S is made, and an engineering assessment is carried out regarding hydrogen production from H2S in the Black Sea using a process design based on the catalytic solar thermolysis approach. Possibility of a modular plant is considered for production at larger scale.

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.

The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

This paper proposes a way to obtain valuable electric power and valuable fuel starting from renewable variable electric power plus biomass and/or waste products. Biomass/biofuel can be oxyburned using electrolytic oxygen to generate electric power. Gas turbines or internal combustion engines are suitable to such a task, but there is the problem of very high temperatures connected to oxy combustion. In the case of gas turbine the inlet temperature could be controlled by adding steam and/or carbon dioxide, while in the case of internal combustion engines only carbon dioxide could be used. In such a way the exhaust gas continues to be formed by carbon dioxide and steam which can be easily separated by condensation. Carbon dioxide is fed to a Sabatier process together with electrolytic hydrogen to generate a gas with characteristics similar to natural gas. Although electrolytic hydrogen could be used directly both in internal combustion engines and fuel cells, significant problems to hydrogen distribution and on-board storing still exists. Therefore the substitute of natural gas could be a real bridge solution for the short/medium term. A  simulation has been carried out and the resulting efficiencies range from 0.52 to 0.58.

Brazil has decreased the utilization of wood under the form of either charcoal or fuel wood to about 10% of its energy consumption (year 2000). The same is not true for the Brazilian Amazonia where there is a growing demand of charcoal for the production of pig iron in the Greater Carajas Program. The objective of the present study is to verify the feasibility of using electrolytic hydrogen instead of charcoal for the direct reduction of iron ore in that region. Techno, economic and environmental aspects are considered. This study can be benefcial to Brazil in general and Amazonia in particular since natural resources might be preserved and pollution avoided.

The review is devoted to the modern state of science in the field of light scattering techniques application in the biomedicine and ecology. The theoretical basis of dynamic and static light scattering and the results of modern works of their using for different aims are presented in the work. Since these methods are non-invasive and do not disturb the essential course of different processes, they are useful and irreplaceable for studying the biological samples. Application of the methods for studying of the hydrodynamic radii, molecular weights and distributions of light scattering on biomacromolecular particle sizes in biological liquids already led to the development of techniques of diagnostics of different socially-important deceases (cancer, cardiovascular deceases, and diabetes). The authors of diagnostics found that the ratio of the light intensity on the sizes of albumins and globulins, the mean hydrodynamic radius of protein aggregates and the second virial coefficient are the sensitive parameters to pathological processes development in the human body. The review also presents the results of the works devoted to the study of theinflu ence of the low doses of ions of heavy metals and radioactive radiation on different groups of the population by light scattering. The results showed, for example, that the people involved in the nuclear industry have metabolic disorders. Such works open the possibility of application of light scattering technique for sanogenetic control of the population health, which is relevant from the ecological point of view of environmentally unfriendly territories and industries. The study of the structure and properties of the polymeric and biological gels and effects of different factors on them (including nanoparticles) is the perspective field of light scattering application. The works and their results presented in the review show the broad application of light scattering technique for different biological and ecological aims.

The article considers the oscillations of interband magneto-optical absorption in semiconductors with the Kane dispersion law. We have compared the changes in oscillations of the joint density of states with respect to the photon energy for different Landau levels in parabolic and non-parabolic zones. An analytical expression is obtained for the oscillation of the combined density of states in narrow-gap semiconductors. We have calculated the dependence of the maximum photon energy on the magnetic field at different temperatures. A theoretical study of the band structure showed that the magnetoabsorption oscillations decrease with an increase in temperature, and the photon energies nonlinearly depend on a strong magnetic field. The article proposes a simple method for calculating the oscillation of joint density of states in a quantizing magnetic field with the non-quadratic dispersion law. The temperature dependence of the oscillations joint density of states in semiconductors with non-parabolic dispersion law is obtained. Moreover, the article studies the temperature dependence of the band gap in a strong magnetic field with the non-quadratic dispersion law. The method is applied to the research of the magnetic absorption in narrow-gap semiconductors with nonparabolic dispersion law. It is shown that as the temperature increases, Landau levels are washed away due to thermal broadening and density of states turns into a density of states without a magnetic field. Using the mathematical model, the temperature dependence of the density distribution of energy states in strong magnetic fields is considered. It is shown that the continuous spectrum of the density of states, measured at the temperature of liquid nitrogen, at low temperatures turns into discrete Landau levels. Mathematical modeling of processes using experimental values of the continuous spectrum of the density of states makes it possible to calculate discrete Landau levels. We have created the three-dimensional fan chart of magneto optical oscillations of semiconductors with considering for the joint density of energy states. For a nonquadratic dispersion law, the maximum frequency of the absorbed light and the width of the forbidden band are shown to depend nonlinearly on the magnetic field. Modeling the temperature  dependence allowed us to determine the Landau levels in semiconductors in a wide temperature spectrum. Using the proposed model, the experimental results obtained for narrow-gap semiconductors are analyzed. The theoretical results are compared with experimental results.