Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world’s energy demand today, are being depleted fast. Also, their combustion products are causing the global problems, such as the greenhouse effect, ozone layer depletion, acid rains and pollution, which are posing great danger for our environment and eventually for the life in our planet. Many engineers and scientists agree that the solution to these global problems would be to replace the existing fossil fuel system by the hydrogen energy system. Hydrogen is a very efficient and clean fuel. Its combustion will produce no greenhouse gases, no ozone layer depleting chemicals, little or no acid rain ingredients and pollution. Hydrogen, produced from renewable energy (e.g., solar) sources, would result in a permanent energy system, which we would never have to change. However, there are other energy systems proposed for the post-petroleum era, such as a synthetic fossil fuel system. In this system, synthetic gasoline and synthetic natural gas will be produced using abundant deposits of coal. In a way, this will ensure the continuation of the present fossil fuel system. The two possible energy systems for the post-fossil fuel era (i.e., the solar-hydrogen energy system and the synthetic fossil fuel system) are compared with the present fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar-hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st century.

The world consists of many countries having differences in many areas, ranging from size to economic level, from population to education, etc. Consequently, they are not going to convert to hydrogen-fueled transportation at the same time. Some will have the right conditions to convert to clean hydrogen transportation early, and other countries will have conditions which will result in a delay in conversion to hydrogen-fueled transportation. In order to find out which countries are the candidates for early conversion to hydrogen fueled transportation and which countries might convert to hydrogen-fueled transportation later, an analysis has been carried out covering almost all of the countries in the world.

This article reports the results of thermodynamic modelling of the chemical interaction between iron phosphides and CaSi₂ in the systems 4CaSi₂-Fe₂P, 2CaSi₂-Fe₂P, 1,2CaSi₂- Fe₂P, 2/3СаSi₂- Fe₂P. It was established that the rate of chemical reaction between СаSi₂ and Fe₂P with the release of gaseous phosphorus increases, when the mole fraction of Fe₂P in decreased in the studied systems. The Completion of the interaction of СаSi₂ with Fe₂P is observed at Т=1500⁰С and a mole fraction of Fe₂P 20 %. The interaction of СаSi₂ with Fe₂P in the system 4СаSi₂-Fe₂P occurs stepwise to the consecutive formation of FeP₂, FeP and P₂, P₄.

Using microwave irradiation reduced graphene oxide (RGO) and nickel hydroxide as precursors the composites (Ni-RGO) of variable composition were prepared in two ways : by precipitation of Ni(OH)₂ on RGO in situ, and mixing the suspensions RGO and Ni(OH)2. It was established that the Ni-RGO composites have a high specific capacity when tested as a super-capacitor electrode in 1M KOH (150 to 330 F/g). It was shown that RGO has high stability during cycling mode of the charge-discharge capacity but a low (~ 25 F/g). Pure Ni(OH)₂, on the contrary, has a high specific capacity in the range of 450-500 F/g, but lack the stability during cycling. Capacitive and stability galvanostatic tests of composites Ni-RGO take intermediate values compared with their components, depending on the percentage of Ni(OH)₂. The introduction of RGO enhanced the resistance of electrode mass during cycling during the first 100 charge/discharge cycles. Thus, RGO can serve as a stabilizing additive which increase the life and the range of the operating current of super-capacitors based on Ni(OH)₂.

The articles present results of the generation of THz pulse in 0.1-1.5 THz band via optical rectification of femtosecond laser pulses in a wedge nonlinear crystal. The fmite-element method was employed to model and simulate the THz wave propagation in a TiNbO₃ wedge antenna in order to analyze experimental results and to visualize how the form of the crystal influences the THz radiation both inside and outside the crystal in the near-field zone.

268.1 GW of solar thermal plants (ST) operate in the world with a total area of the solar collectors (SC) 383 million m², where vacuum collectors SC are dominant (62.3 %). Flat SC type of collectors is dominant in Europe (87 %). One of the areas of improvement ST is the use of the integrated storage collector, where glazing and flat absorbers of with thermally insulated tanks of thermosiphon ST are structurally combined. The analysis of the integrated storage collector of six leading manufacturers, found that their shape can be a parallelepiped-shaped trough-shaped and spherical. Transparent insulation is made from glass or polycarbonate. Absorber and tanks are made from stainless steel, copper, or plastic. Area of the integrated storage collector is in the rnage of 0.6 to 2 , 65 m², tanks capacity varies from 60 to 250 liters. Some integrated storage collectors can be assembled into blocks and used for hot water and heating.

In article presents experimental research on the photo-electric module for the creation of mobile autonomous power station for the pastures development in South-East Kara Kum. Climatic characteristics and Solar energy radiation mode were studied in South-East Kara Kum of Turkmenistan. The obtained data include: volt-amperometric parameters of photo module at the various installiton angles, the efficiency of the photo-converter studied at various temperatures on its surface and the regression equations and standard deviations, representing the results.

In 2012 there were 383 million m² of solar power plants (GU) in the world, with total power output of 268 MWt (GU) heat power output of 225 TVT · h/year. The majority of GU (64,9%) operate in China. Europe is on the second place (16,7%). The highest value of GU power per 1000 people is in Cyprus - 774 m² (542 kW). In the world most of GU are constructed with the vacuum solar collectors (SC) - 208,76 million m² (62,3%). Flat SK are dominating in Europe (87%). According to their functionality the most GU are dedicated to supply of water (GVS) - 85%. According to heat transfer method the most popular are thermosiphon GU (76%). The total area of GU, used for the centralized heating makes 3,35 million m² in the world. Each country has the structure of purpose of GU.

Solar energy is free. universally accessible and environmentally friendly. However. it has a number of disadvantages. the most important of which are low power density. and variability in solar radiation reaching the surface of the Earth. Variability of solar radiation (SR) depends on the time of year. month. day. and also on the climatic factors such as cloudiness. In this context. this work aims to review and to analyze satellite images of Earth’s surface together with the solar module real-time data in order to monitor the actual status and to predict weather conditions. including the SR values while taking cloudiness into the account. The techniques of monitoring. analysis and forecasting of the diffuse and direct solar radiation in the cloudy and clear weather were considered. The possibility of the short-term forecast of clouds using satellite images and observing the movements of the clouds was shown.

The article reports that in a high-resistance single-crystal p-GaSe and p-InSe the increase in radiation results in a slight increase in electrical conductivity. Under http://teacode.com/online/udc/54/54.06.htmlthe irradiation low-resistance p-GaSe crystal low-resistance makes a sharp transition into high-resistance. This occurs because irradiation of single p-type crystals increased the level of available acceptors. The certain threshold value of radiation dose cause a jump in electric conductivity. Irradiation of n -InSe single crystal with the increasing dose cause the compensation of the available acceptors level by donors, and the transition from the low-resistance to high-resistance state occurred much slower .

Estimation of energy potential of Ukrainian geothermal wells worked out. These wells were revealed the thermal waters and ready for commercial development. The total potential of geothermal resources is 1.9 billions MW · h per year. It will save 309 million tons of nominal fuel per year.

The paper discusses some aspects of recycling of organic waste from meat plants. The process of waste oxidation in the presence of fat-containing fuzz filler and reagent was investigated. It was shown that in the presence of fat the biological decay of organic waste is inhibited. The possibility of utilizing of such waste as an alternative energy source was proposed and the fuel efficiency of organic waste was evaluated. The method of the complete utilization of such fuel in the inverted type gasifier accompanied by the synthesis gas production was studied. The proposed utilization of organic waste as an alternative fuel source allows to improve the ecology and to reduce the energy consumption of the company.

The article discusses how to simplify a complex electrical power supply systems with an emphasis on linear equivalent distribution of the motor load in the presence of high harmonics. The nonlinear dependence of the active and inductive resistances on the high harmonics serial number is defined in the equivalent circuit.

A theoretical study investigating the effect of electrolyte on size and coalescence of bubbles formation in over-saturated aqueous medium is presented. The influence of the salt concentration on surface tension on the solution was studied. The increase of the concentration of the electrolyte did affect the size of the seeding bubbles but led to the decrease of an average radius of a bubble due to the decrease of the coalescence efficiency. Several models describing interaction of bubbles at the various collision rates and at evaluating states of the surfaces of the bubble were developed. Determined the critical values of electrolyte concentration, which decrease coalescence of the seeding bubbles.

The article defines the features and principles of researches methodology of soil-forming processes in destructive edaphotopes and the controls. It is concluded that ecological role of soil-forming processes of edafotop in the steppe is essential for providing the needs of agriculture, forestry , water , utilities and other industries. During the time of anthropogenic impact on natural ecosystems The importance of soil-forming processes is highlighted.