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In this paper, we present some practical considerations regarding the design of power voltage stabilizer equipment. Nowadays, technologies for raising and/or lowering the voltage to a level required by the power line or a consumer are increasingly used (in wind or solar power generation systems, or in energy conversion systems with a direct current intermediate circuit). Our study refers to a conversion solution consisting of two converter stages. The first stage consists of two boost converters operating in antip...

Mannitol is an important raw material in the production of resins, lubricants, coatings, surfactants, explosives, cosmetics and drugs. One of the promising ways to obtain it is the catalytic conversion of inulin, a natural polyfructosan found in large quantities in some agricultural crops. In this study a Ru-containing magnetic catalyst was proposed for the process of hydrolytic hydrogenation of inulin to mannitol. Under optimal reaction conditions a high mannitol selectivity of 44.3 % was obtained 100 % conversio...

The present research explores the integration of a photovoltaic system for an educational building through a comparative analysis using the PVsyst and Simulink platforms. The building, intended for university education, is located in Cluj-Napoca, Romania. Considering the building-s location and specific climate, the feasibility of installing a photovoltaic system was analyzed with the aim of reducing electricity consumption from the electrical grid. The study began with a PVsyst simulation, which indicated that a ...

Hydrogen-based energy production involves the use of fuel cells or the direct combustion of hydrogen (a particular case being hydrogen combustion in internal combustion engines). Direct hydrogen combustion is still in the testing phase, with challenges arising from its energetic properties, which continue to be a difficult factor. For instance, hydrogen has a low calorific value (about three times lower than methane) in its gaseous phase, which is the phase where combustion occurs, a very high combustion speed (ab...

Biomass is the first form of energy used by man at the same time with the discovery of fire, means all the products of animal and vegetable origin used in present in the production of energy. Actually, the biomass approximately half (44-65 %) of the total renewable energy sources used in the EU, and occupies a third place as a primary energy source in the world, after coal and oil. At the same time represents a sustainable alternative to reduce carbon emissions. The experimental territory is located in the middle ...

Based on the principles of prevention, the employer must seek to eliminate risk at source and, in order of priority, to replace hazards through non-dangers, to separate or isolate areas where there are hazards, ensuring adequate collective and individual protection. However, workers from high and very high voltage power substations continue to be exposed to occupational hazards, suffering accidents at work and occupational diseases with significant repercussions on their health, on colleagues or National Power Sys...

Hybrid electricity storage systems are becoming essential for efficiently managing renewable energy sources and enhancing the stability of power grids. As the adoption of renewables expands, these systems are crucial for balancing supply and demand, mitigating intermittency issues, and ensuring grid reliability. This paper offers an in-depth review of different system configurations used in hybrid storage systems, emphasizing the significance of understanding and optimizing their intricate designs. Recent technolo...

The SWOT analysis of the energy resources of hydrocarbons comes in the context in which the possibility of a black-out is very likely, and the lack of energy resources can cause major damage through enormous financial losses, which through the domino effect can spread economic and national insecurity. In this context, the SWOT analysis energy resources become an essential issue of national security and makes this paper of real interest. The authors consider that the security supply with energy resources of hydroca...

Urgent task of energy policy in the near term, in addition to diversification will encourage vigorous national economy, reducing dependence on natural gas and both demand-side measures (in the energy supply of buildings are mainly to improve the thermal protection) by measures on the production, transmi ssion and distribution (increasing efficiency of energy transforma tion and increasing the share of renewable energy at the expense of natural gas).Natural gas can be easily replaced in the supply heat buildings, a...

Here we try to find a compromise way of controlling a continuous variable power system by adopting a hybrid architecture in which the renewable energy sources are coupled with the classic power grid. In such an architecture, a big issue is the control algorithm for management of the energy sources, which had to be designed in such a way that the final consumer remain powered on at all times. We proposed a control algorithm which compares the input and output powers, if the input power is lower than the output, the...

Lead-free solutions for protective coatings as an alternative for ecological galvanized steel sheets obtaining were studied in this paper. The lead from zincing baths was eliminated and replaced with bismuth as non hazardous elements. Also other alloying elements (nickel, tin, and aluminium) in zinc melts were added. The making technology of these galvanizing free-lead alloys wa s established in accordance with alloying elements properties. The tec hnological conditions for obtai ning zinc-bismuth coatings with va...

Nowadays, when the amount of exhaustible energy resources in the world are reducing and their prices are increasing proportionately , mankind tries to find alternative sources of energy. Use of solar radiation has huge potential in th e future. Already today, the sunlight is transformed into heat or electric energy. For the conversion of solar energy into electricity we are using photovoltic cells. The Slovak Republic is in the use of photovoltaic systems on the tail in the Euro pean Union. Electricity produced by...

Structure of the mathematical model of underground coal gasification process in terms of material and energy (heat) balance is presented in this paper. Base inputs of gasification process are coal (coal model) and oxidant (a mixture of oxygen and air), which appropriate combination has to ensure the best possible conditions for the gasification process. The expected energy output from coal gasification process is a synthetic gas - syngas. Components such as ash, tar and unburned coal are side outputs of the proces...

The contribution deals by the suggestion of new manufacturing technology for hand- made screw blade for wind-power plant. A wind turbine is a device that converts kinetic energy from the wind into electricity for distribution. Wind turbine blades are most often fabricated by hand using multiple layers of fi breglass cloth. The traditional method is for the sheets to be cut to shap e, laid down in a mould by hand, sprayed or rolled with resins, and finally cured. The automation of the manufacturing of hand-made pro...

Iran is a country with an area of 1,648,198 Km 2 in the Middle East. When it comes to sun, there are 300 days of pure high UV sunshine in 95% of the country. There is a triangular great desert from center to the East of Iran, which due to its position receives a large amount of solar energy. Because this area is enclosed by the high ridge Alburz Mountains in the North, the Zagros Mountains in the West and the Makran Mountains in the East, there is no climate variability and also its geographi cal and environmental...

As traditional organic fuel resources are being depleted in the modern world, energy crisis and environmental situation aggravate and the attention of the mankind is increasingly drawn towards untraditional, renewable sources of energy and opportunities of their efficient use. Georgia has significant geothermal resources concentrated in numerous thermal springs and basins. There are two main basins of thermal waters in Georgia. The water in the Kolkheti basin is distinguished for its low mineralization, it is over...

This paper highlights several aspects regarding energetic and functional advantages of hydraulic transmissions based on adjustable volumetric machines, located in their primary and secondary sectors. To this end, numerical simulations were performed upon hypothetic hydraulic transmissions of primary or secondary adjustment, as well as numerical simulations and experimental research on MOOG radial piston pump type RKP-D. This servo pump, which can operate either in closed loop of flow or in closed loop of pressure,...

In this study, simulation modelling of insulation layer (di), for residential buildings in 81 cities classified into four climatic regions in Turkey was. This stimulus model is constructed into Rule-Based Mamdani-Type Fuzzy Modelling (RBMTF) using input parameters (Uw, Te,Met, Te,TSE, Rwt, qTSE) and output parameter di described by RBMTF if-then rules. RBMTF has been designed using the MATLAB fuzzy logic toolbox.

The paper presents a hydraulic system used for the recovery kinetic energy from the road motor vehicle in the braking phases and using it, in the acceleration phases, in order to energy saving of the motor vehicles. All the system is conceived like a mechatronics system, for the medium and heavy motor vehicles. The hydraulic system allows the extrapolation to different sizes of vehicles and can be mounted on new motor vehicles, as well as old cars, in the framework of rehabilitation actions. The energy recovery hy...

After the entry to the European Union the energetic policy of the Slovak republic became an integral part of the European Union energetic policy as well as the element of the world market with the energetic resources. Slovak republic imports around 90 percent of its primary energetic resources that are at the same time poorly diversified because most of them are originated in the Russian Federation. In spite of the significant structural changes in the last two decades the Slovak economy still remains heavily depe...

This paper considers potential changes in storm occurrence and intensity over the western Black Sea through analysis of long term series of wind and wave conditions simulated with relatively high resolution. It is a result of coupling of atmospheric and wave models and spans period of more than 60 years (1948-2008). On the basis of the established methodology of wave climate clustering, wave events capable of producing a noticeable morphological response are separated from the remaining part of the dataset. Furthe...

Knowing wind energy and its features can help programmers in using this clean, free and renewable energy. Iran is located in the west wind region, and the common wind direction is from north-west to south-west in Iran. But in some regions of Iran, due to special regional conditions as well as the synoptic factors of atmosphere, the wind direction is different from the common wind direction in Iran. The wind speed is also higher than the average speed of west winds. Based on the statistics from wind speed and direc...

Many countries has used the wind energy for agricultural pumping water for many years. Mechanical energy or electrical energy which is converted from the wind energy drives the pump. Water is not directly convey the target areas due to discontinuous wind regime. Therefore water is conveyed the storage tank. In addition, using the drip irrigation system at this system is provided saving at the agricultural economy. The increasing use of wind energy instead of the fossil energy provides to decrease pollutant emissio...

The purpose of this article is to present methods and software tools to ensure an optimal decision process for controlling the greenhouse climate. The efficiency of plant production in greenhouses depends significantly on the adjustment of optimal climate growth conditions to achieve high yield at low expense, good quality and low environmental load. To achieve these goals several components (temperature, air humidity and CO2 concentration) must be controlled optimally given certain criteria through heating, venti...