Slovak Republic
The Effect of Electrolytic Hydrogenation on Mechanical Properties of T92 Steel Weldments under Different PWHT Conditions
Aug 2020
Publication
In the present work the effects of electrolytic hydrogen charging of T92 steel weldments on their room-temperature tensile properties were investigated. Two circumferential weldments between the T92 grade tubes were produced by gas tungsten arc welding using the matching Thermanit MTS 616 filler material. The produced weldments were individually subjected to considerably differing post-welding heat treatment (PWHT) procedures. The first-produced Read More
Medium-Energy Synthesis Gases from Waste as an Energy Source for an Internal Combustion Engine
Dec 2021
Publication
The aim of the presented article is to analyse the influence of synthesis gas composition on the power economic and internal parameters of an atmospheric two-cylinder spark-ignition internal combustion engine (displacement of 686 cm3 ) designed for a micro-cogeneration unit. Synthesis gases produced mainly from waste contain combustible components as their basic material (methane hydrogen and carbon monoxide) as well as inert gases (carbon dio Read More
Radiation Damage of Reactor Pressure Vessel Steels Studied by Positron Annihilation Spectroscopy—A Review
Oct 2020
Publication
Safe and long term operation of nuclear reactors is one of the most discussed challenges in nuclear power engineering. The radiation degradation of nuclear design materials limits the operational lifetime of all nuclear installations or at least decreases its safety margin. This paper is a review of experimental PALS/PLEPS studies of different nuclear reactor pressure vessel (RPV) steels investigated over last twenty years in our laboratories. Positron annihil Read More
Factors Affecting Hydrogen Adsorption in Metal–Organic Frameworks: A Short Review
Jun 2021
Publication
Metal–organic frameworks (MOFs) have significant potential for hydrogen storage. The main benefit of MOFs is their reversible and high-rate hydrogen adsorption process whereas their biggest disadvantage is related to their operation at very low temperatures. In this study we describe selected examples of MOF structures studied for hydrogen adsorption and different factors affecting hydrogen adsorption in MOFs. Approaches to improving hydrogen Read More
Effect of Hydrogen Addition on the Energetic and Ecologic Parameters of an SI Engine Fueled by Biogas
Jan 2021
Publication
The global policy solution seeks to reduce the usage of fossil fuels and greenhouse gas (GHG) emissions and biogas (BG) represents a solutions to these problems. The use of biogas could help cope with increased amounts of waste and reduce usage of fossil fuels. Biogas could be used in compressed natural gas (CNG) engines but the engine electronic control unit (ECU) needs to be modified. In this research a spark ignition (SI) engine was tested for mi Read More
Hydrogen Production as a Clean Energy Carrier through Heterojunction Semiconductors for Environmental Remediation
Apr 2022
Publication
Today as a result of the advancement of technology and increasing environmental problems the need for clean energy has considerably increased. In this regard hydrogen which is a clean and sustainable energy carrier with high energy density is among the well-regarded and effective means to deliver and store energy and can also be used for environmental remediation purposes. Renewable hydrogen energy carriers can successfully substitute fossil Read More
The Effects of Electrochemical Hydrogen Charging on Room-Temperature Tensile Properties of T92/TP316H Dissimilar Weldments in Quenched-and-Tempered and Thermally-Aged Conditions
Aug 2019
Publication
The influence of isothermal aging at 620 °C in combination with subsequent electrochemical hydrogen charging at room-temperature was studied on quenched-and-tempered T92/TP316H martensitic/austenitic weldments in terms of their room-temperature tensile properties and fracture behavior. Hydrogen charging of the weldments did not significantly affect their strength properties; however it resulted in considerable deterioration of their Read More
Is Hydrogen the Fuel of the Future?
Jul 2019
Publication
Global warming and melting of the ice on both poles of the Earth is caused by the greenhouse effect which is the result of CO2 production. This gas is considered as the main gas causing the greenhouse effect although not the only one. To reduce the total amount of CO2 emitted to the atmosphere mankind looks for an alternative fuel with no carbon present in its molekules. Hydrogen is such a fuel although emissions are produced also during the fuel Read More
Degradation Mechanisms in the Operation of Pressured Pipelines
Aug 2019
Publication
Many non-standard situations like subsoil slipping vibrations ... as well as degradation mechanisms of pipeline materials can occur in the operation of pressured pipelines. The article deals with the mechanisms of the degradation processes and their formation like corrosion brittleness and steel ageing that may occur in operation of pipeline systems. Material ageing of steels is documented on specimens created from pipeline materials and obtained b Read More
Hydrogen Production Possibilities in Slovak Republic
Mar 2022
Publication
Slovak Republic is a member of the European Union and is a part of the European energy market. Although Slovakia contributes only marginally to global emissions there is an effort to meet obligations from the Paris climate agreement to reduce greenhouse gases. As in many countries power industry emissions dominate Slovakia’s emissions output but are partly affected and lowered by the share of nuclear energy. The transition from fossil fuel Read More
Performance and Weight Parameters Calculation for Hydrogen and Battery-Powered Aircraft Concepts
May 2023
Publication
This article describes the creation of a program that would be useful for calculating mathematical models in order to estimate the weight of aircraft components. Using several parameters it can calculate other parameters of civil transport aircraft powered by batteries or fuel cells. The main goals of this research were to add the missing dimensions and parameters to the aircraft database create a simple but effective program for creating mathem Read More
Assessing the Role of Hydrogen in Sustainable Energy Futures: A Comprehensive Bibliometric Analysis of Research and International Collaborations in Energy and Environmental Engineering
Apr 2024
Publication
The main results highlighted in this article underline the critical significance of hydrogen technologies in the move towards carbon neutrality. This research focuses on several key areas including the production storage safety and usage of hydrogen alongside innovative approaches for assessing hydrogen purity and production-related technologies. This study emphasizes the vital role of hydrogen storage technology for the future utilization of hydrogen as Read More
A Newly Proposed Method for Hydrogen Storage in a Metal Hydride Storage Tank Intended for Maritime and Inland Shipping
Aug 2023
Publication
The utilisation of hydrogen in ships has important potential in terms of achieving the decarbonisation of waterway transport which produces approximately 3% of the world’s total emissions. However the utilisation of hydrogen drives in maritime and inland shipping is conditioned by the efficient and safe storage of hydrogen as an energy carrier on ship decks. Regardless of the type the constructional design and the purpose of the aforesaid vessels the pref Read More
Enriching Natural Gas with Hydrogen: Implications for Burner Operation
Feb 2024
Publication
This paper presents the results of increasing the hydrogen concentration in natural gas distributed within the territory of the Slovak Republic. The range of hydrogen concentrations in the mathematical model is considered to be from 0 to 100 vol.% for the resulting combustion products temperature and heating value and for the scientific assessment of the environmental and economic implications. From a technical perspective it is feasible to consider enri Read More
Techno-economic Assessment of Green Hydrogen Production Integrated with Hybrid and Organic Ranking Cycle (ORC) Systems
Feb 2024
Publication
This study aims to determine the most cost-effective approach for production of green hydrogen a crucial element for global decarbonization efforts despite its high production costs. The primary research question addresses the optimal and economically viable strategy for green hydrogen production considering various scenarios and technologies. Through a comprehensive analysis of eight scenarios the study employs economic parameters such as net pr Read More
Application of the Metalog Probability Distribution Family to Predict Energy Production by Photovoltaic Systems for the Purposes of Generating Green Hydrogen
Jul 2024
Publication
The article presents the application of the metalog family of probability distributions to predict the energy production of photovoltaic systems for the purpose of generating small amounts of green hydrogen in distributed systems. It can be used for transport purposes as well as to generate energy and heat for housing purposes. The monthly and daily amounts of energy produced by a photovoltaic system with a peak power of 6.15 kWp were analyzed usi Read More
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