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Hydrogen production using a thermochemical cycle
Jurij Avsec, Urška Novosel, Dušan Strušnik, 2022, original scientific article

Abstract: Sustainable methods of clean fuel production are needed throughout the world due to depleting oil reserves and the need to reduce carbon dioxide emissions. The technology based on fuel cells for electricity production or the transport sector has already been developed. However, a key missing element is a large-scale method of hydrogen production. The copper-chlorine (CuCI) combined thermochemical cycle is a promising thermochemical cycle that can produce large amounts of cheap hydrogen. A particularly promising part of this process is its use in combination with nuclear or thermal power plants. This paper focuses on a CuCl cycle and describes the models used to calculate thermodynamic and transport properties. This paper discusses the mathematical model for computing the thermodynamic properties for pure HCl and CuCl2. The mathematical model developed for the solid phase takes into account vibrations of atoms in molecules and intermolecular forces. This mathematical model can be used for the calculation of the thermodynamic properties of polyatomic crystals on the basis of the Einstein and Debye equations. The authors of this paper developed the model in the low temperature and high temperature region. All the analytical data have been compared with some experimental results and show a relatively good match. For the solid phase, the authors developed a model to calculate thermal conductivity based on electron and phonon contributions.
Keywords: thermodynamics, energy, hydrogen production, solid phase, fluid phase
Published in DKUM: 30.10.2023; Views: 230; Downloads: 4
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Proceedings of the international conference on innovations in energy engineering & cleaner production
2022, proceedings of peer-reviewed scientific conference contributions (international and foreign conferences)

Keywords: energetics, renewable energy sources, production, alternative energy sources, environmental protection
Published in DKUM: 27.10.2023; Views: 355; Downloads: 13
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Reducing carbon footprint in an oem supply chain caused by inadequate interpretation of x-ray results of hidden defects in ductile iron castings
Tadej Pavlin, Iztok Brinovar, Bojan Stergar, Zdravko Praunseis, 2022, original scientific article

Abstract: In the global market, the casting industry recorded a growth trend for ductile iron last year. Ductile iron is used due to its excellent mechanical properties, machinability and castability. The microstructure of nodular cast iron consists of a metal matrix and graphite extruded in the form of beads and nodules. In recent years, the production of ductile iron castings has increased significantly for parts for heavy transport vehicles and containers for permanent disposal of nuclear waste, and it is expected that this trend of expansion will continue for at least the next twenty years. When poured in sand moulds, the quality of products can not be reached. There can be defects on the raw surface and/or on the machining surface, as well as hidden defects inside the material. For casting products, defects can be detected on raw and machining surfaces and inside material defects by carrying out a visual inspection. The results of the inspection depend on the inspection method used. In general, basic methods of cutting or milling inspection are used in the casting industry, which means that products are classified in terms of whether or not they meet the drawing specification(s). The authors of this paper focused on the hidden defects inside ductile iron material, which can be detected by carrying out a cutting or milling inspection or through an X-ray inspection. Huge amounts of energy and energy sources are used in the production of nodular cast iron, which creates a negative environmental footprint. Therefore, by being preventively rational and through appropriate control procedures it is possible to significantly reduce the carbon footprint.
Keywords: carbon footprint, ductile iron, X-ray inspection, cutting inspection, hidden mistakes, defects, porosity, inclusion, green energy, reduced production of energy, decrease in production emissions
Published in DKUM: 26.10.2023; Views: 227; Downloads: 4
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Science, human awareness and environmental attitudes
Boris Aberšek, 2022, short scientific article

Abstract: The environment is a system, a complex system, which we are unable to comprehend, let alone truly understand, with the help of simplified models that we, humans, are able to process. Our human understanding of the complexity of a grain of sand simply isn’t enough to construe and adapt the universe! This would require time and knowledge, which we do not have today, and which we will not have for a long time. So, everything is in interpretation. Let us start our stories with some basic truths. The main premise is, that man doesn't need an outside enemy, he's the greatest threat to himself. But he's not just a threat to himself, he's a threat also to everything around him. No living thing on earth destroys it more than it takes for its existence, except for human.
Keywords: complex systems, human awareness, environmental attitudes, energy production
Published in DKUM: 08.08.2023; Views: 301; Downloads: 28
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Agronomski in okoljski vidiki prekrivnih posevkov v ekološki pridelavi zelenjadnic
Martina Robačer, 2019, doctoral dissertation

Abstract: Cover crops can reduce the use of external inputs such as pesticides and fertilisers and can at the same time suppress weeds as well as improve or maintain soil fertility. Cover crops can also modify the microclimate which affects pest populations and diseases. Determining cover crop species and management practices is based on the needs and goals of production. The effects of introducing living mulch (LM) and management strategies on cash crop yield, product quality and energy use were studied in certain European countries (Slovenia, Italy, Germany and Denmark) in different climatic and soil conditions. In Slovenia, in organic production of cauliflower and leek, the effects of two terms of sowing white clover with additive design were compared with a production with black foil and with the usual agricultural practice by hoeing. In the field experiments the effect of LM on arthropod dynamics and activity density was investigated. The results demonstrated that the LM systems with a substitutive design, can be effectively implemented in vegetable production if the value of the ecological services (positive externalities) delivered by LM can counterbalance the yield loss due to the cash crop density reduction. If an additive design is used, the LM should be sown several weeks after the cash crop planting. Different cash crop genotypes (i.e., open pollinated/local cultivars in comparison with the hybrids) performed similarly. Use of human labor (HL) and fossil fuel (FF) energy slightly increased in LM systems (7%). The farmers’ acceptance of the LM techniques was quite high (75% of the interviewed sample). The LM technique did not affect the infestation of cabbage caterpillar Pieris spp., showing no detrimental effect of this technique on this key pest of cabbage. In Denmark, aphid populations were higher in the sole crop system than in the LM system. In Italy, a level of larval parasitization was detected and in the first year the percentage of parasitization was higher in LM (88%) than in sole crop (63%). Overall, the LM positively affected the activity density of Carabid beetles, also increasing the diversity and evenness of species (Slovenia and Italy) or activity density of some taxa (Slovenia and Denmark). Due to numerous agroecological services of cover crops, growing simultaneously with vegetables as LM, this could be promising technique for organic and others production systems in the future.
Keywords: organic vegetable production, cover crops, agroecological service, living mulch, energy consumption, biodiversity, soil arthropod
Published in DKUM: 01.02.2019; Views: 2016; Downloads: 270
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Material and energy balance in the planning of production costs
Manuela Ingaldi, Dorota Klimecka-Tatar, 2016, independent scientific component part or a chapter in a monograph

Keywords: material, energy, manufacturing system model, production costs, planning
Published in DKUM: 11.05.2018; Views: 1459; Downloads: 90
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Farms and mines: a conflicting or complimentary land use dilemma in western Australia?
Fiona Haslam McKenzie, 2009, review article

Abstract: The Western Australian economy has always been underpinned by farming and mining. Over the last five years the economy has experienced phenomenal growth due to unprecedented global demand for resources and increasingly, agricultural land is being given up for mining. Changing land uses challenge industry and community leaders; some communities are overwhelmed by a new population connected with mining, bringing with it a range of social and economic tensions that small communities struggle to cope with. This paper will discuss the conflicting issues regarding land use planning, local and environmental governance and sense of place while also canvassing positive developments that have enhanced community and regional economic development, thus building a resilient future.
Keywords: regional economic development, mining and energy sector, agricultural production, Australia
Published in DKUM: 26.03.2018; Views: 2531; Downloads: 86
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Determining energy production of CdTe photovoltaic system
Jan Šlamberger, Peter Virtič, 2013, original scientific article

Abstract: This paper presents a method for determining energy production of Cadmium-Telluride photovoltaic system, which has a different working performance than the most used Silicon photovoltaic systems. The main difference is sensitivity to the temperature and the solar irradiance. The CdTe cells are less sensitive to the temperature and in contrast to the Si Cells they have a higher efficiency at lower irradiance.
Keywords: photovoltaic module, energy production, annual energy yield, Cadmium-Telluride
Published in DKUM: 10.07.2015; Views: 1782; Downloads: 70
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