1. Engineering Materials and Process Technologies : 2nd Conference of Programme Groups of the Faculty of Mechanical Engineering University of Maribor, Book of Abstracts2025 Abstract: The publication presents an overview of the research achievements of Programm Groups of the Faculty of Mechanical Engineering: P2-0424 Design of Novel Properties of (Nano)Materials & Applications, P2-0063 Design of Cellular Structures, P2-0120 Technologies of Metastable Materials, P2-0118 Textile Chemistry and Advanced Textile Materials, and P2-0196 Research in Power, Process, and Environmental Engineering from 2024 to 2025. Members of the program group present their research innovations and progress achieved within the framework of the program group's activities.
Keywords: advanced textile materials, composites, nanomaterials, biotechnology, surface functionalization and modification, cellular structures, metastable materials, power, process and environmental engineering
Published in DKUM: 03.11.2025; Views: 0; Downloads: 2
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3. Review of bioplastics characterisation by terahertz techniques in the view of ensuring a circular economyAndreja Abina, Tjaša Korošec, Uroš Puc, Aleksander Zidanšek, 2023, review article Abstract: The increasing scarcity of natural resources, worsening global climate change, environmental degradation, and rising demand for food are forcing the biotechnology and plastics industries to seek and apply circular economy models that would lead to a sustainable transition in the production and use of bioplastics. Circular economy models can improve the economic productivity of bio-based plastics and have a positive impact on the environment by reducing conventional plastic waste and the consumption of petrochemical feedstocks for plastic production. In addition, some agricultural wastes that have the potential to be used as bioplastics can be reused. Terahertz (THz) systems are already used in the plastics and rubber industries for non-destructive testing, detection, imaging, and quality control. Several reports have highlighted the potential applications of THz spectroscopy and imaging in polymer analysis and plastics characterisation. This potential is even greater with chemometric methods and artificial intelligence algorithms. In this review, we focus on applications that support the transformation of the biotechnology sector to the circular economy, particularly via the transition from conventional plastics to bioplastics. In this review, we discuss the potential of THz systems for the characterisation and analysis of bioplastics and biopolymers. The results of previous studies on biopolymers in the THz frequency range are summarised. Furthermore, the potential of using artificial intelligence approaches such as machine learning as advanced analytical methods in THz spectroscopy and imaging, in addition to the conventionally used chemometric methods, is discussed. The results of this review highlight that THz technology can contribute to closed technological circles in important areas of biotechnology and the related plastics and rubber industries.
Keywords: terahertz spectroscopy, terahertz imaging, circular economy, biopolymer, biotechnology, bioplastics
Published in DKUM: 16.04.2024; Views: 354; Downloads: 202
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4. Agricultura2002, journal Abstract: The journal publishes scientific works from the following fields: animal science, plant production, farm mechanisation, farm buildings, land management, agricultural economics, rural sociology, and ecology, preservation of biodiversity, biotechnology, microbiology, physiology, soil science and bioethics. In addition, papers discussing innovative pedagogical methods, philosophy of education or solutions to teaching problems in life science may be included.
Keywords: agriculture, ecology, biotechnology, microbiology
Published in DKUM: 24.04.2018; Views: 2662; Downloads: 112
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5. Production of biogas by CSF technologyMaša Knez Marevci, Mojca Škerget, Željko Knez, 2016, original scientific article Abstract: Hydrogen is expected to become an important fuel in the long-term since in combination with fuel cells it offers the opportunity of an intrinsically clean energy supply. By application of supercritical water gasification (SCWG) concept, sustainable hydrogen can be produced from biomass and waste. The paper offers an overview of some recently published papers dealing with SCWG of model compounds and a summary of the investigations on SCWG of real agricultural and food processing wastes. In the frame of our work an intense research was performed to support analyses of SCWG of glycerol and was supported by the investigation of phase equilibrium for the systems gas/water and gas mixtures/water. When glycerol/water solutions were directly injected in the reactor operating at supercritical conditions, gases with high C2+ were obtained by the reforming in supercritical water unit. To reduce the hydrocarbon concentrations and to obtain a syngas with higher CO/CO2 ratios from a mixture of gases (H2, CO, CO2 and CH4), catalytic reactions at high pressure and temperature were introduced reflecting in an increase of the content of H2 and CO. Solubility measurements were conducted for the binary systems of gas and water at elevated pressures and temperatures.
Keywords: biogas, SCF technology, biotechnology
Published in DKUM: 19.07.2017; Views: 1091; Downloads: 213
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6. Micropropagation of the narrow endemic Hladnikia pastinacifolia (Apiaceae)Jana Ambrožič-Dolinšek, Terezija Ciringer, Mitja Kaligarič, 2016, original scientific article Abstract: The monotypic Hladnikia pastinacifolia Rchb. is a narrow endemic species, with an extremely small distribution area in Slovenia, prone to any kind of threat that could lead to species extinction. Tissue culture techniques are proposed as a conservation measure for rapid propagation and ex-situ conservation. Tissue culture was initiated from seeds and juvenile plants obtained from natural sites on a solid Murashige and Skoog (MS) medium, with and without growth regulators. We tested various combinations and concentrations of growth regulators, and the best proliferation of axillary shoots, on average 14, was obtained on MS medium with 5 μM BAP and 3 μM IBA and 3% sucrose. Rooting was achieved after transferral of the shoots to an MS medium with 2 μM IBA and 3% sucrose. The rooted plants were acclimatized on a mixture of limestone sand, potting soil and vermiculite in a ratio of 10:2:2, with pH in the range of 7.5–8.0. In vitro propagation methods provide an important opportunity for the propagation and preservation of H. pastinacifolia by rapidly increasing the number of plants, without disturbing the wild population.
Keywords: biotechnology, micropropagation, micropropagation, tissue culture, Hladnikia pastinacifolia, Apiaceae
Published in DKUM: 28.03.2017; Views: 1992; Downloads: 506
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7. The importance of education of future elementary teachers about modern biotechnology issuesJana Ambrožič-Dolinšek, Andrej Šorgo, 2011, original scientific article Abstract: The tremendous development of science and technology has influenced many aspects of our everyday lives, society and environment. A good example of such technology is biotechnology. However, besides its promise, this technology has also raised several controversial issues to which answers are not easily available. With increasing knowledge and applications on one side and controversy on the other the teaching of science is, anything but easy. Development of competencies for these issues, and questions like why, when, and how to integrate modern biotechnology into science education are becoming prominent in the near future. Nowadays, when we are confronted with issues of varying degrees of complexity and importance, it is necessary that teachers at all levels of education have the basic tools to cope with these issues. This is one of reason why we have attempted to establish what kind of knowledge, values and opinions about genetic engineering and genetically modified organisms (GMOs) are characteristic for the students, future Elementary Teachers, at three Slovene Faculties of Education. We collected answers of 360 questionnaires from pre-service elementary school teachers and analysed their statements from the field of general and classical genetics, modern biotechnology, legislation and the acceptance of different kind of GMOs. Prospective teachers have some knowledge of general and classical genetics and less knowledge about the use of modern biotechnology. They have concerns and fears about different kind of GMOs, mostly negative attitudes towards different kinds of GMOs, or they hold no strong opinions about them. Microorganisms and plants are generally more acceptable than GM animal. Furthermore, more knowledge does not mean that individual GMOs are more acceptable.
Keywords: genetically modified organisms, GMO, students of elementary education, biotechnology, knowledge
Published in DKUM: 21.12.2015; Views: 6801; Downloads: 56
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8. Enzymatic fatty ester synthesisSimona Pečnik, Željko Knez, 1992, original scientific article Abstract: Fatty ester synthesis with immobilized 1,3-specific lipase from Mucor Miehei is described. 1,2-Isopropylidene glycerol was peoduced by condensation of glycerol with acetone was esterified with oleic acid in the presence of a Mucor Miehei lipaze (Lipozyme TM) to obtain 1,2 isopropylidene- 3-oleoyl glycerol. The effects of various process parameters (temperature and pressure)and various ratios (enzyme/substrate) have been investigated to determine optimal conditions for the esterification process. The highest conversion of oleic acid (80% w/w) was obtained at 55 oC and 57.057 bar, while the optimal addition of lipase to substrate was determined to be 0,096 g per gram of reaction mixture. The esterification can be modelled successfully as a reverse second order reaction. Thermodynamic properties of the reaction system at 55 oC and 0.057 bar were also determined. Activation energy was 20.82 kJ/mole, entropy of activation -0,26 kJ/(Kmole) and free energy of activation was 103.32 kJ/mole.
Keywords: chemical engineering, biotechnology, esterification, syntheses, esters, enzymes, lipase, Mucor miehei, reaction kinetics, reaction thermodynamics, 1, 2-isopropylidene-3-oleoyl glycerol
Published in DKUM: 06.06.2012; Views: 2549; Downloads: 101
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9. Silica aerogels as support for lipase catalyzed esterifications at sub- and supercritical conditionsZoran Novak, Maja Leitgeb, Vlasta Krmelj, Željko Knez, 2003, original scientific article Abstract: The enzymes (lipases from Candida rugosa and porcine pancreas) were immobilized on silica aerogels by sol-gel procedure followed by supercritical drying with CO2. Such immobilized enzymes were used as biocatalysts for esterification in supercritical CO2 and near critical propane at 40 °C and 100 bar. It was found out that the initial reaction rates in propane rose two to three times in comparison with the same reaction, catalyzed by free lipase. SC CO2 deactivated the non-immobilized lipase in reaction mixture while with the immobilized enzyme the conversion was 35%. The initial reaction rates in propane were 20 times higher than in water medium due to the properties of propane as a medium for esterification of fatty acids.
Keywords: chemical processing, biotechnology, esterification, immobilization of enzymes, supercritial CO2, propane, lipases, supercritical CO2 drying
Published in DKUM: 01.06.2012; Views: 1880; Downloads: 31
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10. Ecological alternatives to the reduction and oxidation processes in dyeing with vat and sulphur dyesMojca Božič, Vanja Kokol, 2008, review article Abstract: This article gives a summary of the most commonly used ecologically unfriendly processes for the reduction and oxidation of vat and sulphur dyes. It also describes the new alternatives that are in the development stage and could be important in the near future. Sodium dithionite as the dominant reducing agent produces large amounts of sodium sulphate, and also toxic sulphite and thiosulphate as by-products. Consequently, high amounts of hydrogen peroxide and alkali are required for the treatment of effluents, which add to the cost of the process. Attempts have been made to use organic biodegradable reducing agents, enzymes, catalytic hydrogenation, and also indirect or direct, electrochemical reductive methods that employ a redox mediator (electron-carrier). The reduction has also been carried out via the dye radical molecule or, in the case of indigo, by direct electrochemical reduction using graphite as the electrode material. Physical techniques, for example using ultrasound, magnetic fields or UV have been shown to be effective only when used to accelerate methods using classical reduction and oxidation processes. However, although these methods offer some environmental benefits, there is still no satisfactory alternative reducing and/or oxidising agent available today.
Keywords: textile dyeing, vat dyes, sulphur dyes, reduction, oxidation, catalysis, ecology, organic agents, electrochemistry, ultrasound, magnetic field, UV application, biotechnology
Published in DKUM: 01.06.2012; Views: 3143; Downloads: 124
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