University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Incorporation of reverse logistics model into in-plant recycling process: A case of aluminium industry

Abstract: In order to maximize the efficiency of ever increasing aluminium recycling, different mutually related aspects need to be optimised. Economic efficiency of aluminium recycling is crucially dependent on the costs, arising at different stages of recycling process. Among these, transportation costs represent very important part of overall cost balance. The general model, based on the principles of reverse logistics, was developed and applied with the aim of reducing the extent of internal aluminium scrap transportation required between certain production units of an aluminium manufacturing plant. Linear optimisation model was used for calculating minimum annual transport costs and optimal way of in-plant transport for two transport models in order to determine the most efficient option. In case of in-plant aluminium recycling only collected aluminium materials are transported which means that the most important factors in such case are fixed transport costs and variable transport costs, latter depending on distance, transported quantity, energy used for transport and other operating costs. In the first transport model, the direct transport of collected aluminium scrap from each individual source to in-plant processing units was assumed. In the second transport model, one collection site was assumed where scrap is collected and then transported to in-plant processing units. The optimisation model was also applied for determining a dependence of optimal transport model on annual quantities transported internally and on the distances between sources and processing units. It was found out that the annual transported quantities and distances between sources and in-plant processing units have a significant impact on the optimal transport model. The developed optimisation model showed that environmental and economic objectives are not always in conflict. It is also shown and commented which aspects influence reverse logistics model for in-plant recycling.

Measurement and Modeling of the CO2 Solubility in Poly(ethylene glycol) of Different Molecular Weights

Abstract: The solubility of supercritical carbon dioxide (scCO2) in solid (298 K) and melted (323 K) poly(ethylene glycol) (PEG), in the pressure range (7 to 25) MPa, was measured using a magnetic suspension balance. The phase behavior of the CO2 + PEG system was modeled by using the Sanchez−Lacombe equation of state (EOS) and statistical associating fluid theory (SAFT). The results show a good solubility of CO2 in polymer and a good accuracy of the thermodynamic models in describing the phase equilibrium of the working system. The experimental data are also in good agreement with the solubility values previously described in the literature, obtained by employing different experimental techniques.

The Role of Culture in the Relationship Between Religiosity and Psychological Well-being

Abstract: Several measures of religious practice and religious orientation (intrinsic/extrinsic/quest) and two measures of psychological well-being (positive affect and negative affect) have been employed in a cross-cultural survey of undergraduate university students from five different cultural/religious environments: Slovenia, Bosnia and Herzegovina, Serbia, the United States of America, and Japan. Results suggest that measures of exstrinsic, intrinsic, and quest religiosity are not entirely applicable in most of the cultures observed. Nevertheless, it was possible to discern abbreviated cross-culturally valid scales for each dimension. The strength and direction of the correlation between psychological well-being and a particular type of religious orientation proved to depend substantially upon culture. More importantly, the cultural environment plays a crucial role in shaping the relationship between general measures of religiosity and psychological well-being. According to the data, higher general levels of religiosity at the societal level are linked to more positive correlations between religiosity and psychological well-being. The overall picture leads to the conclusion that there is no culturally universal pattern in the relationship between measures of religiosity and psychological well-being and that the particular cultural and religious context should always be considered in studies dealing with this issue.

Do all pieces make a whole? Thiele cumulants and the free energy decomposition

Abstract: The partitioning of the free energy into additive contributions originating from different groups of atoms or force field terms has the potential to provide relationship between structure and biological activity of molecules. In this article, the theoretical foundation for the free energy decomposition in the free energy perturbation (FEP) methodology is formulated using Thiele cumulants, a powerful tool from the arsenal of probability theory and mathematical statistics. We establish that rigorous decomposition of the free energy into its components is precluded by the presence of mixed potential energy terms in Thiele cumulants of second and higher orders. However, we also show that the resultant nonadditivity error can be reduced to an arbitrary value by increasing the number of FEP steps. Consequently, the whole system can be in the limit of small perturbation steps adequately represented by the sum of its constituent parts.

Preparation of multi-membrane alginate aerogels used for drug delivery

Abstract: A significant amount of investigation has already taken place into alginate spherical hydrogels’ attractiveness for application as drug delivery carriers. One of their weaknesses is, however, their short lives within dry air conditions. In this study we used a multi-step sol–gel process for generating dry and stable complex alginate aerogels with multi-membranes. Firstly, the formation was performed of spherical hydrogels within a CaCl2 solution. These cores were further immersed in alginate solution, filtered through a sieve, and dropped into the salt solution again. Different multi-membrane hydrogels were obtained by repeating the above process. They were further converted into aerogels by supercritical drying. The effect of the membranes’ numbers was investigated regarding the model drug nicotinic acid's loading and release. The drug loading increased and the drug release was prolonged by adding more membranes around the core. By increasing the amount of drug inside the multi-membrane spheres, the burst drug release was even further inhibited compared to the lower drug-loaded samples.