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Povzetek: Shallow geothermal energy (SGE) is a renewable energy that could contribute to the decarbonatization of the heating and cooling sector. SGE is predominantly harnessed through ground source heat pump (GSHP) systems. The choice of which type of GSHP system depends on various factors. Understanding these factors is crucial for optimizing the efficiency of GSHP systems and fostering their implementation. In this paper, we have analysed the spatial distribution of GSHPs in Slovenia. We identified 1073 groundwater and 1122 ground-coupled heat pump systems with a total heat pump capacity of almost 30 MW. We quantitatively assessed the influence of geological, hydrogeological, and climate conditions on their spatial distribution. Using the χ2 test and information value method, we identified hydrogeological conditions as the most influential factor for the GSHP systems’ spatial distribution. We also performed the spatial analysis of geological and hydrogeological data in 22 European countries, including Slovenia. We collected the reported numbers of installed GSHP units in 2020 and were able to distinguish the shares of groundwater and ground-coupled heat pump systems for 12 of these countries. The analysis showed that ground-coupled heat pumps predominate in most countries, even if the natural conditions are favourable for groundwater heat pumps.
Ključne besede: shallow geothermal energy, renewable heating and cooling, ground-source heat pump, spatial distribution, natural condition
Objavljeno v DiRROS: 19.03.2024; Ogledov: 86; Prenosov: 44
Celotno besedilo (15,39 MB)

Povzetek: Direct-co-direct product $G\circledast H$ of graphs $G$ and $H$ is a graph on the vertex set $V(G)\times V(H)$. Two vertices $(g,h)$ and $(g',h')$ are adjacent if $gg'\in E(G)$ and $hh'\in E(H)$ or $gg'\notin E(G)$ and $hh'\notin E(H)$. We show that if at most one factor of $G\circledast H$ is connected, then the distance between two vertices of $G\circledast H$ is bounded by three unless some small number of exceptions. All the exceptions are completely described which yields the distance formula.
Ključne besede: direct-co-direct product, distance, eccentricity, disconnected graphs
Objavljeno v DiRROS: 19.03.2024; Ogledov: 80; Prenosov: 45
Celotno besedilo (450,88 KB)
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Povzetek: Background. Pseudoaneurysms are rare complications of myocardial infarction with propensity for rupture. There is still a challenge with which diagnostic imaging we performed a final diagnosis of pseudoaneurysm and differentiate it from true aneurysm what is clinically important due to the different treatment. Case report. We presented the unusual case of a 56-year-old man with signs of decompensated heart failure which had worsened a few months before hospitalization. We believed that during worsening of symptoms the patient suffered a silent myocardial infarction complicated by subacute free wall rupture which resulted into left ventricular pseudoaneurysm formation without tamponade. Echocardiography showed dilatativecardiomyopathy which was already present years before and a very rare location of the left ventricular pseudoaneurysm on the anterolateral part of the left ventricle. Pseudoaneurysm was confirmed with CT scan. Due to the severity of contractile dysfunction and no response in treatment for congestive heart failure the directive for the resection was tempered and the patient died due to the progressive heart failure and embolic phenomena. Conclusions. This report shows the importance of non-invasive imaging diagnostic evaluation of acute decompensated heart failure where echocardiography and chest X-ray are the first diagnostic steps. Based on those findings further imaging diagnostic steps must be performed such as CT scan in our case which finally confirms left ventricular pseudoaneurysm with dilatative cardiomyopathy.
Objavljeno v DiRROS: 19.03.2024; Ogledov: 92; Prenosov: 59
Celotno besedilo (415,90 KB)
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Povzetek: The complementary prism of a graph $\Gamma$ is the graph $\Gamma \overline{\Gamma}$, which is formed from the union of $\Gamma$ and its complement $\overline{\Gamma}$ by adding an edge between each pair of identical vertices in $\Gamma$ and $\overline{\Gamma}$. Vertex-transitive self-complementary graphs provide vertex-transitive complementary prisms. It was recently proved by the author that $\Gamma \overline{\Gamma}$ is a core, i.e. all its endomorphisms are automorphisms, whenever $\Gamma$ is vertex-transitive, self-complementary, and either $\Gamma$ is a core or its core is a complete graph. In this paper the same conclusion is obtained for some other classes of vertex-transitive self-complementary graphs that can be decomposed as a lexicographic product $\Gamma = \Gamma_1 [\Gamma_2]$. In the process some new results aboutthe homomorphisms of a lexicographic product are obtained.
Ključne besede: graph homomorphism, core, complementary prism, self-complementary graph, vertex-transitive graph, lexicographic product
Objavljeno v DiRROS: 19.03.2024; Ogledov: 76; Prenosov: 43
Celotno besedilo (411,68 KB)
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Povzetek: Due to climate extremes and limited natural resources, especially water, we can expect increased demand in the future for species that can better tolerate climate extremes such as drought. One potentially valuable horticultural species is the endemic species of the Dinaride Mountains Micromeria croatica (Pers.) Schott (family Lamiaceae). It grows in the crevices of carbonate rocks, extending from an altitude of 150 m to more than 2000 m. This study aims to provide additional insight into the genetic and morphological diversity of this endemic species, focusing on valuable horticultural traits. To achieve this goal, morphological and molecular analyses were performed on ten natural populations. Through STRUCTURE and PCoA analyses, ten M. croatica populations were placed into western and eastern genetic groups, with several individuals from western populations assigned to the eastern group and vice versa. These atypical individuals assigned to the new genetic group by BAPS analysis indicate gene flow between western and eastern populations. Similarly, an analysis of molecular variance revealed fewer genetic differences than within studied populations. Both PCA and CANDISC analysis based on eleven morphological traits largely confirmed the existence of two slightly different genetic groups. Two populations containing plants with the most flowers per shoot, one with white-flowered individuals, one with the roundest leaves, and one with the narrowest leaves proved to be the most horticulturally valuable. The genetic and morphological variability found should be a sufficient basis for the potential selection of M. croatica populations and individuals for horticultural purposes.
Ključne besede: morphological characterization, molecular characterization, Micromeria croatica (Lamiaceae), Dinaric Alps
Objavljeno v DiRROS: 19.03.2024; Ogledov: 97; Prenosov: 64
Celotno besedilo (3,55 MB)
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