Direct current (DC) power systems are gaining interest in the last decade due to increased utilization of DC outputted power sources, DC based energy storage (ES) elements and DC inputted loads. Microgrids are also becoming widely researched as the main foundation of smart grid. It is therefore logical to try to utilize DC microgrid (DCMG) concepts in organization of power systems in wide range of applications. DC microgrids have several important advantages compared to alternating current (AC) microgrids. The control system is essential in order to keep DCMG operating properly, reliable and efficient. Their control structures, with special interest in hierarchical control are explored and compared in this paper in terms of architecture and techniques. This paper presents real world applications using DCMG concept. Future research propositions given in the final chapter can be used as a foundation for researchers exploring the area.

A building-integrated microgrid (BIM) has been a widely utilized concept in low-carbon smart cities. The key advantages of microgrids are using locally available renewable energy sources (RES) and reducing dependency on fossil fuels. Solar photovoltaic (PV) systems and battery storage systems play a crucial role in BIM to achieve desired goals. Due to legal/regulatory and technical restrictions, the distribution system operator (DSO) often imposes zero energy export (ZEE) for these microgrids. Therefore, the sizing of solar-battery systems in BIM, which will be technically feasible and economically optimized, is a challenge for designers, owners and DSO. The objective of this paper is to show the practical approach for design and sizing a microgrid for public buildings using the real data sets of a power consumption and solar energy production. As an example, the BIM for the Faculty of Electrical Engineering, University of Sarajevo is presented.

This aim of this study was to investigate surface gloss changes of different composite dental materials after chemical degradation or polishing. Five different composites were used (Evetric, GrandioSO, Admira Fusion, Filtek Z550, Dynamic Plus). The gloss of the tested material was measured with a glossmeter before and after chemical degradation in different acidic beverages. Statistical analysis was performed using a t-test for dependent samples, ANOVA, and a post hoc test. For comparison between groups, a level of significance was set at 0.05. Initial gloss values ranged from 51 to 93 at baseline to 32 to 81 after chemical degradation. The highest values were obtained for Dynamic Plus (93.5 GU) and GrandioSO (77.8 GU), followed by Admira Fusion (82 GU) and Filtek Z550 (70.5 GU). Evetric showed the lowest initial gloss values. After acidic exposures, the gloss measurements revealed different patterns of surface degradation. The results showed that the gloss of the samples decreased with time regardless of the treatment. The interaction between chemical-erosive beverages and the composite could lead to a decrease in the surface gloss of the composite restoration. The nanohybrid composite showed less gloss changes under acidic conditions, suggesting that it is more suitable for anterior restorations.

Clear cell renal cell carcinoma (ccRCC) is the deadliest neoplasm of the urinary tract, and we are still far from completely understanding ccRCC development and treatment. The renal tissue paraffin blocks (20) of patients with ccRCC were collected at the University Hospital in Split from 2019 to 2020, and tissue sections were stained with patched (PTCH), anti-smoothened (SMO) and anti-Sonic Hedgehog (SHH) antibodies. SHH was highly expressed (31.9%) in grade 1 tumour, it being higher than all other grades and the control (p < 0.001–p < 0.0001). The trend of a linear decrease in the expression of SHH was observed with the progression of the tumour grade (p < 0.0001). PTCH expression was significantly lower in grades 1 and 2 in comparison to the control (p < 0.01) and grade 4 (p < 0.0001). A significant increase in the expression of SMO was found in grade 4 compared to all other grades (p < 0.0001) and the control (p < 0.001). The strong expression of SHH was observed in carcinoma cells of the G1 stage with a diffuse staining pattern (>50% of neoplastic cells). Stroma and/or inflammatory infiltrate display no staining and no expression of SHH in G1 and G2, while mild focal staining (10–50% of neoplastic cells) was observed in G3 and G4. Patients with high PTCH and low SMO expression had significant time survival differences (p = 0.0005 and p = 0.029, respectively). Therefore, high levels of PTCH and low levels of SMO expression are important markers of better survival rates in ccRCC patients.

Graphene has a large optical nonlinearity and supports electrically-tunable and long-lived plasmons. We present an experimental study of harmonic generation in graphene heterostructures, which enhance the nonlinearity and allow plasmons to mediate the non-linear response.

In this paper, the possible synergistic effects of fly wood biomass ash (WBA) and recycled tire polymer fibres (RTPF) on long-term autogenous shrinkage and drying shrinkage in mortar were investigated, and the pore structures of mortar specimens with WBA and RTPF were determined. The results showed that the use of RTPF and WBA has an effect on the pore structure of mortars and thus on the results of autogenous shrinkage. When WBA and RTPF were used, the autogenous shrinkage tended to decrease; however, this was not the case for the drying shrinkage. The greatest reduction in autogenous shrinkage was achieved by the addition of WBA and RTPF; autogenous shrinkage was reduced by 62 % after 90 days compared with the reference mixture.