We investigate how the inverse degree index of graphs depends on their cyclomatic number. In particular, we provide sharp lower bounds on the inverse degree index over all graphs on a given number of vertices with a given cyclomatic number. We also deduce some structural properties of extremal graphs. Some open questions regarding the upper bound over the same class of graphs are discussed and some possible further developments are indicated.

In dieser Arbeit wird eine Strategie zur Bewertung des Zuverlässigkeitsniveaus von gemauerten Gründerzeithäusern im Erdbebenlastfall vorgestellt. Die Nachbemessungsstrategie ermöglicht eine normgerechte Bewertung der Schubtragfähigkeit, des Erdbebenerfüllungsfaktors sowie des personenbezogenen Risikos einzelner Schubwände (aussteifende Zwischenwände) in Form von Nachbemessungstafeln. Die Nachbemessungstafeln ergeben sich im Wesentlichen durch die einschlägigen Normen, der aktuell angewandten Pushover-Berechnungsmethode im gemauerten Altbestand, der gründerzeitlichen Bauwerkscharakteristika und der Standortgegebenheiten im Raum Wien. Die methodische Herangehensweise umfasste eine ausführliche Bestandsanalyse von mehr als 200 Gründerzeithäuser, die Nachweisführung der betrachteten Bestandsobjekte im Erdbebenlastfall, eine Sensitivitätsanalyse der Einflussparameter auf das sich einstellende Sicherheitsniveau und die Ableitung sowie Vorstellung der Nachbemessungstafeln. Die Mauerwerksqualität konnte anhand von umfangreichen Mauerwerksuntersuchungen von 125 gründerzeitlichen Objekten in der vorgestellten Strategie berücksichtigt werden.

The study of aerosol dispersion in indoor environments is essential to understanding and mitigating airborne virus transmission, such as SARS-CoV-2. Computational Fluid Dynamics (CFD) has emerged as a valuable tool for investigating aerosol dispersion, providing an alternative to costly experimental methods. In this study, we investigated the performance of four (4) Reynolds-averaged Navier-Stokes (RANS) turbulence models in predicting aerosol dispersion from a human body coughing in a small, ventilated indoor environment. We compared the Standard, RNG, Realizable k-ϵ models and the SST k- ω model using the same boundary conditions. We initially observed that the horizontal distance of the coughed aerosols after 10.2s dispersion time was substantially shorter with the standard k-ϵ turbulence compared to the other three turbulence models compared to the SST k-ω model, the RNG, and realizable k-ϵ models exhibit a high degree of similarity in their dispersion patterns. Specifically, we observed that the aerosols dispersed horizontally faster with the RNG and Realizable k-ϵ models. In conclusion, when compared to qualitative data from the literature, our observations exclude the standard k-ϵ turbulence. However, to select the most appropriate turbulence model for capturing the cough flow and aerosol dispersion dynamics, further detailed validation against both quantitative and qualitative data is needed.

The paper considers the possibility of improving the technical characteristics of gas surge arresters for the co-ordination of insulation at low voltage, medium voltage and high voltage levels. The idea for improving the characteristics of a gas surge arrester is based on the application of the radioactive source 241Am in the area of the surge arrester cathode. Intensive ionization with alpha particles significantly increases the number of free electrons in the space between electrodes, which shortens the time of their transition to initial electrons. This changes the Paschen curve of the gas surge arrester, narrows and flattens its impulse characteristic and reduces the stochasticity of the response of the gas surge arrester. All this results in a significant improvement in the characteristics of the gas surge arrester at all voltage levels. This improvement is particularly noticeable in the case of low voltage surge arresters. The paper is basically theoretical-experimental research. The experiments were performed under well-controlled laboratory conditions. The combined measurement uncertainty of all measurements was acceptable.

The acoustic adaptation hypothesis (AAH) is often tested between species from open and closed habitats. However, the acoustic differences are rather small and thus the evidence is ambiguous. We tested the AAH between subterranean and surface-dwelling species living in very different acoustic environments. Lower frequencies (<1 kHz) are transmitted best in subterranean burrows and there is a high-frequency cut off around 3 kHz. The other important factor influencing the frequencies of vocal signals is body size. Acoustic allometry – a negative relationship between body size and frequency of acoustic signals – indicates that larger species tend to produce sounds of lower frequencies than smaller species, due to their larger vocal apparatus. The present study shows, that acoustic allometry applies to subterranean as well as surface-dwelling rodents and that the environment influences the main frequency of their vocalization. Besides, the subterranean species tend to have lower vocal signals than surface-dwelling species.

Everyone is born with the right to life and the right to live that life with the dignity of a human being and a citizen, to have the right to choose education, place of residence, the right but not the obligation to start a family, the right to earn money and the freedom to dispose of it. Every man and citizen is a woman. However, it hasn't always been like that: The work deals with the position of women in society, and what is reflected on her position and status in the family throughout history and modern times. The main goal of the work is, through a cross-section of the past with a comparative analysis of the contemporary era, to realize productivity and full equality of the sexes in the near future. The work is based on the analysis of a heterogeneous family (the family of a man and a woman).

The paper deals with taxes and the tax system in Bosnia and Her­zegovina. Modern tax systems are based on taxation of income and con­sumption. For developing countries like Bosnia and Herzegovina, the tax­ation of consumption is more dominant than the taxation of income. This means that in such countries the participation of indirect taxes concerning direct taxes is higher. The basic taxation categories in Bosnia and Herzego­vina are corporate income tax, personal income tax, value-added tax, so­cial security contributions, and excises. The taxation system in Bosnia and Herzegovina is characterized by low tax rates. Personal income tax is paid at the rate of 10% which means that we have proportional tax rates. But so­cial security rates are high as follows (employee’s share): 17% for pension in­surance, 12,5% for health insurance and 1,5% for health insurance. We need some fiscal reforms within fiscal policy if we want to have higher salaries and standard of living.

The paper deals with foreign direct investments (FDI) with a spe­cial focus on Bosnia and Herzegovina. Most of the world’s economies are in­terested in FDI, especially today in a globalized society. They can generate new jobs, and contribute to the development of new technology, and their special contribution is reflected in the stimulation of economic growth, development and employment. In recent years, Bosnia and Herzegovina made a lot of effort to attract foreign direct investments as one of the important ways to stimulate economic development and solve the problem of unemployment Considerable progress in this field has been achieved by adjusting the legislation and institutional framework. The costs, procedures and time of registration of craft-entrepreneurial activ­ities have been reduced, and various benefits in the field of customs and tax­es have been provided, which will be presented in the paper

Plant extracts contain a large number of organic compounds, and one of the large groups of compounds present are phenolic compounds. Researchers have shown that a certain number of these compounds can be used as effective metal corrosion inhibitors. Plant extracts of raspberries (leaves, flowers, and fruit) were obtained by ultrasonic extraction using 96% ethanol as a solvent. The UV/Vis spectrophotometric method was used to determine the content of total phenols in plant extracts. Phenolic acids and flavonoids in plant extracts were separated and quantified using the HPLC method. Tafel extrapolation was used for electrochemical characteristics. The corrosion characteristics and behavior of bronze in 3% NaCl solution, with and without the presence of plant extracts were investigated. The content of total phenols in leaves was found to be 107.14±3.63 mg/g in flowers 148.99±9.02 mg/g and in fruits was 8.75±0.61 mg/g. Leaf extract in a concentration of 0.04828 g/L according to the Tafel extrapolation method provides the best protection for bronze in a 3% NaCl solution. The same concentration in the case of flower and fruit extracts proved to be the most favorable.

Soil erosion is a problem that affects the landscape at different scales and represents a serious challenge for land management and soil conservation in both natural forests and meadows. The aim of this study was to determine how the parent material and land use affect the physical and chemical properties of the soil in the area of the Fruska gora Mountain. The soils were developed on five bedrock types: serpentinite, marl, trachyte, shale, loess and two land use types: forest and meadow. Twenty-three forest soil and 24 meadow soil from a depth of 0-20 cm were sampled from the Fruska gora Mt. Following properties were determined: pH, electrical conductivity, oxidation-reduction potential, content of organic carbon, sodium adsorption ratio, aggregate size and stability. There is no statistically significant difference in pH, Eh, EC, and SAR values between the analyzed forest and meadow soils, but there is a statistically significant difference in the content of Corg. It can be conculded that both the parent matrial, and to a slightly less extent, land use have a great influence on physico-chemical properties of the soil.