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On March 15, 2020, the Serbian government introduced a nationwide lockdown to prevent the spread of COVID-19. The enforcement of lockdown measures led to changes in the daily lives of dog owners, which, in turn, affected the routines of their dogs. Therefore, this study aimed to investigate the effects of Serbian lockdown measures enforced for the control of the COVID-19 pandemic on pet dog management. An online questionnaire survey with Serbian dog owners was conducted in the period from July 15 to August 31, 2021. A total of 384 pet owners older than 18 years participated. The survey comprised 34 questions about owners' demographic information, information about their dogs, changes in dog walking and feeding practices, as well as behavior before and after the COVID-19 lockdown. Most questions were closed-ended with the option to mark one or more proposed responses, while some questions had the option to add free text predefined as "other". The survey also included several open-ended questions. The responses of the survey participants in the two different periods (before and during the lockdown) were compared to determine their interdependence. The obtained data indicated that there was no notable rise in the rate of dog adoption or purchase. Furthermore, it was found that dog owners decreased the frequency of walks for their pets in nature or walking fields, choosing instead to keep them indoors or confine them to the backyard more frequently. Some owners believed that their dogs became slightly passive or nervous as a response to enforced lockdown restrictions. No significant changes in dog feeding practices were reported, although a minority of dog owners noted that their dogs consumed slightly less food during the lockdown but gained a small amount of weight. Additionally, owners reported no pronounced changes in the amount of money they spent on dog food. Overall, data collected indicated that lockdown restrictions had a limited impact on dog management; however, further research should be performed to determine any long-term effects.

The technical features of the issues caused by the brick industry's usage of petroleum coke as a fuel were identified in this study. The effects were evaluated in terms of the concentration of hazardous materials in petroleum coke, the CO2, SO2 and NOx emissions in the flue gases, the corrosion of refractory materials in the furnace, the corrosion of pipelines and metal structures in the dryer and furnace, the deposition of sulfate scum on dry products, and the fixation of white scum on finished products. To assess the microstructure and composition of the regions of the samples exposed to flue gases and that inside the material, refractory brick samples from the furnace walls were examined under a microscope. The compressive stress of the part of the sample affected by the flue gas from the kiln is lowered by 37.3 %, which is caused by the agglomeration of sulfate salts and the presence of a high quantity of vanadium. It was determined that, regardless of potential energy savings, the sulfur concentration in petroleum coke must be below 5% if utilized as an energy source in the brick sector since there are suitable conditions for accelerated corrosion processes.

Phyllosilicate mineral pyrophyllite is predominantly used in the ceramic industry because it exhibits high refractoriness. Due to its thermal transformation into mullite, pyrophyllite is stable at elevated temperatures, making it a suitable mineral additive for refractory non-shaped materials and various ceramic shaped products. In this study, pyrophyllite is employed as 50 % clay replacement in the ceramics and up to 30 % cement replacement in mortars. Physico-mechanical properties were investigated. The firing shrinkage in the ceramics treated at 1200 °C was reduced by pyrophyllite addition. Pyrophyllite acted as additional pozzolana during cement hydration. Within the microstructure, it formed micro-reinforcement in the shape of crystalline folia, which improves the mechanical properties of ordinary Portland cement, high aluminate cement, and blended cement mortars. The investigation proved the efficiency and suitability of pyrophyllite employed as a substitution for clay in ceramics and a cement replacement in mortars.

Four monitoring campaigns of sedimentable dust were provided from two large non-sanitary landfills (Zrenjanin and Novi Sad) in Serbia during 2021. Particle size analysis by laser diffraction and inductively coupled plasma-optical emission spectrometry were carried out in order to obtain the particle size distribution (PSD) and the toxic elements (TEs) concentrations. The health risk assessment of the landfill employees was performed according to the United States Environmental Protection Agency methods based on TEs concentrations. The PSD results demonstrated that the majority of sedimentable dust samples mass were not concentrated neither within PM2.5 neither within PM10 fraction. Analysis revealed high concentration of TEs at both landfills: an extremely high concentrations of Cr and Zn in samples from Zrenjanin landfill was detected. Health risk potential of elements was as follows for both landfills: Cr > Co > Pb > Ni > Zn > Cu. According to the results, maximal hazard index for landfill employees in Zrenjanin (0.197) and Novi Sad (0.113) showed that non-cancer risk was very low. For both landfill sites, cancer risk was highest for Cr (2.75×10-5 for Zrenjanin and 2.02×10-7 for Novi Sad), though still within the defined threshold for tolerable cancer risk.

Biomass ash is currently attracting the attention of science and industry as an inexhaustible eco-friendly alternative to pozzolans traditionally used in commercial cement manufacture (fly ash, silica fume, natural/calcined pozzolan). This paper explores a new line of research into Marabou weed ash (MA), an alternative to better-known conventional agro-industry waste materials (rice husk, bagasse cane, bamboo, forest waste, etc.) produced in Cuba from an invasive plant harvested as biomass for bioenergy production. The study entailed full characterization of MA using a variety of instrumental techniques, analysis of pozzolanic reactivity in the pozzolan/lime system, and, finally its influence on the physical and mechanical properties of binary pastes and mortars containing 10% and 20% MA replacement content. The results indicate that MA has a very low acid oxide content and a high loss on ignition (30%) and K2O content (6.9%), which produces medium–low pozzolanic activity. Despite an observed increase in the blended mortars' total and capillary water absorption capacity and electrical resistivity and a loss in mechanical strength approximately equivalent to the replacement percentage, the 10% and 20% MA blended cements meet the regulatory chemical, physical, and mechanical requirements specified. Marabou weed ash is therefore a viable future supplementary cementitious material. [ABSTRACT FROM AUTHOR]

Due to rapid urbanisation, urban microclimate research has become increasingly popular in the last decade. Significant variation in microclimate conditions can be created due to diversity in urban geometry and it can affect outdoor thermal comfort. Biometeorological measurements and survey were conducted in different urban settings (square, park, street) of the city of Novi Sad during a warm autumn day in October 2019. Air temperature, relative humidity, wind speed and globe temperature, but also outdoor thermal comfort indices such as Mean Radiant Temperature (Tmrt) and Physiological Equivalent Temperature (PET) were obtained for each location. The largest differences in the biometeorological conditions are noticed between the urban park and other urban areas. The maximum average value of Ta was at the city square with 27.9 oC, while in the urban park and street Ta were about 25 oC. The values of RH were the lowest at the city square. Globe temperature (Tg) had the highest values, on average, at the city square (about 40 oC), while the average values in the urban park and street were about 26-28 oC. The highest average PET values are registered at the city square (41.4 oC), followed by substantially lower average PET registered in urban park (27.1 oC) and urban street canyon (26.2 oC). The analysis showed that during about 70% of the time, urban dwellers experience extreme heat stress at the city square. Contrary to that, no extreme heat stress is noticed in urban park and street canyon.

This study analyzed the last 20 years` data available on power plant coal ashes used in clay brick production. The statistical analysis has been carried out for a total of 302 cases based on the relevant parameters reported in the literature. The chemical composition of the clays and coal ashes, percentage incorporation and maximum particle size of ash, size of fired samples, peak firing temperature, and the corresponding soaking time were selected as inputs for modeling. The product characteristics i.e. open porosity, water absorption, and compressive strength was taken as output parameters. An artificial neural network model has been developed and showed a satisfactory fit to experimental data and predicted the observed output variables with the overall coefficient of determination (r2) of 0.972 during the training period. Besides, the reduced chi-square, mean bias error, root mean square error, and mean percentage error were utilized to check the correctness of the obtained model, which proved the network generalization capability. The sensitivity analysis of the model suggested that the quantity of Na2O coming from brick clays, the percentages of SiO2 and K2O coming from ashes, and MgO coming from clays were the most influential parameters in descending order for the ash-clay composite bricks` quality, mostly owing to the influence of fluxes during firing.

Тhe influence of thermally induced microstructural transformations on magnetic properties of Fe72Cu1V4Si15B8 ribbon with combined amorphous/nanocrystalline structure is presented. The experiments showed that thermally induced structural changes are in correlation with the appearance of magnetic hysteresis, i.e. with inverted hysteresis loops (IHL) and exchange bias (EB) effects. It was found that the ratio of surface to volume of a ribbon sample have an influence on hysteresis loop appearance. The inverted hysteresis loops were observed for the 1.5 mm wide and 55 μm thick alloy samples shorter than 10 mm, but for the samples longer than 10 mm hysteresis loops were normal. With an increase of annealing temperature, a shift of the hysteresis loops measured at room temperature was noticed. The highest positive exchange bias field Heb was observed for the sample annealed at 723 K, together with the lowest magnetic field at which the changes from inverted to normal hysteresis loop occurred. Annealing at the temperature of 823 K resulted in negative Heb.

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