Given the energy crisis and climate change due to pollution, and given that the largest emissions of greenhouse gases are produced by the energy industry, we must turn our attention to the efficient use of solar energy, which is the cleanest and most abundant of all renewable energies. In this paper, based on an analysis of the specialized literature, we studied the effect of dust accumulation on the surface of photovoltaic modules on some performance characteristics and on the efficiency of these panels and modules compared to the efficiency of clean modules. We analyzed the cause of dust accumulation and the influence of the tilt angles of the photovoltaic panels on the dust deposition rate. We highlighted the influence of atmospheric temperature, solar radiation, wind speed, and relative humidity depending on the density of the dust deposited on the surface of the photovoltaic panel, and we found a decrease in the efficiency of the panel based on the increase in dust density for slightly high values of solar radiation, wind speed, and relative humidity. We highlighted the reduction in CO₂ emissions by replacing electricity from fossil fuels with solar energy. The efficient use of solar energy is a solution for the decarbonization of the energy sector.

Polycyclic aromatic hydrocarbons (PAHs) are considered hazardous pollutants due to their negative impact on the environment and human health. PAHs can accumulate and be retained in the soil, so PAH pollution is a worldwide problem. This review paper highlights the sources of PAH soil pollution, factors affecting the bioavailability of PAHs in soil, and soil bioremediation methods, as well as the advantages and limitations of the application of these methods. Aspects regarding the impact of the application of surfactants are presented in order to obtain good bioavailability during PAH bioremediation. Bioremediation techniques of soil polluted by these hydrocarbons are addressed: phytoremediation, rhizoremediation, composting, vermiremediation, micoremediation, and electrokinetic bioremediation of PAH-polluted soils. A comprehensive overview of bioremediation technologies for PAH-polluted soils is needed so that the right soil remediation technology is chosen. It has been observed the bioremediation of contaminated soils through rhizoremediation proved to be an effective process, the future of organic pollutants in interaction with plants and microbes must be researched. Vermiremediation, electrokinetic bioremediation, and microcomposting are effective processes for treating soils in situ. Phytoremediation is a sustainable and ecological method of PAH depollution. It improves soil fertility by releasing different organic matter in the soil, and it can be applied on a large scale.

Considering the global climate changes that have disrupted the availability of fresh water and led to the emergence of drought, an effective management strategy for water quality must be implemented. In this work, we analyzed the possibility of used and treated water being reused and the effect of its use on soil on the development of plants. In the case of irrigation with treated wastewater, the following parameters increased: calcium carbonate equivalent, organic matter, content of phosphorus, calcium, potassium, sodium, nitrogen, biochemical oxygen consumption; chemical oxygen demand (COD), decreased sodium absorption rate, soil electrical conductivity, pH, magnesium content, and soil bulk density. Due to the micronutrients it contains, the use of treated wastewater in irrigation can be an organic fertilizer for the soil. Wastewater is a source of soil water supply. Untreated wastewater may contain, depending on the source (industry, pharmacies, medicine, households), toxic compounds, bacteria, viruses, and helminths, which, if used for long periods of time in irrigation, can have a negative impact on health and the environment, reaching the soil, the roots of the crops, and then the underground water. Therefore, these waters must be used after adequate treatment. Global climate change disrupts the availability of fresh water and negatively influences the occurrence of floods, droughts, and water quality, which is why any water source must be managed correctly.

The baking process in tunnel ovens can be influenced by many parameters. Among these, the most important can be considered as: the baking time, the volume of dough pieces, the texture and humidity of the dough, the distribution of temperature inside the oven, as well as the flow of air currents applied in the baking chamber. In order to obtain a constant quality of bakery or pastry products, and for the efficient operation of the oven, it is necessary that the solution made by the designers be subjected to modelling, simulation and analysis processes, before their manufacture, and in this sense it can be applied to the Computational Fluid Dynamics (CFD) numerical simulation tool. In this study, we made an analysis of the air flow inside the baking chamber of an oven. The analyzed oven was used very frequently on the pastry lines. After performing the modelling and simulation, the temperature distribution inside the oven was obtained in the longitudinal and transverse planes. For the experimental validation of the temperatures obtained in the computer-assisted simulation, the temperatures inside the analyzed electric oven were measured. The measured temperatures validated the simulation results with a maximum error of 7.6%.

The current study evaluated the effect of powder fractionation based on particle size on the chemical composition of macronutrients such as proteins and sugars, on the phytochemical properties (total content of polyphenolic compounds, vitamin C, and antioxidant activity), on preservation capacity (water activity), powder functional properties (water absorption capacity and water solubility index), and physicochemical properties (particle size distribution and moisture content) of blackthorn berry (Prunus spinosa) powders. The fruits were separated from the plant material and seeds, dried, and then ground using an universal mill for dry materials. Eight fractions were obtained after sieving on sieves with different mesh sizes, such as 1 mm, 0.8 mm, 0.630 mm, 0.450 mm, 0.315 mm, 0.200 mm, and 0.125 mm. The grinding/sieving procedure was effective in separating Prunus spinosa powder into sufficiently different size classes. The maximal moisture content and water activity were 5.61% and 0.250, respectively, showed good preservation from a microbiological point of view, and ensured the prevention of oxidation of biologically active compounds of blackthorn berry powders. For samples with reduced particle sizes, the powder functional properties were greatly improved. The total phenolic content, carbohydrates, and antioxidant activity showed significantly different values for some particle size classes compared to the un-sieved sample. A considerable content of vitamin C was presented in the fraction with large particle sizes, precisely because they did not undergo intense degradation processes. Therefore, the technique of grinding and successive sieving proved effective in enhancing the physicochemical and functional characteristics of powdered blackthorn berries, particularly for smaller particles.

This paper primarily presents statistics on the variation of physical characteristics (dimensions and mass) for the coulter discs of double-disc seeders. This statistic was calculated based on actual measurements of the probability density and cumulative probability for the mass of the discs, their average thickness, and outer diameter. These parameters (m = 4000 g, g = 4 mm, D = 380 mm) are tracked from the design phase to the actual realization phase, being the parameters specified in the purchase phase by users from agricultural machinery distributors. The standard deviation and deviation from the mean for a cumulative normal (Gaussian) distribution were calculated, and an analysis was made for the decrease of the mentioned parameters in discs already used for sowing cereals on an area of 80 hectares, due to the wear that appeared as a trace of the contact with the soil and the abrasive wear caused by it. Testing of disk parameters using both logarithmic and Gaussian distributions was performed, and test results are presented through appropriate graphs. With small deviations (which appeared for known or unknown reasons), it can be stated that the distribution of the mentioned parameters is generally a normal-type distribution. If the new discs are 15″ in diameter, experts recommend that they be replaced when they reach a diameter of less than 14.5 inches. This study can provide a reference for improving the physical characteristics of opener discs of seed drills in no-till conditions and beyond.