University of Forestry

Cultivation of horticultural crops in riverbank soils which are enriched by deposition of nutrient-rich sediments is one of the most common practices in arid and semi-arid regions around the globe. However, contamination of river streams by urban, industrial, and agricultural runoffs resulted in the accumulation of excessive levels of certain nutrients and heavy metals in such crops. Keeping in view, the present study was conducted to understand the impact of Yamuna (non-contaminated) and Solani (urban sewage contaminated) Rivers streams on riverbank soils and planted Armenian cucumber [Cucumis melo var. flexuosus (L.) Naudin.] in a two-year (2022 and 2023) study. The results showed that C. melo cultivated in Solani River water irrigated soils had significantly (p < 0.05) higher growth, yield, and biochemical constitutes as compared to Yamuna River water irrigated soils. The bioaccumulation factor (BAF) studies showed that concentrations of eight heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were higher in C. melo grown in Solani River soils. However, the levels of heavy metals were found below the safe limits as indicated by dietary intake of metal (DIM), health risk index (HRI < 1), and target hazard quotient (THQ < 1) indices. Overall, this study evidenced that river water impacted by urban sewage could result in elevated levels of heavy metals in river water, soil, and cultivated food crops, thus, signifying their regular biomonitoring in order to mitigate any associated health risk.

The study aimed to explore suitable substrates comprising locally available hardwood sawdusts for the cultivation of Shiitake (Lentinula edodes) in Lebanon. Sawdusts of oak (OS), maple (MAP), and eucalyptus (EUC) were used alone or in combination, supplemented equally by wheat bran (WB). Results showed that complete mycelia run, fruiting, and harvest dates were the minimum in OS-WB: 800–200 by 72.2, 75.5, and 79.5 days after spawning (DAS) respectively, and the maximum in EUC-MAP-WB: 400-400-200 (by 88.3, 87.5, and 92.0 DAS, respectively). The substrate EUC-OS-WB: 400-400-200 had the highest biological efficiency (74.1%) compared to all treatments. Mushroom numbers ranged between 13.0 and 29.5 at harvest 1 (H1) and between 9.5 and 26.5 at harvest 2 (H2), showing a significant decrease in H2 in comparison to H1 in all treatments. Mushroom weight ranged between 8.8 and 25.9 at H1 and between 5.9 and 14.6 at H2. Furthermore, stepwise correlation showed that total biological yield (TBY) was positively affected by the biological yield at first harvest (BYH1) in OS-WB: 800–200 (R² = 0.943), and at BYH2 in EUC-WB:800–200 (R² = 0.944) and MAP-WB: 800–200 (R² = 0.998), and it was negatively affected by BYH1 and stipe diameter in MAP-OS-WB: 400-400-200 (R² = 0.946). Also, there was an improvement in mushroom protein, crude fibers, and vitamin C contents, and a decrease in carbohydrate contents on most substrates compared to control. Mushrooms obtained in EUC-OS-WB:400-400-200 recorded the highest protein and crude fiber contents (15.1 and 5.4%). Therefore, the mixture containing oak and eucalyptus sawdust has a good potential to improve shiitake yield and nutritional value compared to oak sawdust and could be an appropriate alternate for producing shiitake mushrooms.

Twelve clinically healthy and sexually mature New Zealand White rabbits were studied. The non-contrast imaging included T1-weighted and T2-weighted spin-echo and gradient-echo sequences in the transverse, sagittal and dorsal planes. Transverse MRI (T2-weighted image) through L1 demonstrated only the right kidney. The transverse T2-weighted image through L2 showed both kidneys. The cranial part of the urinary bladder on T1-weighted transverse scans through L4 was flexed to the left. The T2-weighted sagittal image 30 mm to the right of the median plane showed the right kidney, the right ureter and the urinary bladder. The T2-weighted sagittal image 30 mm to the left of the median plane showed part of the left kidney, the left ureter and the urinary bladder. The T2-weighted sagittal image 45 mm to the left of the median plane presented the lateral part of the left kidney. The dorsal MRI image (T2-weighted sequence) through the horizontal plane 30 mm ventral to the spine demonstrated the whole organs. These data will be useful in imaging anatomy and diagnostic studies of various pathologies of the excretory system in rabbits and other mammalian species.

The rising environmental concerns and the growing demand for renewable materials have surged across various industries. In this context, lignin, being a plentiful natural aromatic compound that possesses advantageous functional groups suitable for utilization in biocomposite systems, has gained notable attention as a promising and sustainable alternative to fossil-derived materials. It can be obtained from lignocellulosic biomass through extraction via various techniques, which may cause variability in its thermal, mechanical, and physical properties. Due to its excellent biocompatibility, eco-friendliness, and low toxicity, lignin has been extensively researched for the development of high-value materials including lignin-based biocomposites. Its aromatic properties also allow it to successfully substitute phenol in the production of phenolic resin adhesives, resulting in decreased formaldehyde emission. This review investigated and evaluated the role of lignin as a green filler in lignin-based lignocellulosic composites, aimed at enhancing their fire retardancy and decreasing formaldehyde emission. In addition, relevant composite properties, such as thermal properties, were investigated in this study. Markedly, technical challenges, including compatibility with other matrix polymers that are influenced by limited reactivity, remain. Some impurities in lignin and various sources of lignin also affect the performance of composites. While lignin utilization can address certain environmental issues, its large-scale use is limited by both process costs and market factors. Therefore, the exact mechanism by which lignin enhances flame retardancy, reduces formaldehyde emissions, and improves the long-term durability of lignocellulosic composites under various environmental conditions remains unclear and requires thorough investigation. Life cycle analysis and techno-economic analysis of lignin-based composites may contribute to understanding the overall influence of systems not only at the laboratory scale but also at a larger industrial scale.

The aim of the study is an influential trend in architecture and design called biophilia, which contributed to the formation of the style of a new type of biophilic design. The phenomenon called biophilia can be traced in the development of human civilization, from antiquity to the present day. However, it was only in the twentieth century that it became scientifically understood and formalized. Only in our days has biophilia become a conscious, purposeful and organized practical activity of man. It is in our days that "biophilic design" was born, which organically and logically fits into the so-called "green movement" and the world policy of sustainable development. The historiography of the topic presents authors who introduced the concepts of biophilia and biophilic design and the corresponding terms into scientific and practical circulation. Historical examples of early biophilic design are given. The reasons for the activation of biophilic design in the modern world and its development within the framework of the "green movement" are explained. The practice of biophilic design, its benefits for a person on a physical and emotional level are described. Using individual examples from contemporary residential and public interiors, urban environments and, on an even larger scale, entire cities, it is shown that this new specific type of design is a very relevant trend at the present time. As a result, it is concluded that, given the development of the modern urban environment and the deepening global climate, environmental and energy problems, biophilic design will become increasingly relevant in the future.

Aim To research subjective perceptions in additive color mixing. Material and methods A survey was administered to 79 individuals, who determined the colors they perceived in two photographs. Graphical modeling is applied to determine the result of color mixing. Results In additive mixing of monochromatic colors, a new color is obtained. Interestingly, different individuals perceive observed images in different ways. Mix neighboring colors on the spectrum and those in different ranges. Distinction between the physical mixing of laser beams with different colors was found. The visual perception in the presence of two colors is subjective and is determined by the viewer's greater sensitivity to one of the colors. Due to additive color mixing, additional parts of objects appear golden or orange when there is a yellow color in a picture with blue tones. When the background is violet, the sensitivity of the blue cones decreases. Conclusions It has been confirmed that visual perception, in the presence of two colors is subjective and is determined by the viewer's greater sensitivity to one of the colors. A method is proposed that physically demonstrates the mixing of green and red colors, resulting in the colors yellow or orange.

With ongoing global warming, increasing water deficits promote physiological stress on forest ecosystems with negative impacts on tree growth, vitality, and survival. How individual tree species will react to increased drought stress is therefore a key research question to address for carbon accounting and the development of climate change mitigation strategies. Recent tree‐ring studies have shown that trees at higher latitudes will benefit from warmer temperatures, yet this is likely highly species‐dependent and less well‐known for more temperate tree species. Using a unique pan‐European tree‐ring network of 26,430 European beech ( Fagus sylvatica L. ) trees from 2118 sites, we applied a linear mixed‐effects modeling framework to (i) explain variation in climate‐dependent growth and (ii) project growth for the near future (2021–2050) across the entire distribution of beech. We modeled the spatial pattern of radial growth responses to annually varying climate as a function of mean climate conditions (mean annual temperature, mean annual climatic water balance, and continentality). Over the calibration period (1952–2011), the model yielded high regional explanatory power ( R ² = 0.38–0.72). Considering a moderate climate change scenario (CMIP6 SSP2‐4.5), beech growth is projected to decrease in the future across most of its distribution range. In particular, projected growth decreases by 12%–18% (interquartile range) in northwestern Central Europe and by 11%–21% in the Mediterranean region. In contrast, climate‐driven growth increases are limited to around 13% of the current occurrence, where the historical mean annual temperature was below ~6°C. More specifically, the model predicts a 3%–24% growth increase in the high‐elevation clusters of the Alps and Carpathian Arc. Notably, we find little potential for future growth increases (−10 to +2%) at the poleward leading edge in southern Scandinavia. Because in this region beech growth is found to be primarily water‐limited, a northward shift in its distributional range will be constrained by water availability.

For the first time, the magnetic and optical (bandgap) properties of co‐doped Mg/Dy, Al/Dy, and Mn/Nd (SFO) at Sr and Fe sites are investigated using a microscopic model and the Green's function theory. It is shown that the co‐doping at both Sr and Fe sites can change the behavior of the magnetization which decreases by transition metal or nonmagnetic ion doping at the Fe site (with doping ions larger than the host Fe ions), but by additive co‐doping at the Sr site with rare‐earth ion (which ionic radius is smaller than that of Sr) the magnetization increases with increasing the co‐doping concentration. The bandgap energy decreases in the co‐doped SFO. The mechanism of this co‐doping effect is explained on microscopic level. It is due to the changes of the spin‐exchange interaction constants at the doped sites caused by the appearance of different strain by the doping with two ions. The theoretical results are compared with the existing experimental data and are in good qualitative agreement.

In recent years, 3D printing technology has become very important in many fields of science, manufacturing, design, medicine, aviation, sports, etc. Furniture design and manufacturing are also not left out of this trend. In this study, the results of bending moments and stiffness of joints of thin structural elements connected by 3D printing with polylactic acid (PLA) connectors are given. The connectors are newly developed, and information on their strength characteristics is lacking in the literature. Ten joints were investigated, made with 9 and 12 mm plywood and 6 mm MDF. The tested joints constructed by 3D-printed connecting elements show a high strength under arm compression bending load, between 44.16 and 24.02 N·m. The stiffness coefficients of joints with 3D-printed connecting elements are between 348 and 145 N·m/rad and are higher than those of conventional detachable mitre joints but lower than those of glued ones. The type of filling of the hollow section of the connecting elements and the wall thickness influenced the joints’ strength and stiffness. Reducing the width of the connecting elements from 40 to 30 mm and the inner radius between the arms from 2 to 1 mm does not significantly affect the joints’ strength and stiffness coefficients.

Citation: Apostolov, A.T.; Apostolova, I.N.; Wesselinowa, J.M. Multiferroic and Phonon Properties of the Double Perovskite Pr 2 FeAlO 6. Materials 2024, 17, 4785. https://doi. Abstract: With the help of a microscopic model and Green's function technique, we studied the multiferroic and phonon properties of the recently reported new multiferroic Pr 2 FeAlO 6 (PFAO) compound, which belongs to the double perovskite A 2 BB'O 6 family. The magnetization decreases with the increase in temperature and disappears at the ferromagnetic Curie temperature T FM C. The polarization increases with the application of an external magnetic field, indicating strong magne-toelectric coupling and confirming the multiferroic behavior of PFAO. In the curves of dependence of the phonon energy and their damping with respect to temperature, a kink is observed at T FM C. This is due to the strong anharmonic spin-phonon interactions, which play a crucial role below T FM C and are frequently observed in other double perovskite compounds. Above T FM C , only anharmonic phonon-phonon coupling remains. The phonon mode is controlled by an external magnetic field.

The jet stream is an important dynamic driver of climate variability in the Northern Hemisphere mid-latitudes1–3. Modern variability in the position of summer jet stream latitude in the North Atlantic–European sector (EU JSL) promotes dipole patterns in air pressure, temperature, precipitation and drought between northwestern and southeastern Europe. EU JSL variability and its impacts on regional climatic extremes and societal events are poorly understood, particularly before anthropogenic warming. Based on three temperature-sensitive European tree-ring records, we develop a reconstruction of interannual summer EU JSL variability over the period 1300–2004 ce (R² = 38.5%) and compare it to independent historical documented climatic and societal records, such as grape harvest, grain prices, plagues and human mortality. Here we show contrasting summer climate extremes associated with EU JSL variability back to 1300 ce as well as biophysical, economic and human demographic impacts, including wildfires and epidemics. In light of projections for altered jet stream behaviour and intensified climate extremes, our findings underscore the importance of considering EU JSL variability when evaluating amplified future climate risk.

Naryksky Reserve is located on lands within the boundaries of the Belovsky, Novokuznetsk, and Prokopyevsky municipal districts of Kemerovo Oblast. Three large mining companies are located near the reserve: LLC Resurs, LLC UK Kuzbassrazrezugol, and LLC Razrezdobycha Kuzbass. Studies have shown that 345 species from 204 genera and 67 families grow on the territory. The synanthropization coefficient of the flora is low and averages 3.9%. Four species are classified as invasive with status 2: Amoria hybrida, Conium maculatum, Pastinaca sativa, Plantago lanceolata. Three species grow on the territory of the reserve, included in the 3rd edition of the Red Book of the Kemerovo Oblast: Asarum europaeum, Erythronium sibiricum, Drosera rotundifolia L.

In a first theoretical investigation of the multiferroic properties of Pb 5 Fe 3 F 19 (PFF) and Pb 5 Cr 3 F 19 (PCF), we analyze their magnetic, ferroelectric, and dielectric characteristics as functions of temperature, magnetic field, and ion doping concentration using a microscopic model and Green's function theory. The temperature-dependent polarization in PFF and PCF shows a distinctive kink at the magnetic Neel temperature T N , which vanishes when an external magnetic field is applied, indicating the multiferroic behavior of these two compounds. Ion doping effectively tunes the properties of PFF and PCF. In PFF, Cr ion doping leads to a decrease in the Neel temperature T N , while Cr and Al ion doping lowers the ferroelectric Curie temperature T C. In the case of PCF, we observe the enhancement of T C by Fe ion doping and the reduction by Al ion doping. The last result coincides well quantitatively with the experimental data. Additionally, the magnetodielectric coefficient of PFF is enhanced with the increasing magnetic field.

Using a microscopic model and Green’s function theory, we have investigated the co-doping effect on ferroelectric KNbO3 nanoparticles. Let us emphasize that while the doping with transition metal ions at the Nb site leads an increase in the ferromagnetism and a reduction the band gap, it also decreases the ferroelectricity. On the other hand, doping with La or Ba at the K site leads to enhanced polarization, but does not lead to the appearance of ferromagnetism and reduction in the band gap. Therefore, we have studied co-doping with La/Cr and La/Co ions, which leads to increasing the magnetization and polarization as well as to strongly decreasing the band gap energy. Thus, we observe a multiferroic material with room-temperature ferromagnetism and ferroelectricity as well as small band gap energy which can be tuned using various co-doping ions. There is a good agreement with the existing experimental data.

Heterocycles are a vital class of compounds in numerous fields, including drug discovery, agriculture, and materials science. Efficient methods for the synthesis of heterocycles remain critical for meeting the demands of these industries. Recent advances in multicomponent reactions (MCRs) utilizing 2‐aminobenzothiazole (ABT) have shown promising results for the formation of heterocycles. The versatility of 2‐aminobenzothiazole in this context has enabled the rapid and efficient construction of diverse heterocyclic structures. Various synthetic methodologies and reactions involving 2‐aminobenzothiazole are discussed, highlighting its importance as a valuable building block in the synthesis of complex heterocycles. The potential applications of these heterocycles in drug discovery and material science are also explored. Overall, this review provides a comprehensive overview of the current state of research in the field and offers insights into the future directions of this promising area of study. We highlight the potential of ABT as a versatile and sustainable starting material in heterocyclic synthesis via MCRs, with significant implications for the chemical industry.

A hybrid adhesive system composed of phenol-formaldehyde (PF) resin and polymeric methylene diphenyl diisocyanate (pMDI), modified with two types of alkaline catalysts, namely NaOH and CaCO3 at 20% (w/v), was used for manufacturing the oriented strand board (OSB) from sengon (Paraserianthes falcataria L. Nielsen) wood. The catalyst was added at a concentration of 1% of the solids content of PF adhesive, and pMDI was added at 2.5% and 5.0% of the PF adhesive solids content. Adding catalysts and cross-linking agents increased the solids content and viscosity of the adhesive and accelerated the gelation time. The water absorption of OSB increased with the addition of catalysts and crosslinking agents compared to the control PF. Still, the CaCO3 catalyst worked optimally in reducing the thickness swelling of OSB. The mechanical properties of the laboratory-fabricated OSB panels increased with the addition of catalyst and cross-linker, except for the modulus of elasticity parallel to the grain. The optimal performance of OSB was obtained by adding 1% CaCO3 and 2.5% pMDI based on the PF's solids content.

The present study aimed to describe the skull and mandibles of the brown bear (U. arctos) from the Dancing Bear Belitsa Park using advanced 3D morpho-geometric techniques. The objective was to explore how sexual dimorphism and size influence cranial structures using advanced 3D geometric morphometric methods. Three-dimensional models of the skulls and mandibles of 12 brown bears were used. Differences in skull morphology between male and female brown bears were observed in this study. The male brown bear skull, larger than the female, exhibited a more pronounced extension of the upper part of the nuchal region towards the posterior. Additionally, the posterior part of the frontal region appeared notably thinner in male brown bears compared to females. Analysis of the mandible revealed that the masseteric fossa was more developed in males than females. These shape differences between males and females were found to be influenced by body size. Statistical analyses indicated a significant allometric effect of body size on skull PC1 values , suggesting that giant bears tend to have more elongated skulls. This implies a relationship in which larger individuals exhibit greater cranial elongation. In contrast, mandible PC1 values showed no size-related variation, indicating that mandibular shape is less influenced by overall body size. However, PC2 values in the mandible increased significantly with larger specimens, indicating a larger masseteric fossa in larger bears. This morphological adaptation potentially enhances feeding efficiency and bite strength in larger individuals, reflecting functional adaptations in brown-bear mandibular morphology.

Using a microscopic model and the Green's function theory, the size and co-doping effects on the multiferroic and optical (band gap) properties of BiFeO 3 (BFO) nanoparticles are investigated. The magnetization increases, whereas the band gap energy decreases with decreasing nanoparticle size. The substitution with Co/Mn, Nd/Sm, Ce/Ni, and Cd/Ni is discussed and explained on a microscopic level. By the ion co-doping appear different strains due to the difference between the doping and host ionic radii, which leads to changes in the exchange interaction constants for tuning all properties. It is observed that by co-doping with Nd/Sm at the Bi site or with Co/Mn at the Fe site, the multiferroic properties are larger than those by doping with one ion. Moreover, by doping with Ni, the multiferroic properties are reduced. But by adding another ion (for example Ce or Cd), an increase in these properties is obtained. This shows the advantages of the co-doping, its flexibility, and its greater possibility of tuning the multiferroic properties compared to single ion substitution. The band gap energy decreases for all co-dopants. The polarization increases with increasing magnetic field. This is evidence of magnetoelectric coupling, which is enhanced by co-doping with Co/Mn. The observed theoretical results are in good qualitative agreement with the existing experimental data.

The aim of this study was to assess the prevalence of Coxiella burnetii infection among veterinary medicine students from two Bulgarian Universities, located in Sofia and Stara Zagora. Blood samples were collected from a total of 185 veterinary students for the detection of C. burnetii phase II antibodies and presence of DNA using an enzyme-linked immunosorbent assay (ELISA) and end-point PCR test. Out of all samples, 29.7% were positive for at least one C. burnetii phase II antibody marker or by the result of the PCR test. Veterinary students from Stara Zagora showed a significantly high seropositivity for Q fever (33.6%), as compared to the students in Sofia (23%; p < 0.05). Evidence of recent exposure with detection of anti-C. burnetii phase II IgM (+) antibodies was observed in 14.6% of the students under study. Seroprevalence among students in Stara Zagora was higher (15.3%). Anti-C. burnetii phase II IgG antibodies were detected in 21.6% of examined samples. Our study revealed a higher seropositivity among the male students (32.8%) as compared to females (16.0%; p < 0.05). The end-point PCR assay detected 5.9% blood samples as positive. The relative risk (RR) of Q fever exposure for male students was 40.7%, whereas it was 24.6% in females (p < 0.05). The findings from this study indicate that the C. burnetii infection is widely distributed amongst veterinary students in Bulgaria. This study emphasizes the need for improved safety protocols and infection control measures in veterinary training programs.