Some aspects of the use of solar energy in Serbia

This article presents the aspects of solar radiation and the use of solar energy in Serbia. It also considers why Serbia does not use thermal conversion of solar radiation in spite of much greater potential comparing to the countries of the Western and Central Europe, which are leading in the use of solar energy. The low standard of living, low electricity prices, the low level of energy efficiency in all areas of energy use, lack of knowledge, and political decisions are the main causes of insufficient use of renewable energy sources in Serbia.     

Mapping Application Requirements to Virtualization-Enabled Software Defined WSN

With the emergence of resource powerful sensor nodes, the concept of WSN virtualization is gaining increasing attention from the research community and the industry. One approach to achieve WSN virtualization is to exploit the capabilities of individual sensor nodes to execute tasks of multiple applications concurrently. In this paper, we consider the problem of task allocation in software-defined WSNs (SD-WSNs), which are distinguished by centralized control plane and programmable data plane. We extend our previous work on this topic, where we proposed the control algorithm which determines suitability of a sensor node for task allocation based on the active routing paths and residual energy in the network. Availability of such information can be easily justified in SD-WSNs. Through extensive simulations, the performance of this strategy has been evaluated and compared with two conventional task allocation approaches, which assume traditional minimum-hop routing. In addition, we analysed performance of more simple software defined networking-based approach, which performs resource allocation by considering only residual energy in the network. The obtained results demonstrate benefits of SD-WSN architecture when it comes to virtualization efficiency, and clarify improvements achieved by mutual correlation of routing and task allocation decisions.     

A Fungal N‐Dimethylallyltryptophan Metabolite from Fusarium fujikuroi

The range of secondary metabolites (SMs) produced by the rice pathogen Fusarium fujikuroi is quite broad. Several polyketides, nonribosomal peptides and terpenes have been identified. However, no products of dimethylallyltryptophan synthases (DMATSs) have been elucidated, although two putative DMATS genes are present in the F. fujikuroi genome. In this study, the in vivo product derived from one of the DMATSs (DMATS1, FFUJ_09179) was identified with the help of the software MZmine 2. Detailed structure elucidation showed that this metabolite is a reversely N‐prenylated tryptophan with a rare form of prenylation. Further identified products probably resulted from side reactions of DMATS1. The genes adjacent to DMATS1 were analyzed; this showed no influence on the biosynthesis of the product.     

Sorption of Pb2+, Cd2+, and Sr2+ Ions on Calcium Hydroxyapatite Powder Obtained by the Hydrothermal Method

The sorption of Pb2+, Cd2+, and Sr2+ ions from aqueous solutions by carbonate-substituted calcium hydroxyapatite (HAP) obtained by the hydrothermal decomposition of urea and calcium–ethylenediaminetetraacetic acid chelates was investigated. The shift of the point of zero charge (pHpzc) of HAP toward lower pH values in solutions of Pb2+ and Cd2+ ions, which was more pronounced for Pb2+ ions than for Cd2+ ions, indicates that specific adsorption of these cations on HAP had occurred. There was no shift of the pHpzc in the solution containing Sr2+ ions, suggesting that specific adsorption of this cation on HAP had not occurred. The sorption isotherms suggest that the sequence of the efficiency of sorption by HAP is Pb2+>Cd2+>Sr2+. Ion exchange is the main mechanism of removal of Sr2+ ions from aqueous solution by apatite, whereas during the sorption of Cd2+ ions, this mechanism occurs simultaneously with the process of specific adsorption. The interaction of the apatite with Pb2+ ions includes the previously mentioned mechanisms and dissolution of the apatite, followed by the precipitation of lead hydroxyapatite.     

Performance and Efficiency of Anionic Dishwashing Liquids with Amphoteric and Nonionic Surfactants

Performance and efficiency of anionic [sodium lauryl ether sulfate (SLES) and sodium α-olefin sulfonate (AOS)] and amphoteric [cocamidopropyl betaine (CAB)] as well as nonionic [cocodiethanol amide (DEA), various ethoxylated alcohols (C₁₂–C₁₅–7EO, C₁₀–7EO and C₉–C₁₁–7EO) and lauramine oxide (AO)] surfactants in various dishwashing liquid mixed micelle systems have been studied at different temperatures (17.0, 23.0 and 42.0 °C). The investigated parameters were critical micelle concentration (CMC), surface tension (γ), cleaning performance and, foaming, biodegradability and irritability of anionic (SLES/AOS) and anionic/amphoteric/nonionic (SLES/AOS/CAB/AO) as well as anionic/nonionic (SLES/AOS/DEA/AO, SLES/AOS/C₁₂-C₁₅-7EO/AO, SLES/AOS/C₁₀–7EO/AO and SLES/AOS/C₉–C₁₁–7EO/AO) dishwashing surfactant mixtures. In comparison to the starting binary SLES/AOS surfactant mixture, addition of various nonionic surfactants promoted CMC and γ lowering, enhanced cleaning performance and foaming, but did not significantly affect biodegradability and irritability of dishwashing formulations. The anionic/nonionic formulation SLES/AOS/C₉–C₁₁–7EO/AO shows both the lowest CMC and γ as well as the best cleaning performance, compared to the other examined dishwashing formulations. However, the results in this study reveal that synergistic behavior of anionic/nonionic SLES/AOS/ethoxylated alcohols/AO formulations significantly improves dishwashing performance and efficiency at both low and regular dishwashing temperatures (17.0 and 42.0 °C) and lead to better application properties.     

Spreading of Isolated Ptch Mutant Basal Cell Carcinoma Precursors Is Physiologically Suppressed and Counteracts Tumor Formation in Mice

Basal cell carcinoma (BCC) originate from Hedgehog/Patched signaling-activated epidermal stem cells. However, the chemically induced tumorigenesis of mice with a CD4Cre-mediated biallelic loss of the Hedgehog signaling repressor Patched also induces BCC formation. Here, we identified the cellular origin of CD4Cre-targeted BCC progenitors as rare Keratin 5⁺ epidermal cells and show that wildtype Patched offspring of these cells spread over the hair follicle/skin complex with increasing mouse age. Intriguingly, Patched mutant counterparts are undetectable in age-matched untreated skin but are getting traceable upon applying the chemical tumorigenesis protocol. Together, our data show that biallelic Patched depletion in rare Keratin 5⁺ epidermal cells is not sufficient to drive BCC development, because the spread of these cells is physiologically suppressed. However, bypassing the repression of Patched mutant cells, e.g., by exogenous stimuli, leads to an accumulation of BCC precursor cells and, finally, to tumor development.     

Extraction of Oil from Rosehip Seed: Kinetics,Thermodynamics, and Optimization

Rosehip (Rosa canina L.) oil (RSO) was recovered from waste rosehip seeds by cold pressing as well as maceration and Soxhlet extraction using n-hexane. The influence of the extraction temperature, the solvent-to-seed ratio (SSR), and the extraction time on RSO yield was examined for the maceration process. The extraction technique did not influence the fatty acid profile of the RSO. All process factors had a significant effect on the oil yield. The kinetics was described using the model involving instantaneous washing followed by diffusion. The RSO maceration was spontaneous, endothermic, and irreversible.     

Electrophysical properties of woven polymer mesh fabrics

The investigation was performed on three woven mesh fabrics made of polyethylene terephthalate (PET), polyamide (PA) 6.6 monofilaments, and PA 6.6 with carbon filament (CF). The dielectric properties were examined as functions of frequency at room conditions and as functions of frequency and temperature under the vacuum. It was observed at lower frequency higher changes of dielectric permittivity for the sample with CFs at room conditions. For PET and PA 6.6, dielectric permittivity in the vacuum was steady and little lower; furthermore, dielectric spectra showed the existence of γ-, β-, and α-relaxations. The dc volume electrical resistivity was investigated in the function of relative humidity at room temperature for PA 6.6 and PA 6.6 with CF. For the sample with the CF, a decrease in the dc electrical resistivity of nine orders of magnitude in the direction with CF was registered as compared to the direction without a conductive filament. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48456.     

Extraordinary Adaptive Plasticity of Colorado Potato Beetle: “Ten-Striped Spearman” in the Era of Biotechnological Warfare

Expanding from remote areas of Mexico to a worldwide scale, the ten-striped insect, the Colorado potato beetle (CPB, Leptinotarsa decemlineata Say), has risen from being an innocuous beetle to a prominent global pest. A diverse life cycle, phenotypic plasticity, adaptation to adverse conditions, and capability to detoxify or tolerate toxins make this insect appear to be virtually “indestructible”. With increasing advances in molecular biology, tools of biotechnological warfare were deployed to combat CPB. In the last three decades, genetically modified potato has created a new challenge for the beetle. After reviewing hundreds of scientific papers dealing with CPB control, it became clear that even biotechnological means of control, if used alone, would not defeat the Colorado potato beetle. This control measure once again appears to be provoking the potato beetle to exhibit its remarkable adaptability. Nonetheless, the potential for adaptation to these techniques has increased our knowledge of this pest and thus opened possibilities for devising more sustainable CPB management programs.     

Structural and Optical Characterization of Flower-Like Rutile Nanostructures Doped with Fe3+

Flower-like agglomerates with sizes of 200–400 nm of pure and Fe³⁺-doped TiO₂ with rutile crystalline structure were synthesized by the coprecipitation method. The morphology of the agglomerates was determined by electron microscopy (TEM and HRTEM). TiO₂ agglomerates consist of nanorods with clearly visible crystalline faces, parallel to the axis of elongation whose direction was along the [101] direction of pure TiO₂ and the [111] direction of doped TiO₂. Furthermore, nanorods consist of "chains" of spherical particles, most likely interconnected through the so-called oriented attachment or grain-rotation-induced grain coalescence (GRIGC) process. UV/Vis reflection measurements revealed that the absorption of pure TiO₂ was significantly shifted from UV toward the visible spectral region upon the incorporation of Fe³⁺ into the TiO₂ host.