Maria Curie-Sklodowska University in Lublin
Recent publications
The specific physico-chemical properties of chitosan (Ch), a biopolymer isolated from chitin, and its impact on the stability of colloidal dispersity have focused the interest of science and industry. However, in some cases chitosan alone is not enough to provide high stability to dispersions, making it necessary to add surfactant to the chitosan/oxide system, leading to superior stabilizing properties due to the association of polymer and surfactant molecules to form complexes that can modify the ability of bare chitosan for adsorbing on colloidal materials. This study explores the interactions between chitosan and alumina in the presence of three different anionic surfactants: the hydrocarbon SDS (sodium dodecyl sulfate), the fluorocarbon FS-91 (Capstone® FS-91), and the silicone A-Si (Silphos A-100). Different analytical methods evidenced chitosan adsorption on the alumina surface, forming hybrid organic-inorganic materials. This process can be enhanced by adding surfactant, with SDS leading to a strong increase of chitosan adsorption. Elemental mapping and scanning electron microscope imaging have provided a confirmation of the co-adsorption of polymer and surfactant on the alumina surface. The latter emerges as a very important finding because the results have shown that small quantities of surfactant (as low as 0.002% v/v) can strongly influence the adsorption and stability of multicomponent colloidal systems. This allows decreasing the chitosan amount required for the enhancement of the colloidal stability in relation to dispersions without added surfactants, providing the basis for reducing the production costs of colloidal dispersion, which opens new opportunities to chemical industry.
In the last years, there is great progress in the field of studies on the thermal transformation of wastes into valuable materials such as biochar. High-temperature processes, however, are connected with the formation of polycyclic aromatic hydrocarbons (PAHs) with confirmed toxicity. However, during pyrolysis, some derivatives containing oxygen, nitrogen, or sulfur can also be formed. Their toxicity is expected to be higher than parent PAHs. However, the key parameter in the agricultural application of carbonaceous materials is PAHs’ bioavailability. The aim of the presented studies was the determination of the effect of various feedstock (wheat straw (Triticum L.), willow (Salix viminalis), sunflower, residues from softwood and hardwood, sewage sludges, and residues from biogas production) on the formation of PAHs and their derivatives (O-, N-PAHs) in biochar and their bioavailability. The results indicated that the content of total and bioavailable PAHs in obtained biochar was rather low. The concentration of total PAHs in plant-derived biochar reached 57 ± 3 ng g⁻¹ - 181 ± 8 ng g⁻¹, whereas sewage sludge-derived biochar contained from 121 ± 6 ng g⁻¹ to 188 ± 9 ng g⁻¹ of PAHs. The highest concentration of PAHs was noted in biochar obtained from residues from biochar production – up to 202 ± 9 ng g⁻¹. The total concentration of bioavailable PAHs was lower and reached 2–4.45 ng L⁻¹ for plant-derived biochar, 3–40 ng L⁻¹ for sewage sludge-derived biochar. The highest content of bioavailable PAHs was noted in biochar obtained from residues from biogas production: 9–42 ng L⁻¹ indicating that increased attention should be paid to using this type of biochar. Among PAHs derivatives, nitronaphthalene, 1-methyl-5-nitronaphthalene, 1-methyl-6-nitronaphthalene, 9,10-anthracenedione, 4H-cyclopenta(def)phenanthrene, nitropyrene were determined at various levels and their concentrations were from below the limit of detection (LOD) to 28 ng L⁻¹ for plant-derived biochar, 3–16 ng L⁻¹ for biochar obtained from residues from biogas production, and 5–45 ng L⁻¹ for sewage sludge-derived biochar. The content of bioavailable PAHs derivatives was, generally, one order of magnitude lower than parent PAHs derivatives, and reached from below LOD up to almost 1 ng L⁻¹ for plant-derived biochar, from 0.5 to 2 ng L⁻¹ for biochar obtained from residues from biogas production, and from 0.2 to almost 5 ng L⁻¹ for sewage sludge-derived biochar confirming the safety of agricultural usage of biochar.
The ejection of a mixture of solid (soil) and liquid (water) phases is one of the aspects of the energy dissipation of the impacting drop during the soil splash phenomenon. All calculations to date have only been taking into account the ejection of solid phase material and were based on significant simplifications of the measured quantities. Therefore, the aim of the study was an improved calculation of the falling drop energy transferred to the ejected material, while considering that such material was a mixture of solid soil particles and water droplets and therefore, “two-phase”. Experimental variants included combinations of soils with different textures and initial moisture contents as well as various falling water-drop energies. Two complementary methods of i) splash cup measurements and ii) image analysis based on high-speed cameras were used for the calculation of quantities i.e. the number of ejected particles, their mass, and their ejection velocity. Based on the obtained results, it was stated that the kinetic energy of ejected particles, expressed as a percentage of falling drop energy, ranged from 1 % to 14 %. This percentage depended strongly on soil texture as well as initial moisture content. The highest values were obtained for soil with the largest amount of sand fraction and the lowest for the soil with the largest amount of finer fractions. All tested soils showed a trend of a higher drop energy transferred to the splashed particles with increasing initial soil moisture content. Taking into account the varied energy of the falling drop variants, the amount of energy transferred to ejected particles was constant.
The synthesis and characterization of polymeric cross-linked composites derived from bisphenol A glycerolate diacrylate (BPA.GDA) and N-vinyl-2–2pyrrolidone (NVP) are presented. Commercially available kraft lignin with different weight % (0, 5, and 20) was applied as an environmentally friendly filler. The composites were made by bulk polymerization using a photoinitiator (2-dimethoxy-2-phenylacetophenone) in special glass molds and cut into 10 mm × 10 mm fragments for testing. The chemical structures of the composites were confirmed by means of ATR-FTIR spectroscopy. Polymers modified with the addition of lignin were introduced into cultures of three species of white rot fungi: Cerrena unicolor, Pycnoporus sanquineus, and Abortiporus biennis. The biochemical and profilometric analyses showed clear changes both in the course of selected metabolic processes in the fungal cells and in the structure of the biomaterials. Clear changes in the activity of such enzymes as laccase, β-glucosidase, or acid proteases caused by the selected polymers were observed in the culture fluids.
Polycyclic aromatic hydrocarbons (PAHs) are widespread in marine environments, having negative implications on both ecological systems and human health. At the same time, research on highly–efficient and environmentally–friendly alternatives compared to conventional remediation techniques must be stepped up. In this work, for the first time, a novel modification procedure of willow–derived biochar based on volatile fatty acids (VFA) has been employed to enhance biochar structures aimed at avoiding phenanthrene (PHE) desorption. Batch adsorption-desorption experiments showed a PHE removal of 93% and a hysteresis index of 4.9 after 72 hours with biochar pyrolyzed at 400 °C (BC400) and modified with VFAs (MBC400), respectively. A lower efficiency was obtained with higher temperature-produced biochars (i.e. 700 °C) due to lower surface area and functional group abundance compared to the biochars obtained at 400 °C. Physisorption and chemisorption mechanisms were mainly involved in a multilayer PHE adsorption onto the heterogeneous BC400 and MBC400 surfaces, as shown by pseudo-first- and -second-order kinetic (R² = 0.988) and Freundlich isotherm (R² = 0.951-0.995) models. A more complicated and advanced subsequent application of biochar in PHE-polluted marine sediments with a dosage of 0.1-5% (w/w) led to the reduction of pore water PHE up to 24% after 28 days. An ecotoxicological test showed a mitigated toxicity of the sediment remediated with BC400 and MBC400 towards Folsomia candida springtails due to a decrease in adult mortality and reproduction inhibition, which was directly correlated with the reduction of PHE bioavailability (rPHE–FC = 0.76).
The recurrent dredging of marine sediments needs the use of ex–situ technologies such as sediment washing (SW) to effectively remove polycyclic aromatic hydrocarbons. Notwithstanding, the large volumes of generated spent SW effluents require adequate treatment by employing highly–efficient, inexpensive and environmentally–friendly solutions. This study proposes the phenanthrene (PHE) desorption from sediments using Tween® 80 (TW80) as extracting agent and the treatment of the resulting spent SW solution in a biochar (BC) immobilized–cell bioreactor. The SW process reached the highest PHE removal of about 91% using a surfactant solution containing 10,800 mg·L⁻¹ of TW80. The generated amount of spent PHE–polluted SW solution can be controlled by keeping a solid to liquid ratio of 1:4. A PHE degradation of up to 96% was subsequently achieved after 43 days of continuous reactor operation, aerobically treating the TW80 solution in the BC immobilized–cell bioreactor with a hydraulic retention time of 3.5 days. Brevundimonas, Chryseobacterium, Dysgonomonas, Nubsella, and both uncultured Weeksellaceae and Xanthobacteraceae genera were mainly involved in PHE biodegradation. A rough economic study showed a total cost of 342.60 €·ton⁻¹ of sediment, including the SW operations, TW80 and BC supply and the biological treatment of the SW solution.
Recent studies along the southern Baltic Sea coast have revealed sedimentary records of catastrophic storm surges that significantly exceed the magnitude of storms documented by instrumental measurements. The present study aimed to apply heavy mineral analysis for storm surge deposits along coasts of Gulf of Gdańsk (southern Baltic), as well as for contemporary marine, beach, dune and coastal plain sediments, to test the applicability of the method and to provide new insights into the depositional processes and sediment sources of the storm deposits. The transparent, 0.12 5-0.25 mm heavy mineral fraction (>2.85 g/cm3) in 118 sediment samples was investigated, and the results were subjected to multivariate statistical analyses (cluster, PCA, LDA). Storm deposits showed higher concentrations of heavy minerals comprising enrichment in garnet, zircon, and rutile. General heavy mineral assemblage depended on regional provenance and primary sediment sources. However, flooding regime (overwash or inundation) played a key role in selective hydrodynamic sorting of grains and mineralogical composition of storm deposits. Interpretation of deposits formed in inundation regime was more certain than deposits formed in overwash regime. In the latter case, deposits showed more similarities to adjacent mineral provinces. Statistical analyses proofed that heavy minerals together with other sedimentological descriptors may be a promising proxy for recognition of deposits related to defined sedimentary environment or identification of particular sedimentological process, e.g. event layers resulted from storm surges. paper available from: https://www.sciencedirect.com/science/article/pii/S1040618221002962?via%3Dihub
Pollution characteristics and associated ecological risks of PAHs in sediments from Brunei Bay, Brunei were investigated. The concentrations of ∑16 PAHs ranged from 826.7 to 2955.3 μg kg⁻¹, indicating moderate to high level of pollution. Source apportionment of PAHs by molecular isomeric ratios and positive matrix factorization model indicated impact of potential anthropogenic PAH sources including combustion of biomass and fossil fuels. The data indicated relatively no significant ecotoxicological risk for most of PAH compounds. To estimate the individual c-PAH toxicity, the toxic equivalent quantity (c-TEQ) was calculated. Results of the TEQ analysis showed that BaP followed by DBA and BaA are the most carcinogenic of PAHs examined in the study area. The evaluation of human health risk of PAHs revealed that the cancer risk of PAHs for adults and children was higher than the USEPA threshold (<1E−06) and lower than 1E-3, implying low to moderate risk.
Hyperfine parameters and the pressure dependence of the magnetic transition temperatures of FeRhGe 2 have been investigated. Sample has been prepared using high pressure - high temperature synthesis technique. FeRhGe 2 consists of two B20 structure phases with close lattice constants. The phase separation stays constant in the temperature range 4 - 300 K. The magnetic transition temperatures T c1 = 213 K and T c2 = 135 K of FeRhGe 2 slightly increases with pressure in the range 0-4.5 GPa. We have compared this pressure dependence with some others compounds in the family Fe 1-x Rh x Ge. The two phases in FeRhGe 2 have slightly different values of the hyperfine magnetic fields.
We study the classical statistical problem of the estimation of quantiles by order statistics of the random sample. For fixed sample size, we determine the single order statistic which is the optimal estimator of a quantile of given order. We propose a totally new approach to the problem, since our optimality criterion is based on the use of nonparametric sharp upper and lower bounds on the bias of the estimation. First, we determine the explicit analytic expressions for the bounds, and then, we choose the order statistic for which the upper and lower bound are simultaneously as close to 0 as possible. The paper contains rigorously proved theoretical results which can be easily implemented in practise. This is also illustrated with numerical examples.
Introduction Triticum aestivum is a self-pollinated species with a high proportion of cleistogamous flowers constituting a blockade for out-crossing. Therefore, male parent characteristics are the main goal in the production of hybrid wheat seeds. Methods In a two-year study conducted in Lublin (Poland), the features of flowering biology that can be relevant for the cross-pollination ability of the pollen donor were investigated in winter wheat genotypes. In particular, the anther extrusion capacity, pollen production at the anther and spike levels, and pollen biological value were examined. The pollen production in the anthers was established using an electronic particle counter. The pollen biological value was assessed based on viability (acetocarmine staining) and in vitro pollen germination (raffinose medium) assays. Results The inter-genotype effect for anther extrusion was significantly correlated to the post-anthesis filament length. The anther extrusion for the individual genotypes fluctuated significantly between the years of the study; however, the interaction with meteorological factors was not assessed. The considerable inter-genotype variability in the pollen donor capability for cross-pollination was highly significantly correlated with the proportion of extruded anthers rather than pollen production, indicating that anther extrusion plays a more important role in the contribution to the final amount of pollen available for cross pollination. The pollen viability determined by staining was high (between 97.5% and 100%), while the in vitro pollen germination varied substantially among the genotypes (between 17.3% and 87.8%). Conclusion The pollen dispersal ability for cross-pollination in wheat can be improved mainly by increasing the proportion of extruded anthers; however, the pollen production and pollen germination potential cannot be ignored if complete characterization of the ideal male idiotype is to be achieved.
Raspberry stalks-derived biochar (BC), magnetic biochar-iron oxide composite (BC–Fe) and its derivative modified with urea (BC–Fe–U) were synthesized, characterized and tested as(V) and Cr(VI) ion sorbents. The surface area of BC, BC-Fe and BC-Fe-U was 259, 163 and 117 m² g⁻¹, respectively. The structure of BC was dominated by micropores, while in BC-Fe and BC-Fe-U mesopores predominated. Based on the XRD results, it was found that the magnetic properties of the biochar-iron oxide composites are due to the presence of ferrimagnetic magnetite (Fe3O4) and maghemite (Fe2O3). The optimal pH of As(V) and Cr(VI) adsorption onto the studied sorbents is in the range of 2.3–5.7. Pristine biochar (BC) does not adsorb As(V) ions; however, it enables rapid adsorption of Cr(VI) with the static adsorption capacity of 19.2 mg g⁻¹. The maximum static adsorption capacities of As(V) and Cr(VI) ions onto BC-Fe and BC-Fe-U are within the range of 13.5–16.3 mg g⁻¹. For most adsorption systems tested, adsorption equilibrium is reached within 4 h, though even a few minutes is enough to reach half of the adsorption static value. Phosphates over 0.005 mol L⁻¹ hinder adsorption of As(V) and Cr(VI) ions. Application of at least 5 mol L⁻¹ nitric acid allows about 95% of Cr(VI) and As(V) to be desorbed from adsorbate-loaded BC-Fe material. For other materials, the desorption efficiencies are significantly lower. BC-Fe and BC-Fe-U materials were successfully used for simultaneous Cr(VI) and As(V) removal from river water.
Following Beurling’s theorem the natural compressions of the multiplication operator in the classical L2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$L^2$$\end{document} space are compressions to model spaces and to their orthogonal complements. Here, two possibly different model spaces are considered, hence asymmetric truncated Toeplitz and asymmetric dual truncated Toeplitz operators are investigated. The main purpose of the paper is to characterize operators which intertwine compressions of the unilateral shift.
Background: In this review, we summarize data concerning action potentials (APs) - long-distance electrical signals in Characean algae and liverworts. These lineages are key in understanding the mechanisms of plant terrestrialization. Liverworts are postulated to be pioneer land plants, whereas aquatic Charophytes are considered the closest relatives to land plants. The drastic change of the habitat was coupled with the adaptation of signalling systems to the new environment. Scope: APs fulfil the "all-or-nothing" law, exhibit refractory periods, and propagate with a uniform velocity. Their ion mechanism in the algae and liverworts consists of a Ca 2+ influx (from external and internal stores) followed by/coincident with a Cl - efflux, which both evoke the membrane potential depolarization, and a K + efflux leading to the repolarization. The molecular identity of ion channels responsible for these fluxes remains unknown. Publication of the Chara braunii and Marchantia polymorpha genomes opened new possibilities for studying the molecular basis of APs. Here we present the list of genes which can participate in AP electrogenesis. We also point out the differences between these plant species, e.g. the absence of Ca 2+-permeable glutamate receptors (GLRs) and Cl --permeable SLAC1 channel homologues in the Chara genome. Both these channels play a vital role in long-distance signalling in liverworts and vascular plants. Among the common properties of APs in liverworts and higher plants is the duration of APs (dozens of seconds) and the speed of propagation (mm s -1), which are much slower than in the algae (seconds, and dozens of mm s -1, respectively). Conclusions: Future studies with combined application of electrophysiological and molecular techniques should unravel ion channel proteins responsible for AP generation, their regulation, and transduction of those signals to physiological responses. This should also help to understand the adaptation of the signalling systems to the land environment and further evolution of APs in vascular plants.
Wax collection behavior has not yet been described in the honeybee; it is typical of another Apis species. The wax collection was more difficult to observe due to the different biology of Apis mellifera and the fact that beekeepers do not display combs around the apiary to avoid the spread of bee diseases and robberies. The transport of wax in the pollen basket is typical of Apis florea ; additionally, these bees have preferences for natal combs, which are significantly greater than for non-natal combs. Before they abandon their nests, these migratory bees following the nectar flow collect and transport some wax in their pollen baskets. This helps them to build a new nest quickly. The collection of available wax by both A. florea and A. mellifera is economically justified, as it reduces consumption of energy and honey supplies for the production of wax. The economic balance is believed to determine the collection of wax covers of Ceroplastes sp. soft scale insects by A. mellifera . This can be confirmed by the comparison of the energy value of wax (12.7 kcal/g) and honey (3.1 kcal/g), which indicates an over fourfold energy gain in favor of honey stored in the bee colony. The energetic trade-off between wax secretion and collection from an old nest may explain why A. florea is probably the only honeybee species known to recycle wax if the new breeding site is located at a distance lower than 100–200 m away from the nesting site. In such a case, it energetically pays off to recycle the wax. The same is probably true in A. mellifera , as we observed that wax was placed on the tops of the apiary hives at a distance lower than 100 m away from the colony. This is also reflected by the economic conversion rates, as a bee colony consumes from 4 to 8 kg of honey to produce 1 kg of wax. Our observations show that A. mellifera collect wax in pollen baskets. In addition, wax collection by honeybees is a static process occurring at the site where wax is present; bees do not have to flight, unlike in the case of pollen pellets, which are formed during flight. This paper addresses two completely unknown issues that make up two hypotheses: one is associated with collection of propolis into the pollen basket to stick the light wax fragments, and the other assumes saving energy required from the bee organism, which can be used to support colony functioning.
In recent years there has been a huge increase in consumer interest in products with the reduced fat content and the additional health-promoting properties. The interactions between the fiber and the ingredients of the cheese sauce have not yet been investigated and described. The aim of the research was examination of the effect of pumpkin and kale fibers on physicochemical properties and stability of the processed cheese sauces (PCS) obtained with the whey protein concentrate (WPC80), acid casein (AC) and different fat sources. In samples with the kale (KF) and rapeseed oil (RO) addition an increase in the value of characteristics such as hardness, adhesiveness, product stability (TSI) and surface roughness was observed. The results of measurements of storage (G′) and loss (G″) moduli showed the same upward trend with an increase in the amount of added kale fiber. They were related to the hardness and roughness parameters determined by measure of surface properties using the optical profilometer and the stability examined using Turbiscan. In the PCS with kale fiber addition based on RO an increase in stability (6.41–1.86 TSI) and roughness (2.2–16 qm) values along with the amount of fiber added was observed. Also optical microscopy images present the compacted structure of produced sauces. This article provides results and relevant literature, discussing the impact of different fibers and other ingredients on structure of PCS. In the future, these fibers may replace typical hydrocolloids used in processed cheese sauces production.
New sodium complexes of quercetin-5’-sulfonic acid (HQSA) have been obtained. The aqua complex of the general formula [NaQSA∙(H2O)2]∙2H2O (1) was a starting compound for solvothermal syntheses of acetone and dimethylsulfoxide (S) complexes: [NaQSA(S)](S) (2 – acetone) and [NaQSA(S)]∙2(S) (3a and 3b – DMSO). The fourth complex obtained from the reaction of HQSA excess used in the reaction with NaOH is [Na(QSA)2∙2H2O][(EtOH)2H] (4). The molecular and crystal structures of 1 – 4 were determined by X-ray crystallography. The sodium cations are coordinated by six or seven oxygen atoms; Na⁺ coordinating groups are sulfonic, hydroxyl, and carbonyl of the QSA⁻ anion. The bridging role of some functional groups causes the formation of polymeric complexes. The coordination spheres are completed by oxygen atoms from the coordinating water (in 1 and 4), acetone (2) or DMSO molecule (3a and 3b). In each structure non-coordinating interstitial solvate molecules are also present; they are two H2O (1), acetone (2), two DMSO (3a and 3b), and the hydrogen bisethanol cation [EtOH…H⁺…EtOH] (4). The last of these is a rare type of Zundel type cation. Unstable complexes (2 and 3), that decompose under normal conditions, are formed and they have a structure of intercalation clathrates. The solvating molecules, located between 1D or 2D polymeric complexes, play a unique role as a network bonding agent. Theoretical calculations showed charge separation between Na⁺ and SO3⁻. The FTIR and Raman spectra are consistent with the solved crystal structures and, importantly, enable the identification of acetone and DMSO molecules in the powder samples.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
1,567 members
Kalina Grzesiuk
  • Chair of Marketing
Anna Dluzewska
  • Department of Earth Sciences and Spatial Management
Zbigniew Osiński
  • Library and Information Science
Bożena Czech
  • Department of Radiochemistry and Environmental Chemistry
Information
Address
Akademicka19, 20-033, Lublin, Poland
Website
http://umcs.pl
Phone
0048815375968
Fax
0048815375959