Repozytorium Uniwersytetu Śląskiego RE-BUŚ
Not a member yet
23505 research outputs found
Sort by
Best Practice Forever? Dynamics behind the Perception of Farm-Fed Anaerobic Digestion Plants in Rural Peripheries
Get PDFAnaerobic digestion (AD) plants undoubtedly represent an integral and irreplaceable element in rural energy transition and sustainable waste management. In our study, we focus on an advanced understanding of the dynamics behind the changing perceptions of AD plants in host communities in Poland, Slovakia, and the Czech Republic. The surveyed AD plant case studies were selected to represent best-practice examples of AD plant operations in their countries. By means of a comparative survey in three host communities, we seek to learn more about the shift in perceptions of AD plants between their planning and operational phases. We find that, although our cases are considered best-practice examples of AD plant operations, their overall support in their communities dramatically dropped in the operational phase consequent to real-life experience with living in the neighbourhood of an AD plant. Additionally, our findings indicate that respondents who reported the most severe deterioration of AD plant perceptions were, surprisingly, those who had participated in the planning process more than other respondents. The most frequently mentioned type of participation in the planning phase was reported to be visits to the local administration office to inspect an AD plant’s planning documentation. We argue that deteriorating perceptions of best-practice examples of AD plant operations negatively impact the further development and acceptance of the biogas sector in Eastern Europe. The element of acceptance by the locals of AD plant operations urgently requires reflection in the definition of best practices to inspire and upgrade both existing and planned biogas energy projects
Density Scaling of Translational and Rotational Molecular Dynamics in a Simple Ellipsoidal Model near the Glass Transition
Get PDFIn this paper, we show that a simple anisotropic model of supercooled liquid properly
reflects some density scaling properties observed for experimental data, contrary to many previous
results obtained from isotropic models. We employ a well-known Gay–Berne model earlier
parametrized to achieve a supercooling and glass transition at zero pressure to find the point of glass
transition and explore volumetric and dynamic properties in the supercooled liquid state at elevated
pressure. We focus on dynamic scaling properties of the anisotropic model of supercooled liquid to
gain a better insight into the grounds for the density scaling idea that bears hallmarks of universality,
as follows from plenty of experimental data collected near the glass transition for different dynamic
quantities. As a result, the most appropriate values of the scaling exponent
are established as
invariants for a given anisotropy aspect ratio to successfully scale both the translational and rotational
relaxation times considered as single variable functions of density
/temperature. These scaling
exponent values are determined based on the density scaling criterion and differ from those obtained
in other ways, such as the virial–potential energy correlation and the equation of state derived from
the effective short-range intermolecular potential, which is qualitatively in accordance with the results
yielded from experimental data analyses. Our findings strongly suggest that there is a deep need to
employ anisotropic models in the study of glass transition and supercooled liquids instead of the
isotropic ones very commonly exploited in molecular dynamics simulations of supercooled liquids
over the last decades
A Generalized view of longwall emergency stop prevention (Ukraine)
Get PDFBased on both theoretical and practical experiences, the measures aimed at controlling emergency shutdowns of stopes have been highlighted. These stopes are connected with the emergency rigid settlements of powered complexes. In terms of the Western Donbas mines, there are certain risks of a shutdown of stopping operations within the zone of primary roof caving. Thus, the causes of emergency rigid settlements of the support may include the following: layers of the main roof rocks are hanging and not timely delaminated; sudden changes in lithology; hydraulic overloading of the main roof; structural flaws of support under certain conditions of its use, etc. In this paper, the theoretical method of scientific cognition was applied, which, with its help, makes it possible to switch from single low-efficiency measures to a set of actions aimed at preventing any uncontrolled situation. Obtaining certain generalized knowledge means obtaining a much deeper representation of reality, penetrating into its essence. The study also involves statistical analysis, being the basis for outlining a zone of primary caving where a high degree of risk is observed. Certainly, the generalization of these measures does not solve the problem completely. Consequently, there will be further attempts to search for and achieve principal new solutions in the future
Transformations of Religiosity during the SARS-CoV-2 Pandemic-On the Example of Catholic Religious Practices of Polish Students
Get PDFThis paper attempts to identify the changes in religiosity among Catholic practitioners in
Poland that occurred during the COVID-19 pandemic, based on the changes in the realization of
religious practices by students (N = 354). A questionnaire prepared by the authors was used for the
study. We sought to answer the question of the extent to which the socio-demographic characteristics
of the subjects, a history of COVID-19, and the death of a family member due to SARS-CoV-2 infection
differentiated the subjects’ opinions about religiosity and their undertaking of religious practices.
The paper also addresses the issue of media-facilitated religious practices. The study showed that
the frequency of religious practices was influenced by the perceived religiosity of the family, the
religiosity of the respondent, and the declaration concerning the belief in God. The same factors most
often significantly differentiated respondents’ opinions on COVID-19. No relationship was confirmed
between having COVID-19 and subjects’ beliefs about the pandemic or frequency of religious practice.
Among the respondents, the pandemic did not intensify the practice of religion. In the face of danger,
respondents did not turn to God; there was no revitalization of religion. The situation of limiting the
physical experience communion of the Church was treated not as an acute undersupply but as an
opportunity or a pretext to abandon the practice of religion
Free-radical polymerization of 2-hydroxyethyl methacrylate (HEMA) supported by a high electric field
Get PDFIn macromolecular science, tuning basic polymer parameters like molecular weight (Mn) or molecular
weight distribution (dispersity, Đ) is an active research topic. Many prominent synthetic protocols concerning
the chemical modification of a polymerization mixture (adding additional reagents) and equipment
modification have been adopted for this purpose. On the other hand, less attention has been paid
to studying the impact of external stimuli such as pressure, light, and spatial restrictions on the properties
of resulting polymers. Here, we present a robust synthetic protocol in which a high electric field (an external
factor) supports the thermally-induced free-radical polymerization (FRP) of 2-hydroxyethyl methacrylate
(HEMA). The reactions were conducted with 0.1 wt% of 2’-azobisisobutyronitrile (AIBN) in the presence
of high dc (direct current) electric fields with various magnitudes ranging from 0 kV cm−1 to 140 kV
cm−1. By combining dielectric spectroscopy, nuclear magnetic resonance spectroscopy, exclusion
chromatography, and differential scanning calorimetry, we have explored the effect of an external electric
field on the progress of polymerization (via dielectric spectroscopy) and product characteristics. We
found that HEMA FRP supported by a high dc voltage results in charged macromolecules (polyelectrolytes)
with high conductivity ∼ 10−10 S cm−1 at a glass transition temperature, markedly reduced molecular
weight of Mn ≈41–58 kg mol−1 (E > 14 kV cm−1), and low/moderate Đ ∼ 1.1–1.3, which is an unexpected
finding for non-controlled free radical polymerization. In contrast, the polymer produced in the absence
of an electric field was characterized by Mn ≈ 103 kg mol−1 and much higher Đ = 1.73. Therefore, we
found that the electric field can be another efficient external factor such as a spatial restriction or compression
that allows for fine-tuning of polymer properties
How Does Long-Term Storage Influence the Physical Stability and Dissolution of Bicalutamide from Solid Dispersions and Minitablets?
No full textThe stability of amorphous drugs is among the main challenges in the development of solid dosage forms. This paper examines the effect of storage conditions (25 °C/60% RH and 40 °C/75% RH) and different packaging materials, i.e., polystyrene containers and PVC/Al blisters, on the crystallinity and dissolution characteristics of solid dispersions containing bicalutamide and polyvinylpyrrolidone. The results confirmed drug amorphization upon milling and improved dissolution resulting from the lack of a crystal lattice. These properties varied with time regarding sample composition, storage conditions, and packaging material. The most resistant to storage conditions was the 1:1 solid dispersion packed into blisters. Based on the obtained results, the 1:1 solid dispersion was formulated into minitablets, which were then tested after tableting and then packed into PVC/Al blisters and stored for six months in the same conditions as solid dispersions. We proved that efficient stabilization of amorphous bicalutamide depends on the barrier properties of packaging materials and that a properly chosen material protected the drug substance from the influence of unfavorable storage conditions such as elevated temperature and humidity
Plant association with dark septate endophytes: When the going gets tough (and stressful), the tough fungi get going
No full textDark septate endophytes (DSEs) comprise a diverse and ubiquitous group of fungal generalists with broad habitat niches that robustly colonize the roots of plants in stressful environments. DSEs possess adaptation strategies that determine their high tolerance to heavy metal (HM) contamination, drought, and salinity. Most DSEs developed efficient melanin-dependent and melanin-independent mechanisms of HM detoxification and osmoprotection, including intracellular immobilization and extracellular efflux of HMs and excess ions, and the scavenging of reactive oxygen species. DSEs form mutualistic relationship with plants according to the hypothesis of “habitat- adapted associations”, supporting the survival of their hosts under stressful conditions. As saprophytes, DSEs mineralize a complex soil substrate improving plants’ nutrition and physiological parameters. They can protect the host plant from HMs by limiting HM accumulation in plant tissues and causing their sequestration in root cell walls as insoluble compounds, preventing further HM translocation to shoots. The presence of DSE in drought- affected plants can substantially ameliorate the physiology and architecture of root systems, improving their hydraulic properties. Plant growth-promoting features, supported by the versatility and easy culturing of DSEs, determine their high potential to enhance phytoremediation and revegetation projects for HM-contaminated, saline, and desertic lands reclamation
Morfologia i ewolucyjne modyfikacje czułkowych sensilli u pluskwiaków wodnych (Insecta: Heteroptera: Nepomorpha)
No full textPraca zawiera artykuły w języku angielskim.Nepomorpha is a group of hemipteran insects living in water. The majority of them have a specific: the short antennae hidden beneath the eyes. The shorter antennae clearly differentiate Nepomorpha from terrestrial bugs, whose antennae are often very long and extend over the head. The antennae perform a very important function in the life of insects because they bear sensillar structures. The sensillar structures of 61 species of water bugs (38 genera and 11 families) were analyzed to assess whether the adaptation of Nepomorpha to the aquatic environment contributed to changes in its set of sensory organs (sensilla). Thirty different morphological forms of sensilla were described, including 9 types of mechanoreceptive sensilla (sensilla trichodea, chaetica, cone-like, brush-like, club-like, paddle-like, squamiformia, campaniformia and basiconica), 2 types of chemoreceptive sensilla (sensilla basiconica and coeloconica), 2 types of thermo-hygroreceptive sensilla (sensilla coeloconica and ampullacea), and 2 types of sensilla of unknown function which are probably olfactory sensilla (sensilla plate-like and placodea multilobated). It was shown that for some taxa the sets of sensilla are very uniform, while for others very diverse. This diversification was visible in the taxa that inhabits different types of environment, which shows that sensilla evolved along with the antennae during secondary adaptations to aquatic habitats. On the other hand, the set of sensilla specific for the studied taxon coincides with the basic set of sensilla present in terrestrial bugs and other terrestrial insects.
A cladistic analysis based on the examined features was conducted, which confirmed the monophyly of some families (Belostomatidae, Nepidae, Micronectidae, Corixidae, Gelastocoridae, Ochteridae, Notonectidae and Pleidae). A great variety of sensillar types and their various distributions on antennomeres, within the lower systematic units (subfamily, genera, species), lead to the assessment that sensilla are not useful for basic taxonomic studies on Nepomorpha
Band Structure Studies of the R5Rh6Sn18 (R = Sc, Y, Lu) Quasiskutteridite Superconductors
Get PDFWe report on X-ray photoelectron spectroscopy and ab initio electronic structure investigations
of the skutterudite-related R5Rh6Sn18 superconductors, where R = Sc, Y, and Lu. These
compounds crystallise with a tetragonal structure (space group I41/acd) and are characterised by
a deficiency of R atoms in their formula unit (R5dRh6Sn18, d 1). Recently, we documented that
the vacancies d and atomic local defects (often induced by doping) are a reason for the enhancement
in the superconducting transition temperature Tc of these materials, as well as metallic (d = 0) or
semimetallic (d 6= 0) behaviours in their normal state. Our band structure calculations show the
pseudogap at a binding energy of 0.3 eV for the stoichiometric compounds, which can be easily
moved towards the Fermi level by vacancies d. As a result, dychotomic nature in electric transport of
R5Rh6Sn18 (metallic or semimetallic resistivity) depends on d, which has not been interpreted before.
We have shown that the densities of states are very similar for various R5Rh6Sn18 compounds, and
they practically do not depend on the metal R, while they are determined by the Rh d-and Sn s- and
p-electron states. The band structure calculations for Sc5Rh6Sn18 have not been reported yet. We
also found that the electronic specific heat coefficients g0 for the stoichiometric samples were always
larger with respect to the g0 of the respective samples with vacancies at the R sites, which correlates
with the results of ab initio calculations
Transcriptome Analysis Reveals a Gene Expression Pattern That Contributes to Sugarcane Bud Propagation Induced by Indole-3-Butyric Acid
Get PDFSugarcane is a cash crop that plays an integral part in the sugar industry. The Sustainable Sugarcane Initiative (SSI) has been adopted globally, ensuring enough and aiming for more yield, helping increase disease-free sugarcane cultivation. Single-bud seeds could be the best approach for sugarcane cultivation. Indole-3-butyric acid (IBA) is a rooting agent utilized significantly in seedling propagation. Greenhouse experiment results discovered the significant growth promotion in sugarcane seedlings and accumulation of plant hormones at 100 ppm IBA. Next, we performed transcriptomic analysis of sugarcane buds using RNA sequencing and compared their gene expression during root development due to affect of IBA (100 ppm). A total of 113,475 unigenes were annotated with an average length of 836 bp (N50 = 1,536). The comparative RNA-seq study between the control (CK) and IBA-treated (T) buds showed significant differentially expressed unigenes (494 upregulated and 2086 downregulated). The IBA influenced major biological processes including metabolic process, the cellular process, and single-organism process. For cellular component category, cell, cell part, organelle, membrane, and organelle part were mainly affected. In addition, catalytic activity and binding were primarily affected in the molecular function categories. Furthermore, the expression of genes related to plant hormones and signaling pathways was analyzed by qRT-PCR, which was consistent with the RNA-seq expression profile. This study provides new insights into the IBA response to the bud sprouting in sugarcane based on RNA sequencing, and generated information could help further research on breeding improvement of sugarcane