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Of the many environmental factors that modulate the phytoextraction of elements, little has been learnt about the role of metal interactions. The study aimed to show how different concentrations of Cu, Pb and Zn in the cultivation medium influenced the biomass, plant development and phytoextraction abilities of Acer platanoides L. seedlings. Additionally, the impact on the content and distribution of Ca, K, Mg and Na in plant parts was studied with an analysis of phenols. Plants treated with a mixture of two metals were characterised by lower biomass of leaves and higher major elements content jointly than those grown in the salt of one element. Leaves of A. platanoides cultivated in Pb5 + Zn1, Pb1 + Zn1 and Pb1 + Zn5 experimental systems were characterised by specific browning of their edges. The obtained results suggest higher toxicity to leaves of Pb and Zn present simultaneously in Knop solution than Cu and Pb or Cu and Zn, irrespective of the mutual ratio of the concentrations of these elements. Antagonism of Cu and Zn concerning Pb was clearly shown in whole plant biomass when one of these elements was in higher concentration (5 mmol L−1) in solution. In the lowest concentrations (1 mmol L−1), there was a synergism between Cu and Zn in plant roots. Plants exposed to Zn5, Cu1 + Pb5, Pb5 + Zn1 and Cu1 + Zn1 were characterised by higher total phenolic content than the rest plants. Both the presence and the concentration of other elements in the soil are significant factors that modulate element uptake, total phenolic content, and plant development. Graphical Abstract

This paper is an introduction to the issue of buoys, i.e. signs normally produced with the non-dominant hand to ensure a spatial reference point for signs produced with the dominant hand. Simultaneous constructions of this type have been noticed in numerous sign languages, yet their equivalents have not been described in any detail for Polish Sign Language (PJM). The paper presents what can be said about the use of buoys in PJM on the basis of an analysis of a collection of empirical data extracted from the Corpus of Polish Sign Language (KPJM). The research confi rms that certain buoy types (fragment and depicting buoys) are frequent in PJM and can be found in recurring contexts, which speaks for considering them as a part of grammar of this language

The aim of this paper is to discuss the major differences and similarities between the Corpus of Polish Sign Language (KPJM), which has been developed for a decade by the team of the Section for Sign Linguistics, Faculty of Polish Studies, University of Warsaw, and corpora of phonic languages (and in particular the National Corpus of Polish (NKJP)). The KPJM is a general corpus with an ambition to represent the whole language, used by the Polish Deaf. Unlike the corpora of phonic languages, which are collections of existing texts, the material of the KPJM was generated purposefully by recording and annotating an extensive set of videos. The paper shows that the sign language corpus should be viewed as analogous to spoken language corpora rather than to written language corpora. The KPJM can be perceived as a model of Polish Sign Language.

Knowledge of the impacts of sex on plant mortality and biomass production has scientific and practical importance. In the case of willows, we know relatively little about such effects. The main objective of this study was to evaluate whether the sex of individuals of different willow species determines their biomass and mortality. An additional goal was to determine whether the secondary sex characteristics, such as leaf traits, depend on sex. The experiment was conducted from 2011 to 2014 with 8100 plants comprising 150 willow genotypes, including 8 species, 16 interspecies hybrids, cultivars, and specimens differentiated by sex. Statistical analysis of the leaf traits revealed their relationship to sex. On average, male specimens have longer and wider leaves. They also have longer petioles. Males of the studied Salix genotypes were characterized by higher biomass and showed a greater survival rate than females but only under better site conditions; when the site conditions were poorer, males had higher mortality than females.

Aluminium titanate - tialite belongs to the compounds with pseudobrookite structure. The polycrystals made of tialite show valuable useful thermal properties: low thermal expansion, very low thermal conductivity and high resistance to thermal shock. These properties result from the cracks present in the microstructure, resulting from significant differences in the lattice coefficients of aluminium titanate. The basic disadvantage of tialite consist in a thermal decomposition occurring at the temperatures of about 750–1280 °C. This decomposition can be limited by structural and microstructural stabilization. The addition of cations, e.g. magnesium or iron, leads to the formation of stable solid solutions, while the addition of SiO2 or ZrO2 leads to the formation of secondary phases - diffusion barriers occurring at intergranular boundaries. Most often these additives are introduced simultaneously and at the reaction sintering stage. Stable solid solutions are usually produced by a classical solid phase reaction between the initial oxides: Al2O3, TiO2 and MgO. In this work, an innovative synthesis was applied to produce solid solutions, involving a heterogeneous isostructural nucleation with magnesium titanate. The polycrystals obtained in this way, at a much lower temperature, with a high content of solid solutions (95–96 %), high density, homogeneous microstructure with necessary microcracks were obtained. As a result, the obtained polycrystals exhibit the typical pseudobrookite structure behaviour as a function of temperature.

There is strong evidence that neuronal bases for language processing are remarkably similar for sign and spoken languages. However, as meanings and linguistic structures of sign languages are coded in movement and space and decoded through vision, differences are also present, predominantly in occipitotemporal and parietal areas, such as superior parietal lobule (SPL). Whether the involvement of SPL reflects domain-general visuospatial attention or processes specific to sign language comprehension remains an open question. Here we conducted two experiments to investigate the role of SPL and the laterality of its engagement in sign language lexical processing. First, using unique longitudinal and between-group designs we mapped brain responses to sign language in hearing late learners and deaf signers. Second, using transcranial magnetic stimulation (TMS) in both groups we tested the behavioural relevance of SPL’s engagement and its lateralisation during sign language comprehension. SPL activation in hearing participants was observed in the right hemisphere before and bilaterally after the sign language course. Additionally, after the course hearing learners exhibited greater activation in the occipital cortex and left SPL than deaf signers. TMS applied to the right SPL decreased accuracy in both hearing learners and deaf signers. Stimulation of the left SPL decreased accuracy only in hearing learners. Our results suggest that right SPL might be involved in visuospatial attention while left SPL might support phonological decoding of signs in non-proficient signers.

Pollinators are important to wild and cultivated plants, and the same plants are important to pollinators as well. A very important source of pollen and nectar to pollinators are willows (Salix spp.). The aim of this study was to demonstrate which Apoidea species are attracted by a species-diverse willow plantation (Poznan University of Life Sciences Willow Collection, Poland), the proportion of the number of honeybees to other species from the Apoidea superfamily visiting willow plantations, and whether the flowering date of male and female willow individuals affect the species composition and number of pollinators. Observations of willow phenology were carried out in the second year of willow growth, from March 9 to December 7, 2012. The insects were observed between April 6 and May 11, 2012. The results of this study showed 30 Apoidea species. Among 1591 Apoidea individuals, only 17 honeybee individuals were noted. The results show that the willow pollen production optimum occurred when the minimum air temperatures stopped dropping below zero. This parameter and this period are also related to the intensification of the occurrence of the noted insects. It can also be concluded that the pollen production season precedes the flowering optimum of female flowers and that the optimum flowering of female flowers is correlated with a significant increase in air temperature.

A fire retardant composite adhesive for bonding wood and wood-based elements has been developed and characterized. To obtain the enhanced fire-proof properties of the wood adhesive dispersion based on the poly(vinyl acetate) (PVAc), ceramic fillers (17.5 wt% total)—alumina, silica, kaolin and glass fibers were applied. Moreover, fire retardants such as melamine, melamine phosphate and melamine polyphosphate (up to 7 wt%) were also used. Thermal analysis (TG-DSC), strength tests, rheology, pH and flammability measurements (PCFC) were performed. The best properties of the adhesive were achieved for ceramic additives supported by melamine phosphate. A slight improvement of shear strength, shift of the last decomposition step of PVAc (residue degradation) towards higher temperatures by about 50 °C, reduction in mass loss from 100 wt% to less than 70 wt% and about 30–40% improvement of flammability parameters such as heat release capacity, total heat release or peak heat release rate were found compared to the pure poly(vinyl acetate) adhesive.

This article describes the project of producing Polish Sign Language (PJM) translations of a series of Polish primary-school textbooks. We discuss the multimedia software application that presents ...

The aim of this work was to obtain dense Cu2S superionic thermoelectric materials, homogeneous in terms of phase and chemical composition, using a very fast and cheap induction-melting technique. The chemical composition was investigated via scanning electron microscopy (SEM) combined with an energy-dispersive spectroscopy (EDS) method, and the phase composition was established by X-ray diffraction (XRD). The thermoelectric figure of merit ZT was determined on the basis of thermoelectric transport properties, i.e., Seebeck coefficient, electrical and thermal conductivity in the temperature range of 300–923 K. The obtained values of the ZT parameter are comparable with those obtained using the induction hot pressing (IHP) technique and about 30–45% higher in the temperature range of 773–923 K in comparison with Cu2S samples densified with the spark plasma sintering (SPS) technique.

Crystallization under hydrothermal conditions allowed us to prepare nanometric powders in the MgO–ZrO2 system of different magnesia concentrations. Sintering runs of these powder compacts studied using dilatometry measurements during heating and cooling revealed essential differences in their behavior. The microstructure of the resulting polycrystal is strongly related to the magnesia content in the starting powder, which strongly influences the phase composition of the resulting material and its mechanical properties. It should be emphasized that the novel processing method of such materials differs from the usual applied technology and leads to magnesia–zirconia materials of a different microstructure than that of “classical” materials of this kind.

Scots pine (Pinus sylvestris L.) is a widespread species in Eurasia, but its natural range can be significantly altered by a variety of stressors. The ability of pine to regenerate naturally is significantly reduced by its occurrence in unsuitable habitats. The processes of natural selection of pine from select habitats can be followed in stands of national parks where forestry activities are excluded. The possibility of pine regeneration is influenced by the following factors: characteristics of produced seeds, competition, and genetic characteristics. In the present study, selected factors associated with limiting the natural regeneration potential of pine were analysed. The present work generated important information related to the natural regeneration potential of pine in Central and Eastern Europe. The main objective of the analyses was to discuss the possibility of the natural regeneration of pine stands without human intervention. In addition, the genetic diversity of naturally germinating seedlings was analysed. The obtained results confirmed the high reproductive potential of pine despite the advanced age of the studied trees. The obtained seeds produced by old growth Scots pine trees had high viability, while a significant difference was observed in terms of the average number of cones per dominant tree between studied stands. Thus, the number of cones was the main element determining the regeneration potential of the stands. It should be emphasised that the number of cones did not influence the occurrence of natural regeneration. Based on the obtained results, the regeneration potential of pine stands depends mainly on the habitat and the competitive pressure. In addition, a correlation between genetic parameters and the regeneration potential of stands should be established, which may be the beginning of further research on the process discussed in this publication.

The study focuses on obtaining Inconel 625-NbC composites for high-temperature applications, e.g., jet engines, waste-to-energy combusting systems or gas engine turbines, and characterizing them in terms of their microstructure and hardness improvement. Synthesis was performed utilizing Spark Plasma Sintering (SPS) at 1150 degrees C under the load of 45 MPa in medium vacuum (under 10(-3) MPa) for a total time of 60 min. Four sets of samples with different Inconel 625 to NbC weight ratios were prepared (5, 10, 20, and 30 wt.%), followed by a reference sample containing no ceramic reinforcement. Obtained materials were hot-rolled at 1150 degrees C with a 10% reduction step and later cut and polished to perform characterization utilizing scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) module and microhardness testing device equipped with Vickers indenter. Hardness was improved proportionally to NbC addition achieving an increase of up to 20% of reference values. Additional heat treatment was conducted on the hot-rolled samples at 1200 degrees C in an argon atmosphere to further observe the interaction between reinforcement and alloy. Their microstructure revealed the coarsening of precipitates within the metal matrix and partial reinforcement dissolution, which proved to be crucial to obtaining the highest quality composites with homogenous hardness improvement.

The incorporation of Lucanus cervus (L.) in Annex 2 of the EU Habitats Directive imposed on EU member countries the obligation to prepare protection plans and undertake adequate measures aimed at the preservation of this species. A necessary precondition for their implementation was connected with the identification of current localities of L. cervus. This paper presents the distribution of L. cervus localities in Poland, identified on the basis of a survey conducted in the areas administered by the State Forests. Habitat preferences for the selection of biotopes by stag beetles were evaluated in terms of forest-site types. This will facilitate effective protection of L. cervus by indicating potential biotopes for this species, particularly in areas with high abundance. The survey showed the presence of L. cervus in 176 localities distributed in 47 forest districts. Most of them were found in three main areas comprising forests in the areas of Zielona Góra, Wrocław and the Świętokrzyskie Mts. They constitute large-scale refuges. In 98% of cases the development of L. cervus was associated with oaks Quercus robur and Quercus petraea. Other host plants included Fagus sylvatica and Acer pseudoplatanus. The age of trees colonised by stag beetles ranged from 70 to 248 years, 134 years on average. Lucanus cervus was most frequently found in deciduous mesic forest sites (41% of localities) and deciduous mixed mesic forest sites (24% of localities). Over 90% of recorded localities are situated in forested areas, understood to include stands, residual trees and stumps, as well as localities at forest edges and along roads in the vicinity of forests.

The present article explores the early modern preoccupation with omens – extraordinary occurrences observed both on earth and in the sky – which were universally believed to presage some future events and/or provide humans with providential signs and messages. Animals apparently formed a category of particularly common portents, due to their ubiquity and traditional links with the supernatural. Numerous examples of such omens demonstrate that animals and their behaviour were capable of evoking a variety of interpretations (moral, political, religious, etc.) and were indispensable in upholding the emblematic vision of the world, which, providentially, was supposed to be full of signs that could be deciphered by careful observers for their own benefit.

The study describes the physicochemical properties of transition metal (Co,Cu,Mg,Ni,Zn)O high-entropy oxide prepared using mechanochemical synthesis (MS) followed by thermal treatment, as well as the structural evolutions in the powder with milling time. The microstructure and electrical properties of the materials were studied using x-ray diffraction, scanning electron microscopy—energy dispersive spectroscopy and electrochemical impedance spectroscopy. The powders obtained after 30 h and 100 h of MS contained a mixture of two phases with a rock salt structure and, in addition, about 11 wt.% of Co3O4. Sintering these materials for 10 h in air at 1273 K led to the formation of a single-phase, solid solution with a rock salt structure. The developed sinters exhibited a fine-crystalline structure of grains and a uniform distribution of elements. The highest electrical conductivity was measured at 1148 K, and it was equal to 8.03 × 10−2 S cm−1.

The chemical composition of wood depends on many factors, including plant growth conditions. Among the many dangerous elements it was decided in this study to select arsenic in various forms: As(III), As(V) and cacodylic acid (DMAA), as well as various concentrations and mutual combinations. The experiment was conducted on 1-year old elm seedlings planted in pots with an addition of Knop medium and arsenic. Supplementation of the substrate with each arsenic form caused changes in contents of cellulose and lignin as well as extractive substances and those soluble in 1% NaOH. Arsenic also led to changes in the structure of basic wood components. The FTIR analysis showed the greatest changes under the influence of As(V), As(III)/As(V)/DMA. Despite high arsenic concentration in the substrate 1-year old elm seedlings survived the period of the experiment, thus providing valuable results and broadening our knowledge on the response of trees to the environment contaminated with arsenic.

The work concerns the characterization of polycrystalline materials composed in Ti–Al–C system such as Ti2AlC and Ti3AlC2. The starting powders were synthesized from metal powder in nitrogen overpressure with the use of SHS method. Such obtained powders were chemically described and hot-pressed at temperatures 1100 °C and 1300 °C. The densification measurements were taken on obtained sintered bodies. The chemical composition analysis and microstructural observation of hot-pressed materials were made. The obtained MAX phase Young’s modulus was examined in the temperature range 25–600 °C by resonance method. The thermal properties of the thermogravimetric analysis were made in air flow to determine the oxygen resistance. The MAX phase polycrystals were taken under laser flash analysis, which allowed to measure directly thermal diffusivity and specific heat and to calculate indirectly thermal conductivity up to the temperature of 700 °C. Additionally, the polycrystalline material was laser treated in continuous work mode. The hot-pressed MAX nanolaminates were laser ablation and laser welding processed, which is new in the literature. The laser beam-treated material places were microstructurally investigated by scanning electron microscopy and chemically by energy-dispersive X-ray spectroscopy. The result of laser processing was discussed regarding material preparation route and its thermal properties.

The study aimed to answer the question of previously obtained Inconel 625-NbC metal matrix composites (MMC) applicability in high-temperature and/or oxidative environments, that were proven to possess improved mechanical properties. To achieve that goal, a similar manufacturing process was performed, utilizing spark plasma sintering (SPS) at 1100 degrees C under 45 MPa, and in a medium vacuum (under 10-3 MPa). The total time for each sample equaled 60 min. Four sets of samples were obtained with ceramic reinforcement additions equaling 0, 5, 10, and 20 wt%. Hot rolling at 1100 degrees C with a 10% reduction step was applied to sintered materials in order to fully replicate previous technology. Oxidation tests were performed in furnaces with free flow of air for three total time periods: 24, 49, and 100 h at 800 degrees C. It was revealed that all samples kept their ability to form passive layers by matrix, but those layers were locally breached due to grain growth and thermal stresses of the oxidized reinforcement phase. Two different passive layer formations were observed and discussed: (Cr/Ni)-rich covering composite surface and (Cr/Nb)-rich forming around ceramic reinforcement. Total mass gain during oxidation was kept under 1 mg/cm2 for each sample series, with samples containing 5 wt% of NbC performing similarly to reference material. Hardness loss (up to 15%) was observed in near-surface zones of obtained MMC due to composite oxidation.

The aim of the work was to obtain copper (I) selenide Cu2Se material with excellent thermoelectric properties, synthesized using the hydrothermal method and densified by the spark plasma sintering (SPS) method. Chemical and phase composition studies were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. Measurements of thermoelectric transport properties, i.e., electrical conductivity, the Seebeck coefficient, and thermal conductivity in the temperature range from 300 to 965 K were carried out. Based on these results, the temperature dependence of the thermoelectric figure of merit ZT as a function of temperature was determined. The obtained, very high ZT parameter (ZT~1.75, T = 965 K) is one of the highest obtained so far for undoped Cu2Se.

The aim of the work was to obtain copper (I) selenide Cu2Se material with excellent thermoelectric properties, synthesized using the hydrothermal method and densified by the spark plasma sintering (SPS) method. Chemical and phase composition studies were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. Measurements of thermoelectric transport properties, i.e., electrical conductivity, the Seebeck coefficient, and thermal conductivity in the temperature range from 300 to 965 K were carried out. Based on these results, the temperature dependence of the thermoelectric figure of merit ZT as a function of temperature was determined. The obtained, very high ZT parameter (ZT~1.75, T = 965 K) is one of the highest obtained so far for undoped Cu2Se.

Biodiversity at the species and individual levels is one of the fundamental elements characterizing an ecosystem. It is assumed that the greater the level of biodiversity, the more tolerant the environment is to changes in external conditions. In recent years, dynamic climate change has negatively impacted the health of many forest trees across Europe, in particular Scots pine. Tree health is commonly characterized by crown defoliation. The study presented here describes and correlates crown defoliation with biodiversity indicators at the species and individual tree levels. Research was conducted in two national parks in Poland (Kampinoski and Bory Tucholskie). Since stands have been under legal protection for many years and forest management is not practiced there, stand development processes taking place there are similar to natural ones. This study provided empirical data on ecosystem response to external stresses based on species and genetic structure. The results confirm differing health of the populations, which results from, among other factors, stand age and the environmental conditions in which they grow. Pine stands in both national parks are genetically diverse but with low genetic variability. Differences in stand health are related to the number of alleles forming the genetic pool. This conclusion is supported by a high correlation coefficient for interactions between defoliation, the number of alleles, and the Shannon index for genotypes. This suggests that greater gene diversity is likely to provide a wider range of phenotypic responses to environmental change.

Early sensory deprivation, such as deafness, shapes brain development in multiple ways. Deprived auditory areas become engaged in the processing of stimuli from the remaining modalities and in high-level cognitive tasks. Yet, structural and functional changes were also observed in non-deprived brain areas, which may suggest the whole-brain network changes in deaf individuals. To explore this possibility, we compared the resting-state functional network organization of the brain in early deaf adults and hearing controls and examined global network segregation and integration. Relative to hearing controls, deaf adults exhibited decreased network segregation and an altered modular structure. In the deaf, regions of the salience network were coupled with the fronto-parietal network, while in the hearing controls, they were coupled with other large-scale networks. Deaf adults showed weaker connections between auditory and somatomotor regions, stronger coupling between the fronto-parietal network and several other large-scale networks (visual, memory, cingulo-opercular and somatomotor), and an enlargement of the default mode network. Our findings suggest that brain plasticity in deaf adults is not limited to changes in the auditory cortex but additionally alters the coupling between other large-scale networks and the development of functional brain modules. These widespread functional connectivity changes may provide a mechanism for the superior behavioral performance of the deaf in visual and attentional tasks. Electronic supplementary material The online version of this article (10.1007/s11682-020-00346-y) contains supplementary material, which is available to authorized users.

It has been proposed that the auditory cortex in the deaf humans might undergo task-specific reorganization. However, evidence remains scarce as previous experiments used only two very specific tasks (temporal processing and face perception) in visual modality. Here, congenitally deaf/hard of hearing and hearing women and men were enrolled in an fMRI experiment as we sought to fill this evidence gap in two ways. First, we compared activation evoked by a temporal processing task performed in two different modalities, visual and tactile. Second, we contrasted this task with a perceptually similar task that focuses on the spatial dimension. Additional control conditions consisted of passive stimulus observation. In line with the task specificity hypothesis, the auditory cortex in the deaf was activated by temporal processing in both visual and tactile modalities. This effect was selective for temporal processing relative to spatial discrimination. However, spatial processing also led to significant auditory cortex recruitment which, unlike temporal processing, occurred even during passive stimulus observation. We conclude that auditory cortex recruitment in the deaf and hard of hearing might involve interplay between task-selective and pluripotential mechanisms of cross-modal reorganization. Our results open several avenues for the investigation of the full complexity of the cross-modal plasticity phenomenon.SIGNIFICANCE STATEMENTPrevious studies suggested that the auditory cortex in the deaf may change input modality (sound to vision) while keeping its function (e.g., rhythm processing). We investigated this hypothesis by asking deaf or hard of hearing and hearing adults to discriminate between temporally and spatially complex sequences in visual and tactile modalities. The results show that such function-specific brain reorganization, as has previously been demonstrated in the visual modality, also occurs for tactile processing. On the other hand, they also show that for some stimuli (spatial) the auditory cortex activates automatically, which is suggestive of a take-over by a different kind of cognitive function. The observed differences in processing of sequences might thus result from an interplay of task-specific and pluripotent plasticity.

Analysis of dense Potassium Sodium Niobate (KNN) ceramic obtained by hot pressing (HP) method at 1100 &deg, C are presented in this paper. The synthesis of KNN-based piezoelectrics meets the following challenges&mdash, low density of material, uncontrolled K/Na ratio, multiphase composition and formation of different KNN structures. The classical hot pressing approach results in contamination by carbon originating from graphite molds. The proposed hexagonal Boron Carbide (h-BN) layer between green sample and graphite mold could protect samples from carbon contamination. Additionally, the presence of h-BN may decrease the formation of oxygen vacancies, which allows us to maintain the semiconductor features of the KNN structure. Remaining issues were addressed with the addition of excess Na and Er2O3 doping. The results showed that excess Na addition allowed us to compensate evaporation of sodium during the synthesis and sintering. Er2O3 was added as sintering aid to limit abnormal grain growth caused by h&ndash, BN addition. The modification of amount of Na and Er2O3 addition resulted in high purity KNN samples with tetragonal structure and apparent density higher than 97%. Finally, piezoelectric features of prepared dense samples were measured and presented.

Hybrid polyacrylate-silicate hydrogels were obtained in the presence of N,N&prime, methylenebisacrylamide (NNMBA) as the cross-linking monomer and sodium thiosulphate/potassium persulphate (NTS/KPS) as the redox initiators. The results of the tests allowed us to conclude that a hybrid structure with a polyacrylate scaffolding and a silicate matrix had been obtained. The results of the rheological analysis revealed that the hydrogel sample with a 1:7 mass ratio of sodium water glass to the sodium polyacrylate is characterized by the highest complex viscosity. Thermal analysis (Thermogravimetry/Differential Scanning Calorimetry (TG/DSC)) showed that water begins to evaporate at higher temperatures, from 120 &deg, C to even 180 &deg, C. These results were confirmed by mid-infrared spectroscopy (MIR) and nuclear magnetic resonance spectroscopy (NMR) analysis. Differences in the intensity of the peaks derived from water in the MIR spectra indicate that most of the water is bounded. In turn, NMR results showed that the mobility of water molecules decreases as the amount of sodium water glass in the mixture increases.

In this work, three-dimensional (3D) shaping of aluminum nitride (AlN) UV-curable dispersions using CeraFab 7500 device equipped with the light engine emitting 365 nm wavelength (a UV-LCM device) is presented. The purpose of this study was the shaping of AlN pieces with microchannels for the future potential use as microchannel heat exchangers. The dispersions were characterized by the means of the particle size distribution, rheological measurements, and the cure depth evaluation. In shaping via UV-LCM, we applied dispersions containing 40 vol % solid load and different types of photoinitiators and their concentrations, as well as different settings of the printing parameters. Cuboidal plates with channels and cylindrical 3D structures were fabricated, debound, and sintered. For comparing ceramics properties, reference samples were prepared via uniaxial and cold isostatic pressing, using the same powder mixture as in the dispersions, and later sintered. The thermal conductivity of the sintered specimens was calculated, based on density and thermal diffusivity measurements.

Analysis of dense KNN ceramic obtained by hot pressing (HP) methodat 1100°C are presented in this paper. The synthesis of KNN-based piezoelectrics meets following challenges: low density of material, uncontrolled K/Na ratio, multiphase composition and formation of different KNN structures. Classical hot pressing approach results incontaminationby carbon originating from graphite moulds. The proposed h-BN protection layer between green sample and graphite mouldprevented carbon reaction with powder. Additionally, h-BN presence may decrease formation of oxygen vacancies which allows to maintain semiconductor features of KNN structure. Remaining issues were addressed with the addition of excess Na and Er2O3 doping. The results showed that excessNa addition allowed to compensate evaporation of sodium during the synthesis and sintering. Er2O3 was added as sintering aid to limit abnormal grain growth. The modification of amount of Na and Er2O3 addition resulted in high purity KNN samples with tetragonal structure andapparent density higher than 97%. Finally, piezoelectric features of prepared dense samples were measured and presented.

Yttria stabilized tetragonal zirconia polycrystals were prepared using mixtures of two different powders. One is composed of nanometric particles of 3.5mol% Y2O3 solid solution in ZrO2 and the other one of pure zirconia particles. The latter shows elongated particles of about 200 nm length and monoclinic symmetry and the former consists of isometric tetragonal particles of about 7 nm size. Both powders were synthesized under hydrothermal conditions at 240?C in water (the 3.5mol% Y2O3-ZrO2 solid solution) or in 4M NaOH solution (the pure ZrO2 powder). Two homogenous mixtures of these powders were prepared; the one with 5wt.% and the other one with 10 wt.% of the elongated zirconia particles. Compacts of 10mm diameter were isostatically pressed (250MPa) and sintered in a dilatometer furnace at 1400?C with no soaking time. A set of samples heated up to the selected temperatures allowed us to follow phase changes of the materials vs. temperature by X-ray diffraction. It was confirmed that all materials show tetragonal symmetry at the final temperature (1400?C). Density and mean grain size decrease with the elongated zirconia particle additives. The dense samples were polished and their hardness and fracture toughness were determined by Vickers indentation. No hardness changes, due to the elongated zirconia particles additives, were observed, but essential increase of fracture toughness occurred. The observations of the crack runs suggest crack deflection as a potential mechanism of the fracture toughness increase.

The aim of this research was to answer the question of whether the floristic- phytosociological characteristics of the forest communities described in the mid-twentieth century in the Zielonka Experimental Forest (Poland) have changed, and if so, what were the reasons for these changes and what were their environmental and economic consequences. The basis of the research was a comparison of plant community descriptions drawn up in 1957-1961 to descriptions of the states of those communities in 2010-2017. The study showed a significant decrease in the number of plant species. The reasons for the disappearance of some plant communities are seen in the natural or artificial changes of pine in sandy habitats, which evolved towards richer communities. The disappearance of xero-thermophile oak woods had two main causes: a natural cause, which was a consequence of regeneration towards oak-hornbeam woods after the anthropogenic phenomena responsible for their management, and anthropogenic disturbance related to the planting of Fagus sylvatica trees or Prunus serotina. The second case is described more broadly and considers both the positive and negative roles of changing the floristic compositions of forest ecosystems.