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The effect of elastic anisotropy on thermal diffusivity determination by transient grating spectroscopy (TGS) was studied. In experiments performed on a set of cubic single crystals, it was observed that TGS measurements may indicate anisotropy of thermal diffusivity in otherwise thermally isotropic materials, and that the strength of this apparent anisotropy is correlated with the strength of the elastic anisotropy. To find a source of the observed phenomenon, finite-element simulations of the TGS measurements were carried out. Time-domain TGS signals were generated from the simulations and processed identically to the experimental data. The simulation results revealed that the elastic anisotropy affects the detected time-domain signals. Consequently, the thermal diffusivity coefficients determined from them showed the artificial directional dependence. For the chosen set of cubic crystals, ranging from nearly isotropic to strongly anisotropic in terms of elastic constants, this simulated directional dependence was in full agreement with the one observed in the experiments. [ABSTRACT FROM AUTHOR]

Aim: How community composition varies in space and what governs the variation has been extensively investigated in macroorganisms. However, we have only limited knowledge of microorganisms, especially fungi, despite their ecological and economic significance. Based on previous research, we define and test a series of hypotheses regarding the composition of fungal communities, their most influential drivers and their spatial scale dependence. Location: Czech Republic. Time period: Present. Taxa studied: Fungi. Methods: We analysed the distance decay relationships, community composition and its drivers (physical distance, litter and soil chemistry, tree composition and climate) in fungi using multivariate analyses. We compared the results across three fungal ecological guilds (ectomycorrhizal fungi, saprotrophs and yeasts), two forest microhabitats (litter and bulk soil) and six spatial scales (from 5 m to 80 km) that comprehensively cover the Czech Republic. Results: We found that, similar to macroorganisms, the ectomycorrhizal fungi and saprotrophs showed marked distance–decay relationships, and their community composition was driven mainly by vegetation and dispersal at local scales but, at regional scales, by environmental effects. In contrast, the third fungal guild, the unicellular yeasts, showed little distance decay, suggesting extraordinary spatial homogeneity, as often seen in microorganisms, such as bacteria. Main conclusions: Our results underscore the remarkable variation in the community ecology of fungi, which seems to range well‐known patterns both from the macro‐ and the microworld. Knowledge of these patterns advances our understanding of the ecology of fungi, rather understudied organisms of significant ecological and economic importance, which our findings identify as a potentially suitable model for bridging the gaps between the biogeography of micro‐ and macroorganisms. [ABSTRACT FROM AUTHOR]

Proof of concept salt tolerance and plasticity. Wild germplasm may represent a precious source of genetic variability for salt tolerance. This study evaluated the morphological changes occurring under controlled and saline conditions in tuber-bearing S. bulbocastanum, S. commersonii, S. chomatophyllum, S. multidissectum, S. pinnactisectum, S. phureja, and cultivated S. tuberosum. An in vitro screening method was employed. Significant phenotypic variations were observed for all phenotypic traits analyzed at all NaCl levels (0, 40, 60, and 120 mM). In addition, a significant correlation between root plasticity and salt tolerance was found. Further, changes in proline and total phenolic content were assessed to envisage the metabolic adjustments of tolerant clones towards salinity. The most promising sources of tolerance were identified in S. commersonii and S. multidissectum and information obtained is discussed from a breeding perspective. [ABSTRACT FROM AUTHOR]

The Colorado potato beetle (CPB, Leptinotarsa decemlineata Slechtd.) is an invasive pest with economic importance worldwide. Sex ratios during egg-hatching and a frequency of polyandry in single-female families were analysed to clarify the reproduction strategy of CPB, which was still known only in fragments. 1296 just hatching 1st instar CPB larvae were collected from 19 single-female families, of which 13 were random families collected from potato fields and 6 were families produced by laboratory farming of naturally fertilised females. All larvae were analysed to detect a sex using a qPCR-based method and to detect polymorphisms in genotypes of 9 microsatellite (SSR) markers. The bias in sex ratio in favour of females was confirmed using linear mixed-effects model in both experimental groups of families: field collections (F = 36.39; P = 0.0001) and laboratory farming (F = 13.74; P = 0.0139). The analysis of diversity in microsatellites proved the polyandry in all progenies as 73% of analysed segregation patterns did not match with the patterns expected for full-sib progenies; on average per locus, 46% of allelic and 49.7% of genotype ratios showed irregular segregation. Both findings contribute toward understanding CPB success rate as an invasive species, as the preferential bearing of females with polyandry has a great potential to keep fitness of progenies, to maintain and operate population diversity, and to accelerate the reproduction of the pest. [ABSTRACT FROM AUTHOR]

Prophylactic stump treatments against the conifer root rot fungus Heterobasidion annosum s.l. should take into account the airborne inoculum density of the pathogen, in order to be economically feasible. Our objective was to test if an automatic volumetric spore trap (AVST) could be used as a sensitive alternative of passive traps for quantifying Heterobasidion airspora in forest stands. The routinely used wood disc exposure method (WDE) was implemented simultaneously with AVST in five coniferous monocultures and three near-natural stands without silvicultural management in Czechia. Air sampling took place for 24-h intervals in five months of the main sporulation period. The atmospheric concentration of H. annosum s.l. spores (cHa) was determined by qPCR with generic and species-specific primers. AVST detected more target species than WDE on 77% of sampling occasions. When comparing the relative abundance of the three European H. annosum s.l. species detected by AVST and WDE, H. parviporum and H. abietinum were found to be overrepresented on wood discs. cHa in November was significantly higher than in May and June, confirming the seasonal pattern typical for temperate Europe. For an accurate and rapid estimation of Heterobasidion primary infection risk, the usage of AVST is highly recommended. [ABSTRACT FROM AUTHOR]

Somatic hybridization has been frequently used to overcome sexual incompatibility between potato and its secondary germplasm. The primary objective of this study was to produce and evaluate somatic hybrids of Solanum tuberosum (Stub) and S. bulbocastanum (Sblb) for breeding purposes. In 2007, 23 somatic hybrids were produced using an electrofusion of mesophyll protoplasts of diploid (2n = 2x = 24) potato line StubDH165 and S. bulbocastanum PI24351 (Sblb66). Phenotype of somatic hybrids in field conditions were evaluated, together with constitution and stability of 30 nuclear (ncSSR) and 27 cytoplasmic (cpSSR) microsatellite markers and content of main glycoalkaloids. All somatic hybrids had very high field resistance against late blight, but the plants were infertile: the viability of pollen grains insignificantly varied between 0.58 and 8.97%. A significant somaclonal variation was observed in terms of the morphology of plants, the date of emergence, the quantity of harvested tubers, the content of glycoalkaloids in foliage, and nuclear microsatellite markers (ncSSR). The analysis of ncSSR identified five distinct genotypes of hybrids partly associated with phenotype variations. The process of somatic hybridization with regeneration of shoots was identified as the most likely source of somaclonal variation because the ncSSR genotypes of hybrids, which were maintained in vitro, remained stable for more than 10 years. The infertile somatic hybrids have no practical breeding potential, but they are considered very suitable for advanced studies of the differential expression of genes in the pathways linked to dormancy of tubers and synthesis of glycoalkaloids. [ABSTRACT FROM AUTHOR]

This review summarizes the current trends and developments in the field of polyvinylidene fluoride (PVDF) for use mainly as a nanogenerator. The text covers PVDF from the first steps of solution mixing, through production, to material utilization, demonstration of results, and future perspective. Specific solvents and ratios must be selected when choosing and mixing the solution. It is necessary to set exact parameters during the fabrication and define whether the material will be flexible nanofibers or a solid layer. Based on these selections, the subsequent use of PVDF and its piezoelectric properties are determined. The most common degradation phenomena and how PVDF behaves are described in the paper. This review is therefore intended to provide a basic overview not only for those who plan to start producing PVDF as energy nanogenerators, active filters, or sensors but also for those who are already knowledgeable in the production of this material and want to expand their existing expertise and current overview of the subject. [ABSTRACT FROM AUTHOR]

This review summarizes recent advances in first‐principles simulations of the structural, mechanical, and magnetomechanical properties of Ni–Mn–Ga‐based ferromagnetic shape memory alloys from the perspective of experimental characterization. It focuses on calculations that can capture the main features of the low‐temperature phases, particularly the appearance of spatial modulations, the occurrence of intermartensitic transitions, and the high mobility of the twin boundaries, which allows for magnetically induced reorientation. Although the calculations can only be used to interpret some of these features and are not yet ready to be used as a tool for designing new alloys with the required properties, the gap between experimental observations and simulations is narrowing. When experiments and theory are discussed together, new challenges arise for both. In addition, new results on first‐principles‐determined elastic constants of the 10M martensite of Ni–Mn–Ga are presented and discussed with respect to the high mobility of the twin boundaries. [ABSTRACT FROM AUTHOR]

The identification of sex in larvae of insects is usually challenging or even impossible, while in adults the sexual dimorphism is usually evident. Here, we used copy number analysis to develop a method of sex detection in Colorado potato beetle (Leptinotarsa decemlineata), which has an X0 sex determination system. The X linked gene LdVssc and autosomal gene LdUBE3B were identified as appropriate target and reference loci, respectively. The copy numbers (CNV) of LdVssc in males and females were estimated using standard droplet digital PCR (ddPCR) and real-time PCR (qPCR). With both methods, CNVs were bimodally distributed (BAddPCR = 0.709 and BAqPCR = 0.683) with 100% ability to distinguish females from males. The use of qPCR-based sex detection in a broad collection of 448 random CPB adults showed a perfect association (Phi = 1.0, p < 0.05) with the true sexes of adults, with mean CNV in females of 2.032 (SD = 0.227) and 0.989 in males (SD = 0.147). In the collection of 50 random 4th instar larvae, 27 females and 23 males were identified, consistent with the expected 1:1 sex ratio (p = 0.689). The method is suitable for sexing in all stages of ontogenesis. The optimal cost-effective application of the method in large populations requires the DNA extraction using CTAB, the qPCR assay in one biological replicate and three technical replicates of each marker, and the use of one randomly chosen male per run to calibrate calculation of CNV. [ABSTRACT FROM AUTHOR]

Somatic hybridization has been frequently used to overcome sexual incompatibility between potato and its secondary germplasm. The primary objective of this study was to produce and evaluate somatic hybrids of Solanum tuberosum (Stub) and S. bulbocastanum (Sblb) for breeding purposes. In 2007, 23 somatic hybrids were produced using an electrofusion of mesophyll protoplasts of diploid (2n = 2x = 24) potato line StubDH165 and S. bulbocastanum PI24351 (Sblb66). Phenotype of somatic hybrids in field conditions were evaluated, together with constitution and stability of 30 nuclear (ncSSR) and 27 cytoplasmic (cpSSR) microsatellite markers and content of main glycoalkaloids. All somatic hybrids had very high field resistance against late blight, but the plants were infertile: the viability of pollen grains insignificantly varied between 0.58 and 8.97%. A significant somaclonal variation was observed in terms of the morphology of plants, the date of emergence, the quantity of harvested tubers, the content of glycoalkaloids in foliage, and nuclear microsatellite markers (ncSSR). The analysis of ncSSR identified five distinct genotypes of hybrids partly associated with phenotype variations. The process of somatic hybridization with regeneration of shoots was identified as the most likely source of somaclonal variation because the ncSSR genotypes of hybrids, which were maintained in vitro, remained stable for more than 10 years. The infertile somatic hybrids have no practical breeding potential, but they are considered very suitable for advanced studies of the differential expression of genes in the pathways linked to dormancy of tubers and synthesis of glycoalkaloids. [ABSTRACT FROM AUTHOR]

Adequate integrated management of potato leaf diseases can have an influence on pathogens which are challenging to control and cause main potato tuber diseases. Deriving from this hypothesis, an experiment was designed to evaluate the efficacy of foliar application of twelve fungicides on late blight in tubers, common scab, black scurf and silver scurf. In the period of 2013 to 2017, the fungicides were equally applied six times in registered doses during the growing seasons. Eight tuber disease indicators and eight yield characteristics were then evaluated in harvested tuber samples. Significant differences were found among the fungicides used. In comparison to the negative control (n. c.), the application of Infinito, Ranman Top and Revus Top reduced the quantity of tubers infected by late blight by 72% on average. The incidence of common scab increased by 65% of n. c. under the effect of copper oxychloride, while an average reduction by 19% of n. c. was observed with the use of Acrobat MZ WG, Curzate Gold and Consento. The occurrence of silver scurf was significantly enhanced by Curzate Gold and Consento (105% of n. c.), while it was suppressed by Revus Top and Revus (85% of n. c.). All fungicides were ineffective on black scurf yet had a positive influence on the potato yield and quality, with the choice of fungicide having a great impact on the quality of tubers. The application of any safe fungicide is important, especially in years similar to 2015, which was the most devastating recent year for potato production in terms of structural changes in yield of tubers. [ABSTRACT FROM AUTHOR]

Although spatial and temporal variation are both important components structuring microbial communities, the exact quantification of temporal turnover rates of fungi and bacteria has not been performed to date. In this study, we utilised repeated resampling of bacterial and fungal communities at specific locations across multiple years to describe their patterns and rates of temporal turnover. Our results show that microbial communities undergo temporal change at a rate of 0.010–0.025 per year (in units of Sorensen similarity), and the change in soil is slightly faster in fungi than in bacteria, with bacterial communities changing more rapidly in litter than soil. Importantly, temporal development differs across fungal guilds and bacterial phyla with different ecologies. While some microbial guilds show consistent responses across regional locations, others show site‐specific development with weak general patterns. These results indicate that guild‐level resolution is important for understanding microbial community assembly, dynamics and responses to environmental factors. [ABSTRACT FROM AUTHOR]

A phenomenological model for polycrystalline NiTi shape-memory alloys with a refined dissipation function is here enhanced by a thermomechanical coupling and rigorously analyzed as far as existence of weak solutions and numerical stability and convergence of the numerical approximation performed by a staggered time discretization. Moreover, the model is verified on one-dimensional computational simulations compared with real laboratory experiments on a NiTi wire. [ABSTRACT FROM AUTHOR]

Most wood‐decay fungi contribute to the healthy functioning of forest ecosystems, whereas others cause infectious diseases of woody plants and high economic losses for forest management. In this study, we pursued the hypothesis that pathogenic wood‐rotting Agaricomycetes occur less frequently in undisturbed forests than in managed stands, especially artificial monocultures. The prevalence of two important pathogens, Armillaria spp. and Heterobasidion annosum s.l., was assessed in managed and unmanaged beech, oak and mixed forests, and spruce plantations in South Moravia, Czechia. In addition, the presence of saproparasitic fungi in decayed wood was examined. Identification of fungal species from wood, soil, basidiome and rhizomorph samples was performed by DNA‐based methods. Possible ecological patterns in the distribution of fungi were investigated. Armillaria spp. were ubiquitous; A. cepistipes seems to act as a decomposer, A. gallica is potentially hazardous to oak stands, while A. ostoyae threatens spruce plantations. Basidiomes and epiphytic rhizomorphs of Armillaria were absent in unmanaged stands. Heterobasidion annosum s.s. and H. abietinum basidiocarps were present in 21% and 4% of managed stands, respectively, mostly on conifer stumps. Fomitopsis pinicola, Schizophyllum commune and Stereum spp. were detected in a wide range of hosts and stand types. The results indicate that near‐natural forests are less endangered by root rot disease than monoculture plantations. [ABSTRACT FROM AUTHOR]

Butterfly wings have complex structure lending it several interesting properties. Coloration of the wing is one of the first things to encounter and the overall visual effect is in fact influenced by several factors. Chemical pigments set the base color of the wing, topographical structures on the wing scales cause color shift by interference and their arrangement into diffraction grating causes iridescence. The thin film interference can be attributed to microscopic ridges covering wing scales. Observation and calculation of the color shift on wings of Euploea mulciber species using Fourier transform of images obtained by atomic force microscopy is the focus of this article. [ABSTRACT FROM AUTHOR]

Elastic moduli (Young’s modulus, shear modulus and bulk modulus) of three ultrafine-grained Mg-based alloys AZ31, AE42 and LAE442 were studied by resonant ultrasound spectroscopy. Evolution of these moduli and the corresponding high-frequency internal friction were measured in a temperature cycle between the room temperature and 310 °C, i.e., with heating above the recrystallization threshold temperature. The results reveal that the Li content in the LAE442 alloy has a strong impact on its elastic performance, resulting in a high E/ρ ratio, which is consistent with predictions of ab initio calculations. Simultaneously, the relaxation due to grain boundary sliding has significantly lower activation energy in LAE442 alloy. [ABSTRACT FROM AUTHOR]

The influence of a polycrystals' grain structure on elastic wave scattering is studied with analytical and numerical methods in a broad frequency range. A semi-analytical attenuation model, based on an established scattering theory, is presented. This technique accurately accounts for the grain morphology without prior assumptions on grain statistics. This is achieved by incorporating a samples' exact spatial two-point correlation function into the theory. The approach is verified by using a finite element method (FEM) to simulate P-wave propagation in 3D Voronoi crystals with equal mean grain diameter, but different grain shape uniformity. Aluminum and Inconel serve as representatives for weak and strong scattering cubic class materials for simulations and analytical calculations. It was found that the shape of the grains has a strong influence on the attenuation curve progression in the Rayleigh-stochastic transition region, which was attributed to mode conversion scattering. Comparisons between simulations and theory show excellent agreement for both materials. This demonstrates the need for accurately taking the microstructure of heterogeneous materials into account, to get precise analytical predictions for their scattering behaviour. It also demonstrates the impressive accuracy and flexibility of the scattering theory which was used. [ABSTRACT FROM AUTHOR]

The diversity of three non-coding plastid DNA loci (trnL/trnF spacer, trnV/16SrRNA spacer, trnL/trnL intron) was assessed in 16 Solanum L. species (135 individuals). Polymorphisms were detected by denaturing gradient gel electrophoresis (DGGE) and verified by direct sequencing. No intraspecific diversity and only poor interspecific diversity was detected. Unique S. mochiquense Ochoa specific length polymorphism at the trnL/trnL locus represented by duplication of an 18 bp segment was discovered. The detected DGGE interspecific trnL/trnF locus polymorphism did not specifically associate with single point mutations in the sequence confirmed by sequencing. The DGGE method was found to be a simple and cheap pre-exploring tool for mutation detection in compared DNA regions. Some identified polymorphisms can be used in the management of genetic resources. [ABSTRACT FROM AUTHOR]

Textured polycrystals of NiTi-based shape memory alloys (SMA) exhibit pronounced anisotropic properties which significantly influence their response to mechanical and thermal loading. In this work, a constitutive model tailored for non-proportional multi-axial loading of NiTi SMA exhibiting two-stage phase transformation via R-phase is enhanced so that the anisotropy of martensitic structure is captured. Numerical simulations of the mechanical response of a NiTi SMA helical spring subjected to thermal cycling at a constant applied force are performed and compared with experimental data. Quantitative correspondence between experiments and simulations demonstrates the predictive potential of the model. Simulations also provide detailed information on the evolution of distributions of phase fractions and stress within a cross-section of the wire forming the spring. Because the loading is non-proportional, the evolution is rather complex and intriguing. [ABSTRACT FROM AUTHOR]

We present a three-dimensional constitutive model for NiTi polycrystalline shape memory alloys exhibiting transformations between three solid phases (austenite, R-phase, martensite). The ‘full modelling sequence’ comprised of formulation of modelling assumptions, construction of the model, mathematical analysis and numerical implementation and validation is presented. Namely, by formulating micromechanics-inspired modelling assumptions we concentrate on describing the dissipation mechanism: a refined form of this description makes our model especially useful for complex loading paths. We then embed the model into the so-called energetic framework (extended to our case) while taking advantage of describing the dissipation mechanism through the so-called dissipation distance. We prove the existence of energetic solutions to our model by a backward Euler scheme. This is then implemented into finite element software, and numerical simulations compared with experiments are also presented. [ABSTRACT FROM AUTHOR]

Internal friction in ultrafine-grained AZ31 magnesium alloy is investigated by resonant ultrasound spectroscopy. It is shown that the internal friction significantly increases at elevated temperatures ( $${\gtrsim }100$$ °C), and that this increase can be attributed to grain boundary sliding (GBS). The evolution of this phenomenon with grain refinement is studied by comparing the results obtained for an extruded material and for materials after additional one, two, and four passes of equal channel angular pressing. It is observed that the activation energy for diffusive GBS significantly decreases with decreasing grain size, and so does also the threshold temperature above which this internal friction mechanism is dominant. The results prove that the ultrafine-grained AZ31 alloys exhibit diffusive GBS at temperatures close to the ambient temperature, which is an interesting finding with respect to the possible applications of these alloys in superplastic forming technologies. [ABSTRACT FROM AUTHOR]

Ultrasonic measurements combined with numerical modelling are used to analyze the elastic and acoustic properties of morphologically complex ceramic bodies assembled by the Robocasting technique. It is shown that the micromechanics of the robocast periodic scaffolds leads to several metamaterial-like wave propagation phenomena. Besides the expectable prominent elastic anisotropy and the frequency band structure resulting from the periodicity of the scaffold, a wave-mode mixing is observed that disables the conventional distinguishing between quasi-longitudinal, quasishear, and pure shear modes for propagation in the symmetry planes of the structure. This paper proves the capability of Robocasting, as a versatile three-dimensional (3D) printing method, to produce tailored acoustic metamaterials with very low damping and outstandingly strong acoustic anomalies. [ABSTRACT FROM AUTHOR]

Corrosion behavior of superelastic NiTi shape memory alloy wires with cracked TiO surface oxide layers was investigated by electrochemical corrosion tests (Electrochemical Impedance Spectroscopy, Open Circuit Potential, and Potentiodynamic Polarization) on wires bent into U-shapes of various bending radii. Cracks within the oxide on the surface of the bent wires were observed by FIB-SEM and TEM methods. The density and width of the surface oxide cracks dramatically increase with decreasing bending radius. The results of electrochemical experiments consistently show that corrosion properties of NiTi wires with cracked oxide layers (static load keeps the cracks opened) are inferior compared to the corrosion properties of the straight NiTi wires covered by virgin uncracked oxides. Out of the three methods employed, the Electrochemical Impedance Spectroscopy seems to be the most appropriate test for the electrochemical characterization of the cracked oxide layers, since the impedance curves (Nyquist plot) of differently bent NiTi wires can be associated with increasing state of the surface cracking and since the NiTi wires are exposed to similar conditions as the surfaces of NiTi implants in human body. On the other hand, the potentiodynamic polarization test accelerates the corrosion processes and provides clear evidence that the corrosion resistance of bent superelastic NiTi wires degrades with oxide cracking. [ABSTRACT FROM AUTHOR]

A problem of random clinical failures of the braided esophageal NiTi stents has been addressed by performing physical simulation experiments on helical NiTi springs loaded in cyclic tension in air, water, and simulated biological fluid. Strains and stresses involved in spring deformation were analyzed through simulation by FEM implemented SMA model. It was found that the fatigue life of NiTi springs is significantly lower in fluids than in the air pointing toward the corrosion fatigue mechanism. There is, however, a fatigue limit roughly corresponding to the onset of martensitic transformation in the wire, which is not common for corrosion fatigue. It is proposed that surface TiO oxide cracking plays major role in that. Once the oxide layer on the NiTi wire surface fractures, typically during the first mechanical cycle, cracks in the oxide layer periodically open and close during subsequent mechanical cycling. This leads to the localization of mechanical and corrosion attacks under the oxide cracked regions. Microcracks within the surface oxide layer crossing over into the NiTi matrix were indeed revealed by scanning electron microscopy of FIB sections of fatigued wires. A corrosion assisted mechanism for fatigue crack nucleation at the interface between the surface oxide and NiTi matrix is proposed based on the available evidence. The approach opens a space for a better assessment of the corrosion fatigue performance of superelastic NiTi and ultimately for estimation of the lifetime of implanted braided NiTi stents. [ABSTRACT FROM AUTHOR]

Copyright of American Journal of Potato Research is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The applicability of resonant ultrasound spectroscopy on materials with weak spatial gradients in elastic coefficients and density is analyzed. It is shown that such gradients do not affect measurably the resonant spectrum but have a significant impact on the modal shapes. A numerical inverse procedure is proposed to explore the possibility of reconstructing the gradients from experimentally obtained modal shapes. This procedure is tested on synthetic data and applied to determine the gradient of the shear modulus in a continuously graded silicon nitride ceramic material. The results are in a good agreement with the gradient calculated for the examined material theoretically as well as with the results of other experimental methods. [ABSTRACT FROM AUTHOR]

In this paper, linearized approximations of both the forward and the inverse problems of resonant ultrasound spectroscopy for the determination of mechanical properties of thin surface layers are presented. The linear relations between the frequency shifts induced by the deposition of the layer and the in-plane elastic coefficients of the layer are derived and inverted, the applicability range of the obtained linear model is discussed by a comparison with nonlinear models and finite element method (FEM), and an algorithm for the estimation of experimental errors in the inversely determined elastic coefficients is described. In the final part of the paper, the linearized inverse procedure is applied to evaluate elastic coefficients of a 310 nm thick diamond-like carbon layer deposited on a silicon substrate. [ABSTRACT FROM AUTHOR]

The Phellinus igniarius group comprises several closely related wood-decaying basidiomycetes with poroid hymenophores that are sometimes difficult to identify on a morphological basis. The delimitation of pileate species belonging to the group was the subject of ITS (internal transcribed spacer of ribosomal DNA) and tefa (translation elongation factor 1 alpha) DNA sequence analyses applied to specimens from central and northern Europe. The results confirmed the distinctiveness of P. alni, P. igniarius, P. lundellii, P. nigricans, P. populicola, P. tremulae, and P. tuberculosus in Europe. The specimens of the previously distinguished species P. cinereus were found to be identical with either P. nigricans or P. alni. Thus, Phellinus cinereus does not follow the species criteria of phylogenetic species recognition. In addition, a recently described species, P. neolundellii, was grouped within the P. alni clade. The ITS and tefa analyses produced a different topology for P. populicola and P. igniarius. P. alni had the largest spectrum of hosts, including woody plants from nine families, and records on Aesculus hippocastanum and Ulmus glabra are reported for the first time. P. igniarius s.s. has been collected not only on Salix spp. as expected but also, though rarely, on Populus nigra, and it has been observed once on Malus domestica. The host specificity of the remaining species resembles previous data. An additional analysis of basidiospore dimensions did not reveal any differences between P. alni and P. igniarius, but both are distinguishable from those of P. nigricans. [ABSTRACT FROM AUTHOR]

The genus Porodaedalea is a taxonomically difficult complex of morphologically similar species that inhabit conifers. The evolutionary relationships of European species were examined using sequences of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA and of translation elongation factor 1 alpha (tefa). Our results confirm the occurrence of Porodaedalea chrysoloma, P. pini and P. laricis in Europe. P. laricis is newly reported in Fennoscandia on Picea and in the Central European mountains (Alps, High Tatras, and Bohemian forest) on Larix and Pinus spp. These specimens had been previously identified as Porodaedalea chrysoloma or Phellinus vorax (an invalidly described species). Although frequently confused, P. chrysoloma and P. laricis can be distinguished on the basis of pore morphology. We also report our finding of P. pini on Larix. In general, the tefa sequences are more variable than the ITS sequences and reveal the remarkable affinity of some Scandinavian and Central European specimens of P. laricis to those from Central Asia. Furthermore, we discovered evidence of interspecific hybridisation between P. pini and P. laricis. In addition, our study revealed the presence of an undescribed species in Morocco. Our results are compared with the results of compatibility tests in this genus that have been published previously. [ABSTRACT FROM AUTHOR]

Wild hop (Humulus lupulus L., Cannabaceae) is a dioecious perennial plant, native to the northern hemisphere and its cultural forms are mainly used in brewery. Populations of wild hop are a potential source of new features and therefore valuable for breeders. Further studies of hop populations are informative about the hop evolution as a species. Tested was the mode of inheritance, linkage and possibility of null allele presence at 8 microsatellite loci in 118 plants of one full–sib family and their genetic variability was compared with genetic diversity of 57 plants supposed to be natural population in the locality "Vinarická hora". We found that one locus does not fit to Mendelian segregation ratio, two are in linkage and in two loci the occurrence of null allele is possible. It was also found that 8 genotypes of hybrid progeny do not have expected combination of parental alleles. Heterozygote excess, low number of individual genotypes, small sampling area and population structure assigned highly similar pattern, as a structure of hybrid progeny are indicators that population "Vinarická hora" has origin in two or only few sexually propagating plants. [ABSTRACT FROM AUTHOR]

Recent experimental and theoretical improvements of resonant ultrasound spectroscopy (RUS) are summarized to investigate elastic constants of phases in shape memory alloys. The proposed inversion procedure, described in this work, is particularly suitable to reliable evaluation of the temperature dependence of elastic constants of low-symmetry ferroelastic materials which may be strongly elastically anisotropic and tend to exist in twinned forms. The method is applicable even for the evaluation of single-crystal elastic constants from RUS measurements on microtwinned crystals, since it involves a homogenization algorithm based on the macroscopic deformation response of the layered structure. This potentially allows performing meaningful acoustic studies on samples with a general submicron-size layered structure. [ABSTRACT FROM AUTHOR]

Armillaria cepistipes and A. gallica (Basidiomycota, Physalacriaceae) are morphologically similar species, and they are often nearly indistinguishable using DNA-based methods targeting the ITS region of ribosomal DNA. The aim of this study was to examine morphological and ecological features of A. cepistipes and A. gallica, and to test other DNA-based methods to distinguish the two species. Our results revealed discriminative macro- and micromorphological features between these two species, especially the presence of a distinct central pileus ocella, the shape of the annulus, the character of the velar stipe remnants and the length of the terminal cells of the pileus scales. Ecologically, A. gallica generally prefers warmer areas in lowlands (oak and alluvial forests), while A. cepistipes is more common in hilly and lower montane beech forests in Central Europe. Nevertheless, despite differences in ecological preferences, certain locations between 300 and 500 m a.s.l. are known to sympatrically support both species. The sequences of the translation elongation factor 1-alpha showed high interspecific variability, and this gene is a more appropriate candidate for distinguishing A. gallica from A. cepistipes. [ABSTRACT FROM AUTHOR]

Copyright of Agriculture / Pol'nohospodárstvo is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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The paper specifies the electrostatic spinning process of specific polymeric materials, such as polyvinylidene fluoride (PVDF), polyamide-6 (PA6, Nylon-6) and their combination PVDF/PA6. By combining nanofibers from two different materials during the spinning process, new structures with different mechanical, chemical, and physical properties can be created. The materials and their combinations were subjected to several measurements: scanning electron microscopy (SEM) to capture topography; contact angle of the liquid wettability on the sample surface to observe hydrophobicity and hydrophilicity; crystallization events were determined by differential scanning calorimetry (DSC); X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR) to describe properties and their changes at the chemical level. Furthermore, for the electrical properties of the sample, the dielectric characteristics and the piezoelectric coefficient were measured. The advantage of the addition of co-polymers was to control the properties of PVDF samples and understand the reasons for the changed functionality. The innovation point of this work is the complex analysis of PVDF modification caused by mixing with nylon PA6. Here we emphasize that the application of nylon during the spin influences the properties and structure (polarization, crystallization) of PVDF. [ABSTRACT FROM AUTHOR]

The method of inclusion of various additives into a polymer depends highly on the material in question and the desired effect. In the case of this paper, nitride salts were introduced into polyvinylidene fluoride fibers prepared by electrospinning. The resulting changes in the structural, chemical and electrical properties of the samples were observed and compared using SEM-EDX, DSC, XPS, FTIR, Raman spectroscopy and electrical measurements. The observed results displayed a grouping of parameters by electronegativity and possibly the molecular mass of the additive salts. We virtually demonstrated elimination of the presence of the γ-phase by addition of Mg(NO3)2, Ca(NO3)2, and Zn(NO3)2 salts. The trend of electrical properties to follow the electronegativity of the nitrate salt cation is demonstrated. The performed measurements of nitrate salt inclusions into PVDF offer a new insight into effects of previously unstudied structures of PVDF composites, opening new potential possibilities of crystalline phase control of the composite and use in further research and component design. [ABSTRACT FROM AUTHOR]

The article presents a study regarding the photosensitizing and photocatalytic effect of Fe(III) ions and methylene blue reactions in the photochemical degradation of 4-chlorophenoxyacetic acid with hydrogen peroxide. The study used ultraviolet-visible spectroscopy (UV-VIS) and high performance liquid chromatography (HPLC) analysis. Results showed that methylene blue was an efficient photosensitizer which was enhanced by the addition of ferric ions.

Modern material science often makes use of polyvinylidene fluoride thin films because of various properties, like a high thermal and chemical stability, or a ferroelectric, pyroelectric and piezoelectric activity. Fibers of this polymer material are, on the other hand, much less explored due to various issues presented by the fibrous form. By introducing carbon nanotubes via electrospinning, it is possible to affect the chemical and electrical properties of the resulting composite. In the case of this paper, the focus was on the further improvement of interesting polyvinylidene fluoride properties by incorporating carbon nanotubes, such as changing the concentration of crystalline phases and the resulting increase of the dielectric constant and conductivity. These changes in properties have been explored by several methods that focused on a structural, chemical and electrical point of view. The resulting obtained data have been documented to create a basis for further research and to increase the overall understanding of the properties and usability of polyvinylidene fluoride fiber composites. [ABSTRACT FROM AUTHOR]

An electrochemical amperometric ethylene sensor with solid polymer electrolyte (SPE) and semi-planar three electrode topology involving a working, pseudoreference, and counter electrode is presented. The polymer electrolyte is based on the ionic liquid 1-butyl 3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][NTf2] immobilized in a poly(vinylidene fluoride) matrix. An innovative aerosol-jet printing technique was used to deposit the gold working electrode (WE) on the solid polymer electrolyte layer to make a unique electrochemical active SPE/WE interface. The analyte, gaseous ethylene, was detected by oxidation at 800 mV vs. the platinum pseudoreference electrode. The sensor parameters such as sensitivity, response/recovery time, repeatability, hysteresis, and limits of detection and quantification were determined and their relation to the morphology and microstructure of the SPE/WE interface examined. The use of additive printing techniques for sensor preparation demonstrates the potential of polymer electrolytes with respect to the mass production of printed electrochemical gas sensors. [ABSTRACT FROM AUTHOR]

The communication presents the pieces of information of the ecosystem services estimation of the four research localities transformed from an arable land to vegetation features—bosks. These bosks should dispose several ecological functions, primarily anti-erosion measures, additionally the local biodiversity increase, unfavorable microclimate mitigation, shelter provision for small game, birds and insects, or wood and fruit production, etc. One of these benefits, the biodiversity increase, can be evaluated using the Habitat Valuation Method (HVM) and expressed by the financial value obtained on the basis of a combination of expert valuation and cost replacement method. The various combinations of local woody plants and bushes within the project Multifunction anti-erosion measures as a part of adaptable landscape were planted or sown at the project localities (South Moravia and Žďárské vrchy, Czech Republic) in March 2019. Ecosystem services evaluation was one of the fundamental outcomes of the project. The most important result was the calculated value increase of the service termed "environment for the species life providing and genetic diversity conserving". The increase means the difference between the state prior to planting and the expected target state after 30 years as specified in HVM. In total, the increase of this ecosystem service of the four bosks was valued at 2,633,809.64 CZK (97,206.48 EUR/114,399.06 USD). [ABSTRACT FROM AUTHOR]

We discuss the suitability of laser-based resonant ultrasound spectroscopy (RUS) for the characterization of soft shearing modes in single crystals of shape memory alloys that are close to the transition temperatures. We show, using a numerical simulation, that the RUS method enables the accurate determination of the c ′ shear elastic coefficient, even for very strong anisotropy, and without being sensitive to misorientations of the used single crystal. Subsequently, we apply the RUS method to single crystals of three typical examples of shape memory alloys (Cu-Al-Ni, Ni-Mn-Ga, and NiTi), and discuss the advantages of using the laser-based contactless RUS arrangement for temperature-resolved measurements of elastic constants. [ABSTRACT FROM AUTHOR]

The aim of this study is motivated by the pursuit to investigate the performance of new and as yet untested precursors such as hydrazinium chloride (N2H5Cl) and triisobutylaluminum Al(C4H9)3 in the AlN atomic layer deposition (ALD) process as well as to study effects of successive annealing on the quality of the resulting layer. Both precursors are significantly cheaper than their conventional counterparts while also being widely available and can boast easy handling. Furthermore, Al(C4H9)3 being a rather large molecule might promote steric hindrance and prevent formation of undesired hydrogen bonds. Chemical analysis is provided by X-ray photoelectron spectroscopy (XPS) and secondary-ion mass spectrometry (SIMS) techniques; surface morphology was studied using atomic force microscopy (AFM). Chlorine containing precursors such as AlCl3 are usually avoided in ALD process due to the risk of chamber contamination. However, experimental data of this study demonstrated that the use of N2H5Cl does not result in chlorine contamination due to the fact that temperature needed for HCl molecules to become reactive cannot be reached within the AlN ALD window (200–350 °C). No amount of chlorine was detected even by the most sensitive techniques such as SIMS, meaning it is fully removed out of the chamber during purge stages. A part of the obtained samples was subjected to annealing (1350 °C) to study effects of high-temperature processing in nitrogen atmosphere, the comparisons with unprocessed samples are provided. [ABSTRACT FROM AUTHOR]

Analyte flow influences the performance of every gas sensor; thus, most of these sensors usually contain a diffusion barrier (layer, cover, inlet) that can prevent the negative impact of a sudden change of direction and/or the rate of analyte flow, as well as various unwanted impacts from the surrounding environment. However, several measurement techniques use the modulation of the flow rate to enhance sensor properties or to extract more information about the chemical processes that occur on a sensitive layer or a working electrode. The paper deals with the experimental study on how the analyte flow rate and the orientation of the electrochemical sensor towards the analyte flow direction influence sensor performance and current fluctuations. Experiments were carried out on a semi-planar, three-electrode topology that enabled a direct exposure of the working (sensing) electrode to the analyte without any artificial diffusion barrier. The sensor was tested within the flow rate range of 0.1–1 L/min and the orientation of the sensor towards the analyte flow direction was gradually set to the four angles 0°, 45°, 90° and 270° in the middle of the test chamber, while the sensor was also investigated in the standard position at the bottom of the chamber. [ABSTRACT FROM AUTHOR]