Search

Presently used experimental techniques for the characterization of tensile and compressive behavior of active layers in lithium-ion batteries have limitations of different kinds. This is particularly true for measurements of compressive properties. Furthermore, the characterizations of time-dependent stress-strain behavior are largely missing. In order to characterize the stress-strain relationship for a dry cathode active layer in lithium-ion batteries, a mechanical testing method is presented that previously has been applied to the testing of optical fibers. The method is based on U-shaped bending of single-side coated aluminum foils, which enables separate measurements of tensile and compressive properties. In particular, the method has clear advantages for measurements of compressive properties in comparison to previously reported techniques. Relaxation experiments are also conducted in order to characterize the time-dependent properties of the dry active layer and to check if these effects could explain the measured hysteresis. It is found that the elastic modulus in compression is significantly larger than the elastic modulus in tension and that the compressive modulus increases with strain level. Contrary, the tensile modulus is approximately independent of strain. Furthermore, hysteresis effects are present at loading-unloading measurements, both for tension and compression. The low values of the measured elastic moduli show that the electrode properties are largely controlled by the binder and carbon additives. It is concluded that the development of particle-particle contacts most likely is the reason for the higher modulus in compression in comparison to tension. The time-dependent effects are significant, primarily for shorter time scales, which explains the relaxation behavior, but they cannot fully explain the hysteresis effects. Most likely non-linear micro-mechanisms do contribute as well. [ABSTRACT FROM AUTHOR]

The REDD+ scheme of the United Nations intends to offer developing countries financial incentives to reduce the rates of deforestation and forest degradation for reducing global CO emissions. This is combined with building carbon stocks in existing wooded ecosystems and fostering other soil, biodiversity and water conservation objectives. Successful application of REDD+ to the Xylophone Triangle of West Africa faces substantial challenges and risks to both meeting REDD+ objectives and to the local people's rights and livelihoods. The transnationality of the culturally coherent area requires collaboration of three national governments. The opportunities, however, are great to capitalize on the region's biodiversity, the well-developed traditional ecological knowledge and the use of local medicinal plants as an integral part of the agro-ecosystem. Possibilities open to, not only sequester carbon, but also to increase the resilience of the ecosystem and of independent rural livelihoods in the face of climate change and globalization. [ABSTRACT FROM AUTHOR]

The trapping, manipulation and conversion of light by nanostructures are of great interest at present, both scientifically and for applications. An important part of this is the interaction of light with optical waveguides, mediated by plasmon-active metal-nanoparticle arrangements. Strong coupling of incident light to waveguide-plasmon polaritons has been demonstrated by means of nanoparticle lattices, as well as by disordered metal-island film distributions, and it has further been used to enhance the efficiency of solar cells and LED (ref. 6). Here, we show that a disordered metal-nanoparticle layer, supported by a 40-nm-thick Si3N4 membrane, enables coupling of a single laser pulse to the waveguided modes of the membrane, and that, under certain conditions, this leads to reorganization of the nanoparticle ensemble into ordered one- and two-dimensional grating patterns. Such self-patterning has not been observed before, and could lead to useful methods for the fabrication of complex nanostructures and advanced photonic devices. [ABSTRACT FROM AUTHOR]

The ability to control optical effects at the nanoscale is a challenge that could be of great importance for a range of photonic applications. However, progress requires a deep understanding of the relationship between near-field and far-field properties of the individual elements of the nanostructure, as well as of the role of nano-optical interactions. Here, we show that the strong interaction between nanoholes in optically thin metal films can be used to readily tune their spectral response and visibility. Control of this interaction in short chains of nanoholes enables either amplification or almost total suppression of the scattered light. The phenomena are interpreted in terms of hole coupling mediated via antisymmetric surface plasmon polaritons, which makes the nanohole chains effectively behave as linear wire antennas. [ABSTRACT FROM AUTHOR]

High resolution OVRO CO 1-0 observations of the inner 30? in the LINER galaxy NGC 5218 reveal the presence of a double centrally peaked molecular concentration with extensions out to a radius of 12?. The molecular mass detected is 2.4 × 109M? and the gas surface density is high, ~3000M? pc square in the inner 500 pc. The SFR is 2-3M? yr-1 and the SFE is ~13, which are low or moderate values for that gas surface density. We interpret the inner feature as a rotating molecular ring with a radius of ~ 200 pc. We furthermore suggest that the LINER activity in NGC 5218 is not caused by an aging starburst, but by a buried AGN. [ABSTRACT FROM AUTHOR]

Focuses on landscape change patterns in mountains, land use and environmental diversity. Features of the summer farming system, developed in mountains; Examples from human shaped ecosystems in mountains where the fragmentation of semi-natural habitats is addressed.

Interface-engineered ramp-edge junctions (IEJ) have been characterised by high-resolution transmission electron microscopy, X-ray analysis and electron energy loss spectroscopy. The IEJ are prepared by plasma etching an ion-milled YBa2 Cu3 O7-δ (YBCO) ramp-edge and subsequently a top YBCO layer is deposited. The results show that the YBCO at the plasma-etched interface has a modified structure. The modified barrier structure has a pseudo cubic unit cell which is rotated 45° around the [001] axis with respect to the underlying YBCO. [ABSTRACT FROM AUTHOR]

Ramp-type Josephson junctions with barrier layers of Ga doped PrBa2 Cu3 O7-δ have been investigated using scanning and transmission electron microscopy. The microstructures have been correlated to the ramp geometry. The junctions exhibited low excess current. This is believed to be due to the uniform thickness of barrier layer deposited on the ion-milled edges. The uniformity of the barrier is presumed to be a result of the smooth ramp, which promoted uniform nucleation and epitaxial growth. [ABSTRACT FROM AUTHOR]

Ley cultivation by ploughing and fertilising constitute a severe impact on plant community patterns in semi-natural subalpine communities. Since the 1950ties, such cultivation have been an important part of the agroecosystem in subalpine areas in Norway, and regularly practised. Today, several former leys are left for grazing management. Plant species diversity and heterogeneity was studied in subalpine grasslands in Valdres, southern Norway (ca. 950 m a.s.l.) at different successional phases after ploughing. Fourteen sites (100 m2) varying from recently ploughed grasslands (3–5 years at phase 1) to unploughed sites were used to construct a temporal gradient by a space for time substitution. Small-scale species diversity (0.25m2) of vascular plants increased continuously with the time since last ploughing, while the variation in gamma-diversity was minor among late successional phases 3–5 (>23–28 years, 32–39 years and unploughed sites) after an evident increase from phase 1–3. The number of exclusive species peaked within unploughed sites (10), and included perennial herbs (Antennaria alpina, Hieracium auricula, Viola canina), spore-producing species (Botrychium lunaria, Selaginella selaginoides) and woody life-forms. Species diversity of cryptogams was low at both a small and large scale within successional phases 1 and 2 (<12 years). Small scale cryptogam diversity peaked at the unploughed sites, while gamma diversity peaked at phase 3 (23–28 years). This intermediate phase 3 also had the highest number of exclusive species (12) which exceeded unploughed sites (8). A coarse spatial structure of cryptogams at phase 3 was indicated by a low mean of species distribution. The soil of uncultivated grasslands (phase 5) was, at the end of the growing season (mid August), quite base-rich with a higher content for all measured nutrients as compared to intermediate phases of continuity (phase 3 and 4) The exception was nitrate which was not detectable from phase 3 to 5, and available phosphate which peaked at an intermediate phase of succession (phase 3 and 4). Heterogeneity of vascular plants reached a minimum value at the intermediate phase (3) while cryptogam heterogeneity peaked at this phase. Differences in heterogeneity cycles among these species groups implies that structuring processes act on different temporal scales for vascular plants as compered to cryptogams along the successional gradient in grasslands after ploughing. The importance of continuity in management for plant biodiversity in subalpine grasslands is finally discussed from a conservation point of view. [ABSTRACT FROM AUTHOR]

Twenty-five patients with fractures of the lower leg treated by closed reduction and plaster fixation were examined an average of 7 years and 8 months after trauma. The end result was assessed according to the following: (1) The patient's own opinion; (2) clinical examination including comparing range of motion in knee and ankle in the fractured and non-fractured leg, leg length discrepancy, malrotation of the injured extremity and muscle force analysis; (3) radiological examination. All fractures had healed after a mean of 13.4 weeks. Twelve of the 25 patients had no complaints. Subjective and objective assessment of the end results were in good correlation. Only eight patients had remaining radiological displacement, in only one of which it was severe. The slight remaining malpositionings did not influence the final functional result. The muscle force analysis showed that fractures caused by high-energy trauma also brought permanent reduction of muscular strength to the fractured extremity. [ABSTRACT FROM AUTHOR]

Two data sets, one from the 1960s and one from 1990, from continuously managed semi-natural meadows (semi-natural grasslands used for hay-cutting) in Småland, southern Sweden, were analysed to describe the vegetation and in an attempt to characterise changes that have occurred in the vegetation. Based on a classification of the data set, nine plant communities were recognised. The main vegetational differences, as revealed by an ordination, were due to variation in soil moisture, which ranged from wet to dry. During the investigation period, the amount of hay meadow area decreased, particularly the area of wet-moist meadows. In addition, the total variation in the vegetation diminished, and three plant communities more or less disappeared. The turnover index of species in the data set was 36%, and most of the species that were lost had initially been uncommon. Lost species included rare taxa, such as Gentianella campestris and Linum catharticum, while the new species tended to be common in the region. Annual and biennial species accounted for a greater proportion of the lost taxa than did perennial species. The mean cover of species per plot and the relative abundance of graminoids per plot increased. The recorded changes in the vegetation may be related to the increased loads of nitrogen pollutants as well as to a decrease in management intensity. The diminished area is related to changes in land-use. The meadow sites in Småland have been part of a landscape rich in grasslands, but today they have a more or less relict status. They differ from grasslands found elsewhere in Sweden and Scandinavia. In Sweden, the majority (68%) of endangered vascular plants belong to the agricultural landscape. To ensure the survival of individual species it is important to preserve all types of meadows, not only a few selected ones, since no two meadows are alike. [ABSTRACT FROM AUTHOR]

The Cervidae show one of the largest variations in chromosome number found within a mammalian family. The five species of the deer family which are the subject of this study vary in chromosome number from 2n=70 to 2n=6. Digestion with the restriction enzymes EcoRI, HpaII, HaeIII and MspI reveals that there is a series of highly repetitive sequences forming similar band patterns in the different species. To obtain information on the degree of homology among these conserved sequences we isolated a HpaII restriction fragment of approximately 990 base pairs from reindeer DNA. This DNA sequence wasP-labelled and hybridized by the Southern blot technique to DNAs cleaved with HpaII and HaeIII from the reindeer and four other Cervidae species. Hybridization to specific restriction fragments was recorded in all species. The patterns of hybridization showed a higher degree of similarity between reindeer, elk and roe deer than between reindeer and the Asiatic species (fallow deer and muntjac). Homologies are still present between the highly repetitive sequences of the five species despite the drastic reorganization that led to a change in chromosome number from 6 to 70. [ABSTRACT FROM AUTHOR]

Copyright of International Orthopaedics 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.)

Copyright of International Orthopaedics 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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.)

Copyright of Zeitschrift für Physik 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 observation of a high-mobility two-dimensional electron gas between two insulating complex oxides, especially LaAlO3/SrTiO3, has enhanced the potential of oxides for electronics. The occurrence of this conductivity is believed to be driven by polarization discontinuity, leading to an electronic reconstruction. In this scenario, the crystal orientation has an important role and no conductivity would be expected, for example, for the interface between LaAlO3 and (110)-oriented SrTiO3, which should not have a polarization discontinuity. Here we report the observation of unexpected conductivity at the LaAlO3/SrTiO3 interface prepared on (110)-oriented SrTiO3, with a LaAlO3-layer thickness-dependent metal-insulator transition. Density functional theory calculation reveals that electronic reconstruction, and thus conductivity, is still possible at this (110) interface by considering the energetically favourable (110) interface structure, that is, buckled TiO2/LaO, in which the polarization discontinuity is still present. The conductivity was further found to be strongly anisotropic along the different crystallographic directions with potential for anisotropic superconductivity and magnetism, leading to possible new physics and applications. [ABSTRACT FROM AUTHOR]

Conventional electron spectroscopy is an established one-electron-at-the-time method for revealing the electronic structure and dynamics of either valence or inner shell ionized systems. By combining an electron-electron coincidence technique with the use of soft X-radiation we have measured a double ionisation spectrum of the allene molecule in which one electron is removed from a C1s core orbital and one from a valence orbital, well beyond Siegbahns Electron-Spectroscopy-for-Chemical-Analysis method. This core-valence double ionisation spectrum shows the effect of symmetry breaking in an extraordinary way, when the core electron is ejected from one of the two outer carbon atoms. To explain the spectrum we present a new theoretical approach combining the benefits of a full self-consistent field approach with those of perturbation methods and multi-configurational techniques, thus establishing a powerful tool to reveal molecular orbital symmetry breaking on such an organic molecule, going beyond Löwdins standard definition of electron correlation., (© 2023. The Author(s).)