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The growing pressure on school curricula has meant crystals and the science of crystallography have been cut from or made optional for many educational programs. This omission is a serious disservice to the history and understanding of modern sciences, given that crystallography underpins many of the greatest advancements in science over the past century, is a critical component of many modern research papers and patents, and has 29 Nobel Prizes awarded in the field. This contribution describes a simple activity to target classroom and public engagement with crystallography, using marshmallows or equivalent sweets/candy to represent atoms and cocktail sticks to represent bonds, together with examples of how crystals are studied and how they are useful. Though it has a simple basis, this activity can be extended in numerous ways to reflect the aims of the demonstrator, and a few of these are described. [ABSTRACT FROM AUTHOR]

The flexibility of the zeolite Rho framework offers great potential for tunable molecular sieving. The fully copper‐exchanged form of Rho and mixed Cu,H‐ and Cu,Na‐forms have been prepared. EPR spectroscopy reveals that Cu2+ ions are present in the dehydrated forms and Rietveld refinement shows these prefer S6R sites, away from the d8r windows that control diffusion. Fully exchanged Cu‐Rho remains in an open form upon dehydration, the d8r windows remain nearly circular and the occupancy of window sites is low, so that it adsorbs CO2 rapidly at room temperature. Breakthrough tests with 10 % CO2/40 % CH4 mixtures show that Cu4.9‐Rho is able to produce pure methane, albeit with a relatively low capacity at this pCO2 due to the weak interaction of CO2 with Cu cations. This is in strong contrast to Na‐Rho, where cations in narrow elliptical window sites enable CO2 to be adsorbed with high selectivity and uptake but too slowly to enable the production of pure methane in similar breakthrough experiments. A series of Cu,Na‐Rho materials was prepared to improve uptake and selectivity compared to Cu‐Rho, and kinetics compared to Na‐Rho. Remarkably, Cu,Na‐Rho with >2 Cu cations per unit cell exhibited exsolution, due to the preference of Na cations for narrow S8R sites in distorted Rho and of Cu cations for S6R sites in the centric, open form of Rho. The exsolved Cu,Na‐Rho showed improved performance in CO2/CH4 breakthrough tests, producing pure CH4 with improved uptake and CO2/CH4 selectivity compared to that of Cu4.9‐Rho. [ABSTRACT FROM AUTHOR]

We report the aperiodic titanate Ba10Y6Ti4O27 with a room‐temperature thermal conductivity that equals the lowest reported for an oxide. The structure is characterised by discontinuous occupancy modulation of each of the sites and can be considered as a quasicrystal. The resulting localisation of lattice vibrations suppresses phonon transport of heat. This new lead material for low‐thermal‐conductivity oxides is metastable and located within a quaternary phase field that has been previously explored. Its isolation thus requires a precisely defined synthetic protocol. The necessary narrowing of the search space for experimental investigation was achieved by evaluation of titanate crystal chemistry, prediction of unexplored structural motifs that would favour synthetically accessible new compositions, and assessment of their properties with machine‐learning models. [ABSTRACT FROM AUTHOR]

This article celebrates the remarkable changes which have occurred in the provision of abortion care in Ireland following the vote to remove the restrictive Eighth Amendment to the Constitution of Ireland in May 2018. However, it also identifies ways in which the emerging legal, ethical and clinical landscape is still impeding the conscientious provision of abortion care. It argues that in order to address these impediments, more attention needs to be paid to the ethical context for conscientious provision. This requires political leadership as well as ongoing leadership by professional bodies to develop both the clinical and the ethical guidance for conscientious provision. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell 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.)

MFM‐300(Al) shows reversible uptake of NH3 (15.7 mmol g−1 at 273 K and 1.0 bar) over 50 cycles with an exceptional packing density of 0.62 g cm−3 at 293 K. In situ neutron powder diffraction and synchrotron FTIR micro‐spectroscopy on ND3@MFM‐300(Al) confirms reversible H/D site exchange between the adsorbent and adsorbate, representing a new type of adsorption interaction. High storage capacity: MFM‐300(Al) shows reversible uptake of NH3 over 50 cycles with an exceptional packing density of 0.62 g cm−3 at 293 K. Neutron diffraction and FTIR micro‐spectroscopy confirm reversible H/D site exchange between the adsorbent and adsorbate, representing a new type of adsorption interaction. [ABSTRACT FROM AUTHOR]

Liquid oceans and ice caps, along with ice crusts, have long been considered defining features of the Earth, but space missions and observations have shown that they are in fact common features among many of the solar system's outer planets and their satellites. Interactions with rock‐forming materials have produced saline oceans not dissimilar in many respects to those on Earth, where mineral precipitation within frozen seawater plays a significant role in both determining global properties and regulating the environment in which a complex ecosystem of extremophiles exists. Since water is considered an essential ingredient for life, the presence of oceans and ice on other solar system bodies is of great astrobiological interest. However, the details surrounding mineral precipitation in freezing environments are still poorly constrained, owing to the difficulties of sampling and ex situ preservation for laboratory analysis, meaning that predictive models have limited empirical underpinnings. To address this, the design and performance characterization of a transmission‐geometry sample cell for use in long‐duration synchrotron X‐ray powder diffraction studies of in situ mineral precipitation from aqueous ice–brine systems are presented. The cell is capable of very slow cooling rates (e.g. 0.3°C per day or less), and its performance is demonstrated with the results from a year‐long study of the precipitation of the hydrated magnesium sulfate phase meridianiite (MgSO4·11H2O) from the MgSO4–H2O system. Evidence from the Mars Rover mission suggests that this hydrated phase is widespread on the present‐day surface of Mars. However, as well as the predicted hexagonal ice and meridianiite phases, an additional hydrated sulfate phase and a disordered phase are observed. [ABSTRACT FROM AUTHOR]

Herein, we report the catalytic decarboxylation of γ-valerolactone (GVL) over Zn/ZSM-5 to butene, followed by aromatization at high yield with co-feeding of water. An evaluation of the catalytic performance after prolonged periods of time showed that a water molecule is essential to maintain the decarboxylation and aromatization activities and avoid rapid catalyst deactivation. Synchrotron X-ray powder diffraction and Rietveld refinement were then used to elucidate the structures of adsorbed GVL and immobilized Zn species in combination with EXAFS and NMR spectroscopy. A new route for the cooperative hydrolysis of GVL by framework Zn−OH and Brønsted acidic sites to butene and then to aromatic compounds has thus been demonstrated. The structures and fundamental pathways for the nucleophilic attack of terminal Zn−OH sites are comparable to those of Zn-containing enzymes in biological systems. [ABSTRACT FROM AUTHOR]

The structures and functional properties of Na0.5Bi0.5TiO3- xKNbO3 (NBT-xKN) solid solutions, with x in the range from 0.01 to 0.09, were investigated using a combination of high-resolution synchrotron X-ray powder diffraction (SXPD) and ferroelectric property measurements. For low KN contents, an irreversible transformation from cubic to rhombohedral phases was observed after the application of a high electric field, indicating that the polar nanoregions (PNRs) in the unpoled state can be transformed into metastable long-range ordered ferroelectric domains in the poled state. In contrast, the near-cubic phase of the unpoled ceramics was found to be remarkably stable and was retained on cooling to a temperature of −175°C. Upon heating, the field-induced metastable ferroelectric rhombohedral phase transformed back to the nanopolar cubic state at the structural transformation temperature, TST, which was determined as approximately 225°C and 125°C for KN contents of 3% and 5% respectively. For the field-induced rhombohedral phase in the poled specimens, the pseudo-cubic lattice parameter, ap, exhibited an anomalous reduction while the inter-axial angle increased towards a value of 90° on heating, resulting in an overall increase in volume. The observed structural changes were correlated with the results of temperature-dependent dielectric, ferroelectric and depolarization measurements, enabling the construction of a phase diagram to define the stable regions of the different ferroelectric phases as a function of composition and temperature. [ABSTRACT FROM AUTHOR]

A new synchrotron X-ray powder diffraction instrument has been built and commissioned for long-duration experiments on beamline I11 at Diamond Light Source. The concept is unique, with design features to house multiple experiments running in parallel, in particular with specific stages for sample environments to study slow kinetic systems or processes. The instrument benefits from a high-brightness X-ray beam and a large area detector. Diffraction data from the commissioning work have shown that the objectives and criteria are met. Supported by two case studies, the results from months of measurements have demonstrated the viability of this large-scale instrument, which is the world's first dedicated facility for long-term studies (weeks to years) using synchrotron radiation. [ABSTRACT FROM AUTHOR]

Microporous H-ZSM-5 containing one Brønsted acid site per asymmetric unit is deliberately chosen to host pyridine, methanol, and ammonia as guest molecules. By using new-generation in situ synchrotron X-ray powder diffraction combined with Rietveld refinement, the slight but significant alteration in scattering parameters of framework atoms modified by the guest molecules enables the user to elucidate their adsorption geometries and interactions with the Brønsted acid sites in H-ZSM-5 in terms of atomic distances and angles within experimental errors. The conclusion, although demonstrated in the H-ZSM-5, is expected to be transferable to other zeolites. This approach provides a stepping stone towards the rational engineering of molecular interaction(s) with acid sites in zeolitic catalysis. [ABSTRACT FROM AUTHOR]

Background: The production of causal sentences (e.g. The house went on fire because the girl was playing with matches) is a key component of the ability to produce explanations, which in turn is an important aspect of children's developing discourse skills. While informal observations by professionals suggest that children with language impairments often have difficulties in producing (and comprehending) causal sentences, there is a dearth of systematic research evidence on the scope and characteristics of such difficulties. Aims: The study reported herein aimed to establish the scope and characteristics of the difficulties that children with language impairments have with causal sentence production. In particular, it investigated whether they have difficulties with (1) producing causal connectives (because and so), (2) producing semantically appropriate causal sentences, and (3) coordinating the production of more than one clause. Methods & Procedures: The performance of 5–7-year-old children with language impairments (the LI group, n = 30) was compared with that of typically developing chronological age peers (the CA group, n = 30) on four elicited production tasks designed to encourage children to talk about pictures of causally related events. The tasks required the children to answer causal questions, to complete and imitate causal sentences, and to produce full causal sentences. Outcomes & Results: Although the groups did not differ in the overall frequency with which they used causal connectives, the LI group produced fewer causal connectives than the CA group on tasks involving higher processing demands, as well as producing a lower percentage of semantically appropriate responses on most tasks. The LI group found imitating causal sentences more difficult than answering causal questions and completing causal sentences, whereas the CA group showed a similar level of performance across these three tasks. Conclusions: Although 5–7-year-old children with language impairments have causal expressions in their repertoire, they have marked and extensive problems in using these expressions appropriately and in producing full causal sentences even when these are modelled for them. Given the educational importance of explanation, there is a clear need for interventions to target both the semantic appropriateness of causal sentence production and the frequency of use of causal connectives, especially in contexts where children have to cope with the additional processing demands associated with producing two-clause sentences and/or with producing causal sentences autonomously. [ABSTRACT FROM AUTHOR]

Porous MFM‐300(Al) can store and release ammonia gas at room temperature without degradation over 50 cycles of adsorption and release, as reported by S. Yang, M. Schröder, and co‐workers in their Communication on page 14778 ff. A high packing density of ammonia was observed, and in situ neutron powder diffraction and synchrotron FTIR micro‐spectroscopy of ND3@MFM‐300(Al) confirmed reversible H/D site exchange between the adsorbent and adsorbate, representing a new type of adsorption interaction in MOFs. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell 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.)

Polycrystalline samples of the layered perovskite Ca3-xSrxMn2O7 (x = 0-2) are prepared by firing stoichiometric amounts of CaCO3, SrCO3, and MnO2 in an O2 stream (1340-1650 °C). [ABSTRACT FROM AUTHOR]

The adsorption geometries and interactions of pyridine molecules with the Brønsted acid sites of microporous zeolite H‐ZSM‐5 were studied. In their Communication on page 5981 ff. S. C. E. Tsang et al. report on the adsorption of pyridine molecules in H‐ZSM‐5. The image was generated by an in situ synchrotron X‐ray diffraction technique combined with Rietveld refinement, which is based on the slight but significant alternation in scattering parameters of framework atoms modified by the pyridine molecules. [ABSTRACT FROM AUTHOR]

Die Adsorptionsgeometrien …… und Wechselwirkungen von Pyridinmolekülen mit den Brønsted ‐ sauren Zentren des mikroporösen Zeoliths H ‐ ZSM ‐ 5 wurden untersucht. In ihrer Zuschrift auf S. 6085 ff. berichten S. C. E. Tsang et al. über die Adsorption von Pyridinmolekülen in H ‐ ZSM ‐ 5. Das Bild wurde mit Synchrotron ‐ Röntgenbeugung und Rietveld ‐ Verfeinerung erzeugt und basiert auf der kleinen, aber deutlichen Änderung in den Streuparametern von Gerüstatomen, die mit Pyridinmolekülen modifiziert wurden. [ABSTRACT FROM AUTHOR]