Acetylene-ammonia-18-crown-6 (1/2/1)

The title compound, C2H2·C12H24O6·2NH3, was formed by co-crystallization of 18-crown-6 and acetylene in liquid ammonia. The 18-crown-6 molecule has threefold rotoinversion symmetry. The acteylene molecule lies on the threefold axis and the whole molecule is generated by an inversion center. The two ammonia molecules are also located on the threefold axis and are related by inversion symmetry. In the crystal, the ammonia molecules are located below and above the crown ether plane and are connected by intermolecular N-H...O hydrogen bonds. The acetylene molecules are additionally linked by weak C-H...N interactions into chains that propagate in the direction of the crystallographic c axis. The 18-crown-6 molecule [occupancy ratio 0.830 (4):0.170 (4)] is disordered and was refined using a split model

How Does Democracy Cause Growth?

Recent empirical work has established that 'democracy causes growth'. In this paper, we determine the underlying institutions which drive this relationship using data from the Varieties of Democracy project. We sketch how incentives and opportunities as well as the distribution of political power shaped by underlying institutions, in combination with the extent of the market, endogenously form an 'economic blueprint for growth', which likely differs across countries. We take our model to the data by adopting novel heterogeneous treatment effects estimators, which allow for non-parallel trends and selection into institutional change, and run horse races between underlying institutions. We find that freedom of expression, clean elections, and legislative executive constraints are the foremost drivers of long-run development. Erosion of these institutions, as witnessed recently in many countries, may jeopardise the perpetual growth effect of becoming a liberal democracy we establish for the post-WWII period

In situ deformation observation via EBSD and EDS during high temperature tensile testing

Tensile testing is the backbone of mechanical characterization for materials science. The possibility to combine mechanical testing with advanced imaging and characterization methods and the option to operate at high temperatures up to 800°C opens a large variety of possibilities for materials research. In this work in situ annealing experiments are shown, where the grain growth is observed via EBSD over the course of the experiment. Different annealing states are achieved and tested after cooling to room temperature. Using the EBSD information, high Schmid factor grains can easily be identified and monitored during the in situ tensile experiment and therefore even the first yielding grains are captured. Further in situ high temperature tensile tests on steel samples up to a temperature of 800 °C are presented. An example of a tested steel specimen is shown in Figure 1. Here, slip band formation is easily observable in BSD contrast. By enabling feature tracking, the chosen region of interest remains in the field of view and is imaged correctly. Please click Download on the upper right corner to see the full abstract

LINGUIST: Language Model Instruction Tuning to Generate Annotated Utterances for Intent Classification and Slot Tagging

We present LINGUIST, a method for generating annotated data for Intent Classification and Slot Tagging (IC+ST), via fine-tuning AlexaTM 5B, a 5-billion-parameter multilingual sequence-to-sequence (seq2seq) model, on a flexible instruction prompt. In a 10-shot novel intent setting for the SNIPS dataset, LINGUIST surpasses state-of-the-art approaches (Back-Translation and Example Extrapolation) by a wide margin, showing absolute improvement for the target intents of +1.9 points on IC Recall and +2.5 points on ST F1 Score. In the zero-shot cross-lingual setting of the mATIS++ dataset, LINGUIST out-performs a strong baseline of Machine Translation with Slot Alignment by +4.14 points absolute on ST F1 Score across 6 languages, while matching performance on IC. Finally, we verify our results on an internal large-scale multilingual dataset for conversational agent IC+ST and show significant improvements over a baseline which uses Back-Translation, Paraphrasing and Slot Catalog Resampling. To our knowledge, we are the first to demonstrate instruction fine-tuning of a large-scale seq2seq model to control the outputs of multilingual intent- and slot-labeled data generation.Comment: Accepted to The 29th International Conference on Computational Linguistics (COLING 2022) October 12-17, 2022, Gyeongju, Republic of Korea https://coling2022.org

Democracy Doesn't Always Happen Over Night: Regime Change in Stages and Economic Growth

How substantial are the economic benefits from democratic regime change? We argue that democratisation is often not a discrete event but a two-stage process: autocracies enter into 'episodes' of political liberalisation which eventually culminate in regime change or not. To account for this chronology and the implicit counterfactual groups, we introduce a repeated-treatment difference-indifference implementation capturing non-parallel trends and selection into treatment. We find that modelling regime change in two stages rather than a single event yields stronger long-run growth effects. Among democratizers, experiencing repeated episodes without regime change reduces growth in democracy whereas length of episode does not

Core-shell ZnO nanorod lasers

Room-temperature ultraviolet lasing in [0001] oriented zinc oxide nanorods grown on silicon and fused silica substrates by a simple vapor transport and condensation process. These wide band-gap semiconductor nanorods form natural laser cavities with diameters varying from 150 to 350 nm and lengths up to 10 µm. Under optical excitation, surface-emitting lasing action was observed at 385 nm. The dielectric core-shell Al2O3@ZnO nanorods exhibit enhanced axial Fabry-Pérot resonating characteristics with (0001) crystal faces as mirror facets improved by a metallic reflector at one end. This metallic coating and dielectric oxide shell greatly increase near-band edge emission while reducing excitation power thresholds due to lower losses and increased optical density from improved refractive index mediated waveguiding during optical pumping

TKA following high tibial osteotomy versus primary TKA - a matched pair analysis

<p>Abstract</p> <p>Background</p> <p>High tibial osteotomy (HTO) is a well established technique for the treatment of medial osteoarthritis of the knee with varus malalignment. Results of total knee arthroplasty (TKA) after previous HTO are still discussed controversially. The aim of this study was to elucidate the clinical and radiological results as well as perioperative data of prior HTO on TKA.</p> <p>Methods</p> <p>Forty-one TKA after HTO were compared to 41 primary TKA at minimum of six years follow-up. Patients were matched according to age, gender, follow-up, etiology, and prosthetic design. Surgical data and complications were evaluated. Clinical outcome was assessed using a number of clinical scores and the visual analogue scale (VAS) for pain. X-rays were evaluated by the method of the American Knee Society. The patellar position was measured by the Insall-Salvati ratio.</p> <p>Results</p> <p>There was no significant difference in mean operation time (p = 0.47) and complication rate (p = 0.08). The Knee Score of the KSS (p = 0.0007) and the ROM (p = 0.006 for extension and p = 0.004 for flexion, respectively) were significantly better in the control group. Mid-term results of the VAS, WOMAC, Lequesne, UCLA, Feller's Patellar Score and SF-36 showed no significant difference. Femoral and tibial component alignment were similar in both groups. One tibial component showed suspect radiolucencies in the HTO group. The Insall-Salvati ratio showed three patients with patella alta and one patient with patella baja in the HTO group. At latest follow-up all implants were still in place.</p> <p>Conclusions</p> <p>Evaluating the clinical and radiological outcome, significant differences were only detected for range of motion and the Knee Score of the KSS. The present study suggests that the results of TKA with and without prior HTO are mainly identical. Although patients with a previous HTO had more complications, no statistically significant differences were noted with this group size.</p

Mixed metal-organic framework mixed-matrix membranes : insights into simultaneous moisture-triggered and catalytic delivery of nitric oxide using cryo-scanning electron microscopy

Funding: This work was supported by the European Research Council grant ADOR (Advanced Grant 787073). The authors acknowledge the EPSRC Light Element Analysis Facility Grant (EP/T019298/1) and the EPSRC Strategic Equipment Resource Grant (EP/R023751/1).The fundamental chemical and structural diversity of metal–organic frameworks (MOFs) is vast, but there is a lack of industrial adoption of these extremely versatile compounds. To bridge the gap between basic research and industry, MOF powders must be formulated into more application-relevant shapes and/or composites. Successful incorporation of varying ratios of two different MOFs, CPO-27-Ni and CuBTTri, in a thin polymer film represents an important step toward the development of mixed MOF mixed-matrix membranes. To gain insight into the distribution of the two different MOFs in the polymer, we report their investigation by Cryo-scanning electron microscopy (Cryo-SEM) tomography, which minimizes surface charging and electron beam-induced damage. Because the MOFs are based on two different metal ions, Ni and Cu, the elemental maps of the MOF composite cross sections clearly identify the size and location of each MOF in the reconstructed 3D model. The tomography run was about six times faster than conventional focused ion beam (FIB)-SEM and the first insights to image segmentation combined with machine learning could be achieved. To verify that the MOF composites combined the benefits of rapid moisture-triggered release of nitric oxide (NO) from CPO-27-Ni with the continuous catalytic generation of NO from CuBTTri, we characterized their ability to deliver NO individually and simultaneously. These MOF composites show great promise to achieve optimal dual NO delivery in real-world medical applications.Publisher PDFPeer reviewe

Resonances in a two-dimensional electron waveguide with a single delta-function scatterer

We study the conductance properties of a straight two-dimensional electron waveguide with an s-like scatterer modeled by a single delta-function potential with a finite number of modes. Even such a simple system exhibits interesting resonance phenomena. These resonances are explained in terms of quasi-bound states both by using a direct solution of the Schroedinger equation and by studying the Green's function of the system. Using the Green's function we calculate the survival probability as well as the power absorption and show the influence of the quasi-bound states on these two quantities.Comment: 5 pages, 6 figures, to be published in Physical Review