[3-(5-Hy­droxy-5H-dibenzo[a,d]cyclo­hepten-5-yl)prop­yl]dimethyl­ammonium 3-carboxyprop-2-enoate

In the cation of the title salt, C20H24NO+·C4H3O4 −, the N atom in the dimethyl­ammonium group is protonated. The dihedral angle between the mean planes of the two six-membered rings fused to the cyclo­hepten-5-yl ring is 54.4 (1)°. An intra­molecular O—H⋯O hydrogen bond occurs in the anion. The crystal packing is stabilized by inter­molecular O—H⋯O and N—H⋯(O,O) hydrogen bonds and weak C—H⋯O inter­actions, forming a two-dimensional network

2-Chloro-N-[2-(2-fluoro­benzo­yl)-4-nitro­phen­yl]-N-methyl­acetamide

The title compound, C16H12ClFN2O4, crystallizes with two mol­ecules in the asymmetric unit in which the dihedral angles between the mean planes of the two benzene rings are 65.1 (7) and 65.6 (6)°. In each mol­ecule, the nitro group displays rotational disorder over two orientations in a 0.503 (11):0.497 (11) ratio and the Cl atom is disordered in a 0.432 (5):0.568 (5) ratio. In one mol­ecule, the F atoms is statistically disordered over two positions. The crystal packing features weak inter­molecular C—H⋯O and C—H⋯Cl inter­actions, which form a layered network

Machine-learning-corrected quantum dynamics calculations

Quantum scattering calculations for all but low-dimensional systems at low energies must rely on approximations. All approximations introduce errors. The impact of these errors is often difficult to assess because they depend on the Hamiltonian parameters and the particular observable under study. Here, we illustrate a general, system and approximation-independent, approach to improve the accuracy of quantum dynamics approximations. The method is based on a Bayesian machine learning (BML) algorithm that is trained by a small number of rigorous results and a large number of approximate calculations, resulting in ML models that accurately capture the dependence of the dynamics results on the quantum dynamics parameters. Most importantly, the present work demonstrates that the BML models can generalize quantum results to different dynamical processes. Thus, a ML model trained by a combination of approximate and rigorous results for a certain inelastic transition can make accurate predictions for different transitions without rigorous calculations. This opens the possibility of improving the accuracy of approximate calculations for quantum transitions that are out of reach of rigorous scattering calculations.Comment: 6 pages, 4 figure

Combined DC-Link Fed Parallel-VSI-Based DSTATCOM for Power Quality Improvement of a Solar DG Integrated System

In present day power systems, Power Quality (PQ) issues are causing great concern owing to the increased use of power electronic controlled drives and fluctuating and other non-linear loads. This problem is further aggravated by a steady increase in the integration of renewable energy-based Distribution Generation (DG), employing power electronic converters to distribution systems. Custom power devices with suitable control strategies provide an effective solution to these power quality issues. In this work, a typical three-phase distribution system supplying non-linear load and with DG integration is considered. A shunt connected DSTATCOM at PCC of the system is employed to mitigate power quality concerns. Initially, a parallel-VSI based DSTATCOM configuration, employing individual DC-Link and working basically on the principle of current sharing, has been proposed. The analysis is carried out for variable load conditions for PQ enhancement making use of a more effective control theory viz. Instantaneous Real-Reactive Power (IRP) theory for the generation of suitable switching patterns to the individual VSIs of the parallel DSTATCOM. Further, an improvement over the above configuration viz. combined/common DC-Link-fed parallel DSTATCOM is proposed. This configuration has the advantages of minimized sensing elements, reliable operation and low-cost compensation. A similar analysis is carried out for PQ improvement, making use of the same IRP theory with some modifications (known as MIRP theory). The effectiveness of this configuration is established from the simulation results. In all the above cases, the analyses are carried out using MATLAB/Simulink platform and the simulation results are presented in detail. Thus, the proposed parallel VSIs-based DSTATCOM configurations employing suitable control strategies provide effective solutions for power quality issues under varying load conditions in conventional distribution systems

Tramadol hydro­chloride–benzoic acid (1/1)

In the cation of the title co-crystal salt {systematic name: [2-hydroxy-2-(3-meth­oxy­phen­yl)cyclo­hexyl­meth­yl]dimethyl­aza­nium chloride–benzoic acid (1/1)}, C16H31NO2 +·Cl−·C7H6O2, the N atom is protonated and the six-membered cyclo­hexane ring adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the benzene rings in the cation and the benzoic acid mol­ecule is 75.5 (9)°. The crystal packing is stabilized by weak inter­molecular O—H⋯Cl, N—H⋯Cl and C—H⋯π inter­actions, forming a two-dimensional chain network along the b axis. The benzoic acid mol­ecule is not involved in the usual head-to-tail dimer bonding, but instead is linked to the ammonium cation through mutual hydrogen-bonding inter­actions with the chloride anion

Six-minute walk distance after coronary artery bypass grafting compared with medical therapy in ischaemic cardiomyopathy

Background: In patients with ischaemic left ventricular dysfunction, coronary artery bypass surgery (CABG) may decrease mortality, but it is not known whether CABG improves functional capacity. Objective: To determine whether CABG compared with medical therapy alone (MED) increases 6 min walk distance in patients with ischaemic left ventricular dysfunction and coronary artery disease amenable to revascularisation. Methods: The Surgical Treatment in Ischemic Heart disease trial randomised 1212 patients with ischaemic left ventricular dysfunction to CABG or MED. A 6 min walk distance test was performed both at baseline and at least one follow-up assessment at 4, 12, 24 and/or 36 months in 409 patients randomised to CABG and 466 to MED. Change in 6 min walk distance between baseline and follow-up were compared by treatment allocation. Results: 6 min walk distance at baseline for CABG was mean 340±117 m and for MED 339±118 m. Change in walk distance from baseline was similar for CABG and MED groups at 4 months (mean +38 vs +28 m), 12 months (+47 vs +36 m), 24 months (+31 vs +34 m) and 36 months (−7 vs +7 m), P>0.10 for all. Change in walk distance between CABG and MED groups over all assessments was also similar after adjusting for covariates and imputation for missing values (+8 m, 95% CI −7 to 23 m, P=0.29). Results were consistent for subgroups defined by angina, New York Heart Association class ≥3, left ventricular ejection fraction, baseline walk distance and geographic region. Conclusion: In patients with ischaemic left ventricular dysfunction CABG compared with MED alone is known to reduce mortality but is unlikely to result in a clinically significant improvement in functional capacity

9,9-Dimethyl-9,10-dihydroanthracene

In the title compound, C16H16, the central benzene ring adopts a boat conformation, with a dihedral angle of 34.7 (9)° between the mean planes of the two fused benzene rings. The two methyl groups at the apex of the central benzene ring are in axial and equatorial conformations. The crystal packing is stabilized by weak C—H⋯π inter­molecular inter­actions

(2E)-1-(1,3-Benzodioxol-5-yl)-3-(2-bromo­phen­yl)prop-2-en-1-one

The mol­ecule of the title compound, C16H11BrO3, is essentially planar with a maximum deviation of 0.178 (4) Å and the configuration of the keto group with respect to the olefinic double bond is typically s-cis. In the crystal structure, inter­molecular Br⋯O inter­actions [3.187 (3)Å] give rise to chains parallel to the b axis. Adjacent chains are further linked along the a axis by C—H⋯π inter­actions. The crystal studied was a racemic twin with a 0.595 (13):0.405 (13) ratio