A structural study of copper(II) carboxylates: Crystal structure and physical characterisation of [Cu2(2-bromopropanoato)4(caffeine)2]

Based on the bond-valence sum model the continual transition between the bidentate and monodentate bonding mode of carboxylato group and minimum of Cu-O bond lengths were estimated. The dependence of Cu⋯Cu separation on Cu-N bond length in binuclear Cu(II) carboxylates with caffeine were derived and fitted to the observed data. The crystal structure of [Cu2(2-bromopropanoato)4(caffeine)2] has been determined by X-ray crystallography. The structure consists of centrosymmetric binuclear units where the two Cu atoms are coordinated by four disordered bridging 2-bromopropionates and two caffeine ligands at the apices of a bicapped square prism. Both 2-bromopropionates show disorder of their -Br and -CH3 substituents. Stacking π·π interactions between the adjacent caffeine molecules link the complex units in 1-D networks. The binuclear structure of the studied compound is consistent with magnetic data and EPR spectru

Radial Distribution of Distant Trans-Neptunian Objects Points to Sun's Formation in a Stellar Cluster

The Scattered Disk Objects (SDOs) are a population of trans-Neptunian bodies with semimajor axes $50< a \lesssim 1000$ au and perihelion distances $q \gtrsim 30$ au. The detached SDOs with orbits beyond the reach of Neptune (roughly $q>35$~au) are of special interest here as an important constraint on the early evolution of the outer Solar System. The semimajor axis profile of detached SDOs at 50--500~au, as characterized from the Dark Energy Survey (DES), is radially extended, but previous dynamical models of Neptune's early migration produce a relatively compact profile. This problem is most likely related to Sun's birth environment in a stellar cluster. We perform new dynamical simulations that account for cluster effects and show that the orbital distribution of SDOs can be explained if a particularly close stellar encounter occurred early on (e.g., M dwarf with the mass $\simeq 0.2$ $M_\odot$ approaching the Sun at $\simeq 200$ au). For such an encounter to happen with a reasonably high probability the Sun must have formed in a stellar cluster with $\eta T \gtrsim 10^4$ Myr pc$^{-3}$, where $\eta$ is the stellar number density and $T$ is the Sun's residence time in the cluster

Multi-academy Trusts: do they make a difference to pupil outcomes?

This report is published as a supplement to the main project research report, Hierarchy, Markets and Networks: Analysing the ‘self-improving school-led system’ agenda in England and the implications for schools. The main project report analyses how schools in England have interpreted and begun to respond to the government’s ‘self-improving school-led system’ (SISS) policy agenda, an overarching narrative for schools policy since 2010 that encompasses an ensemble of reforms including academies, multi-academy trusts (MATs) and teaching school alliances (TSAs). The statistical analysis of MAT impact on pupil attainment and progress set out in this supplementary report is the first published analysis to compare schools in MATs over a three-year period with standalone academies and maintained schools with similar characteristics and levels of prior pupil attainment. The analysis set out here uses 2013–15 attainment data and 2016 data on the composition of MATs. Our finding in this paper that there is no positive impact from MAT status overall is largely consistent with other recent studies (Hutchings and Francis, 2017; Andrews, 2019). Where this report provides significant new evidence is in terms of MAT size, as we show that pupils in small and mid-sized MATs tend to perform better, on average, than their peers in comparable maintained schools in both phases and, in the primary phase, than comparable standalone academies. Conversely, secondary school pupils in larger MATs (with 16+ schools) tend to do worse compared to those in both standalone academies and maintained schools. These findings suggest that the economic drive for MAT growth promoted in contemporary policy may well be in tension with an educational argument for smaller groupings of schools

Proposta de utilização de embalagem Flexitank na indústria de suplemento animal

Orientador : Prof. Dr. Roberto CerviMonografia (especialização) - Universidade Federal do Paraná, Curso de MBA em Gerencia de Sistemas Logísticos.Inclui referênciasResumo : O presente artigo visa descrever a viabilidade na implementação da embalagem flexitank, num estudo de caso à realizar-se em uma empresa situada em Biguaçu – SC. Seu segmento refere-se à produção de suplemento animal com venda no mercado interno e exportação de seus produtos. Atualmente, as exportações são realizadas através do envase de seus produtos utilizando embalagens do tipo IBC em seus embarques internacionais. O estudo propõe a alteração da embalagem atual por embalagens do tipo flexitank, visando mais eficiência no processo e redução de custos em todo o fluxo operacional. No decorrer do artigo, define-se o conceito de embalagem, sua importância e principais funções e aplicações na indústria e na logística. Descreve-se também, os custos operacionais que podem ocorrer em todo o fluxo de carregamento e sugere a capacitação e treinamento de pessoal adequado para acompanhamento de todos os embarques. A metodologia empregada nesta pesquisa foi do tipo quantitativo, exploratório, documental, sendo um estudo de caso. Com a análise dos dados obtidos, através de pesquisa realizada na organização, demonstrou-se que a mudança, do tipo de embalagem utilizada na empresa no processo de embarque, seria efetiva e acertada, pois diminuiria os custos operacionais e de tempo de trabalho, aumentando a eficiência da organização

A Bayesian approach to Mendelian randomization with multiple pleiotropic variants.

We propose a Bayesian approach to Mendelian randomization (MR), where instruments are allowed to exert pleiotropic (i.e. not mediated by the exposure) effects on the outcome. By having these effects represented in the model by unknown parameters, and by imposing a shrinkage prior distribution that assumes an unspecified subset of the effects to be zero, we obtain a proper posterior distribution for the causal effect of interest. This posterior can be sampled via Markov chain Monte Carlo methods of inference to obtain point and interval estimates. The model priors require a minimal input from the user. We explore the performance of our method by means of a simulation experiment. Our results show that the method is reasonably robust to the presence of directional pleiotropy and moderate correlation between the instruments. One section of the article elaborates the model to deal with two exposures, and illustrates the possibility of using MR to estimate direct and indirect effects in this situation. A main objective of the article is to create a basis for developments in MR that exploit the potential offered by a Bayesian approach to the problem, in relation with the possibility of incorporating external information in the prior, handling multiple sources of uncertainty, and flexibly elaborating the basic model

Photo-oxygenation of Indene and 1,2-Dihydronaphthalene: Formation of 1,2-Dioxetanes and 1,2,4-Trioxanes

The methylene blue (MB)-sensitized photo-oxygenation of indene (1) in CH3OH gave trans-2-hydroperoxy-1-methoxyindane (9), homophthalaldehyde (4), and its cyclic acetal 8. The same reaction conducted in acetaldehyde gave only 4. Repetition of the photo-oxygenation of 1 in slightly acidic aq. acetone (1:9) gave essentially trans-2-hydroperoxy-1-hydroxyindane (14) together with some cis-5,6-dihydro-3,3-dimethyl-1,2,4-trioxinol[1,2-e]indene. The MB-sensitized photo-oxygenation of 1,2-dihydronaphthalene (16) in CH3OH gave l,4-dihydro-1-hydroperoxynaphthalene (17) and trans-l,2,3,4-tetrahydro-2-hydroperoxy-1-methoxynaphthalene (19). In acetaldehyde, 16 furnished only 17. In aq. acetone (1:9) 16 gave 17 and trans-2-hydroperoxy-1-hydroxy-1,2,3,4-tetrahydronaphthalene (23). Product compositions were rationalized in terms of the 2-peroxides of the 1-cation of 1 and 16, namely 11 and 20. Treatment of 23 with aldehydes and ketones on catalysis with Amberlyst-15 or trimethylsilyl trifluoromethanesulfonate afforded the trans-fused 1,2,4-trioxanes 25. The 1,2-dioxetanes of 1 and 16 condensed with acetaldehyde on catalysis with CF3COOH to give the cis-fused 1,2,4-trioxanes 12 and 22