1,584 research outputs found

    Ionic Liquids as Both Solvent and Reagent in Electrophilic Addition Reactions

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    Ionic Liquids (ILs) are an environmentally friendly alternative to organic and aqueous reaction solvents. ILs do not emit hazardous gasses, are readily recycled and reused, and often do not require an excess volume of harmful reagents and purification solvents. The IL anion’s capacity to participate in a reaction as the nucleophile source is a much less understood area of this research, and it may advance the use of ILs in organic synthesis, particularly for addition and substitution reactions. Markovnikov hydrohalogenation of alkenes is one addition reaction that is generally taught as an introduction to organic chemical reactions; however, this reaction is difficult to successfully complete in the laboratory. ILs overcome the challenges posed in those traditional methods and can be used as both a reaction solvent and halogen source to successfully complete the Markovnikov addition of H-X across a double bond. The hydrohalogenation reaction was completed over 100 times using a variety of ionic liquids including imidazolium, pyridinium, pyrrolidinium, and piperidinium cations. Products were isolated using organic extraction and analyzed with NMR and GC-MS. Bromide anion ILs were consistently successful with all substrates, iodide was most efficient under nitrogen, and chloride was successful with additional heat. Hydrohalogenation of styrene was successful in all ILs used and most successful in the imidazolium-based bromide ILs. Reactions with cyclic aliphatic substrates were less successful with lower yields. Finally, hydrohalogenation of styrene derivatives was recently investigated with moderate success after modification of reaction conditions

    Unraveling complexity in changing mental health care towards person-centered care

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    BackgroundMental health care (MHC) needs to shift towards person-centered care to better meet people’s individual needs. Open Dialogue (OD) is well-aligned with this perspective and brings it into practice. This study focuses on exploring the change process within a pilot project involving three MHC teams as they transition to a person-centered OD practice. Our aim is to identify and reflect on the challenges faced by MHC professionals in adopting person-centered care, and shedding light on the underlying complexity of these challenges. By gaining a better understanding of these obstacles, we hope to contribute to the adoption of the person-centered approach in MHC practice.MethodsOur research employed a qualitative design, involving a total of 14 semi-structured interviews with MHC professionals who were either trained in OD, OD trainees, or MHC professionals without OD training. To analyze the data, we utilized a hybrid approach that combined deductive – and inductive thematic analysis.ResultsWe identified four distinctive challenges: (1) understanding and knowledge transfer, (2) (inter)personal process, (3) emotional discomfort, and (4) the need for multi-stakeholder participation and support. In practice, these challenges intersect and the appearance of and relationships between these challenges are not linear or disentangleable.ConclusionUpon careful consideration of these interdependent challenges, it became evident that embedding a person-centered approach like OD brings about systemic change, leading to an unfamiliar situation X. The research findings indicated that understanding and conveying the concept of person-centered care in practical settings poses significant challenges. The field of knowledge management helps to capture the complexity of understanding and transferring this knowledge. The change process necessitates an (inter)personal process and elicits emotional discomfort, as person-centered OD practice confronts a deeply entrenched paradigm in MHC. Achieving a shared understanding of person-centered care requires dedicated time and attention, while introducing this approach prompts broader discussions on underlying values and human rights in MHC. Current implementation efforts may underestimate or overlook these underlying values, but initiating an open dialogue can serve as an initial step in addressing the complexities

    Analytical Bethe Ansatz for A2n−1(2),Bn(1),Cn(1),Dn(1)A^{(2)}_{2n-1}, B^{(1)}_n, C^{(1)}_n, D^{(1)}_n quantum-algebra-invariant open spin chains

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    We determine the eigenvalues of the transfer matrices for integrable open quantum spin chains which are associated with the affine Lie algebras A2n−1(2),Bn(1),Cn(1),Dn(1)A^{(2)}_{2n-1}, B^{(1)}_n, C^{(1)}_n, D^{(1)}_n, and which have the quantum-algebra invariance U_q(C_n), U_q(B_n), U_q(C_n), U_q(D_n)$, respectively.Comment: 14 pages, latex, no figures (a character causing latex problem is removed

    Comparison of the ActiDes-Blue and CARELA HYDRO-DES technology for the sanitation of contaminated cooling water systems in dental units

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    Background: The hygienic-microbiological control of 6 dental units being in use for the past 16 years revealed a significantly increased microbial contamination of their cooling water system. In order to comply with the requirements of the drinking water directive (“Trinkwasserverordnung”), the commercially available production system ActiDes, producing on-site ActiDes-Blue which is based on hypochlorous acid (HOCl) and generated by anodic oxidation, was investigated

    Quantum Group Invariant Supersymmetric t-J Model with periodic boundary conditions

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    An integrable version of the supersymmetric t-J model which is quantum group invariant as well as periodic is introduced and analysed in detail. The model is solved through the algebraic nested Bethe ansatz method.Comment: 11 pages, LaTe

    The algebraic Bethe ansatz for open vertex models

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    We present a unified algebraic Bethe ansatz for open vertex models which are associated with the non-exceptional A2n(2),A2n−1(2),Bn(1),Cn(1),Dn(1)A^{(2)}_{2n},A^{(2)}_{2n-1},B^{(1)}_n,C^{(1)}_n,D^{(1)}_{n} Lie algebras. By the method, we solve these models with the trivial K matrix and find that our results agree with that obtained by analytical Bethe ansatz. We also solve the Bn(1),Cn(1),Dn(1)B^{(1)}_n,C^{(1)}_n,D^{(1)}_{n} models with some non-trivial diagonal K-matrices (one free parameter case) by the algebraic Bethe ansatz.Comment: Latex, 35 pages, new content and references are added, minor revisions are mad

    Phase transition in an asymmetric generalization of the zero-temperature Glauber model

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    An asymmetric generalization of the zero-temperature Glauber model on a lattice is introduced. The dynamics of the particle-density and specially the large-time behavior of the system is studied. It is shown that the system exhibits two kinds of phase transition, a static one and a dynamic one.Comment: LaTeX, 9 pages, to appear in Phys. Rev. E (2001
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