1,998 research outputs found
catena-Poly[[[cis-aquadibromidocobalt(II)]-μ-(pyrazine-2-carboxylic acid)-κ3 N 1,O:N 4] monohydrate]
The title compound, {[CoBr2(C5H4N2O2)(H2O)]·H2O}n, is a one-dimensional coordination polymer which crystallizes as a monohydrate. The asymmetric unit contains one CoII atom in a distorted octahedral geometry, forming a chain parallel to [010] with the pyrazine carboxylic acid ligands coordinating on one side in a bidentate fashion through one N and one O atom, and in a monodentate fashion through a N atom, with N atoms trans, and with both ligands lying in the same plane. The bromide atoms are cis to each other, while a water molecule occupies the final octahedral coordination site. The chains are linked together though an O—H⋯Br hydrogen bonding network, and are further stabilized by an O—H⋯Br and O—H⋯O hydrogen-bonding framework with the solvent water molecule
4,4′-Dichloro-N,N′-(o-phenylene)dibenzenesulfonamide
The title compound, C18H14Cl2N2O4S2, is a diamine that is a precursor to a quinonoid bidentate redox-active ligand. The dihedral angles between the central phenyl ring and the end rings are 87.5(1) and 60.7(1)°, while the two end rings make a dihedral angle of 82.5(1)°. The crystal structure is stabilized by two weak intermolecular N—H⋯O hydrogen bonds, as well as one intramolecular C—H⋯O and one N—H⋯N hydrogen bond
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Food geographies I: relational foodscapes and the busy-ness of being more-than-food
The study of foodscapes has spread throughout geography at the same time as food scholarship has spearheaded post-disciplinary research. This report argues that geographers have taken to post-disciplinarity to explore the ways that food is ‘more-than-food’ through analyses of the visceral nature of eating and politics and the vital (re)materializations of food’s cultural geographies. Visceral food geographies illuminate what I call the ‘contingent relationalities’ of food in the critical evaluation of the indeterminate, situated politics of ‘feeling food’ and those of the embodied collectivities of obesity. Questions remain, however, about how a visceral framework might be deployed for broader critiques within foodscapes and the study of human geography. The study of food’s vital materialisms opens up investigation into the practices of the ‘makings’ of meat, food waste and eating networks. Analysis of affect, embodiment and cultural practices is central to these theorizations and suggests consideration of the multiple materialisms of food, space and eating. There is, I contend, in the more radical, ‘post-relational’ approaches to food, the need for a note of caution. Exuberant claims for the ontological, vital agency of food should be tempered by, or at least run parallel to, critical questions of the real politik of political and practical agency in light of recent struggles over austerity, food poverty and food justice
Scenario planning for the Edinburgh city region
This paper examines the application of scenario planning techniques to the detailed and daunting challenge of city re-positioning when policy makers are faced with a heavy history and a complex future context. It reviews a process of scenario planning undertaken in the Edinburgh city region, exploring the scenario process and its contribution to strategies and policies for city repositioning. Strongly rooted in the recent literature on urban and regional economic development, the text outlines how key individuals and organisations involved in the process participated in far-reaching analyses of the possible future worlds in which the Edinburgh city region might find itself
Electrical manipulation of spin states in a single electrostatically gated transition-metal complex
We demonstrate an electrically controlled high-spin (S=5/2) to low-spin
(S=1/2) transition in a three-terminal device incorporating a single Mn2+ ion
coordinated by two terpyridine ligands. By adjusting the gate-voltage we reduce
the terpyridine moiety and thereby strengthen the ligand-field on the Mn-atom.
Adding a single electron thus stabilizes the low-spin configuration and the
corresponding sequential tunnelling current is suppressed by spin-blockade.
From low-temperature inelastic cotunneling spectroscopy, we infer the
magnetic excitation spectrum of the molecule and uncover also a strongly
gate-dependent singlet-triplet splitting on the low-spin side. The measured
bias-spectroscopy is shown to be consistent with an exact diagonalization of
the Mn-complex, and an interpretation of the data is given in terms of a
simplified effective model.Comment: Will appear soon in Nanoletter
Pressure-induced Jahn-Teller suppression in Rb2CuCl4( H2O )2: Pseudo-Jahn-Teller effect
In this work we investigate the variation of the local structure around Cu2+ as well as the crystal structure in Rb2CuCl4(H2O)2 through x-ray absorption spectroscopy (XAS) and x-ray diffraction (XRD) as a function of pressure. We show that the application of pressure induces a local structural change in the Jahn-Teller (JT) CuCl4(H2O)22− complex from an axially elongated complex to a compressed one, yielding disappearance of the JT distortion related to the four in-plane Cl− ligands, which are responsible for the antiferrodistortive structure displayed by the crystal at ambient pressure. According to the Pseudo-Jahn-Teller (PJT) theory (electron-phonon coupling E⊗e), the presence of water ligands enhances the JT release at pressures well below the metallization pressure. The results are compared with recent pressure experiments on A2CuCl4 layered perovskites and heteronuclear CuCl4L2 complex series, L :Cl→H2O→NH3, and explained on the basis of the PJT model
Pressure-Induced Two-Color Photoluminescence in MnF2 at Room Temperature
A novel two-color photoluminescence (PL) is found in MnF2 at room temperature under high pressure.
Contrary to low-temperature PL, PL at room temperature is unusual in transition-metal concentrated
materials like MnF2, since the deexcitation process at room temperature is fully governed by energy
transfer to nonradiative centers. We show that room-temperature PL in MnF2 originates from two distinct
Mn2 emissions in the high-pressure cotunnite phase. The electronic structure and the excited-state
dynamics are investigated by time-resolved emission and excitation spectroscopy at high pressure
Social Network Evolution during Long-term Migration: A comparison of three case studies in the South Wales region
Ten years after Poland joined the European Union (EU), a sizable number of the once considered short-term migrants that entered the United Kingdom (UK) post-2004 have remained. From the literature, it is known that when initially migrating, social networks, composed of family and friends, are used to facilitate migration. Later, migrants’ social networks may evolve to include local, non-ethnic members of the community. Through these networks, migrants may access new opportunities within the local economy. They also serve to socialise newcomers in the cultural modalities of life in the destination country. However, what if migrants’ social networks do not evolve or evolve in a limited manner? Is cultural integration still possible under these conditions? Using data collected from three case studies in the South Wales region –Cardiff, Merthyr Tydfil & Llanelli- from 2008-2012, the aim of this article is to compare Polish migrants’ social network usage, or lack thereof, over time. This comparison will be used to understand how these social networks can be catalysts and barriers for cultural integration. The findings point to the migrants’ varied use of their local social networks, which is dependent upon their language skill acquisition and their labour market mobility in the destination country
Quasi-one-dimensional antiferromagnetism and multiferroicity in CuCrO
The bulk magnetic properties of the new quasi-one-dimensional Heisenberg
antiferromagnet, CuCrO, were characterized by magnetic susceptibility, heat
capacity, optical spectroscopy, EPR and dielectric capacitance measurements and
density functional evaluations of the intra- and interchain spin exchange
interactions. We found type-II multiferroicity below the N\'{e}el temperature
of 8.2(5) K, arising from competing antiferromagnetic nearest-neighbor () and next-nearest-neighbor () intra-chain spin exchange
interactions. Experimental and theoretical results indicate that the ratio
is close to 2, putting CuCrO in the vicinity of
the Majumdar-Ghosh point.Comment: 9 pages, 8 figures, submitted to PR
Professor Mark Wainberg
When Kuan-Teh Jeang (‘Teh’ to everyone) made the bold and prescient decision to join the earliest wave of pure online academic publishing and founded the journal Retrovirology, Mark Wainberg was one of the simplest and most obvious choices for him to invite to join the editorial team. Mark’s long established and highly respected position in the field of HIV and AIDS research added enormously to the embryonic journal’s immediate credibility and stature. Mark’s seminal achievements in recent years have been in antiretroviral therapy and viral resistance mechanisms but, in a publishing career on HIV spanning 30 years and over 550 publications, there were few areas of HIV research that he did not investigate and he brought that enormous range of expertise and experience to Retrovirology. His many achievements in the field will be described in detail by others, including his trainees and colleagues from Canada, in a shortly to be published obituary in this journal. When Teh himself was so sadly taken from us it was again Mark’s stature and reputation and his boundless enthusiasm and energy that was so important in maintaining the momentum and profile of the Journal as he took on the role of Co-Editor in Chief
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