84 research outputs found
Product and Packaging Innovation: Attitudes, Behaviours, and Strategies for Sustainable Packaging
The report presents findings of a large consumer survey on packaging, environmental issues and the media, conducted by Dr Martina Topic, Ben Mitchell and Olga Munroe. The survey was conducted on a representative sample of 1000 respondents, and forms a backbone of the future research and research outputs currently being prepared. This report has been distributed to the clients of the Retail Institute and will be presented at the Annual Retail Institute conference in September 2018
KRb Feshbach Resonances: Modeling the interatomic potential
We have observed 28 heteronuclear Feshbach resonances in 10 spin combinations
of the hyperfine ground states of a 40K 87Rb mixture. The measurements were
performed by observing the loss rates from an atomic mixture at magnetic fields
between 0 and 700 G. This data was used to significantly refine an interatomic
potential derived from molecular spectroscopy, yielding a highly consistent
model of the KRb interaction. Thus, the measured resonances can be assigned to
the corresponding molecular states. In addition, this potential allows for an
accurate calculation of the energy differences between highly excited levels
and the rovibrational ground level. This information is of particular relevance
for the formation of deeply bound heteronuclear molecules. Finally, the model
is used to predict Feshbach resonances in mixtures of 87Rb combined with 39K or
41K.Comment: 4 pages, 3 figure
Spontaneous breaking of spatial and spin symmetry in spinor condensates
Parametric amplification of quantum fluctuations constitutes a fundamental
mechanism for spontaneous symmetry breaking. In our experiments, a spinor
condensate acts as a parametric amplifier of spin modes, resulting in a twofold
spontaneous breaking of spatial and spin symmetry in the amplified clouds. Our
experiments permit a precise analysis of the amplification in specific spatial
Bessel-like modes, allowing for the detailed understanding of the double
symmetry breaking. On resonances that create vortex-antivortex superpositions,
we show that the cylindrical spatial symmetry is spontaneously broken, but
phase squeezing prevents spin-symmetry breaking. If, however, nondegenerate
spin modes contribute to the amplification, quantum interferences lead to
spin-dependent density profiles and hence spontaneously-formed patterns in the
longitudinal magnetization.Comment: 5 pages, 4 figure
Radio frequency association of heteronuclear Feshbach molecules
We present a detailed analysis of the production efficiency of weakly bound
heteronuclear KRb-Feshbach molecules using radio frequency association in a
harmonic trap. The efficiency was measured in a wide range of temperatures,
binding energies and radio frequencies. A comprehensive analytical model is
presented, explaining the observed asymmetric spectra and achieving good
quantitative agreement with the measured production rates. This model provides
a deep understanding of the molecule association process and paves the way for
future experiments which rely on Feshbach molecules e.g. for the production of
deeply bound molecules.Comment: 5 pages, 4 figure
Parametric amplification of vacuum fluctuations in a spinor condensate
Parametric amplification of vacuum fluctuations is crucial in modern quantum
optics, enabling the creation of squeezing and entanglement. We demonstrate the
parametric amplification of vacuum fluctuations for matter waves using a spinor
F=2 Rb-87 condensate. Interatomic interactions lead to correlated pair creation
in the m_F= +/- 1 states from an initial unstable m_F=0 condensate, which acts
as a vacuum for m_F unequal 0. Although this pair creation from a pure m_F=0
condensate is ideally triggered by vacuum fluctuations, unavoidable spurious
initial m_F= +/- 1 atoms induce a classical seed which may become the dominant
triggering mechanism. We show that pair creation is insensitive to a classical
seed for sufficiently large magnetic fields, demonstrating the dominant role of
vacuum fluctuations. The presented system thus provides a direct path towards
the generation of non-classical states of matter on the basis of spinor
condensates.Comment: 5 pages, 4 figure
Multi-resonant spinor dynamics in a Bose-Einstein condensate
We analyze the spinor dynamics of a Rb-87 F=2 condensate initially prepared
in the m_F=0 Zeeman sublevel. We show that this dynamics, characterized by the
creation of correlated atomic pairs in m_F=+/-1, presents an intriguing
multi-resonant magnetic field dependence induced by the trap inhomogeneity.
This dependence is directly linked to the most unstable Bogoliubov spin
excitations of the initial m_F = 0 condensate, showing that, in general, even a
qualitative understanding of the pair creation efficiency in a spinor
condensate requires a careful consideration of the confinement.Comment: 5 pages, 4 figure
Transport of a quantum degenerate heteronuclear Bose-Fermi mixture in a harmonic trap
We report on the transport of mixed quantum degenerate gases of bosonic 87Rb
and fermionic 40K in a harmonic potential provided by a modified QUIC trap. The
samples are transported over a distance of 6 mm to the geometric center of the
anti-Helmholtz coils of the QUIC trap. This transport mechanism was implemented
by a small modification of the QUIC trap and is free of losses and heating. It
allows all experiments using QUIC traps to use the highly homogeneous magnetic
fields that can be created in the center of a QUIC trap and improves the
optical access to the atoms, e.g., for experiments with optical lattices. This
mechanism may be cascaded to cover even larger distances for applications with
quantum degenerate samples.Comment: 7 pages, 8 figure
Women and Succession Planning in SMEs
A Summary This report is based on findings from a survey of the SME employees and managers based in the Leeds City Region. A survey was conducted asking questions specifically on succession planning, which is a largely unexplored area of research in the SME literature. The questions were focused on asking survey participants to identify character traits that one needs to have to become a successor in any SME. The findings showed that participants did not perceive either gender, race or class as relevant for succession planning and outlined instead personal characteristics. The existing research has shown the weaknesses of homogenous hiring but in the study, 41.3% of respondents believe cultural fit is the most important factor in succession, this is a considerable weakness for gender equality and diversity as firms continue to preserve their culture. Equally, existing research emphasises the importance of âsoft skillsâ for a successful succession whilst this study highlighted a lack of knowledge in this as a desirable trait, as empathy received the lowest level of importance when considered a trait for successors to have. The abductive analysis showed that women tend to assess gender as more influential in succession than men, however, views are divided on the extent of influence of this characteristic. The majority of women did rate gender highly on the scale of influence (17 women total), most with either 4 or 5. Equally, women were inclined to recognise class as influential albeit to a meaningfully lower extent than gender and those who recognised class seem to often be from working class origin. Race seems to be least recognised except for, not surprisingly, BAME women who rated race either higher or equally influential as gender, but BAME women did not rate class as influential, this characteristic was more recognised by men than women generally and then more by white women than BAME women. Only one man in the sample recognised gender as a relevant characteristic for succession, thus pointing towards a conclusion that men do not recognise womenâs inequality in large numbers
Quantum dynamics of molecules in 4He nano-droplets: Microscopic Superfluidity
High resolution spectroscopy of doped molecules in 4He nano-droplets and
clusters gives a signature of superfluidity in microscopic system, termed as
microscopic superfluidity. Ro-vibrational spectrum of 4HeN-M clusters is
studied with the help of some important observations, revealed from experiments
(viz., localised and orderly arrangement of 4He atoms, although, being free to
move in the order of their locations; individual 4He atoms can not be tagged as
normal/ superfluid, etc.) and other factors (e.g., consideration that the 4He
atoms which happen to fall in the plane of rotation of a molecule, render a
equipotential ring and thus, do not take part in rotation; etc.) which effect
the rotational and vibrational spectrum of the system. This helps us in
successfully explaining the experimental findings which state that the
rotational spectrum of clusters have sharp peaks (indicating that the molecule
rotates like a free rotor) and moment of inertia and vibrational frequency
shift have a non-trivial dependence on N
Proteome sequence features carry signatures of the environmental niche of prokaryotes
<p>Abstract</p> <p>Background</p> <p>Prokaryotic environmental adaptations occur at different levels within cells to ensure the preservation of genome integrity, proper protein folding and function as well as membrane fluidity. Although specific composition and structure of cellular components suitable for the variety of extreme conditions has already been postulated, a systematic study describing such adaptations has not yet been performed. We therefore explored whether the environmental niche of a prokaryote could be deduced from the sequence of its proteome. Finally, we aimed at finding the precise differences between proteome sequences of prokaryotes from different environments.</p> <p>Results</p> <p>We analyzed the proteomes of 192 prokaryotes from different habitats. We collected detailed information about the optimal growth conditions of each microorganism. Furthermore, we selected 42 physico-chemical properties of amino acids and computed their values for each proteome. Further, on the same set of features we applied two fundamentally different machine learning methods, Support Vector Machines and Random Forests, to successfully classify between bacteria and archaea, halophiles and non-halophiles, as well as mesophiles, thermophiles and mesothermophiles. Finally, we performed feature selection by using Random Forests.</p> <p>Conclusions</p> <p>To our knowledge, this is the first time that three different classification cases (domain of life, halophilicity and thermophilicity) of proteome adaptation are successfully performed with the same set of 42 features. The characteristic features of a specific adaptation constitute a signature that may help understanding the mechanisms of adaptation to extreme environments.</p
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