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A design framework for enabling sustainability in the clothing sector
This article discusses general strategies to enable environmental sustainability within the clothing sector, providing a framework for decision makers involved in the development of programs and policies for this sector. It initially revises the environmental impact of the clothing system and determines its key environmental sustainability priorities. The framework involves five evolutionary strategies for enabling sustainable consumption and production: 1) environmental improvement of flows throughout the supply chain; 2) environmental redesign of existing clothes; 3) design of new clothes intrinsically more sustainable; 4) design of cloth-service systems and 5) promoting life styles towards sufficient consumption. The practical implications of each strategy is analysed based on correspondent ex-post-facto case studies identified in Brazil, using data collected through literature review and desktop research
Effect of charging on CdSe/CdS dot-in-rods single-photon emission
The photon statistics of CdSe/CdS dot-in-rods nanocrystals is studied with a
method involving post-selection of the photon detection events based on the
photoluminescence count rate. We show that flickering between two states needs
to be taken into account to interpret the single-photon emission properties.
With post-selection we are able to identify two emitting states: the exciton
and the charged exciton (trion), characterized by different lifetimes and
different second order correlation functions. Measurements of the second order
autocorrelation function at zero delay with post- selection shows a degradation
of the single photon emission for CdSe/CdS dot-in-rods in a charged state that
we explain by deriving the neutral and charged biexciton quantum yields.Comment: 10 pages, 5 figure
Photon correlations for colloidal nanocrystals and their clusters
Images of semiconductor `dot in rods' and their small clusters are studied by
measuring the second-order correlation function with a spatially resolving ICCD
camera. This measurement allows one to distinguish between a single dot and a
cluster and, to a certain extent, to estimate the number of dots in a cluster.
A more advanced measurement is proposed, based on higher-order correlations,
enabling more accurate determination of the number of dots in a small cluster.
Nonclassical features of the light emitted by such a cluster are analyzed.Comment: 4 pages, 4 figure
Designing for oral storytelling practices at home: A parental perspective
Storytelling at home is typically an oral practice that supports parents and children to make sense of their family identity. Parents play a key role in crafting the story plot and facilitating the child’s participation in the storytelling process. Yet in the context of digital technology, interaction design researchers have tended to focus on children and how digital storytelling tools can support them in their learning. Adopting a “family lens” the aim of this research is to understand the character of oral storytelling practice and identify opportunities for digital storytelling design. The findings outline a co-design workshop that involved a team of designers and parents, who regularly engaged in oral storytelling. Grounded in a systematic video analysis of the workshop alongside a reflection of the design decisions that unfolded, we contribute four new design opportunities centring on the themes of flexibility, shared experience, minimalism, and autobiographical memories. These opportunities can guide interaction design researchers interested in designing new digital oral storytelling tools for families
Experimental estimation of one-parameter qubit gates in the presence of phase diffusion
We address estimation of one-parameter qubit gates in the presence of phase
diffusion. We evaluate the ultimate quantum limits to precision, seek for
optimal probes and measurements, and demonstrate an optimal estimation scheme
for polarization qubits. An adaptive method to achieve optimal estimation in
any working regime is also analyzed in details and experimentally implemented.Comment: revised version, to appear on PR
Optical interferometry in the presence of large phase diffusion
Phase diffusion represents a crucial obstacle towards the implementation of
high precision interferometric measurements and phase shift based communication
channels. Here we present a nearly optimal interferometric scheme based on
homodyne detection and coherent signals for the detection of a phase shift in
the presence of large phase diffusion. In our scheme the ultimate bound to
interferometric sensitivity is achieved already for a small number of
measurements, of the order of hundreds, without using nonclassical light
Environmental effects in molecular electronics
Researchers have looked at the possibility of using single molecules as functional building blocks in electronics circuits since the 1970s. The field of molecular electronics, despite its experimental and theoretical challenges, has continued to grow incessantly from a simple scientific curiosity to an emerging field with hundreds of publications per year. Thanks to the development of scanning probe microscopy a variety of techniques currently used to characterise the electrical properties of single molecules has been developed, and molecular systems mimicking the behaviour of traditional electronic components, such as transistors or rectifiers, have been prepared. Despite the obvious fact that supramolecular interactions must play a role in the charge transfer process, only a small number of reports on the subject have been published. In this thesis a set of molecular wires with an oligothiophene central unit, sandwiched between two insulating chains, has been used to probe the effect of such interactions on molecular conductance using several scanning tunnelling microscopy techniques. It has been found that the side-chain length has little effect on molecular conductance, but the presence of water in the surrounding environment triggers an increase in conductance and a switch in the behaviour from activationless to thermally-activated. Furthermore, upon exposure to electron-withdrawing small molecules, these oligothiophene molecular wires form charge transfer complexes, with conductance enhanced by a factor up to 100. Measurements performed in UHV confirmed the observed behaviour, and theoretical calculations were performed to explain it in the coherent tunnelling regime. A gateway state arising from coupling of the molecular backbone to the sulfur contacts accounts for the observed shallow decay of conductance with length, while shifting of transport resonances upon interaction with water and the appearance of interference features upon charge transfer complexation explained the temperature dependence and the conductance enhancement, with experimental observation closely matched by DFT calculations
Spontaneous photon production in time-dependent epsilon-near-zero materials
Quantum field theory predicts that a spatially homogeneous but temporally varying medium will excite photon pairs out of the vacuum state. However, this important theoretical prediction lacks experimental verification due to the difficulty in attaining the required nonadiabatic and large amplitude changes in the medium. Recent work has shown that in epsilon-near-zero (ENZ) materials it is possible to optically induce changes of the refractive index of the order of unity, in femtosecond time scales. By studying the quantum field theory of a spatially homogeneous, time-varying ENZ medium, we theoretically predict photon-pair production that is up to several orders of magnitude larger than in non-ENZ time-varying materials. We also find that while in standard materials the emission spectrum depends on the time scale of the perturbation, in ENZ materials the emission is always peaked at the ENZ wavelength. These studies pave the way to technologically feasible observation of photon-pair emission from a time-varying background with implications for quantum field theories beyond condensed matter systems and with potential applications as a new source of entangled light
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