5,350 research outputs found
Possible experimental signatures at the LHC of strongly interacting electro-weak symmetry breaking
If electro-weak symmetry is broken by a new strongly interacting sector, new
physics will probably manifest itself in gauge boson scattering at the LHC. The
relevant dynamics is well described in terms of an effective lagrangian. We
discuss the probable size of the coefficients of the relevant operators under a
combination of model-independent constraints and reasonable assumptions based
on two models of the strongly interacting sector. We compare these values with
LHC sensitivity and argue that they will be too small to be seen. Therefore,
the presence of vector and scalar resonances required by unitarity will be the
only characteristic signature. We analyze the most likely masses and widths of
these resonances.Comment: 14 pages, pdftex, 5 figures, improved discussion of bounds, 1
footnote remove
On the stability of thick brane worlds non-minimally coupled to gravity
We analyze a class of 5D models where a 3 brane is generated by a bulk scalar
field non minimally coupled to gravity. We show that perturbative stability of
such branes is normally guaranteed although non minimal couplings are not
innocuous in general. After the physical states are identified the linearized
equations for propagating modes are evaluated into a Schroedinger form and
supersymmetric quantum mechanics provides the absence of tachyons. The spectrum
contains a tower of spin 2 and spin 0 fields with continuous masses starting
from zero ones. For regular geometries the scalar spectrum contains a state
with zero mass which is always non normalizable. The propagating massive scalar
states are repelled off the brane due to a centrifugal potential.Comment: 15 page
REPORT drawn up on behalf of the Commit tee on the Rules of Petition, Verification of Credentials and Immunities on the election of committee vice-chairmen. EP Working Documents 1990, Document A 3-127/90, 7 June 1990
The bearable compositeness of leptons
Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating observables. We put forward a U(1)3 Ă CP symmetry of the composite sector, in order to allow the new physics to be not far above the TeV scale. This hypothesis effectively suppresses the new contributions to the electron EDM and ÎŒ â eÎł, by far the most constraining observables, and results in a novel pattern of flavor violation and neutrino masses. The CP violation in the elementary-composite mixing is shown to induce a CKM phase of the correct size, as well as order-one phases in the PMNS matrix. We compare with the alternative possibility of introducing multiple scales of compositeness for leptons, that also allow to evade flavor and CP constraints. Finally, we examine violations of lepton flavor universality in B-meson semi-leptonic decays. The neutral-current anomalies can be accommodated, predicting strong correlations among different lepton flavors, with a few channels close to the experimental sensitivity
Distribution of Relaxation Times Based on Lasso Regression: A Tool for High-Resolution Analysis of IMPS Data in Photoelectrochemical Systems
Intensity-modulated photocurrent spectroscopy (IMPS) has been largely employed in semiconductor characterization for solar energy conversion devices to probe the operando behavior with widely available facilities. However, the implementation of IMPS data analysis to complex structures, whether based on the physical rate constant model (RCM) or the assumption-free distribution of relaxation times (DRT), is generally limited to a semi-quantitative description of the charge carrier kinetics of the system. In this study, a new algorithm for the analysis of IMPS data is developed, providing unprecedented time resolution to the investigation of Όs to s charge carrier dynamics in semiconductor-based systems used in photoelectrochemistry and photovoltaics. The algorithm, based on the previously developed DRT analysis, is herein modified with a Lasso regression method and available to the reader free of charge. A validation of this new algorithm is performed on a α-Fe2O3 photoanode for photoelectrochemical water splitting, identified as a standard platform in the field, highlighting multiple potential-dependent charge transfer paths, otherwise hidden in the conventional IMPS data analysis
Business of Fashion, Textiles & Technology: Summary Report: Mapping the UK Fashion, Textiles and Technology Ecosystem
The UK fashion, apparel and textiles industry is a globally competitive growth sector. The 2015 Value of Fashion report by Oxford Economics, commissioned by the British Fashion Council, found that the direct economic value of a flourishing sector including retail, manufacturing and textiles was ÂŁ28.1 billion â and calculated its indirect impact at a further ÂŁ22.6 billion, making a total contribution to gross domestic product of over ÂŁ50 billion[3]. However, it is less well understood than other creative industries. The final product is generally perceived as catwalk-related in some way. In order to shift that perception, the Business of Fashion, Textiles and Technology (BFTT) report considers the fashion, textiles and technology industry as a wide range of intersecting sectors, spanning â quite literally â from agriculture to advertising.
To date, the industry has been constrained by lack of innovation in business strategy and the late adoption of technology. These structural factors have severely limited investment in research, development and knowledge exchange within the broader Fashion, Textiles and Technology (FTT) ecosystem. Currently, the industry lacks robust data and compelling evidence compared to other creative industries regarding research and development (R&D) opportunities, business growth options, job creation and investment. Official data sources on the fashion industry are limited to âdesigner fashionâ, which is conflated with âother designâ activity, and focuses on established brands and large retailers, and unrelated textiles manufacturers. In response to this deficit and to concerns around R&D, identified through the development of the BFTT creative R&D partnership proposal (2017), the BFTTâs first task was to launch a UK-wide survey of the FTT ecosystem (2019).
Approximately one year later, the survey consultation (the launch of which preceded Covid-19 and Britainâs exit from the EU) had engaged over 2,400 small, medium and micro businesses (SMEs) and over 100 stakeholders and intermediaries, including industry specialists, trade bodies and workspace providers. The consultation received 814 survey responses and led to 65 stakeholder interviews, making it one of the most extensive baseline studies to date on FTT SMEs.
BFTT surveyed and interviewed across the entire UK fashion and wider apparel value chain. Therefore, this report for the first time positions the UK sector as not weighted toward fashion only. It illustrates the textile, materials and technology elements as key parts of this ecosystem and shows the industry is highly heterogeneous, made up of intersecting textiles and technology companies that inform an array of multiple sectors
In vitro selection of resistance in Streptococcus pneumoniae at in vivo fluoroquinolone concentrations
Methods: Twenty strains of S. pneumoniae susceptible to fluoroquinolones were used. The frequencies of spontaneous single-step mutations at plasma and epithelial lining fluid (ELF) peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial subcultures on agar plates containing a linear gradient from peak to trough antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. Resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing gyrA, gyrB, parC and parE genes. Results: Levofloxacin and moxifloxacin showed the lowest frequencies of mutations (median <10 211 ) at plasma peak and at ELF concentrations, while medians ranging from 10 28 to 10 26 were observed for ciprofloxacin and prulifloxacin. In a multi-step selection assay, ciprofloxacin and prulifloxacin selected for the highest number of resistant strains (19 and 31, respectively). No selection of resistance was observed for levofloxacin at ELF concentrations and for moxifloxacin at plasma and ELF concentrations. Mutations in parC, parE and gyrA genes were found in ciprofloxacin- and prulifloxacinresistant strains, while only parC mutations were found for levofloxacin. Conclusions: Levofloxacin and moxifloxacin are characterized by a lower propensity to select in vitro for resistance in S. pneumoniae than ciprofloxacin and prulifloxacin, when tested at plasma and lung concentrations
The Submillimeter Properties of the 1 Ms Chandra Deep Field North X-ray Sample
We present submillimeter observations for 136 of the 370 X-ray sources
detected in the 1 Ms exposure of the Chandra Deep Field North. Ten of the X-ray
sources are significantly detected in the submillimeter. The average X-ray
source in the sample has a significant 850 micron flux of 1.69+/-0.27 mJy. This
value shows little dependence on the 2-8 keV flux from 5e-16 erg/cm^2/s to
1e-14 erg/cm^2/s. The ensemble of X-ray sources contribute about 10% of the
extragalactic background light at 850 microns. The submillimeter excess is
found to be strongest in the optically faint X-ray sources that are also seen
at 20 cm, which is consistent with these X-ray sources being obscured and at
high redshift (z>1).Comment: 5 pages, submitted to The Astrophysical Journal Letter
Potential and challenges of improving photosynthesis in algae
Sunlight energy largely exceeds the energy required by anthropic activities, and therefore its exploitation represents a major target in the field of renewable energies. The interest in the mass cultivation of green microalgae has grown in the last decades, as algal biomass could be employed to cover a significant portion of global energy demand. Advantages of microalgal vs. plant biomass production include higher lightâuse efficiency, efficient carbon capture and the valorization of marginal lands and wastewaters. Realization of this potential requires a decrease of the current production costs, which can be obtained by increasing the productivity of the most common industrial strains, by the identification of factors limiting biomass yield, and by removing bottlenecks, namely through domestication strategies aimed to fill the gap between the theoretical and real productivity of algal cultures. In particular, the lightâtoâbiomass conversion efficiency represents one of the major constraints for achieving a significant improvement of algal cell lines. This review outlines the molecular events of photosynthesis, which regulate the conversion of light into biomass, and discusses how these can be targeted to enhance productivity through mutagenesis, strain selection or genetic engineering. This review highlights the most recent results in the manipulation of the fundamental mechanisms of algal photosynthesis, which revealed that a significant yield enhancement is feasible. Moreover, metabolic engineering of microalgae, focused upon the development of renewable fuel biorefineries, has also drawn attention and resulted in efforts for enhancing productivity of oil or isoprenoids
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