1,996 research outputs found
Form factor in K+ --> pi+ pi0 gamma: interference versus direct emission
We analyze the effect of a form factor in the magnetic contribution to K+ -->
pi+ pi0 gamma. We emphasize how this can show up experimentally: in particular
we try to explore the difference between a possible interference contribution
and a form factor in the magnetic part. The form factor used for K+ --> pi+ pi0
gamma is analogous to the one for KL --> pi+ pi- gamma, experimentally well
established.Comment: 9 pages revtex, 10 eps figures; improved presentation of theoretical
and experimental status; refs. adde
Production of Succinic Acid From Basfia succiniciproducens
Basfia succiniciproducens is a facultative anaerobic capnophilic bacterium, isolated
from rumen, that naturally produces high amounts of succinic acid by fixing CO2 and
using fumarate as final electron acceptor. This metabolic feature makes it one of the
ideal candidates for developing biotechnological industrial routes that could
eventually replace the polluting and environment unfriendly petrochemical ones
that are still main sources for the production of this value-added compound. In
fact, due to the large number of applications of succinic acid that range from the more
traditional ones as food additive or pharmaceutical intermediate to the most recent as
building block for biopolymers and bioplastic, increasing demand and market size growth
are expected in the next years. In line with a âgreen revolutionâ needed to preserve our
environment, the great challenge is the establishment of commercially viable production
processes that exploit renewable materials and in particular preferably non-food
lignocellulosic biomasses and waste products. In this review, we describe the currently
available literature concerning B. succiniciproducens since the strain was first isolated,
focusing on the different renewable materials and fermentation strategies used to improve
succinic acid production titers to date. Moreover, an insight into the metabolic engineering
approaches and the key physiological characteristics of B. succiniciproducens deduced
from the different studies are presented
Zooplankton diversity of a protected and vulnerable wetland system in southern South America (Llancanelo area, Argentina)
In arid regions, climatic conditions exert a great control on the aquatic systems present, but recent changes in climate have produced an enhanced salinization of the aquatic environments located there. Consequently, a major reduction in biodiversity would be expected in those wetlands that were originally fresh water. Salinity is a principal cause of reduced biodiversity particularly in zooplankton because few of those species can adapt to the salt pressure of saline environments. Therefore, the aim of this study was to gain essential information on the diversity of aquatic invertebrates in Llancanelo basin by focussing the analysis on the zooplankton community and exploring seasonal and spatial differences in the zooplankton assemblages of this vulnerable wetland system within an arid region of Argentina. Seasonal samples were taken at nine sites in the basin (a shallow lake, 4 springs, streams, and the MalargĂŒe River). A total of 45 species were identified. The zooplankton abundance in the lake displayed a clear seasonal contrast and was higher than that recorded in the springs and lotic environments. Boeckella poopoensis, Fabrea salina, and Brachionus plicatilis predominated in the lake, indicating their halophilia. The presence of the crustaceans Alona sp., Macrocyclops albidus, and Paracyclops fimbriatus was restricted to the springs; whereas Notholca labis and Notholca squamula were found only in running water. The zooplankton species richness in the Llancanelo area is low because of both the salt content in the lake and the irregularity of freshwater entry in all locations during the annual cycle.Instituto de LimnologĂa "Dr. Raul A. Ringuelet
Teaching design in emerging countries A train-the-trainer methodology
Design disciplines have constantly evolved to keep up with the emerging demands of the 21st Century. Design education is thus called to change its methods, tools and approaches. There is an increasing interest in emerging economies in design education, especially in India, where the role of creativity, communication and technology can support social and economic development. This paper aims to present the educational approach developed in the context of the Erasmus+ KA2 project entitled âDesign and Innovation Capacity Building in India/DESINNOâ. The modernisation and internationalisation of Indian universities with innovative and contemporary design courses have been the main goals of a set of research and training activities. In this paper, the state-of-the-art methodologies in design thinking, sustainability, design research, social innovation and ethical issues in design are presented, leading to a bespoke educational approach that provides a platform for Indian design academics to apply modern educational approaches
to their specificities and needs
Chronic venous insufficiency strengthens the thrombo-embolic risk in congestive heart failure in elderly patients
The s ---> d gamma decay in and beyond the Standard Model
The New Physics sensitivity of the s ---> d gamma transition and its
accessibility through hadronic processes are thoroughly investigated. Firstly,
the Standard Model predictions for the direct CP-violating observables in
radiative K decays are systematically improved. Besides, the magnetic
contribution to epsilon prime is estimated and found subleading, even in the
presence of New Physics, and a new strategy to resolve its electroweak versus
QCD penguin fraction is identified. Secondly, the signatures of a series of New
Physics scenarios, characterized as model-independently as possible in terms of
their underlying dynamics, are investigated by combining the information from
all the FCNC transitions in the s ---> d sector.Comment: 54 pages, 14 eps figure
Recommended from our members
Dynamics of Post-Injection Fuel Flow in Mini-Sac Diesel Injectors Part 1: Admission of 1 External Gases and Implications for Deposit Formation
Samples of unadditized, middle distillate diesel fuel were injected through real-size optically accessible mini-sac diesel injectors into ambient air at common rail pressures of 250 bar and 350 bar respectively. High-resolution images of white light scattered from the internal mini-sac and nozzle flow were captured on a high-speed monochrome video camera. Following the end of each injection, the momentum-driven evacuation of fuel liquid from the mini-sac and nozzle holes resulted in the formation of a vapour cloud and bubbles in the mini-sac, and vapour capsules in the nozzle holes. This permitted external gas to gain entrance to the nozzle holes.
The diesel fuel in the mini-sac was observed to rotate with large initial vorticity, which decayed until the fuel became stationary. The diesel fuel remaining in the nozzle holes was observed to move inwards towards the mini-sac or outwards towards the nozzle exit in concert with the rotational flow in the mini-sac. The mini-sac bubblesâ internal pressure differences revealed that the bubbles must have contained previously dissolved oxygen and nitrogen. Under diesel engine operating conditions, this multi-phase mixture would be highly reactive and could initiate local pyrolysis and/or oxidation reactions. Finally, the dynamical behaviour of the diesel fuel in the nozzle holes would support the admission of external hot combustion gases into the nozzle holes, establishing the conditions for oxidation/pyrolysis reactions with surrounding liquid fuel films
Iso-singlet Down Quark Mixing And CP Violation Experiments
We confront the new physics models with extra iso-singlet down quarks in the
new CP violation experimental era with and
measurements, events, and
limits. The closeness of the new experimental results to the standard
model theory requires us to include full SM amplitudes in the analysis. In
models allowing mixing to a new isosinglet down quark, as in E, flavor
changing neutral currents are induced that allow a mediated contribution
to mixing and which bring in new phases. In ,
, and plots we still find much
larger regions in the four down quark model than in the SM, reaching down to
, , , and down to zero, all at 1. We elucidate
the nature of the cancellation in an order four down quark mixing
matrix element which satisfies the experiments and reduces the number of
independent angles and phases. We also evaluate tests of unitarity for the
CKM submatrix.Comment: 14 pages, 16 figures, REVTeX
Interpreting experimental bounds on D^0 - \bar{D^0} mixing in the presence of CP violation
We analyse the most recent experimental data regarding D^0 - \bar{D^0}
mixing, allowing for CP violation. We focus on the dispersive part of the
mixing amplitude, M^D_{12}, which is sensitive to new physics contributions. We
obtain a constraint on the mixing amplitude: |M^D_{12}| < 6.2\times 10^{-11}
MeV at 95% C.L. . This constraint is weaker by a factor of about three than the
one which is obtained when no CP violation is assumed.Comment: 9 pages, revtex4; One reference updated, one reference added,
footnote 3 correcte
Estimate of B(K -> pi nu nubar) from Standard Model fits to lambda_t
We estimate B(K -> pi nu nubar) in the context of the Standard Model by
fitting for lambda_t = Vtd x V*ts of the `kaon unitarity triangle' relation. We
fit data from epsilon_K, the CP-violating parameter describing K-mixing, and
a_{psi K}, the CP-violating asymmetry in B -> J/psi K decays. Our estimate is
independent of the CKM matrix element Vcb and of the ratio of Bs to Bd mixing
frequencies. The measured value of B(K+ -> pi+ nu nubar) can be compared both
to this estimate and to predictions made from the ratio of B mixing
frequencies.Comment: 8 pages, including 6 figures. v3 includes an expanded discussion of
correlations between SM inputs to the lambda_t fit, clarifies the discussion
of the independence of this result from the ratio of B mixing frequencies,
includes minor updates to the values of SM input parameters, and includes
some new and some updated reference
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