391 research outputs found
Characterization of aroma-active compounds in black sapote (Diospyros digyna Jacq.)
The volatile compounds of black sapote fruit were isolated by simultaneous distillation-solvent extraction and analysed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. A total of 32 volatile constituents were detected, which represented 4.57 mg kgâ1 of the fruit. The composition of volatile constituents of the fruit included 9 terpene compounds (49.1% of the total volatile composition), 11 ketones (9%), 5 aldehydes (29.2%), 4 alcohols (3.6%), 2 esters (8.2%) and a paraffin (0.8%). Major compounds were (Z)-b-ocimene (26.6% of the total volatile composition), (E)-cinnamaldehyde (25.5%) and limonene (17.0%). By application of odour activity values, seven constituents were considered as aroma-active volatiles, from which the most important were (E)-cinnamaldehyde, 3-methylbutanal, limonene, (Z)-ÎČ-ocimene, linalool, methyl (E)-cinnamate, and ÎČ-caryophyllene
Special fast diffusion with slow asymptotics. Entropy method and flow on a Riemannian manifold
We consider the asymptotic behaviour of positive solutions of the
fast diffusion equation
posed for x\in\RR^d, , with a precise value for the exponent
. The space dimension is so that , and even
for . This case had been left open in the general study \cite{BBDGV} since
it requires quite different functional analytic methods, due in particular to
the absence of a spectral gap for the operator generating the linearized
evolution.
The linearization of this flow is interpreted here as the heat flow of the
Laplace-Beltrami operator of a suitable Riemannian Manifold (\RR^d,{\bf g}),
with a metric which is conformal to the standard \RR^d metric.
Studying the pointwise heat kernel behaviour allows to prove {suitable
Gagliardo-Nirenberg} inequalities associated to the generator. Such
inequalities in turn allow to study the nonlinear evolution as well, and to
determine its asymptotics, which is identical to the one satisfied by the
linearization. In terms of the rescaled representation, which is a nonlinear
Fokker--Planck equation, the convergence rate turns out to be polynomial in
time. This result is in contrast with the known exponential decay of such
representation for all other values of .Comment: 37 page
Didactic Software for Autistic Children
In this paper we describe the aims and requirements of a project devoted to designing and developing Open Source didactic Software (SW) for children in the autism disorder spectrum, conforming to the Applied Behaviour Analysis (ABA) learning technique. In this context, participatory design with therapists and child?s parents is necessary to ensure a usable product that responds to these children?s special needs and respects education principles and constraints of the ABA methodology
14. VIGENCIA DE LOS CONCEPTOS, MĂTODOS, HERRAMIENTAS Y MATRICES DE LA PLANEACIĂN ESTRATĂGICA: UNA REVISIĂN BIBLIOGRĂFICA
Las Micro, Pequeñas y Medianas empresas (Mipymes) constituyen gran parte del tejido empresarial a nivel local, esto les asiente una alta influencia en la economĂa del paĂs debido a la generaciĂłn de empleo y de riqueza. Cabe destacar que el Ă©xito y la permanencia de estas, obedece entre muchos factores a la planeaciĂłn estratĂ©gica de las mismas. Sin embargo, el desconocimiento de mĂ©todos de planeaciĂłn y la priorizaciĂłn de acciones diarias de la actividad del negocio hace que las empresas no planeen sus acciones y en consecuencia fracasen en el primer y segundo año de su creaciĂłn. Es por ello, que esta investigaciĂłn estĂĄ encaminada a plantear unas bases para el desarrollo de una herramienta tecnolĂłgica que le permita a las Mipymes la planificaciĂłn de sus operaciones estratĂ©gicas y tĂĄcticas a corto, mediano y largo plazo. El estudio consta de tres fases: estado del arte, desarrollo del aplicativo, y transferencia tecnolĂłgica. Para esta primera fase, se realizĂł una revisiĂłn bibliogrĂĄfica de los Ășltimos 5 años con el fin de identificar conceptos, mĂ©todos, herramientas y matrices implementadas por diversas compañĂas, de los cuales algunos de ellos estĂĄn plasmados en el presente artĂculo de revisiĂłn bibliogrĂĄfica. De esta manera se pretende tener el insumo necesario para la propuesta del desarrollo de la herramienta tecnolĂłgica objeto de la investigaciĂłn y con ello lograr contribuir en la actividad misional de las Mipymes
Spray drying and process optimization of sour orange juice
In this study, production of sour orange juice powder utilizing a spray dryer was investigated. To prevent stickiness, maltodextrin DE 12 was used as a drying agent. While feed flow rate, feed temperature, and air flow rate were kept constant, inlet air temperature (120â160 °C) and maltodextrin content (maltodextrin dry solids/100 g feed mixture dry solids; 10â20%, w/w) were selected as the independent variables. Product properties investigated included ascorbic acid, volatile compounds, and moisture content. Ascorbic acid retention, volatiles retention, and moisture content were used in optimization of the process by response surface methodology. The optimum inlet air temperature and maltodextrin content were 156 °C and 20% w/w maltodextrin, respectively. This study revealed that by applying these optimal conditions, sour orange juice powder with 81.5% ascorbic acid retention, 5.5%, w/w moisture content, and 78% volatiles retention was produced
Porous medium equation with nonlocal pressure
We provide a rather complete description of the results obtained so far on
the nonlinear diffusion equation , which describes a flow through a porous medium driven by a
nonlocal pressure. We consider constant parameters and , we assume
that the solutions are non-negative, and the problem is posed in the whole
space. We present a theory of existence of solutions, results on uniqueness,
and relation to other models. As new results of this paper, we prove the
existence of self-similar solutions in the range when and , and the
asymptotic behavior of solutions when . The cases and were
rather well known.Comment: 24 pages, 2 figure
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Stochastic Acceleration by Turbulence
The subject of this paper is stochastic acceleration by plasma turbulence, a
process akin to the original model proposed by Fermi. We review the relative
merits of different acceleration models, in particular the so called first
order Fermi acceleration by shocks and second order Fermi by stochastic
processes, and point out that plasma waves or turbulence play an important role
in all mechanisms of acceleration. Thus, stochastic acceleration by turbulence
is active in most situations. We also show that it is the most efficient
mechanism of acceleration of relatively cool non relativistic thermal
background plasma particles. In addition, it can preferentially accelerate
electrons relative to protons as is needed in many astrophysical radiating
sources, where usually there are no indications of presence of shocks. We also
point out that a hybrid acceleration mechanism consisting of initial
acceleration by turbulence of background particles followed by a second stage
acceleration by a shock has many attractive features. It is demonstrated that
the above scenarios can account for many signatures of the accelerated
electrons, protons and other ions, in particular He and He, seen
directly as Solar Energetic Particles and through the radiation they produce in
solar flares.Comment: 29 pages 7 figures for proceedings of ISSI-Bern workshop on Particle
Acceleration 201
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