1,595 research outputs found
Block freeze-concentration of coffee extract: Effect of freezing and thawing stages on solute recovery and bioactive compounds
Coffee extract was freeze-concentrated using the total block technique. The effects of four parameters
were evaluated: the initial coffee mass fraction (5 and 15% w/w), the cooling temperature ( 10 and
20 C), the heating temperature (20 and 40 C) and the freezing direction (parallel and counter-flow
to the thawing direction). The solid concentration was measured during the thawing stage to quantify
the solute recovery and the concentration index for one stage of freeze concentration. The coffee mass
fraction, the freezing direction and the cooling temperature significantly influenced the solute recovery.
A concentration index between 1 and 2.3 was obtained in one cycle. The effect of block freeze concentration
on the bioactive compound concentration and the antioxidant activity was measured. The coffee bioactive
compounds were distributed in proportion to the total solid content in the ice and liquid.
Therefore, block freeze concentration is an effective technique to preserve functional properties of coffee
extracts.Postprint (published version
Neutrino masses from operator mixing
We show that in theories that reduce, at the Fermi scale, to an extension of
the standard model with two doublets, there can be additional dimension five
operators giving rise to neutrino masses. In particular there exists a singlet
operator which can not generate neutrino masses at tree level but generates
them through operator mixing. Under the assumption that only this operator
appears at tree level we calculate the neutrino mass matrix. It has the Zee
mass matrix structure and leads naturally to bimaximal mixing. However, the
maximal mixing prediction for solar neutrinos is very sharp even when higher
order corrections are considered. To allow for deviations from maximal mixing a
fine tuning is needed in the neutrino mass matrix parameters. However, this
fine tuning relates the departure from maximal mixing in solar neutrino
oscillations with the neutrinoless double beta decay rate.Comment: 11 pages, 1 figure, revte
Inspiral-merger-ringdown waveforms for black-hole binaries with non-precessing spins
We present the first analytical inspiral-merger-ringdown gravitational
waveforms from binary black holes (BBHs) with non-precessing spins, that is
based on a description of the late-inspiral, merger and ringdown in full
general relativity. By matching a post-Newtonian description of the inspiral to
a set of numerical-relativity simulations, we obtain a waveform family with a
conveniently small number of physical parameters. These waveforms will allow us
to detect a larger parameter space of BBH coalescence, including a considerable
fraction of precessing binaries in the comparable-mass regime, thus
significantly improving the expected detection rates.Comment: To appear in Phys. Rev. Lett. Significant new results. One figure
removed due to page limitatio
Robust Application of New Deep Learning Tools: An Experimental Study in Medical Imaging
El trabajo forma parte de la tesis doctoral del primer autor, Dr. Laith Alzubaidi, siendo José Santamaría investigador invitado por el autor del artículo en la co-supervision de dicha tesis doctoral, correspondiendo este con uno de los varios artículos científicos que fueron desarrollados y publicados durante y después de la tesis doctoral del Dr. Alzubaidi.Nowadays medical imaging plays a vital role in diagnosing the various types of diseases
among patients across the healthcare system. Robust and accurate analysis of medical
data is crucial to achieving a successful diagnosis from physicians. Traditional diagnostic
methods are highly time-consuming and prone to handmade errors. Cost is reduced and
performance is improved by adopting computer-aided diagnosis methods. Usually, the
performance of traditional machine learning (ML) classification methods much depends
on both feature extraction and selection methods that are sensitive to colors, shapes, and
sizes, which conveys a complex solution when facing classification tasks in medical
imaging. Currently, deep learning (DL) tools have become an alternative solution to
overcome the drawbacks of traditional methods that make use of handmade features. In
this paper, a new DL approach based on a hybrid deep convolutional neural network
model is proposed for the automatic classification of several different types of medical
images. Specifically, gradient vanishing and over-fitting issues have been properly
addressed in the proposed model in order to improve its robustness by means of different
tested techniques involving residual links, global average pooling layers, dropout layers,
and data augmentation. Additionally, we employed the idea of parallel convolutional
layers with the aim of achieving better feature representation by adopting different filter
sizes on the same input and then concatenated as a result. The proposed model is trained
and tested on the ICIAR 2018 dataset to classify hematoxylin and eosin-stained breast
biopsy images into four categories: invasive carcinoma, in situ carcinoma, benign tumors,
and normal tissue. As the experimental results show, our proposed method outperforms
several of the state-of-the-art methods by achieving rate values of 93.2% and 89.8% for
both image- and patch-wise image classification tasks, respectively. Moreover, we fine-
tuned our model to classify foot images into two classes in order to test its robustness by
considering normal and abnormal diabetic foot ulcer (DFU) image datasets. In this case the model achieved an F1 score value of 94.80% on the public DFU dataset and 97.3% on
the private DFU dataset. Lastly, transfer learning (TL) has been adopted to validate the
proposed model with multiple classes with the aim of classifying six different wound
types. This approach significantly improves the accuracy rate from a rate of 76.92% when
trained from scratch to 87.94% when TL was considered. Our proposed model has
proven its suitability and robustness by addressing several medical imaging tasks dealing
with complex and challenging scenarios
Effects of high-pressure on the structural, vibrational, and electronic properties of monazite-type PbCrO4
We have performed an experimental study of the crystal structure,
lattice-dynamics, and optical properties of PbCrO4 (the mineral crocoite) at
ambient and high pressures. In particular, the crystal structure, Raman-active
phonons, and electronic band-gap have been accurately determined.
X-ray-diffraction, Raman, and optical-absorption experiments have allowed us
also to completely characterize two pressure-induced structural phase
transitions. The first transition is isostructural, maintaining the monoclinic
symmetry of the crystal, and having important consequences in the physical
properties; among other a band-gap collapse is induced. The second one involves
an increase of the symmetry of the crystal, a volume collapse, and probably the
metallization of PbCrO4. The results are discussed in comparison with related
compounds and the effects of pressure in the electronic structure explained.
Finally, the room-temperature equation of state of the low-pressure phases is
also obtained.Comment: 32 pages, 9 figures, 3 table
Majorons and supernova cooling
We consider the role of Majoron emission in supernova cooling and its implications for the neutrino mass and lifetime in generic single Majoron models. It is found that, for ντ with mass m, if the lifetime for the decay ντ→Majoron+νe,μ is shorter than 10−7 (m/MeV) sec, then Majorons are so strongly trapped by the inverse process that the resulting Majoron luminosity is small enough not to destabilize the observed νe pulse from SN 1987A. For ντ with a longer lifetime, the Majoron luminosity can be large enough to destroy or significantly shorten the duration of the neutrino pulse. We then find the range of parameters, e.g., the ντ mass m and the B−L-breaking scale v, that is excluded by giving such a large Majoron luminosity. Our results imply that, for v between 1 GeV and 1 TeV, a wide range of m allowed by terrestrial experiments can be excluded in view of the observed νe, pulse from SN 1987A
KATANA - a charge-sensitive triggering system for the SRIT experiment
KATANA - the Krakow Array for Triggering with Amplitude discrimiNAtion - has
been built and used as a trigger and veto detector for the SRIT TPC at
RIKEN. Its construction allows operating in magnetic field and providing fast
response for ionizing particles, giving the approximate forward multiplicity
and charge information. Depending on this information, trigger and veto signals
are generated. The article presents performance of the detector and details of
its construction. A simple phenomenological parametrization of the number of
emitted scintillation photons in plastic scintillator is proposed. The effect
of the light output deterioration in the plastic scintillator due to the
in-beam irradiation is discussed.Comment: 14 pages, 11 figure
Suppressing the and neutrino masses by a superconformal force
The idea of Nelson and Strassler to obtain a power law suppression of
parameters by a superconformal force is applied to understand the smallness of
the parameter and neutrino masses in R-parity violating supersymmetric
standard models. We find that the low-energy sector should contain at least
another pair of Higgs doublets, and that a suppression of \lsim O(10^{-13})
for the parameter and neutrino masses can be achieved generically. The
superpotential of the low-energy sector happens to possess an anomaly-free
discrete R-symmetry, either or , which naturally suppresses certain
lepton-flavor violating processes, the neutrinoless double beta decays and also
the electron electric dipole moment. We expect that the escape energy of the
superconformal sector is \lsim O(10) TeV so that this sector will be
observable at LHC. Our models can accommodate to a large mixing among neutrinos
and give the same upper bound of the lightest Higgs mass as the minimal
supersymmetric standard model.Comment: 24 page
Probing neutrino properties with charged scalar lepton decays
Supersymmetry with bilinear R-parity violation provides a predictive
framework for neutrino masses and mixings in agreement with current neutrino
oscillation data. The model leads to striking signals at future colliders
through the R-parity violating decays of the lightest supersymmetric particle.
Here we study charged scalar lepton decays and demonstrate that if the scalar
tau is the LSP (i) it will decay within the detector, despite the smallness of
the neutrino masses, (ii) the relative ratio of branching ratios Br({tilde
tau}_1 --> e sum nu_i)/ Br({tilde tau}_1 --> mu sum nu_i) is predicted from the
measured solar neutrino angle, and (iii) scalar muon and scalar electron decays
will allow to test the consistency of the model. Thus, bilinear R-parity
breaking SUSY will be testable at future colliders also in the case where the
LSP is not the neutralino.Comment: 24 pages, 8 ps figs Report-no.: IFIC/02-33 and ZU-TH 11/0
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