Papers by Alberto Mario Ruiz
Animals, 2021
The effects of porcine plasma protein hydrolysate (PPH) on growth, feed efficiency, and immune re... more The effects of porcine plasma protein hydrolysate (PPH) on growth, feed efficiency, and immune responses was evaluated in Sparus aurata. Fish were fed two isoproteic (48% protein), isolipidic (17% fat), and isoenergetic diets (21.7 MJ/kg) diets, one of them containing 5% PPH at the expense of fishmeal. Both diets were tested for 92 days. A significant increase in growth was observed in fish fed the PPH diet in comparison to the control group (182.2 ± 4.4 vs. 173.8 ± 4.1 g), as well as an increase in feed intake without worsening FCR values. An ex vivo assay, with splenocytes incubated with lipopolysaccharide, was conducted to evaluate the cellular immune competence of fish. Genes involved in humoral immunity (lys, IgM), pro- (tnf-α, il-1β), and anti-inflammatory (tgf-β1, il10) cytokines were upregulated in the PPH group in comparison to the control group. The inclusion of PPH in diets enhanced the antibacterial capacity of skin mucus, as the co-culture of selected bacteria (E. coli,...
Journal of Materials Engineering and Performance, 2022
In the oil, gas, and thermal power plant industries, it is highly desirable to assess the integri... more In the oil, gas, and thermal power plant industries, it is highly desirable to assess the integrity of components manufactured with duplex stainless steel (DSS) while in service. One problem is the detection the 475 °C embrittlement; the phenomenon is composition and temperature dependent and is usually evaluated by some special laboratory techniques such as low-angle neutron scattering and Mössbauer spectroscopy. This constraint motivated the search for in-field methods as an alternative and literature research shows that nondestructive evaluation (NDE) methods are capable of measuring microstructural transformations in different metallic alloys; therefore, they are good candidates for in-field 475 °C embrittlement assessment. Although considerable evidence is reported, it is still not clear how the chemical composition affects the NDE variables. In this study, three NDE methods, namely ultrasonic shear wave birefringence (SWB), thermoelectric power (TEP) coefficient, and electric conductivity (EC) measurements, were conducted to track the effects of thermal aging at 475 °C in two different chemical composition DSS alloys. The experimental results were compared to Vickers microhardness measurements and scanning electron microscopy (SEM) and Electron Back-Scattering Diffraction (EBSD). EC and TEP techniques appear to be the most promising to track nondestructively the embrittlement phenomenon in the field.
Land, 2021
The stabling of livestock farming implies changes in both local ecosystems (regeneration of fores... more The stabling of livestock farming implies changes in both local ecosystems (regeneration of forest stands via reduced grazing) and those located thousands of kilometers away (deforestation to produce grain for feeding livestock). Despite their importance, these externalities are poorly known. Here we evaluated how the intensification and confinement of livestock in Spain has affected forest surface changes there and in South America, the largest provider of soybeans for animal feed to the European Union. For this purpose, we have used Spanish soybean import data from Brazil, Paraguay and Argentina and a land condition map of Spain. The area of secondary forest in Spain that has regenerated as a result of livestock stabling has been ~7000 kha for the decade 2000–2010. In the same period, 1220 kha of high value South American ecosystems (e.g., Chaco dry Forest, Amazonian rainforest or Cerrado) have been deforested. While these figures may offer a favorable interpretation of the curren...
Nuclear Engineering and Technology, 2021
One of the consequences of the 475 C embrittlement of duplex stainless steels is the reduction of... more One of the consequences of the 475 C embrittlement of duplex stainless steels is the reduction of the resistance to localized corrosion. Therefore, the detection of this type of embrittlement before the material exhibits significant loss in toughness, and corrosion resistance is important to ensure the structural integrity of critical components under corrosion threats. In this research, conductivity measurements are performed using the alternating current potential drop (ACPD) technique with using a portable fourpoint probe as a nondestructive evaluation (NDE) method for detecting the embrittlement in a 2507 (UNS S32750) super duplex stainless steel (SDSS) aged at 475 C from as-received condition to 300 h. The electric conductivity results were compared against two electrochemical tests namely double loop electrochemical potentiokinetic reactivation (DL-EPR) and critical pitting temperature (CPT). Mechanical tests and the microstructure characterized using scanning electron microscopy (SEM) imaging are conducted to track the progress of embrittlement. It is shown that the electric conductivity correlates with the changes in impact energy, microhardness, and CPT corrosion tests result demonstrating the feasibility of the four-point probe as a possible field-deployable method for evaluating the 475 C embrittlement of 2507 SDSS.
Ecology and Evolution, 2016
We present toBeeView, a program that produces from a digital photograph, or a set of photographs,... more We present toBeeView, a program that produces from a digital photograph, or a set of photographs, an approximation of the image formed at the sampling station stage in the eye of an animal. toBeeView is freely available from https://github.com/EEZA-CSIC/ compound-eye-simulator. toBeeView assumes that sampling stations in the retina are distributed on a hexagonal grid. Each sampling station computes the weighted average of the color of the part of the visual scene projecting on its photoreceptors, and the hexagon of the output image associated with the sampling station is filled in this average color. Users can specify the visual angle subtended by the scene and the basic parameters determining the spatial resolution of the eye: photoreceptor spatial distribution and optic quality of the eye. The photoreceptor distribution is characterized by the vertical and horizontal interommatidial angles-which can vary along the retina. The optic quality depends on the section of the visual scene projecting onto each sampling station, determined by the acceptance angle. The output of toBeeView provides a first approximation to the amount of visual information available at the retina for subsequent processing, summarizing in an intuitive way the interaction between eye optics and receptor density. This tool can be used whenever it is important to determine the visual acuity of a species and will be particularly useful to study processes where object detection and identification is important, such as visual displays, camouflage, and mimicry.
The Science of the total environment, Jan 9, 2017
This work illustrates the application of a simulation model to analyse how swiftly large-scale la... more This work illustrates the application of a simulation model to analyse how swiftly large-scale land-use changes can drive broad territories to collapse. In this sense, the economic needs of a population should not clash with the natural environment but rather be reconciled with it. Abundant literature deals with the integration of socioeconomic drivers, ecological aspects, farming management, and climatology related to Algerian rangeland degradation. The present study seeks to compare the time course of Alfa grass biomass and the livestock raised on these distinctive rangelands under two different land-use strategies. The traditional one has nomads as the main inhabitants of these lands. For centuries, their strategy for alleviating pressure on resources was to move from one area to other. The more recent sedentary land-use leads to overgrazing supported by the massive use of cheap supplemental feed. Additionally, the model was used as a platform to launch scenarios for sustainable ...
The Journal of organic chemistry, May 5, 2017
The diastereoselective synthesis of cis and trans steroid-fulleropyrrolidines hybrids by reaction... more The diastereoselective synthesis of cis and trans steroid-fulleropyrrolidines hybrids by reaction of N-metalated azomethine ylides [Cu(II) or Ag(I)] with the appropriate chiral ligand and C60 is described. The experimental findings reveal that the azomethine ylide stabilized by an allylic group cycloadds to [60]fullerene in an efficient manner and with a good diastereomeric excess. Furthermore, the new generated stereocenters are fully controlled by the catalytic systems used without being influenced by the chirality of the steroid. Interestingly, by this synthetic methodology the each one of the four possible stereoisomers have efficiently been obtained and characterized by CD spectra.
Remote Sensing, 2016
States of ecological maturity and temporal trends of drylands in Morocco, Algeria and Tunisia nor... more States of ecological maturity and temporal trends of drylands in Morocco, Algeria and Tunisia north of 28˝N are reported for 1998-2008. The input data were Normalized Difference Vegetation Index databases and corresponding climate fields, at a spatial resolution of 1 km and a temporal resolution of one month. States convey opposing dynamics of human exploitation and ecological succession. They were identified synchronically for the full period by comparing each location to all other locations in the study area under equivalent aridity. Rain Use Efficiency (RUE) at two temporal scales was used to estimate proxies for biomass and turnover rate. Biomass trends were determined for every location by stepwise regression using time and aridity as predictors. This enabled human-induced degradation to be separated from simple responses to interannual climate variation. Some relevant findings include large areas of degraded land, albeit improving over time or fluctuating with climate, but rarely degrading further; smaller, but significant areas of mature and reference vegetation in most climate zones; very low overall active degradation rates throughout the area during the decade observed; biomass accumulation over time exceeding depletion in most zones; and negative feedback between land states and trends suggesting overall landscape persistence. Semiarid zones were found to be the most vulnerable. Those results can be disaggregated by country or province. The combination with existing land cover maps and national forest inventories leads to the information required by the two progress indicators associated with the United Nations Convention to Combat Desertification strategic objective to improve the conditions of ecosystems and with the Sustainable Development Goal Target 15.3 to achieve land degradation neutrality. Beyond that, the results are also useful as a basis for land management and restoration.
Analysis & PDE, 2016
We give a necessary condition for a Riemannian manifold to admit limiting Carleman weights in ter... more We give a necessary condition for a Riemannian manifold to admit limiting Carleman weights in terms of its Weyl tensor (in dimensions 4 and higher), or its Cotton-York tensor in dimension 3. As an application we provide explicit examples of manifolds without limiting Carleman weights and show that the set of such metrics on a given manifold contains an open and dense set.
Inverse Probl Imaging, 2010
International Mathematics Research Notices
The following initial value problem for the Schrödinger equation with a nontrivial potential V is... more The following initial value problem for the Schrödinger equation with a nontrivial potential V is considered: i∂ t u+Δ x u+V(x,t)u=0,(x,t)∈ℝ n ×ℝ,u(x,0)=u 0 (x)· The following estimate is proved: sup x 0 ,R 1 R∫ B(x 0 ,R) ∫ -∞ ∞ |D x 1/2 e itΔ u 0 | 2 dtdx≤C∥u 0 ∥ L 2 (ℝ n ) 2 , where (D x s f) ∧ (ξ)=|ξ| s f ^(ξ), and other regularity results are discussed.
Inverse Problems & Imaging, 2010
It is proved that, in two dimensions, the Calderón inverse conductivity problem in Lipschitz doma... more It is proved that, in two dimensions, the Calderón inverse conductivity problem in Lipschitz domains is stable in the L p sense when the conductivities are uniformly bounded in any fractional Sobolev space W α,p α > 0, 1 < p < ∞.
Revista Matemática Complutense, 2008
We study two problems closely related to each other. The first one is concerned with some smoothi... more We study two problems closely related to each other. The first one is concerned with some smoothing weighted estimates with weights in a certain Morrey-Campanato spaces, for the solution of the free Schrödinger equation. The second one is a weighed trace inequality.
Journal of Functional Analysis, 2014
We establish optimal conditions under which the Gconvergence of linear elliptic operators implies... more We establish optimal conditions under which the Gconvergence of linear elliptic operators implies the convergence of the corresponding Dirichlet to Neumann maps. As an application we show that the approximate cloaking isotropic materials from [19] are independent of the source.
Remote Sensing of Environment, 2010
Description 2dRUE is a methodology to make a diagnostic of land condition in a large territory du... more Description 2dRUE is a methodology to make a diagnostic of land condition in a large territory during a given time period. The following projects have funded this package: DeSurvey IP (EC FP6 Integrated Project contract No. 003950), DesertWatch (ESA DUE contract No. 18487/04/I-LG) and MesoTopos (Junta de Andalucia PE ref. RNM-4023).
Publicacions Matemàtiques, 1995
The purpose of this note is twofold. First it is a corrigenda of our paper [RV1]. And secondly we... more The purpose of this note is twofold. First it is a corrigenda of our paper [RV1]. And secondly we make some remarks concerning the interpolation properties of Morrey spaces.
Mathematische Nachrichten, 2009
We prove weighted local smoothing estimates for the resolvent of the Laplacian in three dimension... more We prove weighted local smoothing estimates for the resolvent of the Laplacian in three dimensions with weights belonging to the Kerman-Sawyer class. This class contains the well-known global Kato and Rollnik classes. We go on to discuss dispersive and Strichartz estimates for perturbations of the Laplacian by small potentials, and apply our results and observations to the well-posedness in L 2 of the Cauchy problem for some linear and semilinear Schrödinger equations.
Mathematische Annalen, 2009
We prove that the singularities of a complex valued potential q in the Schrödinger hamiltonian + ... more We prove that the singularities of a complex valued potential q in the Schrödinger hamiltonian + q can be reconstructed from the linear Born approximation for full scattering data by averaging in the extra variables. We prove that, with this procedure, the accuracy in the reconstruction improves the previously known accuracy obtained from fixed angle or backscattering data. In particular, for q ∈ W α,2 for α ≥ 0, in 2D we recover the main singularity of q with an accuracy of one derivative; in 3D the accuracy is > 1/2, increasing with α. This gives a mathematical basis for diffraction tomography. The proof is based on some new estimates for multidimensional bilinear Fourier multipliers of independent interest.
Journal of Mathematical Analysis and Applications, 1996
A short and self-contained proof of the existence of the scattering solution in exterior domains ... more A short and self-contained proof of the existence of the scattering solution in exterior domains is presented for some class of second order elliptic equations. The method does not use the integral equation; it is based on Fredholm theory and the limiting absorption principle for solutions in the whole space. It covers domains with Lipschitz boundaries, domains satisfying a cone condition, and those with the so-called local compactness property.
Journal of Functional Analysis, 2006
We prove the local smoothing effect for Schrödinger equations with repulsive potentials for n 3. ... more We prove the local smoothing effect for Schrödinger equations with repulsive potentials for n 3. The estimates are global in time and are proved using a variation of Morawetz multipliers. As a consequence we give sharp constants to measure the attractive part of the potential and its rate of decay, which turns out to be different whether dimension 3 or higher are considered. Also a notion of zero resonance arises in a natural way. Our smoothing estimate allows us to use Sobolev inequalities and treat nonradial perturbations.
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Papers by Alberto Mario Ruiz