18 research outputs found
Global study of 9 Be + p at 2.72 A MeV
Background: In our recent experiment,
9
Be
+
p
at
5.67
A
MeV, the breakup decay rates to the three configurations,
α
+
α
+
n
,
8
Be
∗
+
n
and
5
He
+
4
He
of
9
Be
, were observed and quantified in the proton recoil spectra, in a full kinematics approach. Unfolding step by step the accessibility to the above configurations, it will require similar experiments at lower or/and higher energies. It will also require the interpretation of the data in a theoretical framework. Three-body models for the structure of
9
Be
have been developed and applied to reactions with heavy targets. Further research on lighter targets is required for the best establishment of the model. Such models are relevant for the calculation of the corresponding radiative capture reaction rate,
α
(
α
,
γ
)
9
Be
followed by
9
Be
(
α
,
n
)
12
C
. The last is essential for the
r
-process abundance predictions.
Purpose: Investigate the breakup decay rate of
9
Be
+
p
at
2.72
A
MeV, where the direct configuration
α
+
α
+
n
is mainly accessible. Compare and interpret data at this low energy and at the higher energy of
5.67
A
MeV into a four-body continuum discretized coupled-channel formalism. Point out and discuss couplings to continuum.
Methods: Our experimental method includes an exclusive breakup measurement in a full kinematic approach of
9
Be
incident on a proton target at 24.5 MeV (
2.72
A
MeV). Complementary the elastic scattering is measured and other reaction channels are evaluated from previous measurements under the same experimental conditions. The interpretation of present data at
2.72
A
MeV and previous data at
5.67
A
MeV, are considered in a four-body continuum discretized coupled channel (CDCC) approach, using the transformed harmonic oscillator method for the three-body projectile.
Results: An elastic scattering angular distribution at
2.72
A
MeV is measured, which compares very well with CDCC calculations, indicating a strong coupling to continuum. At the same energy, the breakup and total reaction cross sections are measured as
σ
break
=
2.5
±
1
mb
and
σ
tot
=
510
±
L
90
mb
, in good agreement with the calculated values of 3.7 and 433 mb, respectively. Further on, into the same theoretical framework, the elastic scattering and breakup cross section data at
5.67
A
MeV are found in very good agreement with the CDCC calculations.
Conclusions: It was confirmed in a global experimental framework that four-body CDCC calculations can describe very well the data even at low energies. Coupling to continuum is very strong despite the small measured breakup cross section. Moreover, the present results support further our three-body model for the structure of
9
Be
, validating relevant radiative reaction rates obtained previously.Programa de investigación e innovación de la Unión Europea HORIZON2020 No. 654002-ENSAR2European Research Council (ERC) 714625Ministerio de Ciencia, Innovación y Universidades de España. PGC2018-095640-B-I00Ministerio de España de Economía y Competitividad y Fondo de Desarrollo de la Unión Europea (FEDER) FIS2017- 88410-PFondos SID 2019 (Università degli Studi di Padua, Italia) CASA_SID19_0
Desacidificación por destilación mediante arrastre con nitrógeno. Posible aplicación a la refinación de grasas comestibles
The possibility of substituting direct steam by nitrogen as stripper in the deodorizing or neutralizing distillation of oils and fats has been the subject of research in recent years. Although this is a practical possibility, it implies a greater cost due to the higher price of nitrogen, and the need to adapt the technology in order to maintain the deodorizer head pressure (as nitrogen does not condensate). These disadvantages would be compensated by a better quality of the oils and condensates, and a decrease in pollution.
The tests carried out indicate that the efficiency calculated in each of the operations is within the theoretical values, and that using from 1 to 1.5 times the theoretical amount of nitrogen, the refined oils are graded physically as good and very good by an expert. The condensates obtained have been of good quality.En los últimos años se está investigando la posibilidad de sustituir por nitrógeno el vapor de agua directo utilizado en la desodorización o la destilación neutralizante de aceites y grasas. Dicha posibilidad es factible, sin embargo implica un mayor costo debido al mayor precio del nitrógeno, y una necesidad de adecuar la tecnología para mantener la presión en cabeza del desodorizador (al no condensar el nitrógeno). Estos inconvenientes deben ser solventados por una mejor calidad de los aceites, de los condensados y por una disminución de la contaminación.
Los ensayos realizados indican que la "eficacia" calculada en cada una de las operaciones realizadas está dentro de los valores teóricos; y que los aceites refinados físicamente, mediante el paso de 1 a 1,5 veces la cantidad teórica de nitrógeno, tienen calificaciones de bueno y muy bueno dadas por un experto. Los condensados obtenidos han sido de buena calidad
Multicentre, randomised, open-label, phase IV-III study to evaluate the efficacy of cloxacillin plus fosfomycin versus cloxacillin alone in adult patients with methicillin-susceptible Staphylococcus aureus bacteraemia: Study protocol for the SAFO trial
Introduction Methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia is a frequent condition, with high mortality rates. There is a growing interest in identifying new therapeutic regimens able to reduce therapeutic failure and mortality observed with the standard of care of beta-lactam monotherapy. In vitro and small-scale studies have found synergy between cloxacillin and fosfomycin against S. aureus. Our aim is to test the hypothesis that cloxacillin plus fosfomycin achieves higher treatment success than cloxacillin alone in patients with MSSA bacteraemia. Methods We will perform a superiority, randomised, open-label, phase IV-III, two-armed parallel group (1:1) clinical trial at 20 Spanish tertiary hospitals. Adults (=18 years) with isolation of MSSA from at least one blood culture =72 hours before inclusion with evidence of infection, will be randomly allocated to receive either cloxacillin 2 g/4-hour intravenous plus fosfomycin 3 g/6-hour intravenous or cloxacillin 2 g/4-hour intravenous alone for 7 days. After the first week, sequential treatment and total duration of antibiotic therapy will be determined according to clinical criteria by the attending physician. Primary endpoints: (1) Treatment success at day 7, a composite endpoint comprising all the following criteria: patient alive, stable or with improved quick-Sequential Organ Failure Assessment score, afebrile and with negative blood cultures for MSSA at day 7. (2) Treatment success at test of cure (TOC) visit: patient alive and no isolation of MSSA in blood culture or at another sterile site from day 8 until TOC (12 weeks after randomisation). We assume a rate of treatment success of 74% in the cloxacillin group. Accepting alpha risk of 0.05 and beta risk of 0.2 in a two-sided test, 183 subjects will be required in each of the control and experimental groups to obtain statistically significant difference of 12% (considered clinically significant). Ethics and dissemination Ethical approval has been obtained from the Ethics Committee of Bellvitge University Hospital (AC069/18) and from the Spanish Medicines and Healthcare Product Regulatory Agency (AEMPS, AC069/18), and is valid for all participating centres under existing Spanish legislation. The results will be presented at international meetings and will be made available to patients and funders. © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ
Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network
Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star
Ultralight vector dark matter search using data from the KAGRA O3GK run
Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM
Quarry restoration treatments from recycled waste modify the physicochemical soil properties, composition and activity of bacterial communities and priming effect in semi-arid areas
The selection of a suitable organic amendment for recovery of semi-arid soils degraded by mining is key to the success of an ecological restoration. The aim of this research is to study the short-term responses of physicochemical, biochemical and biological properties, as well as the changes of a soil bacterial community at the genus level after application of five types of organic amendments in a limestone quarry in Almería (SE, Spain). The relationship among bacterial taxa with biochemical and physicochemical properties and priming effect from restored soils was also analysed. Six months after the application of organic amendments, the values of different soil status, such as total organic carbon, total nitrogen, assimilable phosphorus and labile organic matter forms (carbohydrates and polyphenols), basal respiration (BR) and enzymatic activities increased significantly with respect to unrestored soils. Similarly, a positive priming effect of soil organic matter mineralisation was produced by all organic amendments, being significantly higher (p < 0.05) in sewage sludge-treated soils. Bacterial diversity was higher in restored than in control soils. The restoration caused changes in soil bacterial communities' composition at the phylum and genus levels. It was observed that soil bacterial communities were significantly related to several physical, chemical and biochemical soil properties, establishing two different co-occurrence patterns between restored and unrestored soils. A first bacterial co-occurrence pattern showed significant positive correlations to pH and C/N ratio and negativity with the rest of the soil properties. The second bacterial pattern was positively correlated with carbohydrates, μg of C, priming effect, BR, β-glucosidase and phosphatase and negatively with pH and C/N ratio. It was concluded that soil bacterial communities are clearly influenced by the types of organic amendments applied. Bacterial taxa such as Taibaiella or Pseudomonas could perform key functions in the carbon cycle in restored soils.This work was supported by the Spanish FEDER-Ministry of Science, Innovation and Universities Research Project BIORESOC (CGL2017-88734-R) and AGL2017-85755-R MINECO/AEI/FEDER, UE, and FEDER-Junta de Andalucía Research Projects RESTAGRO (UAL18-RNM-A021-B) and Restoration of Abandoned Agricultural Soils in Semiarid Zones to Improve Productivity and Soil Quality and Enhance Carbon Sequestration (P18-RT-4112). Natalia Rodríguez-Berbel acknowledges a Ph.D. research grant from Spanish Government (PRE2018-084964). Isabel Miralles is grateful for funding received from the Ramón y Cajal Research Grant (RYC-2016-21191) from Spanish Ministry of Economy, Industry and Competitiveness (MINECO) and Raúl Ortega thanks his postdoctoral contract HIPATIA at University of Almería Research Plan. The authors wish to emphasize that this work was made possible by the kindness of CEMEX ESPAÑA OPERACIONES, S.L.U. (“CEMEX”) owners of the land located in the cement factory in Gádor (Almería) on which the study was carried out and BIOMASAS DEL GUADALQUIVIR, S.A. and Servicios Ambientales las Chozas, S.L. companies, for giving their composting products to this researc
Desacidificación por destilación mediante arrastre con nitrógeno. Posible aplicación a la refinación de grasas comestibles
Physical refining of edible oils using nitrogen as stripping gas. Process optimization
The use of nitrogen as a stripping gas in physical refining of edible oils represents a technological improvement with potential advantages such as the possibilities of recovering high quality deodorized distillates and eliminating pollution. <br /> The objectives of the present paper are to study, evaluate and optimize, as far as possible, independent variables involved in the process (nitrogen flow, operating temperature and the height of the oil layer inside the deodorizer) in reference to the quality of the obtained oils as well as the manufacturing requirements. <br /> All the experiments were carried out with sunflower oil in a discontinuous deodorizer with a 200 Kg capacity. A 4x4 latin square experimental design was used, consisting of three factors, each of which had four different levels. <br /> The results led to the establishment of charts that allow to determine the most suitable conditions in which to carry out the processing in accord with the desired quality of the finished oil and the functional objectives of the factory. These charts are presented in the paper. The results were checked by another set of experiments.<br><br>La utilización de nitrógeno como gas de arrastre en la refinación física de aceites comestibles representa un avance tecnológico con ventajas potenciales, como la posibilidad tanto de recoger destilados de desodorización de alta calidad como de eliminar polución.<br /> Los objetivos del presente trabajo son estudiar, evaluar y optimizar, tanto como sea posible, las variables que intervienen en el proceso (flujo de nitrógeno, temperatura de operación y altura de la capa de aceite en el desodorizador) en función de la calidad de los aceites obtenidos así como de los requerimientos de producción. <br /> Los ensayos se han realizado con aceite de girasol en un desodorizador discontinuo de 200 kg de capacidad. Se ha utilizado un diseño de experimento en cuadrado latino de 4x4, constituido por tres factores a cuatro niveles cada uno. <br /> Los resultados obtenidos han permitido establecer abacos adecuados para determinar las condiciones más interesantes en las que llevar a cabo el proceso, según la calidad de aceite final deseada y la función objetivo de la factoría. Dichos ábacos son presentados en el trabajo. Los resultados se han contrastado mediante una nueva serie de experiencias