ABSTRACT
Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.
ABSTRACT
Conventional water treatments are generally inadequate for degradation of emerging pollutants such as ionic liquids (ILs). The use of heterogeneous electro-Fenton (HEF) has attracted great interest, due to its ability to efficiently oxidize a wide range of organic pollutants operating in cycles or in continuous mode. In this study, the removal of a complex IL from the imidazolinium family (1,3-Bis(2,4,6-trimethylphenyl)imidazolinium chloride), by means of HEF using iron alginate spheres as catalyst has been investigated, resulting in significant TOC decay after 6â¯h. The optimization of the key process parameters (current, IL concentration and catalyst dosage) has been performed using a Box-Behnken experimental design and achieving 76.98% of TOC abatement in 2â¯h of treatment. Current proved to be a crucial parameter and high catalyst dosage is required to achieve the maximum removal. In addition, an insight about the availability of iron into the reactor and the evolution of several intermediates has been carried out by employing differential pulse voltammetry on screen-printed carbon electrodes. The evolution of the different voltammetric peaks confirmed the influence of iron release, and the generation of several iron complexes has permitted the comprehension of the degradation pathway, which has been validated by chromatographic techniques.
Subject(s)
Ionic Liquids/chemistry , Water Purification/methods , Catalysis , Electrochemical Techniques , Electrodes , Hydrogen Peroxide/chemistry , Imidazolines , Iron/chemistry , Oxidation-Reduction , Water Pollutants, Chemical/chemistryABSTRACT
A simple strategy for covalent immobilizing DNA sequences, based on the formation of stable diazonized conducting platforms, is described. The electrochemical reduction of 4-nitrobenzenediazonium salt onto screen-printed carbon electrodes (SPCE) in aqueous media gives rise to terminal grafted amino groups. The presence of primary aromatic amines allows the formation of diazonium cations capable to react with the amines present at the DNA capture probe. As a comparison a second strategy based on the binding of aminated DNA capture probes to the developed diazonized conducting platforms through a crosslinking agent was also employed. The resulting DNA sensing platforms were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and spectroscopic ellipsometry. The hybridization event with the complementary sequence was detected using hexaamineruthenium (III) chloride as electrochemical indicator. Finally, they were applied to the analysis of a 145-bp sequence from the human gene MRP3, reaching a detection limit of 210 pg µL(-1).
Subject(s)
DNA/analysis , Diazonium Compounds/chemistry , Nucleic Acid Hybridization/methods , Biosensing Techniques , Carbon/chemistry , DNA Probes/chemistry , Electrochemical Techniques , Electrodes , Humans , Limit of DetectionABSTRACT
The 63Ni(n,γ) cross section has been measured for the first time at the neutron time-of-flight facility n_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian averaged cross sections were calculated for thermal energies from kT=5-100 keV with uncertainties around 20%. Stellar model calculations for a 25Mâ star show that the new data have a significant effect on the s-process production of 63Cu, 64Ni, and 64Zn in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.
ABSTRACT
In 2002, an innovative neutron time-of-flight facility started operation at CERN: n_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n_TOF is presented, together with plans for new measurements related to nuclear industry.
Subject(s)
Neutron Capture Therapy/instrumentation , Neutron Capture Therapy/methods , Nuclear Reactors , Equipment Design , Equipment Failure Analysis , Neutrons , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.
ABSTRACT
No disponible
Subject(s)
Humans , Hydrogen Peroxide/therapeutic use , Peroxides/therapeutic use , Halitosis/drug therapy , Anti-Infective Agents, Local/therapeutic useABSTRACT
No disponible
Subject(s)
Adult , Female , Humans , Phlebitis/diagnosis , Veins/pathology , Thorax , Phlebitis/drug therapy , Anti-Inflammatory Agents, Non-Steroidal , Anti-Inflammatory Agents/therapeutic useABSTRACT
The rate of the spontaneous decomposition of 4-methylbenzenediazonium tetrafluoroborate, 4MBD, was determined. The effects of solvent composition (MeOH/H2O) on its electrochemical processes and on those of the derivatized 2-naphthol-6-sulfonate-4-toluene (6S2NPT) azo dye were investigated by Differential Pulse Polarography (DPP). This electrochemical technique shows an effective sensitivity for detecting arenediazonium ions and derivatized azo dyes.
ABSTRACT
El dolor dental constituye una causa frecuente de consulta en atención primaria. Aunque en la mayoría de los casos la actuación por parte del médico general se limita a la aplicación de medidas terapéutico-paliativas del dolor y la inflamación, resulta interesante conocer las diferentes formas de presentación del dolor dental y las posibles causas que lo producen, con el fin de mejorar la comprensión del problema y la utilización de los fármacos, en ocasiones innecesarios, si se recurre al tratamiento por parte del odontólogo (AU)
Subject(s)
Humans , Toothache/etiology , Periodontal Diseases/complications , Toothache/classification , Toothache/diagnosis , Toothache/therapy , Periodontal Diseases/classification , Periodontal Diseases/diagnosis , Periodontal Diseases/therapyABSTRACT
El síndrome de boca ardiente es un cuadro relativamente frecuente en la consulta de atención primaria, caracterizado por la sensación de ardor o dolor en alguna zona de la mucosa oral sin ningún signo clínico evidente. Este trabajo revisa los posibles factores etiopatogénicos, su clínica, así como las diferentes actitudes diagnósticas y terapéuticas (AU)
