Search results for "BN"
showing 10 items of 1136 documents
Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution
2009
Anion-exchange chromatography of element 105, dubnim (Db), produced in the 206 Cm( 19 F, 5n) 262 Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K d ) of Db on an anion-exchange resin is successfully determined by running cycles of 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta ≈ Nb > Db > Pa.
Chemical studies on rutherfordium (Rf) at JAERI
2005
SummaryChemical studies on element 104, rutherfordium (Rf), at JAERI (Japan Atomic Energy Research Institute) are reviewed. The transactinide nuclide261Rf has been produced in the reaction248Cm(18O, 5n) at the JAERI tandem accelerator with the production cross section of about 13 nb. On-line anion-exchange experiments on Rf together with the lighter homologues, group-4 elements Zr and Hf, in acidic solutions have been conducted with a rapid ion-exchange separation apparatus. From the systematic study of the anion-exchange behavior of Rf, it has been found that the properties of Rf in HCl and HNO3solutions are quite similar to those of Zr and Hf, definitely confirming that Rf is a member of …
Anionic Fluoro Complex of Element 105, Db
2009
We report on the characteristic anion-exchange behavior of the superheavy element dubnium (Db) with atomic number Z=105 in HF/HNO3 solution at the fluoride ion concentration [F−]=0.003 M. The resul...
Fluoride complexation of rutherfordium (Rf, element 104)
2000
The fluoride complexation of the group-4 elements Zr, Hf and Rf, and of the pseudo-homolog Th, has been investigated in mixed HNO3/HF solutions by studying Kd values on both cation exchange resins (CIX) and anion exchange resins (AIX) using the automated rapid chemistry apparatus ARCA. On the CIX, the four elements are strongly retained as cations below 10-3M HF. For Zr and Hf, the decrease of the Kd values due to the formation of fluoride complexes occurs between 10-3M HF and 10-2M HF. For Rf and Th, this decrease is observed at one order of magnitude higher HF concentrations. On the AIX, for Zr and Hf, a rise of the Kd values due to the formation of anionic fluoride complexes is observed …
SWALLOWING, SPEECH AND OROFACIAL DISORDERS IN CHILDREN WITH ADENOTONSILLAR HYPERTROPHY
2022
A prospective observational study was conducted to evaluate the presence of swallowing, speech and orofacial muscle imbalance (OMI) disorders in patients with adenotonsillar hypertrophy and their regression after surgery. ENT, speech therapist and dentistry examination were conducted before and 12 months after surgery in 78 children between the ages of 2 and 12 with dysphagia, speech disorders and OMI adenotonsillar hypertrophy related with sleep-disordered breathing. Of the 78 patients enrolled, 62 underwent adenotonsillectomy, 9 adenoidectomy and 7 volume reduction of the palatine tonsils with a 12-month post-operative increase in SWAL-QOL score, weight gain, correction of ogival palate, …
Problemas en la estimación y en el contraste de los rendimientos anormales a largo plazo: Estado de la cuestión
2002
-Jose.E.Farinos@uv.es -Ana.M.Ibanez@uv.es El paradigma de la eficiencia ha sido puesto en entredicho en las últimas décadas como consecuencia de la obtención de rendimientos anormales, estadística y económicamente significativos, durante amplios periodos de tiempo tras algunas importantes decisiones empresariales. No obstante, los problemas conceptuales y estadísticos que presenta la medición y contrastación de los rendimientos anormales a largo plazo ha supuesto que la evidencia obtenida pase a calificarse como anomalía. Dada la escasa proliferación de este tipo de estudios en nuestro mercado y el desafortunado desarrollo de algunos de los existentes, en este trabajo presentamos estos prob…
The cost of equity and exchange listing evidence from the French stock market
1997
We reconsider the behaviour of prices around the period close to the listing on the Marché à Règlement Mensuel (RM). First, an event study based on a sample of 60 firms has been set up to test the existence of the exchange listing effect on the French market. Then we discuss and test the financial reasons which can justify abnormal returns around the announcement day and the day of the listing. We explore four reasons to explain the impact of the stock exchange listings: one is the informative content of the operation which induces an upward revision of the future earnings. Three other hypotheses rely on a decrease in the discount rate originated by less risky cash flows, an increase in tra…
Sirenomelia, case report and review of the literature.
2020
We present a case of sirenomelia diagnosed in the first trimester of pregnancy. The ultrasound examination showed fused lower extremities and an anechoic structure in the lower abdomen that is clue in the early diagnosis. The postmortem study showed the existence of a single umbilical artery (vitelline artery), with an origin in the abdominal aorta. This finding not only explained the presence of a vascular steal with subsequent underdeveloped of pelvic organs, but also differentiated this condition from caudal regression syndrome.
Didáctica de la numeración en educación infantil: la metodología de algoritmos abiertos basados en números
2016
El presente Trabajo de Fin de Grado se centra en analizar los resultados extraídos de la implementación de una propuesta didáctica fundamentada en el método de algoritmos Abiertos Basados en Números (ABN). Ésta se llevó a cabo en un grupo de 22 alumnos de 5-6 años, en una escuela de titularidad pública y durante el curso escolar 2015-2016. Los objetivos que se plantearon fueron, por un lado, evaluar el desarrollo del sentido numérico en los participantes, y por otro lado, valorar si la enseñanza de la numeración y la aritmética básica, mediante una unidad didáctica sustentada en dicho método, conseguía adaptarse a la diversidad existente en el aula. Para ello, se realizó una observación del…
EFFECT OF THE IMPase INHIBITOR L690,330 ON SEA URCHIN DEVELOPMENT
1998
Abstract A variety of concentrations of the IMPase inhibitor L690,330 were added to sea urchin embryos. Immediate arrest of development was obtained for concentrations from 7.5 m m on. Concentrations lower than 3.5 m m permitted gastrulation but inhibited skeletogenesis and disturbed elongation along the animal–vegetal axis. The latter results are similar to those obtained by counteracting lithium effect with myoinositol, which are suggested to be due to partial relief of IMPase inhibition.