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Search Results: 1 - 10 of 834008 matches for " A.I. de Sá "
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Semiconductive properties of anodic niobium oxides
Sá,A.I. de; Rangel,C.M.; Skeldon,P.; Thompson,G.E.;
Portugaliae Electrochimica Acta , 2006,
Abstract: the semiconductive properties of anodic niobium oxides formed at constant potential and constant current density to different final voltages have been examined by mott-schottky analysis. thin anodic oxides were formed on sputtered niobium specimens at constant potential in the range of 2.5 to 10 vag/agcl in a borate buffer solution. thicker oxides were formed, also on sputtered niobium specimens, at a constant current density of 5 ma cm-2 in 0.1 m ammonium pentaborate solution to final voltages of 10, 50 and 100 v. capacitance measurements were performed in a borate buffer solution of ph 8.8, at a frequency range of 200 to 2000 hz, at a sweep rate of 5 mv s-1 from +2.5 to -1 vag/agcl. the results obtained show n-type semiconductor behaviour with a carrier density in the range of 8 ′ 1018 - 6 ′ 1019 cm-3 on films formed to 10 v. thicker films showed lower carrier densities in the range of 1 ′ 1018 - 2 ′ 1018 cm-3 with a calculated charge depletion layer of 33-36 nm.
Semiconductive properties of anodic niobium oxides
A.I. de Sá,C.M. Rangel,P. Skeldon,G.E. Thompson
Portugaliae Electrochimica Acta , 2006,
Abstract: The semiconductive properties of anodic niobium oxides formed at constant potential and constant current density to different final voltages have been examined by Mott-Schottky analysis. Thin anodic oxides were formed on sputtered niobium specimens at constant potential in the range of 2.5 to 10 V Ag/AgCl in a borate buffer solution. Thicker oxides were formed, also on sputtered niobium specimens, at a constant current density of 5 mA cm-2 in 0.1 M ammonium pentaborate solution to final voltages of 10, 50 and 100 V. Capacitance measurements were performed in a borate buffer solution of pH 8.8, at a frequency range of 200 to 2000 Hz, at a sweep rate of 5 mV s-1 from +2.5 to -1 V Ag/AgCl. The results obtained show n-type semiconductor behaviour with a carrier density in the range of 8 ′ 10(18) - 6 ′ 10(19) cm-3 on films formed to 10 V. Thicker films showed lower carrier densities in the range of 1 ′ 10(18) - 2 ′ 10(18) cm-3 with a calculated charge depletion layer of 33-36 nm.
Effects of terrace construction on runoff and erosion in a recently burnt forest area in north-central Portugal
M.A.S. Martins,D. Serpa,A.I. Machado,R.F.H. de Lenne
Flamma , 2013,
Abstract: In present-day Portugal, wildfires are a common phenomenon that, on average, affects some 100.000 ha of forest lands each year. Fires can markedly increase runoff generation and the associated sediment transport, nevertheless the magnitude of these impacts strongly depends on post-fire forestry management practices. This study evaluates the effect of terrace construction on runoff and erosion at micro-plot and catchment scale, six months after a wildfire in a forest area in north central Portugal. At the micro-plot scale, there was a clear trend for greater runoff volumes and sediment losses after the construction of terraces. In addition, pre-terracing sediment losses showed a visible relationship with rainfall amounts unlike post-terracing losses. At the catchment scale, an increase in sediment losses was observed after terracing consistently with micro-plot data.
Contracepción de emergencia: Una perspectiva desde la adolescencia
Brasa Andrés,J.; Celada Pérez,M. S.; Estepa Jorge,A.I.; Menéndez Ortiz de Zárate,M.M.;
Index de Enfermería , 2007,
Abstract: justification: emergency contraceptive (ea), is an increasing demanded on the different ages collectives. aim: describe the knowledge grade, attitudes and teenagers practices on ea. design: transversal descriptive. methodology: though self filling enquire and anonymous with 30 items about knowledge, attitudes, and practices relatives to ea to 446 students from the two "i.e.s torrijos". results: women the 53.4% average age: 15.6 years old ( rate: 13 to 19). the 33.1% (ic 95%, 28.7-37.6) have had sexual relations, noticing differences on ages (p 0.001). the knowledge valuation about ea was 3.9 over 10; bigger on women (4.3vs3.5; p 0.001) and on older ages (p 0.001). the main information source are the media, but the most wanted (wished) are the sanitary professional (86.3%). the 61.1% prefer to obtain it on especial centres to young people. the 61.1 % agree with must be use only when the usual contraceptive faies. a 8.4% (95%, 14.5-14.9) whom have had sexual relations has used at least once ea. a 9.1% are repeated. the 54.5% got it at the ap emergency. the 45.5% had troubles to get it. conclusion: the knowledge grade about ea is not so high. a high percentage don?t consider the method as an "emergency" one. on the age?s rate analysed, the use is scarce.
Contracepción de emergencia: Una perspectiva desde la adolescencia Emergency contraception: a perspective from the adolescence
J. Brasa Andrés,M. S. Celada Pérez,A.I. Estepa Jorge,M.M. Menéndez Ortiz de Zárate
Index de Enfermería , 2007,
Abstract: Justificación: La anticoncepción de emergencia es una demanda creciente en los diferentes grupos de edad. Objetivo: Describir el grado de conocimiento, actitudes y prácticas de adolescentes sobre anticoncepción de emergencia. Dise o: Descriptivo transversal. Participantes y métodos: Mediante encuesta autocumplimentada y anónima con 30 ítems sobre conocimientos, actitudes y prácticas relativas a anticoncepción de emergencia a 446 alumnos de dos Institutos de Educación Secundaria de Torrijos. Resultados: Son mujeres el 53.4%. Edad media: 15.6 a os (rango: 13 a 19). El 33.1% (Intervalo de confianza de 95% 28.7-37.6) han mantenido relaciones sexuales, apreciando diferencia por edades (p<0.001). La valoración de conocimientos sobre anticoncepción de emergencia fue de 3.9 sobre 10; mayor en mujeres (4.3 vs. 3.5; p<0.001) y en edades superiores (p<0.001). La principal fuente de información son los medios de comunicación (45.3%), pero la más deseada son los profesionales sanitarios (86.3%). El 61.1% prefiere obtenerla en centros especiales para jóvenes. El 66.1% está de acuerdo en que solo debe usarse cuando falla el anticonceptivo habitual. Un 8.4% (Intervalo de confianza de 95% 4.5-14.9) de los que han mantenido relaciones sexuales ha usado alguna vez anticoncepción de emergencia. Un 9.1% son repetidoras. El 54.5% la obtuvo en urgencias de Atención Primaria. El 45.5% tuvo dificultades para conseguirla. Conclusiones: el grado de conocimiento sobre anticoncepción de emergencia es bajo. Un alto porcentaje no considera el método como de "emergencia". En el rango de edades analizado, el uso es escaso. Justification: Emergency contraceptive (EA), is an increasing demanded on the different ages collectives. Aim: Describe the knowledge grade, attitudes and teenagers practices on EA. Design: Transversal descriptive. Methodology: Though self filling enquire and anonymous with 30 items about knowledge, attitudes, and practices relatives to EA to 446 students from the two "I.E.S Torrijos". Results: Women the 53.4% Average age: 15.6 years old ( rate: 13 to 19). The 33.1% (IC 95%, 28.7-37.6) have had sexual relations, noticing differences on ages (p 0.001). The knowledge valuation about EA was 3.9 over 10; bigger on women (4.3vs3.5; p 0.001) and on older ages (p 0.001). The main information source are the media, but the most wanted (wished) are the sanitary professional (86.3%). The 61.1% prefer to obtain it on especial centres to young people. The 61.1 % agree with must be use only when the usual contraceptive faies. A 8.4% (95%, 14.5-14.9) whom have had sexual relations
Eficacia de la detección percutánea de oxígeno como guía terapéutico-quirúrgica en lesionados medulares con úlceras por presión crónicas: estudio preliminar Eficacy of percutaneous oxygen detection as therapeutic-surgical guide in spinal cord injury patients with chronic pressure ulcers: preliminary report
J.M. Arévalo Velasco,A.I. de la Pe?a González,M. Solís Mozos,V. Lozano Berrio
Cirugía Plástica Ibero-Latinoamericana , 2012,
Abstract: En el presente estudio clínico realizamos detección transcutánea de oxígeno (TcpO2) en 11 pacientes consecutivos lesionados medulares parapléjicos crónicos (de más de 1 a o de evolución) con úlceras por presión (upp) crónicas de grado IV (de más de 6 meses de evolución). En todos analizamos los valores de la TcpO2 tanto en el momento preoperatorio como postoperatorio, llevando a cabo las siguientes comprobaciones. En la posición 1 preoperatorio (P1-pre: a 1 cm del borde de la upp) los valores obtenidos fueron de 27,28±13,83 mm Hg, mientras que en P1 postoperatorio fueron de 34,96±19,06 (p < 0.05). El valor medio del electrodo de referencia (no1) en el momento preoperatorio (51,63±12,53mm Hg) fue estadísticamente significativo (p < 0.05) al compararlo con el valor obtenido con el electrodo no1 (38,60±14,63 mm Hg) en el postoperatorio. El valor medio del electrodo de referencia (no1) en el momento del preoperatorio (50,07±13,54 mm Hg) es estadísticamente significativo (p < 0.05) al compararlo con los valores medios obtenidos de TcpO2 de las posiciones (P1+P2+P3) de los electrodos no2 (29,17±15,03 mm Hg), no3 (34,51±13,15 mm Hg) y no4 (30,37±17,81 mm Hg) analizados en el preoperatorio. Demostramos con estos hallazgos los niveles hipoxémicos a 1 cm del borde de una upp grado IV y su evolución postoperatoria. De esta forma, la técnica de detección transcutánea de oxígeno puede considerarse una guía terapéutica en la detección y en la monitorización del tratamiento de las upp, con la posibilidad de establecer intervenciones terapéuticas para poder mejorar los niveles de oxígeno detectados en las mismas. In this clinical study the detection of transcutaneous oxygen has been performed (TcpO2) to 11 consecutive patients with spinal cord injury chronic paraplegics (more than 1 year of evolution) with chronic pressure ulcers grade IV (more than 6 months). In all patients were analyzed preoperative and postoperative TcpO2 values, with the following results. In the preoperative position 1 (P1-pre: to 1 cm of the ulcer edge) values obtained are of 27.28 ± 13.83 mm Hg, while in P1 postoperative were 34.96 ± 19.06 (p < 0.05). The average value of the reference electrode (no 1) preoperative (51.63 ± 12.53 mm Hg) is statistically significant (p < 0.05) when compared with the value obtained with the electrode no1 (38.60 ± 14, 63 mmHg) in the postoperative state. The average value of the reference electrode (no 1) preoperative (50.07 ± 13.54 mm Hg) is statistically significant (p < 0.05) when compared with the average values of the positions (P1, P2, P3) obtained of TcPO2
Estrabismo y cataratas congénitas
Merino,P.; Gómez-de-Lia?o,P.; Gil,M.R.; Fernández,A.I.; Yá?ez,J.; Cortés,C.;
Archivos de la Sociedad Espa?ola de Oftalmología , 2007, DOI: 10.4321/S0365-66912007001000006
Abstract: purpose: to study the prevalence, characteristics, indications for and results of strabismus treatment secondary to congenital cataracts. materials and methods: this was a retrospective study of 21 cases from 29 with congenital cataracts with strabismus (unilateral in 11 and bilateral in 10 cases). in 20 patients surgery on the cataracts was performed, with an intraocular lens inserted in 15 patients. botulinum toxin and/or strabismus surgery were deemed to be indicated when the deviation was stable after rehabilitation therapy. a good motor end result was considered when the final deviation was ≤ 5o, and a good sensorial result was when there was no suppression in the worth test even without stereopsis in the tno test. results: the strabismus prevalence was 72.4%. strabismus was present before cataract surgery was performed in 12 cases, 8 with esotropia (et) and 4 with exotropia (xt). strabismus which appeared after cataract surgery was classified as 13 et, 5 xt, 1 et with vertical anisotropia in ?v?, and 2 xt with dissociated vertical deviation (dvd). the strabismus angle was variable in 6 patients and was not treated. the other 6 cases required strabismus treatment. botulinum toxin was injected as the only treatment in 1 patient, strabismus surgery was performed in 4, and strabismus surgery and botulinum toxin were used in another case. the average age at the time of treatment was 5.2 years. the motor result was good in 5 cases (83.3%) and the sensorial result good in two (33.3%). conclusions: strabismus secondary to congenital cataracts occurred in a significant number of patients and increased after cataract extraction. esotropia occurred twice as often as exotropia. strabismus surgery was not required in most of the cases. the motor results were better than sensorial results.
Relevancia clínica de los aislamientos de micobacterias no tuberculosas Clinical relevance of nontuberculous Mycobacteria
Y. Salicio,A.I. álvaro,A.I. Bermejo,A. Navascués
Anales del Sistema Sanitario de Navarra , 2008,
Abstract: Fundamento. El aislamiento de micobacterias no tuberculosas (MNT) se ha incrementado en los últimos a os debido en gran parte a la utilización de medios de cultivo líquidos. Estos aislamientos carecen en muchos casos de relevancia clínica, por lo que la valoración de su significado debe realizarse en base a unos criterios clínicos internacionales. En el presente trabajo hemos estudiado el impacto que supondría la aplicación de los criterios que la American Thoracic Society (ATS) ha establecido para diferenciar en muestras respiratorias una infección de una colonización por MNT. Métodos. Estudio microbiológico y clínico de los pacientes con aislamientos repetidos de MNT en muestras respiratorias registrados en nuestro laboratorio entre los a os 2000-2004. Resultados. Se obtuvieron 116 cultivos positivos de MNT aisladas repetidamente en 46 episodios correspondientes a 42 pacientes. Se identificaron 11 especies distintas: M. xenopi (16 casos), M. avium (12), M. kansasii (7), M. fortuitum (5), M. malmoense (2) y finalmente 1 de cada una de las siguientes: M. genavense, M. simiae, M. gordonae y M. lentiflavum. Se pudieron estudiar 36 pacientes, de los que 17 cumplían los criterios de la ATS y, de estos, sólo 12 recibieron tratamiento específico. En los casos que no se cumplían los criterios de la ATS los aislamientos no tuvieron ninguna repercusión clínica. En ambos grupos, tratados y no tratados, no se observó una evolución claramente diferenciada. Conclusiones. Ante la dificultad de atribuir a una MNT de muestras respiratorias un papel etiológico, es necesario atenerse a criterios internacionales como los de la ATS antes de iniciar un tratamiento específico para evitar tratamientos incorrectos a los pacientes. Background. The isolation of nontuberculous mycobacterias (NTM) has increased in recent years largely due to the use of liquid cultivation media. In many cases such isolations lack clinical relevance, which is why the evaluation of their meaning must be carried out on the basis of international clinical criteria. This article studies the impact of using the criteria that the American Thoracic Society (ATS) has established for differentiating an infection of NTM colonisation in respiratory samples. Methods. Microbiological and clinical study of the patients with repeated isolations of NTM in respiratory samples registered in our laboratory between 2000 and 2004. Results. One hundred and sixteen positive cultivations of NTM were obtained, repeatedly isolated in 46 episodes corresponding to 42 patients. Eleven different species were identified: M. xenop
Inhibitory Effects of Marama (Tylosema esculentum) on the Growth of Oat (Avena sativa) and Barley (Hordeum vulgare)
I.S. Travlos,G. Economou,A.I. Karamanos
Journal of Biological Sciences , 2008,
Abstract: This study was conducted in order to evaluate the allelopathic potential of marama bean (Tylosema esculentum (Burch) A. Schreib), a drought-avoider legume of Africa, which produces seed and tubers with potential for use as human food and animal fodder. Fresh, senesced and decaying leaves from marama were evaluated for their allelopathic potential on oat (Avena sativa) and barley (Hordeum vulgare) through in vivo studies. The studies were performed in growth chambers, using 10, 20 and 30 g of leaf tissue mixed with screened perlite as a substrate. The effects of the different leaf types were evaluated by determining root fresh and dry weight, shoot length and shoot fresh and dry weight. The results indicated the allelopathic potential of the marama leaves, being more pronounced in the fresh, moderate in the senesced and lower in the decaying leaves.
The Quantization of the Absorption Spectrum for Amorphous Semiconductor Films
Mazinov A.S.-A.,Shevchenko A.I.
Proceedings of the International Conference Nanomaterials : Applications and Properties , 2013,
Abstract: Approach to the description of the photoelectric converter built on the basis of nanosized semiconductor film was presented. The absorption coefficient of the incident quantum flux was presented as the sum of the vibration modes, determined by their own energies have been picked up from the Schr dinger equation, which describes the disordered atomic matrix.
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