959 resultados para PN1997.2 W35 2008
Resumo:
This Green Guide provides a brief summary of the alarming evidence of changing climate in the Cayman Islands. As we illustrated in our first Green Guide (2008), our lives on these three magical islands are intimately connected to the land and the surrounding sea. Our economy depends on keeping our islands healthy, because our coral reefs, our beaches, our natural heritage, all draw many thousands of overseas visitors to our shores. It is our responsibility, as stakeholders sharing this beautiful environment, to do what we can to minimise our impact upon it... [PDF contains 32 pages]
Resumo:
506 p.
Resumo:
HIGHLIGHTS FOR FY 2008 1. Completed the first of a two-year Gulf sturgeon population study on the Choctawhatchee River, Florida. The sub adult and adult Gulf sturgeon population was estimated at 2,800 fish. 2. Gulf sturgeon eggs were collected at three hard bottom sites in the Apalachicola River, Florida; two sites were previously confirmed spawning areas and one was a newly confirmed spawning area. 3. Documented 55 potential environmental threats to Gulf sturgeon spawning habitat in the Pea River, Florida and Alabama. 4. Assigned the Eglin AFB Road-Stream Crossing Working Group to guide the closure, repair and maintenance of roads and road stream crossings that impact threatened and endangered species. 5. Conducted 81 assessments of fish and stream invertebrates on and in watersheds surrounding Eglin AFB. 6. Provided technical support for the 5-year status review and reclassification proposed rule for the Okaloosa darter. 7. Initiated an intensive population genetic analysis of the Okaloosa darter throughout its range. Tissues from over 200 Okaloosa darters were collected and analyzed. 8. Established a GIS database to serve as a host for data from any sites sampled for mussels in Northeast Gulf of Mexico drainages. 9. Conducted habitat surveys at 115 locations in the Apalachicola River to assess the effects of drought-related mussel mortality and strandings, evaluate habitat conditions, and assess population demography. 10. A land use/aerial imagery threats assessment data analysis was completed for the Chipola River. A total of 266 impoundments/borrow pits and 471 unpaved road crossings were identified among the threats. 11. Okaloosa darters marked with elastomeric dyes were monitored in Mill Creek, Eglin AFB, to determine movement and habitat use following completion of a fish passage project. 3 12. Partners for Fish and Wildlife funded a streambank and riparian restoration project on Econfina Creek consisting of 3,900 feet of streambank fencing to exclude cattle access. One acre of riparian floodplain was planted with native trees. 13. We provided design and on-the-ground assistance for restoring surface hydrology at St. Vincent NWR. The project restored approximately 1.5 miles of tidal stream and 100 acres of wetlands. 14. A study was completed on 11 coastal streams to document large wood debris relationships with fluvial geomorphic characteristics. 15. We developed a Population Viability Analysis model for the fat threeridge mussel to determine current and future risk of extinction. 17. A Gulf Sturgeon Friends Group, “Gulf Sturgeon Preservation Society” was organized in FY 08. 18. Multiple outreach projects were completed to detail aquatic resource conservation needs and opportunities, including National Fishing Week, Earth Day, several festivals and school outreach.
Resumo:
We report on the conversion of near-ultraviolet radiation of 250-350 nm into near-infrared emission of 970-1100 nm in Yb3+-doped transparent glass ceramics containing Ba2TiSi2O8 nanocrystals due to the energy transfer from the silicon-oxygen-related defects to Yb3+ ions. Efficient Yb3+ emission (F-2(5/2)-> F-2(7/2)) was detected under the excitation of defects absorption at 314 nm. The occurrence of energy transfer is proven by both steady state and time-resolved emission spectra, respectively, at 15 K. The Yb2O3 concentration dependent energy transfer efficiency has also been evaluated, and the maximum value is 65% for 8 mol % Yb2O3 doped glass ceramic. These materials are promising for the enhancement of photovoltaic conversion efficiency of silicon solar cells via spectra modification.
Resumo:
Near-infrared to ultraviolet upconversion luminescence was observed in the Pr3+ :Y2SiO5 crystal with 120 fs, 800 mn infrared laser irradiation. The observed emissions at around 270 nm and 305 nm could be assigned to 5d -> 4f transitions of Pr3+ ions. The relationship between the upconversion luminescence intensity and the pump power of the femtosecond laser reveals that the UV emission belongs to simultaneous three-photon absorption induced upconversion luminescence. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
A temática deste estudo está centrada na participação da enfermeira obstétrica no modelo humanizado de atenção ao parto e teve como objetivos: identificar as práticas de enfermeiras obstétricas atuantes no trabalho de parto e parto em uma maternidade municipal do Rio de Janeiro; avaliar a consonância das práticas desenvolvidas por enfermeiras obstétricas durante o trabalho de parto e parto com as recomendações do MS/OMS; analisar a implementação das práticas das enfermeiras obstétricas na assistência ao trabalho de parto e parto entre 2004 e 2008. Trata-se de um estudo descritivo, quantitativo, transversal. O período pesquisado foi de setembro de 2004 a setembro de 2008. A coleta dos dados foi através do livro de registro de partos onde foram registrados 4.510 partos assistidos por enfermeiras. Para a análise foram calculadas a média, mediana e proporção de cada variável estudada, conforme a indicação. As análises foram realizadas utilizando os programas Epi info versão 3.5.1 e Microsoft Word Excel 2007. Verificou-se que a maioria das parturientes assistidas foram jovens, sendo a mediana de idade de 23 anos, que já tinham engravidado duas vezes ou mais e que já tinham parido anteriormente pelo menos uma vez. Com relação à assistência pré-natal 92,8% realizaram o mesmo, contudo apenas 68,2% destas mulheres realizaram seis consultas ou mais. Identificou-se que o acompanhante esteve presente em 60,6% dos partos, porém esta presença foi maior nos partos das adolescentes (77,4%). A posição do parto predominante durante todo o período do estudo foi a vertical (77,6%). As lacerações perineais ocorreram em 52,3% dos partos e a mais incidente foi a laceração de primeiro grau (34,2%). As parturientes que não sofreram qualquer injúria perineal, seja esta espontânea ou cirúrgica, representaram 30,2% dos casos. As práticas obstétricas que não interferem na fisiologia do parto foram realizadas por 85,3% das parturientes, sendo que as mais utilizadas foram os exercícios respiratórios (73,6%), os movimentos pélvicos (42,1%) e a deambulação (29,8%). 67,9% das mulheres assistidas pelas enfermeiras receberam as práticas intervencionistas à fisiologia do parto, destas as mais registradas foram: a realização da amniotomia (25,1%), a administração endovenosa de ocitocina (54%), a realização da episiotomia (22,9%). A episiotomia foi mais utilizada entre as adolescentes (34,8%), nulíparas (44%) e naquelas que pariram na posição horizontal (28,8%). 40,2% das mulheres que não realizaram episiotomia não tiveram laceração perineal e a posição de parto com a menor incidência de laceração perineal foi a quatro apoios (25%), sendo esta classificada como primeiro grau. As adolescentes (55,1%) e as multíparas (71,8%) foram as que menos apresentaram lacerações de períneo. Conclui-se que tanto a prática apoiada no modelo tecnocrático, quanto àquela baseada no modelo humanizado de atenção ao parto, foram registradas na unidade pesquisada. Considera-se que tal fato pode ser investigado em outros estudos, com o objetivo de identificar os fatores que levam à realização de práticas que interferem na fisiologia do parto durante a assistência das enfermeiras obstétricas.
Resumo:
An optical communication scheme of 2-D pattern transfer based on imaging optics for submarine laser uplink communication (SLUC) is suggested. Unlike the methods aiming at avoiding neighboring crosstalk used in traditional multi-channel optical beam transferring, we make full use of the overlapping of each spreading beam other than controlling divergence effect of each beam to avoid interference noise. The apparent parameters have been introduced to simplify theoretical analysis of optical pattern transfer problem involving underwater condition, with the help of which the complex beam propagation inside two kinds of mediums can be easily reduced to brief beam transfer only inside air medium. In this paper, optical transmission path and receiver terminal optics geometry have been described in detail. The link range equation and system uplink performance analysis have also been given. At last, results of a proof-of-concept experiment indicate good feasibility of the proposed SLUC model. © 2007 Elsevier GmbH. All rights reserved.
Resumo:
O presente estudo tem por objetivos compilar e analisar percepções sobre o uso de ferramentas web 2.0 no ensino de inglês como língua estrangeira e aliar a análise de atitudes à teoria da Andragogia, que trata do aprendizado de adultos, proposta por Knowles (1973, 1975, 1984, 1990). O assunto parece não contar com estudos coordenados, visto que Thomas (2010) apenas muito recentemente editou um compêndio com trabalhos envolvendo as possíveis aplicações de recursos da web 2.0 no estudo de uma língua estrangeira e as percepções de alunos, embora outros estudos, como os de Rosell-Aguilar (2004), Conole (2008), Kárpáti (2009) e Jarvis e Szymczyk (2010) tenham discutido o assunto isoladamente. Neste trabalho é realizada a compilação das opiniões de alunos adultos e de professores de inglês como língua estrangeira. Como instrumento de coleta de dados optou-se pela utilização de questionários fechados. Tal abordagem possivelmente dá a esta pesquisa um caráter inédito, ao menos no que se refere à coleta de atitudes de alunos adultos e professores brasileiros de um curso de idiomas quanto ao uso de ferramentas web 2.0 no ensino de uma língua estrangeira. A análise dos dados mostrou que aprendizes adultos e professores têm atitudes positivas e estão preparados para a utilização de recursos web 2.0 em sala de aula. Conclui-se, entretanto, que embora a maioria dos participantes desta pesquisa concorde que o uso de tais ferramentas contribui para o ensino de inglês como língua estrangeira, alguns ajustes e procedimentos ainda devem ser implementados para que as ferramentas web 2.0 se tornem não apenas um acessório, mas parte integrante do processo de aquisição do idioma
Resumo:
The Er3+-Yb3+ codoped Al2O3 has been prepared by the sol-gel method using the aluminium isopropoxide [Al(OC3H7)(3)]-derived Al2O3 sols with addition of the erbium nitrate [Er(NO3)(3) center dot 5H(2)O] and ytterbium nitrate [Yb(NO3)(3) center dot 5H(2)O]. The phase structure, including only two crystalline types of doped Al2O3 phases, theta and gamma, was obtained for the 1 mol% Er3+ and 5 mol% Yb3+ codoped Al2O3 at the sintering temperature of 1,273 K. By a 978 nm semiconductor laser diodes excitation, the visible up-conversion emissions centered at about 523, 545, and 660 nm were obtained. The temperature dependence of the green up-conversion emissions was studied over a wide temperature range of 300-825 K, and the reasonable agreement between the calculated temperature by the fluorescence intensity ratio (FIR) theory and the measured temperature proved that Er3+-Yb3+ codoped Al2O3 plays an important role in the application of high temperature sensor.
Resumo:
Para analisar cepas de Salmonella ser. Typhimurium isoladas de processos entéricos e extraintestinais humanos ocorridos no período de 1970 a 2008 de diferentes regiões do país foram selecionadas, com base nos registros contidos no banco de dados do Laboratório de Enterobactérias do IOC/FIOCRUZ, RJ, amostras do fagotipo prevalente 193, visando precipuamente o reconhecimento de clones epidêmicos. Foram selecionadas 553 cepas de Salmonella ser. Typhimurium fagotipo 193 representadas por 91, 65, 70 e 327 amostras referentes as décadas de 70, 80, 90 e ao período de 2000 a 2008, respectivamente. Na análise global da sensibilidade destas cepas, 52% apresentaram um ou mais marcadores de resistência a antibióticos incluídos no perfil ACSSuT. Este perfil de resistência completo foi verificado em 20,9% dos isolados, sendo os 21,9% restantes, sensíveis a todas as drogas testadas, especialmente no período de 2000 a 2008, representadas por 121 amostras (37,0%) em relação as 327 culturas dessa época. O maior percentual de resistência foi observado nas amostras da década de 70 (99%) sendo o perfil ACSSuT detectado em 35,2% dos isolados, ressaltando-se que todas as amostras foram isoladas de processos gastroentéricos ocorridos na cidade de São Paulo. Ao longo das quatro décadas de estudo, descreve-se um ponto de ruptura entre a prevalência de resistência e a suscetibilidade na transição entre as décadas de 80 e 90. Embora o número de isolados de Salmonella ser. Typhimurium fagotipo 193 tenha aumentado no último período considerado, o percentual de mono e multirresistência aos antimicrobianos se situou em nível elevado (63,0%). A análise do polimorfismo obtido após macrorrestrição com a enzima XbaI revelou que cepas isoladas na década de 90 apresentaram elevado percentual de similaridade (≥85%) com cepas isoladas recentemente (período de 2000-2008), sendo agrupadas nos mesmos subclusters. Por outro lado, as cepas da década de 70 inserem-se em subclusters independentes, embora o percentual de similaridade entre tais subclusters e os demais seja ≥70%; o mesmo sendo observado para as cepas isoladas durante a década de 80. Em conclusão, este estudo mostrou que a prevalência de isolados humanos de Salmonella ser. Typhimurium fagotipo 193 no Brasil vem progredindo desde a década de 1990, enquanto a detecção do modelo R (ACSSuT) está diminuindo e a avaliação através da PFGE indicou a presença de multiplicidade de perfis de macrorrestrição no fagotipo 193, entretanto com elevados percentuais de similaridade entre si, sugerindo alguma clonalidade, tendo em vista o período entre o isolamento e a análise
Resumo:
Two new hydrazone chelating ligands, 2-(2-(5-methylisoxazol-3-yl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione (HL1) and 2-(2-(5-tert-butylisoxazol-3-yl)hydrazono)-5,5-dimethylcyclohexane- 1,3-dione (HL2), and their nickel(II) and copper(II) complexes were synthesized using the procedure of diazotization, coupling and metallization. Their structures were postulated based on elemental analysis, H-1 NMR, ESI-MS, FT-IR spectra and UV-vis electronic absorption spectra. Smooth films of these complexes on K9 glass substrates were prepared using spin-coating and their absorption properties were evaluated. The thermal properties of the metal(II) complexes were investigated by thermogravimetry (TG) and differential thermogravimetry (DTG). Different thermodynamic and kinetic parameters namely activation energy (E
Resumo:
Sheet resistance of laser-irradiated Ge2Sb2Te5 thin films prepared by magnetron sputtering was measured by the four-point probe method. With increasing laser power the sheet resistance undergoes an abrupt drop from 10(7) to 10(3) Omega/square at about 580 mW. The abrupt drop in resistance is due to the structural change from amorphous to crystalline state as revealed by X-ray diffraction (XRD) study of the samples around the abrupt change point. Crystallized dots were also formed in the amorphous Ge2Sb2Te5 films by focused short pulse laser-irradiated, the resistivities at the crystallized dots and the non-crystallized area are 3.375 x 10(-3) and 2.725 Omega m, sheet resistance is 3.37 x 10(4) and 2.725 x 10(7) Omega/square respectively, deduced from the I-V Curves that is obtained by conductive atomic force microscope (C-AFM). (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
We demonstrate passive Q-switching of short-length double-clad Tm3+-doped silica fiber lasers near 2 mu m pumped by a laser diode array (LDA) at 790 nm. Polycrystalline Cr2+:ZnSe microchips with thickness from 0.3 to 1 mm are adopted as the Q-switching elements. Pulse duration of 120 ns, pulse energy over 14 mu] and repetition rate of 53 kHz are obtained from a 5-cm long fiber laser. As high as 530 kHz repetition rate is achieved from a 50-cm long fiber laser at similar to 10-W pump power. The performance of the Q-switched fiber lasers as a function of fiber length is also analyzed. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Thermal effects in Nd:YAG planar waveguide lasers with non-symmetrical claddings are discussed. The heat generated in the active core can be removed more efficiently by directly contacting the active core to the heat sink. Several cladding materials are compared to optimize the heat removal. Furthermore, uniform pumping is achieved with oblique edge-pumping technique. Using quasi-CW pumping at 1 KHz repetition rate, an average output power of 280 W with a slope efficiency of 38% is obtained with a positive unstable resonator. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
Cylindrical vector beams were produced from laser diode end-pumped Nd:YAG ceramic microchip laser by use of two types of subwavelength multilayer gratings as the axisymmetric-polarization output couplers respectively. The grating mirrors are composed of high- and low-refractive-index (Nb2O5/SiO2) layers alternately while each layer is shaped into triangle and concentric corrugations. For radially polarized laser output, the beam power reached 610mW with a polarization extinction ratio ( PER) of 61: 1 and a slope efficiency of 68.2%; for azimuthally polarized laser output, the beam power reached 626mW with a PER of 58: 1 and a slope efficiency of 47.6%. In both cases, the laser beams had near-diffraction limited quality. Small differences of beam power, PER and slope efficiency between radially and azimuthally polarized laser outputs were not critical, and could be minimized by further optimized adjustment to laser cavity and the reflectances of respective grating mirrors. The results manifested, by use of the photonic crystal gratings mirrors and end-pumped microchip laser configuration, CVBs can be generated efficiently with high modal symmetry and polarization purity. (C) 2008 Optical Society of America.