Atributos químicos de solos influenciados pela substituição do carbonato por silicato de cálcio

A aplicação de silicatos pode promover incrementos na capacidade de troca de cátions, favorecer a disponibilização de ânions, especialmente o H2PO4- (fosfato diácido), elevar o pH, amenizar a toxidez de Al e, de maneira geral, incrementar a disponibilidade de nutrientes para as plantas, apresentando, porém, uma eficiência agronômica inferior em comparação aos carbonatos. Com o objetivo de avaliar o efeito da substituição do carbonato de Ca por silicato de Ca sobre as propriedades químicas dos solos, especialmente em relação à disponibilidade de P, foram realizados quatro experimentos em casa de vegetação, num delineamento inteiramente casualizado, com quatro repetições. Os tratamentos consistiram de cinco níveis de substituição (0, 25, 50, 75 e 100 %) do carbonato de Ca por silicato de Ca, mantendo uma relação estequiométrica Ca:Mg de 4:1 e o mesmo conteúdo de CaO, suficientes para elevar V = 60 %. Os tratamentos foram aplicados em amostras de 4 dm³ de Neossolo Quartzarênico órtico, Latossolo Vermelho-Amarelo textura média, Latossolo Vermelho-Amarelo textura argilosa e Latossolo Vermelho textura muito argilosa, sendo cada solo um experimento. Foram determinados os valores dos atributos químicos dos solos: pH em H2O, P, P remanescente (P-rem), K, Ca, Mg, Si, Al, H + Al, matéria orgânica (MO), Cu, Mn, Zn e B, soma de bases (S), a CTC efetiva (t), a CTC em pH 7,0 (T), a saturação por bases (V) e a saturação por Al (m), os quais foram submetidos à analise de variância e ao ajuste de modelos de regressão simples, considerando os níveis de substituição de CaCO3 por CaSiO3. Verificou-se que a substituição de carbonato por silicato promoveu aumentos significativos nos valores de Si, Al, H + Al e m e redução nos valores de P-rem, pH, S, t e V; já os valores de P Mehlich-1, K, Mg, MO, T, Mn, Cu e B não foram influenciados significativamente. Houve declínio na disponibilidade de Zn somente no solo RQo. A eficácia do silicato de Ca foi inferior à de carbonato de Ca na melhoria das condições químicas do solo.

Radiative association of C and P, and Si and P atoms

The rate coefficients for the formation of carbon monophosphide (CP) and silicon monophosphide (SiP) by radiative association are estimated for temperatures ranging from 300 to 14 100 K. In this temperature range, the radiative association rate coefficients are found to vary from 1.14 x 10(-18) to 1.62 x 10(-18) cm(3) s(-1) and from 3.73 x 10(-20) to 7.03 x 10(-20) cm(3) s(-1) for CP and SiP, respectively. In both cases, rate coefficients increase slowly with the increase in temperature.

Amorphous HfO(2) and Hf(1-x)Si(x)O via a melt-and-quench scheme using ab initio molecular dynamics

We have performed ab initio molecular dynamics simulations to generate an atomic structure model of amorphous hafnium oxide (a-HfO(2)) via a melt-and-quench scheme. This structure is analyzed via bond-angle and partial pair distribution functions. These results give a Hf-O average nearest-neighbor distance of 2.2 angstrom, which should be compared to the bulk value, which ranges from 1.96 to 2.54 angstrom. We have also investigated the neutral O vacancy and a substitutional Si impurity for various sites, as well as the amorphous phase of Hf(1-x)Si(x)O(2) for x=0.25, 0375, and 0.5.

Nanocrystalline p-layer for a-Si:H p-i-n solar cells and photodiodes

We report on structural, electronic, and optical properties of boron-doped, hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited by plasma-enhanced chemical vapor deposition (PECVD) at a substrate temperature of 150 degrees C. Film properties were studied as a function of trimethylboron-to-silane ratio and film thickness. The absorption loss of 25% at a wavelength of 400 nm was measured for the 20 nm thick films on glass and glass/ZnO:Al substrates. By employing the p(+) nc-Si:H as a window layer, complete p-i-n structures were fabricated and characterized. Low leakage current and enhanced sensitivity in the UV/blue range were achieved by incorporating an a-SiC:H buffer between the p- and i-layers.

A 3-phase model for VIS/NIR mu C-Si : H p-i-n detectors

The spectral response and the photocurrent delivered by entirely microcrystalline p-i-n-Si:H detectors an analysed under different applied bias and light illumination conditions. The spectral response and the internal collection depend not only on the energy range but also on the illumination side. Under [p]- and [n]-side irradiation, the internal collection characteristics have an atypical shape. It is high for applied bias and lower than the open circuit voltage, shows a steep decrease near the open circuit voltage (higher under [n]-side illumination) and levels off for higher voltages. Additionally, the numerical modeling of the VIS/NIR detector, based on the band discontinuities near the grain boundaries and interfaces, complements the study and gives insight into the internal physical process.

Clonal variation in nutrient content in woody biomass of hybrid aspen (Populus tremula L. x P. tremuloides Michx.)

Abstract

Identificação morfológica de organismos semelhantes à anaplasmataceae em monócitos de surubim híbrido (Pseudoplatystoma reticulatum x P. corruscans) – relato de caso

The aim of this study was to report the occurrence of Anaplasmataceae-like organisms in monocytes from the hybrid surubim catfish. During the hematological evaluation of fish infected by Pseudomonas sp. in a fish farm located in the State of Mato Grosso do Sul we observed into the monocytes the presence of numerous pleomorphic inclusions of various sizes, rough in appearance which presented basophilic staining. These inclusions were similar to elementary bodies, initial bodies and morule of the bacteria from Anaplasmataceae family, often diagnosed in domestic mammals. This is the first report of its occurrence possibly belonging to the family of Anaplasmataceae in cultured fish in Brazil. Additional studies are necessary for molecular characterization of this bacteria, pathogenic potential, life cycle and impact on the intensive production of fish.

Officia propria sanctorum Toletanae Ecclesiae et Diocesis : a SS. D.N. Gregorio XIII olim approbata deindè à Sixto V. Clemente VIII. Paulo V. Gregorio XV. Urbano VIII. Alexandro VII & novisime à Clemente X P.P. M.M. concesa & ampliata : ad officij novi formana redacta /

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Novum Testamentum graece et latine : expressum ad binas editiones a Leone X. P.M. adprobatas complutensium scilicet et Erasmi Roterod. : additae sunt recensionum Roberti Stephani, C. F. de Matthaei et J. J. Griesbachii variantes lectiones graecae : una cum Vulgata latina, editionis Clementinae ... /

Errata page included.

Genetic control of adventitious rooting on stem cuttings in two Pinus elliottii x P-caribaea hybrid families

Genetic control of adventitious rooting was characterised in two unrelated Pinus elliottii x P. caribaea families, an outbred F-1 (n = 287) and an inbred F-2 ( n = 357). Rooting percentage was assessed in three settings and root biomass was measured on a sub-set of clones ( n = 50) from each family in the third setting. On average, clones in the outbred F-1 had a higher rooting percentage (mean +/- SE; 59 +/- 1.9%) and biomass (mean +/- SD; 0.41 +/- 0.24 g) than clones in the inbred F-2 family ( mean +/- SE; 48 +/- 1.8% and mean +/- SD; 0.19 +/- 0.13 g). Genetic determination for rooting percentage was strong in both families, as indicated by high individual setting clonal repeatabilities ( e. g. Setting 3; outbred F-1 0.62 +/- 0.03 and inbred F-2 0.68 +/- 0.02 (H-2 +/- SE)) and the moderate-to-high genetic correlations amongst the three settings. For root biomass, clonal repeatabilities for both families were lower (outbred F-1 0.35 +/- 0.09 and inbred F-2 0.44 +/- 0.10 (H-2 +/- SE)). Weak positive genetic correlations between rooting percentage and root biomass in both families suggested a concomitant gain in root biomass would be insignificant when selecting solely on the more easily assessable rooting percentage.

Identificação morfológica de organismos semelhantes à anaplasmataceae em monócitos de surubim híbrido (Pseudoplatystoma reticulatum x P. corruscans) – relato de caso

The aim of this study was to report the occurrence of Anaplasmataceae-like organisms in monocytes from the hybrid surubim catfish. During the hematological evaluation of fish infected by Pseudomonas sp. in a fish farm located in the State of Mato Grosso do Sul we observed into the monocytes the presence of numerous pleomorphic inclusions of various sizes, rough in appearance which presented basophilic staining. These inclusions were similar to elementary bodies, initial bodies and morule of the bacteria from Anaplasmataceae family, often diagnosed in domestic mammals. This is the first report of its occurrence possibly belonging to the family of Anaplasmataceae in cultured fish in Brazil. Additional studies are necessary for molecular characterization of this bacteria, pathogenic potential, life cycle and impact on the intensive production of fish.

New p-i-n Si : H imager configuration for spatial resolution improvement

Amorphous glass/ZnO-Al/p(a-Si:H)/i(a-Si:H)/n(a-Si1-xCx:H)/Al imagers with different n-layer resistivities were produced by plasma enhanced chemical vapour deposition technique (PE-CVD). An image is projected onto the sensing element and leads to spatially confined depletion regions that can be readout by scanning the photodiode with a low-power modulated laser beam. The essence of the scheme is the analog readout, and the absence of semiconductor arrays or electrode potential manipulations to transfer the information coming from the transducer. The influence of the intensity of the optical image projected onto the sensor surface is correlated with the sensor output characteristics (sensitivity, linearity blooming, resolution and signal-to-noise ratio) are analysed for different material compositions (0.5 < x < 1). The results show that the responsivity and the spatial resolution are limited by the conductivity of the doped layers. An enhancement of one order of magnitude in the image intensity signal and on the spatial resolution are achieved at 0.2 mW cm(-2) light flux by decreasing the n-layer conductivity by the same amount. A physical model supported by electrical simulation gives insight into the image-sensing technique used.

Image and color recognition using amorphous silicon p-i-n photodiodes

Large area hydrogenated amorphous silicon single and stacked p-i-n structures with low conductivity doped layers are proposed as monochrome and color image sensors. The layers of the structures are based on amorphous silicon alloys (a-Si(x)C(1-x):H). The current-voltage characteristics and the spectral sensitivity under different bias conditions are analyzed. The output characteristics are evaluated under different read-out voltages and scanner wavelengths. To extract information on image shape, intensity and color, a modulated light beam scans the sensor active area at three appropriate bias voltages and the photoresponse in each scanning position ("sub-pixel") is recorded. The investigation of the sensor output under different scanner wavelengths and varying electrical bias reveals that the response can be tuned, thus enabling color separation. The operation of the sensor is exemplified and supported by a numerical simulation.