741 resultados para Orto fosfato


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Este trabalho objetivou avaliar o efeito de fontes fosfatadas, ácidos húmicos e fungos solubilizadores de fosfato em trigo cultivado em solo de Cerrado. O experimento foi instalado em delineamento inteiramente casualizado com 7 tratamentos: 1) ácidos húmicos (30 kg ha-1); 2) ácidos húmicos + fosfato de Arad (800 kg ha-1); 3) ácidos húmicos + pó de basalto (526 kg ha-1); 4) fosfato de Arad; 5) pó de basalto; 6) FSF (108 UFC mL-1), 7) testemunha e 4 repetições. As espécies de fungo usadas foram: um isolado de Penicillium sp e um de Aspergillus sp. A combinação de fosfato de Arad e ácidos húmicos incrementou o desenvolvimento de trigo. A inoculação de FSF não se mostrou efetiva para beneficiar o desenvolvimento de trigo.

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Sclerolobium panicudatum Vogel (taxi-branco-da-terra-firme) uma espécie nativa da Região Amazônica, de rápido crescimento, elevada produção de biomassa, capaz de associar-se com bactérias do gênero Rhizobium e com fungos micorrízicos. A madeira desta espécie possui características comparáveis àquelas tradicionalmente utilizadas no Sul do Brasil como fonte de energia. É de suma importância que sejam realizados estudos sobre as exigências nutricionais desta essência florestal tão promissora. Visando estudar o crescimento, foi desenvolvida a presente pesquisa, com o objetivo de avaliar os efeitos da aplicação do Fosfato natural trauíra superior na fase dc muda. O experimento foi instalado em casa de vegetação da Embrapa Amazônia Oriental, em vasos contendo Latossolo Amarelo álico. O delineamento experimental foi de blocos ao acaso, em esquema fatorial 4 x 5, sendo quatro doses: 0, 30, 60 e 90 ppm de fósforo (P); e cinco idades: 30. 60. 90. 120 c 150 dias. Foram avaliadas as variáveis: altura, número de folhas, área foliar, produção de matéria seca das folhas, caule, pane aérea, raiz e total. Constatou-se efeito significativo em todas as variáveis em função das idades, o número de folhas apresentou um ponto máximo de 9,59 folhas/planta, aos 110.62 dias. Quanto à aplicação das doses de fósforo, observou-se efeito significativo apenas nas variáveis área foliar, obtendo-se ponto máximo de 515.91 cm²/planta com aplicação da dose estimada de 52,86 ppm de P e na variável produção de matéria seca foliar com ponto máximo de 2,44 g/planta na dose estimada de 44,25 ppm de P.

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The use of remote sensing imagery as auxiliary data in forest inventory is based on the correlation between features extracted from the images and the ground truth. The bidirectional reflectance and radial displacement cause variation in image features located in different segments of the image but forest characteristics remaining the same. The variation has so far been diminished by different radiometric corrections. In this study the use of sun azimuth based converted image co-ordinates was examined to supplement auxiliary data extracted from digitised aerial photographs. The method was considered as an alternative for radiometric corrections. Additionally, the usefulness of multi-image interpretation of digitised aerial photographs in regression estimation of forest characteristics was studied. The state owned study area located in Leivonmäki, Central Finland and the study material consisted of five digitised and ortho-rectified colour-infrared (CIR) aerial photographs and field measurements of 388 plots, out of which 194 were relascope (Bitterlich) plots and 194 were concentric circular plots. Both the image data and the field measurements were from the year 1999. When examining the effect of the location of the image point on pixel values and texture features of Finnish forest plots in digitised CIR photographs the clearest differences were found between front-and back-lighted image halves. Inside the image half the differences between different blocks were clearly bigger on the front-lighted half than on the back-lighted half. The strength of the phenomenon varied by forest category. The differences between pixel values extracted from different image blocks were greatest in developed and mature stands and smallest in young stands. The differences between texture features were greatest in developing stands and smallest in young and mature stands. The logarithm of timber volume per hectare and the angular transformation of the proportion of broadleaved trees of the total volume were used as dependent variables in regression models. Five different converted image co-ordinates based trend surfaces were used in models in order to diminish the effect of the bidirectional reflectance. The reference model of total volume, in which the location of the image point had been ignored, resulted in RMSE of 1,268 calculated from test material. The best of the trend surfaces was the complete third order surface, which resulted in RMSE of 1,107. The reference model of the proportion of broadleaved trees resulted in RMSE of 0,4292 and the second order trend surface was the best, resulting in RMSE of 0,4270. The trend surface method is applicable, but it has to be applied by forest category and by variable. The usefulness of multi-image interpretation of digitised aerial photographs was studied by building comparable regression models using either the front-lighted image features, back-lighted image features or both. The two-image model turned out to be slightly better than the one-image models in total volume estimation. The best one-image model resulted in RMSE of 1,098 and the two-image model resulted in RMSE of 1,090. The homologous features did not improve the models of the proportion of broadleaved trees. The overall result gives motivation for further research of multi-image interpretation. The focus may be improving regression estimation and feature selection or examination of stratification used in two-phase sampling inventory techniques. Keywords: forest inventory, digitised aerial photograph, bidirectional reflectance, converted image co­ordinates, regression estimation, multi-image interpretation, pixel value, texture, trend surface

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The purpose of this series of studies was to evaluate the biocompatibility of poly (ortho) ester (POE), copolymer of ε-caprolactone and D,L-lactide [P (ε-CL/DL-LA)] and the composite of P(ε-CL/DL-LA) and tricalciumphosphate (TCP) as bone filling material in bone defects. Tissue reactions and resorption times of two solid POE-implants (POE 140 and POE 46) with different methods of sterilization (gamma- and ethylene oxide sterilization), P(ε-CL/DL-LA)(40/60 w/w) in paste form and 50/50 w/w composite of 40/60 w/w P(ε-CL/DL-LA) and TCP and 27/73 w/w composite of 60/40 w/w P(ε-CL/DL-LA) and TCP were examined in experimental animals. The follow-up times were from one week to 52 weeks. The bone samples were evaluated histologically and the soft tissue samples histologically, immunohistochemically and electronmicroscopically. The results showed that the resorption time of gamma sterilized POE 140 was eight weeks and ethylene oxide sterilized POE 140 13 weeks in bone. The resorption time of POE 46 was more than 24 weeks. The gamma sterilized rods started to erode from the surface faster than ethylene oxide sterilized rods for both POEs. Inflammation in bone was from slight to moderate with POE 140 and moderate with POE 46. No highly fluorescent layer of tenascin or fibronectin was found in the soft tissue. Bone healing at the sites of implantation was slower than at control sites with the copolymer in small bone defects. The resorption time for the copolymer was over one year. Inflammation in bone was mostly moderate. Bone healing at the sites of implantation was also slower than at the control sites with the composite in small and large mandibular bone defects. Bone formation had ceased at both sites by the end of follow-up in large mandibular bone defects. The ultrastructure of the connective tissue was normal during the period of observation. It can be concluded that the method of sterilization influenced the resorption time of both POEs. Gamma sterilized POE 140 could have been suitable material for filling small bone defects, whereas the degradation times of solid EO-sterilized POE 140 and POE 46 were too slow to be considered as bone filling material. Solid material is difficult to contour, which can be considered as a disadvantage. The composites were excellent to handle, but the degradation time of the polymer and the composites were too slow. Therefore, the copolymer and the composite can not be recommended as bone filling material.

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Se realizó un muestreo de suelos en parcelas experimentales de un ensayo de campo, con el fin de evaluar los efectos de la aplicación de tres dosis de Abonos Orgáníeos (AO), combinadas con fertilizante químico, sobre la densidad aparente (á) y el espacio poroso total (FPT) de un suelo volcánico nicaragüense. El ensayo se realizó durante la época de Postrera (Septiembre -Diciembre) de 1989, en la Finca Experimental La Compañía, Carazo, Nicaragua; sobre un suelo franco - arenoso derivado de cenizas volcánicas (Typic Durandepts). Se utilizó un experimento Bifactorial en diseño de parcelas divididas en Bloques completos al azar, con cuatro réplicas. Los AO empleados fueron Gallinaza, Compost y Pulpa de café, siendo las dosis ensayadas de 5, 10 y 15 ton.ha 1 de cada uno, combinadas con Fosfato Díamónico a razón de 64.8 kg.ba· 1• Se observó una disminoción de la d y un aumento del EPT con la aplícacion de los AO, siendo este efecto influido por las dosis incorporadas. Las parcelas que presentaron la menor d y el mayor EPT, fueron aquellas donde se incorporó el Compost.