366 research outputs found
Deficiência de macronutrientes, boro e ferro em Eucalyptus urophylla
The present was work carried out in order to study: a. the effect of the omission and presence of N, P, K, Ca, Mg, S, B and Fe on the growth of Eucalyptus urophylla. b. deficiency symptoms; c. the effect of the deficiencies on the dry matter production and on the chemical composition. Seedlings of Eucalyptus urophylla were grown in pots containing nutritive solution (HOAGLAND & ARNON, 1950, modificated by SARRUGE, 1970). Clear cut deficiencies symptoms of N, P, K, Mg, B, Fe were observed. The morphological deficiencies symptoms of phosphorus and calcium observed in the leaves were not in complete agreement with the symptoms reported in the literature. The leaves presented the following mineral contents (% and ppm expresse in dry matter weight):Mudas de Eucalyptus urophylla foram cultivadas em soluções nutritivas carentes nos macronutrientes e em boro e ferro, com a finalidade de se obter o quadro sintomatologico das carências de N, P, K, Ca, Mg, S, B e Fe; aquilatar o efeito da omissão e presença dos nutrientes sobre o crescimento e composição química das folhas superiores, medianas e inferiores; assim como do caule e das raízes. Os autores obtiveram em quadro sintomatologico da omissão destes nutrientes, aliados aos seguintes níveis de carência, expresso em função da materia seca: N - 0,69%; P - 0,04%; K - 0,14%; Ca - 0,04%; Mg - 0,05%; S < 0,05%; B - 8,0 ppm; Fe - 50 ppm. A omissão dos elementos da solução nutritiva teve efeito depressivo no crescimento do Eucalyptus, com exceção do tratamento - S que não deferiu do tratamento completo
Ciclagem de nutrientes em florestas implantadas de Eucalyptus e Pinus I. distribuição no solo e na manta
From a grove of E. citriodora (20 years) and P. taeda (24 years) site on a red-yellow podzolic (ultisol), at Piracicaba (22° 43' S, 47° 38' W, elev. 1933 ft., av. annual precipt 1,170 mm), SP, Brazil, leaves, litter fall an soil samples (0 - 10 and 10 - 20 cm depth) were collected. Chemical analysis were run for macro and micronutrients, except for Cl and Mo, by conventional modes. The authors concluded: 1. The E. citriodora was better supplied in nutrients than P. taeda, except for iron; 2. Both forest species hence the organic carbon content in the soil; 3. E. citriodora improved the potassium and magnesium contents in the soil. 4. P. taeda improved the available aluminium of the soil; 5. Both forest species henced the potassium content the litter fall; 6. The fall was improved in iron by P. taeda.Em dois povoamentos Pinus taeda e Eucalyptus citriodora de 20 e 24 anos de idade respectivamente situados em um solo podzólico vermelho amarelo variação Laras no Município de Piracicaba, SP (22°43' lat. S, 47° 38' long. W a 580 m de altitude, preciptação média anual de 1.170 mm), foram coletadas amostras de solo, folhas e manta orgânica. Para um melhor conhecimento da mobilidade dos nutrientes as amostras foram divididas em: folhas novas, maduras e velhas, manta superior e inferior, solo superficial (0 - 10 cm) e sub superficial (10 - 20 cm). Determinaram os teores dos elementos, contidos na matéria seca e no solo
Nutrição mineral de hortaliças: XXXIII. acúmulo de matéria seca e de nutrientes pela cultura do jiló (Solanum gilo, cultivar morro grande oblongo)
In order to find out the concentration of macro and micronutrients, as well, the total amounts of nutrients absorved by Solanum gilo, var. Morro Grande Oblongo, plants were collected from field from 30 days up to 180 days and analysed for the elements. At the flowering stage the leaves presented the following concentration: N-0.55%; P-0.30%; K-2.00%; Ca-1.21%; Mg-0.22%; S-0,27%; B-50 ppm; Cu-11 ppm; Fe-774 ppm; Mn-69 ppm; Mo-0.5 ppm; Zn-22 ppm. A production of 9 M.T./ha. effective harvested content: N-26 kg.; P-4 kg.; K-24 kg.; Ca-5 kg.; Mg-2 kg.; S-2 kg.; B-25 gr.; Cu-17 gr.; Fe-89 gr.- Mn-37 gr.; Mo-0.8 gr.; Zn-34 gr..No intuito de se obter dados básicos para estudos de adubação, plantas de jiló (Solanum gilo cultivar Morro Grande Oblongo), foram coletadas em épocas diversas, situadas em um solo Terra Roxa Estruturada, série "Luiz de Queiroz", Piracicaba. As plantas coletadas aos 30, 55, 80, 105, 130, 155 e 180 dias após a germinação receberam uma adubação fundamental de 100 g da formula 4-12-8 por cova (duas plantas). Quinze dias após aplicou-se 20 g de sulfato de amônio por cova sendo a aplicação repetida 40 dias após. O material coletado foi dividido em folhas, caule e frutos. O jiló apresenta um crescimento lento até aos 105 dias, aumentando bruscamente até ao final do ciclo. Por ocasião do florescimento as folhas apresentam a seguinte concentração em função da mate ria seca: N-4, 5%; P-0, 30%, K-2,00%; Ca-1,21%; Mg-0,22%; S-0,27%; B-50 ppm; Cu-11 ppm; Fe-774 ppm; Mn-69 ppm; Mo-0,5 ppm; Zn-22 ppm. Uma população de 25.000 plantações/ha extrae aos 180 dias (folha + caule + frutos): N-154 kg; P-16 kg; K-164 kg; Ca-60 kg; Mg-20 kg; S-14 kg; B-221 g; Cu-106 g; Fe-1118 g; Mn-490 g; Mo-7,4 g; Zn-147 g. O jilo é uma hortaliça tropical exigente em nutrientes
Efeitos da aplicação de fósforo, boro, zinco e calagem no teor de macronutrientes das folhas de mudas de Eucalyptus grandis (Hill, Ex-Maiden) Cultivadas em solo de cerrado
Utilizando-se um Latossol Vermelho Amarelo fase arenosa, originalmente sob vegetação de Cerrado do município de Itirapina (SP), foi desenvolvido um experimento em vasos, em casa de vegetação, na E. S.A. "Luiz de Queiroz", em Piracicaba (SP), com a finalidade de se verificar o efeito da aplicação de níveis de P (0, 16 e 32 ppm), níveis de B (0, 2 e 4 ppm), níveis de Zn (0, 3 e 6 ppm) e níveis de calagem (0 e 6,0 g CaCO3 + 2,5 g MgCO3) por cada vaso, na concentração de N, P, K, Ca e Mg das folhas de mudas de Eucalyptus grandis (Hill, Ex-Maiden), A calagem e as adubações fosfatadas, com boro ou com zinco, alteraram as concentrações dos macronutrientes dos tecidos foliares das plantas.A factorial experiment, consisting of 3³ x 2 with two replications was conducted in a greenhouse at Piracicaba (SP), Brazil. Three levels of P (0.0, 16.0 and 32.0 ppm), B (0.0, 2.0 and 4.0 ppm), Zn (0.0, 3.0 and 6.0 ppm). two levels of lime (0.0 and 6.0 gr. CaCO3 + 2.5 gr. MgCO3) were applied to 8.0 kg of an Orthox soil originated from a "Cerrado" area from Itirapina (SP), Brazil. The application of phosphorus, Boron, Zinc and lime, changed the concentration of the mayor elements in the foliar tissue. The application of lime and phosphorus increased the concentration of these elements in the foliar tissue
Efeitos da aplicação de fósforo, boro, zinco e calagem na altura e na produção de matéria seca em mudas de Eucalyptus grandis (Hill, Ex-Maiden) cultivadas em um solo de cerrado
Three levels of P (0.0, 16.0 and 32.0 ppm), B (0.0, 2.0 and 4.0 ppm), Zn (0.0, 3.0 and 6.0 ppm) and two levels of lime (0.0 and 6.0 gr. CaCO3 + 2.5 gr. MgCO3) were applied to 8.0 kg of an orthox soil, originated from "Cerrado" area from Itirapina (SP, Brazil). A factorial experiment consisting of 3³ x 2 with two replications was conducted in a greenhouse at Piracicaba (SP), Brazil). Phosphorus and liming had a significant effect on growth and matter production by Eucalyptus. The boron levels (2.0 ppm and 4.0 ppm) interacted with lime, P and Zn application. The addition of 3.0 ppm and 6.0 ppm of zinc to the soil interacted negatively with B and P on the growth of the plants.Foi desenvolvido um experimento em casa de vegetação na Escola Superior de Agricultura "Luiz de Queiroz", em Piracicaba (SP) utilizando-se Latossol Vermelho Amarelo, fase arenosa, originalmente sob vegetação de cerrado, do município de Itirapina (SP), com o objetivo de estudar o efeito de três níveis de P (0, 16 e 32 ppm), três níveis de B (0, 2 e 4 ppm), tres níveis de Zn (0, 3 e 6 ppm) e dois níveis de calagem (0 e 6,0 g CaCO3 + 2,5 g MgC0(3)) por cada vaso no crescimento em altura e na produção de matéria seca de mudas de Eucalyptus grandis (Hill, Ex-Maiden). A adubação fosfatada, provocou aumento no crescimento em altura e na produção de matéria seca das plantas. A adição de 2 e 4 ppm de boro ao solo, provocou efeitos de interação com calagem, fósforo e zinco, ocasionando alterações no crescimento em altura das plantas. A adição de 3 e 6 ppm de zinco ao solo, ocasionou interação com o boro e fósforo adicionados, diminuindo o crescimento em altura das plantas
Electrochemical behavior of Ti/Al2O3 interfaces produced by diffusion bonding
In the field of biomedical applications a special interest exists regarding the study of the physicochemical and mechanical behaviour of materials, with special focus on the electrochemical degradation of metal/ceramic interfaces. In fact, etal/ceramic interfaces may be present in several
biomedical devices, ranging from external or implantable sensors, to dental implants. Diffusion
bonding represents an important technique since, in opposition to other production technologies,
such as active metal brazing, avoid the possible liberation of certain chemical components
harmful to health. The aim of this work is to study the electrochemical degradation of the interface
formed between commercially pure Ti and Al2O3 produced by diffusion bonding, in contact with
a physiological solution. The present approach included the evaluation of the contribution of individual
and pairs of interfacial layers on the global degradation processes. For this propose d.c.
electrochemical techniques were used to monitor the open-circuit potential, and to perform
potentiodynamic polarization and galvanic corrosion evaluation. Also, electrochemical impedance
spectroscopy was used as a complementary technique of the corrosion behaviour of the
interface. Chemical composition and morphology of samples and corrosion products were evaluated
by SEM and EDS analysis. According to experimental results, two principal reaction layers
were formed in the interface: TiAl and Ti3Al. The TiAl layer appears to be the responsible for the
strong increase in corrosion rate of the interface.Fundação para a Ciência e Tecnologia -POCTI/CTM/33384/2000; SFRH/BPD/
5518/2001
The Two-Nucleon Potential from Chiral Lagrangians
Chiral symmetry is consistently implemented in the two-nucleon problem at
low-energy through the general effective chiral lagrangian. The potential is
obtained up to a certain order in chiral perturbation theory both in momentum
and coordinate space. Results of a fit to scattering phase shifts and bound
state data are presented, where satisfactory agreement is found for laboratory
energies up to about 100 Mev.Comment: Postscript file; figures available by reques
Dimensional Dependence of Black Hole Formation in Self-Similar Collapse of Scalar Field
We study classical and quantum self-similar collapses of a massless scalar
field in higher dimensions, and examine how the increase in the number of
dimensions affects gravitational collapse and black hole formation. Higher
dimensions seem to favor formation of black hole rather than other final
states, in that the initial data space for black hole formation enlarges as
dimension increases. On the other hand, the quantum gravity effect on the
collapse lessens as dimension increases. We also discuss the gravitational
collapse in a brane world with large but compact extra dimensions.Comment: Improved a few arguments and added a figur
Ciclagem de nutrientes em florestas implantadas de Eucalyptus e Pinus I. distribuição no solo e na manta
An overview of anti-diabetic plants used in Gabon: Pharmacology and Toxicology
© 2017 Elsevier B.V. All rights reserved.Ethnopharmacological relevance: The management of diabetes mellitus management in African communities, especially in Gabon, is not well established as more than 60% of population rely on traditional treatments as primary healthcare. The aim of this review was to collect and present the scientific evidence for the use of medicinal plants that are in currect by Gabonese traditional healers to manage diabetes or hyperglycaemia based here on the pharmacological and toxicological profiles of plants with anti-diabetic activity. There are presented in order to promote their therapeutic value, ensure a safer use by population and provide some bases for further study on high potential plants reviewed. Materials and methods: Ethnobotanical studies were sourced using databases such as Online Wiley library, Pubmed, Google Scholar, PROTA, books and unpublished data including Ph.D. and Master thesis, African and Asian journals. Keywords including ‘Diabetes’ ‘Gabon’ ‘Toxicity’ ‘Constituents’ ‘hyperglycaemia’ were used. Results: A total of 69 plants currently used in Gabon with potential anti-diabetic activity have been identified in the literature, all of which have been used in in vivo or in vitro studies. Most of the plants have been studied in human or animal models for their ability to reduce blood glucose, stimulate insulin secretion or inhibit carbohydrates enzymes. Active substances have been identified in 12 out of 69 plants outlined in this review, these include Allium cepa and Tabernanthe iboga. Only eight plants have their active substances tested for anti-diabetic activity and are suitables for further investigation. Toxicological data is scarce and is dose-related to the functional parameters of major organs such as kidney and liver. Conclusion: An in-depth understanding on the pharmacology and toxicology of Gabonese anti-diabetic plants is lacking yet there is a great scope for new treatments. With further research, the use of Gabonese anti-diabetic plants is important to ensure the safety of the diabetic patients in Gabon.Peer reviewedFinal Accepted Versio
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