Dinâmica de nutrientes na solução do solo em pomar fertirrigado de citros

O objetivo deste trabalho foi avaliar a dinâmica de nutrientes na solução do solo após a aplicação, via fertirrigação, de nitrogênio, fósforo e potássio a laranjeiras. O experimento foi realizado entre setembro de 2007 e outubro de 2009, em pomares de laranjeiras 'Valência' e 'Hamlin', enxertadas sobre citrumeleiro 'Swingle'. Foram avaliadas cinco doses de N, P2O5 e K2O (0, 25, 50, 100 e 200% da dose recomendada). A solução do solo foi extraída a 30 e 60 cm de profundidade, com o auxílio de extratores com cápsulas porosas. Foram realizadas 11 avaliações durante o período experimental, com as extrações iniciadas após 12 horas das fertirrigações. O aumento das doses reduziu o pH (pH~3,5, na maior dose), e aumentou a condutividade elétrica (CE~1,5 dS m-1, na maior dose) e os teores de NH4, NO3, P, K, Mn e Zn na solução do solo, nas duas profundidades amostradas. Nos meses com maior precipitação pluvial, houve perda potencial de nutrientes por lixiviação, pois maiores concentrações de NO3, K e B foram observadas à profundidade de 60 cm. A análise da solução do solo, obtida por extratores com cápsula de cerâmica porosa, pode ser considerada ferramenta auxiliar para monitorar e avaliar a disponibilidade de nutrientes às plantas.

Medida indireta da clorofila e sua relação com o manejo da adubação nitrogenada em plantas cítricas fertirrigadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nutrientes na seiva de plantas cítricas fertirrigadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

EFFECT of GAMMA IRRADIATION on CAPROLACTAM MIGRATION FROM MULTILAYER POLYAMIDE 6 FILMS INTO WATER FOOD SIMULANT and VALIDATION of THE METHOD

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propriedades ópticas de nanocristais de SiGe: efeitos de dopagem e desordem

We have used ab initio calculations to investigate the electronic structure of SiGe based nanocrystals (NC s). This work is divided in three parts. In the first one, we focus the excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals. We also estimate the changes induced by the effect of strain the electronic structure. We show that Ge/Si (Si/Ge) NC s exhibits type II confinement in the conduction (valence) band. The estimated potential barriers for electrons and holes are 0.16 eV (0.34 eV) and 0.64 eV (0.62 eV) for Si/Ge (Ge/Si) NC s. In contradiction to the expected long recombination lifetimes in type II systems, we found that the recombination lifetime of Ge/Si NC s (τR = 13.39μs) is more than one order of magnitude faster than in Si/Ge NC s (τR = 191.84μs). In the second part, we investigate alloyed Si1−xGex NC s in which Ge atoms are randomly positioned. We show that the optical gaps and electron-hole binding energies decrease linearly with x, while the exciton exchange energy increases with x due to the increase of the spatial extent of the electron and hole wave functions. This also increases the electron-hole wave functions overlap, leading to recombination lifetimes that are very sensitive to the Ge content. Finally, we investigate the radiative transitions in Pand B-doped Si nanocrystals. Our NC sizes range between 1.4 and 1.8 nm of diameters. Using a three-levels model, we show that the radiative lifetimes and oscillator strengths of the transitions between the conduction and the impurity bands, as well as the transitions between the impurity and the valence bands are strongly affected by the impurity position. On the other hand, the direct conduction-to-valence band decay is practically unchanged due to the presence of the impurity

Motivação para o trabalho: um estudo com os profissionais de saúde das unidades básicas de saúde do município de Natal RN

This thesis studied the motivation to work among health professionals of the Basic Unities (BUH) in the health network of the city of Natal (RN). It was understood that the work motivation is a process. Then, the expectation theory was applied and motivation components (results of work, expectative, valence, instrumentality, and motivational force) were used to analyses. It s understanding the motivation as multifaceted phenomenon, the psycho sociological perspective was adopted. The research was developed in two phases: one with application of Work Motivation and Meaning Inventory (WMMI), and another with interview. In the first phases, the analysis of results revealed that the major factors contributing to increase the motivational force to health professionals in the BUH´s are: in valence, Self Expression and Personal Realization (VF2), Personal and Family Survival (VF3); in expectative, Self Expression and Work Justice (EF1), Safety and Dignity (EF2) and Responsibility (EF4); in instrumentality, Involvement (IF1) and Recognition and Economic Independence (IF4). In opposition, the factors that more contribute to reduce the motivational force are Wear and Dehumanization factors in valence (VF4), in expectative (EF3), and in instrumentality (IF4), behind the Work Justice Factor (IF2). Basing in content analysis of interviews, it was possible to associate by equivalence, the senses presented by health professionals with obtained results of first phase, indicating that the results of second phase corroborated and complemented those of first one. This possibility broadened the comprehension of the studied phenomenon. In speaking of the respondents, it was visible the presence of contents showing that they perceive the Health System and BUH´s in degradation. In the first phase, the participants´ instruction also predict the results in motivation, and in the interviews can be saw that the instruction is associated with the opportunities in outside of system. As work motivation is a process, the impact of personal and occupational characteristics tend to interact with contextual aspects. It was concluded the majority of health professionals present the moderated motivational force, but it was falling because they experience and perceive a degrading context with work condition increasingly unfavorable.

Kant e a epigênese a propósito do inato

Este artigo discute a posição de Kant acerca do inato, por meio do exame das metáforas orgânicas e do léxico biológico constantes nas reflexões manuscritas dos anos 1770 e em duas passagens da primeira Crítica. Considerando, em seguida, demais referências do autor à epigênese (agora em sentido estrito, na Crítica da faculdade do juízo), como também ao inato, o artigo aventa a possibilidade da ocorrência de um sentido biológico dessa forma de representação, que já estaria presente nos textos do filósofo.

Propriedades estruturais e optoeletrônicas dos compostos SrSnO3, SrxBa1-xSnO3 e BaSnO3

In this work we present a study for the structural, electronic and optical properties, at ambient conditions of SrSnO3, SrxBa1