Qualidade da semente e densidade de semeadura no estabelecimento e na produtividade do milho.

Uma das principais causas da baixa produtividade de milho é a qualidade da semente, que afeta o estande inicial, o vigor das plantas, e conseqüentemente, a produtividade. O objetivo deste trabalho foi determinar o efeito da qualidade da semente e a densidade de semeadura no estabelecimento e na produtividade de milho. Quatro lotes de sementes de milho BRS 201, com germinação de 95%, 90%, 85% e 75%, foram semeados em três densidades de semeadura: 50, 60 e 70 mil sementes/ha, nos anos de 1996/97 e 1997/98. A baixa qualidade da semente provocou reduções acentuadas na emergência de campo, no número de plantas e, conseqüentemente, na produtividade do milho BRS 201.O aumento da densidade de 50 para 70 mil sementes/ha, na semeadura, não compensou a redução da qualidade da semente. Para o acréscimo de 15% na germinação, foi observado, em média, um ganho de produtividade de 30%. Com base nos resultados destes trabalho, recomenda-se aos produtores de milho a utilização de lotes de sementes com germinação superior a 90% e densidade de semeadura entre 50 e 60 mil sementes/ha.bitstream/CNPMS/15812/1/Bol_01.pd

Sludge Treatment and Disposal

"Sludge Treatment and Disposal is the sixth volume in the series Biological Wastewater Treatment. The book covers in a clear and informative way the sludge characteristics, production, treatment (thickening, dewatering, stabilisation, pathogens removal) and disposal (land application for agricultural purposes, sanitary landfills, landfarming and other methods). Environmental and public health issues are also fully described. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 1: Waste Stabilisation Ponds; Volume 2: Basic Principles of Wastewater Treatment; Volume 3: Waste Stabilization Ponds; Volume 4: Anaerobic Reactors; Volume 5: Activated Sludge and Aerobic Biofilm Reactors

Efeito do tamanho e da forma da semente na produtividade do milho.

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Integrating a Global Induction Mechanism into a Sequent Calculus

Most interesting proofs in mathematics contain an inductive argument which requires an extension of the LK-calculus to formalize. The most commonly used calculi for induction contain a separate rule or axiom which reduces the valid proof theoretic properties of the calculus. To the best of our knowledge, there are no such calculi which allow cut-elimination to a normal form with the subformula property, i.e. every formula occurring in the proof is a subformula of the end sequent. Proof schemata are a variant of LK-proofs able to simulate induction by linking proofs together. There exists a schematic normal form which has comparable proof theoretic behaviour to normal forms with the subformula property. However, a calculus for the construction of proof schemata does not exist. In this paper, we introduce a calculus for proof schemata and prove soundness and completeness with respect to a fragment of the inductive arguments formalizable in Peano arithmetic.Comment: 16 page

Study of The Corrosion Processes On Roman And Byzantine Glasses From Northern Tunisia

The present investigation focuses on some glass objects among those discovered in an area around the ancient city of Thugga in northern Tunisia, particularly flourishing during the Roman and Byzantine periods (1). The Late Roman-Byzantine time is not characterised by elaborate vessel shapes derived from precious metal prototypes, but rather by simpler multifunctional forms, as beakers, goblets, and dishes with similar features in the whole Mediterranean world. Also the glass composition seems to change between the 4th and the 5th century, turning to a yellowish-green or olive green colouration of the glass instead of the typical Roman blue-greenish colouration of earlier times. This new glass colouration varies further drastically in the 7th century, when a characteristic light blue-turquoise glass becomes the most widespread. A complete chemical characterization of these objects was carried out in a previous study (2) aimed to investigate the production technology including the chromophores responsible for the different shades. In the present work we have investigated the degradation and corrosion processes affecting some of these shards. It is worth to note that to ascertain the composition of the glass surfaces the analyses have been carried out by means of non-destructive techniques such as XPS (X-ray photoelectron spectroscopy), SEM-EDX (scanning electron microscopy coupled with energy dispersive X-ray analysis) and laser-ablation ICP-MS ((Inductively Coupled Plasma \u2013 Mass Spectrometry)

Classical and Intuitionistic Subexponential Logics are Equally Expressive

International audienceIt is standard to regard the intuitionistic restriction of a classical logic as increasing the expressivity of the logic because the classical logic can be adequately represented in the intuitionistic logic by double-negation, while the other direction has no truth-preserving propositional encodings. We show here that subexponential logic, which is a family of substructural refinements of classical logic, each parametric over a preorder over the subexponential connectives, does not suffer from this asymmetry if the preorder is systematically modified as part of the encoding. Precisely, we show a bijection between synthetic (i.e., focused) partial sequent derivations modulo a given encoding. Particular instances of our encoding for particular subexponential preorders give rise to both known and novel adequacy theorems for substructural logics

On Subexponentials, Synthetic Connectives, and Multi-level Delimited Control

International audienceWe construct a partially-ordered hierarchy of delimited control operators similar to those of the CPS hierarchy of Danvy and Filinski. However, instead of relying on nested CPS translations, these operators are directly interpreted in linear logic extended with subexponentials (i.e., multiple pairs of ! and ?). We construct an independent proof theory for a fragment of this logic based on the principle of focusing. It is then shown that the new constraints placed on the permutation of cuts correspond to multiple levels of delimited control