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Search Results: 1 - 10 of 243567 matches for " F.T.;Negrisoli "
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Eficácia do carfentrazone-ethyl no controle de plantas aquáticas latifoliadas em caixas-d'água
Carvalho, F.T.;Velini, E.D.;Negrisoli, E.;Rossi, C.V.S.;
Planta Daninha , 2005, DOI: 10.1590/S0100-83582005000200018
Abstract: some herbicides are being currently developed for the control of aquatic weeds.the objective of this work was to evaluate the efficiency of aurora 400 ce in aquatic environment for the post-emergence control of eichhornia crassipes, pistia stratiotes and salvinia auriculata. the experiment was developed in boxes of water, from 22/07 to 20/09/2004, at nupam-fca/unesp, botucatu, sp, brazil. the experimental design was in randomized blocks with seven treatments and four repetitions, with the units consisting of boxes of water. the following treatments were used: control without herbicide; aurora 400 ce (75, 150 and 300 ml ha-1); roundup (3,0 l ha-1); aurora 400 ce + roundup (75 ml + 3,0 l ha-1) and aurora 400 ce + arsenal n.a. (75 ml + 2.0 l ha-1). it was observed that the treatment with aurora 400 ce (300 ml ha-1) is highly efficient in the control of pistia stratiotes; roundup (3,0 l ha-1) is highly efficient in the control of eichhornia crassipes; aurora 400 ce + roundup (75 ml + 3.0 l ha-1) is efficient in the control of e. crassipes, p. stratiotes and salvinia auriculata and aurora 400 ce + arsenal (75 ml + 2.0 l ha-1) are efficient in the control of e. crassipes and p. stratiotes. the mixture aurora 400 ce + roundup (75 ml + 3.0 l ha-1) was viable and the only efficient treatment in the control of the three studied species.
Influência da turbidez da água do rio Tietê na ocorrência de plantas aquáticas
Carvalho, F.T.;Velini, E.D.;Cavenaghi, A.L.;Negrisoli, E.;Castro, R.M.;
Planta Daninha , 2005, DOI: 10.1590/S0100-83582005000200025
Abstract: aquatic plants are studied as an effect of pollution unbalance and/or river flooding. the excessive amount of plants,as a consequence of such unbalance, hinders navigation and electric power production. the objective of this work was to identify the main aquatic plants of the tietê river and to relate them with water turbidity of the different reservoirs. all the foci of aquatic immersed, floating and submerged vegetation in each reservoir were evaluated in all their extension. those species presenting a dominant character were considered important.the reservoirs were found to present aquatic plant problems with the quality of infestation varying among the reservoirs. the following species were considered to be dominant: brachiaria mutica, brachiaria subquadripara, eichhornia crassipes, egeria densa, egeria najas, typha angustifolia and enidra sessilis.there was a tendency for a greater occurrence of floating and submerged (marginal) plants in the reservoirs with greater turbidity and for a larger occurrence of submerged plants in reservoirs with less turbidity. for the two brachiarias it was observed that the frequency of the species increased with the increase of turbidity up to the limit of 34.93 ntu. e. crassipes occurred with high frequency indexes (above 50%) in all the tietê river reservoirs, independent of the characteristic of the water. for egerias, frequency increased gradually with reduced turbidity and t. angustifolia did not present a relationship with the studied index. the species e. sessilis was found to be rather dependent on the quality of the water,its frequency increasing with increased turbidity.
Cinemática relativística: paradoxo dos gêmeos
Falciano, F.T.;
Revista Brasileira de Ensino de Física , 2007, DOI: 10.1590/S1806-11172007000100006
Abstract: the twin paradox was first formulated almost 100 years ago but still nowadays is one of the best ways to present the dependence on the definition of space and time of the state of motion of the observer. in this paper we present the conventional formulation of the twin paradox pointing out some of its key concepts and analyse one of its modification in which we compactify one of the spatial dimensions. given the compactification, it is no more necessary to accelerate one of the twins to rejoin them. in this way, we circunvent the conventional explanation to the asymmetry between the twins. following this reasoning, we move to clarify the fundamental role played by acceleration and conclude with some comments on synchronization of clocks and observables in special relativity.
Geometria, espa?o-tempo e gravita??o: conex?o entre conceitos da relatividade geral
Falciano, F.T;
Revista Brasileira de Ensino de Física , 2009, DOI: 10.1590/S1806-11172009000400010
Abstract: the theory of general relativity is formulated in a precise, but very complex, mathematical formalism. in spite of being necessary, this mathematical rigour may become an insurmountable obstacle. notwithstanding this theory is grounded in principles and ideas accessible to anyone. we will try to construct a logical path between the ideas that helped einstein formulate general relativity and connect concepts at first glance so apart as geometry, curved space-times and gravitation. we have chosen to favour a constructive approach at the expense of lack of accuracy from a historical perspective. we hope to clarify the main concepts and principles involved in general relativity focusing mainly on its epistemological and philosophical implications.
Evaluation of the Benefits of Infiltration Pits on Soil Moisture in Semi-arid Zimbabwe
F.T. Mugabe
Journal of Agronomy , 2004,
Abstract: Rainfall is low and erratic in the semi-arid areas such that crop production fails in most years. Water harvesting techniques have been observed to harvest and concentrate rainwater and this results in increased soil moisture and yields. Most of this study has been done on in-field water harvesting techniques while there has not been any similar work to evaluate the benefits of in-contour water harvesting techniques on soil moisture and crop yields. Soil water storage was monitored above and below an infiltration pit over a season to identify differences in soil water storage of access tubes that are at different distances both above and below an infiltration pit. Soil moisture storage in the access tubes decreased from the infiltration pit both down slope and up slope. The difference in soil moisture between these access tubes increased during dry periods. The study highlights that the benefits of infiltration pits on soil moisture are realised during the dry spells because the water that is captured by the infiltration pits slowly seeps downwards to replenish soil moisture that is lost through evapotranspiration.
Monitoramento de problemas com plantas aquáticas e caracteriza??o da qualidade de água e sedimento na UHE Mogi-Gua?u
Cavenaghi, A.L.;Velini, E.D.;Negrisoli, E.;Carvalho, F.T.;Galo, M.L.B.T.;Trindade, M.L.B.;Corrêa, M.R.;Santos, S.C.A.;
Planta Daninha , 2005, DOI: 10.1590/S0100-83582005000200008
Abstract: this research was carried out at the mogi gua?u reservoir owned by aes tiete. assessment of aquatic plants and water and sediment sampling were carried out in july 2001 (dry season), november 2001 (start of rainy season) and march 2002 (end of rainy season). a total of 846 water and 516 sediment analyses were performed, with 47 water and 41 sediment characteristics being evaluated. marginal and floating species were the main weeds in the reservoir, the most outstanding being brachiaria subquadripara, eichornia crassipes, polygonum lapathifolium, panicum rivulare, salvinia auriculata and pistia stratiotes. turbidity and low light transmission by water column made the growth of the submerged plants impossible. phosphorus and nitrogen concentration both in the water and sediment was adequate to support aquatic plant growth. the occurrence of marginal and floating plants was associated with the intense process of sedimentation in the reservoir.
Caracteriza??o da qualidade de água e sedimento relacionados com a ocorrência de plantas aquáticas em cinco reservatórios da bacia do rio Tietê
Cavenaghi, A.L.;Velini, E.D.;Galo, M.L.B.T.;Carvalho, F.T.;Negrisoli, E.;Trindade, M.L.B.;Simionato, J.L.A.;
Planta Daninha , 2003, DOI: 10.1590/S0100-83582003000400007
Abstract: this research is part of a project aiming to develop aquatic plant integrated management programs in five reservoirs of the tietê watershed (s?o paulo, brasil) used to produce electric energy. the occurrence of aquatic plants was correlated to water and sediment composition. water and sediment samplings and field evaluations were performed in june 2001 (drought season), october/november of 2001 (start of rainy season) and february/march 2002 (end of rainy season). water samples were used to estimate the transmission or extinction of light from 190 to 900 nm by 1 m-thick water columns. to better understand and register (in digital pictures) the problems encountered with the formation of sediment banks and aquatic plants, all the reservoirs were overflown using a helicopter, on june 4th and 5th. the results allowed to conclude that the occurrence of submersed plants, mainly egeria densa and egeria najas, is highly dependent on water transparency and light transmission. the higher turbidity and content of suspended solids, as well as the lower light transmission change the frequency of submersed plants. promiss?o and nova avanhandava reservoirs were the most infested with submersed plants. the occurrence of marginal and floating plants is highly dependent on the formation of sediment banks. barra bonita, bariri and ibitinga reservoirs were the most infested with marginal and floating plants. p and n concentrations, turbidity and the contents of suspended solids were reduced by the downstream movement along the sequence of reservoirs (barra bonita => bariri => ibitinga => promiss?o => nova avanhandava).
Mejoras del Aprendizaje y del Rendimiento de Grupos Reducidos de Estudiantes en una Asignatura de Proyectos de Ingeniería
Bogumil,F.T; Abad,F;
Formación universitaria , 2008, DOI: 10.4067/S0718-50062008000300003
Abstract: the characteristics, theoretical results and final conclusions of an experience for the improvement of the learning process and of its evaluation of a reduced group of students of a university course, is presented in this article. the experiment was done with an engineering project course at the technical university school of industrial engineers of terrassa, spain. the methodology considered the application of a questionnaire to evaluate the following aspects: individual work, group work, and preparation of oral presentations. during the academic course, several evaluations were done which allowed detecting students with low efficiency and making the necessary corrections to integrate them into the dynamics of the group. the results demonstrate that the new evaluation method allowed to achieve the objectives of motivation for the course, cohesion of the group and subject learning.
Effect of Landform and Irrigation Frequency on Cotton (Gossypium) Yield in Semi-arid Zimbabwe
F.T. Mugabe,F. Munyanyi
Journal of Biological Sciences , 2004,
Abstract: The effect of planting irrigated cotton on Tied Ridge (TR) and Flat (F) under three irrigation frequencies (75, 40 and 30% Depletion of Available Moisture, DAM) on yield and water use efficiency was studied at Chiredzi Research Station for two seasons 1990/91 and 1991/92. Growing cotton on tied ridges gave 19 and 35% more yield than on flat in the 1990/91 and 1991/92 seasons, respectively. More available moisture due to water collection on tied ridges as compared to flat was given as the reason for the yield increase. Yields were not affected by frequency of irrigation.
Ethical research as the target of animal extremism: an international problem
Michael Conn, P.;Rantin, F.T.;
Brazilian Journal of Medical and Biological Research , 2010, DOI: 10.1590/S0100-879X2010005000006
Abstract: animal extremism has been increasing worldwide; frequently researchers are the targets of actions by groups with extreme animal rights agendas. sometimes this targeting is violent and may involve assaults on family members or destruction of property. in this article, we summarize recent events and suggest steps that researchers can take to educate the public on the value of animal research both for people and animals
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