Avaliação da contaminação por hidrocarbonetos do solo e da água da região de Avaré

Pós-graduação em Engenharia Civil e Ambiental - FEB

Arcabouço hidroestratigráfico e evolução temporal dos níveis d´água no sistema aquífero guarani na cidade de Araraquara-SP

Pós-graduação em Geociências e Meio Ambiente - IGCE

Representação de linhas de transmissão trifásicas diretamente no domínio das fases por meio da matriz ABCD

Pós-graduação em Engenharia Elétrica - FEIS

Estrutura e algumas propriedades ópticas de difenilfosfinatos de terras-raras

Coordination compounds of trivalent lanthanides cations with diphenylphosphinate are originated from direct reaction between a lanthanide salt and diphenylphosphinic acid. These complexes have peculiar and intriguing features, as (i) quickly obtainment through wet process precipitation, (ii) appreciable thermal stability, similar to inorganic phosphates, (iii) polymeric structure, and consequently, (iv) low solubility in both polar and non-polar solvents. Nowadays, coordination polymers are classified as coordination networks or, in case of porous materials, as metal-organic frameworks (MOFs). By this study, we aim to determine some optical properties of rare-earth diphenylphosphinate (RE = La3+, Eu3+, Gd3+, Lu3+) and conduct an updated classification of these compounds, bringing more details of its structure and the possible proposal of new materials with applications in lighting, detection of ionizing radiation and magnetism. The complexes of trivalent rare-earth cation with diphenylphosphinate were prepared by direct mixture of diphenylphosphinic acid with rare-earth metal chloride, both in ethanolic solution. The solution of diphenylphosphinic acid was kept in a beaker under constant stirring with pH measurements of the solution and gadolinium chloride solution was then dripped slowly with the aid of a burette until its complete addition; the following metal:ligand molar ratios were tested: 1:1, 1:2, 1:3, 2:1 e 3:1. The compounds were characterized by spectroscopic and structural techniques. By Fourier Transform Infrared Spectroscopy (FT-IR), it was possible to check the total ionization of diphenylphosphinic acid in synthesized complexes, confirmed by the absence of the band type A, B, C related to ѵ(O-H) of the acid (2663 cm-1, 2168 cm-1, 1684 cm-1), as well as the disappearance of ѵ(P-OH)=961 cm-1. Furthermore, the occurrence of bands shifts of ѵ(POO-) [symmetrical and asymmetrical] of...

Desenvolvimento de uma planilha eletrônica em VBA para o dimensionamento didático de instalações de recalque de água

This study aims to develop a computer program based on VBA programming language, using Microsoft Excel, for designing pumping systems of water. The program allows the user to determine the economical diameter, using the equation of Bresse, for a given installation, since the geometric elevation, the material of the tube, the accessories along the line and the volumetric flow are known. In addition, the program estimates the total annual cost of the installation for three different diameters, in order to compare which diameter is more advantageous from an economical perspective. The program interface is designed to be simple and intuitive with the intention of being didactic and offering to engineering students an advantageous tool to analyze this type of project. Microsoft Excel was chosen for this work because is present in virtually all personal computer, and is an indispensable tool for educational purposes

Book Review of Determining the Economic Value of Water: Concepts and Methods by Robert A. YoungBook Review of Determining the Economic Value of Water: Concepts and Methods by Robert A. Young

Water has been and will continue to be a contentious issue for policy makers, landowners, municipalities, environmentalists, and citizens who feels they have an undeniable right to clean water delivered to their homes (at least in the United States). With so many groups coming into conflict over what, at least in the West and the Great Plains, continues to be a diminishing resource per capita, an understanding of the economic value of this resource is critical. It is important to note, as Robert Young does throughout his book, that the true economic value of water goes beyond what we pay our city services each month, or the cost to farmers or ranchers for pumping and distributing that water on their land. The value of water must take into account the value of the competing uses which are sometimes difficult to price.

Hydrogeologic Setting and Ground-Water Flow Simulations of the Eastern High Plains Regional Study Area, Nebraska

The transport of anthropogenic and natural contaminants to public-supply wells was evaluated in a part of the High Plains aquifer near York, Nebraska, as part of the U.S. Geological Survey National Water-Quality Assessment Program. The aquifer in the Eastern High Plains regional study area is composed of Quaternary alluvial deposits typical of the High Plains aquifer in eastern Nebraska and Kansas, is an important water source for agricultural irrigation and public water supply, and is susceptible and vulnerable to contamination. A six-layer, steady-state ground-water flow model of the High Plains aquifer near York, Nebraska, was constructed and calibrated to average conditions for the time period from 1997 to 2001. The calibrated model and advective particle-tracking simulations were used to compute areas contributing recharge and travel times from recharge areas to selected public-supply wells. Model results indicate recharge from agricultural irrigation return flow and precipitation (about 89 percent of inflow) provides most of the ground-water inflow, whereas the majority of ground-water discharge is to pumping wells (about 78 percent of outflow). Particle-tracking results indicate areas contributing recharge to public-supply wells extend northwest because of the natural ground-water gradient from the northwest to the southeast across the study area. Particle-tracking simulations indicate most ground-water travel times from areas contributing recharge range from 20 to more than 100 years but that some ground water, especially that in the lower confined unit, originates at the upgradient model boundary instead of at the water table in the study area and has travel times of thousands of years.

Weather Derivatives as a Potential Risk Management Tool for Irrigators

Irrigators in the Republican Basin and in parts of the North Platte Basin must learn to incorporate multiple year drought risk into their management plans, as they adapt to the limitations imposed by five-year pumping allocations. A major concern involves the implications of being water-short during the later years of the allocation period, because of an accumulative rainfall shortage or drought. Currently, producers can either ignore the risk of substantially lower incomes if their allocation is exhausted too soon, or reduce the risk by using less water early in the allocation period. The latter approach, however, may substantially reduce the present value of total net income over the five-year period. Alternatively, in the future it may be possible to use weather derivatives to manage income risk.

Estrutura e algumas propriedades ópticas de difenilfosfinatos de terras-raras

Coordination compounds of trivalent lanthanides cations with diphenylphosphinate are originated from direct reaction between a lanthanide salt and diphenylphosphinic acid. These complexes have peculiar and intriguing features, as (i) quickly obtainment through wet process precipitation, (ii) appreciable thermal stability, similar to inorganic phosphates, (iii) polymeric structure, and consequently, (iv) low solubility in both polar and non-polar solvents. Nowadays, coordination polymers are classified as coordination networks or, in case of porous materials, as metal-organic frameworks (MOFs). By this study, we aim to determine some optical properties of rare-earth diphenylphosphinate (RE = La3+, Eu3+, Gd3+, Lu3+) and conduct an updated classification of these compounds, bringing more details of its structure and the possible proposal of new materials with applications in lighting, detection of ionizing radiation and magnetism. The complexes of trivalent rare-earth cation with diphenylphosphinate were prepared by direct mixture of diphenylphosphinic acid with rare-earth metal chloride, both in ethanolic solution. The solution of diphenylphosphinic acid was kept in a beaker under constant stirring with pH measurements of the solution and gadolinium chloride solution was then dripped slowly with the aid of a burette until its complete addition; the following metal:ligand molar ratios were tested: 1:1, 1:2, 1:3, 2:1 e 3:1. The compounds were characterized by spectroscopic and structural techniques. By Fourier Transform Infrared Spectroscopy (FT-IR), it was possible to check the total ionization of diphenylphosphinic acid in synthesized complexes, confirmed by the absence of the band type A, B, C related to ѵ(O-H) of the acid (2663 cm-1, 2168 cm-1, 1684 cm-1), as well as the disappearance of ѵ(P-OH)=961 cm-1. Furthermore, the occurrence of bands shifts of ѵ(POO-) [symmetrical and asymmetrical] of...

Desenvolvimento de uma planilha eletrônica em VBA para o dimensionamento didático de instalações de recalque de água

This study aims to develop a computer program based on VBA programming language, using Microsoft Excel, for designing pumping systems of water. The program allows the user to determine the economical diameter, using the equation of Bresse, for a given installation, since the geometric elevation, the material of the tube, the accessories along the line and the volumetric flow are known. In addition, the program estimates the total annual cost of the installation for three different diameters, in order to compare which diameter is more advantageous from an economical perspective. The program interface is designed to be simple and intuitive with the intention of being didactic and offering to engineering students an advantageous tool to analyze this type of project. Microsoft Excel was chosen for this work because is present in virtually all personal computer, and is an indispensable tool for educational purposes

Six-element circuit for maximum power point tracking in photovoltaic-motor systems with variable-frequency drives

A low-cost circuit was developed for stable and efficient maximum power point (MPP) tracking in autonomous photo voltaic-motor systems with variable-frequency drives (VFDs). The circuit is made of two resistors, two capacitors, and two Zener diodes. Its input is the photovoltaic (PV) array voltage and its output feeds the proportional-integral-derivative (PID) controller usually integrated into, the drive. The steady-state frequency-voltage oscillations induced by the circuit were treated in a simplified mathematical model, which was validated by widely characterizing a PV-powered centrifugal pump. General procedures for circuit and controller tuning were recommended based on model equations. The tracking circuit presented here is widely applicable to PV-motor system with VFDs, offering an. efficient open-access technology of unique simplicity. Copyright (C) 2010 John Wiley & Sons, Ltd.

Impacts of interruption of the Agulhas leakage on the tropical Atlantic in coupled ocean-atmosphere simulations

In this paper we use a coupled ocean-atmosphere model to investigate the impact of the interruption of Agulhas leakage of Indian ocean water on the tropical Atlantic, a region where strong coupled ocean-atmosphere interactions occur. The effect of a shut down of leakage of Indian ocean water is isolated from the effect of a collapse of the MOC. In our experiments, the ocean model is forced with boundary conditions in the southeastern corner of the domain that correspond to no interocean exchange of Indian ocean water into the Atlantic. The southern boundary condition is taken from the Levitus data and ensures an MOC in the Atlantic. Within this configuration, instead of warm and salty Indian ocean water temperature (cold) and salinity (fresh) anomalies of southern ocean origin propagate into the South Atlantic and eventually reach the equatorial region, mainly in the thermocline. This set up mimics the closure of the ""warm water path"" in favor of the ""cold water path"". As part of the atmospheric response, there is a northward shift of the intertropical convergence zone (ITCZ). The changes in trade winds lead to reduced Ekman pumping in the equatorial region. This leads to a freshening and warming of the surface waters along the equator. Especially in the Cold Tongue region, the cold and fresh subsurface anomalies do not reach the surface due to the reduced upwelling. The anomaly signals are transported by the equatorial undercurrent and spread away from the equator within the thermocline. Part of the anomaly eventually reaches the Tropical North Atlantic, where it affects the Guinea Dome. Surprisingly, the main effect at the surface is small on the equator and relatively large at the Guinea Dome. In the atmosphere, the northward shift of the ITCZ is associated with a band of negative precipitation anomalies and higher salinities over the Tropical South Atlantic. An important implication of these results is that the modified water characteristics due to a shut down of the Agulhas leakage remain largely unaffected when crossing the equatorial Atlantic and therefore can affect the deepwater formation in the North Atlantic. This supports the hypothesis that the Agulhas leakage is an important source region for climate change and decadal variability of the Atlantic.

Impact of biannual rossby waves on the Indian Ocean Dipole

Topex/Poseidon sea surface height anomalies during 1993-2002 are decomposed using 2-D finite impulse response filters which showed biannual Rossby waves (BRWs) in the equatorial Indian Ocean (peak at 1.5 degrees S) and in the southern tropical Indian Ocean (peak at 10.5 degrees S) during Indian Ocean Dipole (IOD) years. Anomalous downwelling BRWs in the equatorial Indian Ocean triggered by the wind stress curl-induced Ekman pumping near the eastern boundary started propagating westward from the eastern boundary in July/August 1993 and 1996, i.e., more than one year prior to the formation of the IOD events of 1994 and 1997 respectively. These strong downwelling signals reach the western equatorial Indian Ocean during the peak dipole time.

Burrow ventilation and associated porewater irrigation by the polychaete Marenzelleria viridis

Burrow ventilation of benthic infauna generates water currents that irrigate the interstices of the sediments surrounding the burrow walls. Such activities have associated effects on biogeochemical processes affecting ultimately important ecosystem processes. In this study, the ventilation and irrigation behavior of Marenzelleria viridis, an invasive polychaete species in Europe, was analyzed using different approaches. M. viridis showed to perform two types of ventilation: (1) muscular pumping of water out of the burrow and (2) cilia pumping of water into the burrow. Flowmeter measurements presented muscular pumping in time averaged rates of 0.15 ml min(-1). Oxygen needle electrodes positioned above the burrow openings revealed that muscular undulation of the worm body pumps anoxic water out of the burrow. On the other hand, microscope observations of the animal showed that ventilation of oxygen-rich water in the burrow occurs by ciliary action. The volume of water irrigated by M. viridis appears to vary linearly within the first 24 h incubation, with rates ranging from 0.003 to 0.01 ml min(-1). From those rates we could estimate that the time averaged rate of cilia ventilation should be about 0.16 ml min(-1). Since the cilia pumping into the burrow occurs in periods of 24 +/- 12 min and at 50-70% of the measured time, considerable amounts of water from deeper sediments may percolate upwards to the sediment surface. This water is rich in reduced compounds and nutrients and may have important associated ecological implications in the ecosystem (e.g. affecting redox conditions, organic matter degradation, benthic recruitment and primary production). (C) 2010 Elsevier B.V. All rights reserved.

New species of Moenkhausia Eigenmann (Characiformes: Characidae) from Rio Xingu and Rio Tapajos basins, Brazil, with comments on a putative case of polymorphic Batesian mimicry

A new species of Moenkhausia is described from Rio Xingu and Rio Tapajos basins, Brazil. The new species is distinguished from its congeners, except from Moenkhausia moisae, by having more scales in the lateral series, 43-47 (v. 23-41 in the remaining congeners). The new species is distinguished from M. moisae by its colour pattern, which consists of a dark midlateral stripe, and an asymmetrical caudal blotch (inconspicuous or faded in specimens from the Rio Arinos) continuous with the midlateral stripe (v. narrow dark midlateral line and conspicuous, regularly rounded and symmetrical blotch not continuous with the midlateral line). The new species is putatively assumed to be mimetic to Jupiaba apenima, in the Rio Xingu and Rio Teles Pires drainages, and to Jupiaba yarina in the Rio Arinos. The two species of Jupiaba are sympatric and remarkably similar in size, general external morphology and colouration to the new species. A small difference occurs in the colouration between the two species of Jupiaba and is also observed in the two respectively sympatric morphotypes of the new species of Moenkhausia. The occurrence of polymorphic Batesian mimicry is therefore discussed for neotropical freshwater fishes. (C) 2009 The Authors Journal compilation (C) 2009 The Fisheries Society of the British Isles