scholarly journals Acartia tonsa production in the Patos Lagoon estuary, Brazil

2011 ◽  
Vol 69 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Erik Muxagata ◽  
Waldemar J. A. Amaral ◽  
Carla N. Barbosa
Keyword(s):  
Acartia Tonsa ◽  
Monitoring Programme ◽  
Marine Science ◽  
Production Rates ◽  
Daily Production ◽  
Patos Lagoon ◽  
Dominant Taxon ◽  
Patos Lagoon Estuary ◽  
High Production ◽  
Very High

Abstract Muxagata, E., Amaral, W. J. A., and Barbosa, C. N. 2012. Acartia tonsa production in the Patos Lagoon estuary, Brazil. – ICES Journal of Marine Science, 69: 475–482. Acartid copepods are abundant in estuaries, harbours, and semi-enclosed waters. A monitoring programme with the objective of evaluating copepod production, particularly that of Acartia tonsa, the dominant taxon in the Patos Lagoon estuary, was implemented. Zooplankton samples are collected monthly from two fixed locations with bongo nets 30 cm in diameter with nets of 90 and 200 μm mesh. Over a full year, 33 quantitative samples were analysed; copepods represented 40% of the organisms collected with the 90-μm mesh. Adults and copepodites of A. tonsa accounted for ∼19% of the total copepod fauna at both locations. Daily production rates of A. tonsa were calculated as 0.40 mg C m−3 d−1 for the inner estuary and 3.65 mg C m−3 d−1 in the channel. The value of 1 333 mg C m−3 year−1 calculated for A. tonsa at the channel station is very high relative to the situation in other estuaries, indicating that the estuary has a high production of copepods.

scholarly journals Biota of the Patos Lagoon estuary and adjacent marine coast: long-term changes induced by natural and human-related factors

2017 ◽  
Vol 13 (1) ◽  
pp. 3-8 ◽  
Author(s):  
Clarisse Odebrecht ◽  
Eduardo Resende Secchi ◽  
Paulo Cesar Abreu ◽  
José Henrique Muelbert ◽  
Franz Uiblein
Keyword(s):  
Related Factors ◽  
Patos Lagoon ◽  
Long Term Changes ◽  
Patos Lagoon Estuary

An ESP Production Optimization Algorithm Applied to Unconventional Wells

2021 ◽  
Author(s):  
Fernando Bermudez ◽  
Noor Al Nahhas ◽  
Hafsa Yazdani ◽  
Michael LeTan ◽  
Mohammed Shono
Keyword(s):  
Gas Production ◽  
Oil Wells ◽  
Production Optimization ◽  
Operating Conditions ◽  
Tight Oil ◽  
Daily Production ◽  
Free Gas ◽  
Maximum Production ◽  
Electrical Submersible Pumps ◽  
High Production

Abstract The objectives and Scope is to evaluate the feasibility of a Production Maximization algorithm for ESPs on unconventional wells using projected operating conditions instead of current ones, which authors expect will be crucial in adjusting the well deliverability to optimum frequencies on the rapidly changing conditions of tight oil wells. Actual production data for an unconventional well was used, covering from the start of Natural Flow production up to 120 days afterwards. Simulating what the production would be if a VFD running on IMP Optimization algorithms had been installed, new values for well flowing pressures were calculated, daily production scenarios were evaluated, and recommended operating frequencies were plotted. Result, observations, and conclusions: A. Using the Intelligent Maximum Production (IMP) algorithm allows maximum production from tight oil wells during the initial high production stage, and the prevention of gas-locking at later stages when gas production increases. B. The adjustment of frequency at later stages for GOR wells is key to maintaining maximum production while controlling free gas at the intake when compared against controlling the surface choke. Novel/additive information: The use of Electrical Submersible Pumps for the production of unconventional wells paired with the use of a VFD and properly designed control algorithms allows faster recovery of investment by pumping maximum allowable daily rates while constraining detrimental conditions such as free gas at the intake.

scholarly journals Trophic quality of waters in the Patos Lagoon estuary: a comparison between its margins and the port channel located in Rio Grande, RS, Brazil

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Rafela Neves Marreto ◽  
Maria da Graça Zepka Baumgarten ◽  
Mônica Wallner-Kersanach
Keyword(s):  
Water Flow ◽  
Effluent Treatment ◽  
Trophic State Index ◽  
Patos Lagoon ◽  
Nitrogenous Compounds ◽  
Hydrological Conditions ◽  
Quality Of Waters ◽  
Patos Lagoon Estuary ◽  
State Index

Abstract: Aim This study aimed to evaluate the Trophic State Index (TSI) at the margin and in the channel of the Patos Lagoon estuary, considering different hydrological conditions. Methods Surface and bottom water samples were collected in three sites in the channel (margin and center) and in two sites at the Saco da Mangueira in different hydrological conditions in 2011. Results Waters at the Saco da Mangueira are very contaminated by phosphate and nitrogenous compounds. The TSI classifies these waters as being hypereutrophic, the consequence of both the release of effluents which were poorly treated and the low water flow in the inlet. Contamination was mild at the margins of the channel, where waters were classified as being eutrophic and mesotrophic. Trophic balance (mesotrophic waters - oligotrophic surface - bottom) was found in the center of the channel as a consequence of strong water flow and dilution of contaminants coming from the margins. Conclusions Spatial variation in the TSI value enabled clear distinction to be observed between the areas at the margins and in the channel, because it reflected the punctual presence of anthropogenic input in the marginal waters, mainly in the Saco da Mangueira. Effluent treatment must be required in order to control severe trophic imbalance in the waters at the margins of the city. Variations of the proposed index are a useful tool to identify sources of phosphate compounds in other aquatic environments.

High Production Well Operating Plant in a Traditional Design: Piping & Instrumentation Challenges

2021 ◽  
Author(s):  
Jordana Luiza Barbosa da Costa Veiga ◽  
Antonio Jose Renno Chaves ◽  
Breno De Souza e Silva ◽  
Ivan Noville Rocha Correa Lima ◽  
Ilvan Porto Jr Pereira ◽  
...  
Keyword(s):  
Production Potential ◽  
Great Expectation ◽  
Deep Waters ◽  
Alternative Approach ◽  
Production Wells ◽  
Full Production ◽  
High Production ◽  
Technical Assessment ◽  
Very High ◽  
Operating Plant

Abstract During the exploration design phase of recent pre-salt development in Santos Basin, it was identified great potential for the production of some wells, generating great expectation by how it would perform in the production phase, above the average of 30,000 bpd. The Subsea and Topside design were developed based on this expectation and therefore, diameters were limited considering the premises of 45,000 bpd production from the well to the FPSO. As a result of first oil production the expectation not only became a reality but also was largely supersede, confirming a very high production potential of up to 65,000 bpd per well, some of which are at the world top list of highest production wells for deep and ultra-deep waters. Despite the outstanding high potential of the well, full production was then, not able to be achieved due to limitations considered in the design's premises of 45,000 bpd per well, what overcome the already great expectation. In this scenario, there was intense effort to make the real production potential of the wells viable. To fit the design to the new dynamic flow conditions, a multidisciplinary technical assessment team was mobilized involving several disciplines such as: Subsea Equipment, Wells, Risers, Process, Piping, Instrumentation and Automation, in addition to Operational Safety, a non-negotiable value. After technical discussions between those different disciplines, alternative proposals were raised that could make possible a safe operation under this new challenging condition. The defined actions were implemented and currently the wells already operate on high levels of production. On the FPSO with those high production wells, due to this individual increase in the production, whose potentials exceed by 45% the design capacity, generating a significant increase in the profitability of the asset, contributing to revenues anticipation in the company's cash flow. This article presents the piping and instrumentation study to deal with a high flow velocity issue. The methodology adopted to overcome the challenges in vibration and erosion considered an unusual design approach, leading to some field test to check the effectiveness of the solution. This alternative approach allowed this increment in production rate per well piping branch.

scholarly journals Comparison of 1982–1983 and 1997–1998 El Niño effects on the shallow-water fish assemblage of the Patos Lagoon estuary (Brazil)

Estuaries ◽  
2004 ◽  
Vol 27 (6) ◽  
pp. 905-914 ◽  
Author(s):  
A. M. Garcia ◽  
J. P. Vieira ◽  
K. O. Winemiller ◽  
A. M. Grimm
Keyword(s):  
Shallow Water ◽  
El Niño ◽  
Fish Assemblage ◽  
El Nino ◽  
Patos Lagoon ◽  
Water Fish ◽  
Patos Lagoon Estuary

Numerical Analysis and Comparison of Airflow in Rotors with U and V Groove during Rotor Spinning Process

2016 ◽  
Vol 11 (4) ◽  
pp. 155892501601100
Author(s):  
Rui-Hua Yang ◽  
Chao Liu ◽  
Yuan Xue ◽  
Hongbo Wang ◽  
Weidong Gao
Keyword(s):  
Numerical Analysis ◽  
Process Parameters ◽  
Static Pressure ◽  
Optimum Process ◽  
Production Rates ◽  
Rotor Spinning ◽  
Yarn Quality ◽  
Spinning Process ◽  
High Production

Rotor spinning is known for high production rates and uniformity of the resulting yarn. However, determining machine components which will produce the optimum process parameters such as airflow speed to result in the best combinations of yarn quality and uniformity can be a difficult task. The aim of this study is to simulate and analyze the airflow characteristics in rotors with U and V grooves during the rotor spinning process. The results obtained showed that airflow speed resulting from a rotor with the V groove is higher than that of U type. As a result, the static pressure resulting from the use of the V type groove is lower than that of U groove.

scholarly journals Exposure to exogenous estrogens in food: possible impact on human development and health

1999 ◽  
Vol 140 (6) ◽  
pp. 477-485 ◽  
Author(s):  
AM Andersson ◽  
NE Skakkebaek
Keyword(s):  
Human Development ◽  
Steroid Hormones ◽  
Scientific Data ◽  
Animal Tissues ◽  
Production Rates ◽  
Daily Production ◽  
Prepubertal Children ◽  
The Us ◽  
Residue Levels ◽  
Low Levels

There has been increasing concern about the impact of environmental compounds with hormone-like action on human development and reproductive health over the past decades. An alternative but neglected source of hormone action that may be considered in this connection is hormone residues in meat from husbandry animals treated with sex steroid hormones for growth promotion. Treatment of cattle with naturally occurring or synthetic sex hormones may enhance lean muscle growth and improve feed efficiency and is therefore a very cost effective procedure for cattle producers who have used it for decades in some Western countries, including the USA and Canada. The Joint Food and Agricultural Organisation/World Health Organisation (FAO/WHO) expert committee on food additives (JECFA) and the US Food and Drug Administration (FDA) considered, in 1988, that the residues found in meat from treated animals were safe for the consumers. We have re-evaluated the JECFA conclusions regarding the safety of estradiol residues in meat in the light of recent scientific data, with special emphasis on estradiol levels in prepubertal children. These levels are needed for estimates of the normal daily production rates of estradiol in children, who may be particularly sensitive to low levels of estradiol. In our opinion, the conclusions by JECFA concerning the safety of hormone residues in meat seem to be based on uncertain assumptions and inadequate scientific data. Our concerns can be summarized as follows. 1) The data on residue levels in meat were based on studies performed in the 1970's and 1980's using radioimmunoassay (RIA) methods available at the time. The sensitivity of the methods was generally inadequate to measure precisely the low levels found in animal tissues, and considerable variation between different RIA methods for measuring steroids exists. Therefore the reported residue levels may be subject to considerable uncertainty. 2) Only limited information on the levels of the various metabolites of the steroids was given despite the fact that metabolites also may have biological activity. 3) Reliable data on daily production rates of steroid hormones were and are still lacking in healthy prepubertal children. This lack is crucial as previous guidelines regarding acceptable levels of steroid residues in edible animal tissues have been based on very questionable estimates of production rates in children. Thus, even today the US FDA bases its guidelines on the presumably highly overestimated production rates in prepubertal children given in the JECFA 1988 report. 4) The possible biological significance of very low levels of estradiol is neglected. In conclusion, based on our current knowledge possible adverse effects on human health by consumption of meat from hormone-treated animals cannot be excluded.

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