scholarly journals Numerical Modeling of Multiphase Extraction (MPE) Aiming at LNAPL Recovery in Tropical Soils

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2248 ◽  
Author(s):  
Bortoni ◽  
Schlosser ◽  
Barbosa
Keyword(s):  
Tropical Soils ◽  
Diesel Oil ◽  
Silty Sand ◽  
System Configuration ◽  
Fluid Extraction ◽  
System Sensitivity ◽  
Flow And Transport ◽  
Tube Position ◽  
Definition Of ◽  
Multiphase Extraction

Subsurface contamination by light non-aqueous phase liquids (LNAPL) is a widespread global problem that requires appropriate techniques to remediate soil and groundwater. In this paper, the subsurface transport over multiple phases (STOMP) model was used to simulate LNAPL multiphase flow and transport during multiphase extraction (MPE) application in two Brazilian tropical soils (silty sand and oxisol) contaminated by diesel. The model was applied to a hypothetical contamination site, with the initial LNAPL thickness observed in well extraction. The first part consisted of the MPE system sensitivity analysis, varying the applied vacuum and tip tube position. The Van Genuchten α parameter and hydraulic conductivity were the properties that most affected LNAPL saturation and fluid extraction volumes. Suitable applied vacuum and tip tube position parametrization was imperative for the efficiency of LNAPL extraction. After the definition of an appropriate MPE system configuration, simulations demonstrated that the immobile LNAPL saturation affected fluid extraction and diesel oil concentrations in aqueous and gas saturation. The model applied is able to predict LNAPL contaminant behavior in porous media during MPE technique application.

The Berkeley Lower Extremity Exoskeleton

2005 ◽  
Vol 128 (1) ◽  
pp. 14-25 ◽  
Author(s):  
H. Kazerooni ◽  
R. Steger
Keyword(s):  
Lower Extremity ◽  
Control Algorithm ◽  
Local Area Network ◽  
Control Method ◽  
Local Area ◽  
Area Network ◽  
System Sensitivity ◽  
Trade Offs ◽  
Control Schemes ◽  
Definition Of

The first functional load-carrying and energetically autonomous exoskeleton was demonstrated at the University of California, Berkeley, walking at the average speed of 1.3m∕s(2.9mph) while carrying a 34kg(75lb) payload. Four fundamental technologies associated with the Berkeley lower extremity exoskeleton were tackled during the course of this project. These four core technologies include the design of the exoskeleton architecture, control schemes, a body local area network to host the control algorithm, and a series of on-board power units to power the actuators, sensors, and the computers. This paper gives an overview of one of the control schemes. The analysis here is an extension of the classical definition of the sensitivity function of a system: the ability of a system to reject disturbances or the measure of system robustness. The control algorithm developed here increases the closed-loop system sensitivity to its wearer’s forces and torques without any measurement from the wearer (such as force, position, or electromyogram signal). The control method has little robustness to parameter variations and therefore requires a relatively good dynamic model of the system. The trade-offs between having sensors to measure human variables and the lack of robustness to parameter variation are described.

scholarly journals Multi-objective optimization of retaining wall using genetic algorithm

2021 ◽  
Vol 8 (1-2) ◽  
pp. 58-65
Author(s):  
Filip Dodigović ◽  
Krešo Ivandić ◽  
Jasmin Jug ◽  
Krešimir Agnezović
Keyword(s):  
Genetic Algorithm ◽  
Optimization Problem ◽  
Retaining Wall ◽  
Silty Sand ◽  
Embedment Depth ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Multi Objective ◽  
Definition Of ◽  
The Cost

The paper investigates the possibility of applying the genetic algorithm NSGA-II to optimize a reinforced concrete retaining wall embedded in saturated silty sand. Multi-objective constrained optimization was performed to minimize the cost, while maximizing the overdesign factors (ODF) against sliding, overturning, and soil bearing resistance. For a given change in ground elevation of 5.0 m, the width of the foundation and the embedment depth were optimized. Comparing the algorithm's performance in the cases of two-objective and three objective optimizations showed that the number of objectives significantly affects its convergence rate. It was also found that the verification of the wall against the sliding yields a lower ODF value than verifications against overturning and soil bearing capacity. Because of that, it is possible to exclude them from the definition of optimization problem. The application of the NSGA-II algorithm has been demonstrated to be an effective tool for determining the set of optimal retaining wall designs.

Supercritical fluid extraction of planar and mono-ortho PCB in selected tropical soils

Chemosphere ◽  
1998 ◽  
Vol 36 (7) ◽  
pp. 1565-1573 ◽  
Author(s):  
Lars Baetz Reutergardh ◽  
Preeda Parkpian ◽  
Chompoonut Chaiyaraksa
Keyword(s):  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Tropical Soils ◽  
Fluid Extraction

Design and Implementation of Software Configuration Tool for Integrated Modular Avionics

2014 ◽  
Vol 651-653 ◽  
pp. 1827-1830
Author(s):  
Ok Kyoon Ha ◽  
Eu Teum Choi ◽  
Yong Kee Jun
Keyword(s):  
System Configuration ◽  
Space Partitioning ◽  
Time And Space ◽  
Real Time Operating System ◽  
Design And Implementation ◽  
Software Configuration ◽  
Configuration Data ◽  
Interface Definition ◽  
Definition Of ◽  
Integrated Modular Avionics

ARINC 653 specification has been introduced as a standardized interface definition of real-time operating system to simplify the development of Integrated Modular Avionics. The ARINC 653 provides a strict and robust time and space partitioning to guarantee the reliability of avionics by isolating the failures of the system. Configuration data for the time and space partitions in the ARINC 653 can be defined as the XML configuration file that can be accessed only by system OS. Unfortunately, it is quite tedious activity to confirm the integrity of partition scheduling and to check the syntax errors of XML during the integration tasks. In this paper, we present a software configuration tool that provides generating the configuration data and verifying the integrity of partitioning based on XML Scheme of the ARINC 653 standard.

Solar-Powered/Fuel-Assisted Rankine Cycle Power and Cooling System: Sensitivity Analysis

1984 ◽  
Vol 106 (4) ◽  
pp. 447-456 ◽  
Author(s):  
N. Lior ◽  
K. Koai
Keyword(s):  
Sensitivity Analysis ◽  
Cooling System ◽  
Rankine Cycle ◽  
Energy Performance ◽  
System Configuration ◽  
System Sensitivity ◽  
Average Value ◽  
Climatic Regions ◽  
The Subject ◽  
Solar Powered

The subject of this analysis is a solar power/cooling system based on a novel hybrid steam Rankine cycle. Steam is generated by the use of solar energy collected at about 100°C, and it is then superheated to about 600°C in a fossil-fuel-fired superheater. The addition of about 20–26 percent of energy as fuel doubles the power cycle’s efficiency as compared to organic fluid Rankine cycles operating at similar collector temperatures. A sensitivity analysis of the system’s performance to the size and type of its components was performed by a transient (hourly) computer simulation over the month of August in two representative climatic regions (Washington, D.C. and Phoenix, Ariz.), and led to the description of a system configuration which provides optimal energy performance. The newly designed turbine’s predicted efficiency is seen to be essentially invariant with system configuration, and has a monthly average value of about 73 percent.

Environmental Risk Analysis and Risk Assessment for Osbra Pipeline: A New Approach

2004 ◽  
Author(s):  
Carlos Alberto Rodrigues Torres ◽  
Regiane Tiemi Teruya Yogui ◽  
Renato Mendes ◽  
Maria Eula´lia Rocha Carneiro ◽  
Wilson Jose´ de Oliveira
Keyword(s):  
Risk Assessment ◽  
Hazard Analysis ◽  
Federal District ◽  
Diesel Oil ◽  
Quantitative Risk Assessment ◽  
Detailed Knowledge ◽  
Liquefied Petroleum Gas ◽  
Right Of Way ◽  
Accident Scenarios ◽  
Definition Of

Osbra pipeline (Oleoduto Sa˜o Paulo – Brasi´lia), about 1000 Km long, is one of the main pipelines of Petrobras Transportes S. A. - Transpetro and its function is to carry gasoline, diesel oil, aviation kerosene and liquefied petroleum gas throughout the Center-West region of Brazil. As it crosses several states of Brazil (Sa˜o Paulo, Minas Gerais and Goia´s) and Federal District (Brasi´lia), the process of renewal of the environmental license at the federal level required a series of environmental studies. Accordingly, a new study is being performed, considering, in addition to the already consecrated Quantitative Risk Assessment, a new methodology for recognition and analysis of the vulnerable environmental elements along the pipeline right-of-way in what concerns oil spill. This study intends to present the aforementioned methodology according to the following topics: Characterization of the undertaking and of the surrounding region; identification of the notable points; identification of the sensitive environmental elements in the hydrographic basins; Preliminary Hazard Analysis; definition of accident scenarios; dimension of possible leaks along the pipeline right-of-way and their consequences (physical effects); calculation of frequencies; calculation and evaluation of risks (social and individual); classification of environmental sensitivity; contingency actions analysis and conclusions. Development of this work brings as a result a more detailed knowledge of the consequences of an occasional accident arising from pipeline related activities, to the end of preventing and protecting the vulnerable elements (man and environment) along the pipeline right-of-way.

14 Analysis on the System Configuration of Digital Substations

2013 ◽  
Vol 765-767 ◽  
pp. 2559-2562
Author(s):  
Fei Ma ◽  
Ze Ju Ma ◽  
Ying Ying Su
Keyword(s):  
Structure And Function ◽  
System Configuration ◽  
Iec 61850 ◽  
Network Solution ◽  
Electronic Transformer ◽  
Spacer Layer ◽  
Digital Substation ◽  
Definition Of ◽  
And Function

In accordance with the definition of the IEC 61850 standard, a digital substation is hierarchically distributed and divided into the process layer, the spacer layer and the station layer. On the basis of the analysis of its structure and function, this work is focused on the configuration of different layers and that of the dual bus wiring electronic transformer and merged unit, as well as the GOOSE network solution under the relay double configuration.

Degradation of Anthracene by Bacteria Isolated from Oil Polluted Tropical Soils

2000 ◽  
Vol 55 (11-12) ◽  
pp. 890-897 ◽  
Author(s):  
Matthew O. N. Ilori ◽  
Dan-Israel Amund
Keyword(s):  
Crude Oil ◽  
Carbon Sources ◽  
Tropical Soils ◽  
Diesel Oil ◽  
Engine Oil ◽  
Polluted Soils ◽  
Ring Fission ◽  
Catechol 1,2 Dioxygenase ◽  
Oil Concentration ◽  
Benzene Toluene

Four bacteria, identified as Pseudomonas aeruginosa, Alcaligenes eutrophus, Bacillus subtilis and Micrococcus'luteus were isolated from crude oil polluted soils using anthracene as the sole carbon and energy source. All the organisms utilized n-hexadecane, n-tetradecane, diesel oil, engine oil and naphthalene as sole carbon sources. None could utilize hexane, cycloheptane, xylene, benzene, toluene, phenol, fluoranthene,and kerosene as carbon sources. Highest cell density obtained with 0.1% (w/v) anthracene were 4.5 × 107 (cfu/ml), 8.6 × 106 (cfu/ml), 5.4 × 106 and 2.4 × 106 (cfu/ml) respectively, for P. aeruginosa, A. eutrophus, B. subtilis and M. luteus after 30 days incubation. Growth of the organism s on a Nigerian crude oil resulted in a residual oil concentration of 22.2% , 33.3% , 39.3% ,44% and 91.7% respectively, for P. aeruginosa, A. eutrophus, B. subtilis, M. luteus and the noninoculated control on the 14 th day. Ring fission enzymes of the meta pathway were detected in induced cells of P. aeruginosa and A. eutrophus while ortho pathway enzymes were detected in B. subtilis and M. luteus. P. aeruginosa and A. eutrophus had specific catechol-2,3-dioxygenase activities of 3.8 ± 0.183 and 0.64 ± 0.032 μmol / min × mg protein respectively while catechol-1,2-dioxygenase activities of 1.95 ± 0.029 and 1.89 ± 0.026 μmol / min x mg protein were detected in B. subtilis and M. luteus respectively. This work , highlights the capability of these unreported tropical strains of A. eutrophus, B. subtilis and M. luteus as anthracene degraders.

The residual shear strength of tropical soils

2006 ◽  
Vol 43 (4) ◽  
pp. 431-447 ◽  
Author(s):  
Marcelo Luvison Rigo ◽  
Rinaldo José Barbosa Pinheiro ◽  
Luiz Antônio Bressani ◽  
Adriano Virgílio Damiani Bica ◽  
Rodrigo Moraes da Silveira
Keyword(s):  
Shear Strength ◽  
Clay Fraction ◽  
Friction Angle ◽  
Tropical Soils ◽  
Plasticity Index ◽  
Residual Soils ◽  
Residual Shear Strength ◽  
Ring Shear Tests ◽  
Definition Of ◽  
Soil Behaviour

The paper discusses the residual shear strength of tropical soils. Ring shear tests have been performed with tropical soils from southern Brazil using the Bromhead apparatus. The data from the study are compared with data obtained in a comprehensive literature review of the subject. The residual friction angle of tropical residual soils from sedimentary formations decreases with increasing plasticity index following a general trend presented in the literature. Most of the residual soils described herein have also shown this trend. However, some of these residual soils, particularly basalt saprolitic soils, have shown quite low residual friction angles despite having low plasticity index and clay fraction values. It has been confirmed that the residual shear strength of tropical soils depends chiefly on mineralogy, particle size distribution, effective stress, parent rock, weathering degree, pedogenetic evolution and - when partly weathered minerals are present - degradation upon shearing. The substantial range of new data shown in the paper has allowed the definition of general boundaries of different soil behaviour in a chart of residual friction angle versus plasticity index. Each region has been associated with a different type of tropical soil.Key words: tropical soils, residual soils, residual shear strength, laboratory tests.

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