Schmieder L.,The Mustang Group |
Schmieder L.,University of Texas at Dallas |
Mellon D.,136 County Road 1998 |
Mellon D.,University of Texas at Dallas |
Saquib M.,University of Texas at Dallas
IEEE Transactions on Aerospace and Electronic Systems | Year: 2010
We propose a novel beamforming algorithm for a three-element system that suppresses an interference signal while still being able to measure a target's interferometer phases. Unlike most direction-of-arrival (DOA) estimation algorithms, our algorithm does not use a grid search. Instead the estimates result from a closed-form solution, a great advantage in time-sensitive applications. The derivation of the algorithm is presented, and its statistical performance is examined with simulations. Additionally, our numerical results demonstrate that our algorithm is capable of achieving more reliable DOA estimates than those found with the well-known multiple signal classification (MUSIC) algorithm. Finally, a radar signal processing example is presented. © 2010 IEEE.
Wu J.,Wuhan Polytechnic University |
Yu H.,The Mustang Group |
Shi X.,Washington State University
Journal of Materials in Civil Engineering | Year: 2016
A total of 12 multielectrode array sensors were utilized to assess the individual effectiveness of two corrosion inhibitors and one coating under cyclic deicer exposure conditions. There were four sensor groups, and each group consisted of nine-pin probes that were fabricated from 1008 carbon steel, 304 stainless steel, and 1100 aluminum, respectively. A total of two environmental exposure tests were conducted, in which 2.3% NaCl and 3.0% MgCl2 solutions were used as salt, respectively. The two tests each included eight environmental cycles and with 24 h per cycle. For all the exposed sensors, the most severe corrosion occurred at the beginning of the humidity stage. For sensors in the control group, MgCl2 exhibited a corrosion attack throughout the exposure period, whereas NaCl only exhibited an apparent corrosion attack during the humidity stage. Both the sensor corrosion rates and mass loss results indicate that the inhibitors had a much greater effect for MgCl2 than for NaCl. Although the coating showed significant benefits in protecting the metallic substrates, the cyclic exposure to MgCl2 led to greater coating deterioration than did NaCl. For validation, impedance measurements were conducted on carbon steel panels subjected to similar exposures, and three-dimensional laser profilometer scans were performed to characterize their surface morphology after the exposures. © 2015 American Society of Civil Engineers.
Chen C.-C.,The Mustang Group |
Liu Y.-S.,The Mustang Group |
Palmer R.E.,The Mustang Group
15th Topical Conference on Gas Utilization 2015 - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety | Year: 2015
In order to produce high purity ethane and to prevent potential hydrate formation from a wet natural gas liquid (NGL) feed, an effective high pressure deethanizer design has been developed. Gas hydrates, which are crystalline solids composed of water and light hydrocarbon molecules, often result in safety and operational issues. If a high purity ethane is to be produced, the deethanizer condenser and the top tray temperatures may be lower than the hydrate point. This condition may cause gas hydrates to form at these locations if the wet NGL is not dehydrated. Conventional methods of preventing hydrate formation include removal of water content in a glycol or a dry desiccant dehydration unit, both of which require a complex dehydration and regeneration system. This paper discusses a design method that eliminates the requirement for a dehydration unit. The deethanizer condenser temperature increases rapidly while the hydrate formation temperature increases slowly with pressure. Based on this phenomenon, a high purity ethane can be obtained by increasing the deethanizer pressure to a practical level without the use of a dehydration unit. The major benefits of this method without dehydration include its construction and operational simplicity as well as space savings. Using this method can save some capital cost but requires slightly more utility consumptions. The advantages, disadvantages, and the limitations of this approach will be discussed in detail in this paper. This method has been successfully demonstrated commercially. © Copyright American Institute of Chemical Engineers. All rights reserved.
Fjelde I.,The Mustang Group |
Lohne A.,The Mustang Group |
Abeysinghe K.P.,The Mustang Group
EUROPEC 2015 | Year: 2015
The theory and procedures for surfactant flooding were developed for water-wet sandstone, but many sandstone reservoirs are today characterized as mixed-wet. The objective for the study was to carry out critical investigation of experimental methods used to evaluate the potential for surfactant flooding in mixed-wet sandstone reservoirs. Water flooding and surfactant flooding experiments were performed in mixed-wet Berea outcrop sandstone, and in reservoir sandstone rock. During water flooding long tail-end production was observed for both the mixed-wet Berea and reservoir rock. The relative permeability (kr)-curves estimated by history matching were similar for these rocks. Since kr of oil (kro) is low at higher water saturations, the residual oil saturation (Sor) will not be reached with realistic injection volumes. The remaining oil saturation (ROS) was both in the water floods and surfactant floods strongly dependent on the volumes injected. The focus should therefore be on the alteration of kr-curves by the surfactant rather than reduction of Sor. Solubilization of oil into the surfactant phase is challenging in relative permeability experiments at mixed-wet conditions. When injected surfactant solution was not in equilibrium with the oil, it was not possible to correct the oil production for the solubilization because the surfactant phase was not in equilibrium with the remaining oil in the rock. The estimated kr-curves should therefore have been at higher water-saturations. The uncertainty related to solubilization of oil can be reduced by flooding with surfactant systems with equilibrium between the phases. In mixed-wet rock having negative Pc at higher water saturation (Sw), capillary forces will act to reduce the oil production rate. The effect increases in shorter core plugs and at lower injection rates and it also seems to be more important if displaced oil phase has low viscosity. It is recommended to always evaluate capillary end effects when dealing with mixed-wet rock material to secure that additional oil production due to reduced end effects is not included in the surfactant flooding potential. Simulation of surfactant flooding in mixed-wet formations require a fair representation of the capillary number (Nc) dependent kr curvature. It is demonstrated that this is possible using a simple surfactant model available in commercial simulators and a practical cut-off value for Sor at low Nc in the model. Recommendations are given on how to secure the quality of surfactant flooding experiments and the interpretation of these experiments to allow robust data for scaling of the laboratory results to field. Copyright 2015, Society of Petroleum Engineers.
Black P.,The Mustang Group
Control | Year: 2014
Regulatory mandates for the stringent control of air quality, including greenhouse gas emissions, are being increasingly tightened in the US. Agencies at the federal, state and local levels are requiring more data collected by direct measurement from continuous emissions monitoring system (CEMS) equipment instead of relying on factors to calculate emissions based on other process measurements. These directives require more stringent auditability requirements and transparency of emission calculations. Request for comprehensive data are technology advances that continue to provide instruments with the measurement capability to collect larger, more massive datasets are being made to complement this objective. The goal of air emissions data collection is to generate accurate and consistent environmental reports as part of a larger enterprise information management strategy.
Shah G.C.,The Mustang Group
28th Center for Chemical Process Safety International Conference 2013, CCPS - Topical Conference at the 2013 AIChE Spring Meeting and 9th Global Congress on Process Safety | Year: 2013
Today, there is considerable emphasis being placed on learning from near-miss incidents and applying additional safeguards which would minimize possibility of escalating adverse impact of these events in the future. Not all near-miss incidents have potential for major adverse impact. It is important to focus on near-miss incidents which could result into incidents with major adverse impact. This paper applies a modified "Risk Assessment Matrix," that is commonly used for conducting PHA assessments such as HAZID and HAZOP, to estimate potential future risk indication conveyed by near-misses. In a strategic sense, near-miss management spans all work systems of an organization and its culture: IT system, operations, legal, and many others.
Shah G.C.,The Mustang Group
Pipeline and Gas Journal | Year: 2014
SCADA is a pivotal tool in achieving impressive productivity and reliability of pipelines. However, SCADA systems face cyber threats that could render them inoperable, causing substantial adverse effects on profitability. A discussion covers SCADA cyber threats and possible solutions from the viewpoint of management; managerial level, and details of intricate technical nature, e.g., SCADA programming, firewall protocols and intrusion detection system protocols are omitted.
Shah G.C.,The Mustang Group
Pipeline and Gas Journal | Year: 2014
Safety assessment of pipeline projects involves coordination with a large number of groups, often spread over diverse geographical regions. Managers will have an opportunity, as well as a challenge, to communicate to a wide spectrum of personnel. Establishing a good rapport at an early stage of the safety assessment process is essential. Having a strategic understanding of local issues and the safety impacts is the key to pipeline safety assessments. A discussion covers getting vital risk assessment information; health, safety, security and environmental management systems; and the cyber security of pipeline controls and SCADA systems.
News Article | March 11, 2010
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