Operations Research, Systems Engineering and Industrial Engineering Commons^™

Acuta Enews August 2007, Vol. 36, No. 8

ACUTA Newsletters

ln This lssue

From the President ............. Walt Magnussen, Ph,D., Texas A&M University

Tech Talk: ls This a Phone That You Want on Your Network? ............ Kevin Tanzillo, Dux PR 2 ACUTA Resources Make Membership a Great Value

DC Update ............... Jeanne Jansenius, Sewonee, The University of the South

Board Report............... Riny Ledgerwood, San Diego State Univ., ACUTA Sec./Treasurer

IPFIX Standard (NetFlow) and lT Staff |mpact.............. Gary Audin, Delphi lnc.

Check lt Out: RFls/RFPs, Job Postings, Press Releases

FYI: Useful lnformation from the Campus................. Student Monitor

Web Tip: Address Change for ACUTA Listservs ..... Aaron Fuehrer, ACUTA lnformation Technology Mgr. …

Detection Of Aortic Calcification During Vertebral Fracture Assessment (Vfa) Compared To Digital Radiography, John T. Schousboe, Kevin E. Wilson, Thomas N. Hangartner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Background: Cardiovascular disease is the most common cause of mortality among post-menopausal women. Our objective was to determine whether or not lateral spine images obtained on a bone densitometer to detect prevalent vertebral fracture can also accurately detect radiographic abdominal aortic calcification (AAC), an important risk factor for cardiovascular disease independent of clinical risk factors.

Methodology/Principal Findings: One hundred seventy four postmenopausal women had bone densitometry, lateral spine densitometry imaging (called vertebral fracture assessment, or VFA), and lateral spine digital radiographs. Radiographs and VFA images were scored for AAC using a previously validated 24 point scale and a simplified, …

Integrated Nurse Staffing And Assignment Under Uncertainty, Prattana Punnakitikashem

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

One of the major problems in the United States health care system is a shortage of nurses. Baby boomers and an increasing elderly population are the main reasons for a rapidly growing demand for nurses. Besides the decline in enrollments in registered nurse degree programs, many nurses have suffered from work burnout. High workloads and undesirable schedules are two major issues that cause nurses' job dissatisfaction. As a result, nurses plan to leave their jobs causing low retention and low entering rates. One consequence of the shortage is that excessive workload on nurses decreases the quality of patient care. Many …

A Data-Integrated Simulation-Based Optimization Approach For Nurse-Patient Assignment, Duraikannan Sundaramoorthi

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This research develops a novel data-integrated simulation to evaluate nurse-patient assignments (SIMNA) based on a real data set provided by Baylor Regional Medical Center (Baylor) in Grapevine, Texas. Tree-based models and kernel density estimation were utilized to extract important knowledge from the data for the simulation. Classification and Regression Tree models, data mining tools for prediction and classification, were used to develop five tree structures: (a) four classification trees, from which transition probabilities for nurse movements are determined; and (b) a regression tree, from which the amount of time a nurse spends in a location is predicted based on factors …

System And Method For The Pooling Of Sterile Product, David A. Edelen

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This dissertation defines an automated system and method for removing the tops from individual sealed bottles and pooling the small volumes of liquid contained in each bottle together in a collection container while maintaining the sterility of the product. This research further applied system development and process improvement methodology. More particularly, this research solved a previously unsolved problem through the unique research and development, and application of ultrasonic technology, to mitigate both product and personnel risk, and provide process improvement, as associated with the aseptic process for the pooling of sterile product.

A Robust Cooperative Localization System For A Heterogeneous Team Of Small Unmanned Ground Vehicles, Veera Jawahar Vibeeshanan

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This dissertation presents an organic approach to the cooperative localization problem by sequentially solving the problems of sensor calibration, multi-sensor fusion filtering, and cooperative localization. Successful navigation of unmanned ground vehicles requires accurate localization. Localization refers to the determination of the pose (position and orientation) of an unmanned ground vehicle with respect to a local or a global frame of reference. Cooperative localization is suited to multi-vehicle systems where vehicles with better accuracy in localization can assist those with poor accuracy through communication and relative pose sensing. A parametric modeling approach is presented for sensor calibration. Designed experiments are conducted …

Leanness And Agility In Job Shops: A Framework For A Survey Instrument Developed Using The Delphi Method, Zaki Kuruppalil

All-Inclusive List of Electronic Theses and Dissertations

Manufacturers are facing new challenges as competition has become global. Manufacturing companies arc looking for strategies which would help them gain an edge over their competitors. In the United States, lean manufacturing and agile manufacturing have been gaining importance among industries. Agile manufacturing was developed when the United States Department of Defense (DOD) requested Iacocca Institute at Lehigh University to develop a manufacturing framework that could give US companies an edge over their worldwide competitors whereas lean manufacturing has its roots tied to the Toyota Production System (TPS). This raises the questions: what is the clear difference between the two …

Using Reconstructability Analysis For Input Variable Reduction: A Business Example, Stephen Shervais, Martin Zwick

Complex Systems Faculty Publications and Presentations

We demonstrate the use of reconstructability analysis (RA) on the UCI Australian Credit dataset to reduce the number of input variables for two different analysis tools. Using 14 variables, an artificial neural net (NN) is able to predict whether or not credit was granted, with a 79.1% success rate. RA preprocessing allows us to reduce the number of independent variables from 14 to two different sets of three, which have success rates of 77.2% and 76.9% respectively. The difference between these rates and that of the 14-variable NN is not statistically significant. The three-variable rulesets given by RA achieve success …

Case Studies On Usage Of Axiomatic Design Methodology In The U.S. Industries, Alireza Alavizadeh

All-Inclusive List of Electronic Theses and Dissertations

Axiomatic Design, originally developed by Nam Suh, is a design methodology that attempts to systematize the design practices and to provide a basis on which design can be carried out and optimized according to two main axioms, namely, Independence and Information axioms. Although various scholars in both academia and industry have studied the applicability and effectiveness of this methodology, the extent to which Axiomatic Design has been implemented in industry, particularly in the U.S., is unknown. l1l This study was conducted to identify the extent to which Axiomatic Design is known to the U.S. industries. Other purposes of this study …

Understanding Sub-20 Nm Breakdown Behavior Of Liquid Dielectrics, Kumar R. Virwani, Ajay P. Malshe, Kamlakar P. Rajurkar

Department of Industrial and Management Systems Engineering: Faculty Publications

Nanoscale confinement of dielectric molecules is expected to influence their breakdown mechanism in applications such as nanoprobe based machining, molecular electronics, and other related technologies. This Letter presents the first experimental study of the breakdown of nonpolar, nonthiolated liquid dielectrics in the nanometer regime and develops a field emission assisted avalanche based approach to model such behavior. The studies show that dielectric breakdown in the sub-20 nm regime is independent of the cathode materials and is dominated by the electron emission and atomic cluster migration due to the ‘‘sub-20 nm scale confinement of the liquid dielectric.’’

Preface, Hans Müller-Steinhagen, M. Reza Malayeri, A. Paul Watkinson

Heat Exchanger Fouling and Cleaning VII

No abstract provided.

Table Of Contents, Hans Müller-Steinhagen, M. Reza Malayeri, Paul Watkinson

Heat Exchanger Fouling and Cleaning VII

No abstract provided.

Applying Technology Advancements To Improve Heat Exchanger Economic And Environmental Performance In Refinery Crude Preheat Trains, Himanshu Joshi, Fred Hoeve, Eric Van Der Zijden

Heat Exchanger Fouling and Cleaning VII

Fouling of heat exchangers in crude preheat trains is a major refinery operations business factor. It is realised that fouling cannot be completely eliminated, but considerable economic and environmental benefits are available with the proper application of improved technology in both the equipment and software asset management tools areas. This paper presents a technology update of refinery applications of a heat exchanger network analysis software to identify optimal crude preheat train cleaning.

Designing Two-Phase Flow Heat Exchangers For Mitigating Fouling, C.B. Panchal, Blazo Ljubicic

Heat Exchanger Fouling and Cleaning VII

Significant progress has been made in understanding the underlying mechanisms of hydrocarbon fouling and characterizing the effects of physical and chemical parameters in single-phase flows. However, the interactive effects of two-phase flows and fouling mechanisms are poorly understood. Many of the industrial heat exchangers in refining and petrochemical processing operate under multiphase flow conditions with varying flow regimes. Fouling and localized corrosion are generally experienced due to maldistribution of vapor and liquid phases in such heat exchangers. This is because design methods are inadequate to determine localized process conditions that could induce severe fouling locally, which could also lead to …

Crystallization Fouling Behaviour Of Uranium Oxide And Alumnosilicate Scale In High Level Nuclear Waste Medium, Jonas Addai-Mensah, Jun Li, Bill Wilmarth

Heat Exchanger Fouling and Cleaning VII

During high level nuclear waste (HLNW) liquor processing in evaporators operating in the temperature range 30 - 140 °C, dissolved silica, alumina, sodium hydroxide, uranium-235 and transuranic species (e.g. plutonium-238) invariably become concentrated. As the liquor evaporation proceeds, the sodium aluminosilicate (SAS) and radionuclides may exceed their solubility limits and co-precipitate, fouling the tubes and walls of the evaporator. If the fouling process is not effectively controlled or mitigated, radionuclide scale accumulation exceeding the critical mass necessary for self-sustaining nuclear fission reaction may proceed at an alarming rate, posing a serious criticality concern. To probe the mechanisms underpinning uranium oxide-sodium …

Precipitation And Fouling In Heavy Oil–Diluent Blends, E Hong, A. Paul Watkinson

Heat Exchanger Fouling and Cleaning VII

Heavy oil fractions rich in asphaltenes were mixed with diluents containing from 0.6-25% aromatics, and the resulting blends subjected to batch precipitation experiments at 85°C, and thermal fouling tests at surface temperatures in the range 230-310ºC. Deposit compositions were determined, and are compared with suspended asphaltene composition. When the heavy oils were blended with the most aromatic diluents, precipitation and fouling were negligible. As the aromaticity of the diluents was decreased, the extent of asphaltene precipitation and the fouling rates increased. The solubility parameter of the blends, δmix, and the flocculation solubility parameter for asphaltenes, δf , were determined from …

Costs Due To Utility Fouling In China, Xu Zhi-Ming, Zhang Zhong-Bin, Yang Shan-Rang

Heat Exchanger Fouling and Cleaning VII

This paper puts forward a method for evaluating the fouling costs of boilers and turbines in power plants. Furthermore, the Huaneng Dalian Power Plant and Changshan Power Plant are taken as examples for analyzing the costs of fouling. Based on data of on-site measurements in the above Power Plants, the costs due to fouling such as excess surface area, product loss, operating maintenance and increase of product costs are calculated. Results show that the total economical loss due to boiler and turbine fouling in China reaches 4.68 billion dollars, which covers is about 0.169% GDP of China in 2006.

Crude Oil Fouling In A Pilot-Scale Parallel Tube Apparatus, B. D. Crittenden, S. T. Kolaczkowski, T. Takemoto, D. Z. Phillips

Heat Exchanger Fouling and Cleaning VII

Maya crude oil fouling reveals a seemingly straightforward dependency of initial fouling rate on surface temperature but a maximum is found in the initial fouling rate – velocity relationship which mirrors that found in a model chemical system of styrene polymerization. The linear dependency of the logarithm of the pre-exponential factor on apparent activation energy for the crude oil is also found in the styrene system. The apparent activation energy for the crude oil ranged from 26.4 kJ/mol at 1.0 m/s to 245 kJ/mol at 4.0 m/s. Such strong dependencies of apparent activation energy on velocity, even at high velocity, …

Crude Oil Fouling: Petronas Refineries Experience, M.S. Rafeen, M.F. Mohamed, M.Z. Mamot, N.A. Manan, Dr A. Shafawi, Dr M. Ramasamy

Heat Exchanger Fouling and Cleaning VII

Managing crude oil fouling has been a challenge in PETRONAS refineries. Over the past several years, numerous initiatives have been conducted in order to have better control of the situation [1][2][3][4]. The control strategy currently implemented is to periodically clean the heat exchanger based on the heat exchanger monitoring parameter and supported by antifouling chemical injection program. A review was conducted in one of PETRONAS’ refineries in order to come up with a better fouling control strategy. The review is separated into two parts. Firstly, the plant operational data for two selected hot pre-heat exchanger trains was analyzed. From the …

Scale Deposits In Porous Media And Their Removal By Edta Injection, J. Moghadasi, H. Müller-Steinhagen, M. Jamialahmadi, A. Sharif

Heat Exchanger Fouling and Cleaning VII

Formation damage has been observed in several oil reservoirs and production equipment in Iranian oil fields. Laboratory and field testing confirmed that the primary cause of damage was the build-up of calcium carbonate, calcium sulfate and strontium sulfate scale either in the perforation tunnels or in the formation sandstone nears the wellbore. Conventional acid treatments could dissolve this scale, but scale precipitation from the spent acid caused rapid productivity decline. A scale removal treatment with Na2H2EDTA has been developed that can effectively dissolve scale and chelate the dissolved metal ions. Chelation of the dissolved scale prevents scale reprecipitation. This study …

The Effect Of Fouling On Heat Transfer, Pressure Drop And Throughput In Refinery Preheat Trains: Optimisation Of Cleaning Schedules, E. M. Ishiyama, W. R. Paterson, D. I. Wilson

Heat Exchanger Fouling and Cleaning VII

Optimising cleaning schedules for refinery preheat trains requires a robust and reliable simulator, reliable fouling models and the ability to handle the thermal and hydraulic impacts of fouling. The interaction between thermal and hydraulic effects is explored using engineering analyses and fouling rate laws based on the ‘threshold fouling’ concept; the potential occurrence of a new phenomenon, ‘thermo-hydraulic channeling’ in parallel heat exchangers, is identified. The importance of the foulant thermal conductivity is highlighted. We also report the development of a highly flexible preheat train simulator constructed in MATLAB&#;/Excel&#;. It is able to accommodate variable throughput, control valve operation and …

Formation Of Gum And Deposits In An Oxygenated Naphtha Stream, Yonghua Li, Paul Watkinson, Patricio Herrera, Feridoun Fahiminia, Morgan James

Heat Exchanger Fouling and Cleaning VII

Gums formed when organic fluids are in contact with air can cause fouling of process equipment. The oxidation and formation of gum in a naphtha stream was studied in a stirred batch reactor as a function of temperature (96 to 130ºC) and at a total pressure of 584 kPa. Mixtures of air and nitrogen in the pressurizing gas gave dissolved oxygen contents in the range 10-270 ppm wt. Peroxide and existent (dissolved) gum contents were measured over periods of up to 80 hours. Rates of reaction were low, with maximum concentrations of peroxide typically below 4 meq/L, and gum formation …

Observation Of An Isokinetic Temperature And Compensation Effect For High Temperature Crude Oil Fouling, C. A. Bennett, R. S. Kistler, K. Nangia, W. Al-Ghawas, N. Al-Hajji, A. Al-Jemaz

Heat Exchanger Fouling and Cleaning VII

The initial fouling rates of four crude oils were determined at a nominal bulk temperature of 315 °C, an initial heated wall shear stress of 13 Pa, and initial surface temperatures between 375 and 445 °C. These initial fouling rates ranged from 1.3(10-6) to 7.8(10-5) m2 K/kJ. Corresponding Arrhenius plots were linear with the initial fouling rates passing through an isokinetic temperature of 407.5 °C. A plot of the natural logarithm of the preexponential factors (7.6(104) – 5.2(1015) m2 K/kJ) versus the apparent activation energies (128 – 269 kJ/mol) was also linear, confirming the validity of the isokinetic temperature and …

Investigation Of The Mechanisms Of Heat Exchanger Corrosion In A Municipal Waste Incineration Plant By Analysis Of The Raw Gas And Variation Of Operating Parameters, C. Deuerling, J. Maguhn, H. Nordsieck, B. Benker, R. Zimmermann, R. Warnecke

Heat Exchanger Fouling and Cleaning VII

The detailed mechanism of high temperature chlorine corrosion, the dominant cause of corrosion in a municipal solid waste incinerator (MSI), has still to be clarified (Schroer, 2002). Upon its way through the boiler the raw gas is subject to various physical and chemical processes and interactions. Of these, sulphation of chlorides is supposed to have the major impact on chlorine corrosion (Neumann, 1997). The physical and chemical mechanisms of corrosion were investigated at a municipal solid waste incinerator. Both, the particulate and gas phase of the flue gas, were chemically and physically analyzed during their way through the boiler, at …

Milk Protein Fouling In A Tubular Heat Exchanger: Effect Of Milk Temperature And Reynolds Number, D.H.G. Pelegrine, K.F. Oliveira, M.T.M.S. Gomes

Heat Exchanger Fouling and Cleaning VII

In the present work, β-lactoglobulin fouling phenomenon was studied, when milk flowed in a tubular heat exchanger, where hot water was used to raise milk temperature. Experiments have been carried out to determine the effect of Reynolds number and fluid temperature in whey protein fouling, in a tubular heat exchanger and the results showed that fouling increases as the fluid temperature increases. In addition, as the Reynolds number increases, the total amount of fouling (obtained by integrating the whole amount of deposit down the tube dividing by the total area) decreased.

The Thermo-Hydrodynamics Of A Concentric Ohmic Heater For Processing Dairy Fluids, H.J. Tham, X.D. Chen, B. Young, B. Bansal, L. Zhang, G. Duffy

Heat Exchanger Fouling and Cleaning VII

The thermo-hydraulic performance of a 300W concentric annular ohmic heater was investigated. To minimize possible electrochemical reactions and corrosion, a higher frequency was applied and factors of field strength and frequency were studied. 2D computer simulation solving momentum, thermal and electrical energy was performed using the FlexPDE software. A good agreement between experimental and analytical analysis of static heating was obtained. There were significant differences between calculated and measured wall temperature near the entrance. The calculated outlet temperature was however in reasonable agreement with the experiment value.

Influence Of Different Surface Materials On Nucleation And Crystal Growth In Heat Exchangers, T. Geddert, S. Kipp, W. Augustin, S. Scholl

Heat Exchanger Fouling and Cleaning VII

The influence of different materials on the fouling tendency in saline calcium sulfate solution was investigated. The effects of the untreated material on the crystallization process have been studied experimentally in the micro- and macroscopic scale. The crystallization in the induction period was visualized with SEM and AFM to locate preferred nucleation spots and to visualize the crystal growth. The different materials are showing different crystal growth behavior (number and size of the crystals). These results are corresponding with the macroscopic fouling results with limited shear stress. Also different roughness values on stainless steel have been studied with respect to …

Fouling In A Centritherm Evaporator With Whey Solutions, R. S. Jebson, H. Chen, O. H. Campanella

Heat Exchanger Fouling and Cleaning VII

Fouling caused by sweet cheese whey and reconstituted whey powder solutions was studied in a Centritherm evaporator, the behaviour being estimated by measuring the change in the overall heat transfer coefficients with the time. It was found that there was no fouling detectable for the reconstituted whey powder solution. For sweet cheese whey, the fouling rate was linked strongly with the evaporating temperature and temperature difference. Visual observation showed that the deposit layer on the evaporator surface was very thin and soft, and like the type A milk deposit described by other investigators. A high velocity of liquid film delayed …

Simulation Of Calcium Phosphate Deposition On Stainless Steel Surfaces: A New Approach Based On Cellular Automata, F. G. Martins, T. Campos, R. Rosmaninho, L. F. Melo

Heat Exchanger Fouling and Cleaning VII

Fouling caused by calcium phosphate upon heating is basically a crystallization/precipitation process, which starts with the formation of stable clusters of ions or molecules in a process called nucleation that occurs either in the bulk liquid or at the surface. The cellular automata are useful tools to model complex systems of the universe. They could be considered as a good alternative to differential equations and have been used to model many physical/biological systems. In this preliminary work, a two dimensional space was considered where the cellular automata lattice was represented as a grid of squares, with each square representing a …

Experimental Investigation Of Crystallization Fouling On Grooved Stainless Steel Surfaces During Convective Heat Transfer, A. Al-Janabi, M.R. Malayeri, H. Müller-Steinhagen

Heat Exchanger Fouling and Cleaning VII

The beneficial aspects of enhanced or extended heat transfer surfaces may be off-set if operated under fouling conditions. In the present paper, preliminary experimental results for crystallization fouling of CaSO4 solutions onto surfaces with different structures are reported. Flat stainless steel plates (50 mm x 59 mm) with 'V' shaped grooves on the side of fluid flow were used as heat transfer surfaces. Experiments were carried out both under clean and fouling conditions to discern how the same surface structures perform under such circumstances. In addition, the impact of both, the direction of grooves with respect to fluid flow (crossed, …