Gulf Petro Initiative (open access)

Gulf Petro Initiative

In this report, technologies for petroleum production and exploration enhancement in deepwater and mature fields are developed through basic and applied research by: (1) Designing new fluids to efficiently drill deepwater wells that can not be cost-effectively drilled with current technologies. The new fluids will be heavy liquid foams that have low-density at shallow dept to avoid formation breakdown and high density at drilling depth to control formation pressure. The goal of this project is to provide industry with formulations of new fluids for reducing casing programs and thus well construction cost in deepwater development. (2) Studying the effects of flue gas/CO{sub 2} huff n puff on incremental oil recovery in Louisiana oilfields bearing light oil. An artificial neural network (ANN) model will be developed and used to map recovery efficiencies for candidate reservoirs in Louisiana. (3) Arriving at a quantitative understanding for the three-dimensional controlled-source electromagnetic (CSEM) geophysical response of typical Gulf of Mexico hydrocarbon reservoirs. We will seek to make available tools for the qualitative, rapid interpretation of marine CSEM signatures, and tools for efficient, three-dimensional subsurface conductivity modeling.
Date: February 5, 2011
Creator: Boukadi, Fathi
System: The UNT Digital Library
North Dakota Refining Capacity Study (open access)

North Dakota Refining Capacity Study

According to a 2008 report issued by the United States Geological Survey, North Dakota and Montana have an estimated 3.0 to 4.3 billion barrels of undiscovered, technically recoverable oil in an area known as the Bakken Formation. With the size and remoteness of the discovery, the question became 'can a business case be made for increasing refining capacity in North Dakota?' And, if so what is the impact to existing players in the region. To answer the question, a study committee comprised of leaders in the region's petroleum industry were brought together to define the scope of the study, hire a consulting firm and oversee the study. The study committee met frequently to provide input on the findings and modify the course of the study, as needed. The study concluded that the Petroleum Area Defense District II (PADD II) has an oversupply of gasoline. With that in mind, a niche market, naphtha, was identified. Naphtha is used as a diluent used for pipelining the bitumen (heavy crude) from Canada to crude markets. The study predicted there will continue to be an increase in the demand for naphtha through 2030. The study estimated the optimal configuration for the refinery at 34,000 …
Date: January 5, 2011
Creator: Hill, Dennis; Swenson, Kurt; Tuura, Carl; Simon, Jim; Vermette, Robert; Marcha, Gilberto et al.
System: The UNT Digital Library
Qualification of a Carbon Analyzer to Support the Defense Waste Processing Facility (open access)

Qualification of a Carbon Analyzer to Support the Defense Waste Processing Facility

The I-O Model 1030 carbon analyzer has been qualified for use at the Defense Waste Processing Facility (DWPF). The qualification was a side-by-side comparison of the Model 1030 system with the currently used Model 1010 Analyzer. This recommendation is based on side-by-side comparisons of the new unit to the currently used Model 1010 analyzer that are presented in this report. The side-by-side testing included standards and process samples. The standards, which were used for instrument calibration verifications in the measurement of total inorganic carbon (TIC) and of total organic carbon (TOC), were traceable back to the National Institute of Standards and Technology. The process samples included TIC analyses of Sludge Receipt and Adjustment Tank samples and TOC analyses for Slurry Mix Evaporator (SME) samples. After the Model 1030 has been used for production reporting, DWPF should consider an investigation into the uncertainties associated with the TOC measurements to determine how far below the 18,916 ppm limit DWPF must control the average of the measurements for a set of SME samples to account for the uncertainties of the measurements from this new analyzer. Based upon the results presented in this report, it is recommended that the Model 1030 carbon analyzer is …
Date: July 5, 2011
Creator: Edwards, T. & Feller, M.
System: The UNT Digital Library
The Function of the Early Trichomes Gene in Arabidopsis and Maize. (open access)

The Function of the Early Trichomes Gene in Arabidopsis and Maize.

Lateral organ polarity in Arabidopsis is regulated by antagonistic interactions between genes that promote either adaxial or abaxial identity, but the molecular basis of this interaction is largely unknown. We show that the adaxial regulator ASYMMETRIC LEAVES2 (AS2) is a direct target of the abaxial regulator KANADI1 (KAN1), and that KAN1 represses the transcription of AS2 in abaxial cells. Mutation of a single nucleotide in a KAN1 binding site in the AS2 promoter causes AS2 to be ectopically expressed in abaxial cells, resulting in a dominant, adaxialized phenotype. We also show that the abaxial expression of KAN1 is mediated directly or indirectly by AS2. These results demonstrate that KAN1 acts as a transcriptional repressor and that mutually repressive interactions between KAN1 and AS2 contribute to the establishment of adaxial-abaxial polarity in plants. A screen for mutations that affect the expression of a GFP reporter for KANADI2 produced mutations in two genes, CENTER CITY (CCT) and GRAND CENTRAL (GCT). Mutations in GCT and CCT delay the specification of central and peripheral identity and the globular-to-heart transition, but have little or no effect on the initial growth rate of the embryo. Mutant embryos eventually recover and undergo relatively normal patterning, albeit at …
Date: December 5, 2011
Creator: Poethig, Scott
System: The UNT Digital Library
Annual Illness and Injury Surveillance Report: Hanford Site, 2010 (open access)

Annual Illness and Injury Surveillance Report: Hanford Site, 2010

The U.S. Department of Energy's (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: October 5, 2011
Creator: United States. Department of Energy. Office of Health, Safety, and Security.
System: The UNT Digital Library
Improved Transport Processes for CCSM (open access)

Improved Transport Processes for CCSM

In atmospheric modeling, global spectral methods have dominated weather and climate simulation for the past two decades. However, global methods based upon the spherical harmonic basis functions require expensive non-local communication and thus have difficulty in exploiting the full potential of current high-performance parallel computers. The primary objective of HOMME ((11)) is the development of a class of high-order scalable conservative atmospheric models for climate and general atmospheric modeling applications. The spatial discretizations are based on continuous Galerkin (spectral element method) and discontinuous Galerkin (DG). These are local methods based on high-order accurate spectral basis functions which have been shown to perform well on massively parallel supercomputers at any resolution (18). HOMME employs a cubed-sphere geometry (26) exhibiting none of the singularities present in conventional latitude-longitude spherical geometries. The element based formulation enables the use of general curvilinear geometries and adaptive conforming or non-conforming meshes.
Date: May 5, 2011
Creator: Tufo, Henry
System: The UNT Digital Library
Passive Superconducting Flux Conservers for Rotating-Magnetic-Field-Driven Field-Reversed Configurations (open access)

Passive Superconducting Flux Conservers for Rotating-Magnetic-Field-Driven Field-Reversed Configurations

The Princeton Field-Reversed Configuration (PFRC) experiment employs an odd-parity rotating magnetic field (RMFo) current drive and plasma heating system to form and sustain high-Β plasmas. For radial confinement, an array of coaxial, internal, passive, flux-conserving (FC) rings applies magnetic pressure to the plasma while still allowing radio-frequency RMFo from external coils to reach the plasma. The 3 ms pulse duration of the present experiment is limited by the skin time (τfc) of its room-temperature copper FC rings. To explore plasma phenomena with longer characteristic times, the pulse duration of the next-generation PFRC-2 device will exceed 100 ms, necessitating FC rings with (τfc > 300 ms. In this paper we review the physics of internal, discrete, passive FCs and describe the evolution of the PFRC's FC array. We then detail new experiments that have produced higher performance FC rings that contain embedded high-temperature superconducting (HTS) tapes. Several HTS tape winding configurations have been studied and a wide range of extended skin times, from 0.4 s to over 103 s, has been achieved. The new FC rings must carry up to 3 kA of current to balance the expected PFRC-2 plasma pressure, so the dependence of the HTS-FC critical current on the …
Date: January 5, 2011
Creator: Oz, E.; Myers, C. E.; Edwards, M. R.; Berlinger, B.; Brooks, A. & Cohen, S. A.
System: The UNT Digital Library
Final Report: Imaging of Buried Nanoscale Optically Active Materials (open access)

Final Report: Imaging of Buried Nanoscale Optically Active Materials

This is a final report covering work done at University of Maryland to develop a Ballistic Electron Emission Luminescence (BEEL) microscope. This technique was intended to examine the carrier transport and photon emission in deeply buried optically-active layers and thereby provide a means for materials science to unmask the detailed consequences of experimentally controllable growth parameters, such as quantum dot size, statistics and orientation, and defect density and charge recombination pathways.
Date: July 5, 2011
Creator: Appelbaum, Ian
System: The UNT Digital Library
MAR ASSESSMENTS OF THE HIGH LEVEL WASTE SYSTEM PLAN REVISION 16 (open access)

MAR ASSESSMENTS OF THE HIGH LEVEL WASTE SYSTEM PLAN REVISION 16

High-level waste (HLW) throughput (i.e., the amount of waste processed per unit of time) is primarily a function of two critical parameters: waste loading (WL) and melt rate. For the Defense Waste Processing Facility (DWPF), increasing HLW throughput would significantly reduce the overall mission life cycle costs for the Department of Energy (DOE). Significant increases in waste throughput have been achieved at DWPF since initial radioactive operations began in 1996. Key technical and operational initiatives that supported increased waste throughput included improvements in facility attainment, the Chemical Processing Cell (CPC) flowsheet, process control models and frit formulations. As a result of these key initiatives, DWPF increased WLs from a nominal 28% for Sludge Batch 2 (SB2) to {approx}34 to 38% for SB3 through SB6 while maintaining or slightly improving canister fill times. Although considerable improvements in waste throughput have been obtained, future contractual waste loading targets are nominally 40%, while canister production rates are also expected to increase (to a rate of 325 to 400 canisters per year). Although implementation of bubblers have made a positive impact on increasing melt rate for recent sludge batches targeting WLs in the mid30s, higher WLs will ultimately make the feeds to DWPF more …
Date: August 5, 2011
Creator: Peeler, D. & Edwards, T.
System: The UNT Digital Library
JSWG and KRI Crosswalks (open access)

JSWG and KRI Crosswalks

None
Date: January 5, 2011
Creator: White, G. K.
System: The UNT Digital Library
Overview of Deployed EDS Technologies And Third Party Involvement with Advancedments (open access)

Overview of Deployed EDS Technologies And Third Party Involvement with Advancedments

None
Date: January 5, 2011
Creator: Martz, H E & Crawford, C R
System: The UNT Digital Library
MAGNESIUM MONO POTASSIUM PHOSPHATE GROUT FOR P-REACTOR VESSEL IN-SITU DECOMISSIONING (open access)

MAGNESIUM MONO POTASSIUM PHOSPHATE GROUT FOR P-REACTOR VESSEL IN-SITU DECOMISSIONING

The objective of this report is to document laboratory testing of magnesium mono potassium phosphate grouts for P-Reactor vessel in-situ decommissioning. Magnesium mono potassium phosphate cement-based grout was identified as candidate material for filling (physically stabilizing) the 105-P Reactor vessel (RV) because it is less alkaline than portland cement-based grout (pH of about 12.4). A less alkaline material ({<=} 10.5) was desired to address a potential materials compatibility issue caused by corrosion of aluminum metal in highly alkaline environments such as that encountered in portland cement grouts. Information concerning access points into the P-Reactor vessel and amount of aluminum metal in the vessel is provided elsewhere. Fresh and cured properties were measured for: (1) commercially blended magnesium mono potassium phosphate packaged grouts, (2) commercially available binders blended with inert fillers at SRNL, (3) grouts prepared from technical grade MgO and KH{sub 2}PO{sub 4} and inert fillers (quartz sands, Class F fly ash), and (4) Ceramicrete{reg_sign} magnesium mono potassium phosphate-based grouts prepared at Argonne National Laboratory. Boric acid was evaluated as a set retarder in the magnesium mono potassium phosphate mixes.
Date: January 5, 2011
Creator: Langton, C. & Stefanko, D.
System: The UNT Digital Library
Qualification of the First ICS-3000 ION Chromatograph for use at the Defense Waste Processing Facility (open access)

Qualification of the First ICS-3000 ION Chromatograph for use at the Defense Waste Processing Facility

The ICS-3000 Ion Chromatography (IC) system installed in 221-S M-13 has been qualified for use. The qualification was a head to head comparison of the ICS-3000 with the currently used DX-500 IC system. The crosscheck work included standards for instrument calibration and calibration verifications and standards for individual anion analysis, where the standards were traceable back to the National Institute of Standards and Technology (NIST). In addition the crosscheck work included the analysis of simulated Sludge Receipt Adjustment Tank (SRAT) Receipt, SRAT Product, and Slurry Mix Evaporator (SME) samples, along with radioactive Sludge Batch 5 material from the SRAT and SME tanks. Based upon the successful qualification of the ICS-3000 in M-13, it is recommended that this task proceed in developing the data to qualify, by a head to head comparison of the two ICS-3000 instruments, a second ICS-3000 to be installed in M-14. The Defense Waste Processing Facility (DWPF) requires the analysis of specific anions at various stages of its processing of high level waste (HLW). The anions of interest to the DWPF are fluoride, formate, chloride, nitrite, nitrate, sulfate, oxalate, and phosphate. The anion analysis is used to evaluate process chemistry including formic acid/nitric acid additions to establish …
Date: July 5, 2011
Creator: Edwards, T & Mahannah, R.
System: The UNT Digital Library
SDI CFD MODELING ANALYSIS (open access)

SDI CFD MODELING ANALYSIS

The Savannah River Remediation (SRR) Organization requested that Savannah River National Laboratory (SRNL) develop a Computational Fluid Dynamics (CFD) method to mix and blend the miscible contents of the blend tanks to ensure the contents are properly blended before they are transferred from the blend tank; such as, Tank 50H, to the Salt Waste Processing Facility (SWPF) feed tank. The work described here consists of two modeling areas. They are the mixing modeling analysis during miscible liquid blending operation, and the flow pattern analysis during transfer operation of the blended liquid. The transient CFD governing equations consisting of three momentum equations, one mass balance, two turbulence transport equations for kinetic energy and dissipation rate, and one species transport were solved by an iterative technique until the species concentrations of tank fluid were in equilibrium. The steady-state flow solutions for the entire tank fluid were used for flow pattern analysis, for velocity scaling analysis, and the initial conditions for transient blending calculations. A series of the modeling calculations were performed to estimate the blending times for various jet flow conditions, and to investigate the impact of the cooling coils on the blending time of the tank contents. The modeling results were …
Date: May 5, 2011
Creator: Lee, S.
System: The UNT Digital Library
Large Area Divertor Temperature Measurements Using A High-speed Camera With Near-infrared FiIters in NSTX (open access)

Large Area Divertor Temperature Measurements Using A High-speed Camera With Near-infrared FiIters in NSTX

Fast cameras already installed on the National Spherical Torus Experiment (NSTX) have be equipped with near-infrared (NIR) filters in order to measure the surface temperature in the lower divertor region. Such a system provides a unique combination of high speed (> 50 kHz) and wide fi eld-of-view (> 50% of the divertor). Benchtop calibrations demonstrated the system's ability to measure thermal emission down to 330 oC. There is also, however, signi cant plasma light background in NSTX. Without improvements in background reduction, the current system is incapable of measuring signals below the background equivalent temperature (600 - 700 oC). Thermal signatures have been detected in cases of extreme divertor heating. It is observed that the divertor can reach temperatures around 800 oC when high harmonic fast wave (HHFW) heating is used. These temperature profiles were fi t using a simple heat diffusion code, providing a measurement of the heat flux to the divertor. Comparisons to other infrared thermography systems on NSTX are made.
Date: April 5, 2011
Creator: Lyons, B. C.; Zweben, S. J.; Gray, T. K.; Hosea, J.; Kaita, R.; Kugel, H. W. et al.
System: The UNT Digital Library
TESTS WITH HIGH-BISMUTH HLW GLASSES FINAL REPORT VSL-10R1780-1 REV 0 12/13/10 (open access)

TESTS WITH HIGH-BISMUTH HLW GLASSES FINAL REPORT VSL-10R1780-1 REV 0 12/13/10

This Final Report describes the testing of glass formulations developed for Hanford High Level Waste (HLW) containing high concentrations of bismuth. In previous work on high-bismuth HLW streams specified by the Office of River Protection (ORP), fully compliant, high waste loading compositions were developed and subjected to melter testing on the DM100 vitrification system. However, during heat treatment according to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) HLW canister centerline cooling (CCC) curves, crucible melts of the high-bismuth glasses were observed to foam. Clearly, such an occurrence during cooling of actual HLW canisters would be highly undesirable. Accordingly, the present work involves larger-scale testing to determine whether this effect occurs under more prototypical conditions, as well as crucible-scale tests to determine the causes and potentially remediate the observed foaming behavior. The work included preparation and characterization of crucible melts designed to determine the underlying causes of the foaming behavior as well as to assess potential mitigation strategies. Testing was also conducted on the DM1200 HLW Pilot melter with a composition previously tested on the DM100 and shown to foam during crucible-scale CCC heat treatment. The DM1200 tests evaluated foaming of glasses over a range of bismuth concentrations poured …
Date: January 5, 2011
Creator: KS, MATLACK; AA, KRUGER; I, JOSEPH; H, GAN; WK, KOT; M, CHAUDHURI et al.
System: The UNT Digital Library
Qualification of the Nippon Instrumentation for use in Measuring Mercury at the Defense Waste Processing Facility (open access)

Qualification of the Nippon Instrumentation for use in Measuring Mercury at the Defense Waste Processing Facility

The Nippon Mercury/RA-3000 system installed in 221-S M-14 has been qualified for use. The qualification was a side-by-side comparison of the Nippon Mercury/RA-3000 system with the currently used Bacharach Mercury Analyzer. The side-by-side testing included standards for instrument calibration verifications, spiked samples and unspiked samples. The standards were traceable back to the National Institute of Standards and Technology (NIST). The side-by-side work included the analysis of Sludge Receipt and Adjustment Tank (SRAT) Receipt, SRAT Product, and Slurry Mix Evaporator (SME) samples. With the qualification of the Nippon Mercury/RA-3000 system in M-14, the DWPF lab will be able to perform a head to head comparison of a second Nippon Mercury/RA-3000 system once the system is installed. The Defense Waste Processing Facility (DWPF) analyzes receipt and product samples from the Sludge Receipt and Adjustment Tank (SRAT) to determine the mercury (Hg) concentration in the sludge slurry. The SRAT receipt is typically sampled and analyzed for the first ten SRAT batches of a new sludge batch to obtain an average Hg concentration. This average Hg concentration is then used to determine the amount of steam stripping required during the concentration/reflux step of the SRAT cycle to achieve a less than 0.6 wt% Hg …
Date: July 5, 2011
Creator: Edwards, T. & Mahannah, R.
System: The UNT Digital Library
Case for an Improved Effective-Atomic-Number for the Electronic Baggage Scanning Program (open access)

Case for an Improved Effective-Atomic-Number for the Electronic Baggage Scanning Program

Z{sub eff}, a parameter representing an 'effective atomic number' for a material, plays an important role in the Electronic Baggage Scanning Program (EBSP) to detect threats in dual-energy computed tomography (CT) baggage-scanning systems. We believe that Z{sub eff}, as defined and used on this program, does not provide the accurate representation of a material's x-ray absorption properties that is needed by the EBSP. We present the case for a new method that defines an effective atomic number for compounds and mixtures, which we refer to as Z{sub e}. Unlike Z{sub eff}, Z{sub e} is tied by definition to the x-ray absorption properties of each specific material. Use of this alternative will provide a more accurate scale for calibrating Micro-CT and EDS systems against standard reference materials and will provide a more accurate physical characterization of the x-ray properties of materials evaluated on those systems. This document: (1) Describes the current usage of the Z{sub eff} parameter; (2) Details problems entailed in the use of the Z{sub eff} parameter; (3) Proposes a well-defined alternative - Z{sub e}; (4) Proposes and demonstrates an algorithm for optimally associating Z{sub e} with any specified compound or mixture; (5) Discusses issues that can impact the …
Date: April 5, 2011
Creator: Smith, J. A.; Martz, H. E. & Kallman, J. S.
System: The UNT Digital Library
Review of the Hatfield and Dawson RF assessment for Bechtel (open access)

Review of the Hatfield and Dawson RF assessment for Bechtel

None
Date: October 5, 2011
Creator: Kane, R. J.
System: The UNT Digital Library
Analysis of a Nuclear Accident: Fission and Activation Product Releases from the Fukushima Daiichi Nuclear Facility as Remote Indicators of Source Identification, Extent of Release, and State of Damaged Spent Nuclear Fuel (open access)

Analysis of a Nuclear Accident: Fission and Activation Product Releases from the Fukushima Daiichi Nuclear Facility as Remote Indicators of Source Identification, Extent of Release, and State of Damaged Spent Nuclear Fuel

Evidence of the release Pu from the Fukushima Daiichi nuclear power station to the local environment and surrounding communities and estimates on fraction of total fuel inventory released
Date: December 5, 2011
Creator: Schwantes, Jon M.; Orton, Christopher R. & Clark, Richard A.
System: The UNT Digital Library
The Program for climate Model diagnosis and Intercomparison: 20-th anniversary Symposium (open access)

The Program for climate Model diagnosis and Intercomparison: 20-th anniversary Symposium

Twenty years ago, W. Lawrence (Larry) Gates approached the U.S. Department of Energy (DOE) Office of Energy Research (now the Office of Science) with a plan to coordinate the comparison and documentation of climate model differences. This effort would help improve our understanding of climate change through a systematic approach to model intercomparison. Early attempts at comparing results showed a surprisingly large range in control climate from such parameters as cloud cover, precipitation, and even atmospheric temperature. The DOE agreed to fund the effort at the Lawrence Livermore National Laboratory (LLNL), in part because of the existing computing environment and because of a preexisting atmospheric science group that contained a wide variety of expertise. The project was named the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and it has changed the international landscape of climate modeling over the past 20 years. In spring 2009 the DOE hosted a 1-day symposium to celebrate the twentieth anniversary of PCMDI and to honor its founder, Larry Gates. Through their personal experiences, the morning presenters painted an image of climate science in the 1970s and 1980s, that generated early support from the international community for model intercomparison, thereby bringing PCMDI into existence. Four …
Date: January 5, 2011
Creator: Potter, Gerald L; Bader, David C; Riches, Michael; Bamzai, Anjuli & Joseph, Renu
System: The UNT Digital Library
EVALUATION OF ARG-1 SAMPLES PREPARED BY CESIUM CARBONATE DISSOLUTION DURING THE ISOLOK SME ACCEPTABILITY TESTING (open access)

EVALUATION OF ARG-1 SAMPLES PREPARED BY CESIUM CARBONATE DISSOLUTION DURING THE ISOLOK SME ACCEPTABILITY TESTING

Evaluation of Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) recently completed the evaluation of one of these opportunities - the possibility of using an Isolok sampling valve as an alternative to the Hydragard valve for taking DWPF process samples at the Slurry Mix Evaporator (SME). The use of an Isolok for SME sampling has the potential to improve operability, reduce maintenance time, and decrease CPC cycle time. The SME acceptability testing for the Isolok was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 and was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNLRP-2011-00145. RW-0333P QA requirements applied to the task, and the results from the investigation were documented in SRNL-STI-2011-00693. Measurement of the chemical composition of study samples was a critical component of the SME acceptability testing of the Isolok. A sampling and analytical plan supported the investigation with the analytical plan directing that the study samples be prepared by a cesium carbonate (Cs{sub 2}CO{sub 3}) fusion dissolution method and analyzed by Inductively Coupled Plasma - Optical Emission …
Date: December 5, 2011
Creator: Edwards, T.; Hera, K. & Coleman, C.
System: The UNT Digital Library
DUSEL Facility Cooling Water Scaling Issues (open access)

DUSEL Facility Cooling Water Scaling Issues

Precipitation (crystal growth) in supersaturated solutions is governed by both kenetic and thermodynamic processes. This is an important and evolving field of research, especially for the petroleum industry. There are several types of precipitates including sulfate compounds (ie. barium sulfate) and calcium compounds (ie. calcium carbonate). The chemical makeup of the mine water has relatively large concentrations of sulfate as compared to calcium, so we may expect that sulfate type reactions. The kinetics of calcium sulfate dihydrate (CaSO4 {center_dot} 2H20, gypsum) scale formation on heat exchanger surfaces from aqueous solutions has been studied by a highly reproducible technique. It has been found that gypsum scale formation takes place directly on the surface of the heat exchanger without any bulk or spontaneous precipitation in the reaction cell. The kinetic data also indicate that the rate of scale formation is a function of surface area and the metallurgy of the heat exchanger. As we don't have detailed information about the heat exchanger, we can only infer that this will be an issue for us. Supersaturations of various compounds are affected differently by temperature, pressure and pH. Pressure has only a slight affect on the solubility, whereas temperature is a much more sensitive …
Date: April 5, 2011
Creator: Daily, W D
System: The UNT Digital Library
Utilize Cementitious High Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt Pavement as Base Coarse (open access)

Utilize Cementitious High Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt Pavement as Base Coarse

The purpose of this study was to evaluate the performance of cementitious high carbon fly ash (CHCFA) stabilized recycled asphalt pavement as a base course material in a real world setting. Three test road cells were built at MnROAD facility in Minnesota. These cells have the same asphalt surface layers, subbases, and subgrades, but three different base courses: conventional crushed aggregates, untreated recycled pavement materials (RPM), and CHCFA stabilized RPM materials. During and after the construction of the three cells, laboratory and field tests were carried out to characterize the material properties. The test results were used in the mechanistic-empirical pavement design guide (MEPDG) to predict the pavement performance. Based on the performance prediction, the life cycle analyses of cost, energy consumption, and greenhouse gasses were performed. The leaching impacts of these three types of base materials were compared. The laboratory and field tests showed that fly ash stabilized RPM had higher modulus than crushed aggregate and RPM did. Based on the MEPDG performance prediction, the service life of the Cell 79 containing fly ash stabilized RPM, is 23.5 years, which is about twice the service life (11 years) of the Cell 77 with RPM base, and about three times …
Date: February 5, 2011
Creator: Wen, Haifang; Li, Xiaojun; Edil, Tuncer; O'Donnell, Jonathan & Danda, Swapna
System: The UNT Digital Library