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Simulating Potential Switchgrass Production in the United States (open access)

Simulating Potential Switchgrass Production in the United States

Using results from field trials of switchgrass (Panicum virgatum L.) in the United States, the EPIC (Environmental Policy Integrated Climate) process-level agroecosystem model was calibrated, validated, and applied to simulate potential productivity of switchgrass for use as a biofuel feedstock. The model was calibrated with a regional study of 10-yr switchgrass field trials and subsequently tested against a separate compiled dataset of field trials from across the eastern half of the country. An application of the model in a national database using 8-digit watersheds as the primary modeling unit produces 30-yr average switchgrass yield estimates that can be aggregated to 18 major watersheds. The model projects average annual switchgrass productivity of greater than 7 Mg ha-1 in the Upper Mississippi, Lower Mississippi, and Ohio watersheds. The major factors limiting simulated production vary by region; low precipitation is the primary limiting factor across the western half of the country, while moderately acidic soils limit yields on lands east of the Mississippi River. Average projected switchgrass production on all crop land in the continental US is 5.6 Mg ha-1. At this level of productivity, 28.6 million hectares of crop land would be required to produce the 16 billion gallons of cellulosic ethanol …
Date: December 31, 2009
Creator: Thomson, Allison M.; Izaurralde, Roberto C.; West, T. O.; Parrish, David J.; Tyler, Donald D. & Williams, Jimmy R.
Object Type: Report
System: The UNT Digital Library
Annual Groundwater Detection Monitoring Report for the Idaho CERCLA Disposal Facility (2008) (open access)

Annual Groundwater Detection Monitoring Report for the Idaho CERCLA Disposal Facility (2008)

This report presents the data collected for groundwater detection monitoring at the Idaho Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Disposal Facility (ICDF) during calendar year 2008. The detection-monitoring program developed for the ICDF groundwater-monitoring wells is applicable to six wells completed in the uppermost portion of the Snake River Plain Aquifer − five wells downgradient of the ICDF and one well upgradient. The ICDF detection-monitoring program was established to meet the substantive requirements of Title 40 Code of Federal Regulations (CFR) Parts 264.97 and 264.98, which are applicable or relevant and appropriate requirements under CERCLA. Semiannual groundwater samples were collected and analyzed for indicator parameters in March and September. The indicator parameters focus on constituents that are found in higher concentrations in ICDF leachate than in groundwater (bicarbonate alkalinity, sulfate, U-233, U-234, and U-238). The only detection monitoring limits that were exceeded were for bicarbonate alkalinity. Bicarbonate alkalinity is naturally occurring in groundwater. Bicarbonate alkalinity found in ICDF detection monitoring wells is not a result of waste migration from the ICDF landfill or the evaporation pond. The U.S. Department of Energy will continue with detection monitoring for the ICDF, which is semiannual sampling for indicator parameters.
Date: July 31, 2009
Creator: Cahn, Lorie
Object Type: Report
System: The UNT Digital Library
Residential and Transport Energy Use in India: Past Trend and Future Outlook (open access)

Residential and Transport Energy Use in India: Past Trend and Future Outlook

The main contribution of this report is to characterize the underlying residential and transport sector end use energy consumption in India. Each sector was analyzed in detail. End-use sector-level information regarding adoption of particular technologies was used as a key input in a bottom-up modeling approach. The report looks at energy used over the period 1990 to 2005 and develops a baseline scenario to 2020. Moreover, the intent of this report is also to highlight available sources of data in India for the residential and transport sectors. The analysis as performed in this way reveals several interesting features of energy use in India. In the residential sector, an analysis of patterns of energy use and particular end uses shows that biomass (wood), which has traditionally been the main source of primary energy used in households, will stabilize in absolute terms. Meanwhile, due to the forces of urbanization and increased use of commercial fuels, the relative significance of biomass will be greatly diminished by 2020. At the same time, per household residential electricity consumption will likely quadruple in the 20 years between 2000 and 2020. In fact, primary electricity use will increase more rapidly than any other major fuel -- even …
Date: March 31, 2009
Creator: de la Rue du Can, Stephane; Letschert, Virginie; McNeil, Michael; Zhou, Nan & Sathaye, Jayant
Object Type: Report
System: The UNT Digital Library
Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada Test Site, Nevada (open access)

Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada Test Site, Nevada

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for the 92-Acre Area, the southeast quadrant of the Radioactive Waste Management Site, located in Area 5 of the Nevada Test Site (NTS). The 92-Acre Area includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' Data Quality Objectives (DQOs) were developed for the 92-Acre Area, which includes CAU 111. The result of the DQO process was that the 92-Acre Area is sufficiently characterized to provide the input data necessary to evaluate corrective action alternatives (CAAs) without the collection of additional data. The DQOs are included as Appendix A of this document. This CADD/CAP identifies and provides the rationale for the recommended CAA for the 92-Acre Area, provides the plan for implementing the CAA, and details the post-closure plan. When approved, this CADD/CAP will supersede the existing Pit 3 (P03) Closure Plan, which was developed in accordance with Title 40 Code of Federal Regulations (CFR) Part 265, 'Interim Status Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities.' This document will also serve as the Closure Plan and the Post-Closure Plan, which are required by 40 CFR 265, for the 92-Acre Area. …
Date: July 31, 2009
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Chemical, Biological, and Explosive Sensors for Field Measurements (open access)

Chemical, Biological, and Explosive Sensors for Field Measurements

Special Technologies Laboratory (STL) is developing handheld chemical, biological, and explosive (CBE) detection systems and sensor motes for wireless networked field operations. The CBE sensors are capable of detecting and identifying multiple targeted toxic industrial chemicals (TICs) and high-explosive vapor components. The CBE devices are based on differential mobility spectrometry (DMS) coupled with fast gas chromatography (GC) or mass spectrometry. The systems all include the concepts of: 1. Direct air/particulate “smart” sampling 2. Selective, continuous real-time (~1 sec) alert monitoring using DMS 3. Highly selective, rapid dual technology separation/verification analysis The biosensor technology is based on Raman aerosol particle flow cytometry for target detection and identification. Monitoring and identifying trace level chemical vapors directly from ambient air will allow First Responders to quickly adapt situational response strategies and personal protective equipment needs to the specific response scenario being encountered. First Responders require great confidence in the measurements and ability of a given system to detect CBE below threshold levels without interferences. The concept of determining the background matrix in near real-time to allow subsequent automated field-programmable method selection and cueing of high-value assets in a wide range of environs will be presented. This provides CBE information for decisions prior to …
Date: January 31, 2009
Creator: Kevin Kyle, Manuel Manard, Stephan Weeks
Object Type: Article
System: The UNT Digital Library
FLASH Beam-Off RF Measurements and Analyses (open access)

FLASH Beam-Off RF Measurements and Analyses

The FLASH L-band (1.3 GHz) superconducting accelerator facility at DESY has a Low Level RF (LLRF) system that is similar to that envisioned for ILC. This system has extensive monitoring capability and was used to gather performance data relevant to ILC. In particular, waveform data were recorded with beam off for three, 8-cavity cryomodules to evaluate the input rf stability, perturbations to the SC cavity frequencies and the rf overhead required to achieve constant gradient during the 800-s pulses. In this paper, we discuss the measurements and data analysis procedures and present key findings on the pulse-to-pulse input rf and cavity field stability.
Date: March 31, 2009
Creator: Pei, Shilun; Adolphsen, Chris & Carwardine, John
Object Type: Article
System: The UNT Digital Library
Annual Performance Assessment and Composite Analysis Review for the ICDF Landfill FY 2008 (open access)

Annual Performance Assessment and Composite Analysis Review for the ICDF Landfill FY 2008

This report addresses low-level waste disposal operations at the Idaho Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Disposal Facility (ICDF) landfill from the start of operations in Fiscal Year 2003 through Fiscal Year 2008. The ICDF was authorized in the Operable Unit 3-13 Record of Decision for disposal of waste from the Idaho National Laboratory Site CERCLA environmental restoration activities. The ICDF has been operating since 2003 in compliance with the CERCLA requirements and the waste acceptance criteria developed in the CERCLA process. In developing the Operable Unit 3-13 Record of Decision, U.S. Department of Energy Order (DOE) 435.1, 'Radioactive Waste Management', was identified as a 'to be considered' requirement for the ICDF. The annual review requirement under DOE Order 435.1 was determined to be an administrative requirement and, therefore, annual reviews were not prepared on an annual basis. However, the landfill has been operating for 5 years and, since the waste forms and inventories disposed of have changed from what was originally envisioned for the ICDF landfill, the ICDF project team has decided that this annual review is necessary to document the changes and provide a basis for any updates in analyses that may be necessary to continue …
Date: August 31, 2009
Creator: Rood, Karen Koslow Arthur
Object Type: Report
System: The UNT Digital Library
[Letter from Fantasy of Flight to Helen Wyatt Snapp, March 31, 2009] (open access)

[Letter from Fantasy of Flight to Helen Wyatt Snapp, March 31, 2009]

Letter from Stephanie Conner of Fantasy of Flight to Helen Snapp, thanking her for her participation in the "Living History Series celebrating the accomplishments of the Women Air Service Pilots."
Date: March 31, 2009
Creator: Conner, Stephanie
Object Type: Letter
System: The Portal to Texas History
The Panola Watchman (Carthage, Tex.), Vol. 137, No. 43, Ed. 1 Sunday, May 31, 2009 (open access)

The Panola Watchman (Carthage, Tex.), Vol. 137, No. 43, Ed. 1 Sunday, May 31, 2009

Semiweekly newspaper from Carthage, Texas that includes local, state, and national news along with advertising.
Date: May 31, 2009
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Polk County Enterprise (Livingston, Tex.), Vol. 127, No. 43, Ed. 1 Sunday, May 31, 2009 (open access)

Polk County Enterprise (Livingston, Tex.), Vol. 127, No. 43, Ed. 1 Sunday, May 31, 2009

Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.
Date: May 31, 2009
Creator: Reddell, Valerie
Object Type: Newspaper
System: The Portal to Texas History
Polk County Enterprise (Livingston, Tex.), Vol. 127, No. 105, Ed. 1 Thursday, December 31, 2009 (open access)

Polk County Enterprise (Livingston, Tex.), Vol. 127, No. 105, Ed. 1 Thursday, December 31, 2009

Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.
Date: December 31, 2009
Creator: Reddell, Valerie
Object Type: Newspaper
System: The Portal to Texas History
Power Systems Development Facility (open access)

Power Systems Development Facility

In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, has routinely demonstrated gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This final report summarizes the results of the technology development work conducted at the PSDF through January 31, 2009. Twenty-one major gasification test campaigns were completed, for a total of more than 11,000 hours of gasification operation. This operational experience has led to significant advancements in gasification technologies.
Date: January 31, 2009
Creator: Southern Company Services
Object Type: Report
System: The UNT Digital Library
Jointly Sponsored Research Program (open access)

Jointly Sponsored Research Program

U.S. Department of Energy (DOE) Cooperative Agreement DE-FC26-98FT40321 funded through the Office of Fossil Energy and administered at the National Energy Technology Laboratory (NETL) supported the performance of a Jointly Sponsored Research Program (JSRP) at the Energy & Environmental Research Center (EERC) with a minimum 50% nonfederal cost share to assist industry in commercializing and effectively applying highly efficient, nonpolluting energy systems that meet the nation's requirements for clean fuels, chemicals, and electricity in the 21st century. The EERC in partnership with its nonfederal partners jointly performed 131 JSRP projects for which the total DOE cost share was $22,716,634 (38%) and the nonfederal share was $36,776,573 (62%). Summaries of these projects are presented in this report for six program areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, and (6) advanced materials. The work performed under this agreement addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration; near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic …
Date: March 31, 2009
Creator: Sondreal, Everett A.; Hendrikson, John G. & Erickson, Thomas A.
Object Type: Report
System: The UNT Digital Library
Molecular mechanism of crystallization impacting calcium phosphate cements (open access)

Molecular mechanism of crystallization impacting calcium phosphate cements

In summary, SPM data has shown that (1) Mg inhibits growth on all steps but relatively high Mg/Ca ratios are needed. Extracting the mechanism of interaction requires more modeling of the kinetic data, but step morphology is consistent with incorporation. (2) Citrate has several effects depending on the citrate/Ca ratio. At the lowest concentrations, citrate increases the step free energy without altering the step kinetics; at higher concentrations, the polar step is slowed. (3) Oxalate also slows the polar step but additionally stabilizes a new facet, with a [100]{sub Cc} step. (4) Etidronate has the greatest kinetic impact of the molecules studied. At 7{micro}M concentrations, the polar step slows by 60% and a new polar step appears. However, at the same time the [10-1]{sub Cc} increases by 67%. It should be noted that all of these molecules complex calcium and can effect kinetics by altering the solution supersaturation or the Ca to HPO{sub 4}{sup 2-} ratio. For the SPM data shown, this effect was corrected for to distinguish the effect of the molecule at the crystal surface from the effect of the molecule on the solution speciation. The goal of this paper is to draw connections between fundamental studies of …
Date: May 31, 2009
Creator: Giocondi, J L; El-Dasher, B S; Nancollas, G H & Orme, C A
Object Type: Article
System: The UNT Digital Library
High Temperature Battery for Drilling Applications (open access)

High Temperature Battery for Drilling Applications

In this project rechargeable cells based on the high temperature electrochemical system Na/beta''-alumina/S(IV) in AlCl3/NaCl were developed for application as an autonomous power source in oil/gas deep drilling wells. The cells operate in the temperature range from 150 C to 250 C. A prototype DD size cell was designed and built based on the results of finite element analysis and vibration testing. The cell consisted of stainless steel case serving as anode compartment with cathode compartment installed in it and a seal closing the cell. Critical element in cell design and fabrication was hermetically sealing the cell. The seal had to be leak tight, thermally and vibration stable and compatible with electrode materials. Cathode compartment was built of beta''-alumina tube which served as an electrolyte, separator and cathode compartment.
Date: December 31, 2009
Creator: Caja, Josip
Object Type: Report
System: The UNT Digital Library
Soil Samplers:  New Techniques for Subsurface Sampling for Volatile Organic Compounds (open access)

Soil Samplers: New Techniques for Subsurface Sampling for Volatile Organic Compounds

Soil sampling techniques for volatile organic analysis must be designed to minimize loss of volatile organic compounds (VOCs) from the soil that is being sampled. Preventing VOC loss from soil cores that are collected from the subsurface and brought to the surface for subsampling is often difficult. Subsurface bulk sample retrieval systems are designed to obtain intact cylindrical cores of soil ranging anywhere from one to four inches in diameter, and one to several feet in length. The current technique that is used to subsample these soil cores for VOC analysis is to expose a horizontal section of the soil core to the atmosphere; screen the exposed soil using a photoionization detector (PID) or other appropriate device to locate contamination in the soil core; and use a hand-operated coring tool to collect samples from the exposed soil for analysis. Because the soil core can be exposed to the atmosphere for a considerable length of time during screening and sample collection, the current sub-sampling technique provides opportunity for VOCs to be lost from the soil. This report describes three alternative techniques from the current technique for screening and collecting soil samples from subsurface soil cores for VOC analysis and field testing …
Date: March 31, 2009
Creator: Sorini, Susan; Schabron, John; Rovani, Joseph & Sanderson, Mark
Object Type: Report
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

As proposed, the main effort in this project is the development of software capable of performing real-time monitoring of micro-seismic activity recorded by an array of sensors deployed around an EGS. The main milestones are defined by the development of software to perform the following tasks: • Real-time micro-earthquake detection and location • Real-time detection of shear-wave splitting • Delayed-time inversion of shear-wave splitting These algorithms, which are discussed in detail in this report, make possible the automatic and real-time monitoring of subsurface fracture systems in geothermal fields from data collected by an array of seismic sensors. Shear wave splitting (SWS) is parameterized in terms of the polarization of the fast shear wave and the time delay between the fast and slow shear waves, which are automatically measured and stored. The measured parameters are then combined with previously measured SWS parameters at the same station and used to invert for the orientation (strike and dip) and intensity of cracks under that station. In addition, this grant allowed the collection of seismic data from several geothermal regions in the US (Coso) and Iceland (Hengill) to use in the development and testing of the software.
Date: March 31, 2009
Creator: Rial, J.A. & Lees, J.
Object Type: Report
System: The UNT Digital Library
Energy Conservation Projects to Benefit the Railroad Industry (open access)

Energy Conservation Projects to Benefit the Railroad Industry

The Energy Conservation Projects to benefit the railroad industry using the Norfolk Southern Company as a model for the railroad industry has five unique tasks which are in areas of importance within the rail industry, and specifically in the area of energy conservation. The NIU Engineering and Technology research team looked at five significant areas in which research and development work can provide unique solutions to the railroad industry in energy the conservation. (1) Alternate Fuels - An examination of various blends of bio-based diesel fuels for the railroad industry, using Norfolk Southern as a model for the industry. The team determined that bio-diesel fuel is a suitable alternative to using straight diesel fuel, however, the cost and availability across the country varies to a great extent. (2) Utilization of fuel cells for locomotive power systems - While the application of the fuel cell has been successfully demonstrated in the passenger car, this is a very advanced topic for the railroad industry. There are many safety and power issues that the research team examined. (3) Thermal and emission reduction for current large scale diesel engines - The current locomotive system generates large amount of heat through engine cooling and heat …
Date: December 31, 2009
Creator: Mirman, Clifford & Vohra, Promod
Object Type: Report
System: The UNT Digital Library
Development of Hydrologic Characterization Technology of Fault Zones -- Phase I, 2nd Report (open access)

Development of Hydrologic Characterization Technology of Fault Zones -- Phase I, 2nd Report

This is the year-end report of the 2nd year of the NUMO-LBNL collaborative project: Development of Hydrologic Characterization Technology of Fault Zones under NUMO-DOE/LBNL collaboration agreement, the task description of which can be found in the Appendix 3. Literature survey of published information on the relationship between geologic and hydrologic characteristics of faults was conducted. The survey concluded that it may be possible to classify faults by indicators based on various geometric and geologic attributes that may indirectly relate to the hydrologic property of faults. Analysis of existing information on the Wildcat Fault and its surrounding geology was performed. The Wildcat Fault is thought to be a strike-slip fault with a thrust component that runs along the eastern boundary of the Lawrence Berkeley National Laboratory. It is believed to be part of the Hayward Fault system but is considered inactive. Three trenches were excavated at carefully selected locations mainly based on the information from the past investigative work inside the LBNL property. At least one fault was encountered in all three trenches. Detailed trench mapping was conducted by CRIEPI (Central Research Institute for Electric Power Industries) and LBNL scientists. Some intriguing and puzzling discoveries were made that may contradict with …
Date: March 31, 2009
Creator: Karasaki, Kenzi; Onishi, Tiemi; Black, Bill & Biraud, Sebastien
Object Type: Report
System: The UNT Digital Library
Methodology for Developing the REScheckTM Software through Version 4.2 (open access)

Methodology for Developing the REScheckTM Software through Version 4.2

This report explains the methodology used to develop Version 4.2 of the REScheck software developed for the 1992, 1993, and 1995 editions of the MEC, and the 1998, 2000, 2003, and 2006 editions of the IECC, and the 2006 edition of the International Residential Code (IRC). Although some requirements contained in these codes have changed, the methodology used to develop the REScheck software for these five editions is similar. REScheck assists builders in meeting the most complicated part of the code─the building envelope Uo-, U-, and R-value requirements in Section 502 of the code. This document details the calculations and assumptions underlying the treatment of the code requirements in REScheck, with a major emphasis on the building envelope requirements.
Date: August 31, 2009
Creator: Bartlett, Rosemarie; Connell, Linda M.; Gowri, Krishnan; Lucas, R. G.; Schultz, Robert W.; Taylor, Zachary T. et al.
Object Type: Report
System: The UNT Digital Library
Ultrasonic Examination of Double-Shell Tank 241-AW-105 Examination Completed April 2009. (open access)

Ultrasonic Examination of Double-Shell Tank 241-AW-105 Examination Completed April 2009.

AREVA Federal Services LLC (AFS), under a contract from Washington River Protection Solutions (WRPS), has performed an ultrasonic examination of selected portions of Double-Shell Tank 241-AW-105. PNNL is responsible for preparing a report(s) that describes the results of the AFS ultrasonic examinations.
Date: May 31, 2009
Creator: Pardini, Allan F.; Weier, Dennis R.; Anderson, Kevin K. & Hathaway, John E.
Object Type: Report
System: The UNT Digital Library
JV Task 124 - Understanding Multi-Interactions of SO3, Mercury, Selenium, and Arsenic in Illinois Coal Flue Gas (open access)

JV Task 124 - Understanding Multi-Interactions of SO3, Mercury, Selenium, and Arsenic in Illinois Coal Flue Gas

This project consisted of pilot-scale combustion testing with a representative Illinois basin coal to explore the multi-interactions of SO{sub 3}, mercury, selenium and arsenic. The parameters investigated for SO{sub 3} and mercury interactions included different flue gas conditions, i.e., temperature, moisture content, and particulate alkali content, both with and without activated carbon injection for mercury control. Measurements were also made to track the transformation of selenium and arsenic partitioning as a function of flue gas temperature through the system. The results from the mercury-SO{sub 3} testing support the concept that SO{sub 3} vapor is the predominant factor that impedes efficient mercury removal with activated carbon in an Illinois coal flue gas, while H{sub 2}SO{sub 4} aerosol has less impact on activated carbon injection performance. Injection of a suitably mobile and reactive additives such as sodium- or calcium-based sorbents was the most effective strategy tested to mitigate the effect of SO{sub 3}. Transformation measurements indicate a significant fraction of selenium was associated with the vapor phase at the electrostatic precipitator inlet temperature. Arsenic was primarily particulate-bound and should be captured effectively with existing particulate control technology.
Date: March 31, 2009
Creator: Zhuang, Ye; Martin, Christopher & Pavlish, John
Object Type: Report
System: The UNT Digital Library
Second Quarter Hanford Seismic Report for Fiscal Year 2009 (open access)

Second Quarter Hanford Seismic Report for Fiscal Year 2009

The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. The Hanford Seismic Network recorded over 800 local earthquakes during the second quarter of FY 2009. Nearly all of these earthquakes were detected in the vicinity of Wooded Island, located about eight miles north of Richland just west of the Columbia River. Most of the events were considered minor (magnitude (Mc) less than 1.0) with 19 events in the 2.0-2.9 range. The estimated depths …
Date: July 31, 2009
Creator: Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.; Clayton, Ray E. & Devary, Joseph L.
Object Type: Report
System: The UNT Digital Library
An Integrated Surface Engineering Technology Development for Improving Energy Efficiency of Engine Components (open access)

An Integrated Surface Engineering Technology Development for Improving Energy Efficiency of Engine Components

Frictional losses are inherent in most practical mechanical systems. The ability to control friction offers many opportunities to achieve energy conservation. Over the years, materials, lubricants, and surface modifications have been used to reduce friction in automotive and diesel engines. However, in recent years, progress in friction reduction technology has slowed because many of the inefficiencies have been eliminated. A new avenue for friction reduction is needed. Designing surfaces specifically for friction reduction with concomitant enhanced durability for various engine components has emerged recently as a viable opportunity due to advances in fabrication and surface finishing techniques. Recently, laser ablated dimples on surfaces have shown friction reduction properties and have been demonstrated successfully in conformal contacts such as seals where the speed is high and the load is low. The friction reduction mechanism in this regime appears to depend on the size, patterns, and density of dimples in the contact. This report describes modeling efforts in characterizing surface textures and understanding their mechanisms for enhanced lubrication under high contact pressure conditions. A literature survey is first presented on the development of descriptors for irregular surface features. This is followed by a study of the hydrodynamic effects of individual micro-wedge dimples …
Date: May 31, 2009
Creator: Hsu, Stephen; Chang, Liming & Zhan, Huan
Object Type: Report
System: The UNT Digital Library