Oxygen-Fired CO{sub 2} Recycle for Application to Direct CO{sub 2} Capture form Coal-Fired Power Plants (open access)

Oxygen-Fired CO{sub 2} Recycle for Application to Direct CO{sub 2} Capture form Coal-Fired Power Plants

The Southern Research/Southern Company 1 MWth Pilot-Scale Coal-Fired Test Facility was successfully retrofit to fire in either the traditional air-fired mode or with 100% oxygen and recycled flue gas, with a fully integrated feedback and control system, including oxygen and recycled flue gas modulation during startup, transfer, and shutdown, safety and operational interlocks, and data acquisition. A MAXON Staged Oxygen Burner for Oxy-Coal Applications produced a stable flame over a significant range of firing turn-down, staging, and while firing five different U.S. coal types. The MAXON burner design produces lower flame temperatures than for air firing, which will enable (A) Safe operation, (B) Reduction of recycle flow without concern about furnace flame temperatures, and (C) May likely be affective at reducing slagging and fouling in the boiler and super heater at full-scale Power Plants. A CFD model of the Oxy-fired Combustion Research Facility (OCRF) was used to predict the flame geometry and temperatures in the OCRF and make a comparison with the air-fired case. The model predictions were consistent with the experimental data in showing that the MAXON burner fired with oxygen produced lower flame temperatures than the air-fired burner while firing with air.
Date: September 26, 2010
Creator: Gale, Thomas
System: The UNT Digital Library
Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting (open access)

Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting

Efforts to promote rechargeable electric lighting as a replacement for fuel-based light sources in developing countries are typically predicated on the notion that lighting service levels can be maintained or improved while reducing the costs and environmental impacts of existing practices. However, the extremely low incomes of those who depend on fuel-based lighting create a need to balance the hypothetically possible or desirable levels of light with those that are sufficient and affordable. In a pilot study of four night vendors in Kenya, we document a field technique we developed to simultaneously measure the effectiveness of lighting service provided by a lighting system and conduct a survey of lighting service demand by end-users. We took gridded illuminance measurements across each vendor's working and selling area, with users indicating the sufficiency of light at each point. User light sources included a mix of kerosene-fueled hurricane lanterns, pressure lamps, and LED lanterns.We observed illuminance levels ranging from just above zero to 150 lux. The LED systems markedly improved the lighting service levels over those provided by kerosene-fueled hurricane lanterns. Users reported that the minimum acceptable threshold was about 2 lux. The results also indicated that the LED lamps in use by the …
Date: August 26, 2010
Creator: Alstone, Peter; Jacobson, Arne & Mills, Evan
System: The UNT Digital Library
He Transport and Fate of Tempered Martensitic Steels: Summary of Recent TEM Observations (open access)

He Transport and Fate of Tempered Martensitic Steels: Summary of Recent TEM Observations

As an extension of prior work [1-4], we summarize recent observations made on a He-implanted tempered martensitic steel (TMS), F82H mod 3, irradiated in the HFIR, in both as-tempered (AT) and cold-worked (CW) conditions. A novel implantation technique was used to uniformly inject He into 3-mm diameter TEM discs to depths ranging from ≈ 5-8 µm. The He is generated by two-step transmutation reactions in Ni contained in a NiAl coating layer adjacent to paired 3 mm TEM discs. NiAl layers from 1 to 4 μm thick produced He/dpa ratios between 5 and 40 appm/dpa. The irradiations were at temperatures of 300, 400 and 500°C from 3.9 to 9 dpa and 90 to 380 appm He. Electron transparent samples were prepared by a cross-sectional thinning technique that allowed investigating microstructural evolution over a range of implantation depths. Irradiation of the AT alloy to 9 dpa at 500°C and 380 appm He resulted in relatively large, faceted cavities, that are likely voids, along with a much higher density of smaller He bubbles. The cavities were most often aligned in pearl necklace like strings, presumably due to their formation on pre-existing dislocations. A finer distribution of cavities was also present on precipitate …
Date: February 26, 2010
Creator: Edwards, Danny J.; Kurtz, Richard J.; Odette, G Robert & Yamamoto, Takuya
System: The UNT Digital Library
Technetium Waste Form Development Progress Report (open access)

Technetium Waste Form Development Progress Report

The approach being followed to evaluate the use of an iron-based alloy waste form to immobilize the Tc-bearing waste streams generated during the aqueous and electrochemical processing of used fuel that is being studied in the DOE Advanced Fuel Cycle Initiative (AFCI) is presented in this report. The objective is to develop an alloy waste form that provides high waste loading within waste form processing limitations, meets waste form performance requirements for durability and the long-term retention of radionuclides, and can be produced with consistent physical, chemical, and radiological properties that meet regulatory acceptance requirements for disposal. Microanalysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was used to analyze non-radioactive Fe-Mo-Re samples. A sample was prepared for SEM; however, significant unforeseen instrument problems led to delays in conducting the detailed work. The TEM was not available for this particular sample and therefore only preliminary SEM work can be reported. The results are in agreement with previous studies [Ebert 2009]; however, a rhenium-rich region within the Re-Mo phase is clearly visible.
Date: February 26, 2010
Creator: Buck, Edgar C.
System: The UNT Digital Library
Calculation of Ambient (H*(10)) and Personal (Hp(10)) Dose Equivalent from a 252Cf Neutron Source (open access)

Calculation of Ambient (H*(10)) and Personal (Hp(10)) Dose Equivalent from a 252Cf Neutron Source

The purpose of this calculation is to calculate the neutron dose factors for the Sr-Cf-3000 neutron source that is located in the 318 low scatter room (LSR). The dose factors were based on the dose conversion factors published in ICRP-21 Appendix 6, and the Ambient dose equivalent (H*(10)) and Personal dose equivalent (Hp(10)) dose factors published in ICRP Publication 74.
Date: March 26, 2010
Creator: Traub, Richard J.
System: The UNT Digital Library
Primer on Use of Multi-Spectral and Infra Red Imaging for On-Site Inspections (open access)

Primer on Use of Multi-Spectral and Infra Red Imaging for On-Site Inspections

The purpose of an On-Site Inspection (OSI) is to determine whether a nuclear explosion has occurred in violation of the Comprehensive Nuclear Test Ban Treaty (CTBT), and to gather information which might assist in identifying the violator (CTBT, Article IV, Paragraph 35) Multi-Spectral and Infra Red Imaging (MSIR) is allowed by the treaty to detect observables which might help reduce the search area and thus expedite an OSI and make it more effective. MSIR is permitted from airborne measurements, and at and below the surface to search for anomalies and artifacts (CTBT, Protocol, Part II, Paragraph 69b). The three broad types of anomalies and artifacts MSIR is expected to be capable of observing are surface disturbances (disturbed earth, plant stress or anomalous surface materials), human artifacts (man-made roads, buildings and features), and thermal anomalies. The purpose of this Primer is to provide technical information on MSIR relevant to its use for OSI. It is expected that this information may be used for general background information, to inform decisions about the selection and testing of MSIR equipment, to develop operational guidance for MSIR use during an OSI, and to support the development of a training program for OSI Inspectors. References are …
Date: October 26, 2010
Creator: Henderson, J. R.
System: The UNT Digital Library
RECOMMENDATIONS FOR ASSESSING THE UNCERTAINTY IN TANK 18-F WALL SAMPLES (open access)

RECOMMENDATIONS FOR ASSESSING THE UNCERTAINTY IN TANK 18-F WALL SAMPLES

Tank 18-F in the F-Area Tank Farm at the Savannah River Site (SRS) has had measurements taken from its inner vertical sides in order to determine the level of radionuclide and other analyte concentrations attached to the tank walls. In all, three samples have been obtained by drilling shallow holes into the carbon steel walls and consolidating the material. An Upper Wall Sample (Sample ID: Tk 18-1) was formed by combining two drill samples taken at a height of 17 ft above the tank floor, and a Lower Wall Sample (Sample ID: SPD4) was formed by combining two drill samples taken between 10 and 12 ft above the tank floor. A Scale Sample (Sample ID: Tk 18-2) was formed by combining 5 drill samples obtained between 6 and 7 ft above the tank floor. Photographs of the sampled material and a more detailed description of the samples and the concentration results are presented by Hay and others [2009]. The objective of this report is to determine a method and use it to place an upper confidence bound on the concentrations in the wall samples using only the currently available sample information. None of the three wall locations (tank heights) has …
Date: October 26, 2010
Creator: Shine, G.
System: The UNT Digital Library
Facilitation of the Estuary/Ocean Subgroup for Federal Research, Monitoring, and Evaluation, FY10 Annual Report (open access)

Facilitation of the Estuary/Ocean Subgroup for Federal Research, Monitoring, and Evaluation, FY10 Annual Report

The Estuary/Ocean Subgroup (EOS) is part of the research, monitoring, and evaluation (RME) effort that the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) developed in response to obligations arising from the Endangered Species Act as applied to operation of the Federal Columbia River Power System (FCRPS). The goal of the EOS project is to facilitate activities of the estuary/ocean RME subgroup as it coordinates design and implementation of federal RME in the lower Columbia River and estuary. The EOS is one of multiple work groups in the federal research, monitoring, and evaluation (RME) effort developed in response to responsibilities arising from the Endangered Species Act as a result of operation of the FCRPS. The EOS is tasked by NOAA Fisheries and the Action Agencies to design and coordinate implementation of the federal RME plan for the lower Columbia River and estuary, including the plume.
Date: October 26, 2010
Creator: Johnson, Gary E.
System: The UNT Digital Library
100 Area D4 Project Building Completion Report: December 2008 to December 2009 (open access)

100 Area D4 Project Building Completion Report: December 2008 to December 2009

This report documents the final status of buildings after the completion of D4 activities at the 100 Area of the U.S. Department of Energy Hanford Site from December 1, 2008, to December 31, 2009.
Date: October 26, 2010
Creator: K.G. Finucane, J.P. Harrie
System: The UNT Digital Library
2008 East Tennessee Technology Park Annual Illness and Injury Surveillance Report (open access)

2008 East Tennessee Technology Park Annual Illness and Injury Surveillance Report

The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence of workdays, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: October 26, 2010
Creator: United States. Department of Energy. Office of Illness and Injury Prevention Programs.
System: The UNT Digital Library
Evaluating Cumulative Ecosystem Response to Restoration Projects in the Lower Columbia River and Estuary, 2009 (open access)

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Lower Columbia River and Estuary, 2009

This is the sixth annual report of a seven-year project (2004 through 2010) to evaluate the cumulative effects of habitat restoration actions in the lower Columbia River and estuary (LCRE). The project, called the Cumulative Effects Study, is being conducted for the U.S. Army Corps of Engineers Portland District (USACE) by the Marine Sciences Laboratory of the Pacific Northwest National Laboratory (PNNL), the Pt. Adams Biological Field Station of the National Marine Fisheries Service (NMFS), the Columbia River Estuary Study Taskforce (CREST), and the University of Washington. The goal of the Cumulative Effects Study is to develop a methodology to evaluate the cumulative effects of multiple habitat restoration projects intended to benefit ecosystems supporting juvenile salmonids in the 235-km-long LCRE. Literature review in 2004 revealed no existing methods for such an evaluation and suggested that cumulative effects could be additive or synergistic. From 2005 through 2009, annual field research involved intensive, comparative studies paired by habitat type (tidal swamp versus marsh), trajectory (restoration versus reference site), and restoration action (tidegate replacement vs. culvert replacement vs. dike breach).
Date: October 26, 2010
Creator: Johnson, Gary E.; Diefenderfer, Heida L.; Borde, Amy B.; Bryson, Amanda J.; Cameron, April; Coleman, Andre M. et al.
System: The UNT Digital Library
Macroalgae as a Biomass Feedstock: A Preliminary Analysis (open access)

Macroalgae as a Biomass Feedstock: A Preliminary Analysis

A thorough of macroalgae analysis as a biofuels feedstock is warranted due to the size of this biomass resource and the need to consider all potential sources of feedstock to meet current biomass production goals. Understanding how to harness this untapped biomass resource will require additional research and development. A detailed assessment of environmental resources, cultivation and harvesting technology, conversion to fuels, connectivity with existing energy supply chains, and the associated economic and life cycle analyses will facilitate evaluation of this potentially important biomass resource.
Date: September 26, 2010
Creator: Roesijadi, Guritno; Jones, Susanne B.; Snowden-Swan, Lesley J. & Zhu, Yunhua
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter (open access)

Proceedings of RIKEN BNL Research Center Workshop: P- and CP-odd Effects in Hot and Dense Matter

This volume contains the proceedings of the RBRC/CATHIE workshop on 'P- and CP-odd Effects in Hot and Dense Matter' held at the RIKEN-BNL Research Center on April 26-30, 2010. The workshop was triggered by the experimental observation of charge correlations in heavy ion collisions at RHIC, which were predicted to occur due to local parity violation (P- and CP-odd fluctuations) in hot and dense QCD matter. This experimental result excited a significant interest in the broad physics community, inspired a few alternative interpretations, and emphasized the need for a deeper understanding of the role of topology in QCD vacuum and in hot and dense quark-gluon matter. Topological effects in QCD are also closely related to a number of intriguing problems in condensed matter physics, cosmology and astrophysics. We therefore felt that a broad cross-disciplinary discussion of topological P- and CP-odd effects in various kinds of matter was urgently needed. Such a discussion became the subject of the workshop. Specific topics discussed at the workshop include the following: (1) The current experimental results on charge asymmetries at RHIC and the physical interpretations of the data; (2) Quantitative characterization of topological effects in QCD matter including both analytical (perturbative and non-perturbative using …
Date: April 26, 2010
Creator: Deshpande, A.; Fukushima, K.; Kharzeev, D.; Warringa, H. & Voloshin, S.
System: The UNT Digital Library
Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications (open access)

Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications

When hazardous material is accidently or intentionally released into the atmosphere, emergency response organizations look to decision support systems (DSSs) to translate contaminant information provided by atmospheric models into effective decisions to protect the public and emergency responders and to mitigate subsequent consequences. The Department of Homeland Security (DHS)-led Interagency Modeling and Atmospheric Assessment Center (IMAAC) is one of the primary DSSs utilized by emergency management organizations. IMAAC is responsible for providing 'a single piont for the coordination and dissemination of Federal dispersion modeling and hazard prediction products that represent the Federal position' during actual or potential incidents under the National Response Plan. The Department of Energy's (DOE) National Atmospheric Release Advisory Center (NARAC), locatec at the Lawrence Livermore National Laboratory (LLNL), serves as the primary operations center of the IMAAC. A key component of atmospheric release decision support systems is meteorological information - models and data of winds, turbulence, and other atmospheric boundary-layer parameters. The accuracy of contaminant predictions is strongly dependent on the quality of this information. Therefore, the effectiveness of DSSs can be enhanced by improving the meteorological options available to drive atmospheric transport and fate models. The overall goal of this project was to develop and …
Date: April 26, 2010
Creator: Arnold, E; Simpson, M; Larsen, S; Gash, J; Aluzzi, F; Lundquist, J et al.
System: The UNT Digital Library
Analytical Data Report of Grab Samples Collected From 200-ZP-1 Remedial Action Wells (open access)

Analytical Data Report of Grab Samples Collected From 200-ZP-1 Remedial Action Wells

This is an analytical data report prepared for CHPRC from grab samples received for 200-ZP-1 operable unit.
Date: February 26, 2010
Creator: Lindberg, Michael J.
System: The UNT Digital Library
Review of the IEEE Standard for Computerized Operating Procedure Systems (open access)

Review of the IEEE Standard for Computerized Operating Procedure Systems

Increasingly nuclear power plant procedures, such as emergency operating procedures, are being presented in computer form with functionality to support operator use and management of the procedures. The U.S. Nuclear Regulatory Commission (NRC) currently has guidance for the review of computer-based procedures (CBPs); however, there remain CBP functions and human performance issues for which up-to-date guidance is lacking. The Institute of Electrical and Electronics Engineers (IEEE) has initiated a standard development effort to address the human factors engineering (HFE) aspects of CBP systems. When completed, it may provide guidance to supplement the NRC staff's review criteria. The purpose of our study was to evaluate the suitability of the IEEE Standard for use in the NRC's HFE safety reviews of CBP systems and to ensure that the guidance meets the NRC's standard for scientific and engineering rigor used in its own guidance development efforts. We established the following criteria with which to evaluate the Standard: (1) it should meet an existing need of NRC reviewers, (2) it should be based in sound HFE principles, (3) it should be thoroughly peer-reviewed, and (4) it should address CBP-related human performance issues identified in the literature. This report describes the methodology we used to …
Date: February 26, 2010
Creator: O'Hara, J. & Higgins, J.
System: The UNT Digital Library
Final Report for Phase I Northern California CO2 Reduction Project (open access)

Final Report for Phase I Northern California CO2 Reduction Project

On June 8, 2009, the U. S. Department of Energy's National Energy Technology Laboratory released a Funding Opportunity Announcement (DE-FOA 0000015) with the title, Recovery Act: Carbon Capture and Sequestration from Industrial Sources and Innovative Concepts for Beneficial CO{sub 2} Use. C6 Resources (C6), an affiliate of Shell Oil Company, responded with a proposal for Technology Area 1: Large-scale industrial carbon capture and sequestration (CCS) projects from industrial sources. As DOE Federally Funded Research and Development Center (FFRDC) Contractors, Lawrence Livermore National Laboratory (LBNL) and Lawrence Berkeley National Laboratory (LLNL) proposed to collaborate with C6 and perform technical tasks, which C6 included in the C6 proposal, titled the Northern California CO{sub 2} Reduction Project. The proposal was accepted for Phase I funding and C6 received DOE Award DEFE0002042. LLNL and LBNL each received Phase I funding of $200,000, directly from DOE. The essential task of Phase I was to prepare a proposal for Phase II, which would be a five-year, detailed technical proposal, budget, and schedule for a complete carbon capture, transportation, and geologic storage project, with the objective of starting the injection of 1 million tons per year of industrial CO2 by the end of FY2015. LLNL and LBNL …
Date: October 26, 2010
Creator: Wagoner, J
System: The UNT Digital Library
VERIFICATION SURVEY ACTIVITIES IN FS SURVEY UNITS 7, 8, 9, 10, 11, 13 & 14 AT THE SEPARATIONS PROCESS RESEARCH UNIT (open access)

VERIFICATION SURVEY ACTIVITIES IN FS SURVEY UNITS 7, 8, 9, 10, 11, 13 & 14 AT THE SEPARATIONS PROCESS RESEARCH UNIT

FINAL INTERIM REPORT VERIFICATION SURVEY ACTIVITIES IN FINAL STATUS SURVEY UNITS 7, 8, 9, 10, 11, 13 AND 14 AT THE SEPARATIONS PROCESS RESEARCH UNIT, Niskayuna, New York 0496-SR-03-0. The Separations Process Research Unit (SPRU) facilities were constructed in the late 1940s to research the chemical separation of plutonium and uranium. SPRU operated between February 1950 and October 1953. The research activities ceased following the successful development of the reduction/oxidation and plutonium/uranium extraction processes that were subsequently used by the Hanford and the Savannah River sites.
Date: May 26, 2010
Creator: JADICK, M.G.
System: The UNT Digital Library
INDEPENDENT VERIFICATION REVIEW AND SURVEY of the Argonne National Laboratory Building 301 Footprint (open access)

INDEPENDENT VERIFICATION REVIEW AND SURVEY of the Argonne National Laboratory Building 301 Footprint

INDEPENDENT VERIFICATION REVIEW AND SURVEY of the Argonne National Laboratory Building 301 Footprint, Argonne Illinois 5061-SR-01-0
Date: May 26, 2010
Creator: Bailey, E.N.
System: The UNT Digital Library
The Effects of Degraded Digital Instrumentation and Control Systems on Human-system Interfaces and Operator Performance: HFE Review Guidance and Technical Basis (open access)

The Effects of Degraded Digital Instrumentation and Control Systems on Human-system Interfaces and Operator Performance: HFE Review Guidance and Technical Basis

New and advanced reactors will use integrated digital instrumentation and control (I&C) systems to support operators in their monitoring and control functions. Even though digital systems are typically highly reliable, their potential for degradation or failure could significantly affect operator performance and, consequently, impact plant safety. The U.S. Nuclear Regulatory Commission (NRC) supported this research project to investigate the effects of degraded I&C systems on human performance and plant operations. The objective was to develop human factors engineering (HFE) review guidance addressing the detection and management of degraded digital I&C conditions by plant operators. We reviewed pertinent standards and guidelines, empirical studies, and plant operating experience. In addition, we conducted an evaluation of the potential effects of selected failure modes of the digital feedwater system on human-system interfaces (HSIs) and operator performance. The results indicated that I&C degradations are prevalent in plants employing digital systems and the overall effects on plant behavior can be significant, such as causing a reactor trip or causing equipment to operate unexpectedly. I&C degradations can impact the HSIs used by operators to monitor and control the plant. For example, sensor degradations can make displays difficult to interpret and can sometimes mislead operators by making it …
Date: February 26, 2010
Creator: O'Hara, J. M. & W. Gunther, G. Martinez-Guridi
System: The UNT Digital Library
Simulation of Intense Beams and Targets for Heavy-Ion-Fusion Science (HEDLP / Inertial Fusion Energy) (open access)

Simulation of Intense Beams and Targets for Heavy-Ion-Fusion Science (HEDLP / Inertial Fusion Energy)

None
Date: August 26, 2010
Creator: Friedman, A.; Barnard, J. J.; Cohen, R. H.; Dorf, M.; Eder, D.; Grote, D. P. et al.
System: The UNT Digital Library
Advanced Initiation Systems Manufacturing Level 2 Milestone Completion Summary (open access)

Advanced Initiation Systems Manufacturing Level 2 Milestone Completion Summary

None
Date: August 26, 2010
Creator: Chow, R & Schmidt, M A
System: The UNT Digital Library
Reaction Mechanisms for Barite Dissolution and Growth (open access)

Reaction Mechanisms for Barite Dissolution and Growth

In Stack and Rustad (2007), the reactive flux method (Rey and Hynes, 1996) and molecular dynamics (MD) were used to simulate the {001} barite-water interface structure and water exchange rate of aqueous barium ions and barium surface species. Atomic-level mineralwater interfacial structure and kinetics are being studied with increasing precision due to advances in spectroscopic methods at synchrotron x-ray sources as well as improved computational capacity. Better characterization of these interfaces in turn is leading to advances in the understanding of many macroscopic geochemical properties. Overall the barite-water interfacial structure was found to compare well to that estimated using X-ray reflectivity (XRR) measurements (Fenter et al., 2001), but there was an important difference: the MD predicted an intricate water structure present at the interface with one major peak and several minor peaks whereas the XRR found only a single layer of water. This discrepancy is thought to result from a limited resolution in the Fenter et al. (2001) study as well as over-coordination of surface sulfates by the MD model.
Date: July 26, 2010
Creator: Stack, Andrew G.
System: The UNT Digital Library
Measurements of the Motion of Plasma Filaments in a Plasma Ball (open access)

Measurements of the Motion of Plasma Filaments in a Plasma Ball

Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ~106 cm/sec at the driving frequency of ~26 kHz, and drift upward through the ball at ~1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.
Date: January 26, 2010
Creator: M. Campanell, J. Laird, T. Provost, S. Vasquez, S.J. Zweben
System: The UNT Digital Library