946 Matching Results

Search Results

Advanced search parameters have been applied.

The Repair of Farm Equipment

Description: Report discussing the proper care and maintenance of farm equipment, including tools necessary for repair work and shop facilities capable of repair work. Contains illustrations of tools.
Date: 1909
Creator: Beattie, W. R. (William Renwick), b. 1870
Partner: UNT Libraries Government Documents Department

Building America

Description: Film on US infrastructure development, with topics including homes of the future, the role of lumber dealers in home building, the importance of home maintenance, and the importance of urban development. This film includes animated sequences.
Date: unknown
Creator: Price, Sherman
Partner: UNT Media Library

The National Park Service's Maintenance Backlog: Frequently Asked Questions

Description: This report addresses frequently asked questions about NPS deferred maintenance also known as the maintenance backlog. The discussion is organized under the headings of general questions, funding-related questions, management-related questions, and questions on Congress's role in addressing the backlog.
Date: August 23, 2017
Creator: Comay, Laura B.
Partner: UNT Libraries Government Documents Department

Deferred Maintenance of Federal Land Management Agencies: Fiscal Year 2007-Fiscal Year 2016 Estimates and Issues

Description: This report discusses the maintenance backlogs/deferred maintenance at the four federal land management agencies (the National Park Service, the Fish and Wildlife Service, the Bureau of Land Management, and the Forest Service). It first provides agency deferred maintenance estimates for FY2016, the most recent fiscal year for which this information is available. It also discusses changes in deferred maintenance over the past decade (FY2007-FY2016) and then identifies some of the factors that likely contributed to these changes.
Date: April 25, 2017
Creator: Vincent, Carol Hardy
Partner: UNT Libraries Government Documents Department

Repair of Waterstop Failures: Case Histories

Description: This report discusses case studies of failures in waterstops that prevent water passage through the monolith joints of concrete dams and locks. "The primary objective of this study was to identify materials and techniques which have been used in repair of waterstop failures. Also, based on a review and evaluation of current practices, a secondary objective was to identify those areas where research is needed to supplement existing technology" (abstract).
Date: November 1986
Creator: McDonald, J. E.
Partner: UNT Libraries Government Documents Department

Abrasive Blasting for Cleaning Parts

Description: Abstract: A demonstration on August 22, 1945, showed that Alpha or Beta M or K parts, including insulators, can be well cleaned with a pressure-feed abrasive blaster. The abrasive is a slurry of alumina and water mixed with high velocity air in a special feed nozzle. The slurry is continuously recycled.
Date: September 1945
Creator: McWherter, Jack R. & Yerazunis, Stephen
Partner: UNT Libraries Government Documents Department

Cleaning E-Units by Blasting

Description: Abstract: An air-water-abrasive blasting system thoroughly cleans copper parts of E units without damage to the parts. Little abrasive is required because of the continuous recycle of the abrasive slurry.
Date: 1945
Creator: McWherter, Jack R. & Yerazunis, Stephen
Partner: UNT Libraries Government Documents Department


Description: Radiation can damage cellular components, including DNA. Organisms have developed a panoply of means of dealing with DNA damage. Some repair paths have rather narrow substrate specificity (e.g. photolyases), which act on specific pyrimidine photoproducts in a specific type (e.g., DNA) and conformation (double-stranded B conformation) of nucleic acid. Others, for example, nucleotide excision repair, deal with larger classes of damages, in this case bulky adducts in DNA. A detailed discussion of DNA repair mechanisms is beyond the scope of this article, but one can be found in the excellent book of Friedberg et al. [1] for further detail. However, some DNA damages and paths for repair of those damages important for photobiology will be outlined below as a basis for the specific examples of genetic and molecular analysis that will be presented below.
Date: July 26, 2001
Creator: Sutherland, B. M.
Partner: UNT Libraries Government Documents Department

Care and Repair of Farm Implements: No. 5, Grain Separators

Description: "An enormous waste of grain and great loss of time result every year through the inefficient work of thrashing machines that are not properly repaired and put in thorough working condition before the beginning of the working season.... The separator should be overhauled at the close of the thrashing season or during the winter, needed parts ordered, and necessary repairs and adjustments made. This will tend to lengthen the life of the machine, and prevent loss of time and money from breakdowns at the busy season. This bulletin gives instructions for overhauling and adjusting separators which will reduce to the minimum the losses and delays from breakdowns during the operating season." -- p. 2
Date: 1919
Creator: Johnson, Elmer
Partner: UNT Libraries Government Documents Department

Metal inhibition of human alkylpurine-DNA-N-glycosylase activityin base excision repair

Description: Cadmium (Cd{sup 2+}), nickel (Ni{sup 2+}) and cobalt (Co{sup 2+}) are human and/or animal carcinogens. Zinc (Zn{sup 2+}) is not categorized as a carcinogen, and rather an essential element to humans. Metals were recently shown to inhibit DNA repair proteins that use metals for their function and/or structure. Here we report that the divalent ions Cd{sup 2+}, Ni{sup 2+}, and Zn{sup 2+} can inhibit the activity of a recombinant human N-methylpurine-DNA glycosylase (MPG) toward a deoxyoligonucleotide with ethenoadenine (var epsilonA). MPG removes a variety of toxic/mutagenic alkylated bases and does not require metal for its catalytic activity or structural integrity. At concentrations starting from 50 to 1000 {micro}M, both Cd{sup 2+} and Zn{sup 2+} showed metal-dependent inhibition of the MPG catalytic activity. Ni{sup 2+} also inhibited MPG, but to a lesser extent. Such an effect can be reversed with EDTA addition. In contrast, Co{sup 2+} and Mg{sup 2+} did not inhibit the MPG activity in the same dose range. Experiments using HeLa cell-free extracts demonstrated similar patterns of inactivation of the var epsilonA excision activity by the same metals. Binding of MPG to the substrate was not significantly affected by Cd{sup 2+}, Zn{sup 2+}, and Ni{sup 2+} at concentrations that show strong inhibition of the catalytic function, suggesting that the reduced catalytic activity is not due to altered MPG binding affinity to the substrate. Molecular dynamics (MD) simulations with Zn{sup 2+} showed that the MPG active site has a potential binding site for Zn{sup 2+}, formed by several catalytically important and conserved residues. Metal binding to such a site is expected to interfere with the catalytic mechanism of this protein. These data suggest that inhibition of MPG activity may contribute to metal genotoxicity and depressed repair of alkylation damage by metals in vivo.
Date: February 28, 2006
Creator: Wang, Ping; Guliaev, Anton B. & Hang, Bo
Partner: UNT Libraries Government Documents Department

Monolith Joint Repairs: Case Histories

Description: This report discusses a study to identify materials and techniques to repair monolith joints, a common location for deficiencies in dams and locks. It also identified areas for further investigation to supplement existing technologies.
Date: August 1989
Creator: May, James G. & McDonald, James E.
Partner: UNT Libraries Government Documents Department

Workshop on Concepts for Self-Healing Critical Infrastructures

Description: This report describes a workshop on self-healing infrastructures conducted jointly by Sandia National Laboratories, Infrastructure & Information Division, and the Massachusetts Institute of Technology, Engineering Systems Division. The workshop was held in summer, 2002 and funded under Laboratory-Directed Research and Development (LDRD) No.5 1540. The purpose of the workshop was to obtain a working definition of a self-healing infrastructure, explore concepts for self-healing infrastructures systems, and to propose engineering studies that would lay the foundation for the realization of such systems. The workshop produced a number of useful working documents that clarified the concept of self-healing applied to large-scale system-of-systems exemplified by the US National Critical Infrastructure. The workshop eventually resulted in a joint proposal to the National Science Foundation and a continuing collaboration on intelligent agent based approaches to coordination of infrastructure systems in a self-healing regime.
Date: June 1, 2003
Partner: UNT Libraries Government Documents Department

Epoxy injection repairs to concrete in 225-B Building

Description: In 1982, the damaged anchor areas (67 total) in the Operating Gallery and cold manipulator shop ceiling reinforced concrete slabs were epoxy injection repaired by Construction Technology Laboratories (CTL), Portland Cement Association. The through depth vertical cracks (10 total) in the ceiling slabs in the galleries and manipulator shops were sealed and structurally repaired using epoxy injection procedures. The details of the epoxy reRair are reported. Sonic nondestructive (NDT) testing before and after the epoxy injection repairs were made by CTL to confirm that the repairs are structurally effective. CTL recommended to expedite the installation of lateral bracing for the manipulator monorail in order to avoid re-darnage to the repaired anchor areas.
Date: September 19, 1996
Creator: Vollert, F.R.
Partner: UNT Libraries Government Documents Department

Small Sample Experimental Design Optimization and Repair

Description: The primary goal of using Design of Experiment (DOEx) methods is to extract the maximum amount of information concerning experimental factors and their interactions from as few observations as possible. DOEx methodology allows an experimenter to selectively and systematically adjust process settings to learn which factors have the greatest impact on process and product performance. Using information about these factors, process settings can be adjusted until optimum performance is obtained.
Date: April 1, 1999
Creator: Honson, A. J.; DeCarli, D. & Crowder, S. V.
Partner: UNT Libraries Government Documents Department

Defense Primer: Department of Defense Maintenance Depots

Description: This report discusses the Department of Defense's (DOD) maintenance depots which provide dedicated equipment repair for the military's vehicles, weapons systems, and electronics and provides the locations and services of each depot divided by each military service.
Date: November 7, 2017
Creator: Williams, Lynn M. & Purdy, Jason A.
Partner: UNT Libraries Government Documents Department

Defining interactions between DNA-PK and ligase IV/XRCC4

Description: Non-homologous end joining (NHEJ) is a major pathway for the repair of DNA double-strand breaks in mammalian cells. DNA-dependent protein kinase (DNA-PK), ligase IV, and XRCC4 are all critical components of the NHEJ repair pathway. DNA-PK is composed of a heterodimeric DNA-binding component, Ku, and a large catalytic subunit, DNA-PKcs. Ligase IV and XRCC4 associate to form a multimeric complex that is also essential for NHEJ. DNA-PK and ligase IV/XRCC4 interact at DNA termini which results in stimulated ligase activity. Here we define interactions between the components of these two essential complexes, DNA-PK and ligase IV/XRCC4. We find that ligase IV/XRCC4 associates with DNA-PK in a DNA-independent manner. The specific protein-protein interactions that mediate the interaction between these two complexes are further identified. Direct physical interactions between ligase IV and Ku as well as between XRCC4 and DNA-PKcs are shown. No direct interactions are observed between ligase IV and DNA-PKcs or between XRCC4 and Ku. Our data defines the specific protein pairs involved in the association of DNA-PK and ligase IV/XRCC4, and suggests a molecular mechanism for coordinating the assembly of the DNA repair complex at DNA breaks.
Date: April 10, 2001
Creator: Hsu, Hsin-Ling; Yannone, Steven M. & Chen, David J.
Partner: UNT Libraries Government Documents Department

Deterioration and Repair of Concrete in the Lower Monumental Navigation Lock Wall

Description: "This report discusses surface deterioration and repairs of concrete in the Lower Monumental Lock on the Snake River in Washington. It includes discussion of laboratory studies, testing, construction, and field evaluation of the original concrete and of the various cementitious coatings used for repairs" (p. i).
Date: June 1981
Creator: Schrader, Ernest K.
Partner: UNT Libraries Government Documents Department

Rehabilitation of the South Jetty, Ocean City, Maryland

Description: Partial abstract: Frequent dredging requirements and scouring at the foundation of Ocean City Inlet's south jetty resulted in a study to determine the source of the shoaling and scouring. The study concluded that sand was being transported northward along Assateague Island, through and over the south jetty, and deposited inside the inlet. The sand was then transported north by ebb currents where it encroached on the Federal navigation channel. A rehabilitation program was initiated to create a littoral barrier to eliminate the shoaling problem and to repair the scour hold. Three headland breakwaters were constructed to stabilize Northern Assateague Island. The site was selected as part of the Monitoring Completed Coastal Projects (MCCP) Program to determine how well the rehabilitation project accomplished its design purpose.
Date: March 1994
Creator: Bass, Gregory P.; Fulford, Edward T.; Underwood, Steven G. & Parson, Larry E.
Partner: UNT Libraries Government Documents Department

Practical Issues in Component Aging Analysis

Description: This paper examines practical issues in the statistical analysis of component aging data. These issues center on the stochastic process chosen to model component failures. The two stochastic processes examined are repair same as new, leading to a renewal process, and repair same as old, leading to a nonhomogeneous Poisson process. Under the first assumption, times between failures can treated as statistically independent observations from a stationary process. The common distribution of the times between failures is called the renewal distribution. Under the second process, the times between failures will not be independently and identically distributed, and one cannot simply fit a renewal distribution to the cumulative failure times or the times between failures. The paper illustrates how the assumption made regarding the repair process is crucial to the analysis. Besides the choice of stochastic process, other issues that are discussed include qualitative graphical analysis and simple nonparametric hypothesis tests to help judge which process appears more appropriate. Numerical examples are presented to illustrate the issues discussed in the paper.
Date: September 1, 2008
Creator: Kelly, Dana L.; Rodionov, Andrei & Uwe-Klugel, Jens
Partner: UNT Libraries Government Documents Department

8-oxoguainine enhances bending of DNA that favors binding of glycosylases

Description: Molecular dynamics (MD) simulations were carried out on the DNA oligonucleotide GGGAACAACTAG:CTAGTTGTTCCC in its native form and with guanine in the central G19:C6 base pair replaced by 8-oxoguanine (8oxoG). A box of explicit water molecules was used for solvation and Na+ counterions were added to neutralize the system. The direction and magnitude of global bending were assessed by a technique used previously to analyze simulations of DNA containing a thymine dimer. The presence of 8oxoG did not greatly affect the magnitude of DNA bending; however, bending into the major groove was significantly more probable when 8oxoG replaced G19. Crystal structures of glycosylases bound to damaged-DNA substrates consistently show a sharp bend into the major groove at the damage site. We conclude that changes in bending dynamics that assist the formation of this kink are a part of the mechanism by which glycosylases of the base excision repair pathway recognize the presence of 8oxoG in DNA.
Date: April 23, 2003
Creator: Miller, John H.
Partner: UNT Libraries Government Documents Department