Szabo D.T.,U.S. Environmental Protection Agency |
Szabo D.T.,University of North Carolina at Chapel Hill |
Szabo D.T.,Technical Integrity |
Pathmasiri W.,Research Triangle Institute International |
And 4 more authors.
Environmental Health Perspectives | Year: 2017
Background: Hexabromocyclododecane (HBCD) is a high production volume brominated flame retardant added to building insulation foams, electronics, and textiles. HBCD is a commercial mixture (CM-HBCD) composed of three main stereoisomers: α-HBCD (10%), β-HBCD (10%), and γ-HBCD (80%). A shift from the dominant stereoisomer γ-HBCD to α-HBCD is detected in humans and wildlife. Objectives: Considering CM-HBCD has been implicated in neurodevelopment and endocrine disruption, with expected metabolism perturbations, we performed metabolomics on mice serum obtained during a window-of-developmental neurotoxicity to draw correlations between early-life exposures and developmental outcomes and to predict health risks. Methods: Six female C57BL/6 mice at postnatal day (PND) 10 were administered a single gavage dose of α-, γ-, or CM-HBCD at 3, 10, and 30 mg/kg. Nuclear magnetic resonance metabolomics was used to analyze 60 μL serum aliquots of blood collected 4 days post-oral exposure. Results: Infantile mice exposed to α-, γ-, or CM-HBCD demonstrated differences in endogenous metabolites by treatment and dose groups, including metabolites involved in glycolysis, gluco-neogenesis, lipid metabolism, citric acid cycle, and neurodevelopment. Ketone bodies, 3-hydroxy-butyrate, and acetoacetate, were nonstatistically elevated, when compared with mean control levels, in all treatment and dose groups, while glucose, pyruvate, and alanine varied. Acetoacetate was significantly increased in the 10 mg/kg α-HBCD and was nonsignificantly decreased with CM-HBCD. A third ketone body, acetone, was significantly lower in the 30 mg/kg α-HBCD group with significant increases in pyruvate at the same treatment and dose group. Metabolites significant in differentiating treatment and dose groups were also identified, including decreases in amino acids glutamate (excitatory neurotransmitter in learning and memory) and phenylalanine (neurotransmitter precursor) after α-HBCD and γ-HBCD exposure, respectively. Conclusions: We demonstrated that 4 days following a single neonatal oral exposure to α-, γ-, and CM-HBCD resulted in different serum metabolomic profiles, indicating stereoisomer- and mixture-specific effects and possible mechanisms of action. © 2017, Public Health Services, US Dept of Health and Human Services. All rights reserved.
Pikas J.,Technical Integrity
NACE - International Corrosion Conference Series | Year: 2017
Due to metallurgical improvements in the steel industry, higher strength steels have made significant strides in: specified minimum yield strength (SMYS), wall thickness control, toughness, weight per foot, etc. However, one significant factor in these improvements was "no consideration for corrosion allowances". Corrosion allowances in steel have decreased with every incremental increase in the improvements of making of higher strength steels. Corrosion in carbon steel is the same whether it is a 35,000-yield pipe or an 80,000-yield pipe; or 0.375" wall thickness versus 0.215" wall thickness. Example: a 36.8 % wall loss on 35,000 yield pipe results in a 73.6 % loss on higher strength steel pipe. Lower strength steel direct assessments can result in recoat type repairs, while higher strength steels may result in composite repairs or replacement. Unfortunately, the US coating industry and pipeline operators have not addressed these changes to offset or compliment the improvements made in higher strength steel. To address the dilemma, either add more corrosion allowances to the steel, improve coatings or do both. Coatings are supposed to be the first line of defense against corrosion, while cathodic protection is secondary. Is this really occurring? The findings of direct examination digs appear to show otherwise. © 2017 by NACE International.
Podlaha J.,Technical Integrity
Radwaste Solutions | Year: 2010
The Czech Republic became a pilot country to carry out a shipment from the NRI to the Russian Federation by means of specially developed casks, which are compatible with both the technology of Russian-designed research reactors and the technology of the reprocessing plant/n the Russian Federation. The crane and lift fixtures are equipped with a digital dynamometer that is used to monitor the weight of the basket during reinstallation into the cask. It prevents the disruption of the central suspension/hanger. The VPVR/M cask underwent three demonstrations to verify that the design was acceptable technically for handling and loading spent fuel at the research reactor facilities and for receiving and unloading at the Mayak facilities in the Russian Federation. NRI is participating in shipments of SNF from other countries within the framework of the GTRI program.
Liu Q.,Defence Science and Technology Organisation, Australia |
Janardhana M.,Technical Integrity |
Hinton B.,Monash University |
Brandt M.,RMIT University |
And 2 more authors.
International Journal of Structural Integrity | Year: 2011
Purpose The purpose of this paper is to demonstrate the preliminary work on using laser cladding technology for the restoration of structural integrity. Design/methodology/approach The primary methodology used in this research is to develop a laser cladding-based metal deposition technique to articulate restoration of structural geometry affected by corrosion damages. Following from this method, it is planned to undertake further work to use the laser cladding process to restore geometry and the associated static/fatigue strength. Findings This work has found that it is possible to use laser cladding as a repair technology to improve structural integrity in aluminium alloy aircraft structures in terms of corrosion reduction and geometrical restoration. Initial results have indicated a reduction of static and fatigue resistance with respect to substrate. But more recent works (yet to be published) have revealed improved fatigue strength as measured in comparison to the substrate structural properties. Originality/value The research is based on an acceptable materials processing technique. © 2011 Emerald Group Publishing Limited. All rights reserved.
Dian J.,Charles University |
Konecny M.,Charles University |
Broncova G.,Institute of Chemical Technology Prague |
Krondak M.,Institute of Chemical Technology Prague |
And 2 more authors.
International Journal of Electrochemical Science | Year: 2013
Electrochemical functionalization of porous silicon surface with polypyrrole via cyclic voltammetry method is presented. Surface morphology and spatial distribution of elements in the porous silicon/polypyrrole layer were inspected using Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy, respectively. Changes of surface chemical composition during electrodeposition were determined by Fourier-transform infrared spectrometry. Porous silicon samples were subsequently tested for selectivity improvement of photoluminescence sensor response in chemical sensors of organic vapors. Combined effect of polarity and size of detected analytes played a decisive role in interaction of analyte with polypyrrole layer and determined modified sensor response of porous silicon/polypyrrole composite. © 2013 by ESG.
Sirnes H.,Technical Integrity |
NACE - International Corrosion Conference Series | Year: 2012
Experience with Black powder in pipelines on the Norwegian Continental Shelf (NCS) is limited to a few pipelines. The cleaning of one of the pipelines has recently started and the analysis of the dust is on-going. Pipeline cleaning or operational pigging is a part of the maintenance program. The business driver for cleaning the pipeline is to be able to perform an inline inspection and avoid under deposit corrosion in the pipeline. 1 First operational cleaning runs after pipeline commissioning gave slurry as the pigging product. Some years later the slurry changed to black powder and caused operational challenges. Due to the low radioactivity (LRA) and the composition of the dust some restrictions for the receiving facility were identified. Modifications at the receiving facilitys have been performed to be able to clean the pipeline in a safe manner. The main business driver for the modifications at the receiving facilities is to ensure an environmentally friendly and safe operation. The dust has not given any problems in daily operation. After the first incident with black powder the Gas Processing Plant installed filter modules to handle the dust in daily operation. Prior to the start of the pipeline cleaning activities, additional filter capacity has been installed in order to ensure a proper protection of the Gas Processing Plant. This paper describes some of the history for the pipeline, the cleaning history, challenges and limitations and the analysis of the dust compared to previous analysis. ©2012 by NACE International.
Ayling J.,Australian Aerospace Aus Aerospace |
Bowler A.,RAAF Base Edinburgh |
Brick G.,Technical Integrity |
Advanced Materials Research | Year: 2014
The AP-3C Orion aircraft is the oldest aircraft in the Royal Australian Air Force (RAAF) inventory. The planned fleet withdrawal has been extended far beyond the original design service objective. Continued safe and effective operation has required the development of a robust ageing aircraft management approach. A fundamental aspect was supplementing the structural certification basis with appropriate standards in the form of fatigue management requirements from Federal Aviation Regulations (FAR) 25.571  and Federal Aviation Administration Advisory Circular (FAA AC) 120-93 . To develop and underpin the ageing aircraft management plan and transition to the supplementary fatigue management standards, the RAAF collaborated with the Original Equipment Manufacturer, Lockheed Martin Aeronautics Company, the United States Navy (USN) and other operators to form the P-3C Service Life Assessment Program (SLAP). This program provided Full Scale Fatigue Test (FSFT) data, associated analyses and analysis tools to support management in accordance with FAR 25.571. An important element of the ageing aircraft management plan included the introduction of a rigorous Safety By Inspection (SBI) maintenance regime to assure structural airworthiness. FAA AC 120-93 requires assessment of structural repairs to determine revised fatigue management and inspection requirements. Often, this information is derived using tailored analysis tools and detailed models on a case-by-case basis. This approach is specialized, expensive and usually occurs after the repair has been designed and installed. To avoid these limitations, the AP- 3C Repair Assessment Manual (RAM)  was developed to provide the repair designer with a design handbook approach to fatigue analysis. In conjunction with some simple Finite Element (FE) models, the RAM supports complete repair analysis prior to an aircraft leaving the maintenance venue. This paper will present the history of the SBI program, the genesis of the RAM and actual examples of assessing structural repairs on the P-3 platform using the RAM. © (2014) Trans Tech Publications, Switzerland.
Ciaraldi S.,Technical Integrity
Proceedings of the 22nd Pipeline Pigging and Integrity Management Conference | Year: 2010
A presentation on risk-based inspection covers the purposes of risk analysis; risk definition for pipelines; probability of failure; pipeline corrosion threats; onshore oil and gas pipeline failure; pipeline integrity management; holistic vs. specific risk assessments; and specific risk ranking examples. This is an abstract of a paper presented at the Pipeline Pigging & Integrity Management Conference (Houston, TX 2/17-18/2010).
Pistora V.,Technical Integrity |
Posta M.,Technical Integrity |
Lauerova D.,Technical Integrity
Nuclear Engineering and Design | Year: 2014
Rector pressure vessel (RPV) is a key component of all PWR and VVER nuclear power plants (NPPs). Assuring its integrity is therefore of high importance. Due to high neutron fluence the RPV material is embrittled during NPP operation. The embrittled RPV may undergo severe loading during potential events of the type of pressurised thermal shock (PTS), possibly occurring in the NPP. The resistance of RPV against fast fracture has to be proven by comprehensive analyses. In most countries (with exception of the USA), proving RPV integrity is based on the deterministic PTS assessment. In the USA, the "screening criteria" for maximum allowable embrittlement of RPV material, which form part of the USA regulations, are based on the probabilistic PTS assessment. In other countries, probabilistic PTS assessment is performed only at research level or as supplementary to the deterministic PTS assessment for individual RPVs. In this paper, description of complete probabilistic PTS assessment for a VVER 1000 RPV is presented, in particular, both the methodology and the results are attached. The methodology corresponds to the Unified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs, "VERLIFE", Version 2008. The main parameters entering the analysis, which are treated as statistical distributions, are as follows:initial value of material reference temperature T0,reference temperature shift ΔT0 due to neutron fluence,neutron fluence,size, shape, position and density of cracks in the RPV wall,fracture toughness of RPV material (Master Curve concept is used). The first step of the analysis consists in selection of sequences potentially leading to PTS, their grouping, establishing their frequencies, and selecting of representative scenarios within all groups. Modified PSA model is used for this purpose. The second step consists in thermal hydraulic analyses of the representative scenarios, with the goal to prepare input data for the structural analyses (pressure and temperature variations in the reactor downcomer). The third step consists in performing structural analyses, covering (deterministic) temperature and stress fields calculations for all representative scenarios, and finally, probabilistic fracture mechanics analyses. The results of the third step analyses are conditional probabilities of initiation of fast fracture for all selected representative scenarios. Combining them with frequencies of all groups, the final value of (unconditional) frequency of initiation of fast fracture of the RPV is established. In this paper, examples of both input data and the results are presented. © 2013 Elsevier B.V.