Chemical Durability of Copper Canisters Under Crystalline Bedrock Repository Conditions

1994 ◽  
Vol 353 ◽  
Author(s):  
Rolf Sjöblom ◽  
Hans-Peter Hermansson ◽  
Örjan Amcoff
Keyword(s):  
Copper Surface ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Near Surface ◽  
Crystalline Bedrock ◽  
Reducing Conditions ◽  
Bentonite Buffer ◽  
Long Time ◽  
The Stability ◽  
High Chloride

AbstractIn the Swedish waste management programme, the copper canister is expected to provide containment of the radionuclides for a very long time, perhaps millions of years. The purpose of the present paper, is to analyse prerequisites for assessments of corrosion lifetimes for copper canisters.The analysis is based on compilations of literature from the following areas: chemical literature on copper and copper corrosion, mineralogical literature with emphasis on the stability of copper in near surface environments, and chemical and mineralogical literature with emphasis on the stabilities and thermodynamics of species and phases that may exist in a repository environment.Three main types of situations are identified: (1) under oxidizing and low chloride conditions, passivating oxide type of layers may form on the copper surface; (2) under oxidizing and high chloride conditions, the species formed may all be dissolved; and (3) under reducing conditions, non-passivating sulfide type layers may form on the copper surface.Considerable variability and uncertainty exists regarding the chemical environment for the canister, especially in certain scenarios. Thus, the mechanisms for corrosion can be expected to differ greatly for different situations. The lifetime of a thick-walled copper canister subjected to general corrosion appears to be long for most reasonable chemistries. (It is assumed that the canister has no defects from manufacturing and that the bentonite buffer is intact). Localized corrosion may appear for types (1) and (3) above but the mechanisms are widely different in character. The penetration caused by localized corrosion can be expected to be very sensitive to details in the chemistry.

Thin-Wall Titanium Condenser Tubing: The Next Plateau

2002 ◽  
Author(s):  
Dennis J. Schumerth
Keyword(s):  
Performance Enhancement ◽  
Cost Savings ◽  
Further Education ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Thin Wall ◽  
Reducing Conditions ◽  
And Performance ◽  
Data Elements ◽  
Considerable Work

Commercially pure (cp.) titanium and its alloys provide excellent resistance to general and localized corrosion attack under most oxidizing, neutral and inhibited reducing conditions in aqueous environments. Titanium is also notable for its outstanding resistance to chlorides and other halides generally present in most process streams. In addition, titanium resists other malicious phenomenon including steam and particle erosion, crevice corrosion, galvanic attack and MIC. Given this general corrosion immunity, designers have increasingly applied thin-wall condenser tubing in pursuit of cost savings and performance enhancement. Typically, these thin-wall applications have, over the past several years, been limited to 25 BWG or 0.020”/0.5mm walls or heavier. The “industry” has, out of necessity, moved to address the special nuances of the 25 BWG including design, procurement, handling, fabrication and testing parameters with increasing success. It would appear however, that designers, operators and pundits alike require further education and refinement on the specific operational characteristics when integrated into the powerplant environment. Considerable work has been recently completed investigating even thinner wall titanium tubing. This paper will address the essential data elements of this expanded research focusing specifically on Grade 2 titanium in 27 BWG or 0.016”/0.4mm. Since a significant portfolio of 27 BWG installations is rapidly taking shape, it is prudent to examine key ingredients that would warrant consideration of this “next-plateau” gauge material. Indeed, work is currently underway exploring the technology required to fabricate condenser tubes as thin as 30 BWG /0.013”/0.3 mm.) In summary, the paper will present and summarize substantive evidence suitable for comparison against previously acquired empirical data and prior art.

Sustainability and adaptability of regional development in the conditions of digitalization

2020 ◽  
Vol 19 (9) ◽  
pp. 1550-1613
Author(s):  
O.E. Akimova ◽  
S.K. Volkov ◽  
E.A. Gladkaya ◽  
I.M. Kuzlaeva
Keyword(s):  
Sustainable Development ◽  
Regional Development ◽  
Economic Behavior ◽  
Regional Inequality ◽  
Environmental Damage ◽  
Economic Potential ◽  
Human Welfare ◽  
Long Time ◽  
The Stability ◽  
Smart Technologies

Subject. The article discusses the sustainability of regional economy development, its definition, and the substance of sustainable development. Objectives. We aim at performing a comprehensive analysis of indicators of sustainability and adaptability of regional development in the context of digitalization, formulating a strategy for economic behavior that takes into account the multidimensional nature of regional inequality and is focused on boosting the economic potential of regions. Methods. The study draws on dialectic and systems approaches, general scientific methods of retrospective, situational, economic and statistical, and comparative analysis. Results. The sustainability of the region focuses on improving the human welfare over long time horizon. This happens in three areas, i.e. maximizing the efficiency of resource use; ensuring justice and democracy; minimizing resource consumption and environmental damage. The stability of the region can be assessed by using one parameter, or by combining the parameters in accordance with the type of region and expected results. Conclusions. The adaptation of a region to changing conditions depends on its type (‘adapted’, ‘adaptive’, and ‘non-adapted’). Regional inequality has two main components: difference in economic potential and social satisfaction of residents. Another component, affecting the stability and adaptability of regions, is the level of their digitalization. However, some regions have only formally embarked on the path of digitalization. Moreover, a focus on smart technologies, solutions and digitalization often leads to ignoring the goals of sustainable development. Smart technologies should be aimed at ensuring sustainability within the framework of the smart sustainable city concept.

scholarly journals Climate Change and Internet of Things Technologies—Sustainable Premises of Extending the Culture of the Amurg Cultivar in Transylvania—A Use Case for Târnave Vineyard

2021 ◽  
Vol 13 (15) ◽  
pp. 8170
Author(s):  
Veronica Sanda Chedea ◽  
Ana-Maria Drăgulinescu  ◽  
Liliana Lucia Tomoiagă  ◽  
Cristina Bălăceanu ◽  
Maria Lucia Iliescu 
Keyword(s):  
Climate Change ◽  
Weather Conditions ◽  
White Wine ◽  
Time Investment ◽  
Protected Designation Of Origin ◽  
Average Annual Temperature ◽  
Insect Infestations ◽  
Long Time ◽  
The Stability ◽  
Red Grape

Known for its dry and semi-dry white wine, the Târnave vineyard located in central Transylvania is challenged by the current climate change, which has resulted in an increase of the period of active vegetation by approximately 15–20 days, the average annual temperature by 1–1.5 °C and also the amount of useful temperatures (useful thermal balance for the grapevine). Furthermore, the frost periods have been reduced. Transylvania is an important Romanian region for grapevine cultivation. In this context, one can use the climatic changes to expand their wine assortment by cultivating an autochthonous grapevine variety called Amurg. Amurg is a red grape cultivar homologated at SCDVV Blaj, which also homologated 7 cultivars and 11 clones. Because viticulture depends on the stability of meteorological and hydrological parameters of the growing area, its foundations are challenged by climate change. Grapevine production is a long time investment, taking at least five years before the freshly planted vines produce the desired quality berries. We propose the implementation of a climate change-based precision viticulture turn-key solution for environmental monitoring in the Târnave vineyard. This solution aims to evaluate the grapevine’s micro-climate to extend the sustainable cultivation of the Amurg red grapes cultivar in Transylvania with the final goal of obtaining Protected Designation of Origin (PDO) rosé and red wines from this region. Worldwide, the changing conditions from the existing climate (a 30-year average), used in the past hundred years to dictate local standards, such as new and erratic trends of temperature and humidity regimes, late spring freezes, early fall frosts, storms, heatwaves, droughts, area wildfires, and insect infestations, would create dynamic problems for all farmers to thrive. These conditions will make it challenging to predict shifts in each of the components of seasonal weather conditions. Our proposed system also aims to give a solution that can be adapted to other vineyards as well.

Distribution of Acidity and Alkalinity on Degraded Manuscripts Containing Iron Gall Ink

2015 ◽  
Vol 36 (3) ◽  
Author(s):  
Eva Marín ◽  
Maria Carme Sistach ◽  
Jessica Jiménez ◽  
Miguel Clemente ◽  
Guillem Garcia ◽  
...  
Keyword(s):  
Good Condition ◽  
Degradation Process ◽  
Degradation Processes ◽  
Alkaline Reserve ◽  
Hydrolysis Of Cellulose ◽  
Relevant Variables ◽  
Long Time ◽  
Iron Gall ◽  
The Stability

AbstractLong-time preservation of manuscripts depends on the stability of their support. One of the most important degradation processes of paper manuscripts containing iron gall ink is the acid hydrolysis of cellulose. The heterogeneity of the distribution of their constituent materials, together with the defined position of ink as a source of degradation agents, makes it difficult to obtain reliable and detailed information about degradation processes. The aim of this study is to contribute to the knowledge of the acid degradation process by looking at the distribution of relevant variables (pH, acidity and alkaline reserve) on real untreated iron gall ink containing manuscripts at different degradation stages. The study discusses the well-known differences between surface and cold extraction pH determination. It corroborates the relationship between pH, acidity and alkalinity and degradation stages, pointing out that acidity values for some manuscripts in apparent good condition are not far from those obtained for degraded manuscripts. The results indicate that in some partially degraded manuscripts, the coexistence of acid areas and areas with an alkaline reserve which do not participate in the neutralization process is possible. The role of water as a solvent for this equilibrium has also been evaluated.

scholarly journals Analysis of Urban Effects in Oklahoma City using a Dense Surface Observing Network

2016 ◽  
Vol 55 (3) ◽  
pp. 723-741 ◽  
Author(s):  
Xiao-Ming Hu ◽  
Ming Xue ◽  
Petra M. Klein ◽  
Bradley G. Illston ◽  
Sheng Chen
Keyword(s):  
Metropolitan Area ◽  
Land Surface ◽  
Critical Role ◽  
Central Business District ◽  
Temperature Inversion ◽  
Oklahoma City ◽  
Near Surface ◽  
Open Questions ◽  
The Stability ◽  
Business District

AbstractMany studies have investigated urban heat island (UHI) intensity for cities around the world, which is normally quantified as the temperature difference between urban location(s) and rural location(s). A few open questions still remain regarding the UHI, such as the spatial distribution of UHI intensity, temporal (including diurnal and seasonal) variation of UHI intensity, and the UHI formation mechanism. A dense network of atmospheric monitoring sites, known as the Oklahoma City (OKC) Micronet (OKCNET), was deployed in 2008 across the OKC metropolitan area. This study analyzes data from OKCNET in 2009 and 2010 to investigate OKC UHI at a subcity spatial scale for the first time. The UHI intensity exhibited large spatial variations over OKC. During both daytime and nighttime, the strongest UHI intensity is mostly confined around the central business district where land surface roughness is the highest in the OKC metropolitan area. These results do not support the roughness warming theory to explain the air temperature UHI in OKC. The UHI intensity of OKC increased prominently around the early evening transition (EET) and stayed at a fairly constant level throughout the night. The physical processes during the EET play a critical role in determining the nocturnal UHI intensity. The near-surface rural temperature inversion strength was a good indicator for nocturnal UHI intensity. As a consequence of the relatively weak near-surface rural inversion, the strongest nocturnal UHI in OKC was less likely to occur in summer. Other meteorological factors (e.g., wind speed and cloud) can affect the stability/depth of the nighttime boundary layer and can thus modulate nocturnal UHI intensity.

scholarly journals Modeling early in situ wetting of a compacted bentonite buffer installed in low permeable crystalline bedrock

2016 ◽  
Vol 52 (8) ◽  
pp. 6207-6221 ◽  
Author(s):  
B. Dessirier ◽  
A. Frampton ◽  
Å. Fransson ◽  
J. Jarsjö
Keyword(s):  
Compacted Bentonite ◽  
Crystalline Bedrock ◽  
Bentonite Buffer

scholarly journals Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Fluoride Concentration ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Nacl Solution ◽  
Galvanic Coupling ◽  
Beta Titanium

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

The Compliance Method for Measurement of Near Surface Residual Stresses—Analytical Background

1994 ◽  
Vol 116 (4) ◽  
pp. 550-555 ◽  
Author(s):  
M. Gremaud ◽  
W. Cheng ◽  
I. Finnie ◽  
M. B. Prime
Keyword(s):  
Numerical Simulation ◽  
Residual Stresses ◽  
Random Errors ◽  
Residual Stress Field ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Zero Shift ◽  
Stress States ◽  
The Stability ◽  
Piecewise Functions

Introducing a thin cut from the surface of a part containing residual stresses produces a change in strain on the surface. When the strains are measured as a function of the depth of the cut, residual stresses near the surface can be estimated using the compliance method. In previous work, the unknown residual stress field was represented by a series of continuous polynomials. The present paper shows that for stress states with steep gradients, superior predictions are obtained by using “overlapping piecewise functions” to represent the stresses. The stability of the method under the influence of random errors and a zero shift is demonstrated by numerical simulation.

Effects of Stress and Plastic Deformation on the Corrosion of Steel

CORROSION ◽  
1970 ◽  
Vol 26 (5) ◽  
pp. 189-199 ◽  
Author(s):  
W. D. FRANCE
Keyword(s):  
Plastic Deformation ◽  
Electrochemical Techniques ◽  
Chloride Ions ◽  
Localized Corrosion ◽  
Dissolution Behavior ◽  
Potential Range ◽  
Chemical Corrosion ◽  
Effects Of Ph ◽  
Current Densities ◽  
The Stability

Abstract The rate and type of corrosion exhibited by mild steel in the annealed, stressed, and plastically deformed state have been investigated. Precise electrochemical techniques provided potential and polarization data to supplement the results of chemical corrosion tests. Experiments were conducted in 0.6M NH4NO3 solutions in which steel exhibits active-passive dissolution behavior as well as localized corrosion. At active potentials, the anodic polarization curves for annealed and deformed specimens were nearly identical, with only slight increases in current densities for the deformed steel. Results at passive potentials demonstrated that increased plastic deformation can markedly decrease the passive potential range, the stability of passivity, and the ability to passivate. At certain passive potentials, the deformed steel exhibited current densities that were 400 times greater than those for annealed steel. The effects of pH, chloride ions, and crevices on the corrosion of deformed steel were examined in detail. The differences between the dissolution behavior of annealed and deformed steel were most distinctive in the approximate pH range of 3 to 6. This work is relevant to the understanding of the initiation of localized corrosion and to anodic protection.

The stability of the stratospheric ozone layer during the end-Permian eruption of the Siberian Traps

2007 ◽  
Vol 365 (1856) ◽  
pp. 1843-1866 ◽  
Author(s):  
David J Beerling ◽  
Michael Harfoot ◽  
Barry Lomax ◽  
John A Pyle
Keyword(s):  
Organic Matter ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Ultraviolet B ◽  
Large Reservoir ◽  
Near Surface ◽  
Siberian Traps ◽  
Northern Latitudes ◽  
The Stability ◽  
Mutagenic Effects

The discovery of mutated palynomorphs in end-Permian rocks led to the hypothesis that the eruption of the Siberian Traps through older organic-rich sediments synthesized and released massive quantities of organohalogens, which caused widespread O 3 depletion and allowed increased terrestrial incidence of harmful ultraviolet-B radiation (UV-B, 280–315 nm; Visscher et al . 2004 Proc. Natl Acad. Sci. USA 101 , 12 952–12 956). Here, we use an extended version of the Cambridge two-dimensional chemistry–transport model to evaluate quantitatively this possibility along with two other potential causes of O 3 loss at this time: (i) direct effects of HCl release by the Siberian Traps and (ii) the indirect release of organohalogens from dispersed organic matter. According to our simulations, CH 3 Cl released from the heating of coals alone caused comparatively minor O 3 depletion (5–20% maximum) because this mechanism fails to deliver sufficiently large amounts of Cl into the stratosphere. The unusual explosive nature of the Siberian Traps, combined with the direct release of large quantities of HCl, depleted the model O 3 layer in the high northern latitudes by 33–55%, given a main eruptive phase of less than or equal to 200 kyr. Nevertheless, O 3 depletion was most extensive when HCl release from the Siberian Traps was combined with massive CH 3 Cl release synthesized from a large reservoir of dispersed organic matter in Siberian rocks. This suite of model experiments produced column O 3 depletion of 70–85% and 55–80% in the high northern and southern latitudes, respectively, given eruption durations of 100–200 kyr. On longer eruption time scales of 400–600 kyr, corresponding O 3 depletion was 30–40% and 20–30%, respectively. Calculated year-round increases in total near-surface biologically effective (BE) UV-B radiation following these reductions in O 3 layer range from 30–60 (kJ m −2  d −1 ) BE up to 50–100 (kJ m −2  d −1 ) BE . These ranges of daily UV-B doses appear sufficient to exert mutagenic effects on plants, especially if sustained over tens of thousands of years, unlike either rising temperatures or SO 2 concentrations.

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