scholarly journals Predicting Changes of the State of a Bridge Reinforced with Concrete Superstructures in View of Operational Changes

2019 ◽  
Vol 29 (3) ◽  
pp. 134-152
Author(s):  
Pavlo Ovchynnykov ◽  
Olha Dubinchyk ◽  
Oleksii Tiutkin ◽  
Vitalii Kildieiev ◽  
Volodymyr Sedin ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Service Life ◽  
Corrosion Rate ◽  
Crack Width ◽  
Laboratory Experiments ◽  
The State ◽  
Reinforcement Corrosion ◽  
Creep Theory ◽  
Corrosion Depth ◽  
Over Time

Abstract To solve the problem of predicting the service life of superstructures, this work proposes the basis and methodological developments of creep theory with increasing loads as well as regression analysis of the results of laboratory experiments. The main limitation in terms of reinforcement is corrosion in the concrete cracks, which was determined during laboratory experiments. Based on the results, the approximate analytical dependences concerning reinforcement corrosion depth change over time at a constant value of crack width were selected. The paper substantiates the validity of the analytical dependences as a result of regression analysis; it proposes formulae for determining the corrosion rate of rebars in reinforced concrete superstructures. The obtained analytical dependences allowed for the developing of a process for predicting changes to the state of the superstructure in light of operational changes.

Biocorrosion research: Are we barking up the right trees?

2020 ◽  
Author(s):  
Hans-Curt Flemming ◽  
Brenda Little ◽  
Dan Blackwood ◽  
Jamie Hinks ◽  
Federico Lauro ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Laboratory Experiments ◽  
Review Paper ◽  
The State ◽  
Microbially Influenced Corrosion ◽  
Corrosion Science ◽  
The Right ◽  
State Of Art ◽  
Made In

<p>Microbially influenced corrosion (MIC), is acknowledged to be the direct cause of catastrophic corrosion failures, with damages ranging to many billions of US$. In spite of extensive research and numerous publications, fundamental questions still remain unanswered. In 1993, J.F.D. Stott published a review paper in Corrosion Science, entitled “What progress in the understanding of microbially influenced corrosion has been made in the last 25 years?“ He concluded, “The most commonly asked question about MIC is: what will be the expected corrosion rate of material x in an environment where aggressive microorganisms proliferate?... For many materials we can no more answer this question now than we could 25 years ago.” Now, over 50 years later, that question is still open. Current MIC research does not provide data related to detection and verification in the field, diagnosing, modelling or prediction. Laboratory experiments seldom attempt to recreate relevant natural or industrial electrolytes. A sober, solution-oriented contemplation of the state-of-art and acknowledgement of the substantial deficiencies in our understanding may help shift MIC research into a direction which could actually produce useful answers.</p>

Prediction of Crack Width of Chloride Contaminated Reinforced Concrete Structures

2006 ◽  
Vol 302-303 ◽  
pp. 610-617
Author(s):  
Jia Jin Zheng ◽  
Xin Zhu Zhou ◽  
Shi Lang Xu
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Corrosion Rate ◽  
Crack Width ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Cover Depth ◽  
Steel Bar ◽  
Bar Diameter ◽  
Chloride Contaminated

Crack width is a significant parameter for assessing service life of reinforced concrete structures in chloride-laden environments. Corrosion-induced concrete cracking is a predominant causal factor influencing premature degradation of reinforced concrete structures, incurring considerable costs for repairs and inconvenience to the public due to interruptions. This gives rise to the need for accurate prediction of crack width in order to achieve cost-effectiveness in maintaining serviceability of concrete structures. It is in this regard that the present paper attempts to develop a quasi-brittle mechanical model to predict crack width of chloride contaminated concrete structures. Assuming that cracks be smeared uniformly in all directions and concrete be a quasi-brittle material, the displacement and stress in a concrete cover, before and after surface cracking, were derived respectively in an analytical manner. Crack width, as a function of the cover depth, steel bar diameter, corrosion rate and time, was then determined. Finally, the analysis results were verified by comparing the solution with the experimental results. The effects of the cover depth, steel bar diameter and corrosion rate on the service life were discussed in detail.

Opponent Center-Surround Contrast: Colour to Grey Conversion

2020 ◽  
Vol 2020 (1) ◽  
pp. 105-108
Author(s):  
Ali Alsam
Keyword(s):  
Evolutionary Algorithms ◽  
Three Dimensional ◽  
The State ◽  
Colour Space ◽  
Vision Science ◽  
State Of Art ◽  
Over Time

Vision is the science that informs us about the biological and evolutionary algorithms that our eyes, opticnerves and brains have chosen over time to see. This article is an attempt to solve the problem of colour to grey conversion, by borrowing ideas from vision science. We introduce an algorithm that measures contrast along the opponent colour directions and use the results to combine a three dimensional colour space into a grey. The results indicate that the proposed algorithm competes with the state of art algorithms.

Environmentalists, Nuclear Waste, and the Politics of Passive Exclusion in Germany

2001 ◽  
Vol 19 (4) ◽  
pp. 43-63 ◽  
Author(s):  
Christian Hunold
Keyword(s):  
Public Policy ◽  
Public Sphere ◽  
Nuclear Waste ◽  
Environmental Movement ◽  
The State ◽  
Radioactive Wastes ◽  
Liberal Democratic ◽  
Democratic State ◽  
Ecological Democracy ◽  
Over Time

In this essay I examine the dispute between the German GreenParty and some of the country’s environmental nongovernmentalorganizations (NGOs) over the March 2001 renewal of rail shipmentsof highly radioactive wastes to Gorleben. My purpose indoing so is to test John Dryzek’s 1996 claim that environmentalistsought to beware of what they wish for concerning inclusion in theliberal democratic state. Inclusion on the wrong terms, arguesDryzek, may prove detrimental to the goals of greening and democratizingpublic policy because such inclusion may compromise thesurvival of a green public sphere that is vital to both. Prospects forecological democracy, understood in terms of strong ecologicalmodernization here, depend on historically conditioned relationshipsbetween the state and the environmental movement that fosterthe emergence and persistence over time of such a public sphere.

Introduction

2018 ◽  
Author(s):  
Christine Cheng
Keyword(s):  
Theoretical Framework ◽  
Political Authority ◽  
The State ◽  
Dual Nature ◽  
For Profit ◽  
Business Interests ◽  
Local Populations ◽  
Post Conflict ◽  
Over Time ◽  
Commercial Environment

This chapter introduces the concept of extralegal groups and a theoretical framework for analyzing them—how they emerge, develop, and become entrenched over time. It explores their dual nature as threats to the state and as local statebuilders. Formally, an extralegal group is defined as a set of individuals with a proven capacity for violence who work outside the law for profit and provide basic governance functions to sustain its business interests. This framing shows how political authority can develop as a by-product of the commercial environment, even where the state has little or no presence. In post-conflict societies, the predatory nature and historical abuses of citizens conducted in the name of the state means that government is not always more trusted or better able to look after the interests of local populations than an extralegal group. Ultimately, extralegal groups blur the lines between the formal and informal; the licit and illicit.

scholarly journals The Impact of B Corp Certification on Growth

2021 ◽  
Vol 13 (13) ◽  
pp. 7191
Author(s):  
Valerie Paelman ◽  
Philippe Van Cauwenberge ◽  
Heidi Vander Bauwhede
Keyword(s):  
Regression Analysis ◽  
Propensity Score ◽  
Panel Regression ◽  
Medium Term ◽  
Difference In Differences ◽  
Dual Purpose ◽  
Full Effect ◽  
The Impact ◽  
Positive Effect ◽  
Over Time

We empirically test whether B Corp certification affects the short- and medium-term growth rates of sustainable enterprises. These businesses are growing in popularity and prevalence but, due to their hybrid nature, often suffer from external credibility issues and competing internal logics. Because of the rigorous and time-involving audit procedure, B Corp certification potentially sends a credible signal about the sustainable nature of the enterprise to its stakeholders. In addition, the B Corp label could help to straighten out internal tensions and align the company towards its dual purpose. Hence, B Corp certification could contribute to company success. We observe 129 firms that were certified between 2013 and 2018 over a period between six years prior and five years post-certification. Using propensity score matching, we identify 129 non-certified matching companies. On this sample, we conduct a difference-in-differences panel regression analysis to investigate the effect of certification. Our dataset allows us to study how the effects of B Corp certification evolve over time, which was previously untested. Our study documents a positive effect of B Corp certification on turnover growth and also that this effect increases with the time since certification, implying that certification requires some time for its full effect to become apparent.

Canadian Exceptionalism: Explaining Differences over Time in Provincial and Federal Voter Turnout

2001 ◽  
Vol 34 (2) ◽  
pp. 299-319 ◽  
Author(s):  
Donley T. Studlar
Keyword(s):  
Regression Analysis ◽  
Population Density ◽  
Multiple Regression Analysis ◽  
Voter Turnout ◽  
The Political ◽  
Federal Level ◽  
Industrial Democracies ◽  
Different Types ◽  
Over Time ◽  
Cross National

Canada is unusual among advanced industrial democracies in having some provinces which regularly have greater voter turnouts for provincial than for federal elections. Provincial and federal turnouts by province in Canada are analyzed for the 1945-1998 period using multiple regression analysis, both for each set of elections and by comparing differences between the two. Federal turnout has declined over the years but provincial turnout appears to have increased slightly. Although the effects found here largely confirm previous findings about the relative effects of different types of variables found for the Canadian federal level only, several of the political explanations previously supported in cross-national research find less support. Instead, region, population density, months since the last federal or provincial election, and season of the year generally have greater and sometimes more consistent effects. This suggests the need for more studies of turnout in democracies at sub-central levels.

Belief Movement, Uncertainty Reduction, and Rational Updating*

2021 ◽  
Author(s):  
Ned Augenblick ◽  
Matthew Rabin
Keyword(s):  
Statistical Tests ◽  
Uncertainty Reduction ◽  
The State ◽  
Data Sets ◽  
New Information ◽  
The World ◽  
Core Concepts ◽  
Market Beliefs ◽  
Over Time

Abstract When a Bayesian learns new information and changes her beliefs, she must on average become concomitantly more certain about the state of the world. Consequently, it is rare for a Bayesian to frequently shift beliefs substantially while remaining relatively uncertain, or, conversely, become very confident with relatively little belief movement. We formalize this intuition by developing specific measures of movement and uncertainty reduction given a Bayesian’s changing beliefs over time, showing that these measures are equal in expectation and creating consequent statistical tests for Bayesianess. We then show connections between these two core concepts and four common psychological biases, suggesting that the test might be particularly good at detecting these biases. We provide support for this conclusion by simulating the performance of our test and other martingale tests. Finally, we apply our test to data sets of individual, algorithmic, and market beliefs.

The Effect of Cracks on Chloride Penetration into Concrete

2007 ◽  
Vol 348-349 ◽  
pp. 769-772 ◽  
Author(s):  
In Seok Yoon ◽  
Erik Schlangen ◽  
Mario R. de Rooij ◽  
Klaas van Breugel
Keyword(s):  
Service Life ◽  
Crack Length ◽  
Significant Influence ◽  
Crack Width ◽  
Chloride Transport ◽  
Crack Depth ◽  
Chloride Penetration ◽  
Critical Crack ◽  
Chloride Migration ◽  
Migration Testing

This study is focused on examining the effect of critical crack width in combination with crack depth on chloride penetration into concrete. Because concrete structures have to meet a minimum service-life, critical crack width has become an important parameter. Specimens with different crack width / crack length have been subjected to rapid chloride migration testing (RCM). The results of this study show a critical crack width of about 0.012 mm. Cracks smaller than this critical crack width are considered not to have a significant influence on the rate of chloride transport inwards, while chloride penetration does proceed faster above this critical crack width.

On the State of Genre/Form Vocabulary: A Quantitative Analysis of LCGFT Data in WorldCat

2021 ◽  
Vol 65 (2) ◽  
pp. 52
Author(s):  
Colin Bitter ◽  
Yuji Tosaka
Keyword(s):  
Quantitative Analysis ◽  
Detailed Analysis ◽  
The State ◽  
Bibliographic Databases ◽  
Moderate Increase ◽  
Large Set ◽  
Library Of Congress ◽  
Bibliographic Data ◽  
Innovative Solutions ◽  
Over Time

The purpose of this paper is to report on a quantitative analysis of the LCGFT vocabulary within a large set of MARC bibliographic data retrieved from the OCLC WorldCat database. The study aimed to provide a detailed analysis of the outcomes of the LCGFT project, which was launched by the Library of Congress (LC) in 2007. Findings point to a moderate increase in LCGFT use over time; however, the vocabulary has not been applied to the fullest extent possible in WorldCat. Further, adoption has been inconsistent between the various LCGFT disciplines. These and other findings discussed here suggest that retrospective application of the vocabulary using automated means should be investigated by catalogers and other technical services librarians. Indeed, as the data used for the analysis show somewhat uneven application of LCGFT, and with nearly half a billion records in WorldCat, it remains a certainty that much of LCGFT’s full potentials for genre/form access and retrieval will remain untapped until innovative solutions are introduced to further increase overall vocabulary usage in bibliographic databases.

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