Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 5 )

2018 ( 10 )

2017 ( 16 )

2016 ( 24 )

Custom range...

Search Results: 1 - 10 of 10580 matches for " Andreas Westendarp "
All listed articles are free for downloading (OA Articles)
Page 1 /10580
Display every page Item
Approaches for Modelling the Residual Service Life of Marine Concrete Structures
Amir Rahimi,Christoph Gehlen,Thorsten Reschke,Andreas Westendarp
International Journal of Corrosion , 2014, DOI: 10.1155/2014/432472
Abstract: This paper deals with the service life design of existing reinforced concrete structures in a marine environment. The general procedure of condition assessment for estimating the residual service life of structures before a repair measure is illustrated. For assessment of the residual service life of structures which have undergone a repair measure a simplified mathematical model of chloride diffusion in a 2-layer system is presented. Preliminary probabilistic calculations demonstrate the effect of various conditions on the residual service life. First studies of the chloride diffusion in a 2-layer system have been conducted using the finite element method. Results of a long-term exposure test are presented to illustrate the performance of two different repair materials. The distribution of residual chlorides after application of a repair material is being studied in laboratory investigations. The residual chlorides migrate from the concrete layer into the new layer immediately after the repair material has been applied to the concrete member. The content and gradient of residual chlorides, along with the thickness and the chloride ingress resistance of both the remaining and the new layer of cover, will determine the residual service life of the repaired structures. 1. Introduction Concrete structures in a marine environment such as locks, dams and bridges are affected by a wide range of degradation phenomena. Chloride-induced corrosion is the decisive aspect in the durability of such structures. Reinforcement corrosion is initiated when a critical chloride content is reached at the surface of the rebars. Chloride contents higher than the critical value can cause disruption of the protective passive layer, leading to corrosion of the rebars. The time required to initiate corrosion depends, apart from some environmental factors, on the properties of the concrete, in particular on its resistance to chloride diffusion. The following period, the propagation period, refers to the evolution of different forms of deterioration after corrosion has been initiated (cracking, spalling, loss of bond between rebars, and concrete and reduction in the rebar cross-section). Although the service life of structures is the sum of these two periods, in most cases the initiation period defines the service life because the propagation period may be very short. A traditional and feasible repair method consists of removing the chloride-contaminated concrete layer and replacing the removed volume by cement-based repair mortars or concretes. The aim of this measure is either to
Economic Growth and a Low Carbon Economy―Does the Earth Suffer from an “Easter Island Syndrome”?  [PDF]
Andreas Oberheitmann
Low Carbon Economy (LCE) , 2011, DOI: 10.4236/lce.2011.24024
Abstract: The history of the Eastern Islands in the Pacific with an increasing over-utilization of natural resources reminds us of the mistakes modern societies are making and the question is obvious whether the Earth is suffering from an Eastern Islands Syndrome, in other words whether the egoism inherent in humans long-term might have fatal consequences for our species homo sapiens. Climate research identified two important phenomena, which should remind us of the Easter Islands: feedbacks and tipping points, i.e. self-accelerating phenomena of global warming and reaching irreversible points of climate change. Only a quick worldwide return to a low carbon economy is able to stabilize global warming on a bearable level. Both, Annex-I countries and Non-Annex-I countries have to contribute to reaching this goal taking their historical, current and future responsibilities into account. A post Kyoto regime based on cumulative per-capita CO2-emission rights and a international emission trading could provide for incentives to achieve a low carbon economy, especially for newly industrialized countries.
Development of a Low Carbon Economy in Wuxi City  [PDF]
Andreas Oberheitmann
American Journal of Climate Change (AJCC) , 2012, DOI: 10.4236/ajcc.2012.12007
Abstract: The development of a Low Carbon Economy is a vital instrument to encounter climate change and take into account the growing challenges of an increasing urbanization in China. Wuxi City in East China’s Jiangsu Province is starting to implement a Low Carbon City Plan for safeguarding a sustainable development of the city until 2020 and beyond. This paper aims at estimating the impact of the Low Carbon City plan for Wuxi’s energy demand and CO2-emissions until 2050. Using an econometric energy supply and demand model to estimate and forecast the Wuxi energy and CO2-balance aggregates until 2050, it compares a scenario without specific Low Carbon City measures to reduce sectoral CO2-intensities to a Low Carbon scenario implementing these measures according to the Low Carbon City Plan until 2020 and beyond. The decomposition of the Kaya-identity reveals that the increase of per capita income has the largest impact on the growth of CO2-emissions and the decrease of energy intensity of Gross Value Added the largest impact on the reduction of CO2-emissions in Wuxi. A decrease of population and CO2-intensity of Primary energy supply only have average contributions. The decrease of energy intensity of Gross Value Added is due to energy efficiency gains in the single economic sectors, but to a large extent due to structural changes of the economy away from energy intensive sectors such as iron and steel, chemical industry or cement industry towards the energy extensive service sectors. A growing residential sector also reduces the industrial share of energy demand. Only following the assumed national trend with a shift from CO2-intensive industries to a CO2-extensive service economy, the Low Carbon goal of a 50% reduction of CO2-intensity of Gross Value Added compared to 2005 cannot be reached in Wuxi. Specific sectoral CO2 -intensity goals have to be successfully observed by the economic sectors in Wuxi, especially by the industry. The promotion of combined heat and power generation also has to contribute to the specific activities in Wuxi.
A Global Solution of the Einstein-Maxwell Field Equations for Rotating Charged Matter  [PDF]
Andreas Georgiou
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.329168
Abstract: A stationary axially symmetric exterior electrovacuum solution of the Einstein-Maxwell field equations was obtained. An interior solution for rotating charged dust with vanishing Lorentz force was also obtained. The two spacetimes are separated by a boundary which is a surface layer with surface stress-energy tensor and surface electric 4-current. The layer is the spherical surface bounding the charged matter. It was further shown, that all the exterior physical quantities vanished at the asymptotic spatial infinity where spacetime was shown to be flat. There are two different sets of junction conditions: the electromagnetic junction conditions, which were expressed in the traditional 3-dimensional form of classical electromagnetic theory; and the considerably more complicated gravitational junction conditions. It was shown that both—the electromagnetic and gravitational junction conditions—were satisfied. The mass, charge and angular momentum were determined from the metric. Exact analytical formulae for the dipole moment and gyromagnetic ratio were also derived. The conditions, under which the latter formulae gave Blackett’s empirical result for rotating stars, were investigated.
The Breakdown of the Traditional Mechanistic Worldview, the Development of Complexity Sciences and the Pretence of Knowledge in Economics  [PDF]
Andreas Liening
Modern Economy (ME) , 2013, DOI: 10.4236/me.2013.44034

This article is an introduction to complexity theory, which will be discussed using the example of economic science. In this context, a short historical overview is intended to demonstrate why the traditional mechanistic worldview persistently remains a part of economic science and how it led to the development of the theory of complex systems, which, for example, can be subsumed under chaos theory. Furthermore, a simple supply and demand model is employed as an example to discuss this new theory and to describe the characteristics of complexity in comparison with the general mechanistic principle. For this purpose, specially designed software is used for the simulation and analysis of selected complex systems.

Growth Theory and Endogenous Human Capital Development: A Contribution to the Theory of Complex Systems  [PDF]
Andreas Liening
Theoretical Economics Letters (TEL) , 2013, DOI: 10.4236/tel.2013.32016

As economic phenomena become increasingly complex, the demands on models to reflect this complexity also increase. Economic growth, for example, which depends on a variety of factors, is such a complex phenomenon. Especially the relevance of human capital development for modern service societies is a significant growth factor. This is, however, considered only in few discussions. In order to represent such complex phenomena, adequate models are needed that go beyond linear approaches. This paper points out that models from the dynamic system theories are well suited to illustrate human capital as a factor of economic growth.

Some Remarks on the Individual Contribution to Climate Change  [PDF]
Andreas Oberheitmann
American Journal of Climate Change (AJCC) , 2013, DOI: 10.4236/ajcc.2013.23020

Climate change is one of the most important challenges of the 21st Century. As greenhouse gas concentration of the atmosphere has reached the 400ppm threshold of a 2°C global warming on 9 May 2013 and irreversible tipping points of the climatic system at some point of time have got even more likely, the question of the individual contribution to climate change becomes more and more virulent. For a long time, the absorption capacity of the environment has been regarded as limitless, and based on this perception, the economic entities used the environment for hundreds of years without constraints. Today, with progress of scientific knowledge, we are now aware of the possible negative impacts of climate change to environmental, economic and social systems on Earth. This awareness, however, did not lead to a significant change of individual behavior, because the perceived individual contribution to both the anthropogenic cause of climate change and its mitigation is still regarded as marginal. To encounter this misperception or diffusion of environmental responsibility, this article presents an alternative calculation of the individual contribution to climate change taking the incremental approach to a tipping point or a 2°C global warming threshold into account.

Synergetics—Fundamental Attributes of the Theory of Self-Organization and Its Meaning for Economics  [PDF]
Andreas Liening
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.58077

The current article will focus on the fundamental idea of synergetics. It addresses the question of how to explain self-organization in a complex system. For this purpose synergetic will be explained with the use of the classic physical example, the laser light. Although the synergetic theory was developed in the field of physics, it is an interdisciplinary approach enabling the general examination of self-organization of complex systems, especially in economic contexts. The so-called swarm intelligence contributes as a bright example from another context. Furthermore, exemplifying for economic application a simple national economy will be interpreted from the synergetic perspective. From an economic perspective, finally the conclusion includes a critical reflection of the approach.

Modern Economization—Only a Burden on Diaconia and Church?  [PDF]
Andreas Pawlas
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.55061

Although Diaconia/Caritas and Protestant/Roman Katholic Churches are large service providers in Germany, they often feel economic thinking as a burden or even a nuisance. It is regarded as something “not authentic” in the aid and assistance to the poor, miserable and needy as successors in the love of Jesus Christ. But economic thinking has to be seen as careful handling of the entrusted goods and is justified in the sense of belief in creation and the “Two Natures Doctrine” of Christ. It must be regarded as an important expression of all the earthly. On the other hand an exclusively economic profit-oriented attitude easily can turn in greed and avarice. And that makes it blind not only for the responsibility to one’s neighbor and but also for essential risks. Therefore many companies went to develop their own “corporate culture”, in which should be deployed the ethical principles of the companies. However in the companies of the Diaconia it is not necessary to develop new ethical principals because diaconal work should be founded in a “culture of charity” of Christianity that creates engaged employees.

The Angular Momenta, Dipole Moments and Gyromagnetic Ratios of the Neutron and the Muon  [PDF]
Andreas Georgiou
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.67104
Abstract: The dipole moments, angular momenta and gyromagnetic ratios of the electron and the proton were obtained earlier. In this note, we derive the corresponding expressions for the neutron and the muon. This work relies on the results obtained earlier for the angular momenta and dipole moments of rotating spherical bodies.
Page 1 /10580
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.