Ganzheitliche Wirtschaftlichkeitsbetrachtungen bei Verbundbrücken unter Berücksichtigung des Bauverfahrens und der Nutzungsdauer

Economic efficiency of composite bridges in consideration of the construction procedures and the life‐cycle‐costs. This abstract deals with various possibilities of economic investigations of different bridge constructions. Not only manufacturing costs are examined, but a complete view of all arising costs in service, maintenance and reconstruction are included. Within the comparison different construction methods the total lifetime costs are evaluated and investigated. With this investigation a basis is created where beyond the pure consideration of the manufacturing costs, cost offers can be valued and different criteria for the evaluation of buildings are given. This report is based on an expertise which has been compiled on behalf of the Hessian Road and Traffic Administration in the frame of the major project Traffic Congestion Free Hessen 2015.     

Empfehlungen des Arbeitskreises 6.1 “Geotechnik der Deponiebauwerke” der Deutschen Gesellschaft für Geotechnik e., V. (DGGT)

Recommendations of the DGGT Committee “Geotechnics of Landfill Structures”. The Committee “Geotechnics of Landfill Structures” published up to now 76 recommendations. The series is continued by the fundamentally revised recommendation E2‐36 “Capping Systems with Geosynthetic Clay Liners”, published in 2001 as first edition. Recent results of research as well as experiences of practicing engineers with planning, construction and monitoring of such liners are considered in this new edition.     

Combined Raman and dielectric spectroscopy on the curing behaviour and stress build up of carbon nanotube–epoxy composites

Single-walled carbon nanotubes (SWCNT) were incorporated into different epoxy matrices to monitor the internal stresses arising from the curing process. The curing reaction of the neat and SWCNT-modified epoxies was investigated by differential scanning calorimetry and parallel-plate rheometry. In situ Raman spectroscopy and electrical conductivity measurements were performed in parallel and the ongoing changes at both spectra were interpreted in terms of evolving stresses. Preliminary investigations were necessary to analyse the temperature dependence of the SWCNT Raman spectra, and its contribution to the overall shifts observed at the curing experiments. Thermal compressive strains were found to develop in the samples only below their glass transition temperature, pointing at a stress releasing effect above it. Chemical shrinkage effects were found to be negligible, or at least undetectable with our technique, in comparison to the temperature-induced Raman shifts.     

Dependence analysis for outer loop parallelization of existing Fortran-77 programs

We have used six static parallelization tools on four Fortran-77 programs used in physics simulations. We indicate areas where current tools have difficulties in recognizing parallelism, and illustrate these issues with simple examples. We suggest that a dynamic dependency analysis tool is needed to aid the user in the parallelization of dusty decks.     

Dyeing behaviour of aqueous solutions of dispersant–free disperse dyes in the high–temperature dyeing of polyester (Part 2)

High–temperature dyeing of polyester with true solutions of crude dyes and dispersant–free disperse dyes dissolved in the presence of a surfactant mixture has been simulated with the help of two mathematical models. The dyeing behaviour, i. e. the kinetics of exhaustion and of dye distribution in the fibre have been evaluated for nine hypothetical dyes. In the first method kinetics of hypothetical crystalline modifications of three Terasil dyes and in the second method for hypothetical surfactants have been studied. For both methods the laws governing the dyeing behaviour have been formulated. The advantages and disadvantages of the methods and the scope for implementing them are discussed.     

Atom Transfer Radical Polymerization of Pyrrole-Bearing Methacrylate for Production of Carbonyl Iron Particles with Conducting Shell for Enhanced Electromagnetic Shielding

The conducting polymer poly(2-(1H-pyrrole-1-yl)ethyl methacrylate (PPEMA) was synthesized by conventional atom transfer radical polymerization for the first time from free as well as surface-bonded alkyl bromide initiator. When grafted from the surface of carbonyl iron (CI) a substantial conducting shell on the magnetic core was obtained. Synthesis of the monomer as well as its polymer was confirmed using proton spectrum nuclear magnetic resonance (¹H NMR). Polymers with various molar masses and low dispersity showed the variability of this approach, providing a system with a tailorable structure and brush-like morphology. Successful grafting from the CI surface was elucidate by transmission electron microscopy and Fourier-transform infrared spectroscopy. Very importantly, thanks to the targeted nanometer-scale shell thickness of the PPEMA coating, the magnetization properties of the particles were negligibly affected, as confirmed using vibration sample magnetometry. Smart elastomers (SE) consisting of bare CI or CI grafted with PPEMA chains (CI-PPEMA) and silicone elastomer were prepared and dynamic mechanical properties as well as interference shielding ones were investigated. It was found that short polymer chains grafted to the CI particles exhibited the plasticizing effect, which might be interesting from the magnetorheological point of view, and more interestingly, in comparison to the neat CI-based sample, it provided enhanced electromagnetic shielding of nearly 30 dB in thickness of 500 μm. Thus, SE containing the newly synthesized CI-PPEMA hybrid particles also exhibited considerably enhanced damping factor and proper mechanical performance, which make the material highly promising from various practical application points of view.     

Learning-Assisted Automated Reasoning with Flyspeck

The considerable mathematical knowledge encoded by the Flyspeck project is combined with external automated theorem provers (ATPs) and machine-learning premise selection methods trained on the Flyspeck proofs, producing an AI system capable of proving a wide range of mathematical conjectures automatically. The performance of this architecture is evaluated in a bootstrapping scenario emulating the development of Flyspeck from axioms to the last theorem, each time using only the previous theorems and proofs. It is shown that 39 % of the 14185 theorems could be proved in a push-button mode (without any high-level advice and user interaction) in 30 seconds of real time on a fourteen-CPU workstation. The necessary work involves: (i) an implementation of sound translations of the HOL Light logic to ATP formalisms: untyped first-order, polymorphic typed first-order, and typed higher-order, (ii) export of the dependency information from HOL Light and ATP proofs for the machine learners, and (iii) choice of suitable representations and methods for learning from previous proofs, and their integration as advisors with HOL Light. This work is described and discussed here, and an initial analysis of the body of proofs that were found fully automatically is provided.     

Near-inertial wave driven dissolved oxygen transfer through the thermocline of a large lake

The offshore regions of large temperate lakes are characterized by strong summer temperature stratification that limits vertical mass flux, and enables near-inertial internal wave motions. Here, we investigate the contribution of near-inertial baroclinic velocity shear on enhancing the vertical transport of dissolved oxygen (DO) through the thermocline of the central basin of Lake Erie. The lake is prone to severe annual hypoxia in the hypolimnion and also has strong near-inertial Poincaré wave activity. Using field measurements, analytical arguments and a numerical model under idealized conditions, we show that the near-inertial waves drive baroclinic shear instabilities that enhance the vertical turbulent diffusivity and reduce the rate of DO depletion in the hypolimnion by up to 12% over the entire basin. Results from modeling large-spatial variability in the enhanced thermocline flux to match the distribution of near-inertial wave energy density, indicate that the observed oxygen budgets will vary as a function of location of sampling.     

Advances in Biologically Applicable Graphene-Based 2D Nanomaterials

Climate change and increasing contamination of the environment, due to anthropogenic activities, are accompanied with a growing negative impact on human life. Nowadays, humanity is threatened by the increasing incidence of difficult-to-treat cancer and various infectious diseases caused by resistant pathogens, but, on the other hand, ensuring sufficient safe food for balanced human nutrition is threatened by a growing infestation of agriculturally important plants, by various pathogens or by the deteriorating condition of agricultural land. One way to deal with all these undesirable facts is to try to develop technologies and sophisticated materials that could help overcome these negative effects/gloomy prospects. One possibility is to try to use nanotechnology and, within this broad field, to focus also on the study of two-dimensional carbon-based nanomaterials, which have excellent prospects to be used in various economic sectors. In this brief up-to-date overview, attention is paid to recent applications of graphene-based nanomaterials, i.e., graphene, graphene quantum dots, graphene oxide, graphene oxide quantum dots, and reduced graphene oxide. These materials and their various modifications and combinations with other compounds are discussed, regarding their biomedical and agro-ecological applications, i.e., as materials investigated for their antineoplastic and anti-invasive effects, for their effects against various plant pathogens, and as carriers of bioactive agents (drugs, pesticides, fertilizers) as well as materials suitable to be used in theranostics. The negative effects of graphene-based nanomaterials on living organisms, including their mode of action, are analyzed as well.