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Reactivity of Different Crystalline Surfaces of C3S During Early Hydration by the Atomistic Approach
(2019-05-09)
Early hydration of tricalcium silicate (C3S) has received great attention over the years due to the increased use of composite cement with a reduced number of clinker phases, especially the addition of what should be very reactive C3S to guarantee early strength. Although many mechanisms have been proposed, the dissolution of polygonal C3S at the material interface is not yet fully understood. Over the last decade, computational methods have been developed to describe the reaction in the cementitious system. This ...
Aufsatz
Comparing Electrical Energy Storage Technologies Regarding Their Material and Carbon Footprint
(2018-12-03)
The need for electrical energy storage technologies (EEST) in a future energy system, based on volatile renewable energy sources is widely accepted. The still open question is which technology should be used, in particular in such applications where the implementation of different storage technologies would be possible. In this study, eight different EEST were analysed. The comparative life cycle assessment focused on the storage of electrical excess energy from a renewable energy power plant. The considered EEST ...
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Income Vulnerability of West African Farming Households to Losses in Pollination Services: A Case Study from Ouagadougou, Burkina Faso
(2018-11-17)
Urban and peri-urban agriculture (UPA) in West African countries is developing rapidly in response to population growth and changing consumer preferences. Furthermore, UPA offers opportunities to secure income and social integration for the urban poor. However, little is known about household (HH) income security effects of the ongoing shift in UPA land use from crops that do not rely on insect pollinators for fruit development (e.g., sorghum and millet) to pollinator-dependent crops. In our study we developed a ...
Aufsatz
Environmental Assessment of Ultra-High-Performance Concrete Using Carbon, Material, and Water Footprint
(2019-03-13)
There is a common understanding that the environmental impacts of construction materials should be significantly reduced. This article provides a comprehensive environmental assessment within Life Cycle Assessment (LCA) boundaries for Ultra-High-Performance Concrete (UHPC) in comparison with Conventional Concrete (CC), in terms of carbon, material, and water footprint. Environmental impacts are determined for the cradle-to-grave life cycle of the UHPC, considering precast and ready-mix concrete. The LCA shows that ...
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Instability Resistance Training Decreases Motor Noise During Challenging Walking Tasks in Older Adults: A 10-Week Double-Blinded RCT
(2019-02-27)
Locomotor stability is challenged by internal perturbations, e.g., motor noise, and external perturbations, e.g., changes in surface compliance. One means to compensate for such perturbations is to employ motor synergies, defined here as co-variation among a set of elements that acts to stabilize, or provide similar trial-to-trial (or step-to-step) output, even in the presence of small variations in initial conditions. Whereas evidence exists that synergies related to the upper extremities can be trained, the extent ...
Aufsatz
Direct evidence for radiative charge transfer after inner-shell excitation and ionization of large clusters
(2018-01-16)
We directly observe radiative charge transfer (RCT) in Ne clusters by dispersed vacuum-ultraviolet photon detection. The doubly ionized Ne^2+ – Ne_n-1 initial states of RCT are populated after resonant 1s–3p photoexcitation or 1s photoionization of Ne_n clusters with {n} \approx 2800. These states relax further producing Ne^+ – Ne^+ – Ne_n-2 final states, and the RCT photon is emitted. Ab initio calculations assign the observed RCT signal to the Ne^2+(2p^-2 [^1D]) - Ne_n-1 initial state, while transitions from other ...
Aufsatz
Circular Dichroism in Fluorescence Emission Following the C 1s→π* Excitation and Resonant Auger Decay of Carbon Monoxide
(2018-06-26)
Dichroism in angle-resolved spectra of circularly polarized fluorescence from freely-rotating CO molecules was studied experimentally and theoretically. For this purpose, carbon monoxide in the gas phase was exposed to circularly polarized soft X-ray synchrotron radiation. The photon energy was tuned across the C 1s→π* resonant excitation, which decayed via the participator Auger transition into the CO+ A 2Π state. The dichroic parameter β1 of the subsequent CO+ (A 2Π → X 2Σ+) visible fluorescence was measured by ...
Aufsatz
Adoption of Organic Farming as an Opportunity for Syrian Farmers of Fresh Fruit and Vegetables: An Application of the Theory of Planned Behaviour and Structural Equation Modelling
(2017-11-04)
Exporting organic fresh fruit and vegetables (FFV) to the European Union could represent a great opportunity for Syrian farmers and exporters. Yet, the organic sector in Syria is comparatively young and only a very small area of FFV is organically managed. To date, little is known about Syrian farmers’ attitudes towards organic FFV production. Therefore, the aim of this study was to explore the intentions and attitudes of Syrian farmers of FFV towards organic farming and how likely they are to convert their farms to ...
Aufsatz
Different strength declines in leg primary movers versus stabilizers across age - Implications for the risk of falls in older adults?
(2019-03-07)
This study investigated differences in the declines of isometric strength in hip abductors and adductors versus knee extensors across four different age groups (n = 31: 11.2 ± 1.0 y, n = 30: 23.1 ± 2.7 y, n = 27: 48.9 ± 4.4 y, and n = 33: 70.1 ± 4.2 y) with a total of 121 female subjects. As a starting point, we assumed that, during their daily activities, elderly people would use their leg stabilizers less frequently than their leg primary movers as compared to younger people. Given that muscle strength decreases ...
Aufsatz
Der „Sekundenkleber“ der Stummelfüßer
(2019-12-05)
Der biologische Sekundenkleber der Stummelfüßer ist eine Quelle der Inspiration für die nachhaltige Produktion „intelligenter“ polymerbasierter Materialien. In der Natur jagen die Stummelfüßer ihre Beute mit dem proteinreichen Sekret, welches in der Lage ist, enorm belastbare Fasern zu bilden. Die Anleitung für diese Transformation ist in den Bausteinen programmiert und läuft selbstständig ohne jegliche Regulation durch den tierischen Körper ab. Elektrostatische Wechselwirkungen zwischen geladenen Proteinarealen und ...