Prof. Dr.-Ing. Alexander Taffe  Sarah Vonk 《Beton- und Stahlbetonbau》2020,115(9):642-652

Accuracy of concrete cover measurement and detection limit of close neighboured rebars using Radar The classic concrete cover measurement is generally carried out to prove durability. According to the required minimum concrete cover of the exposure classes of max. 40 mm and 15 mm tolerance on cover to reinforcement, concrete cover of a maximum of 60 to 70 mm is relevant. This coincides with the maximum achievable detection depth of magnetic inductive devices (usually based on eddy current). Larger concrete covers are only of interest from a static point of view. This is especially applied when the load-bearing capacity of a structure has to be verified with deep reinforcement and the measurement of the installation depth of the reinforcement is necessary in order to, for e.g. to determine the inner lever arm. Therefore, the results published here on concrete cover measurement with radar are aimed at the later application for the recalculation of structures based on the results of the non-destructive testing (NDT-Statics). This article is about determining the accuracy of radar measurements and the ability to differentiate between adjacent bars. Therefore, the manufacturing of test specimens and their accuracy with regard to the implemented installation depth of the reinforcement is also dealt with.  相似文献   

    

Ilya Fridman  Robbie Napper  Sarah Roberts 《CoDesign》2020,16(2):171-187

ABSTRACT

Design and research teams working on public product service systems (PPSS) are often confronted with large data sets, presented in a complex language. This paper presents a method for how designers may translate quantitative aggregated data with a toolkit that enables qualitative co-synthesis to generate novel PPSS proposals. The toolkit development and application is shown through a specific case study in Melbourne, Australia, that focused on reimagining a public transport bus service in light of emerging propulsion and information technologies. People affected by the service were able to assist in co-synthesising existing data from transport planning literature into emergent ideas for system upgrades or even complete overhauls. A variety of multi-faceted service interventions were developed through a series of workshops with different participant groups. Workshop outcome variations further support the notion of emergence in co-creation, and reinforce the importance of running multiple sessions due to their potential impact on project outcomes. This paper proposes that co-synthesising complex data with the help of a toolkit, which may be a powerful way to inform PPSS design. An application framework is presented to summarise this process and to generate discussion towards broader application and further refinement.  相似文献   

    

Nasser Y. Mostafa  Mohsen M. Qhtani  Saad H. Alotaibi  Zaki I. Zaki  Sarah Alharthi  Mateusz Cieslik  Karolina Gornicka  Jacek Ryl  Rabah Boukherroub  Mohammed A. Amin 《国际能源研究杂志》2020,44(13):10695-10709

The high electrochemical stability of Zirconia (ZrO₂) at high potentials strongly suggested it as an alternative to carbon supports, which experience reduced efficiency due to some corrosion problems particularly during prolonged electrocatalysis activity. However, the use of ZrO₂ was limited by its low electrical conductivity and surface area. In this work, we developed a methodology for synthesizing monoclinic ZrO₂ NPs with increased surface area and improved electrical/electrocatalytic characteristics without using any carbon-based co-support material or any metallic nanoparticles. In this context, for the first time, highly defective hydroxyl-functionalized ZrO₂ NPs (designated here as ZT NPs) were prepared by a hydrothermal route in the presence of sodium tartrate as a mineralizer. XRD analysis demonstrated that the produced zirconia was semicrystalline microspheres, consisting of monoclinic ZrO₂ NPs with high lattice defects. The addition of tartrate ions decreased the crystallite size and increased the defects and microstrain. At the same time, the alkaline hydrogen evolution reaction (HER) catalytic activity of ZrO₂ NPs was significantly increased when using sodium tartrate as mineralizer; the overpotential required to obtain 10 mA cm⁻² (η₁₀) dropped down from 490 to merely 235 mV, while an exchange current density (j_o) increased 12 times to 0.22 mA cm⁻². The presence of structural defects (revealed by XRD) and the increased number of active surface sites contending O-H groups (evidenced from ATR-FTIR and XPS) as well as the enhanced electrochemical active surface area (confirmed from double-layer capacitance measurements) were the main reasons behind the high catalytic performance. The ZrO₂ NPs catalytic activity increased even further during the long-term stability tests under severe cathodic conditions (ZT*, ZrO₂ NPs obtained after the long-term stability, has j_o = 0.47 mA cm⁻² and η₁₀ = 140 mV), approaching the activity of Pt/C catalyst. This process was assisted by mineralizer removal from the catalyst (testified by XPS). Our studies revealed that ZT* are characterized by larger electroactive surface area and more structure defects compared to ZT, where surface area and microstrains resulting from surface hydroxylation open cavities in zirconia structure.  相似文献   

    

Troy J. Plumb  Luis Alvarez  Dennis L. Ross  Joseph J. Lee  Jeffrey G. Mulhern  Jeffrey L. Bell  Graham Abra  Sarah S. Prichard  Glenn M. Chertow  Michael A. Aragon 《Hemodialysis international. International Symposium on Home Hemodialysis》2020,24(1):22-28

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Tobias Bomholt  Sara Larsson  Marianne Rix  Sarah Rytter  Bo Feldt‐Rasmussen  Mads Hornum  Carsten Lundby 《Hemodialysis international. International Symposium on Home Hemodialysis》2020,24(2):252-260

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Silvia Campioni  Massimo Bagnani  Dorothea Pinotsi  Sarah Lecinski  Simona Rodighiero  Jozef Adamcik  Raffaele Mezzenga 《Advanced Materials Interfaces》2020,7(11)

Amyloid fibrils formed by the α‐Synuclein (α‐Syn) protein are the pathological hallmark of multiple human disorders, generally termed α‐synucleinopathies. The aggregation process of α‐Syn into amyloids appears to be highly dependent on the presence of: i) hydrophobic–hydrophilic interfaces, and ii) pre‐formed seed fibrils. By combining Thioflavin T binding measurements with different microscopy techniques (direct stochastic optical reconstruction microscopy, atomic force microscopy, correlative super‐resolution light microscopy, and scanning electron microscopy), the effect of the air–water interface (AWI) is tested on seeded α‐Syn aggregation. The correlation of the results provided by each method reveals striking differences in the mechanism of formation, yield, length, thickness, and morphology of fibrils obtained from samples having equal initial amounts of seeds and monomers, but incubated in the presence or absence of an AWI. Overall, the results indicate that the AWI determines how amyloids grow and proliferate, the final balance between monomer and aggregates, and the morphological properties of the aggregates themselves. These observations may set the basis for amplifying and tuning the properties of specific fibril polymorphs of interest, in structural biology and cytotoxicity studies, as well as in those materials science applications featuring amyloids.  相似文献   

    

Jennifer M. Kelly  Jose M. Ordovas  Gregory Matuszek  Caren E. Smith  Gordon S. Huggins  Hassan S. Dashti  Reiko Ichikawa  Sarah L. Booth 《Molecular nutrition & food research》2019,63(24)

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Claudia Mary Donkor  Jackie Lee  Natasha Lelijveld  Melanie Adams  Marjolein Meande Baltussen  Gifty Gyamah Nyante  Marko Kerac  Sarah Polack  Maria Zuurmond 《Food Science & Nutrition》2019,7(1):35-43

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Sarah P. Church  Nicholas Babin  Belyna Bentlage  Michael Dunn  Jessica D. Ulrich‐Schad  Pranay Ranjan  Joe Magner  Eileen McLellan  Susi Stephan  Mark D. Tomer  Linda S. Prokopy 《Journal of Contemporary Water Research & Education》2019,167(1):78-96

This paper presents the case of a voluntary watershed project that addressed the need for improving water quality by reducing agricultural nutrient loss. The Beargrass Creek Watershed Approach Project in Wabash County, Indiana aimed to demonstrate that it is possible to achieve ambitious water quality goals and maximize the effectiveness of conservation funding through locally‐led efforts that bring together multiple stakeholders throughout the process. The project focused on implementing the “right practices” in the “right places” through a goal‐oriented, science‐based, and locally‐adapted approach to voluntary conservation. We examine and evaluate all three phases of the project and discuss successes and lessons learned from the point of view of both agricultural producers and agency staff from the local Soil and Water Conservation District and the Natural Resources Conservation Service.  相似文献   

    

Aaron Steinfeld  Leslie Bloomfield  Sarah Amick  Yun Huang  Will Odom  Qian Yang 《城市工程杂志》2019,26(3):45-64

While several studies note the challenges that people with disabilities face when using public transit, little work has investigated how mobile transit information apps affect accessibility. To address this gap, we recruited transit riders who are blind, who have low vision, who use mobility devices, and who have no disabilities. We asked them to use a transit information app, Tiramisu, for 21 days during their regular travel. We observed participants struggling with a number of barriers that had previously been reported. However, the localized transit information also removed barriers to travel; we observed participants engaging in less preplanning and more opportunistic travel. We also identified new opportunities to improve transit use through mobile information.  相似文献