bluuebunny/crossref_metadata_2025 huggingface dataset:
SARS-CoV-2 Nsp6 damages Drosophila heart and mouse cardiomyocytes through MGA/MAX complex-mediated increased glycolysis
Authors: Zhu Jun-yi , Wang Guanglei , Huang Xiaohu , Lee Hangnoh , Lee Jin-Gu , Yang Penghua , van de Leemput Joyce , Huang Weiliang , Kane Maureen A. , Yang Peixin , Han Zhe
Published: September 2022

SARS-CoV-2 infection causes COVID-19, a severe acute respiratory disease associated with cardiovascular complications including long-term outcomes. The presence of virus in cardiac tissue of patients with COVID-19 suggests this is a direct, rather than secondary, effect of infection. Here, by expressing individual SARS-CoV-2 proteins in the Drosophila heart, we demonstrate interaction of virus Nsp6 with host proteins of the MGA/MAX complex (MGA, PCGF6 and TFDP1). Complementing transcriptomic data from the fly heart reveal that this interaction blocks the antagonistic MGA/MAX complex, which shifts the balance towards MYC/MAX and activates glycolysis—with similar findings in mouse cardiomyocytes. Further, the Nsp6-induced glycolysis disrupts cardiac mitochondrial function, known to increase reactive oxygen species (ROS) in heart failure; this could explain COVID-19-associated cardiac pathology. Inhibiting the glycolysis pathway by 2-deoxy-D-glucose (2DG) treatment attenuates the Nsp6-induced cardiac phenotype in flies and mice. These findings point to glycolysis as a potential pharmacological target for treating COVID-19-associated heart failure.
Extreme conditions affect neuronal oscillations of cerebral cortices in humans in the China Space Station and on Earth
Authors: Zhang Peng , Yan Juan , Liu Zhongqi , Yu Hongqiang , Zhao Rui , Zhou Qianxiang
Published: September 2022

Rhythmical oscillations of neural populations can reflect working memory performance. However, whether neuronal oscillations of the cerebral cortex change in extreme environments, especially in a space station, remains unclear. Here, we recorded electroencephalography (EEG) signals when volunteers and astronauts were executing a memory task in extreme working conditions. Our experiments showed that two extreme conditions affect neuronal oscillations of the cerebral cortex and manifest in different ways. Lengthy periods of mental work impairs the gating mechanism formed by theta-gamma phase-amplitude coupling of two cortical areas, and sleep deprivation disrupts synaptic homeostasis, as reflected by the substantial increase in theta wave activity in the cortical frontal-central area. In addition, we excluded the possibility that nutritional supply or psychological situations caused decoupled theta-gamma phase-amplitude coupling or an imbalance in theta wave activity increase. Therefore, we speculate that the decoupled theta-gamma phase-amplitude coupling detected in astronauts results from their lengthy periods of mental work in the China Space Station. Furthermore, comparing preflight and inflight experiments, we find that long-term spaceflight and other hazards in the space station could worsen this decoupling evolution. This particular neuronal oscillation mechanism in the cerebral cortex could guide countermeasures for the inadaptability of humans working in spaceflight.
Complex effects of chytrid parasites on the growth of the cyanobacterium Planktothrix rubescens across interacting temperature and light gradients
Authors: Wierenga Joren , Thomas Mridul K , Ranjan Ravi , Ibelings Bas W
Published: September 2022

Chytrids are important drivers of aquatic ecosystems as phytoplankton parasites. The interaction between these parasites and their hosts are shaped by abiotic factors such as temperature and light. Here, we performed a full-factorial experiment to study how temperature and light interact to affect the dynamics of the bloom-forming toxic cyanobacterium Planktothrix rubescens and its chytrid parasite. We used a dynamic host-parasite model to explore how temperature and light affect long term dynamics. At low temperatures, chytrids do not survive. Higher light and temperature levels stimulated both phytoplankton and chytrid growth, with complex effects on their dynamics. Model exploration indicates that increasing temperature and light shifts equilibrium outcomes from P. rubescens persisting alone to stable coexistence and then to limit cycles. This provides an alternative biological explanation for why P. rubescens is mainly found in the relatively cold and dark lake metalimnion – it may enable avoidance of its parasite. Our study emphasizes the importance of investigating how abiotic factors interact with biotic interactions to drive complex outcomes.
A data-driven digital twin for water ultrafiltration
Authors: Møller Jan Kloppenborg , Goranović Goran , Brath Per , Madsen Henrik
Published: September 2022

Membrane-based separations are proven and useful industrial-scale technologies, suitable for automation. Digital twins are models of physical dynamical systems which continuously couple with data from a real world system to help understand and control performance. However, ultrafiltration and microfiltration membrane separation techniques lack a rigorous theoretical description due to the complex interactions and associated uncertainties. Here we report a digital-twin methodology called the Stochastic Greybox Modelling and Control (SGMC) that can account for random changes that occur during the separation processes and apply it to water ultrafiltration. In contrast to recent probabilistic approaches to digital twins, we use a physically intuitive formalism of stochastic differential equations to assess uncertainties and implement updates. We demonstrate the application of our digital twin model to control the filtration process and minimize the energy use under a fixed water volume in a membrane ultrafiltration of artificially simulated lakewater. The explicit modelling of uncertainties and the adaptable real-time control of stochastic physical states are particular strengths of SGMC, which makes it suited to real-world problems with inherent unknowns.
Chromatographic analysis of bromhexine and oxytetracycline residues in milk as a drug analysis medium with greenness profile appraisal
Authors: Sharkawi Marco M. Z. , Safwat Mark T. , Abdelaleem Eglal A. , Abdelwahab Nada S.
Published: September 2022

TLC densitometric and RP-HPLC methods for the determination of oxytetracycline and bromhexine with the sensitivity required for their analysis in milk samples accompanied by green profile appraisal.
Chemical design of organic ferroelectrics using dynamics of alkylamide chains
Authors: Takeda Takashi , Akutagawa Tomoyuki
Published: September 2022

The polypeptide chain is an important structural unit that forms the secondary structure of proteinsviaintermolecular amide-type N–H⋯O hydrogen bonds.
Controlling the photophysical properties of ionic transition-metal complexes through various counterions
Authors: Xing Guohui , Du Tingchen , Liu Shujuan , Ma Yun , Zhao Qiang
Published: September 2022

This paper lists the counterions that can be used to tune the photophysical properties of ionic transition-metal complexes, and it also summarizes the advances towards their information encryption and anti-counterfeiting applications.
NIR light-driven deflagration of energetic copper complexes through photothermal effect
Authors: Tan Bin , Chen Chao , Chen Yun-Rui , Zhang Jie , Yang Guo-Yu
Published: September 2022

Energetic coordination complexes constructed from non-explosive and stable nitro bearing ligands and Cu2+ have been presented, and are laser-ignitable on the basis of the coordination-induced photothermal conversion.
The synthesis of metal halide perovskite nanocrystals: surface and interface engineering
Authors: Zeng Ying , Xie Jinfeng , Xue Qi , Ni Chuanxin , Qian Qingyi , Guan Yuxiang , Huang He
Published: September 2022

Metal halide perovskites have emerged as a new class of colloidal semiconductor nanomaterials. This highlight emphasizes an overview of surface and interface engineering for enhancing their chemical stability and optical properties.
The solid-state hierarchy and iodination potential of [bis(3-acetaminopyridine)iodine(i)]PF6
Authors: Ward Jas S.
Published: September 2022

The hierarchical iodine(i) species [bis(3-acetaminopyridine)iodine(i)]PF6possesses two temperature-dependent solid-state connectivities of the hydrogen bonding and demonstrates unprecedented iodination reactivity towardtBuOMe.
Correction: Effects of structurally-related impurities on the crystal growth of curcumin spherulites
Authors: Heffernan Claire , Soto Rodrigo , Ukrainczyk Marko , Zeglinski Jacek , Hodnett Benjamin K. , Rasmuson Åke C.
Published: September 2022

Correction for ‘Effects of structurally-related impurities on the crystal growth of curcumin spherulites’ by Claire Heffernan et al., CrystEngComm, 2022, 24, 5156–5169, https://doi.org/10.1039/D2CE00223J.
Ultrafast 2D-IR spectroscopy of [NiFe] hydrogenase from E. coli reveals the role of the protein scaffold in controlling the active site environment
Authors: Wrathall Solomon L. D. , Procacci Barbara , Horch Marius , Saxton Emily , Furlan Chris , Walton Julia , Rippers Yvonne , Blaza James N. , Greetham Gregory M. , Towrie Michael , Parker Anthony W. , Lynam Jason , Parkin Alison , Hunt Neil T.
Published: September 2022

Ultrafast two-dimensional infrared (2D-IR) spectroscopy of Escherichia coli Hyd-1 (EcHyd-1) reveals the structural and dynamic influence of the protein scaffold on the Fe(CO)(CN)2 unit of the active site.
Donor–acceptor covalent organic framework promotes visible light-induced oxidative coupling of amines to imines in air
Authors: Feng Jingwen , Cheng Jie , Pang Jun , Tang Mingqiang , Liu Zewei , Rong Chunying , Tan Rong
Published: September 2022

The donor–acceptor COF greatly improved light harvesting and charge separation through a push–pull electron effect, realizing the efficient oxidative coupling of amines to imines with air under visible light irradiation.
Increasing the cytotoxicity of Ru(ii) polypyridyl complexes by tuning the electron-donating ability of 1,10-phenanthroline ligands
Authors: Lu Yang , Hou Zhiying , Li Mengshan , Wang Ning , Wang Jinhui , Ni Feng , Zhao Yufen , Zhang Bin , Xi Ning
Published: September 2022

We proposed that increasing the electron densities of ruthenium would provide better bioactivity and they were also potential cellular imaging probes.
Improving the efficiency of fully hydrocarbon-based proton-exchange membrane fuel cells by ionomer content gradients in cathode catalyst layers
Authors: Nguyen Hien , Sultanova Dilara , Heizmann Philipp A. , Vierrath Severin , Breitwieser Matthias
Published: September 2022

The optimized hydrocarbon catalyst layer enables high performance in higher potentials (0.7 V) and peak power density under hot and dry operation conditions.
Exploiting valuable supramolecular materials from waste plastics
Authors: Liu Xuehui , Zhao Xu , An Wenli , Du Rongcheng , Wu Gang , Xu Shimei , Zhang Fan , Wang Yu-Zhong
Published: September 2022

Chemical upcycling of plastic wastes into a new low-molecular-weight supramolecular adhesive with excellent performances.
Evaluation of the structural and electrical properties of perovskite NKN-LN ceramics for energy storage applications
Authors: Athikesavan Venkatraj , Kumar E. Ranjith , Suryakanth J.
Published: September 2022

A way to prepare a family of lead-free piezoelectric perovskite sodium potassium niobate–lithium niobate ceramics using a solid-state reaction technique is described.
Nanoetching TiO2 nanorod photoanodes to induce high-energy facet exposure for enhanced photoelectrochemical performance
Authors: Liu Canjun , Zuo Jian , Su Xin , Guo Huili , Pei Yong , Zhang Jie , Chen Shu
Published: September 2022

A nanoetching technology is demonstrated to induce the exposure of (101) facets of TiO2 nanorods, exhibiting a significantly enhanced photoelectrochemical activity.
Enhanced dielectric permittivity of hierarchically double-gyroid nanocomposites via macromolecular engineering of block copolymers
Authors: Xu Zhanwen , Dong Qingshu , Zhang Liangshun , Li Weihua
Published: September 2022

With the aid of the concept of macromolecular engineering, this work proposes mixtures of A(AB)n miktoarm star copolymers and nanoparticles to obtain bicontinuous gyroid nanostructures with high loading of functionalized nanoparticles.
Controlling the speciation and selectivity of Si3N4supported palladium nanostructures for catalysed acetylene selective hydrogenation
Authors: Li Rongrong , Yue Yuxue , Li Yongkun , Chen Xianlang , Chang Renqin , Zhang Jiaxin , Zhao Bo , Ying Xia , Wang Zijian , Zhao Jia , Li Xiaonian
Published: September 2022

A convexity model is used to predict the catalytic performance of Pd catalysts in acetylene semi-hydrogenation. The surface Pdδ−species determines the catalytic activity and selectivity, and the Pd–Nx(Pdδ+) species regulates the catalyst stability.
Effect of (H2O)n (n = 0–3, 13) on the NH3 + OH reaction in the gas and liquid phases
Authors: Zhou Yujie , Cao Qi , Yang Yu , Ma Dandan , Zhu Quan , Ma Jianyi
Published: September 2022

We used DFT and CCSD(T) methods with PCM solvation model to study the water cluster effect and solvation effect on the NH3 + OH reaction.
Norsesquiterpenoids from the octocoral Paralemnalia thyrsoides (Ehrenberg 1834)
Authors: Phan Gia Hung , Hu Hao-Chun , Chang Fang-Rong , Wen Zhi-Hong , Chen Jih-Jung , Chung Hsu-Ming , Tsai Yu-Chi , Sung Ping-Jyun
Published: September 2022

Three norsesquiterpenoids, pathyspirolactones A (1) and B (2), and napalilactone (3), featuring a γ-spirolactone moiety, were isolated from the cultured octocoral Paralemnalia thyrsoides.
Retraction: Down-regulation of HOXB5 inhibits TGF-β-induced migration and invasion in hepatocellular carcinoma cells via inactivation of the PI3K/Akt pathway
Authors: Sun Jin-Ping , Ge Quan-Xing , Ren Zheng , Sun Xin-Fang , Xie Shu-Ping
Published: September 2022

Retraction of ‘Down-regulation of HOXB5 inhibits TGF-β-induced migration and invasion in hepatocellular carcinoma cells via inactivation of the PI3K/Akt pathway’ by Jin-Ping Sun et al., RSC Adv., 2018, 8, 41415–41421, https://doi.org/10.1039/C8RA06860G.
Highly effective identification of drug targets at the proteome level by pH-dependent protein precipitation
Authors: Zhang Xiaolei , Wang Keyun , Wu Sijin , Ruan Chengfei , Li Kejia , Wang Yan , Zhu He , Liu Xiaoyan , Liu Zhen , Li Guohui , Hu Lianghai , Ye Mingliang
Published: September 2022

An energetics-based approach for highly effective identification of drug targets at the proteome level using stability shift induced by pH-dependent protein precipitation.
Fe/Fe3C modification to effectively achieve high-performance Si–C anode materials
Authors: Lin Xuqi , Gao Jingguo , Zhong Kehua , Huang Yongcong , Yao Hurong , Lin Yingbin , Zheng Yongping , Huang Zhigao , Li Jiaxin
Published: September 2022

For obtaining high-capacity and long cycling silicon–carbon based anodes used in lithium-ion batteries, there is an urgent need to rationally construct a stable solid electrolyte interface film and load a high proportion of silicon content.
Monovalent copper-mediated UV to NIR luminescence down-shifting in Yb3+-doped glass
Authors: Jiménez José A.
Published: September 2022

Sensitized NIR emission from Yb3+ ions is realized under near-UV excitation of Cu+ and a Cu2+–Yb2+ CTS model is proposed to explain the luminescence down-shifting.
Two-dimensional Cu nanostructures for efficient photo-catalytic degradation of methylene blue
Authors: Chandan Mohammed Rehaan , Kumar Kodi Rajesh , Shaik Aabid Hussain
Published: September 2022

Rapid and toxic chemical-free usage reduction technique was developed for synthesizing Cu nanosheets. Cu nanosheets show better degradation efficiency in MB dye as compared to hybrid nanosheets synthesized using conventional expensive techniques.
Orthogonal phase mixing for improved linearity phase interpolator
Authors: Sumesaglam Taner
Published: September 2022

As the demand for high‐speed low‐power transceivers grows, it is critical to have precise clock timing circuits such as phase interpolators (PI) that allow maximizing link margin. A linearization technique which optimizes linearity without increasing power and area is presented. Implemented in a 7‐nm complimentary metal oxide silicon (CMOS) technology, PI achieves less than 0.5 integral non‐linearity (INL) while consuming only 184 μA from a 0.75‐V supply at 4.3 GHz.
An integrated two‐dimensional merging trajectory optimization model for automated vehicles considering mixed traffic flow
Authors: Li Shurong , Wei Chong , Cao Jianfei , Wang Ying , Lin Zeng
Published: September 2022

Recently, automated vehicles have been recognized as a promising tool to address the problem of on‐ramp merging. However, the complexity of the problem includes ignorance of the vehicle's lateral dynamics, the limitation of the fixed merging point, the mismatch problem caused by the sequential optimization scheme, and the fixed terminal states assumption. These factors make it intractable in practical driving scenarios. This paper proposed an integrated optimization model for on‐ramp automated vehicles, which can guide the vehicle to complete the merging behaviour from the ramp lane to the main lane safely and efficiently. A merging path is first constructed in the two‐dimensional plane with two critical parameters recommended by a neural network predictor, enabling it to incorporate both longitudinal and lateral dynamics. Then, an integrated Mixed Integer Quadratic Program (MIQP) model is built to determine the optimal velocity profiles and merging gap simultaneously while considering the safety and efficiency factors. Specifically, with the introduction of discretization and linearization techniques, linear collision avoidance constraints and smooth transition constraints can be built, which can address the challenging computational problem. The effectiveness of the proposed model is validated through the microscopic and macroscopic numerical results under different levels of mixed traffic.
Addressing spatial service provision equity for pooled ride‐hailing services through rebalancing
Authors: Schlenther Tilmann , Leich Gregor , Maciejewski Michal , Nagel Kai
Published: September 2022

Ride‐hailing services have the potential to play a major role within future transport systems. While the operation as well as environmental, social and economic consequences are research subjects, the focus in the literature lies on system efficiency and profitability. In this study, vehicle relocation strategies are investigated with respect to service provision equity using an agent‐based simulation approach. The aim is to identify ways of operation that support social fairness while maintaining the profitability and effectiveness of the service. The results show that a typical demand‐anticipatory relocation strategy leads to an imbalance in the spatial distribution of mean wait times for the use case of Berlin. This can be significantly improved by applying different relocation strategies. As a consequence, the overall demand for the system rises while the ratio of empty vehicle kilometres increases slightly.
Towards a cooperative hierarchical healthcare architecture using the HMAN offloading scenarios and SRT calculation algorithm
Authors: Jasim Ahmed M. , Al‐Raweshidy Hamed
Published: September 2022

The Internet of medical things (IoMT) is one of the most promising fields that is expected to rapidly expand in the near future. Consequently, vast amounts of data will be generated, necessitating faster and more intensive processing capabilities. Several healthcare architectures based on Edge/Fog technologies have been created to lower healthcare expenses and provide better and more reliable services. Scalability, availability, capacity, latency, and privacy are some of the most pressing issues to consider when designing such architectures due to the critical and sensitive nature of healthcare data. To contribute to the reliability and robustness of electronic health services, this work proposes Healthcare Metropolitan Area Network (HMAN), a cooperative hierarchical Edge/Fog computing‐based architecture for the urban healthcare systems. The presented architecture suggests HMAN offloading scenarios and system response time calculation (HOSSC) algorithm which is specially designed to provide an abundance of offloading and processing scenarios within the network. The architecture also connects patients to the healthcare system by utilising the existing infrastructure in cities (e.g. medical centres and hospitals). Simulation results revealed that the designed architecture produced a ubiquitous and scalable healthcare system with promising and competitive performance, such as the computing capacity and service availability, by adopting multiple cooperative hierarchical offloading scenarios across the framework units. Moreover, the HMAN system was evaluated for latency and found to be very robust, with a short response time ranging between 6.043 and 31.45 ms in responding to 1 to 300 patients simultaneously sending. In addition to these appealing features, the proposed architecture ensures patients' privacy because the data are locally stored and processed in the most anticipated scenarios. The proposed architecture is a viable solution to providing healthcare services to a large number of patients.
Investigation on combined effect of humidity–temperature on partial discharge through dielectric performance evaluation
Authors: Ji Yatai , Giangrande Paolo , Zhao Weiduo , Madonna Vincenzo , Zhang He , Li Jing , Galea Michael
Published: September 2022

The humidity role in the partial discharge (PD) inception mechanism is quite challenging, especially when considering the environmental temperature. Indeed, there is no general rule to explain the humidity effect on the PD phenomenon. In this paper, the PD activity in inter‐turn insulation is experimentally investigated for different relative humidity (RH) conditions at three different ambient temperatures, that is, 30°C, 60°C, and 90°C. Partial discharge inception voltage (PDIV) is directly measured through a photomultiplier tube (PMT), whereas the tip‐up tests are performed aiming at monitoring both dissipation factor (tanδ) and insulation capacitance (IC). These extra measurements (diagnostic dielectric markers) allow better assessing the insulation status. The adoption of the tip‐up test enables the insulation properties measurement. Based on the tip‐up tests’ findings, the interfacial polarization process starts at 75% RH under 60°C, while the high conductivity area is already formed at 75% RH when the ambient temperature is 90°C. The water film formation deduced from the tip‐up test is then used to explain the trend of PDIV, and the validity is further proved by finite element analysis (FEA).
Reliability analysis of boom of new lifting equipment based on improved wolf swarm algorithm
Authors: Guan Huashen , Tang Bo , Zhou Xiangman , Tan Haoxin , Liang Zhuwei , Li Ye , Sun Guofu , Zhang Junjie
Published: September 2022

Aiming at the low accuracy or inability to solve the problem when the traditional reliability optimization method deals with the practical engineering reliability analysis problem, this paper proposes a structural reliability analysis method using the improved wolf swarm algorithm (IWSA). Firstly, the reliability optimization mathematical model is established with the minimum reliability index as the objective function and the limit state equation as the equality constraint. Then the augmented multiplier method is used to transform the constrained optimization mathematical model into an unconstrained optimization mathematical model. Finally, IWSA is used to solve the problem. The proposed method is applied to a numerical example and an engineering example. The computation results of the proposed method in solving the numerical example are compared with the Monte Carlo simulation (MCS), which verifies that the proposed method in this paper has good calculation accuracy. The maximum deformation under the working condition is used as the target to establish a limit state function, and the reliability index is obtained by the proposed method combining with the finite element analysis software, which provides a certain theoretical guiding significance for the reliability analysis of engineering structures.
An old warm Jupiter orbiting the metal-poor G-dwarf TOI-5542
Authors: Grieves Nolan , Bouchy François , Ulmer-Moll Solène , Gill Samuel , Anderson David R. , Psaridi Angelica , Lendl Monika , Stassun Keivan G. , Jenkins Jon M. , Burleigh Matthew R. , Acton Jack S. , Boyd Patricia T. , Casewell Sarah L. , Eigmüller Philipp , Goad Michael R. , Goeke Robert F. , Günther Maximilian N. , Hawthorn Faith , Henderson Beth A. , Henze Christopher E. , Jordán Andrés , Kendall Alicia , Mishra Lokesh , Moyano Maximiliano , Osborn Hugh , Revol Alexandre , Sefako Ramotholo R. , Tilbrook Rosanna H. , Udry Stéphane , Unger Nicolas , Vines Jose I. , West Richard G. , Worters Hannah L.
Published: September 2022

We report the discovery of a 1.32−0.10+0.10 MJup planet orbiting on a 75.12 day period around the G3V 10.8−3.6+2.1 Gyr old star TOI-5542 (TIC 466206508; TYC 9086-1210-1). The planet was first detected by the Transiting Exoplanet Survey Satellite (TESS) as a single transit event in TESS Sector 13. A second transit was observed 376 days later in TESS Sector 27. The planetary nature of the object has been confirmed by ground-based spectroscopic and radial velocity observations from the CORALIE and HARPS spectrographs. A third transit event was detected by the ground-based facilities NGTS, EulerCam, and SAAO. We find the planet has a radius of 1.009−0.035+0.036 RJup and an insolation of 9.6−0.8+0.9 S⊕, along with a circular orbit that most likely formed via disk migration or in situ formation, rather than high-eccentricity migration mechanisms. Our analysis of the HARPS spectra yields a host star metallicity of [Fe/H] = −0.21 ± 0.08, which does not follow the traditional trend of high host star metallicity for giant planets and does not bolster studies suggesting a difference among low- and high-mass giant planet host star metallicities. Additionally, when analyzing a sample of 216 well-characterized giant planets, we find that both high masses (4 MJup < Mp < 13 MJup) and low masses (0.5 MJup < Mp < 4 MJup), as well as both both warm (P > 10 days) and hot (P < 10 days) giant planets are preferentially located around metal-rich stars (mean [Fe/H] > 0.1). TOI-5542b is one of the oldest known warm Jupiters and it is cool enough to be unaffected by inflation due to stellar incident flux, making it a valuable contribution in the context of planetary composition and formation studies.
Mechanical properties and self-sensing ability of amorphous metallic fiber-reinforced concrete
Authors: Bouillard Théophile , Turatsinze Anaclet , Balayssac Jean-Paul , Toumi Ahmed , Helson Olivier , Bourbon Xavier
Published: September 2022

The aim of this research work is to develop a corrosion resistant fiber-reinforced concrete for radioactive waste disposal structures. In the case of precast concrete, the use of fibers is a solution to reduce the amount of steel reinforcement while maintaining high mechanical performance and durability. Concrete has a low strain capacity and a limited tensile strength. Generally, reinforcing bars are used to ensure tensile strength. A fiber reinforcement can also help to overcome such a mechanical weakness. For this purpose, an amorphous metallic fiber (AMF), corrosion-resistant and suitable for application in severe environment conditions are used. The fresh and hardened properties of the self-compacting fiber reinforced concrete (SCFRC) are studied with volume fractions of AMF of 0% and 0.28% and with three different aspect ratios (82, 114 and 123). Flexural tensile tests according to European standard EN 14651 are conducted to quantify the contribution of the fiber reinforcement on the residual flexural tensile strength. Since these fibers are electrically conductive, they are also tested to design a smart concrete. For this purpose, electrical resistance of specimens submitted to cyclic flexural loadings are monitored using a Wheatstone bridge.
Factors Influencing the Electrical Properties of Ettringite Binders as Repair Materials
Authors: Tuinukuafe Atolo , Noor Lamiya , Ideker Jason H. , Isgor O. Burkan
Published: September 2022

Ettringite binders are increasingly being used as rapid-repair materials to extend the service-life of reinforced concrete where rebar corrosion has caused deterioration and spalling. The transport properties of these ettringite binders are important in assessing the longevity of such repairs. This study demonstrates how the electrical properties of such binders can be interpreted to obtain meaningful results related to the transport properties. In addition to the pore solution chemistry, the degree of saturation in calcium sulfoaluminate (CSA) cement was found to be an important factor in the electrical properties since ettringite binders can have greater self-desiccation at earlier ages than ordinary portland cement (OPC). After one day of hydration, the electrical properties suggested that the CSA containing mixtures had greater pore network connectivity than the OPC mixture and this can be attributed to the varying phase compositions. Thermodynamic modelling confirmed a high amount of ettringite formation in the CSA system and a lower capillary water and capillary porosity associated with this. The lower internal relative humidity of ettringite binders should be considered when using electrical measurements to evaluate their transport properties since it increases the total electrical resistivity.
Durability of untreated fine recycled aggregate concrete: a literature review
Authors: Gamieldien Areej , Beushausen Hans , Alexander Mark
Published: September 2022

Unlike natural aggregate particles, recycled concrete aggregates contain hardened cement paste phases and multiple interfacial transition zones. These differences in properties may be linked to a decrease in durability performance in recycled aggregate concrete. This paper presents a review of the literature published on the durability performance of concrete produced using untreated fine recycled concrete aggregate (fRCA). From the available literature, the durability performance of concrete made using fRCA is strongly linked to the w/b used and the porosity of the resulting concrete matrix. Water absorption, gas permeability, and chloride penetration were found to increase with fRCA replacement. A possible maximum replacement level of 30% was observed in this regard. Carbonation resistance was found to increase with fRCA replacement due to the presence of calcium hydroxide in fRCA samples.
Influence of red mud addition in alkali-activated mortars on corrosion resistance of steel
Authors: Kancir Ivana Vladić , Radoš Vinko , Serdar Marijana
Published: September 2022

Alkali-activated materials (AAM) consist of a precursor, which is a source of aluminosilicates, and an alkali source. The precursors are usually waste materials from various industries such as fly ash from thermal power plants and slags from the metallurgical industry. Due to the increasing use of these materials in the cement industry and strategies for decommissioning coal-fired power plants, alternative raw materials from waste streams are increasingly being explored. One of these materials is waste from the aluminium industry, known as red mud. Due to its chemical composition, which is similar to that of other cementitious materials, red mud is suitable for use in the cement industry. It can also be used as a source of aluminosilicates in the synthesis of AAM. In this study, the corrosion behaviour of steel in chloride exposed AAMs based on fly ash and slag was investigated with and without the addition of red mud. During exposure of AAM to tap water and a 3.5 wt.% NaCl solution, the corrosion process was monitored by corrosion potential and polarisation resistance. AAM mixes containing red mud exhibited better corrosion resistivity and lower current density values compared to mixes without red mud, indicating a possible contribution of the red mud to chloride binding and improving the passivity of the steel.
Reinforcement corrosion of circular concrete columns under sustained load
Authors: Jabbour Samer , Martín-Pérez Beatriz , Liu Michelle
Published: September 2022

This paper presents the results of an experimental study of the axial capacity of circular spirally-reinforced concrete columns that were subjected to accelerated corrosion while sustaining a constant compressive service load. Two sets of columns of five columns each were designed with different spiral pitch to investigate the effect of concrete confinement on the corrosion propagation. Columns with non-confining spiral reinforcement had only their longitudinal reinforcing steel corroded, whereas in the other set of specimens, the spiral reinforcement was corroded and isolated from the vertical reinforcing steel. The cracking initiation, pattern, and widening of the concrete cover were monitored for a period of 4-10 months, and relations obtained between the crack widening and propagation and the elastic shortening of the column and steel mass loss were established. After the accelerated corrosion period, eight columns were tested to failure under either concentric or eccentric load; the vertical deformation, cracking pattern and failure type were monitored and recorded. The failure of specimens with non-confining spiral reinforcement was characterized by sudden crushing of the concrete and longitudinal reinforcement buckling, with a reduction in load capacity of 30-40%. Columns with confinement reinforcement failed in a ductile manner by progressive spalling of the concrete cover, maintaining their load capacity in spite of the corroded spiral reinforcement.
Use of fibres in improving the mechanical properties of a multifunctional cement for structural repair purposes
Authors: Ajoku Chinedu A. , Turatsinze Anaclet , Abou-Chakra Ariane
Published: September 2022

Calcium phosphate cement (CPC) is a multifunctional cement whose potential application depends on the reactants used to synthesise it. Just like many inorganic cements, the pure CPCs synthesised in all cases are very brittle and have low toughness values under loading. In this research, the CPC material is formed from the exothermic reaction between phosphoric acid and calcium silicate at controlled room temperature. Three fibre types, namely; macro polypropylene fibres, amorphous metallic fibres and recycled carbon fibres were chosen due to their corrosion resistance in acid to enhance the mechanical performance of this cement as a repair material. 1.5% by volume of each of these fibres were added to the CPC material and autogenously cured for 14 days at room temperature. Mechanical destructive and non-destructive tests were carried out on the resulting composites. The experimental results revealed that each type of fibre contributes to increase flexural strength, compressive strength, fracture energy and dynamic elastic modulus of CPC material. However, for this purpose the recycled carbon fibres have proven to be more efficient.
Crack control for repair and strengthening of reinforced concrete structures using the multi-cracking behaviour of Ultra-high Performance Fibre Reinforced Shotcrete (UHPFRSC)
Authors: Strotmann Andre , Jungwirth Jörg
Published: September 2022

Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is an innovative material for the repair and/or strengthening of reinforced concrete structures. In the field of traffic infrastructure, the outstanding mechanical properties are used as a protective surface layer and to increase the load capacity of the structure. UHPFRC is characterised by a dense granular structure and correspondingly high resistance against chloride attack. The material is typically applied as cast in-situ concrete. To optimise implementation of the strengthening and repair method, the UHPFRC is applied as sprayed concrete, so-called Ultra-High Performance Fibre Reinforced Shotcrete (UHPFRSC). The research aims to increase the service life of damaged and/or overloaded structures. Crack widths in the UHPFRSC layer must be limited to avoid migration of chlorides. The thin UHPFRSC layer provides crack distribution and control of localised macro cracks in the existing reinforced concrete structure. The fibres in the Ultra-High Performance Shotcrete (UHPSC) allows for limiting the crack width to 50 µm. When the UHPFRSC is applied on cracked reinforced concrete, it can be assumed that multi-cracking in the UHPFRSC surface layer will provide a chloride-dense layer equivalent to a coating. Under load, the two layers - UHPFRC and RC - act as a composite. For structural analysis, a particular focus must be placed on the interaction between cementitious materials. In addition, the pre-damage and pre-loading of the existing structure will influence the structural behaviour and crack formation. The paper presents the results of bending tests of UHPFRC - RC composite elements. The investigation shows the outstanding crack control behaviour of UHPFRSC. Based on this investigation, an analytical model will be provided, and a calculation of the crack widths will be derived. The research presents a central aspect of a large interdisciplinary research project at Munich University of Applied Science, called i-SCUP.
Application of RFID Corrosion Environment Sensing System to Repair Work and Results of 10-year study
Authors: Eriguchi Akira , Fujiwara Hiromi , Isaka Yukitoshi
Published: September 2022

To perform preventive maintenance of reinforcing steel corrosion in reinforced concrete, developed an RFID corrosion environment detection system that can wirelessly measure iron sensors that simulate reinforcing bars. This system can be embedded in concrete for a long period of time according to the life cycle of the structure, and semiconductor parts can be used for the passive RFID used in the communication interface. Therefore, it is necessary to confirm long-term durability. In this study, applied an RFID corrosion environment detection system to the repair work of bridge piers in addition to the conventional method of diagnosing rebar corrosion, and this paper report the results of our research conducted over a period of 10 years. The RFID corrosion environment detection system was compared with the expansion ring sensor system and the rebar self-potential measurement results. In addition, EPMA was used to analyze the chloride ion permeation of cores sampled from 5- and 10-year-old structures. The reaction results of the RFID corrosion environment sensor were compared with the permeation of chloride ions inside the structure.
Carbonation and chloride penetration of repair mortars with water treatment plant sludge and sugarcane bagasse ash sand
Authors: Hemkemeier Thiago A. , Almeida Fernando C.R. , Sales Almir , Klemm Agnieszka J.
Published: September 2022

Water treatment plant sludge (WTPS) and sugarcane bagasse ash sand (SBAS) (wastes from water treatment and sugar/ethanol industries) can be used as replacements of natural sand in concrete. Thus, this paper aims to evaluate carbonation depth and chloride penetration of cementitious repair mortars produced with WTPS and SBAS. Three mortars compositions were analysed: plain reference sample (REF); sample with 3% of WTPS (3WTPS); and sample with 30% of SBAS (30SBAS). They were subjected to tests of accelerated carbonation and immersion in NaCl solution up to 84 days (12 weeks). The results showed that SBAS mortars had the best performance in relation to carbonation and chloride penetration tests. 3WTPS mortars had similar results to the reference sample. This is due to refinement of pores given by incorporation of fine waste materials making it difficult for aggressive agents to penetrate cement matrices. Therefore, 3WTPS and 30SBAS composites can be satisfactorily used in buildings repair services for more sustainable and durable construction.
Thin Bonded Overlays with Carbon Reinforcement for Concrete Pavements
Authors: Neumann Julia , Breitenbücher Rolf
Published: September 2022

Here a possible alternative joint design in plain concrete pavements was investigated. The basis for this is to cover the concrete pavement with a thin jointless carbon reinforced concrete layer (CRC layer) of 50 to 70 mm as the top concrete. In the process, the classic joints already present in the lower concrete layer are also covered. The carbon reinforcement with a very high load capacity is intended to generate a finely distributed crack pattern in the upper concrete layer, thus preventing the penetration of moisture and other fluids into the joint area. This method thus represents an alternative to conventional joint sealing. Such a construction method is applicable both in the context of repair and new construction measures. In addition to tests on the cracking behaviour of CRC for concrete pavements, the main focus was on tests on large scale composite beams (classic jointed lower concrete + CRC layer). The focus was on the effects of static and cyclic bending on the material behaviour of the CRC over the moving joints in the lower concrete and the bond behaviour of lower and carbon reinforced concrete. The influence of differently designed bond breakers on the crack formation in the joint area was also considered.
A Rapid Test to Screen the Functionality of Galvanic Anodes for Cathodic Protection of Reinforced Concrete
Authors: Cobbs Ryan , Brueckner Rene , Atkins Chris , Goyal Arpit
Published: September 2022

Galvanic anodes are increasingly popular in the repair, rehabilitation, and maintenance of reinforced concrete structures suffering from chloride-induced corrosion for the added durability benefits. There is a consensus among engineers that demand will increase due to ageing infrastructure stock, climate change, and the option to reuse structures which is a logical solution to help reduce carbon emissions. New manufacturers will likely emerge to meet the needs of a growing market. However, there is no standard for galvanic anodes for use in concrete. In theory, products may come to market that fails to work as anodes, and hence corrosion may not be arrested, and repeated intervention could be required. This paper presents a methodology that has been developed for demonstrating anodes function as intended in a short-term test. Anodes were cast into concrete, and drive voltage, resistivity, and resultant current were measured when connected to an external cathode. The test setup was applied to several commercially available galvanic anodes. All anodes achieved a current output of 0.35 mA in this experimental setup. This could provide a rapid test to screen anodes new to the market. The analyses show inherent anode behaviour varied with different manufacturers, and there were also performance differences among replicate anodes. Such behavioural characteristics may affect the long-term performance of the anodes. These results provide new data on galvanic anodes and demonstrate the potential need for standardisation in the industry.
Quantified point clouds and enriched BIM-Models for digitalised maintenance planning
Authors: Morgenstern Hendrik , Raupach Michael
Published: September 2022

Digitisation in the construction industry continues to advance and, together with the increasing dissemination and further development of hardware and software, is steadily opening up further opportunities for innovative ways of working. Building Information Modelling (BIM) is currently becoming the standard for new construction but has not yet been optimised for use in existing buildings. Therefore, the Institute of Building Materials Research (ibac) is researching new methods and possibilities for BIM-based building preservation. In this paper, the automated creation and analysis of point clouds as well as the implementation of further information from in situ diagnosis and monitoring systems in BIM-Models are presented. On a practical example, the different steps of a subsequent digitisation of an existing building are demonstrated considering new possibilities as autonomous robots and the intelligent utilisation of sensors and diagnostics tools. The goal is a decision support tool, which is independent from proprietary software, adaptive to different types of buildings and open for various interfaces. Current results show that quantifying point clouds and making BIM-models usable beyond the planning and execution phase for new buildings are essential steps for the digitisation of building maintenance. The proposed digital workflow holds great potential for effective building diagnoses and efficient service life management.
Application of mine tailings sand as construction material – a review
Authors: Ikotun Jacob , Adeyeye Rhoda , Otieno Mike
Published: September 2022

Tailings are found during the exploration and processing of mineral ores. They contain a mixture of grounded rocks, processed effluent, and some trace elements that have the potential to damage the environment. Recent urbanisation has led to a large stockpile of tailings in many mining environment constituting health hazard. It becomes very important to develop disposal techniques that will reduce the huge mountain of tailings in mining environment. One of such method is the application of tailings in sustainable concrete production. It is shown that physical and chemical characteristics of tailings are comparable to crusher sand used in engineering construction and therefore, tailings can be used to partially replace sand in bituminous and concrete mixtures. In this review, specific interest has been given to iron, copper, and gold tailings, this is due to their dominance in mining areas of Kwa-Zulu Natal province of South Africa.
Textile Reinforced Concrete for free-form concrete elements: Influence of the binding type of textile reinforcements on the drapability for manufacturing double-curved concrete elements
Authors: Bhat Shantanu , Kalthoff Matthias , Shroeder Patrick , Gries Thomas , Matschei Thomas
Published: September 2022

Textile reinforced concrete (TRC) is a sustainable composite material consisting of a cementitious based matrix in combination with an open meshed technical textile reinforcement made of carbon or glass fibres. In the future, TRC could be increasingly used in the form of double-curved concrete elements with the aim of producing filigree yet load-bearing concrete shell structures. To assess whether a textile is suitable as a reinforcement structure in double-curved textile concrete elements, numerous properties need to be investigated and evaluated. The most important of these include good handling properties, bending stiffness tailored to the application, sufficiently pronounced mesh openings, and defect-free drapability. In the course of this work, biaxially reinforced knitted fabrics with five different stitch types (pillar open, pillar closed, tricot counterlaid, tricot closed and plain) were investigated to evaluate the above properties. The draping tests were conducted on a robot-controlled draping test apparatus and evaluated with the aid of an optical measuring system. In addition, the geometric relationship between surface curvature of the double curved elements and the shear angle of different textiles was used to classify the influence of the stitch type on the drapability. Finally, for a given double curved geometry, based on the results the selection of an appropriate textile reinforcement which fulfil the component requirements is carried out and a double curved TRC demonstrator element is prefabricated.