Modelling and Allocation of Hydrogen-Fuel-Cell-Based Distributed Generation to Mitigate Electric Vehicle Charging Station Impact and Reliability Analysis on Electrical Distribution Systems

The research presented in this article aims at the modelling and optimization of hydrogen-fuel-cell-based distributed generation (HFC-DG) to minimize the effect of electric vehicle charging stations (EVCSs) in a radial distribution system (RDS). The key objective of this work is to address various challenges that arise from the integration of EVCSs, including increased power demand, voltage fluctuations, and voltage stability. To accomplish this objective, the study utilizes a novel spotted hyena optimizer algorithm (SHOA) to simultaneously optimize the placement of HFC-DG units and EVCSs. The main goal is to mitigate real power loss resulting from the additional power demand of EVCSs in the IEEE 33-bus RDS. Furthermore, the research also investigates the influence of HFC-DG and EVCSs on the reliability of the power system. Reliability is crucial for all stakeholders, particularly electricity consumers. Therefore, the study thoroughly examines how the integration of HFC-DG and EVCSs influences system reliability. The optimized solutions obtained from the SHOA and other algorithms are carefully analyzed to assess their effectiveness in minimizing power loss and improving reliability indices. Comparative analysis is conducted with varying load factors to estimate the performance of the presented optimization approach. The results prove the benefits of the optimization methodology in terms of reducing power loss and improvising the reliability of the RDS. By utilizing HFC-DG and EVCSs, optimized through the SHOA and other algorithms, the research contributes to mitigating power loss caused by EVCS power demand and improving overall system reliability. Overall, this research addresses the challenges associated with integrating EVCSs into distribution systems and proposes a novel optimization approach using HFC-DG. The findings highlight the potential benefits of this approach in terms of minimizing power loss, enhancing reliability, and optimizing distribution system operations in the context of increasing EV adoption

Service Life and Life-Cycle Assessment of Reinforced Concrete with Fly ash and Limestone Calcined Clay Cement

Environmental impact due to the emission of carbon dioxide during concrete production can be taken care by reducing the clinker content in the cement. The clinker content can be reduced by replacing it with fly ash and limestone calcined clay. Such systems can have a potential to exhibit enhanced durability/service life when exposed to chloride and carbon dioxide. However, estimating probabilistic service life of concretes with such alternative binder systems is difficult due to the lack of quantitative estimates of the input parameters such as chloride diffusion coefficient (DCl), ageing coefficient (m), carbonation coefficient (KCO2), and chloride threshold (Clth). This paper presents the experimentally observed estimates of these parameters for the following systems: (i) 100% OPC, (ii) 70% OPC + 30% fly ash, and (iii) limestone calcined clay cement (LC3) – known as OPC, PFA, and LC3 concretes, respectively, herein. A total of three concrete mixes were designed. Also, based on these input parameters, the probabilistic service life estimates of a bridge pier and a girder made of these three concretes and exposed to chlorides and carbon dioxide are presented. For chloride ingress study, Fick’s 2nd Law of diffusion and Clth have been used. For carbonation study, a recently developed model for estimating carbonation depth (using mixture proportion) have been used. Then, the life‑cycle assessment (LCA) of these three concrete systems in terms of the CO2 emissions per unit of concrete per year of estimated service life is presented - for both chloride and carbonation induced corrosion. In chloride laden environments, the service life of the bridge pier and girder systems could be enhanced by about 10 times by using fly ash or LC3 concretes – for similar strength grade concretes. Also, the average annual CO2 emissions (during the expected service life) of PFA and LC3 concretes could be about 3 and 7 times, respectively, lower than that of OPC concretes of similar strength grade. In case of carbonation-induced corrosion, the limited experimental data indicate that the PFA and LC3 concretes could exhibit a lower service life and higher average annual CO2 emissions (during the expected service life) than OPC concretes

Influence of limestone addition on sodium sulphate activated blast furnace slag cements

The effect of limestone replacement in the reaction and phase assemblage evolution of two sodium sulfate activated slag cements was investigated. The slag composition and its reactivity influenced the reaction kinetics of these materials. Paste with limestone addition exhibited an acceleration in reaction kinetics, particularly for slowly reacting slags. Ettringite and an aluminium substituted calcium silicate hydrate were identified as main reaction products in these cements, independently of the slag type or limestone replacement level. No significant changes in phase assemblages were observed with limestone addition for over 365 days of testing; however, these composite cements exhibited an increased compressive strength, consistent with a refined pore structure. These results indicate that it is possible to partially replace slag by limestone in sulfate activated slag cements without changing the type of reaction products forming in these systems, while also increasing compressive strength and achieving a similar refined pore structure

Reactivity tests for supplementary cementitious materials: RILEM TC 267-TRM phase 1

A primary aim of RILEM TC 267-TRM: “Tests for Reactivity of Supplementary Cementitious Materials (SCMs)” is to compare and evaluate the performance of conventional and novel SCM reactivity test methods across a wide range of SCMs. To this purpose, a round robin campaign was organized to investigate 10 different tests for reactivity and 11 SCMs covering the main classes of materials in use, such as granulated blast furnace slag, fly ash, natural pozzolan and calcined clays. The methods were evaluated based on the correlation to the 28 days relative compressive strength of standard mortar bars containing 30% of SCM as cement replacement and the interlaboratory reproducibility of the test results. It was found that only a few test methods showed acceptable correlation to the 28 days relative strength over the whole range of SCMs. The methods that showed the best reproducibility and gave good correlations used the R3 model system of the SCM and Ca(OH)2, supplemented with alkali sulfate/carbonate. The use of this simplified model system isolates the reaction of the SCM and the reactivity can be easily quantified from the heat release or bound water content. Later age (90 days) strength results also correlated well with the results of the IS 1727 (Indian standard) reactivity test, an accelerated strength test using an SCM/Ca(OH)2-based model system. The current standardized tests did not show acceptable correlations across all SCMs, although they performed better when latently hydraulic materials (blast furnace slag) were excluded. However, the Frattini test, Chapelle and modified Chapelle test showed poor interlaboratory reproducibility, demonstrating experimental difficulties. The TC 267-TRM will pursue the development of test protocols based on the R3 model systems. Acceleration and improvement of the reproducibility of the IS 1727 test will be attempted as well

Dataset for 'Influence of limestone addition on sodium sulphate activated blast furnace slag cements'

The data contained in this workbook has been used to create the following figures in the journal article: Marsh, A.T., Yue, Z., Dhandapani, Y., Button, K., Adu-Amankwah, S. and Bernal, S.A., 2022. Influence of limestone addition on sodium sulphate activated blast furnace slag cements. Construction and Building Materials, 360, p.129527. https://doi.org/10.1016/j.conbuildmat.2022.12952

Performance of cementitious systems containing calcined clay in a chloride-rich environment: a review by TC-282 CCL

Acknowledgements: Participation of Y. Dhandapani was sponsored by the National Science Foundation (NSF) through award 1903457 and the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/T008407/1 and EP/W021811/1. Dr. Zunino is supported by the Swiss National Science Foundation (SNSF) through an Ambizione fellowship (Grant 208719). Members of TC-CCL are acknowledged for some of their suggestions and feedbacks on the final version of the article.AbstractIn this review by TC- 282 CCL, a comprehensive examination of various facets of chloride ingress in calcined clay-based concrete in aggressive chloride-rich environments is presented due to its significance in making reinforced concrete structures susceptible to chloride-induced corrosion damages. The review presents a summary of available literature focusing on materials characteristics influencing the chloride resistance of calcined clay-based concrete, such as different clay purity, kaolinite content and other clay minerals, underscoring the significance of pore refinement, pore solution composition, and chloride binding mechanisms. Further, the studies dealing with the performance at the concrete scale, with a particular emphasis on transport properties, curing methods, and mix design, are highlighted. Benchmarking calcined clay mixes with fly ash or slag-based concrete mixes that are widely used in aggressive chloride conditions instead of OPC is recommended. Such comparison could extend the usage of calcined clay as a performance-enhancing mineral admixture in the form of calcined clay or LC2 (limestone-calcined clay). The chloride diffusion coefficient in calcined clay concrete is reported to be significantly lower (about 5–10 times in most literature available so far) compared to OPC, and even lower compared to fly ash and slag-based concrete at early curing ages reported across recent literature made with different types of cements and concrete mixes. Limited studies dealing with reinforcement corrosion point out that calcined clay delays corrosion initiation and reduces corrosion rates despite the reduction in critical chloride threshold. Most of these results on corrosion performance are mainly from laboratory studies and warrant field evaluation in future. Finally, two case studies demonstrating the application of calcined clay-based concrete in real-world marine exposure conditions are discussed to showcase the promising potential of employing low-purity calcined clay-based concrete for reducing carbon footprint and improving durability performance in chloride exposure.</jats:p

Report of TC 238-SCM: hydration stoppage methods for phase assemblage studies of blended cements—results of a round robin test

For many microstructural studies it is necessary to “stop” cement hydration—to remove free water. This paper describes the results of a round robin test on the impact of hydration stoppage methods on the composition of hydrated cements. A regular and a fly ash blended Portland cement hydrated for 90 days were selected. Ten laboratories participated in the round robin test. Four common hydration stoppage methods were studied: (1) oven drying at 105 °C, (2) solvent exchange by isopropanol, (3) vacuum drying and (4) freeze drying. After the stoppage of hydration powder samples were studied by thermogravimetry (TG) and X-ray diffraction (XRD). Bound water and Ca(OH)2 content were determined based on the TG data. Portlandite and ettringite content were quantified by Rietveld analysis of the XRD data. The goal was to establish interlaboratory reproducibility and to identify the best available protocols for research and standardization purposes. Based on the results of the round robin test three recommendations are made. (1) Oven drying at 105 °C is not recommended. This dehydrates, alters and decomposes calcium aluminate hydrates significantly more than other methods and often produced carbonation artefacts. (2) Isopropanol exchange is the most appropriate hydration stoppage method for the study of the complete hydrate assemblage of cements, including calcium aluminate hydrates such as ettringite and AFm phases. (3) For quantification of portlandite (Ca(OH)2) all tested hydration stoppage protocols are satisfactory, with the exception of oven drying.status: publishe

RILEM TC-238 SCM recommendation on hydration stoppage by solvent exchange for the study of hydrate assemblages

© 2018, RILEM. This recommendation is an outcome of the work carried out by a working group within the RILEM Technical Committee 238-SCM “Supplementary Cementitious Materials”. The working group studied the effect of supplementary cementitious materials on the pore solution, the microstructure and the hydration product assemblage of hardened Portland cements blended with common supplementary cementitious materials. The recommendation reflects the results of a round robin test programme on common hydration stoppage methods in 10 participating laboratories. Among four different methods tested, solvent exchange by isopropyl alcohol (isopropanol) gave the best results in terms of preservation of the cement hydrate assemblage and overall reproducibility of the results [1]. The current protocol is developed based on best laboratory practices of the participating laboratories and literature reports [2–4]. The presented hydration stoppage protocol is recommended for the study of Portland cement-based hydrate assemblages by common material characterization techniques such as thermogravimetry and X-ray powder diffraction.status: publishe

AQP1 ablation mimicks M2 functional differentiation induced in WT macrophages by IL4/IL13: A- CD206 redistribution into ruffles. (A) Confocal images.

<p><i>Aqp1</i>^<i>+/+</i> and <i>Aqp1</i>^-/- macrophages were maintained for 24h in serum-containing medium without supplements (to keep macrophages in undifferentiated M0 state; upper row), or with LPS (to orient towards M1 phenotype; middle row) or IL4/IL13 (to orient towards M2 phenotype; lower row). Cells were fixed/permeabilized and double-immunolabelled for CD206 (green) and F4/80 (red) by reference to nuclei (Topro-3; blue). Representative of 2 independent experiments. Insets of M0 (<i>Aqp1</i>^<i>-/-</i>; panel b) and M2 macrophages (<i>Aqp1</i>^<i>+/+</i> and <i>Aqp1</i>^-/-; panels e and f) show strong recruitment of CD206 (green) into ruffles, contrasting with preferential perinuclear localization in WT M0 and M1 macrophages (panels a and c). Scale bars, 5μm. <b>(B) Morphometry: redistribution of CD206 in ruffles.</b> From left to right, analysis was performed on 54, 35, 30, 31, 10 and 7 cells, pooled from 2 independent experiments. NS, not significantly different; ***, p<0.001.</p