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AbstractIn this study, the compatibility of polycarboxylate-based water-reducing admixtures (PCEs) with cementitious systems containing fly ash (FA) was investigated. For this purpose, PCEs with carboxylate, phosphate, and sulfonate anionic groups having different anionic charge densities were synthesized. The effects of PCEs on fresh properties and compressive strength of cementitious systems containing FA were investigated. The PCE with 9% phosphate substitution and high anionic charge density was found to be the most effective, requiring the least amount for the target flow. Similarly, in terms of the PCE requirement for the minimum Marsh funnel flow time and rheological parameters, the best performance was obtained with 5% sulfonate substituted PCE having high anionic charge density. While FA had a positive effect on the PCE requirement and consistency retention of the mixtures; it had a negative effect on Marsh funnel flow time, rheological properties, and compressive strength. However, the rheological properties of the mortar mixtures were not adversely affected by the FA substitution as much as that of the paste mixtures. Regarding the 28-day compressive strength of mortar mixtures, the optimum FA substitution ratio was 15%. Fly ash substitution above this level reduced the compressive strength at all ages including 28-day strength. Anionic charge density variation of PCE had no significant influence on the compressive strength of the mortars. [ABSTRACT FROM AUTHOR]

Mechanical grinding is a common method used to enhance the pozzolanic activity of tailings, and these activated tailings can be used as supplementary cementitious materials in cement production. However, the addition of activated tailings usually reduces the workability of cement paste, and the mechanism of influence of different minerals in tailings on workability varies. In this study, three kinds of principal silicate minerals in tailings—quartz, feldspar, and mica—were mechanically activated. The influence of these activated minerals on the rheological properties of cement paste were studied in the absence or presence of PCE (polycarboxylate ether) superplasticizers, and the influence mechanism was investigated using rheology, TOC, contact angles, zeta potential, XPS, ICP-OES, and XRD. The results showed that quartz has the highest fluidity, and mica has the lowest. An increase in hydrophilicity decreased the flowability of the blended cement paste. The increase in the metal cation dissolution rate was the main reason for the decrease in the fluidity of PCE-blended cement pastes. The knowledge gained provides a valuable reference for the utilization of activated tailings in cement production. [ABSTRACT FROM AUTHOR]

The current study employs numerical simulations via the SCAPS-1D platform to investigate the performance of solar cells based on perovskite, with RbGeI3 utilized as an absorber material possessing a wide bandgap of 1.31 eV. Through systematic exploration of various parameters including temperature, layer thickness, doping, and defects, the study aims to enhance the efficiency of the solar cells, considering their sensitivity to temperature variations. Results demonstrate that the proposed configuration effectively extends the absorption spectrum into the near-infrared region, with the thickness of the RbGeI3 layer emerging as a critical factor influencing device performance. Analysis reveals that the series resistance peaks at 2 Ω·см2, while the shunt resistance achieves optimal output parameters of up to 103 Ω·см2. Moreover, optimization efforts yield a solar cell exhibiting a power conversion efficiency of 24.62%, fill factor of 82.8%, open circuit voltage of 0.99V, and short circuit current density of 33.20 mA/cm2 at a RbGeI3 thickness of 0.6 um. This comprehensive numerical investigation not only enhances understanding of the intricate factors influencing perovskite solar cells but also suggests promising avenues for future advancements in the field.

Perovskite-based solar cells are currently attracting growing interest from researchers and industry alike, thanks to the advantages of this type of solar cell, particularly in terms of manufacturing simplicity and the promising power conversion efficiency, which has recently reached remarkable levels. This paper focuses on numerical simulation to improve the performance of the Formamidinium Tin Iodide (FASnI3) solar cell configuration by using Cerium Dioxide (CeO2) as ETL and Poly (Triaryl Amine) (PTAA) as HTL. The simulation has been carried out using Solar Cell Capacitance Simulator (SCAPS-1D) tool under the spectrum of AM 1.5 G. An intensive modeling has been realized to improve the output parameters of the suggested configuration based on FASnI3 as absorber. The proposed structure (ITO/CeO2/FaSnI3/PTAA/Au) achieves a tremendous power conversion efficiency (PCE) of 39.24%, an open-circuit voltage (VOC) of 1.31 V, a short-circuit current density (JSC) of 33.7 mA/cm2 and a fill factor (FF) of 90.12%.

Background and aimsLipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD) but is not included in the Pooled Cohort Equations (PCE). We aimed to assess how well the PCE predict 10-year event rates in individuals with elevated Lp(a), and whether the addition of Lp(a) improves risk prediction.MethodsWe compared observed versus PCE-predicted 10-year ASCVD event rates, stratified by Lp(a) level and ASCVD risk category using Poisson regression, and evaluated the association between Lp(a) > 50 mg/dL and ASCVD risk using Cox proportional hazards models in the Multi-Ethnic Study of Atherosclerosis (MESA). We evaluated the C-index and net reclassification improvement (NRI) with addition of Lp(a) to the PCE.ResultsThe study population included 6639 individuals (20%, n = 1325 with elevated Lp(a)). The PCE accurately predicted 10-year event rates for individuals with elevated Lp(a) with observed event rates falling within predicted limits. Elevated Lp(a) was associated with increased risk of CVD events overall (HR 1.27, 95% CI 1.00-1.60), particularly in low (HR 2.45, 95% CI 1.40-4.31), and high-risk (HR 1.41, 95% CI 1.02-1.96) individuals. Continuous NRI (95% CI) with the addition of Lp(a) to the PCE for CVD was 0.0963 (0.0158-0.1953) overall, and 0.2999 (0.0876, 0.5525) among low-risk individuals.ConclusionsThe PCE performs well for event rate prediction in individuals with elevated Lp(a). However, Lp(a) is associated with increased CVD risk, and the addition of Lp(a) to the PCE improves risk prediction, particularly among low-risk individuals. These results lend support for increasing use of Lp(a) testing for risk assessment.

To explore the effect of polycarboxylate superplasticizers on the strength and hydration performance of alkali slag building materials, this study prepared cross-linked polycarboxylate superplasticizers with different ratios of hydrogen peroxide, methyl allyl alcohol polyoxyethylene ether, acrylic acid, polyethylene glycol diacrylate, monomer aqueous solution, reducing agent, chain transfer agent, etc. according to certain ratios, and tested their effects on the hydration performance and strength of alkali slag building materials. Through experimental analysis, it was found that the higher the proportion of cross-linked polycarboxylate based high-efficiency water-reducing agents, the lower the initial flowability of building material slurry; The addition of cross-linked polycarboxylate water-reducing agent will prolong the initial and final setting time of alkali slag building materials, delaying the hydration time of building materials; Cross linked polycarboxylate superplasticizers can reduce the electrical conductivity of alkali slag building material slurry, delaying its hydration rate; Different ratios of water-reducing agents have a significant impact on the water reduction rate of alkali slag building materials, with V2 water-reducing agent having the highest water-reduction rate of 28.6%; Cross linked polycarboxylate superplasticizers can increase the flexural and compressive strength of alkali slag building materials. Therefore, cross-linked polycarboxylate water-reducing agents have shown great potential in regulating the properties of alkali slag building materials.

Background: The significance of induction chemotherapy (IC) in the treatment of squamous cell carcinoma of the head and neck (SCCHN) with unresectable locoregional recurrence after curative surgery has not been clarified. The aim of this study was to evaluate the efficacy of IC followed by chemoradiotherapy (CRT) in these patients. Methods: Among patients with unresectable locoregional recurrent SCCHN who had not undergone prior irradiation and were eligible for cisplatin, we conducted a retrospective analysis of patients who received CRT following IC with paclitaxel, carboplatin, or cetuximab (IC-PCE group) and those who received CRT without prior IC (CRT group) between June 2013 and August 2021. Result: Forty-two patients were included. The CRT group and IC-PCE group consisted of 15 and 27 patients, respectively. Primary site was the oral cavity (n=25), oropharynx (n=3), hypopharynx (n=13) and larynx (n=1). Objective response rate (ORR) with IC-PCE was 55.6%; 24 patients (88.9%) subsequently received CRT. ORR after completion of CRT was significantly better in the IC-PCE group (95.8% in the IC-PCE group vs. 66.7% in the CRT group, p=0.024). Progression-free survival (PFS) of the total population on median follow-up of 2.4 years (range: 0.8-7.3) tended to be better in the IC-PCE group (2-year PFS: 55.6% in the IC-PCE group vs. 33.3% in the CRT group, log-rank p=0.176), especially in oral cancer (2-year PFS: 37.5% in the IC-PCE group vs. 0% in the CRT group, log-rank p=0.015). Conclusion: Therapeutic strategies including IC-PCE in patients with unresectable locoregional recurrent SCCHN after curative surgery may contribute to improved prognosis, especially in oral cancer. [ABSTRACT FROM AUTHOR]

• Due to widespread connectivity of the PCC to other regions, posterior cingulate epilepsy included polymorphic semiology of the seizures. • Behavioral arrest is the most common symptoms followed by automatisms and complex motor behaviors. Autonomic seizure was very rare in PCE. • Because of the extensive reciprocal connections between PCC and hippocampus, both hippocampal and PCC lesions may serve as seizure onset zones. • The intracerebral electrical stimulation mapping of PCC was induced vestibular responses were located in the dPCC and RSC and visual responses were located in the left RSC. Autonomic responses were elicited in vPCC and RSC. This study aimed to explore seizure semiology and the effects of intracerebral electrical stimulation on the human posterior cingulate cortex (PCC) using Stereoelectroencephalography (SEEG) to deepen our comprehension of posterior cingulate epilepsy (PCE). This study examined the characteristics of seizures through video documentation, by assessing the outcomes of intracranial electrical stimulation (iES) during SEEG. We further identified the connection between the observed semiology and precise anatomical locations within the PCC subregions where seizure onset zones (SOZ) were identified. Analysis was conducted on 59 seizures from 15 patients recorded via SEEG. Behavioural arrest emerged as the predominant manifestation across the PCC subregions. Where ictal activity extended to both the mesial and lateral temporal cortex, automatism was predominantly observed in seizures originating from the ventral PCC (vPCC). The retrosplenial cortex (RSC) is associated with complex motor behaviour, with seizure discharges spreading to the temporal lobe. Seizures originating from the PCC include axial tonic and autonomic seizures. Only one case of positive clinical seizures was documented. High frequencies of iES within the PCC induced various clinical responses, categorised as vestibular, visual, psychological, and autonomic, with vestibular reactions primarily occurring in the dorsal PCC (dPCC) and RSC, visual responses in the left RSC, and autonomic reactions in the vPCC and RSC. The manifestations of seizures in PCE vary according to the SOZ and the patterns of seizure propagation. The occurrence of seizures induced by iES is exceedingly rare, indicating that mapping of the PCC could pinpoint the primary sector of PCC. [ABSTRACT FROM AUTHOR]

Physiotherapy is a treatment that may be required permanently by many patients. As a result, a robot that can execute physiotherapy exercises for the legs like a professional therapist with adequate performance and acceptable safety may be efficient and widely used. In this study, a robust control system for a Stewart platform with six degrees of freedom is provided. First, the Newton-Euler approach is used in conjunction with a methodology and some simplification tools to achieve explicit dynamics formulation for the Stewart platform. For the primary application of this research, which is to follow the specified trajectory of ankle rehabilitation, computed torque control law (CTCL) and polynomial chaos expansion (PCE) were used to examine and consider any uncertainty in geometric and physical parameters. In fact, this strategy integrated the uncertainties with CTCL using PCE. The suggested PCE-based CTCL eliminates the system's nonlinearity by applying feedback linearization to evaluate generalized driving forces; hence, the nondeterministic multi-body system follows the desired direction. Uncertainties in the patient's foot as well as the main diameter parameters of the moment of inertia of the upper platform of the Stewart robot with various uniform, beta, and normal distributions, have been analyzed. The PCE technique's results were compared to the Monte Carlo method's outcomes, and the strengths and weaknesses of each method were investigated. In brief, the PCE method operated far better than the Monte Carlo (MC) method in speed, accuracy, and numerical volume. [ABSTRACT FROM AUTHOR]

Despite significant development of perovskite solar cells (PSCs) in the last few years, several issues need to be addressed for commercialization. The fabrication of a 2-dimensional/3-dimensional (2D/3D) perovskite layer as the light absorbing layer has recently come up as one of the most efficient methods to overcome this barrier without compromising the physical functionality of the device. Additionally, the inverted p–i–n configuration of2D/3D bilayer PSCs has caught lots of attention in the recent years owing to low-cost, low-temperature growth process and inhibited hysteresis properties. In this study, we introduce an inverted 2D/3D bilayer PSC with a novel configuration of FTO/NiOx/BA2MA3Pb4I13/MAPbI3/C60/Au and computationally study the parameters that affect the performance of the modeled device. Considerable power conversion efficiency (PCE) of 28.24% was achieved after optimizing the performance. [ABSTRACT FROM AUTHOR]

Global efforts to minimise carbon dioxide emissions are also leading to attempts to use calcined clays (CC) as a partial substitute for cement in concrete. While the hydration mechanism of such CC blended cements is now well understood, the range of effective admixtures like polycarboxylate ethers (PCE) is limited. There are PCE types that promise relatively high effectiveness, but the mechanisms of action are not yet sufficiently understood. For a detailed understanding of the adsorption of such PCEs, spatially resolved studies of the binder were performed using a combination of fluorescence and scanning electron microscopy. In a comparison of two superplasticisers, the investigations have shown different sites of preferred adsorption in a CC blended system and the results can be correlated with flow tests and setting behaviour. The investigations have shown that a certain PCE type has a higher adsorption on CC and other components of a blended system in comparison to other types. LAY DESCRIPTION: Efforts to reduce carbon dioxide emissions globally are driving attempts to use calcined clays as a partial replacement for cement in concrete. Although the hardening mechanism of cements blended with calcined clays is well understood, the range of effective admixtures, such as plastisicing agents, is limited. While some plastisicing agent types show relatively high effectiveness, their mechanisms of action are not yet fully understood. To understand how these plastisicing agents interact with the compounds, fluorescence and scanning electron microscopy has been used to study this interaction. Two different plastisicing agent types have been compared and it was found that they prefer different sites of the compounds to interact with in a blended cement. These results can be correlated with flow tests and setting behaviour. The investigations have shown that one particular type of plastisicing agents has a higher affinity to calcined clay and other components of a blended system compared to other types. [ABSTRACT FROM AUTHOR]

Currently, surface reflection of incident sunrays over solar cells results in degradation of output performance of the solar cells. This can be sorted out using an antireflection coating. In this investigation, ARC materials such as Titanium dioxide (TiO 2), Aluminium oxide (Al 2 O 3) and blended TiO 2 – Al 2 O 3 were utilized over the mono-crystalline Si (m-Si) solar cells. The ARCs for m-Si solar cell was coated using RF sputtering method. The optical, structural, electrical, I–V characteristics and temperature behavior of solar cell samples with coating and bare cells were studied. The elemental analysis was carried out using X-ray diffraction (XRD) method. The morphological study was conducted using High Resolution Transmission Electron Microscopy (HR-TEM) and Atomic Force Microscope (AFM). The electrical resistivity was measured in dark at room temperature using four-point probe technique. Optical characteristics was determined using UV–visible spectroscopy. It was discovered that the TiO 2 – Al 2 O 3 blend coated cell (I3) shows great performance than the other coatings. I3 solar cell demonstrated high power conversion efficiency (PCE) of 19.42 % and 20.16 %, when exposed to direct sunlight and neodymium radiation in both open and controlled environments. The findings indicate that TiO 2 – Al 2 O 3 blends are a suitable material for ARC applications, since they effectively reduce the incident photons scattering. [ABSTRACT FROM AUTHOR]

Zhang Wang,1 Xue Yang,1 Longxin Li,1 Xiaobo Zhang,2 Wenlin Zhou,1 Sixue Chen1 1Department of Geriatrics, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China; 2The Third People’s Hospital of Beichuan Qiang Autonomous County, Mianyang, People’s Republic of ChinaCorrespondence: Zhang Wang, Department of Geriatrics, The General Hospital of Western Theater Command, No. 270 Rongdu Road, Chengdu, 610083, People’s Republic of China, Tel +86-18981780413, Email 969281094@qq.comPurpose: To evaluate the performance of the Framingham cardiovascular risk score (FRS)/pooled cohort equations (PCE)/China prediction for atherosclerotic cardiovascular disease (ASCVD) risk (China-PAR model) in a prospective cohort of Chinese older adults.Patients and Methods: We assessed 717 older adults aged 75– 85 years without ASCVD at the baseline from the Sichuan province of China. The participants were followed annually from 2011 to 2021. We obtained the participants’ information through the medical records of physical examination and evaluated their 10-year ASCVD risk using FRS, PCE, and China-PAR. We further evaluated the predictive abilities of three assessment models.Results: During the 10-year follow-up, 206 participants developed ASCVD, with an incidence rate of 28.73%. The FRS and China-PAR moderately underestimated the risk of ASCVD (22.1% and 12.4%, respectively), but while PCE overestimated the risk (36.1%). FRS and China-PAR were found to underestimate the risk of ASCVD (26% and 63%, respectively) for men, while PCE overestimated the risk by 8%; For women, FRS and China-PAR were found to underestimate the risk of ASCVD (14% and 35%, respectively), while PCE overestimated the risk by 88%.Conclusion: The 10-year ASCVD risk was found to be overestimated by PCE. China-PAR had the most accurate predictions in women, while FRS was particularly well-calibrated in males. All three risk models have good discrimination, with FRS and PCE being well-calibrated in men and all three being well-calibrated in women. Therefore, accurate risk models are warranted to facilitate the prevention of ASCVD at the baseline among Chinese older adults.Keywords: ASCVD, risk prediction model, FRS, PCE, China-PAR

ABSTRACTThe significant effect of plastic waste separation on quality enhancement of recycled plastics comes with a cost of reduced quantity with its negative implications of higher prices. This paper aims to examine the effect of innovation on the sustainability of plastic circular economy (PCE) using a two-state cyclical dynamic closed model of plastic waste management based on ordinary differential equations. The performances of plastic waste separation models with and without innovation were compared under four pragmatic scenarios; the full force of plastic waste discard and incineration, the single force of plastic waste discard, the single force of plastic waste incineration and the complete riddance of plastic waste discard and incineration. In general, the simulated results evince that PCE cannot be sustained subject to the first three scenarios; it is however, sustainable only under the fourth scenario which endorses the complete prohibition of plastic waste discard and incineration. Under all the scenarios, the innovation-driven separation model outperformed the model without innovation in both the forward and reverse transitional phases of PCE. The paper therefore has policy directives for sustainable: PCE, environment, public health, water resources, climate through reduced greenhouse emission, employment and poverty reduction, which constitute strategic goals of the SDGs.

Cardiovascular disease (CVD) remains the leading cause of mortality worldwide, caused by a complex interplay of genetic and environmental factors. This study aimed to evaluate the combined efficacy of multi-polygenic risk scores and pooled cohort equations (PCE) for predicting future CVD risks in the Korean population. In this longitudinal study, 7,612 individuals from the Ansan and Ansung cohorts were analyzed over a 17-year follow-up period. The participants were genotyped using the Korea Biobank Array, and qualitycontrolled genetic data were subjected to imputation analysis. The weighted sum of the PRSs (wPRSsum) was calculated using PRS-CS with summary statistics from myocardial infarction, ischemic stroke, coronary artery disease, and hypertension genome-wide association studies. The recalibrated PCE was used to assess clinical risk, and the participants were stratified into risk groups based on the wPRSsum and PCE. Associations between these risk scores and incident CVD were evaluated using Cox proportional hazards models and Kaplan-Meier analysis. The wPRSsum approach showed a significant association with incident CVD (HR = 1.15, p = 7.49 × 10-5), and the top 20% high-risk genetic group had an HR of 1.50 (p = 5.04 × 10-4). The recalibrated PCE effectively differentiated between the low and high 10-year CVD risk groups, with a marked difference in survival rates. The predictive models constructed using the wPRSsum and PCE demonstrated a slight improvement in prediction accuracy, particularly among males aged <55 years (C-index = 0.640). We demonstrated that while the integration of wPRSsum with PCE did not significantly outperform the PCE-only model (C-index: 0.703 for combined and 0.704 for PCE-only), it provided enhanced stratification of CVD risk. The highest risk group, identified through the combination of high wPRSsum and PCE scores, exhibited an HR of 4.99 for incident CVD (p = 1.45 × 10-15). These findings highlight the potential of integrating genetic risk assessments with traditional clinical tools for effective CVD risk stratification. Although the addition of wPRSsum to the PCE provided a marginal predictive improvement, it proved valuable in identifying high-risk individuals and supporting personalized treatment strategies. This study reinforces the utility of multi-PRS in conjunction with clinical risk assessment tools, paving the way for more tailored approaches for CVD prevention and management in diverse populations. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have garnered remarkable attention for their efficiency and tunable optoelectronic properties. However, their instability to moisture and heat poses challenges. Traditional trial‐and‐error approaches for finding stable halide perovskites are inefficient due to the vast compositional possibilities within ABX3 perovskite structure. This study uses machine learning (ML) to predict bandgaps and photovoltaic parameters of PSCs, using a dataset of 447 data points containing chemical composition, bandgaps, and photovoltaic parameters. Various ML models including support vector regressor, random forest, gradient boost regressor, XGBoost, extratree Regressor, and AdaBoost Regressor have been used herein. Positional average elemental property (PAEP) approach is introduced to featurize the data. As ABX3 perovskite involves distinct A, B, and X sites, the proposed PAEP model captures site‐specific effects, enhancing model accuracy. The best model exhibits impressive r‐values of 0.98 for bandgap prediction and 0.86 for power conversion efficiency of PSCs. Elemental properties of B and X sites, such as ionization energy, electron affinity, and electronegativity, are found to be crucial features in the analysis by Shapley additive explanation. This study underscores the potential of ML in designing novel, stable, and efficient PSCs, offering a more efficient alternative to conventional trial‐and‐error methods. [ABSTRACT FROM AUTHOR]

This paper presents a high performing Cu(In1 − xGax)Se2 (CIGS) based solar cell that uses naturally abundant and non-toxic InP (indium phosphide) as an electron transport layer and CuI (copper iodide) as a hole transport layer. These materials, InP and CuI, are better replacements for toxic material based solar cells. The proposed structure comprises a glass substrate/n-ZnO (Zinc oxide)/n-InP/p-CIGS/p-CuI/metal electrode. A graded CIGS layer (i.e. varying energy band gap and electron affinity) is used in this structure for a better harvesting of broad spectrum of solar energy. The proposed PV cell is optimized for different band gap grading of CIGS layer to enhance the performance of the cell. For further optimization of the proposed cell, thickness, doping concentration, and defect density of different layers are varied. After optimization, the proposed cell shows a maximum power conversion efficiency of 30.50% (Voc = 0.8857 V, Jsc = 39.57 mA cm−2, FF = 87.05%) for 1100 nm thickness of the CIGS layer. The optimized device is further analyzed for various temperatures and resistances (series and shunt). All the simulations are done at room temperature (300 K) using SCAP-1D software. [ABSTRACT FROM AUTHOR]

Planar n–i–p carbon perovskite solar cells (PSCs) with a hole transport layer that can be fabricated at low temperatures at low‐cost exhibit great potential for large‐scale manufacturing. Moreover, 2D perovskites have attracted considerable attention owing to their higher stability. In this work, scalable and highly efficient fully printed large‐area carbon electrode‐based 2D perovskite modules are reported through the insertion of a thin naphthaleneimide derivative (CATNI)‐based interfacial layer between tin (IV) oxide and the perovskite layer. The results show that this facilitates the formation of the interfacial contact, suppresses energy losses, and substantially improves the performance parameters of the PSCs, especially their VOC value. A significantly enhanced VOC of 1.13 V is achieved resulting in the device PCE value reaching over 18%, which is one of the highest reported for fully printed PSCs so far. It is found that with the deployment of this CATNI‐based interfacial layer, a more efficient carrier extraction is achieved. This ultimately contributed to enhanced spectral response as well as improved VOC for these carbon electrodes based on fully printed devices. Finally, the carbon‐perovskite solar modules (carbon‐PSMs) are fabricated on ITO glass substrates with dimensions of 5.0 × 5.0 cm. These prepared modules exhibited outstanding photovoltaic performance with the highest PCE value of over 14.6%. [ABSTRACT FROM AUTHOR]

Temperature and humidity are the two vital outdoor factors that significantly affect the dye sensitized solar cells (DSSCs) efficiency. The complete performance of DSSCs depends on various aspects including electrolyte properties, dye adsorption over semiconductor, charge separation, etc. Both the temperature and humidity may influence DSSCs on these aspects to affect their performance. In this study, DSSCs were prepared and tested under various temperature and humidity conditions. It was observed that the power conversion efficiency (PCE) of DSSCs was significantly decreased by ~ 48% while the temperature was increased from 25 to 60 °C. Further, the PCE was dropped by ~ 67% when both the temperature and humidity were increased together from 25 to 60 °C and 75 to 100% respectively. High temperature and humid conditions may lead to dye desorption at semiconductor, electrolyte decomposition, and increase charge recombination. High temperature and high humidity exhibited a great impact on the JSC and VOC and hence they decreased the overall performance of the device. This work shall substantially contribute to the understanding of progress of DSSCs for their performance in real weather conditions for possible commercialization. [ABSTRACT FROM AUTHOR]

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Photovoltaic panels play a vital role in expanding renewable energy usage and mitigating environmental impacts. Ensuring the efficient integration of PV panels in diverse regions worldwide relies on precise calculations, considering factors like sunlight variability, climatic conditions, and grid connectivity. This study evaluates the performance of amorphous silicon (a-Si), polycrystalline silicon (pc-Si), and monocrystalline silicon (mc-Si) solar panels in the West Black Sea's Düzce province, Turkey. The respective capacities of these panels are 2.4 kW, 2.64 kW, and 2.35 kW. Over 6 years (2014–2019), we collected detailed data, including temperature, irradiance, wind speed, and power outputs, totaling 7.39 kW. We calculated the performance ratio, power conversion efficiency, and degradation rate for a-Si, pc-Si, and mc-Si panels under varying environmental conditions. The findings showed that a-Si panels had a PR of 71.391%, pc-Si panels scored 75.394%, and mc-Si panels excelled with a PR of 85.113%. The annual average DR relative to PR was − 0.577%/year, − 0.583%/year, and − 0.582%/year, respectively. PCE over the 6-year period was 4.519% for a-Si panels, while pc-Si and mc-Si panels achieved 10.478% and 12.736%. Six-year experimental study conducted in real-world conditions provides highly reliable data valuable to PV panel stakeholders and offers robust insights, particularly regarding region-specific panel selection. The results indicate monocrystalline silicon (mc-Si) as the most suitable PV panel type for Düzce, affirming its potential in the West Black Sea Region. [ABSTRACT FROM AUTHOR]

The numerous defect‐induced non‐radiative recombination losses and residual stress in the preparation of perovskite film greatly hinder the further improvement of the efficiency and stability of flexible perovskite solar cells (PSCs). Here, a natural spice 7‐amino‐4‐(trifluoromethyl)‐2‐benzopyrone (ATB) containing amino (─NH2), carbonyl (─C═O), and trifluoromethyl (─CF3) functional groups is introduced into the perovskite precursor solution, thereby preparing high‐quality perovskite film with low defect density. It is revealed that the utilization of ATB is beneficial to comprehensively passivate the defects and release the residual stress of perovskite film through the synergistic effect of functional groups, thereby improving the crystallinity and enhancing the carrier lifetime of perovskite film. Moreover, the introduction of ATB contributes to an improved energy levels alignment between the perovskite and adjacent layers, which facilitates fast carrier transport and suppresses the recombination loss in the flexible PSCs. Combined with the multifunctional effects of ATB, the target flexible and rigid PSCs with ATB modification yield remarkable photoelectric conversion efficiency (PCE) of 21.08% and 23.79%, respectively. More importantly, the ATB‐modified flexible device exhibits outstanding stability and retains 87.3% and 91.6% of the original efficiency after aging for 3000 h at 50 ± 5 relative humidity and 5000 bending cycles, respectively. [ABSTRACT FROM AUTHOR]

Organic solar cell (OSC) devices suffer from low power conversion efficiency (PCE) due to deep trap states that absorb photogenerated charges, act as recombination centers, and reduce charge collection. To further improve the PCE, an optimized hole transport layer (HTL) must be engineered for efficient hole transport and reduced deep trap states. A hybrid HTL consisting of organic and inorganic materials was formed using a combination of CuO nanoparticles (NPs) having an average size of 50 nm and poly(3-hexylthiophene) (P3HT). The hybrid HTL was used in the fabrication and characterization of an inverted OSC device structure. In consequence, the incorporation of CuO-NPs into the P3HT resulted in an increase of 8.66% in photocurrent density. Additionally, the PCE increased from 3.77 to 4.22% while the open circuit voltage (Voc) was maintained. The higher hole mobility obtained for the optimum device using the charge extraction by increasing voltage (CELIV) measurement was 8.47 × 10− 4 cm2 V− 1 s− 1. This highlights the potential of designing novel organic solar cells with inorganic nanoparticles, offering enhanced performance and efficiency. [ABSTRACT FROM AUTHOR]

As a transmission medium and heating energy, microwave is widely favored due to its high efficiency, strong selectivity, and easy control. Here, the effects of different heating methods (conventional thermal induction (CI) and microwave induction (MI)) on the polymerization rate of polycarboxylate superplasticizer (PCE) were investigated. Compared with CI, MI significantly boosted the polymerization rate (by approximately 51 times) and markedly decreased the activation energy (Ea), from 46.83 kJ mol−1 to 35.07 kJ mol−1. The polar of the monomers and initiators in the PCE synthesis contributes to varying permittivities and loss factors under the microwave field, which are influenced by their concentration and reaction temperature. The insights gained from the microwave thermal effects and the micro-kinetics of the PCE polymerization system are able to propose theoretical underpinnings for the industrial-scale application of microwave induction polymerization, potentially steering the synthesis of polymer materials towards a more efficient and cleaner process. [ABSTRACT FROM AUTHOR]

Sb2Se3 has a high absorption coefficient of 105 cm−1 in the visible light range, which is an excellent absorber layer material. Currently, a better band alignment between conventional CdS and Sb2Se3 has led to the widespread adoption of CdS as the electron transport layer (ETL) in Sb2Se3 solar cells. However, CdS is toxic, necessitating the exploration of alternative ETL materials that are eco-friendly and possess an appropriate energy band with Sb2Se3. In this study, we endeavor to pioneer an all-inorganic, green solar cell structure of Au/MoS2/Sb2Se3/WS2/ITO by employing MoS2 as the hole transport layer (HTL) and WS2 as the ETL. We primarily optimized Sb2Se3 thickness and its hole doping concentration (NA) by SCAPS-1D numerical simulation. Based on the analysis of built-in electric field and carrier recombination rate along Sb2Se3, the optimal thickness and NA ranges of Sb2Se3 are determined, which are 0.9–1.1 μm and 1016-1018 cm−3 respectively. Through a series of optimization, the structure achieves the highest power conversion efficiency (PCE) of about 25.3 % in the current simulation of Sb2Se3 solar cells. After comparing the novel WS2 ETL with the conventional CdS ETL, we find that WS2 has a larger built-in potential (Vbi) and charge recombination resistance (Rrec). In addition, from the analysis of energy band structure, the spike-like band at Sb2Se3/WS2 interface can effectively inhibit the carrier recombination, which makes the device obtain a larger open circuit voltage (VOC) of 0.69 V. This study can provide theoretical reference for the development of non-toxic and efficient Sb2Se3 solar cells.

Perovskite solar cells (PSCs) are a favorable option for the upcoming generation of photovoltaic systems due to their simplicity and high energy conversion efficiency. The third iteration of thin-film solar cells including copper-tin-sulphide (CTS) is easily accessible on Earth, possesses excellent optoelectrical properties, and does not include any harmful substances, making it environmentally sustainable. Using the solar cell capacitance simulator (SCAPS), this study examines the performance of a PSC based on copper oxide (Cu2O) and zinc selenide (ZnSe). The study investigates the factors that influence the performance of CTS-based SCs, such as absorber layer thickness, absorber defect density, interface defect densities, doping densities, and working temperature on the performance of the PSC. The results show that 30.37 % perovskite cell efficiency (PCE) increased from 20.94 % after optimization with 0.9403 V of open circuit voltage, 37.2682 mA/cm2 of short circuit current and 86.67 % of fill factor.

A sufficient green strength of refractory castables is necessary to avoid damage during demoulding and heating up of refractory linings and prefabricated parts. However, there is a lack of knowledge on the mechanisms underlying the build-up of green strength in refractory castables. This work focuses on how green strength is formed within the matrix of PCE-dispersed and CA cement bonded refractory castables during their setting.Setting was monitored using several measuring methods, such as sonic velocity, amount of hydrate phases formed from CA cement, ζ-potential (stability resp. coagulation of the matrix suspension), porosity, and specific surface area and was linked to the corresponding increase of green strength of refractory castables during setting.Considered by time after adding water, the first stiffening of the refractory castables is related to the collapse of the rheological system of their matrix suspension (coagulation), resulting in a very low increase in green strength (apparent hardening). This stiffening occurs early if Ca-precipitates are formed together with molecules of the dispersing agent (Ca-PCE, PCE with short side chains) or if the amount of pore water is being reduced below a critical value (rheologically stable matrix due to dispersion of hydrate phases by PCE with long side chains). The major increase in green strength occurs when a significant amount of CA cement reacts to hydrate phases and, correspondingly, water is being bonded. This main increase in green strength may occur directly after stiffening (if CA cement is being hydrated quickly) or several hours after stiffening (if the hydration of CA cement is retarded).Regarding the green strength, the predominant factor influencing the build-up of green strength in refractory castables is the reduction of free water in the pores due to its bond in hydrate phases (reduction of a lubricating, interparticle water film). Minor influences are the reduction in porosity (volume expansion by hydration of CA cement), the increase in the specific surface area (hydrate phases are finer than the initial CA cement particles), and the entanglement of plate-like hydrate phases.

Recently, a lot of focus has been placed on cesium lead iodide (CsPbI3) since it is considered a potentially useful inorganic halide perovskite with improved stability. Moreover, another potential absorber material is the mixed chalcogenide CZTSSe, which is abundant on Earth, cheap, environmentally acceptable, and has excellent photovoltaic performance. This research numerically simulated a novel double absorber solar cell structure employing CsPbI3 and CZTSSe absorbers in the active layer in SCAPS-1D. The current study analyses the effects of various electron and hole transport materials, back contact material's work functions, working temperatures, variations in defect concentration, and absorber thickness on the performance of photovoltaic devices. After researching a variety of distinct arrangements of double absorber solar cells, it was realized that the FTO/STO/CsPbI3/CZTSSe/NiO/W cell configuration exhibited the best overall performance with an open circuit voltage (Voc) at 1.0207 V, a short circuit current density (Jsc) at 41.815426 mA/cm2, Fill Factor (FF) at 87.50 %, and a Power Conversion Efficiency (PCE) at 37.35 %. The modeling of the device showed that a thickness of around 1.4 µm for the CZTSSe absorber is optimal. This simulation shows that when the working temperature in the cell and the defect concentration in the absorber increase, the efficiency of the device reduces uniformly, and the device is stable at 300 K temperature. In conclusion, if the material's work function is greater than 5.20 eV, then it is suitable for use as an anode.

Background and aimsWe aimed to determine the utility of coronary artery calcium (CAC) for atherosclerotic cardiovascular disease (ASCVD) risk stratification in women with and without early menopause (EM).MethodsTo examine the association between CAC and incident ASCVD, we performed Kaplan-Meier survival analysis and multivariable Cox proportional hazards modeling using data from 2,456 postmenopausal women in the Multi-Ethnic Study of Atherosclerosis (MESA) with or without EM, defined as occurring at 50% of middle-aged postmenopausal women with EM had CAC = 0, similar to those without EM. Among women with CAC = 0, those with EM had a low to borderline 10-year risk of ASCVD, but the 15-year risk was significantly higher for women with EM versus those without EM. When CAC ≥ 1, the incidence of ASCVD was similar for women with and without EM. These findings support the use of CAC to help improve ASCVD risk stratification in women with EM.Condensed abstractThis study investigated the association between coronary artery calcium (CAC) and incident atherosclerotic cardiovascular disease (ASCVD) in postmenopausal women with and without early menopause (EM). We found that >50% of women had CAC = 0 and an associated low-to-borderline 10-year cumulative incidence of ASCVD. However, the risk for ASCVD was significantly higher for women with EM after 15-years follow-up. Additional research is needed to better understand the differences in long-term ASCVD risk between women with and without EM who have CAC = 0.

Abstract Background Adverse childhood experiences (ACE) have been documented to have long-term impacts on sleep disturbances. However, less is known about how ACE co-occurs with positive childhood experiences (PCE) and modulate their effects on adult sleep disturbances, particularly in the context of persistent insomnia. Building on resilience theory, this study aims to examine the interplay between ACE and PCE and their effects on persistent insomnia during emerging adulthood. Methods A total of 2,841 emerging adults were recruited from the Taiwan Youth Project. Persistent insomnia during emerging adulthood was assessed using two adult surveys (mean age = 19.8 and 21.9). The ACE (10 items) and PCE (7 items) were obtained from the baseline survey (mean age = 13.8). A series of logistic regression analyses were conducted. Results Among the emerging adults, 29.22% had persistent insomnia. Consistent with the compensatory model, ACE and PCE exerted opposing effects on persistent insomnia during emerging adulthood. In line with the protective model, the negative effect of ACE is mitigated when individuals have high PCE. However, consistent with the challenge model, the protective effect of PCE on persistent insomnia was inhibited in individuals with four or more ACE. Conclusions PCE serves as a protective factor, shielding emerging adults from the adverse effects of ACE on persistent insomnia. It is essential to prioritize positive experiences during early life to promote lifelong sleep health.

Mechanical grinding is a common method used to enhance the pozzolanic activity of tailings, and these activated tailings can be used as supplementary cementitious materials in cement production. However, the addition of activated tailings usually reduces the workability of cement paste, and the mechanism of influence of different minerals in tailings on workability varies. In this study, three kinds of principal silicate minerals in tailings—quartz, feldspar, and mica—were mechanically activated. The influence of these activated minerals on the rheological properties of cement paste were studied in the absence or presence of PCE (polycarboxylate ether) superplasticizers, and the influence mechanism was investigated using rheology, TOC, contact angles, zeta potential, XPS, ICP-OES, and XRD. The results showed that quartz has the highest fluidity, and mica has the lowest. An increase in hydrophilicity decreased the flowability of the blended cement paste. The increase in the metal cation dissolution rate was the main reason for the decrease in the fluidity of PCE-blended cement pastes. The knowledge gained provides a valuable reference for the utilization of activated tailings in cement production.

Risk for atherosclerotic cardiovascular disease (ASCVD) shows considerable heterogeneity both in generally healthy persons and in those with known ASCVD. The foundation of preventive cardiology begins with assessing baseline ASCVD risk using global risk scores based on standard office-based measures. Persons at low risk are generally recommended for lifestyle management only and those at highest risk are recommended for both lifestyle and pharmacologic therapy. Additional "risk enhancing" factors, including both traditional risk factors and novel biomarkers and inflammatory factors can be used to further assess ASCVD risk, especially in those at borderline or intermediate risk. There are also female-specific risk enhancers, social determinants of health, and considerations for high-risk ethnic groups. Screening for subclinical atherosclerosis, especially with the use of coronary calcium screening, can further inform the treatment decision if uncertain based on the above strategies. Persons with pre-existing ASCVD also have variable risk, affected by the number of major ASCVD events, whether recurrent events have occurred recently, and the presence of other major risk factors or high-risk conditions. Current guidelines define high to very high risk ASCVD accordingly. Accurate ASCVD risk assessment is crucial for the appropriate targeting of preventive therapies to reduce ASCVD risk. Finally, the clinician-patient risk discussion focusing on lifestyle management and the risks and benefits of evidence-based pharmacologic therapies to best lower ASCVD risk is central to this process. This clinical practice statement provides the preventive cardiology specialist with guidance and tools for assessment of ASCVD risk with the goal of appropriately targeting treatment approaches for prevention of ASCVD events.

Background: Adverse childhood experiences (ACE) have been documented to have long-term impacts on sleep disturbances. However, less is known about how ACE co-occurs with positive childhood experiences (PCE) and modulate their effects on adult sleep disturbances, particularly in the context of persistent insomnia. Building on resilience theory, this study aims to examine the interplay between ACE and PCE and their effects on persistent insomnia during emerging adulthood. Methods: A total of 2,841 emerging adults were recruited from the Taiwan Youth Project. Persistent insomnia during emerging adulthood was assessed using two adult surveys (mean age = 19.8 and 21.9). The ACE (10 items) and PCE (7 items) were obtained from the baseline survey (mean age = 13.8). A series of logistic regression analyses were conducted. Results: Among the emerging adults, 29.22% had persistent insomnia. Consistent with the compensatory model, ACE and PCE exerted opposing effects on persistent insomnia during emerging adulthood. In line with the protective model, the negative effect of ACE is mitigated when individuals have high PCE. However, consistent with the challenge model, the protective effect of PCE on persistent insomnia was inhibited in individuals with four or more ACE. Conclusions: PCE serves as a protective factor, shielding emerging adults from the adverse effects of ACE on persistent insomnia. It is essential to prioritize positive experiences during early life to promote lifelong sleep health. [ABSTRACT FROM AUTHOR]

The development of Pb‐free alternatives for perovskite‐based photovoltaics is extremely important due to the toxicity of Pb to the environment. Sn‐based organic inorganic hybrid halide perovskites are considered to be the most suitable alternative to Pb‐based ABX3 perovskites due to their similar optoelectronic properties. The selection of A site cation in ABX3 type perovskites is crucial for favorable structural and mechanical properties. Using first principle methods, we have designed and investigated Sn–I based hybrid halide perovskite materials with different organic cations mixed in equal proportions. Observed tolerance (TF) and octahedral factors (μ) indicate the formation of stable three‐dimensional perovskite structure. Our studied materials also exhibit thermodynamic stability due to the negative value of their formation energies. Observed band gap values indicate the semiconducting nature of our studied perovskite materials. Calculated optical properties indicate that all of the compounds exhibit suitable dielectric functions and absorption coefficients in the visible range of the electromagnetic spectrum. The observed highest value of theoretical power conversion efficiency of MA‐AMSnI3 (11.24%) indicates its potential to be used in photovoltaics. Our investigation will be beneficial for researchers to develop less toxic and efficient perovskite materials for the fabrication of optoelectronic devices. [ABSTRACT FROM AUTHOR]

The effect of resting time on the rheological properties of cement suspensions is generally explained by early formed structure and overconsumption of polycarboxylate superplasticizers (PCEs). In this paper, we propose that the influence of resting time on the rheological properties is closely related to size variation of non‐absorbed PCE. To identify this, glass bead suspensions were prepared with various amounts of PCE and ionic solution, and their rheological properties were evaluated at various times. We found that the yield stress increases with time at higher PCE concentrations and higher ionic strength solutions. Adsorbed PCE during resting tends to bridge the particles rather than disperse them. In addition, it was found that hydrodynamic radius of PCE increased with resting time, and depletion forces resulting from non‐absorbed PCE size changes correlate well with the increased yield stress. [ABSTRACT FROM AUTHOR]

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The toxicity and stability concerns of lead based perovskite solar cells have limited the commercialization. The lead-free Cesium based double perovskite could be a viable answer to these issues. In this present work a theoretical analysis of Cesium based double perovskite solar cell using Spiro-OMeTAD as hole transport layer and effect of different ETLs such as SnO2, ZnO-NR, TiO2 and CdS has been studied. The optimized active layer thickness of 0.3 μm has been used and a device structure of FTO/ETLs/Cs2AgBiBr6/Spiro-OMeTAD/Cu was simulated. The Solar Cell Capacitance Simulator (SCAPS-1D) was used for one dimensional simulation and analysis. The maximum PCE of 5.62 % was found using SnO2 as ETL. The device performance has been optimized by employing various ETLs and the most suitable ETL for this structure was found to be SnO2. The maximum quantum efficiency of 86.09 % has been found for SnO2 electron transport layer. The simulation results obtained in this study are encouraging and will provide insightful guidance in replacing toxic Pb-based perovskite with eco-friendly inorganic perovskite solar cell. [ABSTRACT FROM AUTHOR]

Based on experimental results, this theoretical study presents a new approach for investigating polymers' solar cells. P-type PZT:C1 and N-type PBDB:T were used to construct a blend for use as a photoactive layer for the proposed all-polymer solar cell. Initially, an architecture of an ITO/PEDOT:PSS/PBDB:T/PZT:C1/PFN-Br/Ag all-polymer solar device calibrated with experimental results achieved a PCE of 14.91%. A novel inverted architecture of the same solar device, proposed for the first time in this paper, achieved a superior PCE of 19.92%. Furthermore, the optimization of the doping of the transport layers is proposed in this paper. Moreover, the defect density and the thickness of the polymer are studied, and a PCE of 22.67% was achieved by the optimized cell, which is one of the highest PCEs of polymer solar devices. Finally, the optimized polymer solar cell showed good stability amidst temperature variations. This theoretical study sheds light on the inverted structure of all-polymer solar devices. [ABSTRACT FROM AUTHOR]

The increasing demand for energy and electricity and the depletion of fossil fuels are global problems. In recent years, dye-sensitized solar cell (DSSC) technologies have gained notoriety for their application in solar energy. DSSCs are considered a promising alternative renewable energy source to both inorganic and organic photovoltaic (PV) cells. Many types of dyes are being investigated to enhance the light-harvesting properties of DSSCs, but the actual realization of these absorbers in cell structure requires optimum parameters. The main aim of this study was to simulate proposed zinc phthalocyanine (ZnPC)-based structures to validate their design, assess their performance for commercial implementation, and optimize the cell parameters for optimum efficiency. To that end, Scaps-1D was employed to evaluate the performance of DSSCs to determine their optimum parameters. We found that ZnPC and isopropoxy ZnPC molecules outperform others molecules because of better optoelectronic properties. Several other parametric effects, such as photoactive layer thicknesses, doping densities, trap densities, and charge carrier mobilities, were also evaluated to observe their impact on device performance. The results show that moderate thickness, low defect density, moderate doping, and charge carrier mobility are favorable for better device performance due to low recombination losses, electrical losses, and better transport of charge carriers. The utmost power conversion efficiency values found for ZnPC- and ZnPC: PC70BM-based DSSCs after optimization were 9.50% and 9.81%. This paper also suggests a practical method for efficiently using DSSC cells by modifying factors that are significantly reliant on DSSC performance and output. [ABSTRACT FROM AUTHOR]

The importance of polycarboxylate ethers (PCE) as concrete superplasticizers has significantly increased in recent decades, both technically and commercially. At the least, three descriptors describe the average PCE structure: the side chain length (P), the charge density (N), and the number of repeating units (n). The synthesis parameters determine the average composition of the PCEs and, consequently, their performance in cementitious materials. This study examines the rheological properties of 27 different PCE structures, which were synthesized using redox‐initiated free‐radical copolymerization. We independently varied the parameters P and N and produced three PCEs with different molar weights for each combination of P and N. Cement pastes with low PCE dosages of 0.035 wt% were tested in a rheometer using a plate‐plate geometry. It turns out that when the PCE is added directly to the mixing water, the PCE has a complex influence on the very early hydration. Consequently, the obtained rheology data is not entirely in line with available structure‐activity relationships. Additionally, we attempted to model the observed rheology data based on three structural PCE descriptors. While a multivariate linear regression model failed to accurately describe the relationship, a random forest model delivered a better model. In summary, we conclude that the impact of PCEs on early hydration significantly affects the rheology of the paste. The changed hydration pathway causes a deviation of our results from existing structure‐activity relationships and makes it challenging to statistically model the sparse rheology data with a minimal set of three structural descriptors. [ABSTRACT FROM AUTHOR]

Studies have shown that in an aqueous suspension of inert glass beads, the yield stress is increased as a function of resting time. This study investigates this unexpected phenomenon, focusing on solid surface potentials, PCE size in ionic solutions, and their possible relations to rheological behaviour with resting time. Results indicated that PCE in artificial pore solution will result in a higher yield stress with time. PCE with lower anionic charges and molecular weight can significantly increase the yield stress after 2 h of resting. The absolute value of the zeta potential grows to a certain degree after resting phase. Dynamic light scattering (DLS) results showed that the size of PCE molecules in ionic solutions increases over time, suggesting an enhanced depletion force or bridging force among glass bead particles, which could be the reasons for the increase in yield stress over time. Furthermore, the possible impacts of the depletion force or bridging force resulting from the PCE size change on the rheological properties of cement suspension are discussed. [ABSTRACT FROM AUTHOR]

With over 15 Mio tons of annual production, polycarboxylates (PCEs) currently dominate the global superplasticizer market. Among them, HPEG and IPEG PCEs have attained a prominent position as they present the most cost‐effective PCEs known at present. Recently, new vinyl ether PCEs designated as EPEG and GPEG PCEs were introduced, thus broadening the family of VPEG PCEs. Furthermore, novel phosphated comb polymers which significantly reduce the stickiness of concrete have been developed. For calcined clay blended cements, HPEG PCEs of specific molecular design as well as zwitterionic (amphoteric) PCEs have proven to be highly effective. Moreover, NaOH activated AAS binder systems were successfully fluidized with APEG or HPEG PCEs exhibiting particularly short side chains (nEO < 10). While for Na2CO3, Na2SiO3 and Na2SO4 activated systems, the search for effective superplasticizers is still ongoing. This review underlines the critical role which chemical admixtures will play in the successful transition of the construction industry to a net zero carbon age. [ABSTRACT FROM AUTHOR]

The cement industry is coming into focus, as the annual production of around 4 Gt of cement is responsible for the emission of 1.5 Gt of CO2 and thus for over 8 % of anthropogenic CO2 emissions. This leads to the search for alternative binders. Such binders are calcined clays, which are available worldwide but vary greatly in their chemical and mineralogical composition. In many studies, particularly low‐calcium metakaolin is used as calcined clay, which reacts to form a low‐calcium aluminosilicate binder when mixed with a calcium‐free alkaline activator. The adjustment of the properties in the fresh state, especially regarding the consistency of these binders, is almost exclusively achieved by the addition of water, since commercially available superplasticizers are usually ineffective in low calcium geopolymer systems. The objective of this study was to investigate various PCE superplasticizers (MPEG‐, IPEG‐, HPEG‐PCE) with respect to their stability in different alkaline activators (NaOH, KOH, sodium, and potassium silicate solutions). The effectiveness of superplasticizers in low calcium geopolymer binders was verified by rheological tests. Size exclusion chromatography was used to investigate if structural degradation of the superplasticizers occurs. The investigated PCE superplasticizers showed no liquefying effect in the low calcium geopolymer system. This is due to a degradation process, i.e., the hydrolysis of the PEG side chains depending on the alkalinity of the activator. [ABSTRACT FROM AUTHOR]