The American Petroleum Institute (API) filter press test has been used for decades in the construction industry as part of the quality control regime for bentonite-based excavation support fluids. The industry has carried over the use of this test to polymer fluids despite the lack of published evidence of its suitability for these fluids and the very different mechanisms by which polymer fluids and bentonite slurries achieve excavation support. This paper presents the first systematic investigation of this issue through a combination of laboratory testing and theoretical analysis. The investigation demonstrates the very different behaviours of bentonite slurries and polymer fluids. In contrast to the results for bentonite slurries, API filter press results for polymers are shown to be highly sensitive to the filter paper used. In particular, repeatability testing revealed a substantial variation in the polymer fluid loss rates attributable to three primary factors: (a) the filter paper pore size, (b) filter paper damage resulting from the applied test pressure, (c) apparent 'clogging' of the filter paper pore space. Furthermore, the study demonstrates the poor repeatability of the API filter press test for polymer fluids even when filter papers of the same type are used. Interestingly, analysis of polymer flow with respect to filter paper pore size and the applied pressure showed that the filter papers were behaving as porous media rather than a simple bundle of capillaries; their behaviour could not be modelled using a simple capillary bundle model. Importantly, this finding shows that the filter press may provide a rapid method of assessing the apparent viscosity of polymer fluids in porous media at high shear rates; data which cannot be obtained by rotational viscometry, and which would otherwise require resort to permeameter testing of coarse soils. The investigation demonstrates that the filter press test is not useful for the on-site quality control of polymer fluids but, given the theory presented in the paper, it can be a useful laboratory tool that provides valuable insight into polymer fluid flow behaviour in soils of high hydraulic conductivity, the most challenging soils for polymer fluid support.

Sustainable foam lightweight soil (FLS) with the introduction of solid waste-based binders and dredged mud has shown high engineering and environmental value in expressway reconstruction and extension projects. Accelerated testing through high-temperature curing is considered a crucial method for early-stage assessment of sustainable FLS construction quality. This study aims to explore the curing temperature effect on the strength development of the FLS with different mix proportions and the applicability of accelerated curing method. Strength tests were first conducted on kaolin clay-based FLS with three wet densities and three water contents under different curing temperatures (T), and the strength of the dredged mud-based FLS was also tested to broaden the applicability. Results indicate that higher T and increased wet density significantly enhance the strength of clay-based FLS at any curing age, while higher water content reduces it. The wet density and water content of the proposed FLS recommended in this study considering the strength and lightweight requirements are 800 kg/m3 and 100%, respectively. Moreover, the effectiveness of the accelerated aging method for clay-based FLS is demonstrated by the fact that no dramatic strength loss occurs due to foam expansion and collapse at elevated T of up to 50 degrees C. On this basis, a strength prediction model based on the concept of activation energy is proposed for both kaolin clay-based and dredged mud-based FLS considering the temperature effect. Changes in wet density have a minimal impact on model parameters, but variations in soil type and water content require updating these parameters to ensure prediction accuracy. Finally, an early quality control method is introduced for applying the sustainable FLS in field projects.

The influence of curing temperature on the strength development of cement-stabilized mud has been well documented in terms of strength-increase rate and ultimate strength. However, the strength development model is not mature for the extremely early stages. In addition, there is a lack of studies on quality control methods based on early-stage strength development. This paper presents a strength model for cement-stabilized mud to address these gaps, considering various curing temperatures and early-stage behaviors. In this study, a series of laboratory experiments was conducted on two types of muds treated with Portland blast furnace cement and ordinary Portland cement under four different temperatures. The results indicate that elevated temperatures expedite strength development and lead to higher long-term strength. The proposed model, which combines a three-step conversion process and a hyperbolic model at the reference temperature, enables accurate estimate of the strength development for cement-treated mud with any proportions cured under various temperatures. With this model, a practical early quality control method is introduced for applying cement-stabilized mud in field projects. The back-analysis parameters obtained from a 36-h investigation at temperature of 60 degrees C demonstrated a sufficient accuracy in predicting strength levels in practical applications. (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

Alzheimer's disease (AD) is a complex neurodegenerative disorder that is classically defined by the extracellular deposition of senile plaques rich in amyloid-beta (A beta) protein and the intracellular accumulation of neurofibrillary tangles (NFTs) that are rich in aberrantly modified tau protein. In addition to aggregative and proteostatic abnormalities, neurons affected by AD also frequently possess dysfunctional mitochondria and disrupted mitochondrial maintenance, such as the inability to eliminate damaged mitochondria via mitophagy. Decades have been spent interrogating the etiopathogenesis of AD, and contributions from model organism research have aided in developing a more fundamental understanding of molecular dysfunction caused by A beta and toxic tau aggregates. The soil nematode C. elegans is a genetic model organism that has been widely used for interrogating neurodegenerative mechanisms including AD. In this review, we discuss the advantages and limitations of the many C. elegans AD models, with a special focus and discussion on how mitochondrial quality control pathways (namely mitophagy) may contribute to AD development. We also summarize evidence on how targeting mitophagy has been therapeutically beneficial in AD. Lastly, we delineate possible mechanisms that can work alone or in concert to ultimately lead to mitophagy impairment in neurons and may contribute to AD etiopathology.

Terrain displacement due to the seasonal thaw of the active layer above permafrost can be sensitive to climate change; however, its accurate characterization remains a challenge. This study aimed to improve the measurement of the subsidence or vertical ground surface displacement using differential synthetic aperture radar interferometry (InSAR). Existing methods for reliable phase unwrapping are hindered by the decorrelation between time -series of SAR acquisitions that can result due to the heterogeneity and structural sensitivity of permafrost landscapes to external conditions. In this study, an advanced phase unwrapping method was proposed, in which three types of regions, namely non-residue, sparse residue, and dense residue objects, were obtained from wrapped interferogram and residue map using a segmentation method. Two variants of Polynomial-Based Region Growing Phase Unwrapping (PBRGPU) were developed, which are sparse-residue Object-based PBRGPU(SOP) and dense-residue Object-based PBRGPU(DOP). The results demonstrated that the proposed method outperformed the existing phase unwrapping methods by partially suppressing the decorrelation phase and enhancing robustness for complex terrain deformation in the absence of measured field data. Both the PBRGPU variants and segmentation strategies compose the object-based unwrapping method for permafrost, and also provide a new framework by combining the segmentations and scenarios for phase unwrapping for permafrost regions.

This study explores the potential of X-ray fluorescence (XRF) as a rapid, nondestructive, and cost-effective technique for in situ sulfate quantification. Gypsum, the main source of sulfate in soils, reacts with calcium -based stabilizers to form expansive minerals, which reduces the longterm strength of the treated soil. Therefore, accurate detection of sulfate content prior to employing calcium -based chemical stabilization is important to mitigate the possibility of expansive mineral formation and ensure acceptable engineering behavior of the stabilized soil. Portable handheld XRF (PXRF) has shown the ability to estimate gypsum content accurately, utilizing calcium as a proxy. However, detecting sulfur, in the form of sulfite or sulfate remains challenging due to device sensitivity limitations. This research aims to address this limitation and develop a method for direct sulfur detection, enhancing the utility of PXRF for in situ sulfate quantification. Laboratory standards were created with known amounts of gypsum and portions were sent to a commercial laboratory for whole rock analysis. The remainder of the reference standards were used to calibrate several soil library standards within the PXRF. The calibrated PXRF was able to accurately detect the anhydrous form of gypsum, anhydrite (CaSO4), 4 ), in these reference standards for contents ranging from 0 to 8 %. The proposed XRF-based approach offers the potential to revolutionize sulfate detection in soils, providing a rapid and reliable tool for assessing soil stability and optimizing chemical stabilization efforts. By enabling real-time, on -site analysis, this method holds promise for improving construction practices and reducing the risk of structural damage associated with soils containing sulfatebearing minerals.