Local Degradation Research Articles

Underwater image co-enhancement based on physical-guided transformer interaction

Most existing underwater image enhancement methods only focus on enhancing a single image. However, underwater images taken in the same scene often exhibit similar degradation characteristics, which can provide richer complementary information to each other. In this paper, a novel underwater image co-enhancement based on physical-guided Transformer interaction (UICE-PTI), which adopts a multi-scale encoder–decoder structure to effective mine the rich semantic information, is proposed. Specifically, considering that the degradation of underwater image is directly related to scene depth, the Dark Channel Prior-guided Transformer (DCPT) module is embedded into the framework before the preliminary feature extraction. Then, the convolution operation in the preliminary feature extraction is proposed for the local degradation of the underwater image. After that, considering the non-local and heterogeneous degradation of the underwater images across different channels and pixels, the CS-Transformer block with second-order statistics is proposed, which incorporates both channel and spatial Transformer modules. Furthermore, considering the rich complementary information between images of the same scene for enhancement, the Feature Transformer Interaction Module (FTIM) is proposed to capture the correlation between two branches in the network bottleneck layer. Additionally, the proposed UICE-PTI can also be extended to underwater stereo image enhancement. Finally, the experimental results demonstrate the superior performance of the proposed UICE-PTI and the effectiveness of each module.

First Validation of Robust REBCO Insert Concept on a Large 20-Pancake Prototype Reaching Up to 25 T

We recently proposed a robust REBCO HTS (RareEarth BaCuO) insert coil concept in the framework of a project to upgrade the 25 T Cryogen-Free Superconducting Magnet at the High Field Laboratory For Superconducting Materials to reach 30 T. In this concept, the conductor consists of a two-tape bundle to mitigate the risks posed by local tape degradation. So-called edge impregnation is used to enhance the mechanical stiffness while reducing delamination risk, providing conduction-cooling capability at the same time. This insert is to be protected against the risk of thermal runaway simply by using dump resistor, thanks to an early detection concept. The different ideas forming the robust REBCO insert coil concept were tested successfully on various small scale prototypes. We report here their first implementation on a large-size insert coil, consisting of 20 stacked pancakes from the 30 T CSM upgrade insert. The mechanical behavior of the coil is modelled and validated with experiments. The thermal runaway detection setup is introduced. Its sensitivity and selectivity is discussed based on previous works on thermal runaway scenarios.

5D Analysis of Capacity Degradation in Battery Electrodes Enabled by Operando CT-XANES.

For devices encountering long-term stability challenges, a precise evaluation of degradation is of paramount importance. However, methods for comprehensively elucidating the degradation mechanisms in devices, particularly those undergoing dynamic chemical and mechanical changes during operation, such as batteries, are limited. Here, a method is presented using operando computed tomography combined with X-ray absorption near-edge structure spectroscopy (CT-XANES) that can directly track the evolution of the 3D distribution of the local capacity loss in battery electrodes during (dis)charge cycles, thereby enabling a five-dimensional (the 3D spatial coordinates, time, and chemical state) analysis of the degradation. This paper demonstrates that the method can quantify the spatiotemporal dynamics of the local capacity degradation within an electrode during cycling, which has been truncated by existing bulk techniques, and correlate it with the overall electrode performance degradation. Furthermore, the method demonstrates its capability to uncover the correlation among observed local capacity degradation within electrodes, reaction history during past (dis)charge cycles, and electrode microstructure. The method thus provides critical insights into the identification of degradation factors that are not available through existing methods, and therefore, will contribute to the development of batteries with long-term stability.

Vimentin-mediated myosin 10 aggregation at tips of cell extensions drives MT1-MMP-dependent collagen degradation in colorectal cancer.

Colorectal cancer (CRC) is a high prevalence adenocarcinoma with progressive increases in metastasis-related mortality, but the mechanisms governing the extracellular matrix (ECM) degradation important for metastasis in CRC are not well-defined. We investigated a functional relationship between vimentin (Vim) and myosin 10 (Myo10), and whether this relationship is associated with cancer progression. We tested the hypothesis that Vim regulates the aggregation of Myo10 at the tips of cell extensions, which increases membrane-type 1 matrix metalloproteinase (MT1-MMP)-associated local collagen proteolysis and ECM degradation. Analysis of CRC samples revealed colocalization of Vim with Myo10 and MT1-MMP in cell extensions adjacent to sites of collagen degradation, suggesting an association with local cell invasion. We analyzed cultured CRC cells and fibroblasts and found that Vim accelerates aggregation of Myo10 at cell tips, which increases the cell extension rate. Vim stabilizes the interaction of Myo10 with MT1-MMP, which in turn increases collagenolysis. Vim depletion reduced the aggregation of Myo10 at the cell extension tips and MT1-MMP-dependent collagenolysis. We propose that Vim interacts with Myo10, which in turn associates with MT1-MMP to facilitate the transport of these molecules to the termini of cell extensions and there enhance cancer invasion of soft connective tissues.

A similarity-based remaining useful life prediction method using multimodal degradation features and adjusted cosine similarity

When a large amount of full life-cycle data are available, similarity-based methods are the preferred method for remaining useful life (RUL) prediction due to their reliability and accuracy. Traditional similarity-based RUL prediction methods use a single model and single-scale degradation features, which are incapable of fully capturing the degradation behavior of the system. Additionally, the similarity of spatial orientation is neglected in the similarity-matching process. To fill these research gaps, a novel method is developed based on multimodal degradation features and adjusted cosine similarity (ACS) to tackle complex-system RUL prediction in this paper. Complete ensemble empirical mode decomposition with adaptive noise is employed to decouple global degradation and random fluctuations in run-to-failure sensor data. Slow feature analysis is utilized to obtain local degradation features, and residual terms are used as global degradation features. Then, multimodal degradation features are transformed into one-dimensional health degradation indicators by bidirectional gated recurrent unit autoencoder. An ACS is developed to estimate the matching similarity between the test degradation curve and the training degradation curve. The proposed scheme captures the time-varying multimodal degradation behavior and provides libraries of health curves with multiple degradation patterns. The designed scheme is evaluated on the C-MAPSS dataset and the results illustrate the competitiveness and effectiveness of the proposed method.

Thermo-Electro-Mechanical Modeling and Experimental Validation of Thickness Change of a Lithium-Ion Pouch Cell with Blend Positive Electrode

Lithium-ion battery cells exhibit a complex and nonlinear coupling of thermal, electrochemical, and mechanical behavior. In order to increase insight into these processes, we report the development of a pseudo-three-dimensional (P3D) thermo-electro-mechanical model of a commercial lithium-ion pouch cell with graphite negative electrode and lithium nickel cobalt aluminum oxide/lithium cobalt oxide blend positive electrode. Nonlinear molar volumes of the active materials as function of lithium stoichiometry are taken from literature and implemented into the open-source software Cantera for convenient coupling to battery simulation codes. The model is parameterized and validated using electrical, thermal and thickness measurements over a wide range of C-rates from 0.05 C to 10 C. The combined experimental and simulated analyses show that thickness change during cycling is dominated by intercalation-induced swelling of graphite, while swelling of the two blend components partially cancel each other. At C-rates above 2 C, electrochemistry-induced temperature increase significantly contributes to cell swelling due to thermal expansion. The thickness changes are nonlinearly distributed over the thickness of the electrode pair due to gradients in the local lithiation, which may accelerate local degradation. Remaining discrepancies between simulation and experiment at high C-rates might be attributed to lithium plating, which is not considered in the model at present.

Hepatic depletion of nucleolar protein mDEF causes excessive mitochondrial copper accumulation associated with p53 and NRF1 activation

Copper is an essential component in the mitochondrial respiratory chain complex IV (cytochrome c oxidases). However, whether any nucleolar factor(s) is(are) involved in regulating the mitochondrial copper homeostasis remains unclear. The nucleolar localized Def-Capn3 protein degradation pathway cleaves target proteins, including p53, in both zebrafish and human nucleoli. Here, we report that hepatic depletion of mDEF in mice causes an excessive copper accumulation in the mitochondria. We find that mDEF-depleted hepatocytes show an exclusion of CAPN3 from the nucleoli and accumulate p53 and NRF1 proteins in the nucleoli. Furthermore, we find that NRF1 is a CAPN3 substrate. Elevated p53 and NRF1 enhances the expression of Sco2 and Cox genes, respectively, to allow more copper acquirement in the mDefloxp/loxp, Alb:Cre mitochondria. Our findings reveal that the mDEF-CAPN3 pathway serves as a novel mechanism for regulating the mitochondrial copper homeostasis through targeting its substrates p53 and NRF1.

Underwater Ranker: Learn Which Is Better and How to Be Better

In this paper, we present a ranking-based underwater image quality assessment (UIQA) method, abbreviated as URanker. The URanker is built on the efficient conv-attentional image Transformer. In terms of underwater images, we specially devise (1) the histogram prior that embeds the color distribution of an underwater image as histogram token to attend global degradation and (2) the dynamic cross-scale correspondence to model local degradation. The final prediction depends on the class tokens from different scales, which comprehensively considers multi-scale dependencies. With the margin ranking loss, our URanker can accurately rank the order of underwater images of the same scene enhanced by different underwater image enhancement (UIE) algorithms according to their visual quality. To achieve that, we also contribute a dataset, URankerSet, containing sufficient results enhanced by different UIE algorithms and the corresponding perceptual rankings, to train our URanker. Apart from the good performance of URanker, we found that a simple U-shape UIE network can obtain promising performance when it is coupled with our pre-trained URanker as additional supervision. In addition, we also propose a normalization tail that can significantly improve the performance of UIE networks. Extensive experiments demonstrate the state-of-the-art performance of our method. The key designs of our method are discussed. Our code and dataset are available at https://li-chongyi.github.io/URanker_files/.

Multi-functional regulation of cGAS by the nuclear localization signal2 (NLS2) motif: Nuclear localization, enzyme activity and protein degradation

Cyclic GMP-AMP synthase (cGAS), which recognizes double-stranded DNA (dsDNA) and activates the innate immune system, is mainly localized in the cytosol, but also shows nuclear localization. Here, we sought to determine the role of nuclear cGAS by mutating known nuclear localization signal (NLS) motifs in cGAS and assessing its functionality by monitoring phosphorylation of the downstream target, interferon regulatory factor-3 (IRF3). Interestingly, NLS2-mutated cGAS failed to promote phosphorylation of IRF3, reflecting the loss of its ability to produce cyclic GMP-AMP (cGAMP). We further found that insertion of an NLS from SV40 large T antigen could not restore this loss of activity, indicating that this loss was attributable to the mutation of NLS2 itself, but not dependent on the inability of cGAS to enter the nucleus. NLS2-mutant cGAS protein also showed decreased stability dependent on polyubiquitination, an effect that was independent of both its loss of catalytic function and its inability to enter into the nucleus. Collectively, these findings indicate that the NLS2 motif of cGAS is not only involved in regulating the subcellular localization of cGAS protein but also influences its stability and enzymatic activity through independent mechanisms, highlighting the novel roles of NLS2 in regulating the intracellular functions of cGAS.

Strain-based analysis of reinforced concrete pull-out tests under monotonic and repeated loading

This paper presents the results of an experimental campaign on standard pull-out specimens instrumented with refined strain measurement techniques. The quasi-continuous strain measurements allowed the derivation of experimentally substantiated local bond stress-slip relationships for static and repeated loading. It was shown that the force transfer between concrete and reinforcement along the bond length is not uniform and that redistribution occurs with increasing as well as repeated load. The variation of bond stresses along the bond length is of great importance for fatigue studies, as the fatigue damage depends on the level of the applied stress. In addition, the refined measurements revealed non-uniformities in the unloading behaviour. Thus, a slip reversal occurs mainly on the loaded side of the pull-out specimen. The experiments confirmed that the residual nominal bond strength after repeated loading does not significantly vary from the initial bond strength, and the redistribution capacity was identified as a possible cause. The comparison with the nominal bond-slip relationship obtained in a conventional test setup agreed well with the mean value of the refined measurements. However, local degradation processes, such as fatigue, cannot be investigated properly with conventional pull-out tests.

Research on the Characteristics of Thermosyphon Embankment Damage and Permafrost Distribution Based on Ground-Penetrating Radar: A Case Study of the Qinghai–Tibet Highway

In order to research the special embankment (thermosyphon embankment) damages and the distribution of permafrost under the Qinghai–Tibet Highway (QTH) embankment. The section K2952–K2953, which is a typical representative of the QTH, was chosen for the detection and research of the permafrost and embankment damages in order to determine the sources of the damages. In this study, the performance characteristics of the embankment, the active layer, and the permafrost table found in ground-penetrating radar (GPR) images were researched, combined with multi-source. According to the research findings, the construction of the embankment in this section has stabilized the effect on the permafrost table. Under the embankment of the unemployed thermosyphon section, the permafrost distribution has good structural integrity and continuity, with the permafrost table at a depth of around 5 m. The continuity of the permafrost distribution under the embankment in the thermosyphon section was poor, and there was localized degradation, with the permafrost table being approximately 6 m deep. The main cause of the irregular settlement and other damage in this section is the presence of a loose area at the base of the embankment. Although the thermosyphon on both sides of the embankment also plays a role in lifting the permafrost table, it is not ideal for managing the damage to high embankments where the type of permafrost under the embankment is high-temperature permafrost with a high ice content and where the sunny–shady slope effect is obvious. The research results described in this article can therefore provide a crucial foundation for the detection of highway damage and permafrost under embankments in permafrost regions in the future.

Solid Oxide Cell Performance: Spatially Resolved Oxygen Electrode Stability

Several aspects of TNO SOC performance characteristics will be discussed, with a focus on steam electrolysis performance and lifetime behaviour during endurance tests of several thousand hours. Excellent steam electrolysis performance of the TNO SOE cells is observed at thermoneutral voltage, achieving current density values of −1.7 A/cm2 at an operating temperature of 750 °C. Lifetime assessment and material degradation of the SOC will be discussed, with a focus on the analysis of observed degradation phenomena in the oxygen electrode material. As oxygen electrode degradation can be critical for SOC performance in a stack environment, it is important to have a good understanding of the degradation processes and the ability to monitor them. At TNO, a novel approach of high-resolution 2D mapping of the lateral conductivity of the oxygen electrode has been used as an effective tool for quality control and validation of the oxygen electrode development. Additionally, the combination of 2D sheet resistance mapping, SEM-EDX and XRD techniques provides a powerful combination of tools to obtain a spatially resolved (3D) view of the localized degradation observed in the oxygen electrode after several thousand hours of steam electrolysis.

Medium-Range Aircraft Conceptual Design from a Local Air Quality and Climate Change Viewpoint

This paper presents an overall performance assessment of hybrid-electric medium-range transport aircraft, with the aim to evaluate the potential of such a propulsion technology towards the reduction in the environmental impact of aviation transport, in terms of both local air quality degradation in airport areas and climate change. The proposed approach presents distinct analyses of the environmental impact of transport aircraft, distinguishing climate-changing effects from local pollution effects so that the integration of hybrid-electric propulsion is carried out to face the two issues specifically. The proposed analysis, although of conceptual nature, presents a clear scenario in which, given the technological limitations of batteries, the use of hybrid-electric propulsion on medium-haul aircraft can only be useful to reduce local pollution. In contrast, other solutions are needed to mitigate the climate-changing impact.

A first-principles study on the early-stage corrosion of a NiWNb alloy in a chloride salt environment

In this work a representative nickel superalloy, Ni70W20Nb10, was investigated in the presence of chlorine to quantify its early-stage dissolution behavior. Surface structures were generated from a bulk configuration sampled in equilibrium using a multi-cell Monte Carlo method for phase prediction. The predicted solid-phase at 800∘C was Ni72W19Nb9 in a body-centered tetragonal crystal structure closely resembling the Ni4W structure. Chlorine adsorption onto the energetically favored (110) surface showed preference to niobium which acted as a trapping sink on the top surface of the slab model. Our findings suggested that niobium and tungsten enhanced the corrosion resistance of nickel as their presence created regions that were thermodynamically preferred by the incoming chlorine and less susceptible to chlorine-facilitated dissolution from the alloy. Nickel, niobium, and tungsten resisted chlorine-induced dissolution from the surface model up to a 1/3 monolayer coverage of chlorine indicating that all constituents of this alloy possessed superior resistance to localized surface degradation such as corrosive pitting. Further analysis and comparisons between the corrosion resistance of the three metallic species was performed. This work may provide insights that aid in the development of improved structural materials for molten salt reactors.

Duodenal macrophages control dietary iron absorption via local degradation of transferrin

AbstractIron is an essential cellular metal that is important for many physiological functions including erythropoiesis and host defense. It is absorbed from the diet in the duodenum and loaded onto transferrin (Tf), the main iron transport protein. Inefficient dietary iron uptake promotes many diseases, but mechanisms regulating iron absorption remain poorly understood. By assessing mice that harbor a macrophage-specific deletion of the tuberous sclerosis complex 2 (Tsc2), a negative regulator of mechanistic target of rapamycin complex 1 (mTORC1), we found that these mice possessed various defects in iron metabolism, including defective steady-state erythropoiesis and a reduced saturation of Tf with iron. This iron deficiency phenotype was associated with an iron import block from the duodenal epithelial cells into the circulation. Activation of mTORC1 in villous duodenal CD68+ macrophages induced serine protease expression and promoted local degradation of Tf, whereas the depletion of macrophages in mice increased Tf levels. Inhibition of mTORC1 with everolimus or serine protease activity with nafamostat restored Tf levels and Tf saturation in the Tsc2-deficient mice. Physiologically, Tf levels were regulated in the duodenum during the prandial process and Citrobacter rodentium infection. These data suggest that duodenal macrophages determine iron transfer to the circulation by controlling Tf availability in the lamina propria villi.

Experimental Investigation on Reversible Swelling Mechanisms of Lithium-Ion Batteries under a Varying Preload Force

The safety of lithium-ion batteries has to be guaranteed over the complete lifetime considering geometry changes caused by reversible and irreversible swellings and degradation mechanisms. An understanding of the pressure distribution and gradients is necessary to optimize battery modules and avoid local degradation bearing the risk of safety-relevant battery changes. In this study, the pressure distribution of two fresh lithium-ion pouch cells was measured with an initial preload force of 300 or 4000 N. Four identical cells were electrochemically aged with a 300 or 4000 N preload force. The irreversible thickness change was measured during aging. After aging, the reversible swelling behavior was investigated to draw conclusions on how the pressure distribution affected the aging behavior. A novel test setup was developed to measure the local cell thickness without contact and with high precision. The results suggested that the applied preload force affected the pressure distribution and pressure gradients on the cell surface. The pressure gradients were found to affect the locality of the irreversible swelling. Positions suffering from large pressure variations and gradients increased strongly in thickness and were affected in terms of their reversible swelling behavior. In particular, the edges of the investigated cells showed a strong thickness increase caused by pressure peaks.

Process optimization of nanosecond pulsed packed‐bed discharge plasma for SF6 degradation based on response surface methodology

AbstractIn this work, a nanosecond pulsed packed‐bed discharge (PBD) plasma was developed for SF6 degradation under different dilution gases. The discharge form transfers from filamentary discharge to the combination of surface discharge and microdischarge after introducing the packing material regardless of the dilution gas used, and the local electric field strength and SF6 degradation performance are promoted. The mean electron energy and rate coefficient for SF6 excitation in SF6/Ar system are significantly higher than those in SF6/N2 or SF6/air system, which results in higher SF6 degradation efficiency in SF6/Ar system. Moreover, the response surface methodology based on the Box–Behnken design model was constructed to optimize several key process parameters including pulsed voltage, gas flow rate, oxygen content, and relative humidity, as well as assess the contribution of each parameter to SF6 degradation. The proposed optimization model shows a satisfactory correlation between the predicted and the experimental results. The energy yield concerning SF6 degradation in nanosecond pulsed PBD plasma achieves approximately 75.3 g/kWh with nearly complete degradation. This work is expected to provide an efficient and energy‐saving plasma technique for SF6 degradation.

Modeling and simulation of zero-group velocity combined harmonic generated by guided waves mixing

In this paper, modelling and numerical perspective of zero-group velocity (ZGV) combined harmonic generated by guided waves mixing are investigated. The conditions for the generation of the ZGV combined harmonic are analyzed by S0-S0 and SH0-SH0 guided waves mixing in an isotropic plate, respectively. The generation of ZGV combined harmonics at sum frequency caused by counter-directional guided waves mixing is observed. It is confirmed that the ZGV combined harmonic with a considerable magnitude can be generated by this counter-directional guided waves mixing when both the internal resonant condition and non-zero power flux are satisfied. The application of generated ZGV combined harmonics for localized material degradation assessment is numerically examined in the given plate. The obtained results indicate that the generated ZGV combined harmonic induced by the counter-directional guided waves mixing can be used to assess the localized material degradation with improved signal-to-noise ratio. This study provides an insight into the physical process of the ZGV combined harmonic generation, and meanwhile offer a promising means for localized material degradation assessment by ZGV combined harmonics generated by guided waves mixing.

NTSR1 glycosylation and MMP dependent cleavage generate three distinct forms of the protein

NTSR1 abnormal expression by cancer cells makes it a strategic target for antitumoral therapies, such as compounds that use NTSR1 binding probes to deliver cytotoxic agents to tumor cells. Success of these therapies relies on NTSR1 protein availability and accessibility; therefore, understanding the protein’s biology is crucial. We studied NTSR1 protein in exogenously and endogenously expressing non-tumoral and tumoral cells. We found NTSR1 to be expressed as three distinct protein forms: the NTSR1-high form, a glycosylated protein; the NTSR1-low form, a N-terminally cleaved and de-glycosylated protein; and the NTSR1-LP protein with the MW size predicted by its NTSR1 amino acid sequence. We show that the NTSR1-high form is cleaved by MMPs to generate the NTSR1-low form, a process that is promoted by the Neurotensin (NTS) ligand. In addition, NTS induced the internalization of plasma membrane localized NTSR1 and degradation of NTSR1-low form via the proteasome. Importantly, we found NTSR1-low form to be the most abundant form in the tumoral cells and in PDAC Patient Derived Xenograft, demonstrating its physiopathological relevance. Altogether, our work provides important technical and experimental tools as well as new crucial insights into NTSR1 protein biology that are required to develop clinically relevant NTSR1 targeting anti-tumoral therapies.

Mask‐guided image person removal with data synthesis

AbstractAs a special case of common object removal, image person removal is playing an increasingly important role in social media and criminal investigation domains. Due to the integrity of person area and the complexity of human posture, person removal has its own dilemmas. In this paper, a novel idea is proposed to tackle these problems from the perspective of data synthesis. Concerning the lack of a dedicated dataset for image person removal, two dataset production methods are proposed to automatically generate images, masks and ground truths, respectively. Then, a learning framework similar to local image degradation is proposed so that the masks can be used to guide the feature extraction process and more texture information can be gathered for final prediction. A coarse‐to‐fine training strategy is further applied to refine the details. The data synthesis and learning framework combine well with each other. Experimental results verify the effectiveness of the method quantitatively and qualitatively, and the trained network proves to have good generalization ability either on real or synthetic images.