Layer Thickness Research Articles

Achieving beyond 30% efficiency for hole-transport-layer-free CsSnI3 perovskite solar cell: a comprehensive simulation study

In recent years, the growing significance of lead-free CsSnI3 perovskite can be credited to its outstanding optoelectronic properties and environmentally friendly nature. Nevertheless, the photovoltaic potential of CsSnI3 is limited due to challenges in achieving defect-free device structures. The current study thoroughly analyzed the performance of CsSnI3-based perovskite solar cells (PSCs) using the SCAPS-1D software. An in-depth investigation was performed on multiple physical parameters, including the thickness of perovskites layer, acceptor density (NA), operating temperature, defect densities, shunt resistance (RSh) and series resistance (RS). This comprehensive study aimed to identify the optimal device configuration that yields the highest power conversion efficiency (PCE) for the hole-transport-layer (HTL)-free CsSnI3-based PSCs. The obtained results confirmed that it is crucial to decrease the number of defects (Nt) at the perovskites/electron transport layer (ETL) interface to improve the efficiency of CsSnI3-based PSCs. The optimized device demonstrated exceptional performance, achieving an open-circuit voltage (VOC) of 1.12 V, a fill factor (FF) of 85.08%, a short-circuit current density (JSC) of 33.29 mA cm−2 and an efficiency of 31.87%. This high efficiency simulated result provide valuable insights into the design of high-performance CsSnI3-based PSCs, paving the way for potential breakthroughs in cost-effective and eco-friendly solar energy technologies.

Towards MnN as a replacement for IrMn

There is an urgent need to identify new antiferromagnetic materials that offer a replacement for IrMn alloys for room temperature and above applications. This is driven by the scarcity and high cost of Ir. Recently, MnN with {002} texture grown on a Ta seed layer has been proposed as a cost-effective alternative. However, two key issues need to be addressed before this material can be considered a realistic alternative to IrMn: thick layers of approximately 30 nm are required due to its relatively low magnetocrystalline anisotropy and nitrogen diffusion into the Ta layer at relatively low temperatures results in poor temperature performance. In this work, we show a potential pathway to overcome these issues. By using a W rather than a Ta seed layer, N diffusion is minimized, if not eliminated, at temperatures exceeding 300∘C\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$300\\,^{\\circ }\\hbox {C}$$\\end{document}. Furthermore, preferential {111} growth is achieved and a significantly enhanced anisotropy, 2.6·106erg/cm3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$2.6 \\cdot 10^{6}\\,\\hbox {erg}/\\hbox {cm}^{3}$$\\end{document}, has been measured. This value is almost identical to that measured for 3D randomly oriented IrMn.

Enhancing Multi-Junction Solar Cell Performance: Advanced Predictive Modeling and Cutting-Edge CIGS Integration Techniques

Historically, multi-junction solar cells have evolved to capture a broader spectrum of sunlight, significantly enhancing efficiency beyond conventional solar technologies. In this study, we utilized Silvaco TCAD tools to optimize a five-junction solar cell composed of AlInP, AlGaInP, AlGaInAs, GaInP, GaAs, InGaAs, and Ge, drawing on advancements documented in the literature. Our research focused on optimizing these cells through sophisticated statistical modeling and material innovation, particularly examining the relationship between layer thickness and electrical yield under one sun illumination. Employing III-V tandem solar cells, renowned for their superior efficiency in converting sunlight to electricity, we applied advanced statistical models to a reference solar cell configured with predefined layer thicknesses. Our analysis revealed significant positive correlations between layer thickness and electrical performance, with correlation coefficients (R2 values) impressively ranging from 0.86 to 0.96 across different regions. This detailed statistical insight led to an improvement in overall cell efficiency to 44.2. A key innovation in our approach was replacing the traditional germanium (Ge) substrate with Copper Indium Gallium Selenide (CIGS), known for its adjustable bandgap and superior absorption of long-wavelength photons. This strategic modification not only broadened the absorption spectrum but also elevated the overall cell efficiency to 47%. Additionally, the optimization process involved simulations using predictive profilers and Silvaco Atlas tools, which systematically assessed various configurations for their spectral absorption and current–voltage characteristics, further enhancing the cell’s performance. These findings underscore the critical role of precise material engineering and sophisticated statistical analyses in advancing solar cell technology, setting new efficiency benchmarks, and driving further developments in the field.

Non-destructive testing for thickness measurement of the adhesive layer and defect detection in ceramic-metal bonded structures using THz waves

Ceramics, owing to their superior thermal barrier properties, are employed by bonding them to primary structures exposed to elevated temperatures, such as the external components of aircraft and spacecraft. However, when these bonded structures are subjected to thermal impact resulting from high-temperature environments or rapid temperature variations, issues such as debonding, crack formation, and degradation may ensue. These issues can significantly undermine the reliability of the structures, necessitating nondestructive testing (NDT) to monitor the condition of the adhesive layer before and after thermal impact. In this article, we evaluated the integrity of adhesive structures before and after thermal impact using Terahertz (THz) waves, which offer exceptional penetration and resolution for NDT of nonmetallic materials without causing damage to the structure. To achieve this, ceramic-metal bonded structures were mounted on a robotic arm, and scanning was performed over a 70 mm area at 1 mm intervals and 0.5° increments. The peak-to-peak time of the THz signal through the adhesive layer was calculated to determine the thickness distribution. Based on experimental results, the average thickness of the ceramic layer before thermal shock was measured at 9.48 mm (standard deviation: 0.03) and the average thickness of the adhesive layer was 0.234 mm (standard deviation: 0.03). Additionally, four suspected defect areas within the adhesive layer were identified. After thermal shock, the ceramic layer’s thickness decreased by an average of 0.02 mm (0.17%), resulting in an average thickness of 9.46 mm, and the adhesive layer’s thickness decreased by an average of 0.002 mm (0.99%), resulting in an average thickness of 0.232 mm. The four suspected defect areas were confirmed to be in the same locations before thermal impact. To validate the NDT method using THz wave, the ceramic-metal bonded structure was cut to identify debonding defects in the suspected areas. The difference between the thickness distribution obtained using the THz wave-based NDT and that measured using optical microscopy after cutting was 4.4%, confirming the accuracy of the THz wave-based method for defect detection and thickness measurement.

Evaluation of the effect of binder type and layer thickness on the performnce of open graded friction courses

To improve the long-term durability and functionality of open graded friction courses (OGFC), the Florida Department of Transportation (FDOT) investigated the use of a highly modified asphalt binder and increased thickness using Accelerated Pavement Testing (APT). A total of six test sections with combinations of two modified binder types (PG 76–22 and PG 82–22) and three lift thicknesses of 0.75 (19.05 mm), 1.25 (31.75 mm) and 2 (50.8) inches were constructed at FDOT’s APT facility. Accelerated loading was performed using a Heavy Vehicle Simulator (HVS) to evaluate the relative rutting performance of the test sections. Supplementary field and laboratory tests to evaluate tensile strength, Cantabro loss, field permeability, surface characteristics, and asphalt binder properties were also conducted. Test results indicated that the use of PG 82–22 polymer modified asphalt (PMA) binder may be beneficial to improve long-term durability of the OGFC. Thicker layers of OGFC were found to have considerably lower durability. It is recommended that the use of a highly modified PMA asphalt binder in OGFC layers be considered when raveling and other durability issues are of concern.

Investigation of chimeric transcripts derived from LINE-1 and Alu retrotransposons in cerebellar tissues of individuals with autism spectrum disorder (ASD)

LINE-1 and Alu retrotransposons are components of the human genome and have been implicated in many human diseases. These elements can influence human transcriptome plasticity in various mechanisms. Chimeric transcripts derived from LINE-1 and Alu can also impact the human transcriptome, such as exonization and post-transcriptional modification. However, its specific role in ASD neuropathology remains unclear, particularly in the cerebellum tissues. We performed RNA-sequencing of post-mortem cerebellum tissues from ASD and unaffected individuals for transposable elements profiling and chimeric transcript identification. The majority of free transcripts of transposable elements were not changed in the cerebellum tissues of ASD compared with unaffected individuals. Nevertheless, we observed that chimeric transcripts derived from LINE-1 and Alu were embedded in the transcripts of differentially expressed genes in the cerebellum of ASD, and these genes were related to developments and abnormalities of the cerebellum. In addition, the expression levels of these genes were correlated with the significantly decreased thickness of the molecular layer in the cerebellum of ASD. We also found that global methylation and expression of LINE-1 and Alu elements were not changed in ASD, but observed in the ASD sub-phenotypes. Our findings showed associations between transposable elements and cerebellar abnormalities in ASD, particularly in distinct phenotypic subgroups. Further investigations using appropriate models are warranted to elucidate the structural and functional implications of LINE-1 and Alu elements in ASD neuropathology.

An Efficient Algorithm for Gravity Forward Modeling (GFM) with Masses of Arbitrary Shapes and Density Distributions

Summary Currently, gravimetric forward modelling of mass density structures with arbitrary geometries and density distributions typically involves subdividing the mass body into individual geometric elements (such as rectangular prisms), calculating their gravitational contributions that are then summed up to obtain the gravitational attraction of the whole body. To achieve a more accurate approximation of the true geometric shape and density distribution, this rectangular prism model requires fine dividing, which significantly increases computational load and reduces numerical efficiency. To address this issue, we propose the algorithm for gravimetric forward modeling of arbitrary geometric shapes and density distributions in spectral domain that significantly improves numerical efficiency while preserves computational accuracy. The novelty of our proposed algorithm lies in dividing the masses into multiple layers of equal thickness in the vertical direction, providing constant upper and lower bounds. This allows to extended Parker's formulas and apply the Fast Fourier Transform (FFT) to increase numerical efficiency. The algorithm is tested using synthetic models and then used to compute gravitational effects of topography and sediments using real data from Tibet. Results show high accuracy and numerical efficiency than rectangular prism approach.

Ciliated foregut cysts involving the hepatopancreaticobiliary system: a clinicopathological evaluation with focus on atypical features

AimsForegut cystic malformations are rare developmental abnormalities, which may involve the hepatopancreaticobiliary tract (HPBT). These cysts are composed of inner ciliated epithelium; subepithelial connective tissue layer; smooth muscle layer; and...

Implicit hydromechanical representation of fractures using a continuum approach

Fractures control fluid flow, solute transport, and mechanical deformation in crystalline media. They can be modeled numerically either explicitly or implicitly via an equivalent continuum. The implicit framework implies lower computational cost and complexity. However, upscaling heterogeneous fracture properties for its implicit representation as an equivalent fracture layer remains an open question. In this study, we propose an approach, the Equivalent Fracture Layer (EFL), for the implicit representation of fractures surrounded by low-permeability rock matrix to accurately simulate hydromechanical coupled processes. The approach assimilates fractures as equivalent continua with a manageable scale (≫1 μm) that facilitates spatial discretization, even for large-scale models including multiple fractures. Simulation results demonstrate that a relatively thick equivalent continuum layer (in the order of cm) can represent a fracture (with aperture in the order of μm) and accurately reproduce the hydromechanical behavior (i.e., fluid flow and deformation/stress behavior). There is an upper bound restriction due to the Young's modulus because the equivalent fracture layer should have a lower Young's modulus than that of the surrounding matrix. To validate the approach, we model a hydraulic stimulation carried out at the Bedretto Underground Laboratory for Geosciences and Geoenergies in Switzerland by comparing numerical results against measured data. The method further improves the ability and simplicity of continuum methods to represent fractures in fractured media.

Optimizing Optoelectronics Performance: Theoretical and Experimental study on ZnO Thin Film for Al/ZnO/p-Si Photodiode

Abstract In this study investigates the optimization of ZnO thin film photoelectric devices, specifically focusing on ZnO/p-Si heterojunction photosensitive devices and photodiodes (PDs) using Al contacts. Through an experimental and theoretical analysis approach aims to evaluate the effects of important parameters, including ZnO layer thickness, defect density, and contact materials, on PD’s efficiency. Numerical analysis simulations comparatively examine the experimentally fabricated device performance at a 5 nm ZnO layer thickness by balancing photon absorption and carrier formation while minimizing carrier transport limitations. Experimentally process, an Atomic Layer Deposition (ALD) system was used to grow ZnO interlayers on one side of the polished Si wafer. Then, Al metallic contacts were created on the ZnO layers using a hole array mask. The PDs were then subjected to electrical characterization using I-V and I-t measurements under various illumination densities. Al/ZnO/p-Si PD's device with active performance has been produced and analyzed with electrical parameters such as barrier height, photocurrent, spectral response, ideality factor and EQE were derived, analyzed and studied. In conclusion, this work provides a comprehensive understanding of the performance of Al/ZnO/p-Si PD at varying illumination intensities and offering a detailed analysis of key parameters influencing device efficiency for future optoelectronics applications.

Study on the initial corrosion characteristics of weathering steel bridges with corrugated steel webs

In this study, the characteristics and influencing factors of the early corrosion evolution process of the weathering steel (WS) bridge in northwest China were examined, revealing the seldom-studied corrosion evolution law of the corrugated web of weathering steel. The corrosion losses and average corrosion thickness of WS bridge components were measured and evaluated. The results revealed that compared with traditional flat steel webs, the corrosion of corrugated steel webs was enhanced in the vertical direction and at the wave peak, and resulted in a more complex corrosion pattern. The trend of the rust layer on the inner and outer surfaces of the box girder is related to the stage characteristics of the corrosion products. The appearance of microscopic characteristics of the rust layer is periodic, with the rust layer thickness, colour, and particle size varying with the bridge’s location. The development of the corrosion pit followed a lognormal distribution, and the corrosion rate was balanced in the radial and depth directions. These results can serve as a basis for designers or inspectors to design WS bridge structures, select correct corrosion allowances, and improve corrosion monitoring and detection techniques.

Epoxy Coating as a Novel Method to Prevent Avian Electrocutions and Electrical Faults on Distribution Pylons with Grounded Steel Crossarms

Electrical faults caused by power escaping electric systems can lead to power outages, equipment damage, and fires. Faults sometimes occur when birds perched on power structures are electrocuted. Distribution power lines supported by concrete and steel pylons are particularly fault-prone because small separations between conductors and grounded components allow even small birds to inadvertently create faults while being electrocuted. Most conservation solutions focus on covering energized wires and components to prevent contact by birds and, although usually effective when installed correctly, covers can sometimes be dislodged thus becoming ineffective. Glass Flake Epoxy (GFE) is a non-conductive thermoset plastic that can adhere to steel crossarms and not be dislodged. We hypothesized that GFE-coated crossarms might reduce faults (proxies for avian electrocutions), and we conducted laboratory and field trials to evaluate that hypothesis. In the laboratory, we found a 2000 micrometer (μm)-thick layer of GFE coating that created a dielectric strength of 12.30 ± 0.21 kV, which was sufficient to prevent the formation of a phase-to-ground fault on up to 20 kV distribution lines. This should allow birds to perch on metal crossarms without being electrocuted. In field trials, we substituted 24% of a 20 kV distribution pylon’s crossarms with GFE-treated crossarms and found that doing so correlated with a 28% decrease in faults. Although we did not measure avian electrocutions directly, our findings suggest GFE coatings may offer a novel method of reducing avian electrocutions on power lines.

Relationship between vertical variation of cloud microphysical properties and thickness of the entrainment interfacial layer in Physics of Stratocumulus Top stratocumulus clouds

AbstractThis study examines the vertical variations of cloud microphysics and their correlation with the thickness of the entrainment interfacial layer (EIL) in stratocumulus clouds, observed in the Physics of Stratocumulus Top (POST) aircraft measurement campaign. From the mixing fraction analysis, we identified EIL between the free atmosphere and cloud top for all 15 POST flights, and found that EIL thickness significantly influenced the vertical variation of cloud microphysics and thermodynamics. In several flights, a trend toward stronger homogeneous mixing traits with increasing depth from the cloud top was found, indicative of the vertical movement of mixed (i.e., entrainment‐affected and diluted) parcels. However, in one flight, this trend was limited to the middle part of the cloud only, with the correlation between virtual potential temperature and liquid water content being strongly negative near the cloud top, suggesting limited downward movement of mixed parcels. Another important finding is that there was a robust negative correlation between long‐wave cooling rate near the cloud top and EIL thickness, highlighting differences in radiative cooling rates between mixed and unmixed parcels due to differences in liquid water content between them. These insightful findings will be crucial for enhancing our understanding of the role of EIL in modulating entrainment and the vertical movement of mixed parcels in stratocumulus clouds.

Enhancing structural protection of reinforced concrete structures against high dynamic loads using post-installed UHPFRC/UHPFRSC

Recently there has been an observed change in security policy across the globe which implies that humanity must prepare for hybrid and asymmetric acts of war. This security situation will result in spontaneous attacks from non-military groups. The threats include ballistic attacks from commercially available weapons, detonation of explosives, and impact of vehicles. These attacks are focused on critical infrastructures. Reinforced concrete (RC) elements with ballistic and explosion protection are of huge relevance. This requires new concepts and innovative solutions for the protection of new buildings and/or for the strengthening of existing structures. In this paper a method for the increase of structural safety is shown using Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) or sprayed UHPFRC, so called UHPFRSC, as a surface layer for reinforced concrete structures. The UHPFRC/UHPFRSC is applied in thin layers of 30 - 80 mm on the protection side. The interaction of the two different cementitious materials results in increased resistance to high dynamic loads. The traditional reinforced concrete on the impact side absorbs a major fraction of the energy of impact. On the back side (protection side), tensile forces are generated by the impact, which can excellently be handled by the UHPFRC/UHPFRSC. For proof of concept of the hybrid strengthening method, tests were carried out on UHPFRC - RC composite elements. In the test campaign, ballistic tests were performed using test specimens with dimensions of 500 × 500 mm. The layer thicknesses were 120 mm reinforced concrete and 40 mm UHPFRC. Additional steel rebars in the UHPFRC layer were applied for half of the specimens. The investigation demonstrated the effectiveness of the strengthening method, showing high resistance to high-dynamic loads. This behavior is attributed to the absorption and transfer of tensile stresses by the UHPFRC, that reduces penetration depth and damage, ensuring remaining load-bearing capacity after gunfire.

Opening the Hysteresis Loop in Ferromagnetic Fe3GeTe2 Nanosheets Through Functionalization with TCNQ Molecules

Ferromagnetic metal Fe3GeTe2 (FGT), whose structure exhibits weak van‐der‐Waals interactions between 5‐atom thick layers, was subjected to liquid‐phase exfoliation (LPE) in N‐methyl pyrrolidone (NMP) to yield a suspension of nanosheets that were separated into several fractions by successive centrifugation at different speeds. Electron microscopy confirmed successful exfoliation of bulk FGT to nanosheets as thin as 6 nm. The ferromagnetic ordering temperature for the nanosheets gradually decreased with the increase in the centrifugation speed used to isolate the 2D material. These nanosheets were resuspended in NMP and treated with an organic acceptor, 7,7,8,8‐tetracyano‐quinodimethane (TCNQ), which led to precipitation of FGT‐TCNQ composite. The formation of the composite material is accompanied by charge transfer from the FGT nanosheets to TCNQ molecules, generating TCNQ•– radical anions, as revealed by experimental vibrational spectra and supported by first principles calculations. Remarkably, a substantial increase in magnetic anisotropy was observed, as manifested by the increase in the coercive field from nearly zero in bulk FGT to 1.0 kOe in the exfoliated nanosheets and then to 5.4 kOe in the FGT‐TCNQ composite. The dramatic increase in coercivity of the composite suggests that functionalization with redox‐active molecules provides an appealing pathway to enhancing magnetic properties of 2D materials.

Study on the Effect of Liquefiable Overburden Foundations of Rockfill Dams Based on a Pore Pressure Model

China’s southwestern region boasts abundant hydropower resources. However, the area is prone to frequent strong earthquakes. The areas surrounding dam sites typically have deep overburden, and the liquefaction of saturated sand foundations by earthquakes poses significant safety risks to the construction of high dams in the southwest. The effects of liquefaction and reinforcing measures on the foundations of rockfill dams on liquefiable overburden under seismic action are currently the subject of somewhat unsystematic investigations. The paper utilizes the total stress and effective stress methods, based on the equivalent linear model, to perform numerical simulations on the overburden foundations of rockfill dams. The study explores how factors such as dam height, overburden thickness, liquefiable layer depth, liquefiable layer thickness, ground motion intensity, and seismic wave characteristics affect the liquefaction of the overburden foundations. Additionally, it examines how rockfill dams impact the dynamic response, considering the liquefaction effects in the overburden. The results show that although the total stress method, which ignores the cumulative evolution of pore pressure during liquefaction, can reveal the basic response trend of the dam, its results in predicting the acceleration response are significantly biased compared to those of the effective stress method, which comprehensively considers the cumulative changes in liquefaction pore pressure. Specifically, when the effect of soil liquefaction is considered, the predicted acceleration response is reduced compared to that when liquefaction is not considered, with the reduction ranging from 4% to 30%; with increases in the thickness and burial depth of the liquefiable layer, the effective stress method considering liquefaction significantly reduces the predicted peak acceleration; the effect of liquefiable soil on the attenuation of the speed response is more sensitive to the low-frequency portion of the seismic wave. The study’s findings are a significant source of reference for the planning and building of rockfill dams on liquefiable overburden.

The Potential Utility of Retinal Biomarkers to Index Central Nervous System Effects of Repetitive Blast Exposure in Military Personnel.

Military personnel exposed to blasts receive repeated subconcussive head impacts. Although these events typically do not cause immediate symptoms and do not lead to medical evaluation, the cumulative effects of subconcussive impacts can be significant and can include postconcussive symptoms, changes in brain structure and function, long-term cognitive dysfunction, depression, and chronic traumatic encephalopathy. Retinal measures such as thickness of retinal neural layers, density of retinal microvasculature, and strength of retinal neuronal firing are associated with cognitive function and brain structure and function in healthy populations and in neurodegenerative disease cohorts, and changes over time in retinal indices predict cognitive decline and brain atrophy in longitudinal studies in a range of medical populations. This commentary highlights the potential benefits of using retinal biomarkers in the routine screening and monitoring of brain health in warfighters and veterans. Retinal measures can be rapidly acquired (often in a matter of seconds) using methods that are inexpensive and noninvasive, and they can be collected with movable and often portable equipment that uses automated scoring routines that can be used for prediction and decision-making at the individual level. To date, however, retinal biomarkers have not been included in studies of blast overpressure exposures in military personnel. Despite this, preclinical and human evidence suggests that they could be among the most effective methods for tracking central nervous system damage in people exposed to repeated blasts. Retinal biomarkers could also contribute to brief test batteries to determine who is most at risk for long-term negative effects of future exposures. In addition, the sensitivity of retinal indices to blast exposure and mild traumatic brain injury suggests that they should be incorporated into research on strategies to minimize or prevent blast-related short- and long-term central nervous system changes in blast-exposed military personnel.

Single-stack multilayer infrared mirrors with selectable higher-order interference peaks

A concept for the design of single-stack multilayer mirrors with multiple reflection peaks is presented. Its realization in the infrared is demonstrated by the sputter deposition of TiO2/Al2O3 bilayers on sapphire and HastelloyX substrates and corresponding reflection measurements. Even or odd higher-order interference peaks are selected by adjusting the optical thicknesses of the individual layers. The peak positions are very well reproduced by multiple scattering calculations. With the HastelloyX substrate, a potential application for high temperatures and aggressive atmospheres, e.g., in aircraft turbines, is addressed. A design for matching up to three turbine gas emission bands (CO2, H2O) is proposed.

Bile duct ligation impairs visual acuity in rats by ammonia- and bilirubin-induced retinal degeneration.

Patients with hepatic failure are often accompanied by hepatic retinopathy, but the cellular and molecular mechanisms underlying the hepatic retinopathy remain unclear. In this study, we investigated how liver failure leads to hepatic retinopathy using bile duct ligation (BDL) rats as a cholestasis animal model. Light-dark box test was used to assess sensitivity to light, indexed as visual acuity. On D28 post-BDL, rats were subjected to light-dark box test and blood samples were collected for biochemical analyses. The rats then were euthanized. Liver, spleen and both side of eye were quickly harvested. We showed that BDL impaired rat sensitivity to light, significantly decreased the thickness of inner nuclear layer (INL), outer nuclear layer (ONL) and total retina, as well as the retinal cell numbers in ONL and ganglion cell layer (GCL). The expression of rhodopsin (RHO), brn-3a and GPX4 was significantly decreased in retina of BDL rats, whereas the expression of cleaved caspase 3, 8, 9, bax/bcl-2, RIP1, GFAP, and iba-1, as well as TUNEL-positive cells were significantly increased. In cultured retinal explant, we found that NH4Cl (0.2, 1, 5 mM) concentration-dependently impaired activity of retinal explant, decreased thickness of INL and ONL, downregulated expression of brn-3a, RHO and GFAP, increased expression of cl-caspase 3 and TUNEL-positive cell numbers, with NH4Cl (5 mM) almost completely disrupting the structure of the cultured retina; bilirubin (1 μM) significantly upregulated GFAP expression, whereas high level (10 μM) of bilirubin downregulated expression of GFAP. We further demonstrated in vivo that hyperammonemia impaired rat sensitivity to light, decreased thickness of INL and ONL, downregulated expression of RHO, brn-3a, GFAP and increased expression of cl-caspase 3; hyperbilirubinemia impaired rat sensitivity to light, upregulated expression of GFAP and iba-1. In conclusion, BDL impaired rat visual acuity due to the elevated levels of ammonia and bilirubin. Ammonia induced loss of retinal ganglion cells and rod photoreceptor cells via apoptosis-mediated cell death. Bilirubin impaired retinal function via activating microglia and Müller cells.

Fluid depth-dependent biofilm characteristics and their influence on sulfate-reducing bacteria-induced corrosion of carbon steel

This study investigates the response of biofilm characteristics to variations in fluid depth and their influence on the corrosion behavior of carbon steel (C1020) under low-flow fluid conditions, utilizing Desulfovibrio vulgaris. The experiments were conducted in an anaerobic chamber at 30 °C, utilizing modified Baar's medium as the testing medium. The findings reveal that fluid depth significantly impacts biofilm-corrosion product composite formation, with deeper depths promoting thicker and more heterogeneous biofilm-corrosion product layer compared to shallower depths, where a thinner and more uniform biofilm-corrosion product layer is observed. Moreover, the characteristics of initially attached biofilms was verified as the primary factor affecting subsequent corrosion behavior during prolonged exposure. Corrosion analysis reveals that greater fluid depth leads to increased weight loss (91 ± 13.2 mg/cm2) and deeper pit depths (540 ± 69 μm), surpassing those observed in shallower test media (21 ± 2.3 mg/cm2 and 105 ± 17 μm) after 28 days of exposure. The corrosion products within the biofilm were predominantly FeS and Fe3(PO4)2·8H2O. A direct relationship was observed between the thickness of this biofilm-corrosion product layer and the progression of pit depth, suggesting a strong correlation between carbon steel corrosion and biofilm development in limited fluid depths (e.g., 5–15 mm). Furthermore, a significant association between the deepest pits (average) and the number of sessile cells within the biofilm underscores the pivotal role of sessile cell numbers in carbon steel corrosion.