Foundation Material Research Articles

Geology of Mudstones Atop the Sangonghe Formation, Shuixigou Group, Turpan‐Hami Basin: New Insights and Their Implications for Petroleum Geology

ABSTRACTAs the exploration of deep‐seated oil and gas resources in the Turpan‐Hami Basin intensifies, there is an urgent need to thoroughly depict the geological characteristics of newly uncovered, underexplored strata in sub‐sag centers. This study undertakes the inaugural systematic geochemical analysis of mudstones atop the Sangonghe Formation, including palynological identification, maceral identification, biomarker analysis, total organic carbon (TOC) analysis, and pyrolysis. The findings reveal that the mudstone sequence, as the target layer, was deposited in a warm and moist paleoclimate and a weakly reducing to weakly oxidising saline water environment, fostering the growth of prolific algae and bacteria, thus ensuring substantial foundational materials for source rock formation. The organic matter in the mudstone sequence displays pronounced laminar accumulation. Despite the overall modest abundance, the organic matter features notable hydrocarbon‐generating potential per unit of organic carbon and favourable types. Humic‐sapropelic kerogens (type II1) are found in the mudstones, with organic matter generally reaching a mature to highly mature stage. These characteristics establish the mudstones as effective source rocks, furthermore, the hydrocarbon expulsion in the Xishanyao Formation precedes that of the Sangonghe Formation and that both formations constitute a sequential process in terms of hydrocarbon generation and expulsion timing and hydrocarbon contribution. Reanalyzing this mudstone sequence not only revises prior geological understanding of it as direct cap rocks, but also facilitates the reclassification of deep‐seated strata into three distinct petroleum systems. Centered around this source rock layer, dual modes, namely the “lower‐source rock and upper‐reservoir” and the “ lower‐reservoir and upper‐source rock” modes can be formed. These new insights will offer profound implications for hydrocarbon resource evaluation and future hydrocarbon exploration endeavours in the Shuixigou Group within the Taibei sag.

In situ formation SiC nanowires on loofah sponge-derived porous carbon for efficient electromagnetic wave absorption

A lightweight, heterogeneous, three-dimensional network-structured composite has been meticulously developed with the specific goal of optimizing impedance matching and elevating electromagnetic wave absorption properties. SiC nanowires-carbon composites were synthesized through a novel process involving combined carbothermal reduction and chemical vapor deposition, utilizing loofah sponge as the foundational material. Accessible and cost-effective organosilane waste was applied as the silicon source. The resulting composites manifest exceptional electromagnetic wave absorption performance with a minimum reflection loss of − 46.34 dB and a wide effective bandwidth of 3.84 GHz at a thin thickness of 1.9 mm. Superior electromagnetic wave absorption is attributed to synergistic interplay of multiple interfacial polarizations, dipole polarization, conductive losses, and multiple reflections and scattering. This work presents an innovative pathway toward fabricating highly efficient electromagnetic wave-absorbing materials while effectively repurposing recycled waste.

PFEI-Net: A profound feature exploration and interaction network for ceramic substrate surface defect detection

Ceramic substrates serve as the foundational material for numerous electronic devices, and their surface quality directly affects performance and longevity. Therefore, surface defect detection on ceramic substrates is an indispensable task during the manufacturing process. Ceramic substrate surface defects exhibit low contrast, along with intraclass difference and interclass similarity, posing substantial challenges for automated visual inspection. Existing deep learning-based methods utilize carefully crafted backbone networks and feature pyramid structures that perceive multilevel information to deal with the above challenges. However, these methods still suffer from insufficient extraction of discriminative features and low effectiveness in feature fusion, thereby hindering the detection performance. To address these issues, we propose the profound feature exploration and interaction network (PFEI-Net). Initially, we propose the discriminative feature mining backbone (DFM-backbone) to progressively explore the effective discriminative features. In the DFM-backbone, the global information grated perception module is devised to construct long-range feature dependencies and aggregate rich features, whereas the contextual semantic flexible extraction module is designed to meticulously perceive contextual semantic information in a targeted manner, enhancing the comprehensive representation of the discriminative features. Then, we propose the multipath semantic interaction guided-feature pyramid network (MSIG-FPN) to facilitate the fusion and interaction of the valuable information. In the MSIG-FPN, the hierarchical refocus–reaggregation module is constructed to refocus on task-relevant features and provide reliable guidance for the network, whereas the cross-stage semantic deep fusion module is designed to integrate multi-level contextual information deeply across stages and is employed to construct the semantic complementary paths, thereby preventing the loss of crucial features. Finally, built upon the backbone of DFM-backbone and MSIG-FPN, we establish the PFEI-Net, achieving accurate detection of surface defects on ceramic substrates. Experimental results highlight that the PFEI-Net achieves excellent performance with a remarkable 89.3 % mean average precision (mAP) and an inference time of 26.1 ms, which offers a promising and viable solution for automated surface defect detection of ceramic substrate.

DESIGNING EARTHQUAKE-RESISTANT FOUNDATIONS: A GEOTECHNICAL PERSPECTIVE ON SEISMIC LOAD DISTRIBUTION AND SOIL-STRUCTURE INTERACTION

The design of earthquake-resistant foundations is a critical aspect of geotechnical engineering, particularly in regions susceptible to seismic activity. This study explores the role of seismic load distribution and soil-structure interaction in the development of resilient foundation systems. By integrating advanced geotechnical analysis techniques, the research examines various soil types, foundation materials, and structural configurations to identify the optimal conditions for mitigating seismic impacts. Emphasis is placed on understanding the interaction between soil properties, foundation stiffness, and seismic forces, with the goal of improving the safety and durability of built environments. The findings contribute to better predictive models for designing foundations that can withstand seismic loads while ensuring long-term stability.

Stepping Back: How Should Pass/Fail Scoring Influence Step 1 Timing?

Although most students complete Step 1 before clerkships, some institutions delay the exam until after clerkships. The change to pass/fail grading adds additional complexity that should be considered when deciding about exam timing. Both early and late administration may affect learning outcomes, learner behavior, student well-being, and residency match success. Step 1 completion before clerkships promotes learning outcomes (e.g., integration and mastery of foundational material), may encourage students to focus on the curriculum, and may better prepare students for clinical science exams (CSEs). However, delaying the exam ensures that students maintain foundational knowledge and may encourage clinical educators to demonstrate basic science illustrations. An early Step 1 may affect learner behavior by allowing clerkship students to focus on clinical learning. The associated National Board of Medical Examiners performance report may also be used for Step 2 and CSE preparation. However, delaying Step 1 allows greater scheduling flexibility based on developmental milestones. Administration of Step 1 before clerkships removes a significant stressor from the clinical year and decompresses the residency application period. However, a delayed Step 1 reduces the pressure on students to engage in numerous extracurricular and research activities to distinguish themselves due to the pass/fail change. An early Step 1 exam may also lead to improved CSE performance, which is often linked to clerkship honors criteria, an increasingly valuable distinction for residency match success after the change to pass/fail. In contrast, delaying Step 1 is associated with higher first-time pass rates, which may be especially important for students at risk for failure. Medical educators and students should collaboratively approach the question of Step 1 timing, considering these factors within the context of the medical school program, curricular constraints and priorities, and students' individual needs and goals.

Expression of goat poxvirus P32 protein and monoclonal antibody preparation.

P32 protein serves as a crucial structural component of Goat pox virus (GTPV), which causes a highly virulent infectious disease in sheep and goats. Despite the fact that P32 has been widely expressed in the previous studies, it is difficult to obtain recombinant P32 efficiently. This study aimed to achieve soluble expression of P32 recombinant protein and to develop its specific monoclonal antibody. The gene fragment of P32Δ (GP32Δ) was synthesized by optimizing the coding sequence of amino acids 1-246 of the known goatpox P32 protein. Subsequently, GP32Δ was cloned into a prokaryotic expression vector for expression and purification, resulting in the successful production of soluble recombinant protein rP32Δ. Utilizing rP32Δ, an indirect ELISA method was established by immunizing 6-week-old BALB/c mice with inactivated GTPV as the antigen. Through hybridoma technology, three monoclonal antibody hybridoma cell lines secreting anti-goat pox virus rP32Δ were screened, designated as 2F3, 3E8, and 4H5, respectively. These monoclonal antibodies, classified as IgG1, IgG2a, and IgG2b, respectively, with κappa light chains, were characterized following ascites preparation and purification. Indirect ELISA results demonstrated that the ELISA potency of the three monoclonal antibodies exceeded 1:12800. Furthermore, Western blot analysis revealed specific reactivity of both 3E8 and 4H5 with rP32Δ, while immunofluorescence assays confirmed 3E8's ability to specifically recognize GTPV in cells. The preceding findings demonstrate the successful acquisition of the soluble expressed recombinant P32 protein and its specific monoclonal antibody 3E8 in this study, thereby laying a foundational material basis for the establishment of a GTPV detection method.

Comparison of Bond Strength of Soft Denture Liner on the Denture Base Materials Produced by Different Methods and Effect of Thermocycling

Aim: This study set out to determine the tensile bond strength between denture bases (produced by 3D printing technology, conventional technique, and computer-aided design and computer-aided manufacturing [CAD/CAM] milled) and silicone-based soft lining material. The consequence of thermocycling on the bonding strength was also investigated. Materials and Methods: The bonding between denture foundation materials produced through three distinct techniques (conventional, CAD/CAM milled, and 3D printed) and silicone-based soft lining material was examined. Before tensile testing, half of the samples underwent thermocycling (5–55°C, 5,000 cycles) in 37°C distilled water for 48 hours. A universal testing apparatus employed a crosshead speed of 5 mm/min. The failure type was identified visually, and the maximum tensile strength was noted. The Shapiro-Wilk test and analysis of variances ( P = .05) were used to assess the statistics. Results: CAD/CAM milled denture base material (1.56 ± 0.62/1.36 ± 0.16 MPa) showed higher bond strength values than the other denture bases in the tensile test conducted before and after thermocycling ( P < .001). The denture base material made conventionally had the lowest bond strength (1.02 ± 0.24/0.77 ± 0.1 MPa) ( P < .001). The tensile bond strength values of the conventional and 3D printing groups showed a statistically significant drop before and after thermocycling ( P = .001). Regardless of thermocycling, adhesive failure was primarily seen in all groups (76.6%). Conclusion: Compared to conventionally produced denture bases, the bond strength of soft relining materials to CAD/CAM milled and 3D printed denture base is different. In denture base materials that are conventionally, CAD/CAM and 3D printed, the thermocycling method reduced bonding strength values.

CT imaging‐enhanced numerical simulation of microscopic structure and resilient safety of asphalt concrete

AbstractAsphalt concrete is a foundational material in water conservancy projects, serving a critical function in the construction of impermeable structures such as dams. The seismic response characteristics and resilient safety of concrete dams are heavily influenced by the arrangement and evolution of the microscopic structure of the dam material. In this study, a high‐precision computed tomography (CT) scanning technique, in conjunction with advanced numerical simulations, was employed to analyze the internal damage and crack extension mechanism of asphalt concrete. Microstructural images of the asphalt concrete specimen were accurately captured by CT scanning, followed by the construction of corresponding numerical models. Presented simulation results show that the displacement deformation of asphalt concrete reaches its maximum value in the top region of the model and subsequently decreases with depth. Material damage was first observed at the interface between aggregate and asphalt matrix, where microcracks emerge and extend to the entire asphalt matrix, resulting in a gradual deterioration of the model performance. The simulation results indicate that the overall strength of asphalt concrete is primarily influenced by the strength characteristics of its aggregates. The stress–strain curves obtained from the numerical simulations exhibit a hyperbolic relationship, which is in high agreement with the physical test results. This study not only enhances our comprehension of the mechanical behavior of concrete but also contributes to the analysis of seismic response and risk assessment in dam engineering through dynamic experimental testing and numerical simulation.

Effect of nanomaterials on the melting/freezing characteristics of phase-change material

A novel variant of composite phase-change material (PCM) was developed by incorporating 0.5 wt% aluminum oxide (Al2O3), silicon dioxide (SiO2), copper (II) oxide (CuO) and silver (Ag) nanomaterials into myristic acid. In this formulation, myristic acid served as the foundational material, while aluminum oxide, silicon dioxide, copper (II) oxide and silver were employed as supporting components. The morphology and crystalline structure of the nanomaterials were studied using field-emission scanning electron microscopy and X-ray diffraction analysis, respectively. The composite PCMs were fabricated using a two-step process. The phase-change properties of the composite PCMs were assessed using differential scanning calorimetry. The nanomaterials (0.5 wt% aluminum oxide, silicon dioxide, copper (II) oxide and silver) were suspended in myristic acid separately to investigate the heat-transfer performance of the composite PCMs during phase-change processes (melting and freezing). The results clearly indicated that the duration of the melting and freezing processes of the composite PCMs decreased compared with that of the pure PCM. Thus, the newly prepared composite PCMs are potential candidates for harvesting solar energy for low-temperature heating applications.

튀르키예 정체성 정치의 맥락과 담론에 관한 소고

Türkiye recently declared a vision called the “Century of Türkiye” amid economic crisis and diplomatic rifts. This vision draws on the context of 'identity politics' that has been utilized from the first President to the current one. Throughout the nation-building process, Türkiye has consistently employed identity politics for national unity and crisis mitigation. This paper analyzes the background and content of Türkiye's discourse on identity politics, which has been utilized in various forms, and how narratives and framing have been constructed from a theoretical perspective. In particular, to discuss identity politics, Türkiye's diverse and complex identities will be distinguished at each level. Contextual analysis of this discourse is necessary for analyzing Türkiye's diplomatic principles and long-term strategies. It will also serve as foundational material to strengthen supra-national cooperation and communication with Türkiye in Korean diplomacy.

Offshore geotechnical challenges of the energy transition

Offshore wind is the most mature of the offshore renewable energy technologies and has a significant role to play in the energy transition. 2000 GW of offshore wind capacity is anticipated globally by 2050 in order meet the targets of the Paris Agreement; 35 times the current installed capacity. The pace and scale of offshore wind ambitions to support the energy transition present a range of challenges for the offshore geotechnical sector and the broader offshore wind sector. Challenges extend across the life-cycle of projects from marine spatial planning, site investigation, design, manufacturing, installation, operation and decommissioning, and across the supply chain regarding availability of raw materials for foundations, anchors and mooring systems, vessels and equipment for site investigation and installation, and trained geotechnical personnel. This paper identifies five key challenges and sets out the necessary shifts in technology, culture and practice in geotechnical engineering to achieve the ambitious targets to deliver offshore wind at the pace and scale required for the energy transition. The paper closes with a reflection on the consequence of delaying or not meeting net-zero targets, and thus identifying the urgency for these shifts in technology, culture and practice to be developed and adopted.

The mechanical and microstructure investigations of jute fabric epoxy reinforced with microfibers from banana and coconut

AbstractThis study investigates the use of jute cloth epoxy reinforced with microfibers from coconuts and bananas to investigate bio‐inspired composite materials. The development and assessment of the mechanical qualities of two composite types—jute fabric containing 10% banana microfibers and jute fabric containing 10% coconut microfibers—were the main goals. These composites were made for the study, and then they underwent extensive mechanical testing (such as tensile, bending, and impact tests) and scanning electron microscopy (SEM) microstructural examination. Jute cloth, which is renowned for its sustainability, was utilized as the foundation material, and epoxy was utilized as the matrix to improve structural stability. Fibers from bananas and coconuts were included because of their durability and low weight. The findings suggested that, maybe as a result of variations in density, the composite containing 10% coconut fibers performed better mechanically than the one containing banana fibers. These discoveries signify a substantial breakthrough in bio‐inspired materials and have potential uses in sectors looking for environmentally friendly substitutes. This research may help create green composites with improved mechanical properties by deepening our understanding of the interactions between jute, epoxy, and natural fibers.Highlights Banana and coconut fibers enhance the composite's tensile strength significantly. The material's bending properties show promise for diverse load‐bearing applications. High impact resistance makes the composite viable for impact‐prone environments. SEM analysis confirms homogeneous integration of fibers within the epoxy matrix.

SC-CNTs: Thin Film Transistors for High-Performance, Low-Power, Flexible Electronics

Single Walled Carbon Nanotubes (SWNTs) have gained a great deal of media attention over the past almost-two decades. From their theoretical usage as the foundational material for space elevators that would take travelers beyond earth’s atmosphere, to an active material that would allow engineers to create nanobots that internally repair or treat the human body, applications for SWNTs are numerous and have resonated within the imagination of scientists and the media alike. Fast forwarding to the modern era, we find that nanotubes still have a great deal of technological promise, some of which parallel those usages that were theoretically conceived many years ago.For over a decade, NanoIntegris Technologies Inc. has been at the forefront of synthesizing high-purity, electronically enriched SWNT’s and, during that time, has found that our materials have proven to transcend from the theoretical to practical-usage realm. With over 1,900 publications citing the usage of NanoIntegris’ high performance materials, we have not only seen the beneficial properties of our materials studied via techniques such as scanning electron microscopy but have also received many positive use-cases for our materials such as being an additive of highly-conductive, electrode (anode/ cathode) slurries of next-generation lithium-ion batteries, to being used as an active for the highly-sensitive detection of COVID antigens.Within my talk, I will display the usage of our high-purity semiconducting (≥99%) single walled carbon nanotubes to make the next generation of high-performance electronics. I will focus upon the usage of our IsoSol-S100 semiconducting solution that served as the spin-coated semiconducting layer within a short channel (<10 µm) thin film transistor with ON/OFF of 104, a device thickness of 400 nm, and a mobility of 39 cm2V-1s-1. I will further discuss the usage of our IsoNanotubes-S 99% solution to serve as the active material within a low-power, wearable Radio Frequency biosensor that covers the GSM spectra, with an operation frequency up to 2.1GHz, and that can serve as both a frequency multiplier and mixer.

Preparation of Fe-Modified Diatomite-Based Ceramsite for Efficient Phosphate Adsorption: Utilizing Diatomite’s Distinctive Porous Structure and Surface Silanol Groups

Ceramsites are extensively employed as substrates for adsorbents in studies focused on phosphorus adsorption, leaving ceramsites crafted from diatomite less explored. Diatomite-based ceramsite, with its distinct porous architecture and surface silanol functionalities, is adept at supporting a variety of metal oxides, presenting a distinct advantage over other ceramsite variants. In light of this, the present study embarked on producing diatomite-based ceramsite using diatomite as the foundational material, subsequently enhancing it through the incorporation of Fe, thus yielding an Fe-modified diatomite-based ceramsite. Through adsorption testing, the modified ceramsite demonstrated a significantly improved adsorption capacity of 4.06 mg P/g, marking a substantial enhancement from the initial capacity of 0.9 mg P/g. The process of phosphorus adsorption exhibited a strong alignment with the Langmuir isotherm model and the pseudo-second-order kinetic model. In-depth analyses employing XRD, FTIR, zeta potential, and XPS techniques have revealed that the principal mechanisms driving the adsorption process are centered on interactions involving electrostatic forces, the formation of chemical precipitates, and the exchange of ligands. This investigation not only opens new avenues for the application of diatomite-based ceramsite but also lays down a theoretical foundation for its modification, thereby enriching the spectrum of its utility.

Consensus in Data Management: With Use Cases in Edge-Cloud and Blockchain Systems

Consensus is a fundamental problem in distributed systems, involving the challenge of achieving agreement among distributed nodes. It plays a critical role in various distributed data management problems. This tutorial aims to provide a comprehensive primer for data management researchers on the topic of consensus and its fundamental and modern applications in data management. We begin by exploring the basic principles of consensus, including the problem statement, system models, failure scenarios, and various consensus algorithms such as Paxos and its variants. The tutorial then delves into the applications of consensus in distributed data management, focusing on distributed atomic commitment and data replication. We explain how consensus is integral to these areas and present examples of research and industry work that apply consensus to data management. The tutorial extends to modern use cases of consensus in the evolving landscapes of edge-cloud systems and blockchain technology. We discuss how consensus mechanisms are being adapted and applied in these areas, highlighting their growing importance in emerging areas of data management. By exploring these cutting-edge applications, participants will gain insights into how consensus is shaping ongoing and future research on distributed data management. The tutorial builds on the authors' recent book "Consensus in Data Management: from Distributed Commit to Blockchain". The book will serve as the foundation and reading material for the tutorial. This tutorial targets data management researchers and practitioners to equip them with the knowledge and perspective needed to innovate in these emerging fields. This includes graduate students and junior researchers starting their careers in the area of distributed data management. Also, it includes researchers in other areas of data management who wish to explore the area of distributed data management with the goal of utilizing it in their own fields.

Sustainable Body Positivity Movement: Analysis of the Discourse on Body Image in Korean Society

In contemporary society, the discourse on body image is increasingly emerging as a notable social issue. In particular, the body positivity movement is promoting healthy body image and self-esteem through various means. This study was conducted to analyze the discourse on sustainable body image in Korean society. User-generated content from 1 January 2014 to 31 July 2023 underwent data refinement and term frequency (TF), TF–inverse document frequency (TF–IDF), and Latent Dirichlet Allocation (LDA) analyses. The number of blog posts in 2020 was nearly triple the number in 2019. Thus, the analysis period was divided into first (from 2014 to 2019) and second (from 2020 to 31 July 2023) periods. The TF–IDF analysis showed that shooting, photo, diet, exercise, goal, and challenge were among the top words in the first period, while Instagram-related words were mosr frequent in the second period. This finding suggested that social distancing policies significantly affected social media usage. The LDA analysis revealed five topics that were common in the first and second periods and three topics that emerged in the second period. Overall, while Western societies tend to idealize specific body types, body image discourse in Korea is centered around exercise as a means to achieve “photography” or “photo shoot”-related goals. Exercise is perceived as an activity performed for pleasure rather than attaining a particular body shape. Furthermore, there is a desire to document one’s body beautifully and maintain exercise habits in the long run. The results of this study could serve as foundational material for establishing and sustaining a positive body image culture.

Numerical modeling of the effects of impact conditions, foundation stiffness, and cable pretension on the behavior of high-tension guard cable systems

Cable barriers are one type of road restraint system commonly used on highways across the United States to contain and redirect errant vehicles and to prevent crossover accidents. These systems are typically tested under the provisions from safety manuals considering standard crash conditions (e.g., vehicle speed and impact angle). To understand the performance of cable barriers, it is important to evaluate the effects of non-standard crash and system conditions, including various vehicle speeds, impact angles, foundation material stiffness, and cable pretension loads. For that purpose, we created a set of full-scale finite element models in LS-DYNA to assess the effects of these non-standard conditions on the performance of high-tension cable barrier systems. The results from the models show that soft soils and under-tensioned systems yield higher cable deflections. Moreover, the results indicate that speeding vehicles colliding at non-standard angles increase cable tensions by up to 91% and cable deflections by up to 318%. These findings highlight the importance of evaluating cable barrier performance under more severe scenarios, which could lead to system failure and more severe collision consequences.

Study on heavy metal leaching from steel slag in coastal soft soil and its environmental impact

ABSTRACT To explore the environmental impact of steel slag deposited within a coastal soft soil foundation, the steel slag produced by a steel plant in Fangchenggang city was chosen as a case study. Seawater was collected from the coastal foundation, and water with different levels of salinity was obtained by low-temperature evaporation, filtration, sterilisation, and dilution. Leaching tests of steel slag in artificial seawater with different levels of salinity were carried out according to the Toxicity Characteristic Leaching Procedure (TCLP). The results showed that with the increase in the leaching time and salinity of the solution, the concentration of heavy metals in solution displayed an upward trend; however, the rate of increase decreased once the concentration reached a certain level. From an environmental perspective, it is not advisable to use steel slag as a filler near drinking water, and steel slag should not be used as a foundation material in the high-salinity coastal soft soil layer.

Optimizing surface finish in FDM-printed polycarbonate spur gears through abrasive flow finishing: insights from physics and material science perspectives

In recent times, the usage of polymers has experienced notable growth across diverse manufacturing sectors. Polymeric gears, integral to automation, material handling systems, toys, and household appliances, have become ubiquitous. Although additive manufacturing techniques, especially Three-Dimensional (3D) printing, offer versatile applications, they grapple with challenges, notably poor surface finishing attributed to layer accumulation. This work explores the field of abrasive flow machining (AFM) in experimental settings using FDM-printed polymeric gears. The AFM medium concoction involves coal ash powder as the foundational material, EDM oil as the carrier fluid, and the infusion of glycerin as additives. Rigorous investigations were undertaken to pinpoint the optimal viscosity of the AFM medium and refine process parameters with a central focus on enhancing surface quality. A Taguchi L9 Design of Experiment (DOE) was meticulously crafted for parameter optimization using the Minitab statistical software. The investigation established a functional relationship between the output parameter (surface roughness) and key input variables (layer thickness, abrasive percentage, abrasive mesh size, and finishing time). The maximum level of AFM media optimization was attained at 33% abrasive concentration, 220 abrasive mesh size, and 60% liquid synthesizer. Additionally, the results of the investigation showed that a media viscosity of 0.50 Pa-sec, layer thickness of 0.1, and culminating time of 45 min were the optimal values for the most % improvement in surface roughness. The initial surface roughness underwent a profound reduction from 12.30 μm to 0.30 μm, marking an exceptional improvement of 97.56%. This inquiry contributes significant insights into the refinement of AFM parameters for elevating the surface finish of FDM-printed polymeric gears, promising enhanced performance across diverse applications.

Drift damage limit estimation based on cracks of concrete gravity dam considering dam-foundation interaction

ABSTRACT This study focuses on estimating the drift limits associated with different damage states of concrete gravity dams, emphasizing the role of cracks along the dam base and the interaction between the dam and its foundation. Employing a comprehensive framework and nonlinear pushover analysis, the research accounts for uncertainties in concrete and foundation material parameters, evaluating three distinct models with varying height-to-base width ratios (1, 1.25 and 1.5) through 20 runs based on central composite design. The findings indicate that as the height-to-base width ratio increases, the concrete gravity dam demonstrates greater resilience against lateral movements, highlighting its ability to withstand larger drifts without incurring damage. Additionally, the study’s proposed mathematical model accurately predicts the drift limits across different levels of damage, facilitating a comprehensive understanding of the structural behavior and its implications for seismic risk assessments. The research underscores the significance of considering the varying degrees of damage and their impact on the concrete gravity dam’s operational capability and safety, offering crucial insights for ensuring the integrity and stability of these essential infrastructures.