bluuebunny/crossref_metadata_2025 huggingface dataset:
ROS‐responsive modified chitosan oligosaccharide nanocapsules for improving pesticide efficiency and intelligent release
Authors: Li Lin‐jie , Zhao Rui , Wang Yin‐min , Pan Shou‐he , Yu Meng , Sun Zhe , Ma Ying‐jian , Guo Xin‐yu , Xu Yong , Wang Hong‐mei , Wu Xue‐min
Published: May 2023

BACKGROUND

Some traditional pesticide formulations are inefficient, leading to excessive use and abuse of pesticides, which in turn effects environment. Intelligent release pesticide formulations are ideal for improving pesticide utilization and persistence while reducing environmental pollution.

RESULTS

We designed a benzil‐modified chitosan oligosaccharide (CO‐BZ) to encapsulate avermectin (Ave). Ave@CO‐BZ nanocapsules are prepared based on a simple interfacial method via cross‐linking of CO‐BZ with diphenylmethane diisocyanate (MDI). The Ave@CO‐BZ nanocapsules have an average particle size of 100 nm and exhibited a responsive release performance for ROS. The cumulative release rate of nanocapsules at 24 h with ROS increased by about 11.4% compared to that without ROS. The Ave@CO‐BZ nanocapsules displayed good photostability. Ave@CO‐BZ nanocapsules can penetrate root‐knot nematodes more easily and exhibited better nematicidal activity against root‐knot nematodes. The pot experiment showed that the control effect of Ave CS at low concentration was 53.31% at the initial stage of application (15 d), while Ave@CO‐BZ nanocapsules was 63.54%. Under the same conditions, the control effect of Ave@CO‐BZ nanocapsules on root‐knot nematodes was 60.00% after 45 days of application, while Ave EC was only 13.33%. The acute toxicity experiments of earthworms showed that the toxicity of nanocapsules was significantly lower than that of EC.

CONCLUSION

The ROS‐responsive nanocapsules can improve the utilization of pesticides and non‐target biosafety. This modified chitosan oligosaccharide has great potential as a bio stimuli‐responsive material, and this simple and convenient method for preparing Ave@CO‐BZ nanocapsules provides a direction for the effective utilization of pesticides. © 2023 Society of Chemical Industry.
Isoamericanin A improves lipopolysaccharide‐induced memory impairment in mice through suppression of the nicotinamide adenine dinucleotide phosphateoxidase‐dependent nuclear factor kappa B signaling pathway
Authors: Yang Yanqiu , Chen Ru , Che Yue , Yao Xiaohu , Fang Mingxia , Wang Yingjie , Zhou Di , Li Ning , Hou Yue
Published: May 2023

Alzheimer's disease (AD) is the most frequent cause of dementia in the elderly. Isoamericanin A (ISOA) is a natural lignan possessing great potential for AD treatment. This study investigated the efficacy of ISOA on memory impairments in the mice intrahippocampal injected with lipopolysaccharide (LPS) and the underlying mechanism. Y‐maze and Morris Water Maze data suggested that ISOA (5 and 10 mg/kg) ameliorated short‐ and long‐term memory impairments, and attenuated neuronal loss and lactate dehydrogenase activity. ISOA exerted anti‐inflammatory effect demonstrating by the reduction of ionized calcium‐binding adapter molecule 1 positive cells and suppression of marker protein and pro‐inflammation cytokines expressions induced by LPS. ISOA suppressed the nuclear factor kappa B (NF‐κB) signaling pathway by inhibiting IκBα phosphorylation and NF‐κB p65 phosphorylation and nuclear translocation. ISOA inhibited superoxide and intracellular reactive oxygen species accumulation by reducing nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, demonstrating by suppressing NADP+ and NADPH contents, gp91phox expression, and p47phox expression and membrane translocation. These effects were enhanced in combination with NADPH oxidase inhibitor apocynin. The neuroprotective effect of ISOA was further proved in the in vitro models. Overall, our data revealed a novel pharmacological activity of ISOA: ameliorating memory impairment in AD via inhibiting neuroinflammation.
A generalized, compactly supported correlation function for data assimilation applications
Authors: Gilpin Shay , Matsuo Tomoko , Cohn Stephen E.
Published: May 2023

This work introduces a new, compactly supported correlation function that can be inhomogeneous over Euclidean three‐space, anisotropic when restricted to the sphere, and compactly supported on regions other than spheres of fixed radius. This function, which we call the Generalized Gaspari–Cohn (GenGC) correlation function, is a generalization of the compactly supported, piecewise rational approximation to a Gaussian introduced by Gaspari and Cohn in 1999 and its subsequent extension by Gaspari et al in 2006. The GenGC correlation function is a parametric correlation function that allows two parameters and to vary, as functions, over space, whereas the earlier formulations either keep both and fixed or only allow to vary. Like these earlier formulations, GenGC is a sixth‐order piecewise rational function (fifth‐order near the origin), while the coefficients now depend explicitly on the values of both and at each pair of points being correlated. We show that, by allowing both and to vary, the correlation length of GenGC also varies over space and introduces inhomogeneous and anisotropic features that may be useful in data assimilation applications. Covariances produced using GenGC are computationally tractable due to their compact support and have the added flexibility of generating compact support regions that adapt to the input field. These features can be useful for covariance modeling and covariance tapering applications in data assimilation. We derive the GenGC correlation function using convolutions, discuss continuity properties relating to and and its correlation length, and provide one‐ and two‐dimensional examples that highlight its anisotropy and variable regions of compact support.
On the inverse power law‐normal model for life prediction of organic light emitting diodes
Authors: Abdul Majid Mohammed , Helal Sara , Kittaneh Omar
Published: May 2023

In accelerated life testing analysis with nonthermal accelerating stress, the inverse power law (IPL) is often solely merged with a particular lifetime probability distribution with a shape parameter. Although many fundamental lifetime distributions, such as the normal distribution, are excellent fits to the experimental lifetime data, they have not been considered as they lack the shape parameter. As such, this paper, for the first time, demonstrates that the shape parameter can be replaced by the coefficient of variation, allowing the use of normal distributions in this context. The work further introduces the IPL‐normal model in a rigorous mathematical setup that precisely leads to the least squares estimating equations and maximum likelihood estimates of the IPL‐normal accelerating parameters and the general coefficient of variation. The proposed model uses accelerated experimental data to successfully predict the lifetime of organic light‐emitting diodes (OLEDs) at use conditions. Based on these fundamentals, the predictions are benchmarked with prior works that were validated by market studies.
Distributed extended high‐gain observers for the generalized strict‐feedback system
Authors: Ji Yuehui , Xu Zhao , Liu Junjie , Song Yu
Published: May 2023

Two distributed extended high‐gain observers are studied for the generalized strict‐feedback system in presence of external disturbance. The system state dynamics are reconstructed admissibly based on the limited measured output. First, a distributed high‐gain observer is constructed to ensure the semiglobal ultimate uniform convergence of the state estimation error between the estimated state in each local observer and system state, for any prescribed initial system values. However, the dimension of the proposed distributed observer is n + 1 and the high‐gain parameter is powered up to n + 1. Therefore, a 2(n + 1)‐dimension distributed high‐gain low‐power observer is delicately designed, with the high‐gain parameter powered fixed to 2. The formulated distributed observer is easy‐implementation and the estimation error can reach fast convergence. Finally, a chaotic oscillator and a pendulum‐cart system are introduced to verify the effectiveness of the theoretical results.
Surface analysis insight note: X‐ray photoelectron spectroscopy analysis of battery electrodes—Challenges with nickel–manganese–cobalt and Li examples using an Al Kα x‐ray source
Authors: Strange Lyndi E. , Engelhard Mark H. , Easton Christopher D. , Kim Ju‐Myung , Baer Donald R.
Published: May 2023

X‐ray photoelectron spectroscopy (XPS) has become a highly important tool for the analysis of battery materials and components. However, both anecdotal and detailed analysis of selected parts of the literature indicate that many reports of XPS on battery electrodes have significant analysis or data flaws. In this paper, we highlight several of the common challenges that analysts face when using XPS for battery materials, pointing to recent literature that addresses many of the critical issues associated with sample preparation as well as data collection and analysis. A common error for battery materials (and other materials) involves ignoring peak overlaps and interferences. Specifically, when a “minor” peak associated with a component in relatively high concentration overlaps or contributes to the primary peak (or one recommended for quantitative analysis) from a different element in the material. Overlap issues apply to many battery electrodes composed of many elements with complex photoelectron peak structures, as well as those involving peaks with seemingly simpler spectral envelopes such as Li and F. Examples of issues associated with battery systems are highlighted by a discussion of challenges associated with XPS analysis of Li and nickel–manganese–cobalt (NMC) electrodes in battery systems. Lithium analysis has challenges associated with the preparation and an often‐unrecognized peak overlap with F. In our laboratory and in the literature, NMC electrodes are often examined and new XPS users do not always recognize interference of the Auger signal from FKLL (in or on the electrode) with Ni 2p photoelectron spectrum when generated with Al Kα X‐rays. The use of simulated spectra involving both F and NiO demonstrates the extent of F Auger contributions to the Ni 2p signal strength as a function of the F/Ni atom ratio in the material and suggests spectra information that can be used to identify how significant effects will be on the resultant spectra. Our analysis demonstrates that in many cases overlap issues are significant for real electrode materials.
Rational Loading of Linear Multi‐Site Receptors with Functional Lanthanide Containers: The Missing Link between Oligomers and Polymers
Authors: Mirzakhani Mohsen , Naseri Soroush , Egger Charlotte , Rosspeintner Arnulf , Nozary Homayoun , Piguet Claude
Published: May 2023

Although metal‐containing organic polymers are becoming essential for modern applications in lighting, catalysis, and electronic devices, very little is known about their controlled metallic loading, which mainly limits their design to empirical mixing followed by characterization and often hampers rational developments. Focusing on the appealing optical and magnetic properties of 4f‐block cations, the host–guest reactions leading to linear lanthanidopolymers already display some unexpected dependence of the binding‐site affinities on the length of the organic polymer backbone: a drift usually, and erroneously, assigned to intersite cooperativity. Taking advantage of the parameters obtained for the stepwise thermodynamic loading of a series of rigid linear multi‐tridentate organic receptors with increasing length, N = 1 (monomer L1), N = 2 (dimer L2), and N = 3 (trimer L3), with [Ln(hfa)3] containers in solution (Ln = trivalent lanthanide cations, hfa− = 1,1,1,5,5,5‐hexafluoro‐pentane‐2,4‐dione anion), it is demonstrated here that the site‐binding model, based on the Potts–Ising approach, successfully predicts the binding properties of the novel soluble polymer P2N made up of nine successive binding units . An in‐depth examination of the photophysical properties of these lanthanidopolymers shows impressive UV→vis downshifting quantum yields for the europium‐based red luminescence, which can be modulated by the length of the polymeric chain.
Multifunctional Buried Interface Modification Enables Efficient Tin Perovskite Solar Cells
Authors: Chen Yali , Qi Heng , Wang Kun , Kang Ziyong , Pan Guangjiu , Everett Christopher R. , Müller‐Buschbaum Peter , Tong Yu , Wang Hongqiang
Published: May 2023

Tin perovskite solar cells (PSCs) are considered promising candidates to promote lead‐free perovskite photovoltaics. However, their power conversion efficiency (PCE) is limited by the easy oxidation of Sn2+ and low quality of tin perovskite film. Herein, an ultra‐thin 1‐carboxymethyl‐3‐methylimidazolium chloride (ImAcCl) layer is used to modify the buried interface in tin PSCs, which can induce multifunctional improvements and remarkably enhance the PCE. The carboxylate group (CO) and the hydrogen bond donor (NH) in ImAcCl can interact with tin perovskites, thus significantly suppressing the oxidation of Sn2+ and reducing the trap density in perovskite films. The interfacial roughness is reduced, which contributes to a high‐quality tin perovskite film with increased crystallinity and compactness. In addition, the buried interface modification can modulate the crystal dimensionality, favoring the formation of large bulk‐like crystals instead of low‐dimensional ones in tin perovskite films. Therefore, the charge carrier transport is effectively promoted and the charge carrier recombination is suppressed. Eventually, tin PSCs show a remarkably enhanced PCE from 10.12% to 12.08%. This work highlights the importance of buried interface engineering and provides an effective way to realize efficient tin PSCs.
Effect of polycyclic aromatic hydrocarbons on cancer risk causally mediated via vitamin D levels
Authors: Chen Silu , Li Shuwei , Li Huiqin , Du Mulong , Ben Shuai , Zheng Rui , Zhang Zhengdong , Wang Meilin
Published: May 2023

Polycyclic aromatic hydrocarbons (PAHs) widely exist in environmental substrates and are closely related to individual circulating vitamin D levels and tumorigenesis. Therefore, we proposed to evaluate the relationship between PAH exposure, vitamin D, and the risks for 14 cancer types via a causal inference framework underlying the mediation analysis. We evaluated seven urine monohydroxylated PAH (OH‐PAH) and serum vitamin D concentrations of 3306 participants from the National Health and Nutrition Examination Survey between the 2013 and 2016 survey cycles and measured PAH concentrations in 150 subjects from the Nanjing cohort. We observed a significant negative dose–response relationship between increased OH‐PAH levels and vitamin D deficiency. Each unit increase in ∑OH‐PAHs could lead to a decrease in vitamin D levels (βadj = −0.98, Padj = 2.05 × 10−4). Body mass index could have interaction effects with ∑OH‐PAHs and affect vitamin D levels. Coexposure to naphthalene and fluorene metabolites mutually affected vitamin D levels. Notably, vitamin D could causally mediate the relationship between OH‐PAHs and nine types of cancer (e.g., colorectal cancer, liver cancers, etc.). This study first emphasizes the causal cascade of individual OH‐PAHs, vitamin D, and cancer risk, providing insights into prevention via the environment.
Daphnetin attenuates intestinal inflammation, oxidative stress, and apoptosis in ulcerative colitis via inhibiting REG3A‐dependent JAK2/STAT3 signaling pathway
Authors: He Zhi , Liu Jingjing , Liu Yang
Published: May 2023

Daphnetin is a natural coumarin compound with anti‐inflammatory, anti‐oxidant, and anti‐apoptotic effects, which has been previously demonstrated to ameliorate DSS‐induced ulcerative colitis (UC). However, the molecular mechanism involved in the daphnetin‐mediated pathological process of UC remains unclarified. The current study used DSS‐induced mice and LPS‐challenged Caco‐2 cells as UC models. Bodyweight, disease activity index (DAI) score, and colon length were used to evaluate the severity of colitis. The histological changes in colon tissues were observed using H&E and PAS staining. Protein levels were detected by western blot. The malondialdehyde (MDA) and superoxide dismutase (SOD) activities were used to assess oxidative stress. Inflammatory responses were evaluated by detecting the levels of inflammatory cytokines (IFN‐r, IL‐1β, IL‐6, and TNF‐α) using flow cytometry. CCK‐8 and TUNEL assay were employed to determine cell growth and cell death, respectively. The results showed that daphnetin could ameliorate the severity of colitis and attenuate the damage to intestinal structure in DSS‐induced mice. Compared with the DSS group, the expression of ZO‐1, occludin, and anti‐apoptotic protein (BCL‐2) was increased while the level of pro‐apoptotic proteins (Bax and cleaved caspase 3) was decreased in DSS + daphnetin group. The activity of MDA and SOD, as well as the levels of inflammatory cytokines were substantially suppressed by daphnetin. In consistency, in vitro assays indicated that daphnetin protected Caco‐2 cells from LPS‐stimulated viability impairment, apoptosis, oxidative stress, and inflammation. Furthermore, daphnetin suppressed the activity of JAK2/STAT signaling in LPS‐induced Caco‐2 cells in a REG3A‐dependent manner. REG3A overexpression abated the ameliorative effects of daphnetin while JAK2/STAT signaling inhibition functioned synergically with daphnetin in LPS‐stimulated Caco‐2 cells. Collectively, this study deepened the understanding of the therapeutic effects of daphnetin on UC and uncovered for the first time that daphnetin functioned through REG3A‐activated JAK2/STAT3 signaling in UC, which may provide novel insights for the treatment of UC.
Designing with and for Emerging Materials: Framework, Tools, and Context of a Unique Design Method
Authors: Ferraro Venere
Published: May 2023

The present chapter describes the unique design (teaching) method developed within the European Project DATEMATS by providing a framework to design with and for new materials, educate future designers, and give them the right knowledge to take advantage of the whole spectrum of opportunities (i.e., meaning and performance) offered by EM&Ts. It firstly depicts the core knowledge at the base of new Emerging Materials and Technologies (EM&Ts), namely: Interactive Connected Smart Materials, wearable based (ICS), Nanomaterials, Advanced Growing Materials, and Experimental Wood-Based Materials. It then provides the theoretical findings of a literature review carried out to perimeter the peculiarities of the four areas, the used approaches, and methodologies; the results of a collaborative workshop aimed at re-elaborating the findings of the literature review and setting the ground for the contents of the original framework for designing and teaching EM&Ts. It finally displays the result of both the literature review and the collaborative workshop in the form of the unique method divided into three phases (understanding, shaping, and applying). It will also include a section dedicated to the tools elaborated to support the method, such as a material toolkit and integration cards. A discussion closes the text by showing the pro and cons of the new method and its further development.
How Do We Approach and Involve Companies in Design Fields? Lessons Learned from Surveys and Participative Workshops
Authors: Obiols Alba
Published: May 2023

In the last few years, both materials and technologies are becoming one of the leading elements of product design practice as a lever to foster innovation and add value to final products. Despite the relevance of materials and technologies for advances in many fields, and particularly its importance to the success of the creative industries, there is a gap between the innovative design of products that meet the needs of the market and the research and development of new materials and technologies to be used in these products. The lack of collaboration between researchers and creative industries is at the heart of this issue (Innovamatnet, February 2013). Building on this ground the chapter shows the results of a survey submitted to more than one hundred companies in five different countries (Italy, Spain, Sweden, Finland, and Denmark). It was generated with the aim of collecting information regarding their specific interests and needs related to the four exemplified EM&T (ICS Materials, Nanomaterials, Advanced Growing Materials, Experimental Wood-based Materials) and the internal methods to manage knowledge related to them and the way they use to collaborate with academia and the channels they would prefer to use. The chapter also depicts the findings derived from a qualitative analysis done with academia and performed to identify their preferred channels to transfer knowledge. It finally describes the Company Manifesto, considered an engaging way to enhance and support the collaboration between Academia and the industrial sector.
A Supporting Tool to Design with and for EM&Ts: The Materials Toolkit
Authors: Esteban Gemma , Kann Geraldine , Sarbach Veronica , Amandolese Daniela
Published: May 2023

The chapter gives an exhaustive description of the so-called EM&Ts toolkit, a collection of tangible samples displaying emerging materials and technologies and containing five samples for each EM&Ts. Aim of the EM&Ts transfer toolkit is to provide a tool to facilitate the understanding and application potentials of emerging materials and technologies. Every material example has its box, containing: (1) Physical sample, (2) An “Understanding” card: it provides basic knowledge about the material and the manufacturer, Technology Readiness Level, crucial characteristics, and features. The sensorial qualities and performance, sustainability, and smart properties are listed for a clearer understanding of the materials potential; (3) A “Shaping” card: it contains information about the manufacturing process, the form in which the material is available and possible transformations. This information is useful to understand how the material can be processed for production, finishing, and transformation, to get to the final product. The card highlights, which processes that, have been associated with the material so far; (4) An “Applying” card: it gives information and pictures about the field the material is currently used. The material characteristics are compared with other better-known alternatives. In addition, other potential applications are listed, associated with meaningful case studies. The toolkit was created to be used as an aid in educational contexts with students and during workshops with companies and professionals. It is a powerful tool to provide students with information about the materials and their opportunities and limits, and to inspire them during the concept development. On the other side, it has potentialities to provide decision makers of the company with information about the emerging materials and technologies, their opportunities and limits, and to inspire them for innovation in product development. The chapter describes the continuous iterative process through which the toolkit was created and evaluated. Indeed, the toolkits have been used and tested in the academic context, with more than 100 students of diverse design backgrounds during EM&Ts workshops in Spain, Italy, Denmark, and Finland but also in professional context, during participative workshops with 94 companies, design studios, and professionals.
The Concept of Non-Territorial Autonomy: Origins, Developments, and Subtypes
Authors: Salat Levente
Published: May 2023

The aim of the chapter is to propose a possible framing of the NTA concept, considering the historical legacies by which the usage of the term is loaded, on the one hand, and the complex empirical realities the notion is expected to map, on the other hand. First, the idea of non-territoriality will be explored briefly, with highlight on the circumstances that bring about arrangements generally referred to when the NTA concept as an umbrella term is used. Then the origin and the semantic content of several subjacent terms—national autonomy, national cultural autonomyNCA (national cultural autonomy), cultural autonomy, personal autonomy, functional autonomy, administrative autonomy, consociationalism—will be discussed, together with the problems triggered by the concurrent attempts to provide precise definitions to the various institutional embodiments of the general NTA idea. The chapter will conclude with a brief assessment of the consequences for the NTA scholarship which follow from the two main limitations of the NTA notion: the underdetermination of the widely used concepts and the gap between theory and empirical realities.
Origins and Early Implementations of Non-Territorial Autonomy
Authors: Germane Marina , Kuzmany Börries
Published: May 2023

This chapter explores the origins of the idea of non-territorial autonomy and traces its theoretical development, as well as actual implementations, across time and space from the late Habsburg and Russian Empires to the Paris Peace Conference and to the interwar nation-states. Upon completing this chapter, you will learn how the concept of NTA came into being; what were its main features; who were the concept’s main proponents; which political currents supported the idea and which opposed it; and, finally, how historical events and changes at both the state and the international levels shaped the NTA concept’s ideological metamorphoses and determined its practical applications.
NTA as a Democratization Tool
Authors: Smith David J.
Published: May 2023

Having been implemented in several contexts and extensively discussed internationally during 1900–1940, NTA largely disappeared from the international legal and political agenda immediately after World War Two, only to again attract interest from scholars and policymakers from the 1960s onwards. This revived interest partly reflected the emergence of new multicultural models of state and citizenship—and attendant NTA-style arrangements for minorities—in some established Western democracies but was given further impetus by the start of democratisation in Central and Eastern Europe following the end of communist rule in the region. The adoption of laws and institutional arrangements bearing the NTA label in Hungary, Estonia, Russia, Slovenia, Croatia, Montenegro and Serbia (among others) coincided with the elaboration of new international standards on minority protection by European and Euro-Atlantic International Organizations, which today serve as a benchmark against which different forms of NTA can be assessed in terms of their potential to support democratization and the sustainable accommodation of ethnic diversity. This chapter first examines the origins and drivers of the new more contemporary variants of NTA, before sketching the main lines of how a democratic NTA arrangement should look. This ideal-type model is then used to assess contemporary examples of NTA and their potential to support democratization (or otherwise) in post-Cold War Europe.
Language and Religion Within Cultural Autonomy Arrangements: An Exercise in Minority Agency?
Authors: Topidi Kyriaki
Published: May 2023

Given the, often, abstract conceptual understanding of NTA, the aim of this chapter is not to provide an analysis of the ideal type(s) of cultural autonomy arrangements in minority group contexts. Instead, it purports to evaluate the design, implementation and evolution of such arrangements between states and minority groups as applied in specific areas of minority culture. Following a first brief section that describes the main features of cultural autonomy (see also Chapter8), the chapter will focus on two important identity markers of minority groups to show how these have formed the basis for a number of NTA arrangements. These are language and religion which are at the heart of the protection of minority identities. Through the lens of these two important identity-markers, the chapter will adopt a double objective: first, to outline the variety of cultural NTA arrangements and their limitations from a diversity governance perspective on the basis of language and religion and second, to highlight the link between cultural forms of NTA and minority agency.
Study on the Influence of the Arrangement of Thermal Insulation Floor on the Thermal Insulation and Mechanical Properties of Hollow Slab
Authors: Liu Yuchen
Published: May 2023

In order to study the influence of the arrangement of thermal insulation floor on the thermal insulation and mechanical properties of hollow slab, ABAQUS is used to establish the model of thermal analysis and mechanical behavior of hollow slab. By investigating distribution of temperature, distribution of heat flux, damage and deformation of floor, deformation of mid-span deflection and other characteristics of the floor section, it is concluded that although the transmission of heat can be effectively obstructed by the thermal insulation slab, the heat will be transferred to the interior of the floor through the gap between the thermal insulation slabs. The arrangement of thermal insulation slab is not the main factor which affect the thermal insulation properties of the floor with the same coverage area. Different arrangement of the thermal insulation slab has a certain impact on the mechanical performance of floor. It is recommended to arrange the thermal insulation slab in equal sections to fully improve the contact area between steel bar and concrete, which can effectively provide the bearing capacity of the floor.
Experimental Investigation of Effectiveness of FRP Composite Repair System on Offshore Pipelines Subjected to Pitting Corrosion Under Axial Compressive Load
Authors: Wei Chang Jia , Liang Ong Zhen , Jarghouyeh Ehsan Nikbakht
Published: May 2023

The application of FRP composite is quite well demonstrated in strengthening on RC structures but on strengthening of steel structures is still being investigated by many researchers. The aggressive marine environment can cause corrosion to the offshore pipelines which would affect the structural performance such as pitting corrosion which could be considered as the most destructive corrosion was simulated in this research. This study had attempted to carry out experimental investigation of effectiveness of FRP composite repair system on offshore pipelines subjected to pitting corrosion under axial compressive load. 3 groups of specimens have been categorized such as intact, corroded and repaired. Results such as compressive peak load, failure modes and load–displacement behavior were concerned in this study. The pitting corrosion has been investigated and proved that it has significant effect on the ultimate strength of pipelines. Number of CFRP layer such as 3 layers has been investigated which the results showed the FRP composite repair system capable of strengthening of corroded offshore pipelines. However, more detailed studies are required to be conducted in the future such as consideration of internal pressure in order to expand the understanding of this composite repair system.
Research on Axial Force Coherence of Steel Support Based on Active Control
Authors: Sheng Jianchao , Sun Jiuchun , Jiang Donglai , Xiao Yuanjie , Lv Rundong , Wang Zhe
Published: May 2023

Using servo steel support system for active control of deformation during foundation fit excavation has high superiority. To investigate the coherence of the servo support axial force, PLAXIS 3D is used to carry out numerical analysis on the coherence of the axial force applied by the construction and compare with the field test results; Field tests were conducted on the diaphragm wall joint deformation during the axial force application based on the principle of the generation of axial force coherence. The results show that the farther away from the active axial force, from which suffered get the smaller influence, and the size of the applied axial force’s effect on the support in other directions in the order of horizontal, vertical, and oblique. Moreover, the higher the application position of the active axial force of the servo support, the greater the lateral axial force loss rate generated by other supports, while the opposite in vertical axial force loss rate is true. The maximum axial force loss rate is 19%. The deformation of the diaphragm wall joint in the servo steel support zone is more significant than that in the pre-stressed steel support zone. The deformation of the joint will, in turn, affect the axial force.
Analysis of the Discriminability of High-Temperature Performance Indices of Modified Asphalt Mixtures
Authors: Gu Mengjun
Published: May 2023

Different indices have various capabilities to evaluate the high-temperature performance of modified asphalt mixtures. This study aims at investigate the discriminability of high-temperature performance indices. The values of five indices were determined from wheel tracking test, Marshall test and uniaxial penetration test, including dynamic stability (DS), comprehensive stability index (CSI), maximum rutting depth (RD), Marshall stability (MS), and uniaxial penetration strength (UPS). The discriminability of five indices was further examined by entropy weight method and CRITIC method, respectively. The results show that DS, MS and UPS are not appropriate to evaluate the high-temperature performance of modified asphalt mixtures, but CSI and RD show preferable distinguishing ability to evaluate the high-temperature performance. As a consequence, RD is recommended to be employed as secondary index to supplement the CSI in wheel tracking test. The findings of this study will contribute to the optimization of evaluation on high-temperature performance of modified asphalt mixtures.
Curvature Ductility of Confined HSC Columns
Authors: Bouzid Haytham , Rabia Benferhat , Daouadji Tahar Hassaine
Published: May 2023

To avoid brittle collapse of reinforced concrete (RC) structures, RC elements such as beams, columns, and shear walls are invited to ensure a minimum level of ductility. In this paper, an analytical method for predicting the curvature ductility factor of confined RC columns is developed. The stress–strain model of confined concrete provided by Eurocode 2 is adopted, and the effective lateral confining pressure is calculated according to the Eurocode 8. The curvature ductility factor is defined by the ratio of ultimate to yield curvature. In this context, a new hypothesis is adopted to calculate the yield curvature while the ultimate curvature is calculated based on axial load and the mechanical ratios of tension, web, and compression reinforcement. The results showed that the developed method has an excellent performance compared to the experimental results collected from previous researches, where the mean value and the standard deviation of the ratios predicted to experimental factors are equal to 1.02 and 0.17, respectively. Moreover, the calculated coefficient of determination is very close to 1.
Buckling Behaviour of Locally Dented GFRP Cylindrical Shells Under External Pressure—A Numerical Study
Authors: Fazlalipour Neda , Ghalghachi Robab Naseri , Firouzsalari Saeed Eyvazinejad
Published: May 2023

Structural applications of composite materials are used in various structures of the oil and gas industry, water supply and sewage systems and a wide range of industries, such as marine, aerospace, and military industries. This paper aims to numerically investigate the influence of local dent caused by an indenter on the buckling behaviour of glass fabric-reinforced polymer cylindrical shells when subjected to external pressure. For this purpose, 24 finite element numerical models with five layers and a stacking sequence [30/-30/30/-30/30] were simulated in ABAQUS. The effect of dent depth (2, 4, 6 and 8 mm) and orientation (0 and 90 degrees) that was created at the mid-height, the 1/3rd and the 2/3rd of the shell height on the buckling behaviour of the composite cylindrical shells were evaluated. The results underscored that whilst the location of the local dent and the depth affected the shells’ buckling capacity, the dent's orientation had minimal effect on the buckling capacity of the cylindrical shells.
Research and Application of Ultra High Performance Concrete in Engineering Projects in Japan
Authors: Zhou Jian
Published: May 2023

Japan is located in the international seismic zone, and is also a resource intensive country. It has unique features in the research and application of ultra-high performance concrete materials. The paper analyzes and summarizes the engineering application cases of concrete strength grade above 150 N/mm2, including structural system, mix design, production process, strength grade, etc. Silica fume composite cement, with strict calculation of sand and stone gradation, improves the compactness beyond the conventional concrete; The super high performance water reducing agent can greatly reduce the water cement ratio and improve the working performance, especially the expansion degree; Organic fiber and steel fiber are especially important in fire resistance, explosion resistance and ductility. Ultra-high performance concrete could improve the seismic performance of building structures and the utilization rate of building area, and new materials could provide more choices for design and engineering application.
Experiment and Engineering Application Study on the Compression Properties of Foundation Soil in the Process of Reinforcing Existing Buildings with Composite Piled Foundation
Authors: Tang Qiufeng , Tong Jianxing , Jia Ning , Zhou Shengbin
Published: May 2023

When an existing building has excessive settlement and has no convergence tendency due to foundation problems, the composite piled foundation is often used to partially underpin the upper load. However, considering that the compression properties of the foundation soil have changed greatly, the compressibility index provided by the initial survey report is no longer suitable for calculating the settlement of the reinforced foundation. In this paper, a consolidation test is designed to simulate the compression state of the foundation soil in the process of building construction, reinforcement, and settlement stability. The test results show that the recompression modulus Ers of the soil sample is 2.5–3.5 times the compression modulus Es1-2. In the engineering example, the recompression modulus is used to calculate the settlement of the reinforced foundation according to the settlement calculation method of the composite foundation with settlement-reducing piles, and the results are close to the actual settlement. In actual engineering, in the absence of supplementary survey, it is recommended to obtain the recompression modulus Ers through simulated test or use 2.5–3.5 times the compression modulus Es1-2 to calculate the settlement of the reinforced foundation.
Study on Comprehensive Detection and Treatment Measures of Qinlan Tunnel of Tianba Expressway Crossing Large Karst Cave
Authors: Wang Xiaoming , Zhou Yongxing , Zhang Gang , Chen Xueqi , Liu Zhiqiang , He Xiaoyong
Published: May 2023

Aiming at the problem of comprehensive detection technology and treatment measures for tunnels crossing large karst caves, this paper systematically carried out the research on advanced detection of karst geology and treatment measures of karst caves in combination with the Qinlan Tunnel Project of Tianba Expressway in Guangxi. The comprehensive detection method of “karst geological survey + geological radar detection + advanced horizontal drilling + three-dimensional laser scanning + geological sketch” is used for advanced detection. On the basis of ascertaining the spatial location and development scale of karst caves, the scheme of tunnel excavation after advanced reinforcement and support treatment such as advanced small pipe grouting is determined. It has been successfully applied to the construction practice of Qinlan Tunnel crossing ZK89+110 large karst caves, and the treatment measures of “root pile + lining strengthening” are put forward. It effectively avoids the occurrence of disasters caused by karst caves, and has important reference significance for similar projects.
Analysis on the Modeling of Rockbusrt Prediction in Deep Tunnels Based on Machine Learning
Authors: Zhang Yong , Liu Haijun , Ma Yueyuan , Chen Xueqi , Li Weinan , Huang Zheng
Published: May 2023

Deep tunnels will face complex mechanical behavior problems of rock mass during construction and operation, among which the rockburst disaster is particularly prominent. Therefore, how to scientifically predict the rockburst activities of deep tunnels has become an urgent problem to be solved. According to the three aspects of energy conditions, lithology conditions and stress intensity that rockburst must meet, the strain energy storage coefficient (Wet), stress concentration factor (SCF) and brittleness index of rock mass (σc/σt) are selected as the discrimination indexes. On this basis, combining with the method of cluster analysis, some abnormal data are removed and a case database is constructed. Aiming at the defects of traditional prediction methods, this paper proposes a support vector machine method to establish the rockburst prediction model. According to the prediction model proposed in this paper to predict the rockburst situation of several deep tunnel engineering in China. The results show that the tunnel rockburst prediction model based on support vector machine is well consistent with the actual situation, indicating that the model has strong feasibility in practical application.
Application Practice of 3D Integration of Pipeline Information in Large-Scale and Complex Project Sites-Take Changsha Airport Addition and Alteration Project as an Example
Authors: Jiang Cheng , Dai Xiaogang , Huang Yinqiang , Li Jinlei
Published: May 2023

Based on the practice of Changsha Airport Addition and Alteration Project, this paper refines, studies and summarizes the type, integration and interaction of pipeline information in large-scale and complex project sites, According to the whole life cycle of the Project, four types of pipeline information, including self-owned attribute, system attribute, management attribute and additive attribute, are sorted out. In actual engineering projects, there are two modeling ways, Method I: direct BIM design modeling, Method II: transformation and modeling after CAD design. The difference between Method I and Method II mainly sits on the difference in presentation form. One is three-dimensional and the other is two-dimensional. However, the base of both of them representing pipeline information is attributes and data. As long as these attributes and data can be extracted, information integration can be realized and applied to project management in the later stage. Based on the integrated research on the airport pipeline information, a corresponding BIM collaboration and management and control platform has been developed for the Project, and research results have been applied to the actual management of the project pipeline in an exploratory way, so as to achieve the project management requirements of the airport pipeline in terms of design, progress, cost, prefabrication and processing, and prepare for the later digital delivery and intelligent operation and maintenance management.
Numerical Simulation of Seismic Liquefaction for Treasure Island Site
Authors: Lu Hua , Lin Ziyun , Zhan Xudong , Yang Yanxin , Wu Di
Published: May 2023

By conducting numerical simulations of Treasure Island site in 1989 Loma Prieta earthquake, the Hilbert-Huang transform was used to study soil liquefaction. The UBC3D-PLM constitutive model was used to simulate the dynamic behavior of sand, the non-liquefied soil was simulated by Hardening Small Strain model, and the seismic information recorded in the PEER database was used for deconvolution analysis by one-dimensional equivalent linear analysis method, and the within motion was applied. Rayleigh damping is used in the numerical simulation process, and the damping ratio is 5%. Based on the Hilbert-Huang transform analysis, it is concluded that the UBC3D-PLM constitutive model can effectively simulate the dynamic behavior of soil. The amplification of the peak acceleration was from the bottom of Sandy fill to the ground surface, and the low-frequency content was shifted due to liquefaction in the process of transmission to the surface, and the high-frequency content was identified at the surface.
Analysis of Mode and Response Spectrum of an OBS Anti-trawl Sinking Coupling Frame Based on ANSYS Workbench
Authors: Zong Le , Yu Kaiben , Zhao Yuexia , Yu Shengqi , Zhao Lichuan , Ran Jun , Yang Zhiguo , Liu Baohua
Published: May 2023

Three-dimensional solid modeling of an OBS anti-trawl sinking coupling frame was carried out using the ANSYS, and modal simulation analysis of the overall structure of the anti-trawl sinking coupling frame was made through the ANSYS Workbench. The natural frequencies and mode shape contour diagrams of the first six modes were extracted. The displacement response spectrum was analyzed, and the equivalent stress and directional displacement contour diagrams were obtained. Simulation results show that the natural frequency of the anti-trawl sinking coupling frame evades the working frequency band of the OBS, which verifies the effectiveness of the anti-trawl structure design.
Force Analysis of Anti-slip Pile Bodies on Soil Mudstone Slopes Under Heavy Rainfall
Authors: Liu Xiaobin
Published: May 2023

The soil mudstone slope anti-slip piles are used as the object of study to analyse the pile forces under the action of heavy rainfall. Introduction to the project, description of the general topographic elevation of the area; extraction of seepage potential energy from soil mudstone, calculation of rainfall and rainfall infiltration, assumption of vertical wall backs and horizontal fill behind the wall, calculation of lateral pressure on the rock supported by anti-slip piles, analysis of its damage mode according to the morphology of the bedrock surface and the conditions of the rock outwash structural surface, and calculation of slope stability under the action of strong rainfall. Analysis of the results: setting the length of the anti-slip piles at 15.5–17.5 m is most reasonable under the effect of heavy rainfall.
Mechanical Properties and Micromechanism of Geopolymers to Replace Cement Stabilized Crushed Stone
Authors: Li Yongxiang , Yang Lijuan , Li Xiao , Li Yongfei , Zhang Qiang , Pang Shoude
Published: May 2023

In order to realize the resource utilization of solid waste, the principle of alkali excitation is used to prepare geopolymers with fly ash, mineral powder and wet carbide slag as the main materials to replace part of the cement as the cementing material for the pavement base. Geopolymer-stabilized crushed stone was prepared by compounding cement and aggregate with geopolymer, and the unconfined compression strength, indirect tensile strength, compression rebound modulus, scour resistance and microscopic X-ray diffraction (XRD) and scanning electron microscopy (SEM) tests were carried out to study the effect of the change of geopolymer content on the mechanical properties of geopolymer-stabilized crushed stone and its mechanism. The test results show that when adding 30% geopolymer, the mechanical properties similar to those of cement can be obtained to a certain extent. XRD and SEM analysis showed that the geopolymer provided appropriate amount of silico-alumina and calcareous components to form calcium silicate hydrate (C–S–H) and calcium silicate (aluminum) hydrate (C–(A) –S–H) condensation. The glue can form a dense structure and increase the strength of the mixture.