bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic activity of metal oxides supported on graphene oxide in oxidative desulfurization and denitrogenation
Authors: Shadmehri Mehdi A. , Housaindokht Mohammad Reza , Nakhaei Pour Ali
Published: September 2023

In this work, the effect of different parameters on catalyst efficiency in the catalytic oxidative desulfurization (ODS) and denitrogenation (ODN) process is studied. A series of samples with different metal compounds, including Ni, Cu, Co, CoNi, CoCu, and CuNi on a reduced graphene oxide (GO) were prepared by an impregnation method. The synthesized samples were carefully characterized by Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), X‐ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and X‐ray powder diffraction (XRD) techniques. The potential of this methodology was illustrated by the oxidation of 84.11% carbazole (CBZ) and 88.36% dibenzothiophene (DBT) in model fuel containing 500 ppmw sulfur and nitrogen. The effect of DBT and CBZ initial concentration and oxidant type on the oxidation process was investigated. The initial concentration of 250 ppmw for DBT and 100 ppmw for CBZ showed more efficiency than other initial concentrations (1,000, 750, 500, 250 ppmw) for DBT and (500, 400, 250, 100 ppmw) for CBZ, and NaClO as an oxidant showed higher performance than H2O2, formic acid, and oxygen. The results indicated that the Co‐Cu/rGO catalyst shows higher activity than other prepared catalysts in the oxidation of DBT and CBZ. Moreover, the catalyst could be regenerated three times with no discernible decrease in its catalytic activity. Lastly, the catalytic oxidation of CBZ and DBT was the proposed reaction mechanism.
Treatment of palm oil mill effluents using rambutan (Nephelium lappaceum) and its modeling using artificial neural networks
Authors: Bunyamin Amirul Ashraf , Sethu Vasanthi , Arumugasamy Senthil Kumar , Selvarajoo Anurita
Published: September 2023

Palm oil extraction is one of the important industries in Malaysia. The extraction of palm oil will not only result in the production of palm oil for human consumption but also generate palm oil mill effluent (POME), which contains highly polluting properties. Synthetic coagulants such as aluminum sulfate (alum), aluminum chloride, and sodium aluminate contribute toward environmental pollution and risk to human health. Thus, natural coagulants and flocculants have been introduced throughout the globe to slowly replace synthetic coagulants. In this study, rambutan (Nephelium lappaceum) seed was used as natural coagulants combining with aloe vera as natural flocculants. The standard jar test experiments were conducted to study the effects of pH, coagulant dosages, and rapid mixing speed on the removal efficiency of chemical oxygen demand (COD), total suspension solid (TSS), and turbidity of POME. The model of the coagulation–flocculation process was evaluated by using response surface methodology (RSM) and artificial neural network (ANN). RSM associated with Box–Behnken design was used to identify the optimum parameters (inputs), which consist of pH, coagulants dosages and rapid mixing speed for the optimum removal efficiency (outputs) of COD, TSS, and turbidity of POME. In terms of removal efficiency of COD, TSS, and turbidity of POME, rambutan seed has the optimum removal efficiency of 28.48%, 56.38%, and 60.36%, respectively. ANN was utilized with the aim of evaluating the performance of 12 training algorithms to predict the output results. Levenberg–Marquardt (LM) training algorithm was verified to be the best training algorithm for coagulation–flocculation process of rambutan seed based on the lowest mean squared error (MSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) for validation data and the correlation coefficient R of .9347.
Estimation and rejection of periodic disturbance in a preview repetitive control system
Authors: Lan Yong‐Hong , Liu Da
Published: September 2023

This paper deals with the problem of two‐dimensional (2D) system‐based preview repetitive control (PRC) with external periodic disturbance for a class of continuous‐time linear systems. First, a repetitive learning‐based estimator (RLE) is incorporated into the controller block to compensate for the periodic disturbance. Next, the PRC law with repetitive learning compensation disturbance is obtained by combining the observer and RLE. Then, we combine the 2D system theory with the linear matrix inequality (LMI) method to derive sufficient conditions to ensure the robustness and stability of the closed‐loop system. Finally, numerical simulations verify the superiority of the proposed method.
Mechanoluminescence and photoluminescence properties of Eu3+‐activated SrGa2O4 phosphors
Authors: Vasanthi Baby , Gopakumar Narayana Panickar , Anjana Prabhakaran Sreekumari , Nair Girija
Published: September 2023

Red‐emitting Eu3+ activated SrGa2O4 phosphors were synthesized using a conventional solid‐state reaction method. The structural, optical, and luminescence properties were systematically investigated. The synthesized phosphors are single phase with a monoclinic structure. There are no significant changes in the phase and the crystal structure of the host matrix after incorporating Eu3+ ions. The undoped and Eu3+ doped SrGa2O4 phosphors exhibited good mechanoluminescence (ML) emission without any irradiation with ultraviolet (UV) or gamma rays. Eu3+‐activated SrGa2O4 phosphors have prominent red emission attributed to 5D0 → 7F2 forced electric dipole transition excited at 395 nm. The colour coordinates and purity of the SrGa2O4: 0.08 Eu3+ phosphor were calculated to be (0.6102, 0.3810) and 97.6%, respectively. The quantum efficiency is 12.68%, and was better than that of commercially available red phosphors. The ML and photoluminescence studies revealed that the synthesized phosphors can act as potential candidates for stress sensors, UV or near‐UV light‐emitting diodes (NUV LEDs) and components of phosphor‐converted white light‐emitting diode (pc‐WLED) applications.
The retinacular ligaments of the digital extensor expansion revisited: An anatomical and biomechanical study
Authors: Borgström Tomas , Dahlin Lars B. , Tranum‐Jensen Jørgen
Published: September 2023

Our aim was to clarify the anatomy and function of the retinacular ligaments. Forty‐eight fingers were dissected and the thickness of the oblique retinacular ligament (ORL) was graded. In four fingers, the motion in the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints was subjected to an in‐depth analysis before and after sectioning of either the lateral bands (LB) or the ORLs. The function of the ORLs in restricting flexion of the DIP joint with full extension of the PIP joint was measured in 10 fingers. An ORL could be identified on both sides in all 48 fingers. The distribution of the insertion on the proximal phalanx was 7/96 (7%) in the distal third, 70/96 (73%) in the middle third and 19/96 (20%) in the proximal third. Among the specimens, 29% were graded as having a strong bundle of fibers, 51% as having well‐defined and regular fibers and 20% as having thin and sparse fibers. With the PIP joint extended, there was a statistically significant increase in flexion of the DIP joint after the ORL was cut. After the LB was sectioned, the ORL was able to extend the DIP joint with an extension lag of 10–22°. Cutting the ORL did not affect the ability to extend that joint. We conclude that the retinacular ligaments are consistent. Their major role is not connected with finger movement, but to provide stabilizing links between the PIP and DIP joints. They are active in not only specific, uncommon finger positions but also in ordinary use of the fingers.
Health‐related quality of life and survival outcomes for patients with major depressive disorder and anxiety: A longitudinal study in pancreatic ductal adenocarcinoma
Authors: Ji Yuchen , Chen Haoda , Yang Yuxuan , Zhou Yiran , Li Hongzhe , Jin Haiyan , Xie Junjie , Shen Baiyong
Published: September 2023

Background

Major depressive disorder (MDD) and anxiety were recognized in treating pancreatic ductal adenocarcinoma (PDAC). This longitudinal study identified risk factors for MDD and anxiety and established associations with patients' quality of life (QoL) and survival outcomes.

Materials and Methods

We used PHQ‐9 and GAD‐7 questionnaires to diagnose MDD and anxiety in PDAC patients between October 2021 and March 2022 at a Chinese center. Characteristics and clinical data were analyzed for risk factors and EORTC QLQ‐C30 questionnaire was administered for QoL before the first chemotherapy. Furthermore, chemotherapy compliance and 1‐year survival were compared during follow‐up.

Results

MDD and anxiety occurred in 51.8% and 44.7% of 114 patients over the half‐year period. Employment at work (odds ratio [OR]: 5.514, p = 0.001; OR: 3.420, p = 0.011) was an independent risk factor, while radical surgery (OR: 0.342, p = 0.034; OR: 0.238, p = 0.004) was a protective factor. Several aspects of decreased QoL were discovered after their onsets. Higher incidences of physical disorders (p = 0.004; p < 0.001), mental disorders (p = 0.001; p < 0.001), anti‐therapy emotions (p = 0.002; 0.001), and chemotherapy suspensions (p = 0.001; p = 0.043) were observed. Furthermore, the 1‐year mortalities for all patients and those receiving radical surgeries were correlated with MDD (p = 0.007; 0.036) and anxiety (p = 0.010; 0.031).

Conclusions

MDD and anxiety are common in PDAC patients and correlated with poor QoL and survivals. Therefore, appropriate mental management is required in future.
Risk of cardiovascular disease in cancer survivors: A cohort study of 446,384 New Zealand primary care patients
Authors: Tawfiq Essa , Pylypchuk Romana , Elwood J. Mark , McKeage Mark , Wells Sue , Selak Vanessa
Published: September 2023

Background

Given advances in the management of cancer, it is increasingly important for clinicians to appropriately manage the risk of cardiovascular disease (CVD) among cancer survivors. It is unclear whether CVD risk is increased among cancer survivors overall, and there is inconsistency in evidence to date about CVD incidence and mortality by cancer type.

Methods

Patients aged 30‐74 years entered an open cohort study at the time of first CVD risk assessment, between 2004 and 2018, in primary care in New Zealand. Patients with established CVD or cancer within 2 years prior to study entry were excluded. Cancer diagnosis (1995–2016) was determined from a national cancer registry. Cause‐specific hazard models were used to examine the association between history of cancer and two outcomes: (1) CVD‐related hospitalization and/or death and (2) CVD death.

Results

The study included 446,384 patients, of whom 14,263 (3.2%) were cancer survivors. Risk of CVD hospitalization and/or death was increased among cancer survivors compared with patients without cancer at cohort entry (multivariable‐adjusted hazard ratio, mHR, 1.11, 95% CI 1.05‐1.18), more so for CVD death (1.31, 1.14‐1.52). Risk of CVD hospitalization and/or death was increased in patients with myeloma (2.66, 1.60‐4.42), lung cancer (2.19, 1.48‐3.24) and non‐Hodgkin lymphoma (1.90, 1.42‐2.54), but not for some cancers (e.g., colorectal, 0.87, 0.71‐1.06). Risk of CVD death was increased in several cancer types including melanoma (1.73, 1.25‐2.38) and breast cancer (1.56, 1.16‐2.11).

Conclusion

CVD risk management needs to be prioritized among cancer survivors overall, and particularly in those with myeloma, lung cancer and non‐Hodgkin lymphoma given consistent evidence of increased risk.
Spatial Variation in Yield, Chemical Composition, and Phytotoxic Activity ofCistus ladaniferEssential Oils
Authors: Pérez‐Izquierdo Carlos , Jordán Bueso María Josefa , del Carmen Rodríguez‐Molina María , Pulido Fernando
Published: September 2023

Cistus ladaniferL. (rockrose) is a widespread shrub species of the Mediterranean region with products highly valued by the perfume and cosmetics industry. In this research, the variability in yield, chemical composition and phytotoxic activity ofC. ladaniferessential oils collected from 12 plots belonging to four natural populations and settled on two different types of edaphic substrates were evaluated. The essential oils were analyzed by GC‐MS. The essential oil content ranged from 0.19 to 0.42 mL/100 g. The volatile profiles were found to be rich in oxygenated sesquiterpenes and oxygenated monoterpenes. PCA analysis clustered the samples into two groups that were mainly attributed to the type of substrate on which the plants grow. Furthermore, CCA and correlation analysis revealed that soil organic matter was the most effective edaphoclimatic driver accounting for these high levels of variation in essential oil yield and composition. Finally,C. ladaniferessential oils showed strong phytotoxic activity onR. sativusseedlings, indicating its potential use as a natural bio‐herbicide in agriculture. The results showed that the effect associated to local edaphoclimatic conditions not only impacted on the quality and quantity of the essential oil, but also on the industrial uses derived from its biological activities.
Glycolipids from Sargassum filipendula, a Natural Alternative for Overcoming ABC Transporter‐Mediated MDR in Cancer
Authors: Muñoz‐Losada Kelly , Da Costa Kelli Monteiro , Muñoz‐Castiblanco Tatiana , Mejía‐Giraldo Juan Camilo , Previato José Osvaldo , Mendonça‐Previato Lucia , Puertas‐Mejía Miguel Ángel
Published: September 2023

Chemotherapy is a widely used strategy to treat cancer, a disease that causes millions of deaths each year. However, its efficacy is reduced by the overexpression of ABC transporters, which are proteins that expel the drugs used in chemotherapy and involved in the multidrug resistance (MDR). Glycolipids have been identified as potential inhibitors of ABC transporters. Algae of the genus Sargassum contain high levels of glycolipids, making them a promising therapeutic alternative against the MDR phenotype. Sargassum filipendula glycolipids were obtained by exhaustive maceration with chloroform/methanol, purified by column and thin layer chromatography, and then characterized by FTIR, NMR, and LC‐MS. Cell viability by PI labeling and inhibition of ABC transporters were analyzed by flow cytometry. Assessment of resistance reversal was determined by MTT assay. Ten sulfoquinovosylglycerol‐type compounds were found, and six of them are reported for the first time. In particular, moiety 4 (GL‐4) showed strong and moderate inhibitory activity against ABCC1 and ABCB1 transporters respectively. Treatment of GL‐4 in combination with the antineoplastic drug vincristine sensitized Lucena‐1 cell model to drug and reversed the MDR phenotype. This is the first report of glycolipids isolated from S. filipendula capable of inhibiting ABC transporters and thus overcoming acquired drug resistance.
A Case of Convergent Evolution: The Bacterial Sesquiterpene Synthase for 1‐epi‐Cubenol from Nonomuraea coxensis
Authors: Dickschat Jeroen S. , Quan Zhiyang , Schnakenburg Gregor
Published: September 2023

A terpene synthase from Nonomuraea coxensis was identified as (+)‐1‐epi‐cubenol synthase. The enzyme is phylogenetically unrelated to the known enzyme of the same function that is widespread in streptomycetes. Isotopic labelling experiments were performed to unambiguously assign the NMR data and to investigate hydrogen migrations during terpene cyclisations. Epoxidations of (+)‐1‐epi‐cubenol and of the plant derived compounds (−)‐cubenol and (−)‐1‐epi‐cubenol confirmed the structure of a natural product isolated from the brown alga Dictyopteris divaricata and allowed to conclude on its absolute configuration. The crystal structures of the epoxides from (+)‐ and (−)‐1‐epi‐cubenol and the acid catalysed conversion into an isomeric ketone are reported.
Concept to assess the performance on degrading concrete structures components
Authors: Binder Fritz , Burtscher Stefan L.
Published: September 2023

The infrastructure of ASFiNAG is mainly built from reinforced and prestressed concrete, which despite all regular maintenance measures, is subject to ageing and degradation. The major degradation process is chloride attack, followed by carbonation, which both lead to corrosion of the reinforcing steel. A new method, which represents a significant improvement on previous assessments, is used in this paper to analyze chlorides in concrete. The paper also introduces a new concept for the durability assessment by using objective indicators, like chloride content, electrical resistivity, and corrosion potential. For objectivity and a reliable determination of the condition state, an overall performance index derived from the condition indices using an analytic hierarchy process (AHP) is adapted. The model is applied to excellent and dense data from a monitoring system and investigations taken from reinforced concrete components beside a motorway.
Sustainability assessment of bridge structures in the operation phase based on a digital twin
Authors: Jäkel Jan‐Iwo , Kaus Michelle , Klemt‐Albert Katharina
Published: September 2023

There are about 65,000 bridge structures in the infrastructure network of the Federal Republic of Germany. Due to the long operating phase of bridges, they have an influence on sustainability. To evaluate the sustainability of bridges in the operational phase, digital building models can serve as a consistent and structured database to increase the efficiency and transparency.

In this article, an innovative evaluation system for measuring and assessing the sustainability of a bridge structure in the operational phase based on a digital bridge twin is developed. First, the workflow is presented in a process model and the necessary requirements for the digital twin of the bridge structure are defined. In addition, the semi‐automatic sustainability assessment system is described and the linkage via an interoperable interface to the digital twin is designed. The approach is tested and validated using a real demonstrator. The result of the paper shows an approach to use digital twins for a novel and semi‐automatic sustainability assessment in the operation of bridge structures.
Structural evaluation by reverse engineering with 3D laser scanner
Authors: Jang Arum , Jeong Sanggi , Park Min Jae , Ju Young K.
Published: September 2023

In the modern era, there has been a surge of interest in researching the integration of high‐tech in construction. Many different technologies are currently being explored as potential solutions for future construction projects. BIM technology using high‐tech equipment is spotlighted as promising for future construction projects. As structures age, there is a growing demand for safety inspections. However, current safety inspection methods are traditional and rely heavily on the subjective opinions of workers, leaving much room for error. To address this issue, there is a need to develop existing maintenance technology. Recently, there has been a significant increase in research on building safety inspections using 3D laser scanners, which use LIDAR technology to allow for precise and rapid acquisition of building information. This technology even allows for reverse engineering through point cloud data modeling. In light of this, a new evaluation system for building stability using 3D technology is proposed in this study, which aims to revolutionize the way that safety inspections are carried out.
Life cycle management for service life extension of structures
Authors: Strauss Alfred , Zimmermann Thomas , Bergmeister Konrad
Published: September 2023

A very important task to improve the sustainability of existing structures is to extend their service life especially in terms of resource conservation and sustainability. Therefore, the assessment and the required safety level of an existing structure are of particular importance (condition monitoring). This contribution focusses on how data from established inspection and monitoring approaches are essential and examines the more advanced, additional approaches currently under review. Both the load‐bearing capacity and the serviceability must be guaranteed over a certain period of time at or above the required safety level. The serviceability of a structure can be measured by performance indicators. It is examined how the definition and measurement of performance indicators in conjunction with a well‐designed life cycle management action can be used to extend the service life while ensuring safety levels.
Uncertainty quantification of satellite InSAR‐monitoring of bridges: a case study
Authors: Tonelli Daniel , Valentini Andrea , Rocca Alfredo , Zorzi Stefano , Lotti Alessandro , Zonta Daniele
Published: September 2023

Traditional structural health monitoring (SHM) systems provide accurate and objective information to assess the condition state of bridges; however, they are expensive and typically installed only on strategic bridges. Innovative technologies offer a potential solution. Interferometric Synthetic Aperture Radar (InSAR) takes multiple satellite radar images of a given area over time and extracts displacement time series of reflective point targets on the ground. The literature on InSAR‐based SHM of bridges lacks systematic studies aiming at quantifying the metrological uncertainty of the displacements measured. Furthermore, the topographic context and the magnitude of displacements of these structures between successive satellite passes significantly impact the uncertainty of results. This paper aims to evaluate the effectiveness of InSAR‐based SHM of bridges by comparing displacement time series obtained from InSAR with those from an on‐site topographic system. Displacements are measured from a prestressed concrete bridge in the Alpine region. Moreover, this study models the deformed shape of the bridge based on satellite and on‐site measurements and compares the results to determine whether bridge distortions can be reconstructed using satellite data alone.
Cementitious materials with biological additive for enhanced durability in marine environment
Authors: Iovane Giacomo , Kim Hayeon , Tizzano Domenico , Mazzolani Federico M. , Landolfo Raffaele , Park Solmoi , Faggiano Beatrice , Lee H.K.
Published: September 2023

Concrete structures suffer from cracking that leads to deterioration and shortening of service life. This is very critical for underwater structures, i.e., immersed bridge piles, immersed tunnel or submerged floating tunnels, which are consistently susceptible to ingress of harmful ions (chloride, sulphate and carbonate ions). Autonomous healing of concrete cracks can be beneficial to assure durability performance during the service life. In this context the paper presents a preliminary experimental activity carried out to study the self‐healing capacity of cementitious composites in marine environment. Four series of paste samples are prepared to evaluate the autonomous healing capabilities, achieved through biotic and abiotic additions. The experimental campaign is articulated in four phases, such as: specimen preparation; tests in compression; immersion in water; crack healing evaluation. The specimen performances are examined and compared in terms of mechanical strength and crack width healing over time. Results highlight the efficiency of the technology for crack healing.
Data based reliability and risk based assessment for service life extension of structures
Authors: Strauss Alfred , Zimmermann Thomas , Bergmeister Konrad
Published: September 2023

One very important contribution to improving the sustainability of existing structures is to extend their service life. This also makes a valuable contribution to resource conservation. Therefore, the assessment and the required safety level of an existing structure are of particular importance. This is one of two contributions which together summarize the past, current and developing approaches to extending service life while ensuring safety. Herein it is presented the reasons why many existing structures no longer meet structural safety requirements. Both the loadbearing capacity and the usability must be guaranteed over a certain period of time at or above a certain safety level. It is examined how these, and their future development, can be reliably assessed by collecting and analysing key data and how this can be used to extend the service life of structures.
Validation of the digital inspection of bridges
Authors: Kreslin Maja , Triller Petra , Eržen Vid , Žnidarič Aleš , Slokan Tomaž , Anžlin Andrej
Published: September 2023

The paper presents the main results of the development project “Digitalization of monitoring the condition of bridge structures on highways and expressways in the Republic of Slovenia”. Within the project, test cases of the digitalized inspection method were carried out on three different concrete bridges. To enable validation of digitalization, a traditional and digital inspections for all three bridges have been conducted, focusing on the three important types of reinforced concrete bridges damages: delamination, cracks and reinforcement corrosion. The comparison of the results has shown that digital inspection can already strongly support bridge inspections, especially during detailed inspections, as it can, to some extent, completely replace the time‐consuming damage mapping. In addition, the analyses show that, already today, digital inspection is often economically justifiable.
Numerical Investigation on Buckling Response of Cylindrical Steel Storage Tanks Under Seismic Excitation
Authors: Ullah Shafqat , Mamaghani Iraj H.P.
Published: September 2023

This paper presents the buckling response and vibration characteristic of the cylindrical steel liquid storage tanks filled with water when subjected to strong earthquake excitations. Finite element analysis (FEA) is performed by using ABAQUS software. The geometrically perfect tanks with different R/t and H/R ratios are considered for modal and linear seismic analysis. The modeling method, appropriate element type, and the necessary number of elements for numerical analysis are recommended. Field observations during past earthquakes and published experimental results are used to substantiate the accuracy of employed FEA. The accuracy of the current design guidelines is assessed based on the extensive parametric study. According to the results of the parametric study of the perfect tanks, the buckling strength decreases significantly as the radius‐to‐thickness ratio (R/t) increases. Furthermore, it decreases slightly as the height‐to‐diameter ratio (H/R) increases.
A full‐scale case study of vibration‐based structural health monitoring of bridges: prospects and open challenges
Authors: Reuland Yves , Garcia‐Ramonda Larisa , Martakis Panagiotis , Bogoevska Simona , Chatzi Eleni
Published: September 2023

The implementation of Structural Health Monitoring (SHM) offers the prospect for sustainable and safe service‐life extension of existing bridges, a large portion of which is approaching the end of their nominal life. Many SHM frameworks for civil infrastructure address timely damage detection and identification. However, the scarcity of case studies on real damaged bridges hinders the generalized application of SHM in practice. In this contribution, monitoring data from a four‐day campaign on the Ponte‐Moesa bridge, a three‐span concrete box‐girder bridge, is presented as a benchmark for data‐driven damage diagnosis schemes. The monitoring data, covering accelerations from ambient and forced vibrations, contains the reference state after concluding the service life along with several gradually increasing damage states, including drilling holes and cutting reinforcement rebars and prestressed cables. The potential of damage‐sensitive features to identify damage is presented and the uncertainties, resulting from the environmental and operational conditions and sensor malfunctioning, pertaining to robust damage detection are discussed. Drawing from real bridge monitoring data, a range of prospects and open challenges of vibration‐based SHM for bridges are reviewed.
Damage processes and performance indicators for tunnel structures
Authors: Strauss Alfred , Bergmeister Konrad , Zimmermann Thomas
Published: September 2023

Infrastructures such as bridges and tunnels should be designed to cater for a defined function. This typically mirrors the distance of travel or the level of traffic flow. Infrastructure networks in most countries will therefore reflect the development of a hierarchy of infrastructure, with motorways at the highest level and local access roads at the lowest. In practice, a hierarchy will naturally emerge as the more heavily used infrastructures are constructed with stricter standards. But it is important that the hierarchy is established to clear guidelines by linking design to function, throughout the network. This is particularly necessary where different functional levels or different geographical areas are managed by different infrastructure operators. In this contribution, the focus associated with the classification for infrastructures is on tunnels. The classification is based on vulnerability and consequence class concepts and comprises objects built after the 60's.
Inspection and Monitoring of post‐tensioned bridges – advantages of electrically isolated tendons (EIT)
Authors: Elsener Bernhard
Published: September 2023

Problems in existing post‐tensioning structures with metallic ducts occur mainly related to corrosion of the tendons due to chloride ingress at “weak points” in the structure. Despite this PT technology overall can be considered as proven and successful, sometimes severe damages and collapses without warning are reported. As none of the existing inspection and monitoring methods allows a complete and meaningful evaluation of post‐tensioning tendons in existing structures, owners and engineers face uncertainty regarding safety and durability of existing post‐tensioned structures with metallic ducts.

The situation changed with the introduction of corrugated polymer ducts and electrically isolated anchorages (EIT) in civil engineering practice about 25 years ago. Polymer ducts prevent the ingress of aggressive substances into the tendons and the electrical isolation allows monitoring of the tendons with simple, hand‐held instrumentation over the whole service life. Based on many results from laboratory and field It is concluded that EIT tendons can be considered a smart structure not necessitating additional sensors. For the first time the most important structural elements, the tendons, can be easily monitored over time and initiation of damage can be detected early.
Optimization of Extradosed Bridge and Analysis of Parameters' Sensitiveness as a Case Study on Abay Bridge
Authors: Lamesgin Abeba , Golla Alemayehu , Rasool Ghulam , Jemanenh Wubishet
Published: September 2023

The paper describes analytical sensitivity analysis and structural optimization for Abay extradosed cable‐stayed bridge. Identify significant design variables using sensitivity analysis by considering cable stiffness, girder weight and stay cable tension force. The aim of the study is weight minimization of superstructure components of Abay bridges. It has span length (100+180+100) m. For structural optimization, it was carried out by taking total material weight of girders, pylon and stayed‐cable as an objective function and all requirements of strength, stability, serviceability, and fatigue as constraint functions. The formulated optimization problem was coded into Matlab R2019a software and analysis results are retrieved from MIDAS CIVIL 2019 software. The paper gives more reduced weight of bridge from conventional design output by using same material grade. The result shown that optimum stay cable length was reduced from conventional design output by 10% from total values, optimum design of pylon height reduced weight of conventional design by 20.03% and optimum design of box girder reduced girder weight by 19.47%.
A LCCA framework for the management of bridges based on data fusion from visual inspections and SHM systems.
Authors: Ierimonti Laura , Mariani Francesco , Venanzi Ilaria , Ubertini Filippo
Published: September 2023

Bridges' integrity, safety and serviceability are fundamental targets that need to be ensured during the structural lifetime, owing to the crucial role that such infrastructure components play in modern communities. Recently, a particular attention is being paid to the management of bridges since many of them have reached the end of their expected service life. To this purpose, the Italian Ministry of Sustainable Mobility issued in 2020 the “Guidelines for risk classification and management, safety assessment and monitoring of bridges” that regulate visual inspections, risk assessment based on multilevel protocols and consequent monitoring and maintenance activities. In this context, structural health monitoring (SHM) systems play a fundamental role to guarantee safety and adequate performance levels. However, the synergy between visual inspections and SHM is yet to be fully understood and exploited. The main goal of this research work is to contribute to filling this gap by proposing a general probabilistic framework, based on Life‐Cycle Cost Analysis (LCCA), able to fuse information from SHM data and visual inspections, with the aim to plan over time short‐term and long‐term interventions and to optimize fund allocation by considering all the stored information.
Repair and Retrofit of Bridge structural elements: New Cementitious Materials
Authors: Ramaswamy Ananth
Published: September 2023

The condition of infrastructure, the constant need to repair and maintain them and the increasing costs associated with the maintenance has led to the search for replacements for steel in new concrete infrastructure around the world. Further, alternatives for repair and strengthening of existing concrete structures ranging from the use of FRP as plates or fabrics wraps to the use of ultra‐high‐performance concrete (UHPC) elements as external reinforcements to achieve requisite strength and serviceability requirements are being attempted. The present study evaluates the performance of repaired/retrofitted structural concrete elements and sub‐assemblages damaged in flexure or shear using different repair schemes including those based on use of FRP plates or wraps, UHPC elements, etc., to restore the capacity of damaged structural concrete elements. An ANSYS based finite element model that accounts for both the constitutive properties of the primary structure in its damaged state and the repair material is used in this study to assess the different repair schemes. The analysis is shown to predict the test results very well. The importance of considering bond slip between rebar and surrounding concrete in the analysis is highlighted. Likewise, the consequence of bond between repair material and the primary structure on the overall structural performance is clearly seen. Performance of normal and high performance of concrete under high temperature resulting in spalling and significant damage from a fire and its rehabilitation with geopolymer concrete will be shown in lab scale tests and simulations. Finally, a field application of load testing of a defunct masonry arch bridge, its retrofit strategy and subsequent deployment with cementitious mixes as a repair to operationalise the bridge with significant cost saving will be illustrated.
Existing standardization on monitoring, safety assessment and maintenance of bridges and tunnels
Authors: Allaix Diego Lorenzo , Vliet Agnieszka Bigaj‐van
Published: September 2023

Bridges and tunnels have in many cases reached their design service life and keep ageing, with the maintenance needs constantly increasing. Besides, transport infrastructure currently carries significantly more traffic loads than what it has been originally designed for and traffic keeps changing e.g. due to introduction of platooning or autonomous vehicles. Such conditions bring safety risks to bridges and tunnels. In the last two decades there have been nearly 40 major failures of road and railway bridges and tunnels in Europe, with hundreds of people killed and injured. At the same time, resources and capacity for conservation and care are too limited and should be used in an optimised way to counteract the growing backlog of maintenance. There is a strong conviction that use of novel technologies for condition survey may aid the task of managing the safety risks to transport infrastructure. Despite increasing amount of good practice, uniform approach to data‐informed safety and risk assessment, and maintenance decision‐making is however missing.

This contribution presents the review of the current state of standardization on monitoring, data‐informed safety assessment and maintenance policies of bridges and tunnels in the European countries.
Life cycle costs and asset management for protective structures against natural hazards
Authors: Hoffmann Markus , Donev Valentin , Brauner Michael
Published: September 2023

With increasing risks from natural hazards in alpine regions in Austria OEBB‐Infra and Hoffmann‐Consult have developed a consistent methodology for condition assessment, prediction, and life cycle optimization of protective structures. Based on a thorough assessment of the asset stock standardized life cycles for key structures like rockfall and avalanche protection structures have been derived. The developed life cycle models allow a generalized assessment of asset condition, residual service life, and remaining asset value. In contrast to typical transport assets, protective structures are both subject to natural aging processes and random events with a certain occurrence rate. Beyond standardized life cycles on network level an adjustment to project level is necessary to account for actual condition development and asset specific events. The paper provides an overview on the developed generic life cycle with application to rockfall protection structures with prices 2022 in Austria.
Analysis of environmental data obtained from meteorological road stations in Latvia for 20 years
Authors: Paeglitis Ainars , Paeglite Ilze , Zugs Maris
Published: September 2023

The events of recent years indicate climate change in nature. Climate change could affect the lifetime of transport infrastructure. Changes in the temperature, humidity, and use of de‐icing material may stimulate the development of damages in road and bridge structures. According to Latvian Environment, Geology, and Meteorology Centre data, average air temperature values have increased by 0.7 °C (1981‐2010 compared to 1961‐1990 g). Road maintenance organizations need information on the actual weather conditions on each road: above the road pavement, on the surface, and below the surface. Sixtyfive meteorological stations on roads throughout Latvia's territory provide this information. This paper analyzes data from six road metrological stations obtained from 2001 to 2021. The results show that over the 20 years period, the average temperature determined nearby asphalt pavement of the road has increased by 1.4 C. This is because the road asphalt pavement heats more, and the temperature measured in its vicinity is higher and should be considered when modeling the development of damage to the transport infrastructure.
Permanent Structural Health Monitoring of a new prestressed concrete bridge
Authors: Wimmer Johannes , Braml Thomas
Published: September 2023

The digitization of processes and methods has been in the focus of construction industry in recent years. Whereas in the automotive industry predictive maintenance is state of the art, the prediction of the service lifetime for bridges is not standardized due to missing sufficient data to develop and train machine learning algorithms. Structural Health Monitoring (SHM) for bridges is used, e.g., to monitor a local damage trend or a structure's response to external influence. Because of the typical SHM tasks, sensors are often built to be attached temporarily to the structure and to be removed afterwards. For predictive maintenance, there is a demand for data from the beginning of the lifetime. In this paper we show challenges and solutions to implement sensors during construction like the integration in the construction planning, the geo‐localization of the sensors, and durability of the sensors to obtain data from first day of lifetime.

All these aspects are shown in a practical example for the newly built Isen bridge in Schwindegg, Germany, where a sensory SHM‐system has been installed to measure the bridge's condition starting from day one of its service lifetime. The results show that with a flexible installation team, the installation does not lead to delay in construction.
A comparison of modal parameter identification tests in laboratory conditions
Authors: Đukić Đorđe , Anžlin Andrej , Hekič Doron , Bohinc Uroš , Kosič Mirko
Published: September 2023

Modal parameter evaluation is widely used for structural health monitoring, damage detection, and numerical model calibration. This study benchmarks two methods for modal identification under controlled laboratory conditions using operational modal analysis to compare dynamic parameters from ambient vibrations and shaker tests. A 2‐storey 3D spatial steel frame equipped with 3‐axial accelerometers is used as a case study. The identified dynamic parameters are benchmarked against a preliminary finite element model by computing Auto‐MAC and MAC matrices. It can be concluded that the preliminary FEM approach performs better in the prediction of modes shapes than natural frequencies. It was found that analysing the structural response to both ambient and artificially induced excitations provide a more complete understanding of a structure's dynamic characteristics. An additional mode shape was identified from the artificially induced excitation that was not previously captured from the ambient excitation.
High‐speed drive‐by monitoring: field testing with an intercity express train (ICE)
Authors: Rupp Maximilian Michael , Lorenzen Steven Robert , Fritzsche Max Alois , Riedel Henrik , Kohl Antonia , Apostolidi Eftychia , Schneider Jens
Published: September 2023

The structural condition of bridges in Germany is often affected by aging and increased traffic loads. However, retrofitting or renewing all bridges is not always feasible due to limited resources. Indirect or drive‐by monitoring of bridges with sensors on passing vehicles has been explored as a cost‐effective and scalable alternative to direct monitoring. In this study, we propose a novel High‐Speed Monitoring (HSM) method for determining natural frequencies, based on accelerometers mounted on train axles, developed for speeds under normal operating conditions. In combination with Bayesian optimisation, a resonance curve can be generated using only a few bridge passages, from which the dominant bending natural frequency of a bridge can be determined with an accuracy comparable to direct monitoring. Measurements on an ICE‐TD passaging bridges travelling at high speeds of up to 200 km/h have shown that the natural frequencies can be determined with the same accuracy as direct measurements. Thus, in this study we were able to show that the method is not only accurate, cost‐effective and scalable, but can also be applied at high speeds without affecting operations.
Performance of Joint Structure of Bent L‐Shaped Steel Members for GFRP Wall Railings
Authors: Sekimoto Masaki , Hayashi Gen , Yamaguchi Takashi , Kubo Keigo
Published: September 2023

Glass fibre reinforced polymer (GFRP) has excellent material properties such as light weight and corrosion resistance, and has been applied to bridge appendages such as wall railings. In this case, bent L‐shaped steel members (bent members) are used at the joints with the floor slab. The GFRP wall railings were designed to consider the wind loads acting on them, and the bolt holes for the anchor bolts were slotted hole for ease of installation. In this study, the effects of loading conditions and bolt arrangement of anchor bolts slotted holes in the performance of the joint structure were analytically investigated for the base joints of GFRP wall railings.

The results presented that, in the initial stiffness of the base, the loading condition was smaller for the negative loading than for the positive loading, and the bolt arrangement was smaller on the outside than on the inside. It is shown that the incremental bolt axial force of the anchor bolts is borne by four bolts in the positive loading, however, is biased to only two bolts in the negative loading, focusing on the neutral axis position.
Initiation and propagation of failures in steel truss bridges
Authors: López Santiago , Makoond Nirvan , Sánchez‐Rodríguez Ana , Adam José M. , Riveiro Belén
Published: September 2023

Bridge collapses are catastrophic events with countless consequences. However, bridge engineering has progressed thanks to the knowledge acquired analyzing collapsed structures. In this direction, modern forensic techniques allow detecting weaknesses and vulnerable zones in the structural systems. It has been demonstrated that the data related to bridge failures has been fundamental for engineers to propose and update theories, concepts, and designs in bridge engineering. This paper presents a methodology to analyze the initial damage and its propagation on steel truss bridges. The first part of the paper presents a comprehensive review of state‐of‐the‐art and scientific challenges. The methodology is described in detail in the second part of the paper; it comprises two main tasks that are further divided into several activities. This methodology was developed as part of the “Pont3” project and has proven to be of great value in gaining a better understanding of how progressive collapse occurs in steel truss bridges. By using this methodology, it is possible to detect initial damage and evaluate the structural behavior of steel truss bridges, which will ultimately lead to safer and more reliable structures.
A New Methodology for the Prioritization of Visual Inspections of Bridges and Viaducts
Authors: Meoni Andrea , García‐Macías Enrique , Venanzi Ilaria , Ubertini Filippo
Published: September 2023

The assessment of risk conditions of bridges and viaducts allows management authorities to ensure the safety of the users and the proper allocation of economic resources for maintenance and retrofitting interventions. A common circumstance in practice regards the lack of information as well as the need to update it, causing delays in the risk evaluation and, consequently, in the entire decision‐making process. Especially in the managing of large bridge assets, the retrieval/updating of information can be costly, both in terms of time and economic resources. In this regard, the execution of visual inspections to determine the defect level of bridges and viaducts is the most resource‐intensive operation on the part of the management authorities. In this paper, a new methodology to prioritize visual inspections of bridges according to their risk condition and operating costs is proposed and illustrated with a real case study. A novel aspect of the proposed methodology regards the use of information gain criteria to refine the outcomes from the risk assessment and prioritization process. Finally, the outcomes of the methodology are implemented in a GIS framework to ensure high interoperability and facilitate the construction of intuitive risk maps to assist inspection plans.