bluuebunny/crossref_metadata_2025 huggingface dataset:
Out‐of‐plane Stability Design by GMNIA – Equivalent Imperfections and Strain Limits
Authors: Quan Chunyan , Walport Fiona , Kucukler Merih , Gardner Leroy
Published: September 2022

An accurate and consistent approach to the out‐of‐plane stability design of steel beams and structures utilising geometrically and materially nonlinear analysis with imperfections (GMNIA) and strain limits is proposed. The method is implemented using computationally efficient beam elements, with the ultimate structural resistance defined either by (i) the ultimate load factor or (ii) the load factor at which a strain limit, determined on the basis of the continuous strength method (CSM), is attained, whichever occurs first. In the present paper, the scope of this method is extended from the in‐plane design of steel structures and structural components to scenarios in which out‐of‐plane stability effects, with a focus on lateral‐torsional buckling (LTB), govern. First, two shapes and corresponding amplitudes of equivalent imperfections, which consider the combined influence of both geometric imperfections and residual stresses, for the out‐of‐stability design of steel and stainless steel members by GMNIA are established. The existing CSM strain limits for in‐plane design are then extended to allow for the influence of shear, torsion and warping, to enable their general applicability to three‐dimensional buckling problems. It is shown that employing the proposed design method together with the proposed equivalent imperfections generally provides more accurate and consistent ultimate strength predictions than traditional Eurocode design calculations and also streamlines the design process by eliminating the need for cross‐section classification and individual member design checks.
Revision of EN 1993‐1‐1 – Design Rules for Member Buckling
Authors: Bureau Alain , Snijder Bert , Knobloch Markus , Kuhlmann Ulrike , Gardner Leroy , Taras Andreas , da Silva Luis
Published: September 2022

In the framework of the revision of Eurocode 3 Part 1‐1, several amendments have been proposed and accepted in order to improve the rules for the resistance to member buckling. For clarification, a flow‐chart connecting the global analysis (1st or 2nd order), the imperfections and the type of verification has been implemented for ease of use. Since the publication of the standard in 2005, many research projects have been carried out across Europe on this topic and their results have contributed to provide appropriate answers to problems identified in practice. Therefore, the revised code provides new design rules for stability. Important works of calibration have been performed in these different projects to derive appropriate values of the partial factor on the resistance side.

For example, a new formulation for lateral torsional buckling has been introduced for the calculation of the reduction factor. The consequence is a reduction of the discrepancy between the results obtained by these new methods and those from experimental or numerical tests. In order to extend the scope of Eurocode 3 Part 1‐1, additional methods have been implemented in an annex to cover the stability of members with mono‐symmetric cross‐section under compression axial force, biaxial bending, with or without torsion. The format of the resistance criteria remains similar to the format of the current interaction formulae so that the designers can easily identify the evolution of the rules. This paper presents in a systematic way the new implementations in prEN 1993‐1‐1.
Structural Stability Verification for Steel Beam‐columns in Fire ‐ a Consistent Approach with Ambient Temperature Rules
Authors: Schaper Lukas , Knobloch Markus
Published: September 2022

Steel structures are characterized by a slender design, which makes stability verifications particularly important. While the design methods for steel members at ambient temperatures have been continuously developed and revised for the second generation of Eurocode 3, the method for elevated temperatures in prEN 1993‐1‐2 is still based on the corresponding rules of ENV 1993‐1‐1 of 1992. This leads to a divergence of methodology for ambient and elevated temperatures and to unnecessarily complex design methods for the engineering practice. Therefore, a harmonization of design models for ambient temperature and fire design is desirable.

This paper presents a theoretical and numerical study on the stability behaviour of steel members at elevated temperatures. The structural fire behaviour of steel beams, columns and beam‐columns, i.e. flexural buckling under pure compression, lateral torsional buckling under major axis bending and spatial buckling of members under combined bending and axial compression has been investigated. Based on results available in the literature as well as an extensive numerical parametric study, reduction factors and interaction factors were determined. The new reduction and interaction factors were used to develop a design model for the member stability verification in fire that follows the format of FprEN 1993‐1‐1. Thus, engineering practice is provided with a harmonized verification method for steel members in bending and compression for ambient temperature and fire design.
Application of Machine Learning to Predict the Mechanical Properties of High Strength Steel at Elevated Temperature
Authors: Shaheen Mohamed , Presswood Rebecca , Afshan Sheida
Published: September 2022

High strength steels are increasingly used in several areas of construction offering structural solutions with a high strength‐to‐weight ratio. Safe fire design of these structures relies heavily on accurate predictions of mechanical properties of the material with temperature. This paper presents the results obtained using Machine Learning (ML) algorithms to predict the mechanical properties, including ultimate tensile strength, yield strength and elastic modulus, of high strength steel plate material. The mechanical properties collected from the literature experimental tests show a high degree of scatter, implying that they are influenced significantly by various factors such as the testing method, manufacturing process and chemical composition. However, the current methods for predicting the mechanical properties of high strength steels at elevated temperatures by using ‘reduction factors’ adopted by the structural design codes do not consider these effects and may lead to inaccurate predictions. These deficiencies are overcome by using a ML‐based prediction method, where the effects of the chemical composition on these reduction factors are considered. Deep Neural Networks is trained to predict the mechanical properties with temperatures. The ML‐based method together with the obtained results are presented where it is shown that the trained algorithm gives an excellent correlation coefficient with very small error value.
Direct Design of Stainless Steel Frames: Recommendations and Case Studies
Authors: Arrayago Itsaso , Rasmussen Kim J.R. , Zhang Hao , Real Esther
Published: September 2022

Acknowledging the potential of system‐based design approaches, most international design standards for steel structures include preliminary versions of such alternative design methods. The Direct Design Method (DDM) is one of these approaches, which allows designing steel structures directly using advanced numerical analyses without requiring further member checks. This paper presents the DDM design (and verification) procedure and summarizes the key aspects of the advanced finite element model necessary for the determination of the system strength, with an emphasis on cold‐formed stainless steel portal frames. Through the design of two frames, the DDM design procedure is illustrated and the resulting cross‐sections are compared with those derived using the traditional two‐step design approach in the Eurocode and ASCE design frameworks. The results demonstrate that the DDM verification process is simpler and more direct, and that lighter structures are obtained when designing using the DDM for strength considerations. Finally, this paper also highlights that allowing larger deformations in the ultimate limit state design for the DDM does not have additional negative effects on the serviceability requirements if compared to the traditional two‐step design approach.
Numerical Modelling for Resistance of Welds in Steel Structures from High‐Strength Steel
Authors: Ghimire Abhishek , Wald František
Published: September 2022

This paper presents the overview of the numerical design model of welds in structural steels using finite element shell element. Many researches are emerging in the field of advanced modelling of welds in steel connections by using finite element analysis in order to represent accurate geometry and stiffness of welds. There are several weld modelling techniques used for the computation of structural hot spot stresses in fatigue; oblique shell elements, rigid links and increased thickness techniques. The article intends to eliminate the gaps in knowledge about the numerical modelling of welds using shell elements to compute the direct resistance of the welds in structural steels.

This paper focuses on the study of numerical design calculation for the resistance of the welds in steel structures from high‐strength steels. Inclined shell elements are used to represent geometry and the stiffness of the welds during modelling of transverse fillet welds in double lapped joint. Several design standards, and guidelines are widely used to check the resistance of the welds. To verify and validate the results of finite element models, analytical and experiment results from literature are used in the undermatching welding conditions. Based on numerical design calculations, a general approach of inclined shell element is recommended to represent the welds for computation of the direct resistance of the welds in steel structures.
Large Scale Buckling Tests of Bar Bundle Columns
Authors: Röß Rudolf , Schäfers Michael , Mensinger Martin , Ameri Shaghayegh , Zehfuß Jochen
Published: September 2022

Bar bundle columns are a new type of composite column. For this purpose, a bundle of high‐strength reinforcing bars with a yield strength of 670 N/mm2 is set in a steel tube and then grouted with mortar.

Due to the lower cross‐sectional thickness of the threaded bars, no strength reduction due to material thickness effects is required compared to a solid core cross‐section. The bundling of the steel bars results in a high steel content in relation to the total cross‐section; as a result, the novel composite column achieves load‐bearing capacities that are usually typical for columns with significantly larger cross‐sectional dimensions. In addition, bar bundle columns exhibit better heating behavior compared to composite columns with solid cross sections, as the bars only touch at certain points. As part of the AiF research project IGF‐ 20352 N, 10 buckling tests with lengths between 3.5 m and 8 m were carried out. Cross sections with 1, 3, 7 and 19 bars as core were investigated. The experimental setup, the measurement technique and the results are shown here.
Influence of Longitudinal Stiffeners on the Local Stresses in Crane Runway Girders ‐ Experimental and Numerical Investigations
Authors: Kettler Markus , Unterweger Harald
Published: September 2022

Crane runway girders with slender webs are often strengthened by additional longitudinal stiffeners to avoid local plate buckling of the web. It is expected that this leads to an increase of local vertical bending stresses near the top edge of the web due to eccentric wheel loads. These local stresses have a significant impact on the fatigue design of the flange‐to‐web connections and the required girder dimensions. However, the current design model in EN 1993‐6 for crane supporting structures does not consider this effect. In order to study this behaviour in detail, laboratory tests and numerical finite element calculations are carried out on crane runway girders with longitudinal stiffeners at different positions of the web. It is verified that the local stresses increase with decreasing distance of the stiffeners from the top edge of the web plate. Based on these results and a modified proposal from literature, the design model in EN 1993‐6 is extended to also cover additional stiffeners. Finally, the model is validated through a comparison with tests and numerical calculations.
Nonlinear Thermal Buckling Analysis of Thin‐walled Structures: Solid‐shell Discretization, Continuation Method and Reduction Technique
Authors: Liguori Francesco S. , Magisano Domenico , Leonetti Leonardo , Madeo Antonio , Garcea Giovanni
Published: September 2022

This work presents an accurate and efficient numerical tool for geometrically nonlinear thermoelastic analyses of thin‐walled structures. The structure is discretized by an isogeometric solid‐shell model with an accurate approximation of geometry and kinematics avoiding the parameterization of finite rotations. An efficient modeling of thermal strains, temperature‐dependent materials and general temperature profiles based on a numerical pre‐integration through the shell thickness is proposed. Then, a generalized path‐following method is developed for solving the discrete equations with the temperature amplifier as additional unknown, in order to trace the temperature‐displacement nonlinear curve also in case of limit points and unstable paths. A consistent definition of the tangent operators and a mixed integration point strategy give a robust and efficient analysis. Finally, a reduction technique is derived for a quick estimate of the nonlinear thermal buckling point. The reduced model consists of the initial path tangent, the first linearized buckling modes and their second order corrections. Numerical applications are given.
A New Displacement‐based Design Procedure for the Retrofitting of RC Buildings with Steel Braces
Authors: Moreira Rodrigo Falcão , Castro José Miguel , Varum Humberto
Published: September 2022

This paper proposes a new displacement‐based methodology for the design of concentric steel‐brace retrofitting systems for RC framed buildings. It relies on deformation control for different levels of seismic intensity and explicitly considers the interaction between both structural systems. When dealing with the seismic assessment and strengthening of existing RC buildings, practitioners are likely to resort to the q‐factor approach, due to its simplicity and popularity for the design of new structures. However, in non‐seismically designed RC structures, the uncertainties associated to the nonlinear behaviour are relevant, making it therefore very difficult to define a direct correlation between the real internal forces that develop in structural members during the seismic excitation, and those experienced by an equivalent indefinitely elastic structure. Consequently, several authors have argued that the force‐based seismic assessment and retrofitting of existing RC structures will not yield, in general, satisfactory results. The design methodology proposed herein thus addresses this limitation, offering a solution which is intuitive and fit to be used in practical applications, while providing retrofitted structures with adequate and more predictable seismic performance.
Variability in the Nonlinear Modelling Parameters of Steel I‐shaped Beams Subjected to Cyclic Loading Considering Manufacturing Tolerances
Authors: Mohabeddine Anis I. , Eshaghi Cyrus , Barros Rui Carneiro de , Correia José A.F.O , Castro José M.
Published: September 2022

This paper focuses on the probabilistic characterization of the cyclic behaviour of steel deep members with European I‐shaped profiles. The variability of the behaviour of the member depends on several factor such as the material variability and geometrical imperfections. The effect of material variability is well recognized by the scientific community and has been considered in international design codes such Eurocode 8. European hot rolled profiles may be produced with some tolerable deviation from the nominal section in terms of shape and dimensions, which are limited by the European standard EN10034. The effect of geometrical imperfections received considerable research attention in the past. However, to the best knowledge of the authors, there are no studies that investigated the effect of the manufacturing tolerances on the behaviour of I‐shaped steel members. The tolerance range on the dimensions of the profile can be significant. The change in the dimensions of the profile changes the web and flange slenderness which may have a significant influence on the flexural behaviour. Thus, the characterisation of the effect of the manufacturing tolerances on the behaviour of the members is of paramount interest. For this purpose, an advanced finite element model, validated with past experimental data, was developed and an extensive parametric study is conducted. Then, statistical methods are used to characterise the variability using different distributions
Steel and Composite Joints for MRFs in Moderate Seismicity: Experimental and Numerical Program
Authors: Don Rafaela , Balaskas Georgios , Vulcu Cristian , Hoffmeister Benno
Published: September 2022

Within an ongoing German‐funded research project, a series of beam‐to‐column joints with dissipative bolted connections was developed for Moment‐Resisting Frames designed for moderate seismicity. Due to the new provisions of the German National Annex to EN 1998‐1, the seismic hazard grew in relevance: extended seismic areas and increased spectral acceleration. Thus, seismic load may become a decisive factor on the design of steel and composite frames. Therefore, it was considered reasonable to exploit the inherent ductility of the steel components. However, the demand is considerably lower in Germany than in other regions. While the motivation was to find solutions to address these challenges, the approach was to develop pre‐qualified dissipative beam‐to‐column joints classified as semi‐rigid and partial‐strength for office and industrial buildings that could allow for the use of behavior factors in the range of 1.5/3. The development of the end‐plate connections was based on the German catalogue of typical connections designed for use in the elastic range. These were optimized to perform beyond the elastic range and adapted to the new requirements of the German National Annex. The ongoing experimental tests are performed on full‐scale specimens under monotonic and cyclic loading.
On the Modelling of “Fork” Supports Using geometrically Exact Thin‐walled Beam Finite Elements
Authors: Gonçalves Rodrigo , Ritto‐Corrêa Manuel
Published: September 2022

This paper discusses issues related to the modelling of so‐called “fork” supports using geometrically exact 3D thin‐walled beam finite elements whose rotations are parametrized using the rotation vector. This study is motivated by the fact that isolated members with “fork” supports are commonly employed in numerical and experimental studies, for the development of design rules for steel members. These supports are defined in the small displacement range, restraining the cross‐section in‐plane displacements and the torsional rotation of the beam (along the beam initial axis). This definition is usually extended to the large displacement case for beam finite element models, whereas in experimental tests and shell finite element models, a two‐axis gimbal‐type support is used instead. This paper thus aims at (i) showing how the two‐axis gimbal support may be modelled using beam elements which are based on a rotation vector parametrization of finite rotations and (ii) highlighting the differences between the two support types. Numerical examples are presented to illustrate the differences, which are quite significant for moderate‐to‐large displacements, but do not seem to affect the collapse load of standard steel members.
An Enhanced Design Approach for Global and Local Buckling Resistance of Welded Box Section Columns
Authors: Radwan Mohammad , Kövesdi Balázs
Published: September 2022

The construction industry is witnessing an increased utilization of steel elements due to their effectiveness and durability, with the ability to fabricate lightweight sections having high bearing capacity. Welded box‐section is one of those elements that gain more attention as it is easy to fabricate and has limited stability issues. Buckling is considered one of the major issues that hinder the ability of the steel box‐section to attain its full capacity. The buckling problem for this type of column can be classified into three major types: overall buckling, local buckling, and interacting buckling. Different research activities studied the overall and the local buckling stabilities of box‐section columns, while only a limited number of researchers studied the interaction stability that compromises both types of buckling. Additionally, the available design standards do not account for the nonlinear nature of combining these two buckling types and only use a simple approach to account for their combined effect, leading to a considerably conservative estimation of the buckling capacity. The current research utilizes a FEM‐based design approach to account for the combined nonlinear effect through the utilization of geometrical and material nonlinear analysis (GMNIA) by the creation of a numerical model of square welded box‐section columns, applying a nonlinear material model, an improved combination of local and global imperfections developed by the authors during previous research as well as the residual stresses. The numerical model is validated against experimental tests available in the literature. Then, it is used to carry out a numerical parametric study with a significant number of tests to build a numerical database that can be used to develop an enhanced design approach for the interactive buckling resistance of box‐sections columns under pure compression. The new approach is based on a reliable and accurate numerical model considering an improved combination of the local and global geometric imperfections and residual stresses, which gives more accurate results than the previous model published in international literature. The paper also describes the way of the imperfection combinations to be applied. The new design approach also considers the interaction of the global and local reduction factors depending on the global and local slenderness ratio leading to accurate buckling resistance.
A Study on the Capacity of Steel Portal Frames using Shell Finite Elements
Authors: Couto Carlos , Oliveira Diogo , Real Paulo Vila
Published: September 2022

Steel portal frames are common structures used in practice. Owing to their optimization, members with tapered geometry and slender sections are prevalent. Since local buckling is a possible mode of failure, an additional complexity arises that requires the use of shell finite elements to assess the ultimate capacity of these structures. On the other hand, imperfections, either of geometric or material nature, must be considered because they are unavoidable and reduce the overall capacity of the frames to carry load. The main focus of this study is therefore to characterize the influence of imperfections. Plate imperfections (or local), global (or member) and frame imperfections, are considered as well as material imperfections such as residual stresses that may contribute to degrade the frame's behaviour.

An extensive parametric study comprising a total of 24 frames and 15 different imperfection sets was carried out and based on this large pool of results, recommendations for the definition of imperfections are given and conclusions are drawn on their influence. This work aims to be a step further in establishing a numerical framework to generate results that can be later used to validate existing design methods.
Ultimate Resistance of Diagonally Stiffened Thin Steel Webs in I‐girders
Authors: Martins João Pedro , da Silva Luis Simões , Cardoso Hermano
Published: September 2022

A common structural feature in steel bridges is the use of twin‐I‐girders as the main structural elements. These can reach large dimensions and high weight presenting high values of local slen‐derness resulting in reduced resistance values due to local buckling of the web. This paper explores alternative structural solutions to enhance the stability of slender webs in steel bridges. The central concept to be analyzed is adding a diagonal stiffener able to transfer the shear loading near the supports, avoiding the shear buckling of the web. One problem with this solution is that welding may not be suitable as it introduces residual stresses and local distortion of the web, thus eliminating the potential benefits of the diagonal stiffener. To characterize the ultimate behavior of I‐girders, an experimental study was envisaged and published by the authors and now is used to calibrate a numerical model. The main goal of the calibrated numerical is to develop a parametric study of diagonally stiffened I‐girders which ultimately will allow to propose an analytical model to compute the ultimate load.
Finite Element Analysis of Telecommunication Structure Reinforcement
Authors: Fitzalan Jake , Mashiri Fidelis
Published: September 2022

Frequent technology upgrades in telecommunications have led to an increase in wind load on the towers that hold this equipment. The legs of lattice towers are critical members to the structure's integrity as they transfer large portions of compressive load through to the foundations. Through the increasing amount of compressive load, these members could eventually fail due to insufficient strength, which has raised the need to reinforce existing structures. Currently within industry, retrofitting new members onto the existing legs is common, however there is currently little research that has been carried out to investigate the effectiveness of these methods. This research investigates the retrofit of a Circular Hollow Section (CHS) that has been strengthened with two steel rods and aims to provide greater clarity on the effectiveness of the design through numerical analysis. This was completed using ABAQUS 2021 by performing both linear and non‐linear buckling analysis. It has been found that the design can improve compressive strength by up to 277.3% for the short column which matches the predicted strength. For the long column, an increase of 130.2% was recorded which is significantly less then calculated values. The results obtained further stress the need for continued research in this field, with an emphasis on experimental results.
DOTP versus DOTA as Ligands for Lanthanide Cations: Novel Structurally Characterized CeIV and CeIII Cyclen‐Based Complexes and Clusters in Aqueous Solutions
Authors: Dovrat Gev , Pevzner Svetlana , Maimon Eric , Vainer Radion , Iliashevsky Olga , Ben‐Eliyahu Yeshayahu , Moisy Philippe , Bettelheim Armand , Zilbermann Israel
Published: September 2022

The coordination and redox chemistry of aqueous CeIV/III macrocyclic compounds were studied by using the ligands DOTA and DOTP (1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetrayl)tetraacetic acid and 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetra(methylene phosphonic acid), respectively). The hydrolysis tendency of the tetravalent cation in the presence of DOTA is shown to result in the formation of a highly ordered, fluorite‐like [CeIV6(O)4(OH)4(H2O)8(DOTAH)4] oxo‐hydroxo structure both in solution and in the solid state. The lifetime of the analogous species formed in the presence of DOTP was found to be much shorter. Spectroscopic measurements of the latter suggest its similarity to the former. Its gradual decomposition in solution leads to the accumulation of the in‐cage complexes [CeIVDOTP] and [CeIIIDOTP(H2O)], which were crystallographically characterized in this study. The redox energetics and spectroscopic characteristics for the transition between these two in‐cage complexes in aqueous solutions were studied as well. Together with the crystallographic structures of the above‐mentioned species, the in‐cage [CeIVDOTA(H2O)] complex structure is presented herein for the first time. An elaborative analysis of the X‐ray crystallographic structural data obtained for the in‐cage complexes studied herein and similar structures published previously suggests that hard‐bonding cyclen‐derived ligands are, counter‐intuitively, better suited for encapsulating, and perhaps kinetically stabilize softer cations than harder ones with DOTP, marked as a possible adequate chelator for the study of the aqueous properties of LnII and AcIII cations.
A Piezo‐Fenton System with Rapid Iron Cycling and Hydrogen Peroxide Self‐Supply Driven by Ultrasound
Authors: Ge Lin , Xiao Jie , Liu Wencheng , Ren Guolan , Zhou Chi , Liu Junan , Zou Ji‐Jun , Yang Zixin
Published: September 2022

The piezo‐Fenton system has attracted attention not only because it can enhance the Fenton reaction activity by mechanical energy input, but also because it is expected to realize a class of stimuli‐responsive advanced oxidation systems by regulating energy input and hydrogen peroxide self‐supply, thus greatly enriching the application possibilities of Fenton chemistry. In this work, a series of Fe‐doped g‐C3N4 (g‐C3N4‐Fe) as a piezo‐Fenton system were synthesized where the iron stably immobilized through Fe−N interaction. The piezo‐induced electrons generate on g‐C3N4 matrix support the conversion of Fe(III) to Fe(II) and promote rate‐limiting step of Fenton reaction. With the optimal Fe loading, g‐C3N4‐0.5Fe can achieve methylene blue (MB) degradation under ultrasonic treatment with first‐order kinetic rate constants of 75×10−3 min−1. Most importantly, the g‐C3N4‐Fe can maintain good catalytic activity in a wide pH range (pH=2.0∼9.0) and be cyclic used without iron leaching to solution (<0.001 μg ⋅ L−1), overcoming the disadvantage of traditional Fe‐based Fenton catalysts that can only be applied under acidic conditions and prone to secondary pollution. In addition, g‐C3N4‐0.5Fe also exhibits antibacterial properties of Escherichia coli and Staphylococcus aureus under ultrasound. Hydroxyl radicals mainly contribute to the degradation of MB and the sterilization process. Our work is an attempt to clarify the role of g‐C3N4‐Fe in the conversion of mechanical energy to ROS and provide inspirations for the piezo‐Fenton system design.
Quantification and Tuning of Surface Oxygen Vacancies for the Hydrogenation of CO2 on Indium Oxide Catalysts
Authors: Baumgarten Robert , Naumann d'Alnoncourt Raoul , Lohr Stephen , Gioria Esteban , Frei Elias , Fako Edvin , De Sandip , Boscagli Chiara , Drieß Matthias , Schunk Stephan , Rosowski Frank
Published: September 2022

The direct hydrogenation of CO2 to methanol is an attractive approach to employ the greenhouse gas as a chemical feedstock. However, the commercial copper catalyst, used for methanol synthesis from CO‐rich syngas, suffers from deactivation at elevated CO2 partial pressure. An emerging alternative is represented by In2O3 as it withstands the hydrothermal conditions induced by the reverse water‐gas shift reaction. The active sites for the adsorption of CO2 and the subsequent conversion into methanol were shown to be oxygen vacancies on the surface of In2O3. In this study, N2O was utilized as a probe molecule to quantify the number of vacancies on indium oxide catalysts. The number of inserted oxygen atoms could be correlated to the respective CO2 hydrogenation activity. Furthermore, the atomic efficiency of indium was enhanced by applying atomic layer deposition of indium oxide on ZrO2.
A Highly Sensitive Fibrous Luminescent Probe Based on Anthracene Triarylamine for Nitroaromatic Explosives
Authors: Zhao Qiang , Xia Yongrong , Xue Wei , Song Zhao , Lu Wei , Jin Dong , Xie Linghai , Zhao Jianfeng , Shi Naien
Published: September 2022

The rapid, sensitive, and efficient detection of nitroaromatic explosives (NAEs) is extremely important for human health and public safety; however, it is still a big challenge, especially for the detection of trace amounts of explosive vapors. In this study, a small‐molecule luminescent probe of an anthracene triarylamine derivative was synthesized and employed as a highly efficient and sensitive sensor for the detection of NAEs, including 2,4‐dinitrotoluene (DNT), 4‐nitrotoluene (4‐NT), and nitrobenzene (NB). The fluorescence intensity varied linearly along with the concentration of NAEs in the diluted tetrahydrofuran solution. The KSV values (Stern‐Volmer equation coefficient) were 2457, 1735, and 1286 M−1 for DNT, 4‐NT, and NB, respectively (DNT>4‐NT>NB). Furthermore, polystyrene/LiCl/AnPh electrospun fibrous films were manufactured and proved to be efficient fluorescence sensors for NAEs vapor. This quenching can be ascribed to the photo‐induced electron transfer (PET) process between the AnPh probe and NAEs analytes. The large contact area between the nanofibers and analytes in the film also contributed to the efficient quenching effect. This work will stimulate the design of new fluorescent probes for electrospun fibrous NAEs sensors and pave the way for their applications in future practical fields of public safety control.
Determining the Gibbs Energy Contributions of Ion and Electron Transfer for Proton Insertion in ϵ‐MnO2
Authors: Malaie Keyvan , Scholz Fritz , Schröder Uwe , Wulff Harm , Kahlert Heike
Published: September 2022

Electrochemically active ϵ‐MnO2and ɣ‐MnO2as tunnel‐type host‐guest structures have been extensively studied by crystallography and electrochemical techniques for application in battery cathode materials. However, the Gibbs energies of the underlying ion and electron transfer processes across the electrode interfaces have not yet been determined. Here we report for the first time these data for ϵ‐MnO2. This was possible by measuring the mid‐peak potentials in cyclic voltammetry and the open‐circuit potentials under electrochemically reversible conditions.
Sensory processing in depression: Assessment and intervention perspective
Authors: Paquet Aude , Calvet Benjamin , Lacroix Aurélie , Girard Murielle
Published: September 2022

Few studies have examined sensory processing in mood disorders, including depression. The interactions between sensory inputs and adaptive behaviour have yet to be clarified in this pathology. We assessed sensory profiles among people with major depressive disorder (MDD) with the Adult/Adolescent Sensory Profile scale and determined whether sensory processing patterns were associated with clinical variables such as anxiety, depression, psychomotor retardation or self‐esteem. We compared 25 participants with MDD (MDD group) and 25 healthy controls (HC group) to identify sensory processing patterns (low registration, sensation seeking, sensory sensitivity and sensation avoiding). The Hamilton Depression Rating Scale and Clinical Outcomes in Routine Evaluation scale were used to assess depressive symptomatology. Both groups completed the Hamilton Anxiety Rating Scale, Frontal Assessment Battery and Rosenberg Self‐Esteem Inventory. The MDD group significantly differed from the HC group in each sensory processing patterns. They had higher low registration (p < 0.001), sensory sensitivity (p < 0.001) and sensation avoidance (p < 0.001) and lower sensation seeking (p = 0.005) than HC. Extreme sensory processing patterns in MDD patients were linked to depressive symptomatology, including anxiety. Sensory processing disorders should be assessed and taken into account when developing nondrug treatment strategies.
Use PANSS‐6 to predict nonresponse to antipsychotics in youth
Authors: Knopf Alison
Published: September 2022

Youth with first‐episode psychosis who don't respond to aripiprazole or extended‐release quetiapine early should switch to another antipsychotic drug, according to recent research focusing on the use of three different tests to predict outcomes.
Is extra naloxone needed for overdose reversal in the fentanyl era?
Authors: Knopf Alison
Published: September 2022

The news that more naloxone than the standard 2‐mg dose is needed in many overdose victims is largely tied to the potent illicit fentanyl. Typically, the first responder waits to make sure the naloxone is working, that the patient starts breathing again, and if not, administers a second dose. But some people now say that it's important to give enough right away, and that those moments without oxygen can be damaging. Naloxone has no effect on someone without opioids in their system; on someone who has overdosed, it pushes the opioids off the receptors and reverses the overdose. On someone who is physically dependent on opioids, it will also produce withdrawal symptoms. Either way, the victim recovers, but if the naloxone is given in a high enough dose to someone who is dependent, that recovery will come with unpleasant withdrawal symptoms.
A visual understanding of electrical transformations and generalized abc to αβ0 and dq0 transformation
Authors: Madnani Rohan , Mishra Mahesh K.
Published: September 2022

Varied control applications in electrical engineering find the utility of the theory of transformation of three‐phase quantities from
to
and
reference frames. These transformations are vital in simplifying the control equations and their implementation. However, for different applications, different orientations of the
‐,
‐, and
‐axes are used. This results in a different transformation matrix for each such orientation. In this paper, a generalized
to
and
transformation matrix is proposed which can be utilized for any possible orientation and thus effectuates faster derivation of the transformation matrix. This is achieved by defining two parameters
and
whose values are obtained by observing the orientation of the axes. The transformation equation can therefore be obtained without having to undergo the steps of resolving
quantities into their components along the
‐ or
‐axes. Furthermore, this paper discusses the visual understanding of transformed electrical quantities. It is shown that the complex plots of real versus imaginary parts of instantaneous positive and negative symmetrical components have shapes which exhibit specific characteristics of electrical quantities and give a direct understanding about unbalance and presence of harmonics in the system.
Microbial and human transcriptome in vaginal fluid at midgestation: Association with spontaneous preterm delivery
Authors: Wikström Tove , Abrahamsson Sanna , Bengtsson‐Palme Johan , Ek Joakim , Kuusela Pihla , Rekabdar Elham , Lindgren Peter , Wennerholm Ulla‐Britt , Jacobsson Bo , Valentin Lil , Hagberg Henrik
Published: September 2022

Background

Intrauterine infection and inflammation caused by microbial transfer from the vagina are believed to be important factors causing spontaneous preterm delivery (PTD). Multiple studies have examined the relationship between the cervicovaginal microbiome and spontaneous PTD with divergent results. Most studies have applied a DNA‐based assessment, providing information on the microbial composition but not transcriptional activity. A transcriptomic approach was applied to investigate differences in the active vaginal microbiome and human transcriptome at midgestation between women delivering spontaneously preterm versus those delivering at term.

Methods

Vaginal swabs were collected in women with a singleton pregnancy at 18 + 0 to 20 + 6 gestational weeks. For each case of spontaneous PTD (delivery <37 + 0 weeks) two term controls were randomized (39 + 0 to 40 + 6 weeks). Vaginal specimens were subject to sequencing of both human and microbial RNA. Microbial reads were taxonomically classified using Kraken2 and RefSeq as a reference. Statistical analyses were performed using DESeq2. GSEA and HUMAnN3 were used for pathway analyses.

Results

We found 17 human genes to be differentially expressed (false discovery rate, FDR < 0.05) in the preterm group (n= 48) compared to the term group (n= 96). Gene expression of kallikrein‐2 (KLK2), KLK3 and four isoforms of metallothioneins 1 (MT1s) was higher in the preterm group (FDR < 0.05). We found 11 individual bacterial species to be differentially expressed (FDR < 0.05), most with a low occurrence. No statistically significant differences in bacterial load, diversity or microbial community state types were found between the groups.

Conclusions

In our mainly white population, primarily bacterial species of low occurrence were differentially expressed at midgestation in women who delivered preterm versus at term. However, the expression of specific human transcripts including KLK2, KLK3 and several isoforms of MT1s was higher in preterm cases. This is of interest, because these genes may be involved in critical inflammatory pathways associated with spontaneous PTD.
Mitochondrial regulation of acute extrafollicular B‐cell responses to COVID‐19 severity
Authors: Cao Tianyu , Liu Li , To Kelvin Kai‐Wang , Lim Chun‐Yu , Zhou Runhong , Ming Yue , Kwan Ka‐Yi , Yu Sulan , Chan Chun‐Yin , Zhou Biao , Huang Haode , Mo Yufei , Du Zhenglong , Gong Ruomei , Yat Luk‐Tsz , Hung Ivan Fan‐Ngai , Tam Anthony Raymond , To Wing‐Kin , Leung Wai‐Shing , Chik Thomas Shiu‐Hong , Tsang Owen Tak‐Yin , Lin Xiang , Song You‐qiang , Yuen Kwok‐Yung , Chen Zhiwei
Published: September 2022

Background

Patients with COVID‐19 display a broad spectrum of manifestations from asymptomatic to life‐threatening disease with dysregulated immune responses. Mechanisms underlying the detrimental immune responses and disease severity remain elusive.

Methods

We investigated a total of 137 APs infected with SARS‐CoV‐2. Patients were divided into mild and severe patient groups based on their requirement of oxygen supplementation. All blood samples from APs were collected within three weeks after symptom onset. Freshly isolated PBMCs were investigated for B cell subsets, their homing potential, activation state, mitochondrial functionality and proliferative response. Plasma samples were tested for cytokine concentration, and titer of Nabs, RBD‐, S1‐, SSA/Ro‐ and dsDNA‐specific IgG.

Results

While critically ill patients displayed predominantly extrafollicular B cell activation with elevated inflammation, mild patients counteracted the disease through the timely induction of mitochondrial dysfunction in B cells within the first week post symptom onset. Rapidly increased mitochondrial dysfunction, which was caused by infection‐induced excessive intracellular calcium accumulation, suppressed excessive extrafollicular responses, leading to increased neutralizing potency index and decreased inflammatory cytokine production. Patients who received prior COVID‐19 vaccines before infection displayed significantly decreased extrafollicular B cell responses and mild disease.

Conclusion

Our results reveal an immune mechanism that controls SARS‐CoV‐2‐induced detrimental B cell responses and COVID‐19 severity, which may have implications for viral pathogenesis, therapeutic interventions and vaccine development.
Enhancing I0/I− Conversion Efficiency by Starch Confinement in Zinc–Iodine Battery
Authors: Zhao Danyang , Zhu Qiancheng , Zhou Qiancheng , Zhang Wenming , Yu Ying , Chen Shuo , Ren Zhifeng
Published: September 2022

The redox couple of I0/I− in aqueous rechargeable iodine–zinc (I2‐Zn) batteries is a promising energy storage resource since it is safe and cost‐effective, and provides steady output voltage. However, the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide (I3− and I5−) and side reactions on the Zn anode. Starch is a very low‐cost and widely sourced food used daily around the world. “Starch turns blue when it encounters iodine” is a classic chemical reaction, which results from the unique structure of the helix starch molecule–iodine complex. Inspired by this, we employ starch to confine the shuttling of polyiodide, and thus, the I0/I− conversion efficiency of an I2‐Zn battery is clearly enhanced. According to the detailed characterizations and theoretical DFT calculation results, the enhancement of I0/I− conversion efficiency is mainly originated from the strong bonding between the charged products of I3− and I5− and the rich hydroxyl groups in starch. This work provides inspiration for the rational design of high‐performance and low‐cost I2‐Zn in AZIBs.
Transition Metal‐Catalyzed Intermolecular Hydroarylation of Allenes
Authors: Pagès Lucas , Abed Ali Abdine Racha , Monnier Florian , Taillefer Marc
Published: September 2022

The intermolecular transition‐metal catalyzed hydroarylation of allenes has been widely explored since the early 1980s. This reaction allows the selective access to high‐value allylic or vinylic motifs through the formation of C−C bonds. In this frame, arenes (ArH), which are employed without any pre‐functionalisation, represent one of the most used families of aryl sources. Organoboronic derivatives (acids ArB(OH)2 and esters ArB(OR)2) constitute alternative, accessible and generally more reactive coupling partners, while aryl halides (ArX) are a third, less used type of aryl source. Whereas gold‐ and palladium‐based catalysts are often used with arenes and aryl boronic derivatives, respectively, as aryl sources, a wide range of other transition metals have also been employed. Experimental and theoretical studies have often been reported, thus affording mechanistic insights and allowing to suggest catalytic cycles.
Perspective on the present state and future usefulness of marama bean (Tylosema esculentum)
Authors: Cullis Christopher , Chimwamurombe Percy , Kunert Karl , Vorster Juan
Published: September 2022

Recent focus on indigenous knowledge of plant species that have long been consumed by mankind, but not having a prominent place in organized agriculture, has raised the profile of what steps are needed to bring such potentially useful plant species into formal agriculture practice. Many of these orphan plants have been cultivated, albeit usually without much improvement. Tylosema esculentum (marama bean) is unusual; in that, it has not been grown as a crop but only collected from wild stands. The nutritious seeds have been consumed, and other potentially useful products from the marama seeds and tubers have been identified. The marama bean grows under inhospitable environments, particularly hot arid conditions, and, if domesticated, could be grown in environments where there are no high‐yielding alternatives. The perspective of this article is to view the current status of the marama bean domestication and the possible pathways to bring this plant into wider agricultural use. The scientific basis for an improved crop yield needs to be coupled with the identification of possible added value characteristics for growers. These include acceptability as a food, possible industrial use, the development and distribution of improved seed, and the recruitment of growers to plant marama as a crop. The authors' international collaboration has already made advances in some of these areas. We discuss the current ongoing developments and existing gaps in moving this plant into formal agriculture, along with a plan for the future developments necessary for marama to provide food security under climate change, particularly in Africa. Even as the process of domestication of marama bean is proceeding, its unusual and potentially useful characteristics will greatly benefit the improvement of other legume crops needed to provide adequate nutrition to about 35% of the world population living in semi‐arid to arid regions of the developing world.