bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Mungbean Genotypes for Phenophases and Morpho-physiological Traits during Heat and Water Stress Conditions for Optimizing Productivity
Authors: Ansari Zuby Gohar , Gontia A. S. , Singh Pragya
Published: September 2021

An experiment was carried out to study the effect of phenophases, morpho-physiological parameters and yield attributing traits on mungbean under different dates of sowing during summer seasons of 2017-18 and 2018-19 at the Research area, Department of Plant Physiology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh). The experiment was laid out in a factorial randomized block design replicated thrice. Treatments consisted of three sowing environments viz., Feb 12th, Feb 27th and Mar 14th and five mungbean varieties viz., PDM 139, Pusa Ratna, Pusa Vishal, Pusa 1431 and TJM 3. PDM139 (V1) had an earliest attainment of all the phenophases and registered the lowest time for reproductive period (32.00 days) as well as span of seed filling period (18.66 days) and also recorded average highest LAI (0.723), LAD (7717.48 cm2. days), CGR (0.00125 g cm2 day-1), RGR (0.03614 g g-1 day-1), SLA (391.94 cm2 g-1) and carbon sequestration (58.93 g plant-1). PDM139 (V1) outyielded (5.78 g plant-1 and 787.74 Kg ha-1) others owing higher magnitudes of physiological parameters and mechanisms reflected in maximum yield components and subsequently yield. On the other hand D2 (27th Feb.) took comparatively more time to achieve all the phenophase as compared to the former as well as average highest magnitudes of these parameters. Among sowing dates sowing carried out on 14th Mar (D3) acquired the minimum time to attain all the phenophases. Among interactions, V1D2 (PDM139 sown on 27th Feb.) took comparatively more time to attain flower initiation (26.33 days) besides a short duration of reproductive span (31.00 days) and a comparatively low magnitudes of seed filling period (18.00 days) and as well as recorded average maximum magnitudes of LAI (Leaf Area Index), LAD (Leaf Area Duration, CGR (Crop Growth Rate), RGR (Relative Growth Rate), SLA (Specific Leaf Area), SLW (Specfic Leaf Weight) and carbon sequestration. Therefore, based on above results selection of genotypes could bring out desired improvement in yield and its attributing characters of mungbean cultivars.
Comparative Study between Patients with Hyperemesis Gravidarum and Normal Pregnancy Regarding Presence of Helicobacter Pylori Antibodies
Authors: Aleem Nada S. Abdul , El-Dakhakhni Raghda A. , Hazzaa Sahar M. , Aglaan Nagwa I. , Borg Hesham M.
Published: September 2021

Background: The severe form of nausea and vomiting of pregnancy called hyperemesis gravidarum (HG) that if left untreated may lead to significant maternal morbidity and adverse birth outcomes. Helicobacter pylori (H. pylori) is a prevalent gram-negative flagellated spiral bacterium that colonizes the stomach of half of the world’s population. Researchers have hypothesized that maternal hormonal and immunological changes during pregnancy that prevent allogenic rejection of fetus reactivates the bacterium. Aim of the work is to compare between patients with hyperemesis gravidarum and normal pregnancy regarding presence of Helicobacter pylori antibodies for proper management.

Materials and Methods: A case-control study was carried out on ninety pregnant women at 5-15 weeks of gestation, thirty pregnant females with single living fetus complaining of HG (Group A), Thirty pregnant females who were multiple pregnancy and/or trophoblastic disorders complaining of HG (Group B) and Thirty pregnant females with normal pregnancy (Group C). Serum test for H. pylori IgG antibody titer was done for all patients and controls using enzyme immunoassay-based kit.

Results: H. pylori were noted in 32 hyperemetic cases and 6 control subjects. The presence of H. pylori increased the risk of HG more than two fold (OR = 2.923, 95% CI: 1.326-6.446, P < 0.05).

Conclusion: There is powerful correlation between H. pylori and hyperemesis gravidarum which proved in single, multiple pregnancy and/or trophoblastic disorders.
Malaria in Pregnancy Amidst Possession of Insecticide Treated Bed Nets (ITNs) in Orlu L.G.A. of Imo State, Nigeria
Authors: Ogomaka I. A. , Obeagu Emmanuel Ifeanyi
Published: August 2021

Malaria is one of the most dreadful diseases in pregnancy due because it affects not only the pregnant mother, but also the foetus especially in the Tropical African countries. Most endemic nations have embarked on free or affordable distribution of insecticide treated bed net as an alternative to drug interventions, yet many people, especially children and pregnant women stand the risk of malaria attack annually. Hence the study on the malaria status and possession of insecticide treated bed net (ITN) among pregnant women in Orlu LGA in 2019.A total of 600 pregnant women were encountered in health care service centersin the area, out of which 514 gave their consent and participated in the study. Blood samples were collected using finger pricking method, stains made directly on slides allowed to dry and then taken to diagnostic laboratory for parasitological analysis. The slides were stained with Giemsa stain and examined using X100 oil immersion objective lens. Biodata and other relevant information on the use/ non use of ITN were obtained using well- structured questionnaire and focus group discussions. The results obtained revealed that out of 514 participants examined,318(61.9%) had malaria parasites while 196(38.1%) had no malaria. Gravid related prevalence showed primed of having the highest prevalence of 69.1%, while the least infected were those of thirdgravidae, (44.3%). Trimester related prevalence also had the first trimester group of having the highest prevalence of 71.5%, while the least was observed among the second trimesters, 55.5%.  Of 217 (42.2%) who use ITN,129 (59.4%) were infected while 63.6% of those who do not use had a malaria infection as well. Generally, this study revealed that it is not only the distribution or possession of ITN that reduces or prevents malaria infection, but the zeal and enabling environment to use the nets appropriately. A lot more is needed to really prevent malaria infection among the most vulnerable and indeed the entire populace through improved education strategy. Better enlightenment of the public as well as availability of coping strategies to really ameliorate the effect of extra heat and rashes from the bed nets are paramount.
Essential Oils Bearing Plants of Cameroon – An Update
Authors: Fogang Vougmo , Meriçli Filiz , ÖzkumYavuz Dudu , Clovis Talla , Fogang Kenfack , Mamno Tagne
Published: September 2021

In Cameroon, several plants are used both for their medicinal properties and as food. Many of them contain essential oils as one of their secondary metabolites. Although traditional healers rarely, if ever, use essential oils as the basis for their treatments, it is thought that the latter would be found in their products in view of the preparation processes used. And therefore several activities attributed to their drugs are linked to the presence of essential oils. Many studies have revealed the presence of essential oils in several plants found in Cameroon, and validated their traditional use. The purpose of this study is to identify these plants on the basis of studies carried out in order to make a review which will serve as support for future studies. This work reviewed available and accessible original articles in EBSCO, Ovid MEDLINE®, PubMed®, ScienceDirectTM, Scopus® and Web of ScienceTM databases on Cameroon plants studied for their essential oils. We have identified ninety plants that have been the subject of proven studies and scientific publication. They are mainly distributed in the families of Lamiaceae (14: 16%), Annonaceae (11: 12%), Rutaceae (10: 11%), Asteraceae (10 : 11%) and Myrtaceae (09 : 10%). We believe that an important work remains to be done in the search for new essential oils in Cameroon, because the country is endowed with a very great botanical diversity.
Effect of Formulation Parameter on Dissolution Rate of Flurbiprofen Using Liquisolid Compact
Authors: Sulaiman Halah Talal , Jaber Saba Hadee
Published: September 2021

Attempts were made to improve solubility and the liquisolid technology dissolving of medication flurbiprofen. Liquisolid pill was developed utilizing transcutol-HP, polyethylene glycol 400, Avecil PH 102 carrier material and Aerosil 200 layer coating material. Suitable excipient amounts were determined to produce liquisolid powder using a mathematical model. On the other hand, flurbiprofen tablet with the identical composition, directly compressed, was manufactured for comparison without the addition of any unvolatile solvent. Both powder combination characterizations and after-compression tablets were evaluated. The pure drug and physical combination, and chosen liquisolid tablets were studied in order to exclude interacting with the differentional scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR).

The results showed that transcutol is the ideal solvent with a solubility of 260±3.9 mg/ml in flurbiprofen. All formula developed were determined to be flowable within the specified limitations. The transcutol-like liquidsolid tablet formula of 35 percent w/w flurbiprofen and carrier to coating ratio of 10 was the most acceptable for the disintegration time, the tablet weight and other approved tablet characteristics.

DSC thermographs demonstrated the development of a solid flurbiprofen amorphic solid solution for both the physical blend of the chosen liquisolid system and its tablets. The lack of chemicals interaction in medication and other components of the formula was demonstrated by the retention of all flurbiprofen characteristic peaks in all FTIR spectra. As an option to enhance solubility and dissolve flurbiprofen, which has a poor water solubility, liquisolid tablet has been evaluated.
Hepatoprotective Potential of Tecomella undulata Bark on Paracetamol and CCL4 Induced Hepatotoxicity in Rats: Invitro Analysis
Authors: Saxena Prasoon Kumar , Nanda Deepak , Gupta Ritu
Published: September 2021

In this study the T. undulata bark was tested for its hepatoprotection against paracetamol (PCM) induced hepatic damage and Carbon tetra chloride (CCl4) induced hepatotoxicity. The Invitro study was performed on HepG2 cell line .The Levels of serum marker enzymes i.e. AST, ALT (aminotransferases), ALP (alkaline phosphatase), GSH (reduced glutathione) and MDA (Malondialdehyde) in 70% Ethanol treated rats were monitored, respectively. The 70% Ethanol extract gave promising results as studied in detail. The Present study showed that the 70 % ethanolic extract of bark of T.undulata apparently revive the physiological integrity of hepatocytes. Thus the present study demonstrated the Hepatoprotective property of Tecomella undulate Bark.
Serodiagnosis of Hepatitis B Virus Using PreS Antigen from Pakistani Isolate SBS001
Authors: Iftikhar Saima , Aslam Farheen , Akhtar Muhammad
Published: September 2021

Background: An estimated 325 million people worldwide live with hepatitis B and/or C and approximately, 5 million people are affected with hepatitis B. in Pakistan.This study aimed at developing PreS protein from Hepatitis B Virus Pakistani isolate (SBS001) with enhanced sensitivity to detect antibodies in serum as a diagnostic method.

Methods: Gene encoding PreS region from hepatitis B Virus was cloned and expressed in Escherchia coli. The recombinant protein preS-His was purified by Ni-IDA affinity chromatography. Antibodies were raised in rabbit. This protein was screened for detection of antibodies in HBV patients’ sera through ELISA. This ELISA procedure was compared with commercially available Kit used for diagnosis of HBV infection.

Results: Single band purified recombinant PreS protein was obtained with high titer of antibodies raised in rabbits. This recombinant protein was used in ELISA as antigen coated on the plate. That efficiently detected antibodies present in HBV patients. It was concluded that preS-His antigen/ protein A HRP-conjugate ELISA method was more sensitive than the commercial kit for detecting the antibodies present in HBV patient sera.

Conclusion: It was concluded that SBS001 PreS recombinant protein can be used in ELISA kits for detection of HBV in Pakistani population.
The Digital Reindustrialisation of Cities
Authors: Guallart Vicente
Published: September 2021

The advanced technology of the early 21st century – digital fabrication, robots and global virtual connections – is giving us the opportunity to re‐evaluate our modes and locations for industrial production. Equally these notions can enhance our ability to tackle climate change. Vicente Guallart, co‐founder and former Director of the Institute for Advanced Architecture of Catalonia and principal of Guallart Architects, explains why.
Programmable Multistable Perforated Shellular
Authors: Shi Jiahao , Mofatteh Hossein , Mirabolghasemi Armin , Desharnais Gilles , Akbarzadeh Abdolhamid
Published: September 2021

Developing bistable metamaterials has recently offered a new design paradigm for deployable structures and reusable dampers. While most bistable mechanisms possess inclined/curved struts, a new 3D multistable shellular metamaterial is developed by introducing delicate perforations on the surface of Schwarz's Primitive shellular, integrating the unique properties of shellular materials such as high surface area, stiffness, and energy absorption with the multistability concept. Denoting the fundamental snapping part by motif, certain shellular motifs with elliptical perforations exhibit mechanical bistability. To bring the concept of multistability to a single motif, multistable shellular motifs are developed by introducing multilayer staggered perforations that form hinges and facilitate local instability. Adopting an n‐layer staggered perforation (n hinges) design leads to a maximum 2n−1 stable states within one shellular motif during loading and unloading. Three‐directional multistable shellulars are attained by extending the perforation design in three orthogonal directions. Harnessing snap‐through and snap‐back behaviors and self‐contact, the introduced multistable perforated shellulars exhibit strong rigidity both in loading and unloading, and enhanced energy dissipation. The introduced design strategy opens up new horizons for creating multidirectional multistable metamaterials with load bearing capabilities for applications in soft robotics, shape‐morphing architectures, and reusable and deployable energy absorbers/dampers.
Precise Layer‐Dependent Electronic Structure of MBE‐Grown PtSe2
Authors: Zhang Lei , Yang Tong , Sahdan Muhammad Fauzi , Arramel  , Xu Wenshuo , Xing Kaijian , Feng Yuan Ping , Zhang Wenjing , Wang Zhuo , Wee Andrew T. S.
Published: September 2021

2D platinum diselenide (PtSe2) has received significant attention for 2D transistor applications due to its high carrier mobility. Here, using molecular beam epitaxy, the growth of 2D PtSe2 is investigated on highly oriented pyrolytic graphite (HOPG) and their electronic properties are unveiled via X‐ray photoelectron spectroscopy, Raman spectra, and scanning tunnelling microscopy/spectroscopy as well as density functional theory (DFT) calculations. PtSe2 adopts a layer‐by‐layer growth mode on HOPG and shows a decreasing bandgap with increasing layer number. For the layer numbers from one to four, PtSe2 has bandgaps of 2.0 ± 0.1, 1.1 ± 0.1, 0.6 ± 0.1, and 0.20 ± 0.1 eV, respectively, and becomes semimetal from the fifth layer. DFT calculations reproduce the layer‐dependent evolution of both the bandgap and band edges, suggest an indirect bandgap structure, and elucidate the underlying physics at the atomic level.
A novel microdeletion upstream of HOXD13 in a Chinese family with synpolydactyly
Authors: Jia Weimin , Zhou Xiaopei , Guo Naiqiang , Zhang Dazhi , Hou Meiqi , Luo Yalin , Peng Xuejie , Yang Xue , Zhang Xianqin
Published: September 2021

Synpolydactyly (SPD) is a digital malformation with the typical clinical phenotype of the webbing of 3/4 fingers and/or 4/5 toes, and combined with polydactyly. In this study, we investigated a Chinese family with SPD and genetic analysis found that all of the affected individuals in the family carry a heterozygous 11,451 bp microdeletion at chr2:176933872‐176945322 (GRCh37), which is located upstream of HOXD13 gene, the known disease gene for SPD1. All the affected individuals in the family carry the heterozygous deletion variant, and the variant co‐segregated with SPD in the family. Thus, we speculate that the 11,451 bp microdeletion is the disease‐causing variant in the family. To date, the microdeletion associating with SPD1 which we identified is the smallest deletion upstream of the HOXD13 gene and not altering the sequence of the HOXD13 gene.
Biosynthesis of Fungal Drimane‐Type Sesquiterpene Esters
Authors: Huang Ying , Hoefgen Sandra , Valiante Vito
Published: September 2021

Drimane‐type sesquiterpenes exhibit various biological activities and are widely present in eukaryotes. Here, we completely elucidated the biosynthetic pathway of the drimane‐type sesquiterpene esters isolated from Aspergillus calidoustus and we discovered that it involves a drimenol cyclase having the same catalytic function previously only reported in plants. Moreover, since many fungal drimenol derivatives possess a γ‐butyrolactone ring, we clarified the functions of the cluster‐associated cytochrome P450 and FAD‐binding oxidoreductase discovering that these two enzymes are solely responsible for the formation of those structures. Furthermore, swapping of the enoyl reductase domain in the identified polyketide synthase led to the production of metabolites containing various polyketide chains with different levels of saturation. These findings have deepened our understanding of how fungi synthesize drimane‐type sesquiterpenes and the corresponding esters.
Copper‐Catalyzed Aza‐Sonogashira Cross‐Coupling To Form Ynimines: Development and Application to the Synthesis of Heterocycles
Authors: Lavernhe Rémi , Torres‐Ochoa Rubén O. , Wang Qian , Zhu Jieping
Published: September 2021

Nitrogen‐substituted alkynes, such as ynamines and ynamides, are versatile synthetic building blocks. Ynimines bearing additional nucleophilic and electrophilic centers relative to ynamines and ynamides are expected to have high synthetic potential. However, their chemical reactivity remains unexplored owing mainly to the lack of synthetic accessibility. We report herein a versatile copper‐catalyzed synthesis of ynimines from readily available O‐acetyl ketoximes and terminal alkynes. A wide range of O‐acetyl ketoximes derived from diaryl ketones, aryl alkyl ketones and dialkyl ketones underwent cross‐coupling with a diverse set of terminal alkynes to afford the ynimines in good to excellent yields. An unprecedented [5+1] heteroannulation reaction exploiting the reactivity of the ynimine generated in situ was subsequently developed for the synthesis of medicinally important heterocycles, including isoquinolines, azaindoles, azabenzofurans, azabenzothiophenes and carbolines.
Pharmacophore‐linked pyrazolo[3,4‐d]pyrimidines as EGFR‐TK inhibitors: Synthesis, anticancer evaluation, pharmacokinetics, and in silico mechanistic studies
Authors: Gaber Ahmed A. , El‐Morsy Ahmed M. , Sherbiny Farag F. , Bayoumi Ashraf H. , El‐Gamal Kamal M. , El‐Adl Khaled , Al‐Karmalawy Ahmed A. , Ezz Eldin Rogy R. , Saleh Marwa A. , Abulkhair Hamada S.
Published: September 2021

Targeting the epidermal growth factor receptors (EGFRs) with small inhibitor molecules has been validated as a potential therapeutic strategy in cancer therapy. Pyrazolo[3,4‐d]pyrimidine is a versatile scaffold that has been exploited for developing potential anticancer agents. On the basis of fragment‐based drug discovery, considering the essential pharmacophoric features of potent EGFR tyrosine kinase (TK) inhibitors, herein, we report the design and synthesis of new hybrid molecules of the pyrazolo[3,4‐d]pyrimidine scaffold linked with diverse pharmacophoric fragments with reported anticancer potential. These fragments include hydrazone, indoline‐2‐one, phthalimide, thiourea, oxadiazole, pyrazole, and dihydropyrazole. The synthesized molecules were evaluated for their anticancer activity against the human breast cancer cell line, MCF‐7. The obtained results revealed comparable antitumor activity with that of the reference drugs doxorubicin and toceranib. Docking studies were performed along with EGFR‐TK and ADMET profiling studies. The results of the docking studies showed the ability of the designed compounds to interact with key residues of the EGFR‐TK through a number of covalent and noncovalent interactions. The obtained activity of compound 25 (IC50 = 2.89 µM) suggested that it may serve as a lead for further optimization and drug development.
Red‐Blood‐Cell‐Membrane‐Coated Metal‐Drug Nanoparticles for Enhanced Chemotherapy
Authors: Liang Shuya , Wang Miaomiao , Wang Jun , Chen Guanzhi
Published: September 2021

To overcome high toxicity, low bioavailability and poor water solubility of chemotherapeutics, a variety of drug carriers have been designed. However, most carriers are severely limited by low drug loading capacity and adverse side eﬀects. Here, a new type of metal‐drug nanoparticles (MDNs) was designed and synthesized. The MDNs self‐assembled with Fe(III) ions and drug molecules through coordination, resulting in nanoparticles with high drug loading. To assist systemic delivery and prolong circulation time, the obtained MDNs were camouflaged with red blood cell (RBCs) membranes (RBCs@Fe‐DOX MDNs) to improve their stability and dispersity. The RBCs@Fe‐DOX MDNs presented pH‐responsive release functionalities, resulting in drug release accelerated in acidic tumor microenvironments. The outstanding in vitro and in vivo antitumor therapeutic outcome was realized by RBCs@Fe‐DOX MDNs. This study provides an innovative design guideline for chemotherapy and demonstrates the great capacity of nanomaterials in anticancer treatments.
Mode Interaction in Cold‐Formed Steel Members: State‐of‐Art Report
Authors: Camotim Dinar , Martins André D. , Dinis Pedro B. , Young Ben , Chen Man‐Tai , Landesmann Alexandre
Published: September 2021

This work provides a state‐of‐art report on the most recent findings concerning the behaviour, strength and Direct Strength Method (DSM) design of cold‐formed steel (CFS) columns and beams affected by mode coupling phenomena not adequately covered by the current specifications for CFS members, namely local‐distortional (L‐D), local‐distortional‐global (L‐D‐G), distortional‐global (D‐G) and global‐global (flexural‐torsional/flexural ‐ FT‐F) interaction. The paper addresses experimental tests, numerical simulations and DSM‐based design approaches, intended to (i) acquire in‐depth knowledge on the non‐linear behaviour (elastic and elastic‐plastic), load‐carrying capacity and failure mode nature of the members under consideration, and (ii) make use of the above knowledge to develop, propose and assess the merit of efficient DSM‐based design approaches to estimate their failure loads or moments. Initially, illustrative column results are briefly presented to help grasp some fundamental concepts, namely the characterisation of the (i) above mode coupling phenomena, (ii) different sources of mode interaction that may lead to failure load/moment erosion and (iii) the most detrimental initial geometrical imperfections ‐ also presented are the currently codified DSM design curves, as well as two recently developed strength curves for column flexural‐torsional and beam distortional failures. Then, the paper addresses separately each mode coupling phenomenon dealt with, for columns, and only L‐D and D‐G interaction for beams. For columns undergoing L‐D and L‐D‐G interaction, beams experiencing L‐D interaction and angle columns susceptible to FT‐F interaction, the work reported includes experimental studies, numerical simulations and DSM‐based design considerations and/or guidelines. For the remaining coupling phenomena only numerical results are reported, but they unveil interesting (and unexpected) behavioural features that will help plan future test campaigns and achieve efficient design approaches. Finally, the paper closes with a few concluding remarks and a perspective about future developments in this field.
Analysis of EHB Joints to Concrete‐filled Steel Columns: Combined Failure in Tension
Authors: Cabrera Manuela , Tizani Walid , Mahmood Mohammed
Published: September 2021

Structural hollow sections are popular in the building industry as they offer many structural, economical and architectural advantages over other sections. However, their use is limited due to the difficulties in performing site bolting connections using standard bolts. Blind‐bolted systems were developed to overcome this limitation as they only require access to one side of the hollow section to tighten the bolt. This paper reviews the available information in the literature regarding the combined failure mode of the Extended Hollo‐Bolt (EHB) blind fastener. The assessment of the effects of bolt grade on the behaviour of the tension zone of the connection is also presented. A Finite Element (FE) model was developed, validated and used in a parametric study. It is concluded that the use of a higher bolt grade has clear effect on the component global load‐displacement curve and the failure mode. The failure of the connection is first controlled by the plastic resistance of the component, which is limited by concrete crushing accompanied with hollow section yielding. Then it depends on the strength of the bolt. An experimental test setup and variable ranges for the parameters affecting the connection behaviour in tension are proposed.
The bottom triangular cell: an improvement for patch loading resistance in launched bridges
Authors: Alonso Tomás Ripa , López‐de Lucía , López Abajo
Published: September 2021

This paper deals with the improvement in patch loading resistance achieved by a bottom triangular cell attached to a steel T‐shaped girder flange. As local introduction of the reaction from the bearings onto the webs during incremental launching is a specific limit state for structures designed with steel webs, the attachment of a bottom triangular cell allows using wider launching pads since T‐flange transverse bending is no longer critical; web panel slenderness is also reduced, achieving an increase in critical buckling load of the web panel. But, in addition and most important, a supplementary resistant mechanism is generated, as the bottom triangular cell also works a continuous beam in bending, spanning the vertical stiffeners, so that part of the local concentrated load is directly transmitted to the stiffeners, significantly increasing patch loading resistance of the web.

The analyses carried out by hybrid beam and plate non‐linear finite element models show both resistant mechanisms: web resistance and the additional contribution of vertical stiffeners through the triangular cell bending stiffness. Finally, a numerical model is proposed for evaluating the contribution of vertical stiffeners to patch loading resistance, in order to improve present formulation.
New ideas for steel‐concrete composite bridges overpassing highways – VFT‐RS technology
Authors: Zanon Riccardo , Seidl Günter , Rademacher Dennis
Published: September 2021

Roads overpassing highways or speedways are rather a common case, as such bridges occur in average every 2 km of highways in densely populated areas. Due to the high number and similar boundary conditions, the design and realization tends to be standardized and repetitive. The total length ranges mostly between 40 and 55 m, whereas the construction height is a limiting factor since minimum clearance heights must be guaranteed both for safety as well as for driving comfort. Due to these reasons, highway overpasses have been a field of application where steel‐framed composite decks have proven their efficiency for this task.

Starting from Germany, the VFT technology (prefabricated composite beam) has spread in several European countries in the last decades as further development of the standard steel‐concrete composite solution. Its configuration fits perfectly to integral frame bridges built over existing infrastructure with the scope to minimize the traffic disturbance.

In this paper a further step is proposed: the VFT‐RS technology. The change consists in using standard rolled sections by adapting them into the integral frame bridge configuration, further enhancing the structural efficiency with the benefits of high‐steel strength. The possibility of weathering steel or hot‐dip galvanization create the unique offer of a maintenance‐free solution.
Steel frames analyzed by use of advanced displacement mode‐based beam and joint elements
Authors: Hansen Anders Bau , Jönsson Jeppe
Published: September 2021

This paper addresses a linear elastic methodology for analysis of thin‐walled steel frames. The analysis is based on structural meaningful displacement modes that considerably reduce the number of degrees of freedom needed compared to a similar analysis using shell finite elements. The methodology allows the use of an adequate reduced number of higher order displacement modes. The methodology uses advanced beam elements to model the major structural elements within the frame and advanced joint elements to model the connections between the beam elements. Each joint element is a super element modeled by use of other finite elements such as shell elements. This allows the user to model virtually any geometry of the connection. Furthermore, the advanced beam element is formulated based on a linear combination of structural meaningful displacement modes belonging to each individual beam. Since the methodology is based on displacement modes of the (advanced) beams, it is possible to extract and identify critical displacement patterns for the frame as well as for each beam and joint within the frame. This gives the designer an in‐depth understanding of the behavior of the frame and hence a powerful tool to optimize its design.
Web Crippling Behavior of Sigma Purlins
Authors: Almatrafi Meshal , Theofanous Marios , Bock Marina , Dirar Samir
Published: September 2021

Due to their thin‐walled nature and complex geometry, cold‐formed steel purlins are prone to a variety of instabilities. In most applications, purlins rely on the attached sheeting to restrain member buckling and hence their cross‐section is optimized to maximize their cross‐sectional resistance to local and distortional buckling caused by sagging bending moments under the action of a uniformly distributed load. Sigma purlins are a family of cold‐formed steel members with folding‐lines along their webs. The non‐straight geometry of their web is beneficial in terms of reducing the local slenderness of the web, however it increases their susceptibility to web crippling in case the purlins are subjected to concentrated transverse loads and hence it may reduce the overall moment resistance. This study reports a series of experimental tests on sigma purlins interior‐one‐flange (IOF) loading condition. The tested specimens employ two different section geometries and three different bearing plate widths. The test results show that all the specimens failed by web crippling, however two distinct failure modes and corresponding load‐deformation curves are observed depending on the section geometry. To investigate further the effect of web geometry on the IOF web crippling strength of sigma sections, an FE model was developed and validated against the reported test results. Following successful replication of the experimental observations, a comprehensive parametric study was performed and several sigma sections were numerically tested. Furthermore, the applicability of a novel slenderness‐based design approach previously proposed by Duarte and Silvestre for the web crippling design of channel sections is assessed and design recommendations are proposed.
Analysis of tapered composite hybrid steel inverted T‐section beam models and RC flange
Authors: Melhem Abdul Qader , Elrafidi Hussein
Published: September 2021

The aim of this paper is to investigate analytical and experimental flexural behavior of a latest composite beam model. The cross section comprises tapered inverted steel T‐beam embedded within the RC concrete slab, by simple steel reinforcement bar bent in to L‐shape as shear connectors welded to web. The slab is reinforced with longitudinal and transverse bars fixed on the top of L‐shape connectors. The paper shows the structural behavior difference between the composite model with a tapered inverted steel T‐beam and the composite model with non‐tapered inverted steel T‐beam. Failure modes either by cracking of compression concrete or L‐shape connection failure, will be investigated. Suggested designing curves and valuable equations will be presented. This model is of a great bid for roofs and fast accommodations, due to its convenience, flexibility, cost‐effective and availability of its low‐priced components.
On the Load‐Bearing Behaviour of the Steel‐Concrete‐Steel Composite (SCSC) Plate
Authors: Palotás Bálint , Takács Patrik , Fink Josef
Published: September 2021

The presented innovative steel‐concrete‐steel composite (SCSC) plate is being researched at TU Wien, Institute of Structural Engineering, Research Unit Steel Structures. The research aim is to use the SCSC plate for single‐track short‐span railway bridges in Austria. The SCSC plate is projected to be a load‐bearing structure in transverse direction, transferring the loads to the main steel girders of the cross section. Based on finite element analyses using ABAQUS, the complex load‐bearing behaviour of the SCSC plate will be described in this paper. In addition, an engineering model will be presented to reproduce the ABAQUS calculation results. With a spring framework model it is possible to consider cyclic loading and inelastic slip. This yields an increase of the global vertical displacements, which are discussed in the paper.
Study on the ductility of open‐rib and re‐entrant composite slabs
Authors: Soltanalipour Milad , Ferrer Miquel , Marimon Frederic
Published: September 2021

Composite slabs with profiled steel sheeting and cast‐in‐place concrete are a conventional structural flooring system worldwide. The partial connection method (PCM) is a design method limited to slabs showing a ductile longitudinal shear failure. The ductility is defined in Eurocode‐4 in terms of additional strength after certain initial slip is produced, regardless of the steel sheet profiling shape. This article shows that the slip behavior is significantly different depending on the shape of the sheeting profile. On the one hand, the slip magnitude in reentrant slabs can be large enough to drive the two materials to their yielding stresses; on the other hand, in open‐rib profiles, the slab failure is due to the vertical release of the concrete, when the slip overpasses certain geometric limit. This failure mode is generally produced much before the materials reaches their yielding stresses. This finding is consistent with both the experimental and FEM results carried out in this study.
Experimental and Numerical Study of Compression Zone in Steel Connections
Authors: BOUGOFFA Sabra , DURIF Sébastien , MEZGHANNI Omar , BOUCHAIR Abdelhamid , DAOUD Atef
Published: September 2021

To study the compression zone in steel connections, web panels loaded by double opposite patch loading are analyzed using experimental tests and finite element model. The panels are stiffened by transverse stiffeners with different configurations considering partial or full height and different positions (intermediate or edge). A total of 24 panels, hot rolled and welded I sections, have been tested. The stiffeners are welded to the web panels or the web and flanges. The resistances of the stiffened panels are obtained from the load‐displacement curves. The results of the experimental tests are compared with those given by the finite element model based on shell elements using CAST3M software. The comparison makes it possible to validate the nonlinear model considering the elastic‐plastic behavior of materials, the failure modes and the ultimate strengths. Results of the finite element model show compatibility with the results of tests that allows the model to represent the behavior of compressed stiffened I sections. The finite element model is used to explain the behavior of the stiffened panels through parametric study.
Comparative Study of Steel Design Provisions Using AISC‐360, CSA S16, EC3, JSCE and AIJ‐2017
Authors: Cordova Misael , Mahamid Mustafa
Published: September 2021

The study presented herein introduces a comprehensive comparison study between AISC‐360, CSA S16‐09, EC3 EN‐1993, JSCE‐2009 and AIJ‐2017 design specifications of structural steel members. This comparison provides a summary of the key provisions in all standards considered in this study. This study can be used as a guide for engineer that execute projects in at least one of the areas where these provisions rule. Thus, for Engineers that design projects around the world, this study gives them the opportunity to verify the element design base in dominant local provisions. The study provides graphs and tables that easily show the similarities and differences in the limit states and relevant provisions across the various design standards. The results of several analysis show similar tendency despite the use of different procedures and factors the various design specifications require.
Behaviour and design of fixed‐ended steel equal‐leg angle section columns
Authors: Behzadi‐Sofiani Behnam , Gardner Leroy , Wadee M. Ahmer , Dinis Pedro B. , Camotim Dinar
Published: September 2021

The mechanical behaviour and design of fixed‐ended steel equal‐leg angle section members subjected to axial compression are addressed in this study. First, the critical buckling behaviour is described. Experimental data on steel equal‐leg angle section columns collected from the literature are then used for the validation of numerical (shell finite element) models, developed within the commercial package ABAQUS. Validation is performed by means of comparisons between the test and numerical results, considering ultimate loads, failure modes and the load‐deformation responses, all of which are shown to be generally in good agreement. A numerical parametric study is then presented considering steel angle section columns with a wide range of slenderness values. The behaviour and load‐carrying capacity of the columns is shown to be dependent on, not only the column slenderness, but also the ratio of the elastic torsional‐flexural buckling load to the elastic minor‐axis flexural buckling load. Finally, the collected experimental and generated numerical results are used to develop a new design approach for fixed‐ended steel equal‐leg angle section columns, reflecting the observations made. The proposed approach offers improved accuracy and consistency in strength predictions compared to the existing codified design rules.
Experimental and numerical study of the behavior of HSLA and DP cold‐formed high‐strength steels at elevated temperature
Authors: Xia Yu , Yan Xia , Gernay Thomas , Blum Hannah
Published: September 2021

Due to the rapid development in steel manufacture, a new generation of structural cold‐formed advanced high strength steels have been developed. However, due to the variations in chemical composition, their material properties have not been fully understood, which includes the mechanical performance when exposed to fire. Therefore, a series of steady‐state elevated temperature tests were conducted on dual phase (DP) and high‐strength low alloy (HSLA) steels with different thicknesses and nominal yield strengths up to 700 MPa to investigate their performance in the range of 20°C to 700 °C. This paper presents detailed results and discussion of the experimental study. A two‐stage plus linear model based on Ramberg‐Osgood equation is proposed to depict the stress‐strain relationship for the materials at elevated temperature. The prediction of the new material model and common existing material models to represent the material properties of steel at elevated temperatures are compared to the test data and current code predictions.
Influence of the degree of utilization on the structural behaviour of stainless steel frames subject to fire
Authors: Segura Guillermo , Pournaghshband Asal , Afshan Sheida , Mirambell Enrique
Published: September 2021

Stainless steel is known to have a better behaviour at elevated temperatures than carbon steel. This, combined with its aesthetic appeal and corrosion resistance, makes stainless steel structures an attractive alternative to carbon steel structures. However, EN 1993‐1‐4 does not establish design rules associated with global analysis of stainless steel frames and EN 1993‐1‐2, devoted to carbon steel, provides a conservative approach for the fire design of stainless steel structures. Hence, current European codes do not provide efficient design guidelines for stainless steel frames subject to fire and therefore the response of this type of structures should be assessed by means of experimental tests and/or numerical analyses.

The main objective of the paper is to assess the nonlinear structural response of stainless steel frames subjected to fire, focusing the investigation on the influence of the degree of utilization. A comprehensive numerical analysis on Class 1 and Class 3 stainless steel frames and Class 1 carbon steel frame subjected to fire is carried out varying the degree of utilization. Calibration of the FE models has been carried out as a part of a study of transient thermo‐mechanical models, which are needed to assess the response of stainless steel frames subjected to fire.
The General Method for the fire design of I‐section web‐tapered beams
Authors: Maia Élio , Real Paulo Vila , Lopes Nuno , Couto Carlos
Published: September 2021

The present investigation describes a numerical and parametric study on the validation of the General Method (GM) for the fire design of web‐tapered steel beams using GMNIA. The GM (clause 6.3.4 of EN 1993‐1‐1) covers the safety check of structural elements with complex support conditions and/or of non‐prismatic members. However, the fire part of the Eurocode 3 (EN 1993‐1‐2) gives no further indication regarding its applicability at elevated temperatures, apart from adapting the methodology to fire using the reduction factors for steel material properties, which is identified as a gap in the current version of the norm.

Previous investigations by the authors have shown overly conservative results for the General Method and a calibration of the EN 1993‐1‐2 buckling curve has previously been proposed, although the parametric performed in that study was not extensive enough for a full validation. With that in mind, the present paper has improved these shortcomings by further upgrading the Eurocode 3 formulation and validating the proposal against numerical data from more than 25000 GMNIA simulations.
Collapse Mechanism of a Space Structure Under Fire Conditions
Authors: Naqvi Shariq , Fu Feng
Published: September 2021

This paper investigates the collapse mechanism of a long span space structure under fire. The mechanical and thermal properties of a space structure change drastically when subjected to a fire. The nature in which the space structure fails is dependent on a number of factors including fire load, shape and properties of the space structure and its materials. In order to fully analyze how a space structure would fail in these conditions, a multi‐physics thermal mechanical analysis model was built in ANSYS software. The chosen prototype space structure, Kings Cross Wester Concourse roof is modeled. The models were created using a series of complex features and were made to be geometrically sound with alignments between each member. Coupled steady state thermal and static structural analysis was performed and collapse mechanism of the space structure under fire were investigated the effectiveness of using finite element analysis software for large assemblies' analysis is also discussed.
Development of Flexural Buckling Rules for the New AISC Stainless Steel Design Specification
Authors: Meza Francisco J. , Baddoo Nancy , Gardner Leroy
Published: September 2021

This paper presents the development of flexural buckling curves for austenitic and duplex stainless steel welded I‐sections and structural hollow sections, which are proposed for implementation in the new AISC stainless steel specification. The proposed buckling curves were developed following the same type of reliability analysis employed to develop the flexural buckling curve included in AISC 360 Specification for Structural Steel Buildings for carbon steel, considering all the experimental data available in the literature and a large number of numerical results. In order to facilitate their implementation, the proposed curves follow a similar form as the AISC‐type of curve included in AISC 360, with the only differences being the addition of a yield plateau and the values of selected coefficients used to adjust the shape of the curves.

Three different buckling curves are proposed: one buckling curve for circular hollow section (CHS) columns and I‐section columns buckling about the major axis; one for rectangular hollow section (RHS) columns; and one for I‐section columns buckling about the minor axis. The proposed curves represent a significant improvement with respect to the currently available stainless steel flexural buckling curve included in AISC Design Guide 27, providing an increase in strength predictions of up to 55%.
Statistical data for system‐based reliability analysis of stainless steel structures with hollow sections
Authors: Arrayago Itsaso , Rasmussen Kim J.R. , Real Esther
Published: September 2021

Current codes for steel structures, including AISC 360‐10, AS4100 and Eurocode 3, are in the process of evolving from the current member‐based design method to direct system‐based approaches that allow evaluating the strength of structures directly from numerical simulations. However, these codes do not provide adequate safety factors nor reliability requirements for structural systems. Thus, it is necessary to build a rigorous structural reliability framework to investigate acceptable target reliability indices for structural systems and to provide adequate system safety factors. While this framework has been developed based on advanced Finite Element analysis for carbon steel structures in recent years in the form of the Direct Design Method (DDM), it does not exist for stainless steel structures. This paper presents the first step towards developing a system‐based reliability framework for stainless steel structures by providing statistical distributions of the key parameters governing the strength of systems composed of stainless steel cold‐formed hollow sections. The distributions are based on a comprehensive database collected from the literature including data on the main sources of uncertainty: geometric properties, imperfections and material parameters.