bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictors of periodontal and caries related perinatal oral healthcare, investigation of dentists’ practices: a cross-sectional study
Authors: Javed Muhammad Qasim , Bhatti Usman Anwer , Riaz Arham , Chaudhary Farooq Ahmad
Published: September 2021

Background

The objectives of the study were to assess the knowledge, attitude, and practice of dentists towards providing oral health care to pregnant women and to identify barriers and predictors of periodontal and caries related perinatal oral healthcare practices.

Methods

A cross-sectional analytical survey was conducted on dentists by using a random sampling technique, and a pre-validated questionnaire was delivered to 350 dentists from May 2018 to October 2018. Data were analyzed by utilizing SPSS software. Frequencies and percentages were recorded for descriptive variables. Binary logistic regression was used to analyze the probability of predicting group membership to the dependent variable using different independent variables determined from contingency tables.

Results

Overall response rate was 41%. The mean knowledge score of respondents was 15.86 ± 3.34. The lowest correct responses were noted in the questions related to periodontal health. It was found that the advice to delay dental visits until after pregnancy was eight times more likely to be observed among dentists who lacked the knowledge of importance of oral health during pregnancy (P= 0.04, OR = 8.75). Dentists were more likely to consult obstetricians regarding dental procedures when they fear a risk of labor in the dental practice (P< 0.05, OR = 3.72). Dentists who had the knowledge of periodontal disease association with preterm delivery were about four times more likely to treat periodontal disease during pregnancy (P= 0.01, OR = 3.95). Dentists knowing the association between maternal oral health and childhood decay were more likely to counsel pregnant patients regarding caries prevention (P> 0.05, OR = 3.75).

Conclusions

Collectively the results indicated few gaps in knowledge among some dentists and a need to improve existing attitudes towards perinatal oral health. Dentists failing to recognize the importance of perinatal oral health are more likely to be hesitant in treating pregnant patients. Failing to recognize the link between periodontal disease and obstetric complications increases the possibility of hesitance to counsel pregnant patients regarding the same. The appreciation of the evidence for poor perinatal oral health and risk of early childhood caries increases the likelihood of counseling by dentists on caries prevention.
Procedimiento Inspector y proceso penal. Problemas no resueltos en la doble instrucción de delítos contra la hacienda pública en el Reino de España
Authors: López Martinez Juan
Published: September 2021

En el presente estudio se analizan las relaciones existentes en el derecho positivo español entre la articulación de las instrucciones del procedimiento de regularización de la deuda y el proceso por delito contra la Hacienda Pública. En él se pone de manifiesto que en la normativa que resulta aplicable no se establecen el conjunto de técnicas que de forma precisa articulenlos derechos, deberes y garantías que han de observarse en ambos órdenes. En este sentido se analiza el concepto y efectos de la «noticia criminis» en el procedimiento de Inspección tributaria vigente en España; la naturaleza, el contenido y el alcance del traslado del «tanto de culpa» y, la operatividad y sus límites, del derecho a no autoinculparse en el procedimiento de regularizaciónde deudas. Problemas que resultan nucleares en cualquier regulación que seestablezca para la articulación de las relaciones entre procedimiento y proceso.
Study the Market Competitiveness and Its Performance in Green Chilli Seeds Market
Authors: Raj Stephan , Naik A. D. , Naik B. K. , Kerur N. M.
Published: September 2021

The green chilli seeds market is majorly controlled by private companies in India. As a result, private companies are trying to make a profit with good quality seeds along with taking the good promotion activities in the market. The study was taken in Hassan district of Karnataka, India. In this study to know the market structure, the Herfindal Index was used and it found that East–West Company had a market share of 55.12 per cent followed by Seminis seeds with 22.44 per cent. Herfindal Index was 3,762.75 which depicted a moderate degree of concentration in the green chilli seed market in the study area. To know the performance of each selected company in the green chill market was calculated with help of a grid. The East-West and Beejo Sheetal companies performance was equal in the market. The display of product, appropriating schemes and distribution depth of East-West seeds company was foremost because the East-West company seeds come in metal box package which makes them appear more attractive, quality protected and prove to less damage during transit.
“In your own words, how certain are you?” Post‐identification feedback distorts verbal and numeric expressions of eyewitness confidence
Authors: Kenchel Jillian M. , Greenspan Rachel L. , Reisberg Daniel , Dodson Chad S.
Published: August 2021

After making a lineup identification, eyewitnesses remember being more confident in their identification and having a better view of the initial crime if they are told they correctly identified the suspect compared to witnesses not given this feedback. The present studies investigated whether this effect of feedback occurs similarly when witnesses report their confidence numerically and when they report their confidence in their own words. Across three studies, participants (N = 1396) watched a mock crime video, received either confirmatory feedback or not, and reported their confidence in words, numbers, or both words and numbers. Results showed a significant effect of feedback on both confidence and witnessed experience in all confidence conditions. This effect occurred with both biased and unbiased lineup instructions and with both target‐present and target‐absent lineups. The results advance discussions about the best means for reporting confidence in the field.
The New Industrial Urbanism
Authors: Hatuka Tali
Published: September 2021

A hybrid, heterogeneous model of urban design, ‘New Industrial Urbanism’ can facilitate dynamic, innovative and vibrant sectors of the city. Architect and urban planner Tali Hatuka, Head of the Laboratory of Contemporary Urban Planning and Design (LCUD) at Tel Aviv University, explores its contemporary societal, economic and technological context. She describes its impact on ideas of localism, skilling up the workforce and cross‐disciplinary collaboration.
The New Industrial Commons: Worker‐Owners and Factory Space
Authors: Rappaport Nina
Published: September 2021

Strikes are no longer the only way for workers to put their case. Writer, curator, consultant and educator Nina Rappaport charts the continuing rise of worker empowerment, whether through ‘expropriation’, workers’ collectives or similar employee‐owned businesses, giving varied examples of where such approaches have occurred around the world. The catalyst for these moves has often been where the prevailing capitalist model has left spaces vacant and derelict, due to its relentless search for efficiency and economies of scale.
Occupying Africa: Prototyping a Transformal Makerspace Network
Authors: Osseo‐Asare DK , Abbas Yasmine
Published: September 2021

Experimenting with the varied contexts of work, living, education and making/producing throughout Africa, DK Osseo‐Asare and Yasmine Abbas – both members of the Architecture and Engineering Design Faculty at Pennsylvania State University – have co‐founded and developed the Agbogbloshie Makerspace Platform (AMP). They outline the background and functioning of this enabling system that encourages participants to use the low‐tech resources around them to build their skills and change their environments.
A New Paradigm for the Periphery: The Case Against Reuniting City and Factory
Authors: Barkow Frank
Published: September 2021

Amid all the hype about bringing factories back from the periphery and reintegrating them into the city centre, are some of the downsides of central location being ignored? Frank Barkow, co‐founder of architectural practice Barkow Leibinger with offices in Berlin and New York, argues for a continuation of the industrial edge condition on the grounds of scale, flexibility and adaptability as well as in terms of transport infrastructure.
Freeland: How Residents Are Creating a Dutch City from Scratch
Authors: Maas Winy
Published: September 2021

What would happen if residents were allowed total design control over their new town, its food production, its highways and its fuel consumption? Winy Maas, founding partner and Principal Architect of global practice MVRDV, introduces us to Freeland – an attempt at the total democratisation of masterplanning from the bottom up. Inhabitants can do almost anything but must also take a wider responsibility for the community.
Microalgae‐Derived Health Supplements to Therapeutic Shifts: Redox‐Based Study Opportunities with AIE‐Based Technologies
Authors: Reza A. H. M. Mohsinul , Zhu Xiaochen , Qin Jianguang , Tang Youhong
Published: September 2021

Reactive oxygen species (ROS) are highly reactive molecules, serve the normal signaling in different cell types. Targeting ROS as the chemical signals, different stress based strategies have been developed to synthesis different anti‐inflammatory molecules in microalgae. These molecules could be utilized as health supplements in human. To provoke the ROS‐mediated defence systems, their connotation with the associated conditions must be well understood, therefore, proper tools for studying ROS in natural state are essential. The in vivo detection of ROS with phosphorescent probes offers promising opportunities to study these molecules in a non‐invasive manner. Most of the common problems in the traditional fluorescent probes are lower photostability, excitation intensity, slow responsiveness, and the microenvironment that challenge their performance. Some ROS‐specific aggregationinduced emission luminogens (AIEgens) with pronounced spatial and temporal resolution have recently demonstrated high selectivity, rapid responsiveness, and efficacies to resolve the aggregation‐caused quenching issues. The nanocomposites of some AIE‐photosensitizers can also improve the ROS‐mediated photodynamic therapy. These AIEgens could be used to induce bioactive components in microalgae through altering the ROS signaling, therefore are more auspicious for biomedical research. This study reviews the prospects of AIEgen‐based technologies to understand the ROS mediated bio‐physiological processes in microalgae for better healthcare benefits.
Millisecond Conversion of Photovoltaic Silicon Waste to Binder‐Free High Silicon Content Nanowires Electrodes
Authors: Lu Jijun , Liu Siliang , Liu Junhao , Qian Guoyu , Wang Dong , Gong Xuzhong , Deng Yida , Chen Yanan , Wang Zhi
Published: September 2021

High‐value recycling of photovoltaic silicon waste is an important path to achieve “carbon neutrality.” However, the current remelting and refining technology of Si waste (WSi) is tedious with high secondary energy consumption and repollution, and it can only achieve its relegation recycling. Here, an efficient and high‐value recycling strategy is proposed in which photovoltaic WSi is converted to high energy density and stable Si nanowires (SiNWs) electrodes for lithium‐ion batteries (LIBs) in milliseconds. The flash heating and quenching (≈2100 K, 10 ms) provided by an electrothermal shock drive directional diffusion of Si atoms to form SiNWs within the confined space between graphene oxide films. As a result, the SiNWs self‐assemble to form a conductive SiNWs–reduced graphene oxide composite (SiNWs@RGO). When applied as a binder‐free anode for LIBs the SiNWs@RGO electrode exhibits an ultrahigh initial Coulombic efficiency (89.5%) and robust cycle stability (2381.7 mAh g−1 at 1 A g−1 for more than 500 cycles) at high Si content of 76%. Moreover, full LIBs constructed using the commercial Li[Ni0.8Co0.16Al0.04]O2 cathode exhibit impressive cycling performance. In addition, this clean high‐value recycling method will promote economic, environmentally friendly, and sustainable development of renewable energy.
Pseudo‐Hologram with Aerohaptic Feedback for Interactive Volumetric Displays
Authors: Christou Adamos , Chirila Radu , Dahiya Ravinder
Published: September 2021

The ability to display virtual objects midair that can be seen without special headwear is an attractive proposition for the virtual reality systems of the near future. Volumetric display technologies have demonstrated this concept, allowing users to view virtual objects with real dimensions in 3D space while enabling some forms of interaction. Developments have been witnessed in haptic feedback technologies which are used to deliver a sensation of touch in the digital world. As virtual environments find more applications in today's world, haptic feedback devices have potential to integrate with virtual reality systems and contribute to a more immersive and interactive user experience. Herein, an air‐based haptic feedback device, named Aerohaptics, is presented, which delivers mid‐air tactile feedback while the user is manipulating virtual objects within a pseudo‐holographic display. The developed system constitutes a cost‐effective approach with relatively low complexity and various potential applications as no wearable or handheld peripherals are required. The delivered haptic feedback can be accurately directed at specific locations on the user's hand and its intensity can be controlled to suit various interaction scenarios. Through experiments, localized feedback on the user's fingertips as well as varying feedback force according to the user's hand movement is demonstrated.
Effects of 9/11‐related injury on retirement patterns among World Trade Center Health Registry enrollees
Authors: Seil Kacie , Yu Shengchao , Brackbill Robert , Alper Howard , Maqsood Junaid
Published: September 2021

Background

Many survivors of the 9/11/2001 terrorist attacks in New York City sustained injuries. The aim of this study was to understand how 9/11‐related injuries affected retirement patterns of World Trade Center Health Registry enrollees.

Methods

The study included enrollees who participated in the 2017 Health & Quality of Life Survey, focused on 9/11‐related injuries and quality of life, and the 2017–2018 Health & Employment Survey, focused on retirement and employment (N = 3535). Using Cox proportional hazards and logistic regression modeling, we calculated the risk of retiring at earlier ages and the odds of retirees working again, controlling for relevant covariates.

Results

Results showed that 9/11‐related injuries did affect retirement patterns. Injured enrollees were at greater risk of retiring at younger age compared to non‐injured enrollees. Compared to more severely injured retirees, non‐injured and less severely injured retirees were significantly more likely to work again postretirement. Our results suggested that being injured on 9/11 was associated with retirement, meaning that if the injury had not occurred, the individual may have continued working longer.

Conclusions

The need to retire earlier than planned could be addressed with employer and societal changes. Employers should consider making accommodations for those impacted by 9/11 a priority, as it is imperative for those who were injured on 9/11 to have the ability to work to support their physical, mental, and financial well‐being.
Function of chitosan in aDOPO‐based flame retardant modified epoxy resin
Authors: Wang Xinyu , Zhou Chenyu , Dai Shengsong , Wang Junjie , Pan Zhiquan , Zhou Hong
Published: September 2021

A bio‐based flame retardant (PDE) was synthesized through a facile one‐pot reaction of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) with protocatechualdehyde and ethanol. PDE was fully characterized by fourier transform infrared spectroscopy (FTIR),1H NMR,31P NMR and ESI‐MS. Epoxy resin (EP) with 9 wt% PDE (EP/9%PDE) passed UL94 V‐0 rating and possessed the limited oxygen index (LOI) value of 33.2%, the curved EP thermosets kept transparent. When chitosan (CS) was used to replace one‐third of PDE in EP/9% PDE, the modified EP also passed UL94 V‐0 rating with the LOI value of 32.3%, the curved thermosets kept transparent and owned better absorption effect toward ultraviolet light. Cone calorimeter test and TG‐FTIR analysis were performed on the EP samples, the chars after burning were characterized by scanning electron microscope (SEM), energy‐dispersive X‐Ray spectroscopy (EDX), Raman spectrum and FTIR. The results showed that the synergistic effect of PDE‐CS on flame retardant was ascribed to the protective effect of denser char layer, the release of some phosphorus containing free radicals and the dilution effect of released nonflammable gases such as H2O and CO2.
Improvement of electroacupuncture on APP/PS1 transgenic mice in behavioral probably due to reducing deposition of Aβ in hippocampus
Authors: Sun Run‐Quan , Wang Zi‐Dong , Zhao Jun , Wang Shuai , Liu Yi‐Zhi , Liu Si‐Yuan , Li Zhi‐Gang , Wang Xin
Published: September 2021

Alzheimer's disease (AD) is a fatal neurodegenerative disease for which currently no cure is available. Electroacupuncture (EA) has been widely used in China as an alternative therapeutic approach for neurological diseases. The cognitive decline in patients with AD has been reported to be closely related to the deposition of amyloid‐β (Aβ) in the hippocampus of the brain, and the Morris water maze (MWM) test is a widely used method for assessing the behavior of animal models. In this study, the MWM test was performed to evaluate the effects of EA treatment on cognitive function and memory, and the micro‐positron emission tomography scan was used to assess the hippocampal Aβ deposition. The results showed that the cognitive function of APP/PS1 mice was significantly improved and the rate of [18F]AV‐45 uptake was reduced in the EA group, compared with the AD group. Our study suggested that EA can exert a therapeutic effect in AD by improving spatial learning and memory and inhibiting the hippocampal Aβ deposition.
Advances in 2‐substituted benzothiazole scaffold‐based chemotherapeutic agents
Authors: Haider Kashif , Rehman Sara , Pathak Ankita , Najmi Abul K. , Yar Mohammad S.
Published: September 2021

Targeted therapy plays a pivotal role in cancer therapeutics by countering the drawbacks of conventional treatment like adverse events and drug resistance. Over the last decade, heterocyclic derivatives have received considerable attention as cytotoxic agents by modulating various signaling pathways. Benzothiazole is an important heterocyclic scaffold that has been explored for its therapeutic potential. Benzothiazole‐based derivatives have emerged as potent inhibitors of enzymes such as EGFR, VEGFR, PI3K, topoisomerases, and thymidylate kinases. Several researchers have designed, synthesized, and evaluated benzothiazole scaffold‐based enzyme inhibitors. Of these, several inhibitors have entered various phases of clinical trials. This review describes the recent advances and developments of benzothiazole architecture‐based derivatives as potent anticancer agents.
Rational engineering and applications of functional bioadhesives in biomedical engineering
Authors: Park Jae , Kim Yeonju , Chun Beomsoo , Seo Jungmok
Published: September 2021

For the past decades, several bioadhesives have been developed to replace conventional wound closure medical tools such as sutures, staples, and clips. The bioadhesives are easy to use and can minimize tissue damage. They are designed to provide strong adhesion with stable mechanical support on tissue surfaces. However, this monofunctionality of the bioadhesives hinders their practical applications. In particular, a bioadhesive can lose its intended function under harsh tissue environments or delay tissue regeneration during wound healing. Based on several natural and synthetic biomaterials, functional bioadhesives have been developed to overcome the aforementioned limitations. The functional bioadhesives are designed to have specific characteristics such as antimicrobial, cell infiltrative, stimuli‐responsive, electrically conductive, and self‐healing to ensure stability under harsh tissue conditions, facilitate tissue regeneration, and effectively monitor biosignals. Herein, we thoroughly review the functional bioadhesives from their fundamental background to recent progress with their practical applications for the enhancement of tissue healing and effective biosignal sensing. Furthermore, the future perspectives on the applications of functional bioadhesives and current challenges in their commercialization are also discussed.
The sustainable development of the aerospace industry: Drivers and impact of corporate environmental responsibility
Authors: Gangi Francesco , Mustilli Mario , Daniele Lucia Michela , Coscia Maria
Published: August 2021

The aerospace industry is facing new challenges in managing sustainable development. From an instrumental perspective, eco‐friendly business models should strengthen operations efficiency and improve companies' reputations while also creating conditions for stronger financial performance. Accordingly, the present study examines the drivers leading aerospace companies to engage in corporate environmental responsibility (CER) and its impacts. First, we investigate whether and to what extent the characteristics of the board, as an effective corporate governance (CG) mechanism, foster CER. Second, we analyse the impact of CER engagement on both accounting‐ and market‐based measures of corporate financial performance (CFP). Using a worldwide sample of 157 aerospace companies over the period from 2005 to 2019, this study identifies notable findings. In the first stage, the results show that identified characteristics of the board of directors are positive predictors of higher CER engagement. In the second stage, the findings indicate that CER engagement drives higher profitability and positive appreciation among financial stakeholders. Consistent with this win‐win scenario, we provide empirical support for the conflict resolution hypothesis at the governance level. Furthermore, we recommend that firms in the aerospace industry increase their involvement in environmental policies that enhance competitive advantage and market value.
Smoking status combined with tumor mutational burden as a prognosis predictor for combination immune checkpoint inhibitor therapy in non‐small cell lung cancer
Authors: Sun Li‐Yue , Cen Wen‐Jian , Tang Wen‐Ting , Long Ya‐Kang , Yang Xin‐Hua , Ji Xiao‐Meng , Yang Jiao‐Jiao , Zhang Ren‐Jing , Wang Fang , Shao Jian‐Yong , Du Zi‐Ming
Published: September 2021

Background

This study aimed to explore the prognostic value of tumor mutational burden (TMB) combined with smoking status in advanced non‐small cell lung cancer (NSCLC) patients who received immune checkpoint inhibitor therapy (anti PD‐1/PD‐L1 therapy) combined with chemotherapy or anti‐angiogenesis therapy.

Methods

We conducted a retrospective analysis of NSCLC patients who underwent next‐generation sequencing test (either 295‐gene panel NGS or 1021‐gene panel NGS) from September 2017 to November 2020. The relationship between TMB and smoking status was investigated. Kaplan–Meier survival analysis was used to compare progression‐free survival (PFS) of the NSCLC patients who received combination immunotherapy grouped by TMB value and smoking status.

Results

We enrolled 323 cases and 388 cases of NSCLC patients in the 295‐gene panel cohort and 1021‐gene panel cohort, respectively. Positive correlation between TMB and smoking status was found in lung adenocarcinoma, but not in lung squamous cell carcinoma. Participants with both high TMB and smoking status who received immune checkpoint therapy combined with chemotherapy or anti‐angiogenesis therapy had longer PFS than other participants (p < 0.05).

Conclusions

The combination of TMB with smoking status might be a potential predictor for the efficacy of combination immunotherapy in advanced NSCLC.
Platanic Acid‐Aryl Enones as Potential Anticancer Compounds: Synthesis and Biological Profiling against Breast, Prostate and Lung Cancer Cell Lines
Authors: Ganaie Bilal Ahmad , Shahid Mir , Rashid Auqib , Ara Tabassum , Ahmad Banday Javid , Malik Fayaz , Bhat Bilal A.
Published: September 2021

A series of rationally designed platanic acid‐based compounds derived from naturally occurring betulinic acid were synthesized through a sequence of Lemieux‐Johnson oxidation and Aldol condensation reaction. All the compounds were screened for cytotoxicity against a panel of human cancer and normal cell lines using MTT assay. From the biological data, it was observed that some of these semi‐synthetic congeners exhibited potent biological profiles compared to platanic acid. One of the compounds with the p‐tolyl substitution was found to be most active in this study, and its cytotoxicity against two of the cell lines, MDA‐MB 231 and A‐549 were in tune with the standard compound, 5‐fluorouracil.
Towards Commercialization of Third‐Generation Biofuel Industry for Sustainable Energy Production in Nigeria
Authors: Shiru Suleiman , Shiru Mohammed Sanusi
Published: September 2021

Due to the potential depletion of fossil fuels and the need for the shift from its use to combat the aggravated impacts of climate change, the unsustainable use of these conventional fuels has been widely recognized. This has prompted commercialization of biofuels as an alternative sustainable fuel. This study summarizes the potential of third‐generation biomass feedstocks, algae, for biofuel production on the example of Nigeria, where most biofuel plants still use first‐ and second‐generation feedstocks, which have led to food and land mass competition. It is shown that the production and consumption of third‐generation biofuel is at its infancy in the country. It was also found that the climatic conditions in Nigeria are conducive for the cultivation of microalgae, which are the primary sources of the third‐generation biofuel, even though there are barriers such as inadequate reliable resource database for investment decisions and technical expertise to develop and deploy biofuels in commercial form. The large population of Nigeria is a potential market for biofuel, therefore, commercialization of the third‐generation biofuel can be a viable alternative energy source to conventional fossil fuels and it can generate employment for many in the country.
Photoactivation of Innate Immunity Receptor TLR8 in Live Mammalian Cells by Genetic Encoding of Photocaged Tyrosine
Authors: Yang Yi , Luo Shuchen , Huang Jian , Xiao Yu , Fu Yixuan , Liu Wei , Yin Hang
Published: August 2021

The effectiveness of innate immune responses relies on an intricate balance between activation and regulation. TLR8, a member of the Toll‐like receptor (TLR) family, plays a fundamental role in host defense by sensing viral single‐stranded RNAs (ssRNAs). However, the molecular recognition and regulatory mechanism of TLR8 is not fully understood, especially in a whole‐cell environment. Here, we engineer the first light‐controllable TLR8 model by genetically encoding a photocaged tyrosine, NBY, into specific sites of TLR8. In the caged forms, the activity of TLR8 is masked but can be restored upon decaging by exposure to UV light. To explain the mechanism clearly, we divide the sites with light responsiveness into three groups. They can separately block the ligands that bind to the pockets of TLR8, change the interaction modes between two TLR8 protomers, and interfere with the interactions between TLR8 cytosolic domains with its downstream adaptor. Specifically, we use this chemical caging strategy to probe and evaluate the function of several tyrosine sites located at the interface of TLR8 homodimers with a previously unknown regulatory mode, which may provide a new strategy for TLR8 modulator development. Effects on downstream signaling pathways are monitored at the transcriptional and translational levels in various cell lines. By photoactivating specific cells within a larger population, this powerful tool can provide novel mechanistic insights, with potential in biotechnological and pharmaceutical applications.
Breaking the Bamboo Ceiling: Practical Strategies for Asian American and Pacific Islander Counselor Educators
Authors: Litam Stacey Diane Arañez , Chan Christian D.
Published: September 2021

Asian counselor educators in predominantly White institutions face challenges that are not shared by their White colleagues or by other faculty of color. This article outlines the barriers for Asian counselor educators and establishes a call to action for researchers to act in ways that support Asian faculty retention and success.
Fracture simulation of fully and partially threaded bolts under tension
Authors: Yang Fei , Veljkovic Milan , Cheng Lu
Published: September 2021

The tensile behaviour of bolts has direct effects on the performances of structural bolted joints. Conventional studies mainly focus on the stiffness and strength of bolt assemblies, whereas the deformation and fracture behaviour of fully and partially threaded bolts under tension is rarely investigated. This paper presents a numerical investigation of the fracture behaviour of fully and partially threaded bolts based on the experimental results in literature [5]. Firstly, a combined linear and power stress‐strain relation is used to describe the post‐necking stress‐strain relations of fully and partially threaded bolts. Direct tension tests on fully and partially threaded bolts are modelled using ABAQUS with the explicit solver. The fracture criterion proposed by Bao and Wierzbicki [10] is used to simulate the bolt tensile fracture and thread stripping failure. Numerical results indicate that the large deformation behaviour and the failure mode of fully and partially threaded bolts under tension could be accurately predicted combining the calibrated post‐necking stress‐strain relations and the Bao‐Wierzbicki fracture criterion with suitable parameters.
Behaviour and Design of Cold‐Formed Steel Bolted Portal Frame Connections
Authors: Mojtabaei Seyed Mohammad , Becque Jurgen , Hajirasouliha Iman
Published: September 2021

Cold‐formed steel (CFS) sections have a wide range of applications, among which portal frames take up an ever more popular place. The behaviour of CFS moment‐resisting frames depends mainly on the performance and failure mechanism of their connections (i.e. the beam‐to‐column and column‐to‐base connections). This paper aims to study the structural performance of CFS moment‐resisting connections by investigating a commonly governing failure mode consisting of local buckling of the CFS member web adjacent to the bolted connection. Experimentally validated finite element models of CFS bolted connections were developed in ABAQUS using Python scripts, taking into account material and geometric nonlinearity, geometric imperfections and realistic bolt bearing behavior. The validated models were then used to investigate the effects of the cross‐sectional shape, plate thickness, bolt configuration and bolt group length on the flexural and the axial compressive capacities of CFS bolted connections. It was concluded that, depending on the geometric characteristics of the connection, its ultimate capacity may be significantly affected by the effects of shear lag. The results were subsequently employed to develop design equations for the nominal flexural and axial compressive capacities of CFS bolted moment‐resisting connections.
Structural Study of Steel‐Concrete Double Composite Girder Bridge
Authors: Ohmura Kohei , Imagawa Yusuke , Ohyama Osamu
Published: September 2021

In Japan, the steel‐concrete composite girder bridge is widely used to reduce construction and maintenance cost, and improve constructability and the construction period. As an effort to decrease box girder construction cost, the narrow box girder bridge, which has a reduced box girder width, has been developed. Compared with a conventional box girder bridge, this type of box girder bridge simplifies the structure inside the box by narrowing the space between web plates. Furthermore, it is possible to reduce the number of members, welding length and painting area. The average economical span length is approximately 90m. Similarly, in European countries, a new type of composite girder bridge was developed and constructed for the same purpose as the bridge in Japan. The steel‐concrete double composite girder bridge, which has two concrete slabs on the upper and lower surfaces of the girder only in the region of the intermediate supports, is a type of medium span bridge. An advantage of adopting this structural system is that the cross sections of both the sagging and hogging bending moment areas are classified into the compact section at the ultimate limit state; that is, the maximum flexural strength of these sections can be taken full plastic moment. There are few constructed examples of this type of bridge in Japan. Because of the handling difficulty, the shop manufacturing cost of a box girder is, generally, more expensive than that of an I‐girder. Additionally, the design method for bridges has been revised since January 2018 and has changed from the allowable stress design method to the limit state design method in Japan. Therefore, the authors propose a new type of steel‐concrete double composite I‐girder bridge. The trial design of three‐span continuous girder bridges was conducted. In this paper, the effect of double composite action, for instance, the reduction of the girder height in the region of the intermediate supports, and applicable span length are discussed.
Behaviour of Ferritic Stainless Steel Bolted T‐stubs Under Tension‐Part 2: Numerical Investigations
Authors: YAPICI Orhan , THEOFANOUS Marios , DIRAR Samir , YUAN Huanxin
Published: September 2021

Following the experimental study on EN 1.4003 ferritic stainless steel T‐stubs in tension discussed in the companion paper, this study reports the development and validation of an advanced FE model that can predict the overall behaviour and failure modes of ferritic stainless steel bolted T‐stubs subjected to tension. Key simulation strategies regarding the modelling of bolt geometry and overcoming numerical instabilities are discussed. Following the determination of material properties in the longitudinal, transverse and diagonal direction reported in the companion paper, the effect of allowing for anisotropy in the FE simulations is investigated and modelling recommendations for its inclusion in FE models are made. Moreover, the effect of bolt end and edge spacing on the joint plastic resistance, ultimate capacity, ductility as well as overall response is comprehensively discussed by inspecting the stress distribution through the plate thickness at various locations along the T‐stub, thus revealing both the flexural and the membrane component of the load transfer mechanism. The numerical results were validated against the experimental results reported in the companion paper in terms of predicted plastic and ultimate resistance, ductility and obtained failure modes. On the basis of the obtained results and the discussion, modeling recommendations for the simulation of stainless steel T‐stubs are made.
Numerical modelling of CFST column to I beam end plate joints
Authors: Boukhalkhal Said Hicham , Ihaddoudène A Nacer T , Costa‐Neves Luis F , Madi Wafa , Vellasco Pedro CG , Lima Luciano
Published: September 2021

The use of concrete‐filled tubular structural elements around the world has been boosted in recent years. The most common geometries for these sections are circular (CHS), Square (SHS) and rectangular (RHS). They have been extensively used in multi‐story buildings due to their aesthetical features and structural advantages, due to their favorable resistance to weight ratio. One of the limitations for using these geometries is the inaccessibility to the interior of the section, thus arising difficulties and added costs in materializing the connections. This paper presents a numerical study dealing with tubular columns to I beam end plate joints using welded studs as the connecting elements and aiming to evaluate their structural performance. Following a series of full‐scale monotonic tests performed at the Civil Engineering Department of the University of Coimbra, Portugal, with the abovementioned geometry, several numerical models using 3D nonlinear elements have been developed to investigate the mechanical response of these joints.

The main variables were the column and beam geometries, the thickness of the hollow sections, and the presence or absence of infilling concrete. The numerical results have been compared to the tests performed under positive and negative bending moments, to validate the finite element model. The numerical model was proven to lead to accurate predictions of the initial stiffness and joint resistance. The model validation was followed by a parametric study with the abovementioned variables to investigate the influence of the governing components and behavioral features. The column face loaded out of its plane proved to be the governing component, with its width‐to‐thickness ratio having a significant role in determining both elastic stiffness and resistance, together with the endplate dimensions and the number of bolt rows in tension.
Numerical investigation on the fatigue life of non‐cracked metallic plates repaired with bonded CFRP
Authors: Mohabeddine Anis , Correia J.A.F.O. , Castro J.M , Montenegro P. , De Jesus A.M.P. , Calçada R.A.B.
Published: September 2021

In Europe, a large number of old riveted metallic bridges approach the end of their fatigue life. Past research has shown that the application of CFRP can be very efficient in delaying the crack growth rate of deficient structural elements with existing crack. However, little attention is given to the fatigue resistance of non‐damaged metallic members approaching the end of their fatigue life. This is particularly relevant for old metallic riveted bridges, where many critical components do not have existing cracks. This paper presents a numerical investigation on the fatigue behavior of non‐cracked metallic plates bonded with CFRP using epoxy resin. Nonlinear finite element analyses are performed using the commercial software ABAQUS. The cyclic elasto‐plastic behavior and the fatigue strain life of puddle iron metal are obtained from previous experimental results conducted on specimens extracted from Luiz I Bridge (Porto, Portugal). Debonding failure of the adhesive joint is simulated through the use of cohesive zone model with traction separation law. The cohesive behavior was calibrated using fracture mechanic tests results on the adhesive, conducted in a previous related study. The fatigue crack initiation life was estimated using local approach based on material fatigue strain life. Fatigue resistance curves that relate the number of cycles to failure and the applied nominal stress for unreinforced and reinforced elements are derived. The results show that the application of CFRP can significantly increase the fatigue crack initiation life of a metallic structural component significantly.
Re‐evaluation and extension of fatigue test data for welded attachments and butt joints
Authors: Drebenstedt Karl , Kuhlmann Ulrike
Published: September 2021

Welded structures under fatigue loading are widely used in civil engineering. The fatigue strength of components such as welded attachments and butt joints are often determining for the dimensioning of bridges, crane runways or tower constructions. The existing design rules of Eurocode 3, Part 1‐9 are mainly based on experimental data. However, the experimental background of Eurocode 3 Part 1‐9 is partly incomplete. Some fatigue detail classifications are based on numerical modelling and engineering judgement. New findings from experimental research allow a revision of these details, leading to higher fatigue strength classifications in many cases.

Firstly an overview of an extensive database for fatigue tests on butt joints and welded attachments is addressed. A method for statistical analysis is presented, which allows the consideration of fatigue tests from different sources by using the design philosophy of Eurocode 3 Part 1‐9 and also meeting the requirements of Eurocode 0.

The paper is also going to present some new supplementary experimental investigations on a fatigue detail for transverse end welds of cover plates with blended weld toes, which is traditionally used in German bridge design.

Finally a revised and simplified fatigue detail catalogue for welded attachments and butt joints is addressed which is intended as a suggestion for the next generation of Eurocode 3 Part 1‐9.
Experimental investigation on fire resistance of CFST columns after earthquake
Authors: Tan Jike , Wang Yuhang , Tang Qi , Wang Weiyong , Su Meini
Published: September 2021

Post‐earthquake fire is one of the most prone and dangerous disasters after earthquake. This study investigates the post‐earthquake fire performance of concrete‐filled steel tube (CFST) columns experimentally. An experimental program containing two parts has been carried out ‐ quasi‐static tests and fire tests. During the quasi‐static tests, four square CFST columns were loaded under constant compressive force and cyclic horizontal force, until reaching different degrees of seismic damage. Afterwards, the pre‐damaged columns were loaded under a constant axial compression ratio (i.e. ratio of the applied compressive load to its bearing capacity) of 0.3 at elevated temperatures. The fire resistance time and failure modes of these pre‐damaged CFST columns are reported herein. Local buckling occurred at the bottom of the specimens during the cyclic loading tests, while the mid‐height of the steel tube was found to be softened and buckled seriously during the high temperature tests. When columns reached the limit of fire resistance, their axial deformation increased rapidly. Results showed that pre‐seismic damage significantly affected the fire resistance of specimens – more serious pre‐damage resulted in lower fire resistance. The experimental results will be used to conduct parametric study and propose design rules for the fire performance of CFST columns with different degrees of seismic damage.
Photophysics of Azobenzene Constrained in a UiO Metal–Organic Framework: Effects of Pressure, Solvation and Dynamic Disorder
Authors: Sussardi Alif , Marshall Ross J. , Moggach Stephen A. , Jones Anita C. , Forgan Ross S.
Published: September 2021

Photophysical studies of chromophoric linkers in metal–organic frameworks (MOFs) are undertaken commonly in the context of sensing applications, in search of readily observable changes of optical properties in response to external stimuli. The advantages of the MOF construct as a platform for investigating fundamental photophysical behaviour have been somewhat overlooked. The linker framework offers a unique environment in which the chromophore is geometrically constrained and its structure can be determined crystallographically, but it exists in spatial isolation, unperturbed by inter‐chromophore interactions. Furthermore, high‐pressure studies enable the photophysical consequences of controlled, incremental changes in local environment or conformation to be observed and correlated with structural data. This approach is demonstrated in the present study of the trans‐azobenzene chromophore, constrained in the form of the 4,4’‐azobenzenedicarboxylate (abdc) linker, in a UiO topology framework. Previously unobserved effects of pressure‐induced solvation and conformational distortion on the lowest energy, nπ* transition are reported, and interpreted the light of crystallographic data. It was found that trans‐azobenzene remains non‐fluorescent (with a quantum yield less than 10−4) despite the prevention of trans‐cis isomerization by the constraining MOF structure. We propose that efficient non‐radiative decay is mediated by the local, pedal‐like twisting of the azo group that is evident as dynamic disorder in the crystal structure.
One‐Step Synthesis and Schlenk‐Type Equilibrium of Cyclopentadienylmagnesium Bromides
Authors: Schüler Philipp , Görls Helmar , Krieck Sven , Westerhausen Matthias
Published: September 2021

In the in situ Grignard metalation method (iGMM), the addition of bromoethane to a suspension of magnesium turnings and cyclopentadienes [C5H6 (HCp), C5H5‐Si(iPr)3 (HCpTIPS)] in diethyl ether smoothly yields heteroleptic [(Et2O)Mg(CpR)(μ‐Br)]2 (CpR=Cp (1), CpTIPS (2)). The Schlenk equilibrium of 2 in toluene leads to ligand exchange and formation of homoleptic [Mg(CpR)2] (3) and [(Et2O)MgBr(μ‐Br)]2 (4). Interfering solvation and aggregation as well as ligand redistribution equilibria hamper a quantitative elucidation of thermodynamic data for the Schlenk equilibrium of 2 in toluene. In ethereal solvents, mononuclear species [(Et2O)2Mg(CpTIPS)Br] (2’), [(Et2O)nMg(CpTIPS)2] (3’), and [(Et2O)2MgBr2] (4’) coexist. Larger coordination numbers can be realized with cyclic ethers like tetrahydropyran allowing crystallization of [(thp)4MgBr2] (5). The interpretation of the temperature‐dependency of the Schlenk equilibrium constant in diethyl ether gives a reaction enthalpy ΔH and reaction entropy ΔS of −11.5 kJ mol−1 and 60 J mol−1, respectively.
Electronic Structure and Superconductivity of Compressed Metal Tetrahydrides
Authors: Bi Tiange , Zurek Eva
Published: September 2021

Tetrahydrides crystallizing in the ThCr2Si2 structure type have been predicted to become stable for a plethora of metals under pressure, and some have recently been synthesized. Through detailed first‐principles investigations we show that the metal atoms within these
symmetry MH4 compounds may be divalent, trivalent or tetravalent. The valence of the metal atom and its radius govern the bonding and electronic structure of these phases, and their evolution under pressure. The factors important for enhancing superconductivity include a large number of hydrogenic states at the Fermi level, and the presence of quasi‐molecular H
units whose bonds have been stretched and weakened (but not broken) via electron transfer from the electropositive metal, and via a Kubas‐like interaction with the metal. Analysis of the microscopic mechanism of superconductivity in MgH4, ScH4 and ZrH4 reveals that phonon modes involving a coupled libration and stretch of the H
units leading to the formation of more complex hydrogenic motifs are important contributors towards the electron phonon coupling mechanism. In the divalent hydride MgH4, modes associated with motions of the hydridic hydrogen atoms are also key contributors, and soften substantially at lower pressures.