bluuebunny/crossref_metadata_2025 huggingface dataset:
The aestheticization of business processes: Visualizing their Gestalt for collective thinking
Authors: Blattmeier Monika
Published: March 2023

Business processes, simply defined by Davenport as ‘structures for action’, organize the creation of value in a company. In addition to being carried out visibly, processes also have an inner dimension which remains hidden in the existing mechanistic metaphor of process management models. Aesthetic business processes draw from systems theory and Gestalt theory in order to uncover this inner dimension. The aim of this phenomenological investigation presented here is to describe the super-summative nature of business processes, in other words, to understand them holistically as a Gestalt. Mechanical Engineering students at a university of applied sciences analyzed business processes at different companies to discover patterns which they then visualized with the process participants at those companies. They used Christopher Alexander’s pattern language as a paradigm to make implicit knowledge buried in those business processes explicit. Using this technique, aesthetic business processes were identified as patterns. The format of the patterns served as a tool for collective thinking and as a form of expression for the Gestalt of aesthetic business processes in their visualization. A pattern language as an overview of the many ways to combine business process patterns has yet to be reconstructed based on this investigation. The shared visualizations highlighted the nature of the business processes and made it possible to see, in a metaphorical way, their significant interactions.
Attachment and Maladjustment: The Role of Effortful Control Development During Middle Childhood
Authors: Heylen Joke , Budniok Samuel , Van de Walle Magali , De Raedt Rudi , Bijttebier Patricia , De Winter Simon , Bosmans Guy
Published: March 2023

Latent growth curve modeling was used to investigate the longitudinal link between attachment, effortful control (EC), and maladaptive development during middle childhood. In a community sample, children (Time 1: n = 157; Mage = 10.91) and their mothers were examined three times over a two-year period. Attachment was operationalized at a more strategic (self-reported trust in maternal support) and more automatic level (secure base script knowledge). Mothers reported about children’s EC and maladjustment. Secure attachment was associated with higher EC, but EC development was only linked with baseline self-reported trust. Also, EC indirectly linked baseline self-reported trust with change in externalizing and internalizing problems over time. In addition, self-reported trust was indirectly linked with change in externalizing problems over time through EC development. EC, and, less robustly, EC development were linked with attachment and change in emotional and behavioral problems.
Value of corporate political contributions from the investors’ perspective
Authors: Eun Jihyun , Baik Yoon-Suk , Lee Seung-Hyun
Published: March 2023

In this study we consider corporate political contributions as a special type of social capital reserved for future contingencies. Firms benefit from making such contributions when the government suddenly intervenes in the market. We explore this value-creation mechanism in terms of the firm-investor relationship, not in terms of the traditional firm-government relationship. When a government intervention is being proposed or approved, firms that have made political contributions coordinating with political candidates are likely to enjoy better stock market returns than those that have not made such contributions. We also argue that firms that have made political contributions may experience lower stock returns than those that have not when the intervention plan is rejected. By focusing on the U.S. government’s Troubled Asset Relief Program (TARP) of 2008, our event study analysis with three news announcements finds that financial institutions that made political action committee (PAC) contributions indeed enjoyed higher stock returns when TARP was proposed and eventually approved. However, we do not find support for the investors’ devaluation of political contributions when TARP was once rejected during the review process. The findings propose that managers can use corporate political contributions as a strategic option to help investors reduce investment uncertainty by presenting their readiness for any unexpected change in the regulatory environment.
Living in a City Where Automated Taxis are Operating and Using Them: Does This Affect Consumers’ Preferences?
Authors: Yin Hao , Cherchi Elisabetta , Nettle Daniel
Published: March 2023

In this paper we study the impact of having used an automated taxi (AT) or simply living in a city where ATs are operating on users’ preferences for and attitudes toward ATs. This paper aims then to contribute to the research on ATs and on the impact of experiencing innovations. Data were collected in three major cities in China where ATs were in operation (AT cities), and other major cities where only normal taxis (NTs) were operating (NT cities). A stated choice (SC) experiment was built that included level-of-services attributes, specific AT in-vehicle features, levels of AT adoption and customers’ reviews. In addition, a set of attitudinal statements was included to measure injunctive norms, hedonic motivation and trust. Hybrid choice models were estimated accounting for intra-individual correlation. Results show that living in a city where AT are operating does not affect the willingness to pay for travel and waiting time, which is an expected result. But those living in AT cities compared with those living in NT cities are willing to pay just half the amount to have the in-vehicle feature “change destination during the trip” and around three times as much for good reviews about ATs for trips less than 30 min. Interestingly, trust has a positive and significant impact on the choice of AT only for those living in NT cities, while hedonic motivation is significant only for those living in AT cities. Finally, we did not find differences between those who had used an AT and those who had never used it.
Machine Learning Applied to Public Transportation by Bus: A Systematic Literature Review
Authors: Alexandre Tielle , Bernardini Flávia , Viterbo José , Pantoja Carlos Eduardo
Published: March 2023

Machine learning (ML) solutions have been proposed to make public transportation more attractive. Works that employ ML in bus transportation focus on various problems, such as travel time prediction or passenger flow prediction. These solutions look to improve elements of transportation services, such as the availability of information on passengers’ travel time and the reliability and regularity of the service. An analysis of the solutions proposed in the literature for public transportation by bus can reveal opportunities for data scientists and transportation professionals, and highlight problems that have been only slightly explored. In addition, mapping information about modeling these solutions (e.g., types of data produced by devices on the transportation network, which can be used in modeling a solution) could help beginner data scientists develop public transportation solutions. Transportation professionals can benefit from an overview of possible transportation solutions to improve transportation problems and direct government agency efforts to implement these solutions. This paper presents a survey of ML-based solutions for public bus transportation and details the modeling of these solutions (e.g., data types, ML algorithms). In addition, the problems tackled in the literature are categorized into four themes, and the solutions proposed to deal with them are schematized, highlighting problems that are little explored.
Design and Testing of MASH Test Level 3 Thrie-Beam Guardrail System for Roadside and Median Applications
Authors: Kiani Maysam , Danila James
Published: March 2023

Thrie-beam guardrail systems are used when enhanced Test Level 3 (TL-3) protection above that typically provided with a W-beam guardrail is desired. The currently available Manual for Assessing Safety Hardware ( MASH)-compliant modified thrie-beam system incorporates components that are more costly to fabricate, and the installation creates a wider footprint than a standard W-beam guardrail. The goal of this study was to develop a cost-effective thrie-beam guardrail system (TGS) for roadside and median applications under MASH TL-3 requirements. The roadside and median TGS configurations were developed using computer simulations, and their crashworthiness was evaluated through full-scale crash testing. Additionally, transition designs from a TGS to a standard W-beam system were developed. The TGS uses all the Midwest guardrail system (MGS) standard components except for the thrie-beam rail; it has a thrie-beam rail mounted at 34 in. in height as opposed to the MGS, with a W-beam rail mounted at 31 in. The two systems are attached using a symmetric W-to-thrie-beam transition segment. Based on the results of three successful full-scale crash tests and a computer simulation, both roadside and median TGS configurations meet all safety requirements for MASH TL-3.
Electrical discharge machining assessment of AA7075/Rice Husk Ash composite using response surface methodology
Authors: Gupta Vivudh , Singh Balbir , Mishra RK
Published: March 2023

This study aims to explore electrical discharge machining of green AA7075 composite supplemented with rice husk ash (an agricultural waste) using response surface methodology. Central composite rotatable design for three factors – current, pulse duration and gap voltage – was used for carrying out machining experiments. The effect of these input parameters was evaluated on performance parameters including material removal rate, tool wear rate and surface roughness. Regression models are developed for each response, and model adequacy was checked using the analysis of variance technique. Furthermore, Pareto charts for the standardized effects, normal probability distribution plots, residuals vs fits plots, residual vs order plots, main effect plots and contour plots were also developed for output parameters. Peak current was found to be the major process parameter affecting every response variable. The influence of other linear, squared and interaction effects that are found to be significant for each response are discussed. Multi-response optimization for different process parameters using the composite desirability approach is also highlighted. Confirmatory experiments at optimum process parameters are carried out to analyze variations in predicted values and experimental values. Electrical discharge machined sample was characterized through scanning electron microscopy to study its surface after successive spark discharges.
Investigation of transient machining in the cortical bone drilling process by conventional and axial vibration-assisted drilling methods
Authors: Bai Xiaofan , Qiao Guochao , Liu Zhiqiang , Zhu Weidong
Published: March 2023

A temperature exceeding the safety threshold and excessive drilling force occurring during bone drilling may lead to irreversible damage to bone tissue and postoperative complications. Previous studies have shown that vibration-assisted drilling methods could have lower temperatures and drilling forces than those of the conventional drilling method; we hypothesized that the main reason for these reductions stems from the differences in the transient machining processes between conventional and vibration-assisted drilling methods. To investigate these differences, comparative experiments and two-dimensional finite element models were performed and developed. The differences in the transient machining processes were verified by experimentation and clearly exhibited by the finite element models. Compared with the steady cutting process that produced continuous-spiral chips in the conventional drilling method, transient machining in the low-frequency vibration-assisted drilling method was a periodically dynamic cutting–separation process that produced uniform petal chips with specific settings of drilling and vibration parameters. Moreover, the transient machining process in the ultrasonic vibration-assisted drilling method was transformed into a combined action with high-speed impact and negative rake angle cutting processes; this action produced a large proportion of powdery chips. Therefore, it could be concluded that the superposed axial vibration significantly changed the transient machining process and radically changed the mechanical state and thermal environment; these changes were the main reason for the apparent differences in the drilling performance levels.
Syphilitic balanitis of Follmann in a patient with a history of previous infection
Authors: Campoli Marco , Cozzi Chiara , Caravello Simone , Minuti Anna , Lombardo Maurizio , Salvemini Isabella , Zerbinati Nicola
Published: March 2023

We report a case of syphilitic balanitis of Follmann arising in a man with a history of prior infection with syphilis. Few cases have been described in the literature. In our case, a man with history of multiple unprotected sexual contacts presented with erosive balanitis and painless inguinal bilateral lymphadenopathy. All tests for sexually transmitted infections (STIs) performed were negative with the exception of serology for syphilis. We made the diagnosis of syphilitic balanitis of Follmann that was confirmed by prompt resolution after treatment.
Jasminum elongatum Ameliorates Acetaminophen Induced Hepatotoxicity by Modulating Dysregulated Antioxidant Enzyme System
Authors: Syed Sabeena Hussain , Unavane Supriya , Taru Poonam , Ram Bindurani L. G. P. , Sakat Sachin Shridhar , Manwatkar Sonali , Namdeo Ajay Gajanan
Published: March 2023

Objectives

To evaluate the hepatoprotective activity of fractions of Jasminum elongatum methanolic extract against acetaminophen-induced hepatic damage.

Materials and Methods

Fractions obtained from methanolic extract of J. elongatum (petroleum ether, chloroform and hydroalcoholic) were investigated for hepatoprotective activity. Doses of 100 mg/kg and 200 mg/kg of different fractions were administered for 7 days, and acetaminophen toxicity was induced on the eighth day. After 24 hr of toxicity induction, biochemical markers and histological alterations were measured to determine the amount of hepatoprotection.

Results

The chloroform and hydroalcoholic fractions showed a significant decrease in biochemical parameters when compared to the toxic group, which was confirmed by histopathological changes and antioxidant parameters.

Conclusion

The results of this study revealed that the chloroform and hydroalcoholic fraction of J. elongatum have significant hepatoprotective activity against acetaminophen-induced toxicity.
Godavari to Gulf: Emigration of Dalit Women for Low-Paid Work
Authors: Nookathoti Trinadh , Boda Manohar
Published: March 2023

Dalit women suffer from multiple forms of oppression and discrimination based on gender, caste and class prejudices. This article explores the context and ramifications of emigration to the Gulf by Dalit women hailing from the Indian state of Andhra Pradesh who are mostly employed as domestic workers. Given the scarce opportunities at the place of origin, transnational migration has a meagre effect on the lives of Dalit women even as it contributes to earnings and the sustenance of household financial needs. This marginal gain, however, has a telling cost in terms of exploitative working conditions, adverse repercussions on mental and physical health as well as intra-family relations. The impact of migration on their overall welfare appears to be insignificant in the absence of state support in both origin and destination countries. The empirical analysis highlights that families of Dalit women, despite emigration, continue to reel under poverty, lack of education and remain exposed to exploitation, discrimination and state apathy.
Introduction of a homeless health outreach team in Northern New South Wales: is acute service usage reduced?
Authors: James Mathew , Greenhill Marc , Sullivan Dan
Published: March 2023

Objective

To examine if there is a relationship between introducing a Homeless Health Outreach Team (HHOT) and reduced acute Mental Health service usage.

Methods

Electronic Medical Record (EMR) data were collected on a group of clients of the Tweed Byron HHOT 6 months before and after establishing the service. The data were evaluated for demographics, and differences in Emergency Department (ED) presentations, mental health admissions, length of stay and community mental health engagement.

Results

The introduction of the team coincided with a significant reduction in ED presentations and an increase in community mental health engagement. There was an overall reduction in bed days but an increase in mean length of stay for those admitted post-intervention.

Conclusions

The establishment of the HHOT coincided with reduced acute mental health service usage via ED and inpatient Mental Health Units (MHU). There is scope for expansion of such a service as well as exploration of costings analysis. A long-term focus on ‘housing first’ and outreach approaches to homeless service provision could improve individual and service provision outcomes.
Experimental and numerical investigation on effects of viscoelastic rubber and local resonator mass on broadband vibration attenuation in acoustic-metamaterial plates
Authors: Dwivedi Kush , Das Sachchidanand , Geetha Rajasekharan Sabareesh
Published: March 2023

Vibration attenuation in acoustic-metamaterial plates assembled from a periodic arrangement of unit cells with a cavity containing local resonator system is presented. Each cell incorporates a base aluminum plate with vertical rectangle-shaped cavities containing a viscoelastic membrane supporting a mass forming a local resonator system. These acoustic-metamaterial structures exhibit stop-band behavior due to Bragg scattering and local resonance. Floquet–Bloch approach and eigenvalue analysis is used to identify the stop bands for metamaterial unit cells. The dispersion analysis predictions are validated experimentally by studying the vibration responses of different acoustic-metamaterial plates excited by an electrodynamic shaker over a frequency range of 8−4000 Hz. The attenuation regions observed in the finite element simulation results have been compared to that of the experiments. The obtained results show the potential of FE simulation to predict the metamaterial plate attenuation with reasonably good accuracy. The viscoelastic material properties also affect the attenuation region, as observed while comparing experimental results for different viscoelastic materials. These results show the effectiveness of acoustic-metamaterial plates to provide broadband vibration attenuation.
Low-frequency sound insulation of honeycomb membrane-type acoustic metamaterials with different interlayer characteristics
Authors: Li Yingli , Yan Jiahui , Zhang Yonglin
Published: March 2023

The membrane-type structure that can achieve excellent sound insulation characteristics under lightweight conditions is widely concerned, but it generally involves a small mass block attached to a thin membrane. Although this kind of design can obtain better acoustic insulation performance, the mass block will cause installation and manufacturing issues in industrial applications. This paper presents a multilayer honeycomb membrane-type acoustic metamaterial with an interlayer structure. Similar to the mass block, the interlayer structure makes less sound energy transmitted by varying the eigenmode characteristics of the membrane. Considering the integrated design of the interlayer structure, the issues of installation and manufacturing are solved and the sound transmission loss is enhanced on the fixed overall dimension and small additional mass. The results indicate that the design of interlayer structures can break the bottleneck of ultrathin and lightweight requirements. Meanwhile, the symmetry of interlayer position can lead to the shift in transmission loss valley to a higher frequency, achieving high sound insulation in a wide frequency range.
Screening for and Responding to Suicidality Among Youth Presenting to a Children’s Advocacy Center (CAC)
Authors: Shepard Lindsay D. , Campbell Kristine A. , Byrne Kara A. , Thorn Brian , Keeshin Brooks R.
Published: March 2023

Youth presenting to a Children’s Advocacy Center (CAC) for a forensic interview are at increased risk for suicidality, but no data exist for suicidality or suicide screening and response at the time of the forensic interview. The current study applied a suicide and traumatic stress screening and response protocol, the Care Process Model for Pediatric Traumatic Stress (CPM-PTS), with youth (11–18 years) presenting for a forensic interview to one of 16 participating CAC locations, 2018–2020.46.2% of youth screened for traumatic stress and suicidality ( N = 1651) endorsed thoughts of suicide or self-harm in the past two weeks, and 13.6% were assessed as high risk for suicide. High symptoms of traumatic stress increased the risk of suicidal thinking as well as of high risk suicidality. CAC workers, both clinicians and non-clinicians, facilitated screening and provided prevention response. Suicide screening and response at the CAC at the time of the forensic interview appears important and feasible.
A Comparative Study of Prison Inmates With and Without ADHD: Which Neuropsychological and Self-Report Measures are Most Effective in Detecting ADHD Within Correctional Services?
Authors: Etterlid-Hägg Vanessa , Pauli Malin , Howner Katarina
Published: March 2023

Objective:

In this study we aimed to investigate the screening and diagnostic properties of various self-report instruments to identify measures which most effectively detect ADHD in a correctional sample.

Method:

The sample consisted of 193 male high security prisoners in Sweden. We investigated if measures of ADHD symptoms, executive functioning, impulsivity, estimated IQ and working memory could differentiate participants with ADHD from those with ASPD or no diagnosis.

Results:

Participants with ADHD obtained significantly higher total scores on all included measures. Although we found that some of the measures were more efficient in differentiating ADHD, mean values were generally elevated in the sample.

Conclusion:

Results demonstrate the importance of investigating psychometric properties in relevant samples to assure a measurement’s usefulness in different contexts, in this case a correctional setting, where the high influence of unspecific behavioral indicators in these measurements might negatively affect their validity.
A quantitative trait GWAS on lens thickness identifies novel risk loci on PTPRM in the narrow angle individuals susceptible to PACG
Authors: Chakraborty Sudipta , Sharma Anshul , Pal Soumen , Sharma Arundhati , Sihota Ramanjit , Bhattacharjee Samsiddhi , Acharya Moulinath
Published: March 2023

Purpose

PACG is one of the leading causes of blindness where lens thickness is a major risk factor for narrow-angle individuals. To our knowledge, no literature has been reported on candidate gene for lens thickness as a quantitative trait (QT). Here, we performed a genome-wide association analysis on lens thickness in the narrow-angle individuals.

Materials and Methods

We conducted a genome-wide association study (GWAS) in the narrow angle individuals to investigate comprehensive genetic insights on lens thickness.

Results

 In QT-GWAS, we identified 145 genome-wide suggestive significant loci in the discovery cohort. Subsequently, we observed 13 SNPs that showed statistical significance around the region of PTRRM. Regional association analysis for top significant genotyped variants identified PTPRM as the most likely candidate for increased LT. Integrative bioinformatic analyses confirmed that the associated genomic region has potential regulatory roles for modulating transcription as enhancers. In the replication cohort, the sentinel genotype SNP was further associated significantly (P-value =0.000448) with high LT individuals. In both cohorts, the T allele of rs1941137 in the PTPRM gene indicates as a risk allele for the increased LT.

Conclusion

In this study, we discovered evidence of a genomic association between chromosomal areas around the PTPRM and increased lens thickness, resulting in a narrow angle. The regulatory components corresponding to PTPRM variations might have a role in the thicker lens. We report that the genomic region near PTPRM, a gene of potential interest, is associated with increased lens thickness.
Activating Self-Interest: The Role of Party Polarization in Preferences for Redistribution
Authors: Pastor Mayo Marco
Published: March 2023

Although extensive research has analyzed the factors that moderate economic self-interest—the relationship between individuals’ income positions and their preferences for redistribution—there is little crossnational research that analyzes the role of political parties. This article argues that political parties play a considerable moderating role in (de-)activating economic self-interest based on the polarization they display in their economic and cultural positions. By combining the World/European Values Survey, the World Income Inequality Database, and the Comparative Manifesto Project datasets, the analyses estimate the moderating effect of party polarization on economic self-interest. The results suggest that economic polarization enhances self-interest for the poor (respondents below the mean income), even when controlling for income inequality, but not for the rich. Moreover, cultural polarization also appears to reinforce self-interest for the poor, rather than supplanting it. The findings have important implications regarding ability for political parties to activate issues among the public.
Multilingual children’s imaginative worlds and their language use: A chronotopic analysis
Authors: Mirvahedi Seyed Hadi , Hosseini Mona
Published: March 2023

Aims and objectives:

This study applies the notion of chronotope as an analytical tool to explore the role of globalization, immigration, and transnationalism in shaping multilingual children’s awareness and use of semiotic resources in changing social contexts.

Design/methodology/approach:

This study is a part of an ongoing collaborative autoethnography (CAE), in which the data come from the second author’s cross-cultural transnational family and are shared with the first author for a collaborative interpretation and analysis.

Data and analysis:

Data were collected through recording the observations of language practices of a nine-year-old girl in a transnational family, including her plays on her own or with her peers in and outside the home. An ethnographically grounded discourse-analytic approach was employed in analyzing the data.

Findings/conclusions:

Despite rich linguistic and cultural repertoire, the child situated English on a higher scale level in a hierarchically layered system, and she found imaginative play as a space in which she could explore not only linguistic repertoire but also certain cultural chronotopes. She also demonstrated her awareness of and skills in drawing on variation within the English language to index certain social personae.

Originality:

The originality of the study lies, first, in the uniqueness of the case being in an Indian-Iranian multilingual transnational family and, second, in the unique methodology—using chronotopes as a theoretical and analytic tool to analyze audio-recorded interactions in a multilingual child’s imaginative plays.

Significance/implications:

The study has implications for our understanding of how children pick up indexical meanings of linguistic choices and reproduce them in their imaginative worlds. It also sheds light on how language ideologies and practices reproduced by children may result in hierarchization and power difference between linguistic varieties.
The rise and fall of the Synthetic: The mediatization of Canada's oil sands
Authors: McCurdy Patrick
Published: March 2023

The concept of the Synthetic is developed to trace and trouble the prevailing popular mythology of Alberta's oil sands and place the omnipresence of petro-hegemony into focus in a time of crisis and transition. The Synthetic is theorized as a period of petroculture beginning in the late 1960s with the rise of Alberta's oil sands industry together with a rise in oil sands narratives, docudrama, and the emergence of mediated or synthetic politics reliant upon processed images. Attention focuses on three mediated moments within the Synthetic beginning with the banned 1977 CBC docudrama The Tar Sands and the reaction of Premier Peter Lougheed. This signals the power and grip of oil's hegemony. Second, the short film Synergy produced for Expo 86 captures the thickening of synthetic culture and oil's saturation of the public imagination. Finally, the controversy manufactured by Alberta's Canadian Energy Centre over the animated film Bigfoot Family suggests petro-hegemony's loosening grip.
Challenges in assessing corrosion damage in reinforced concrete beams by vibration-based monitoring: literature analysis and experimental study
Authors: Vandecruys Eline , Vereecken Eline , Anastasopoulos Dimitrios , Verstrynge Els , Caspeele Robby , Reynders Edwin , Lombaert Geert
Published: March 2023

Corrosion is one of the most frequently occurring problems in reinforced concrete (RC) structures. The formation of rust products results in deterioration processes that decrease the durability and structural capacity. Therefore, frequent inspection and monitoring of corrosion damage play a vital role in establishing reliable asset management of civil structures. Vibration-based monitoring (VBM) is particularly useful in studying the global response of a deteriorated structure, since a change in modal characteristics may indicate damage. Although VBM has already been studied thoroughly, a systematic understanding of how corrosion contributes to the changes in modal characteristics is still lacking. In this study, an overview and assessment of the existing literature for dynamic tests on corroded RC beams is provided, aiming to give a critical review of the current knowledge, possibilities and challenges related to this topic. Moreover, this study presents additional data from two test programmes, which enable to point out the challenges in VBM of corroding RC beams. The experimental test programmes include two locally corroded beams and three uniformly corroded beams, as well as non-corroding reference beams. For high corrosion levels, the natural frequencies of beams reported in the literature, as well as the beams of the test programmes, decreased. However, comparison with a non-corroding reference beam proved to be essential to eliminate the influence of other non-negligible factors such as creep and shrinkage. Other modal characteristics, such as the damping ratio and mode shapes, are found to be less sensitive to monitor uniform or local corrosion in RC beams.
Effects of Coupling Agent Concentration and Hygrothermal Ageing on the Fracture Behaviour of Glass Woven Fabric-Reinforced Vinyl Ester Laminates
Authors: Sham Man-Lung , Kim Jang-Kyo , Wu Jingshen
Published: March 2023

The Charpy impact test has been employed to study the fracture toughness and failure mechanisms of E-glass woven fabric reinforced vinyl ester matrix composites with five different types of fibre surface treatment. The results revealed significant dependency of the impact fracture toughness values on silane coupling agents and hygrothermal ageing. Failure mechanisms were characterized using a scanning electron microscope, and correlated with the measured fracture toughness, temperature and water absorption.
Anisotropic Optical Properties of Nylon 6-6 Fibres as a Function of Annealing and Quenching Processes
Authors: Fouda I.M. , Kabeel M.A. , El-Sharkawy F.M.
Published: March 2023

Changes in the structure of nylon 6-6 fibres after annealing and quenching in coarse grained ice at 160°C were studied interferometrically. The Pluta polarising interference microscope has been used to determine the mean refractive indices and mean birefringence of these fibres. The optical orientation function and the molecular structure of the annealed and quenched nylon 6-6 fibres were calculated. The density and the mechanical loss factor of the annealed and quenched fibres were measured by a system based on vibrating strings. The density results were used to calculate the degree of crystallinity. Relationships between the mean refractive indices, birefringence, isotropic refractive index and polarisabilities per unit volume at various times are given for these fibres. The behaviour of fibre density and the mechanical loss factor under different annealing and quenching conditions were discussed with different optical parameters. The results obtained clarify the effect of annealing and quenching conditions on the orientation function, orientation angle and other optical and mechanical parameters. The effect of the annealing conditions on the refractive index profile was studied. Illustrations are given using graphs and microinterferograms.
Penetration of Aromatic Hydrocarbons into Natural Rubber
Authors: Sombatsompop N. , Christodoulou K.J.
Published: March 2023

An investigation of organic solvents penetrating into and out of natural rubber (NR) vulcanisates as a function of time was conducted with respect to degree of swelling and deswelling, diffusion characteristics and mechanical properties. The natural rubber was vulcanised using different techniques to obtain various types of crosslinking; these included flexible and rigid sulphur, peroxide and mixed linkages. Stress-strain measurement was utilised to determine the overall crosslink density and the mechanical properties of the rubber. The degree of swelling and deswelling was conclusively related to the flexibility and mobility of polymer chains, size of the penetrant, temperature, and desulphuration and decomposition reactions of the crosslinks. Before and after equilibrium swelling overall degree of swelling was affected by the penetrant characteristics, whereas during the equilibrium state the degree of swelling was influenced by the types of crosslinks present in the rubber vulcanisates. The reduction in mechanical properties during swelling was due to the conversion of mechanical energy into an activation energy, this being used to achieve the penetration of the solvents into the polymer network. The property recovery after deswelling involved stress relaxation of the polymer network.
Impact Properties and Fracture Mechanism of Epoxy Resin Filled with Irregular-Shaped Alumina Particles
Authors: Yamaguchi Miho , Nakamura Yoshinobu , Iida Takeo
Published: March 2023

The effect of particle size distribution on the impact properties of epoxy resin filled with irregular-shaped alumina particles was studied using an instrumented Charpy impact tester. For this purpose, the alumina particles were prepared by crushing fused α-Al2O3 having a wide size distribution and a mean size of about 10 μm were sorted by air-separation. Particles having narrow size distribution and mean size of about 5 - 7 μm were obtained. The absorbed impact energy by the narrow distribution particle-filled resin was higher than that of the wide distribution particle-filled resin and was almost the same as that of unfilled cured epoxy resin. In general, the impact strength of filled epoxy resins is less than that of unfilled ones. From the result above, controlling the particle-size distribution seems to be one effective technique which improves many mechanical properties without decreasing the impact strength. Observations of the fractured surfaces of specimens were made in order to estimate the mechanism above, using scanning electron microscopy.
Buckling Optimization of Unidirectional Composites with Graded Structures for Weight Reduction
Authors: Kang Tae Jin , Back Sung Ki
Published: March 2023

The buckling optimization of unidirectional square rod composites with a given geometry, subjected to uniaxial compression, has been studied in terms of fibre volume fraction and thickness factor, for discrete structures with fibre volume fraction gradients, using a sequential linear programming method. Graded structures have shown some advantages in the design of composites in terms of weight reduction. They have shown 12–18% reduction in total fibre volume and 8–12% reduction in weight of composites compared to conventional uniform homogeneous structures.
The Effect of Micro-Structure Variations on the Permeability of Preform Materials
Authors: Ranganathan Sridhar , Easterling Robert G. , Advani Suresh G. , Phelan Frederick R.
Published: March 2023

Most efforts at modelling the permeability of preform materials are based on unit cell approaches in which it is assumed that the medium consists of a regular array of structures of uniform size, shape and position. However, the microstructure of real materials almost always has some degree of dimensional fluctuation about a mean. These variations from uniformity have an effect on the overall permeability, which in general cannot be adequately accounted for in model calculations by defining unit cells based on average geometric properties. In this study, a method for incorporating the effect of variations in microstructure into model-based calculations of the permeability of an idealized preform structure is developed. The method is used to model the permeability of a unidirectional material. It is shown that the inherent variation in the material microstructure leads to large deviations in the “local” values of the permeability. These variations are quantified using statistical analysis to obtain an expected value and standard deviation for the permeability. Use of the method leads to a consistent comparison of experimentally measured and numerically computed permeability values.
Compositions Based on Aromatic Block Copolyester and p-Butoxyphenyl Cyclohexyl Phosphinic Acid
Authors: Ozden S. , Shaov A.H. , Charayev A.M. , Bidanikov A.Y.
Published: March 2023

A stabiliser, p-butoxy cyclohexyl phosphinic acid was introduced into two industrial copolyesters, based on bisphenol A and phenolphthalein respectively, and the effects on their mechanical and thermal properties were investigated. The measurements were made immediately following the introduction of the stabiliser. The mechanical properties were sensitive to the amount of stabiliser. Ductility and breaking strength increased with small amounts of stabiliser, while the modulus of elasticity decreased. As the amount of stabiliser increased, the process was reversed. Similarly, thermal stability also increased with small concentrations and decreased at higher concentrations. Heat treatment increased the brittleness and reduced the breaking strength.
Chemical Resistivity of Very Low Density Polyethylene Geomembranes - Sorption/Desorption, Diffusion and Swelling
Authors: Aminabhavi T.M. , Naik H.G.
Published: March 2023

The chemical resistivity testing of very low density polyethylene (VLDPE) geomembranes is important in view of their applications in hazardous waste sites. We present here some useful experimental data on the sorption, desorption, diffusion and swelling of VLDPE with 14 organic liquids at 25, 50 and 70°C. Sorption results were obtained by a gravimetric method, and diffusion coefficients have been calculated using Fick's equation from the initial linear portions of the sorption/desorption curves. Swelling was studied by the measurement of increases in volume, thickness and diameter of the VLDPE geomembrane. The Arrhenius activation parameters have been calculated from the temperature dependence of sorption and diffusion coefficients. Liquid concentration profiles were also calculated from Fick's equation under appropriate initial and boundary conditions. The results of this study may be useful for the application of VLDPE geomembranes in hazardous waste chemical ponds.
Thermorheological and Mechanical Properties of Polysulphone/Poly(ethylene terephthalate) Blends
Authors: Baranov A.O. , Dubnikova I.L. , Kompanietz L.V. , Turusov R.A. , Prut E.V.
Published: March 2023

An experimental investigation of the thermal, rheological and mechanical behaviour of polysulphone (PSF) / poly(ethylene terephthalate) (PET) blends having different blend compositions has been conducted. It was shown that the thermorheological and mechanical properties of the blends are associated with their structure and phase morphology. The observed good agreement between the experimental results and the glass transition temperatures calculated from the Fox equation, and the melting temperatures calculated from the Nishi-Wang equation, indicates a partial compatibility and the formation of homogeneous amorphous areas in PSF/PET blends. It was found that an addition of PET (up to 15 wt.%) to PSF results in a significant decrease in the melt viscosity, and a simultaneous improvement in the mechanical properties of PSF; the Young's modulus values of all the compositions are higher than the corresponding values computed from the proportional additivity rule. Thus, the flow and mechanical characteristics of the PSF/PET systems are governed mainly by the phase structure and morphology of the blends.
Safety and Effectiveness of Carbon Dioxide Contrast Medium in Infra-Inguinal Endovascular Interventions for Patients With Chronic Threatening Lower Limb Ischemia and Renal Impairment: A Multicentric Trial
Authors: Ali Mohamed , Noureldin Mohamed , Kashef Omar El , Zaghlol Hossam
Published: March 2023

Purpose:

To assess the safety and effectiveness of using carbon dioxide (CO2) contrast in both supra- and infra-genicular endovascular interventions in patients with renal impairment.

Material and Methods:

This is a multicentric prospective observational study conducted over a period of 3 years from 2017 to 2020; the study included 114 patients presented with chronic threatening limb ischemia (CTLI) and renal impairment (lowest serum creatinine levels ≥1.3 mg/dL) for whom endovascular procedures were done using CO2 as a contrast medium. Endovascular angiography was guided by CO2 either exclusively (zero contrast) or with the aid of small amount of supplementary iodinated contrast media (ICM) injections. The qualitative assessment of the angiographic images in both supra- and infra-genicular fields were reported and scaled.

Results:

The qualitative diagnostic images were excellent in 86.5% in the supra-genicular and 66.5% in infra-genicular images. There were no significant changes in mean serum creatinine levels from baseline to first and fifth days post procedural (mean 1.8 mg/dL vs mean 1.9 mg/dL and mean 1.7 mg/dL).

Conclusion:

CO2 is a non-nephrotoxic alternative to traditional ICM that could be safely used and well tolerated during endovascular interventions for peripheral arterial disease in patients with renal impairment. Primary safety and efficacy endpoints were achieved in 100% of cases. The use of automated injector system provides adequate delivery, optimizes the dose, and avoids air contamination. For infra-genicular segment opacification, we recommend super-selective injections and some changes in angiographic techniques from contrast preparation to image post-processing.

Clinical Impact

Co2 is a non-nephrotoxic alternative to traditional ICM that could be safely used and well tolerated during peripheral endovascular interventions in patients with renal impairment. The use of automated injector system would provide adequate delivery, optimizes the dose and avoids air contamination. For infra-genicular segment opacification, its recommended to use selective injection as close to the target artery as possible and some changes in angiographic techniques from contrast preparation to image post-processing.
Deep Learning Prediction for Distal Aortic Remodeling After Thoracic Endovascular Aortic Repair in Stanford Type B Aortic Dissection
Authors: Zhou Min , Luo Xiaoyuan , Wang Xia , Xie Tianchen , Wang Yonggang , Shi Zhenyu , Wang Manning , Fu Weiguo
Published: March 2023

Purpose:

This study aimed to develop a deep learning model for predicting distal aortic remodeling after proximal thoracic endovascular aortic repair (TEVAR) in patients with Stanford type B aortic dissection (TBAD) using computed tomography angiography (CTA).

Methods:

A total of 147 patients with acute or subacute TBAD who underwent proximal TEVAR at a single center were retrospectively reviewed. The boundary of aorta was manually segmented, and the point clouds of each aorta were obtained. Prediction of negative aortic remodeling or reintervention was accomplished by a convolutional neural network (CNN) and a point cloud neural network (PC-NN), respectively. The discriminatory value of the established models was mainly evaluated by the area under the receiver operating characteristic curve (AUC) in the test set.

Results:

The mean follow-up time was 34.0 months (range: 12–108 months). During follow-up, a total of 25 (17.0%) patients were identified as having negative aortic remodeling, and 16 (10.9%) patients received reintervention. The AUC (0.876) by PC-NN for predicting negative aortic remodeling was superior to that obtained by CNN (0.612, p=0.034) and similar to the AUC by PC-NN combined with clinical features (0.884, p=0.92). As to reintervention, the AUC by PC-NN was significantly higher than that by CNN (0.805 vs 0.579; p=0.042), and AUCs by PC-NN combined with clinical features and PC-NN alone were comparable (0.836 vs 0.805; p=0.81).

Conclusion:

The CTA-based deep learning algorithms may assist clinicians in automated prediction of distal aortic remodeling after TEVAR for acute or subacute TBAD.

Clinical Impact:

Negative aortic remodeling is the leading cause of late reintervention after proximal thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection (TBAD), and possesses great challenge to endovascular repair. Early recognizing high-risk patients is of supreme importance for optimizing the follow-up interval and therapy strategy. Currently, clinicians predict the prognosis of these patients based on several imaging signs, which is subjective. The computed tomography angiography-based deep learning algorithms may incorporate abundant morphological information of aorta, provide with a definite and objective output value, and finally assist clinicians in automated prediction of distal aortic remodeling after TEVAR for acute or subacute TBAD.
The Legacy of Welsh Botanist Jessie Gwendoline O’Callaghan (née Insole; 1882–1932)
Authors: Statham Michael , Pardoe Heather , Cunningham Vanessa
Published: March 2023

This biographical paper examines the background of collections comprising illustrations of fungi and herbarium specimens attributed to Jessie O’Callaghan, held by the Amgueddfa Cymru—Museum Wales. O’Callaghan was a privileged, wealthy woman born in the Welsh parish of Llandaff, which, in 1922, was incorporated into Cardiff, now Wales’ capital city. Upon her marriage in 1906 she moved to Ireland, but eventually settled in the English county of Surrey. Throughout her life she had an enduring interest in botany, seeking, collecting, painting, and cultivating rare plants. She shared this passion with Eleanor Vachell, the well-regarded Welsh amateur botanist, whom she had known since childhood. Entries in Eleanor’s diaries, and their letters, together with a surviving photograph album, provide fascinating insights into Jessie’s life. The paper also speculates on the fate of O’Callaghan’s collection of 595 watercolour paintings of wild flowers, loaned to the Museum by her daughter in 1932, but later returned to her.