Detailed Categories Research Articles

Residual fatigue lives assessment of riveted lap joints based on a crack growth model

Many riveted joints bear the action of out-of-plane bending moments in steel truss bridges. The fatigue resistance of these joints isn’t stipulated in the current design criteria. Ensuring the safety of structures necessitates analysing the fatigue process of such riveted joints. This paper attempts to evaluate the fatigue life of riveted lap joints from the perspective of engineering applications. The study first found through fatigue tests with two types of fatigue details in riveted lap joints: plate surface cracking and rivet hole edge cracking. Then, the fatigue progression is divided into three stages: the microstructure short crack (MSC) stage, the physical short crack (PSC) stage and the long crack stage. The crack propagation model in the short crack stage is established by combining a scanning electron microscope test of the material and an empirical formula. The crack propagation model of the long crack stage is established by the crack propagation test and considering the crack closure effect. Results show that the fatigue life corresponding to the hole edge crack fatigue detail category is shorter than that to the plate surface crack. In each crack propagation stage, the crack propagation life decreases with increasing load and decreasing load ratio RL. For the two fatigue detail categories, the proportion of the long crack stage to the whole fatigue life is small, and the effect of the crack closure on the overall fatigue life is limited; therefore the effect of the load ratio RL on the fatigue life can be ignored.

O-085 In-depth analysis of embryo development: Differences among monosomic, trisomic and chromosomally chaotic embryos compared to euploid embryos

Abstract Study question Is there any visible variation in the development of aneuploid embryos depending on the type of chromosome abnormality? Summary answer There were significant visible differences in the development of euploid, monosomic, trisomic and, especially, chaotic embryos. What is known already Aneuploidy rates are remarkably high in in vitro fertilized human embryos, with up to 50% of embryos diagnosed as aneuploid based on preimplantation genetic testing for aneuploidies (PGT-A). However, very little is known about the impact of specific aneuploidies during the early human embryo development. A recent publication showed that embryos with single chromosomal gain or loss reached the blastocyst stage later or earlier depending on the chromosome affected (Shahbazi et al., 2020). In our study, we wanted to detect observable differences in embryo behavior between embryos with different chromosomal abnormalities during the entire in vitro development. Study design, size, duration This was a retrospective study including 2,500 blastocysts with PGT-A results. Embryos were cultured in EmbryoScope systems until the fifth/sixth day of development (up to the time of trophectoderm biopsy). Automatic-annotations for division times and quality gradings were supervised routinely by senior embryologists using Guided Annotations Tool. Out of the total, 1,000 were euploid embryos used for reference and 1,500 were aneuploid embryos with one or more defects, including monosomic, trisomic and chromosomally chaotic embryos. Participants/materials, setting, methods Chromosome analysis was performed using next-generation sequence technology. Then, an in-depth analysis of time-lapse videos and supervised-automatic annotations was performed. We calculated the proportion of embryos, in each aneuploid category, that reached one specific event later than the expected value for euploid embryos plus one standard deviation. Later, we calculated the “relative risk” of an embryo of reaching the milestone late. We did the same for the time between milestones and for pairs of milestones. Main results and the role of chance Every aneuploid category was more likely to reach each specific embryo developmental event later than euploid embryos and the time gaps between developmental milestones were also statistically longer in aneuploid embryos (p < 0.0001). The following results were the most interesting relative risks (RR) when we compared the proportion of embryos (in each aneuploid category) to the proportion of euploid embryos (RR for euploid = 1). For reaching the division time to two cells (t2): 1.31 in monosomic embryos, 1.50 in trisomic embryos and 2.43 in chaotic embryos. For the division time to four cells (t4): 1.42 in monosomic embryos, 1.54 in trisomic embryos and 3.07 in chaotic embryos. For the division time to eight cells (t8) and the time of starting blastulation: 1.45 in monosomic embryos, 1.22 in trisomic embryos and 2.74 in chaotic embryos. Combined milestones were stronger indicators than each milestone by itself, the RR were: 1.63 in monosomic embryos, 1.81 in trisomic embryos and 3.35 in chaotic embryos for t2 and t4; 1.50 in monosomic embryos, 1.80 in trisomic embryos and 2.84 in chaotic embryos for t2 and t8; 1.46 in monosomic embryos, 1.90 in trisomic embryos and 3.43 in chaotic embryos for t4 and t8. Limitations, reasons for caution At this stage, we did not go down to specific chromosome abnormality as there were very few cases in each fully detailed category. Also, not all the embryos reached every developmental milestone. Wider implications of the findings Aneuploid embryos were significantly different from euploid embryos in the first five days of development. A large proportion of aneuploid embryos could be rejected because their developmental milestones falling outside the normal range. This could form part of an automated system for determining euploidy/aneuploidy from observation of embryos in vitro. Trial registration number 1902-VLC-018-MM

Individuals, Communities, and Groups in Thomas Kuhn’s Model of Scientific Development

In The Structure of Scientific Revolutions, Thomas Kuhn resorts to concepts from several disciplines in order to describe the general patterns of scientific development. This blend of disciplines can be explained in part by Kuhn's intellectual path, from physics to history and then to philosophy of science; but it also points to a deeper methodological problem, which is the question of what is the real unity of analysis in his model of science. The primary intention of this article is, thus, to give a solution to this difficulty. The answer, I believe, rests on identifying three fundamental units present in Kuhn's theory of scientific development. They are, respectively, the individual, responsible for producing evidence, spreading information, and choosing theories; the community, a set of scientists investigating a series of phenomena; and the groups, individuals with similar behavior but with looser institutional or social ties — a usually neglected category in Kuhnian literature, but equally fundamental for the final outcome of scientific debates. After investigating these categories in detail, I propose a way of integrating them into a general model for explaining the resolution of scientific controversies. Finally, I try to resolve the apparent conflict among disciplinary vocabularies by offering an account of the function of sociological, psychological, and epistemological concepts for describing controversies, and some of the methodologies appropriate for each of these tasks.

Income gradient of pharmaceutical panic buying at the outbreak of the COVID-19 pandemic.

We analyze the timing, magnitude, and income dependence of pharmaceutical panic buying around the outbreak of the COVID‐19 pandemic in Hungary. We use district‐level monthly and daily administrative data on detailed categories of pharmaceutical purchases, merge them to income statistics, and estimate multilevel panel models. Our main results are as follows. First, the days of therapy (DOT) of pharmaceutical purchases increased by more than 30% in March 2020, when major lockdown measures were announced. This pattern holds for almost all categories of pharmaceuticals. Second, shortly after the panic reactions, the aggregate amount of pharmaceutical purchases returned to their preshock levels; however, the frequency of pharmacy visits decreased. Third, the panic buying reaction was significantly stronger in richer geographical areas, where—according to the daily data—people also reacted earlier to the pandemic‐related news. Overall, the results suggest that panic buying of pharmaceuticals can have detrimental effects on vulnerable populations.

Cooking Recipe Annotation Manual for deep and detailed categories

Cooking Recipe Annotation Manual for deep and detailed categories

Cooking Recipe Annotation Manual for deep and detailed categories

Cooking Recipe Annotation Manual for deep and detailed categories

Cooking Recipe Annotation Manual for deep and detailed categories

Cooking Recipe Annotation Manual for deep and detailed categories

Polymer-specific dynamic probabilistic material flow analysis of seven polymers in Europe from 1950 to 2016

Information on the flows of specific polymers through the anthroposphere forms the basis of any assessment of the environmental implications of plastic. This work presents a dynamic probabilistic material flow analysis of seven commodity thermoplastics: low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), expanded polystyrene (EPS), polyvinylchloride (PVC), and polyethylene terephthalate (PET). The analysis examines nine product sectors and 35 product categories, including textiles, across Europe from 1950 to 2016. Total consumption of these seven polymers was 90.0 ± 4.8 kg/cap in 2016. The in-use stock that year was 47 kg/cap for LDPE, 81 kg/cap for HDPE, 81 kg/cap for PP, 21 kg/cap for PS, 56 kg/cap for EPS, 163 kg/cap for PVC, and 16 kg/cap for PET. For EPS and PVC, the fraction contained in the in-use stock is 51% and 39% of the total production. Landfill is the major compartment where LDPE, HDPE, PP, PS, and PET end up (48%–60%). Elimination—incineration and destruction in waste incineration plants—occurs for 15%–19% of LDPE, HDPE, PP, PS, and PET, and 10% of EPS and PVC. Current European recycling rates vary from 11% for PS to 33% for PET. The precise separation of different polymers into very detailed product categories will allow the formulation of future scenarios about interventions to improve the circularity of specific polymers and provide the basis to assess the polymer-specific releases to the environment.

Educational attainment and psychological distress among working-age adults in the United States

This study builds on a growing body of literature analyzing the education-health gradient across detailed educational categories, which documents that US working-age adults who attended college but did not earn a bachelor's degree report equal or worse health than adults with a high school diploma. This is known as the “anomaly” in the education-health gradient. The purpose of this study is to test whether this pattern extends to measures of serious psychological distress (SPD) and individual symptoms by using data from the National Health Interview Survey (NHIS, 1997–2018) and a series of logistic regression models. We find that the anomaly in the education-health gradient is present for a summary measure of SPD as well as for five of the six symptoms that make up this measure. The exception was reporting feeling sad most or all the time during the last month, where adults with “some college” were found to have lower odds than those with a high school diploma. Further stratified analysis by sex revealed that this result for feeling sad was driven by women. In terms of associate degrees, our models show that adults with a vocational/technical associate degree have statically similar odds of SPD and reporting four out of six symptoms (exceptions were feeling hopeless and sadness), while those with an academic associate degree have significantly lower odds in all outcomes. The robustness of the models used is supported by an extensive sensitivity analysis. Overall, we find evidence of the anomaly in the education-health gradient in SPD and individual symptoms of psychological distress at the sub-baccalaureate level, adding to previous studies that document the anomaly in markers of physiological dysregulation, health conditions, vision problems, functional limitations, and pain.

Research on the application of GIS technology in the preparation of village planning--Take Feng Sheng Village as an example

Hubei Province is gradually carrying out the preparation of five levels and three types of territorial spatial planning, to scientifically layout construction space, agricultural space and ecological space, and strengthen the guiding and constraining role of territorial spatial planning for all planning. At the same time, in order to promote the construction of beautiful countryside and rural revitalization, the preparation of village planning in Hubei Province is also in progress; according to the five levels and three categories of territorial spatial planning, village planning belongs to the township-level detailed planning category, and the conventional village planning can no longer meet the requirements of territorial spatial planning, so the ecological space, agricultural space and construction space in village planning should be adjusted and whitened with the help of GIS technology. Therefore, the GIS technology should be used for landuse adjustment, white space delineation, spatial control and comprehensive improvement of the national land space.

Integrated Mapping of Spatial Urban Dynamics—A European-Chinese Exploration. Part 1—Methodology for Automatic Land Cover Classification Tailored towards Spatial Allocation of Ecosystem Services Features

Urbanisation processes inherently influence land cover (LC) and have dramatic impacts on the amount, distribution and quality of vegetation cover. The latter are the source of ecosystem services (ES) on which humans depend. However, the temporal and thematical dimensions are not documented in a comparable manner across Europe and China. Three cities in China and three cities in Europe were selected as case study areas to gain a picture of spatial urban dynamics at intercontinental scale. First, we analysed available global and continental thematic LC products as a data pool for sample selection and referencing our own mapping model. With the help of the Google Earth Engine (GEE) platform and earth observation data, an automatic LC mapping method tailored for more detailed ES features was proposed. To do so, differentiated LC categories were quantified. In order to obtain a balance between efficiency and high classification accuracy, we developed an optimal classification model by evaluating the importance of a large number of spectral, texture-based indices and topographical information. The overall classification accuracies range between 73% and 95% for different time slots and cities. To capture ES related LC categories in great detail, deciduous and coniferous forests, cropland, grassland and bare land were effectively identified. To understand inner urban options for potential new ES, dense and dispersed built-up areas were differentiated with good results. In addition, this study focuses on the differences in the characteristics of urban expansion witnessed in China and Europe. Our results reveal that urbanisation has been more intense in the three Chinese cities than in the three European cities, with an 84% increase in the entire built-up area over the last two decades. However, our results also show the results of China’s ecological restoration policies, with a total of 963 km2 of new green and blue LC created in the last two decades. We proved that our automatic mapping can be effectively applied to future studies, and the monitoring results will be useful for consecutive ES analyses aimed at achieving more environmentally friendly cities.

From land cover to land use: Applying random forest classifier to Landsat imagery for urban land-use change mapping

The extensive record of Landsat imagery is commonly used to map urban land-cover and land-use change. Random forest (RF) classification was applied for mapping more detailed urban land-use and change categories than is typically attempted with Landsat data. Two dates of Landsat imagery (1990 and 2015) were utilized with surface reflectance, Vegetation-Impervious-Soil (V-I-S) fractions, grey-level cooccurrence matrix (GLCM) of V-I-S, and temporal variation of V-I-S inputs. GLCM V-I-S and temporal variation of Vegetation as input features of RF classifiers slightly improved accuracies of land use maps. A change map derived from an overlay analysis between the 2015 map and a Landsat-derived urban expansion map was more accurate than one from post-classification comparison of 1990 and 2015 maps. For the Taiwan study area, Transportation Corridor land use tended to lead conversion to Residential and Employment types in relatively undeveloped districts, and extensive urban land-use change occurred in peri-urban areas.

Chiming In: A Computer-Assisted Analysis of Popular Musicians’ Political Engagement on Twitter

While music as an artistic form is well studied, the individuals behind the art receive relatively less attention. In this article, we provide evidence of celebrity advocacy with a systematic examination of musicians’ political engagement on Twitter. This study estimates the extent to which musicians use Twitter for political purposes, with particular attention to whether such engagement varies across music genres. Through a computational-assisted analysis of 2,286,434 tweets, we group 881 musicians into three categories of political engagement on Twitter: not engaged (comprising the majority of artists), circumstantial engagement, and active political engagement. We examine the latter categories in detail with two qualitative case studies. The findings indicate that musicians from different genres have distinct patterns of political engagement. The Christian music genre shows the most engagement as a whole, especially in philanthropy. On the contrary, the most active accounts are rock and hip-hop artists, some of whom discuss political issues and call for mobilization. We conclude with suggestions for future research.

High Entropy Alloy Coatings and Technology

Recently, the materials research community has seen a great increase in the development of multicomponent alloys, known as high entropy alloys (HEAs) with extraordinary properties and applications. In surface protection and engineering, diverse applications of HEAs are also being counted to benefit from their attractive performances in various environments. Thermally sprayed HEA coatings have outperformed conventional coating materials and have accelerated further advancement in this field. Therefore, this review article overviews the initial developments and outcomes in the field of HEA coatings. The authors have also categorized these HEA coatings in metallic, ceramic, and composite HEA coatings and discussed various developments in each of the categories in detail. Various fabrication strategies, properties, and important applications of these HEAs are highlighted. Further, various issues and future possibilities in this area for coatings development are recommended.

Fatigue experimental characterization of preloaded injection bolts in a metallic bridge strengthening scenario

All over the world, the number of civil engineering structures, particularly bridges with long service periods, has been increasing. The most common evidences of damages are the presence of corroded metallic elements and cracks in structural details due to the fatigue phenomenon. A large number of cases were found in which fatigue cracks were detected in structural details, such as riveted connections. Different strategies can be implemented for repairing and strengthening operations of old metallic riveted bridges. However, the use of injection bolts has been considered as an alternative with important advantages. In this regard, it is essential to study their performance under fatigue loading. In this investigation, an experimental campaign has been performed to assess the fatigue strength of injection bolts by means of comparison with standard bolts. These fatigue tests are defined to be representative of a structural strengthening scenario of an old metallic bridge. Experimental results show that injection bolts contribute to significantly reduce the scatter in the data related to fatigue resistance. For double shear specimens, the characteristic curve proposed for connections with injection bolts presents a detail category with 15% higher value when compared to non-injected specimens. The beneficial effect is also verified in terms of slip deformation. For single shear specimens, the overall effect of the adhesive is not clear.

Reassessment of fatigue detail categories of bolts and rods according to EC 3-1-9

The paper deals with the reassessment of fatigue detail categories of bolts and rods in EC 3-1-9 based on published fatigue test data and further conducted investigations. An elaborate database structure has been set up to evaluate the available fatigue test data in a differentiated way. Detail categories of bolts and rods in tension and shear have been investigated and re-evaluated based on the developed data base. Moreover, fatigue tests and numerical investigations on prestressed bolts in T-joints, L-joints and different types of end plate connections have been performed. Several influences on the fatigue strength (e.g. material influence, size effect, fabrication differences) have been analysed and design recommendations are given. The conducted fatigue tests on bolts in tension fit into the spreading band of 573 tests results conducted in the past, confirming fatigue class 50. However, bolts with rolled threads show a higher fatigue strength than those with cut threads, which has been included into the recommendations for fatigue details of bolts. Fatigue class 100 for bolts in shear has also been confirmed, however based on few data. Numerical investigations show, that bolts should be placed as close as possible to the tension flanges, while end plates should be dimensioned thick enough with an overhang including an additional bolt row.

Incidence of cardiovascular disease and mortality in underweight individuals.

BackgroundFew studies have evaluated the association between being underweight and having cardiovascular disease in the general population. We investigated the incidence of stroke, myocardial infarction (MI), and all‐cause mortality according to detailed underweight categories in a large population cohort.MethodsWe included 4 164 364 individuals who underwent a health examination that was conducted as part of the Korean National Health Insurance Service between January 2009 and December 2012 and followed them up to determine the incidence of stroke, MI, and all‐cause mortality until 31 December 2016. Based on the body mass index, the study population was categorized into normal (18.50–22.99), mild (17.00–18.49), moderate (16.00–16.99), and severe underweight (<16.00) groups. Cox proportional hazards analyses were performed to calculate the hazard ratio for stroke, MI, and mortality according to the severity of underweight in reference to the normal weight. We adjusted for age, sex, lifestyle, economic status, co‐morbidity, blood pressure, glucose, lipid level, and waist circumference.ResultsThe mean age of the 4 164 364 eligible subjects in this study cohort was 44.4 ± 14.3 years, and 46.1% of the participants were male; 46 728 strokes, 30 074 MIs, and 121 080 deaths occurred during 27 449 902 person‐years. The incidence of stroke, MI, and all‐cause mortality increased proportionally with the severity of underweight in the multivariate model. This proportional association became more evident when the waist circumference was additionally adjusted. The respective hazard ratios (95% confidence intervals) for mild, moderate, and severe underweight were 1.10 (1.06–1.15), 1.11 (1.02–1.20), and 1.38 (1.24–1.53) for stroke; 1.19 (1.14–1.25), 1.40 (1.27–1.53), and 1.86 (1.64–2.11) for MI; and 1.63 (1.60–1.67), 2.10 (2.02–2.17), and 2.98 (2.85–3.11) for all‐cause mortality. In stratified analyses based on waist circumference, the severity of underweight was consistently associated with a higher risk of stroke, MI, and death.ConclusionsThe severity of underweight was associated with a higher risk of stroke, MI, and all‐cause mortality.

Cyber Attacks in Transactive Energy Market-Based Microgrid Systems

Due to the increasing integration of distributed energy generation in the electric grid, transactive energy markets (TEMs) have recently emerged to balance the demand and supply dynamically across the grid. TEM enables peer to peer (P2P) energy trading and brings flexibility by reducing users’ demand in the grid. It also enhances the system’s efficiency and reduces the pressure on electricity networks. However, it is vulnerable to major cyber attacks as users equipped with smart devices are participating autonomously in the energy market, and an extensive amount of information is exchanged through the communication channel. The potential attacks and impacts of those attacks need to be investigated to develop an attack resilient TEM-based power system. Hence, in this paper, our goal is to systematically identify possible cyber attacks associated with a TEM-based power system. In order to achieve this goal, we classify the attacks during the P2P and flexibility schemes of TEM into three main categories. Then, we explore the attacks under each category in detail. We further distinguish the adversary roles of each particular attack and see what benefits will be received by an adversary through each specific attack. Finally, we present the impact of the attacks on the market operation, consumers, and prosumers of the TEM in this paper.

Revision of fatigue detail categories of plain members and mechanically fastened joints according to EC3-1-9

The present paper deals with the reassessment of fatigue detail categories of plain members and mechanically fastened joints (Table 8.1 in EC3-1-9) based on published fatigue test data. For a differentiated re-evaluation of details an elaborate database structure has been set up. Detail categories of different types of plain members and mechanically fastened joints have been investigated and revised by evaluating the collected fatigue data. Finally, several influences on the fatigue strength of the revised details have been analysed and design recommendations are given. For shear or gas cut plates, higher fatigue classes have been determined. In case of sheared or gas cut plates with subsequent dressing and double covered preloaded joints, higher inverse slopes of the S-N curves as currently incorporated in EC3-1-9 prove to be more realistic. A dependence of fatigue strength on stress ratio and yield strength as well as fabrication properties have been shown. For double covered preloaded joints, a dependence of fatigue strength on yield strength is significant and it is therefore recommended to include a higher fatigue class for higher strengths into the detail catalogue.

Episodic Autobiographical Memory in Adults With Autism Spectrum Disorder: An Exploration With the Autobiographical Interview.

Introduction: The literature has provided contradictory results regarding the status of episodic memory in autism spectrum disorder (ASD). This might be explained by methodological differences across studies. In the present one, the well-recommended Autobiographical Interview was used in which important aspects of episodic memory were assessed, namely, the number and richness of phenomenological memory details, before and after a retrieval support.Method: Twenty-five well-documented adults with ASD without Intellectual Disability (nine women) and 25 control participants were included and asked to recall six specific autobiographical events. The number and richness of details were assessed globally and for five categories of details (perceptual/sensory, temporal, contextual, emotional, and cognitive), firstly before and then after a specific cueing phase consisting in a series of specific questions to elicit more precise memory details.Results: Cumulatively, from the spontaneous recall to the cueing phase, the number of internal details was lower in ASD individuals compared to controls, but this difference was relevant only after the specific cueing procedure and observed only for contextual details. In contrast, no relevant group difference was observed during spontaneous recall. The detail richness was not impaired in ASD throughout the Autobiographical Interview procedure.Conclusion: Our results speak against a clear impairment of episodicity of autobiographical memory in ASD individuals. They thus challenge previous ones showing both a reduced specificity and episodicity of autobiographical memory in this population and call for further studies to get a better understanding on the status of episodic autobiographical memory in ASD.