bluuebunny/crossref_metadata_2025 huggingface dataset:
Integration of MsrB1 and MsrB2 in the Redox Network during the Development of Orthodox and Recalcitrant Acer Seeds
Authors: Stolarska Ewelina , Bilska Karolina , Wojciechowska Natalia , Bagniewska-Zadworna Agnieszka , Rey Pascal , Kalemba Ewa M.
Published: December 2020

Two related tree species, Norway maple (Acer platanoides L.) and sycamore (Acer pseudoplatanus L.), produce desiccation-tolerant (orthodox) and desiccation-sensitive (recalcitrant) seeds, respectively. We compared the seeds of these two species to characterize the developmentally driven changes in the levels of peptide-bound methionine sulfoxide (MetO) and the abundance of methionine sulfoxide reductases (Msrs) B1 and B2, with respect to the cellular redox environment. Protein oxidation at the Met level was dynamic only in Norway maple seeds, and the reduced MsrB2 form was detected only in this species. Cell redox status, characterized by the levels of reduced and oxidized ascorbate, glutathione, and nicotinamide adenine dinucleotide (NAD)/phosphate (NADP), was clearly more reduced in the Norway maple seeds than in the sycamore seeds. Clear correlations between MetO levels, changes in water content and redox status were reported in orthodox Acer seeds. The abundance of Msrs was correlated in both species with redox determinants, mainly ascorbate and glutathione. Our data suggest that MsrB2 is associated with the acquisition of desiccation tolerance and that ascorbate might be involved in the redox pathway enabling the regeneration of Msr via intermediates that are not known yet.
Mitochondrial Abnormalities in Induced Pluripotent Stem Cells-Derived Motor Neurons from Patients with Riboflavin Transporter Deficiency
Authors: Colasuonno Fiorella , Bertini Enrico , Tartaglia Marco , Compagnucci Claudia , Moreno Sandra
Published: December 2020

Riboflavin transporter deficiency (RTD) is a childhood-onset neurodegenerative disorder characterized by sensorineural deafness and motor neuron degeneration. Since riboflavin plays key functions in biological oxidation-reduction reactions, energy metabolism pathways involving flavoproteins are affected in RTD. We recently generated induced pluripotent stem cell (iPSC) lines from affected individuals as an in vitro model of the disease and documented mitochondrial impairment in these cells, dramatically impacting cell redox status. This work extends our study to motor neurons (MNs), i.e., the cell type most affected in patients with RTD. Altered intracellular distribution of mitochondria was detected by confocal microscopic analysis (following immunofluorescence for superoxide dismutase 2 (SOD2), as a dual mitochondrial and antioxidant marker), and βIII-Tubulin, as a neuronal marker. We demonstrate significantly lower SOD2 levels in RTD MNs, as compared to their healthy counterparts. Mitochondrial ultrastructural abnormalities were also assessed by focused ion beam/scanning electron microscopy. Moreover, we investigated the effects of combination treatment using riboflavin and N-acetylcysteine, which is a widely employed antioxidant. Overall, our findings further support the potential of patient-specific RTD models and provide evidence of mitochondrial alterations in RTD-related iPSC-derived MNs—emphasizing oxidative stress involvement in this rare disease. We also provide new clues for possible therapeutic strategies aimed at correcting mitochondrial defects, based on the use of antioxidants.
NURR1 Alterations in Perinatal Stress: A First Step towards Late-Onset Diseases? A Narrative Review
Authors: Bordoni Laura , Petracci Irene , Calleja-Agius Jean , Lalor Joan G. , Gabbianelli Rosita
Published: December 2020

Perinatal life represents a delicate phase of development where stimuli of all sorts, coming to or from the mother, can influence the programming of the future baby’s health. These stimuli may have consequences that persist throughout adulthood. Nuclear receptor related 1 protein (NURR1), a transcription factor with a critical role in the development of the dopaminergic neurons in the midbrain, mediates the response to stressful environmental stimuli in the perinatal period. During pregnancy, low-grade inflammation triggered by maternal obesity, hyperinsulinemia or vaginal infections alters NURR1 expression in human gestational tissues. A similar scenario is triggered by exposure to neurotoxic compounds, which are associated with NURR1 epigenetic deregulation in the offspring, with potential intergenerational effects. Since these alterations have been associated with an increased risk of developing late-onset diseases in children, NURR1, alone, or in combination with other molecular markers, has been proposed as a new prognostic tool and a potential therapeutic target for several pathological conditions. This narrative review describes perinatal stress associated with NURR1 gene deregulation, which is proposed here as a mediator of late-onset consequences of early life events.
Switching between the Forest and the Trees: The Contribution of Global to Local Switching to Spatial Constructional Abilities in Typically Developing Children
Authors: Zappullo Isa , Trojano Luigi , Cecere Roberta , Raimo Gennaro , Positano Monica , Conson Massimiliano
Published: December 2020

Background: Spatial analysis encompasses the ability to perceive the visual world by arranging the local elements (“the trees”) into a coherent global configuration (“the forest”). During childhood, this ability gradually switches from a local to a global precedence, which contributes to changes in children’s spatial construction abilities, such as drawing or building blocks. At present, it is not clear whether enhanced global or local processing or, alternatively, whether switching between these two levels best accounts for children’s spatial constructional abilities. Methods: We assessed typically developing children 7 to 8 years old on a global/local switching task and on two widely used spatial construction tasks (the Rey–Osterrieth Complex Figure and the Block Design test). Results: The ability to switch from global to local level, rather than a global or a local advantage, best accounted for children’s performance on both spatial construction tasks. Conclusions: The present findings contribute to elucidate the relationship between visual perception and spatial construction in children showing that the ease with which children switch perception from global to local processing is an important factor in their performance on tasks requiring complex drawing and block assembling.
Influence of Cavitation and Mixing Conditions on Oil Droplet Size in Simultaneous Homogenization and Mixing (SHM)
Authors: Gall Vanessa , Karbstein Heike P.
Published: December 2020

High-pressure homogenizers (HPH) equipped with a Simultaneous Homogenization and Mixing (SHM) orifice allow for inducing a mixing stream directly into the disruption unit. Previous studies show that by doing so, synergies between the unit operations “emulsification” and “mixing” can be used to save energy, e.g., in homogenization of dairy products, or to extend the application range of HPH. Up to now, process design has mainly been based on the trial and error principle due to incomplete understanding of flow conditions and droplet break-up in the SHM unit. This study aims at a higher level of understanding of cavitation and mixing effects on emulsion droplet size. Experimental data were obtained using a model emulsion of low disperse phase concentration in order to avoid coalescence effects. The different flow conditions are created by varying the process and geometric parameters of an SHM unit. The results show that the oil droplet size only depends on mixing conditions when the emulsion droplets are added in the mixing stream. Furthermore, a smaller oil droplet size can be achieved by reducing cavitation, especially for droplets fed in the high-pressure stream.
Development and Applications of Transition Metal or Rare Earth-Based Luminescent Inorganic Materials
Authors: Cavalli Enrico
Published: December 2020

This Special Issue is dedicated to luminescent inorganic materials, an extremely vast topic that often and willingly crosses over into other important fields of chemistry and physics [...]
Aerodynamic and Structural Design of a 2022 Formula One Front Wing Assembly
Authors: Castro Xabier , Rana Zeeshan A.
Published: December 2020

The aerodynamic loads generated in a wing are critical in its structural design. When multi-element wings with wingtip devices are selected, it is essential to identify and to quantify their structural behaviour to avoid undesirable deformations which degrade the aerodynamic performance. This research investigates these questions using numerical methods (Computational Fluid Dynamics and Finite Elements Analysis), employing exhaustive validation methods to ensure the accuracy of the results and to assess their uncertainty. Firstly, a thorough investigation of four baseline configurations is carried out, employing Reynolds Averaged Navier–Stokes equations and the k-ω SST (Shear Stress Transport) turbulence model to analyse and quantify the most important aerodynamic and structural parameters. Several structural configurations are analysed, including different materials (metal alloys and two designed fibre-reinforced composites). A 2022 front wing is designed based on a bidimensional three-element wing adapted to the 2022 FIA Formula One regulations and its structural components are selected based on a sensitivity analysis of the previous results. The outcome is a high-rigidity-weight wing which satisfies the technical regulations and lies under the maximum deformation established before the analysis. Additionally, the superposition principle is proven to be an excellent method to carry out high-performance structural designs.
Measuring Centimeter-Scale Sand Ripples Using Multibeam Echosounder Backscatter Data from the Brown Bank Area of the Dutch Continental Shelf
Authors: Koop Leo , van der Reijden Karin J. , Mestdagh Sebastiaan , Ysebaert Tom , Govers Laura L. , Olff Han , Herman Peter M. J. , Snellen Mirjam , Simons Dick G.
Published: December 2020

Backscatter data from multibeam echosounders are commonly used to classify seafloor sediment composition. Previously, it was found that the survey azimuth affects backscatter when small organized seafloor structures, such as sand ripples, are present. These sand ripples are too small to be detected in the multibeam bathymetry. Here, we show that such azimuth effects are time dependent and are useful to examine the orientation of sand ripples in relation to the flow direction of the tide. To this end, multibeam echosounder data at four different frequencies were gathered from the area of the Brown Bank in the North Sea. The acoustic results were compared to video and tide-flow data for validation. The sand ripples affected the backscatter at all frequencies, but for the lowest frequencies the effect was spread over more beam angles. Using the acoustic data made it possible to deduce the orientations of the sand ripples over areas of multiple square kilometers. We found that the top centimeter(s) of the seafloor undergoes a complete transformation every six hours, as the orientation of the sand ripples changes with the changing tide. Our methodology allows for morphology change detection at larger scales and higher resolutions than previously achieved.
The Association between Community Water Fluoridation and Bone Diseases: A Natural Experiment in Cheongju, Korea
Authors: Lee Naae , Kang Sungchan , Lee Woojoo , Hwang Seung-sik
Published: December 2020

The present study aimed to investigate the association between bone diseases and community water fluoridation (CWF). An ecological study with a natural experiment design was conducted in Cheongju, South Korea, from 1 January 2004 to 31 December 2013. The community water fluoridation program was implemented in Cheongju and divided into CWF and non-CWF areas. To observe adverse health effects related to bone diseases, we conducted a spatio-temporal analysis of the prevalence of hip fracture, osteoporosis, and bone cancer in residents who have lived in CWF and non-CWF areas using National Health Insurance Service data. First, we used standardized incidence ratios to estimate the disease risk. Second, the hierarchical Bayesian Poisson spatio-temporal regression model was used to investigate the association between the selected bone diseases and CWF considering space and time interaction. The method for Bayesian estimation was based on the R-integrated nested Laplace approximation (INLA). Comparing the CWF area with the non-CWF area, there was no clear evidence that exposure to CWF increased health risks at the town level in Cheongju since CWF was terminated after 2004. The posterior relative risks (RR) of hip fracture was 0.95 (95% confidence intervals 0.87, 1.05) and osteoporosis was 0.94 (0.87, 1.02). The RR in bone cancer was a little high because the sample size very small compared to the other bone diseases (RR = 1.20 (0.89, 1.61)). The relative risk of selected bone diseases (hip fractures, osteoporosis, and bone cancer) increased over time but did not increase in the CWF area compared to non-CWF areas. CWF has been used to reduce dental caries in all population groups and is known for its cost-effectiveness. These findings suggest that CWF is not associated with adverse health risks related to bone diseases. This study provides scientific evidence based on a natural experiment design. It is necessary to continue research on the well-designed epidemiological studies and develop public health prevention programs to help in make suitable polices.
Mandatory Physical Education Classes of Two Hours per Week Can Be Comparable to Losing More than Five Kilograms for Chinese College Students
Authors: Bao Dawei , Xiao Zixiang , Zhang Yuanyuan , Chen Gang , Miao Xinyu , Wang Bo , Li Jing , Xu Chi , Teng Shuqing N.
Published: December 2020

Despite releases of governmental guidelines for promoting physical fitness among the youth in China, the performance of college students in fitness tests has been declining over the past three decades. Obesity and physical inactivity have been proposed as two main causes. However, their relative importance for improving physical fitness remains unclear. To address this knowledge gap, we collected longitudinal data spanning four consecutive years on the physical fitness test for students from Nanjing University, China. Physical education classes of two hours per week were mandatory for the first two years. Using mixed effects models, we quantify the within-subject effects of weight, muscular endurance, sex, and mandatory physical education courses, among other variables, on physical fitness total score. We found that, in spite of the dominance of normal weight among the students, losing weight was positively associated with the total score, with significant sex differences in the associations. Compulsory exercise provided by physical education classes per week had strong positive impacts on the total score, comparable to losing weight of roughly 15–17 kg for males and 5–10 kg for females. Half sex difference in the total score was explained by male students’ poor performance in the muscular endurance represented by pull-ups. Our results suggest that college students in China should engage in physical activity of higher levels to improve their physical fitness, with a heightened awareness of extra fat under normal weight and insufficient muscular endurance.
Prevalence of Depression, Anxiety, and Stress among the General Population in Saudi Arabia during Covid-19 Pandemic
Authors: Alamri Hasan Saeed , Algarni Abdullah , Shehata Shehata F. , Al Bshabshe Ali , Alshehri Nada N. , ALAsiri Abdalla M. , Hussain Amjad H. , Alalmay Abdulrahman Y. , Alshehri Eman A. , Alqarni Yahya , Saleh Norah F.
Published: December 2020

Coronavirus disease 2019 (COVID-19) pandemic has had a significant impact on public mental health. Our objective was to assess prevalence of depression, anxiety, and stress among the general population in Saudi Arabia during this pandemic. A descriptive cross-sectional approach was used targeting all accessible populations in Saudi Arabia. Data were collected from participants using an electronic pre-structured questionnaire. Psychological impact was assessed using the Arabic version of Depression, Anxiety, and Stress Scale (DASS-21). A total of 1597 participants completed the survey. In total, 17.1% reported moderate to severe depressive symptoms; 10% reported moderate to severe anxiety symptoms; and 12% reported moderate to severe stress levels. Depression, anxiety, and stress were significantly higher among females, younger respondents, and health care providers. Depression was higher among smokers, singles, and non-working respondents. Anxiety was higher among those reporting contacts with COVID-19 positive cases, previously quarantined and those with chronic health problems. Our findings reaffirm the importance of providing appropriate knowledge and specialized interventions to promote the mental well-being of the Saudi population, paying particular attention to high-risk groups.
Effect of Inter-Observer Variation on the Association between Contamination Hazards and the Microbiological Quality of Water Sources: A Longitudinal Study
Authors: Okotto-Okotto Joseph , Trajano Gomes da Silva Diogo , Kwoba Emmah , Thumbi Samuel.M , Wanza Peggy , Yu Weiyu , Wright Jim A.
Published: December 2020

Sanitary risk inspection protocols are often used to identify contamination hazards at water sources; however, different observers sometimes struggle to record hazards consistently. This study aimed to assess the effect of inter-observer variation in hazard observations on the strength of relationships between observed hazards and the bacterial contamination of water sources, particularly relationships with animal-related hazards. In a longitudinal study, five surveyors independently recorded hazards at 93 water sources used by 234 households in Siaya County, Kenya, in both wet and dry seasons. One surveyor collected samples from sources for subsequent Escherichia coli and intestinal enterococci testing. The relationship between each surveyor’s hazard observations and high bacterial contamination was examined using logistic regression. After controlling for water source type and preceding rainfall; percentage scores for animal-related hazards were significantly related to high contamination with enterococci and E. coli for one surveyor (odds ratio 1.02; 95% confidence intervals 1.00–1.03 for both parameters), but not for the remaining four surveyors. The relationship between observed contamination hazards and the microbiological contamination of water sources is sensitive to variation in hazard recording between surveyors. Sanitary risk protocols should be designed to enable robust and consistent observation of hazards.
How High-Polluting Firms Suffer from Being Distracted form Intended Purpose: A Corporate Social Responsibility Perspective
Authors: Zhao Xue-Zhou , Chen Jun , Chen Feng-Wen , Wang Wei , Xia Senmao
Published: December 2020

High-polluting industries are regarded as the main sources of air pollutant emissions and the major factors that significantly destroy the ecological environment. Corporate innovation in high-polluting industries improves the energy consumption efficiency and reduces the emission of air pollutant, which mitigates the conflict between environment and economy. Using the sample of China’s listed firms from 2010 to 2017, this study examines the impact of corporate social responsibility (CSR) and financialization on corporate innovation in high-polluting industries. The results show that there is a positive association between CSR and corporate innovation, while there is a negative association between financialization and corporate innovation. Furthermore, the financialization of high-polluting firms can alleviate the promotion role of CSR in the innovation process. The financialization of state-owned enterprises in high-polluting industries may not have a crowding-out effect on research and development (R&D), but it can limit the R&D promotion effect of CSR engagements. In contrast, the financialization of non-state-owned enterprises will hinder corporate innovation, but it will not affect the association between CSR and technology innovation. We also find that the financialization of high-polluting firms with low financial constraints can alleviate the promotion role of CSR engagements in innovation. Meanwhile, the CSR engagements of high-polluting firms with high financial constraints play a stronger role in corporate innovation. During the implementation of environmental policies, the negative association between financialization and corporate innovation has been strengthened. Our findings can encourage high-polluting firms to make more efforts in environmental protection and social stability.
Shared Situational Awareness in a Professional Soccer Team: An Explorative Analysis of Post-Performance Interviews
Authors: Schei Gaute S. , Giske Rune
Published: December 2020

Sport science research has done little to elaborate on the cognitive factors that turn a collection of individual players into a coordinated elite team. The purpose of this paper is to clarify if the players and coach of an elite soccer team express shared situational awareness. Ten players and one coach were exposed to twelve video pictures from a previous soccer match, and their statements for each picture were recorded and analyzed using a qualitative approach. Two of five game situations were with ball possession and three out of seven were without ball possession; the player statements are contradictory, with a high threat for inadequate coordination. In seven of the twelve game situations, the players’ statements coincided and expressed a shared situational awareness, with good opportunities for adequate defensive and offensive coordination. In two of the game situations, there was a high threat for inadequate coordination. There was consensus among 9 out of 10 players, but the player with the divergent statement was central in the situation. The procedure followed in the study could be used to elucidate if a team has shared situational awareness and clarify in which situations there exists discrepancies and data that can be used to improve team coordination on and off the field.
Evaluation of Distress and Risk Perception Associated with COVID-19 in Vulnerable Groups
Authors: Orte Carmen , Sánchez-Prieto Lidia , Domínguez David Caldevilla , Barrientos-Báez Almudena
Published: December 2020

Preventive behavior developed by the population is essential in the face of the risk of coronavirus infection (COVID-19). However, preventive measures will depend on the risk perception acquired. In addition, lockdown can directly affect mental health, provoking distress. Distress could affect risk perception. This study’s objective was to analyze whether experiencing distress had an influence on risk perception with respect to vulnerable groups. The sample consisted of 806 participants. The study was conducted during the first week of lockdown declared by the Spanish Government. The Brief Symptom Inventory BSI-18 and a risk perception questionnaire about vulnerable groups was administered. The study revealed the appearance of distress in 9.6% of the sample (85.7% women). Experiencing distress influenced risk perception. This study’s main contribution is the link between experiencing distress and the risk perception with respect to vulnerable groups. Risk perception is relevant since it can influence how the population faces the pandemic. Transmission of accurate information could help to minimize the effect of certain cognitive biases that affect risk perception and foster preventive behavior.
Issue of Accumulation and Redistribution of Oil and Gas Rental Income in the Context of Exhaustible Natural Resources in Arctic Zone of Russian Federation
Authors: Kirsanova Natalia , Lenkovets Olga , Hafeez Muhammad
Published: December 2020

The significant resource potential of the Arctic has attracted the attention of its adjacent countries and extra-regional states. The mineral and raw material base of the Arctic Zone of the Russian Federation (AZRF) comprises a wide range of minerals. However, due to its hydrocarbon reserves, the Arctic is considered to be the most important geopolitical and geo-economic macro-region for Russia. A significant portion of the Arctic hydrocarbons (about 19%) is concentrated in the territory of Russia’s shelf. The extraction of Arctic marine oil and gas resources and ensuring the sustainability of the Russian energy complex depend significantly on the level of Arctic development. Thus, the pace and quality of the development of AZRF are strategically important to ensure the national interests of the country. It has been proven that the implementation of the state program for AZRF development and strategic plans of the largest companies operating in the region consolidate the raw material nature of AZRF development. Rent becomes the main form of income. This article addresses the main directions of the region’s development and the factors that prevent a high level of industrialization, which increase attention to the withdrawal and redistribution of rental income. The article considers the Russian and foreign experiences of withdrawal and redistribution of oil and gas rental income, and analyzes the level of socio-economic development of AZRF. The authors suggest a methodology for assessing the impact of a country’s area and population size on the ability to achieve a high income due to hydrocarbons. The authors also explain the principles of rental income redistribution in the region as a basis for improving the level of AZRF’s socio-economic development and as a condition for transition from the “colonial model” of development to the “sustainable development” model. The study results can be used to elaborate a mechanism for rental income redistribution in AZRF and state programs for the region’s development.
Pleurotus Macrofungi-Assisted Nanoparticle Synthesis and Its Potential Applications: A Review
Authors: Bhardwaj Kanchan , Sharma Anirudh , Tejwan Neeraj , Bhardwaj Sonali , Bhardwaj Prerna , Nepovimova Eugenie , Shami Ashwag , Kalia Anu , Kumar Anil , Abd-Elsalam Kamel A. , Kuča Kamil
Published: December 2020

Research and innovation in nanoparticles (NPs) synthesis derived from biomaterials have gained much attention due to their unique characteristics, such as low-cost, easy synthesis methods, high water solubility, and eco-friendly nature. NPs derived from macrofungi, including various mushroom species, such as Agaricus bisporus, Pleurotus spp., Lentinus spp., and Ganoderma spp. are well known to possess high nutritional, immune-modulatory, antimicrobial (antibacterial, antifungal and antiviral), antioxidant, and anticancerous properties. Fungi have intracellular metal uptake ability and maximum wall binding capacity; because of which, they have high metal tolerance and bioaccumulation ability. Primarily, two methods have been comprehended in the literature to synthesize metal NPs from macrofungi, i.e., the intracellular method, which refers to NP synthesis inside fungal cells by transportation of ions in the presence of enzymes; and the extracellular method, which refers to the treatment of fungal biomolecules aqueous filtrate with a metal precursor. Pleurotus derived metal NPs are known to inhibit the growth of numerous foodborne pathogenic bacteria and fungi. To the best of our knowledge, there is no such review article reported in the literature describing the synthesis and complete application and mechanism of NPs derived from macrofungi. Herein, we intend to summarize the progressive research on macrofungi derived NPs regarding their synthesis as well as applications in the area of antimicrobial (antibacterial & antifungal), anticancer, antioxidant, catalytic and food preservation. Additionally, the challenges associated with NPs synthesis will also be discussed.
Assimilation of Cholesterol by Monascus purpureus
Authors: Nguyen Theresa P. T. , Garrahan Margaret A. , Nance Sabrina A. , Seeger Catherine E. , Wong Christian
Published: December 2020

Monascus purpureus, a filamentous fungus known for its fermentation of red yeast rice, produces the metabolite monacolin K used in statin drugs to inhibit cholesterol biosynthesis. In this study, we show that active cultures of M. purpureus CBS 109.07, independent of secondary metabolites, use the mechanism of cholesterol assimilation to lower cholesterol in vitro. We describe collection, extraction, and gas chromatography-flame ionized detection (GC-FID) methods to quantify the levels of cholesterol remaining after incubation of M. purpureus CBS 109.07 with exogenous cholesterol. Our findings demonstrate that active growing M. purpureus CBS 109.07 can assimilate cholesterol, removing 36.38% of cholesterol after 48 h of incubation at 37 °C. The removal of cholesterol by resting or dead M. purpureus CBS 109.07 was not significant, with cholesterol reduction ranging from 2.75–9.27% throughout a 72 h incubation. Cholesterol was also not shown to be catabolized as a carbon source. Resting cultures transferred from buffer to growth media were able to reactivate, and increases in cholesterol assimilation and growth were observed. In growing and resting phases at 24 and 72 h, the production of the mycotoxin citrinin was quantified via high-performance liquid chromatography-ultraviolet (HPLC-UV) and found to be below the limit of detection. The results indicate that M. purpureus CBS 109.07 can reduce cholesterol content in vitro and may have a potential application in probiotics.
Comparison of Long-Term Strength Development of Steel Fiber Shotcrete with Cast Concrete Based on Accelerator Type
Authors: Yun Kyong , Choi Seunghak , Ha Taeho , Hossain Mohammad , Han Seungyeon
Published: December 2020

This study analyzed the effect of accelerating agents, such as aluminate, cement mineral, and alkali-free accelerators, on the long-term performance of steel-fiber-reinforced shotcrete. The shotcrete performance was studied based on the type and amount of steel fiber added. Performance tests were performed to identify the accelerator providing better long-term performance to the steel-fiber-reinforced shotcrete. Changes in strength and flexural performance over time were investigated. The compressive strength and flexural strength tests on 1-, 3-, 6-, 12-, and 24-month-old test specimens were performed, wherein 37 kg of steel fiber was added to the cement mineral and aluminate mixes, and 40 kg of steel fiber was added to the alkali-free mix. The 1-month compressive strength result of all the test variables satisfied the Korea Expressway Corporation standard. The compressive strength of the cast concrete and shotcrete specimens increased with age, demonstrating a strength reduction, particularly in the 24-month-old shotcrete specimens. Thus, the shotcrete performance may deteriorate in the long-term. In the 24-month-old specimen, substantial flexural strength reduction was observed, particularly in the aluminate and alkali-free specimens. The relative strength of the specimens was compared with that of the cast concrete mold specimens. The results suggest the use of alkali-free accelerators, considering the long-term performance of tunnels and safety of workers. Moreover, increasing the steel fiber performance rather than the amount of low-performance steel fiber must be considered.
Progressive Damage Numerical Modelling and Simulation of Aircraft Composite Bolted Joints Bearing Response
Authors: Gao Guoqiang , An Luling , Giannopoulos Ioannis K. , Han Ning , Ge Ende , Hu Geng
Published: December 2020

Finite element numerical progressive damage modelling and simulations applied to the strength prediction of airframe bolted joints on composite laminates can lead to shorter and more efficient product cycles in terms of design, analysis and certification, while benefiting the economic manufacturing of composite structures. In the study herein, experimental bolted joint bearing tests were carried out to study the strength and failure modes of fastened composite plates under static tensile loads. The experimental results were subsequently benchmarked against various progressive damage numerical modelling simulations where the effects of different failure criteria, damage variables and subroutines were considered. Evidence was produced that indicated that both the accuracy of the simulation results and the speed of calculation were affected by the choice of user input and numerical scheme.
A Study on Material Properties of Intermetallic Phases in a Multicomponent Hypereutectic Al-Si Alloy with the Use of Nanoindentation Testing
Authors: Tupaj Mirosław , Orłowicz Antoni Władysław , Mróz Marek , Trytek Andrzej , Dolata Anna Janina , Dziedzic Andrzej
Published: December 2020

The paper concerns modeling the microstructure of a hypereutectic aluminum-silicon alloy developed by the authors with the purpose of application for automobile cylinder liners showing high resistance to abrasive wear at least equal to that of cast-iron liners. With the use of the nanoindentation method, material properties of intermetallic phases and matrix in a hypereutectic Al-Si alloy containing Mn, Cu, Cr, Ni, V, Fe, and Mg as additives were examined. The scanning electron microscope equipped with an adapter for chemical composition microanalysis was used to determine the chemical composition of intermetallics and of the alloy matrix. Intermetallic phases, such as Al(Fe,Mn,M)Si, Al(Cr,V,M)Si, AlFeSi, AlFeNiM, AlCuNi, Al2Cu, and Mg2Si, including those supersaturated with various alloying elements (M), were identified based on results of X-ray diffraction (XRD) tests and microanalysis of chemical composition carried out with the use of X-ray energy dispersive spectroscopy (EDS). Shapes of the phases included regular, irregular, or elongated polygons. On the disclosed intermetallic phases, silicon precipitations, the matrix, values of the indentation hardness (HIT), and the indentation modulus (EIT) were determined by performing nanoindentation tests with the use of a Nanoindentation Tester NHT (CSM Instruments) equipped with a Berkovich B-L 32 diamond indenter. The adopted maximum load value was 20 mN.
Blast Alleviation of Sacrificial Cladding with Graded and Uniform Cellular Materials
Authors: Ding Yuanyuan , Zheng Yuxuan , Zheng Zhijun , Wang Yonggang , He Siyuan , Zhou Fenghua
Published: December 2020

Graded cellular material is a superb sandwich candidate for blast alleviation, but it has a disadvantage for the anti-blast design of sacrificial cladding, i.e., the supporting stress for the graded cellular material cannot maintain a constant level. Thus, a density graded-uniform cellular sacrificial cladding was developed, and its anti-blast response was investigated theoretically and numerically. One-dimensional nonlinear plastic shock models were proposed to analyze wave propagation in density graded-uniform cellular claddings under blast loading. There are two shock fronts in a positively graded-uniform cladding; while there are three shock fronts in a negatively graded-uniform cladding. Response features of density graded-uniform claddings were analyzed, and then a comparison with the cladding based on the uniform cellular material was carried out. Results showed that the cladding with uniform cellular materials is a good choice for the optimal mass design, while the density graded-uniform cladding is more advantageous from the perspective of the critical length design indicator. A partition diagram for the optimal length of sacrificial claddings under a defined blast loading was proposed for engineering design. Finally, cell-based finite element models were applied to verify the anti-blast response results of density graded-uniform claddings.
Improving the Lifetime of an Out-Patient Implanted Medical Device Using a Novel Flower Pollination-Based Optimization Algorithm in WBAN Systems
Authors: Munivel Karthikeyan Venkatesan , Samraj Tephillah , Kandasamy Vijayakumar , Chilamkurti Naveen
Published: December 2020

The new inventions in health care devices have led to a considerable increase in the human lifespan. Miniaturized bio-sensing elements and dedicated wireless communication bands have led to the development of a new arena called Wireless Body Area Network (WBAN) (IEEE 802.11.6). These Implantable Medical Devices (IMDs) are used for monitoring a chronic patient’s medical condition as well as therapeutic and life-saving functions. The aim of this study is to improve the dynamic channel selection algorithm for an increased Out Patient-Body Network Controller (OP-BNC) medical device during visits to the hospital. There is a fixed number of licensed spectra allocated to the In Patient-Body Network Controller (IP-BNC) and Out-Patient Body Network Controller (OP-BNC). When there is an increase in the OP-BNC, there is an availability of idle spectrum in the IP-BNC. An existing rank-based algorithm is used in the allocation of idle spectrum to the increased OP-BNC. This ranking method takes more time for the processing and selection of an idle channel to the registered user. To avoid it, we proposed an EFPOC model to select from the free idle channels of the IP-BNC licensed spectrum. We also discussed the algorithm complexity of the proposed Enhanced Flower Pollination-based Optimized Channel selection (EFPOC) algorithm and obtained a complexity of O(n2), which is a significant improvement over the existing algorithm rank-based algorithm complexity. Our experimental result shows that the proposed EFPOC algorithm improves the Tier-2 systems lifetime by 46.47%. Then, to prove that the proposed model is time efficient in channel selection, a simulated experimented is conducted. When selecting a number of channels from a Look-Up Table (LUT), the proposed EFPOC method takes 25% less time than the existing algorithms.
Mathematical Models for the Design of Electrical Machines
Authors: Dubas Frédéric , Boughrara Kamel
Published: December 2020

Electrical machines are used in many electrical engineering applications [...]
Optimizing the Shape of Welded Constructions Made through the Technique “Temper Bead Welding”
Authors: Dobrotă Dan
Published: December 2020

Welded constructions are subject to high stresses during operation. One solution for improving the behavior in exploitation of welded constructions in various cases is to use the welding technique “temper bead welding” (TBW). In the paper, the optimization of the geometry of the welded joints by the TBW technique was performed. Thus, corner welded joints made of S355 steel were analyzed. To make the welded joints, three layers of welding seams were deposited, and the intermediate layers were processed through cutting with various radii. To analyze the influence of the size of these rays on the behavior of welded constructions, a research program based on factorial experiences was designed. The samples were tested in terms of fatigue behavior by applying loads between ±8 kN and ±12 kN. The research also focused on determining the hardness of the materials in the joints welded and on determining the microstructure of the materials in the heat affected zone (HAZ). Research has shown that it is possible to improve the characteristics of joints made by the TBW technique in the sense that it can be achieved an improvement in fatigue stress, a decrease in the hardness of the HAZ material and an improvement in the metallographic structure of the HAZ material, meaning that it has a structure made of ferrite and fine pearlite.
Rippite, K2(Nb,Ti)2(Si4O12)O(O,F), a New K-Nb-Cyclosilicate from Chuktukon Carbonatite Massif, Chadobets Upland, Krasnoyarsk Territory, Russia
Authors: Sharygin Victor V. , Doroshkevich Anna G. , Seryotkin Yurii V. , Karmanov Nikolai S. , Belogub Elena V. , Moroz Tatyana N. , Nigmatulina Elena N. , Yelisseyev Alexander P. , Vedenyapin Vitalii N. , Kupriyanov Igor N.
Published: December 2020

Rippite K2(Nb,Ti)2(Si4O12)(O,F)2, a new K-Nb-cyclosilicate, has been discovered in calciocarbonatites from the Chuktukon massif (Chadobets upland, SW Siberian Platform, Krasnoyarsk Territory, Russia). It was found in a primary mineral assemblage, which also includes calcite, fluorcalciopyrochlore, tainiolite, fluorapatite, fluorite, Nb-rich rutile, olekminskite, K-feldspar, Fe-Mn–dolomite and quartz. Goethite, francolite (Sr-rich carbonate–fluorapatite) and psilomelane (romanèchite ± hollandite) aggregates as well as barite, monazite-(Ce), parisite-(Ce), synchysite-(Ce) and Sr-Ba-Pb-rich keno-/hydropyrochlore are related to a stage of metasomatic (hydrothermal) alteration of carbonatites. The calcite–dolomite coexistence assumes crystallization temperature near 837 °C for the primary carbonatite paragenesis. Rippite is tetragonal: P4bm, a = 8.73885(16), c = 8.1277(2) Å, V = 620.69(2) Å3, Z = 2. It is closely identical in the structure and cell parameters to synthetic K2Nb2(Si4O12)O2 (or KNbSi2O7). Similar to synthetic phase, the mineral has nonlinear properties. Some optical and physical properties for rippite are: colorless; Mohs’ hardness—4–5; cleavage—(001) very perfect, (100) perfect to distinct; density (meas.)—3.17(2) g/cm3; density (calc.)—3.198 g/cm3; optically uniaxial (+); ω = 1.737-1.739; ε = 1.747 (589 nm). The empirical formula of the holotype rippite (mean of 120 analyses) is K2(Nb1.90Ti0.09Zr0.01)[Si4O12](O1.78OH0.12F0.10). Majority of rippite prismatic crystals are weakly zoned and show Ti-poor composition K2(Nb1.93Ti0.05Zr0.02)[Si4O12](O1.93F0.07). Raman and IR spectroscopy, and SIMS data indicate very low H2O content (0.09–0.23 wt %). Some grains may contain an outermost zone, which is enriched in Ti (+Zr) and F, up to K2(Nb1.67Ti0.32Zr0.01)[Si4O12](O1.67F0.33). It strongly suggests the incorporation of (Ti,Zr) and F in the structure of rippite via the isomorphism Nb5+ + O2− → (Ti,Zr)4+ + F1−. The content of a hypothetical end-member K2Ti2[Si4O12]F2 may be up to 17 mol. %. Rippite represents a new structural type among [Si4O12]-cyclosilicates because of specific type of connection of the octahedral chains and [Si4O12]8− rings. In structural and chemical aspects it seems to be in close with the labuntsovite-supergroup minerals, namely with vuoriyarvite-(K), K2(Nb,Ti)2(Si4O12)(O,OH)2∙4H2O.
Operation of a Single-Frequency Bismuth-Doped Fiber Power Amplifier near 1.65 µm
Authors: Gomółka Grzegorz , Krajewska Monika , Kaleta Małgorzata , Khegai Aleksandr M. , Alyshev Sergey V. , Lobanov Aleksey S. , Firstov Sergei V. , Nikodem Michał
Published: December 2020

The spectral range between 1650 and 1700 nm is an interesting region due to its potential applications in optical telecommunication and optical-based methane sensing. Unfortunately, the availability of compact and simple optical amplifiers with output powers exceeding tens of milliwatts in this spectral region is still limited. In this paper, a single-frequency continuous-wave bismuth-doped fiber amplifier (BDFA) operating at 1651 and 1687 nm is presented. With the improved signal/pump coupling and modified pump source design, the output powers of 163 mW (at 1651 nm) and 197 mW (at 1687 nm) were obtained. Application of the BDFA to the optical spectroscopy of methane near 1651 nm is also described. We demonstrate that the BDFA can be effectively used for signal amplitude enhancement in photothermal interferometry.
Better Decisions for Children with “Big Data”: Can Algorithms Promote Fairness, Transparency and Parental Engagement?
Authors: Coulthard Beth , Mallett John , Taylor Brian
Published: December 2020

Most countries operate procedures to safeguard children, including removal from parents in serious cases. In England, care applications and numbers have risen sharply, however, with wide variations not explained by levels of socio-economic deprivation alone. Drawing on extensive research, it is asserted that actuarial decision tools more accurately estimate risks to children and are needed to achieve consistency, transparency, and best outcomes for children. To date, however, child protection has not achieved gains made within comparable professions through statistical methods. The reasons are examined. To make progress requires understanding why statistical tools exert effect and how professionals use them in practice. Deep-rooted psychological factors operating within uncertainty can frustrate processes implemented to counter those forces. Crucially, tools constitute evidence; their use and interpretation should not fall to one practitioner or professional body and modifications must be open to scrutiny and adjudication. We explore the potential of novel big data technology to address the difficulties identified through tools that are accurate, simple, and universally applied within child protection. When embraced by all parties to proceedings, especially parents and their advisors, despite societal fears, big data may promote transparency of social work and judicial decisions.
“Life Is Taking Me Where I Need to Go”: Biographical Disruption and New Arrangements in the Lives of Female Family Carers of Children with Congenital Zika Syndrome in Pernambuco, Brazil
Authors: de Melo Ana Paula Lopes , Lyra Tereza , de Araújo Thália Velho Barreto , de Albuquerque Maria do Socorro Veloso , Valongueiro Sandra , Kuper Hannah , Penn-Kekana Loveday
Published: December 2020

The congenital Zika syndrome (CZS) epidemic in Brazil turned the spotlight on many other factors beyond illness, such as poverty, gender, and inequalities in health care. Women were the emblematic subjects in this study, not only because Zika virus is a vertical transmission disease, but also because women—in Brazil and elsewhere—typically represent the primary carers of children. This is a qualitative analytic study using semi-structured interviews with 23 female family carers of children with CZS in Brazil. Through the concept of biographical disruption, we analysed some of the social impacts experienced by women involved in caring for affected children. We identified that the arrival of a child with disabilities resulted in biographical disruption similar to that experienced by people with chronic illnesses. Social support networks were configured through an alliance between women from different generations, revealing solidarity networks, but also highlighting the absence of the state in tackling these social vulnerabilities. Tracing the pathways of these biographical narratives enables us to understand how women have acted to defend the value of their disabled children in a society structured on the model of body normativity and inequality. These results may provide clues to a more inclusive society, which confronts systems of gender oppression and the sexual division of labour focused on women.