bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical and Thermal Neutron Absorbing Properties of B4C/Aluminum Alloy Composites Fabricated by Stir Casting and Hot Rolling Process
Authors: Lee Donghyun , Kim Junghwan , Park Byeongjin , Jo Ilguk , Lee Sang-Kwan , Kim Yangdo , Lee Sang-Bok , Cho Seungchan
Published: March 2021

In this study, to fabricate neutron shielding material, boron carbide (B4C)-reinforced aluminum (Al) alloy composites were successfully fabricated by stir casting followed by a hot rolling process. Microstructural analysis of B4C/Al6061 composites with different volume fractions (5, 10, 20, 25, and 30%) revealed that the composites had volume ratios similar to the target volume ratios of B4C. Furthermore, B4C reinforcements were uniformly dispersed in the Al matrix, forming multi-interfacial layers of Al4C3/(Ti,Cr)B2. The interfacial layer generated during stir casting maintained its own structure after the hot rolling process, indicating strong interfacial bonding strength. The tensile strengths of the B4C/Al6061 composites increased to 20 vol.% and stayed above the value for Al6061, even reaching 30 vol.%. The measured thermal neutron shielding rate increased with increasing B4C content, and the highest thermal neutron shielding rate was observed at 30 vol.% composite, which corresponds to 95.6% neutron shielding at 0.158-cm thickness.
Experimental and Computational Approach to Fatigue Behavior of Polycrystalline Tantalum
Authors: Colas Damien , Finot Eric , Flouriot Sylvain , Forest Samuel , Mazière Matthieu , Paris Thomas
Published: March 2021

This work provides an experimental and computational analysis of low cycle fatigue of a tantalum polycrystalline aggregate. The experimental results include strain field and lattice rotation field measurements at the free surface of a tension–compression test sample after 100, 1000, 2000, and 3000 cycles at ±0.2% overall strain. They reveal the development of strong heterogeneites of strain, plastic slip activity, and surface roughness during cycling. Intergranular and transgranular cracks are observed after 5000 cycles. The Crystal Plasticity Finite Element simulation recording more than 1000 cycles confirms the large strain dispersion at the free surface and shows evidence of strong local ratcheting phenomena occurring in particular at some grain boundaries. The amount of ratcheting plastic strain at each cycle is used as the main ingredient of a new local fatigue crack initiation criterion.
(Bio)dissolution of Glassy and Diopside-Bearing Metallurgical Slags: Experimental and Economic Aspects
Authors: Potysz Anna , Mikoda Bartosz , Napieraj Michał
Published: March 2021

Dissolution of diopside-bearing slag and its amorphous counterpart was investigated to decipher recovery potential of these slags. The contribution of direct slag phase dissolution was investigated using a biotic solution with Acidithiobacillus thiooxidans versus sterile growth medium, whereas citric acid was applied to demonstrate slags dissolution in organic medium. Potential metal donor slag phases and easily released elements were identified by comparing theoretical and experimental dissolution ratios. It was shown that K and Na were the most mobile elements leaching from glassy and diopside slag (up to 99%). Recovery targeted metals were released in the quantities of 56% (Cu)–96% (Zn) from glassy slag and 27% (Cu)–98% (Zn) from diopside slag. Results demonstrated that studied slags are good candidates for Zn recovery during short-term treatment, whereas extension of time would be required for efficient Cu extraction. Abiotic growth medium had little effect on metal leaching (up to 53% versus only 3% for the glassy and diopside slags, respectively). Glassy slag revealed greater susceptibility to dissolution as compared to diopside slag. Further studies improving recovery conditions are expected to improve environmental soundness of proposed treatments and to generate residues depleted in toxic elements. This study highlights the importance of evaluation of individual slags in terms of metal and major elements leachability.
A Novel Approach by Spark Plasma Sintering to the Improvement of Mechanical Properties of Titanium Carbonitride-Reinforced Alumina Ceramics
Authors: Szutkowska Magdalena , Podsiadło Marcin , Sadowski Tomasz , Figiel Paweł , Boniecki Marek , Pietras Daniel , Polczyk Tomasz
Published: March 2021

Ti(C,N)-reinforced alumina-zirconia composites with different ratios of C to N in titanium carbonitride solid solutions, such as Ti(C0.3,N0.7) (C:N = 30:70) and Ti(C0.5,N0.5) (C:N = 50:50), were tested to improve their mechanical properties. Spark plasma sintering (SPS) with temperatures ranging from 1600 °C to 1675 °C and pressureless sintering (PS) with a higher temperature of 1720 °C were used to compare results. The following mechanical and physical properties were determined: Vickers hardness, Young’s modulus, apparent density, wear resistance, and fracture toughness. A composite with the addition of Ti(C0.5,N0.5)n nanopowder exhibited the highest Vickers hardness of over 19.0 GPa, and its fracture toughness was at 5.0 Mpa·m1/2. A composite with the Ti(C0.3,N0.7) phase was found to have lower values of Vickers hardness (by about 10%), friction coefficient, and specific wear rate of disc (Wsd) compared to the composite with the addition of Ti(C0.5,N0.5). The Vickers hardness values slightly decreased (from 5% to 10%) with increasing sintering temperature. The mechanical properties of the samples sintered using PS were lower than those of the samples that were spark plasma sintered. This research on alumina–zirconia composites with different ratios of C to N in titanium carbonitride solid solution Ti(C,N), sintered using an unconventional SPS method, reveals the effect of C/N ratios on improving mechanical properties of tested composites. X-ray analysis of the phase composition and an observation of the microstructure was carried out.
Characterization of Orange Peel Waste and Valorization to Obtain Reducing Sugars
Authors: Ayala José R. , Montero Gisela , Coronado Marcos A. , García Conrado , Curiel-Alvarez Mario A. , León José A. , Sagaste Carlos A. , Montes Daniela G.
Published: March 2021

Annually, millions of tons of foods are generated with the purpose to feed the growing world population. One particular eatable is orange, the production of which in 2018 was 75.54 Mt. One way to valorize the orange residue is to produce bioethanol by fermenting the reducing sugars generated from orange peel. Hence, the objective of the present work was to determine the experimental conditions to obtain the maximum yield of reducing sugars from orange peel using a diluted acid hydrolysis process. A proximate and chemical analysis of the orange peel were conducted. For the hydrolysis, two factorial designs were prepared to measure the glucose and fructose concentration with the 3,5-DNS acid method and UV-Visible spectroscopy. The factors were acid concentration, temperature and hydrolysis time. After the hydrolysis, the orange peel samples were subjected to an elemental SEM-EDS analysis. The results for the orange peel were 73.530% of moisture, 99.261% of volatiles, 0.052% of ash, 0.687% of fixed carbon, 19.801% of lignin, 69.096% of cellulose and 9.015% of hemicellulose. The highest concentration of glucose and fructose were 24.585 and 9.709 g/L, respectively. The results highlight that sugar production is increased by decreasing the acid concentration.
Evaluation of Anti-Biofilm Activity of Mouthrinses Containing Tannic Acid or Chitosan on Dentin In Situ
Authors: Schestakow Anton , Guth Moritz S. , Eisenmenger Tobias A. , Hannig Matthias
Published: March 2021

In contrast to enamel, dentin surfaces have been rarely used as substrates for studies evaluating the effects of experimental rinsing solutions on oral biofilm formation. The aim of the present in situ study was to investigate the effects of tannic acid and chitosan on 48-h biofilm formation on dentin surfaces. Biofilm was formed intraorally on dentin specimens, while six subjects rinsed with experimental solutions containing tannic acid, chitosan and water as negative or chlorhexidine as positive control. After 48 h of biofilm formation, specimens were evaluated for biofilm coverage and for viability of bacteria by fluorescence and scanning electron microscopy. In addition, saliva samples were collected after rinsing and analyzed by fluorescence (five subjects) and transmission electron microscopy (two subjects) in order to investigate the antibacterial effect on bacteria in a planktonic state and to visualize effects of the rinsing agents on salivary proteins. After rinsing with water, dentin specimens were covered by a multiple-layered biofilm with predominantly vital bacteria. In contrast, chlorhexidine led to dentin surfaces covered only by few and avital bacteria. By rinsing with tannic acid both strong anti-adherent and antibacterial effects were observed, but the effects declined in a time-dependent manner. Transmission electron micrographs of salivary samples indicated that aggregation of proteins and bacteria might explain the antiadhesion effects of tannic acid. Chitosan showed antibacterial effects on bacteria in saliva, while biofilm viability was only slightly reduced and no effects on bacterial adherence on dentin were observed, despite proteins being aggregated in saliva after rinsing with chitosan. Tannic acid is a promising anti-biofilm agent even on dentin surfaces, while rinsing with chitosan could not sufficiently prevent biofilm formation on dentin.
Investigation of the Immune Modulatory Potential of Zinc Oxide Nanoparticles in Human Lymphocytes
Authors: Moratin Helena , Ickrath Pascal , Scherzad Agmal , Meyer Till Jasper , Naczenski Sebastian , Hagen Rudolf , Hackenberg Stephan
Published: March 2021

Zinc oxide nanoparticles (ZnO-NP) are commonly used for a variety of applications in everyday life. In addition, due to its versatility, nanotechnology supports promising approaches in the medical sector. NP can act as drug-carriers in the context of targeted chemo- or immunotherapy, and might also exhibit autonomous immune-modulatory characteristics. Knowledge of potential immunosuppressive or stimulating effects of NP is indispensable for the safety of consumers as well as patients. In this study, primary human peripheral blood lymphocytes of 9 donors were treated with different sub-cytotoxic concentrations of ZnO-NP for the duration of 1, 2, or 3 days. Flow cytometry was performed to investigate changes in the activation profile and the proportion of T cell subpopulations. ZnO-NP applied in this study did not induce any significant alterations in the examined markers, indicating their lack of impairment in terms of immune modulation. However, physicochemical characteristics exert a major influence on NP-associated bioactivity. To allow a precise simulation of the complex molecular processes of immune modulation, a physiological model including the different components of an immune response is needed.
The Case for GNMT as a Biomarker and a Therapeutic Target in Pancreatic Cancer
Authors: Heinzman Zachary , Schmidt Connor , Sliwinski Marek K. , Goonesekere Nalin C. W.
Published: March 2021

The high mortality rate for pancreatic cancer (PC) is due to the lack of specific symptoms at early tumor stages and a high biological aggressiveness. Reliable biomarkers and new therapeutic targets would help to improve outlook in PC. In this study, we analyzed the expression of GNMT in a panel of pancreatic cancer cell lines and in early-stage paired patient tissue samples (normal and diseased) by quantitative reverse transcription-PCR (qRT-PCR). We also investigated the effect of 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranoside (PGG) as a therapeutic agent for PC. We find that GNMT is markedly downregulated (p < 0.05), in a majority of PC cell lines. Similar results are observed in early-stage patient tissue samples, where GNMT expression can be reduced by a 100-fold or more. We also show that PGG is a strong inhibitor of PC cell proliferation, with an IC50 value of 12 ng/mL, and PGG upregulates GNMT expression in a dose-dependent manner. In conclusion, our data show that GNMT has promise as a biomarker and as a therapeutic target for PC.
Quantitative Analysis of Rutin by HPTLC and In Vitro Antioxidant and Antibacterial Activities of Phenolic-Rich Extracts from Verbesina sphaerocephala
Authors: Rodríguez-Valdovinos Kathia Yanelly , Salgado-Garciglia Rafael , Vázquez-Sánchez Monserrat , Álvarez-Bernal Dioselina , Oregel-Zamudio Ernesto , Ceja-Torres Luis Fernando , Medina-Medrano José Roberto
Published: March 2021

Verbesina sphaerocephala A. Gray, like other wild plants of the genus Verbesina, has been used in herbal medicine. There is information for other species of the genus related to their phenolic content, antioxidant capacity, and isolation of bioactive compounds with antimicrobial activity. However, there are no reports for V. sphaerocephala, although it has an important presence in the state of Michoacán, México. In this study, the phenolic composition, quantification of rutin, and in vitro antioxidant and antibacterial activities of methanolic extracts from V. sphaerocephala leaves and flowers were determined. The results showed that all the investigated extracts have high phenolic and flavonoid contents. The flavonoid rutin was identified in all the extracts from V. sphaerocephala by high-performance thin-layer chromatography (HPTLC). The V. sphaerocephala extracts showed scavenging activity against DPPH• and ABTS•+ radicals (IC50 and 5.83 ± 0.50 and 0.93 ± 0.01 mg/mL, respectively) as well as relevant antioxidant capacity (51.05 ± 0.36 mg of ascorbic acid/g of dry tissue). The experimental results show that V. sphaerocephala extracts possessed a strong antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. This research indicates that V. sphaerocephala could be considered as a potential source of natural compounds from the point of ethnopharmacological usage.
Volume Resistivity of Viton Polymer under Thermal Aging
Authors: Abdihamzehkolaei Alireza , Ahad Md Tanvir , Siddique Zahed
Published: March 2021

This study examines the influence of various electrical parameters on the volume resistivity of the Viton fluoroelastomer. The transient current, the temperature dependence of volume resistivity, the voltage dependence of resistivity, and the surface morphology of Viton insulators are investigated for new and aged specimens. An accelerated aging process has been employed in order to simulate the natural aging of insulators in service. A detailed comparison between the new and aged samples is presented. The transient effect, which is a challenge to the resistivity measurement of insulators, has been investigated. The first 60 s of the resistivity measurement test showed a significant influence from the transient effect and should be excluded from the data. The volume resistivity of both new and aged samples decreased when the temperature increased. However, the resistivity of the aged sample was lower than the new one at all tested temperatures. When the temperature increased from 35 to 190 °C, resistivity decreased from 4.77 × 1010 to 6.99 × 108 Ω-cm for the new sample and from 2.6 × 1010 to 6.68 × 108 Ω-cm for the aged sample under 500 V. Additionally, the results from this study showed that the volume resistivity is inversely proportional to the applied voltage. Finally, scanning electron microscope (SEM) micrographs/images allowed us to closely examine the surface morphology of new and aged Viton samples. The surface of aged samples has been recognized with higher surface roughness and more significant surface cracks leading to poor performance under high voltage applications.
Structural Analysis of Melt-Spun Polymer-Optical Poly(Methyl Methacrylate) Fibres by Small-Angle X-ray Scattering and Monte-Carlo Simulation
Authors: Kallweit Jan , Vad Thomas , Krooß Felix , Gries Thomas , Houri Mohmmed , Bunge Christian-Alexander
Published: March 2021

The structural properties, mainly the spatial variation of density and chain interaction, of melt-spun polymer optical fibres (POFs) are investigated by small-angle X-ray scattering (SAXS) and compared to Monte-Carlo polymer simulations. The amorphous PMMA POFs had been subjected to a rapid cooling in a water quench right after extrusion in order to obtain a radial refractive-index profile. Four fibre samples with different processing parameters are investigated and the SAXS data analysed via Guinier approach. Distance-distribution functions from the respective equatorial and meridional SAXS data are computed to extract the fibres’ nanostructures in the equatorial plane and along the fibre axis, respectively. Temperature profiles of the cooling process are simulated for different locations within the fibre and taken as input for Monte-Carlo simulations of the polymer structure. The simulation results agree with the SAXS measurements in terms of the cooling profile’s strong influence on the structural properties of the fibre: slower cooling in the centre of the fibre leads to stronger interchain interaction, but also results in a higher density and more homogenous materials with less optical scattering.
A Review of Active Hand Exoskeletons for Rehabilitation and Assistance
Authors: du Plessis Tiaan , Djouani Karim , Oosthuizen Christiaan
Published: March 2021

Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human body; therefore, to understand certain design approaches, the anatomy and biomechanics of the hand are addressed in this paper. The control of these devices is also an arising challenge due to the implementation of intelligent systems and new rehabilitation techniques. This includes intention detection techniques (electroencephalography (EEG), electromyography (EMG), admittance) and estimating applied assistance. Therefore, this paper summarizes the technology in a systematic approach and reviews the state of the art of active hand exoskeletons with a focus on rehabilitation and assistive devices.
Simulating Scenarios of Future Intra-Urban Land-Use Expansion Based on the Neural Network–Markov Model: A Case Study of Lusaka, Zambia
Authors: Simwanda Matamyo , Murayama Yuji , Phiri Darius , Nyirenda Vincent R. , Ranagalage Manjula
Published: March 2021

Forecasting scenarios of future intra-urban land-use (intra-urban-LU) expansion can help to curb the historically unplanned urbanization in cities in sub-Saharan Africa (SSA) and promote urban sustainability. In this study, we applied the neural network–Markov model to simulate scenarios of future intra-urban-LU expansion in Lusaka city, Zambia. Data derived from remote sensing (RS) and geographic information system (GIS) techniques including urban-LU maps (from 2000, 2005, 2010, and 2015) and selected driver variables, were used to calibrate and validate the model. We then simulated urban-LU expansion for three scenarios (business as usual/status quo, environmental conservation and protection, and strategic urban planning) to explore alternatives for attaining urban sustainability by 2030. The results revealed that Lusaka had experienced rapid urban expansion dominated by informal settlements. Scenario analysis results suggest that a business-as-usual setup is perilous, as it signals an escalating problem of unplanned settlements. The environmental conservation and protection scenario is insufficient, as most of the green spaces and forests have been depleted. The strategic urban planning scenario has the potential for attaining urban sustainability, as it predicts sufficient control of unplanned settlement expansion and protection of green spaces and forests. The study proffers guidance for strategic policy directions and creating a planning vision.
Hair Fescue and Sheep Sorrel Identification Using Deep Learning in Wild Blueberry Production
Authors: Hennessy Patrick J. , Esau Travis J. , Farooque Aitazaz A. , Schumann Arnold W. , Zaman Qamar U. , Corscadden Kenny W.
Published: March 2021

Deep learning convolutional neural networks (CNNs) are an emerging technology that provide an opportunity to increase agricultural efficiency through remote sensing and automatic inferencing of field conditions. This paper examined the novel use of CNNs to identify two weeds, hair fescue and sheep sorrel, in images of wild blueberry fields. Commercial herbicide sprayers provide a uniform application of agrochemicals to manage patches of these weeds. Three object-detection and three image-classification CNNs were trained to identify hair fescue and sheep sorrel using images from 58 wild blueberry fields. The CNNs were trained using 1280x720 images and were tested at four different internal resolutions. The CNNs were retrained with progressively smaller training datasets ranging from 3780 to 472 images to determine the effect of dataset size on accuracy. YOLOv3-Tiny was the best object-detection CNN, detecting at least one target weed per image with F1-scores of 0.97 for hair fescue and 0.90 for sheep sorrel at 1280 × 736 resolution. Darknet Reference was the most accurate image-classification CNN, classifying images containing hair fescue and sheep sorrel with F1-scores of 0.96 and 0.95, respectively at 1280 × 736. MobileNetV2 achieved comparable results at the lowest resolution, 864 × 480, with F1-scores of 0.95 for both weeds. Training dataset size had minimal effect on accuracy for all CNNs except Darknet Reference. This technology can be used in a smart sprayer to control target specific spray applications, reducing herbicide use. Future work will involve testing the CNNs for use on a smart sprayer and the development of an application to provide growers with field-specific information. Using CNNs to improve agricultural efficiency will create major cost-savings for wild blueberry producers.
Variable Magnitude and Intensity of Strombolian Explosions: Focus on the Eruptive Processes for a First Classification Scheme for Stromboli Volcano (Italy)
Authors: Calvari Sonia , Giudicepietro Flora , Di Traglia Federico , Bonaccorso Alessandro , Macedonio Giovanni , Casagli Nicola
Published: March 2021

Strombolian activity varies in magnitude and intensity and may evolve into a threat for the local populations living on volcanoes with persistent or semi-persistent activity. A key example comes from the activity of Stromboli volcano (Italy). The “ordinary” Strombolian activity, consisting in intermittent ejection of bombs and lapilli around the eruptive vents, is sometimes interrupted by high-energy explosive events (locally called major or paroxysmal explosions), which can affect very large areas. Recently, the 3 July 2019 explosive paroxysm at Stromboli volcano caused serious concerns in the local population and media, having killed one tourist while hiking on the volcano. Major explosions, albeit not endangering inhabited areas, often produce a fallout of bombs and lapilli in zones frequented by tourists. Despite this, the classification of Strombolian explosions on the basis of their intensity derives from measurements that are not always replicable (i.e., field surveys). Hence the need for a fast, objective and quantitative classification of explosive activity. Here, we use images of the monitoring camera network, seismicity and ground deformation data, to characterize and distinguish paroxysms, impacting the whole island, from major explosions, that affect the summit of the volcano above 500 m elevation, and from the persistent, mild explosive activity that normally has no impact on the local population. This analysis comprises 12 explosive events occurring at Stromboli after 25 June 2019 and is updated to 6 December 2020.
Classification of Nemoral Forests with Fusion of Multi-Temporal Sentinel-1 and 2 Data
Authors: Bjerreskov Kristian Skau , Nord-Larsen Thomas , Fensholt Rasmus
Published: March 2021

Mapping forest extent and forest cover classification are important for the assessment of forest resources in socio-economic as well as ecological terms. Novel developments in the availability of remotely sensed data, computational resources, and advances in areas of statistical learning have enabled the fusion of multi-sensor data, often yielding superior classification results. Most former studies of nemoral forests fusing multi-sensor and multi-temporal data have been limited in spatial extent and typically to a simple classification of landscapes into major land cover classes. We hypothesize that multi-temporal, multi-sensor data will have a specific strength in the further classification of nemoral forest landscapes owing to the distinct seasonal patterns in the phenology of broadleaves. This study aimed to classify the Danish landscape into forest/non-forest and further into forest types (broadleaved/coniferous) and species groups, using a cloud-based approach based on multi-temporal Sentinel 1 and 2 data and a random forest classifier trained with National Forest Inventory (NFI) data. Mapping of non-forest and forest resulted in producer accuracies of 99% and 90%, respectively. The mapping of forest types (broadleaf and conifer) within the forested area resulted in producer accuracies of 95% for conifer and 96% for broadleaf forest. Tree species groups were classified with producer accuracies ranging 34–74%. Species groups with coniferous species were the least confused, whereas the broadleaf groups, especially Quercus species, had higher error rates. The results are applied in Danish national accounting of greenhouse gas emissions from forests, resource assessment, and assessment of forest biodiversity potentials.
Diagnostics of Reinforcement Conditions in Concrete Structures by GPR, Impact-Echo Method and Metal Magnetic Memory Method
Authors: Pospisil Karel , Manychova Monika , Stryk Josef , Korenska Marta , Matula Radek , Svoboda Vaclav
Published: March 2021

It is important to use adequately reliable non-destructive methods that would be capable of determining the reinforcement conditions in concrete structures. Three different methods: ground penetrating radar, impact-echo method, and metal magnetic memory method were used for testing laboratory-prepared reinforced concrete beams (with a reinforcing bar of the same diameter along its whole length, reinforcing bar locally impaired, and reinforcing bar interrupted). The ground-penetrating radar proved the correlation of signal parameters with the reinforcing bar condition. An impairment/interruption reinforcing bar appeared in the record from measurements in the transversal and longitudinal direction by changes of the observed depth of the reinforcing bar from the concrete surface and direct wave attenuation. The impact-echo method proved that the shifts of the dominant frequencies from the response signal correspond with the impairment/interruption of the reinforcing bar. Results of diagnostics by the metal magnetic memory method were presented by a magnetogram of the magnetic field strength and field gradient on the measured distance. The changes in the magnetic field strength proved different stress concentration zones due to the reinforcing bar condition. The used non-destructive methods showed that they are capable of indicating the different reinforcement conditions in reinforced concrete beams. This paper indicates in which cases and for what reason it is appropriate to use these three methods and in what way they differ from each other.
Exploring Suppliers’ Approaches toward Workplace Safety Compliance in the Global Garment Sector: From Bangladesh Perspective
Authors: Mahmood Md Sultan , Ruma Nilima Haque , Ahmed Toufiq , Nagai Yukari
Published: March 2021

The readymade garment (RMG) sector is one of the main drivers of the Bangladesh economy with over 4 million employed. In the 2013 Rana Plaza accident aftermath, the implementation of workplace safety compliance (WSC) became imperative. The paper investigated the WSC initiatives implemented by the RMG sector to overcome safety challenges and their effectiveness for a safe and healthy workplace. We employed a multi-case study research strategy over three Bangladeshi garment manufacturers to resolve these queries. The result revealed that the manufacturers joined in the safety governance programs to protect workers’ health safety rights immediately after the accidents. They participated in inspections and remediations programs over structural, electrical, and fire protection as a priority. Moreover, several other human rights conventions, national labor laws and, buyer code of conduct were also adopted as regulatory and voluntary initiatives to settle workers’ health rights and social needs. The WSC enforcement empowered workers to bargain their rights toward a safe workplace and made them responsible for responding during an emergency. Finally, the paper argues that the WSC in the RMG sector nowadays covers a wide range of initiatives in three broad areas: physical environment safety, workers’ health issues, and workers’ rights.
Eco-Economic Coordination Analysis of the Yellow River Basin in China: Insights from Major Function-Oriented Zoning
Authors: Zhang Zhongwu , Chang Tianying , Qiao Xuning , Yang Yongju , Guo Jing , Zhang Han
Published: March 2021

The ecological-economic coordination degree model is widely used to analyze eco-economic coordination relationships, but methods for determining the relative weights of the ecological and economic systems lack a scientific basis. Examining the Yellow River Basin based on Major Function-Oriented Zoning (MFOZ) in China, the study surveyed 42 experts and used the analytic hierarchy process (AHP)to calculate the ecological and economic weights of the different main function zones. It also improved the model and evaluated the coordination degree of the ecological economic system in 642counties of eight provinces in the Yellow River Basin from 1991 to 2015. The results indicate that (1) the ecological value of the basin increased from 823 billion Yuan in 2001 to 1142 billion Yuan in 2015; (2) the GDP shows a linear growth trend: high- and medium–high-value areas of per capita GDP are clustered around nine metropolitan areas, while cold spots are distributed in ecological protection and agricultural development zones; (3) the ecological and economic coordination of the river basin first rose and then declined; and (4) the coordinated development areas are concentrated in five urban agglomerations that are highly consistent with the per capita GDP hotspots.
An Integrated Approach of Multi-Criteria Decision-Making and Grey Theory for Evaluating Urban Public Transportation Systems
Authors: Alkharabsheh Ahmad , Moslem Sarbast , Oubahman Laila , Duleba Szabolcs
Published: March 2021

Improving the local urban transport system’s quality is often seen as one of the critical points for the government and the local operator. An amelioration of the system can improve users’ satisfaction and attract new users while simultaneously decreasing traffic congestion and pollution. Efficient methodologies are required to achieve sustainable development regarding complex issues associated with traffic congestion and pollution. In this study, we propose using the analytic hierarchy process (AHP) grey values to overcome the limitations of the uncertainty in the classical AHP approach. The presented grey-AHP model assumes an efficient contrivance to facilitate the public transport system’s supply quality evaluation, especially when respondents are non-experts. Finally, we estimate and rank the public transport system’s supply quality criteria by adopting the proposed model for a real-world case study (Amman city, Jordan). The study’s outcome shows the effectiveness and the applicability of the developed approach for enhancing the quality of the public transport system.
The Motivation of Academics in Remote Teaching during the Covid-19 Pandemic in Polish Universities—Opening the Debate on a New Equilibrium in e-Learning
Authors: Kulikowski Konrad , Przytuła Sylwia , Sułkowski Łukasz
Published: March 2021

Online learning helps to continue education in the face of Covid-19 lockdowns and social isolation, but it might largely change characteristics of academic teachers’ jobs and, thus, have some unintended consequences for teachers’ motivating job potential. In this study, using a convenience sample of 202 academic teachers, we tested and supported the hypothesis that academic teachers perceived their motivating job potential as lower during the forced Covid-19 e-learning than before it. We also provided evidence that motivating potential of work during the forced Covid-19 e-learning is associated with work engagement and job satisfaction. Moreover, we provided a modicum of evidence that the relationship between the motivating job potential and academic teachers’ job satisfaction might be moderated by teachers’ assessment of university management actions during the Covid-19 situation, such that this association seems to be stronger among teachers who more positively assess university management. Our results provided initial evidence of possible unintended consequences of the pandemic-forced e-learning for academic teachers. Therefore, we suggested that socially sustainable e-learning required not only concentration on students and organizations of the education process but also on improving the teachers’ motivating job potential.
Reference Frame Induced Symmetry Breaking on Holographic Screens
Authors: Fields Chris , Glazebrook James F. , Marcianò Antonino
Published: March 2021

Any interaction between finite quantum systems in a separable joint state can be viewed as encoding classical information on an induced holographic screen. Here we show that when such an interaction is represented as a measurement, the quantum reference frames (QRFs) deployed to identify systems and pick out their pointer states induce decoherence, breaking the symmetry of the holographic encoding in an observer-relative way. Observable entanglement, contextuality, and classical memory are, in this representation, logical and temporal relations between QRFs. Sharing entanglement as a resource requires a priori shared QRFs.
Power Law Duality in Classical and Quantum Mechanics
Authors: Inomata Akira , Junker Georg
Published: March 2021

The Newton–Hooke duality and its generalization to arbitrary power laws in classical, semiclassical and quantum mechanics are discussed. We pursue a view that the power-law duality is a symmetry of the action under a set of duality operations. The power dual symmetry is defined by invariance and reciprocity of the action in the form of Hamilton’s characteristic function. We find that the power-law duality is basically a classical notion and breaks down at the level of angular quantization. We propose an ad hoc procedure to preserve the dual symmetry in quantum mechanics. The energy-coupling exchange maps required as part of the duality operations that take one system to another lead to an energy formula that relates the new energy to the old energy. The transformation property of the Green function satisfying the radial Schrödinger equation yields a formula that relates the new Green function to the old one. The energy spectrum of the linear motion in a fractional power potential is semiclassically evaluated. We find a way to show the Coulomb–Hooke duality in the supersymmetric semiclassical action. We also study the confinement potential problem with the help of the dual structure of a two-term power potential.
Characterization of Marine-Surface-Dissolved Organic Matter via Amino Acid Enantiomers and Its Implications Based on Diel and Seasonal Observations
Authors: Zhu Zhuo-Yi , Zhou Ying-Chun , Ma Wen-Chao , Wu Ying , Li Ming , Liu Su-Mei , Xu Xue-Wei , Zhou Meng
Published: March 2021

Due to the essential roles of dissolved organic matter (DOM) in both microbiol food loop and marine carbon cycling, changes in marine DOM composition have an important impact on the marine ecosystem and carbon cycling. In October 2014 and June 2015, two field investigations for the DOM in the upper 200 m were conducted in the slope region of the northern South China Sea to characterize the DOM composition via amino acid enantiomers. In June, our sampling locations were under upwelling impact induced by an eddy-pair event, whereas in October there were no eddies. High-frequency sampling (a few hours interval) over 24 h reveals that the variability of the amino acid carbon yield (min. 0.2%) and the D/L alanine ratio (min. 0.02) is larger than its corresponding analytical and propagated errors, suggesting solid short-term changes for these two molecular-based indicators. Section samples from June showed a lower D/L alanine ratio (0.43 vs. 0.53) and a GABA mol% (1.0% vs. 1.6%) relative to the section samples from October, suggesting that DOM in June is more fresh (less degraded) compared to that in October. A higher serine mol% (19.5% vs. 13.2%) and lower D/L serine ratio (0.06 vs. 0.24) from the diel observation in June relative to October further indicates that phytoplankton, rather than bacteria, plays an more important role in DOM composition alternation. This is consistent with the higher phytoplankton biomass found in June, promoted by the eddy-pair.
Dynamic of Dominant Plant Communities in Kettle Holes (Northeast Germany) during a Five-Year Period of Extreme Weather Conditions
Authors: Pätzig Marlene , Düker Eveline
Published: March 2021

Understanding the ecosystem functions and services of central European kettle holes (small wetlands) requires knowledge about their spatiotemporal dynamics. A lot of existing research has been conducted on the wet–dry cycles of North American potholes, but much less is known about kettle holes. Based on the extreme weather conditions between 2015 and 2020, we aimed to quantify differences among dominant plant communities of kettle holes using unmanned aerial systems. Different dominant plant communities were differently affected by dry and wet intervals with a major increase in terrestrial plants. Multivariate analysis showed strong variability in plant community composition for permanent and semi-permanent kettle holes, where hydrophytes decreased and nitrophilous perennials increased. Although we cannot provide quantitative results in succession over a five-year observation period, we found indications of progressive succession towards irreversible alternative stable states with woody plants for some kettle holes, especially of the “storage type”. Therefore, we assume stronger changes in proportion of wetland types in kettle holes compared to potholes and we expect the proportion of wood-dominated kettle holes to increase in the central European landscape in the future, leading to enhanced homogenization of the landscape accompanied by a loss of ecosystem functions and services.
Economic Perspectives on the Impact of Covid Vaccines
Authors: Sangamithra A , Thilagavathy S
Published: March 2021

Vaccination and the impact on health on the world’s people is very difficult to exaggerate. The main aim is to treat people with mental health issues and substance use of disorder. Vaccination is crucial in terms of ensuring the overall health conditions and well–being. The development of vaccines is an expensive and lengthy process. Depreciation is high and takes multiple candidates and long years to produce a licensed vaccine. The access to vaccines that prevent life-threatening infectious diseases remains not equal to all the population. The benefits of vaccination derive from health and economic benefits and the health benefits have diminishing returns as a result of high-risk individuals been vaccinated first. Economic benefits depend both on the health benefits and on how reduced risk of infection and death translates into a leading general economic activity. Department of Government is required to perform a systematic economic analyses of vaccines and to justify their given pressure on both private and public finances on a global level; provoke in the year 2008 financial crash. Mostly, the government supports charities and non-governmental organizations, where people invest in these, with the hope of improving the health conditions.
Analysis of severity and variability of psychopathology disturbances in structure mental health disorders in long-distance sailors depending on their levels of psychosocial stress
Authors: Kosenko K.A.
Published: March 2021

Using clinical-psychopathological and psychodiagnostic methods, we studied the severity and variability of psychopathological symptoms in the structure of mental health disorders in seafarers, depending on the level of psychosocial stress they experienced, to determine the targets of personalized mental health care measures for this contingent. During 2016–2019, 110 officers of the command staff of the Maritime Merchant Navy (CMN), 90 sailors of the Maritime Merchant Navy (SMN), 70 representatives of the command staff of the Maritime Passenger Fleet (CPF) and 30 privates of the Maritime Passenger Fleet (SPF) were surveyed. All were examined by men, citizens of Ukraine. The study included the use of clinical-psychopathological and psychodiagnostic methods. In the inter-voyage period, the vast majority of long-distance sailors are either mentally healthy (30.9 % CMN, 41.1 % SMN, 42.9 % CPF, 33.3 % SPF), or have some signs of mental maladaptation (52.7 % CMN, 37.7 % SMN, 44.3 % CPF, 40.0 % SPF). Clinically delineated disorders of the neurotic register of the F43 cluster (adaptation disorders) are characterized by 26.7 % SPF, 21.1 % SMN, 16.4 % CMN and 12.8 % CPF. The severity and variability of psychopathological manifestations, in general in the sample, correspond to the neurotic level of response, however, have differences among the examined different groups. The greatest severity of symptoms of depression on the background of high levels of anxiety, hostility and psychosis is inherent in SPF, and the greatest severity of anxiety, phobic anxiety, hostility and somatization is inherent in CMN. The lowest severity of psychopathological symptoms is characteristic of CPF. The severity and variability of psychopathological manifestations is directly associated with the level of stress experienced by the subjects: with increasing stress burden, the severity of the psychopathological response increases. The identified patterns should be taken into account in the development of specific measures of psychotherapy and psychoprophylaxis for this contingent, which is the prospect of this study.
Features of changes in the cognitive sphere of patients with a primary episode of bipolar affective disorder
Authors: Mysula Yu.I.
Published: March 2021

153 patients with primary episode of bipolar affective disorder were divided to three groups: with prevalence of depressive symptomatology (44 men and 75 women), with prevalence of manic symptoms (15 men and 8 women) and with simultaneous presence of depressive and manic symptomatology or with rapid or severe manic symptoms (6 men and 5 women) and were examined using the Rey–Osterrieth test. It was found that they had impaired cognitive functioning whose structure and severity were related to the clinical type of the primary episode. In patients with depressive variant revealed approximately equal deterioration of test performance across all assessment vectors, while reproduction (immediate and delayed) observed synchronous deterioration of indicators, with the degree of deterioration of characteristics between copying and immediate and retarded reproduction. In the manic variant the performance of test is significantly different from the depressive variant. Patients with a manic variant showed the lowest indicators in the presence of individual elements of the figure, accuracy and diligence. At the same time, indicators for most estimation vectors are unstable, varying with immediate and delayed reproduction without some systematicity. Such features reflect on the cognitive functions of the maniac state with its acceleration of the speed of thinking, its chaos, instability of attention, difficulties of concentration and inability to productive activity. In patients with mixed episode, the Ray–Osterrieth test scores reflect complex contradictory tendencies of changes in the affective area, related to the rapid phase change and the presence of opposite affective manifestations. Quantitative values of indicators in patients of this group has an intermediate position between indicators of patients with depressive and manic variants. Common disorders inherent in patients of all groups were distortion of the integrity and symmetry of the figure, contamination of the elements of the figure and the omission of minor details. The differences in the structure and severity of cognitive impairment between men and women are not statistically significant.
A Theory for Analysis of Pulse Electromagnetic Radiation
Authors: xiao gaobiao
Published: March 2021

A theory for analyzing the
radiative and reactive energies for pulse radiators in free space is presented.
With the proposed definition of reactive energies and radiative energies, power
balance at arbitrarily chosen observation surfaces are established, which
intuitively shows that the Poynting vector contains not only the power flux
density associated with the radiative energies, but also the influence of the
fluctuation of the reactive energies dragging by the sources. A new vector is
defined for the radiative power flux density. The radiative energies passing
through observation surfaces enclosing the radiator are accurately calculated.
Numerical results verifies that the proposed radiative flux density is more
proper for expressing the radiative power flux density than the Poynting vector.