bluuebunny/crossref_metadata_2025 huggingface dataset:
An Acoustic Treatment to Mitigate the Effects of the Apple Snail on Agriculture and Natural Ecosystems
Authors: Solé Marta , Fortuño José-Manuel , van der Schaar Mike , André Michel
Published: September 2021

Global change is the origin of increased occurrence of disturbance events in natural communities, with biological invasions constituting a major threat to ecosystem integrity and functioning. The apple snail (Pomacea maculata) is a freshwater gastropod mollusk from South America. Considered one of the 100 most harmful invasive species in the world, due to its voracity, resistance, and high reproductive rate, it has become a global problem for wetland crops. In Catalonia, it has affected the rice fields of the Ebre Delta since 2010 with significant negative impact on the local economy. As a gastropod mollusc it possesses statocysts consisting of a pair of sacs, one located on each side of the foot, that contain multiple calcium carbonate statoconia. This study shows the first ultrastructural images of pathological changes in the sensory epithelium of the statocyst of apple snail adults with an increase in the severity of the lesions over time after exposure to low frequency sounds. Sound-induced damage to the statocyst could likely result in an inhibition of its vital functions resulting in a potential reduction in the survival ability of the apple snail and lead to an effective mitigation method for reducing damage to rice fields.
Viability and Performance Analysis, at a Physical Level, of a Maritime Communication Network on Medium Frequency
Authors: López-Diaz Alfonso-Isidro , Gutiérrez Miguel A. , Ortega Piris Andrés , Díaz-Ruiz-Navamuel Emma , Rodríguez-Rosa David
Published: September 2021

This paper analysed the potentialities that have not yet been exploited of the Automatic Vessel Identification System on Medium Frequency (AVISOMEF) that was previously presented to the scientific community. This system expanded the spectrum of possibilities of the Global Maritime Distress and Safety System (GMDSS). By the time AVISOMEF was presented, one of the unexpected benefits was that it could constitute a platform capable of supporting a Maritime Communication Network on Medium Frequency; all remotely located vessels could communicate with each other by using AVISOMEF, making use of the new established network, within the geographic area of implementation, without needing to use satellite techniques. Medium frequency propagation is stable and is not subject to coverage restrictions. To conduct this experiment, we collaborated with the Spanish Maritime Safety Agency (SASEMAR). It was thanks to them that we gathered real-time information about the nationwide maritime traffic that navigated through the Spanish Search and Rescue jurisdiction waters from 2018 to 2020.
Standardising Marine Renewable Energy Testing: Gap Analysis and Recommendations for Development of Standards
Authors: Noble Donald R. , O’Shea Michael , Judge Frances , Robles Eider , Martinez Rodrigo , Khalid Faryal , Thies Philipp R. , Johanning Lars , Corlay Yann , Gabl Roman , Davey Thomas A. D. , Vejayan Nithiananthan , Murphy Jimmy
Published: September 2021

Marine renewable energy (MRE) is still an emerging technology. As such, there is still a lack of mature standards and guidance for the development and testing of these devices. The sector covers a wide range of disciplines, so there is a need for more comprehensive guidance to cover these. This paper builds on a study undertaken in the MaRINET2 project to summarise recommendations and guidance for testing MRE devices and components, by reviewing the recently published guidance. Perceived gaps in the guidance are then discussed, expanding on the previous study. Results from an industry survey are also used to help quantify and validate these gaps. The main themes identified can be summarised as: the development progression from concept to commercialisation, including more complex environmental conditions in testing, accurately modelling and quantifying the power generated, including grid integration, plus modelling and testing of novel moorings and foundation solutions. A pathway to a standardised approach to MRE testing is presented, building on recommendations learnt from the MaRINET2 round-robin testing, showing how these recommendations are being incorporated into the guidance and ultimately feeding into the development of international standards for the marine renewable energy sector.
Structure–Seabed Interactions in Marine Environments
Authors: Guo Zhen , Hong Yi , Jeng Dong-Sheng
Published: September 2021

The phenomenon of soil–structure interactions in marine environments has attracted much attention from coastal and geotechnical engineers and researchers in recent years [...]
Information Matrix-Based Adaptive Sampling in Hull Form Optimisation
Authors: Ouyang Xuyu , Chang Haichao , Feng Baiwei , Liu Zuyuan , Zhan Chengsheng , Cheng Xide
Published: September 2021

Hull form optimisation involves challenges such as large design spaces, numerous design variables, and high nonlinearity. Therefore, optimisation that only use global approximate models alone cannot yield desirable results. An information matrix-based method is proposed for dynamically embedded local approximate models (IM-DEAM) in this paper, which uses the Gaussian-function information matrix to extract one or more subspaces for additional sampling and a Latin hypercube design (LHD) for adaptive sampling. In addition, to prevent overfitting by global approximate models in some spaces because of the uneven distribution of the samples, local approximate models are embedded in the subspaces identified for additional sampling to enable accurate description of subspaces. The effectiveness and robustness of the method are validated and analysed by applying the proposed method to optimise mathematical functions and the hull form of the DTMB 5415. The results demonstrate that the proposed method is effective for improving the accuracies and can produce reliable optimisation results.
Reinterpreting the Bruun Rule in the Context of Equilibrium Shoreline Models
Authors: D’Anna Maurizio , Idier Deborah , Castelle Bruno , Vitousek Sean , Le Cozannet Goneri
Published: September 2021

Long-term (>decades) coastal recession due to sea-level rise (SLR) has been estimated using the Bruun Rule for nearly six decades. Equilibrium-based shoreline models have been shown to skillfully predict short-term wave-driven shoreline change on time scales of hours to decades. Both the Bruun Rule and equilibrium shoreline models rely on the equilibrium beach theory, which states that the beach profile shape equilibrates with its local wave and sea-level conditions. Integrating these two models into a unified framework can improve our understanding and predictive skill of future shoreline behavior. However, given that both models account for wave action, but over different time scales, a critical re-examination of the SLR-driven recession process is needed. We present a novel physical interpretation of the beach response to sea-level rise, identifying two main contributing processes: passive flooding and increased wave-driven erosion efficiency. Using this new concept, we analyze the integration of SLR-driven recession into equilibrium shoreline models and, with an idealized test case, show that the physical mechanisms underpinning the Bruun Rule are explicitly described within our integrated model. Finally, we discuss the possible advantages of integrating SLR-driven recession models within equilibrium-based models with dynamic feedbacks and the broader implications for coupling with hybrid shoreline models.
Dynamic Stability and Protection Design of a Submarined Floater Platform Avoiding Typhoon Wave Impact
Authors: Lin Shueei-Muh , Chen Yang-Yih
Published: September 2021

This research proposes the design of a mooring system that allows the floating platform to stably dive deep enough to prevent damage induced by typhoon waves. The design principle of the mechanism is that the submarined floating platform with negative buoyancy is connected to a pontoon with positive buoyancy. The diving depth of the floating platform is determined by the rope length. If the static equilibrium of the two forces is satisfied, the diving depth will be kept. If the diving depth of the floating platform is enough, the platform will not be directly damaged by the wave impact. In reality, the system will be greatly subjected to the typhoon wave and the ocean current. The stability of the system and the dynamic tension of the rope must be significantly concerned. In this study, the linear elastic model of the mooring system composed of a floater platform, towed parachute, pontoon, traction rope, and mooring foundation is derived. The theoretical solution of the static and dynamic stability analysis of the mooring system is proposed. The dynamic behaviors of the floating platform and pontoon, and the tension of the rope under the effects of waves and ocean currents, are investigated. It is discovered that the buffer spring helps reduce the tension of the rope. The proposed protection procedure can avoid the damage of the floating platform and the mooring line, due to Typhoon wave impact.
Bioactive Secondary Metabolites from Marine Streptomyces griseorubens f8: Isolation, Identification and Biological Activity Assay
Authors: Yang Wenzhi , Liang Guangjie , Sun Yang , Gong Zhijin
Published: September 2021

Marine actinomycetes are a potential source of a wide variety of bioactive natural products. Herein, four cyclic dipeptides, namely, cyclo(L-Val-L-Pro) (compound 1), cyclo(L-Pro-L-Leu) (compound 2), cyclo(L-Pro-L-Tyr) (compound 3) and cyclo(L-Pro-L-Phe) (compound 5), and an N-acetyltyramine (compound 4) were first isolated and identified as products of the marine Streptomyces griseorubens f8. Compounds 3 and 5 exhibit antibacterial activity against Staphylococcus aureus, Klebsiella aerogenes and Proteus vulgaris. The minimum inhibitory concentrations (MICs) against Staphylococcus aureus, Klebsiella aerogenes and Proteus vulgaris are 160 µg/mL, 100 µg/mL, 120 µg/mL for the compound 3 and 180 µg/mL, 130 µg/mL 150 µg/mL for the compound 5, respectively. In addition, compounds 1, 2, 3 and 5 was first found to have the ability to inhibit the invasion and migration of A549 cells (lung cancer cells), which exhibited the potentiality for these compounds to be used as novel anticancer drugs. This study provides a novel production strain for compounds 1, 2, 3 and 5, and four potential promising anticancer agents.
Combined Longshore and Cross-Shore Modeling for Low-Energy Embayed Sandy Beaches
Authors: Tran Yen Hai , Marchesiello Patrick , Almar Rafael , Ho Duc Tuan , Nguyen Thong , Thuan Duong Hai , Barthélemy Eric
Published: September 2021

The present study focuses on the long-term multi-year evolution of the shoreline position of the Nha Trang sandy beach. To this end an empirical model which is a combination of longshore and cross-shore models, is used. The Nha Trang beach morphology is driven by a tropical wave climate dominated by seasonal variations and winter monsoon intra-seasonal pulses. The combined model accounts for seasonal shoreline evolution, which is primarily attributed to cross-shore dynamics but fails to represent accretion that occurs during the height of summer under low energy conditions. The reason is in the single equilibrium Dean number Ωeq of the ShoreFor model, one of the components of the combined model. This equilibrium Dean number cannot simultaneously account for the evolution of strong intra-seasonal events (i.e., winter monsoon pulses) and the annual recovery mechanisms associated with swash transport. By assigning a constant value to Ωeq, when the surf similarity parameter is higher than 3.3 (occurrence of small surging breakers in summer), we strongly improve the shoreline position prediction. This clearly points to the relevance of a multi-scale approach, although our modified Ωeq retains the advantage of simplicity.
The Role of the Cell Integrity Pathway in Septum Assembly in Yeast
Authors: Roncero Cesar , Celador Rubén , Sánchez Noelia , García Patricia , Sánchez Yolanda
Published: September 2021

Cytokinesis divides a mother cell into two daughter cells at the end of each cell cycle and proceeds via the assembly and constriction of a contractile actomyosin ring (CAR). Ring constriction promotes division furrow ingression, after sister chromatids are segregated to opposing sides of the cleavage plane. Cytokinesis contributes to genome integrity because the cells that fail to complete cytokinesis often reduplicate their chromosomes. While in animal cells, the last steps of cytokinesis involve extracellular matrix remodelling and mid-body abscission, in yeast, CAR constriction is coupled to the synthesis of a polysaccharide septum. To preserve cell integrity during cytokinesis, fungal cells remodel their cell wall through signalling pathways that connect receptors to downstream effectors, initiating a cascade of biological signals. One of the best-studied signalling pathways is the cell wall integrity pathway (CWI) of the budding yeast Saccharomyces cerevisiae and its counterpart in the fission yeast Schizosaccharomyces pombe, the cell integrity pathway (CIP). Both are signal transduction pathways relying upon a cascade of MAP kinases. However, despite strong similarities in the assembly of the septa in both yeasts, there are significant mechanistic differences, including the relationship of this process with the cell integrity signalling pathways.
Noninvasive Combined Diagnosis and Monitoring of Aspergillus and Pseudomonas Infections: Proof of Concept
Authors: Dobiáš Radim , Škríba Anton , Pluháček Tomáš , Petřík Miloš , Palyzová Andrea , Káňová Marcela , Čubová Eva , Houšť Jiří , Novák Jiří , Stevens David A. , Mitulovič Goran , Krejčí Eva , Hubáček Petr , Havlíček Vladimír
Published: September 2021

In acutely ill patients, particularly in intensive care units or in mixed infections, time to a microbe-specific diagnosis is critical to a successful outcome of therapy. We report the application of evolving technologies involving mass spectrometry to diagnose and monitor a patient’s course. As proof of this concept, we studied five patients and used two rat models of mono-infection and coinfection. We report the noninvasive combined monitoring of Aspergillus fumigatus and Pseudomonas aeruginosa infection. The invasive coinfection was detected by monitoring the fungal triacetylfusarinine C and ferricrocin siderophore levels and the bacterial metabolites pyoverdin E, pyochelin, and 2-heptyl-4-quinolone, studied in the urine, endotracheal aspirate, or breath condensate. The coinfection was monitored by mass spectrometry followed by isotopic data filtering. In the rat infection model, detection indicated 100-fold more siderophores in urine compared to sera, indicating the diagnostic potential of urine sampling. The tools utilized in our studies can now be examined in large clinical series, where we could expect the accuracy and speed of diagnosis to be competitive with conventional methods and provide advantages in unraveling the complexities of mixed infections.
The Genus Leccinum (Boletaceae, Boletales) from China Based on Morphological and Molecular Data
Authors: Meng Xin , Wang Geng-Shen , Wu Gang , Wang Pan-Meng , Yang Zhu L. , Li Yan-Chun
Published: September 2021

Leccinum is one of the most important groups of boletes. Most species in this genus are ectomycorrhizal symbionts of various plants, and some of them are well-known edible mushrooms, making it an exceptionally important group ecologically and economically. The scientific problems related to this genus include that the identification of species in this genus from China need to be verified, especially those referring to European or North American species, and knowledge of the phylogeny and diversity of the species from China is limited. In this study, we conducted multi-locus (nrLSU, tef1-α, rpb2) and single-locus (ITS) phylogenetic investigations and morphological observisions of Leccinum from China, Europe and North America. Nine Leccinum species from China, including three new species, namely L. album, L.parascabrum and L.pseudoborneense, were revealed and described. Leccinum album is morphologically characterized by the white basidioma, the white hymenophore staining indistinct greenish blue when injured, and the white context not changing color in pileus but staining distinct greenish blue in the base of the stipe when injured. Leccinumparascabrum is characterized by the initially reddish brown to chestnut-brown and then pale brownish to brown pileus, the white to pallid and then light brown hymenophore lacking color change when injured, and the white context lacking color change in pileus but staining greenish blue in the base of the stipe when injured. Leccinumpseudoborneense is characterized by the pale brown to dark brown pileus, the initially white and then brown hymenophore lacking color change when injured, and the white context in pileus and stipe lacking color change in pileus but staining blue in stipe when bruised. Color photos of fresh basidiomata, line drawings of microscopic features and detailed descriptions of the new species are presented.
Poland–Turkey Comparison of Mobile Payments Quality in Pandemic Time
Authors: Chmielarz Witold , Zborowski Marek , Fandrejewska Alicja , Atasever Mesut
Published: September 2021

The main objective of this article is to identify and analyze the use of mobile payments in two countries, Poland and Turkey. The data for the study were collected with the application of the CAWI method in March 2021. The survey covered nearly 650 respondents in total. The basis for comparisons was populations from two culturally distinct countries, Poland and Turkey, which are at a similar level of development as regards the use of the Internet. The studies were carried out simultaneously in both countries and examined the group of young people aged 18–25. The research surveyed the population, which included the most active Internet users who are taking full advantage of the benefits of globalization, which is facilitated by the development of the Internet worldwide. The survey was translated into the respondents’ native languages, initially validated during the pilot studies and then distributed and circulated among the study participants. The obtained findings were subject to comparison, and the differences between the samples were analyzed and commented on to verify the hypotheses formulated in the study. The main limitation of the conducted study was the selection of a random group—the research sample consisted only of members of the academic community. The study presented in the article fills the research gap regarding international comparisons of the use of m-payments in the period of the COVID-19 pandemic. The obtained results indicate the undoubted fact of increased interest in the use of m-payments in e-commerce and e-banking, and even more importantly, differences concerning 40% of the criteria/attributes applied to assess the use of m-payments in both countries. The findings can be used by business practitioners dealing with the development of m-payments. Another potential application is to attempt to bridge the gaps between countries, which may be supported by globalization processes.
Industry, Firm, and Country Level Dynamics of Capital Structure: A Case of Pakistani Firms
Authors: Liaqat Idrees , Khan Muhammad Asif , Popp József , Oláh Judit
Published: September 2021

The capital structure appears to be one of the most researched and the most controversial areas in modern corporate finance. Prior literature on determinants of capital structure has concentrated on firm and country level factors by employing static modeling. Static modeling has certain limitations, which do not allow companies to establish an optimum capital structure in line with economic uncertainty. This study makes a worthy contribution to the existing body of knowledge by filling the gap in the evolution of capital structure by employing a dynamic framework of the financial sector of Pakistan. In addition, the study brings into focus sectors’ importance in determining the firm’s financial behavior. Based on secondary financial sector data from 2006–2019, the article addresses the issues by employing two-step system generalized method of moments (GMM). The findings of the study validated the existence of dynamic capital structure across the financial sector of Pakistan and reinforced the substantial impact of sectors’ unique environment on leverage mechanism. The results are robust under alternative estimation approaches and offer useful policy implications.
The Influence of the Characteristics of Online Itinerary on Purchasing Behavior
Authors: Jin Qian , Hu Hui , Su Xiaozhi , Morrison Alastair M.
Published: September 2021

This study presents insights into the influence of the characteristics of tourism itineraries on tourist purchasing behavior. We adopted data between 1 August 2019 and 30 November 2019 from the Qunar, the biggest online tourism platform in China and 4366 samples on travel itineraries were obtained. The ordinary least square regression (OLS) method was used. Controlling for product-related and channel-related factors, we demonstrate that in terms of tourism destination choice, outbound tourism products attract an increased number of tourists; in terms of the types of travel, private travel has replaced group travel to become the majority of the tourism market; in terms of the length of travel, mid-term travel (4–6 days) is the first choice, outnumbering short-term and long-term ones; price promotions such as discount for early decision, multi-person price reduction and membership prices significantly lead to increased sales; online reviews also have great impact on tourist purchasing behavior. In sum, this study uses a unique data set to reveal the influence of online tourism product characteristics on sales and provide potential guidance of the marketing strategy in response to consumer behavior for the online tourism industry.
Compensation for the Lack of Measured Data on Decisive Cultivation Conditions in Diversified Territories without Losing Correct Information
Authors: Miklós László , Kočický Dušan , Izakovičová Zita , Špinerová Anna , Miklósová Viktória
Published: September 2021

Sustainable precision agriculture requires site-specific management procedures. This needs appropriate information combining traditional measured data and mapped conditions, models, and specific interpretation. It is impossible to cover the entire variety of sites in the territory with measuring devices, and therefore the measured data are insufficient for a detailed description of changing conditions on each geographical unit. However, detailed data on the morphology and pedologic conditions are usually available, and their synthesis creates the basis for detailed interpolation of the entire area’s measured data and mapping. This article presents a procedure for the synthesis of morphometric and soil indices resulting in the definition and mapping of morpho-pedotops, the interpretation of their thermal–moisture condition, and, consequently, the comparison of these conditions with the condition on the sites with installed sensor stations. This procedure enables reasonable logic interpolation of the measured microclimatic data by sensor stations to the whole study area. The result is the definition of the thermal–moisture condition of the whole territory in comparison to the measured sites. Therefore, the results provide the basis for interpolation for the forecast of climatic events developed for the sites of sensor stations to the whole study area and the forecast of temporal disease events, and thus the basis for precise site-specific field management interventions, even in the case of the lack of the whole area covering measured data.
A Fractal Approach to Urban Boundary Delineation Based on Raster Land Use Maps: A Case of Shanghai, China
Authors: Zhao Chong , Li Yu , Weng Min
Published: September 2021

Given the diverse socioecological consequences of rapid urban sprawl worldwide, the delineation and monitoring of urban boundaries have been widely used by local governments as a planning instrument for promoting sustainable development. This study demonstrates a fractal method to delineate urban boundaries based on raster land use maps. The basic logic is that the number of built-up land clusters and their size at each dilation step follows a power-law function. It is assumed that two spatial subsets with distinct fractal characteristics would be obtained when the deviation between the dilation curve and a straight line reaches the top point. The top point is regarded to be the optimum threshold for classifying the built-up land patches, because the fractality of built-up land would no longer exist beyond the threshold. After that, all the built-up land patches are buffered with the optimum threshold and the rank-size distribution of new clusters can be re-plotted. Instead of artificial judgement, hierarchical agglomerative clustering is utilized to automatically classify the urban and rural clusters. The approach was applied to the case of Shanghai, the most rapidly urbanizing megacity in China, and the dynamic changes of the urban boundaries from 1994 to 2016 were analyzed. On this basis, urban–rural differences were further explored through several fractal or nonfractal indices. The results show that the proposed fractal approach can accurately distinguish the urban boundary without subjective choice of thresholds. Extraordinarily different fractal dimensions, aggregation and density and similar average compactness were further identified between built-up land in urban and rural areas. The dynamic changes in the urban boundary indicated rapid urban sprawl within Shanghai during the study period. In view of the popularization and global availability of raster land use maps, this paper adds fuels to the cutting-edge topic of distinguishing the morphological criteria to universally describe urban boundaries.
Comprehensive Evaluation of the Importance of Ecological Land in Arid Hilly Cities in Northwest China: A Case Study of the Core Urban Area of Lanzhou
Authors: Liu Yiping , Lu Chengpeng , Mao Jinhuang , Pang Jiaxing , Liu Zhiliang , Hou Muchen
Published: September 2021

Cities in hilly arid areas of northwest China have generally experienced a low level of economic development; they also have unique natural characteristics such as climate, soil, terrain, environment, and surface cover. High quality ecological lands are those that provide humans and the environment with relatively high levels of ecological services including soil, water, and air purification, adsorbing pollutants, or providing water or nutrients needed by plants. In this study, ecological lands were classified as woodland, grassland, water area, and bare land. The present study constructed an ecological land model designed to evaluate the importance of such land from the perspective of ecological service function and ecological demand intensity. Results revealed that: (1) This model can help researchers to better analyze the structure and spatial characteristics of ecological land in cities and also meet the needs of ecological protection and urban management in highly urbanized areas. (2) In terms of ecological service function and ecological demand intensity, the most important ecological land is mostly distributed in densely populated and urbanized areas, and the spread of urbanization is conducive to the improvement of land ecological value for the arid hilly area of northwest China. (3) Among all types of ecological land, the water area had the highest ecological value in the study area, while the grassland had the most potential for improvement, as careful planning and use can allow grassland to function as an ecological barrier while providing good, aesthetically pleasing space for leisure activities for the general public. (4) Qilihe and Xigu districts have more generally important graded areas of forest, grassland, and bare land, although the current ecological value of these lands is limited, though they have great potential for ecological improvement.
Teaching via Zoom: Emergent Discourse Practices and Complex Footings in the Online/Offline Classroom Interface
Authors: Bannink Anne , Van Dam Jet
Published: September 2021

The COVID-19 pandemic caused educational institutions across the world to face a new reality: when teachers and students do not share the same physical space (fractured ecologies), drastic changes in the everyday procedures and routines of teaching become an immediate necessity. In this paper, we trace some of the effects of this new situation in online classes of three experienced university teachers in the early days of the pandemic. We zoom in on dimensions of the classroom interface such as: turn-taking procedures, socialization, peer scaffolding and feedback; strategic footing changes across institutional and conversational roles; joking and humor. Not surprisingly, we found that the systematic absence of multimodal contextualization cues like gaze direction and tracing the origin of sound/speech were a trouble source in these online multiparty settings. We also saw, however, that teachers and students were successful in reinventing themselves and in devising new ways to deal with the changed circumstances. We end the paper with a number of implications for research into the classroom interface, both online and offline.
Production-Distribution Model Considering Traceability and Carbon Emission: A Case Study of the Indonesian Canned Fish Food Industry
Authors: Handayani Dwi Iryaning , Masudin Ilyas , Rusdiansyah Ahmad , Suharsono Judi
Published: September 2021

Background: Traceability systems and carbon emissions are two important factors involved in production and distribution activities. The involvement of these two factors in production and distribution activities along the supply chain will ensure the safety and quality of food through the manufacture, packaging and distribution of products with minimal costs and in an environmentally friendly way. Objective: This study aimed to develop a model of canned fish food production and distribution integration by considering traceability and carbon emissions to minimize total costs. Method: A mixed-integer linear programming (MILP) approach was used to develop mathematical models and the optimal solution of the model created was obtained using an open-source spreadsheet solver program. Results: The results show that the proposed models produce the minimum total production and distribution cost with high traceability and low carbon emissions. Conclusions: The sensitivity analysis from this study shows that there is a significant relationship between production, carbon emissions, and the total cost of production-distribution. Moreover, it was concluded that the production level, carbon emission level, and emission threshold can have a significant influence in the generation of the total carbon emissions.
CFD Analysis of Journal Bearing with a Heterogeneous Rough/Smooth Surface
Authors: Tauviqirrahman Mohammad , Jamari J. , Wicaksono Arjuno Aryo , Muchammad M. , Susilowati S. , Ngatilah Yustina , Pujiastuti Caecilia
Published: September 2021

In the present study, a computational investigation into acoustic and tribological performances in journal bearings is presented. A heterogeneous pattern, in which a rough surface is engineered in certain regions and is absent in others, is employed to the bearing surface. The roughness is assumed to follow the sand-grain roughness model, while the bearing noise is solved based on broadband noise source theory. Three types of heterogeneous rough/smooth journal bearings exhibiting different placement and number of the rough zone are evaluated at different combinations of eccentricity ratio using the CFD method. Numerical results show that the heterogeneous rough/smooth bearings can supply lower noise and larger load-carrying capacity in comparison with conventional bearings. Moreover, the effect on the friction force is also discussed.
Image Processing of Mg-Al-Sn Alloy Microstructures for Determining Phase Ratios and Grain Size and Correction with Manual Measurement
Authors: Ercetin Ali , Akkoyun Fatih , Şimşir Ercan , Pimenov Danil Yurievich , Giasin Khaled , Gowdru Chandrashekarappa Manjunath Patel , Lakshmikanthan Avinash , Wojciechowski Szymon
Published: September 2021

The study of microstructures for the accurate control of material properties is of industrial relevance. Identification and characterization of microstructural properties by manual measurement are often slow, labour intensive, and have a lack of repeatability. In the present work, the intermetallic phase ratio and grain size in the microstructure of known Mg-Sn-Al alloys were measured by computer vision (CV) technology. New Mg (Magnesium) alloys with different alloying element contents were selected as the work materials. Mg alloys (Mg-Al-Sn) were produced using the hot-pressing powder metallurgy technique. The alloys were sintered at 620 °C under 50 MPa pressure in an argon gas atmosphere. Scanning electron microscopy (SEM) images were taken for all the fabricated alloys (three alloys: Mg-7Al-5Sn, Mg-8Al-5Sn, Mg-9Al-5Sn). From the SEM images, the grain size was counted manually and automatically with the application of CV technology. The obtained results were evaluated by correcting automated grain counting procedures with manual measurements. The accuracy of the automated counting technique for determining the grain count exceeded 92% compared to the manual counting procedure. In addition, ASTM (American Society for Testing and Materials) grain sizes were accurately calculated (approximately 99% accuracy) according to the determined grain counts in the SEM images. Hence, a successful approach was proposed by calculating the ASTM grain sizes of each alloy with respect to manual and automated counting methods. The intermetallic phases (Mg17Al12 and Mg2Sn) were also detected by theoretical calculations and automated measurements. The accuracy of automated measurements for Mg17Al12 and Mg2Sn intermetallic phases were over 95% and 97%, respectively. The proposed automatic image processing technique can be used as a tool to track and analyse the grain and intermetallic phases of the microstructure of other alloys such as AZ31 and AZ91 magnesium alloys, aluminium, titanium, and Co alloys.
The Expression of Allele Changes in NLRP3 (rs35829419) and IL-1β (+3954) Gene Polymorphisms in Periodontitis and Coronary Artery Disease
Authors: Mahendra Jaideep , Rao Abirami Nayaki , Mahendra Little , Sayed Mohammed E. , Mugri Maryam H. , Balaji Thodur Madapusi , Varadarajan Saranya , Jagannathan Raghunathan , Srinivasan Sruthi , Baeshen Hosam Ali , Mathew Reji , Patil Shankargouda
Published: September 2021

Background: Inflammasomes have been shown to play a pivotal role in periodontal disease pathogenesis. However, their role in periodontitis subjects with coronary heart disease remains unclear. This study aimed to obtain the expression of NLRP3 (rs35829419) and IL-1β (+3954) gene polymorphisms in the subgingival plaque and blood samples of generalized periodontitis (GP) subjects with and without coronary heart disease (CHD). Methods: A total of 70 subjects were grouped into two; GP and GP with CHD. Demographic variables and periodontal and cardiac parameters were recorded from both the groups. Subgingival plaque and blood samples were obtained from both the groups and were further subjected to the identification of NLRP3 (rs35829419) and IL-1β (+3954) expression and allele change using a conventional polymerase chain reaction (PCR) and gene sequencing (Sanger’s method). Results: Amongst the demographic variables, age and monthly income were statistically significant between the two groups. Plaque index (PI), clinical attachment level (CAL), high-density lipoprotein (HDL), and low density-lipoprotein (LDL) exhibited statistically significant levels between the two groups. The NLRP3 (rs35829419) and IL-1β (+3954) genes showed a statistically significant association with allele change (frequency) among the groups. The general comparison of all the parameters with the allele change of NLRP3 (rs35829419) and IL-1β (+3954) in the subgingival plaque and blood samples showed statistically significant associations among the two groups. Conclusion: The present study highlighted an allele change in IL-1β (+3954) gene polymorphisms which may play an important role in the pathogenesis of periodontitis and coronary heart disease.
A Generalized Stress State and Temperature Dependent Damage Indicator Framework for Ductile Failure Prediction in Heat-Assisted Forming Operations
Authors: Camberg Alan A. , Erhart Tobias , Tröster Thomas
Published: September 2021

Heat-assisted forming processes are becoming increasingly important in the manufacturing of sheet metal parts for body-in-white applications. However, the non-isothermal nature of these processes leads to challenges in evaluating the forming limits, since established methods such as Forming Limit Curves (FLCs) only allow the assessment of critical forming strains for steady temperatures. For this reason, a temperature-dependent extension of the well-established GISSMO (Generalized Incremental Stress State Dependent Damage Model) fracture indicator framework is developed by the authors to predict forming failures under non-isothermal conditions. In this paper, a general approach to combine several isothermal FLCs within the temperature-extended GISSMO model into a temperature-dependent forming limit surface is investigated. The general capabilities of the model are tested in a coupled thermo-mechanical FEA using the example of warm forming of an AA5182-O sheet metal cross-die cup. The obtained results are then compared with state of the art of evaluation methods. By taking the strain and temperature path into account, GISSMO predicts greater drawing depths by up to 20% than established methods. In this way the forming and so the lightweight potential of sheet metal parts can by fully exploited. Moreover, the risk and locus of failure can be evaluated directly on the part geometry by a contour plot. An additional advantage of the GISSMO model is the applicability for low triaxialities as well as the possibility to predict the materials behavior beyond necking up to ductile fracture.
Review on the Integration of Microelectronics for E-Textile
Authors: Simegnaw Abdella Ahmmed , Malengier Benny , Rotich Gideon , Tadesse Melkie Getnet , Van Langenhove Lieva
Published: September 2021

Modern electronic textiles are moving towards flexible wearable textiles, so-called e-textiles that have micro-electronic elements embedded onto the textile fabric that can be used for varied classes of functionalities. There are different methods of integrating rigid microelectronic components into/onto textiles for the development of smart textiles, which include, but are not limited to, physical, mechanical, and chemical approaches. The integration systems must satisfy being flexible, lightweight, stretchable, and washable to offer a superior usability, comfortability, and non-intrusiveness. Furthermore, the resulting wearable garment needs to be breathable. In this review work, three levels of integration of the microelectronics into/onto the textile structures are discussed, the textile-adapted, the textile-integrated, and the textile-based integration. The textile-integrated and the textile-adapted e-textiles have failed to efficiently meet being flexible and washable. To overcome the above problems, researchers studied the integration of microelectronics into/onto textile at fiber or yarn level applying various mechanisms. Hence, a new method of integration, textile-based, has risen to the challenge due to the flexibility and washability advantages of the ultimate product. In general, the aim of this review is to provide a complete overview of the different interconnection methods of electronic components into/onto textile substrate.
A Novel Simulation Method of Micro-Topography for Grinding Surface
Authors: An Qi , Suo Shuangfu , Bai Yuzhu
Published: September 2021

A novel simulation method of microtopography for grinding surface was proposed in this paper. Based on the theory of wavelet analysis, multiscale decomposition of the measured topography was conducted. The topography was divided into high frequency band (HFB), theoretical frequency band (TFB), and low frequency band (LFB) by wavelet energy method. The high-frequency and the low-frequency topography were extracted to obtain the digital combination model. Combined with the digital combination model and the theoretical topography obtained by geometric simulation method, the simulation topography of grinding surface can be generated. Moreover, the roughness parameters of the measured topography and the simulation topography under different machining parameters were compared. The maximum relative error of Sa, Sq, Ssk and Sku were 1.79%, 2.24%, 4.69% and 4.73%, respectively, which verifies the feasibility and accuracy of the presented method.
A Study to Derive Equivalent Mechanical Properties of Porous Materials with Orthotropic Elasticity
Authors: Pyo Changmin , Kim Younghyun , Kim Jaewoong , Kang Sungwook
Published: September 2021

The need for diverse materials has emerged as industry becomes more developed, and there is a need for materials with pores in various industries, including the energy storage field. However, there is difficulty in product design and development using the finite element method because the mechanical properties of a porous material are different from those of a base material due to the pores. Therefore, in this study, a Python program that can estimate the equivalent property of a material with pores was developed and its matching was verified through comparison with the measurement results. For high-efficiency calculation, the pores were assumed to be circular or elliptical, and they were also assumed to be equally distributed in each direction. The material with pores was assumed to be an orthotropic material, and its equivalent mechanical properties were calculated using the equivalent strain and equivalent stress by using the appropriate material property matrix. The material properties of a specimen with the simulated pores were measured using UTM, and the results were compared with the simulation results to confirm that the degree of matching achieved 6.4%. It is expected that this study will contribute to the design and development of a product in the industrial field.
Improvement and Soil Consistency of Sand–Clay Mixtures Treated with Enzymatic-Induced Carbonate Precipitation
Authors: Mo Yixin , Yue Songlin , Zhou Qizhen , Liu Xiao
Published: September 2021

Recently, microbially induced carbonate precipitation (MICP) has been studied as an alternative for the improvement of sand–clay mixtures. However, the cementing uniformity of MICP-treated sand–clay mixtures cannot be guaranteed. In this present study, enzymatic-induced carbonate precipitation (EICP) was used to deal with it. The ions used in kaolin clay was predicted to affect the production rate for calcium carbonate (CaCO3), which was studied using the calcification test. The solidification test was conducted using two different methods (the premixing method and the diffusion method). The permeability, unconfined compressive strength and the content of CaCO3 of treated samples were obtained to evaluate the solidification effect of the EICP method. Moreover, in EICP treatment, the particle aggregation decreased the liquid limit, but the addition of solution increased it. Therefore, there were contrary effects to the soil consistency. In this study, the two types of liquid limits of treated samples were measured with deionized water and 2M-NaCl brine, respectively. The results show that the Al2O3, NaCl and MgCl2 in the kaolin clay had a slight impact on the production rate for CaCO3, while FeCl3 significantly inhibited it. The EICP method can improve sand–clay mixtures and decrease their permeability. Different from MICP, the EICP method can guarantee the uniformity of treated samples. Moreover, the liquid limit of the sample treated with the premixing method decreased, while that of the sample treated with the diffusion method increased firstly and then decreased with the increasing treatment cycles. Different from the deionized water, the pore-fluid chemistry had a larger effect on the liquid limit with 2M-NaCl brine.
Adaptive Levenberg–Marquardt Algorithm: A New Optimization Strategy for Levenberg–Marquardt Neural Networks
Authors: Yan Zhiqi , Zhong Shisheng , Lin Lin , Cui Zhiquan
Published: September 2021

Engineering data are often highly nonlinear and contain high-frequency noise, so the Levenberg–Marquardt (LM) algorithm may not converge when a neural network optimized by the algorithm is trained with engineering data. In this work, we analyzed the reasons for the LM neural network’s poor convergence commonly associated with the LM algorithm. Specifically, the effects of different activation functions such as Sigmoid, Tanh, Rectified Linear Unit (RELU) and Parametric Rectified Linear Unit (PRLU) were evaluated on the general performance of LM neural networks, and special values of LM neural network parameters were found that could make the LM algorithm converge poorly. We proposed an adaptive LM (AdaLM) algorithm to solve the problem of the LM algorithm. The algorithm coordinates the descent direction and the descent step by the iteration number, which can prevent falling into the local minimum value and avoid the influence of the parameter state of LM neural networks. We compared the AdaLM algorithm with the traditional LM algorithm and its variants in terms of accuracy and speed in the context of testing common datasets and aero-engine data, and the results verified the effectiveness of the AdaLM algorithm.
Convergence Analysis of a Numerical Method for a Fractional Model of Fluid Flow in Fractured Porous Media
Authors: Baigereyev Dossan , Alimbekova Nurlana , Berdyshev Abdumauvlen , Madiyarov Muratkan
Published: September 2021

The present paper is devoted to the construction and study of numerical methods for solving an initial boundary value problem for a differential equation containing several terms with fractional time derivatives in the sense of Caputo. This equation is suitable for describing the process of fluid flow in fractured porous media under some physical assumptions, and has an important applied significance in petroleum engineering. Two different approaches to constructing numerical schemes depending on orders of the fractional derivatives are proposed. The semi-discrete and fully discrete numerical schemes for solving the problem are analyzed. The construction of a fully discrete scheme is based on applying the finite difference approximation to time derivatives and the finite element method in the spatial direction. The approximation of the fractional derivatives in the sense of Caputo is carried out using the L1-method. The convergence of both numerical schemes is rigorously proved. The results of numerical tests conducted for model problems are provided to confirm the theoretical analysis. In addition, the proposed computational method is applied to study the flow of oil in a fractured porous medium within the framework of the considered model. Based on the results of the numerical tests, it was concluded that the model reproduces the characteristic features of the fluid flow process in the medium under consideration.