bluuebunny/crossref_metadata_2025 huggingface dataset:
The COVID-19 pandemic as a fortuitous disruptor in physical education: the case of active homework
Authors: Bailey Richard , Scheuer Claude
Published: April 2022

Measures devised to contain the COVID-19, including isolation, social distancing, and quarantine, have profoundly affected people's lives around the world. One of the consequences of these actions has been a general reduction in the habitual daily physical activity among children and young people for whom schools represent the major setting for the promotion of sports, physically active play, movement skills learning, and other activity supportive of healthy, active lifestyles. Whilst acknowledging the seriousness of these changes, and their concomitant health risks, we suggest that COVID-19 offers an opportunity to think again about important features of school-based activity promotion in light of new lessons learnt during lockdown, emerging technologies, and adapted pedagogies. In these specific cases, COVID-19 could be judged a “fortuitous disruptor” to the extent that it has opened a window of opportunity to schools and teachers to reflect on their assumptions about the scope, content, and delivery of their curricula, and on the new professional knowledge that has emerged. Active Homework, or physical activity-related tasks assigned to students by teachers that are meant to be carried out before, after and away from school, that students can do on their own or with family members, is not a new idea, but the enforced changes to school provision have made it considerably more common since the pandemic. Perhaps Active Homework is a concept worth retaining as schools start to return to “normal”? We offer a typology of Active Homework, and examine opportunities to expand, extend, and enhance physical education and physical activity opportunities by breaking down the presumed boundary between school and home. In conclusion, we suggest that Active Homework is worth exploring as a potentially valuable approach to enhancing the quantity and quality of students' school-based health-related physical activity. If so, considerably more research and curriculum development is needed.
Investigations on alkali-silica reaction products using Raman spectroscopy
Authors: Krüger M.E. , Thome V. , Hilbig H. , Kaliwoda M. , Heinz D.
Published: April 2022

The alkali-silica reaction (ASR) remains a major challenge regarding the durability of concrete structures. The reaction mechanism is not sufficiently understood owing to the difficulty in characterizing the structure of the alkali-silica reaction gel (ASR gel) in concrete. Synthetic ASR gels with different compositions, i.e. Na/Si and Ca/Si molar ratios, were synthesized and analysed by Raman spectroscopy and, for comparison, 29Si NMR spectroscopy. The results show that higher Na/Si ratios increase the number of non-bridging oxygens in the gel structure, thus leading to a decrease in the degree of cross-linking. With increasing calcium content of the sodium-calcium silica gel, the structure tends towards that of C-S-H phases. Raman spectroscopy is a promising method to characterise synthetic ASR gels and provide new information on the effect of alkalis on the gel structure.
Ecological and Economic Importance of Wetlands and Their Vulnerability
Authors: Bhowmik Sudipto
Published: April 2022

Wetlands show a diversity of appearances like salt marshes, tidal wetlands, inland freshwater wetlands, riparian wetlands, peat lands, and many other types. Each of the types host diverse biotic communities of flora and fauna. This biodiversity changes according to the physical and chemical properties of wetlands, climate, and the geological location. This biodiversity regulates the local ecosystem, carbon sequestration, fuelwood supply, fishery-based industries, and on many other ecological and socioeconomic aspects. In addition, the wetlands have other ecological aspects like maintaining freshwater quality by sedimentation, nutrient conservation, etc. However, around the world, the wetlands are subjected to several types of threats like both anthropogenic and natural. This study is a short review work on some of the outcomes of the studies of researchers around the world to see the importance of different types of wetlands, the threats to them by anthropogenic or natural causes, and focus areas for management strategy development.
Receding Dependence on Forests
Authors: Vijayah T. Anantha
Published: April 2022

This chapter considers how modernity has affected the livelihood of Paliyar community and how they have been affected by forest dispossession. Whether the weaning away from the forests has been manufactured or part of the systemic exploitation is discernible. The chapter traces the history of the Paliyars, their belief structures, and indigenous knowledge within sacred spaces. The chapter also presents a discussion of the relation between land and spiritual tradition as well as the importance of land to identity, transfer of oral tradition, and indigenous traditional knowledge. Removing the Paliyar from the land continues to erode their tradition, knowledge, and identity.
Promoting Ecosystems Conservation and Community-Based Economic Alternatives in a Changing Climate
Authors: Salgueiro Joana , Vieira José Guilherme Moreira Simões , Alves Fátima , Soares Amadeu M. V. M. , Azeiteiro Ulisses Miranda , Morgado Fernando
Published: April 2022

Cananéia is the southernmost city in the state of São Paulo, Brazil. It is a municipality where the tertiary sector is the main contributor to the economy parallel to the maintenance of artisanal fishing activities. The authors perform a study on the impact of tourism in the municipality area (performed through surveys in an attempt to determine how the different population segments [residents, promoters, users] see the activity and its impacts on nature and on the local economy). The majority of tourists surveyed come from the state of São Paulo (83.3%) and the rest of Santa Catarina and Paraná, with ages from 19-25 (36.7%) (70% having higher education). 43.3% of the inquired stated that tourism is not correctly managed (however without relevant environmental impacts). 93.3% of the boaters and 66.7% of the interviewed referred lack of information about the sites ecology and the drivers of change of biodiversity, ecosystem services, and climate change. Questionnaires results clearly demonstrated the need for visitor information and interpretation envisaging sustainable tourism implementation.
Forest Firefighting Monitoring System Based on UAV Team and Remote Sensing
Authors: Zharikova Maryna , Sherstjuk Vladimir
Published: April 2022

In this chapter, the authors propose an approach to using a heterogeneous team of unmanned aerial vehicles and remote sensing techniques to perform tactical forest firefighting operations. The authors present the three-level architecture of the multi-UAV-based forest firefighting monitoring system; features of patrolling, confirming, and monitoring missions; as well as functions of UAV in such missions. The authors consider an infrastructure for the UAV ground support and equipment used for the UAVs control. The method of the data integration into a fire-spreading model in a real-time DSS for the forest fire response is proposed. The proposed approach has been tested with the multi-UAV team that included three drones for the patrol missions, one helicopter for the confirmation mission, and one octocopter for the monitoring mission. The performance of such multi-UAV team has been studied in the laboratory conditions. The result of the experiment has shown that the proposed approach provides required credibility and efficiency of fire prediction and response.
Machine Learning and Convolution Neural Network Approaches to Plant Leaf Recognition
Authors: K. V. N. Rajesh , D. Lalitha Bhaskari
Published: April 2022

Plants are very important for the existence of human life. The total number of plant species is nearing 400 thousand as of date. With such a huge number of plant species, there is a need for intelligent systems for plant species recognition. The leaf is one of the most important and prominent parts of a plant and is available throughout the year. Leaf plays a major role in the identification of plants. Plant leaf recognition (PLR) is the process of automatically recognizing the plant species based on the image of the plant leaf. Many researchers have worked in this area of PLR using image processing, feature extraction, machine learning, and convolution neural network techniques. As a part of this chapter, the authors review several such latest methods of PLR and present the work done by various authors in the past five years in this area. The authors propose a generalized architecture for PLR based on this study and describe the major steps in PLR in detail. The authors then present a brief summary of the work that they are doing in this area of PLR for Ayurvedic plants.
Occurrence of Pesticides and Their Removal From Aquatic Medium by Adsorption
Authors: Sofi Irfan Rashid , Bhat Rayees Ahmad , Quadir Rabia , Manzoor Javid
Published: April 2022

Large amounts of pesticides are used annually, and in some cases, a part of the pesticide enters the water bodies by surface runoff to form long-term residues. In the recent past, the adverse effects of pesticides on the environment and human health received serious attention by the public and the competent authorities. Various conventional methods are used to remove these pesticides from water, but those methods are either costly or typical in operation. Therefore, adsorption is considered as an ecofriendly method. The adsorbent derived from biomaterial is considered an encouraging adsorbent due to its cost-effective and high adsorption capacity. In this chapter, detailed information on different types of pesticides, their metabolites, environmental concerns, and present status on degradation methods using adsorbents will be reviewed. This chapter presents a comprehensive overview on the recent advancement in the utilization of different adsorbents for the removal of pesticides. Overall, this study assists researchers to move forward in exploring a simple and economically viable technique to produce adsorbents with outstanding physiochemical properties and excellent adsorption capacity, so that the pesticides can be removed from aquatic ecosystem.
Optimal Methodology for Detecting Land Cover Change in a Forestry, Lakeside Environment Using NAIP Imagery
Authors: Qiu Xiaomin , Sha Dexuan , Meng Xuelian
Published: April 2022

Mapping land cover change is useful for various environmental and urban planning applications, e.g. land management, forest conservation, ecological assessment, transportation planning, and impervious surface control. As the optimal change detection approaches, algorithms, and parameters often depend on the phenomenon of interest and the remote sensing imagery used, the goal of this study is to find the optimal procedure for detecting urban growth in rural, forestry areas using one-meter, four-band NAIP images. Focusing on different types of impervious covers, the authors test the optimal segmentation parameters for object-based image analysis, and conclude that the random tree classifier, among the six classifiers compared, is most optimal for land use/cover change detection analysis with a satisfying overall accuracy of 87.7%. With continuous free coverage of NAIP images, the optimal change detection procedure concluded in this study is valuable for future analyses of urban growth change detection in rural, forestry environments.
Analysis of Terrestrial Vegetation Trends and Correlation Between Vegetation Indices and Climatic Factors
Authors: M. Dhanapriya , Bhatt Hiren P. , S. P. Vyas
Published: April 2022

The chapter analyzes terrestrial vegetation trends and correlation of vegetation indices with climatic factors like LST, Net Radiation, and TRMM. The result shows the positive vegetation trend might be due to the increased vegetation growth and productivity. Negative vegetation trend might be due to changes in a crop choice. Correlation of vegetation indices with climatic factors like LST showed weak to moderate positive correlation. Net radiation showed moderate negative correlation and TRMM showed a weak negative or positive correlation for both the Kharif and Rabi seasons.
FishEye - An Integrated Marine Species' Visualization
Authors: Nascimento Tiago , Gama Sandra Pereira
Published: April 2022

Despite the historical limitations associated with the study of marine species, current technology makes it possible to collect ocean animal data in a more accessible way, with a variety of tagging and tracking devices. Hence, such information is nowadays generated in large amounts, often in textual formats, making it difficult to interpret and analyze. Information visualization, due to its potential to represent large amounts of data while alleviating cognitive load associated with data interpretation, may help overcome this limitation. This article presents the visualization of a marine species that allows the representation and interactive exploration of species' telemetric data through an integrated dashboard with coordinated views. A species image recognition module was implemented together with the described visualization, enabling species recognition. Usability tests have validated its potential in making important patterns immediately perceivable and also showed that FishEye provides exploration and comparison mechanisms to obtain further relevant information.
Forest Fire Scenarios in Digital Platforms
Authors: Gonçalves Liliana , Oliveira Lídia
Published: April 2022

Forest fires are widespread in Portugal, particularly in the summer. Recently, in 2017, Portugal had two great fires. As a result, more than 120 people died, hundreds suffered injuries and registered significant economic and environmental losses. Since then, and due to the evolution and democratization of the internet and technology devices, forest fire content is much more common in cyberspace. Thus, to understand this issue, the authors propose to outline a profile of the digital platforms used in forest fire situations. The goal is to understand the uses and commitment arising from forest fires' issues in digital platforms by presenting a conceptual framework in Portugal's specific case. The authors analyzed webpages, mobile apps, Facebook pages and groups, and YouTube channels, focusing on forest fires contents. By understanding the kind of digital platform, its contents, uses, and interaction, this chapter contributes to understanding digital platforms' role in crisis and disaster scenarios such as wildfires.
AgroForest Biomass and Circular Bioeconomy
Authors: Leitão Alexandra , Rebelo Francisco , Pintado Manuela , Ribeiro Tânia Bragança
Published: April 2022

The agroforest sector plays a leading role as a biomass supplier to obtain bio-based products that allowed an acceleration in the circular bioeconomy transition. This chapter applied a mixed-methods review to identify new attractive bio-based products and to evaluate its market potential in Portugal. Forest biomass was identified as an excellent raw material for (1) low-carbon building materials, (2) biotextiles, and (3) bioplastics. The potential of agro-food waste to obtain new bio-based materials was also emphasised. The new bioproducts identified have high potential and attractive markets. It was estimated that a 5% market share of these bioproducts in the global construction, textiles, and plastics markets in 2030 corresponds to an aggregate increase in revenues of 260-579 million € per year in Portugal. The environmental sustainability implications arising from the diffusion of these new biomaterials are also highlighted, focusing on the decarbonisation of the economy.
Vulnerability of Forest Vegetation Due to Anthropogenic Disturbances in Western Himalayan Region of India
Authors: Akash  , Navneet  , Bhandari Bhupendra Singh , Bijlwan Kamal
Published: April 2022

The Western Himalayan zone of India is not only threatened by rapid climatic changes, natural floods, and fires, but also by anthropogenic activities. Himalayan forests are vulnerable due to climatic changes and faced severe ecological deterioration due to anthropogenic pressures. The degradation of forests due to anthropogenic disturbances is increasing because of overgrowth of population, high poverty ratio, as well as the limitations of alternative livelihood options. Further resources from forest makes it inseparable to manage forest stands without considering the importance of socio-economic status and ecological aspects of forest management to the well-being of local communities. Therefore, the Himalayan forests and the communities depending on forests should be seen as a part of an evolving. This chapter will explore the vulnerability of the knowledge towards Western Himalayan forests and community-based management of forests. Additionally, it will sketch potential sites affected through anthropogenic pressures.
Kinetics of Heavy Metals Adsorption on Gravels Derived From Subsurface Flow Constructed Wetland
Authors: Defo Celestin , Kaur Ravinder
Published: April 2022

Adsorption kinetics of Ni, Cr, and Pb on gravels collected from constructed wetland was studied at varied metal concentrations and contact period for estimating the removal of heavy metals from wastewater. Batch experiments were conducted by shaking 120 ml of metal solutions having 5 concentration levels each of Ni (1.0, 2.0, 3.5, 5.0 and 6.0 mg l-1), Cr (1.0, 2.0, 3.0, 4.5 and 6.0 mg l-1), and Pb (1.0, 3.0, 6.0, 8.0 and 12.0 mg l-1) with 50 g of gravels for as function of time. Adsorption of Ni, Cr, and Pb on gravels ranged from 34.8 to 47.2, 42.7-54.9, and 47.5-56.9%, indicating their removal in the order: Pb > Cr > Ni. Freundlich model showed a good fit for Ni and Cr (R2>0.9) while Langmuir model fitted better for Pb (R2= 0.7). The pseudo-second-order model showed the best fit to simulate the adsorption rates of these metals on gravel.
Institutional Settings, Renewable Energy Development, and Forest Cover Changes in Sub-Saharan Africa
Authors: Anyokwu Ewere Evelyn , Nweke-Eze Chigozie
Published: April 2022

This chapter explores the roles of institutional settings in renewable energy (RE) development in Sub-Saharan Africa, and the effects of RE development on forest cover changes in the region. The study finds that the slow but persistent growth in RE contribution to total energy bundles can be credited to the general improvements in institutional reforms and frameworks. It also finds that unlike biomass-based RE systems, the indirect deforestation effects associated with solar and wind energy systems, are largely offset by the environmental benefits that accrue from them. Based on these findings, the chapter recommends that coordinated institutional interventions should prioritize the deployment of more environmentally sustainable RE technologies such as solar and wind energies.
An Impact of Rapid Urbanization on Wetlands Destruction in Mumbai Metropolitan Region
Authors: Rode Sanjay Jayawant
Published: April 2022

Wetlands are playing an important role in sustaining human health and wellbeing. They support food production, water treatment and water supply, flood control, fishing, recreation, and wildlife habitat. But wetland areas are shrinking very fast all over the world due to the rapid growth of urbanisation. In devepoing countries, the destruction of the wetlands is widely observed. In India, the wetlands area, size, and number are declinging very fast due to population growth and urbanisation. Mumbai Metropolitan Region is not an exception to this phenomenon. The wetland area is significantly declining in all suburbs of region over the period of time. State government should come out with future plans, legislation, and co-ordination among various bodies and NGOs to protect wetlands in region. The protection and scientific conservation of wetlands will improve wetlands-related services and health of the people in the region.
Urban Forestry in Sabah, Malaysia
Authors: Mojiol Andy Russel , Lim Wing Shen
Published: April 2022

This chapter provides a holistic understanding of the existing conditions of urban green spaces in Sabah by reviewing relevant past studies and publications. Nature serves as the foundation in the establishment of pocket parks, urban parks, and forest protected areas that are made available for public access within and outside of the major urban areas in Sabah. Presently, both native and exotic flora and fauna species are coexisting at the local urban green spaces, although some invasive exotic species have developed into urban pests of Sabah. Moreover, the importance and functions of urban green spaces in maintaining the well-being of mankind and ensuring the survival of indigenous wildlife species are acknowledged by society. Nevertheless, much research is required to fill up the research gaps of urban forestry, and also to provide solutions to the existing problems that happened at the urban green spaces in Sabah.
Biodiversity Conservation and Social Science Underpinnings in the Cordillera Highlands of Northern Philippines
Authors: Abansi Corazon Lumbera
Published: April 2022

This article conducts a literature review and synthesis of social science research on biodiversity in the Cordillera of Northern Philippines. The area hosts key biodiversity sites that need protection and conservation but there is little understanding of the socio-cultural, economic and political dynamics that cause the loss of biodiversity and effective conservation. The review showed unequal distribution of social-science among the different sites in the Cordillera with concentration in urban areas. The reviewed materials showed a wide scope of topics, indicating that the social dimension of biodiversity conservation is complex and multidimensional. For social science research to better inform decision-making in biodiversity conservation, social scientists need to be aggressive and openly engaged with practitioners and local policy makers so that relevant research findings could penetrate biodiversity management practice. Partnership among universities and productive research groups could address the disproportionate distribution of research efforts across sites.
A Neutrosophic Intelligent System for Heart Disease Diagnosis
Authors: Radwan Nouran M. , Hanna Wael K.
Published: April 2022

Heart disease diagnosis depends on vague, imprecise, ambiguity and inconsistent combination of clinical and pathological data. Therefore, researches in these fields tend to the use of intelligent systems to overcome the uncertainty found in data. This paper suggests neutrosophic logic to obtain a better decision of heart diagnosis with the desire to reduce the number of tests required to be taken on a patient and solve the information uncertainty issue. This paper analyses the dataset to extract the five common features that affect heart disease in Egypt, which are blood pressure, blood sugar, cholesterol, chest pain, and maximum heart rate. Then; it presents a neutrosophic diagnosing system for heart disease depends on a dataset from Egyptian persons were used and independently verified by three experts using semi-structured questionnaire. Finally, the comparison results between human experts, and the presented neutrosophic diagnosing system shows an accuracy of 87% of the proposed system compared with 73% of the fuzzy system.
IT Governance Maturity for Uganda's Higher Institutions of Learning
Authors: Ndagire Lillian , Maiga Gilbert , Oyo Benedict
Published: April 2022

The daily application of Information Technology (IT) in public sector organizations and its positioning as a critical driver for economic growth require a focus on implementing IT governance. Despite the increasing application of IT, there is limited academic systematic research regarding the maturity of IT governance and process improvement in Higher Institutions of Learning (HILs). IT in HILs is highly complex, and managing complex systems of processes and platforms in HILs necessitates tools to assess and provide guidelines for integrating organizational processes. This research, therefore, evaluated the IT governance processes in HILs in Uganda and established the maturity level to ensure continuous improvement and organizational maturity. Eight HILs in Uganda were measured using 15 IT processes of the COBIT framework and rated with the generic maturity model. Data were analyzed using MS Excel. Results indicated IT governance maturity level of HILs in Uganda was at level 2 (repeatable).
Factors Driving the Purchase of Mobile Phone Top-Ups Services on Social Commerce Based on a Modified UTAUT Theory
Authors: Liu Yijun , Mensah Isaac Kofi , Fang Ziyang , Mwakapesa Deborah Simon
Published: April 2022

This study explored the factors influencing the behavioral intention of Chinese citizens to purchase mobile-phone top-up services on social commerce from the perspective of WeChat users. The UTAUT was applied as the theoretical framework for the research. A questionnaire instrument was used to acquire the research data from 477 respondents. The data analysis was undertaken by the use of Smart PLS by employing the structural equation modeling (SEM) technique. The results indicate that performance expectancy had a direct significant impact on the purchase of mobile phone top-ups on social commerce. In addition, effort expectancy, electronic word of mouth (eWOM), peer influence, and trust in mobile phone top-up services were respectively positive predictors of both performance expectancy and purchase intentions of mobile phone top-up services on social commerce. Further, the results demonstrate that security was significant in moderating the impact of trust in mobile phone top-up services on the purchase of mobile phone top-up services on social commerce.
Determination of New Plasticity Characteristic of Alloys at Mechanical Compression and Tensile Tests and the Influence of Structural Factors on Plasticity
Authors: Milman Yuly V. , Galanov Boris A. , Goncharuk Victor , Voskoboinik Igor V. , Goncharova Irina
Published: April 2022

In physics and mechanics, plasticity is defined as the ability of a material to undergo irreversible (plastic) deformation. Conventionally, the plastic strain at fracture in tensile tests, δ, has been used as a quantitative measure of plasticity. However, δ does not follow the scientific definition of plasticity. The influence of structural factors, temperature and strain rate on the value of δ were not elaborated over many decades. This lack of well-founded quantitative characteristic hindered efforts to control and to increase plasticity of materials. The plasticity characteristic that corresponds to the scientific definition of this quantity, δ* = plastic strain εр/ total strain εt, has been successfully used by many scientists to determine plasticity δ* by indentation. In the present work, the technique for the determination of the plasticity characteristic δ* during mechanical compression and tensile tests of metallic alloys has been introduced for the first time. In this case, δ* is determined more precisely than by indentation, and the second deformation curve δ*=f*(εt) is constructed. A theory of the influence of structural factors (grain size, dislocation density, disperse particles of the second phase) on the plasticity characteristic δ* has now been developed, making it possible to estimate the influence of the indicated factors on δ* and to design alloys with an optimal combination of strength and plasticity. The discovered correlation of the values of δ* and δ for steels and for aluminum alloys allows us to use the developed theory to calculate the influence of the structural factors on d for these materials as well.
Bayesian Network Modelling: Predictor Impact Assessment in Surface Roughness Prediction
Authors: Hweju Zvikomborero , Abou-El-Hossein Khaled
Published: April 2022

In surface roughness prediction modelling, it is crucial to do away with insignificant variables. Retaining variables that are not statistically significant can lower the formulated model’s accuracy. This paper is a presentation of the Bayesian Linear Regression Model (BLRM) in assessing the impact of predictors in surface roughness prediction of single point diamond turned RSA 443 with the assistance of acquired acoustic emission signal parameter (AErms) and primary cutting parameters. The principles behind the BLRM are presented in this paper. It has been observed that the order of decreasing impact of the parameters is as follows: cutting speed, feed rate, depth of cut and AErms. Furthermore, it has been discovered that the regression model containing cutting speed and feed rate has the best prediction power. Depth of cut and AErms have high probabilities of being rejected as linear regression predictors (0.642 and 0.754, respectively). Validation of the variable responses using p-values at 0.05 significance level has produced the same order of variable significance as that produced by the BLRM. Hence, the BLRM can be reliably utilized as a parameter significance assessment prediction tool.
Numerical Analysis Growth Kinetics of Dendrite Tip during Laser Welding Nickel-Based Single-Crystal Superalloy Part II: Expedient Favorite of Undercooling-Limited Epitaxy
Authors: Gao Zhi Guo
Published: April 2022

When multicomponent molten pool nonequilibrium solidification, the interrelationship of location-dependent dendrite tip undercooling on low heat input and optimal growth crystallography is progressively discussed over planar interface morphology stability range to unidirectionally facilitate epitaxial growth by single-crystallinity control during laser repair of nickel-based superalloy to inhibit microstructure heterogeneity. Suppression of disoriented dendrite growth and crystallography orientation deviation along columnar interface is necessary for crackless repair. Axis-symmetrical (001)/[100] welding configuration kinetically reduces dendrite tip undercooling, nucleation and subsequent disoriented dendrite growth rather than unsymmetrical (001)/[110] welding configuration. When comparison between low heat input, within which laser power is limited and welding speed is rapid, and high heat input, within which laser power is considerable and welding speed is insignificant, the former attenuates dendrite tip undercooling and morphology transition between columnar and equiaxed dendrites to stabilize epitaxy and ameliorate dendrite growth with advantageous solidification conditions, especially drastic temperature gradient and small dendrite growth velocity. Axis-symmetrical growth crystallography and low heat input are favored to mitigate size of high-undercooling region, where stray grain formation are dominant, for homologous single-crystallization of epitaxial growth with satisfactory growth kinetics of dendrite tip, and are capable of elimination of undercooling-induced overgrowth for high quality weld, instead of aggressive unsymmetrical growth crystallography and high heat input. Additionally, the achievement of low heat input with axis-symmetrical welding configuration possesses stronger resistance to unstable interface morphology and solidification cracking. When comparison between growth regions of [100] and [010] crystalline orientation, where identical heat input is kept on both sides, wider dendrite tip undercooling is mainly located on the right side than left side to insidiously exacerbate crack-vulnerable dendrite growth, which is a ubiquitous phenomenon in the adverse (001)/[110] welding configuration. The effect of low heat input on dendrite tip undercooling is spontaneously smaller than growth crystallography. Hence, during nonequilibrium solidification of weld pool, the important mechanism of crystallography-induced microstructure heterogeneity obviation due to undercooling-limited epitaxial growth is consequently provided. The theoretical predictions cogently explain the experiment results in a concise way to properly illustrate microstructure degradation phenomena in the both sides of weld by reproducible calculation of mathematical modeling.
Manufacturing of Complex-Shape PM Products Consisting of Several Powder Elements
Authors: Mironovs Viktors , Zemcenkovs Vjaceslavs , Kuzmina Jekaterina
Published: April 2022

The article’s primary purpose is to give a technological assessment of manufacturing complex-shaped parts using powder metallurgy. The process is considered in the example of a complex-shaped product consisting of several elements manufactured separately from the Fe-C-Cu powder mixture and then combined into a single structure. The joining was carried out by impregnation of porous structural elements with the fusion of copper-containing material. It has been demonstrated that the infiltration process is affected by many factors: porosity of structural elements, wettability of their pore channels, fluid flowability of the infiltrating material, and other factors. The research was carried out on the mass products - centrifugal pump stages for oil production. The elements compaction was carried out on hydraulic press at a pressure of 500 MPa, which ensured the average density of the parts after sintering up to 7.8-8.4 g/cm3. During sintering and impregnation, various types of defects of the pieces were detected, which were caused by the excessive thickness of the infiltrating material, different densities of the walls, and insufficient wettability in the connection zones of the elements.The investigations have shown that manufacturing complex components by prefabricating single elements and their subsequent sintering combined with infiltration is feasible. It can be done in a chamber furnace as well as with belt sintering. However, it is necessary to carefully prepare the mold before sintering, choose the infiltrating agent, and analyse possible disadvantages.
Study on Cracks of Last Freeze in Al-Mg Alloy Flat Ingots
Authors: Yan Wen Duan , Li Yang , Wu Yuan Li
Published: April 2022

In casting of Al-Mg alloy, especially in the aluminum alloy with high Mg content of more than 4 wt.% Mg, some cold cracks were found in last freeze of the flat ingots. The depth of cracks was bigger than 200 mm. The size of scrap removal of ingot was thus increased by 70 mm or more, and the yield of the flat ingots was greatly affected. Air cooling time of more than 20 min after casting was a better to reduce cracks in last freeze of Al-Mg alloy flat ingots.
Evaluation of Hardness Distributions around Fracture Surface in Induction-Heated SUJ2 Steel after Rotating Bending Fatigue Test
Authors: Murai Ryosuke , Mizobe Koshiro , Kida Katsuyuki
Published: April 2022

Induction-heated carbon steel is used in various mechanical parts and the fracture mechanism from internal cracks is still being investigated. In order to explain the fracture mechanism of an induction-heated SUJ2 steel bar specimen, we investigated Vickers hardness distributions around the fracture surface after a rotating bending fatigue test. We found an area which is defined as the transition area near the fracture surface whose HV values decreased about 150 HV and this area was formed by the fatigue crack during the rotating bending fatigue test.
Research on the Tribological Properties of Polyoxymethylene - 40Cr
Authors: Li Xue Lei , Hu Wen Hua , Liu Xiao Hang , Tian Hao Bin
Published: April 2022

Bearing sleeve, as one of important parts of bearing structure, determine the bearing performance directly. In this paper, based on the ball joint structure, the tribological properties between Polyoxymethylene (POM) and 40Cr are studied with Ring-Block method. The effects of friction velocity and applied load on friction coefficient are tested and analysed, the analytical model in friction force, friction velocity and applied load are created, which will provide useful technical data to the application.
Non-Uniform Deformation of Slab during Heavy Reduction Process
Authors: Liu Yang , Zong Nan Fu
Published: April 2022

The bulge deformation of slab narrow face can cause surface defects of hot rolled steel plate. A three-dimensional bulging model, was proposed to simulate the evolution of deformation behavior of the continuous casting slab during heavy reduction (HR). The model was taken to investigate the non-uniform deformation of slab during HR process. The bulging deformation behavior of the slab was then calculated in one segment included seven pairs of rollers. To improve the edge defect on hot-rolled steel plates, the relationship between the reduction amount and bulge deformation of slab narrow face has been investigated.
GELS: Generalized Energy-Based Leader Selection in Bio-Inspired Leader‐Follower AUV Network
Authors: Shaik Shakeera , Pokkuluri Pavan Ganesh S.S. , Venkataraman Hrishikesh
Published: April 2022

Abstract An autonomous underwater vehicle (AUV) is a self-propelled, untethered underwater vehicle with minimal or no human supervision. However, the capability of a single AUV to cover large areas underwater is very limited. In this regard, a swarm of AUVs has gained significant
attention in the recent years for underwater applications such as ocean exploration, mine-sweeping, surveillance, rescue missions, seabed mapping, environmental monitoring, etc. Notably, the swarm-based network can be further classified into two types, based on the architecture: cooperative
multi-AUV network and leader‐follower multi-AUV network. Of these, the leader‐follower multi-AUV network with a Fixed Leader is preferable due to its simple architecture and less operational complexity. However, the inherent energy limitations of the leader in the
leader‐follower model become the bottleneck for an efficient mechanism. Hence, there is a need to design a better mechanism for a multi-AUV network. In this paper, a Generalized Energy-based Leader Selection (GELS) algorithm is proposed for a multi-AUV network to increase the AUV network's
transmission range and duration. Significantly, GELS can be superimposed and integrated with the existing algorithms. This proposed work integrates GELS with two bio-inspired mechanisms: Ant Colony Optimization and Particle Swarm Optimization. The dynamic leader selection using GELS results
more in the travel distance and duration than the Fixed Leader network. This is because, in GELS, based on residual energy, the followers could also be allowed to lead the network; whereas, in fixed leader the followers cannot lead the network.
Comparison of Fentanyl plus different doses of dexamethasone with Fentanyl alone on postoperative pain, nausea, and vomiting after lower extremity orthopedic surgery
Authors: Akbari Ghodrat Akhavan , Erdi Ali Mohammadian , Asri Farzad Nabipour
Published: April 2022

Intravenous patient controlled analgesia (PCA) with opioids to provide perioperative analgesia is commonly used after orthopedic surgery, but have side-effects. Addition of adjutant drugs results in reducing the side-effects and the dosage of opioids. The aim of current study was to evaluation the analgesic efficacy of combination of fentanyl and dexamethasone (8 and 16 mg) in compared with fentanyl alone in patients undergoing orthopedic surgery of the lower extremity. In a double-blind clinical trial, 102 patients were randomly allocated to receive PCA, which included: F+S group (fentanyl 1 mcg/ml + isotonic saline), F+8mD group (fentanyl 1 mcg/ml + dexamethasone 8 mg/ml), and F+16mD group (fentanyl 1 mcg/ml + dexamethasone 16 mg/ml). Anesthesia technique and rescue analgesia regimen were standardized. Postoperatively, pain was assessed based on visual analog scale (VAS). In addition, we evaluated the postoperative nausea and vomiting (POVN) in different groups. In over the post-operative period, the mean VAS-score was significantly lower in the F+16mD group than the F+S and the F+8mD groups (p<0.001 and p<0.01, respectively). In addition, the incidence of PONV significantly was lower in the F+18mD group than the F+S group (p<0.05). We conclude that the addition of preoperative intravenous high dose of dexamethasone (16 mg) to fentanyl was effective in reducing postoperative pain and PONV after orthopedic surgery of the lower extremity.
Influence of Maternal Diabetes on the Risk of Neurodevelopmental Disorders in Offspring in the Prenatal and Postnatal Periods
Authors: Perea Verónica , Urquizu Xavier , Valverde Maite , Macias Marina , Carmona Anna , Esteve Esther , Escribano Gemma , Pons Nuria , Giménez Oriol , Gironés Teresa , Simó-Servat Andreu , Domenech Andrea , Alonso-Carril Núria , Quirós Carme , Amor Antonio J. , López Eva , Barahona Maria José
Published: April 2022

Background: This study aimed to evaluate the influence of maternal diabetes in the risk of neurodevelopmental disorders in offspring in the prenatal and postnatal periods.Methods: This cohort study included singleton gestational diabetes mellitus (GDM) pregnancies >22 weeks’ gestation with live newborns between 1991 and 2008. The control group was randomly selected and matched (1:2) for maternal age, weeks of gestation and birth year. Cox regression models estimated the effect of GDM on the risk of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and maternal type 2 diabetes mellitus (T2DM). Moreover, interaction between maternal T2DM and GDM-ADHD relationship was evaluated.Results: Children (n=3,123) were included (1,073 GDM; 2,050 control group). The median follow-up was 18.2 years (interquartile range, 14.2 to 22.3) (n=323 with ADHD, n=36 with ASD, and n=275 from women who developed T2DM). GDM exposure was associated with ADHD (hazard ratio [HR]crude, 1.67; 95% confidence interval [CI], 1.33 to 2.07) (HRadjusted, 1.64; 95% CI, 1.31 to 2.05). This association remained significant regardless of the treatment (diet or insulin) and diagnosis after 26 weeks of gestation. Children of mothers who developed T2DM presented higher rates of ADHD (14.2 vs. 10%, P=0.029). However, no interaction was found when T2DM was included in the GDM and ADHD models (P>0.05). GDM was not associated with an increased risk of ASD (HRadjusted, 1.46; 95% CI, 0.74 to 2.84).Conclusion: Prenatal exposure to GDM increases the risk of ADHD in offspring, regardless of GDM treatment complexity. However, postnatal exposure to maternal T2DM was not related to the development of ADHD.
Effectiveness of Resistance Exercise on Inflammatory Biomarkers in Patients with Type 2 Diabetes Mellitus: A Systematic Review with Meta-Analysis
Authors: Fernández-Rodríguez Rubén , Monedero-Carrasco Sonia , Bizzozero-Peroni Bruno , Garrido-Miguel Miriam , Mesas Arthur Eumann , Martínez-Vizcaíno Vicente
Published: April 2022

Background: Type 2 diabetes mellitus (T2DM) is related to increased inflammatory processes. The effects of resistance exercise on inflammatory biomarkers in T2DM are controversial. Our purpose was to determine the effectiveness of resistance exercise on inflammatory biomarkers in patients diagnosed with T2DM.Methods: We searched four databases until September 2021. We included randomized clinical trials (RCTs) of the effects of resistance exercise on inflammatory biomarkers (C-reactive protein [CRP], tumor necrosis factor alpha, interleukin-6, and interleukin-10) in patients with T2DM. A random effects meta-analysis was conducted to determine the standardized mean difference (SMD) and the raw mean difference (MD) for CRP.Results: Thirteen RCTs were included in the review, and 11 in the meta-analysis for CRP. Lower CRP levels were observed when resistance exercise was compared with the control groups (SMD=–0.20; 95% confidence interval [CI], –0.37 to –0.02). When conducting the MD meta-analysis, resistance exercise showed a significant decrease in CRP of –0.59 mg/dL (95% CI, –0.88 to –0.30); otherwise, in the control groups, the CRP values increased 0.19 mg/dL (95% CI, 0.17 to 0.21).Conclusion: Evidence supports resistance exercise as an effective strategy to manage systemic inflammation by decreasing CRP levels in patients with T2DM. The evidence is still inconclusive for other inflammatory biomarkers.
The Effects of Challenging Walking Conditions on Kinematic Synergy and Stability of Gait in People with Knee Osteoarthritis
Authors: Shafizadegan Zohreh , Sarrafzadeh Javad , Salehi Reza , Farahmand Farzam , Rasouli Omid
Published: April 2022

Background:

Knee osteoarthritis (KOA) may considerably change the gait parameters, including the gait variability patterns. Uncontrolled manifold (UCM) analysis has been used to evaluate the relationship between motor control and gait variability as a useful index for assessing the multi-segmental movements’ coordination during walking. To our knowledge, no research has evaluated the alterations in the gait kinematic parameters during normal and narrow path walking in individuals with KOA as compared to asymptomatic people.

Materials and Methods:

In this cross-sectional study, individuals diagnosed with mild to moderate medial KOA and asymptomatic people will walk at their comfortable preferred speed on a treadmill. A motion capture system will be used to record at least 50 successful gait cycles. The kinematic variability of joints during gait will be analyzed using UCM, with the center of mass (COM) displacement considered as the performance variable. The primary outcome measure will be the lower limb synergy index. Variability of the COM displacement and changes in angles and angular velocities of lower extremity joints will be assessed as the secondary outcomes.

Results:

The results of this protocol study provide information on the lower limb kinematic synergy during gait on normal and narrow paths for individuals with KOA and asymptomatic controls.

Conclusion:

This information will help the researchers and clinicians understand KOA patients’ gait variability characteristics more deeply. Moreover, it may lead to an enhanced evidence-based approach for clinical decision-making concerning improving gait stability and decreasing the falling risk in these people.
A Possible Novel DBS-0 Like Allele
Authors: Allawati Mujtaba Ali , Balushi Badria Al
Published: April 2022

RHD variants are divided into three categories; weak D, partial D, and Del. The variants detection is important during donor testing and pregnancy. Studies shown that the detection of D variants may be missed by standard serologic methods including Indirect Antihuman Globulin Test and may cause anti-D immunization when exposed to D-negative individual. The limitations of serology can be overcome by RHD gene molecular typing. We describe for the first time a possible novel DBS-0 like allele partial D which revealed serological D and E negative in an Omani donor that is different from the previously described DBS-0 with serological positive D and partial E.