119 research outputs found

    Investigation on coming out phenomenon of the shaft from the sleeve by 2-D plate model approach  

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    The ceramics roller can to be used in the heating furnace because of high temperature resistance. The roller consists of ceramics sleeve and steel shaft connected by shrink fitting. Since ceramics is brittle, it should be noted that only low shrink fitting ratio can be applied for the connection. Therefore, coming out of the shaft from the sleeve during rotation should be investigated in this study. In this study, the finite element analysis is applied to simulate this phenomenon. In the previous study, mechanism of coming out has been considered by using 3-D model. However, since 3-D model analysis needs large computational time, only small number of cycle can be considered, and therefore, the coming out phenomenon cannot be predicted easily. In this research, the 2-D plate model approach is proposed in order to reduce computational time, considering the upper and lower alternate load, repeatedly. Then, the effects of the magnitude of the load and shrink fitting ratio are investigated systematically. Finally, the simulation of the coming out phenomenon can be carried out for much larger number of cycles

    Investigation on coming out phenomenon of the shaft from the sleeve by 2-D plate model approach  

    Get PDF
    The ceramics roller can to be used in the heating furnace because of high temperature resistance.The roller consists of ceramics sleeve and steel shaft connected by shrink fitting. Since ceramics is brittle, it should be noted that only low shrink fitting ratio can be applied for the connection. Therefore, coming out of the shaft from the sleeve during rotation should be investigated in this study. In this study, the finite element analysis is applied to simulate this phenomenon. In the previous study, mechanism of coming out has been considered by using 3-D model. However, since 3-D model analysis needs large computational time, only small number of cycle can be considered, and therefore, the coming out phenomenon cannot be predicted easily. In this research, the 2-D plate model approach is proposed in order to reduce computational time, considering the upper and lower alternate load, repeatedly. Then, the effects of the magnitude of the load and shrink fitting ratio are investigated systematically. Finally, the simulation of the coming out phenomenon can be carried out for much larger number of cycles.4th International Conference on Fracture Fatigue and Wear, FFW 2015, Ghent University, Belgium, 27-28 August 201

    Residual stress generation mechanism for hot strip composite rolls during quenching process

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    Composite rolls are widely used in hot rolling mill because of the excellent hardness, wear resistance and high temperature properties. During hot rolling process, composite rolls are subjected to heating-cooling thermal cycles from the hot strip contact and water cooling. The thermal stress is added to already existing residual stress. The thermal fatigue cracking appears at roll surface, and the fracture is possible happen in roll centre when the tensile stress exceeds the centre strength. Therefore, residual stress plays an important role in composite roll. In this paper, FEM (finite element method) simulation is performed to investigate the generation mechanism of the residual stress during quenching process. It should be notedthat a large number of experimental data of the core and shell materials are utilized for the wide range oftemperature considering the quenching process. The results verify that initially the tensile stress appears on the roll surface but finally the compressive stress occurs.Proceedings of 4th International Conference on Fracture Fatigue and Wear, FFW 2015, Ghent University, Belgium, 27-28 August 201

    Identification of Close Relatives in the HUGO Pan-Asian SNP Database

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    The HUGO Pan-Asian SNP Consortium has recently released a genome-wide dataset, which consists of 1,719 DNA samples collected from 71 Asian populations. For studies of human population genetics such as genetic structure and migration history, this provided the most comprehensive large-scale survey of genetic variation to date in East and Southeast Asia. However, although considered in the analysis, close relatives were not clearly reported in the original paper. Here we performed a systematic analysis of genetic relationships among individuals from the Pan-Asian SNP (PASNP) database and identified 3 pairs of monozygotic twins or duplicate samples, 100 pairs of first-degree and 161 second-degree of relationships. Three standardized subsets with different levels of unrelated individuals were suggested here for future applications of the samples in most types of population-genetics studies (denoted by PASNP1716, PASNP1640 and PASNP1583 respectively) based on the relationships inferred in this study. In addition, we provided gender information for PASNP samples, which were not included in the original dataset, based on analysis of X chromosome data

    Population Genetic Structure of Peninsular Malaysia Malay Sub-Ethnic Groups

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    Patterns of modern human population structure are helpful in understanding the history of human migration and admixture. We conducted a study on genetic structure of the Malay population in Malaysia, using 54,794 genome-wide single nucleotide polymorphism genotype data generated in four Malay sub-ethnic groups in peninsular Malaysia (Melayu Kelantan, Melayu Minang, Melayu Jawa and Melayu Bugis). To the best of our knowledge this is the first study conducted on these four Malay sub-ethnic groups and the analysis of genotype data of these four groups were compiled together with 11 other populations' genotype data from Indonesia, China, India, Africa and indigenous populations in Peninsular Malaysia obtained from the Pan-Asian SNP database. The phylogeny of populations showed that all of the four Malay sub-ethnic groups are separated into at least three different clusters. The Melayu Jawa, Melayu Bugis and Melayu Minang have a very close genetic relationship with Indonesian populations indicating a common ancestral history, while the Melayu Kelantan formed a distinct group on the tree indicating that they are genetically different from the other Malay sub-ethnic groups. We have detected genetic structuring among the Malay populations and this could possibly be accounted for by their different historical origins. Our results provide information of the genetic differentiation between these populations and a valuable insight into the origins of the Malay sub-ethnic groups in Peninsular Malaysia

    European and multi-ancestry genome-wide association meta-analysis of atopic dermatitis highlights importance of systemic immune regulation

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    Atopic dermatitis (AD) is a common inflammatory skin condition and prior genome-wide association studies (GWAS) have identified 71 associated loci. In the current study we conducted the largest AD GWAS to date (discovery N = 1,086,394, replication N = 3,604,027), combining previously reported cohorts with additional available data. We identified 81 loci (29 novel) in the European-only analysis (which all replicated in a separate European analysis) and 10 additional loci in the multi-ancestry analysis (3 novel). Eight variants from the multi-ancestry analysis replicated in at least one of the populations tested (European, Latino or African), while two may be specific to individuals of Japanese ancestry. AD loci showed enrichment for DNAse I hypersensitivity and eQTL associations in blood. At each locus we prioritised candidate genes by integrating multi-omic data. The implicated genes are predominantly in immune pathways of relevance to atopic inflammation and some offer drug repurposing opportunities.</p

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
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