Academic literature on the topic 'SURFACE COMPOSITE VIA'

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Journal articles on the topic "SURFACE COMPOSITE VIA"

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Yuvaraj, N. "Improving the Wear Properties of Aluminum 6082 Alloy by Surface Compositing with Zro2 Ceramic Particles Via Friction Stir Processing." Material Science Research India 15, no. 1 (March 30, 2018): 68–74. http://dx.doi.org/10.13005/msri/150108.

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Aluminum based metal matrix composites are given more attention in fabrication of surface engineering applications due to their excellent mechanical and wear properties. In this study, Friction stir processing (FSP) method was used to fabricate the surface composite with inserting different volume % of ZrO2 reinforcement particles in the Aluminum 6082 alloy. The hardness and triblogical characteristics of fabricated surface composites and base alloy were investigated. The higher volume content of reinforcement surface revealed higher hardness and higher wear resistance compared to the lower volume content reinforcement surface and base material. The wear worn-out of composite surfaces and base alloy were examined through SEM for understanding the wear mechanisms.
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Hou, Yacong, Yubo Liu, Lei Chen, Ding Weng, Yuan Ma, Yadong Yu, Yang Wu, and Jiadao Wang. "Controllable Friction of an Epoxy Composite via Thermal Treatment." Applied Sciences 13, no. 17 (September 1, 2023): 9899. http://dx.doi.org/10.3390/app13179899.

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Smart surfaces with controllable friction have generated considerable attention lately. However, most composites prepared with traditional fillers cannot achieve “real-time” friction conversion. Herein, a new smart surface was designed to achieve different friction coefficients (0.65 and 0.12). Different coefficients of friction were reversibly and precisely controlled via heating. Via friction and heating, 1H,1H,2H,2H-perfluorohexyl hexadecane (PHHD), a kind of phase-change material—paraffin wax—was released from the microcapsules, and a stable and complete film was formed. It changed the interface from “solid-solid” to “solid-liquid” in a dry friction state. The composite contains microcapsules that prevent phase separation between PHHD and matrix, which enables the composite to have a long service time and switchable friction performance. In addition, this composite can maintain its extraordinary ability even in harsh environments like UV irradiation. By demonstrating switchable friction based on changes in the interactions between contact interfaces, this work provides a new principle for designing smart tribological composites.
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Skoura, Eva, Peter Boháč, Martin Barlog, Helena Palková, Martin Danko, Juraj Šurka, Andreas Mautner, and Juraj Bujdák. "Modified Polymer Surfaces: Thin Films of Silicate Composites via Polycaprolactone Melt Fusion." International Journal of Molecular Sciences 23, no. 16 (August 15, 2022): 9166. http://dx.doi.org/10.3390/ijms23169166.

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Polymer/layered silicate composites have gained huge attention in terms of research and industrial applications. Traditional nanocomposites contain particles regularly dispersed in a polymer matrix. In this work, a strategy for the formation of a composite thin film on the surface of a polycaprolactone (PCL) matrix was developed. In addition to the polymer, the composite layer was composed of the particles of saponite (Sap) modified with alkylammonium cations and functionalized with methylene blue. The connection between the phases of modified Sap and polymer was achieved by fusing the chains of molten polymer into the Sap film. The thickness of the film of several μm was confirmed using electron microscopy and X-ray tomography. Surfaces of precursors and composite materials were analyzed in terms of structure, composition, and surface properties. The penetration of polymer chains into the silicate, thus joining the phases, was confirmed by chemometric analysis of spectral data and changes in some properties upon PCL melting. Ultimately, this study was devoted to the spectral properties and photoactivity of methylene blue present in the ternary composite films. The results provide directions for future research aimed at the development of composite materials with photosensitizing, photodisinfection, and antimicrobial surfaces.
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Marzuki, Haslan Fadli Ahmad, Mawarni Mohamad, Engku Ahmadhilmi Engku Ubaidillah, Mohd Nasha’ain Nordin, Mohd Fadzlee Zainal Abidin, Norazlan Roslani, Yusli Mohamad Junos, Salleh Omar, and Mariatti Jaafar. "Effect of Anodizing on Strength of Carbon-Fibre Aluminium-Laminated Composites." Advanced Materials Research 748 (August 2013): 216–21. http://dx.doi.org/10.4028/www.scientific.net/amr.748.216.

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Fibre-metal-laminated composites that consist of aluminium and carbon fibre/epoxy was widely use in engineering fields such as in aerospace and civil application. An issue arise for this laminate systems is that aluminium surfaces must be treated to ensure the effectiveness of load transfer mechanism in the interfacial region. In this research, the effect of anodized layer on the aluminium surface towards strength of the carbon fibre-aluminium-laminated composites was studied. Aluminium 6061-T6 was anodized using phosphoric acid as electrolyte and different anodizing voltage to produce different surface morphology. The surface roughness and morphology were determined via Atomic Force Microscopy and its wettability was determined by Static Contact Angle. Then, anodized aluminium was laminated with carbon fibre/epoxy system via vacuum bagging techniques. It shows that the strength of laminated composite with anodized surface increases up to 26% compared to laminates without anodized surfaces. Furthermore, the failure mechanism of laminated composite with anodized surface resulted in partial adhered failure instead of adhesive failure. These show that anodized surfaces contributes to the effectiveness of load transfer mechanism in fibre-metal-laminates composites.
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Alamaria, Abdulhakim, and Ghazali Nawawi. "Dehydration Pervaporation of Ethyl Acetate-Water Mixture via Sago/PVA Composite Membranes Using Surface Methodology." Chemistry & Chemical Technology 9, no. 4 (December 15, 2015): 479–84. http://dx.doi.org/10.23939/chcht09.04.479.

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Wang, Yilong, Hong Xu, Weili Qiang, Hongchen Gu, and Donglu Shi. "Asymmetric Composite Nanoparticles with Anisotropic Surface Functionalities." Journal of Nanomaterials 2009 (2009): 1–5. http://dx.doi.org/10.1155/2009/620269.

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Asymmetric inorganic/organic composite nanoparticles with anisotropic surface functionalities represent a new approach for creating smart materials, requiring the selective introduction of chemical groups to dual components of composite, respectively. Here, we report the synthesis of snowman-like asymmetric silica/polystyrene heterostructure with anisotropic functionalities via a chemical method, creating nanostructure possibly offering two-sided biologic accessibility through the chemical groups. Carboxyl group was introduced to polystyrene component of the snowman-like composites by miniemulsion polymerization of monomer on local surface of silica particles. Moreover, amino group was then grafted to remained silica surface through facile surface modification of the composite nanoparticles. The asymmetric shape of these composites was confirmed by TEM characterization. Moreover, characteristics of anisotropic surface functionalities were indicated by Zeta potential measurement and confocal laser microscopy after being labeled with fluorescent dyes. This structure could find potential use as carriers for biological applications.
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Kim, Daeyoung, Heon Kang, Donghyun Bae, Seungjin Nam, Manuel Quevedo-Lopez, and Hyunjoo Choi. "Synthesis of reduced graphene oxide/aluminum nanocomposites via chemical-mechanical processes." Journal of Composite Materials 52, no. 22 (February 21, 2018): 3015–25. http://dx.doi.org/10.1177/0021998318760152.

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The present study employed a combination of solution-based synthesis and mechanical milling to develop reduced graphene oxide/aluminum composites, in order to achieve uniform dispersion of reduced graphene oxide and strong interfaces between reduced graphene oxide and aluminum. First, spherical aluminum powder was flattened via mechanical milling to afford a large specific surface area and many reaction sites for the graphene oxide. A hydrophilic surface was then created by coating the aluminum powder with polyvinyl alcohol. The polyvinyl alcohol-coated aluminum slurry was mixed with a graphene oxide suspension, thereby inducing a reaction between graphene oxide and polyvinyl alcohol via hydrogen bonding. After thermal reduction, the composite powder was further ball milled and hot-pressed at 500℃ to produce a reduced graphene oxide/aluminum composite. The dispersion of reduced graphene oxide in the composite, as well as the mechanical and thermal behaviors of the composite, improved with increased flattening and specific surface area of the starting aluminum powder.
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Parreño, Ronaldo P., and Arnel B. Beltran. "Hybrid composite of Nafion with surface-modified electrospun polybenzoxazine (PBz) fibers via ozonation as fillers for proton conducting membranes of fuel cells." RSC Advances 12, no. 16 (2022): 9512–18. http://dx.doi.org/10.1039/d2ra00830k.

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Nafion compatibility in the preparation of hybrid composites with electrospun Polybenzoxazine (PBz) surface-modified fibers via ozonation by evaluating the effects on the surface and structure of the composite.
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Wang, Pengjie, Qiang Cao, Yuping Yan, Yangtian Nie, Sheng Liu, and Qing Peng. "Graphene Surface Reinforcement of Iron." Nanomaterials 9, no. 1 (January 4, 2019): 59. http://dx.doi.org/10.3390/nano9010059.

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Graphene is an ideal material in the reinforcement of metal-matrix composites owing to its outstanding mechanical and physical properties. Herein, we have investigated the surface enhancement of iron via a computational nanoindentation process using molecular dynamics simulations. The findings of our study show that graphene can enhance the critical yield strength, hardness and elastic modulus of the composite to different degrees with the change of the number of graphene layers. In the six tested models, the composite with trilayer graphene on the surface produces the strongest reinforcement, with an increased magnitude of 432.1% and 169.5% in the hardness and elastic modulus, respectively, compared with pure iron. Furthermore, it is revealed that high temperature could weaken the elastic bearing capacity of the graphene, resulting in a decrease on the elastic mechanical properties of the graphene/Fe composite.
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Dahotre, Narendra B., and Arvind Agarwal. "Refractory ceramic-composite coatings via laser surface engineering." JOM 51, no. 4 (April 1999): 19–21. http://dx.doi.org/10.1007/s11837-999-0073-z.

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Dissertations / Theses on the topic "SURFACE COMPOSITE VIA"

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Ho, Yee Hsien. "In Vitro Behavior of AZ31B Mg-Hydroxyapatite Metallic Matrix Composite Surface Fabricated via Friction Stir Processing." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc862762/.

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Magnesium and its alloys have been considered for load-bearing implant materials due to their similar mechanical properties to the natural bone, excellent biocompatibility, good bioactivity, and biodegradation. Nevertheless, the uncontrollable corrosion rate in biological environment restrains their application. Hydroxyapatite (HA, Ca10(PO4)6(OH)2) is a widely used bio-ceramic which has bone-like mineral structure for bone fixation. Poor fracture toughness of HA makes it not suitable for load-bearing application as a bulk. Thus, HA is introduced into metallic surface in various forms for improving biocompatibility. Recently friction stir processing (FSP) has emerged as a surface modification tool for surface/substrate grain refinement and homogenization of microstructure in biomaterial. In the pressent efforts, Mg-nHA composite surface on with 5-20 wt% HA on Mg substrate were fabricated by FSP for biodegradation and bioactivity study. The results of electrochemical measurement indicated that lower amount (~5% wt%) of Ca in Mg matrix can enhance surface localized corrosion resistance. The effects of microstructure,the presence of HA particle and Mg-Ca intermetallic phase precipitates on in vitro behavior of Mg alloy were investigated by TEM, SEM, EDX,XRD ,and XPS. The detailed observations will be discussed during presentation.
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Königsmann, Martin. "Modification of Wood Surfaces via controlled Polymerization Methods." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E4BA-1.

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Guttag, Mark A. (Mark Andrew). "Tunable surface topographies via particle-enhanced soft composites." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97851.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 75-76).
We introduce a new class of particle-enhanced soft composites (PESC) that can generate, on demand, custom and reversible surface topographies, with surface features that can be highly localized. These features can be specifically patterned or alternatively can be random in nature. Our PESC samples comprise a soft elastomeric matrix with stiff particles embedded below the surface. The surfaces of the samples presented in this thesis are originally smooth and flat but complex morphologies emerge under application of a stimuli (here we show application of primarily compressive loading). We demonstrate these adaptive surface topographies with both physical experiments and finite element simulations which are used to design and to study the mechanical response. A variety of different surface patterns can be attained by tailoring different dimensionless geometric parameters (e.g. different particle sizes, shapes, and distributions), as well as material properties. The design space of the system and the resulting surface topographies are explored and classified systematically. Given that our method depends primarily on the geometry of the particle arrays, our mechanism for on-demand custom surface patterning is applicable over a wide range of length scales. These surfaces can be used in a variety of different applications including control of fluid flow, adhesion, wettability and many others.
by Mark A. Guttag.
S.M.
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Page, Jonathan. "Formulation et caractérisation d'un composite cimentaire biofibré pour des procédés de construction préfabriquée." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMC244/document.

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Les enjeux économiques liés à la hausse des coûts des ressources fossiles, leur raréfaction, et les impacts environnementaux inhérents à leur fabrication et à leur utilisation, conduisent les acteurs de la construction à s’orienter vers des matériaux biosourcés. Les ressources issues de la biomasse sont alors au premier plan, celles agricoles notamment, dont les fibres provenant des tiges des plantes. Parmi ces fibres, le lin se démarque en raison de ses propriétés mécaniques élevées et sa faible densité, et sa disponibilité en Normandie. L’objectif de cette étude est de développer un matériau composite innovant par l’association des fibres de lin à une matrice cimentaire, qui sera utilisé dans des procédés de construction préfabriquée. Après la caractérisation fine des constituants de départ, nous avons d’abord décrit en détail l’élaboration des mortiers et bétons biofibrés avec un focus sur la méthodologie de formulation. Puis nous avons analysé l’influence de l’incorporation des fibres de lin sur les propriétés rhéologiques (air occlus, consistance, ouvrabilité et fluidité) et physico-chimiques (pH, ATG). Les propriétés physiques (porosité, module d’élasticité) et mécaniques (contraintes à la rupture, indice de ténacité) ont été mesurées par des essais de flexion et de compression à l’état durci. Ces résultats montrent nettement que la présence des fibres de lin réduit de façon importante les propriétés technologiques des pâtes cimentaires, du fait la sensibilité des fibres au milieu très alcalin et de leur caractère fortement hydrophile. Bien que les traitements de surface des fibres expérimentés (plasma atmosphérique, enrobage coulis de ciment et laitier de hauts fourneaux ou à l’huile de lin) aient permis d’améliorer certaines propriétés des mortiers, ils n’ont pas permis de réduire dans le temps la dégradation des fibres au sein de la matrice cimentaire (hydrolyse alcaline des fibres et leur minéralisation sous l’action de l’hydroxyde de calcium). Il apparaît donc nécessaire de recourir à des liants alternatifs pour tenter d’améliorer la durabilité de ces biocomposites à fibres végétales. Ainsi, de nouvelles formulations de mortiers et bétons sont proposées, dans lesquelles le ciment Portland est remplacé partiellement par le métakaolin / le laitier de hauts fourneaux ou totalement par un ciment sulfo-alumineux, sans préjudices pour le comportement rhéologique. L’étude des nouveaux composites formulés avec le métakaolin ou le ciment sulfo-alumineux indique des niveaux de résistance mécanique et de ténacité élevés. Leurs résistances au gel supérieures au béton classique ou celui incorporant des fibres de verre tient à la forte teneur en air (les fibres jouent un rôle d’agent entraîneur d’air)
The economic issues linked to the rising costs of fossil resources, their scarcity, and the environmental impacts inherent in their manufacture and use, are leading the construction industry to move towards bio-based materials. The resources from biomass are then in the foreground, especially agricultural ones, including fibres from plants stems. Among these fibres, flax stands out because of its high mechanical properties and low density, and its availability in Normandy. The objective of this study is to develop an innovative composite material by combining flax fibres with a cement matrix, which will be used in prefabricated construction processes. After the fine characterization of the initial constituents, we first described in detail the development of plant fibre-reinforced mortars and concretes with a focus on the formulation methodology. Then we analysed the influence of the incorporation of flax fibres on the rheological properties (entrapped air, consistency, workability) and physico-chemical properties (pH, ATG). The physical properties (porosity, modulus of elasticity) and mechanical properties (compressive and tensile strength, toughness index) were measured by bending and compressive tests in the hardened state. These results clearly show that the presence of flax fibres significantly reduces the technological properties of cementitious pastes, because of the sensitivity of the fibres to the highly alkaline medium and their highly hydrophilic nature. The surface treatments of the experimental fibres (by using atmospheric plasma, cement grout coating, blast furnace slag or linseed oil) have effectively improved some properties of mortars, the degradation of the fibres within the cement matrix remain active over the long term (alkaline hydrolysis of the fibres and their mineralization under the action of calcium hydroxide). It therefore appears necessary to use alternative binders in an attempt to improve the durability of these plant fibre biocomposites. Thus, new formulations of mortars and concretes are proposed, in which the Portland cement is partially replaced by metakaolin / blast furnace slag or totally by sulfoaluminate cement, without prejudice to the rheological behaviour. The study of the new composites formulated with metakaolin or sulfoaluminate cement indicates high levels of mechanical strength and toughness. Their resistance to frost superior to conventional concrete or concrete incorporating glass fibres is due to the high air content (the fibres act as an air-entraining admixture)
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Beyer, Thibault. "Semi-analytical modeling of damage under contact loading : Application to heterogeneous materials." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI045/document.

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Les pieds d’aubes de soufflantes de turboréacteurs étant soumis à des sollicitations de type fretting, l’introduction de matériaux composites dans la nouvelle génération de moteur d’avion a rendu nécessaire le développement d’outils permettant de modéliser le contact entre des matériaux hétérogènes. En particulier, le comportement tribologique et l’endommagement de ces matériaux est encore mal compris. La mise en place de méthodes numériques capable de prédire les endommagements dans le contact permettrait de mieux prédire la durée de vie des pièces en service et de garantir la sécurité des passagers. Cette thèse porte sur le développement de méthodes semi-analytiques pour la modélisation de l’endommagement dans des conditions de fretting et de roulement
The blade/disk interface in turbofan is subject to fretting loading. Fan blade of the new generation of aircraft engines are made of woven composite materials. The introduction of these new kind of materials create the need for a new numerical tool able to simulate the contact between heterogeneous materials. The tribological behavior and the damage mechanism associated with these kind of material are still not well understood. The developpment of new numerical tool able to model the damage in the contact area would allow to predict the life of engines parts and to guarantee the security of passengers. This PhD is about the developpment of semi-analytical methods for modeling the damage in fretting and rolling contact conditions with some applications to heterogeneous materials
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Tavares, Lucas Alves. "O envolvimento da proteína adaptadora 1 (AP-1) no mecanismo de regulação negativa do receptor CD4 por Nef de HIV-1." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/17/17136/tde-06012017-113215/.

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O Vírus da Imunodeficiência Humana (HIV) é o agente etiológico da Síndrome da Imunodeficiência Adquirida (AIDS). A AIDS é uma doença de distribuição mundial, e estima-se que existam atualmente pelo menos 36,9 milhões de pessoas infectadas com o vírus. Durante o seu ciclo replicativo, o HIV promove diversas alterações na fisiologia da célula hospedeira a fim de promover sua sobrevivência e potencializar a replicação. A rápida progressão da infecção pelo HIV-1 em humanos e em modelos animais está intimamente ligada à função da proteína acessória Nef. Dentre as diversas ações de Nef está a regulação negativa de proteínas importantes na resposta imunológica, como o receptor CD4. Sabe-se que esta ação resulta da indução da degradação de CD4 em lisossomos, mas os mecanismos moleculares envolvidos ainda são totalmente elucidados. Nef forma um complexo tripartite com a cauda citosólica de CD4 e a proteína adaptadora 2 (AP-2), em vesículas revestidas por clatrina nascentes, induzindo a internalização e degradação lisossomal de CD4. Pesquisas anteriores demonstraram que o direcionamento de CD4 aos lisossomos por Nef envolve a entrada do receptor na via dos corpos multivesiculares (MVBs), por um mecanismo atípico, pois, embora não necessite da ubiquitinação de carga, depende da ação de proteínas que compõem os ESCRTs (Endosomal Sorting Complexes Required for Transport) e da ação de Alix, uma proteína acessória da maquinaria ESCRT. Já foi reportado que Nef interage com subunidades dos complexos AP-1, AP-2, AP-3 e Nef não parece interagir com subunidades de AP-4 e AP-5. Entretanto, o papel da interação de Nef com AP-1 e AP-3 na regulação negativa de CD4 ainda não está totalmente elucidado. Ademais, AP-1, AP-2 e AP-3 são potencialmente heterogêneos devido à existência de isoformas múltiplas das subunidades codificadas por diferentes genes. Todavia, existem poucos estudos para demonstrar se as diferentes combinações de isoformas dos APs são formadas e se possuem propriedades funcionais distintas. O presente trabalho procurou identificar e caracterizar fatores celulares envolvidos na regulação do tráfego intracelular de proteínas no processo de regulação negativa de CD4 induzido por Nef. Mais especificamente, este estudo buscou caracterizar a participação do complexo AP-1 na modulação negativa de CD4 por Nef de HIV-1, através do estudo funcional das duas isoformas de ?-adaptina, subunidades de AP-1. Utilizando a técnica de Pull-down demonstramos que Nef é capaz de interagir com ?2. Além disso, nossos dados de Imunoblot indicaram que a proteína ?2-adaptina, e não ?1-adaptina, é necessária no processo de degradação lisossomal de CD4 por Nef e que esta participação é conservada para degradação de CD4 por Nef de diferentes cepas virais. Ademais, por citometria de fluxo, o silenciamento de ?2, e não de ?1, compromete a diminuição dos níveis de CD4 por Nef da membrana plasmática. A análise por imunofluorêsncia indireta também revelou que a diminuição dos níveis de ?2 impede a redistribuição de CD4 por Nef para regiões perinucleares, acarretando no acúmulo de CD4, retirados por Nef da membrana plasmática, em endossomos primários. A depleção de ?1A, outra subunidade de AP-1, acarretou na diminuição dos níveis celulares de ?2 e ?1, bem como, no comprometimento da eficiente degradação de CD4 por Nef. Além disso, foi possível observar que, ao perturbar a maquinaria ESCRT via super-expressão de HRS (uma subunidade do complexo ESCRT-0), ocorreu um acumulo de ?2 em endossomos dilatados contendo HRS-GFP, nos quais também detectou-se CD4 que foi internalizado por Nef. Em conjunto, os resultados indicam que ?2-adaptina é uma importante molécula para o direcionamento de CD4 por Nef para a via ESCRT/MVB, mostrando ser uma proteína relevante no sistema endo-lisossomal. Ademais, os resultados indicaram que as isoformas ?-adaptinas não só possuem funções distintas, mas também parecem compor complexos AP-1 com diferentes funções celulares, já que apenas a variante AP-1 contendo ?2, mas não ?1, participa da regulação negativa de CD4 por Nef. Estes estudos contribuem para o melhor entendimento dos mecanismos moleculares envolvidos na atividade de Nef, que poderão também ajudar na melhor compreensão da patogênese do HIV e da síndrome relacionada. Em adição, este trabalho contribui para o entendimento de processos fundamentais da regulação do tráfego de proteínas transmembrana no sistema endo-lisossomal.
The Human Immunodeficiency Virus (HIV) is the etiologic agent of Acquired Immunodeficiency Syndrome (AIDS). AIDS is a disease which has a global distribution, and it is estimated that there are currently at least 36.9 million people infected with the virus. During the replication cycle, HIV promotes several changes in the physiology of the host cell to promote their survival and enhance replication. The fast progression of HIV-1 in humans and animal models is closely linked to the function of an accessory protein Nef. Among several actions of Nef, one is the most important is the down-regulation of proteins from the immune response, such as the CD4 receptor. It is known that this action causes CD4 degradation in lysosome, but the molecular mechanisms are still incompletely understood. Nef forms a tripartite complex with the cytosolic tail of the CD4 and adapter protein 2 (AP-2) in clathrin-coated vesicles, inducing CD4 internalization and lysosome degradation. Previous research has demonstrated that CD4 target to lysosomes by Nef involves targeting of this receptor to multivesicular bodies (MVBs) pathway by an atypical mechanism because, although not need charging ubiquitination, depends on the proteins from ESCRTs (Endosomal Sorting Complexes Required for Transport) machinery and the action of Alix, an accessory protein ESCRT machinery. It has been reported that Nef interacts with subunits of AP- 1, AP-2, AP-3 complexes and Nef does not appear to interact with AP-4 and AP-5 subunits. However, the role of Nef interaction with AP-1 or AP-3 in CD4 down-regulation is poorly understood. Furthermore, AP-1, AP-2 and AP-3 are potentially heterogeneous due to the existence of multiple subunits isoforms encoded by different genes. However, there are few studies to demonstrate if the different combinations of APs isoforms are form and if they have distinct functional properties. This study aim to identify and characterize cellular factors involved on CD4 down-modulation induced by Nef from HIV-1. More specifically, this study aimed to characterize the involvement of AP-1 complex in the down-regulation of CD4 by Nef HIV-1 through the functional study of the two isoforms of ?-adaptins, AP-1 subunits. By pull-down technique, we showed that Nef is able to interact with ?2. In addition, our data from immunoblots indicated that ?2- adaptin, not ?1-adaptin, is required in Nef-mediated targeting of CD4 to lysosomes and the ?2 participation in this process is conserved by Nef from different viral strains. Furthermore, by flow cytometry assay, ?2 depletion, but not ?1 depletion, compromises the reduction of surface CD4 levels induced by Nef. Immunofluorescence microscopy analysis also revealed that ?2 depletion impairs the redistribution of CD4 by Nef to juxtanuclear region, resulting in CD4 accumulation in primary endosomes. Knockdown of ?1A, another subunit of AP-1, resulted in decreased cellular levels of ?1 and ?2 and, compromising the efficient CD4 degradation by Nef. Moreover, upon artificially stabilizing ESCRT-I in early endosomes, via overexpression of HRS, internalized CD4 accumulates in enlarged HRS-GFP positive endosomes, where co-localize with ?2. Together, the results indicate that ?2-adaptin is a molecule that is essential for CD4 targeting by Nef to ESCRT/MVB pathway, being an important protein in the endo-lysosomal system. Furthermore, the results indicate that ?-adaptins isoforms not only have different functions, but also seem to compose AP-1 complex with distinct cell functions, and only the AP-1 variant comprising ?2, but not ?1, acts in the CD4 down-regulation induced by Nef. These studies contribute to a better understanding on the molecular mechanisms involved in Nef activities, which may also help to improve the understanding of the HIV pathogenesis and the related syndrome. In addition, this work contributes with the understanding of primordial process regulation on intracellular trafficking of transmembrane proteins.
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Su, Heng-Yi, and 蘇恆毅. "Synthesizing of Carbon Composite Nanotubes via Self-Assembly Surface Modification." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/21783671763445011391.

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碩士
國立清華大學
材料科學工程學系
93
Through self-assembly monolayer surface treatment, metal oxide nanoparticles uniformly dispersed onto carbon nanotubes (CNTs) surface are investigated in this paper. Via acid treatment, it is confirmed metal oxide nanoparticles are effectively bonded on the CNTs. By further oxidization treatment, it was found that better bonding effects are resulted from the longer oxidization time (higher O/C ratio). Surface bonding functional groups convert the surface property of CNTs from hydrophobic to hydrophilic and they act an important role to link with metal ions via the ionic adsorption and van der Walls effects. The average diameter of the bonding particles through the self-assembly monolayer surface treatment is about 5-10 nm. Through nickel oxide nanoparticles bonded on the surface of the CNTs and the precursor gas of toluene in 900℃, carbon nanoclusters can be synthesized on the CNTs. After synthesizing, no carbon nanoclusters were observed but merely a layer of accumulated amorphous carbon on the sample was formed without any tin oxide nanoparticles bonded on the CNTs. It was observed that the morphology of the nanoclusters grown through the catalysts exhibits tube-like as well as rod-like structures. The incomplete thermal cracking level of the toluene sparks off the specific structures of the carbon nanoclusters. The more tin oxides bonded on the CNTs the more carbon nanoclusters formed. It also contributes to the higher BET surface area for better application.
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SAH, MANOJ KUMAR. "FABRICATION OF Al7075/ ZrB2 SURFACE COMPOSITE VIA FRICTION STIR PROCESSING." Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15310.

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Friction stir processing is new surface modifying technique to fabricate surface composite layer. A specially designed rotating tool with shoulder and pin is plunged into the surface of material and then processed. The rotating tool pin causes intense plastic deformation of material due to stirring action. The processed region results in refined grain structure and uniform dispersion of reinforcement particles in the matrix. In this project work different volume of ZrB2 reinforcement particles inserted into the Al 7075 alloy and then processed by FSP. Fabricated surface composites were analyzed with microstructural, EDS and XRD studies. Mechanical and wear properties were also examined. To understand the wear and fracture mechanism of composite SEM study were also carried out .The results shows that composites are having higher mechanical and wear properties than the base material. Around 10 % increase in mechanical properties and more than 50% reduction in wear rate was observed. The higher volume content of ZrB2 particles exhibited higher tensile and wear properties compared to lower content of ZrB2 particles. However at higher content of ZrB2 particles there was marginal increase in tensile strength but great reduction in elongation.
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(10997835), Monica Somanagoud Sannamani. "The role of sensitivity matrix formulation on damage detection via EIT in non-planar CFRP laminates with surface-mounted electrodes." Thesis, 2021.

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Carbon fibre reinforced polymers (CFRPs) are extensively used in aerospace, automotive and other weight-conscious applications for their high strength-to-weight ratio. Utilization of these lightweight materials unfortunately also involves dealing with damages unlike those seen in traditional monolithic materials. This includes invisible, below-the-surface damages such as matrix cracking, delaminations, fibre breakage, etc. that are difficult to spot outwardly in their early stages. Robust methods of damage detection and health monitoring are hence important. With the intention of avoiding weight addition to the structure to monitor its usability, it would be desirable to utilize an inherent property of these materials, such as its electrical conductivity, as an indicator of damage to render the material as self-sensing.

To this end, electrical impedance tomography (EIT) has been explored for damage detection and health monitoring in self-sensing materials due to its ability to spatially localize damage via non-invasive electrical measurements.

Presently, EIT has been applied mainly to materials possessing lesser electrical anisotropy than is encountered in CFRPs (e.g. nanofiller-modified polymers and cements), with experimental setups involving electrodes placed at the edges of plates. The inability of EIT to effectively tackle electrical anisotropy limits its usage in CFRP structures. Moreover, most real structures of complex geometries lack well-defined edges on which electrodes can be placed. Therefore, in this thesis, we confront these limitations by presenting a study into the effect of EIT sensitivity matrix formulation and surface-mounted electrodes on damage detection and localization in CFRPs.

In this work, the conductivity is modeled as being anisotropic, and the sensitivity matrix is formed using three approaches – with respect to i) a scalar multiple of the conductivity tensor, ii) the in-plane conductivity, and iii) the through-thickness conductivity. It was found that through-hole damages can be adeptly identified with a combination of surface-mounted electrodes and a sensitivity matrix formed with respect to either a scalar multiple of the conductivity tensor or the in-plane conductivity. This theory was first validated on a CFRP plate to detect a single through-hole damage. Furthermore, EIT was also used to successfully detect both through-hole and impact damages on a non-planar airfoil shaped structure.

Singular value decomposition (SVD) analysis revealed that the rank of the sensitivity matrix is not affected by the conductivity term with respect to which the sensitivity matrix is formed. The results presented here are an important step towards the transition of EIT based diagnostics to real-life CFRP structures.


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Chen, Bing Hong, and 陳秉宏. "A Revival of Waste: Surface Modification via Coating and Plasma Jet in Recycled Si/SiC Composite for Lithium Ion Batteries." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/525qe7.

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博士
國立清華大學
材料科學工程學系
105
In the past decade, the rising development of lithium ion batteries (LIBs) has been recognized as a tidal current for solving energy storage related issues. Under this technical billow, the demands of active materials with lower environmental impact and higher energy density are considered as the criteria for LIBs materials. Especially for anodic material, the present carbon-based electrode is limited in the potential applications with high capacity because of its theoretic capacity (372 mAh/g). To achieve the goal for high capacity anodes, silicon (Si) with 3590 mAh/g theoretical capacity meets the requirement by forming Li15Si4 phase during cycling processes to replace present conventional carbon-based batteries. However, the capacity fading caused by the intrinsic drawbacks of volumetric expansion and continuous formation of solid electrolyte interphase hinders the dissemination of Si-based LIBs. To overcome the disadvantages of Si, numerous studies have endeavored (1) to shrink Si particles to nanometer scales by using various morphology-chemical synthesis techniques, (2) to wrap or mix conductive additives onto particles or into slurries, and (3) to add electrolyte additives. Unfortunately, the as-mentioned methods mostly fail to accommodate the cost-effectiveness of commercialization and low pollution of environmental friendliness. In the pursuit of low cost and high environmental friendly anode material, a distinct resource of Si-based anode material is explored in this study. The recycled material is extracted from the cutting waste fluid produced in solar panel industry. After purification technology of chemical rinsing and physical separation, the obtained composites show much larger particle size than commonly nanolized Si particles, and possess the abundant organic bonds and native oxide on the surface of particle. Unlike conventional methods to focus on the synthesis process of powder, the as-prepared electrodes will be treated via various surface modifications, including techniques of carbon deposition and atmospheric pressure plasma jet. The combined processing reduces the capacity degradation by interfacial control to convert the surface bonds with the effectiveness to suppress the growth of SEI, and then maintain the stabilization of electrode during cycling. In addition, the entire electrode collocates with conductive agent and electrolyte additive to provide the conductivity and to improve the internal SEI formation. Overall, the developed techniques of surface modifications are not only scalable, simple, low-cost and environmental friendly but also effective to achieve the excellent performance with high capacity. It is expected for similar potential usage in others battery system. The selected recycled waste for anodic material should be applicable and suitable for the future blueprint in the commercialization for LIBs.
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Books on the topic "SURFACE COMPOSITE VIA"

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The main objective of this project is to be produce copper reinforced metal matrix composite (MMC) layers using micron sized AlN particles via friction stir processing (FSP) in order to enhance surface mechanical properties. Micro structural evaluation using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) indicated that an increase in traverse speed and a decrease in rotational speed cause a reduction in the grain size of different groove width (0,0.4,0.8,1.2 mm) of stir zone (SZ) for the specimens friction stir processed (FSPed) without AlN particles. It was found that upon addition of AlN particles, wear properties were improved. This behavior was further supported by SEM images of wear surfaces. Results demonstrated that the micro composite produced by FSP exhibited enhanced wear resistance and higher average friction coefficient in comparison with pure copper. Tensile properties and fracture characteristics of the specimens FSPed with and without AlN particles and pure copper were also evaluated. According to the results, the MMC layer produced by FSP showed higher strength and lower elongation than pure copper while a remarkable elongation was observed for FSPed specimen without AlN particles and been greatly developed by the use of AlN. Association of Scientists, Developers and Faculties, 2016.

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Book chapters on the topic "SURFACE COMPOSITE VIA"

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Santos, Thiago F., Caroliny M. Santos, Emad K. Hussein, Lucas Zilio, Mariana Dias, M. R. Sanjay, Rubens Fonseca, Adriano Amaral, and Marcos Aquino. "Tensile Behavior of Weft-Knitted Structure for Potential Use in Composite Reinforcement via Factorial and 3D Surface." In Green Hybrid Composite in Engineering and Non-Engineering Applications, 233–59. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1583-5_14.

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Komarasamy, Mageshwari, Rajiv S. Mishra, John A. Baumann, Glenn Grant, and Yuri Hovanski. "Processing, Microstructure and Mechanical Property Correlation in Al-B4C Surface Composite Produced via Friction Stir Processing." In Friction Stir Welding and Processing VII, 39–46. Cham: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-48108-1_5.

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Komarasamy, Mageshwari, Rajiv S. Mishra, John A. Baumann, Glenn Grant, and Yuri Hovanski. "Processing, Microstructure and Mechanical Property Correlation in Al-B4C Surface Composite Produced via Friction Stir Processing." In Friction Stir Welding and Processing VII, 39–46. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118658345.ch5.

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Douiri, M., M. Boujelbene, Özgür Aslan, and E. Bayraktar. "Optimization of Surface Integrity of Recycled Ti–Al Intermetallic-Based Composite on the Machining by Water Jet Cutting via Taguchi and Response Surface Methodology." In Recycling of Plastics, Metals, and Their Composites, 295–314. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003148760-17.

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Pradeep Devaneyan, S., D. Peter Pushpanathan, and Adhesh Parambath. "On the Mechanical and Microstructural Properties of Novel A356/Kevlar Surface Composite Fabricated via Friction Stir Processing." In Advanced Manufacturing and Materials Science, 421–29. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76276-0_43.

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Prasad, Kumar Shantanu, Gbanaibolou Jombo, Sikiru O. Ismail, Yong K. Chen, and Hom N. Dhakal. "Quantitative Assessment of Damage in Composites by Implementing Acousto-ultrasonics Technique." In Springer Proceedings in Energy, 209–17. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-30960-1_20.

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AbstractThis study focused on quantitative damage severity assessment in composite materials using Acousto-Ultrasonics (AU), an in-service and active non-destructive inspection technique in which Lamb waves are communicated through a damaged zone. This was done by activating a signal onto the composite material surface and acquiring the received waves after their interactions with the damage. It relied on early research that presented a series of stress wave factors (SWFs) derived from the frequency-domain of the AU data, as quantitative identifiers of the received signal. Although, the SWFs have previously been proven to determine the understanding of the spatial arrangements of the impact damage, the degree or severity of the damage inside the impact damage area has not been assessed. Therefore, the current research was a step in the right way toward that aim. AU waves were generated via a laminate with increasing concentrations of ply faults, across longitudinal length. The stress wave factors were first examined for an undamaged composite, and the SWFs were then connected with the fault concentration. The significance of the found linkages and the possible futures of quantitative assessment of the degree of damage by such relationships were examined. The stress wave factors showed clear and consistent patterns, as the fault concentration increased. With a rise in fault density, an element measuring the energy content of the waves significantly changed with R-sq(adj) = 91.33% and almost linearly, and provided a robust measurable trend, while other parameter exhibited lesser shifts with R-sq(adj) = 51.86%. The result obtained from the presented work provided a base to cost-effective and in-service measure to early detection of catastrophic failures in composite structures, including the wind turbine blades for renewable and sustainable energy generation.
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Velasco Manrique, Jorge, Manuel Ignacio González, Carlos Alonso Sastre, Esteban Cañibano Álvarez, and Maria Teresa Fernández Peña. "Research into Novel Coatings on Composites and Technical Polymers, with Tailored Functionalities for the Transport and Biomedical Industries." In Proceedings of the XV Ibero-American Congress of Mechanical Engineering, 98–104. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-38563-6_15.

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AbstractThis work presents the methodology and results of the research into pre-treatments for thermal spray processes, applied to composites and technical polymers, as preparatory stage for the subsequent coating (ceramic and metallic) deposition via wire arc spray process. The research methodology includes the study of the thermal degradation of substrate materials, as well as the execution and characterization of mechanical (sand blasting), laser (surface texturing) and chemical (acid and base etching) pre-treatments. The quality of the proposed solutions is evaluated through visual inspection of the samples, optical micrography, surface roughness measurements, and mechanical adhesion testing of the coating. Finally, the selection of the most appropriate coating pre-treatment is made, considering technical and scalability criteria.
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Lu, D., Z. Sheng, B. Yan, and Z. Jiang. "Co-effects of Graphene Oxide and Silica Fume on the Rheological Properties of Cement Paste." In Lecture Notes in Civil Engineering, 251–58. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_26.

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AbstractPolycarboxylate superplasticizer is typically used to prepare a high-quality graphene oxide (GO) solution before mixing with cement grains. However, even if GO is well dispersed in water, they tend to re-agglomerate in the alkaline cement hydration environment, thus seriously decreasing the workability of the fresh mixture. In this study, we propose a more targeted method by synthesizing GO-coated silica fume (SF) to promote the utilization of GO in cement-based materials. Specifically, the surface of pristine SF was modified to convert their zeta potential (modified SF: MSF), then GO-coated SF (i.e., MSF@GO) was prepared via electrostatic adsorption of GO onto the MSF surface. The experimental results revealed that adding 5MSF@GO hybrid (0.04% GO and 5% MSF, by weight of binder) significantly reduced yield stress and plastic viscosity by 51.5% and 26.2%, respectively, relative to the 0.04% GO-modified sample. These findings indicated that application of GO-coated SF is an effective and environmentally friendly way to develop sustainable cementitious composites.
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Bector, Kartikeya, Aranyak Tripathi, Divya Pandey, Ravi Butola, and Ranganath M. Singari. "A Review on the Fabrication of Surface Composites via Friction Stir Processing and Its Modeling Using ANN." In Lecture Notes in Mechanical Engineering, 1–11. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-8542-5_1.

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Akbas, M. A., D. Mastrobattisto, B. Vance, P. Jurgaitis, S. So, P. Chhillar, and M. K. Aghajanian. "Low CTE & High Stiffness Diamond Reinforced SiC Based Composites with Machineable Surfaces for Mirrors & Structures." In Mechanical Properties and Performance of Engineering Ceramics and Composites VII, 133–41. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118217467.ch13.

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Conference papers on the topic "SURFACE COMPOSITE VIA"

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Asmatulu, R., and M. Ghaddar. "Surface Free Energy Change of UV Exposed Composites and Coatings via Acid-Base Interactions." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62756.

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Surface free energy of composite and coatings are critically important for the performance of the materials since the change in surface free energies can drastically affect the physical, chemical and physicochemical properties, and hence the service life of them. The characterization of the surface free energy is the key issue to understand the mechanisms of the surface degradation. Acid-base interaction is one way of determining the surface free energy change on these surfaces. In the present study, we exposed composite and coating surfaces to UV light, and then measured the contact angle values using various liquids (e.g., DI water, diiodomethane and glycerol). Using the van Oss approach, we calculated the surface energy changes of the surfaces exposed to the UV light. We found that the surface energy, acidity and basicity of the composite and coating materials were drastically changed as a function of UV exposure time. This study can be useful for the moisture uptake of composites, composite degradation, aging and service life of these products.
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Asmatulu, R., K. S. Erukala, and M. M. Rahman. "Enhancing the Strengths of Adhesion Bonds Between Composite Surface and Coating via UV Treatments." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-72455.

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Field of composites is rapidly growing in many industries such as aviation, energy and automotive industries. Composites are known to have a high strength to low weight ratio. Significant improvement in the performance of coatings used in the protection of military and civil aircraft has been achieved the last thirty years. Composite coatings are exposed to many environmental conditions, which can significantly affect their properties. In this research, UV light treatment on the surface of composite was introduced to examine its effects on the adhesion properties between the coating and substrate. A cross-cut test was conducted on the composite panels to assess the adhesion of paint to the substrate after the treatments. Coating performance analyses were also carried out using a Fourier transform infrared spectrometer, water contact angle, and optical microscopic images. The first set of panels was treated with UV radiation for 0, 2, 4 and, 8 days, and the surface wettability was also assessed using the contact angle test. Two coats of paints, including a primer and top coat, were used, and the panels were exposed to UV radiation and immersed in water for 500 hrs and 1000 hrs. It was found that untreated panels showed a much higher contact angle of 106°, whereas the contact angle of panels treated with UV radiation was reduced to 47°. The cross-cut tests showed considerable flaking of the coating along the edges and squares of panels that were not treated, and very small flakes along the edges and parts of the grid square on panels that were UV treated, thus confirming the enhancement of coating adhesion between composite and coating surfaces by UV treatments.
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Ogila, K. O., W. Yang, M. Shao, and J. Tan. "Surface quality of unsaturated polyester resin processed via continuous multi-shot rotational molding." In 2ND INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS AND MATERIAL ENGINEERING (ICCMME 2017). Author(s), 2017. http://dx.doi.org/10.1063/1.4983603.

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Parandoush, Pedram, Timothy Deines, Dong Lin, Hao Zhang, and Chang Ye. "Mechanical Finishing of 3D Printed Continuous Carbon Fiber Reinforced Polymer Composites via CNC Machining." In ASME 2019 14th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/msec2019-2972.

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Abstract 3D printing technology could be extremely beneficial for increasing the flexibly and reducing the cost of carbon fiber reinforced polymer composite (CFRP) production. However, this technology suffers from poor surface quality and uncertain engineering quality. Mechanical finishing processes could concurrently solve these surface issues with the 3D printed composites components. Herein, a mechanical finishing process for 3D printed CFRP composites via CNC milling is proposed to improve the surface quality of two 3D printing methods, namely fused deposition modeling (FDM) and laser assisted-laminated object manufacturing (LA-LOM). The 3D printed CFRP structures fabricated via both methods comprise of continuous carbon fiber reinforcement. The surface roughness and surface morphology of the original unfinished and finished surfaces with various cutting depths are extensively studied to investigate the feasibility of the proposed finishing technique. The surface morphology of the surfaces parallel and perpendicular to the 3D printed layers is the main focus of this work. After the CNC finishing process, the surface roughness of the 3D printed CFRP composites is improved by 70% and 60% for FDM and LA-LOM components, respectively. A smooth, consistent, and predictable surface morphology is achieved for various cutting depths demonstrating a substantial improvement over the original 3D printed surfaces.
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Ranganathan, Soundararajan, Sathishkumar Kuppuraj, Karthik Soundarrajan, and Ashokvarthanan Perumal. "Design and Analysis of Hybrid Metal Matrix Composite Connecting Rod via Stir/Squeeze Casting Route." In International Conference on Advances in Design, Materials, Manufacturing and Surface Engineering for Mobility. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2019. http://dx.doi.org/10.4271/2019-28-0113.

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Ardebili, Mahmoud K., Kerim T. Ikikardaslar, and Feridun Delale. "Strain and Damage Sensing of CNT-Epoxy Composite via Electrical Conductivity." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-39972.

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Self-sensing via piezoresistivity of multiwall carbon nanotube-epoxy resin composite was studied in order to assess its feasibility in strain and damage detection. Self-sensing is an economical and durable component of Structural Health Monitoring of manufactured composite, in which the material is employed as sensor. Objective of the study centered on strain and damage sensing and particularly focused on how applied tension and /or inflicted damage affected electrical conductivity. The MWCNT-epoxy composite was manufactured with non-treated multiwall carbon-nanotubes. They were dispersed in the epoxy employing ultrasonic dispersion and mechanical mixing, prior to addition of curing agent. The samples were rectangular specimen of dimensions 150 mm × 25 mm × 5 mm. Surface electrodes were created with sliver paint, to which copper wire leads were wrapped and affixed with more silver paint or carbon based electrically conductive glue. Kelvin in-line resistivity measurement technique was adopted to assess and monitor composite resistivity. The technique minimizes contact resistance between electrodes and the composite, which could be order of magnitude larger than the material resistance. For strain sensing, the specimen was subjected to increasing tensile strain until failure. In damage sensing, the specimens received different depth surface cuts across their width. During the tensile strain testing the specimens failed at a typical strain of about 4%. The corresponding change in resistance was in range of 2–3%. In damage sensing mode, changes of up to 40% in resistance were recorded for 75% thickness deep damage. For lower depth damages, the change in resistivity were about 4%–10%. The data obtained so far indicate that with proper technique, self-sensing of CNT-epoxy resin composites could be a viable method for monitoring applied strain and structural integrity.
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Akinyede, Oladapo, Ram Mohan, Ajit Kelkar, and Jag Sankar. "Effect of Grafting Methodology of Nano-Particle Reinforcement on the Performance of Structural Hybrid Composite." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13783.

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Inclusion of nano-sized alumina by the surface treatment of S2 fiberglass (fiber modification) or ultrasonically exfoliated in epoxy resin system (resin modification) has been shown to provide epoxy-fiberglass hybrid composite systems with changes in their mechanical/ damage behavior under static tensile loading conditions. Integration of alumina nano-particles in epoxy-S2 fiberglass to form hybrid composites has not only shown improvements in the material properties, but also changes in the failure mechanism of the material system. This phenomenon is influenced by the changes in constituent interaction and its load transfer mechanism. In the processing of these hybrids composite systems, alumina nano-particles (sized at 110nm) are functionalized and grafted into epoxy composite material system during material processing via resin solution treatment and fabric surface treatment. These alumina embedding methodologies to form hybrid composites employed are the resin modification and fiber modification in conjunction with the conventional vacuum assisted resin transfer molding (VARTM) process for the manufacture of composite laminates. The chemical bonding and adhesion between the inorganic alumina and the organic resin is also enhanced via the functional treatment of the alumina particles with a coupling agent in the form of tris-2-methyoxyethoxy vinylsilane- T2MEVS (silane coupling agent). Processing methodologies are used to fabricate particulate reinforcement for various (<5%wt) compositions. Performance evaluation is carried to study the effect of the nano-particulate alumina on mechanical properties. Thermo-physical properties changes caused by particulate inclusion in hybrid material matrix phase are studied via Differential Scanning Calorimetry (DSC) and are also discussed.
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Fang, C. H., X. X. Cheng, F. Ding, and X. N. Zhao. "The prediction study of composite scattering from the ship on the surface via simulation and experiment." In 2015 IEEE 4th Asia-Pacific Conference on Antennas and Propagation (APCAP). IEEE, 2015. http://dx.doi.org/10.1109/apcap.2015.7374482.

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Michopoulos, John G., John G. Hermanson, Athanasios Iliopoulos, Samuel Lambrakos, and Tomonari Furukawa. "On the Constitutive Response Characterization for Composite Materials via Data-Driven Design Optimization." In ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/detc2011-47740.

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In the present paper we focus on demonstrating the use of design optimization for the constitutive characterization of anisotropic material systems such as polymer matrix composites, with or without damage. All approaches are based on the availability of experimental data originating from mechatronic material testing systems that can expose specimens to multidimensional loading paths and can automate the acquisition of data representing the excitation and response behavior of the specimens involved. Material characterization is achieved by minimizing the difference between experimentally measured and analytically computed system responses as described by strain fields and surface strain energy densities. A one dimensional model is presented first to elucidate the design optimization for the general non-linear constitutive response. Small and large strain formulations based on strain energy density decompositions are developed and utilized for determining the constitutive behavior of composite materials. Examples based on both synthetic and actual data demonstrate the successful application of design optimization for constitutive characterization.
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Li, Bo. "Microstructural Characteristics of Surface Composite on Titanium Alloy Fabricated via a Novel Method of Friction-Stir Nitriding." In 2015 2nd International Forum on Electrical Engineering and Automation (IFEEA 2015). Paris, France: Atlantis Press, 2016. http://dx.doi.org/10.2991/ifeea-15.2016.79.

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Reports on the topic "SURFACE COMPOSITE VIA"

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Bryant, C. A., S. A. Wilks, and C. W. Keevil. Survival of SARS-CoV-2 on the surfaces of food and food packaging materials. Food Standards Agency, November 2022. http://dx.doi.org/10.46756/sci.fsa.kww583.

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COVID-19, caused by the SARS-CoV-2 virus, was first reported in China in December 2019. The virus has spread rapidly around the world and is currently responsible for 500 million reported cases and over 6.4 million deaths. A risk assessment published by the Foods Standards Agency (FSA) in 2020 (Opens in a new window) concluded that it was very unlikely that you could catch coronavirus via food. This assessment included the worst-case assumption that, if food became contaminated during production, no significant inactivation of virus would occur before consumption. However, the rate of inactivation of virus on products sold at various temperatures was identified as a key uncertainty, because if inactivation does occur more rapidly in some situations, then a lower risk may be more appropriate. This project was commissioned to measure the rate of inactivation of virus on the surface of various types of food and food packaging, reducing that uncertainty. The results will be used to consider whether the assumption currently made in the risk assessment remains appropriate for food kept at a range of temperatures, or whether a lower risk is more appropriate for some. We conducted a laboratory-based study, artificially contaminating infectious SARS-CoV-2 virus onto the surfaces of foods and food packaging. We measured how the amount of infectious virus present on those surfaces declined over time, at a range of temperatures and relative humidity levels, reflecting typical storage conditions. We tested broccoli, peppers, apple, raspberry, cheddar cheese, sliced ham, olives, brine from the olives, white and brown bread crusts, croissants and pain au chocolat. The foods tested were selected as they are commonly sold loose on supermarket shelves or uncovered at deli counters or market stalls, they may be difficult to wash, and they are often consumed without any further processing i.e. cooking. The food packaging materials tested were polyethylene terephthalate (PET1) trays and bottles; aluminium cans and composite drinks cartons. These were selected as they are the most commonly used food packaging materials or consumption of the product may involve direct mouth contact with the packaging. Results showed that virus survival varied depending on the foods and food packaging examined. In several cases, infectious virus was detected for several hours and in some cases for several days, under some conditions tested. For a highly infectious agent such as SARS-CoV-2, which is thought to be transmissible by touching contaminated surfaces and then the face, this confirmation is significant. For most foods tested there was a significant drop in levels of virus contamination over the first 24 hours. However, for cheddar cheese and sliced ham, stored in refrigerated conditions and a range of relative humidity, the virus levels remained high up to a week later, when the testing period was stopped. Both cheddar cheese and sliced ham have high moisture, protein and saturated fat content, possibly offering protection to the virus. When apples and olives were tested, the virus was inactivated to the limit of detection very quickly, within an hour, when the first time point was measured. We suggest that chemicals, such as flavonoids, present in the skin of apples and olives inactivate the virus. The rate of viral decrease was rapid, within a few hours, for croissants and pain au chocolat. These pastries are both coated with a liquid egg wash, which may have an inhibitory effect on the virus. Food packaging materials tested had variable virus survival. For all food packaging, there was a significant drop in levels of virus contamination over the first 24 hours, in all relative humidity conditions and at both 6°C and 21°C; these included PET1 bottles and trays, aluminium cans and composite drinks cartons.
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Litaor, Iggy, James Ippolito, Iris Zohar, and Michael Massey. Phosphorus capture recycling and utilization for sustainable agriculture using Al/organic composite water treatment residuals. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600037.bard.

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Objectives: 1) develop a thorough understanding of the sorption mechanisms of Pi and Po onto the Al/O- WTR; 2) determine the breakthrough range of the composite Al/O-WTR during P capturing from agro- wastewaters; and 3) critically evaluate the performance of the composite Al/O-WTR as a fertilizer using selected plants grown in lysimeters and test-field studies. Instead of lysimeters we used pots (Israel) and one- liter cone-tainers (USA). We conducted one field study but in spite of major pretreatments the soils still exhibited high enough P from previous experiments so no differences between control and P additions were noticeable. Due to time constrains the field study was discontinued. Background: Phosphorous, a non-renewable resource, has been applied extensively in fields to increase crop yield, yet consequently has increased the potential of waterway eutrophication. Our proposal impetus is the need to develop an innovative method of P capturing, recycling and reuse that will sustain agricultural productivity while concurrently reducing the level of P discharge from and to agricultural settings. Major Conclusions & Achievements: An innovative approach was developed for P removal from soil leachate, dairy wastewater (Israel), and swine effluents (USA) using Al-based water treatment residuals (Al- WTR) to create an organic-Al-WTR composite (Al/O-WTR), potentially capable of serving as a P fertilizer source. The Al-WTR removed 95% inorganic-P, 80% to 99.9% organic P, and over 60% dissolved organic carbon from the agro-industrial waste streams. Organic C accumulation on particles surfaces possibly enhanced weak P bonding and facilitated P desorption. Analysis by scanning electron microscope (SEM- EDS), indicated that P was sparsely sorbed on both calcic and Al (hydr)oxide surfaces. Sorption of P onto WW-Al/O-WTR was reversible due to weak Ca-P and Al-P bonds induced by the slight alkaline nature and in the presence of organic moieties. Synchrotron-based microfocused X-ray fluorescence (micro-XRF) spectrometry, bulk P K-edge X-ray absorption near edge structure spectroscopy (XANES), and P K-edge micro-XANES spectroscopy indicated that adsorption was the primary P retention mechanism in the Al- WTR materials. However, distinct apatite- or octocalciumphosphatelike P grains were also observed. Synchrotron micro-XRF mapping further suggested that exposure of the aggregate exteriors to wastewater caused P to diffuse into the porous Al-WTR aggregates. Organic P species were not explicitly identified via P K-edge XANES despite high organic matter content, suggesting that organic P may have been predominantly associated with mineral surfaces. In screen houses experiments (Israel) we showed that the highest additions of Al/O-WTR (5 and 7 g kg⁻¹) produced the highest lettuce (Lactuca sativa L. var. longifolial) yield. Lettuce yield and P concentration were similar across treatments, indicating that Al/O- WTR can provide sufficient P to perform similarly to common fertilizers. A greenhouse study (USA) was utilized to compare increasing rates of swine wastewater derived Al/O-WTR and inorganic P fertilizer (both applied at 33.6, 67.3, and 134.5 kg P₂O₅ ha⁻¹) to supply plant-available P to spring wheat (TriticumaestivumL.) in either sandy loam or sandy clay loam soil. Spring wheat straw and grain P uptake were comparable across all treatments in the sandy loam, while Al/O-WTR application to the sandy clay loam reduced straw and grain P uptake. The Al/O-WTR did not affect soil organic P concentrations, but did increase phosphatase activity in both soils; this suggests that Al/O-WTR application stimulated microorganisms and enhance the extent to which microbial communities can mineralize Al/O-WTR-bound organic P. Implications: Overall, results suggest that creating a new P fertilizer from Al-WTR and agro-industrial waste sources may be a feasible alternative to mining inorganic P fertilizer sources, while protecting the environment from unnecessary waste disposal.
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PERFORMANCE OPTIMIZATION OF A STEEL-UHPC COMPOSITE ORTHOTROPIC BRIDGE WITH INTELLIGENT ALGORITHM. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.160.

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To address the problems of pavement damage and fatigue cracking of orthotropic steel deck (OSD) in bridges, an innovative composite bridge deck composed of OSD with open ribs and ultra-high performance concrete (UHPC) layer was proposed. Firstly, the stress responses of fatigue-prone details in the composite bridge deck were investigated by refined two-scale finite element analysis. The results show that the rib-to-deck joint can achieve an infinite fatigue life, while the floorbeam detail of rib-tofloorbeam joint indicates finite fatigue life. Then, response surface models of stress ranges of fatigue details and structure weight were derived via both the central composite design and response surface method. Finally, to improve the fatigue performance for achieving an infinite fatigue life under relatively low structure weight, the multi-objective optimization was executed by an Improved Non-dominated Sorting Genetic Algorithm (NSGA-II). The obtained Pareto front shows that there is a strong competition between the stress range of fatigue-prone detail and structure weight.
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