Material Science & Engineering International Journal最新文献

{"title":"Behavior of pile caps on one steel pile","authors":"R. G. Delalibera, Marcell Godoi Sivelli, J. S. Giongo, V. F. Gonçalves, Márcio de Oliveira Filho","doi":"10.15406/mseij.2019.03.00084","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00084","url":null,"abstract":"Piles are slender linear structural elements, whose purpose is to transfer the load from the superstructure to the soil. The connection between the piles and the superstructure is commonly done by pile caps that, according to the NBR 6118, are volumetric structures used to transfer the load coming from the superstructure to the piles. The first studies of great relevance, regarding the design of pile caps, are from Blévot & Frémy1 however, most of the researches on this area studied pile caps on reinforced concrete piles, leaving a vast field to be explored about pile caps on steel piles. According to Velloso & Lopes,2 the main disadvantage of using steel piles, in relation to other types of piles, is its high cost. Still, in some situations the use of steel piles is economically viable as they can be driven in almost any kind of soil and are highly effective against the vibration on the driving process. In agreement with NBR 6122,3 connection between the pile and the cap can be made with an embedment length of the pile in the cap of 20 centimeters and, in addition, a helical reinforcement may be used. After its review, the NBR 61224 suggests only that the connection must be made by using either steel plates on top of the piles, stirrups or steel rebar welded to the pile. Fundações Teoria e Prática5 recommends that a helical reinforcement is placed over the embedment length of the steel pile in the cap. Pfeil6 suggests that straight rebar must be welded over the embedment length of the steel pile, with the addition of helical reinforcement, and that the embedment length of the steel pile must be at least 30 centimeters.","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89550189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vitrification and sinter-crystallization of fly ash with glass cullet","authors":"Barrachina E, Stoyanova Lyubenova T, F. D., Calvet I, Carda Jb","doi":"10.15406/mseij.2019.03.00112","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00112","url":null,"abstract":"Nowadays, in this second decade of this century, the industrial residues they continue generating environmental problems. Such of these wastes (glass cullet and bottom or fly ashes from the coal power stations) are still abundant and not definitive applications or solutions for its immobilizing have been given, though a considerable amount of research has been conducted in the last years. One of the promising applications proposed by laboratories research has been their potential for being used in the construction industry.1,2 With respect the glass cullet from the conventional glass there is abundant research carried out in the last decades of 20th and beginning of this 21st century.3–5 Vitrification process has been demonstrated is an adequate processing method for inertize toxic and abundant residues and even to facilitate their recycling as secondary raw materials in ceramics and glasses industries.6 Transforming of starting glasses after vitrification into glass-ceramics by controlled thermal treatment is possible to reach immobilizing of a wide range of industrial wastes (mineral residues, sludges from dumps, slags, ashes,). Besides, the low cost and great availability of waste make these glass-ceramics materials very attractive from an economical and technological point of view, so synthetic high-performance materials with broad applications in construction and civil engineering can be obtained from residues.7 Therefore, it has been the aim of this research to explore the synthesis of a new type of glass-ceramic by the sinter-crystallization process from soda-lime-silicate glass and several ashes from a coal power thermal station located in Andorra (Teruel, Spain). Materials and methods","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"PP 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84606070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shallow foundation analysis using the discrete element method","authors":"Joaquim Araujo Costa Neto, Márcio Muniz de Farias, Bernardo Cascao Pires e Albuquerque, Jessica Soares da Rocha","doi":"10.15406/mseij.2019.03.00104","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00104","url":null,"abstract":"","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73618974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical and electrochemical behaviour of aluminum-based hybrid composites reinforced with silicon carbide and pride of barbardos seed ash produced by stir casting","authors":"O. Oladayo, Alege Kehinde Sikirat","doi":"10.15406/mseij.2019.03.00110","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00110","url":null,"abstract":"Aluminum matrix composite (AMCs) represent a class of MMCs having characteristics of low density, high stiffness and strength, superior wear resistance, controlled co-efficient of thermal expansion, high fatigue resistance and better stability at elevated temperature. These properties made AMCs a good candidate for the design of various components for advanced engineering applications.1 It has been found that the use of AMCs in engine applications can reduce the overall weight, fuel consumption and pollution in the automobiles and aircrafts.2 MMCs reinforced with ceramic particles are very promising materials for structural applications due to excellent combination of properties.3 AMCs reinforced with either silicon carbide (3.18g/cm3) or alumina (3.9g/cm3) particles are attractive materials for aviation.4,5 Some of the reinforcements are denser than aluminum alloys (2.7g/cm3) and therefore increase the weight of the composites produced depending on the quantity of the reinforcement added.6 Moreover, ceramic particles addition to the Al-alloy increases the hardness and thereby making machining more difficult.6 Hybrid composites, in most cases possess superior strength than monolithic composite. The properties of the hybrid reinforcements (primary and secondary) can be combined to attain better material properties. More so, the use of stir casting method for production of AMCs reduces the cost of the composite.7 Current trends in AMCs show growing concern in the production of hybrid Aluminum Metal Composites (HAMCSs) with better physical and mechanical properties. Resent researches have shown that agro/industrial waste materials such as fly ash, graphite, rice husk ash, amongst others, can be successfully used as a complementary reinforcement in AMCs.7,8 Furthermore, the use of hybrid reinforcements increases the service performance of the composites by the formation of new features. These agro/industrial wastes can reduce the cost of aluminum composites. Secondly, the weight of the composite can be manipulated due to lower density of this agro/industrial waste materials.3 Thirdly, these composites can also offer competitive physical and mechanical properties.7 This research investigates the mechanical and corrosion behavior of Aluminum-hybrid composite produced by reinforcing Aluminum 6063 with pride of Barbados seed ash and silicon carbide via double stir casting method.","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86579802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of heat treatment on the microstructure and hardness of the SLMed TC4 alloy specimens","authors":"Jinwu Kang","doi":"10.15406/mseij.2019.03.00096","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00096","url":null,"abstract":"Titanium alloys have outstanding properties such as corrosion resistance, high strength-to-weight ratio even at high temperatures, which makes them a suitable candidate for high demanding applications such as in aerospace industry. Among the Ti-alloy families, Ti6Al-4V(TC4) has been widely used in additive manufacturing as well as traditional processing such as casting and forging. Additive manufacturing can be used to fabricate titanium alloys with complex geometrical features and reduce material waste, production time and costs. There are many researches about the effect of heat treatment on as-cast or as-forged microstructures.1,2 As additive manufacturing appears, the microstructure features and the effect heat treatment on the additive manufactured specimens come to be the research focus. Jiao et al.,3 found that α laths have a plate morphology, and they precipitated out from β phase following a tetrahedral relationship, a special morphology with mixture of plate-like and rod-like α phase in the fabricated Ti-10V-2Fe-3Al alloy specimen by laser melting deposition additive manufacturing. Aziz4 &Murr5 Thijs6 & Kobyrn7 & Zhu8 & Song9 investigated the microstructure of TC4 titanium alloy in selective laser manufacturing. SLMed samples own good mechanical properties except of ductility. Thus, researchers investigated the way how to improve the ductility by heat treatment. Erhard10 studied the effect of heat treatment on the microstructure and mechanical properties of samples made by SLM. Sabban11 proposed repeated thermal cycling close to but below the β transus temperature to form globular α phase, eliminating the need for plastic deformation prior to heat treatment, which led to the bimodal microstructure consisting of globular α in additively manufactured TC4 alloy. In order to provide the understanding how to improve the mechanical properties, the TC4 titanium alloy samples were made by SLM method and they were heat treated, the effect of heat treatment on microstructure was symmetrically investigated.","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90731798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural analysis of x-ray irradiated carbon nanostructures","authors":"A. Grozdanov, P. Paunović, Violeta Vasilevska-Nikodinovska, A. Dimitrov, V. Yukhymchuk, I. Stojkovski, Zorica Arsova","doi":"10.15406/mseij.2019.03.00105","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00105","url":null,"abstract":"Emerging nanotechnologies in which nuclear applications and radiations play key roles are: nano-electronics in environmental monitoring and remediation, electrode materials in hydrogen economy, polymer based nanocomposites in biotechnology, diagnostics and therapy. Radiation based technology using x-rays, e-beams and ion-beams is the key to avariety of different approaches. Due to the various ionizing irradiations, physical, chemical and biological properties of the materials can be significantly modified. Compared with conventional chemical reduction, the irradiation techniques are environmentally friendly, easily controlled, highly pure and less destructive. The most common defects induced by irradiation are vacancies and interstitials. Carbon based nanostructures with sp2-like hybridization, are exclusive due to the fact that its valence permitted researchers to engineer a large collection of molecular architectures. What makes all these structures truly phenomenal is that they are indeed built from the same component and they still can differ in shape and dimensionality. The most prolific irradiation-induced defects in graphenic carbon nanostructures are vacancies (single or multi vacancies). These carbon sp2nanostrucutres develop an extended reconstruction of the atomic network near the vacancy by saturating two dangling bonds and forming a pentagon. In graphene, single vacancies reconstruct, but in CNT the reconstruction is much stronger owing to the curvature and inherent nanoscale size of the system. It was found that for a CNTs to contract locally to “heal” the hole and thus saturate energetically unfavorable danging bonds. Thus, curved graphitic structures such as CNTs can be referred to as self-healing materials under irradiation. Some of the last experimental studies on the irradiation of MWCNTs reported a broad range of interesting phenomena such as surface reconstructions, modified mechanical properties, ion-irradiation induced changes in electrical coupling between nanotubes.1-3 Kis et al., have shown a strong stiffening of bundles of CNTs after electron irradiation.4 Last years, irradiation with γ-rays was studied as one of the clean and easy method for modification of carbon nanostructures. Namely, the effects of γ-irradiation strongly depend on the irradiation conditions, the materials type and the irradiation medium. Guo et al. observed a dramatic increase in the ID/IG of the Raman spectrum of γ-ray irradiated multi-walled CNTs (MWCNTs), which was attributed to the large presence of sp3-hybridized carbon atoms.5 This is opposite to the trend reported by Xu et al.,6 who noted an 8% decrease in ID/ IG for MWCNTs irradiated to 20Mrad in air, signaling improved graphitic order.6 Also, it was found that γ-irradiation decreased the diameter of MWCNTs, increased their specific surface area and modified their oxygen functional groups.7 The graphitization of MWCNTs was improved with doses of 100kGy, while a higher dose of 150kGy induced","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74169708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solution-processed electrical doping of organic semiconductors and their application for organic devices","authors":"Gunel Huseynova","doi":"10.15406/mseij.2019.03.00098","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00098","url":null,"abstract":"Different electronic devices based on organic semiconductors (OSCs) are being developed and promoted every year due to unique and outstanding properties of the organic materials including flexibility, transparency, light weight, and solution-process ability. However, these materials are not fully commercialized due to their intrinsically low electrical performance and poor stability. And in order to overcome these issues several approaches have been developed and one of them is doping. Doping is the most straightforward method to increase electrical conductivity of the materials in the first place. The organic light-emitting diode (OLED) industry already uses this method to finally commercialize these organic devices successfully.1 It should be noted that doping of OSCs is completely different from that of inorganic ones in which conductivity is enhanced via the increase of charge carriers provided by the impurity atoms that replace the atoms in the host lattice. In organic electronics, no replacement of host lattice atoms by impurity atoms occurs. Rather, it is just simple and direct introduction of extra charge carriers to the whole host molecule via a charge transfer process.2 In this case, the effectiveness of the doping process depends on the energy level differences between the materials’ highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). This requirement seriously limits the doping possibilities of the organic materials as dopant and host molecules with matching energy levels are rare. One of the suggested alternatives for doping of OSCs in which the energy levels of the two materials can be ignored, is application of Lewis acids and bases for pand n-type doping, respectively.3‒7 In this work, two cationic organic dyes, Pyronin B (PyB) and Acridine Orange (AO), are investigated as p-type dopants for a conjugated ambipolar polymer diketopyrrolopyrrole-thieno [3,2-b]thiophene (DPPT-TT). The dopants are conjugated molecules with Lewis acid nature.","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77670371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of the crack behavior interface-fiber: interfacial crack","authors":"R. Sara, S. Boualem","doi":"10.15406/mseij.2019.03.00107","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00107","url":null,"abstract":"The use of composite materials in industrial applications has been increasing for several years, and this in all industries: automotive, aeronautics, space, marine, railway or even sports, medical and nuclear. The performances in terms of mass gain, mechanical properties and manufacturing offer many possibilities of applications, sometimes very complex. Research activities specific to these materials are also very present in laboratories around the world to better understand the behavior of composite structures across many topics of study, with the aim of improving their uses and their adequacy with the industrial application. The joining of ceramics to metals is inherently difficult because of their distinctly different properties. But considerable efforts have devoted to the development of joining technologies during recent past years have led to significant successes.1 Dissimilar materials had to join together in many technical areas. One example of the ceramic to metal joint is to combine the wear resistance, high temperature strength and thermal or electrical resistance of the ceramic with the ductility of the metal. Due to the difference of the elastic properties and the thermal expansion coefficients of the ceramic and metal the high stresses occur at the intersection of edges and the interface of the joint under mechanical or thermal loading.2","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79616310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A finite element analysis of fractured sandwich composite structures under small scale yielding","authors":"Ilias Tourlomousiss","doi":"10.15406/mseij.2019.03.00088","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00088","url":null,"abstract":"The fracture behavior in sandwich composite structures has been directed toward the understanding of crack propagation, and at the same time toward improving the durability of composites against fracture [1-4]. A crack flaw may be introduced during processing or subsequent service conditions. It may result from low velocity impact, from eccentricities in the structural load path, or from discontinuities in structures, which induce a significant out-of-plane stress. Generally for a state of plane stress the stresses normal to the plane of interest are negligibly small. On the other hand plane strain is assumed to occur where the strains to the normal plane are negligibly small. In our study both these cases will be studied. The sandwich beam considered is shown in Figure 1. Material properties and geometrical data are shown in Tables 1 & Tables 2 respectively. Additional information regarding material properties as shear and tensile strength, are given in Table 3. In this study combining the elastoplastic concepts approach with the step by step crack propagation inside the core of a sandwich beam very close to the upper skin interface, a numerical solution is proposed via the finite element analysis.1‒4 An initial crack length is assumed. Methods of evaluating the plastic zone under mixed mode loading conditions and small scale yielding ARE presented. In the presence of plastic zone at the crack tip the stiffness of the component decreases and the compliance increases. To incorporate the effect of plasticity in Fracture analysis the crack is mathematically modeled to be longer than the actual length. In the finite element model this is incorporated by taking into account the radius of singular elements around the crack tip. This radius is at the same order of magnitude with the crack tip plastic zone confronted in our analysis. The relations which relate the fracture parameters and the radius of the plastic as well as the direction of the propagation zone under the three point bending are presented. The extension of the plastic zone along the crack axis is succeeded by finding the point at which one of the yield criteria is satisfied. It is quite difficult to give a proper description of plastic zone shape and size. In all the models to simplify the analysis the material is assumed to be elastic-perfectly plastic. In this study considering that the plastic zones are created around the tips of the cracks under small scale yielding, the stress fields are determined in terms of the stress intensity factors using the asymptotic solutions.","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80485301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial cellulose/phytotherapic hydrogels as dressings for wound healing","authors":"Paula Rf de S Moraes, Sidney J. L. Ribeiro, A. M. Gaspar","doi":"10.15406/mseij.2019.03.00108","DOIUrl":"https://doi.org/10.15406/mseij.2019.03.00108","url":null,"abstract":"Skin, the largest organ of the human body, is formed mainly by epidermis and dermis and its main functions are assurance of mechanical protection and prevention against contamination.1,2 Wound healing begins from a skin-barrier disruption and is divided into inflammatory, proliferative, and maturation phases. The former consists in the recruitment of leukocytes to the site of the lesion. In the proliferative phase, the migration and proliferation of keratinocytes, fibroblasts, and endothelial cells results in reepithelization and formation of granulation tissue with a large quantity of type III collagen. Finally, in the maturation phase, most type III collagen fibers are substituted by type I fibers and the excess collagen is degraded by proteolytic enzymes that promote tissue remodeling. Despite some recent advances in the understanding of such basic processes, wound healing disorders continue to cause diseases and even death.3 Dressings play a substantial role in the conglutination of certain types of open wounds (e.g. traumatic, thermal or chronic wounds), since the moist, warm and nutritious environment of wound beds provides an ideal condition for microbial growth. The wound healing process can interfere with bacterial colonization and subsequent infection, which may cause an excessive and prolonged inflammatory response from the host tissues. The nature of lesions, patient’s physiologic state, wound degree of infection and contamination and other disease processes can interfere with the cutaneous wound healing.4 The basic requirement for a material to be used for tissue engineering purposes is biocompatibility. Over the past two decades, significant advances have been made regarding the development of biodegradable polymers and biodegradability is one of the most important properties, since the scaffold should degrade with time and be replaced with newly regenerated tissues.5","PeriodicalId":18241,"journal":{"name":"Material Science & Engineering International Journal","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85677131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}