2,565 research outputs found

    National Educators' Workshop: Update 1989 Standard Experiments in Engineering Materials Science and Technology

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    Presented here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 89, held October 17 to 19, 1989 at the National Aeronautics and Space Administration, Hampton, Virginia. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community

    MHTTU Implementation Final Project Report

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    Lawrence Livermore National Laboratory has invested considerable effort in developing fireproof high-efficiency particulate air (HEPA) filters. Due to the nature of LLNL’s research, the air leaving its lab facilities must be filtered before it is released into the atmosphere; thus, each laboratory is equipped with large banks of HEPA filters through which all internal air is exhausted. Over the years, however, fires have erupted in the labs and entire banks of HEPA filters have been destroyed, resulting in repairs and crucial downtime that prove costly. Engineers and scientists alike have been seeking a permanent solution to this problem, and one proposition is to make the filters themselves fireproof rather than installing sprinkler systems and other preventative measures to protect them, as is the current practice. The challenge is to make HEPA filters fireproof. HEPA filters are comprised of several critical components: the filter media material, the sealant, and the gasket. None of these components are designed to withstand any more than a few hundred degrees Fahrenheit, so LLNL solicited the help of Cal Poly senior project teams in investigating materials that might

    A Study of Composite Action in Materials After Treatment

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    Research reports: 1985 NASA/ASEE Summer Faculty Fellowship Program

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    A compilation of 40 technical reports on research conducted by participants in the 1985 NASA/ASEE Summer Faculty Fellowship Program at Marshall Space Flight Center (MSFC) is given. Weibull density functions, reliability analysis, directional solidification, space stations, jet stream, fracture mechanics, composite materials, orbital maneuvering vehicles, stellar winds and gamma ray bursts are among the topics discussed

    Experimental Studies on Abrasive Water Jet Cutting of Nano SiC Particles Filled Hybrid Basalt-Glass Fibre-Reinforced Epoxy Composites

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    Abrasive water jet machining (AWJM) is extensively beneficial in machining materials that are hard to cut. This investigation deals with AWJM of Nano SiC filled Epoxy reinforced with basalt-glass fiber hybrid composite. The composite is prepared by compression moulding technique. Experimental trails are performed to evaluate the impact of every process parameter on the responses i.e., surface roughness (Ra) and Material Removal Rate (MRR). The experiments are conducted by changing the standoff distance (SD), traverse speed (TS) and water pressure. The performance of the conducted experiment is analysed using a Swarm intelligence algorithm. Surface roughness and MRR are maximized by using the combination of optimum process parameter levels of 9.72 mm/min speed, 5.78 mm stand-off distance and 553 MPa jet pressure. Scanning Electron Microscopic (SEM) images are employed in detecting the morphology of machined surface and confirmed the presence of voids and fibre pull-out

    Summaries

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    Research Reports: 1984 NASA/ASEE Summer Faculty Fellowship Program

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    A NASA/ASEE Summer Faulty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The Faculty Fellows spent ten weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This document is a compilation of Fellows' reports on their research during the summer of 1984. Topics covered include: (1) data base management; (2) computational fluid dynamics; (3) space debris; (4) X-ray gratings; (5) atomic oxygen exposure; (6) protective coatings for SSME; (7) cryogenics; (8) thermal analysis measurements; (9) solar wind modelling; and (10) binary systems

    3D-glass keypad for future mobile phones of Sony Ericsson Mobile Communications AB

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    Abstract The competition regarding market shares in the mobile handset industry is tough. Today the mobile phone is more and more becoming a personal accessory and trends in shape, color and material are changing rapidly. The keypad is one of a phone’s many components which the end user gets in touch with first. It is used to activate the phone, and it is what the user feels and looks at initially. SEMC believes that offering a product made with new, exciting materials and unique shapes would give the company an added value on the mobile phone market. Therefore, the objective of this Master Thesis has been to perform a study on how 3D-glass can be used to develop an attractive and distinctive keypad, and thereby create a more uniform glass impression for the entire front on future mobile phones of SEMC. Limitations, challenges, possibilities and advantages regarding keypad design and production have been examined. The result from the study is meant to increase the knowledge of this area to the level where a decision can be made whether a 3D-glass keypad is a realistic feature or not for future mobile phone concepts. The project consists of three main phases - a theoretical study phase followed by an empirical study phase and a test phase. During the theoretical study phase two pre-studies were carried out; one within glass materials and one within keypad design. The empirical study phase included close contact with suppliers in the glass forming industry and keypad suppliers. Different production methods and combination of suppliers were considered, the keypad design chosen as a base was alternated, the artwork was revised and several possible aesthetic applications and after treatments of the glass keys were evaluated. After this realization phase, the physical 3D-glass keypad samples were then evaluated through a number of tests performed in the test lab at SEMC in Lund. The outcome of the tests was analyzed and a final evaluation of all the different concepts was performed. Ultimately, the project resulted in a design guideline, where recommendations for 3D-glass as a design material for keypads were made, as well as suggestions on areas for further studies

    DĂ©veloppement de bĂ©ton Ă  ultra-hautes performances (BFUP) Ă  base de verre ─ vers un bĂ©ton Ă©cologique innovant

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    Le bĂ©ton conventionnel (BC) a de nombreux problĂšmes tels que la corrosion de l’acier d'armature et les faibles rĂ©sistances des constructions en bĂ©ton. Par consĂ©quent, la plupart des structures fabriquĂ©es avec du BC exigent une maintenance frĂ©quent. Le bĂ©ton fibrĂ© Ă  ultra-hautes performances (BFUP) peut ĂȘtre conçu pour Ă©liminer certaines des faiblesses caractĂ©ristiques du BC. Le BFUP est dĂ©fini Ă  travers le monde comme un bĂ©ton ayant des propriĂ©tĂ©s mĂ©caniques, de ductilitĂ© et de durabilitĂ© supĂ©rieures. Le BFUP classique comprend entre 800 kg/mÂł et 1000 kg/mÂł de ciment, de 25 Ă  35% massique (%m) de fumĂ©e de silice (FS), de 0 Ă  40%m de poudre de quartz (PQ) et 110-140%m de sable de quartz (SQ) (les pourcentages massiques sont basĂ©s sur la masse totale en ciment des mĂ©langes). Le BFUP contient des fibres d'acier pour amĂ©liorer sa ductilitĂ© et sa rĂ©sistance aux efforts de traction. Les quantitĂ©s importantes de ciment utilisĂ©es pour produire un BFUP affectent non seulement les coĂ»ts de production et la consommation de ressources naturelles comme le calcaire, l'argile, le charbon et l'Ă©nergie Ă©lectrique, mais affectent Ă©galement nĂ©gativement les dommages sur l'environnement en raison de la production substantielle de gaz Ă  effet de serre dont le gas carbonique (CO[indice infĂ©rieur 2]). Par ailleurs, la distribution granulomĂ©trique du ciment prĂ©sente des vides microscopiques qui peuvent ĂȘtre remplis avec des matiĂšres plus fines telles que la FS. Par contre, une grande quantitĂ© de FS est nĂ©cessaire pour combler ces vides uniquement avec de la FS (25 Ă  30%m du ciment) ce qui engendre des coĂ»ts Ă©levĂ©s puisqu’il s’agit d’une ressource limitĂ©e. Aussi, la FS diminue de maniĂšre significative l’ouvrabilitĂ© des BFUP en raison de sa surface spĂ©cifique Blaine Ă©levĂ©e. L’utilisation du PQ et du SQ est Ă©galement coĂ»teuse et consomme des ressources naturelles importantes. D’ailleurs, les PQ et SQ sont considĂ©rĂ©s comme des obstacles pour l’utilisation des BFUP Ă  grande Ă©chelle dans le marchĂ© du bĂ©ton, car ils ne parviennent pas Ă  satisfaire les exigences environnementales. D’ailleurs, un rapport d'Environnement Canada stipule que le quartz provoque des dommages environnementaux immĂ©diats et Ă  long terme en raison de son effet biologique. Le BFUP est gĂ©nĂ©ralement vendu sur le marchĂ© comme un produit prĂ©emballĂ©, ce qui limite les modifications de conception par l'utilisateur. Il est normalement transportĂ© sur de longues distances, contrairement aux composantes des BC. Ceci contribue Ă©galement Ă  la gĂ©nĂ©ration de gaz Ă  effet de serre et conduit Ă  un coĂ»t plus Ă©levĂ© du produit final. Par consĂ©quent, il existe le besoin de dĂ©velopper d’autres matĂ©riaux disponibles localement ayant des fonctions similaires pour remplacer partiellement ou totalement la fumĂ©e de silice, le sable de quartz ou la poudre de quartz, et donc de rĂ©duire la teneur en ciment dans BFUP, tout en ayant des propriĂ©tĂ©s comparables ou meilleures. De grandes quantitĂ©s de dĂ©chets verre ne peuvent pas ĂȘtre recyclĂ©es en raison de leur fragilitĂ©, de leur couleur, ou des coĂ»ts Ă©levĂ©s de recyclage. La plupart des dĂ©chets de verre vont dans les sites d'enfouissement, ce qui est indĂ©sirable puisqu’il s’agit d’un matĂ©riau non biodĂ©gradable et donc moins respectueux de l'environnement. Au cours des derniĂšres annĂ©es, des Ă©tudes ont Ă©tĂ© rĂ©alisĂ©es afin d’utiliser des dĂ©chets de verre comme ajout cimentaire alternatif (ACA) ou comme granulats ultrafins dans le bĂ©ton, en fonction de la distribution granulomĂ©trique et de la composition chimique de ceux-ci. Cette thĂšse prĂ©sente un nouveau type de bĂ©ton Ă©cologique Ă  base de dĂ©chets de verre Ă  ultra-hautes performances (BEVUP) dĂ©veloppĂ© Ă  l'UniversitĂ© de Sherbrooke. Les bĂ©tons ont Ă©tĂ© conçus Ă  l’aide de dĂ©chets verre de particules de tailles variĂ©es et de l’optimisation granulaire de la des matrices granulaires et cimentaires. Les BEVUP peuvent ĂȘtre conçus avec une quantitĂ© rĂ©duite de ciment (400 Ă  800 kg/mÂł), de FS (50 Ă  220 kg/mÂł), de PQ (0 Ă  400 kg/mÂł), et de SQ (0-1200 kg/mÂł), tout en intĂ©grant divers produits de dĂ©chets de verre: du sable de verre (SV) (0-1200 kg/mÂł) ayant un diamĂštre moyen (d[indice infĂ©rieur 50]) de 275 ”m, une grande quantitĂ© de poudre de verre (PV) (200-700 kg/mÂł) ayant un d50 de 11 ”m, une teneur modĂ©rĂ©e de poudre de verre fine (PVF) (50-200 kg/mÂł) avec d[indice infĂ©rieur] 50 de 3,8 ”m. Le BEVUP contient Ă©galement des fibres d'acier (pour augmenter la rĂ©sistance Ă  la traction et amĂ©liorer la ductilitĂ©), du superplastifiants (10-60 kg/mÂł) ainsi qu’un rapport eau-liant (E/L) aussi bas que celui de BFUP. Le remplacement du ciment et des particules de FS avec des particules de verre non-absorbantes et lisse amĂ©liore la rhĂ©ologie des BEVUP. De plus, l’utilisation de la PVF en remplacement de la FS rĂ©duit la surface spĂ©cifique totale nette d’un mĂ©lange de FS et de PVF. Puisque la surface spĂ©cifique nette des particules diminue, la quantitĂ© d’eau nĂ©cessaire pour lubrifier les surfaces des particules est moindre, ce qui permet d’obtenir un affaissement supĂ©rieur pour un mĂȘme E/L. Aussi, l'utilisation de dĂ©chets de verre dans le bĂ©ton abaisse la chaleur cumulative d'hydratation, ce qui contribue Ă  minimiser le retrait de fissuration potentiel. En fonction de la composition des BEVUP et de la tempĂ©rature de cure, ce type de bĂ©ton peut atteindre des rĂ©sistances Ă  la compression allant de 130 Ă  230 MPa, des rĂ©sistances Ă  la flexion supĂ©rieures Ă  20 MPa, des rĂ©sistances Ă  la traction supĂ©rieure Ă  10 MPa et un module d'Ă©lasticitĂ© supĂ©rieur Ă  40 GPa. Les performances mĂ©caniques de BEVUP sont amĂ©liorĂ©es grĂące Ă  la rĂ©activitĂ© du verre amorphe, Ă  l'optimisation granulomĂ©trique et la densification des mĂ©langes. Les produits de dĂ©chets de verre dans les BEVUP ont un comportement pouzzolanique et rĂ©agissent avec la portlandite gĂ©nĂ©rĂ©e par l'hydratation du ciment. Cependant, ceci n’est pas le cas avec le sable de quartz ni la poudre de quartz dans le BFUP classique, qui rĂ©agissent Ă  la tempĂ©rature Ă©levĂ©e de 400 °C. L'addition des dĂ©chets de verre amĂ©liore la densification de l'interface entre les particules. Les particules de dĂ©chets de verre ont une grande rigiditĂ©, ce qui augmente le module d'Ă©lasticitĂ© du bĂ©ton. Le BEVUP a Ă©galement une trĂšs bonne durabilitĂ©. Sa porositĂ© capillaire est trĂšs faible, et le matĂ©riau est extrĂȘmement rĂ©sistant Ă  la pĂ©nĂ©tration d’ions chlorure (≈ 8 coulombs). Sa rĂ©sistance Ă  l'abrasion (indice de pertes volumiques) est infĂ©rieure Ă  1,3. Le BEVUP ne subit pratiquement aucune dĂ©tĂ©rioration aux cycles de gel-dĂ©gel, mĂȘme aprĂšs 1000 cycles. AprĂšs une Ă©valuation des BEVUP en laboratoire, une mise Ă  l'Ă©chelle a Ă©tĂ© rĂ©alisĂ©e avec un malaxeur de bĂ©ton industriel et une validation en chantier avec de la construction de deux passerelles. Les propriĂ©tĂ©s mĂ©caniques supĂ©rieures des BEVUP a permis de concevoir les passerelles avec des sections rĂ©duites d’environ de 60% par rapport aux sections faites de BC. Le BEVUP offre plusieurs avantages Ă©conomiques et environnementaux. Il rĂ©duit le coĂ»t de production et l’empreinte carbone des structures construites de bĂ©ton fibrĂ© Ă  ultra-hautes performances (BFUP) classique, en utilisant des matĂ©riaux disponibles localement. Il rĂ©duit les Ă©missions de CO[indice infĂ©rieur 2] associĂ©es Ă  la production de clinkers de ciment (50% de remplacement du ciment) et utilise efficacement les ressources naturelles. De plus, la production de BEVUP permet de rĂ©duire les quantitĂ©s de dĂ©chets de verre stockĂ©s ou mis en dĂ©charge qui causent des problĂšmes environnementaux et pourrait permettre de sauver des millions de dollars qui pourraient ĂȘtre dĂ©pensĂ©s dans le traitement de ces dĂ©chets. Enfin, il offre une solution alternative aux entreprises de construction dans la production de BFUP Ă  moindre coĂ»t.Abstract : Conventional concrete (CC) may cause numerous problems on concrete structures such as corrosion of steel reinforcement and weaknesses of concrete construction. As a result, most of structures made with CC require maintenance. Ultra-high-performance concrete (UHPC) can be designed to eliminate some of the characteristic weaknesses of CC. UHPC is defined worldwide as concrete with superior mechanical, ductility, and durability properties. Conventional UHPC includes between 800 and 1000 kg/mÂł of cement particles, 25–35%wt of silica fume (SF), 0–40 wt% of quartz powder (QP), and 110–140 wt% quartz sand (QS) (the percentages are based on the total cement content of the mix by weight). UHPC contains steel fibers to improve its ductility and tension capacity. The huge amount of cement used to produce UHPC not only affects production costs and consumes natural resources, limestone, clay, coal, and electric power, but it also negatively impacts the environment through carbon dioxide (CO[subscript 2]) emissions, which can contribute to the greenhouse effect. Additionally, the particle-size distribution (PSD) of cement exhibits a gap at the micro scale that needs to be filled with more finer materials such as SF. Filling this gap solely with SF requires a high amount of SF (25% to 30% by cement weight) which is a limited resource and involves high cost. This significantly also decreases UHPC workability due to high Blaine surface area of SF. QS and QP use is also costly and consumes natural resources. As such, they are considered as impedances for wide use of UHPC in the concrete market and fail to satisfy sustainability requirements. Furthermore, based on an Environment Canada report, quartz causes immediate and long-term environmental harm because its biological effect makes it an environmental hazard. Furthermore, UHPC is generally sold on the market as a prepackaged product, which limits any design changes by the user. Moreover, it is normally transported over long distances, unlike CC components. This increases to the greenhouse-gas effect and leads to higher cost of the final product. Therefore, there is a vital need for other locally available materials with similar functions to partially or fully replace silica fume, quartz sand, or quartz powder, and thereby reduce the cement content in UHPC, while having comparable or better properties. In some countries, and Canada in particular, large quantities of glass cannot be recycled because of the high breaking potential, color mixing, or high recycling costs. Most waste glass goes into landfill sites, which is undesirable since it is not biodegradable and less environmentally friendly. In recent years, attempts have been made to use waste glass as an alternative supplementary cementitious material (ASCM) or ultra-fine aggregate in concrete, depending on its chemical composition and particle-size distribution (PSD). This thesis is based on a new type of ecological ultra-high-performance glass concrete (UHPGC) developed at the UniversitĂ© de Sherbrooke. The concrete’s design involved using waste glass of varying particle-size distributions obtained from cullets and optimizing the packing density of the entire material matrix. UHPGC can be designed with a reduced amount of cement (400–800 kg/mÂł), silica fume (SF) (50–220 kg/mÂł), quartz powder (QP) (0–400 kg/mÂł), and quartz sand (QS) (0–1200 kg/mÂł), while incorporating various waste-glass products: glass sand (GS) (0–1200 kg/mÂł) with an average mean diameter (d[subscript 50]) of 275 ÎŒm, a high amount of glass powder (GP) (200–700 kg/mÂł) with average diameter (d[subscript 50]) of 11 ÎŒm, a moderate content of fine glass powder (FGP) (50–200 kg/mÂł) with d[subscript 50] of 3.8 ÎŒm. UHPGC also contains steel fibers (to increase tensile strength and improve ductility) and superplasticizer (10–60 kg/mÂł) as well as having a water-to-binder ratio (w/b) as low as that of UHPC. Replacing cement and silica-fume particles with non-absorptive and smooth glass particles improves UHPGC rheology. Furthermore, using FGP as a SF replacement reduces the net total surface area of a SF and FGP blend. This decreases the net particle surface area, it reduces the water needed to lubricate particle surfaces and increases the slump flow at the same w/b. Moreover, the use of waste glass material in concrete leads to lower cumulative heat of hydration, which helps minimize potential shrinkage cracking. Depending on UHPGC composition and curing temperature, this type of concrete yields compressive strength ranging from 130 up to 230 MPa, flexural strength above 20 MPa, tensile strength above 10 MPa, and elastic modulus above 40 GPa. The mechanical performance of UHPGC is enhanced by the reactivity of the amorphous waste glass and optimization of the packing density. The waste-glass products in UHPGC have pozzolanic behavior and react with the portlandite generated by cement hydration. This, however, is not the case with quartz sand and quartz powder in conventional UHPC, which react at high temperature of 400 °C. The waste-glass addition enhances clogging of the interface between particles. Waste-glass particles have high rigidity, which increases the concrete’s elastic modulus. UHPGC also has extremely good durability. Its capillary porosity is very low, and the material is extremely resistant to chloride-ion permeability (≈ 8 coulombs). Its abrasion resistance (volume loss index) is less than 1.3. UHPGC experiences virtually no freeze–thaw deterioration, even after 1000 freeze–thaw cycles. After laboratory assessment, the developed concrete was scaled up with a pilot plane and field validation with the construction of two footbridges as a case study. The higher mechanical properties allowed for the footbridges to be designed with about sections reduced by 60% compared to normal concrete. UHPGC offers several economic and environmental advantages. It reduces the production cost of ultra-high-performance concrete (UHPC) by using locally available materials and delivers a smaller carbon footprint than conventional UHPC structures. It reduces the CO[subscript 2] emissions associated with the production of cement clinkers (50% replacement of cement) and efficiently uses natural resources. In addition, high amounts of waste glass cause environmental problems if stockpiled or sent to landfills. Moreover, the use of waste glass in UHPGC could save millions of dollars that would otherwise be spent for treatment and placing waste glass in landfills. Lastly, it provides an alternative solution to the construction companies in producing UHPC at lower cost
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