Relevant bibliographies by topics / Additifs poreux

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Additifs poreux'

Author: Grafiati
Published: 4 June 2021
Last updated: 3 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Additifs poreux.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Additifs poreux"

1

Švinka, Ruta, Visvaldis Svinka, and Julija Bobrovik. "Modification of Porous Cordierite Ceramic." Key Engineering Materials 721 (December 2016): 322–26. http://dx.doi.org/10.4028/www.scientific.net/kem.721.322.

Full text
Abstract:
Highly porous cordierite ceramic by using of talcum, kaolinite and γ-alumina was obtained by method of slip casting of concentrated suspension. Additives of amorphous silica and non-stabilized zirconia in the amount of 5 wt% were used. Sintering temperature of dried samples was in range of 1250 – 1450°C. All the samples contain crystalline phases of cordierite, mullite and corundum but, depending on the additives, as a result of sintering in addition forms spinel, cristobalite or zircon (ZrSiO4). Porosity of obtained materials changes in large scale from 42 to 59 per cent; it is influenced by both sintering temperature and composition. Compressive strength increases with the addition of zirconia. In comparison, compressive strength of samples without additives or with silica additive does not exceed 3.5 MPa. The increase of coefficient of thermal expansion depends both on the composition and sintering temperature. ZrO2 additive increases the coefficient of thermal expansion considerably.
APA, Harvard, Vancouver, ISO, and other styles
2

Lu, Yuan, Jian Feng Yang, Shao Yun Shan, Ji Qiang Gao, and Zhi Hao Jin. "Effects of Sintering Additives on Properties of Porous Silicon Nitride Ceramics Fabricated by Carbothermal Reduction." Key Engineering Materials 368-372 (February 2008): 878–80. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.878.

Full text
Abstract:
In this paper, porous Si3N4 ceramics were fabricated by carbothermal reduction between silicon dioxide and carbon. The influences of four types of sintering additives on the microstructure and mechanical properties of the porous Si3N4 ceramics were investigated. XRD analysis proved complete formation of a single-phase β-Si3N4. SEM analysis showed that the resultant porous Si3N4 ceramics occupied fine microstructure and a uniform pore structure. The sintered sample with Lu2O3 as sintering additive showed finer, a higher aspect ratio β-Si3N4 grains. The addition of Eu2O3 accelerated the densification of porous Si3N4 ceramics, decreased the porosity and increased the flexural strength.
APA, Harvard, Vancouver, ISO, and other styles
3

Kim, Sung Jin, Hee Gon Bang, Jung Wook Moon, and Sang Yeup Park. "Effect of Zirconia on the Physical Properties of Cordierite Honeycomb Filter." Materials Science Forum 544-545 (May 2007): 725–28. http://dx.doi.org/10.4028/www.scientific.net/msf.544-545.725.

Full text
Abstract:
The enhancement of physical properties of porous honeycomb filter for air purification was investigated using cordierite with the addition of pore former and zirconia additive. Because cordierite honeycomb has porous body, binder formulation was varied using graphite for a pore forming agent as well as lubricating agent during the extrusion process. Also, the effect of zirconia additives on the resultant physical properties of honeycomb filter such as porosity, thermal expansion coefficient and mechanical strength was investigated.
APA, Harvard, Vancouver, ISO, and other styles
4

Kim, Jae-Kwang, Rani Vijaya, Likun Zhu, and Youngsik Kim. "Improving electrochemical properties of porous iron substituted lithium manganese phosphate in additive addition electrolyte." Journal of Power Sources 275 (February 2015): 106–10. http://dx.doi.org/10.1016/j.jpowsour.2014.11.028.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Duan, Yanan, Guijie Ji, Shaochun Zhang, Xiufang Chen, and Yong Yang. "Additive-modulated switchable reaction pathway in the addition of alkynes with organosilanes catalyzed by supported Pd nanoparticles: hydrosilylation versus semihydrogenation." Catalysis Science & Technology 8, no. 4 (2018): 1039–50. http://dx.doi.org/10.1039/c7cy02280h.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Shan, Shao Yun, Jian Feng Yang, Ji Qiang Gao, Wen Hui Zhang, Zhi Hao Jin, Rolf Janßen, and Tatsuki Ohji. "Fabrication of Porous Silicon Nitride with High Porosity." Key Engineering Materials 336-338 (April 2007): 1105–8. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1105.

Full text
Abstract:
In this study, porous Si3N4 ceramics were fabricated by carbothermal reduction reaction between silicon dioxide and carbon. The influences of different starting powders and sintering additives on microstructure and mechanical properties were investigated. XRD analysis demonstrated the formation of single-phase β-Si3N4 except for glass phase and minor of α-Si3N4 phase. SEM analysis showed that the resultant porous Si3N4 ceramics occupied fine microstructure and uniform pore structure. The samples with fine starting powder showed fine, high aspect ratio of β-Si3N4 grains and good mechanical properties. The addition of Al2O3 accelerated the densification of porous Si3N4 ceramics. With an increasing in the sintering additive content, the porosity decreased, the flexural strength increased.
APA, Harvard, Vancouver, ISO, and other styles
7

Sych, O. "Effect of fluorine addition on the structure and properties of high-porous glass ceramics applicable for reconstructive surgery." Functional materials 23, no. 4 (March 24, 2017): 046–51. http://dx.doi.org/10.15407/fm24.01.046.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Paganggi, Wira Rante, Amelia Makmur, and Rachmansyah Rachmansyah. "Effect of Addition Polypropylene Fiber on Compressive Strength and Permeability Values in Porous Concrete." MEDIA KOMUNIKASI TEKNIK SIPIL 27, no. 1 (August 20, 2021): 135–42. http://dx.doi.org/10.14710/mkts.v27i1.31536.

Full text
Abstract:
The infrastructure growth has an impact on reducing green areas, which will be followed by reduced water catchment areas. Porous concrete is one of the porous materials that can be used on a pedestrian walk, which is able to drain water. The porous concrete has a limitation strength. This research aims to determine the effect of using various content of chemical additive and polypropylene fibers for porous concrete mixtures related to the compressive strength and permeability values. This experimental method referring to ACI 522R-10 Standard. That specimens using chemical additives and variations of polypropylene fibers: 0.05%, 0.1%, 0.15%, 0.2%, and 0.25% by weight of cement. The results showed that the specimen which had the highest compressive strength was 16.9 MPa, which was added 0.25% polypropylene fiber. The addition of polypropylene fibers increases the compressive strength value by 5.6%. Based on the compressive strength and permeability graphs, it can be estimated that the optimal content of polypropylene fiber is 0.17% by weight of cement.
APA, Harvard, Vancouver, ISO, and other styles
9

Ueno, Shunkichi, Li Ming Lin, and Hideo Nakajima. "Effect of Impurities on Formation of Pores in Porous Alumina during Unidirectional Solidification." Materials Science Forum 569 (January 2008): 313–16. http://dx.doi.org/10.4028/www.scientific.net/msf.569.313.

Full text
Abstract:
A porous alumina with cylindrical pores was fabricated by unidirectional solidification under hydrogen gas flow (0.1 MPa) using alumina feed rods doped with silica, calcia or sodium oxide. The additives in the feed rods strongly affect the formation of porous structure during the solidification. The porosity increases with increasing silica content. The increase of porosity is enhanced by further addition of sodium oxide. The addition of calcia to the feed rod is effective on the homogenization of pore distribution. The porous alumina with 1mol%CaO and 20mol%SiO2 additives showed 50% porosity and homogeneous pores distribution.
APA, Harvard, Vancouver, ISO, and other styles
10

Shahnewaz, S. M., Khairil Azman Masri, and N. A. A. A. Ghani. "Porous Asphalt Modification using Different Types of Additives: A Review." CONSTRUCTION 1, no. 1 (June 30, 2021): 44–53. http://dx.doi.org/10.15282/construction.v1i1.6502.

Full text
Abstract:
Nowadays porous asphalt pavement increase usage other than the traditional type of asphalt pavement. In that sense porous asphalt specially use in the parking areas and walk ways for pedestrian. There are diverse ways that has been done in order to stick up to permanent degradation such as adding fibers and modifiers like polymers, chemical modifiers, expandars, oxidants and antioxidents, hydrocarbons and antistripping to enhance the fatigue and service life of the pavement. To use these type of additives in porous asphalt pavement some additive increase the mechanical performance of porous asphalt mixture and improve the serviceability of the pavement. Digital image processing use these type of pavement to reduce the air void of the asphalt mixture and increase the physical properties of the porous asphalt pavement. This review paper mainly discuss the overall performance and advantage of porous asphalt using different types of additives.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Additifs poreux"

1

García-Loera, Antonio Dumon Michel. "Mélanges réactifs Thermodurcissable / Additifs extractibles." Villeurbanne : Doc'INSA, 2005. http://docinsa.insa-lyon.fr/these/pont.php?id=garcia_loera.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

García-Loera, Antonio. "Mélanges réactifs Thermodurcissable / Additifs extractibles : Phénomènes de Séparation de Phase et Morphologies : Application aux matériaux poreux." Lyon, INSA, 2002. http://theses.insa-lyon.fr/publication/2002ISAL0003/these.pdf.

Full text
Abstract:
La stratégie de la séparation de phase induite par une réaction chimique (RIPS) permet de disperser un additif dans un réseau thermodurcissable. Cette stratégie s'avère intéressante car il est possible d'obtenir des morphologies fermées ou ouvertes (bi-continues). L'intérêt de disperser une deuxième phase est très souvent lié à l'amélioration des propriétés mécaniques. Cependant, il est possible d'envisager la fabrication de thermodurcissables poreux, si la phase dispersée peut être facilement extraite (évaporée ou dégradée) du réseau thermodurcissable. Ce travail porte sur l'étude de réseaux thermodurcissables à base de diglycidyl éther du bisphénol A ou de dicyanate fluoré. Ces réseaux ont été modifiés par trois différents types d'additifs extractibles : un additif de faible masse molaire (l'eau), un additif thermoplastique amorphe (Poly(vinyl méthyl éther)) et un thermoplastique semi-cristallin ( Polyoxyméthylène ). La miscibilité de chaque additif, dans les réseaux thermodurcissables, dépend des contributions entropique (augmentation de la masse molaire) et enthalpique ( interactions entre le réseau et l'additif) du système. L'analyse des morphologies finales montre le potentiel de la technique RIPS dans la fabrication de matériaux poreux
The Reaction Induced Phase Separation (RIPS) technique is an interesting way to blend thermoset networks with diverse additives. Usually, this technique is used to improve the mechanical properties of thermoset networks. An alternative application is the synthesis of porous thermosets. In order to elaborate this kind of thermosets, the dispersed phase must to be easily extracted from the thermoset network. In this work, we investigated the morphology and the phase separation phenomena of thermoset-extractable additives blends. Two thermoset matrices (epoxy-amine and cyanate ester) and three additives (water, polyvinyl ether and polyoxymethylene) were used. The morphologies and the phase separation phenomena of the blends were analysed in order to evaluate the potential of the RIPS technique to synthesizer porous thermosets
APA, Harvard, Vancouver, ISO, and other styles
3

Storck-Gantois, Fanny. "Effet de la compression et de l’ajout d’additifs sur l’amélioration des performances d’un accumulateur au plomb." Paris 6, 2008. http://www.theses.fr/2008PA066370.

Full text
Abstract:
Les travaux de cette thèse visent le développement d’un accumulateur au plomb-acide aux propriétés améliorées en combinant l’utilisation d’additifs et la mise en compression des cellules. L’utilisation d’additifs poreux vise à favoriser la diffusion de l’électrolyte au sein de la matière active positive et l’utilisation d’additifs de conductivité tend à optimiser le réseau de conduction des matériaux actifs. Le maintien de la cohésion des matières en cyclage est assuré par la mise en compression des électrodes. Dans cet objectif, un protocole de fabrication d’électrodes positives a été développé au laboratoire. Un comportement de référence a ensuite été définit en déterminant les performances électriques et les caractéristiques des électrodes témoins soumises à des pressions allant de 0 à 1bar. Puis les effets des additifs ont été évalués lors d’applications en compression. Notre but étant également une meilleure compréhension du système plomb-acide et du mode de fonctionnement des additifs, des mécanismes pour expliquer l’évolution texturale des matériaux actifs positifs en compression et l’interaction entre les additifs et l’application d’une pression ont été proposés
APA, Harvard, Vancouver, ISO, and other styles
4

Lefèvre, Delphine. "Étude expérimentale, modélisation et simulation de la filtration lors de l'écoulement d'une résine chargée de particules à travers un renfort fibreux dans les technologies LCM." Lille 1, 2007. http://www.theses.fr/2007LIL10144.

Full text
Abstract:
La fabrication de pièces composites à matrice organique chargée de particules par un procédé de type LCM (Liquid Composite Molding) soulève le problème de l'écoulement du mélange de la résine avec les charges à travers le renfort fibreux. L'augmentation de la viscosité due aux particules, d'une part, et la filtration éventuelle des charges par le réseau fibreux, d'autre part, sont deux phénomènes à considérer car ils peuvent engendrer d'importants défauts de fabrication. Cette étude, volontairement limitée à une géométrie 1D, comporte une phase expérimentale et une phase de modélisation à l'échelle macroscopique, complémentaires l'une de l'autre, et menées en parallèle. Un moyen simple de mesure de la quantité de charges présentes dans la pièce en fin d'injection a d'abord été mis au point. Des essais d'injection de pièces, menés dans différentes conditions expérimentales, ont mis en évidence l'existence de deux comportements de filtration distincts. La modélisation est basée sur une équation de conservation de la masse et trois équations constitutives. Le modèle de filtration proposé dépend de deux paramètres physiques et d'un seul paramètre numérique, qui ont été identifiés par méthode inverse à partir des résultats expérimentaux. Enfin, la résolution du modèle développé est couplée à celle de l'écoulement d'un fluide à travers un renfort fibreux. Les résultats de la simulation, tant pour le profil de concentration de charges dans la pièce que pour le temps d'injection, sont très satisfaisants et viennent valider la démarche générale de cette étude.
APA, Harvard, Vancouver, ISO, and other styles
5

Kaushik, Swati. "Mécanisme de filtration des suspensions de microgel." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0019/document.

Full text
Abstract:
Les écoulements de suspensions dans des milieux poreux sont particulièrement complexes, notamment à cause du couplage d’écoulements de cisaillement et d’écoulements élongationnels (Herzig, Leclerc et Goff, 1970). On les retrouve fréquemment dans les applications industrielles, l’une des applications principales se trouvant lors des opérations de production de pétrole et de gaz. Lors de la construction d'un puits, des additifs polymères anti perte de fluide empêchent à plusieurs étapes l'écoulement de fluide entre le puits et la formation de roche poreuse environnante. La perte de fluide est un problème grave si elle n’est pas maîtrisée ; elle s’ajoute alors au coût total des opérations et pourrait surtout avoir des conséquences néfastes pour l’environnement et les opérateurs. Parmi les technologies disponibles, des additifs polymères connus sous le nom d'additifs anti perte de fluide, tels que des microgels et des particules de latex, sont ajoutés aux fluides injectés pour limiter les pertes de fluide (généralement de l'eau) via un mécanisme de colmatage / blocage de pores du support poreux.Le comportement de blocage de beaucoup de ces additifs anti perte de fluide a été testé par des méthodes conventionnelles qui impliquent l'application d'une différence de pression élevée (typiquement 35-70 bars) sur le fluide formulé comprenant les additifs contre un filtre représentatif de la taille typique des pores de la formation (une grille métallique, de la céramique ou du papier filtre) et la mesure du volume de filtrat en fonction du temps. Cependant, ces méthodes standard ne permettent pas de comprendre le mécanisme sous-jacent de la dynamique de blocage des supports poreux. Par conséquent, une meilleure compréhension du mécanisme de blocage d’un support poreux par des additifs industriels anti perte de fluide est nécessaire.Dans ce travail, nous utilisons des suspensions de microgels réticulés chimiquement comme additifs anti perte de fluide et nous étudions leur comportement de blocage dans des milieux poreux modèles transparents. Nous utilisons des dispositifs à base de polydiméthylsiloxane (PDMS) comme modèle de support poreux permettant l'observation directe du processus de blocage couplée à des mesures quantitatives. Nous fabriquons des dispositifs microfluidiques de filtration frontale et de filtration latérale avec différentes tailles de pores afin de déterminer comment des paramètres tels que la mouillabilité de la surface, la concentration en particules, la taille des particules et le débit affectent la formation du gâteau de filtration.Nous présentons une méthode de contrôle de la taille des particules constituant les suspensions de microgels. Nous décrivons ensuite une approche pour préparer des suspensions à plus haute concentration et étudions la rhéologie des suspensions en fonction de la concentration en particules. De plus, nous présentons un procédé simple pour former un gâteau de filtration à partir de la suspension de microgels sur une membrane et estimons la perméabilité à l’eau du gâteau de filtration formé selon la loi de Darcy
The flow of suspensions in porous media is a complex phenomenon due to the mechanisms involved such as both shear and extensional flows (Herzig, Leclerc, & Goff, 1970). Their use in industrial applications is quite extensive with one of the major applications being at various stages of oil and gas production operations. At several stages of a well construction, flow of fluid between the well and the surrounding porous rock formation is prevented thanks to the polymeric fluid loss control additives. Fluid loss is a severe problem if not controlled, which would add up to the total cost of operations and more importantly could have hazardous impacts on the environment or operators. Among several technologies industrially available, polymeric additives popularly known as fluid loss additives such as microgels and latex particles are added to the injected fluids to limit the loss of fluid (usually water) via the mechanism of pore clogging/jamming in porous media.Many of these fluid loss additives have been tested for their jamming behaviour by conventional methods which involve the application of a high pressure difference (typically 35-70 bars) on the formulated fluid comprising of the additives against a filter representative of the formation’s typical pore size (either a metallic grid, ceramic or filter paper) and the measurement of the filtrate volume versus time. However, these standard methods do not give any insight in understanding the underlying mechanism of jamming dynamics in porous media, hence, a better understanding of the mechanism of jamming in porous media by industrial fluid loss additives is needed.In this work, we use chemically cross-linked microgel suspensions as the fluid loss additive and study its jamming behaviour in transparent model porous media. We make use of polydimethylsiloxane (PDMS) devices as model porous media which allows direct observation of the jamming process coupled with quantitative measurements. We fabricate microfluidic devices for frontal flow filtration and lateral flow filtration with different pore sizes to see how parameters like surface wettability, particle concentration, particle size and flow rates affect the filter cake formation.We present a method of controlling the size of the microgel suspensions. We then describe an approach for preparing higher concentration suspensions and investigate the rheology of the suspensions as a function of concentration. Furthermore, we present a simple method of forming a filter cake of the microgel suspension on a supporting membrane and estimate the permeability of the filter cake formed for the flow of water using Darcy’s law
APA, Harvard, Vancouver, ISO, and other styles
6

Adam, Jérémy. "Développement, modélisation et caractérisation d'une maille innovante réalisée en fabrication additive pour les grands défauts osseux." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0068/document.

Full text
Abstract:
Ce travail de thèse traite du développement d’une maille en titane imprimée en 3D pour le comblement des grands défauts osseux. La perte de substance osseuse intervient lors de traumatismes importants ou de chirurgies ablatives (dues à des infections ou à des cancers). Lorsque le défaut atteint un stade critique, la régénération osseuse est impossible et on assiste à une perte de fonction. Il faut alors recourir à des chirurgies reconstructrices comme par exemple la reconstruction mandibulaire. Aujourd’hui, la chirurgie communément pratiquée pour reconstruire la mandibule est la reconstruction par lambeaux libres de fibula, laquelle demande un investissement en temps et en ressource colossale pour des résultats mitigés avoisinant les 10% de taux d’échec. En nous basant sur la littérature internationale, nous avons développé une maille en titane imprimée en 3D pour remplacer l’autogreffe de fibula et ainsi limiter les effets secondaires liés au site donneur tout en offrant aux cellules mésenchymateuses des conditions optimales à la colonisation osseuse. D’un point de vue mécanique, cela consiste à abaisser la rigidité native du titane (110GPa) à une rigidité comprise entre 0,1 et 1 GPa. Pour réaliser cette maille, nous avons mis en place une méthodologie de design qui nous a permis d’innover en mettant au point un système de reprise de charge. Ce système de reprise de charge permet d’adapter la réponse de l’implant en fonction de l’intensité de la sollicitation, ce qui permet de combiner une rigidité faible et une résistance à l’effort élevée. Les différentes itérations de design ont été testées par éléments finis, jusqu’au motif final, lequel a été caractérisée lors de tests mécaniques réels en compression, en traction et en flexion. Remplissant la majorité du cahier des charges, nous avons ensuite mis au point une étude animale, laquelle sera réalisée ultérieurement. Enfin, cette étude a permis de mettre en évidence certaines limitations de l’impression 3D métallique, principalement liés aux surfaces non supportées que nécessitent la reprise de charge. Cette maille très prometteuse est aujourd’hui en cours d’optimisation pour permettre d’être rapidement mise à la disposition des patients
The work detailed in this thesis is about a titanium 3D printed mesh for large bone defects. Large bone defects are often due to surgical resections, performed after a cancer or an infection. When the defect reach a critical size, bone regeneration is impossible and it often leads to the loss of function. When it happened, the wound need to be cured using reconstructive surgery. The mandibular reconstruction is one of the most performed reconstructive surgery. Nowadays, we reconstruct the mandible with the fibula free flap technique, which require huge amount of time and resources for mixed results (around 10% failure rate). Based on the international literature, we developed a titanium 3D printed mesh to replace the fibula autograft and limit its side effect while offering to mesenchymal cells optimal growing environment. On the mechanical point of view, this environment requires to decrease the titanium initial rigidity from 110GPa to a range between 0.1 and 1GPa. In order to achieve that goal, we have developed a design methodology that lead us to innovation. We developed a load restauration system that allow us to combine low rigidity and high resistance. In order to find the final design, we used finite element modeling. Then, the final design have been tested mechanically in compression, traction and flexion. Because most of the requirements were reached, we designed an animal study which should take place in the next years. Eventually, we discovered some limitation for metallic 3D printing, essentially due to unsupported areas required for the load restauration. This innovative mesh is today optimized in order to be rapidly given to patients in the need
APA, Harvard, Vancouver, ISO, and other styles
7

Boulvert, Jean. "Traitements acoustiques à porosité contrôlée pour atténuation optimale." Thesis, Le Mans, 2020. http://www.theses.fr/2020LEMA1033.

Full text
Abstract:
Cette thèse exploite certaines possibilités offertes par la fabrication additive pour concevoir et optimiser des traitements pour l'atténuation acoustique à base de matériaux poreux sous un nouvel angle. La fabrication additive permet de contrôler chaque pore d'un matériau individuellement. Le processus de conception de traitement poreux est chamboulé : pour répondre à un problème, au lieu de chercher parmi un catalogue de matériaux existants, il est possible de concevoir directement le matériau adéquat en ajustant sa microstructure. Cette recherche s'inscrit dans une démarche de réduction du bruit des réacteurs d'avion mais s'étend au-delà du domaine aéronautique, aussi bien au niveau théorique qu'à celui de ses possibles applications. Une méthode de prédiction de comportement acoustique de matériaux poreux produits par fabrication additive prenant en compte l'impact des défauts de fabrication est d'abord introduite. Les matériaux poreux à gradient de propriétés contrôlé sont ensuite étudiés. Une méthode d'optimisation des paramètres microstructuraux ou de fabrication est développée. La capacité des matériaux poreux à gradient de propriété à atténuer des fréquences hors de portée des matériaux sans gradient est ainsi prouvée et le gradient optimal pour l'atténuation large bande est défini. L'impact de la taille des parois des pores ainsi que l'impact de possibilité du son de se propager transversalement dans un matériau poreux est étudié. Enfin, un traitement métaporeux permettant l'absorption large bande et sub-longueur d'onde est développé. Les résultats de cette recherche peuvent être mis en application pour créer des traitements poreux à forte capacité d'atténuation du bruit. Cette recherche fait appel à des modèles analytiques et numériques basés sur l'hypothèse selon laquelle le matériau poreux peut être considéré acoustiquement comme un fluide équivalent, à l'analyse physique des comportements et à des validations expérimentales au travers de tests en tube d'impédance de spécimens produits par fabrication additive
This thesis exploits some of the new possibilities offered by additive manufacturing to design and optimize treatments for sound attenuation consisting in porous materials. Additive manufacturing allows to control individually each pore of a material. The porous treatment design process is turned upside down: instead of searching through a catalogue of existing materials to solve a problem, it is possible to directly design the right material by adjusting its microstructure. This research is part of a plan to reduce aircraft engine noise but extends beyond the aeronautical field, both theoretically and in terms of possible applications. A predicting method of the acoustic behaviour of porous materials produced by additive manufacturing and taking into account the impact of manufacturing defects is first introduced. Porous materials with controlled graded properties are then studied. A method for optimizing microstructural or manufacturing parameters is developed. The ability of graded porous materials to attenuate frequencies too low to be attenuated by non-graded materials is then proven and the optimal gradient for broadband attenuation is defined. The impact of the wall thickness of the pores along with the impact of transverse propagation inside porous materials is studied. Finally, a metaporous treatment allowing broadband and sub-wavelength absorption is developed. The results of this research can be applied to create porous treatments with a high noise attenuation. The analytical and numerical models used in this research are based on the hypothesis of porous materials acoustically behaving as equivalent fluids. The results are physically analyzed and experimentally validated through impedance tube testing of specimens produced by additive manufacturing
APA, Harvard, Vancouver, ISO, and other styles
8

Lambert, Océane. "Solutions architecturées par fabrication additive pour refroidissement de parois de chambres de combustion." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI048/document.

Full text
Abstract:
En vue de leur refroidissement, les parois de chambres de combustion aéronautiques sont perforées de trous à travers lesquels de l’air plus froid est injecté. La paroi est ainsi refroidie par convection et un film isolant est créé en surface chaude (film cooling). Cette thèse a pour objectif d’utiliser les possibilités de la fabrication additive pour proposer de nouvelles solutions architecturées qui permettraient d’augmenter les échanges de chaleur internes et d’obtenir ainsi de meilleures efficacités de refroidissement.La première approche consiste à élaborer de nouveaux designs de plaques multiperforées par Electron Beam Melting (EBM) et Selective Laser Melting (SLM) aux limites de résolution des procédés. Les architectures sont caractérisées en microscopie, en tomographie X et en perméabilité. Des simulations aérothermiques permettent de mettre en évidence l’effet de ces nouveaux designs sur l’écoulement et les échanges de chaleur, et de proposer des voies d’amélioration de la géométrie.La deuxième approche consiste à élaborer de façon simultanée une pièce architecturée par EBM, avec des zones denses et poreuses. A partir d’analyse d’images associée à une cartographie EBSD grand champ, il est possible de remonter aux mécanismes de formation du matériau poreux et de relier la perméabilité et la porosité aux paramètres procédé. Afin de favoriser le film cooling, il pourrait être avantageux que les zones microporeuses soient orientées dans le sens de l’écoulement. Pour ce faire, un nouveau procédé dénommé Magnetic Freezing, où des poudres métalliques forment une structure orientée par un champ magnétique, est mis au point.Les diverses solutions développées durant cette thèse sont testées sur un banc aérothermique. Les essais montrent qu’elles offrent un refroidissement plus efficace et plus homogène que la référence industrielle. Enfin, de premiers tests en combustion sur l’une des structures retenues, plus légère et plus perméable que la référence, montrent qu’il s’agit d’une solution aussi efficace à un débit traversant donné, et donc a priori plus efficace à une surpression donnée
Combustion chamber walls are perforated with holes so that a cooling air flow can be injected through them. The wall is cooled by convection and an insulating film is created on the hot surface (film cooling). This PhD thesis aims to use the possibilities of additive manufacturing to provide new architectured solutions that could enhance the internal heat exchanges, and lead to a higher cooling effectiveness.The first approach is to develop new designs of multiperforated walls by Electron Beam Melting (EBM) and Selective Laser Melting (SLM) used at the resolution limits of the processes. They are characterized by microscopy, X-ray tomography and permeability tests. Some aerothermal simulations help understanding the effects of these new designs on the flow and on heat exchanges. These results lead to a geometry adaptation.The second approach is to simultaneously manufacture an architectured part with dense and porous zones by EBM. Thanks to image analysis combined with large field EBSD, it is possible to investigate the mechanisms leading to the porous zones and to link them to permeability and porosity. The film cooling effect could be favoured by the orientation of pores towards the cooling flow. Therefore, a new powder-based manufacturing process named Magnetic Freezing, where metallic powders organize into an oriented structure thanks to a magnetic field, is developed.The various solutions studied during this thesis are tested on an aerothermal bench. They all show a more efficient and homogeneous cooling than the industrial reference. Some first tests on one of the selected solutions are performed on a combustion bench. This lighter and more permeable structure proves to be a solution as efficient as the industrial reference at a given flow rate. It should therefore be a more efficient solution for a given overpressure
APA, Harvard, Vancouver, ISO, and other styles
9

Taniguchi, Naoya. "Effect of pore size on bone ingrowth into porous titanium implants fabricated by additive manufacturing: An in vivo experiment." Kyoto University, 2016. http://hdl.handle.net/2433/215404.

Full text
Abstract:
Subscription articles: Theses and dissertations which contain embedded PJAs as part of the formal submission can be posted publicly by the awarding institution with DOI links back to the formal publications on ScienceDirect.doi:10.1016/j.msec.2015.10.069
Kyoto University (京都大学)
0048
新制・課程博士
博士(医学)
甲第19578号
医博第4085号
新制||医||1013(附属図書館)
32614
京都大学大学院医学研究科医学専攻
(主査)教授 安達 泰治, 教授 開 祐司, 教授 妻木 範行
学位規則第4条第1項該当
APA, Harvard, Vancouver, ISO, and other styles
10

Lacroix, Sébastien. "Solveurs linéaires pour la simulation d'écoulements polyphasiques en milieux poreux, à fortes hétérogénéités et grand nombre de mailles, en modélisation de réservoirs pétroliers." Paris 6, 2004. http://www.theses.fr/2004PA066466.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Additifs poreux"

1

Lefebvre, G. Les enrobes drainants =: Porous asphalt. Paris: Association internationale permanente des congrès de la route, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Glixon, Jonathan E. The Porous Grate. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190259129.003.0006.

Full text
Abstract:
There were several reasons why the nunneries found it necessary to hire male music teachers. While in most cases new nuns learned plainchant from the older members of the choir, in certain situations outside expertise was required. Novices also required training in singing their portions of the rituals of clothing and profession, a role often carried out by secular professionals. The nunneries also housed young women resident students, whose studies, in addition to languages and comportment, sometimes included vocal or instrumental music. Teachers for these various purposes included G. B. Volpe, Giovanni Rovetta, Bartolomeo Barbarino, and Francesco Cavalli. All of these activities involved potentially dangerous interactions between the nuns and unrelated men, so the civil and ecclesiastical authorities attempted to maintain close control, if necessary arresting and trying men, including the organist Giovanni Pichi, who violated procedures.
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Additifs poreux"

1

Singh, Jatender Pal, and Pulak M. Pandey. "Investigations to enhance the strength of open cell porous regular interconnect structure." In Additive Manufacturing, 95–125. First edition. | Boca Raton, FL : CRC Press/Taylor & Francis Group, 2018.: CRC Press, 2018. http://dx.doi.org/10.1201/b22179-3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Hirsch, Andre, Christian Dalmer, and Elmar Moritzer. "Investigation of Plastic Freeformed, Open-Pored Structures with Regard to Producibility, Reproducibility and Liquid Permeability." In Industrializing Additive Manufacturing, 112–29. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-54334-1_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Akiwate, Deepak C., Mahendra D. Date, B. Venkatesham, and S. Suryakumar. "Acoustic Properties of Additive Manufactured Porous Material." In Recent Developments in Acoustics, 129–38. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5776-7_12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Sobotka, James C., and R. Craig McClung. "Characterization of Stress Fields Near Pores and Application to Fatigue Lives." In Structural Integrity of Additive Manufactured Parts, 367–80. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2020. http://dx.doi.org/10.1520/stp162020180141.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Woodard, Erik, Zach Post, and Mark Morrison. "Preclinical Testing of a Novel, Additive-Manufactured, Three-Dimensional Porous Titanium Structure." In Structural Integrity of Additive Manufactured Materials & Parts, 322–39. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2020. http://dx.doi.org/10.1520/stp163120190139.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Dausend, Bettina, and Marion Eiber. "Von der Pore zum Gefüge: Die Auswirkungen von heißisostatischem Pressen auf die Mikrostruktur von Nickelbasiswerkstoffen." In Additive Fertigung von Bauteilen und Strukturen, 85–100. Wiesbaden: Springer Fachmedien Wiesbaden, 2019. http://dx.doi.org/10.1007/978-3-658-27412-2_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Singh, Nand Kishore, Shashi Kant Kumar, Satish K. S. N. Idury, K. K. Singh, and Ratneshwar Jha. "Dynamic Compression Response of Porous Zirconium-Based Bulk Metallic Glass (Zr41Ti14Cu12.5Ni10Be22.5) Honeycomb: A Numerical Study." In Structural Integrity of Additive Manufactured Materials & Parts, 308–21. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2020. http://dx.doi.org/10.1520/stp163120190136.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Ohtsuki, Tomio, Lonnie Smith, Ming Tang, and P. Chris Pistorius. "Origin of Oxides and Oxide-Related Pores in Laser Powder Bed Fusion Parts." In Structural Integrity of Additive Manufactured Materials & Parts, 45–60. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2020. http://dx.doi.org/10.1520/stp163120190137.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Lagerstedt, Torgny. "An Experimental Study of Polymer Induced Drag for Flows Through Porous Medium." In The Influence of Polymer Additives on Velocity and Temperature Fields, 29–39. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-82632-0_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Haas, R., and W. M. Kulicke. "Characterization of Dilute Polyacrylamide and Polystyrene Solutions by Means of Porous Media Flow." In The Influence of Polymer Additives on Velocity and Temperature Fields, 119–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-82632-0_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Additifs poreux"

1

Anderson, Gary A., Anil Kommareddy, Zhengrong Gu, Joanne Puetz Anderson, and Stephen P. Gent. "Experimental Determination of Pressure Loss Through Porous Membranes." In ASME 2014 8th International Conference on Energy Sustainability collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/es2014-6460.

Full text
Abstract:
Air with carbon dioxide is bubbled through Photobioreactors (PBRs) to add carbon dioxide to the reactor medium, remove oxygen, and mix the medium. Most PBR systems use various types of spargers/diffusers that consist of straight or curved tubes with perforation in them to inject air into the PBR reactor volume. A possible novel approach to introducing air into the PBR reactor volume is to use a plenum under the PBR reactor volume in conjunction with a porous membrane that separates the air in the plenum from the liquid medium in the reactor volume. The resistance offered by the porous membrane and the liquid in the reactor volume to air flow needs to be established so that power requirements to provide the desired air flow through the PBR can be determined. Four types of porous membranes were tested: 1)Sintered High Density Polyethylene HDPE 1.59 mm thick with 15–45 μm pore size, 2) Sintered HDPE 0.79 mm thick with 20μm pore size, 3) Genpore black plastic sheet with 45 μm pore size, and 4) Porex 7896 HDPE with pore size of 35 μm). Specimens were tested in a 76.2 mm inside diameter reactor with a depth of 304.8mm and a 76.2 mm plenum depth. Water was used as the reactor medium and the depth was varied between 0 and 228.6 mm. Results showed that the Porex 7896 membrane had little resistance to air flow when the water depth was 0.0mm (1–22 Pa), 1–200 Pa for the Genpore plastic sheet, 1200–1400Pa for the Porex with 20μm pores, and 1100–2500 Pa for the Porex with the 15–45 μm pore sizes for superficial air velocities between 0.00345 m/s to 0.0242 m/s. Water depth was then increased to 228.6 mm in 25.4 mm increments and tested with the same air flow rates. The addition of water significantly increased the resistance to air flow for all membranes (highest being 4200 Pa). Least square correlations for the membranes using water depth and superficial air velocity indicate that resistance to air flow of the membranes was linear with superficial velocity but parabolic with water depth.
APA, Harvard, Vancouver, ISO, and other styles
2

Li, Min, Wei Zhang, Chaosheng Wang, and Huaping Wang. "Fabrication of Conductive Porous Structure Loaded With Carbon Black and/or Carbon Nanotube." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-65122.

Full text
Abstract:
Carbon black (CB) and/or carbon nanotube (CNT) loaded porous PP frame with enhanced conductivity was facilely fabricated via immiscible co-continuous polymer blend and subsequent dissolution process. The SEM result indicated that the agglomerated carbon additives formed continuous phase on the inner wall of the interconnected micro channel. Nitrogen gas adsorption test was carried out to characterize the nano pores resulted from these nano particles. In addition, the electrochemical performance of the material was evaluated by cyclic voltammetry and galvanostatic charge-discharge cycling. Experimental results demonstrate the effectiveness of this novel method to construct conductive material with hierarchical porous structure which integrates co-continuous porous structure with nano pores derived from deposited carbon additives.
APA, Harvard, Vancouver, ISO, and other styles
3

Yang, Li, Zheng Min, Sarwesh Narayan Parbat, and Minking K. Chyu. "Effect of Pore Blockage on Transpiration Cooling With Additive Manufacturable Perforate Holes." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-75310.

Full text
Abstract:
Transpiration Cooling is an effective cooling technology to protect hot section components such as gas turbine airfoils, rocket heads and space craft. This external cooling method has much higher efficiency than film cooling with holes when consuming the same amount of coolant, due to the uniformity of coolant distribution. However, pore blockage, which frequently occur during the operation of transpiration cooled components, prevented its application in turbine components which require long term stability. Dust deposition was one the main reasons causing blockage of pores for transpiration cooling. A lot of effort was devoted into dust deposition and erosion while optimization for the components themselves were generally difficult as the blockage caused by dusts was unpredictable for traditional sintered porous media. Additive manufacturing, with capability to precisely construct structures in small scales, is a considerable tool to enhance the controllability of porous media, and furthermore, to find a good solution to minimize the blockage disadvantage. Present study selected a cooling configurations containing perforate straight holes with an additive manufacturable diameter of 0.4 mm. Computational Fluid Dynamics (CFD) methods were utilized to model the pore blockage and its effect on heat transfer. A scripting code in addition to the ANSYS CFX solver was utilized to simulate the random blockage conditions of the holes. Two hundred numerical cases with four different blockage probabilities were calculated and statistically evaluated to quantify the disadvantage of pore blockage on the cooling effectiveness. Results obtained from the numerical analysis indicated that the overall blockage ratio was a dominating parameter for the cooling effectiveness. Upstream regions of the cooled surface were more sensitive to local blockage compared to downstream regions. Randomness of the cooling effectiveness increased with the increase of blockage probability. Present study provided a quantitative understanding of the random blockage disadvantage on the specific transpiration cooling configuration, and could benefit further optimization effort to reduce the blockage disadvantage of transpiration cooling using additive manufacturing.
APA, Harvard, Vancouver, ISO, and other styles
4

Shrestha, Subin, Thomas Starr, and Kevin Chou. "Porosity Analysis in Metal Additive Manufacturing by Micro-CT." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-87897.

Full text
Abstract:
This study aims at analyzing process-induced pores in selective laser melting (SLM), a laser powder-bed fusion additive manufacturing (AM) process. Porosity is one of the most problematic defects in SLM parts; it impairs the part performance, and yet, is sharply sensitive to the parameters of the SLM process itself. Detailed analysis of SLM pore formations using a computed tomography (CT) technique is desired in order to understand the porosity level under different process conditions. In this study, an SLM system was used to fabricate samples, using Ti-6Al-4V powder, with single tracks formed, at 60 μm layer thickness, with different laser powers and scanning speeds to vary the energy density. A micro-CT (μ-CT) scanner was used to measure the internal features of the SLM specimens without any post-build treatments and to analyze the porosity inside single tracks formed with different energy densities. There are different mechanisms of pore formation in SLM, in particular, this study first focuses on the pore formation due to the keyhole phenomenon, caused by a high energy density. μ-CT scanning at a 6 μm resolution is able to clearly reveal the pores in the SLM samples. From the CT scan and analysis results, it is observed that increasing the energy density increases the volume of pores. For example, with 195 W and 200 mm/s, the number of pores is 93 and the total pore volume is 0.014 mm3 for a scanning length of 12 mm. On the other hand, if the energy density is less than 0.24 J/mm, few or no pores were observed, because possibly the melting process changes from the keyhole mode to the conduction mode.
APA, Harvard, Vancouver, ISO, and other styles
5

Di, Wang, Xiao Zefeng, Song Changhui, and Yang Yongqiang. "Process Characterization of Ideal Porous Structure Manufacture Based on Selective Laser Melting (SLM)." In 1st International Conference on Progress in Additive Manufacturing. Singapore: Research Publishing Services, 2014. http://dx.doi.org/10.3850/978-981-09-0446-3_087.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Zhang, Li-zhi, and Li-xia Pei. "Effects of Peg Additives on Water Vapor Permeability of Porous PVDF Membranes." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18017.

Full text
Abstract:
Porous polyvinylidene fluoride (PVDF) membranes with various structures were prepared via phase inversion using DMF as solvent. Polyethylene glycols (PEG) with three different concentrations and molecular weights were used. Effects of PEG on the structure and performance of porous membranes were investigated. The morphology and structure of the prepared membrane were characterized by scanning electron microscopy (SEM). The water vapor permeability through membranes was evaluated by permeation test. The results showed that PEG was used as pore forming agent in PVDF/DMF/H2O system. Moreover, it has great influences on morphology and water vapor permeability. The membranes becomes more porous with PEG additives. Water vapor transfer resistance was reduced, which leads to improved water vapor permeability.
APA, Harvard, Vancouver, ISO, and other styles
7

Dahifale, Balasaheb S., Ramkumar N. Parthasarathy, and Subramanyam R. Gollahalli. "Experimental Investigation of Porous-Media Combustion Characteristics of Biodiesel Blends." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37527.

Full text
Abstract:
The use of porous-media burners in air-heating systems, gas turbine combustors, and steam generators is a potential method to reduce pollutant emission levels. Biofuels, such as canola methyl ester (CME), are an attractive alternate energy resource; however, pure biofuels have lower energy content than petroleum-based fuels. Therefore, the combustion characteristics of blends of Jet A and CME were studied in a porous-media burner. Two silicon carbide coated carbon-carbon matrix porous media of square section were used. The upstream porous medium with a pore size of 8 pores per centimeter (20 pores per inch) served as the evaporation porous medium; the downstream porous medium with a pore size of 31 ppcm (80 ppi) was used as the combustion porous medium. The CME-Jet A fuel blends were injected from an air-blast atomizer into a coflow of hot air, which entered the evaporation porous medium. The combustion characteristics of three blends (volume percentages of CME equal to 25%, 50% and 75%) were studied at four different initial equivalence ratios. The global pollutant emissions, axial temperature profiles and the radiative heat fraction of the flame downstream of the combustion porous medium were measured. The results indicated that for lean air-fuel mixtures, the addition of CME to Jet A resulted in a reduction of the CO emission index. However, the NOx emission index was increased with the CME content in the blend for a given equivalence ratio. Also, the maximum flame temperature increased with equivalence ratio. In general, it was found that the porous-media burner was useful in reducing emissions and controlling flame temperatures.
APA, Harvard, Vancouver, ISO, and other styles
8

Vajandar, Saumitra K., Dongyan Xu, Deyu Li, Dmitry Markov, John Wikswo, and William Hofmeister. "SiO2-Coated Porous Anodic Alumina Membrane for Electroosmotic Pumping." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15002.

Full text
Abstract:
Electroosmotic pumping has been extensively used in biomedical lab-on-a-chip devices and micropumps for critical applications such as microelectronic cooling. In many applications, a high flow rate is a key requirement in desired performance so constant efforts have been made to increase the pumping flow rate through unit area to achieve the compact design. We report here an attempt of using SiO2-coated anodic porous alumina membrane as the material to achieve high electroosmotic pumping flow rate. High quality porous alumina membranes of controllable pore diameter in the range of 20-300 nm and pore length of 60 - 100 μm have been fabricated with electrochemical anodization. The pores are uniform and hexagonally packed with a high porosity of up to 50% and a tortuosity of a bare minimum of unity. In addition, the inner surface of the pores could be conformally coated with a thin layer (~ 5 nm) of SiO2 with sol-gel chemistry to achieve a high zeta potential. Scanning electron microscopy of the cross section of the membrane verified these facts. Electroosmotic pumping performance of these membranes has been investigated using standard relevant aqueous electrolyte buffer solutions and results showed that SiO2-coated porous alumina could achieve a higher flow rate compared with other microporous materials such as glass frit and porous silicon reported in the literature.
APA, Harvard, Vancouver, ISO, and other styles
9

Ispir, Ali Can, Tugce Karatas, Eren Dikec, and Seyhan Onbasioglu. "Experimental Investigation of Effect of Pore Diameter on Nucleate Boiling Heat Transfer in Reentrant Tunnel Structured Surfaces." In ASME 2017 15th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icnmm2017-5533.

Full text
Abstract:
This paper focuses on experimental studies of boiling heat transfer on surfaces with reentrant tunnels and pores. Three structured surface which have same tunnel width and height but different pore diameter, have been developed for enhancement boiling heat transfer. The experimental studies were carried out for the structured surfaces using distilled water at atmospheric pressure. The narrow reentrant tunnels are parallel to each other and have 3 mm width, 4 mm height. A number of pores whose diameter 1.5 and 2.0 mm were machined on lateral surfaces of tunnels. The surfaces were termed according to their geometric specifications as 3.0W-30-30, 1.5D-3.0W-30-30, 2.0D-3.0W-30-30. D and W capitals represent pore diameter and tunnel width, respectively. 30-30 part of name shows the dimension of square surface. The tunnels were used to increase area of heat transfer and active nucleation sites of vapor bubbles. In addition, sufficient amount of liquid must be supplied and vapor bubbles should be released fast from the boiling surface before they merge on the surfaces under conditions especially with high heat fluxes. Therefore, it was considered that pore structures would help for fluid transition hence the bubble frequency will increase. Pool boiling experiments were held to determine the performance of surfaces in different range of heat fluxes. Besides, high-speed visualization studies were conducted with high speed camera to observe behavior of nucleation of vapor bubbles. Amongst different geometry sizes the surface which has 1.5 mm of pore diameter (1.5D-3.0W-30-30) demonstrated the best nucleate boiling performance at high heat fluxes. However, the pored ones without pores has higher augmentation than pored structures at low heat fluxes. Thus, it is concluded that pored structures caused active nucleation sites to decrease under low heat fluxes.
APA, Harvard, Vancouver, ISO, and other styles
10

Khoda, A. K. M. B., Ibrahim T. Ozbolat, and Bahattin Koc. "Modeling of Multifunctional Porous Tissue Scaffolds With Continuous Deposition Path Plan." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86926.

Full text
Abstract:
A novel modeling technique for porous tissue scaffolds with targeting the functionally gradient variational porosity with continuous material deposition planning has been proposed. To vary the porosity of the designed scaffold functionally, medial axis transformation is used. The medial axis of each layers of the scaffold is calculated and used as an internal feature. The medial axis is then used connected to the outer contour using an optimum matching. The desired pore size and hence the porosity have been achieved by discretizing the sub-regions along its peripheral direction based on the pore size while meeting the tissue scaffold design constraints. This would ensure the truly porous nature of the structure in every direction as well as controllable porosity with interconnected pores. Thus the desired controlled variational porosity along the scaffold architecture has been achieved with the combination of two geometrically oriented consecutive layers. A continuous, interconnected and optimized tool-path has been generated for successive layers for additive-manufacturing or solid free form fabrication process. The proposed methodology has been computationally implemented with illustrative examples. Furthermore, the designed example scaffolds with the desired pore size and porosity has been fabricated with an extrusion based bio-fabrication process.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Additifs poreux"

1

Dehoff, Ryan R., and Michael M. Kirka. Additive Manufacturing of Porous Metal. Office of Scientific and Technical Information (OSTI), June 2017. http://dx.doi.org/10.2172/1362246.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Grote, Christopher John. Additive Manufacturing of Hierarchical Porous Structures. Office of Scientific and Technical Information (OSTI), August 2016. http://dx.doi.org/10.2172/1312627.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Spetzler, Hartmut. Seismic Absorption and Modulus Measurements in Porous Rocks in Lab and Field: Physical, Chemical, and Biological Effects of Fluids (Detecting a Biosurfactant Additive in a Field Irrigation Experiment). Office of Scientific and Technical Information (OSTI), May 2006. http://dx.doi.org/10.2172/1010627.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Costley, D., Luis De Jesús Díaz,, Sarah McComas, Christopher Simpson, James Johnson, and Mihan McKenna. Multi-objective source scaling experiment. Engineer Research and Development Center (U.S.), June 2021. http://dx.doi.org/10.21079/11681/40824.

Full text
Abstract:
The U.S. Army Engineer Research and Development Center (ERDC) performed an experiment at a site near Vicksburg, MS, during May 2014. Explosive charges were detonated, and the shock and acoustic waves were detected with pressure and infrasound sensors stationed at various distances from the source, i.e., from 3 m to 14.5 km. One objective of the experiment was to investigate the evolution of the shock wave produced by the explosion to the acoustic wavefront detected several kilometers from the detonation site. Another objective was to compare the effectiveness of different wind filter strategies. Toward this end, several sensors were deployed near each other, approximately 8 km from the site of the explosion. These sensors used different types of wind filters, including the different lengths of porous hoses, a bag of rocks, a foam pillow, and no filter. In addition, seismic and acoustic waves produced by the explosions were recorded with seismometers located at various distances from the source. The suitability of these sensors for measuring low-frequency acoustic waves was investigated.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Additifs poreux' for particular source types:
Journal articles Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography