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1.
Gianmarco de Felice Maria Antonietta Aiello Carmelo Caggegi Francesca Ceroni Stefano De Santis Enrico Garbin Natalino Gattesco Łukasz Hojdys Piotr Krajewski Arkadiusz Kwiecień Marianovella Leone Gian Piero Lignola Claudio Mazzotti Daniel Oliveira Corina Papanicolaou Carlo Poggi Thanasis Triantafillou Maria Rosa Valluzzi Alberto Viskovic 《Materials and Structures》2018,51(4):95
Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided. 相似文献
2.
Experimental and numerical analysis of heat transfer and airflow on an interactive building facade 总被引:1,自引:0,他引:1
The envelope of a building is mainly responsible for its energy demand. Different kinds of double skin facades (DSFs) are nowadays used as a building envelope to reduce the energy demand and improve aesthetical view of buildings. Although DSF are already extensively used, their thermal performance is not well understood. This study presents a decoupling method capable to evaluate thermal performances and analyze fluid phenomena in a DSF. The solar radiation effects were evaluated with an analytical model and computational fluid dynamics (CFD) simulations were used to evaluate complex flow and thermal effect on a commercial DSF. With the decoupling approach to account for the effects of solar radiation and flow, the numerical results obtained by the CFD approach agree well with the experimental data collected on a full scale test room with a ventilated DSF. The method can be used to establish a database to develop a tool for DSF design. 相似文献
3.
Experimental tests on the shear behaviour of dowels connecting concrete slabs to stone masonry walls
An experimental investigation has been conducted on the behaviour of dowels used to connect concrete slabs to stone masonry walls in order to transfer horizontal shear forces. A technique for embedding the dowels in the stone block without injection of grouting material or resin has been developed. Special experimental equipment has been designed in order to allow the execution ofin situ load tests on representative ancient buildings. Monotonic loading tests have been carried out on eight specimens with the purpose of measuring both stone block displacement and dowel deformation 相似文献
4.
Milene L. da Silva Ana P. Figueiredo Abiney L. Cardoso Ricardo Natalino Márcio J. da Silva 《Journal of the American Oil Chemists' Society》2011,88(9):1431-1437
Biodiesel production from cheap lipid raw materials is economically welcome, but a high free fatty acids (FFA) content makes
it incompatible with traditional alkaline catalysts. Although liquid mineral acids are alternatively used, serious drawbacks
such as high corrosiveness and large effluent generation, as well as the impossibility of catalyst reuse compromises its application.
Contrarily, solid acid catalysts appear to be an attractive option; however, the water present or generated during FFA esterification
provokes the leaching and deactivation of these catalysts. Thus, in this work we have evaluated the use of tin chloride SnCl2, which is less corrosive, water tolerant, and a recyclable Lewis acid catalyst, on FFA ethanolysis using waste cooking oil
samples (WCO). Additionally, the main kinetic parameters of the reactions were assessed. Compared to pTSA (p-toluenesulfonic-acid), a catalyst also evaluated, SnCl2 efficiently promoted FFA ethanolysis even in the presence of high amounts of water (ca. 0.1–5.0% w/w). Moreover, the homogeneous
SnCl2 catalyst was easily recovered and reused successively, without loss of activity. 相似文献
5.
Enzo Benedetti Aldo D'Alessio Claudio Bertolutti Piergiorgio Vergamini Natalino Del Fanti Maurizio Pianca Giovanni Moggi 《Polymer Bulletin》1989,22(5-6):645-651
Five samples of Poly (vinylidene fluoride) with a molecular weight from 45,000 to 260,000 were analyzed by means of FT-IR spectroscopy in order to study the influence of molecular weight
on the crystallization process. The spectra of films obtained from methylethylketone solutions revealed the prevalence of form II () in the case of lower
and of form III () in the higher molecular weight samples. The amount of form III was found to increase as the Mv decreased and as annealing temperatures increased. The deconvolution technique of vibrational spectra allowed detection of small amounts of other forms accompanying the prevailing one. 相似文献
6.
Gulab N. Jham Bryan R. Moser Shailesh N. Shah Ronald A. Holser Onkar D. Dhingra Steven F. Vaughn Mark A. Berhow Jill K. Winkler-Moser Terry A. Isbell Ray K. Holloway Erin L. Walter Ricardo Natalino Jason C. Anderson David M. Stelly 《Journal of the American Oil Chemists' Society》2009,86(9):917-926
Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification
procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)-docosenoic; 45.7 wt.%) acid, with linoleic (9(Z),12(Z)-octadecadienoic; 14.2 wt.%) and linolenic (9(Z),12(Z),15(Z)-octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity,
and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm2 s−1 (40 °C) and 4.8 h (110 °C), respectively. The cloud, pour and cold filter plugging points were 4, −21 and −3 °C, respectively.
Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity,
as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751
and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard
collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production.
Disclaimer: Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants
the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others
that may also be suitable. 相似文献
7.
An experimental investigation on steel-to-timber joints arranged with multiple bolts was carried out, both in the case of
load parallel and perpendicular to the timber grain. The joints were made with timber side members and steel main member;
high strength bolts were used for fasteners. The experimental results allowed determining the stiffness in service, the slip
at failure and the reference loads (proportional limit, yielding, ultimate). A descreasing ductility of joints was observed
at the increase of the number of bolts. With the above characteristic loads the bolt effectiveness of multiple joint loaded
parallel to grain was evaluated and compared with that obtained from some analytical predictions found in the literature.
It was evidenced that the provisions of Eurocode N.5 provide values for the bolt effectiveness quite closer to experimental
reslts. The results of joints loaded perpendicular to the grain were compared with some analytical predictions; significant
differences were noted with all analytical predictions considered.
Résumé Une investigation expérimentale a été conduite pour étudier les joints entre le bois et l'acier, réalisés avec des boulons multiples soumis à une traction aussi bien parallèle que perpendiculaire aux fibres de bois. Les joints ont été construits avec l'élément central en acier et les éléments latéraux en bois; des boulons à haute résistance ont été utilisés. Les résultats des essais ont permis de déterminer la rigidité en service, le glissement à la rupture et les valeurs de résistance caractéristiques (limite de proportionnalité, évervement, limite ultime). En augmentant le nombre de boulons, on a constaté une diminution de ductilité du joint. Avec les valeurs de résistance caractéristiques, on a évalué l'efficacité de boulons des joints chargés parallèlement aux fibres du bois et la valeur a été comparée avec celles obtenues par quelques relations analytiques trouvées en littérature. Le travail de recherche a mis en évidence que la relation proposée par l'Eurocode No. 5 donne des valeurs très proches des résultats expérimentaux. Les résultats des essais sur les joints soumis à une traction perpendiculaire aux fibres de bois, comparés avec quelques relations analytiques, mettent toujours en évidence beaucoup de différences.相似文献
8.
André Nieuwland Jeffrey Kang Om Prakash Gangwal Ramanathan Sethuraman Natalino Busá Kees Goossens Rafael Peset Llopis Paul Lippens 《Design Automation for Embedded Systems》2002,7(3):233-270
The key issue in the design of Systems-on-a-Chip (SoC) is to trade-off efficiency against flexibility, and time to market versus cost. Current deep submicron processing technologiesenable integration of multiple software programmable processors (e.g., CPUs,DSPs) and dedicated hardware components into a single cost-efficient IC. Ourtop-down design methodology with various abstraction levels helps designingthese ICs in a reasonable amount of time. This methodology starts with a high-levelexecutable specification, and converges towards a silicon implementation.A major task in the design process is to ensure that all components (hardwareand software) communicate with each other correctly. In this article, we tacklethis problem in the context of the signal processing domain in two ways: wepropose a modular, flexible, and scalable heterogeneous multi-processor architecturetemplate based on distributed shared memory, and we present an efficient andtransparent protocol for communication and (re)configuration. The protocolimplementations have been incorporated in libraries, which allows quick traversalof the various abstraction levels, so enabling incremental design. The designdecisions to be taken at each abstraction level are evaluated by means of(co-)simulation. Prototyping is used too, to verify the system's functionalcorrectness. The effectiveness of our approach is illustrated by a designcase of a multi-standard video and image codec.He currently works with Magma Design Automation. E-mail: 相似文献
9.
The study of the local behaviour of steel dowels used to transfer horizontal shear loads between concrete slabs and stone masonry walls has been carried out. Monotonic loading tests have been performed on six specimens of stone masonry made in the laboratory concerning three different embedding techniques for dowels. The geometric interferometry technique was adopted to survey the surface displacements, in the load direction, of the loaded stone block and surrounding mortar joints. For applying the shear load to the connection, a special experimental apparatus has been designed so as to allow the arrangement of moiré gratings as well as to capture the sequence of the fringe pattern. 相似文献
10.
A simple method for studying the mechanical response of the mortar in existing masonry buildings is presented herein. The
method is based on the measurement of the penetration depth increment of a steel probe (4 mm diameter) at each hammer blow
(impact energy=2.2 J). Numerous tests were carried out on different laboratory specimens in order to formulate a relationship
between the compressive strength and the probe penetration rate, and a series of tests on actual masonry elements confirmed
that the proposed relationship is sound.
Résumé On présente une méthode d’essai simple pour évaluer la resistance à la compression des mortiers des murs existants. La méthode proposée ici est basée sur la mesure de la profondeur de pénétration d’une sonde d’acier (4 mm de diamètre), à chaque coup de scléromètre (énergie d’impact=2,2 Joule). Les résultats de nombreux essais effectués sur des éprouvettes construites en laboratoire ont permis d’obtenir une relation entre la résistance à la compression du mortier et la vitesse de pénétration de la sonde. En outre, la validité de cette méthode a été confirmée par une série d’essais effectués sur des murs existants.相似文献