Littérature scientifique sur le sujet « Stepped repair »
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Articles de revues sur le sujet "Stepped repair"
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Li, Hui, Cheng Chen, Tongguang Wang et Long Wang. « Experimental Study of Stepped-Lap Scarf Joint Repair for Spar Cap Damage of Wind Turbine Blade in Service ». Applied Sciences 10, no 3 (31 janvier 2020) : 922. http://dx.doi.org/10.3390/app10030922.
Texte intégralRésumé :
The objective of this paper was to design configuration parameters for a stepped-lap scarf joint repair, which can be used for spar cap damage of a wind turbine blade in service and to realize the post-repair monitoring. Two experimental studies were included. First, tensile test for the unidirectional tape specimens with a large aspect ratio repaired using a multiple stepped-lap scarf joint method was carried out. The results showed that the reinforcement layer could effectively improve the load-carrying capacity of the repaired zone. The stepped-lap joint surface was identified as the weak part of the spar cap repair, which should be monitored. Second, by embedding carbon nanotube buckypaper sensors on the stepped-lap joint surface of the repaired specimens, quasi-static tensile tests and fatigue tests were carried out. According to the resistance response of the sensors, the quasi-static tensile test confirmed the failure processes, namely the stiffness turning point, damage evolution, crack propagation, and fracture. The fatigue test could accurately identify the progressive failure, namely the initial damage, damage accumulation, initial cracking, and crack propagation to structural failure. The above tests provided an important configuration parameter basis for evaluating the spar cap repair scheme and presented a promising method for the health monitoring of a spar cap after repair.
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Psarras, Spyridon, Theodoros Loutas, Magdalini Papanaoum, Orestis Konstantinos Triantopoulos et Vasilis Kostopoulos. « Investigating the Effect of Stepped Scarf Repair Ratio in Repaired CFRP Laminates under Compressive Loading ». Journal of Composites Science 4, no 4 (19 octobre 2020) : 153. http://dx.doi.org/10.3390/jcs4040153.
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In this work the effectiveness of stepped repairs to damaged fiber reinforced composite materials is investigated by using previously validated numerical models which were compared with tested repaired composite plates. Parametric studies were carried out in order to assess the scarf ratio (i.e., step length to ply thickness ratio) influence on ultimate forces, displacements, stresses and stiffnesses. FE models with repair scarf ratios varying from the value of 20 to the value 60 with a step increase of 10 were developed. The numerical models allowed a direct comparison of the influence that the scarf ratio had to the strength and stiffness restoration of the repaired composite structure. The study verifies that the restoration of the strength of a damaged laminate depends largely on the size of the repair patch. Generally, the bigger the size of a patch, the stronger the repaired structure is, up to a critical threshold size. To maximize the strength restoration, it is advised that the number of steps in each patch are no less than the number of plies on the base laminate.
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Collombet, Francis, Yves Davila, Sergio Avila, Alexander Morales, Laurent Crouzeix, Yves-Henri Grunevald, Hilario Hernandez, Nathalie Rocher et François Cénac. « Proof of a composite repair concept for aeronautical structures : a simplified method ». Mechanics & ; Industry 20, no 8 (2019) : 812. http://dx.doi.org/10.1051/meca/2020056.
Texte intégralRésumé :
This paper provides an illustration of all stages of primary aeronautical composite structure repair by using industrial tools and scientific methodologies, as well as numerical tools to simplify the cross-over analysis of the mechanical behaviour of the repaired area. Economically and scientifically speaking, one of the main challenges of composite repair (for monolithic long fiber composite parts) consists of promoting a bonded composite patch option without additional riveted doublers. To address this challenge, size reduction of the patch could be mandatory. A patent (jointly owned by ICA, Bayab Industries and CES), entitled “Method for repairing a wall consisting of a plurality of layers”, is devoted to reducing repair patch dimensions of monolithic composite parts provided the bonding zone has a stepped-lap geometry. This patent is based on a simple idea that no overlapping length is required between composite plies for load transfer except in the fiber directions of the plies (unidirectional or biaxial long fiber reinforcements with epoxy matrix). To prove this concept, we consider on one hand, a situation unusual in the literature by studying a composite specimen without fibers aligned along the main loading axis, and on the other hand, a classical situation of where the shape of the specimen is adapted to be studied by uniaxial tension tests. After different manufacturing steps, the studied specimen contains three zones representing both the influence of the total thickness of a repair patch, the stepped-lap area assembled with an adhesive film and the parent composite part. Basically, a simple parent structure consisting of 16 plies of UD Hexply® M21/35%/268/T700GC (close to Airbus composite raw materials on board in A380) is manufactured with a stacking sequence of [+45/−45/−45/+45/+45/−45/−45/+45]s. Then, the parent structure is machined by the Airbus Abrasive Water Jet machine and the final repair area has a stepped-lap geometry by overlapping successive plies of the same nature as the parent plate and after having previously applied an adhesive film (cured at 180 °C). Furthermore, 3 values of overlap length (respectively, 6, 8 and 13 mm) are investigated to include the mean value required by Airbus in the case of the use of the studied prepreg. After abrasive water jet machining of the composite parent part, repair patch manufacturing was performed according to Airbus requirements. The studied specimens were cut from the final plate (involving the parent plate, the stepped lap zone and the zone of the patch itself) and tested in an uniaxial tensile configuration with a loading direction shifted 45° with respect to the fiber direction. Furthermore, studying uniaxial tensile tests on multilayer-pasted interface is innovative in the literature. In this paper, it is shown that the stepped-lap area assembled with an adhesive film is not the weak link of the mechanical response but rather the parent area, i.e. the unrepaired monolithic composite. Numerical calculations confirm this proof of concept by underlying that the level of shear stress in the adhesive film, for these three overlapping values, is below the chosen limit value. These results show that the patch size reduction is possible.
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Psarras, Spyridon, Maria-Panagiota Giannoutsou et Vassilis Kostopoulos. « A Design Optimization Study of Step/Scarf Composite Panel Repairs, Targeting the Maximum Strength and the Minimization of Material Removal ». Journal of Composites Science 8, no 7 (30 juin 2024) : 248. http://dx.doi.org/10.3390/jcs8070248.
Texte intégralRésumé :
This study aimed to optimize the geometry of composite stepped repair patches, using a parametric algorithm to automate the process due to the complexity of the optimization problem and various factors affecting efficiency. More specifically, the algorithm initially calculates the equivalent strengths of the repaired laminate plate according to a max stress criterion, then calculates the dimensions of several elliptical repair patches, taking into account several design methods extracted from the literature. Next, it creates their finite element models and finally, the code conducts an assessment of the examined patch geometries, given specific user-defined criteria. In the end, the algorithm reaches a conclusion about the optimum patch among the designed ones. The algorithm has the potential to run for many different patch geometries. In the current research, five patch geometries were designed and modeled under uniaxial compressive loading at 0°, 45° and 90°. Overall, the code greatly facilitated the design and optimization process and constitutes a useful tool for future research. The results revealed that elliptical stepped patches can offer a near-optimum solution much more efficient than that of the conservative option of the circular patch, in terms of both strength and volume of healthy removed material.
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Kim, Yun-Hae, Kyo-Moon Lee, Seong-Jae Park, Kyung-In Jo et Soo-Jeong Park. « Repair and cryogenic mechanical properties with resin film infused (RFI) GFRP in out-of-autoclave processing ». Modern Physics Letters B 34, no 07n09 (10 mars 2020) : 2040014. http://dx.doi.org/10.1142/s021798492040014x.
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Prepreg technology generates air pockets at the interface of laminates under heating and pressurization. The air pockets cause defects in the through-thickness direction. This includes poor adhesion between layers, which degrades material properties. Therefore, in this study, cryogenic mechanical properties were compared to obtain uniform properties by using prepreg laminated and resin film infused glass fiber reinforced plastic (GFRP) composites (“PP-only” and “RF-only”, respectively) while maintaining the constituent contents of the fiber and polymer. Moreover, stepped repair was applied to extend the life of composites. The results demonstrated that the stiffness of the composites improved, and the brittleness increased in cryogenic environments. In the case of PP-only, numerous voids were observed inside the polymer, which showed higher bending strength than RF-only; however, it exhibited significantly lower interfacial bonding strength. When applied to secondary bonding of stepped repair, RF-only as repair layers showed high strength recovery rate in homogeneous materials, and not in heterogeneous materials. In contrast, the high strength PP-only as a parent material and RF-only as repair layers showed relatively good interfacial bonding strength due to primary damage in the PP of a parent material. Hence, the RF-only can be considered useful as a repair material.
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Mercado-Pagán, Ángel E., et Yunzhi Peter Yang. « Bridging the gap : engineering bone for skeletal injuries ». Biochemist 40, no 1 (1 février 2018) : 12–15. http://dx.doi.org/10.1042/bio04001012.
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For years, mechanical fixators, grafts and cements have provided a surgical solution to bone injuries. However, the inherent restrictions of these treatments have prompted the search for newer options that can fully repair bone and restore its function. But, what are these approaches? What is the future of bone repair? Tissue engineering has stepped up efforts to tackle this difficult topic.
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Gillespie, David I., Andrew W. Hamilton, Robert C. Atkinson, Xavier Bellekens, Craig Michie, Ivan Andonovic et Christos Tachtatzis. « Defect Detection in Aerospace Sandwich Composite Panels Using Conductive Thermography and Contact Sensors ». Sensors 20, no 22 (23 novembre 2020) : 6689. http://dx.doi.org/10.3390/s20226689.
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Sandwich panels consisting of two Carbon Fibre Reinforced Polymer (CFRP) outer skins and an aluminium honeycomb core are a common structure of surfaces on commercial aircraft due to the beneficial strength–weight ratio. Mechanical defects such as a crushed honeycomb core, dis-bonds and delaminations in the outer skins and in the core occur routinely under normal use and are repaired during aerospace Maintenance, Repair and Overhaul (MRO) processes. Current practices rely heavily on manual inspection where it is possible minor defects are not identified prior to primary repair and are only addressed after initial repairs intensify the defects due to thermal expansion during high temperature curing. This paper reports on the development and characterisation of a technique based on conductive thermography implemented using an array of single point temperature sensors mounted on one surface of the panel and the concomitant induced thermal profile generated by a thermal stimulus on the opposing surface to identify such defects. Defects are classified by analysing the differential conduction of thermal energy profiles across the surface of the panel. Results indicate that crushed core and impact damage are detectable using a stepped temperature profile of 80 ∘C The method is amenable to integration within the existing drying cycle stage and reduces the costs of executing the overall process in terms of time-to-repair and manual effort.
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Kozlov, V. B., A. B. Istomin et I. N. Gemba. « Repair and restoration of shafts, couplings, splined and keyed joints ». Glavnyj mekhanik (Chief Mechanic), no 7 (11 juin 2021) : 32–42. http://dx.doi.org/10.33920/pro-2-2107-03.
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The article provides an overview of the methods of restoration and repair of various parts of the equipment: shafts, couplings, splined and keyed joints. Recommendations on the choice of methods, equipment and tools are given. In case of wear, the keyway is repaired by welding the face with subsequent milling. At the same time, the keyway size set by the standard is maintained. Such repairs are also possible: the keyway is expanded and deepened, completely eliminating the traces of wear, after which a stepped key is made to it. However, with such repairs, a high-quality connection is not provided and, therefore, it is used in exceptional cases (during inspections and ongoing repairs). When repairing keyed joints, the worn keyed joints are not repaired, but new ones are made, fitting them to achieve a firm contact with the side surfaces of the grooves of the connected parts. The exception is the taper keys: they are driven into the keyway with a hammer blow so that they are jammed in height. The taper key should also be hammered in such a way that, when loosened, it can be deposited. Between the head of the key and the end of the part, there must be a distance equal to the height of the key. The connection with the help of splines is used for fixing gears, gear wheels, and bushings on the shafts. It has a number of advantages over other types of connection. The component parts of this joint are more easily centered. This significantly reduces mechanical deformations at the bushing boundary. During operation, under the influence of various loads, the spline joint loses its properties. In this case, the splines or grooves in which they are placed are restored. Splines of small rollers are usually not repaired; the parts with worn splines are mostly replaced with new ones. Such work is carried out in specialized workshops. In some cases, the repair and restoration of such products is carried out in a small workshop, but equipped with the necessary machines.
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Ibyldaev, M. H. « PRINCIPLES OF PRESSURE REHABILITATION OF STANDARD SHAFTS ». MECHANICS & ; TECHNOLOGIES, no 3 (30 septembre 2023) : 98–104. http://dx.doi.org/10.55956/spca7436.
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The reliability and performance indicators of the known methods currently used in the country's repair industry for the restoration of stepped shafts cannot compete with the indicators of new parts. The most progressive method of restoring step shafts is the method of hot volume stamping. The technical characteristics of pressure-remanufactured parts indicate that their quality is not inferior to serial parts.
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Xu, Jian Xin, Chen Dou et Ding He Li. « Stress-Based Health Assessment of Composite Open-End Cylindrical Laminated Shell with Stepped-Lap Repairs ». Advanced Materials Research 393-395 (novembre 2011) : 297–303. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.297.
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A three-dimensional finite element model was created in PATRAN to perform stress distribution into the influence of disbonded adhesive in stepped-lap repairs of composite open-end cylindrical laminated shell. Extracted and studied the value of the stress on every ply, and every node, ordered by the X coordinate. A study has been presented that the rim of patch is greatly affected by disbonded types, however, the central area of the patch is less affected relatively, especially between ±20mm, that the diameter is equal to the diameter of the damage, the stresses are flatly changed. And for the whole model, the maximum is in the sixth layer, so that the internal area is the most easily to be damaged. Therefore, it should be force on this special area in experimental health assessment such as using piezoelectric elements. It could provide certain maintenance basis for the future practical repair.
Thèses sur le sujet "Stepped repair"
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Orsatelli, Jean-Baptiste. « Méthodologie de prédiction de la tenue nominale de réparations composites aéronautiques par collage structural ». Electronic Thesis or Diss., Toulouse, ISAE, 2024. http://www.theses.fr/2024ESAE0051.
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Les réparations composites collées apportent plusieurs avantages par rapport aux réparations assembléesmécaniquement à l’aide de boulons ou de rivets. Elles évitent de réaliser des perçages et permettentde réduire la masse additionnelle liée à la réparation. L’emploi de ce type de réparation estaujourd’hui limité aux pièces non structurales, en l’absence (i) de méthode permettant de contrôler laréalisation d’un collage structural et (ii) de méthodologie de dimensionnement standard pour prédirela tenue d’un assemblage collé. Cette thèse propose d’étudier la question du dimensionnement de réparationscollées au travers d’une approche expérimentale et numérique multi-échelles afin d’étudierla fidélité de plusieurs niveaux de modélisation vis-à-vis du comportement observé en essai. Le casd’application étudié est celui d’une réparation de type stepping, sur une structure en tissu carboneépoxyde 8 plis d’épaisseur, représentative d’une peau d’hélicoptère Tigre.Une campagne d’essai a été réalisée pour caractériser le comportement des stratifiés compositesutilisés : le G939/M18 de la structure à réparer et le G939/Hexbond 312-L du patch de réparation. Lesdeux matériaux étant faits du même tissu G939, la matrice d’essais a été réduite pour limiter le nombretotal d’essais. Leurs comportements intralaminaire et interlaminaire ont été étudiés. Des essais de fissurationde fibre ont également été réalisés pour identifier une énergie de fissuration en vue d’alimenterdes modèles d’endommagement progressif.Une étude comparative de différents niveaux de modélisation a été menée. Une méthode de résolutionsemi-analytique a été proposée pour le calcul d’un joint en stepping avec un comportement enmembrane des substrats et une loi d’endommagement de l’adhésif de type bilinéaire. Ce type de résolutionrépond au besoin de modélisation à faible coût pour ce type de problème. Une matrice d’essaisnumériques a été proposée, incluant six modèles macro-éléments et éléments finis différents d’unemême réparation en stepping, testés sur une large gamme de longueurs de step et de ténacité d’adhésifs.Il a été montré qu’un modèle de joint équivalent en 2D déformations planes généralisées est une bonneapproximation d’un modèle 3D complet pour le comportement en traction d’une réparation en stepping,en termes de tenue à rupture de l’adhésif et des substrats.Des essais technologiques ont été menés sur des éprouvettes réparées à l’échelle du coupon et dupanneau, avec différents drapages de réparations, longueurs de steps, et profondeurs de dommage. Undialogue essais-calculs a été proposé avec les modèles 3D et 2D déformations planes généralisées, alimentéspar les propriétés matériaux identifiées lors des essais de caractérisation. Les modèles proposéssont représentatifs du comportement des réparations en termes de raideur et d’effort à rupture sur lagamme de configurations testées sauf dans le cas de steps courts sur des éprouvettes de type couponstraversants. Le comportement d’une réparation à la frontière entre le décollement et la rupture dessubstrats reste à étudier. Les scénarios d’endommagement numériques sont compatibles avec les facièsde rupture observés, mais des essais multi-instrumentés ou interrompus seraient nécessaires pour validerle scénario d’endommagement complet. Les modèles développés ont enfin été automatisés grâceà une macro paramétrique et appliqués au dimensionnement d’un cas industriel de réparation et à larecherche de designs optimauxBonded composite repairs offer several advantages over mechanically fastened repairs using bolts.They eliminate the need for drilling and reduce the additional weight of the repair. The use of thistype of repair is currently limited to non-structural parts due to the lack of (i) a method for controllingthe production of a structural bond and (ii) a standard design method for predicting the strength of abonded assembly. This thesis proposes to investigate the issue of design of bonded repairs using amulti-scale experimental and numerical approach to investigate the fidelity of multiple levels of modelling.The application case studied is that of a stepped repair on an 8-layer carbon-epoxy fabric structure,representative of a Tiger helicopter skin.A test campaign was carried out to characterise the behaviour of the composite laminates used:the G939/M18 of the structure to be repaired and the G939/Hexbond 312-L of the repair patch. Asboth materials are made from the same G939 fabric, the test matrix was reduced to limit the totalnumber of tests. Their intralaminar and interlaminar behaviour was investigated. Fibre crack testswere also carried out to determine a crack energy to feed progressive damage models.A comparative study of different levels of modelling was carried out. A semi-analytical resolutionmethod was proposed for the calculation of a stepping joint with a membrane behaviour of the substratesand a bilinear damage law for the adhesive. This methode meets the need for low-cost modellingfor this type of problem. A matrix of numerical tests was proposed, including six different macroelementand finite-element models of the same stepping repair, tested over a wide range of step lengthsand adhesive toughness. It was shown that a 2D generalized plane deformation equivalent joint modelis a good approximation to a full 3D model for the tensile behaviour of a stepped repair, in terms ofadhesive and substrate fracture toughness.Technological tests were carried out on repaired specimens at coupon and panel scales, with differentrepair drapes, step lengths and damage depths. A test-calculation dialogue has been proposedwith 3D and 2D generalised plane deformation models, fed by the material properties identified duringthe characterisation tests. The models developed are representative of the behaviour of repairs interms of stiffness and stress at failure over the range of configurations tested, except in the case ofshort steps on through-cut type specimens. The behaviour of a repair at the boundary betweendebonding and substrate failure remains to be investigated. The numerical damage scenarios are compatiblewith the observed fracture surfaces, but multi-instrument or interrupted tests would be necessaryto validate the complete damage scenario. Finally, the models developed have been automatedusing a parametric macro and applied to the dimensioning of an industrial repair case and to the searchfor optimal designs
Livres sur le sujet "Stepped repair"
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United States. General Accounting Office, dir. Public-private partnerships : Key elements of federal building and facility partnerships : report to the Honorable Stephen Horn, Committee on Government Reform, House of Representatives. Washington, D.C. (P.O. Box 37050, Washington 20013) : The Office, 1999.
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United States. General Accounting Office., dir. Public-private partnerships : Key elements of federal building and facility partnerships : report to the Honorable Stephen Horn, Committee on Government Reform, House of Representatives. Washington, D.C. (P.O. Box 37050, Washington 20013) : The Office, 1999.
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Boerman-Cornell, William, Josha Ho, David Klanderman et Sarah Klanderman. Using Graphic Novels in the Science, Technology, Engineering, and Mathematics (STEM) Classroom. Bloomsbury Publishing Plc, 2023. http://dx.doi.org/10.5040/9781350279223.
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This book provides everything STEM teachers need to use graphic novels in order to engage students, explain difficult concepts, and enrich learning. Drawing upon the latest educational research and over 60 years of combined teaching experience, the authors describe the multimodal affordances and constraints of each element of the STEM curriculum. Useful for new and seasoned teachers alike, the chapters provide practical guidance for teaching with graphic novels, with a section each for Science, Technology, Engineering, and Mathematics. An appendix provides nearly 100 short reviews of graphic novels arranged by topic, such as cryptography, evolution, computer coding, skyscraper design, nuclear physics, auto repair, meteorology, and human physiology, allowing the teacher to find multiple graphic novels to enhance almost any unit. These include graphic novel biographies of Stephen Hawking, Jane Goodall, Alan Turing, Rosalind Franklin, as well as popular titles such as T-Minus by Jim Ottoviani, Brook Gladstone’s The Influencing Machine, Theodoris Andropoulos’s Who Killed Professor X, and Gene Yang’s Secret Coders series.
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MRes, MACT, MAPCE, MBA, MSc, Danny Moloney. Billions will be REPAID to Millions - TimeOutCreditCards - Stephen Sklaroff : Collateralised Credit Exploitation as practised on AAA None Defaulting ... in Perpetuity. Independently published, 2018.
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Public-private partnerships : Key elements of federal building and facility partnerships : report to the Honorable Stephen Horn, Committee on Government Reform, House of Representatives. Washington, D.C. (P.O. Box 37050, Washington 20013) : The Office, 1999.
Trouver le texte intégralChapitres de livres sur le sujet "Stepped repair"
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Seshadri, Matta, et M. Ramji. « Numerical and Experimental Analysis of Double-Sided Stepped Lap-Repaired CFRP Laminates Under Tensile Loading ». Dans Advances in Structural Integrity, 235–50. Singapore : Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-7197-3_21.
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Lenowitz, Harris. « Introduction The Ritual and the Accounts ». Dans The Jewish Messiahs, 3–22. Oxford University PressNew York, NY, 1998. http://dx.doi.org/10.1093/oso/9780195114928.003.0001.
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Abstract Wherever Judaism has been, its messiahs have arisen. From the first century BCE to the present, they have stepped forth to rescue, as it were, the religious polities of the Jews. They have contended against Rome in Israel. Exiled, they have risen in arms to ride across the plains and mountains of Islamic Persia, wandered the shores of the Mediterranean all but alone, and yet frightened the pope to death; tailored and cobbled in Inquisition Spain and Portugal; called upon the Jews of Italy to repent; strided through the halls of the Vatican and the courts of the Holy Roman Empire; returned to the land of Israel to walk the hills of Safed for a time; had visions and spread their teachings along the Rhine; made the first group voyages to resettle the land of Israel in early modern times; conducted orgies in the role of virtual divinities in Turkey; roamed at the head of caravans across the Carpathians, traversing the rivers of Walachia and Podolia; languished in noble prisons in Turkey and Poland; cured ailments; quickened the wombs of barren women; eaten, drunk, sung, and prayed the world into its repair through the pale of settlement, and into the heartlands of Russia and Brooklyn; hiked the deserts and clambered up the mountains of Yemen to conquer satyrs.
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Kaloyanides, Michael G. « Peter Stephen Kyvelos (1943–2017) ». Dans Greek Music in America, 427–29. University Press of Mississippi, 2018. http://dx.doi.org/10.14325/mississippi/9781496819703.003.0036.
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Peter Kyvelos was a Greek American master luthier who opened Unique Strings in Belmont, MA in 1971. Though he repaired many Western chordophones, his greatest artistry was crafting the oud, the short-necked plucked lute found throughout Greece, Turkey, West Asia, and North Africa. Kyvelos was widely accepted as the premier maker of the instrument in the western hemisphere. He had acquired his first oud at 16 and performed professionally in California during the 1960s. In 2001 Kyvelos was awarded a National Heritage Fellowship as an instrument maker.
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Batt, Jennifer. « ‘The Duty of a grateful Muse’ ». Dans Class, Patronage, and Poetry in Hanoverian England, 91–114. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198859666.003.0006.
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This chapter explores how Stephen Duck adapted to life as a poet at the court of George II and Queen Caroline. The patronage that Queen Caroline extended to Duck in 1730 transformed his life and opened up remarkable new opportunities to him. This chapter explores how Duck strove to repay her generosity. Tentatively at first, and then with more confidence, Duck developed into a reliable Hanoverian panegyrist, ready and able to dispense verse on royal birthdays, weddings, and funerals. Duck performed this role with increasing ambition until the Queen’s death in 1737 brought his close association with courtly pageantry to an abrupt end.
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Howard-Hill, T. H. « Book Production And Distribution ». Dans British Literary Bibliography, 1970–1979, 105–252. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780198181835.003.0005.
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Abstract 962 Parks, Stephen. The English book trade, 1660–1853; 156 titles relating to the early history of English publishing, bookselling, the struggle for copyright and the freedom of the press. Repr.... in 38 vols. Ed. with bibliographical notes, by Skphen Parks. [New York], Garland, [1973?]. [20]p. illus. 22cm. 963 National book league, LONDON. One hundred and one books on the book trade; a selective annotated list of British books published in the last twenty years comp. by the staff of the Mark Longman library and Book information service. [2d ed.] London, Mark Longman library, National book league, 1978. (First pub. 1977). 26p. 20cm.
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Bondareva, Olga, et Vladimir Vashchenko. « SELECTION OF GRAINS IN CONDITIONS OF UNSTABLE HUMIDIFICATION OF THE NORTH-EASTERN STEPPE OF UKRAINE ». Dans Priority areas for development of scientific research : domestic and foreign experience. Publishing House “Baltija Publishing”, 2021. http://dx.doi.org/10.30525/978-9934-26-049-0-37.
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The purpose of the research is to develop a system of methods for assessing the adaptability of the selection material of spring barley and winter wheat, to create varieties with a high yield potential in conditions of unstable moisture. During 2016-2020, the Donetsk State Agricultural Science Station of the National Academy of Sciences of Ukraine conducted research in the direction of creating high-yielding varieties of soft winter wheat and spring barley, adapted to the conditions of the northeastern region of Ukraine. The research was carried out according to the method of field work by B. A. Dospekhov and the method of state variety testing of agricultural crops. Research methods: general scientific, field, laboratory, statistical. Based on the analysis of the biological potential of the productivity elements of spring barley, the parameters of the promising variety were determined. A method for assessing the adaptability of spring barley breeding material when grown in conditions of unstable moisture has been developed. The highest yield was formed by the varieties Stalyy, Bravyy and Repriz – 3,74 t/ha, 3,78 t/ha and 3,74 t/ha, respectively (standard variety Stalker – 3,12 t/ha). To obtain highly productive genotypes of winter wheat in drought-resistant conditions of the Donetsk region, the selection of forms was carried out, the selection of forms was carried out on the basis of early earing According to the results of competitive variety testing of winter wheat, the best hybrid combinations were gk784/1 x Povaha and gk94 / 117 x Dosvid, which formed the grain yield 7,52 and 7,77 t/ha, that is, they exceeded the standard Donetskaya 48 (6,78 t/ha) by 0,74 and 0,99 t/ha. Two samples were identified according to the indicator of early maturity gk491 (gk704 / 1 x Povaha) and gk598 (Lan25 x gk789/1), which vikoloshuyut 2-4 days earlier than the standard Donetskaya 48 and during three years of study stably showed this sign.
Actes de conférences sur le sujet "Stepped repair"
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Stevens, Melinda, Samuel Arellano, Diego Rodriguez, James Wilson, Zady Gutierrez, Noah Trudell, Hamed Momeni et Arvin Ebrahimkhanlou. « Robotic-Based Repair of Concrete Structures : A Surface Crack Filler Robot ». Dans ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-72082.
Texte intégralRésumé :
Abstract Surface cracks in concrete structures are often indicators of more substantial damage and may negatively affect the durability of a structure. To ensure the soundness of these structures, surface cracks should be quickly detected; this project proposes a robot with the ability to detect, map, and fill surface cracks. The robot will use a Bayesian network to fuse the multi-sensor data provided via an RGB camera, a stereo infrared depth sensor, and a LIDAR sensor. It will also be fitted with a newly designed piston-driven syringe system to inject a concrete filler material in a controlled manner. A non-captive lead screw and stepper motor drive the piston along with the syringe, and an arm with two degrees of freedom will allow the robot to position the injector along a crack accurately. To control the arm, the Bayesian network and sensor systems will work in unison to determine when a crack has been filled in a satisfying manner, ensuring a degree of uniformity and consistency in the repaired concrete surface.
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Shargay, Cathleen, Anil Singh, Tim Munsterman et Les Antalffy. « Coke Drum Design and Fabrication Issues ». Dans ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25765.
Texte intégralRésumé :
There are numerous design, materials and fabrication issues which significantly affect the cost, reliability and life of coke drums. Primarily in a pros and cons narrative, this paper discusses many of these critical decisions. It first outlines the potential damage mechanisms resulting from coke drum operation, which are primarily thermal fatigue and bulging and also embrittlement, sulfidation and erosion. Delayed Coking operation is described along with the ever present desire by owners to shorten cycle times to maximize unit throughput. Some examples of the decisions include the choices of alloys for base metals, cladding, and weld overlay, and the desire to maximize postweld heat treatment (PWHT) cycles while maintaining Minimum Design Metal Temperature (MDMT) toughness requirements to permit multiple future drum weld repairs. Design issues are reviewed such as uniform versus stepped thickness wall designs, and preferential placement of shell/cone plates to their optimum locations in relation to their individual thicknesses and yield strengths. Skirts also have options in attachment designs, thicknesses and the use of keyholes. The discussion of these and numerous other issues will hopefully assist the industry in the current development of a technical standard on coke drums being done by the American Petroleum Institute (API).
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Wiklund, Theodore, Mark Heim, Jaret Halberstadt, Michael Duncan, Deven Mittman, Thomas DeAgostino et Christopher Depcik. « Design and Development of a Cost-Effective LIDAR System for Transportation ». Dans ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-11279.
Texte intégralRésumé :
Abstract Light Imaging Detection and Ranging (LIDAR) cameras and Light Detecting and Ranging (LiDAR) rangefinders were initially implemented in the 1960s as a higher-resolution and increased capability alternative to radar. Since then, LIDAR and LiDAR (hereto called lidar) have expanded into applications in aerial geographical surveying and collision-detection systems for autonomous vehicles. Current commercial systems are relatively expensive and potentially oversized for noncommercial applications. Consequently, this deters their use on consumer products like bicycles, where lidar systems can enable safety advancements that are necessary to counter the rising numbers of hazards affecting riders. In addition, widespread usage of inexpensive lidar systems can facilitate a more complete picture of our transportation infrastructure by delivering information (e.g., pavement quality) suited for U.S. Department of Transportation Highway Performance Monitoring System (HPMS) reports. This will aid in the creation of a safer infrastructure by highlighting critical areas in need of improvement and repair. As a result, this effort outlines the development of a compact and cost-effective lidar system. The constructed system includes the ability to generate a static image by collecting several hundred thousand distance signals measured by a lidar rangefinder. Since the rangefinder has no self-contained rotation or translation systems, an Arduino Mega 2560 v3 microcontroller operates a pair of stepper motors that adjusts its azimuthal angle and pitch. Coalescing these signals into an ASCII text file for viewing in MATLAB results in a reasonably accurate picture of the surroundings. While the current system takes 1–2 hours to complete a full sweep, it has the potential to provide sufficient accuracy for HPMS reports at a moderate expenditure: the entire system costs less than $300. Finally, upgrading to a more powerful microprocessor, implementing slip rings for enhanced electrical connectivity, and refining the code by including interpolation between points will enable faster point cloud generation while still maintaining an inexpensive device.
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Slapac, Mariana. « Some details referring to the construction works in the stone fortress of Kilia ». Dans Simpozion Național de Studii Culturale, dedicat Zilelor Europene ale Patrimoniului. Ediția III. Institute of Cultural Heritage, Republic of Moldova, 2022. http://dx.doi.org/10.52603/sc21.14.
Texte intégralRésumé :
In the period June 22 – July 16, 1479, Stephen the Great built or rebuilt the stone fortress of Kilia. The Levantine or Greek-Genoese architect Ioan Privana, who built the Moldavian church of St. Nicholas here, could be involved in the construction works. After 1484 the stone fortress of Kilia was repaired and modernized by the Ottomans. At that time, each major province of the Ottoman Empire had its own chief architect of the Royal Corps of Architects, who dealt with military projects. It was a time when Ottoman specialists created engineering works that even met the standards of the following centuries. In the 18th century, the architect from the city of Hassa Halife Abdullah, the bina emini El Hac Hasan, the kapıcıbaşı Hasan Aga, the nazir’s deputy Salih Efendi, the Ottoman Empire architect chief Mehmed Tahir Aga, El Hac Ahmed, El Hac Emin and others were in charge of the fortress of Kilia in the Moldavian Principality. The stone fortress of Kilia functioned until 1795, when it was demolished and replaced by a bastion fortress of the Vauban type, built by the French engineer François Kauffer at the behest of Sultan Selim III.
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Bennett, Jarod, Mather Saladin, Daniel Sizoo, Spencer Stewart, Graham Wood, Thomas DeAgostino et Christopher Depcik. « Design of an Efficient, Low-Cost, Stationary LiDAR System for Roadway Condition Monitoring ». Dans ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-69308.
Texte intégralRésumé :
Abstract Light Imaging Detection and Ranging (LiDAR) systems generate point cloud imagery by using laser light to measure distance to a surface and then combine numerous points to create a three-dimensional (3-D) image. Since early adaptations, LiDAR is now common in aerial and subterranean geographical surveying and autonomous vehicle operations. The transportation industry uses LiDAR to monitor roadway quality, which can allow hazardous roadway corrosion to be spotted and repaired before endangering drivers. However, a leading issue with LiDAR availability is the respectively high price point for effective systems, therefore preventing widespread usage. Previous work at fabrication of a low-cost LiDAR system generated high resolution 3-D imagery but was faulted by limited portability and a long run-time while also finding issues with gimbal translation and C++ programming. This effort improves the prior work by combining a touchscreen Graphical User Interface (GUI) with a rangefinder (Garmin LiDAR-Lite v3HP) powered by Raspberry Pi 4 Model B hardware. The rangefinder is housed in a 3-D printed gimbal mount that translates via two stepper motors and driver board. The system runs via a Python script that allows the user to select varying levels of resolution on the GUI prior to data collection onto a Secure Digital card or a file accessible through an internet connection. Like the previous work, data output is in Cartesian coordinates through a .xyz file format with a MATLAB script used to create a point cloud and two-dimensional image with a depth gradient. Overall, a more efficient, easier to use, and accurate LiDAR system was created that offers various resolution levels for under the cost of $500.
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Schneider, Jerry, Jeffrey Wagner et Judy Connell. « Restoring Public Trust While Tearing Down Site in Rural Ohio ». Dans The 11th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2007. http://dx.doi.org/10.1115/icem2007-7319.
Texte intégralRésumé :
In the mid-1980s, the impact of three decades of uranium processing near rural Fernald, Ohio, 18 miles northwest of Cincinnati, became the centre of national public controversy. When a series of incidents at the uranium foundry brought to light the years of contamination to the environment and surrounding farmland communities, local citizens’ groups united and demanded a role in determining the plans for cleaning up the site. One citizens’ group, Fernald Residents for Environmental Safety and Health (FRESH), formed in 1984 following reports that nearly 300 pounds of enriched uranium oxide had been released from a dust-collector system, and three off-property wells south of the site were contaminated with uranium. For 22 years, FRESH monitored activities at Fernald and participated in the decision-making process with management and regulators. The job of FRESH ended on 19 January this year when the U.S. Secretary of Energy Samuel Bodman and U.S. Environmental Protection Agency Administrator Stephen Johnson — flanked by local, state, and national elected officials, and citizen-led environmental watchdog groups including FRESH — officially declared the Fernald Site clean of all nuclear contamination and open to public access. It marked the end of a remarkable turnaround in public confidence and trust that had attracted critical reports from around the world: the Cincinnati Enquirer; U.S. national news programs 60 Minutes, 20/20, Nightline, and 48 Hours; worldwide media outlets from the British Broadcasting Company and Canadian Broadcasting Company; Japanese newspapers; and German reporters. When personnel from Fluor arrived in 1992, the management team thought it understood the issues and concerns of each stakeholder group, and was determined to implement the decommissioning scope of work aggressively, confident that stakeholders would agree with its plans. This approach resulted in strained relationships with opinion leaders during the early months of Fluor’s contract. To forge better relationships, the U.S. Department of Energy (DOE) who owns the site, and Fluor embarked on three new strategies based on engaging citizens and interested stakeholder groups in the decision-making process. The first strategy was opening communication channels with site leadership, technical staff, and regulators. This strategy combined a strong public-information program with two-way communications between management and the community, soliciting and encouraging stakeholder participation early in the decision-making process. Fluor’s public-participation strategy exceeded the “check-the-box” approach common within the nuclear-weapons complex, and set a national standard that stands alone today. The second stakeholder-engagement strategy sprang from mending fences with the regulators and the community. The approach for dispositioning low-level waste was a 25-year plan to ship it off the site. Working with stakeholders, DOE and Fluor were able to convince the community to accept a plan to safely store waste permanently on site, which would save 15 years of cleanup and millions of dollars in cost. The third strategy addressed the potentially long delays in finalizing remedial action plans due to formal public comment periods and State and Federal regulatory approvals. Working closely with the U.S. and Ohio Environmental Protection Agencies (EPA) and other stakeholders, DOE and Fluor were able to secure approvals of five Records of Decision on time – a first for the DOE complex. Developing open and honest relationships with union leaders, the workforce, regulators and community groups played a major role in DOE and Fluor cleaning up and closing the site. Using lessons learned at Fernald, DOE was able to resolve challenges at other sites, including worker transition, labour disputes, and damaged relationships with regulators and the community. It took significant time early in the project to convince the workforce that their future lay in cleanup, not in holding out hope for production to resume. It took more time to repair relationships with Ohio regulators and the local community. Developing these relationships over the years required constant, open communications between site decision makers and stakeholders to identify issues and to overcome potential barriers. Fluor’s open public-participation strategy resulted in stakeholder consensus of five remedial-action plans that directed Fernald cleanup. This strategy included establishing a public-participation program that emphasized a shared-decision making process and abandoned the government’s traditional, non-participatory “Decide, Announce, Defend” approach. Fernald’s program became a model within the DOE complex for effective public participation. Fluor led the formation of the first DOE site-specific advisory board dedicated to remediation and closure. The board was successful at building consensus on critical issues affecting long-term site remediation, such as cleanup levels, waste disposal and final land use. Fluor created innovative public outreach tools, such as “Cleanopoly,” based on the Monopoly game, to help illustrate complex concepts, including risk levels, remediation techniques, and associated costs. These innovative tools helped DOE and Fluor gain stakeholder consensus on all cleanup plans. To commemorate the outstanding commitment of Fernald stakeholders to this massive environmental-restoration project, Fluor donated $20,000 to build the Weapons to Wetlands Grove overlooking the former 136-acre production area. The grove contains 24 trees, each dedicated to “[a] leader(s) behind the Fernald cleanup.” Over the years, Fluor, through the Fluor Foundation, also invested in educational and humanitarian projects, contributing nearly $2 million to communities in southwestern Ohio, Kentucky and Indiana. Further, to help offset the economic impact of the site’s closing to the community, DOE and Fluor promoted economic development in the region by donating excess equipment and property to local schools and townships. This paper discusses the details of the public-involvement program — from inception through maturity — and presents some lessons learned that can be applied to other similar projects.