Academic literature on the topic 'Forage directionnel'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Forage directionnel.'
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 "Forage directionnel"
1
WADDINGTON, J. "USE OF A SYSTEMATIC PLANTING DESIGN TO INVESTIGATE THE EFFECTS OF COMPANION CROP POPULATION DENSITY ON YIELD AND ON FORAGE ESTABLISHMENT AND PRODUCTIVITY." Canadian Journal of Plant Science 70, no. 3 (July 1, 1990): 861–67. http://dx.doi.org/10.4141/cjps90-105.
Full textAbstract:
To assess forage response to a companion crop in the seeding year and the residual effects the following year, a one-directional logarithmic progression of companion crop populations was imposed on a uniform seeding of forage. Low-order inverse polynomial equations fit the results well, while allowing a biologically realistic interpretation. All forage-companion crop combinations produced similar results and suggested that for companion crop populations from the near-commercial 180 plants m−2 down to 20 plants m−2, maximum production of both companion crop and forage is not possible. The technique allowed a parsimonious use of materials and land but required superior experimental technique.Key words: companion crop, forage, competition, experimental design.
2
Yurkowski, David J., Nigel E. Hussey, Aaron T. Fisk, Kendra L. Imrie, Ross F. Tallman, and Steven H. Ferguson. "Temporal shifts in intraguild predation pressure between beluga whales and Greenland halibut in a changing Arctic." Biology Letters 13, no. 11 (November 2017): 20170433. http://dx.doi.org/10.1098/rsbl.2017.0433.
Full textAbstract:
Asymmetrical intraguild predation (AIGP), which combines both predation and competition between predator species, is pervasive in nature with relative strengths varying by prey availability. But with species redistributions associated with climate change, the response by endemic predators within an AIGP context to changing biotic–abiotic conditions over time (i.e. seasonal and decadal) has yet to be quantified. Furthermore, little is known on AIGP dynamics in ecosystems undergoing rapid directional change such as the Arctic. Here, we investigate the flexibility of AIGP among two predators in the same trophic guild: beluga ( Delphinapterus leucas ) and Greenland halibut ( Reinhardtius hippoglossoides ), by season and over 30 years in Cumberland Sound—a system where forage fish capelin ( Mallotus villosus ) have recently become more available. Using stable isotopes, we illustrate different predator responses to temporal shifts in forage fish availability. On a seasonal cycle, beluga consumed less Greenland halibut and increased consumption of forage fish during summer, contrasting a constant consumption rate of forage fish by Greenland halibut year-round leading to decreased AIGP pressure between predators. Over a decadal scale (1982–2012), annual consumption of forage fish by beluga increased with a concomitant decline in the consumption of Greenland halibut, thereby indicating decreased AIGP pressure between predators in concordance with increased forage fish availability. The long-term changes of AIGP pressure between endemic predators illustrated here highlights climate-driven environmental alterations to interspecific intraguild interactions in the Arctic.
3
Shi, Xu, Baptiste Schmid, Philippe Tschanz, Gernot Segelbacher, and Felix Liechti. "Seasonal Trends in Movement Patterns of Birds and Insects Aloft Simultaneously Recorded by Radar." Remote Sensing 13, no. 9 (May 9, 2021): 1839. http://dx.doi.org/10.3390/rs13091839.
Full textAbstract:
Airspace is a key but not well-understood habitat for many animal species. Enormous amounts of insects and birds use the airspace to forage, disperse, and migrate. Despite numerous studies on migration, the year-round flight activities of both birds and insects are still poorly studied. We used a 2 year dataset from a vertical-looking radar in Central Europe and developed an iterative hypothesis-testing algorithm to investigate the general temporal pattern of migratory and local movements. We estimated at least 3 million bird and 20 million insect passages over a 1 km transect annually. Most surprisingly, peak non-directional bird movement intensities during summer were of the same magnitude as seasonal directional movement peaks. Birds showed clear peaks in seasonally directional movements during day and night, coinciding well with the main migration period documented in this region. Directional insect movements occurred throughout the year, paralleling non-directional movements. In spring and summer, insect movements were non-directional; in autumn, their movements concentrated toward the southwest, similar to birds. Notably, the nocturnal movements of insects did not appear until April, while directional movements mainly occurred in autumn. This simple monitoring reveals how little we still know about the movement of biomass through airspace.
4
Mukherjee, Sarbajit, and Vladimir Kulyukin. "Application of Digital Particle Image Velocimetry to Insect Motion: Measurement of Incoming, Outgoing, and Lateral Honeybee Traffic." Applied Sciences 10, no. 6 (March 18, 2020): 2042. http://dx.doi.org/10.3390/app10062042.
Full textAbstract:
The well-being of a honeybee (Apis mellifera) colony depends on forager traffic. Consistent discrepancies in forager traffic indicate that the hive may not be healthy and require human intervention. Honeybee traffic in the vicinity of a hive can be divided into three types: incoming, outgoing, and lateral. These types constitute directional traffic, and are juxtaposed with omnidirectional traffic where bee motions are considered regardless of direction. Accurate measurement of directional honeybee traffic is fundamental to electronic beehive monitoring systems that continuously monitor honeybee colonies to detect deviations from the norm. An algorithm based on digital particle image velocimetry is proposed to measure directional traffic. The algorithm uses digital particle image velocimetry to compute motion vectors, analytically classifies them as incoming, outgoing, or lateral, and returns the classified vector counts as measurements of directional traffic levels. Dynamic time warping is used to compare the algorithm’s omnidirectional traffic curves to the curves produced by a previously proposed bee motion counting algorithm based on motion detection and deep learning and to the curves obtained from a human observer’s counts on four honeybee traffic videos (2976 video frames). The currently proposed algorithm not only approximates the human ground truth on par with the previously proposed algorithm in terms of omnidirectional bee motion counts but also provides estimates of directional bee traffic and does not require extensive training. An analysis of correlation vectors of consecutive image pairs with single bee motions indicates that correlation maps follow Gaussian distribution and the three-point Gaussian sub-pixel accuracy method appears feasible. Experimental evidence indicates it is reasonable to treat whole bees as tracers, because whole bee bodies and not parts thereof cause maximum motion. To ensure the replicability of the reported findings, these videos and frame-by-frame bee motion counts have been made public. The proposed algorithm is also used to investigate the incoming and outgoing traffic curves in a healthy hive on the same day and on different days on a dataset of 292 videos (216,956 video frames).
5
Venter, Jan A., Herbert H. T. Prins, Alla Mashanova, and Rob Slotow. "Ungulates rely less on visual cues, but more on adapting movement behaviour, when searching for forage." PeerJ 5 (May 16, 2017): e3178. http://dx.doi.org/10.7717/peerj.3178.
Full textAbstract:
Finding suitable forage patches in a heterogeneous landscape, where patches change dynamically both spatially and temporally could be challenging to large herbivores, especially if they have noa prioriknowledge of the location of the patches. We tested whether three large grazing herbivores with a variety of different traits improve their efficiency when foraging at a heterogeneous habitat patch scale by using visual cues to gaina prioriknowledge about potential higher value foraging patches. For each species (zebra (Equus burchelli), red hartebeest (Alcelaphus buselaphussubspeciescamaa) and eland (Tragelaphus oryx)), we used step lengths and directionality of movement to infer whether they were using visual cues to find suitable forage patches at a habitat patch scale. Step lengths were significantly longer for all species when moving to non-visible patches than to visible patches, but all movements showed little directionality. Of the three species, zebra movements were the most directional. Red hartebeest had the shortest step lengths and zebra the longest. We conclude that these large grazing herbivores may not exclusively use visual cues when foraging at a habitat patch scale, but would rather adapt their movement behaviour, mainly step length, to the heterogeneity of the specific landscape.
6
Schueller, Teresa I., and Robert L. Jeanne. "Cue-Mediated Recruitment in a Swarm-Founding Wasp: Successful Foragers Induce Nestmates to Search Off Nest for a Scented Carbohydrate Resource." Psyche: A Journal of Entomology 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/585014.
Full textAbstract:
The ability of social insect colonies to recruit nestmates to profitable resources increases colony-wide foraging efficiency by providing individuals with information that narrows their search for resources. Here we ask if for the Neotropical swarm-founding waspPolybia occidentalisnaïve nestmates are able to use food-scent cues from rich carbohydrate resources brought to the nest by successful foragers to orient to off nest resources. Foragers were allowed to freely visit a training dish containing a scented sucrose solution. At a second location, in a different direction from the nest, two sucrose-filled dishes were offered, one with the training scent and one with an alternate scent. Naïve foragers preferentially chose the training scent over the alternate scent, indicating that natural rates of resource inflow to the nest are sufficient to induce nestmates to forage at resources with a specific scent. Naïve foragers did not forage more often at the location at which the active foragers were foraging, an indication that directional information is not communicated in this species. The total number of foraging trips made by a colony's foragers was not determined by the size of the foraging force, but rather by the average individual foraging rate for the colony.
7
Sciulli, Paul W. "Dental Asymmetry in a Late Archaic and Late Prehistoric Skeletal Sample of the Ohio Valley Area." Dental Anthropology Journal 16, no. 2 (September 3, 2018): 33–44. http://dx.doi.org/10.26575/daj.v16i2.158.
Full textAbstract:
Dental asymmetry (directional, anti-symmetry, and fluctuating) is analyzed in samples from two prehistoric Native American populations: a terminal Late Archaic population (3200-2700 BP) and a Late Prehistoric population (ca. 750 BP). Both directional and fluctuating asymmetry were found in each sample. Directional asymmetry occurs in only four teeth in the Late Archaic sample and in two teeth in the Late Prehistoric sample. Neither sample exhibits the tendency for opposing arch dominance in directional asymmetry. Fluctuating asymmetry is significantly greater than measurement error for all teeth in each sample. However, contrary to expectations the Late Prehistoric maize agriculturists do not show an overall greater degree of fluctuating asymmetry compared to their forager ancestors. This result coupled with a survey of pathological conditions in these populations suggest that stress levels in Ohio Valley populations, at least that stress which affected dental developmental stability, were not drastically increased with the introduction of maize agriculture. Spearman correlations between relative tooth size variation (coefficient of variation), the magnitude of fluctuating dental asymmetry, and duration of time (per tooth) spent in soft tissue development were obtained for each sample. Coefficients of variation and fluctuating asymmetry are significantly correlated in both samples but fluctuating asymmetry is significantly correlated with duration of soft tissue development only in the Late Prehistoric population.
8
Cheong, Yeon Joon, Wu-Jung Lee, Alexander Ruesch, Matt Schalles, Jana Kainerstorfer, and Barbara Shinn-Cunningham. "Modeling and interpreting the head-related transfer function to understand directional hearing in bottlenose dolphins." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A187. http://dx.doi.org/10.1121/10.0018608.
Full textAbstract:
Toothed whales have evolved to communicate, forage, and navigate effectively underwater using sound. It is generally accepted that toothed whales receive sounds through their lower mandible and the associated fat body, which guide sound to the tympano-periotic complexes (TPCs) enclosing the cochleae. However, little is known about how the direction of an impinging sound wave affects acoustic interactions with these and other structures in the head to alter the signals driving the left and right TPCs. In this work, we constructed a three-dimensional head model using computed tomography (CT) images of a live bottlenose dolphin. Using a finite-element model to simulate sound-structure interactions, we computed how left and right TPC signals vary with sound direction for multiple frequencies to generate dolphin head-related transfer functions (HRTFs). The simulated HRTFs vary strongly with frequency. Importantly, HRTFs for sources off midline exhibit complex frequency-dependent differences, which are acoustic features that could be used to estimate sound source location. We also observed scenarios where interaural level differences (ILDs) may not be reliable directional cues. Results like these can identify which acoustic cues, at which frequencies, support robust directional hearing in toothed whales. [Work supported by ONR.]
9
André, M., T. Johansson, E. Delory, and M. van der Schaar. "Foraging on squid: the sperm whale mid-range sonar." Journal of the Marine Biological Association of the United Kingdom 87, no. 1 (February 2007): 59–67. http://dx.doi.org/10.1017/s0025315407054847.
Full textAbstract:
The sonar capabilities of the sperm whale, Physeter macrocephalus, have been the subject of speculation for a long time. While the usual clicks of this species are considered to support mid-range echolocation, no physical characteristics of the signal have clearly confirmed this assumption nor have they explained how sperm whales forage on squid. The recent data on sperm whale on-axis recordings have allowed us to simulate the propagation of a 15 kHz pulse as well as its received echoes from different targets, taking into account the reflections from the bottom and the sea surface. The analysis was performed in a controlled environment where the oceanographic parameters and the acoustic background could be modified. We also conducted experimental measurements of cephalopod target strength (TS) (Loligo vulgaris and Sepia officinalis) to further investigate and confirm the TS predictions from the geometric scattering equations. Based on the results of the computer simulations and the TS experimental measurements (TS squid=−36.3±2.5 dB), we were able to determine the minimum requirements for sperm whale sonar, i.e. range and directional hearing, to locate a single 24.5 cm long squid, considered to be (from stomach contents) the major size component of the sperm whale diet. Here, we present the development of the analysis which confirms that sperm whale usual clicks are appropriate to serve a mid-range sonar function, allowing this species to forage on individual organisms with low sound-reflectivity at ranges of several hundreds of metres.
10
Rahimi, Yousef, Girma Bedada, Silvana Moreno, Anne-Maj Gustavsson, Pär K. Ingvarsson, and Anna Westerbergh. "Phenotypic Diversity in Domesticated and Wild Timothy Grass, and Closely Related Species for Forage Breeding." Plants 12, no. 19 (October 7, 2023): 3494. http://dx.doi.org/10.3390/plants12193494.
Full textAbstract:
Timothy grass (Phleum pratense L.) is one of the most important forage crops in temperate regions. Forage production, however, faces many challenges, and new cultivars adapted to a changing climate are needed. Wild populations and relatives of timothy may serve as valuable genetic resources in the breeding of improved cultivars. The aim of our study is to provide knowledge about the phenotypic diversity in domesticated (cultivars, breeding lines and landraces) and wild timothy and two closely related species, P. nodosum (lowland species) and P. alpinum, (high altitude species) to identify potential genetic resources. A total of 244 accessions of timothy and the two related species were studied for growth (plant height, fresh and dry weight) and plant development (days to stem elongation, days to booting and days to heading) in the field and in a greenhouse. We found a large diversity in development and growth between the three Phleum species, as well as between the accessions within each species. Timothy showed the highest growth, but no significant difference was found between wild accessions and cultivars of timothy in fresh and dry weight. However, these two groups of accessions showed significant differences in plant development, where timothy cultivars as a group reached flowering earlier than the wild accessions. This suggests that there has not been a strong directional selection towards increased yield during the domestication and breeding of timothy; rather, timothy has been changed for other traits such as earlier heading. Principal component analysis and cluster analysis based on all traits revealed distinct clusters. Accessions falling within the same cluster showed similarities in the development and growth rather than the type of accession. The large diversity found in this study shows the potential of using timothy accessions as genetic resources in crosses with existing cultivars. Also, accessions of P. nodosum with favorable traits can be candidates for the domestication of a novel forage crop, and the high-altitude relative P. alpinum may be a source of genes for the development of more cold and stresstolerant cultivars.
Dissertations / Theses on the topic "Forage directionnel"
1
Kaplan, Julia. "Modélisation tridimensionnelle du comportement directionnel du système de forage rotary." Paris, ENMP, 2003. http://www.theses.fr/2003ENMP1279.
Full text
2
Ben, Hamida Malek. "Analyse et validation du comportement directionnel des outils de forage couplés aux systèmes de forage dirigé." Thesis, Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0054/document.
Full textAbstract:
Nous présentons dans ce mémoire un modèle d'interaction outil-roche qui calcule les efforts de forage en fonction du déplacement dans la roche d'un outil de forage de type PDC, et permet d'évaluer ses propriétés directionnelles, à savoir, son indice d'anisotropie (steerability) et son angle de walk. Le mouvement de l'outil est défini par une translation suivant trois axes et une rotation suivant deux axes. L'angle de tilt, qui définit l'inclinaison de l'outil par rapport à l'axe du trou en cours de forage, est pris en compte dans le calcul des surfaces d'interactions effectives entre les différentes composantes de l'outil (structure de coupe, garde active et garde passive) et la roche. Ce modèle outil est établi à partir d'une modélisation de la coupe de roche par un taillant. Ce modèle de coupe élémentaire est construit de manière à être applicable aux différentes parties de l'outil. Les efforts élémentaires de coupe sont intégrés sur toute la structure de l'outil de forage afin de calculer ses propriétés directionnelles. Le modèle d'interaction outil-roche est validé à partir d'essais de forage directionnel réalisés sur un banc spécialement conçu pour reproduire le comportement des systèmes de forage dirigé existants. Il constitue un outil d'aide à la décision pour la sélection de l'outil de forage en fonction du système au bout duquel il sera fixé. Ce modèle pourra aussi être intégré dans une boucle de régulation automatique ou semi-automatique de contrôle et de correction de la trajectoire en temps réelThis work deals with the formulation of global relationships between kinematic variables describing the penetration of a PDC bit into the rock and drilling forces acting on it. This allows us determine the bit directional properties in terms of steerability, which corresponds to the bit lateral aggressiveness, and walk, which describes the bit azimuth displacement with respect to the side force. The bit kinematic quantities are divided into a three-axis penetration vector and a two-axis angular penetration vector. The bit tilt, which describes the angle between the bit revolution axis and the borehole tangent, is used to compute the effective interaction surface between the bit's different components (cutting structure, active gauge and passive gauge) and the rock. A new cutter-rock interface law is set up and experimentally validated in order to compute elementary forces acting on all parts of a drill bit. Bit directional properties are computed after the integration of these elementary forces. The bit-rock interaction model is experimentally validated with directional drilling tests held on a full-scale drilling bench developed to reproduce Rotary Steerable Systems (RSS) directional behavior. Tests and theoretical results enabled us to fully understand the roles of tilt angle, bit design, operating parameters and rock properties in the deviation process of a PDC bit. The bit-rock interaction model is a decision support tool for optimal drill bit selection according to the RSS being used. It could also be embedded in a real-time Closed-Loop Guided Directional Drilling controller in order to correct the drilling direction or follow a planned borehole trajectory
3
Ben, Hamida Malek. "Analyse et validation du comportement directionnel des outils de forage couplés aux systèmes de forage dirigé." Electronic Thesis or Diss., Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0054.
Full textAbstract:
Nous présentons dans ce mémoire un modèle d'interaction outil-roche qui calcule les efforts de forage en fonction du déplacement dans la roche d'un outil de forage de type PDC, et permet d'évaluer ses propriétés directionnelles, à savoir, son indice d'anisotropie (steerability) et son angle de walk. Le mouvement de l'outil est défini par une translation suivant trois axes et une rotation suivant deux axes. L'angle de tilt, qui définit l'inclinaison de l'outil par rapport à l'axe du trou en cours de forage, est pris en compte dans le calcul des surfaces d'interactions effectives entre les différentes composantes de l'outil (structure de coupe, garde active et garde passive) et la roche. Ce modèle outil est établi à partir d'une modélisation de la coupe de roche par un taillant. Ce modèle de coupe élémentaire est construit de manière à être applicable aux différentes parties de l'outil. Les efforts élémentaires de coupe sont intégrés sur toute la structure de l'outil de forage afin de calculer ses propriétés directionnelles. Le modèle d'interaction outil-roche est validé à partir d'essais de forage directionnel réalisés sur un banc spécialement conçu pour reproduire le comportement des systèmes de forage dirigé existants. Il constitue un outil d'aide à la décision pour la sélection de l'outil de forage en fonction du système au bout duquel il sera fixé. Ce modèle pourra aussi être intégré dans une boucle de régulation automatique ou semi-automatique de contrôle et de correction de la trajectoire en temps réelThis work deals with the formulation of global relationships between kinematic variables describing the penetration of a PDC bit into the rock and drilling forces acting on it. This allows us determine the bit directional properties in terms of steerability, which corresponds to the bit lateral aggressiveness, and walk, which describes the bit azimuth displacement with respect to the side force. The bit kinematic quantities are divided into a three-axis penetration vector and a two-axis angular penetration vector. The bit tilt, which describes the angle between the bit revolution axis and the borehole tangent, is used to compute the effective interaction surface between the bit's different components (cutting structure, active gauge and passive gauge) and the rock. A new cutter-rock interface law is set up and experimentally validated in order to compute elementary forces acting on all parts of a drill bit. Bit directional properties are computed after the integration of these elementary forces. The bit-rock interaction model is experimentally validated with directional drilling tests held on a full-scale drilling bench developed to reproduce Rotary Steerable Systems (RSS) directional behavior. Tests and theoretical results enabled us to fully understand the roles of tilt angle, bit design, operating parameters and rock properties in the deviation process of a PDC bit. The bit-rock interaction model is a decision support tool for optimal drill bit selection according to the RSS being used. It could also be embedded in a real-time Closed-Loop Guided Directional Drilling controller in order to correct the drilling direction or follow a planned borehole trajectory
4
Menand, Stéphane. "Analyse et validation d'un modèle de comportement directionnel des outils de forage monoblocs PDC." Paris, ENMP, 2001. http://www.theses.fr/2001ENMP1051.
Full textAbstract:
La prédiction du comportement directionnel d'un système de forage nécessite d'établir un modèle de comportement directionnel de l'outil de forage. Par une approche cinématique et sur la base d'une simplification de la structure de coupe de l'outil, le modèle élaboré aboutit à une loi reliant les efforts moyens exercés sur l'outil au déplacement de ce dernier. Chaque partie de l'outil, à savoir, la structure de coupe, la garde active et la garde passive, a une influence distincte sur le comportement directionnel en terme d'angle de Walk et de forabilité latérale. Les essais effectués au laboratoire valident les prédictions du modèle théorique développé. La tendance de walk de l'outil peut être alors oBbtenue à partir de simples critères géométriques décrivant le profil de l'outil. Le modèle d'interaction outil-roche développé couplé avec un code de calcul 3D du comportement mécanique de la garniture devrait déboucher sur un outil performant pour la prédiction de l'inclinaison et de l'azimut des trajectoires de forage.
5
Menand, Stéphane. "Analyse et validation d'un modèle de comportement directionnel des outils de forage monobloc pdc." Phd thesis, École Nationale Supérieure des Mines de Paris, 2001. http://pastel.archives-ouvertes.fr/pastel-00000017.
Full textAbstract:
La prédiction du comportement directionnel d'un système de forage nécessite d'établir un modèle de comportement directionnel de l'outil de forage. Par une approche cinématique et sur la base d'une simplification de la structure de coupe de l'outil, le modèle élaboré aboutit à une loi reliant les efforts moyens exercés sur l'outil au déplacement de ce dernier. Chaque partie de l'outil, à savoir, la structure de coupe, la garde active et la garde passive, a une influence distincte sur le comportement directionnel en terme d'angle de walk et de forabilité latérale. Les essais effectués au laboratoire valident les prédictions du modèle théorique développé. La tendance de walk de l'outil peut être alors obtenue à partir de simples critères géométriques décrivant le profil de l'outil. Le modèle d'interaction outil-roche développé couplé avec un code de calcul 3D du comportement mécanique de la garniture devrait déboucher sur un outil performant pour la prédiction de l'inclinaison et de l'azimut des trajectoires de forage.
6
Belaid, Abdessalem. "Modélisation tridimensionnelle du comportement mécanique de la garniture de forage dans les puits à trajectoires complexes : application à la prédiction des frottements garniture-puits." Phd thesis, École Nationale Supérieure des Mines de Paris, 2005. http://pastel.archives-ouvertes.fr/pastel-00579916.
Full textAbstract:
Réussir le forage d'un puits pétrolier le plus rapidement possible et à moindre coût est devenu un défi continu pour les professionnels du secteur. Pour relever ce défi, un bon dimensionnement des installations de forage s'impose. La meilleure prédiction des pertes liées aux frottements entre la garniture de forage et les parois du puits, notamment pour les puits à trajectoires fortement déviées, est un atout majeur pour ce dimensionnement. Les modèles usuels de prédiction des frottements montrent certaines insuffisances lorsque la trajectoire du puits se complexifie. Un nouveau modèle de calcul de frottements dans les puits de forage à trajectoires complexes a été développé et validé. Ce modèle utilise une méthode tridimensionnelle de reconstitution de la trajectoire intégrant à la fois la courbure et la torsion géométrique. Contrairement aux modèles classiques, qui supposent simplement que la garniture repose par gravité sur la paroi basse du trou de forage et qui négligent souvent la rigidité des tiges, le nouveau modèle rigide calcule la vraie déformée de la garniture de forage à l'intérieur du trou via un algorithme itératif de contact unilatéral. En outre, pour un gain important du temps de calcul, le modèle se base sur une intégration numérique directe des équations d'équilibre local sans avoir recours à la méthode des éléments finis.
La comparaison avec un modèle couramment utilisé dans l'industrie de forage, appelé modèle LISSE, a été effectuée sur plusieurs puits réels et théoriques. Il ressort de cette comparaison que le nouveau modèle vient palier plusieurs faiblesses du modèle LISSE dans le cas des trajectoires à géométrie complexe (surestimation des zones de contacts et des forces de contact en présence de micro-tortuosité, non sensibilité au signe du gradient d'azimut en présence de fort gauchissement, hypothèse de contact sur la paroi basse du trou pas toujours vérifiée). Par ailleurs, la confrontation avec les mesures du terrain pour la plupart des puits à géométrie bidimensionnelle ou faiblement tridimensionnelle avec des faibles dog legs (ne dépassant pas 2 à 3°/30 m) fournit généralement des concordances entre les résultats des deux types de modèles et les valeurs mesurées. En revanche, en présence de tortuosités et dog legs locaux le nouveau modèle fournit une meilleure prédiction des pertes en frottement.
Books on the topic "Forage directionnel"
1
Chambre syndicale de la recherche et de la production du pétrole et du gaz naturel. Comité des techniciens., ed. Réalisation des forages dirigés et contrôle des trajectoires. Paris: Technip, 1985.
Find full text
2
American Society of Civil Engineers. Horizontal Directional Drilling Design Guideline Task Committee, ed. Pipeline design for installation by horizontal directional drilling. Reston, Virginia: American Society of Civil Engneers, 2014.
Find full text
3
Air and Gas Drilling Manual: Applications for Oil, Gas, Geothermal Fluid Recovery Wells, Specialized Construction Boreholes, and the History and Advent of the Directional DTH. Elsevier Science & Technology Books, 2020.
Find full text
4
Pang, Changhyun, Chanseok Lee, Hoon Eui Jeong, and Kahp-Yang Suh. Skin and dry adhesion. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199674923.003.0022.
Full textAbstract:
Close observation of various attachment systems in animal skins has revealed various exquisite multi-scale architectures for essential functions such as locomotion, crawling, mating, and protection from predators. Some of these adhesion systems of geckos and beetles have unique structural features (e.g. high-aspect ratio, tilted angle, and hierarchical nanostructure), resulting in mechanical interlocking mediated by van der Waals forces or liquid secretion (capillary force). In this chapter, we present an overview of recent advances in bio-inspired, artificial dry adhesives, and biomimetics in the context of nanofabrication and material properties. In addition, relevant bio-inspired structural materials, devices (clean transportation device, interlocker, biomedical skin patch, and flexible strain-gauge sensor) and microrobots are briefly introduced, which would shed light on future smart, directional, and reversible adhesion systems.
Book chapters on the topic "Forage directionnel"
1
"Aluminum Forging." In Aluminum: Technology, Industry, and Applications, 165–78. ASM International, 2023. http://dx.doi.org/10.31399/asm.tb.atia.t59340165.
Full textAbstract:
Abstract Forged aluminum products vary widely in their production methods and applications. The forging process allows for control of microstructure and directional properties, and their fatigue and fracture resistance are superior to shape castings. This chapter presents the types, equipment, process steps, alloys, and products of aluminum forging.
2
Bickham, Troy O. "The New Imperial Regime at Work." In Savages Within The Empire, 134–68. Oxford University PressOxford, 2005. http://dx.doi.org/10.1093/oso/9780199286966.003.0005.
Full textAbstract:
Abstract The British response to the troubled situation in North America at the end of the Seven Years War took the form of an attempt to assume a more permanent authority over Indian affairs. Broad directional control was given to the secretaries of state, who demonstrated an unprecedented interest in Indian affairs that was matched by a willingness to intervene decisively. Assisting them on the ground were a number of imperial agents, and to some extent elements of the colonial governments them-selves. Together they forged a new form of British imperialism, which was directed from the metropolis and claimed sovereignty—and to varying degrees presided—over a multitude of ‘primitive’ peoples.
3
Cummings, Kristopher W. "Shunts, Intracardiac and Intrapulmonary." In Chest Imaging, 545–50. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780199858064.003.0094.
Full textAbstract:
Shunts, intracardiac and intrapulmonary, are vascular communications that allow mixture of deoxygenated and oxygenated blood within the cardiovascular system. The most common intracardiac shunts encountered in adults allow left (oxygenated) to right (deoxygenated) directional shunting which over time can lead to pulmonary circulation volume overload and pulmonary hypertension. In this chapter, the most common adult intracardiac shunts (atrial septal defects, patent foramen ovale and ventricular septal defects) are discussed. Shunting can also occur at the level of the lung parenchyma with one of the most common examples being a pulmonary arteriovenous malformation (pAVM). PAVMs are very frequently inherited conditions, and their identification has implications both for the patient and immediate family members. The imaging appearances of these intracardiac and intrapulmonary lesions will be discussed.
4
Morris, Michael. "Multidirectional Memory, Many-Headed Hydras and Glasgow." In Britain's History and Memory of Transatlantic Slavery. Liverpool University Press, 2017. http://dx.doi.org/10.5949/liverpool/9781781382776.003.0010.
Full textAbstract:
This chapter forms a case study of memory/amnesia around slavery in Glasgow and proposes that a number of high profile events in the year 2014 may prove to be a turning point in this regard. The first section peels back the overlapping layers of Atlantic, British, Scottish and Glaswegian amnesia which have prolonged the silence around slavery. The second section identifies that all twelve statues in the city’s central George Square have a connection to slavery or abolition. Borrowing from Michael Rothberg’s ‘Multi-directional Memory’ approach, it reads the statues ‘against the grain’ to demonstrate how slavery can be integrated into Glasgow’s public memory of commerce, science, militarism, politics and literature. This recovery of the memory of slavery in Glasgow comes at a dynamic period in Scotland’s history and has the potential to transform its sense of cultural history the better to forge its political future.
5
Boomsma, Jacobus J. "Necessary and sufficient conditions for major evolutionary transitions." In Domains and Major Transitions of Social Evolution, 78–104. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780198746171.003.0004.
Full textAbstract:
Abstract From an individual perspective, there is a fundamental difference between cooperation for mutual benefit and self-sacrificing altruism. However, there is no such difference for the gene’s eye view of social evolution, which stipulates that both types of cooperation are equally self-serving. Gene’s eye explanations of altruism started with the pedigree version of Hamilton’s rule, and were later generalized when Price equation logic produced a statistical and fully general genetic theory of social evolution, and an approximate phenotypic theory amenable to empirical testing. However, this generalization applied to societies with redundant partnerships where relatedness is variable and social adaptations are mediated by condition-dependent altruism at the level of cellular or multicellular agents. Under such conditions, adaptations for the exclusive benefits of the higher-level of organizational complexity cannot evolve. Yet, such adaptations of unconditional somatic altruism universally characterize the convergent major evolutionary transitions (MTEs) towards multicellular organismality and colonial superorganismality. I show that the origins of (super)organismality can be conjectured to have required invariably maximal relatedness among cell copies or siblings, owing to lifetime commitment between a pair of gametes or monogamous parents. Such pairwise closure in terms of genetic information partitions Hamilton’s rule in an invariant necessary condition of relatedness equivalence between dispersing and adhering offspring, and a contingent sufficiency condition (b/c > 1) that is additionally required to forge a MTE origin. This implies that (super)organismality MTEs are expected to evolve by directional kin selection for unconditional, obligate altruism by entire cohorts, which is different from individual selection for conditional altruism in societies. I contrast the predictions of the classical continuous version of Hamilton’s rule for social evolution in societies and the partitioned discontinuous version applicable to MTE origins, and argue that conflict reduction and body- or family-size stabilize societies but played no role in the origin of (super)organismality.
Conference papers on the topic "Forage directionnel"
1
Golubović, Đorđe, Jovan Jović, and Zoran Stojanović. "USMERENA PREKOSTRUJNA ZAŠTITA ZASNOVANA SAMO NA MERENjU STRUJA." In 35. Savetovanje Srpskog nacionalnog komiteta Međunarodnog saveta za velike električne mreže. Srpski nacionalni komitet Međunarodnog saveta za velike električne mreže CIGRE Srbija, 2023. http://dx.doi.org/10.46793/cigre35.0537g.
Full textAbstract:
Conventional directional overcurrent protection are based on direction defined by phase shift between measuring current and appropriate polarizing voltage (angle difference between this two vectors). Past several years, there is a significant growth of interest in possibility to realize directional current based protection devices using current only criteria. This techniques came into focus only due to increased possibilities of small microprocessors. This report should present their basic operation principles. Driving force for development of this devices are growing need for directional overcurrent protection in area of parallel feeders (security) and introduction of significant distributed generation om low and medium voltage levels
2
Švantner, Roman, David Brűnn, Martin Pupiš, Dávid Líška, and Jozef Sýkora. "The Effect Of Isometric Hip Adductors Force On Change Of Direction Speed of Professional Ice-Hockey Players." In 12th International Conference on Kinanthropology. Brno: Masaryk University Press, 2020. http://dx.doi.org/10.5817/cz.muni.p210-9631-2020-46.
Full textAbstract:
Introduction: Ice-hockey is a sport that requires high acceleration of players for optimal performance. The speedof sports players is influenced by several factors. The aim of research was to determine the effect of the isometric muscle strength of hip adductors on speed with directional changes in ice-hockey players. Methods: The sample consisted of 15 members of the Slovakian national ice-hockey team, the average age was 27 years, the average height was 186.46 cm (SD ± 5.04), the average body weight was 90.87 kg (SD ± 5.91). Players completed a GroinBar Test of 60° to determine the isometric force of the hip adductors. We used the 5-10-5 test to determine the speed with directional changes. The 5-10-5 shuttle consists of rapid directional changes in a linear plane. It is commonly used as an assessment in different sports. The 5-10-5 Shuttle Drill, also known as the Pro Agility Drill, is a great tool for working on your agility and short-distance explosiveness. Results: In the research sample consisted of professional hockey players was measured a low degree of correlation (r = 0.006) between isometric muscle strength of the hip adductors and the speed with the directional changes in the 5-10-5 test. The average ice-hockey player’s adductors strength was 476.83 N (SD ± 88.50) and the average time achieved in the 5-10-5 test was 4.984 s (SD ± 0.15). We also found low degree of correlation between right adductor force and right side of 5-10-5 test (r = 0.047) as well as left adductor force and left side of 5–10-5 test (r = 0.067). Conclusion: Research shows a very low degree of correlation in ice-hockey players between the hip adductor strength in the GroinBar Test 60° and the speed with the directional changes in the 5-10-5 test.
3
Banerjee, Arnab, Avishek Chanda, and Raj Das. "A Simplified Exact Compliance Normal-Directional Contact Model." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66492.
Full textAbstract:
Contact is the most abundant phenomena in the field of multi-body dynamics, experienced when two or more bodies come in close vicinity to each other. During contact, one body virtually penetrates within other and therefore is subjected to a large impulsive force due to the deformation; this is the essence of the compliance based models. Subsequently, different compliance models were proposed, each having a different formulation for the impulsive force variation, which is always a function of time and deformation. A novel multi-linear compliance model, calculated on the basis of the Poisson’s law, is introduced in this work. The responses of all the available compliance models have been critically reviewed in previous studies and using the same study and the observed significant models, a comparative study is presented in this work for establishing the proposed model. A few significant models were selected according to the minimum amount of error induced by each while estimating the coefficient of restitution, impulse, and dissipating energy. The contact force-penetration relationship in the compression phase and restitution phase are assumed to be linear with a sharp jump at their transition. The slope of the compression phase of the force-displacement diagram of the non-dimensional system is exactly as desired (1+coefficient of restitution) and moreover, the slope of the restitution phase is equal to the coefficient of restitution helping in retrieving the exact coefficient of restitution pertaining in the pre-impact condition. Also, the post-impact coefficient of restitution, impulse, and dissipating energy are exactly accurate, having 0% error, in accordance with that of the stereo-mechanical model, for the full range of the co-efficient of restitution.
4
Martel, Sylvain, and Mahmood Mohammadi. "Towards Mass-Scale Micro-Assembly Systems Using Magnetotactic Bacteria." In ASME 2011 International Manufacturing Science and Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/msec2011-50171.
Full textAbstract:
Magnetotactic bacteria (MTB) can be used in a coordinated fashion to assemble micro-objects in an orderly manner. To perform micro-assembly tasks, magnetotaxis-based control is used where a directional magnetic field is generated to induce a torque on an embedded chain of membrane-based magnetic nanoparticles (MNP) named magnetosomes. Such chain acts like a nano-compass or a nano-steering system embedded in each bacterium. Such magnetotaxis-based control is then used to orient the MTB in such a way that the laminar flow created by their flagella bundles provides a displacement force on the micro-objects being assembled. Since the force is generated by the bacteria, relatively large micro-objects can be moved with no requirement for electrical energy except for a relatively small value required for inducing a directional torque on the chain of magnetosomes in the cells. Because the energy required to generate the directional torque is independent on the population of MTB being involved but the displacement force can be scaled up with the use of a larger swarm while the total workspace would typically be at microscale dimensions, the energy required for the coils configuration around such workspace and responsible for generating the directional torque can be reduced further to a very low level and hence, makes the implementation of mass-scale bacterial micro-assembly systems, a viable approach. Based on these findings, we propose a corresponding mass-scale system based on many workspaces, each relying on a swarm of MTB to perform micro-assembly tasks in parallel.
5
Trumars, Jenny M. V., Johan O. Jonsson, and Lars Bergdahl. "The Effect of Wind and Wave Misalignment on the Response of a Wind Turbine at Bockstigen." In 25th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/omae2006-92075.
Full textAbstract:
The aim of this work is to evaluate data from the offshore wind farm Bockstigen in order to study the effect of directional spreading of waves and wind wave misalignment on the response of the structure. The development of offshore wind energy has led to wind farms at sites with water depths ranging from approximately 6 to 30 m. The change of location from land to sea changes the design requirements of wind energy converters. In addition to wind loads, the wave load on the structure has to be taken into account. Since a wind turbine is highly damped in the inline direction as compared to the crosswise direction, the effect of directional spreading of waves on the response is studied. Depending on the dynamics of the structure the crosswise force could give a larger response than the corresponding inline force. In this study the influence of the directional spreading of the waves on the response is not clear, however the effect of wind and wave misalignment is clear.
6
Wang, Weizhi, Arun Kamath, and Hans Bihs. "CFD Simulations of Multi-Directional Irregular Wave Interaction With a Large Cylinder." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77511.
Full textAbstract:
Ocean waves are random by nature and can be regarded as a superposition of a finite number of regular waves travelling in different directions with different frequencies and phases. Cylinder-shaped objects are commonly present in most coastal structures. An irregular bottom topography has a significant influence on the wave behaviours and therefore the wave forces on the coastal structures. A numerical approach that is able to calculate the wave forces on a cylinder in a multi-directional irregular wave field over an irregular bottom is desired. As Computational Fluid Dynamics (CFD) is able to represent most of the wave behaviour with few assumptions, it is considered to be an attractive option to address these issues. The open-source CFD wave model REEF3D has shown good performances in simulating wave propagation over irregular bottoms and a good prediction of wave forces on a cylinder in a uni-directional wave field, yet the ability to calculate the wave force in a multi-directional irregular sea needs to be validated. Therefore, this paper attempts to simulate the multi-directional random sea interaction with a large cylinder using REEF3D and validate the results. A novel approach of multi-directional irregular wave generation method in a CFD-based numerical wave tank is introduced. Only even-bottom tanks are considered in this study, leaving the irregular bottom simulation for future studies. Furthermore, among many factors that influence the wave forces, this paper focuses particularly on the effect of the wave steepness. The effects of wave steepness in regular waves, uni-directional irregular waves and multi-directional irregular waves are investigated. Goda’s JONSWAP frequency spectrum and the frequency-independent Mitsuyasu directional spreading function are used to generate the multi-directional irregular waves. The wave forces due to the multi-directional irregular waves in the numerical tank are compared with experimental data. The performance of the CFD simulation is analysed and discussed.
7
Wang, Xin, Peng Zhao, and Tingting Yang. "A THZ cross-guide waveguide directional coupler with high directivity." In 2014 Joint IEEE International Symposium on the Applications of Ferroelectrics, International Workshop on Acoustic Transduction Materials and Devices & Workshop on Piezoresponse Force Microscopy (ISAF/IWATMD/PFM). IEEE, 2014. http://dx.doi.org/10.1109/isaf.2014.6918101.
Full text
8
Shi, Wen, Ye Yuan, Su Song Yang, and Bo Sheng Liang. "A modified broadband hybrid-ring directional coupler in W-band." In 2014 Joint IEEE International Symposium on the Applications of Ferroelectrics, International Workshop on Acoustic Transduction Materials and Devices & Workshop on Piezoresponse Force Microscopy (ISAF/IWATMD/PFM). IEEE, 2014. http://dx.doi.org/10.1109/isaf.2014.6918110.
Full text
9
Ramba, Viswanth, Senthil Selvaraju, Senthilmurugan Subbaih, Muthukumar Palanisamy, Sanjaykumar Gauba, and Suresh Jandial. "Real-Time Evaluation of Structural Integrity of Tubulars in Directional Wellbores." In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18414.
Full textAbstract:
Abstract The actual forces acting on the drill string in directional drilling is relatively complex than vertical drilling. In this work, the different forces acting on the drill string during directional drilling are analyzed using actual drilling data. The calculation of such forces can help driller to predict downhole complications that are caused due to drill string failures. The estimation of effective tension force at the top of the drill string requires both true tension forces and buckling stability forces acting on the drill string. True tension is a function of weight component of the drill string, the forces acting on BHA due to change in cross-sectional area and bottom pressure force acting on the drill bit and the drag forces acting on the string. The buckling stability force is defined as the difference between the internal and external force acting on the drill string. The effective tension is used to calculate the hookload and normal forces acting on the drill string. The calculation of the hookload at the deadline can help the driller to compare with actual hookload and take corrective action before the complication occurs. Further, that requires the relationship between the effective tension force at the top of the drill string and the hookload measured at the deadline. Such a relationship can be established by knowing the efficiency of the rig components such as sheave, block and tackle system, hydraulic lines and weight parameter for remaining components. Considering the unavailability of the efficiency of these components, the following model parameters are introduced: sheave efficiency, correction factor for efficiency of block and tackle system, hydraulic lines and weight parameter for the remaining components. All the three parameters are estimated by tuning the model with actual directional drilling data. In another aspect, the true tension is used to locate the position of neutral point by calculating the axial stress along the drill string. The proposed model is capable of predicting the hookload at the deadline, position of neutral point and normal forces acting along the drill string. The abnormal behavior of the normal forces along the drill string is used to locate the key-seating zones. Further, the model is validated with actual directional drilling data and successfully implemented in real-time monitoring platform and the model is found to be capable of predicting downhole complications such as drill string parting and improper hole cleaning. This study is expected to provide theoretical bases for understanding the stability regions of directional well.
10
Tanaka, Yoshito Y., and Tsutomu Shimura. "Light powered nanomotors and control of light momentum via engineering localized plasmon resonances." In Conference on Lasers and Electro-Optics/Pacific Rim. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleopr.2022.ctua16d_01.
Full textAbstract:
We demonstrate a linear nanomotor using lateral optical force due to directional side scattering by a plasmonic nanoparticle. We also propose of the nanomotors with different functions, direction-controllable nanomotor and nonlinear optical nanomotor.