Vertical Warp Research Articles

Formation History of HD 106906 and the Vertical Warping of Debris Disks by an External Inclined Companion

HD 106906 is a planetary system that hosts a wide-orbit companion, as well as an eccentric and flat debris disk, which hold important constraints on its formation and subsequent evolution. The recent observations of the companion constrain its orbit to be eccentric and inclined relative to the plane of the debris disk. Here, we show that, in the presence of the inclined companion, the debris disk quickly (≲5 Myr) becomes warped and puffy. This suggests that the current configuration of the system is relatively recent. We explore the possibility that a recent close encounter with a free-floating planet could produce a companion with orbital parameters that agree with observations of HD 106906 b. We find that this scenario is able to recreate the structure of the debris disk while producing a companion in agreement with observation.

Age constraints on surface deformation recorded by fossil shorelines at Cape Range, Western Australia

Abstract Laterally continuous terraces along the western flank of Cape Range, Western Australia, record both past sea-level highstands and postdepositional vertical displacement. Four distinct fossil coral reef terraces extend nearly the entire length of the slowly uplifting anticlinal structure (∼100 km), enabling documentation of the timing and degree of deformation-induced elevation contamination of past sea-level estimates from fossil shorelines. Here, we present detailed elevations of the four terraces using differential global positioning system (DGPS) and airborne light detection and ranging (LiDAR) data sets, along with new ages for the three upper terraces. Geochemical dating using strontium isotope stratigraphy techniques revealed, from highest to lowest elevation: a late Miocene reef terrace, a late Pliocene shoreline, and a prominent mid-Pleistocene reef terrace (probably associated with the marine oxygen isotope stage 33–31 interglacial), along with a broad last interglacial (Eemian) reef terrace and lagoon, which terminate at the modern shoreline. Laterally variable elevation data integrated with newly defined ages for the terraces demonstrate a gradual and continuous relative deformation in the region that spans at least the last 6.5 m.y. and constrains the emergence of the Cape Range to sometime prior to the late Miocene. This data set also shows that the most recent interglacial shoreline has undergone <1.3 m of vertical warping, suggesting minimal deformation since deposition. By tracing relative uplift rates over multiple terraces for ∼100 km of coastline, we placed constraints on maximum relative sea level (RSL) for the older terraces. Most notably, we were able to place strict maximum RSL elevations of <+34 m on the Pliocene terrace and <+16.5 m on the mid-Pleistocene terrace, with probable RSL being somewhat lower.

Integration of the vertical warp stop motion positioning in the model-based self-optimization of the weaving process

The warp tension is a critical variable of the weaving process. If the warp tension is too high or too low, the weaving process will be interrupted. In order to find a suitable setting for the weaving machine, the experience of the operator is needed. Self-optimization routines can support the operator in finding optimal settings. Within this paper, the model-based self-optimization of the weaving process developed at Institut fur Textiltechnik der RWTH Aachen University is presented. The self-optimization routine uses an automatic design of experiment to generate data for a full quadratic regression model of the characteristic values of the warp tension. Three weighted quality criteria are used to optimize the machine settings within given boundaries. An improvement is proposed by integrating the vertical warp stop motion position as a factor with high impact on the warp tension. The vertical warp stop motion position is automated and integrated into the optimization process. The adjusted routine is validated on an air jet weaving machine. The test results show that the integration of the warp stop motion position into a self-optimization routine leads to a 35% reduction of tension in the warp yarns. Compared to the existing routine, the integration of the warp stop motion position leads to a 23% higher effect on the warp tension as the target value of the optimization. The statistical validation shows that the quality of the used regression model is high. The described system also reduces the setup time of a weaving machine. Economically, the improvements mean a reduction of production costs by 22%, when producing small lot sizes. The system therefore contributes to the competitiveness of weaving mills in high-wage countries.

Realization of an Automated Vertical Warp Stop Motion Positioning

The tension in the warp yarns is a critical variable in the weaving process. If the warp tension is too high or too low the weaving process will be interrupted. A parameter that directly affects the warp tension is the vertical warp stop motion position. The position of the warp stop motion must be set for every produced new article. The setting procedure is performed completely manual. In this paper we present a mechatronic modification of an air jet-weaving machine to adjust the vertical warp stop motion position with the help of actuators. The parameters for the automated movement are determined and an open loop control, which uses a PLC, is proposed.

ON THE MISALIGNMENT OF THE DIRECTLY IMAGED PLANET β PICTORIS b WITH THE SYSTEM'S WARPED INNER DISK

The vertical warp in the debris disk Beta Pictoris -- an inclined inner disk extending into a flat outer disk -- has long been interpreted as the signpost of a planet on an inclined orbit. Direct images spanning 2004-2010 have revealed Beta Pictoris b, a planet with a mass and orbital distance consistent with this picture. However, it was recently reported that the orbit of planet b is aligned with the flat outer disk, not the inclined inner disk, and thus lacks the inclination to warp the disk. We explore three scenarios for reconciling the apparent misalignment of the directly imaged planet Beta Pictoris b with the warped inner disk of Beta Pictoris: observational uncertainty, an additional planet, and damping of planet b's inclination. We find that, at the extremes of the uncertainties, the orbit of Beta Pictoris b has the inclination necessary to produce the observed warp. We also find that if planet b were aligned with the flat outer disk, it would prevent another planet from creating a warp with the observed properties; therefore planet b itself must be responsible for the warp. Finally, planet b's inclination could have been damped by dynamical friction and still produce the observed disk morphology, but the feasibility of damping depends on disk properties and the presence of other planets. More precise observations of the orbit of planet b and the position angle of the outer disk will allow us to distinguish between the first and third scenario.

Evidence for Significant Neotectonic Thrust Faulting in and around the Monroe Uplift

ABSTRACT Vertical warping and lateral migration of river valleys has long been recognized as evidence of neotectonic activity of the Monroe Uplift in northeastern Louisiana, but the direct cause of this activity has remained elusive. Further detailed analysis of the geomorphology reveals that the uplift is localized along east-west striking zones, with differential uplifts of up to 10 ft (3 m) since the final draining of Paleolake Monroe about 5000 years ago. In addition, small-displacement thrust faults with roughly the same strike and associated plateau-type fracture systems have recently been found (in outcrop) cutting Claiborne Group (Middle Eocene) strata in north-central Louisiana and cutting Eocene to Pleistocene strata in southern Arkansas. Analysis of structural cross-sections through the Monroe Gas Field indicates that the Monroe Gas Rock is cut by thrust faults -- primarily north verging near the north edge of the field and primarily south verging near the south edge of the field. Vertical offsets on these thrusts range up to 100 ft (30 m) along the south edge of the uplift and up to 50 ft (15 m) along the north edge. The primary thrusts in the subsurface can be linked to geomorphically-defined recent uplifts of the surface. The central portion of the Monroe Uplift, therefore, appears to be the result of thrust-related uplift of the central portions of this thrust structure. The uplift is apparently related to an actively growing anticlinal uplift in southern Arkansas that has caused the Ouachita valley to migrate southward during the late Quaternary.

Galactic WARPS and the shape of heavy halos

The outer disks of many spiral galaxies are bent away from the plane of the inner disk; the abundance of these warps suggests that they are long-lived. Isolated galactic disks have long been thought to have no discrete modes of vertical oscillation under their own gravity, and so to be incapable of sustaining persistent warps. However, the visible disk contains only a fraction of the galactic mass; an invisible galactic halo makes up the rest. This paper presents an investigation of vertical warping modes in self-gravitating disks, in the imposed potential due to an axisymmetric unseen massive halo. If the halo matter is distributed so that the free precession rate of a test particle decreases with radius near the edge of the disk, then the disk has a discrete mode of vibration; oblate halos which become rapidly more flattened at large radii, and uniformly prolate halos, satisfy this requirement. Otherwise, the disk has no discrete modes and so cannot maintain a long-lived warp, unless the edge is sharply truncated. Computed mode shapes which resemble the observed warps can be found for halo masses consistent with those inferred from galactic rotation curves.

The Aristotelian Ethics (review)

380 HISTORY OF PHILOSOPHY little he really has to say about the Thaetetus was said already in his second book. At the root of Klein's eccentric interpretation of the Theaetetus is his erroneous contention that knowledge is dealt with thematically in the Sophist. In Klein's treatment of the Statesman he makes much of the faultiness that crops up constantly in the divisions aimed at revealing the statesman (see pages 147, 16o, 161, t63, 17t, 172, t74, 191, esp. t61 and t72 ). He thinks this accords with the subject matter, the statesman, since statesmen seem to be so seriously faulty in their activities and most burdensome to men on account of it. Presumably the faults of the practicing statesman would be eliminated by a truly knowledgeable statesman, that is, a statesman who had the dialectical knowledge of the philosopher. It is Klein's major point in his discussion that the true king must have such knowledge, but he hardly argues for this conclusion. Whatever argument is to be found is on pages 176-77 (for confirmation of this see p. 2oo); here he merely suggests that because the Stranger and young Socrates are becoming more dialectical about all matters, through their search for the statesman, the statesman must have dialectical knowledge about all things. This is no argument at all, unless it is shown that by becoming more dialectical the Stranger and the young Socrates become statesmen or closer to being statesmen. However, Klein never shows this. An interesting point that Klein makes in his discussion of the Statesman is that the means the Stranger uses in the investigation, the method of division and the illustration by models, can be linked directly to the outstanding model of the whole dialogue , that of weaving. The collections at the end of every division are like the taut, vertical warp, and the models, such as that of the age of Cronos, are like the looser, horizontal woof. When these are woven together there is the fabric of the dialogue (see pp. 165-66 ). As has been indicated, this book can be useful; but it has serious flaws. Jacob Klein's earlier books, especially his first, are more highly recommended. RONALD M. POLANSKY Duquesne University Anthony Kenny. The Aristotelian Ethics. Oxford: Oxford University Press, 1978. Pp xi + 250. $22.5o. In The Aristotelian Ethics Anthony Kenny uses the tools of philosopher, classicist, and statistician to solve the mystery of the true home of the books common to the Eudemian and Nicomachean Ethics. Were they lecture notes originally written by Aristotle or his redactor for the one, but then revised and joined onto the later edition for completeness' sake; or were they written expressly for the later work but then added onto the earlier; or were .they independent of both and later tagged onto each? Kenny opts for the second alternative, never seriously considering the first, and argues for the original completeness of the Eudemian and its chronological and philosophical seniority. 9 Ibid., pp. 27-3 I, 158-66. BOOK REVIEWS 381 Kenny's project is ambitious, and there is much to be learned from its painstaking analyses of problem passages and its uncovering of neglected tracts in the Eudemian. But in the end the project is only partially successful. The Euderaian is crowned the winner of his contest, but only at the cost of philosophically discrediting the Nicomachean . Given this price, the contest he elaborately constructs seems an unnecessary shuffle in scientific and historical method.' In addition, Kenny's style is tedious and somewhat pious, and many of his arguments lack imagination and vision. His cooly analytic approach is not unlike the Euderaian that, unsurprisingly, he champions as the true Ethics. Kenny begins his argument citing historical evidence that until the second century A.D. the Eudemian was regarded as The Ethics and the home of the common books. The tide turns with the commentaries of Aspasius and Alexander, who establish the prevailing tradition of the primacy of the Nicomachean. Kenny hopes to turn back the tide by means of a careful philosophical and statistical analysis of the three texts: the undisputed NE, the undisputed EE, and the disputed common books, AE. In...