659 research outputs found
GMT/local-time conversion chart
GMT/local-time conversion is made by a longitude pocket instrument that automatically indicates desired information by simply manipulating the moveable portion of the instrument in accordance with a set of simple instructions imprinted on the reverse side of the instrument
Axial flow compressor design computer programs incorporating full radial equilibrium. Part 1 - Flow path and radial distribution of energy specified /program 2/
Complete radial equilibrium flow computer progra
Au4V – Moment Stability and Spin Fluctuations in the Ordered Phase
Although neither gold nor vanadium generally possess a magnetic moment, the intermetallic compound Au4V is found to be ferromagnetic below 42K. In this paper we report the results of a muon spin relaxation study of the itinerant electron moment fluctuations in Au4V above the Curie temperature. The temperature dependence of the muon spin relaxation rate is found to be similar to that of the weak itinerant helimagnet, MnSi
Recommended from our members
Wildlife Protection, Mitigation and Enhancement Planning for Grand Coulee Dam, Final Report.
The development and operation of Grand Coulee Dam inundated approximately 70,000 acres of wildlife habitat under the jurisdictions of the Colville Confederated Tribes, the Spokane Tribe, and the State of Washington. Under the provisions of the Pacific Northwest Electric Power Planning and Conservation Act of 1980, this study reviews losses to wildlife and habitat, and proposes mitigation for those losses. Wildlife loss estimates were developed from information available in the literature. Habitat losses and potential habitat gains through mitigation were estimated by a modified Habitat Evaluation Procedure. The mitigation plan proposes (1) acquisition of sufficient land or management rights to land to protect Habitat Units equivalent to those lost (approximately 73,000 acres of land would be required), (2) improvement and management of those lands to obtain and perpetuate target Habitat Units, and (3) protection and enhancement of suitable habitat for bald eagles. Mitigation is presented as four actions to be implemented over a 10-year period. A monitoring program is proposed to monitor mitigation success in terms of Habitat Units and wildlife population trends
Sea-level responses to rapid sediment erosion and deposition in Taiwan
Numerous studies have shown that sediment deposition can perturb sea level by several meters over millennial timescales by modifying the gravity field, crustal elevation, and sediment thickness. Relatively few studies have focused on the complementary role of erosion on sea-level change despite its effects on the same quantities, partly because many rapidly eroding mountains are too far from shorelines to strongly perturb sea level at the coast. Taiwan, a mountainous island eroding rapidly within tens of km of the coast, offers an opportunity to investigate the joint influences of rapid onshore erosion and rapid offshore deposition on sea-level change. Here we develop a sediment loading history for Taiwan since the previous interglacial (∼120 ka) by compiling published erosion and deposition rate measurements and by applying a geometric marine sediment deposition and compaction model for sites without deposition rate measurements. We use the resulting sediment redistribution history to drive sea-level responses in a gravitationally self-consistent sea-level model. Our simulations show that the effects of rapid onshore erosion outweigh the effects of rapid offshore deposition along Taiwan's east coast. Along the east coast of Taiwan, sediment redistribution induces rapid sea-level fall, a response that differs in sign from the coastal sea-level rise induced by rapid sediment redistribution in many other river systems around the world. The spatial extent of the modeled sea-level fall is sensitive to the Earth model, particularly the effective elastic thickness of the lithosphere, a sensitivity that we describe in further detail in the Discussion. These results suggest that sediment redistribution could have generated sea-level changes of >10m on the east coast of Taiwan since 10 ka and >100m since 120 ka. This can account for some of the discrepancy between observed and modeled paleo-sea-level marker elevations, which reduces estimates of tectonically driven rock uplift rates inferred from the elevation differences between paleo-sea-level markers and modeled sea level. This highlights the importance of accounting for erosional unloading in interpretations of paleo-sea-level reconstructions and associated estimates of tectonically driven uplift rates
Recommended from our members
Sedimentology, Geochemistry, and Geophysics of the Cambrian Earth System
Within this dissertation, I document how—and hypothesize why—the quirks and qualities of the Cambrian Period demarcate this interval as fundamentally different from the preceding Proterozoic Eon and succeeding periods of the Phanerozoic Eon. To begin, I focus on the anomalous marine deposition of the mineral apatite. Sedimentary sequestration of phosphorus modulates the capacity for marine primary productivity and, thus, the redox state of the Earth system. Moreover, sedimentary apatite minerals may entomb and replicate skeletal and soft-tissue organisms, creating key aspects of the fossil record from which paleontologists deduce the trajectory of animal evolution. I ask what geochemical redox regime promoted the delivery of phosphorus to Cambrian seafloors and conclude that, for the case of the Thorntonia Limestone, apatite nucleation occurred under anoxic, ferruginous subsurface water masses. Moreover, I infer that phosphorus bound to iron minerals precipitated from the water column and organic-bound phosphorus were both important sources of phosphorus to the seafloor. Petrographic observations allow me to reconstruct the early diagenetic pathways that decoupled phosphorus from these delivery shuttles and promoted the precipitation of apatite within the skeletons of small animals. Together, mechanistic understandings of phosphorus delivery to, and retention within, seafloor sediment allow us to constrain hypotheses for the fleeting occurrence of widespread apatite deposition and exquisite fossil preservation within Cambrian sedimentary successions. Next, I describe and quantify the nature of carbonate production on a marine platform deposited at the hypothesized peak of Cambrian skeletal carbonate production. I find that fossils represent conspicuous, but volumetrically subordinate components of early Cambrian carbonate reef ecosystems and that despite the evolution of mineralized skeletons, Cambrian carbonate platforms appear similar to their Neoproterozoic counterparts, primarily reflecting abiotic and microbial deposition. Finally, I investigate the geodynamic mechanism responsible for rapid, oscillatory true polar wander (TPW) events proposed for the Neoproterozoic and Phanerozoic Earth on the basis of paleomagnetic data. Using geodynamic models, I demonstrate that elastic strength in the lithosphere and stable excess ellipticity of Earth’s figure provided sufficient stabilization to return the pole to its original state subsequent to convectively-driven TPW.Earth and Planetary Science
An analysis of chaos via contact transformation
Transition from chaotic to quasi-periodic phase in modified Lorenz model is
analyzed by performing the contact transformation such that the trajectory in
{\Vec R}^3 is projected on {\Vec R}^2. The relative torsion number and the
characteristics of the template are measured using the eigenvector of the
Jacobian instead of vectors on moving frame along the closed trajectory.
Application to the circulation of a fluid in a convection loop and
oscillation of the electric field in single-mode laser system are performed.
The time series of the eigenvalues of the Jacobian and the scatter plot of the
trajectory in the transformed coordinate plane in the former and
in the latter, allow to visualize characteristic pattern change at
the transition from quasi-periodic to chaotic. In the case of single mode
laser, we observe the correlation between the critical movement of the
eigenvalues of the Jacobian in the complex plane and intermittency.Comment: 20 pages, 24 eps figures, 2 gif figures, use elsart.cls, accepted for
publication in Chaos,Solitons & Fractals(2003
- …