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At issue in the present series of experiments was the ability to prospectively perceive the action-relevant properties of hand-held tools by means of dynamic touch. In Experiment 1, participants judged object move-ability. In Experiment 2, participants judged how difficult an object would be to hold if held horizontally, and in Experiments 3 and 4, participants rated how fast objects could be rotated. In each experiment, the first and second moments of mass distribution of the objects were systematically varied. Manipulations of wielding speed and orientation during restricted exploration revealed perception to be constrained by (a) the moments of mass distribution of the hand-tool system, (b) the qualities of exploratory wielding movements, and (c) the intention to perceive each specific property. The results are considered in the context of the ecological theory of dynamic touch. Implications for accounts of the informational basis of dynamic touch and for the development of a theory of haptically perceiving the affordance properties of tools are discussed. (Contains 5 footnotes, 1 table, and 8 figures.)

Different models have been used to evaluate the interfacial Dzyaloshinskii–Moriya interaction (DMI) from the asymmetric bubble expansion method using magneto-optics. Here, we investigate the most promising candidates over a range of different magnetic multilayers with perpendicular anisotropy. Models based on the standard creep hypothesis are not able to reproduce the domain wall (DW) velocity profile when the DW roughness is high. Our results demonstrate that the DW roughness and the interface roughness of the sample layers are correlated. Furthermore, we give guidance on how to obtain reliable results for the DMI value with this popular method. A comparison of the results with Brillouin light scattering (BLS) measurements on the same samples shows that the BLS approach often results in higher measured values of DMI. [ABSTRACT FROM AUTHOR]

The tacit knowledge associated with the application and integration of codified knowledge, personal experience, and the fundamental technical engineering knowledge is typically not developed in engineering students as a result of their coursework. Consequently, engineering students are not fully equipped for the demands of design even if their project requires largely codified knowledge. They require significant guidance and mentorship to describe design bases in their own words, to develop criteria for plausible solutions and then to research, identify, and synthesize plausible solutions. For experienced practitioners, this tacit knowledge is inherent to process, systems, and product design and is fully internalized. Filling or partially filling this knowledge gap comprises the invisible curriculum in undergraduate engineering design education. In this contribution, we describe how tacit engineering and engineering design knowledge is developed iii our process design courses. how we structure implicit learning experiences, attempt to improve learning outcomes, and better prepare our developing engineers for early practice. Practical design projects, instructors with diverse knowledge and experience. a flipped course design (permitting intensive face-to-face interaction, mentorship, and creating opportunities to tell engineering stories during classroom sessions), individual and team assessment, and modeled interactions are used to create meaningful engineering experiences that help students develop their knowledge and understanding of the tacit curriculum. We provide reflections on our experiences. We expect our contribution to be of value across all engineering disciplines, and for professional practice development more broadly. [ABSTRACT FROM AUTHOR]

The Atacama Desert, on the western margin of the Central Andes, hosts some of the world's largest porphyry copper deposits (PCDs). Despite a hyperarid climate, many of these PCDs have undergone secondary "supergene" enrichment, whereby copper has been concentrated via groundwater-driven leaching and reprecipitation, yielding supergene profiles containing valuable records of weathering and landscape evolution. We combine hematite (U-Th-Sm)/He geochronology and oxygen isotope analysis to compare the weathering histories of two Andean PCDs and test the relative importance of climate and tectonics in controlling both enrichment and water table movement. At Cerro Colorado, in the Precordillera, hematite precipitation records prolonged weathering from ~31 to ~2 Ma, tracking water table descent following aridity-induced canyon incision from the late Miocene onward. By contrast, hematite at Spence, within the Central Depression, is mostly younger than ~10.5 Ma, suggesting exhumation ended much later. A heavy oxygen isotopic signature for Spence hematite suggests that upwelling formation water has been an important source of groundwater, accounting for a high modern water table despite persistent hyperaridity, whereas isotopically light hematite at Cerro Colorado formed in the presence of meteoric water. Compared with published paleo-environmental and sedimentological records, our data show that weathering can persist beneath appreciable post-exhumation cover, under hyperarid conditions unconducive to enrichment. The susceptibility of each deposit to aridity-induced water table descent, canyon incision and deep weathering has been controlled by recharge characteristics and morphotectonic setting. Erosional exhumation, rather than aridity-induced water table decay, appears to be more important for the development of supergene enrichment. [ABSTRACT FROM AUTHOR]

We determined the spin-transport properties of Pd and Pt thin films by measuring the increase in ferromagnetic resonance damping due to spin-pumping in ferromagnetic (FM)-nonferromagnetic metal (NM) multilayers with varying NM thicknesses. The increase in damping with NM thickness depends strongly on both the spin- and charge-transport properties of the NM, as modeled by diffusion equations that include both momentum- and spin-scattering parameters. We use the analytical solution to the spin-diffusion equations to obtain spin-diffusion lengths for Pt and Pd. By measuring the dependence of conductivity on NM thickness, we correlate the charge- and spin-transport parameters, and validate the applicability of various models for momentum-scattering and spin-scattering rates in these systems: constant, inverse-proportional (Dyakanov-Perel), and linear-proportional (Elliot-Yafet). We confirm previous reports that the spin-scattering time appears to be shorter than the momentum scattering time in Pt, and the Dyakanov-Perel-like model is the best fit to the data. [ABSTRACT FROM AUTHOR]

Motivated by the importance of magnetization dynamics in nanomagnets for the development and optimization of magnetic devices and sensors, we measured and modeled spin wave spectra in patterned elliptical nanomagnets. Ferromagnetic resonance spectra for multiple nanomagnets of Ni80Fe20, fabricated by electron-beam lithography to have nominal short-axes of 200 nm or 100 nm, were measured by use of heterodyne magneto-optical microwave microscopy. Scanning electron microscope images taken of the same nanomagnets were used to define element shapes for micromagnetic simulations. The measured spectra show significant differences between nominally identical nanomagnets, which could be only partially attributed to uncontrolled shape variations in the patterning process, as evidenced by the limited agreement between the measured and simulated spectra. Agreement between measurements and simulations was improved by including a zone of reduced magnetization and exchange at the edges of the nanomagnets in the simulations. Our results show that the reduction of shape variations between individual magnetic random-access memory elements can potentially improve their performance. However, unambiguous determination of materials parameters in nanomagnets based on analysis and modeling of spin wave spectra remains problematic. [ABSTRACT FROM AUTHOR]

The spin dynamics of sub-100-nm Ni80Fe20 nanomagnets are directly measured using the magneto-optic Kerr effect and a broadband detection scheme. Elliptical dots approximately 68 nm in diameter and 10 nm thick were fabricated in 20×20 μm2 arrays. There is approximately a factor of 2 increase in the effective linewidth when compared to a 20 μm diameter continuous disk of the same material. Using micromagnetic simulations, we model the effect of dot-to-dot size variation on the effective linewidth and find that 2 nm size variations are more than sufficient to account for the effective increase in linewidth. [ABSTRACT FROM AUTHOR]

The structural and magnetic properties of epitaxial Co deposited on Au buffer layers are studied and compared with those of similar samples with one monolayer of Cr introduced at the Au/Co interface. The findings suggest that the in-plane nature of the interface anisotropy term for those samples with Cr was significant in determining their greater sensitivity to increased Co thickness.