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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.

The development and baseline operation of an acoustic view cell for observing fluids, and fluid-fluid and fluid-solid interfaces in porous media over the frequency range of 10-5000 Hz is described. This range includes the industrially relevant frequency range 500-5000 Hz that is not covered by existing devices. Pressure waveforms of arbitrary shape are generated in a 17.46 mm ID by 200 mm and 690.5 mm long glass tubes at flow rates up to 200 ml/min using a syringe pump. Peak-to-peak amplitudes exceeding 80 kPa are readily realized at frequencies from 10 to 5000 Hz in bubble free fluids when actuated with 20 Vpp as exemplified using castor oil. At resonant frequencies, peak-to-peak pressure amplitudes exceeding 500 kPa were obtained (castor oil at 2100 Hz when actuated with 20 Vpp). Impacts of vibration on macroscopic liquid-liquid and liquid-vapour interfaces and interface movement are illustrated. Pressure wave transmission and attenuation in a fluid saturated porous medium, randomly packed 250-330 μm spherical silica beads, is also demonstrated. Attenuation differences and frequency shifts in resonant peaks are used to detect the presence and generation of dispersed micro-bubbles (<180 μm diameter), and bubbles within porous media that are not readily visualized. Envisioned applications include assessment of the impacts of vibration on reaction, mass transfer, and flow/flow pattern outcomes. This knowledge will inform laboratory and pilot scale process studies, where nuisance vibrations may affect the interpretation of process outcomes, and large scale or in situ processes in aquifers or hydrocarbon reservoirs where imposed vibration may be deployed to improve aspects of process performance. Future work will include miscible interface observation and quantitative measurements in the bulk and in porous media where the roles of micro-bubbles comprise subjects of special interest. [ABSTRACT FROM AUTHOR]

Two parallel multi-element ultrasonic acoustic arrays combined with sets of focal laws for acoustic signal generation and a classical tomographic inversion algorithm are used to generate real-time two-dimensional micro seismic acoustic images of multiphase materials. Proof of concept and calibration measurements were performed for single phase and two phase liquids, uniform polyvinyl chloride (PVC) plates, and aluminum cylinders imbedded in PVC plates. Measurement artefacts, arising from the limited range of viewing angles, and the compromise between data acquisition rate and image quality are discussed. The angle range of scanning and the image resolution were varied, and the effects on the quality of the reproduction of the speed of sound profiles of model solids and liquids with known geometries and compositions were analysed in detail. The best image quality results were obtained for a scanning angle range of [-35°, 35°] at a step size of 2.5° post processed to generate images on a 40 µm square grid. The data acquisition time for high quality images with a 30 mm x 40 mm view field is 10 min. Representation of two-phase solids with large differences in speed of sound between phases and where one phase is dispersed in the form of macroscopic objects (greater than 1 mm in diameter) proved to be the most difficult to image accurately. Liquid-liquid and liquid-vapor phase boundaries, in micro porous solids by contrast, were more readily defined. Displacement of air by water and water by heptane in natural porous limestone provides illustrative kinetic examples. Measurement results with these realistic cases demonstrate the feasibility of the technique to monitor in real time and on the micrometer length scale local composition and flow of organic liquids in inorganic porous media, one of many envisioned engineering applications. Improvement of data acquisition rate is an area for future collaborative study. [ABSTRACT FROM AUTHOR]

Speed of sound and acoustic wave attenuation are sensitive to fluid phase composition and to the presence of liquid-liquid interfaces. In this work, the use of an acoustic array comprising 64 elements as a non-intrusive sensor for liquid-liquid interface, phase separation kinetics measurement in bulk fluids, and local composition measurement in porous media is illustrated. Three benchmark examples: the phase behaviour of methanol + mixed hexanes and methanol + heptane mixtures at 25.0 °C and 1 bar, and Athabasca bitumen + heptane in a synthetic silica porous medium at 22.5 °C and 1 bar, illustrate the accuracy of liquid-liquid interface and potential research and industrial applications of the technique. Liquid-liquid interfaces can be detected independently using both speed of sound and acoustic wave attenuation measurements. The precision of the interface location measurement is 300 μm. As complete scans can be performed at a rate of 1 Hz, phase separation kinetics and diffusion of liquids within porous media are readily tracked. The technique is expected to find application where the fluids or porous media are opaque to visible light and where other imaging techniques are not readily applied, or are too costly. A current limitation is that the acoustic probes must be cooled to less than 315 K in order for them to operate. [ABSTRACT FROM AUTHOR]

This paper explores the role of ethics in the work a forensic engineer performs in relation to a project that might progress to a court hearing in which the engineer will give evidence. [ABSTRACT FROM AUTHOR]

Liquid-phase mutual diffusion coefficients are a key parameter in reservoir simulation models related to both primary production and envisioned secondary recovery processes for heavy oil and bitumen. The measurement of liquid-phase mutual diffusion coefficients in bitumen and heavy oil + light hydrocarbon or gas mixtures present numerous experimental and data analysis challenges due to the viscosity and opacity of the mixtures, the variability of density, viscosity and mutual diffusion coefficient with composition, and the multi-phase nature of these mixtures. Data analysis challenges are particularly acute. For example, recently reported mutual diffusion coefficient values for liquid mixtures of bitumen + carbon dioxide vary over three orders of magnitude when different analysis methods are applied to the same experimental data. In this contribution, we illustrate the importance of measuring composition profiles within liquids as a function of time, as a basis for mutual diffusion coefficient computation, and for allowing explicitly for the variation of diffusion coefficient and liquid density with composition in the analysis of composition profile data. Such inclusions eliminate apparent temporal variations of mutual diffusion coefficients and yield values consistent with relevant theories and exogenous data sets. Liquid-phase mutual diffusion coefficients computed for the mixtures Athabasca Bitumen + pentane and Cold Lake Bitumen + heptane exemplify the experimental and data analysis approaches. [ABSTRACT FROM AUTHOR]

Cryostorage of nonhuman primate embryos by time-consuming slow-cooling methods is often limited to early cleavage stages. Effective rapid-cooling methods have been developed for many species and represent valuable tools for laboratory- and field-based studies of nonhuman primate reproductive biology. However, few rapid-cooling protocols have been applied to nonhuman primate embryos in terms of comparing various developmental stages. Here we compare slow cooling vs. two- and three-step rapid cooling of two-, four-, and eight-cell Macaca fascicularis (Mf ) embryos. Rapid cooling was conducted in open pulled straws (OPS) using cooling solutions containing reduced quantities of ethylene glycol (EG) and supplemented with either of two high-molecular-weight polymers, ficoll and dextran. The survival of the slow-cooled embryos, but not the rapid-cooled embryos, was independent of embryonic stage at cryostorage. Slow cooling was associated with greater cell survival (82%) post thaw compared to warming following rapid cooling (18–29%). Slow cooling resulted in a high proportion of embryo survival (18/20; 90%) and cleavage (15/18; 83%) post thaw. Rapid cooling resulted in significantly reduced percentages of embryo survival (26–32%) and embryo cleavage in culture (29–38%) after warming. Conventional slow cooling was more effective than the rapid-cooling protocols employed in this study for cryopreservation of early-cleavage-stage Mf embryos. Am. J. Primatol. 58:169–174, 2002. © 2002 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Presents information on organic electronics. Purpose of research conducted on inorganic electronics; Benefit offered by innovative organic materials on the electronic industry; Classes of passive organic materials that made the possibility of cost/performance ratio of logic chips.

Double packaging, in which an inner straw containing the specimen is inserted into an outer, larger straw (here termed 'straw-in-straw') to prevent the inner straw from coming into direct contact with liquid nitrogen provides a simple strategy for reducing or eliminating the potential contamination risk associated with storage in liquid nitrogen. This approach has in the past been used in conjunction with cryopreservation by slow cooling, but has not previously been tested for use throughout an entire rapid cooling and warming procedure. This study determined whether keeping the straw containing the embryos inside a second protecting container throughout the cryopreservation and storage protocol would compromise embryo viability. We established that a cryoprotectant containing a high polymer concentration (35% dextran or Ficoll) together with 25% ethylene glycol (as the penetrating cryoprotectant) was highly effective for day 2 and day 3 mouse embryos in both single and double straws. The survival and development of all cryopreserved embryos, as assessed both in vitro and in vivo, was not statistically different to their untreated controls. This established that a protein/serum-free cryoprotectant solution supplemented with polymers could provide complete protection of mouse embryos. It also shows, for the first time, that embryos can be cooled by direct immersion in liquid nitrogen and warmed by direct immersion into a waterbath within a double straw arrangement to reduce the likelihood of contamination. [ABSTRACT FROM AUTHOR]

Background: Bone mass and fall propensity are two major risk factors for hip fracture. Our intent was to determine if weight-bearing exercises with added resistance from weighted vests would improve dynamic balance, muscle strength and power, and bone mass in postmenopausal women, thereby reducing risk for falls and hip fracture.Methods: Forty-four nonsmoking, community-dwelling, Caucasian women aged 50-75 years participated in the study. All participants were at least 5 years past menopause and most were estrogen-deplete (n = 36). Bone mass and body composition were assessed by dual-energy x-ray absorptiometry, muscular strength by isokinetic dynamometry, muscular power by modified Wingate Anaerobic Power Test, and indices of postural stability by dynamic posturography. Half of the subjects participated in a 9-month regimen of weight-bearing exercises performed three times a week that emphasized lower-body muscle strength and power development. Resistance was added progressively and individually by the use of a weighted vest. Controls maintained customary diet and activity patterns.Results: Significant improvements were observed for indices of lateral stability, lower-body muscular strength (16-33% increase), muscular power (13% increase), and leg lean mass (3.5% increase) in exercisers vs controls (p < .05). No significant changes (p > .05) were detected for femoral neck bone mass in exercisers or controls at the conclusion of the trial.Conclusions: Lower body exercise, using a weighted vest for resistance, provides an effective means of improving key indices of falls in postmenopausal women. [ABSTRACT FROM AUTHOR]