5,009 research outputs found
A study of the impact of instructional approach on community college studentsâ problem solving and metacognitive abilities in the developmental mathematics course, Introductory Algebra
The purpose of this quasi-experimental study was to examine the cognitive, metacognitive, affective and instructional constructs that influence studentsâ problem solving development in a community college Introductory Algebra course. The study addressed the lack of success that developmental mathematics students in a community college have in the Introductory Algebra course and in subsequent curriculum mathematics courses. Research suggests that the prevalent procedural-oriented instructional methodology used in most mathematics classrooms may be contributing to the lack of student success. The community college students (N = 140) in this study were enrolled in an Introductory Algebra course. The study investigated the relationships among the constructs self-regulation, studentsâ problem solving development, and instructional methods used in the Introductory Algebra course. A correlational design established the quantitative relationships among the constructs. The aim of this study was to heighten the awareness of both the cognitive and non-cognitive aspects of adult student learning, as well as, the importance of attending to the studentsâ conceptual understanding of mathematics
A Novel Cable-Driven Robotic Training Improves Locomotor Function in Individuals Post-Stroke
A novel cable-driven robotic gait training system has been tested to improve the locomotor function in individuals post stroke. Seven subjects with chronic stroke were recruited to participate in this 6 weeks robot-assisted treadmill training paradigm. A controlled assistance force was applied to the paretic leg at the ankle through a cable-driven robotic system. The force was applied from late stance to mid-swing during treadmill training. Body weight support was provided as necessary to prevent knee buckling or toe drag. Subjects were trained 3 times a week for 6 weeks. Overground gait speed, 6 minute walking distance, and balance were evaluated at pre, post 6 weeks robotic training, and at 8 weeks follow up. Significant improvements in gait speed and 6 minute walking distance were obtained following robotic treadmill training through a cable-driven robotic system. Results from this study indicate that it is feasible to improve the locomotor function in individuals post stroke through a flexible cable-driven robot
Effect of solid cattle manure injection on oat crop production in east-central Saskatchewan
Non-Peer Reviewe
Phonon Band Structure and Thermal Transport Correlation in a Layered Diatomic Crystal
To elucidate the relationship between a crystal's structure, its thermal
conductivity, and its phonon dispersion characteristics, an analysis is
conducted on layered diatomic Lennard-Jones crystals with various mass ratios.
Lattice dynamics theory and molecular dynamics simulations are used to predict
the phonon dispersion curves and the thermal conductivity. The layered
structure generates directionally dependent thermal conductivities lower than
those predicted by density trends alone. The dispersion characteristics are
quantified using a set of novel band diagram metrics, which are used to assess
the contributions of acoustic phonons and optical phonons to the thermal
conductivity. The thermal conductivity increases as the extent of the acoustic
modes increases, and decreases as the extent of the stop bands increases. The
sensitivity of the thermal conductivity to the band diagram metrics is highest
at low temperatures, where there is less anharmonic scattering, indicating that
dispersion plays a more prominent role in thermal transport in that regime. We
propose that the dispersion metrics (i) provide an indirect measure of the
relative contributions of dispersion and anharmonic scattering to the thermal
transport, and (ii) uncouple the standard thermal conductivity
structure-property relation to that of structure-dispersion and
dispersion-property relations, providing opportunities for better understanding
of the underlying physical mechanisms and a potential tool for material design.Comment: 30 pages, 10 figure
Picoheterotroph (Bacteria and Archaea) biomass distribution in the global ocean
We compiled a database of 39 766 data points consisting of flow cytometric and microscopical measurements of picoheterotroph abundance, including both Bacteria and Archaea. After gridding with 1° spacing, the database covers 1.3% of the ocean surface. There are data covering all ocean basins and depths except the Southern Hemisphere below 350m or from April until June. The average picoheterotroph biomass is 3.9 ± 3.6 ”g Cl-1 with a 20-fold decrease between the surface and the deep sea. We estimate a total ocean inventory of about 1.3 à 1029 picoheterotroph cells. Surprisingly, the abundance in the coastal regions is the same as at the same depths in the open ocean. Using an average of published open ocean measurements for the conversion from abundance to carbon biomass of 9.1 fg cell-1, we calculate a picoheterotroph carbon inventory of about 1.2 Pg C. The main source of uncertainty in this inventory is the conversion factor from abundance to biomass. Picoheterotroph biomass is ? 2 times higher in the tropics than in the polar oceans
Effect of uniformity of land application of solid cattle manure on crop yield and soil nitrate
Non-Peer ReviewedEquipment used in Western Canada to apply solid cattle manure (SCM) are known to exhibit
uneven uniformity of distribution of material. For organic bio-solid manures to be a viable
supplement or alternative to chemical fertilizers, it is essential that the uniformity of distribution
of the product be measured by the effect that occurs on soil components and crop yields. A
precise field scale solid manure applicator has been developed at the University of Saskatchewan
and Prairie Agricultural Machinery Institute that is capable of precise surface and subsurface
application of solid organic manure. The Low and Mid C.V. treatments at the low SCM
application rate achieved similar grain yield results and were significantly higher than the High
C.V. high SCM rate treatments. Addition of urea fertilizer to the treatments boosted grain yield
production in most of the C.V. and rate treatments, however most of these increases were found
to be not significantly different from urea only fertilized treatment plots. The addition of urea
fertilizer in most of the treatments increased soil NO3-N compared to the non-urea fertilized
treatments. There was however, no significant difference in soil NO3-N among the three C.V.
treatments without the addition of urea fertilizer. The lack of large manure impacts is likely
related to low release of available nutrient in the year in application
Effect of variability in cattle manure application on soil nutrients and crop yield
Non-Peer Reviewe
Relative Permeability of Homogenous-Wet and Mixed-Wet Porous Media as Determined by Pore-Scale Lattice Boltzmann Modeling
We present a pore-scale study of two-phase relative permeability in homogenous-wet porous media, and porous media altered to a mixed-wet state. A Shan-Chen type multicomponent lattice Boltzmann (LB) model is employed to determine pore-scale fluid distributions and relative permeability. Mixed-wet states are created by altering the wettability of solid surfaces in contact with the nonwetting phase at the end of steady state simulation of initially homogenous-wet porous media. To ensure accurate representation of fluid-solid interfacial areas, we compare LB simulation results to experimental measurements of interfacial fluid-fluid and fluid-solid areas determined by X-ray computed microtomography imaging of water and oil distributions in bead packs. The LB simulations are found to match experimental trends observed for fluid-fluid and fluid-solid interfacial area-saturation relationships. The relative permeability of both fluids in the homogenous-wet porous media was found to decrease with a decreasing contact angle. The relative permeability of both fluids in the altered, mixed-wet porous media was found to decrease for all mixed-wet states in comparison to the initial homogenous-wet states. The nonwetting phase relative permeability decreased significantly, while the wetting phase experienced only a minor decrease. The significance of the decrease was found to be dependent on the distribution of the unaltered solid surfaces, with less dependence on the severity of alteration. Key Points Lattice Boltzmann simulation interfacial areas match experimental trends Wetting phase relative permeability is unaffected by wettability alteration Nonwetting phase relative permeability is decreased by wettability alteration © 2014. American Geophysical Union
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