15,565 research outputs found
Connecting Mathematics and the Applied Science of Energy Conservation
To effectively teach science in the elementary classroom, pre-service K-8 teachers need a basic understanding of the underlying concepts of physics, which demand a strong foundation in mathematics. Unfortunately, the depth of mathematics understanding of prospective elementary teachers has been a growing and serious concern for several decades. To overcome this challenge, a two-pronged attack was used in this study. First. students in mathematics courses were coupled with physical science courses by linking registration to ensure co-requisites were taken. This alone improved passing rates. Secondly, an energy conservation project was introduced in both classes that intimately tied the theoretical mathematics base knowledge to problems in physical science, energy efficiency, and household economics. These connections made the mathematics highly relevant to the students and improved both their theoretical understanding and their grades. Together, the two approaches of tying mathematics to physical science and applying mathematical skills to solving energy efficiency problems have shown to be extremely effective at improving student performance. This five-year study not only exhibited record improvements in student performance, but also can be easily replicated at other institutions experiencing similar challenges in training pre-service elementary school teachers
Characterization-curing-property studies of HBRF 55A resin formulations
Characterization curing property investigations on HBRF 55A resin formulations are reported. The initial studies on as received cured samples cut from a full-size FWC are reviewed. Inadequacies of as-received and aged samples are pointed out and additional electron microscopic evidence is offered. Characterization of as-received ingredients of HBRF 55A formulation is described. Specifically, Epon 826, Epon 828, EpiRez 5022, RD-2 and various amines, including Tonox and Tonox 60.40, were characterized. Cure kinetics of various formulations are investigated. Changes in physical/thermal properties (viscosity, specific heat, thermal conductivity and density) during cure are described
Palladium, platinum, and gold distribution in serpentinite seamounts in the Mariana and Izu-Bonin forearcs: evidence from Leg 125 fluids and serpentinites
Palladium, platinum, and gold were analyzed for 20 interstitial water samples from Leg 125. No Pd or Pt was detected in fluids from serpentinite muds from Conical Seamount in the Mariana forearc, indicating that low-temperature seawater-peridotite interaction does not mobilize these elements into the serpentinizing fluids to levels above 0.10 parts per billion (ppb) in solution. However, Au may be mobilized in high pH solutions. In contrast, fluids from vitric-rich clays on the flanks of the Torishima Seamount in the Izu-Bonin forearc have Pd values of between 4.0 and 11.8 nmol/L, Pt values between 2.3 and 5.0 nmol/L and Au values between 126.9 and 1116.9 pmol/L. The precious metals are mobilized, and possibly adsorbed onto clay mineral surfaces, during diagenesis and burial of the volcanic-rich clays. Desorption during squeezing of the sediments may produce the enhanced precious metal concentrations in the analyzed fluids. The metals are mobilized in the fluids probably as neutral hydroxide, bisulfide, and ammonia complexes. Pt/Pd ratios are between 0.42 and 2.33, which is much lower than many of the potential sources for Pt and Pd but is consistent with the greater solubility of Pd compared with Pt in most natural low-temperature fluids
Palladium, platinum, and gold distribution in serpentinite seamounts in the Mariana and Izu-Bonin forearcs: evidence from Leg 125 fluids and serpentinites
Palladium, platinum, and gold were analyzed for 20 interstitial water samples from Leg 125. No Pd or Pt was detected in fluids from serpentinite muds from Conical Seamount in the Mariana forearc, indicating that low-temperature seawater-peridotite interaction does not mobilize these elements into the serpentinizing fluids to levels above 0.10 parts per billion (ppb) in solution. However, Au may be mobilized in high pH solutions. In contrast, fluids from vitric-rich clays on the flanks of the Torishima Seamount in the Izu-Bonin forearc have Pd values of between 4.0 and 11.8 nmol/L, Pt values between 2.3 and 5.0 nmol/L and Au values between 126.9 and 1116.9 pmol/L. The precious metals are mobilized, and possibly adsorbed onto clay mineral surfaces, during diagenesis and burial of the volcanic-rich clays. Desorption during squeezing of the sediments may produce the enhanced precious metal concentrations in the analyzed fluids. The metals are mobilized in the fluids probably as neutral hydroxide, bisulfide, and ammonia complexes. Pt/Pd ratios are between 0.42 and 2.33, which is much lower than many of the potential sources for Pt and Pd but is consistent with the greater solubility of Pd compared with Pt in most natural low-temperature fluids
Laminar flow control leading edge glove flight test article development
A laminar flow control (LFC) flight test article was designed and fabricated to fit into the right leading edge of a JetStar aircraft. The article was designed to attach to the front spar and fill in approx. 70 inches of the leading edge that are normally occupied by the large slipper fuel tank. The outer contour of the test article was constrained to align with an external fairing aft of the front spar which provided a surface pressure distribution over the test region representative of an LFC airfoil. LFC is achieved by applying suction through a finely perforated surface, which removes a small fraction of the boundary layer. The LFC test article has a retractable high lift shield to protect the laminar surface from contamination by airborne debris during takeoff and low altitude operation. The shield is designed to intercept insects and other particles that could otherwise impact the leading edge. Because the shield will intercept freezing rain and ice, a oozing glycol ice protection system is installed on the shield leading edge. In addition to the shield, a liquid freezing point depressant can be sprayed on the back of the shield
Optimal traps in graphene
We transform the two-dimensional Dirac-Weyl equation, which governs the
charge carriers in graphene, into a non-linear first-order differential
equation for scattering phase shift, using the so-called variable phase method.
This allows us to utilize the Levinson Theorem to find zero-energy bound states
created electrostatically in realistic structures. These confined states are
formed at critical potential strengths, which leads to us posit the use of
`optimal traps' to combat the chiral tunneling found in graphene, which could
be explored experimentally with an artificial network of point charges held
above the graphene layer. We also discuss scattering on these states and find
the zero angular momentum states create a dominant peak in scattering
cross-section as energy tends towards the Dirac point energy, suggesting a
dominant contribution to resistivity.Comment: 11 pages, 5 figure
The Solubility and Heat of Solution of Succinic Acid in Water and the Paraffin Alcohols
The following is the report of an investigation undertaken for the purpose of collecting further information concerning the influence of solvent upon certain specific properties of solutions. The solvents chosen, including water, represent the lower homologues of the paraffin alcohol series
Ryegrass control - cultural and chemical systems
RYEGRASS CONTROL - SPRAYTOP - SPRAY SEED + AUTUMN CULTIVATION 75M48 LOCALITY: Merredin Research Station. RYEGRASS CONTROL - SPRAYTOP - SPRAY SEED + AUTUMN- CULTIVATION 75WH67 LOCALITY: Wongan Hills RYEGRASS CONTROL - SPRAYTOP - SPRAYSEED + AUTUMN CULTIVATION 75N22 LOCALITY: Newdegate Research Station. RYEGRASS GERMINATION - EFFECT OF CULTIVATION 76Al0 LOCALITY: Avondale Research Station. RYEGRASS CONTROL - CULTURAL SYSTEMS 75A31 LOCALITY: Avondale Research Station. ANNUAL RYEGRASS CONTROL - CULTURAL SYSTEMS 75M49 LOCALITY: Merredin Research Station. RYEGRASS CONTROL - CULTURAL SYSTEMS 75E20 LOCALITY: Esperance Downs Research Station. RYEGRASS CONTROL - CULTURAL SYSTEMS 75SG16 lOCALITY: Salmon Gums Research Station. CONTROL OF RYEGBASS - CULTURAL SYSTEMS 75N23 Locality - Newdegate Research Station. RYEGRASS CONTROL - CULTURAL SYSTEMS. 75WH68 LOCALITY: Wongan Hills Research Station SOWING SYSTEMS 76NA41 Locality: Beddington - R. Kock RYEGRASS CONTROL DEMONSTRATION LOCATION: C.R. Cunningham, Kalgarin, Experiment 76NA32. RYEGRASS CONTROL DEMONSTRATION 76LG21 Location - Gray, Kukerin. RYEGRASS HERBICIDE TRIAL LOCATION - Cooks, Beverley 76A26. RYEGRASS IN CEREALS LOCATION - Allan Eva at Pingelly, Experiment 76NA44 RYEGRASS CONTROL - CHEMICAL CONTROL EARLY POSTEMERGENCE HEAVY SOIL. Locality - D.P. Holmes, Gnowangerup. RYEGRASS CONTROL DEMONSTRATION. LOCATION: Coxall - Gibson 76ES35. RYEGRASS CONTROL DEMONSTRATION 76NO27. Location: W. Adams, Cunderdin. Ryegrass CONTROL 76KA22. Location: Lloyds, Dumbleyung. HOE 23408 Demonstration - Hoe 23408: Locality: Bells, Katanning; Locality: Jones, Dumbleyung. RYEGRASS CONTROL DEMONSTRATION 76M030. LOCATION: McDonald, Yerecoin. CANARY GRASS CONTROL DEMONSTRATION. Phalaris canaryriensis - 76LG22. LOCATION: D. Timperley - Kukerin
The Adsorption of Certain Vapors by Activated Charcoal
Isotherms for the adsorption of ethane, propane, dimethyl ether and diethyl ether by activated charcoal were obtained at temperatures from 0° to 183° and at pressures varying from less than l mm. to about 1 atm. With the hydrocarbons equilibrium was attainable only after long periods of time. The isotherms for the hydrocarbons are in general almost rectilinear; those for the ethers have the usual form. At low temperatures the isotherms for the hydrocarbons show a peculiar type of break in the curve. The amount of vapor adsorbed decreases with an increase in the complexity of the adsorbed molecules. Semi-log isotherms, double-log isotherms, isobars and isosteres were calculated from the natural isotherms. The heat of adsorption was calculated from the slope of the isosteres
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