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(63
items found)
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Title:
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Polymer Structures |
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Author:
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Leonid V. Zhigilei |
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Description:
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This is a lecture note of a series of lectures offered in the course: Introduction to Materials Science, and it discusses topics including Hydrocarbon and Polymer Molecules, Chemistry of Polymer Molecules, Molecular Weight and Shape, Molecular Structure and Configurations, Copolymers, Polymer Crystals. |
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Context
of Use:
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University
(Lower Div). |
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Title:
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Corrosion of Iron |
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Author:
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Judy Brewer |
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Description:
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This is a video clip showing how irons corrode in experiments. |
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Context
of Use:
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High School. |
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Title:
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ACCELERATORS: THE
NEXT GENERATION |
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Author:
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Lynn Yarris. |
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Description:
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ILSE is a
50-meter long linear accelerator designed to
answer some of the crucial questions that will
help decide whether fusion becomes the energy
source of the next century or remains an elusive
dream. Fusion, the melding together of lighter
atomic nuclei to form heavier nuclei, is the
source of energy that lights up the sun and
every other star in the universe. If it could be
safely harnessed to generate electrical power
here on earth, fusion would last forever and
would not contribute to the greenhouse effect,
acid rain, or the depletion of the ozone layer |
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Context
of Use:
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Secondary Education,
University
First Cycle,
Higher Education. |
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Title:
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green light |
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Author:
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Lynn Yarris. |
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Description:
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Under the current
proposal, the injector will accelerate four
individual beams of ions to 2 million electron
volts (MeV) and send them into the electrostatic
focus accelerator, which will boost the ions in
the beams to 4.5 MeV. A transfer line will then
ferry one of the four beams into the magnetic
accelerator, where its ions will be lifted to 10 MeV |
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Context
of Use:
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Higher Education,
University
Second Cycle,
University
First Cycle. |
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Title:
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High Temperature Fatigue Crack Growth Behavior of Alloy 10 |
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Author:
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John Gayda |
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Description:
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Methods to improve the high temperature, dwell crack growth resistance of Alloy 10, a high strength, nickelbase disk alloy, were studied. Two approaches, heat treat variations and composition modifications, were investigated. Under the heat treat approach, solution temperature, cooling rates, and stabilization, were studied. It was found that higher solution temperatures, which promote coarser grain sizes, coupled with a 1550 ;F stabilization treatment were found to significantly reduce dwell crack growth rates at 1300 ;F. Changes in the niobium and tantalum content were found to have a much smaller impact on crack growth behavior. Lowering the niobium:tantalum ratio did improve crack growth resistance and this effect was most pronounced for coarse grain microstructures. Based on these findings, a coarse grain microstructure for Alloy 10 appears to be the best option for improving dwell crack growth resistance, especially in the rim of a disk where temperatures can reach or exceed 1300 ;F. Further, the use of advanced processing technologies, which can produce a coarse grain rim and fine grain bore, would be the preferred option for Alloy 10 to obtain the optimal balance between tensile, creep, and crack growth requirements for small gas turbine engines. |
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Context
of Use:
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Vocational Training,
Continuous Formation,
Professional Formation. |
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Ratings/Reviews:
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Title:
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metal implants to
bond with bone |
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Author:
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lynn yarris. |
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Description:
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biologically
active glass that enables metal implants to bond
with bone could significantly extend the
lifetime of artificial hips, knees, and other
medical reconstructive devices |
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Context
of Use:
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Primary Education,
Technical
School First Cycle,
University Postgrade,
University
Second Cycle,
University
First Cycle. |
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Title:
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novel metalic glass |
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Author:
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paul preuss. |
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Description:
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Many materials
can heat up somewhat when they are bent or
broken, but few throw off showers of sparks as
hot as those emitted when a new kind of metallic
glass is shattered |
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Context
of Use:
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University
First Cycle,
University Postgrade,
University
Second Cycle. |
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Title:
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A Hysteresis Model for Piezoceramic Materials |
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Author:
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Ralph C. Smith,Zoubeida Ounaies |
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Description:
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This paper addresses the modeling of nonlinear constitutive relations and hysteresis inherent to piezoceramic materials at moderate to high drive levels. Such models are necessary to realize the full potential of the materials in high performance control applications, and a necessary prerequisite is the development of techniques which permit control implementation. The approach employed here is based on the quantification of reversible and irreversible domain wall motion in response to applied electric fields. A comparison with experimental data illustrates that because the resulting ODE model is physic-based, it can be employed for both characterization and prediction of polarization levels throughout the range of actuator operation. Finally, the ODE formulation is amenable to inversion which facilitates the development of an inverse compensator for linear control design. |
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Context
of Use:
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Vocational Training,
Continuous Formation,
Professional Formation. |
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Title:
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Silicon Ingot Lifetime Tester for Large Crystals |
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Author:
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T.F. Ciszek,T.H. Wang,M. Landry |
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Description:
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A lifetime-measurement instrument has been developed to characterize large silicon ingots prior to wafering and polishing. It uses the direct-current photoconductance decay method and localized probing and illumination to achieve the necessary sensitivity on low-resistivity, large samples. A 940-nm, 60-Wp, pulsed-laser diode beam (250-ms width, <100-ns cut-off) lights the as-cropped silicon surface between two ohmic-contact probes. A user-friendly graphical interface supports data acquisition, lifetime calculation, and data storage. Pneumatic systems position the ingot and probes.Three-dimensional, finite-element analysis indicates that the detection depth of this technique is much better than the microwave or radio-frequency techniques. It also shows that the as-cropped surface finish is adequate for measuring bulk lifetimes on the order of 50 ms or less-a typical range for Czochralski ingots used in photovoltaic module production. Measurement repeatability and clear distinction among different grades of feedstock materials have been demonstrated. |
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Context
of Use:
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Vocational Training,
Continuous Formation,
Professional Formation. |
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Title:
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Overview of Sol-Gel Science and Technology |
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Author:
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Sandra K. Young |
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Description:
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Sol-gel science and technology continues to interest researchers decades after its discovery. The reaction is easy to perform, does not require special conditions (can be done on the bench top in a beaker), and does not require high temperatures. The sol-gel reaction consists of a series of simple hydrolysis and condensation reactions. This reaction can be influenced by several factors: quantity of acid catalyst, amount of water used, incorporation of a network modifier, and varying solvent effects. This work presents an overview of sol-gel science and technology, discusses the advantages of sol-gel reactions, and describes the factors that can influence changes in the final sol-gel material. |
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Context
of Use:
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Vocational Training,
Continuous Formation,
Professional Formation. |
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Ratings/Reviews:
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