In printing, size press, and metered size press coating operations, the paper web passes between two rolls and exits the nip causing a film to split between the web and the roll. The physics of the film split location...
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ISBN:
(纸本)9781617387890
In printing, size press, and metered size press coating operations, the paper web passes between two rolls and exits the nip causing a film to split between the web and the roll. The physics of the film split location is not well understood. If coating both sides of the web, the web release point can oscillate from top and bottom rolls generating non-uniform product. A pilot scale metered size press coating unit was run at various speeds, coat weights, and coatings. The location of the web release from the roll was recorded with a camera. A model, based on the thin film equations and a web tension equation, was developed to predict the pressure distribution in the liquid film between the web and the roll as well as the web trajectory. The influence of web speed, coating viscosity, and the web tension are included in the model. All of these parameters are found to influence the web release location. The model predictions agree with trends seen in the pilot scale trial and with other pilot scale results given in the literature.
The ABET criteria for engineeringprograms include that students should have "an ability to apply mathematics, science and engineering", "an ability to design a system, component, or process to meet des...
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The ABET criteria for engineeringprograms include that students should have "an ability to apply mathematics, science and engineering", "an ability to design a system, component, or process to meet desired needs", "an ability to identify, formulate and solve engineering problems", and "an ability to communicate effectively", and "a knowledge of contemporary issues"1. One manner of integrating teamwork and engineering contexts in undergraduate engineering is through the educational construct of Model-Eliciting Activities (MEAs). MEAs are a class of interdisciplinary problems designed to simulate authentic, client-driven situations in classroom settings. MEAs allow teachers and researchers to observe student development of conceptual models by requiring students to make their models explicit through design-test-revise cycles. The solution of an MEA requires the use of one or more mathematical or engineering concepts that are unspecified by the problem - students must make new sense of their existing knowledge and understandings to formulate a generalizable mathematical model that can be used by the client to solve the given and similar problems. An MEA creates an environment in which skills beyond mathematical abilities are valued because the focus is not on the use of prescribed equations and algorithms but on the use of a broader spectrum of skills required for effective engineering problem solving. Carefully constructed MEAs can begin to prepare students to communicate and work effectively in teams;to adopt and adapt conceptual tools;to construct, describe, and explain complex systems;and to cope with complex systems. MEAs provide a learning environment that is tailored to a more diverse population than typical engineering course experiences as they allow students with different backgrounds and values to emerge as talented, and that adapting these types of activities to engineering courses has the potential to go beyond "filling the gaps" to "opening doors" to wom
We present the results of characterization and analysis of the optical dielectric function of monolithic BaxSr1-xTiO3 films prepared by metal-organic solution deposition (MOSD). Lorentz Oscillator + Drude parameters a...
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In the present work, the crystallinity and dimension of crystal lattice of two series of ethylene-propylene copolymers with different propylene contents, which were prepared by a fluorinated bis(phenoxyimine) Ti catal...
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In the present work, the crystallinity and dimension of crystal lattice of two series of ethylene-propylene copolymers with different propylene contents, which were prepared by a fluorinated bis(phenoxyimine) Ti catalyst (FI-EP copolymers) and a conventional Ziegler-Natta catalyst (ZN-EP copolymers), respectively, were studied. It is found that the overall propylene content and crystallization condition have more marked effects on the crystallinity of the FI-EP copolymers with a random comonomer distribution than that of the ZN-EP copolymers with a heterogeneous comonomer distribution. The dimension of a-axis of the PE crystals increases more rapidly with the overall propylene content in the FI-EP copolymers, indicating that more propylene units are included into the PE crystals, whereas the a-axis of the PE crystals remains unchanged for all the ZN- EP copolymers. Quenching of the samples leads to more propylene units getting included into the PE crystals. The effects of comonomer content and crystallization condition on crystallinity and dimension of crystal lattice of FI-EP and ZN-EP copolymers can be explained in terms of their different comonomer distributions.
Photodynamic therapy(PDT)is a promising medical technology for treatment of cancers,which is based on the photochemical reaction mediated through the interaction of photosensitisers(PS),light andtissue *** generate hi...
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Photodynamic therapy(PDT)is a promising medical technology for treatment of cancers,which is based on the photochemical reaction mediated through the interaction of photosensitisers(PS),light andtissue *** generate highly reactive oxygen species when exposed to light and become highly cytotoxic,which induces irreversible tumor cell destruction.1 Important advantages of PDT over other
The dynamics of polymer chains near the surface of a melt and within thin films remains a subject of inquiry along with the nature of the glass transition in these systems. Recent studies show that the properties of t...
The dynamics of polymer chains near the surface of a melt and within thin films remains a subject of inquiry along with the nature of the glass transition in these systems. Recent studies show that the properties of the free surface region are crucial in determining the anomalous glass transition temperature (Tg) reduction of polymer thin films. In this study, by embedding 'dilute' gold nanoparticles in polystyrene (PS) thin films as 'markers', we could successfully probe the diffusive Brownian motion which tracks the local viscosity both at the free surface and within the rest of the single PS thin film far above bulk Tg. The technique used was X-ray photon correlation spectroscopy with resonance-enhanced X-rays that allows us to independently measure the motion in the regions of interest at the nanometer scale. We found the presence of the surface reduced viscosity layer in entangled PS thin films at T>>Tg.
Background: Physicians tailor insulin dosing based on blood glucose goals, response to insulin, compliance, lifestyle, eating habits, daily schedule, and fear of and ability to detect hypoglycemia. Method: We introduc...
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The surfactant chain length and functional groups affected the dispersion of clay nanolayers in the matrix and the overall properties of the nanocomposites. X-ray diffraction (XRD) revealed peaks corresponding to inte...
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The surfactant chain length and functional groups affected the dispersion of clay nanolayers in the matrix and the overall properties of the nanocomposites. X-ray diffraction (XRD) revealed peaks corresponding to intercalated structures;transmission electron microscopy (TEM) observations agreed well with XRD assessment of the composites. SBR/VODAC-MMT system exhibited the best dispersion among the nanocomposites studied. VODAC-MMT was partially exfoliated in SBR matrix and the average aspect ratio of the nanolayer stacks or aggregates was high [20]. Depending on the amount of clay, considerable mechanical reinforcement and gas barrier enhancement were achieved in nanocomposites over pure rubber.
This work obtains the first molecular imaging of wall slip in entangled solutions. Using a combination of confocal fluorescence microscopy and rheometry, molecular images were captured in the nonlinear response regime...
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This work obtains the first molecular imaging of wall slip in entangled solutions. Using a combination of confocal fluorescence microscopy and rheometry, molecular images were captured in the nonlinear response regime of entangled DNA solutions. Conformations of DNA molecules were imaged during shear to correlate with the magnitude of wall slip. Interfacial chain disentanglement results in wall slip beyond the stress overshoot. Sufficient disentanglement can produce tumbling of individual DNA in the entangled solutions.
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