ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInterpenetrating Polymer Networks of Poly(ethyl acrylate) and Poly(styrene-co-methly methacrylate). I. Morphology via Electron MicroscopyVolker Huelck, D. A. Thomas, L. H. SperlingCite this: Macromolecules 1972, 5, 4, 340–347Publication Date (Print):July 1, 1972Publication History Published online1 May 2002Published inissue 1 July 1972https://pubs.acs.org/doi/10.1021/ma60028a002https://doi.org/10.1021/ma60028a002research-articleACS...

Notions of research quality are contextual in many respects: they vary between fields research, review contexts and policy contexts. Yet, the role these co-existing notions policy, is poorly understood. In this paper we offer a novel framework to study understand across three key dimensions. First, distinguish that originate (Field-type) spaces (Space-type). Second, drawing on existing studies, identify attributes (often) considered important for 'good research': its originality/novelty,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInterpenetrating Polymer Networks Based on SBR/PS. 1. Control of Morphology by Level Cross-LinkingA. A. Donatelli, L. H. Sperling, and D. ThomasCite this: Macromolecules 1976, 9, 4, 671–675Publication Date (Print):July 1, 1976Publication History Published online1 May 2002Published inissue 1 July 1976https://pubs.acs.org/doi/10.1021/ma60052a029https://doi.org/10.1021/ma60052a029research-articleACS PublicationsRequest reuse permissionsArticle...

Areas under the linear tan δ–temperature (tA) and loss modulus–temperature (LA) curves of polyacrylate polymethacrylate homologous series their interpenetrating polymer networks (IPNs) were investigated. For poly(methyl acrylate), LA values are independent crosslinking level through 25%, but tA decreases. With increasing side group length, on other hand, remains nearly length for both series, having near 50 65 (units K) acrylate methacrylate respectively. However, decreases steeply with...

Abstract Interpenetrating polymer networks (IPN's) of polybutadiene (PB) and polystyrene (PS) were prepared using both random (containing 36% cis, 55% trans, 9% 1,2 vinyl) PB high‐cis PB. For series, a wide range PB/PS compositions synthesized. Using samples stained with osmium tetroxide, electron microscope studies revealed an irregular cellular structure few hundred Ångstrom diameter the first component, PB, making up cell walls. The size cells was found to depend on crosslink density for...

Abstract The current range and volume of research evaluation-related literature is extensive incorporates scholarly policy/practice-related perspectives. This reflects academic practical interest over many decades trails the changing funding reputational modalities for universities, namely increased selectivity applied to institutional streams perceived importance university rankings other devices. To make sense this highly diverse body literature, we undertake a critical review 350 works...

Research funding is an important factor for public science. Funding may affect which research topics get addressed, and what outputs are produced. However, has often been studied simplistically, using top-down or system-led perspectives. Such approaches restrict analysis to confined national landscapes single organizations instruments in isolation. This overlooks interlinkages, broader researchers might access, trends of growing complexity. paper instead frames a ‘bottom-up’ approach that...

Modeling is at the core of many disciplines, but it especially important in engineering because facilitates communication and constructs complex things from smaller parts. Model or model-driven development, treats software development as a set transformations between successive models requirements to analysis, design, implementation, deployment. We discuss UML MDA tools for developing models. also domain specific languages, domain-oriented programming, platform-specific model engineering.

A software product evaluation process grounded in mathematics and decision theory can effectively determine quality suitability with less risk at lower cost than conventional methods.

Abstract Objective To compare the diagnostic accuracy of two‐dimensional (2D) ultrasound and three‐dimensional (3D) computed tomography (CT) for diagnosis fetal skeletal anomalies. Methods Eleven pregnant women underwent 2D 3D‐CT. Ten fetuses presented anomalies on one fetus had a normal exam but familial history osteopetrosis. We compared retrospectively diagnoses established 3D‐CT with neonatal and/or postmortem work‐up, which were used as gold standard. Results provided correct in only...

Abstract Damping systems based on interpenetrating polymer networks (IPN's) provide noise and vibration attenuation over broad temperature frequency ranges. Semicompatible latex IPN's are employed in both extensional constrained layer configurations. The damping behavior of compositions poly(ethyl methacrylate)/poly( n ‐butyl acrylate) [PEMA/P BA], methacrylate–co–ethyl acrylate)/poly( acrylate–co–ethyl [P(EMA–co–EA)/P( BA–co–EA)], poly(vinyl chloride)/poly(butadiene–co–acrylonitrile)...

Abstract In previous papers, interpenetrating polymer networks were shown to display a cellular structure. The phase domain size of II was depend inversely on the crosslink density I. present paper presents semiempirical derivation equations which show quantitatively dependence crosslinking I, and also interfacial energy overall composition. If is linear, molecular weight included. values sizes so estimated are compared with experimental results. While theory experiment yield good agreement,...

Interpenetrating polymer networks (IPN's) of poly(alkyl methacrylates) and acrylates) have been synthesized in latex form. Dynamic mechanical spectroscopy studies on these materials revealed extraordinarily broad glass transition regions, illustrating the semicompatible nature materials. In a true synergistic effect, value tan δ remains high nearly constant over temperature range for select compositions, emphasizing their potential noise vibration damping applications. Compositionally...

Abstract The creep behavior of a series poly(ethyl acrylate)–poly(methyl methacrylate) interpenetrating polymer networks was investigated. For comparison purposes, some stress relaxation data were included. Master curves containing single broad transition covering approximately 20 decades time found for midrange compositions. Although the time–temperature superposition principle and WLF equation should not strictly apply, reasonable agreement over large portion shift factor versus...

Abstract The areas under the linear loss modulus versus temperature curves (loss area, LA) and tan δ (TA) were evaluated for a number of acrylic, methacrylic, styrenic butadiene based copolymers interpenetrating polymer networks, IPNs, as function crosslink density comliosition, compared with values predicted by group contribution analysis. LAs sequential cross ‐poly(n‐butyl methacrylate)‐ inter ‐ polystyrene, found to exhibit up 30% larger than poly(n‐butyl metacrylate‐ stat ‐styrene)...

Abstract The integral of loss modulus versus temperature plots in the vicinity glass transition (loss area, LA) was characterized for various homopolymers, statistical copolymers, and interpenetrating polymer networks (IPNs), based on acrylics, vinyls, styrenic mers. quantity LA found to be a molecular characteristic, governed by structure individual both IPNs copolymers obeys an additive relation component polymers. A group contribution analysis developed which each moiety contributes...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInterpenetrating Polymer Networks of Poly(ethyl acrylate) and Poly(styrene-co-methyl methacrylate). II. Physical Mechanical BehaviorVolker Huelck, D. A. Thomas, L. H. SperlingCite this: Macromolecules 1972, 5, 4, 348–353Publication Date (Print):July 1, 1972Publication History Published online1 May 2002Published inissue 1 July 1972https://pubs.acs.org/doi/10.1021/ma60028a003https://doi.org/10.1021/ma60028a003research-articleACS PublicationsRequest...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInterpenetrating Polymer Networks Based on SBR/PS. 2. Influence of Synthetic Detail and Morphology Mechanical BehaviorA. A. Donatelli, L. H. Sperling, D. ThomasCite this: Macromolecules 1976, 9, 4, 676–680Publication Date (Print):July 1, 1976Publication History Published online1 May 2002Published inissue 1 July 1976https://pubs.acs.org/doi/10.1021/ma60052a030https://doi.org/10.1021/ma60052a030research-articleACS PublicationsRequest reuse...

Abstract Simultaneous interpenetrating networks were prepared by simultaneously synthesizing crosslinked epoxy and poly (n‐butyl acrylate) polymers. A two‐phase morphology emerged, with the dispersed rubber domains being of order 0.1–0.2 m̈ in size. The actual dimensions phase, extent molecular mixing between two networks, depends on relative rates polymerization, or gelation time. minimum domain size greatest occurs when closest approach to simultaneity is attained. Spherical rather than...

From 2012 USA universities entered new partnerships with private sector companies including Silicon Valley start-up Coursera. Coursera spearheads a broad online learning segment of the fast growing global 'educational technology' (EdTech) sector. They offered free 'massive open courses' (MOOCs) for global, universal learner audiences. Since 2015 several and expanded into 'post-MOOC', paid, accredited modules full degrees. We frame these post-MOOC developments as shaped by dynamic...