Institution
Pennsylvania State University
Education•State College, Pennsylvania, United States•
About: Pennsylvania State University is a education organization based out in State College, Pennsylvania, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 79763 authors who have published 196876 publications receiving 8318601 citations. The organization is also known as: Penn State & PSU.
Topics: Population, Poison control, Dielectric, Context (language use), Galaxy
Papers published on a yearly basis
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TL;DR: In this paper, an implicit algorithm for the computation of viscous two-phase flows is presented, which employs a dual-time, preconditioned, three-dimensional algorithm, with multi-block and parallel execution capabilities.
770 citations
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TL;DR: The results show that the evolutionary pattern of these families is quite different from that of concerted evolution but is in agreement with the birth-and-death model of evolution in which new genes are created by repeated gene duplication and some duplicate genes are maintained in the genome for a long time but others are deleted or become nonfunctional by deleterious mutations.
Abstract: Concerted evolution is often invoked to explain the diversity and evolution of the multigene families of major histocompatibility complex (MHC) genes and immunoglobulin (Ig) genes. However, this hypothesis has been controversial because the member genes of these families from the same species are not necessarily more closely related to one another than to the genes from different species. To resolve this controversy, we conducted phylogenetic analyses of several multigene families of the MHC and Ig systems. The results show that the evolutionary pattern of these families is quite different from that of concerted evolution but is in agreement with the birth-and-death model of evolution in which new genes are created by repeated gene duplication and some duplicate genes are maintained in the genome for a long time but others are deleted or become nonfunctional by deleterious mutations. We found little evidence that interlocus gene conversion plays an important role in the evolution of MHC and Ig multigene families.
769 citations
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TL;DR: Results demonstrate that cathodes used in MFCs can contain very little Pt, and that the Pt can even be replaced with a non-precious metal catalyst such as a CoTMPP with only slightly reduced performance.
Abstract: Cathode catalysts and binders were examined for their effect on power densities in single chamber, air-cathode, microbial fuel cells (MFCs). Chronopotentiometry tests indicated thatthe cathode potential was only slightly reduced (20-40 mV) when Pt loadings were decreased from 2 to 0.1 mg cm(-2), and that Nafion performed better as a Pt binder than poly(tetrafluoroethylene) (PTFE). Replacing the precious-metal Pt catalyst (0.5 mg cm(-2); Nafion binder) with a cobalt material (cobalt tetramethylphenylporphyrin, CoTMPP) produced slightly improved cathode performance above 0.6 mA cm(-2), but reduced performance (<40 mV) at lower current densities. MFC fed batch tests conducted for 35 cycles (31 days) using glucose showed that replacement of the Nafion binder used for the cathode catalyst (0.5 mg of Pt cm(-2)) with PTFE reduced the maximum power densities (from 400 +/- 10 to 480 +/- 20 mW m(-2) to 331 +/- 3 to 360 +/- 10 mW m(-2)). When the Pt loading on cathode was reduced to 0.1 mg cm(-2), the maximum power density of MFC was reduced on average by 19% (379 +/- 5 to 301 +/- 15 mW m(-2); Nafion binder). Power densities with CoTMPP were only 12% (369 +/- 8 mW m(-2)) lower over 25 cycles than those obtained with Pt (0.5 mg cm(-2); Nafion binder). Power densities obtained using with catalysts on the cathodes were approximately 4 times more than those obtained using a plain carbon electrode. These results demonstrate that cathodes used in MFCs can contain very little Pt, and that the Pt can even be replaced with a non-precious metal catalyst such as a CoTMPP with only slightly reduced performance.
769 citations
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TL;DR: In this article, a morphotropic phase boundary (MPB) piezoelectric with ferroelectric phase transition (Tc) exceeding that of PbZrO3-PbTiO3 (PZT) was investigated.
Abstract: New morphotropic phase boundary (MPB) piezoelectrics, with ferroelectric phase transition (Tc) exceeding that of PbZrO3–PbTiO3 (PZT), were investigated. Based on a perovskite tolerance factor-Tc relationship, new high Tc MPB systems were projected in the Bi(Me)O3–PbTiO3 system, where Me is a relatively large B+3-site cation. For the (1-x)BiScO3–(x)PbTiO3 solid solution, a MPB was found at x-0.64 separating the rhombohedral and tetragonal phases, with correspondingly enhanced dielectric and piezoelectric properties. A transition temperature Tc of ~ 450°C was determined with evidence of Tc's on the order of ≥ 600°C in the BiInO3 and BiYbO3 analogues, though issues of perovskite stability remain for the smaller tolerance end-member systems.
769 citations
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TL;DR: In this article, the authors explored the charge-carrier transport mechanism in the organic semiconductor pentacene using thin-film transistor structures and found that the variation of the field-effect mobility with temperature differs from sample to sample, ranging from thermally activated to temperature-independent behavior.
Abstract: The charge-carrier transport mechanism in the organic semiconductor pentacene is explored using thin-film transistor structures. The variation of the field-effect mobility with temperature differs from sample to sample, ranging from thermally activated to temperature-independent behavior. This result excludes thermally activated hopping as the fundamental transport mechanism in pentacene thin films, and suggests that traps and/or contact effects may strongly influence the observed characteristics. These results also indicate that field-effect transistors may not be appropriate vehicles for illuminating basic transport mechanisms in organic materials.
768 citations
Authors
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Name | H-index | Papers | Citations |
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Robert Langer | 281 | 2324 | 326306 |
Zhong Lin Wang | 245 | 2529 | 259003 |
Donald P. Schneider | 242 | 1622 | 263641 |
David J. Hunter | 213 | 1836 | 207050 |
Robert M. Califf | 196 | 1561 | 167961 |
Martin White | 196 | 2038 | 232387 |
Eric J. Topol | 193 | 1373 | 151025 |
Charles A. Dinarello | 190 | 1058 | 139668 |
Jing Wang | 184 | 4046 | 202769 |
Dennis S. Charney | 179 | 802 | 122408 |
David Haussler | 172 | 488 | 224960 |
Chad A. Mirkin | 164 | 1078 | 134254 |
Ian A. Wilson | 158 | 971 | 98221 |
David Cella | 156 | 1258 | 106402 |
Jay Hauser | 155 | 2145 | 132683 |