Pennsylvania State University

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.

Electroactive microorganisms in bioelectrochemical systems

Abstract: The authors acknowledge funding by the US Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) Fuel Cell Technologies Office through a contract from the National Renewable Energy Laboratory (NREL), Project #21263, and by the Environmental Security Technology Certification Program via cooperative research agreement W9132T-16-2-0014 through the US Army Engineer Research and Development Center.

Recent Advances in the Use of TiO2 Nanotube and Nanowire Arrays for Oxidative Photoelectrochemistry

Abstract: In this article, we present recent advances that we have achieved toward improving the properties of anodically formed semiconducting TiO2 nanotubes as well as nanowire arrays as electrodes for oxidative photoelectrochemistry. The morphology, crystallinity, composition, and illumination geometry of nanotube or nanowire arrays are critical factors in their performance as photoelectrodes. We discuss the key aspects relating to each factor and the advances achieved in improving each. With respect to the more fully investigated nanotube arrays, the ability to control the morphological parameters such as pore size, tube length, and wall thickness of the nanotube architecture has enabled high performance in applications such as water photoelectrolysis, photocatalysis, dye-sensitized solar cells, and heterojunction TiO2−polymer hybrid solar cells. We begin by reviewing the photoelectrochemical performance of state-of-the-art nanotube arrays fabricated on planar substrates. We then present more recent results rel...

Further Evidence for Cosmological Evolution of the Fine Structure Constant

Abstract: We describe the results of a search for time variability of the fine structure constant $\ensuremath{\alpha}$ using absorption systems in the spectra of distant quasars. Three large optical data sets and two $21\mathrm{cm}$ and mm absorption systems provide four independent samples, spanning $\ensuremath{\sim}23%$ to $87%$ of the age of the universe. Each sample yields a smaller $\ensuremath{\alpha}$ in the past and the optical sample shows a $4\ensuremath{\sigma}$ deviation: $\ensuremath{\Delta}\ensuremath{\alpha}/\ensuremath{\alpha}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}0.72\ifmmode\pm\else\textpm\fi{}0.18\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ over the redshift range $0.5lzl3.5$. We find no systematic effects which can explain our results. The only potentially significant systematic effects push $\ensuremath{\Delta}\ensuremath{\alpha}/\ensuremath{\alpha}$ towards positive values; i.e., our results would become more significant were we to correct for them.

Structure and Properties of Poly(vinyl alcohol)/Na+ Montmorillonite Nanocomposites

Abstract: Poly(vinyl alcohol)/sodium montmorillonite nanocomposites of various compositions were created by casting from a polymer/silicate water suspension. The composite structure study revealed a coexistence of exfoliated and intercalated MMT layers, especially for low and moderate silicate loadings. The inorganic layers promote a new crystalline phase different than the one of the respective neat PVA, characterized by higher melting temperature and a different crystal structure. This new crystal phase reflects on the composite materials properties. Namely, the hybrid polymer/silicate systems have mechanical, thermal, and water vapor transmission properties, which are superior to that of the neat polymer and its conventionally filled composites. For example, for a 5 wt % MMT exfoliated composite, the softening temperature increases by 25 °C and the Young's modulus triples with a decrease of only 20% in toughness, whereas there is also a 60% reduction in the water permeability. Furthermore, due to the nanoscale d...