Kent State University

About: Kent State University is a education organization based out in Kent, Ohio, United States. It is known for research contribution in the topics: Liquid crystal & Population. The organization has 10897 authors who have published 24607 publications receiving 720309 citations. The organization is also known as: Kent State & KSU.

Pollution disclosures, pollution performance and economic performance

Abstract: This study examines the association between pollution disclosures and pollution performance and between pollution disclosures and economic performance for firms in highly polluting industries. An index of pollution disclosures is developed and correlated with indices of pollution performance and economic performance. The results confirm earlier findings that there is no association between pollution disclosures and pollution performance. As far as the association between economic performance and pollution disclosures is concerned, the results show that the subgroup of large firms with poor economic performance provides the most detailed pollution information. For smaller firms there is no association between economic performance and pollution disclosures.

A 1,000-year sediment record of tsunami recurrence in northern Sumatra

Abstract: Nothing known from written history gave reason to expect the Indian Ocean tsunami that took nearly a quarter million lives on 26 December 2004. That tsunami entered geological history by laying down centimetres of sand on the coastal plains that it overran. Jankaew et al. have now found such sedimentary records of earlier tsunamis preserved in the dark soils of marshy swales at Phra Thong, a barrier island in western Thailand. The cover shows an example from a pit dug there in 2007: the topmost light-coloured layer represents the 2004 tsunami, while a similar layer below records a tsunami in the fourteenth or fifteenth century AD. The ruler divisions are 10 cm long. In a separate study in Aceh, Indonesia, Monecke et al. found the 2004 sand sheet preceded by the deposits of three tsunamis from the past 1,200 years. One of these earlier deposits may match the medieval one found in Thailand. The combined findings suggest that the 2004 tsunami is neither the first nor the last of its kind. The Indian Ocean tsunami of 26 December 2004 reached maximum wave heights of 35 m in Aceh, the northernmost province of Sumatra1,2. Both the tsunami and the associated Sumatra–Andaman earthquake were unprecedented in Acehnese history3,4. Here we use sand sheets to extend tsunami history 1,000 years into Aceh’s past. The 2004 tsunami deposited a sand sheet up to 1.8 km inland on a marshy beach ridge plain. Sediment cores from these coastal marshes revealed two older extensive sand sheets with similar sediment characteristics. These sheets, deposited soon after ad 1290–1400 and ad 780–990, probably resulted from earlier tsunamis. An additional sand sheet of limited extent might correlate with a documented smaller tsunami of ad 1907. These findings, a first step towards a palaeotsunami record for northern Sumatra, suggest that damage-causing tsunamis in Aceh recur infrequently enough for entire human lifetimes to typically elapse between them. Such recurrence adds to the challenge of preparing communities along the northern Indian Ocean shorelines for future tsunamis.

Discrepant hardening observed in cosmic-ray elemental spectra

Abstract: The balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment launched five times from Antarctica has achieved a cumulative flight duration of about 156 days above 99.5% of the atmosphere. The instrument is configured with complementary and redundant particle detectors designed to extend direct measurements of cosmic-ray composition to the highest energies practical with balloon flights. All elements from protons to iron nuclei are separated with excellent charge resolution. Here we report results from the first two flights of ~70 days, which indicate hardening of the elemental spectra above ~200 GeV/nucleon and a spectral difference between the two most abundant species, protons and helium nuclei. These results challenge the view that cosmic-ray spectra are simple power laws below the so-called knee at ~1015 eV. This discrepant hardening may result from a relatively nearby source, or it could represent spectral concavity caused by interactions of cosmic rays with the accelerating shock. Other possible explanations should also be investigated.

Nitrogen and sulfur co-doped TiO2 nanosheets with exposed {001} facets: synthesis, characterization and visible-light photocatalytic activity

Abstract: Nitrogen and sulfur co-doped TiO(2) nanosheets with exposed {001} facets (N-S-TiO(2)) were prepared by a simple mixing-calcination method using the hydrothermally prepared TiO(2) nanosheets powder as a precursor and thiourea as a dopant. The resulting samples were characterized by transmission electron microscope, X-ray diffraction, N(2) adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and UV-Vis absorption spectroscopy. The electronic properties of N,S co-doped TiO(2) were studied using the first-principle density functional theory (DFT). The photocatalytic activity of N-S-TiO(2) was evaluated by degradation of 4-chlorophenol (4-CP) aqueous solution under visible light irradiation. The production of hydroxyl radicals (˙OH) on the surface of visible-light-irradiated samples was detected by photoluminescence technique using terephthalic acid as a probe molecule. The results show that nitrogen and sulfur atoms were successfully incorporated into the lattice of TiO(2), which resulted in N-S-TiO(2) samples exhibiting stronger absorption in the UV-visible range with a red shift in the band gap transition. The first-principle DFT calculations further confirm that N and S co-dopants can induce the formation of new energy levels in the band gap, which is associated with the response of N-S-TiO(2) nanosheets to visible light irradiation. Surprisingly, pure TiO(2) nanosheets show the visible-light photocatalytic activity for the degradation of 4-CP mainly due to the substrate-surface complexation of TiO(2) and 4-CP, which results in extending absorption of titania to visible light region through ligand-to-titanium charge transfer. The N-S-TiO(2) samples studied exhibited an enhanced visible-light photocatalytic activity than pure TiO(2). Especially, the doped TiO(2) sample at the nominal weight ratio of thiourea to TiO(2) powder of 2 showed the highest photocatalytic activity, which was about twice greater than that of Degussa P25. The enhanced activity of N-S-TiO(2) can be primarily attributed to the synergetic effects of two factors including the intense absorption in the visible-light region and the exposure of highly reactive {001} facets of TiO(2) nanosheets. The former is beneficial for the photogeneration of electrons and holes participating in the photocatalytic reactions, and the latter facilitates adsorption of 4-CP molecules on the surface of TiO(2) nanosheets.