pH Dependence of the Spectral Distribution of Hydrogen Peroxide Quantum Yields

Dissolved natural organic matter (DOM) is an important natural photosensitizer, which produces a variety of reactive oxygen species including singlet oxygen, hydroxyl radical, superoxide (O2-) and hydrogen peroxide (H2O2). H2O2 is formed primarily through the dismutation of O2-. Previous work has suggested that neither singlet oxygen nor excited triplet states of DOM are responsible for H2O2 production. Rather, reducing DOM intermediates likely form O2-, which in turn produce H2O2. One such intermediate may be a charge-separated DOM species (DOM+/-) formed by charge transfer (CT) relaxation of excited singlet states. In the CT model, the electron transfer is believed to occur between donors (e.g., phenols and methoxy aromatics) and acceptors (e.g., ketones, aldehydes, and quinones). Using a polychromatic approach (where DOM samples were irradiated with multiple long pass filters), the effect of pH on the wavelength dependence of H2O2 quantum yields for two DOM isolates was studied. These isolates included Suwannee River Natural Organic Matter because it is primarily terrestrial sourced material and Pony Lake Fulvic Acid because it is primarily microbial sourced material. Experiments were conducted over a pH range 4 to 10 for both environmental significance and mechanistic significance. As pH increases, O2- apparent quantum yields increase, as predicted by the charge transfer model, regardless of source type. H2O2 quantum yields further will increase depending on pH. Chloroethanol was used as a scavenger of aqueous electrons to determine the role of photoionization of DOM in O2- production at different wavelengths. No appreciable decrease in H2O2 quantum yields was observed at any wavelength, suggesting no appreciable amount of aqueous electron is contributing to O2- production and subsequent H2O2 production

Diagnosing Movement via the Absence of C-command Relations

In this paper, we propose a new diagnostic for movement. It has been argued in the computational linguistics literature that some constraints can be formalized by path constraints on the sequence of their c-commanders (Graf and Shafiei 2019), and that some constraints can be formalized by the tree configuration they appear in (Graf and Heinz 2015). It holds that path constraints are a special case of tree constraints. We make the observation that path constraints cannot account for phenomena that have been argued to involve movement of the element requiring licensing, namely for ATB-extraction and parasitic gaps. However, the reverse does not hold: adjuncts islands and freezing effects, which also involve movement, can be formalized by path constraints. We thus propose the following one-way generalization: Whenever a phenomenon cannot be captured by path constraints, and can be captured by tree constraints, this phenomenon involves movement. We contend that this is not surprising given the fact that constraints on the well-formedness of the Move operation cannot be captured by path constraints, and rather must be captured by tree constraints (Graf 2018)

Specificity and Differential Object and Subject Marking in Turkish

Diese Arbeit untersucht die Rolle von Spezifität im türkischen Kasussystem. Im Türkischen werden zwei Phänomene, die als differentielle Objektmarkierung (DOM) und differentielle Subjektmarkierung (DSM) bekannt sind, deutlich. Das bedeutet, dass die Kasusmarkierung an direkten Objekten (Akkusativ) und diejenige an Subjekten von Nebensätzen (Genitiv) mit Null-Markierung/Nominativ alterniert. Im Türkischen gibt es zwei Gründe für strukturelle Kasusmarkierung: 1. Semantische Gründe: Für Objekte und Subjekte in Basisposition sind (hauptsächlich) die Kriterien Spezifität und Definitheit ausschlaggebend. Ich diskutiere die semantischen Aspekte von Spezifität unabhängig vom Türkischen und zeige, dass in vielen Fällen Kasus durch verschiedene Typen von Spezifität erklärt werden kann. 2. Syntaktische Gründe: In anderen syntaktischen Positionen oder in der Gegenwart eines Kongruenzmorphems wird Kasusmarkierung erzwungen und kann daher nicht semantische Kriterien aufzeigen. Außerdem wird in manchen Nebensätzen Kasus unterdrückt, was zum selben Neutralisationseffekt führt. Syntaktische Kasusmarkierung hat daher Vorrang gegenüber semantischer Kasusmarkierung. Sprachübergreifend wird oft die Sichtweise von DO/SM angenommen, Objekte und Subjekte zu markieren, wenn sie einander zu ähnlich werden. Türkisch widerlegt diesen Ansatz, da Kasusmarkierung semantische Informationen an der Konstituente unabhängig von derjenigen an anderen Konstituenten anzeigt. Entscheidend ist, dass Türkisch Gegenbeispiele gegen Aissen (2003) vorbringt, die Kasusmarkierung an definiten Objekten und indefiniten Subjekten erwartet, im Türkischen aber werden definite Objekte und definite Subjekte markiert. Ich schließe mich dem Großteil der Literatur über Türkisch dahingehend an, dass diese Sprache starke Evidenz gegen funktionale DO/SM und für einzelsprachliche Erklärungen liefert.This thesis investigates the role of specificity in Turkish case marking. Turkish exhibits two phenomena known as Differential Object Marking (DOM) and Differential Subject Marking (DSM), i.e., 'regular' case marking on direct objects (accusative) and on subjects of subordinate clauses (genitive) alternates with zero/nominative marking. There can be two reasons for structural case marking in Turkish. The first reason is semantic: Objects and subjects in base position receive marking (mostly) by the criteria specificity and definiteness. I discuss the semantic aspects of specificity independently of Turkish and show that many case observations can indeed be explained by different types of specificity. The second reason is syntactic: In any other syntactic position or in the presence of an agreement head, case marking is forced and can therefore not indicate semantic criteria. In some subordinate clauses, case marking is suppressed, which yields the same neutralization effect. Syntactic case marking thus overrides semantic case marking. Cross-linguistically speaking, it is common to adopt a view on DO/SM that case marks objects or subjects when they become too alike. Turkish, however, refutes this approach as it uses case marking to convey semantic information on the constituent irrespective of other constituents. Crucially, Turkish DSM provides counterexamples against Aissen (2003), who claims that case marking is expected on definite objects and indefinite subjects, but Turkish clearly marks definite objects and definite subjects. I agree with most of the literature on Turkish that Turkish is a strong example contra functional DO/SM and pro language-individual accounts

Removal of Algal Toxins by Potassium Permanganate: Incorporating Competition from Natural Water Constituents

Engineering: 3rd Place (The Ohio State University Edward F. Hayes Graduate Research Forum)A three-year embargo was granted for this item

Ionospheric photoelectrons measured at geosynchronous orbit

Measurements of ions and electrons were made by the Los Alamos National Laboratory instrument, the Magnetospheric Plasma Analyzer, onboard spacecraft 1989-046. Observations from five days indicated the presence of both field aligned electrons and equatorially trapped electrons. Correlation existed between occurrences and location in the magnetosphere. Field aligned electrons were measured in the plasmasphere during daylight. On two days, field aligned electrons were also noted in the midnight region of the magnetosphere. Field aligned electrons at energies between 1 and 50 eV were characterized. These electron's spectrum were shown to be similar in shape to the ionospheric photoelectron distribution. Conic distributions of photoelectrons were observed between 08:00 and 10:00 local time on days when both photoelectrons and equatorially trapped electrons were present. V sub parallel versus V sub perpendicular spectrograms clearly indicated that photoelectrons undergo perpendicular acceleration. Lack of any magnetic field measurements or collection of wave data prevented determining the source of the acceleration.http://archive.org/details/ionosphericphoto1094539804Lieutenant. United States NavyApproved for public release; distribution is unlimited

p‑Nitroanisole/Pyridine and p‑Nitroacetophenone/Pyridine Actinometers Revisited: Quantum Yield in Comparison to Ferrioxalate

Chemical actinometry is often used to measure irradiance in environmental photochemistry. Two widely adopted actinometers are p-nitroanisole/pyridine (PNA-pyr) and the related but less popular p-nitroacetophenone/pyridine (PNAP-pyr). We report that PNA-pyr predicts systematically lower (−29%) photon irradiance than the well-characterized ferrioxalate actinometer. Thus, quantum yields previously determined using PNA-pyr should be correspondingly lower. Experiments at various pyridine concentrations produced an updated equation for the pyridine (pyr) dependence of the PNA-pyr quantum yield: Φ = 0.29­[pyr] + 0.00029. Additionally, we present a standard molar absorption spectrum of PNA for future use. A comparison between PNA-pyr and PNAP-pyr suggests the previously reported PNAP-pyr quantum yield is also too high. Preliminary results suggest a suitable equation for the PNAP-pyr system: Φ = 7.4 × 10^–3[pyr] + 1.1 × 10^–5

Ten Years of VINQUEST: First Insight for Breeding New Apple Cultivars with Durable Apple Scab Resistance

Apple scab, caused by Venturia inaequalis, is a major fungal disease worldwide. Cultivation of scab-resistant cultivars would reduce the chemical footprint of apple production. However, new apple cultivars carrying durable resistances should be developed to prevent or at least slow the breakdown of resistance against races of V. inaequalis. One way to achieve durable resistance is to pyramid multiple scab resistance genes in a cultivar. The choice of the resistance genes to be combined in the pyramids should take into account the frequency of resistance breakdown and the geographical distribution of apple scab isolates able to cause such breakdowns. In order to acquire this information and to make it available to apple breeders, the VINQUEST project (www.vinquest.ch) was initiated in 2009. Ten years after launching this project, 24 partners from 14 countries regularly contribute data. From 2009 to 2018, nearly 9,000 data points have been collected. This information has been used to identify the most promising apple scab resistance genes for developing cultivars with durable resistance, which to date are: Rvi5, Rvi11, Rvi12, Rvi14, and Rvi15. As expected, Rvi1, together with Rvi3 and Rvi8, were often overcome, and have little value for scab resistance breeding. Rvi10 may also belong to this group. On the other hand, Rvi2, Rvi4, Rvi6, Rvi7, Rvi9, and Rvi13 are still useful for breeding, but their use is recommended only in extended pyramids of $3 resistance genes

p‑Nitroanisole/Pyridine and p‑Nitroacetophenone/Pyridine Actinometers Revisited: Quantum Yield in Comparison to Ferrioxalate

Chemical actinometry is often used to measure irradiance in environmental photochemistry. Two widely adopted actinometers are p-nitroanisole/pyridine (PNA-pyr) and the related but less popular p-nitroacetophenone/pyridine (PNAP-pyr). We report that PNA-pyr predicts systematically lower (−29%) photon irradiance than the well-characterized ferrioxalate actinometer. Thus, quantum yields previously determined using PNA-pyr should be correspondingly lower. Experiments at various pyridine concentrations produced an updated equation for the pyridine (pyr) dependence of the PNA-pyr quantum yield: Φ = 0.29­[pyr] + 0.00029. Additionally, we present a standard molar absorption spectrum of PNA for future use. A comparison between PNA-pyr and PNAP-pyr suggests the previously reported PNAP-pyr quantum yield is also too high. Preliminary results suggest a suitable equation for the PNAP-pyr system: Φ = 7.4 × 10^–3[pyr] + 1.1 × 10^–5