Free-radical hydrogen abstraction from polycyclic aliphatic hydrocarbons

Six polycyclic aliphatic hydrocarbons were reacted with the trichloromethyl radical photolytically generated from bromotrichloromethane at 40°. Relative rates of reaction were correlated with a computer analysis of the change in strain energy in going from the ground state to the intermediate. A good correlation between the log of the relative rates and the calculated changes in strain energy was obtained

On the detectability of habitable exomoons with Kepler-class photometry

In this paper we investigate the detectability of a habitable-zone exomoon around various configurations of exoplanetary systems with the Kepler Mission or photometry of approximately equal quality. We calculate both the predicted transit timing signal amplitudes and the estimated uncertainty on such measurements in order to calculate the confidence in detecting such bodies across a broad spectrum of orbital arrangements. The effects of stellar variability, instrument noise and photon noise are all accounted for in the analysis. We validate our methodology by simulating synthetic lightcurves and performing a Monte Carlo analysis for several cases of interest. We find that habitable-zone exomoons down to 0.2 Earth masses may be detected and ~25,000 stars could be surveyed for habitable-zone exomoons within Kepler's field-of-view. A Galactic Plane survey with Kepler-class photometry could potentially survey over one million stars for habitable-zone exomoons. In conclusion, we propose that habitable exomoons will be detectable should they exist in the local part of the galaxy.Comment: Accepted for publication in the Monthly Notices of the Royal Astronomical Societ

Improvement of the phase regulation between two amplifiers feeding the inputs of the 3dB combiner in the ASDEX-Upgrade ICRH system

The present ICRF system at ASDEX Upgrade uses 3dB combiners to forward the combined power of a generator pair to a single line. Optimal output performance is achieved when the voltages at the two input lines of a combiner are equal in amplitude and the phase in quadrature. If this requirement is not met, a large amount of power is lost in the dummy loads of the combiner. To minimize losses, it is paramount to reach this phase relationship in a fast and stable way. The current phase regulation system is based on analog phase locked loops circuits. The main limitation of this system is the response time: several tens of milliseconds are needed to achieve a stable state. In order to get rid of the response time limitation of the current system, a new system is proposed based on a multi-channel direct digital synthesis device which is steered by a microcontroller and a software-based controller. The proposed system has been developed and successfully tested on a test-bench. The results show a remarkable improvement in the reduction of the response times. Other significant advantages provided by the new system include greater flexibility for frequency and phase settings, lower cost and a noticeable size reduction of the system

Coordination Implications of Software Coupling in Open Source Projects

The effect of software coupling on the quality of software has been studied quite widely since the seminal paper on software modularity by Parnas [1]. However, the effect of the increase in software coupling on the coordination of the developers has not been researched as much. In commercial software development environments there normally are coordination mechanisms in place to manage the coordination requirements due to software dependencies. But, in the case of Open Source software such coordination mechanisms are harder to implement, as the developers tend to rely solely on electronic means of communication. Hence, an understanding of the changing coordination requirements is essential to the management of an Open Source project. In this paper we study the effect of changes in software coupling on the coordination requirements in a case study of a popular Open Source project called JBoss

The Heating and Ventilating System of Throop College of Technology

No abstract

The Lantern Vol. 11, No. 1, December 1942

• Friends of the Aquarium • Espionage • Fuss-Budget • Dress Blues • Alone • One Easy Lesson in How Not to Study • A Thumbtack Sketch • One Star • A Colonial Inn • Thoughts on a Dark Day • Query • Paul Revere and the World He Lived In • Sunsetshttps://digitalcommons.ursinus.edu/lantern/1028/thumbnail.jp

Karshomyia caulicola (Diptera: Cecidomyiidae) Associated with Sclerotinia-Infected Soybean in the United States and Canada

The white-mold gall midge, Karshomyia caulicola Coquillett, was documented in association with soybean, Glycine max (L.) Merr., infected with the fungus Sclerotinia sclerotiorum (Lib.) de Bary. This mycetophagous cecidomyiid appears widespread in the northern soybean producing region, with confirmed detections from Minnesota, North Dakota and Québec. Though likely not a pest of soybean plants, the presence of K. caulicola in soybean fields may complicate identification, population assessment and decision making for soybean gall midge, Resseliella maxima Gagné, which is a recently described pest of soybean. Here, we provide an overview of the known biology and distribution of K. caulicola and descriptions to aid in distinguishing these two cecidomyiids

Coherent quantum state storage and transfer between two phase qubits via a resonant cavity

A network of quantum-mechanical systems showing long lived phase coherence of its quantum states could be used for processing quantum information. As with classical information processing, a quantum processor requires information bits (qubits) that can be independently addressed and read out, long-term memory elements to store arbitrary quantum states, and the ability to transfer quantum information through a coherent communication bus accessible to a large number of qubits. Superconducting qubits made with scalable microfabrication techniques are a promising candidate for the realization of a large scale quantum information processor. Although these systems have successfully passed tests of coherent coupling for up to four qubits, communication of individual quantum states between qubits via a quantum bus has not yet been demonstrated. Here, we perform an experiment demonstrating the ability to coherently transfer quantum states between two superconducting Josephson phase qubits through a rudimentary quantum bus formed by a single, on chip, superconducting transmission line resonant cavity of length 7 mm. After preparing an initial quantum state with the first qubit, this quantum information is transferred and stored as a nonclassical photon state of the resonant cavity, then retrieved at a later time by the second qubit connected to the opposite end of the cavity. Beyond simple communication, these results suggest that a high quality factor superconducting cavity could also function as a long term memory element. The basic architecture presented here is scalable, offering the possibility for the coherent communication between a large number of superconducting qubits.Comment: 17 pages, 4 figures (to appear in Nature

A coupled hydrology-biogeochemistry model to simulate dissolved organic carbon exports from a permafrost influenced catchment

Funded by Natural Environment Research Council. Grant Number: NE/K000268/1 Natural Sciences and Engineering Research Council of CanadaPeer reviewedPublisher PD

Low photolability of yedoma permafrost dissolved organic carbon

Vast stores of arctic permafrost carbon that have remained frozen for millennia are thawing, releasing ancient dissolved organic carbon (DOC) to arctic inland waters. Once in arctic waters, DOC can be converted to CO2 and emitted to the atmosphere, accelerating climate change. Sunlight-driven photoreactions oxidize DOC, converting a portion to CO2 and leaving behind a photomodified pool of dissolved organic matter (DOM). Samples from the Kolyma River, its tributaries, and streams draining thawing yedoma permafrost were collected. Irradiation experiments and radiocarbon dating were employed to assess the photolability of ancient permafrost-DOC in natural and laboratory generated samples containing a mix of modern and ancient DOC. Photolabile DOC was always modern, with no measurable photochemical loss of ancient permafrost-DOC. However, optical and ultrahigh resolution mass spectrometric measurements revealed that both modern river DOM and ancient permafrost-DOM were photomodified during the irradiations, converting aromatic compounds to less conjugated compounds. These findings suggest that although sunlight-driven photoreactions do not directly mineralize permafrost-DOC, photomodification of permafrost-DOM chemistry may influence its fate and ecological functions in aquatic systems