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Search Results: 1 - 10 of 27451 matches for " Robert McPheat "
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Absorption of infra-red radiation by atmospheric molecular cluster-ions
K. L. Aplin,R. A. McPheat
Physics , 2005, DOI: 10.1016/j.jastp.2005.01.007
Abstract: Protonated water clusters are a common species of atmospheric molecular cluster-ion, produced by cosmic rays throughout the troposphere and stratosphere. Under clear-sky conditions or periods of increased atmospheric ionisation, such as solar proton events, the IR absorption by atmospheric ions may affect climate through the radiative balance. Fourier Transform Infrared Spectrometry in a long path cell, of path length 545m, has been used to detect IR absorption by corona-generated positive molecular cluster-ions. The column concentration of ions in the laboratory spectroscopy experiment was estimated to be ~10^13 m-2; the column concentration of protonated atmospheric ions estimated using a simple model is ~10^14 m-2. Two regions of absorption, at 12.3 and 9.1 um are associated with enhanced ion concentrations. After filtering of the measured spectra to compensate for spurious signals from neutral water vapour and residual carbon dioxide, the strongest absorption region is at 9.5 to 8.8 um (1050 to 1140 cm-1) with a fractional change in transmissivity of 0.03 plus/minus 0.015, and the absorption at 12.5 to 12.1 um (800 to 825 cm-1) is 0.015 plus/minus 0.008.
Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report)
Jonathan Tennyson,Peter F. Bernath,Alain Campargue,Attila G. Csaszar,Ludovic Daumont,Robert R. Gamache,Joseph T. Hodges,Daniel Lisak,Olga V. Naumenko,Laurence S. Rothman,Ha Tran,Nikolai F. Zobov,Jeanna Buldyreva,Chris D. Boone,Maria Domenica De Vizia,Livio Gianfrani,Jean-Michel Hartmann,Robert McPheat,Jonathan Murray,Ngoc Hoa Ngo,Oleg L. Polyansky,Damien Weidmann
Physics , 2014, DOI: 10.1515/pac-2014-0208
Abstract: The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should be called the Hartmann--Tran profile (HTP). The HTP is sophisticated enough to capture the various collisional contributions to the isolated line shape, can be computed in a straightforward and rapid manner, and reduces to simpler profiles, including the Voigt profile, under certain simplifying assumptions.
Laboratory measurements of the optical properties of sea salt aerosol
R. Irshad, R. G. Grainger, D. M. Peters, R. A. McPheat, K. M. Smith,G. Thomas
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2009,
Abstract: The extinction spectra of laboratory generated sea salt aerosols have been measured from 1 μm to 20 μm using a Bruker 66v/S FTIR spectrometer. Concomitant measurements include temperature, pressure, relative humidity and the aerosol size distribution. The refractive indices of the sea salt aerosol have been determined using a simple harmonic oscillator band model (Thomas et al., 2004) for aerosol with relative humidities at eight different values between 0.4% to 86%. The resulting refractive index spectra show significant discrepancies when compared to existing sea salt refractive indices calculated using volume mixing rules (Shettle and Fenn, 1979). Specifically, an additional band is found in the refractive indices of dry sea salt aerosol and the new data shows increased values of refractive index at almost all wavelengths. This implies that the volume mixing rules, currently used to calculate the refractive indices of wet sea salt aerosols, are inadequate. Furthermore, the existing data for the real and imaginary parts of the refractive indices of dry sea salt aerosol are found not to display the Kramers-Kronig relationship. This implies that the original data used for the volume mixing calculations is also inaccurate.
Laboratory measurements of the optical properties of sea salt aerosol
R. Irshad,R. G. Grainger,D. M. Peters,R. A. McPheat
Atmospheric Chemistry and Physics Discussions , 2008,
Abstract: The extinction spectra of laboratory generated sea salt aerosols have been measured from 1 μm to 20 μm using a Bruker 66v/S FTIR spectrometer. Concomitant measurements include temperature, pressure, relative humidity and the aerosol size distribution. The refractive indices of the sea salt have been determined using a simple harmonic oscillator band model (Thomas et al., 2004) for aerosol with relative humidities between 0.1% to 100% sea salt. The resulting refractive index spectra show significant discrepancies when compared to existing sea salt refractive indices.
Introduction to a Requirements Engineering Framework for Aeronautics  [PDF]
Robert Abo
Journal of Software Engineering and Applications (JSEA) , 2010, DOI: 10.4236/jsea.2010.39105
Abstract: This paper introduces a framework to produce and to manage quality requirements of embedded aeronautical systems, called the ‘Requirements Engineering Framework’ (REF). It aims at making the management of the requirement lifecycle easier, from the specification of the purchaser’s needs, to their implementation in the final products, and also their verification, while controlling costs. REF is based on the main standards of aeronautics, in particular RTCA DO-254, and RTCA DO-178B standards. An implementation of REF, using the IBM Rational DOORS and IBM Rational Change tools, is also presented in this paper.
Pricing Options in Jump Diffusion Models Using Mellin Transforms  [PDF]
Robert Frontczak
Journal of Mathematical Finance (JMF) , 2013, DOI: 10.4236/jmf.2013.33037
Abstract:

This paper is concerned with the valuation of options in jump diffusion models. The partial integro-differential equation (PIDE) inherent in the pricing problem is solved by using the Mellin integral transform. The solution is a single integral expression independent of the distribution of the jump size. We also derive analytical expressions for the Greeks. The results are implemented and compared to other approaches.

Australia’s Out-Dated Concern over Fishing Threatens Wise Marine Conservation and Ecologically Sustainable Seafood Supply  [PDF]
Robert Kearney
Open Journal of Marine Science (OJMS) , 2013, DOI: 10.4236/ojms.2013.32006
Abstract:

Seafood plays an important role in human nutrition and its increased consumption is actively recommended for sustenance and health benefits in both developing and developed countries. In parallel to this, the public receives confusing advice as to what seafood is sustainably produced and is frequently misled about the environmental impacts of fishing, especially in locations such as Australia where contemporary fishery management has a conservation and sustainability focus. It is recognised globally that Australia’s traditional fishery management driven by strict sustainability and biodiversity regulations, has achieved impressive results in managing both fish stocks and the effects of fishing on marine environments. Despite this, continued pressure from non-government organisations (NGOs) and a perpetuation of the misuse of management terms such as overfished is used to promote the misguided need for ever increasing fishing restrictions, most obviously in protected areas. This paper questions the motives of some NGOs and governments in Australia in pursuing additional restrictions on fishing which are mostly unnecessary and disproportionate to the sustainability requirements of other sources of food. This is done within the context of the global need for sustainable seafood supply and the need for effective marine conservation that addresses all threats to marine ecosystems in proportion to the magnitude of each threat.

Wearable and wireless accelerometer systems for monitoring Parkinson’s disease patients—A perspective review  [PDF]
Robert LeMoyne
Advances in Parkinson's Disease (APD) , 2013, DOI: 10.4236/apd.2013.24021
Abstract: Parkinson’s disease is a growing medical concern as societies, such as the United States of America, become progressively aged. Therapy strategies exist for the amelioration of Parkinson’s disease symptoms, and the quantification of attributes, such as hand tremor, can provide valuable feedback. Wearable and wireless accelerometer systems for monitoring Parkinson’s disease patients have been progressively advanced over the course of the past half-decade. In particular, wireless accelerometer nodes and smartphones, such as the iPhone, hold promise for optimizing therapy strategy by providing convenient quantified feedback. This perspective review addresses the current advances in wearable and wireless accelerometer systems for monitoring Parkinson’s disease patients and forecasts for the near future.
A Study of Lateralized Cognitive Processes in Upper-Division Electrical Engineering Students’: Correlating Written Language Functions with Analytical Reasoning in Microelectronics  [PDF]
Robert Melendy
World Journal of Engineering and Technology (WJET) , 2014, DOI: 10.4236/wjet.2014.22008
Abstract: The human brain is asymmetrical in function, with each of its two hemispheres being somewhat responsible for distinct cognitive and motor tasks, to include writing. It stands to reason that engineering students who have established entrance into their upper-division programs will have demonstrated cognitive proficiency in math and logical operations, abstract and analytical reasoning and language usage, to include writing. In this study the question was asked: is there a correlation between an upper-division electrical engineering students’ analytical reasoning ability and their descriptive writing ability? Descriptive writing is taken here to mean a students’ ability to identify key physical aspects of a mathematical model and to express—in words—a concise and well-balanced description that demonstrates a deep conceptual understanding of the model. This includes more than a description of the variables or the particular application to an engineering problem; it includes a demonstrated recognition of the basic physics that govern the model, certain limitations (idealizations) inherent in the model, and an understanding of how to make practical experimental measurements to verify the governing physics in the model. A student at this level may demonstrate proficiency in their analytical reasoning skills and hence be capable of correctly solving a given problem. However, this does not guarantee that the same student is skilled in associating equations with their physical meaning on a deep conceptual level or in understanding physical limitations of the equation. Consequently, such a student may demonstrate difficulty in mapping their comprehension of the model into written language that demonstrates a sound conceptual understanding of the governing physics. The findings represent a sample of two independent class sections of Electrical and Computer Engineering junior’s first course in Microe-lectronic Devices and Circuits during fall semesters 2012 and 2013 at a private mid-size university in NW Oregon. A total of three exams were administered to each of the 2012/2013 groups. Correlations between exam scores that students achieved on their descriptive writing of microelectronics phenomena and their analytical problem-solving abilities were examined and found to be quite significant.
Foilized pouches can prevent the transmission of HIV from mother to child using multi-drug therapies  [PDF]
Robert Malkin
Journal of Biomedical Science and Engineering (JBiSE) , 2014, DOI: 10.4236/jbise.2014.71007
Abstract: Children can become HIV positive (HIV+) from their mother during home birth. If the infant ingests antiretroviral (ARV), medications immediately after birth, the risk of transmission can be dramatically reduced. We have previously proposed the use of foilized, polyethylene-lined pouches to store ARV’s. Using the pouch, the mother receives the medication at an antenatal care visit, months before delivery, and if she delivers at home, tears open the pouch and drips the medication into her child’s mouth. In this work, we extend the use of the pouch to store a modern ARV, Lamivudine (3TC), often used in multi-drug regimens. Under laboratory conditions, pouches were filled with 3TC and stored at 25?C/60% relative humidity (RH) for twelve months. We found that the 3TC was stable throughout the year (maximum 5.6% of labeled concentration change). The preservatives were somewhat degraded by the act of repackaging the medicine, but sufficient preservatives remained to maintain the medication. The same impurities were identified in the 3TC stored in the pouches and the samples removed from the bottles indicating that the pouches do not introduce new impurities (impurities that are not already introduced by the bottle). We conclude that the pouch can preserve this modern ARV for up to twelve months.
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