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1دورية أكاديمية
المؤلفون: H. L. Rogers, C. Holmes, J. C. Gates, P. G. R. Smith
المصدر: IEEE Photonics Journal, Vol 4, Iss 2, Pp 310-316 (2012)
مصطلحات موضوعية: Optical properties of photonic materials, gratings, Applied optics. Photonics, TA1501-1820, Optics. Light, QC350-467
الوصف: We demonstrate experimentally a simple technique to measure the wavelength-dependent effective refractive index of a waveguide utilizing integrated Bragg grating structures. A broadband measurement of the Bragg wavelengths yields the effective index of the waveguide and, thus, an accurate total dispersion relationship. An empirical calculation of the waveguide component of the dispersion yields both the waveguide and material dispersion components of the measured total dispersion. The technique allows direct measurement of the effective index of the waveguide and yields a zero dispersion wavelength at 1220.5 nm in our silica-on-silicon platform. Importantly, inclusion of second-order Bragg reflections improves the accuracy of modal refractive index for near-visible wavelengths.
وصف الملف: electronic resource
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2دورية أكاديمية
المؤلفون: N. C. Dickson, K. M. Gierens, H. L. Rogers, R. L. Jones
المصدر: Atmospheric Chemistry and Physics, Vol 10, Iss 14, Pp 6749-6763 (2010)
الوصف: The global observation, assimilation and prediction in numerical models of ice super-saturated (ISS) regions (ISSR) are crucial if the climate impact of aircraft condensation trails (contrails) is to be fully understood, and if, for example, contrail formation is to be avoided through aircraft operational measures. Given their small scales compared to typical atmospheric model grid sizes, statistical representations of the spatial scales of ISSR are required, in both horizontal and vertical dimensions, if global occurrence of ISSR is to be adequately represented in climate models. This paper uses radiosonde launches made by the UK Meteorological Office, from the British Isles, Gibraltar, St. Helena and the Falkland Islands between January 2002 and December 2006, to investigate the probabilistic occurrence of ISSR. Each radiosonde profile is divided into 50- and 100-hPa pressure layers, to emulate the coarse vertical resolution of some atmospheric models. Then the high resolution observations contained within each thick pressure layer are used to calculate an average relative humidity and an ISS fraction for each individual thick pressure layer. These relative humidity pressure layer descriptions are then linked through a probability function to produce an s-shaped curve which empirically describes the ISS fraction in any average relative humidity pressure layer. Using this empirical understanding of the s-shaped relationship a mathematical model was developed to represent the ISS fraction within any arbitrary thick pressure layer. Two models were developed to represent both 50- and 100-hPa pressure layers with each reconstructing their respective s-shapes within 8–10% of the empirical curves. These new models can be used, to represent the small scale structures of ISS events, in modelled data where only low vertical resolution is available. This will be useful in understanding, and improving the global distribution, both observed and forecasted, of ice super-saturation.
وصف الملف: electronic resource
العلاقة: http://www.atmos-chem-phys.net/10/6749/2010/acp-10-6749-2010.pdfTest; https://doaj.org/toc/1680-7316Test; https://doaj.org/toc/1680-7324Test
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3دورية أكاديمية
المؤلفون: D. Brunner, J. Staehelin, H. L. Rogers, M. O. Köhler, J. A. Pyle, D. A. Hauglustaine, L. Jourdain, T. K. Berntsen, M. Gauss, I. S. A. Isaksen, E. Meijer, P. van Velthoven, G. Pitari, E. Mancini, V. Grewe, R. Sausen
المصدر: Atmospheric Chemistry and Physics, Vol 5, Iss 1, Pp 107-129 (2005)
الوصف: This is the second part of a rigorous model evaluation study involving five global Chemistry-Transport and two Chemistry-Climate Models operated by different groups in Europe. Simulated trace gas fields were interpolated to the exact times and positions of the observations to account for the actual weather conditions and hence for the specific histories of the sampled air masses. In this part of the study we focus on a detailed comparison with two selected campaigns, PEM-Tropics A and SONEX, contrasting the clean environment of the tropical Pacific with the more polluted North Atlantic region. The study highlights the different strengths and weaknesses of the models in accurately simulating key processes in the UT/LS region including stratosphere-troposphere-exchange, rapid convective transport, lightning emissions, radical chemistry and ozone production. Model simulated Radon, which was used as an idealized tracer for continental influence, was occasionally much better correlated with measured CO than simulated CO pointing towards deficiencies in the used biomass burning emission fields. The abundance and variability of HOx radicals is in general well represented in the models as inferred directly from the comparison with measured OH and HO2 and indirectly from the comparison with hydrogen peroxide concentrations. Components of the NOy family such as PAN, HNO3 and NO were found to compare less favorably. Interestingly, models showing good agreement with observations in the case of PEM-Tropics A often failed in the case of SONEX and vice versa. A better description of NOx and NOy emissions, chemistry and sinks is thought to be key to future model improvements with respect to the representation of chemistry in the UT/LS region.
وصف الملف: electronic resource
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4دورية أكاديمية
المؤلفون: D. Brunner, J. Staehelin, H. L. Rogers, M. O. Köhler, J. A. Pyle, D. Hauglustaine, L. Jourdain, T. K. Berntsen, M. Gauss, I. S. A. Isaksen, E. Meijer, P. van Velthoven, G. Pitari, E. Mancini, G. Grewe, R. Sausen
المصدر: Atmospheric Chemistry and Physics, Vol 3, Iss 5, Pp 1609-1631 (2003)
الوصف: A rigorous evaluation of five global Chemistry-Transport and two Chemistry-Climate Models operated by several different groups in Europe, was performed. Comparisons were made of the models with trace gas observations from a number of research aircraft measurement campaigns during the four-year period 1995-1998. Whenever possible the models were run over the same four-year period and at each simulation time step the instantaneous tracer fields were interpolated to all coinciding observation points. This approach allows for a very close comparison with observations and fully accounts for the specific meteorological conditions during the measurement flights. This is important considering the often limited availability and representativity of such trace gas measurements. A new extensive database including all major research and commercial aircraft measurements between 1995 and 1998, as well as ozone soundings, was established specifically to support this type of direct comparison. Quantitative methods were applied to judge model performance including the calculation of average concentration biases and the visualization of correlations and RMS errors in the form of so-called Taylor diagrams. We present the general concepts applied, the structure and content of the database, and an overall analysis of model skills over four distinct regions. These regions were selected to represent various atmospheric conditions and to cover large geographical domains such that sufficient observations are available for comparison. The comparison of model results with the observations revealed specific problems for each individual model. This study suggests the further improvements needed and serves as a benchmark for re-evaluations of such improvements. In general all models show deficiencies with respect to both mean concentrations and vertical gradients of important trace gases. These include ozone, CO and NOx at the tropopause. Too strong two-way mixing across the tropopause is suggested to be the main reason for differences between simulated and observed CO and ozone values. The generally poor correlations between simulated and measured NOx values suggest that in particular the NOx input by lightning and the convective transport from the polluted boundary layer are still not well described by current parameterizations, which may lead to significant differences in the spatial and seasonal distribution of NOx in the models. Simulated OH concentrations, on the other hand, were found to be in surprisingly good agreement with measured values.
وصف الملف: electronic resource
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5دورية أكاديمية
المؤلفون: D. Brunner, J. Staehelin, H. L. Rogers, M. O. Köhler, J. A. Pyle, D. A. Hauglustaine, L. Jourdain, T. K. Berntsen, M. Gauss, I. S. A. Isaksen, E. Meijer, P. Van Velthoven, G. Pitari, E. Mancini, V. Grewe, R. Sausen
المساهمون: The Pennsylvania State University CiteSeerX Archives
الوصف: This is the second part of a rigorous model evaluation study involving five global Chemistry-Transport and two Chemistry-Climate Models operated by different groups in Europe. Simulated trace gas fields were interpolated to the exact times and positions of the observations to account for the actual weather conditions and hence for the specific histories of the sampled air masses. In this part of the study we focus on a detailed comparison with two selected campaigns, PEM-Tropics A and SONEX, contrasting the clean environment of the tropical Pacific with the more polluted North Atlantic region. The study highlights the different strengths and weaknesses of the models in accurately simulating key processes in the UT/LS region including stratosphere-troposphere-exchange, rapid convective transport, lightning emissions, radical chemistry and ozone
وصف الملف: application/pdf
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6دورية أكاديمية
المؤلفون: D. Brunner, J. Staehelin, H. L. Rogers, M. O. Köhler, J. A. Pyle, D. A. Hauglustaine, L. Jourdain, T. K. Berntsen, M. Gauss, I. S. A. Isaksen, E. Meijer, P. Van Velthoven, G. Pitari, E. Mancini, V. Grewe, R. Sausen
المساهمون: The Pennsylvania State University CiteSeerX Archives
مصطلحات موضوعية: References
الوصف: An evaluation of the performance of chemistry transport models, Part 2: detailed comparison with two selected campaigns
وصف الملف: application/pdf
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المؤلفون: Roy G. Grainger, Clive D. Rodgers, W. A. Norton, Alyn Lambert, H. L. Rogers, Fredric W. Taylor
مصطلحات موضوعية: Contour advection, Infrared, social sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, respiratory system, Atmospheric sciences, complex mixtures, humanities, Aerosol, Atmosphere, Geophysics, Extinction (optical mineralogy), TRACER, General Earth and Planetary Sciences, Environmental science, Astrophysics::Earth and Planetary Astrophysics, Stratosphere, Astrophysics::Galaxy Astrophysics, Physics::Atmospheric and Oceanic Physics, Water vapor
الوصف: The ambient water vapour and temperature conditions of stratospheric sulphate aerosol particles govern their composition and thereby influence their infrared extinction properties. This causes problems in the use of the infrared aerosol extinction as a tracer because variations in the aerosol composition modify the changes in extinction that may arise from the transport of aerosols. An improved tracer which can be derived from measurements of the infrared aerosol extinction, temperature and water vapour abundance, is the H2SO4 component of aerosols. The application of this tracer to studies of stratospheric transport is demonstrated using data from instruments on the Upper Atmosphere Research Satellite and the results are compared to a contour advection calculation. Copyright 1996 by the American Geophysical Union.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1b873f720fc73fcd210586f3054bd11fTest
https://doi.org/10.1029/96gl02074Test -
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المؤلفون: H L, Rogers, H T, Brotherton, A, de Luis, S L, Olivera-Plaza, A F, Córdoba-Patiño, M L, Peña-Altamar
المصدر: Acta reumatologica portuguesa. 40(1)
مصطلحات موضوعية: Arthritis, Rheumatoid, Male, Socioeconomic Factors, Depression, Humans, Pain, Female, Colombia, Middle Aged, Attitude to Health, Pain Measurement
الوصف: To examine the relationships between psychosocial factors and reported pain in Colombians with Rheumatoid Arthritis (RA).One hundred and three RA patients [85% from the lowest socio-economic strata (SES) in the country] recruited from outpatient centers in Neiva, Colombia were administered the Disease Activity Scale (DAS) , which included a Visual Analog Scale (VAS) arthritis pain/activity rating, Zung Depression Scale, State-Trait Anxiety Inventory (STAI), Interpersonal Support Evaluation List-12 (ISEL-12), and Symptom Checklist-90 Revised (SCL-90R).VAS pain was not associated with socio-demographic or medical factors, but was negatively associated with ISEL tangible subscale (r=-0.22, p0.01; r=0.28, p0.01). VAS pain was positively associated with Zung Depression Scale score (r=0.38, p0.001), STAI-State and STAI-Trait Anxiety (r=0.23 and r=0.25 respectively, p's0.01), SCL-90R Global Severity Index (GSI) and Positive Symptom Total (PST) (r=0.23, p0.05 and r=0.29, p0.01 respectively), and SCL-90R Somatization, Depression, and Anxiety subscales (r=0.30, p0.01; r=0.28, p0.01; and r=0.20, p0.05 respectively). A linear regression model showed that socio-demographic characteristics theoretically associated with pain perception (gender, age, and SES) explained only 2.4% of the variance of VAS scores (R(2)=0.02, p=0.49). The full model, including psychosocial factors significantly associated with VAS scores explained 18.9% of the variance in VAS pain perception scores (R(2)=0.19, p=0.02). The Zung Depression Scale score was the only factor independently associated with VAS pain, such that higher depression scores were associated with higher VAS ratings (β =0.13, p0.01), controlling for gender, age, SES, STAI-State, STAI-Trait, ISEL tangible, SCL-90R GSI, and SCL-90R PST.Depressive symptoms, anxiety, social support, and psychopathological symptom distress were associated with pain ratings, but only depressive symptoms were found to be uniquely associated with higher pain perception, taking into account socio-demographic characteristics and other psychosocial factors. Findings provide evidence for the need to assess and treat pain in RA in Colombia from a bio-psycho-social perspective. Future research is needed to determine effective depression screening and evidence-based interventions for depressive symptoms in RA patients in this socio-cultural context, as intervening in depression may decrease pain perception.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::a87970f6f71cf97e4ce2eec68ca3dd99Test
https://pubmed.ncbi.nlm.nih.gov/25844967Test -
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المؤلفون: P. M. de F. Foster, Christopher W. Wilson, David S. Lee, Peter J. Newton, David Raper, H. L. Rogers
المصدر: The Aeronautical Journal. 106:521-546
مصطلحات موضوعية: Aviation, business.industry, Aerospace Engineering, Civil aviation, Radiative forcing, Environmental economics, Aeronautics, Environmental impact of aviation, Environmental science, Environmental impact assessment, Emissions trading, business, Constraint (mathematics), Air quality index
الوصف: This paper describes the current status of knowledge regarding the impact of aviation on the atmosphere. The growth of the aviation industry is likely to continue in the future and at present there are significant concerns that this will adversely affect climate and local air quality in the vicinity of airports. Indeed, it is possible that air quality may become a constraint to increased capacity of some large hub airports. Currently the radiative forcing impact from aircraft emissions, other than CO2, are not accounted for in the International Civil Aviation Organization emission trading scheme proposals. Taking only this approach, emissions trading could, in theory, increase the radiative forcing, rather than decrease it. The study of improved ‘environmentally friendly’ flight is still in its infancy, however any proposed and actual new developments, in terms of technology and operational practice, should include an environmental assessment.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::d3361fa741dbb4c99c9be3411112afceTest
https://doi.org/10.1017/s0001924000018157Test -
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المؤلفون: H L Rogers, S M Reilly
المصدر: AAOHN Journal. 48:376-384
مصطلحات موضوعية: education.field_of_study, Nursing (miscellaneous), 030504 nursing, business.industry, Population, Public Health, Environmental and Occupational Health, Human factors and ergonomics, Poison control, International business, medicine.disease, Suicide prevention, Occupational safety and health, 03 medical and health sciences, 0302 clinical medicine, Nursing, Injury prevention, Medicine, 030212 general & internal medicine, Medical emergency, 0305 other medical science, business, education, human activities, Psychosocial
الوصف: 1. Few studies examine the travel related health problems of international business travelers (IBTs). Research exists for other travelers, such as tourists, which begins to help clinicians understand the potential health problems faced by IBTs. 2. A review of the literature reveals 36% to 54% of travelers experience physical health problems such as traveler's diarrhea, insomnia, respiratory problems, and skin problems; 6% to 18% report accidents and injuries while abroad. 3. Psychosocial data are equally limited, but support the idea that IBTs may experience stress, anxiety, culture shock, and adjustment problems while overseas. 4. Multiple factors likely contribute to the physical and psychosocial health experiences of IBTs. The historical lack of data for this population of workers combined with the trend towards globalization confirm the need for further study from an occupational health perspective.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::fb95943268b867f0c775bdf575b24202Test
https://doi.org/10.1177/216507990004800803Test
النص الكامل