High precision measurement of a atmospheric trace gases using fourier transform infrared spectroscopy

Studies in recent years have revealed that the global atmosphere is undergoing rapid change due to anthropogenic activities, potentially leading to climate change through greenhouse warming, and to harmful stratospheric ozone dq)letion. There is a need for more and better measurements of the atmospheric trace gases implicated in these processes, so that the global anthrqpograic impact can be quantified and, if possible, minimised. The three main anthropogenic greenhouse gases are carbon dioxide, methane and nitrous oxide. Nitrous oxide is also implicated in stratospheric ozone depletion. Carbon monoxide, while not directly a greenhouse gas, is intimately connected with the oxidative state of the atmosphere. Measurements of the background atmosphere mixing ratios and of biosphere-atmosphere fluxes of trace gases typically employ seme ensemble of Gas-Chromatogr^hy (GC), Non-Dispersive Infrared (NDIR) spectroscopy and Tunable Diode Laser (TDL) spectroscopy instrumentation. If, in addition, stable isotope ratio data are to be retrieved, Isotope-Ratio-Mass-Spectrometry (IRMS) instrumentation is required. These iostruments all provide high-predsiou measurements. However, their usual singlespecies focus, their variety of deteaor response functions, calibration requirements, varying degree of mobility, as well as their complexity and expense, seriously constrains the accumulation of data in both laboratory and field investigations. This thesis reports the development of a mediod of trace gas and isotope ratio analysis based on Icm ^ resolution FITR spectroscopy, deployable in both laboratory and field implications. The species CO2, CH4, CO and N2O may be analysed simultaneously in a single air sample using this method. Its mixing ratio analytical precision is in all cases superior to or competitive with that of the more usual methods mentioned above. In addition, the FTIR instrument may be used to measure the stable isotope ratio of CO2 in ambient air to a gepphysically useful degree of precision; still exceeded, however, by that attainable using IRMS. The novel FTIR method relies on calibration using synthetically calculated absorbance spectra and a chem(Hnetric multivariate calibration algorithm. Classical Least Squares (CLS). Careful experimental design and control of the instrument environment also contributes to the high degree of precision achieved

Hard To Stop: Image and Authorship in the Films of Steven Seagal

Little serious scholarly work has been done on the career of Steven Seagal which is surprising given his immense popularity in the early 1990s. In addition to suggesting more work be done on less traditional stars, this thesis asks what factors lead to an understanding of Steven Seagal as a working class action hero. It makes the case for understanding Seagal as a star because of the impressive box office success of his films along with his immense popularity during that time frame. The thesis focuses mainly on Seagal's films from 1988 until 1995, with only occasional references to his later, less commercially successful work which nonetheless helps explicate the essence of the Seagal persona. The main theoretical texts utilized in this thesis are Richard Dyer's Stars, which examines both the sociological and semiotic implications of stardom, and Rick Altman's Film/Genre, which explores the evolution of the working class action film. The way in which Seagal's working class action hero persona was constructed and sustained lies in the dynamic interactions of three competing forces: the studios, Seagal himself, and his audience. In addition to how his persona was created, the thesis looks at those aspects of Seagal's star persona essential to Seagal's status as a working class action hero. Seagal's principal characters are associated with the Vietnam or a Vietnam-like War; they are men enforce their own codes of conduct and justice; and, they connect in multiple ways with numerous ethnicities and cultures. This thesis performs its analysis of Seagal's star persona through historical and sociological approaches, drawing heavily from industry and popular publications to help gauge public interest in the actor

Evaluation of a Portable Automated Serum Chemistry Analyzer for Field Assessment of Harlequin Ducks, Histrionicus histrionicus

A portable analytical chemistry analyzer was used to make field assessments of wild harlequin ducks (Histrionicus histrionicus) inassociation with telemetry studies of winter survival in Prince William Sound, Alaska. We compared serum chemistry resultsobtained on-site with results from a traditional laboratory. Particular attention was paid to serum glucose and potassiumconcentrations as potential indicators of high-risk surgical candidates based on evaluation of the field data. Themedian differentialfor glucose values (N = 82) between methods was 0.6 mmol/L (quartiles 0.3 and 0.9 mmol/L) with the median value higher whenassayed on site. Analysis of potassium on site returned a median of 2.7 mmol/L (N = 88 ; quartiles 2.4 and 3.0 mmol/L). Serumpotassium values were too low for quantitation by the traditional laboratory. Changes in several serum chemistry values followinga three-day storm during the study support the value of on site evaluation of serum potassium to identify presurgical patients withincreased anesthetic risk.                                      &nbsp

Lyceum: A Multi-Protocol Digital Library Gateway

Lyceum is a prototype scalable query gateway that provides a logically central interface to multi-protocol and physically distributed, digital libraries of scientific and technical information. Lyceum processes queries to multiple syntactically distinct search engines used by various distributed information servers from a single logically central interface without modification of the remote search engines. A working prototype (http://www.larc.nasa.gov/lyceum/) demonstrates the capabilities, potentials, and advantages of this type of meta-search engine by providing access to over 50 servers covering over 20 disciplines

More Than Movies: Social Formations in Informal Networks of Media Sharing

This project examines the social structures, formations, and practices of informal networks of media sharing (INMSs) through both historical and sociological lenses. INMSs are comprised of individuals who distribute and circulate media to one another through noncommercial, unauthorized networks. The networks can be centered around texts, such as the early videophile publication The Videophile’s Newsletter, or they can be constituted by disparate groups of people who come together as a community using digital platforms like BitTorrent. While nominally concerned with circulating media, INMSs are also sources of social sustenance for their members and are sites of struggle for social and symbolic capital and power. They illuminate the complex ways in which community members utilize media as a starting point to satisfy a variety of needs, including developing bodies of cultural and technical knowledge, thinking through legal and ethical concerns, creating social bonds, and engaging in a variety of pedagogical practices. In short, INMSs are loci of social and cultural meaning-making for their members. This dissertation catalogs and analyzes the social practices and formations of three INMSs, the aforementioned Videophile’s Newsletter and two private, BitTorrent networks focused on cinema, Great Cinema and FilmDestruction, showing there to be diachronic and transplatform similarities between different networks. Rather than instances of rupture and divergence, this project argues that these networks are best understood through an evolutionary lens. It contends that INMSs and other similar formations should be increasingly studied because of their prevalence throughout the 20th and 21st centuries and their importance to consumers as unauthorized media distribution spaces whereby network members have greater latitude to experiment with media and create unique, diverse social structures and practices that are not contingent upon restrictions imposed by the media and copyright industries

A general theorem on angular-momentum changes due to potential vorticity mixing and on potential-energy changes due to buoyancy mixing

An initial zonally symmetric quasigeostrophic potential-vorticity (PV) distribution q_i(y) is subjected to complete or partial mixing within some finite zone |y| < L, where y is latitude. The change in M, the total absolute angular momentum, between the initial and any later time is considered. For standard quasigeostrophic shallow-water beta-channel dynamics it is proved that, for any q_i(y) such that dq_i/dy > 0 throughout |y| < L, the change in M is always negative. This theorem holds even when "mixing" is understood in the most general possible sense. Arbitrary stirring or advective rearrangement is included, combined to an arbitrary extent with spatially inhomogeneous diffusion. The theorem holds whether or not the PV distribution is zonally symmetric at the later time. The same theorem governs Boussinesq potential-energy changes due to buoyancy mixing in the vertical. For the standard quasigeostrophic beta-channel dynamics to be valid the Rossby deformation length L_D >> \epsilon L where \epsilon is the Rossby number; when L_D = \infty the theorem applies not only to the beta-channel, but also to a single barotropic layer on the full sphere, as considered in the recent work of Dunkerton and Scott on "PV staircases". It follows that the M-conserving PV reconfigurations studied by those authors must involve processes describable as PV unmixing, or anti-diffusion, in the sense of time-reversed diffusion. Ordinary jet self-sharpening and jet-core acceleration do not, by contrast, require unmixing, as is shown here by detailed analysis. Mixing in the jet flanks suffices. The theorem extends to multiple layers and continuous stratification. A corollary is a new nonlinear stability theorem for shear flows.Comment: 14 pages, 4 figures; Final version, accepted by J. Atmos. Sci, in pres

Global tropospheric ozone modelling:quantifying errors due to grid resolution.

Ozone production in global chemical models is dependent on model resolution because ozone chemistry is inherently nonlinear, the timescales for chemical production are short, and precursors are artificially distributed over the spatial scale of the model grid. In this study we examine the sensitivity of ozone, its precursors, and its production to resolution by running a global chemical transport model at four different resolutions between T21 (5.6° × 5.6°) and T106 (1.1° × 1.1°) and by quantifying the errors in regional and global budgets. The sensitivity to vertical mixing through the parameterization of boundary layer turbulence is also examined. We find less ozone production in the boundary layer at higher resolution, consistent with slower chemical production in polluted emission regions and greater export of precursors. Agreement with ozonesonde and aircraft measurements made during the NASA TRACE-P campaign over the western Pacific in spring 2001 is consistently better at higher resolution. We demonstrate that the numerical errors in transport processes on a given resolution converge geometrically for a tracer at successively higher resolutions. The convergence in ozone production on progressing from T21 to T42, T63, and T106 resolution is likewise monotonic but indicates that there are still large errors at 120 km scales, suggesting that T106 resolution is too coarse to resolve regional ozone production. Diagnosing the ozone production and precursor transport that follow a short pulse of emissions over east Asia in springtime allows us to quantify the impacts of resolution on both regional and global ozone. Production close to continental emission regions is overestimated by 27% at T21 resolution, by 13% at T42 resolution, and by 5% at T106 resolution. However, subsequent ozone production in the free troposphere is not greatly affected. We find that the export of short-lived precursors such as NO x by convection is overestimated at coarse resolution