467 research outputs found
Qualification of the airborne FTIR spectrometer MIPAS-STR and study on denitrification and chlorine deactivation in Arctic winter 2009/10
This work describes the qualification of the airborne Fourier-Transform infrared spectrometer Michelson Interferometer for Passive Atmospheric Sounding-STRatospheric aircraft (MIPAS-STR) and studies on ozone-relevant processes in the Arctic winter stratosphere. Using MIPAS-STR measurements, correlative in-situ measurements and simulations of the Chemical Lagrangian Model of the Stratosphere (CLaMS), the processes denitrification and chlorine deactivation are investigated
Evaluation of cattle handling categories in the beef quality assurance feedyard assessment, compliance of large feedyards with these guidelines, and influence of handling practices on behavior and performance of feedlot cattle, An
Includes bibliographical references.2015 Summer.Animal husbandry and management practices were surveyed in commercial feedlots to document compliance of select feedlots with Beef Quality Assurance (BQA) guidelines for cattle handling under the premise that this data warrants inclusion in the National Beef Quality Audit (NBQA). The BQA Feedyard Assessment for cattle handling has not yet been fully validated, and this work partially substantiates the current assessment categories. The inclusion of this handling data is essential in order to continue the track record of identifying target areas where improvement is needed, and to document growth and positive performance. Collecting and reporting of survey data is part of the verification and ongoing monitoring process that characterizes an effective HACCP plan, which was the system for management that was adopted during formation of the BQA program. It has been said that producers manage what they measure, and systematic measurement of categories for cattle handling and husbandry practices in the BQA can yield valuable information to assist producers in making management decisions. The NBQA, which has been conducted in five year increments since 1991 has accomplished just that, through the identification of targets where improvement is needed, with corresponding recommendations for improvement. The growing repository of data, collected over the course of time, reflects adjustments the industry has made in an effort to continuously improve the quality and consistency of beef production, and thus increase consumer confidence. BQA is a voluntary program that allows the use of self-assessment or third party audits to ensure compliance with the guidelines of the program. The BQA Feedyard Assessment (FA) provides guidelines for cattle handling in commercial feedlots, and is a useful tool for measuring cattle handling practices. Using these guidelines, select feedlots in 3 states (Colorado, Kansas, and Nebraska) were assessed for six current BQA categories (electric prod use, falls, stumbles, jump and run, and chute operation). These states rank 5th, 3rd, and 2nd, respectively, among all states for the number of cattle on feed each year. These three states were selected based on their ranking among the top five states for number of cattle on feed, and for the high density areas of large (1000+ head) feedyards in each state, accounting for approximately 50% of all US fed cattle each year. The feedyards included in this study were all large (1000+ head capacity) yards, with a mean capacity of 34,000 head. Across 28 sites surveyed, rate of electric prod use was 3.8% vs. the 10% current BQA critical limit (CL); only 2 sites surveyed exceeded the CL with 15% and 45% respective rates; and 12 did not use an electric prod. The rate of cattle falling when exiting the squeeze chute was 0.6% vs. BQA CL 2%, and no site surveyed exceeded the CL. The rate of cattle stumbling when exiting the squeeze chute was 5.7% vs. BQA CL 10%, with 4 sites exceeding the CL and 4 sites that had no stumbles. The rate of cattle vocalizing was 1.4% vs. BQA CL 5%; for cattle that jumped or ran when exiting the squeeze chute, 52% vs. BQA CL 25%; and mean score for cattle that were improperly captured in the squeeze chute and not readjusted was 1.2%, vs. BQA CL 0%. A second study was conducted at a commercial feedlot in Kansas. The objective of this study was to investigate if a relationship exists between handling, and behavior and ADG of feedlot cattle. Upon arrival, Hereford steers (n = 496; initial BW = 304 ± 35.6 kg) of similar genetic background were sorted into four pens to determine the effects of handling on behavior and ADG. Two handling conditions prior to processing and two conditions of release from the squeeze chute were imposed. Prior to processing, handlers were required to quietly walk all steers from their home pen to the processing area (SLOW); or handlers were permitted to bring steers to the processing area in the normal fashion (FAST). Since this condition was applied to pens, pen was considered the experimental unit for the full model. Individual steers were randomly assigned to one of two conditions of release from the squeeze chute. The first was a delay no longer than 30 seconds following the completion of procedures to allow cattle to stop struggling (DELAY); the second was release immediately following the completion of procedures (NORM). Vocalization, chute temperament, exit speed and exit behavior scores were assigned to all steers during intake processing. Paired t-tests determined that cattle exiting the chute at a walk or trot vs a run tended (P=0.08) to have higher ADG. Cattle vocalizing during restraint had lower (P=0.04) ADG than those that did not vocalize. The FAST group showed a tendency to vocalize more frequently than the SLOW group. Pearson’s correlation analysis showed a significant, positive correlation between exit speed and vocalization (P= 0.0021, r= 0.14256), and a significant, negative correlation between exit speed and ADG (P= 0.0036, r= -0.13542). Using this approach, handling was correlated with behavior and ADG
Urban risk communication in Ahmedabad - India: between slum dwellers and the municipal corporation.
Since rapid urban growth forces poor households to settle in highly congested urban areas, slum dwellers are increasingly vulnerable due to a multiplicity of hazards rooted in the environment, nature, health, society and the urban economy. Hitherto, the understanding of urban risks and the vulnerability of inhabitants has been an underrepresented subject in urban planning. The different reasoning and rationales of slum dwellers, municipal authorities and other actors provide each with different perceptions of risks. This study focuses on the communication of urban risks between two slum communities and the Municipal Corporation of Ahmedabad by examining endeavours in slum improvement and more responsive urban governance. In using a conceptual framework that synthesises socio-cultural approaches to risk, communication theories and collaborative planning theory, the thesis points out the deficiencies and potentials of risk communication in long-term urban development planning. Currently urban risk management is not recognised as an integrated, cross-sectoral topic by the Municipal Corporation. Due to the structural fabric of the administration and the lack of capacity and guidance, the notion of risk is based on conventional approaches to disaster risk management with responsibilities spread across various departments. By contrast, slum dwellers have a much more integrated understanding of the micro-level risk conditions in which they live and work. The findings of this study suggest that a meaningful two-way communication process can only take place if the interaction of stakeholders is understood in terms of human relationships that go beyond techno-bureaucratic co-ordination and the prevalent notion of mono-directional communication. This concept of communication is underpinned by values such as trust, fairness, credibility and justice in interaction in the context of urban governance. The research approach and the findings suggest areas for improved policy making and further research. The outcome of the research especially contributes to a better understanding of urban risk situations in the social and cultural contexts of poor communities in India. Hence this investigation may be viewed as a potential basis for generating practical guidelines for mitigation policies and their links to urban governance
Two hearts beating in a research centers' chest: how scholars in interdisciplinary research settings cope with monodisciplinary deep structures
Interdisciplinary research is a popular mode of knowledge production that becomes intensively promoted by research centers all across the globe. Despite the facilitation of interdisciplinary research, however, scholars working in these centers are 'disciplined.' Career promotions, funding decisions and scientific publishing are based on peer-review procedures that tend to favor monodisciplinary research. This paper builds on a qualitative study with scholars in interdisciplinary research centers in Germany and asks how scholars cope with these monodisciplinary demands. After deriving a conceptual framework, the study identifies four coping strategies: disciplinary innovation, strategic compliance, niche-seeking, and field creation. Each of these strategies is characterized by a different degree of openness to knowledge bases of other disciplines and a different degree of proactivity towards monodisciplinary demands from the scientific field. The results illuminate how research agendas become disciplined despite interdisciplinary motivation and organizational support of interdisciplinary research
Are Chebyshev-based stability analysis and Urabe's error bound useful features for Harmonic Balance?
Harmonic Balance is one of the most popular methods for computing periodic
solutions of nonlinear dynamical systems. In this work, we address two of its
major shortcomings: First, we investigate to what extent the computational
burden of stability analysis can be reduced by consistent use of Chebyshev
polynomials. Second, we address the problem of a rigorous error bound, which,
to the authors' knowledge, has been ignored in all engineering applications so
far. Here, we rely on Urabe's error bound and, again, use Chebyshev polynomials
for the computationally involved operations. We use the error estimate to
automatically adjust the harmonic truncation order during numerical
continuation, and confront the algorithm with a state-of-the-art adaptive
Harmonic Balance implementation. Further, we rigorously prove, for the first
time, the existence of some isolated periodic solutions of the forced-damped
Duffing oscillator with softening characteristic. We find that the effort for
obtaining a rigorous error bound, in its present form, may be too high to be
useful for many engineering problems. Based on the results obtained for a
sequence of numerical examples, we conclude that Chebyshev-based stability
analysis indeed permits a substantial speedup. Like Harmonic Balance itself,
however, this method becomes inefficient when an extremely high truncation
order is needed as, e.g., in the presence of (sharply regularized)
discontinuities.Comment: The final version of this article is available online at
https://doi.org/10.1016/j.ymssp.2023.11026
Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions
Significant reductions in stratospheric ozone occur inside the polar vortices each spring when chlorine radicals produced by heterogeneous reactions on cold particle surfaces in winter destroy ozone mainly in two catalytic cycles, the ClO dimer cycle and the ClO/BrO cycle. Chlorofluorocarbons (CFCs), which are responsible for most of the chlorine currently present in the stratosphere, have been banned by the Montreal Protocol and its amendments, and the ozone layer is predicted to recover to 1980 levels within the next few decades. During the same period, however, climate change is expected to alter the temperature, circulation patterns and chemical composition in the stratosphere, and possible geo-engineering ventures to mitigate climate change may lead to additional changes. To realistically predict the response of the ozone layer to such influences requires the correct representation of all relevant processes. The European project RECONCILE has comprehensively addressed remaining questions in the context of polar ozone depletion, with the objective to quantify the rates of some of the most relevant, yet still uncertain physical and chemical processes. To this end RECONCILE used a broad approach of laboratory experiments, two field missions in the Arctic winter 2009/10 employing the high altitude research aircraft M55-Geophysica and an extensive match ozone sonde campaign, as well as microphysical and chemical transport modelling and data assimilation. Some of the main outcomes of RECONCILE are as follows: (1) vortex meteorology: the 2009/10 Arctic winter was unusually cold at stratospheric levels during the six-week period from mid-December 2009 until the end of January 2010, with reduced transport and mixing across the polar vortex edge; polar vortex stability and how it is influenced by dynamic processes in the troposphere has led to unprecedented, synoptic-scale stratospheric regions with temperatures below the frost point; in these regions stratospheric ice clouds have been observed, extending over >106km2 during more than 3 weeks. (2) Particle microphysics: heterogeneous nucleation of nitric acid trihydrate (NAT) particles in the absence of ice has been unambiguously demonstrated; conversely, the synoptic scale ice clouds also appear to nucleate heterogeneously; a variety of possible heterogeneous nuclei has been characterised by chemical analysis of the non-volatile fraction of the background aerosol; substantial formation of solid particles and denitrification via their sedimentation has been observed and model parameterizations have been improved. (3) Chemistry: strong evidence has been found for significant chlorine activation not only on polar stratospheric clouds (PSCs) but also on cold binary aerosol; laboratory experiments and field data on the ClOOCl photolysis rate and other kinetic parameters have been shown to be consistent with an adequate degree of certainty; no evidence has been found that would support the existence of yet unknown chemical mechanisms making a significant contribution to polar ozone loss. (4) Global modelling: results from process studies have been implemented in a prognostic chemistry climate model (CCM); simulations with improved parameterisations of processes relevant for polar ozone depletion are evaluated against satellite data and other long term records using data assimilation and detrended fluctuation analysis. Finally, measurements and process studies within RECONCILE were also applied to the winter 2010/11, when special meteorological conditions led to the highest chemical ozone loss ever observed in the Arctic. In addition to quantifying the 2010/11 ozone loss and to understand its causes including possible connections to climate change, its impacts were addressed, such as changes in surface ultraviolet (UV) radiation in the densely populated northern mid-latitudes
Aquaculture in Cooling Water Recirculated From a Generating Plant
Recirculating cooling water from an electric generating plant accumulated dissolved and suspended solids up to ten times that of the make-up water from the Mississippi River. Channel catfish (lctalurus punctatus) and tilapia (Tilapia mossambica) were grown In the cooling water, in clear well water, and in a mixture of the two for seven months as part of an investigation of the use of cooling water for commercial aquaculture. Health of both species was generally excellent in test and control waters; growth was commercially acceptable; bioaccumulation of contaminants was negligible. Organoleptic taste quality was not acceptable, although the cause of the off-flavor is uncertain and may be controllable
Validation of first chemistry mode retrieval results from the new limb-imaging FTS GLORIA with correlative MIPAS-STR observations
We report first chemistry mode retrieval results from the new airborne limb-imaging infrared FTS (Fourier transform spectrometer) GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) and comparisons with observations by the conventional airborne limb-scanning infrared FTS MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding – STRatospheric aircraft). For GLORIA, the flights aboard the high-altitude research aircraft M55 Geophysica during the ESSenCe campaign (ESa Sounder Campaign 2011) were the very first in field deployment after several years of development. The simultaneous observations of GLORIA and MIPAS-STR during the flight on 16 December 2011 inside the polar vortex and under conditions of optically partially transparent polar stratospheric clouds (PSCs) provided us the first opportunity to compare the observations by two different infrared FTS generations directly. We validate the GLORIA results with MIPAS-STR based on the lower vertical resolution of MIPAS-STR and compare the vertical resolutions of the instruments derived from their averaging kernels. The retrieval results of temperature, HNO3, O3, H2O, CFC-11 and CFC-12 show reasonable agreement of GLORIA with MIPAS-STR and collocated in situ observations. For the horizontally binned hyperspectral limb images, the GLORIA sampling outnumbered the horizontal cross-track sampling of MIPAS-STR by up to 1 order of magnitude. Depending on the target parameter, typical vertical resolutions of 0.5 to 2.0 km were obtained for GLORIA and are typically a factor of 2 to 4 better compared to MIPAS-STR. While the improvement of the performance, characterization and data processing of GLORIA are the subject of ongoing work, the presented first results already demonstrate the considerable gain in sampling and vertical resolution achieved with GLORIA
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