871 research outputs found
Laser Raman diagnostics in subsonic and supersonic turbulent jet diffusion flames
Ultraviolet (UV) spontaneous vibrational Raman scattering combined with laser-induced predissociative fluorescence (LIPF) is developed for temperature and multi-species concentration measurements. Simultaneous measurements of temperature, major species (H2, O2, N2, H2O), and minor species (OH) concentrations are made with a 'single' narrow band KrF excimer laser in subsonic and supersonic lifted turbulent hydrogen-air diffusion flames. The UV Raman system is calibrated with a flat-flame diffusion burner operated at several known equivalence ratios from fuel-lean to fuel-rich. Temperature measurements made by the ratio of Stokes/anti-Stokes signal and by the ideal gas law are compared. The single shot measurement precision for concentration and temperature measurement is 5 to 10 pct. Calibration constants and bandwidth factors are determined from the flat burner measurements and used in a data reduction program to arrive at temperature and species concentration measurements. These simultaneous measurements of temperature and multi-species concentrations allow a better understanding of the complex turbulence-chemistry interactions and provide information for the input and validation of CFD models
Experiments and Simulations on Day-to-Day Route Choice-Behaviour
The paper reports laboratory experiments on a day-to-day route choice game with two routes. Subjects had to choose between a main road M and a side road S. The capacity was greater for the main road. 18 subjects participated in each session. In equilibrium the number of subjects is 12 on M and 6 on S. Two treatments with 6 sessions each were run at the Laboratory of Experimental Economics at Bonn University using RatImage. Feedback was given in treatment I only about own travel time and in treatment II on travel time for M and S. Money payoffs increase with decreasing time. The main results are as follows. 1. Mean numbers on M and S are very near to the equilibrium. 2. Fluctuations persist until the end of the sessions in both treatments. 3. Fluctuations are smaller under treatment II .The effect is small but significant. 4. The total number of changes is significantly greater in treatment I. 5. Subjects’ road changes and payoffs are negatively correlated in all sessions. 6. A direct response mode reacts with more changes for bad payoffs whereas a contrary response mode shows opposite reactions. Both response modes can be observed. 7. The simulation of an extended payoff sum learning model closely fits the main results of the statistical evaluation of the data.travel behaviour research, information in intelligent transportation systems, day-to-day route choice, laboratory experiments, payoff sum model
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Testing (beliefs about) social preferences: evidence from an experimental coordination game
We report experimental results on a simple coordination game in which two players can coordinate either on an equal distribution of payoffs or on a Pareto superior but unequal distribution of payoffs. We find that the higher the difference in individual payoffs, the less likely is a successful coordination on the Pareto superior distribution. While this is well in line with the recent models of inequity aversion, our results are best explained not by a preference for equality per se but rather by the belief that the opponent has such a preference
Managing Access to Biobanks:How Can We Reconcile Privacy and Public Interests in Genetic Research?
This article is concerned with the ultimate objectives of genetic biobanks set up to promote the public interest—being the sharing of samples and data for medical research—and the consequences for personal privacy of realising them. Our aim is to chart the values, interests and principles in play, to consider the challenges of realizing biobanking objectives on a global scale, and to propose viable ways forward that ensure, as far as possible, that access provisions remain fit for purpose throughout the entire life of a biobank, while adequately protecting the privacy interests at stake. It is argued that key features in any robust access model must include mechanisms to (a) maintain participant trust in management of the resource and to measure and respond to participants’ expectations, (b) facilitate and promote the sharing of benefits, and (c) respond timeously and effectively to new challenges
Experiments and Simulations on Day-to-Day Route Choice-Behaviour
The paper reports laboratory experiments on a day-to-day route choice game with two routes. Subjects had to choose between a main road M and a side road S. The capacity was greater for the main road. 18 subjects participated in each session. In equilibrium the number of subjects is 12 on M and 6 on S.Two treatments with 6 sessions each were run at the Laboratory of Experimental Economics at Bonn University using RatImage. Feedback was given in treatment I only about own travel time and in treatment II on travel time for M and S. Money payoffs increase with decreasing time. The main results are as follows. 1. Mean numbers on M and S are very near to the equilibrium. 2. Fluctuations persist until the end of the sessions in both treatments. 3. Fluctuations are smaller under treatment II .The effect is small but significant. 4. The total number of changes is significantly greater in treatment I. 5. Subjects' road changes and payoffs are negatively correlated in all sessions.6. A direct response mode reacts with more changes for bad payoffs whereas a contrary response mode shows opposite reactions. Both response modes can be observed. 7. The simulation of an extended payoff sum learning model closely fits the main results of the statistical evaluation of the data
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Commuters route choice behaviour
The paper reports laboratory experiments with a two route choice scenario. In each session 18 subjects had to choose between a main road M and a side road S. The capacity of M was larger. Feedback was given in treatment I only on the subjects' own travel time and in treatment II on travel time for M and S. The main results are as follows:
• Mean numbers on M and S are near to pure equilibrium.
• Fluctuations persist until the end of the sessions.
• The total number of changes is significantly greater in treatment I.
• Subjects' road changes and payoffs are negatively correlated.
• A direct response mode results in more changes for bad payoffs whereas a contrary response mode shows opposite reactions.
• Simulations of an extended payoff sum learning model fits the main results of the statistical evaluation of the data
Chemical Kinetic Models for HCCI and Diesel Combustion
Predictive engine simulation models are needed to make rapid progress towards DOE's goals of increasing combustion engine efficiency and reducing pollutant emissions. These engine simulation models require chemical kinetic submodels to allow the prediction of the effect of fuel composition on engine performance and emissions. Chemical kinetic models for conventional and next-generation transportation fuels need to be developed so that engine simulation tools can predict fuel effects. The objectives are to: (1) Develop detailed chemical kinetic models for fuel components used in surrogate fuels for diesel and HCCI engines; (2) Develop surrogate fuel models to represent real fuels and model low temperature combustion strategies in HCCI and diesel engines that lead to low emissions and high efficiency; and (3) Characterize the role of fuel composition on low temperature combustion modes of advanced combustion engines
Two-phonon 1- state in 112Sn observed in resonant photon scattering
Results of a photon scattering experiment on 112Sn using bremsstrahlung with
an endpoint energy of E_0 = 3.8 MeV are reported. A J = 1 state at E_x =
3434(1) keV has been excited. Its decay width into the ground state amounts to
Gamma_0 = 151(17) meV, making it a candidate for a [2+ x 3-]1- two-phonon
state. The results for 112Sn are compared with quasiparticle-phonon model
calculations as well as the systematics of the lowest-lying 1- states
established in other even-mass tin isotopes. Contrary to findings in the
heavier stable even-mass Sn isotopes, no 2+ states between 2 and 3.5 MeV
excitation energy have been detected in the present experiment.Comment: 10 pages, including 2 figures, Phys. Rev. C, in pres
Belowground competition among invading detritivores
Author Posting. © Ecological Society of America, 2016. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 97 (2016): 160–170, doi:10.1890/15-0551.1.The factors regulating soil animal communities are poorly understood. Current theory favors niche complementarity and facilitation over competition as the primary forms of non-trophic interspecific interaction in soil fauna; however, competition has frequently been suggested as an important community-structuring factor in earthworms, ecosystem engineers that influence belowground processes. To date, direct evidence of competition in earthworms is lacking due to the difficulty inherent in identifying a limiting resource for saprophagous animals. In the present study, we offer the first direct evidence of interspecific competition for food in this dominant soil detritivore group by combining field observations with laboratory mesocosm experiments using 13C and 15N double-enriched leaf litter to track consumption patterns. In our experiments, the Asian invasive species Amynthas hilgendorfi was a dominant competitor for leaf litter against two European species currently invading the temperate deciduous forests in North America. This competitive advantage may account for recent invasion success of A. hilgendorfi in forests with established populations of European species, and we hypothesize that specific phenological differences play an important role in determining the outcome of the belowground competition. In contrast, Eisenoides lonnbergi, a common native species in the Eastern United States, occupied a unique trophic position with limited interactions with other species, which may contribute to its persistence in habitats dominated by invasive species. Furthermore, our results supported neither the hypothesis that facilitation occurs between species of different functional groups nor the hypothesis that species in the same group exhibit functional equivalency in C and N translocation in the soil. We propose that species identity is a more powerful approach to understand earthworm invasion and its impacts on belowground processes.EPS Field Funds;
National Science Foundation Grant Numbers: EEC-0540832, ACI 1244820, EAR-0748574;
Microsoft Researc
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