1,479 research outputs found
Soil moisture control of NO turnover and N<sub>2</sub>O release in nitrogen-saturated subtropical forest soils
Acid forest soils in South China experience a chronically elevated input of atmospheric nitrogen (N), turning them into hot spots for gaseous N emissions. Soil moisture is known to be a major controller for the partitioning of gaseous N loss to nitric (NO) and nitrous oxide (N2O), which may be of particular relevance in the monsoonal climate of South China. To study this partitioning in more detail, we determined gas phase kinetics of NO and N2O release during laboratory dry-out of acidic surface soils from the headwater catchment TieShanPing (TSP), situated close to Chongqing, SW China. Soils were sampled from two hydrologically distinct environments, a well-drained hill slope (HS), and a periodically flooded groundwater discharge zone (GDZ). Production and consumption of NO were studied in an automated flow-through system purged with NO-free or NO-spiked air. Production rates peaked at 21% and 18% water filled pore space (WFPS) in HS and GDZ soils, respectively, suggesting nitrification as the dominant process of NO formation in both landscape units. In HS soils, maximum production and consumption occurred at the same WFPS, whereas GDZ soils displayed maximum NO consumption at higher WFPS than maximum production, suggesting that denitrification is an important NO sink in GDZ soils. Net N2O release was largest at 100% WFPS and declined steadily during drying. Integrated over the entire range of soil moisture, potential NO-N loss outweighed potential N2O-N loss, suggesting that N-saturated, acid forest soil is an important NO source
Transparency of a geographically distributed test platform for fuel cell electric vehicle powertrain systems based on x-in-the-loop approach
X-in-the-loop is a new vehicle development and validation method for increasingly complex vehicle systems, which integrates the driver and the environment. In view of recent developments in fuel cell electric vehicle powertrain systems, Tongji University and Karlsruhe Institute of Technology have jointly developed a set of distributed test platforms based on the X-in-the-loop approach. This platform contains models and test equipment for a fuel cell electric vehicle powertrain system. Due to the involvement of remote connection and the Internet, test with connected test benches will suffer great uncertainty cause of signal transfer delay. To figure out this uncertainty, the concept of transparency is introduced. Four parameters were selected as transparency parameters in this distributed test platform. These include vehicle speed, fuel cell output power, battery output power, and electric motor torque under several different configuration settings. With the help of transparency theory and statistical methodology, especially Analysis of Variance (ANOVA), the transparency of these four parameters was established, vehicle speed, electric motor torque, battery power, and fuel cell power are affected by network state, the degree of influence is enhanced in turn. Using new defined parametric and non-parametric methods, this paper identifies the statistical significance and the transparency limitations caused by Internet under these several configurations. These methods will generate inputs for developer setting the distributed test configuration. These results will contribute to optimize the process of geographically distributed validation and joint development
Turbulent flame shape switching at conditions relevant for gas turbines
Abstract
A numerical investigation is conducted in this work to shed light on the reasons leading to different flame configurations in gas turbine combustion chambers of aeronautical interest. Large eddy simulations (LES) with a flamelet-based combustion closure are employed for this purpose to simulate the DLR-AT Big Optical Single Sector (BOSS) rig fitted with a Rolls-Royce developmental lean burn injector. The reacting flow field downstream this injector is sensitive to the intricate turbulent-combustion interaction and exhibits two different configurations: (i) a penetrating central jet leading to an M-shape lifted flame; or (ii) a diverging jet leading to a V-shaped flame. First, the LES results are validated using available BOSS rig measurements, and comparisons show that the numerical approach used is consistent and works well. The turbulent-combustion interaction model terms and parameters are then varied systematically to assess the flame behavior. The influences observed are discussed in the paper from physical and modelling perspectives to develop physical understanding on the flame behavior in practical combustors for both scientific and design purposes.Clean Sky 2 Joint Undertaking under the European Unionâs Horizon 2020 research and innovation programme (grant agreement No 686332
EEG reinvestigations of visual statistical learning for faces, scenes, and objects
The objective of this ongoing, replication study is to understand temporal and spatial patterns in our environment by using the technique of electroencephalography (EEG). Visual statistical learning (VSL) helps us to understand conditional probabilities from our environments. This concept is why we know that chairs are located under tables, not above. The goal of this study is to understand whether participants can unconsciously associate pairs of items (faces, scenes, and objects) from their short-term memory. Strong pairs become more similar to each other, as compared to weak pairs, which become less similar. In the main task, participants saw items appear on the screen, on at a time, for 100ms each. Items directly followed each other without transitions. In the post-task, participants were asked to rate how familiar pairs of items were, using a sliding scale. There were three types of pairs presented: strong pairs where item B followed item A 100% of the time; weak pairs where item B followed item A 11% of the time; and foil pairs where item B followed item A 0% of the time. In conclusion, results are similar to the current study (n = 10) in that there are behavioral differences between strong vs. foil and strong vs. weak pairs
AISNSW Pilot Prpject: Improving Outcomes for Aboriginal and Torres Strait Islander Students - Final Evaluation Report March 2019
Final evaluation report of phase 1 of a pilot project funded through AISNSW to improve outcomes for Indigenous students and their families in four NSW school
âWeâre Not Being Treated Like Mothersâ: Listening to the Stories of First Nations Mothers in Prison
This article is based on research with over 160 First Nations women in prisons in New South Wales, Australia. The research identified the lived experience of prison sentences for First Nations women in prison. Our research methodology was guided by an Aboriginal womenâs advisory body called sista2sista. It was based on the principles of Dadirri in which we listened to the stories of First Nations women in prison on their terms. Consequently, many stories we heard were not about the criminal sentencing process itself, but about the impacts of imprisonment on their capacity to be caregivers in the community, including as mothers, grandmothers, aunts, sisters, teachers and role models. The findings from this research are dual. First, the importance of listening to and empowering First Nations women in prison in policy making that concerns First Nations women. Second, the need to decarcerate First Nations mothers and listen and respond to their needs, expectations, priorities and aspirations, to ensure they are supported in fulfilling their role and responsibility to care, nurture, strengthen and lead their families and communities.</jats:p
The Flame Emission of Indium from a Pyrotechnical View
Until today, all blueâcolored lightâgenerating pyrotechnics are still based on copper and a halogenâsource providing the blueâemitting species copper(I) chloride, copper(I) bromide or copper(I) iodide. The use of indium as a potential halogenâfree blue light emitter in modern pyrotechnics is described. Therefore, metallic indium was introduced as both fuel and colorant in various pyrotechnical formulations including guanidine nitrate or potassium nitrate as oxidizing agent as well as magnesium, hexamethylentetramine and 5âaminoâ1Hâtetrazole as fuel. The effect of incandescence was examined by applying different magnesium contents within the mixtures. Emission spectra and occurring emission lines of indiumâbased pyrotechnical compositions were recorded and evaluated for the first time. Since the expected blue flame color could not be completely achieved, the emission of indium was discussed from an academic point of view
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