19 research outputs found
TRANSFORMERS Test Drive Results of a new Hybridisation Concept for Truck-Semitrailer Combinations
This contribution is based on results obtained in the collaboration project “TRANSFORMERS”, which has received funding from the European Commission in the FP7-programme. The project has the objective to reduce CO2 emissions per tonne·km by up to 25%, by improved reconfigurable aerodynamic measures, by innovative loading efficiency measures and by a hybrid-on-demand driveline for truck-semitrailer combinations. Besides giving insight to the overall project, this publication focusses on the trailer mounted hybrid-on-demand (HoD) driveline. This electric driveline is combined with a conventionally propelled tractor unit, effectively hybridizing the combination with minimal changes to the tractor. The objective is to save fuel both in long haulage applications and urban dense traffic scenarios. Test results obtained in both test track and public road testing show that an actual fuel saving of up to 12% can be achieved
Taxpayer Compliance, Trust, and Power
Self-assessment system as adopted in Indonesia, focusing on taxpayer awareness. Therefore trust should be the spearhead of tax compliance rather than power. This study aims to examine how trust and power play a role in improving tax compliance by the slippery slope framework. Method of data collection in this research surveys in Central Java. The sampling technique is a multi-stage sampling that combines stratified random sampling and convenience sampling. Data has been collected from October 2015-April 2016, and 242 instruments were collected (86.4 percent response rate). By using multiple regression tests, the results of this study indicate that trust and power both simultaneously and partially affect tax compliance. Based on the coefficient different test, power has a greater impact than trust in creating tax compliance. This means that the compliance created in Indonesia is mandatory compliance that denies from self-assessment system that based on voluntary compliance.JEL Classification: H26; G41DOI: https://doi.org/10.26905/jkdp.v22i2.158
Changes in attentional processing of emotional information following mindfulness-based cognitive therapy in people with a history of depression: towards an open attention for all emotional experiences
Mindfulness-based cognitive therapy (MBCT) has been demonstrated to be successful in the prevention of relapse in patients with recurrent major depressive disorder (MDD). With regard to its working mechanisms, it is hypothesized that mindfulness meditation influences the processing of emotional information and that it could therefore reduce cognitive vulnerability factors that are observed during and after remission of depressive episodes. In this study we investigated the effects of an 8 week MBCT training versus no intervention on the facilitation and inhibition of attention for sad versus happy faces in a group of people with a history of MDD, N = 45. The comparison group consisted of a non-treatment seeking group with a history of MDD, recruited from the community, N = 26. At baseline, we found that formerly depressed patients who applied for MBCT training inhibited attention for positive information, and showed facilitation of attention for negative information. However, the comparison group did not show similar attentional characteristics. After MBCT, participants showed a reduced facilitation of attention for negative information and a reduced inhibition of attention for positive information, which is indicative of open attention towards all emotional information
Efficient EGR technology for future HD diesel engine emission targets
Different systems for achieving short-route cooled EGR on turbocharged and aftercooled heavy-duty diesel engines have been tested on a 12 litre 315 kW engine with 4 valves per cylinder and an electronically controlled unit pump fuel injection system. In all of these systems the exhaust gas was tapped off before the turbine, cooled and mixed with the intake air after the compressor and aftercooler. The systems differed (mainly) in the method used to set up a positive pressure difference across the EGR circuit. This was done either by the use of an exhaust back pressure valve in the exhaust, or by using a turbocharger with variable nozzle turbine (VNT) geometry, or by combining such a VNT turbocharger with a venturi-mixer that was positioned in the intake manifold such as to provide extra suction power to the EGR gas.
The emissions behaviour and efficiency with these different EGR systems were tested in a number of engine working points, including key points of the AVL 8-mode US FTP cycle simulation. The results indicate that for achieving 1998 emissions levels, a VNT only would be the most efficient solution. For achieving 2004 emissions levels, combining the VNT with a venturi-mixer could give a further fuel consumption benefit. Particulate matter emissions will however be unacceptable, making the use of additional particulate reducing technology necessary. A measure of venturi-mixer efficiency is proposed and a new, compact and efficient venturi-mixer design is presented.
Results from flow tests are given and compared with results from CFD calculations
Attentional bias training in depression: therapeutic effects depend on depression severity
Modelling of common rail fuel injection system and influence of fluid properties on injection process
This paper focuses on the modelling of a research type Heavy Duty Common Rail (CR) fuel injection system. More specifically it reports on the observed interaction between fuel properties and injection and on the capability to model this. For that reason a hydraulic model of the fuel injection system has been developed using the AMESim code (Imagine S.A., 2003). The reliability of the numerical results is tested through a comparison between numerical and experimental results when using regular diesel fuel. Basis for this detailed comparison are measurements of injected mass flow rate, needle lift and pressure oscillations in the injection duct for a single injection. Simulation results for regular diesel show good agreement with measured data for pressure oscillations in the injection duct, needle lift and injected fuel mass flow rate. A comparison of experimental and simulated results for Rapeseed oil Methyl Ester (RME) also shows good correspondence, which proves the capability of the model to capture the influence of different fuel properties
Detailed modeling of common rail fuel injection process
Modeling of fuel injection equipment is a tool that is used increasingly for explaining or
predicting the effect of advanced diesel injection strategies on combustion and emissions. This
paper reports on the modeling of the high-pressure part of a research type Heavy Duty Common
Rail (CR) fuel injection system. More specifically, it reports on the observed dynamics of the
injection system and the capability of the model to capture this. For that reason, the total high-pressure part of the injection system, i.e. the fuel pump, rail and injector, has been modeled using the AMESim code (Imagine S.A., 2004). The reliability of the resulting hydraulic model is tested through a comparison between numerical results and actual injection measurements. This detailed comparison is based on measurements of injected mass flow rate, needle lift and
pressure oscillations in the injection duct for a series of single injection events.
It is shown that the hydraulic model is able to accurately simulate the injection rate, needle lift
and injection pressure for different rail pressure levels. For accurate numerical results, it is vital
that the stiffness of the injector needle assembly and the discharge coefficients of the different
flow restrictions in the injector (e.g. nozzle holes) are correctly modeled. Assuming a rigid
injector needle results in a too early start of injection. Discharge coefficient values found in
literature shows a wide spread. This makes it very difficult to simulate the injected mass flow
rate accurately on the basis of literature data. Using the measured injected mass of fuel to tune
the discharge coefficient, together with the inclusion of the elasticity of the injector needle,
results in a good approximation of the injection rate
Experimental study of flame propagation limits resulting from mixture dilution in methane fueled gas engines
Experimental validation of extended NO and Soot model for advanced HD Diesel Engine Combustion
A computationally efficient engine model is developed based on an extended NO emission model and state-of-the-art soot model. The model predicts exhaust NO and soot emission for both conventional and advanced, high-EGR (up to 50 %), heavy-duty DI diesel combustion. Modeling activities have aimed at limiting the computational effort while maintaining a sound physical/chemical basis. The main inputs to the model are the fuel injection rate profile, in-cylinder pressure data and trapped in-cylinder conditions together with basic fuel spray information. Obtaining accurate values for these inputs is part of the model validation process which is thoroughly described. Modeling results are compared with single-cylinder as well as multi-cylinder heavy-duty diesel engine data. NO and soot level predictions show good agreement with measurement data for conventional and high-EGR combustion with conventional timing
Validation of the LES approach in Kiva-3V on a square duct geometry
The LES approach implemented in the Kiva-3V code is evaluated on the fully developed flow through a rectangular duct of square cross section. The Reynolds number based on the bulk velocity and duct width is 8000. The number of grid nodes is 96000.Three subgrid scale models are compared: the Smagorinsky, the WALE and the Vreman model.The results differ mainly in the predicted shear stress levels.The Smagorinsky model shows a large overprediction of the shear at the walls, whereas both the WALE and Vreman models perform better due to a reduced contribution of the subgrid-dissipation. In this study the WALE model gives the best results on simulating the secondary flows and turbulence statistics