Reducing DMU fuel consumption by means of hybrid energy storage

Purpose: This paper discusses a hybrid energy storage concept and its control strategy for hydro-mechanical DMUs. The hybrid energy storage consists of double layer capacitors and batteries. The new concept aims on reducing fuel consumption and avoiding unhealthy emissions during idling in station area. Methods: Development of a hybrid propulsion concept and control strategy requires adequate methods for modeling system behavior. The simulation environment Dymola is used to develop and evaluate the control strategy and for dimensioning the system components. Results: Simulations indicated fuel savings of up to 13% depending on track characteristics. Measurements of a scaled storage system in a HiL-environment showed good accordance of the simulated and measured behavior of battery and double layer capacitor. Conclusions: The newly developed storage system and its control strategy enable reduction of fuel consumption and unhealthy emissions in station areas

MULTISPECTRAL MEASUREMENTS OF ATMOSPHERIC AEROSOLS OVER THE SEA AROUND JAPAN

[Abstract] A portable multispectral polarimeter named PSR-1000, which has the same observing bands as ADEOS/POLDER, has been introduced since 1996. PSR-1000 is designed to measure direct solar radiation and diffuse sky radiation. First of all, a calibration of the PSR-1000 was done based on Langley plot method involving gaseous absorption from October 27 to November 2 in 1997 at Mt. Mauna Kea in Hawaii Island. Then the measurements of polarization and optical thickness of aerosols with the PSR-1000 were undertaken over the ocean around Shikoku Island of Japan in 1997, 1998 and 1999. It is found that the relationship in respect of wavelength dependency between the observed optical thickness and degree of polarization is classified into two groups. The measurements are available to retrieve the optical characteristics of aerosols, e.g., refractive index, size distribution parameters, based on light scattering simulations in the polarization field. From the retrieved results, it can be seen that; (1) heterogeneous particles are good a candidate for our aerosols, (2) contamination rate of water-soluble inclusions to the oceanic matrix of heterogeneous model aerosol decreases from inland to the open sea.application/pdfdepartmental bulletin pape