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Rev. Hegg and Hobbs. 197g; t!I rldl eton P.t a 1. 1980).These wet processes are suggested to be important in the formation of atnospheric sulfate and nitrate particulates in clowis anrl thus contribute to an increase in the acirlity of rain. pH levpls as low as 2.::> 11ere founrl in a recent study of Los 1\n:Jeles fog rlroplets (LA Tir'les. 9/?4/H2).In the post. the assess•nent of the inpact of "''et cheMica 1 processes hns heen 1aruely haserl on the cherlica1 reaction r(!tf'<>. HoNeVE'r. '"tH~n relative hnnirlity is le.:;s than 1mity. riroplets evapornte and thP reaction ri'lte is limited hy the aerosols 1 Pvnrorat.ion time. Ther~>fore in this paper, the lifeti1'1e of these rlror1Pt'i is deter11i ned anrl used to assess the if'lpnrtance of nquen11S reactions undf"r Atnospheric conditions.The lifetine 0f rlrop1ets is prolonged ilt <1 given rel<'itive humidity hy the presence of hygroscopic St'llt nuclei and hy surfi'lctant rnatf'rial forr1erl into n fi 1m on their surf aces. The presP.nce of i nso 1 uh 1 e nateri a 1 (!Ccentuates this effect by acting as a condensation stJrfacE> for tracP inp11rities and by increasing H 1 P concentration of salt, resulting in a lesser requin'!d amount of 1·1ater for a given size rlroplet to forme f:loud anrl fog saf'lples collected by Kuroh1a (1951, 195S) nnd Ogiwilra and Okita (1952) were found to contain soluble and insoltlhle particles ':Jhich werf' similar in nature, form, and size to those prod11Ced hy haze i'lnrl cornhll';tion.The presence of these ir1p11rities in samples of atmospheric liquid water hfis also heen suhstantii'ltect (lfinlll as on the nature and availahility of an oxirli1ing i'l9ent. Liquid ~rlfiter is neerled to initinte the reaction, which can hf> ilCqtlin~cJ hy physical flhsorption on tlw Sttrfnce of ,;m inc;oluble solirl or hy hy\Jroscopic solt1hlP salt ntJclei in the aerosol.\~hPther the ratP. of so 2 convPrc;ion is controllerl hy the rate of diffusion of yaseous po'lltAtants t01-1ard i'\nrl ,.

Simulation studies are performed to evaluate the potential fuel savings and reduction in emissions from using hybrid powered buses on Long Beach City bus routes. Conventional diesels, diesel-hybrid, and gas turbine-hybrids are considered. The results of these studies are compared with experimental data and are in generally good agreement. Fuel economy is shown to be dependent on the bus configuration, component sizing as well as the bus route, with a potential fuel economy improvement of as much as 80%. Emissions are also substantially lowered if hybrid buses equipped with diesels or gas turbines are deployed. Depending on the mission, driving patterns, and road conditions, different control strategies demonstrate the best results. The long-term objective of the project is to investigate the feasibility of utilizing a fleet of small and medium size hybrid passenger vans in metropolitan/urban areas to improve over the overall fuel efficiency, reduce emission, and increase throughput without increasing cost life of the system-thus allowing additional routes to areas where such services are most needed. This is done by allowing fleets consisting of a mix of vehicles such as hybrids and internal combustion engines to operate. The fuel savings and lower emission over the vehicle life will compensate the higher initial capital costs. The results of this study can be extended to address the transportation problems over large metropolitan areas and facilitate implementation of Air Resource Board (ARB), Metropolitan Transit Authority (MTA), and Caltrans mandates in promoting higher use of high-occupancy vehicles (HOV) and sustainable market demand for ultra low and zero emission vehicles.

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