With recent emission regulations aiming to cut down emissions by lowering heavy-duty vehicle particulate matter in terms of mass, there is concern regarding particle size being lowered. Nanoparticles have been known to penetrate to the lowest part of the lung, the alveolar region. Serious complications are known to occur when particles in large concentration tend to deposit in the alveolar region. Formation of these particles depends on various factors like engine operating conditions and dilution ratios. This study focused primarily on the particle mass and number emission from various in-use heavy heavy-duty diesel vehicles operating on different driving cycles. Chemical speciation results are also presented to discuss the formation and composition of particles emitted during various cycles. Tests were performed with West Virginia University's Transportable Heavy Duty Vehicle Emissions Testing Laboratory located at Riverside, California. Five vehicles were selected to cover a wide range of model year from 1989 to 2004. All five vehicles were subjected to chemical speciation and analysis conducted by Desert Research Institute. WVU employed the use of the Scanning Mobility Particle Sizer (SMPS) to measure particle size distributions. Regulated gaseous emissions and total particulate matter from the exhaust were sampled from a full-flow CVS dilution tunnel system. A mini-dilution system was dedicated specifically for particle sizing, which samples partially from the raw exhaust. All vehicles were subjected to California's Heavy Heavy-Duty Diesel Truck (HHDDT) schedule which consisted of an idle, creep, transient and cruise mode. Particle size and chemical speciation data are presented only for the idle and cruise modes since the SMPS can measure a size distribution only during a steady engine operation.

The total fuel consumption in automobile may lead to increase in cost of the fuel, emission rate and great demand for fossil fuel. This lead to development in automobile by using alternative fuels which may includes gaseous fuel, biodiesel and vegetable oil etc. Biomass in the form of cashew nut shell represents a new energy source for the production of an alternative fuels. The oil from the cashew nut shell liquid can be extracted by the method of pyrolysis .In this work, the pyrolysed cashew nut shell liquid (CNSL) along with Oxygenates such as Dimethyl Carbonate (DMC) and Diphenyl ether (DPE) are used to run the diesel engine (CI). The experiments were conducted on the four stroke single cylinder diesel engine with various blends such as 5 % and 10 % of Oxygenates over CNSL oil in diesel engine. Their effects on exhaust emission characteristic were investigated. Their results are compared with neat diesel operation. The engine performance is improved 18% along with reduction in CO, HC and NOX by adding DPE & DMC as oxygenates. The brake thermal efficiency, mechanical efficiency & specific fuel consumption were also increased by blending DPE & DMC with CNSL at 5% and 10% in order to improve its combustion.