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A gas chromatographic technique was used to determine the vapor pressures of blends of six candidate diesel fuel oxygenates with three diesel fuels at 0, 5, 10, 30, and 100 percent blend levels. Both the oxygenates and the diesel fuels were selected to represent a variety of chemical compositions. The vapor pressures were determined over a range of temperatures from -30 C to +30 C. In each case the fraction of the vapor pressure derived from the oxygenate and the fuel was identified. The vapor pressure results showed that there were significant deviations from ideality, leading to both higher and lower vapor pressures than would be predicted from Raoult's Law. These results are significant for fire safety and evaporative emissions as well as for a more basic understanding of the behavior of these blends. Data were also obtained on the heats of vaporization for each of the blends.

Miscibility, water tolerance, cloud point, and flash point data are presented for seven candidate diesel fuel oxygenates: dipentyl ether, dibutoxymethane, 2-ethoxyethyl ether, diethyl maleate, tripropylene glycol monomethyl ether, dibutyl maleate, and glycerol tributrate. These oxygenates were blended with three different diesel fuels: an oil sands diesel, an ultra-low sulfur diesel, and a Fischer-Tropsch diesel. Blend levels included 0, 5, 10, 30, and 100 % oxygenate. Properties were measured at temperatures of -30, -15, 0, 15, and 30 C.

Several candidate oxygenates have been proposed for use with diesel fuel. This paper examines the safety and health issues associated with the use of these oxygenates. The primary fire safety hazard associated with the use of oxygenates is increased diesel fuel volatility and consequent low flash point. Peroxide formation may be a hazard for some oxygenates, but no quantitative information on the extent of the hazard was located for any of the candidate oxygenates. Little information is available on inhalation, ingestion, or skin exposure toxicity hazards. Of the candidate ethers, only pentyl ether, 2-ethoxyethyl ether (diethyl carbitol), and dibutoxymethane (butylal) do not have low flash points or significant known toxicity problems.

Fuel economy estimates are provided for the CleanFleet vans operated for two years by FedEx in Southern California. Between one and three vehicle manufacturers (Chevrolet, Dodge, and Ford) supplied vans powered by compressed natural gas (CNG), propane gas, California Phase 2 reformulated gasoline (RFG), methanol (M-85), and unleaded gasoline as a control. Two electric G-Vans, manufactured by Conceptor Corporation, were supplied by Southern California Edison. Vehicle and engine technologies are representative of those available in early 1992. A total of 111 vans were assigned to FedEx delivery routes at five demonstration sites. The driver and route assignments were periodically rotated within each site to ensure that each vehicle would experience a range of driving conditions. Regression analysis was used to estimate the relationships between vehicle fuel economy and factors such as the number of miles driven and the number of delivery stops made each day.

The CleanFleet project was a 24-month demonstration of five alternative motor fuels and control gasoline in 111 FedEx delivery vans. Original equipment manufacturer (OEM)-supplied vans from Ford, Chevrolet, and Dodge were operated on compressed natural gas, propane gas, California Phase 2 reformulated gasoline (RFG), and methanol (M-85 containing 15 percent RFG). Electric vans on loan from Southern California Edison were also used by FedEx. Data were gathered on fleet operations, vehicle emissions, and facility and vehicle capital and operating costs. This paper focusses on implementation of 24 months of fleet operations. Vehicle activity is documented for each fuel. Practical issues resolved during the demonstration for use of each fuel by a commercial fleet operator are summarized. Topics include procuring vehicles, fueling vehicles, storing vehicles indoors, maintaining vehicles, and training drivers and mechanics.

A validated three-dimensional mathematical model was used to examine the extent of flammable plumes resulting from both large and small CNG leak scenarios inside a typical transit maintenance and storage facility ventilated at a rate of five air changes per hour. The leak rates used were based on an engineering and experimental analysis of actual CNG bus fuel system components. The results showed that both large and small CNG leaks produced flammable plumes, such plumes extended from a half a bus length to several bus lengths away from the leak source, and the plume from a large leak formed a layer along the ceiling before being dispersed by building ventilation.

The complexity of and expense involved in determining the cetane number of diesel fuels using a standard test engine have led to the development and widespread use of the ASTM cetane index. However the cetane index was not intended for use with alternative or unusual diesel fuels; its use with such fuel s can lead to large errors. Using a database of alternative diesel fuel properties, a new cetane number prediction equation has been developed for use with alternative fuels, including alcohols. Compared with the cetane index, the average error in predicted cetane number is reduced by 40% and the number of cases where the error exceeds 5 cetane numbers is reduced by 30%. The significance of the various terms in the equation is discussed.

Data from 101 front seat automobile occupant fatality crashes that the authors had investigated were reviewed along with 70 front seat automobile occupants who had the more severe (AIS 3, 4, or 5) level injuries who did not die. The effectiveness of the lap belt alone, lap-shoulder belt, air bag alone, air bag with lap belt, and the passive shoulder belt were made. The estimates reveal that none of the restraints would have prevented 42 to 51 of the fatalities. The air bag with lap belt, and the lap-shoulder belt system, have the highest effectiveness for reducing fatalities (AB+LB, 34%; LB+SH, 32%). The air bag with lap belt has an effectiveness of 68% in reducing the more serious injuries with the lap-shoulder belt nearly as equal (64%). NHTSA's fatality reduction estimates are excessively high and overly optomistic compared to ours, but theirs are noticeably lower for serious injury reduction than are ours. Comparisons with other restraint effectiveness studies are also made.

The characteristics of large amplitude wave propagation in variable area ducts were investigated in order to gain a more thorough understanding of exhaust systems for power tuned two-stroke engines. An apparatus to simulate the power stroke of a two-stroke motorcycle engine was developed, using a stock Yamaha 360 MX barrel, cylinder head, piston and ring. In this way, a single pulse of pressurized air could be introduced into virtually any duct geometry. An ocilloscope trace of the subsequent exhaust pulse and duct interaction was photographed. The resulting pressure-time histories were used to experimentally evaluate the effects of several duct terminations on the shape and timing of the reflected wave. The investigation resulted in quantifying the effects of an orifice plate and converging cone termination and in determining the best termination for a Yamaha 360 MX engine.

From field crash investigations conducted by the authors, a series of well documented crashes will be presented. In each, at least one occupant was wearing a lap-shoulder belt. Detailed injury reports will be presented along with photographs of car damage, occupant contact areas, and where possible, the estimated impact speeds.