Winterer

Tests on vehicles have shown that the volatility index as defined expresses satisfactorily the fuel contribution during hot operation of the engine (Le Breton, 1984). In France, specifications stipulate that its value be limited to 900, 1000 and 1150, respectively, according to the season (summer, spring/fall, winter). The automobile manufacturers, being even more demanding, require in their own specifications that the FVI not be exceeded by 850 in summer. 

As of 1993, France has selected classes 1, 3 and 6, corresponding to the season summer, fall/spring, winter. 

The cold filter plugging point (CFPP) is the minimum temperature at which a given volume of diesel fuel passes through a well defined filter in a limited time interval (NF M 07-042 and EN 116 standards). For conventional diesel fuels in winter, the CFPP is usually between —15 and —25°C. 

Each country adopts such and such a class as a function of its climatic conditions. France has chosen classes B, E, and F, respectively for the summer, winter, and cold wave periods. The first is from 1 May to 31 October, the second is from 1 November to 30 April, while the third has... 

Regarding product characteristics, European specifications were established in 1992. They concern mainly the motor octane number (MON) that limits the olefin content and which should be higher than 89, and the vapor pressure, tied to the C3/C4 ratio which should be less than 1550 mbar at 40°C (ISO 4256). On the other hand, to ensure easy vehicle start-ups, a minimum vapor pressure for winter has been set which is different for each country and depends on climatic conditions. Four classes. A, B, C, and D, are thus defined in Europe with a minimum vapor pressure of 250 mbar, respectively, at -10°C (A), -5 C (B), 0°C (C) and -t-10°C (Z)). France has chosen class A. 

It is mainly in cold behavior that the specifications differ between bome-heating oil and diesel fuel. In winter diesel fuel must have cloud points of -5 to -8°C, CFPPs from -15 to -18°C and pour points from -18 to 21°C according to whether the type of product is conventional or for severe cold. For home-heating oil the specifications are the same for all seasons. The required values are -l-2°C, -4°C and -9°C, which do not present particular problems in refining. 

The winter period corresponds, of course, to the moment in the year where the diesel fuel and home-heating oil characteristics are noticeably different. Table 5.18 gives a typical example of tbe recorded differences heating oil appears more dense and viscous than diesel fuel, while its initial and final boiling points are higher. 

Characteristics of a diesel fuel and a tiome-fieating oil (for severe winter conditions ). 

The most important point in the use of diesel fuel is its cold temperature behavior. The subject has been addressed previously because it directly affects the engine operation in winter conditions. 

The 15W40 or 15W50 oils are the most widespread in temperate climates (Western Europe), while the 20W40 or 20W50 oils are used in relatively warm climates (Mediterranean countries. Middle East, South America). The 5W or lOW grades are used in countries having severe winters such as Scandinavia and Canada. 

The nature of these paraffins and their concentration in diesel fuel affect the three temperatures that characterize the cold behavior. The cloud point is the temperature at which crystals of paraffins appear when the temperature is lowered. The cold filter pluming point is defined as the temperature under which a suspension no ionger flows through a standard filter. Finally, the pour point is the temperature below which the diesel fuel no longer flows by simple gravity in a standard tube. These three temperatures are defined by regulations and the refiner has three types of additives to improve the quality of the diesel fuel of winter. 

Function of Condoms An Overview, in Winter Annual Meeting of the Am. Soc. Meek. Eng., 1989. 

Winters H F and Coburn J W 1992 Surface science aspects of etching reactions Surf. Sc/. Rep. 14 161... 

Poiian A, Loubeyre P and Boccara N (eds) 1989 Simple Molecular Systems at Very High Density (New York Pienum) Winter R and Jonas J (eds) 1993 High Pressure Chemistry, Biochemistry and Materials Science (Dordrecht Kiuwer) Proceedings of the annuai conference of the European High Pressure Research Group, the most recent of which is ... 

Szotek Z, Temmerman W M and Winter H 1993 Application of the self-interaction correction to transition-metal oxides Phys. Rev. B 47 4029... 

Parks E K, Winter B J, Klots T D and Riley S J 1992 Evidence for polyicosahedral structure in ammoniated iron, cobalt and nickel clusters J. Chem. Rhys. 96 8267... 

Winter B J, Parks E K and Riley S J 1991 Copper clusters the interplay between electronic and geometrical structure J. Chem. Rhys. 94 8618... 

MI] Tredgold R H and Winter C S 1981 Tunneling currents in Langmuir-Blodgett monolayers of stearic acid J. Phys. D Appl Phys. 14 LI 85-8... 

Korzec D, Werner F, Winter R and Engemann J 1996 Scaiing of microwave siot antenna (SLAN) a concept for efficient piasma generation Plasma Sources Sol. Technol. 5 216-34... 

In what may be the single most influential experiment in the field of dry etching, Jolm Cobum and Eiarold Winters of the IBM Almaden Research Centre in San Jose, CA, USA demonstrated that the rate of the F-Si thennal etching... 

Winters H F and Houle F A 1983 Gaseous products from the reaction of XeF, with silicon J. Appl. Phys. 54 1218-... 

Coburn J W and Winters H F 1979 Ion- and electron-assisted gas-surface chemistry—an important effect in plasma etching J. Appl. Phys. 50 3189-96... 

Winters H F and Coburn J W 1985 Etching reactions at solid surfaces Mater. Res. See. Symp. Proc. 38 189-200... 

As a general guide, however, it may be noted that the following have fairly easily recognisable odours methyl and ethyl formate methyl and ethyl acetate (apples) methyl and ethyl benzoate methyl salicylate (oil of winter-green) and ethyl salicylate methyl and ethyl cinnamate. (It is however usually impracticable to distinguish by odour alone between the methyl and ethyl esters of a particular acid.) Methyl and ethyl o. alate, and methyl and ethyl phthalate are almost odourless. Succinic and tartaric esters have faint odours. 

The pressure is reduced by means of a high capacity water pump, preferably constructed of metal the lowest pressure that can be attained is that of the vapour pressure of water at the particular temperature (for a detailed discussion, see Section 11,21). In winter when the temperature of the water may be 6-8° the vapour pressure of water is 7-8 mm., but in summer when the temperature of the water may reach 22°, the corresponding vapour pressure is 20 mm. Thus the vacuum ... 

I would like to credit especially the fundamental contributions of Ron Gillespie to strong acid (superacid) chemistry and also to recall his generous help while I was still working at the Dow Laboratories in Canada. 1 reestablished contact with him during this time. We first met in the winter of 1956 at University College in London, where he worked with Christopher Ingold. Subsequently, he moved to McMaster... 

The sex attractant of the female winter moth has been identified as the tetraene CH3(CH2)8CH=CHCH2CH=CHCH2CH=CHCH=CH2 Devise a synthesis of this material from 3 6 hexadecadien 1 ol and allyl alcohol... 

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