Showing papers by "ExxonMobil published in 1978"

Lithium Ordering in Li x Ti S 2

Abstract: A new electrochemical measurement applied to the Li/Ti${\mathrm{S}}_{2}$ cell reveals subtle changes in slope on the voltage-composition relationship. These anomalies occur at compositions where ordered structures among intercalated lithium are predicted from lattice-gas theories. ${\mathrm{Li}}_{x}\mathrm{Ti}{\mathrm{S}}_{2}$ appears to be a nearly ideal model for the study of composition- and temperature-dependent properties of the two-dimensional lattice gas.

Combination of ethylene polymer, polymer having alkyl side chains, and nitrogen containing compound to improve cold flow properties of distillate fuel oils

Abstract: Oil soluble combinations of (A) ethylene polymer or copolymer, (B) a second polymer having alkyl side chains of 6 to 30 carbon atoms, and derived from carboxylic acid esters and/or olefins, and (C) nitrogen compounds, such as amides, amine salts and ammonium salts, of carboxylic acids or anhydrides, are useful in improving the cold flow properties of distillate hydrocarbon fuel oils.

High-voltage converter circuit

Abstract: An inverter circuit includes a DC voltage supply having a plurality of voltage taps coupled via (1) a first plurality of diodes for unidirectional current flow therefrom to successive common connections between the upper half of a plurality of first transistors connected in cascade across the voltage supply, (2) a second plurality of diodes for unidirectional current flow therefrom to successive common connections between the upper half of a plurality of capacitors, of like number to the first transistors, connected in series and across the DC voltage supply via a pair of diodes providing unidirectional current between the voltage supply and capacitors, (3) a third plurality of diodes for unidirectional current flow thereto from successive common connections between the lower half of the plurality of first transistors, (4) a fourth plurality of diodes for unidirectional current flow thereto from the successive common connections between the lower half of the plurality of capacitors; and a plurality of second transistors connected in cascade across the series string of capacitors, their centralmost common connection being connected to an output terminal, individual ones of a fifth plurality of diodes being connected between successive common connections of the capacitors to and for unidirectional current flow (1) therefrom to the successive common connections between the upper half of, and (2) thereto from the successive common connections between the lower half, of the second transistors, the pluralities of first and second transistors being operable to different combinations of their conductive and nonconductive states for predetermined periods of time for producing a multitiered AC waveform at the output terminal.

Low-temperature solution preparation of group 4B, 5B, and 6B transition-metal dichalcogenides

Abstract: By use of nonhydroxylic solvents, the series of disulfides of the tetravalent transition metals of the left side of the periodic table are preparable via a simple metathetical reaction: TX/sub 4/ + 2A/sub 2/S ..-->.. TS/sub 2/ + 4AX. The crystallinity of the product TS/sub 2/ depends upon T and the conditions of the reaction, and particle sizes are in the submicron range. New amorphous phases have been found. The reactivity of these materials, in particular their intercalative behavior, is contrasted with those prepared by conventional high-temperature procedures. In certain cases, it is possible to obtain dispersions of TS/sub 2/, showing the effect of solvent.

Method of cleaving semiconductor diode laser wafers

Abstract: Thick double heterostructure (Al,Ga)As wafers comprising layers of gallium arsenide and gallium aluminum arsenide on a metallized n-GaAs substrate are separated into individual devices for use as diode lasers. In contrast to prior art techniques employed with thinner wafers of mechanically cleaving the wafer in mutually orthogonal directions, the wafer is first separated into bars of diodes by a process which comprises (a) forming channels of substantially parallel sidewalls about 1 to 4 mils deep into the surface of the n-GaAs substrate (b) etching into the n-GaAs substrate with an anisotropic etchant to a depth sufficient to form V-grooves in the bottom of the channels and (c) mechanically cleaving into bars of diodes. The cleaving may be done by prior art techniques using a knife, razor blade or tweezer edge or by attaching the side of the wafer opposite to the V-grooves to a flexible adhesive tape and rolling the assembly in a manner such as over a tool of small radius. The diode bars may then, following passivation, be further cleaved into individual diodes by the prior art technique of mechanically scribing and cleaving. Processing in accordance with the invention results in good length definition and uniformity, high device yields and low density of striations on laser facets. The inventive process permits handling of thicker wafers on the order of 6 to 10 mils or so, which are cleaved only with great difficulty by prior art techniques. Such thicker wafers are less susceptible to breaking during handling and permit fabrication of shorter diode (cavity) length, which in turn is related to lower threshold current for device operation.

Forming optically anisotropic pitches

Abstract: An improved process for preparing liquid-crystal containing pitches comprises extracting carbonaceous isotropic pitches with an organic solvent system to provide a solvent insoluble fraction which when heated for 10 minutes or less and to temperatures in the range of about 230° C. to 400° C. will upon polarized light microscopy examination of cooled samples display greater than 75% of an optically anisotropic phase.

Organo molybdenum friction-reducing antiwear additives

Abstract: Hydrocarbon-soluble organo molybdenum complexes obtained as the reaction product of a hydrocarbyl substituted hydroxy alkylated amine e.g. N,N',N'-tris(2-hydroxy ethyl)-n-tallow-1,3-diaminopropane, with about one molar equivalent of a molybdenum compound, e.g. ammonium molybdate, are useful hydrocarbon additives particularly in combination with an oil-soluble sulfur donor, e.g. a metal dialkyl dithiophosphate to provide an additive combination for lubricating oils since the lubricating compositions comprising these co-additives exhibit improved anti-friction and anti-wear properties.

The Influence of Internal Waves on Deep-Water Drilling

Abstract: Internal waves were observed during drilling by the drillship Discoverer 534 in the Andaman Sea, offshore Thailand, in water depths ranging from 1,900 ft to more than 3,400 ft. An engineering analysis was conducted on measured internal wave data and simultaneous measured drillship response. Knowledge of internal waves will be required for designing production facilities in deep water.

Molybdenum complexes of ashless oxazoline dispersants as friction reducing antiwear additives for lubricating oils

Abstract: An oil-soluble molybdenum complex of an ashless polyol ester dispersant, preferably of oil-soluble reaction product of a molybdenum compound such as molybdic acid with about 1 to 2 molar equivalents of a polyol ester of a hydrocarbon substituted diacid material such as polybutenyl succinic anhydride or a thio-bis-(hydrocarbyl substituted diacid material), such as thio-bis-(polyalkyl lactone acid) and/or their precursors, the adducts of sulfur chloride and unsaturated diacid materials, e.g., 4,8-bis-polyalkyl-4,8-dichloro-6-thiaundecane-1,2,10,11-tetracarboxylic acid bis-anhydride and their dehydrochlorinated analogs, is a useful additive to a lubricating oil since both the sludge dispersant and antifriction properties of said oil are enhanced.

Icosahedral microclusters a possible structural unit in amorphous metals

Abstract: A model for amorphous metals is proposed. The model is based on the 13 atom icosahedron which is the minimum energy structure for a 13 atom cluster. An amorphous metal is considered as containing a high density of these structural units. The material surrounding the icosahedra is partially ordered. The spaces between the ordered regions may be disordered. This model successfully accounts for the experimental interference functions in amorphous materials. It is explained, why, physically, such a structure should be expected to form. It is also shown that structures such as that proposed are observed when, in a computer experiment, a liquid is quenched very rapidly into the solid phase. Es wird ein Modell fur amorphe Metalle vorgeschlagen. Das Modell beruht auf dem 13-atomigen Ikosaeder, der die Minimumstruktur fur ein 13-atomiges Cluster darstellt. Es wird angenommen, das ein amorphes Metall eine hohe Dichte dieser Struktureinheiten enthalt. Das Material, das die Ikosaeder umgibt, ist teilweise geordnet. Die Raume zwischen den geordneten Bereichen konnen fehlgeordnet sein. Dieses Modell erklart erfolgreich die experimentellen Interferenzfunktionen in amorphen Materialien. Es wird erklart, warum physikalisch erwartet werden kann, das sich eine derartige Struktur bildet. Es wird auch gezeigt, das Strukturen, wie die vorgeschlagene, dann beobachtet werden. wenn in einem Computerexperiment eine Flussigkeit sehr schnell auf die feste Phase abgeschreckt wird.

Liquid membrane generator

Abstract: An apparatus is disclosed for generating a multiple phase dispersion and distributing said multiple phase dispersion as globules in a suspension phase. The apparatus comprises a conduit for introducing a first fluid under pressure into a first zone including a porous fluid dispersing layer. This first zone is in fluid communication with a second zone through the porous fluid dispersing layer. The second zone has introduced into it a second fluid under pressure through inlets. The first fluid is dispersed as bubble-like micro droplets in the second fluid by passage from the first zone through the fluid dispersing layer into the fluid in the second zone. An outlet zone is in contact with the second zone and comprises a perforated nonporous layer having an outer and inner surface and includes a porous flow distribution layer substantially in contact with the inner second zone facing surface of the nonporous layer. The multiple phase dispersion formed in the second zone enters the outlet zone through the porous flow distribution layer and exits the outlet zone as globules of predetermined size through the perforations where the outer surface of said perforated nonporous layer forms an interface with a suspension phase which is immiscible with the second fluid. The instant invention further relates to a process for generating multiple phase dispersions as globules in a suspension phase.

Catalyst for the hydroconversion of heavy hydrocarbons

Abstract: A catalytic hydroconversion process for a hydrocarbonaceous oil is effected by dissolving an oil-soluble metal compound in the oil, converting the compound to a solid, non-colloidal catalyst within the oil and reacting the oil containing the catalyst with hydrogen. Preferred compounds are molybdenum compounds.

Amine regeneration process

Abstract: Impurities such as hydrogen sulfide and carbon dioxide are removed from fluids such as natural gas, synthesis gas or liquid or gaseous hydrocarbons by contact with an aqueous alkanolamine solution which absorbs said impurities from the fluid. The resultant spent impurity-enriched absorbent amine stream containing the absorbed impurities is split into two streams; one stream being routed directly to the top of an amine regenerator column and the second stream being routed to a heat exchanger where it is heated en route to an intermediate point of the regenerator column by heat exchange with the hot regenerated solution coming from the bottom of the regenerator column. The spent amine stream which is passed without prior heating directly to the top of the regenerator column is heated by condensing steam in the column which would normally escape therefrom, thereby reducing the amount of "saturation" steam which is lost from the system. Reducing the losses of "saturation" steam in combination with heating a portion of the spent absorbent amine stream by heat exchange with the hot regenerated solution reduces the overall energy requirements for the system.

Solar cell module

Abstract: A solar cell module is provided having a plurality of circular solar cells arrayed on a support structure in which at least the land areas between the cells have facets with light reflecting surfaces An optical cover medium couples the facets and the cells Importantly the angular relationship of the facet surfaces is such that light impinging thereon will be reflected upwardly into the optical medium and then internally reflected downwardly toward an active cell area thereby effectively increasing the output of the module

Process for the production of an intermediate Btu gas

Abstract: An intermediate Btu gas is produced by reacting steam with a carbonaceous feed material in the presence of a carbon-alkali metal catalyst and substantially equilibrium quantities of added hydrogen and carbon monoxide at a temperature between about 1000° and about 1500° F. and a pressure in excess of about 100 psia to produce a raw product gas consisting essentially of equilibrium quantities, at reaction temperature and pressure, of methane, steam, carbon dioxide, carbon monoxide and hydrogen; withdrawing the raw product gas from the gasifier and treating it for the removal of acid gases to produce a treated gas; withdrawing a portion of the treated gas as an intermediate Btu product gas; mixing the remainder of the treated gas with steam; passing the resultant mixture into a steam reforming furnace where the methane in the gas reacts with the steam to produce additional amounts of carbon monoxide and hydrogen; and passing the effluent from the reforming furnace into the gasifier.

Nonlinear Dynamic Mechanical Moduli for Polycarbonate and PMMA

Abstract: A multiple integral expansion of the Boltzmann superposition principle when applied to sinusoidal shear oscillations becomes σ(t)=γ0[G1′ sinωt+G1″ cosωt]+γ03[G3′ sinωt+H3′ sin3ωt+G3″ cosωt+H3″ cos3ωt]+γ05[0]. We have evaluated this constitutive equation with hollow cylinders of polycarbonate and polymethylmethacrylate at 1 Hz from Tg to below their β transitions. Shear strain amplitude, γ0, was increased incrementally from the linear to the nonlinear region. Phase angles and harmonic content were determined with a Rheophasor digital cross correlator. At the maximum strain used, 2–4%, deformation was completely recoverable, after some time, upon returning to the linear region. G1′ and G1″ vs temperature compare excellently to the literature and our own small strain measurements of G′ and G″ on rectangular bars in free and forced torsion. H3′, H3″, and higher harmonic terms were found to be small. All nonlinearity in the range studied can be modeled by G3′ and G3″ is in the range 1010–1011 N/m2. G3′ is nega...

Hydrocracking of hydrocarbons

Abstract: A catalytic hydrocracking process for a hydrocarbonaceous oil is effected by dispersing a thermally decomposable metal compound in the oil, heating the compound in the presence of a hydrogen-containing gas to form a solid, non-colloidal catalyst within the oil and reacting the oil containing the catalyst with hydrogen. Preferred thermally decomposable compound are molybdenum compounds.

Process for the production of a chemical synthesis gas from coal

Abstract: A high purity chemical synthesis gas is produced by reacting steam with a carbonaceous feed material in the presence of a carbon-alkali metal catalyst and substantially equilibrium quantities of added hydrogen and carbon monoxide at a temperature between about 1000° F. and about 1500° F. and a pressure in excess of about 100 psia to produce a raw product gas consisting essentially of equilibrium quantities, at reaction temperature and pressure, of methane, steam, carbon dioxide, carbon monoxide and hydrogen; withdrawing the raw product gas from the gasifier and treating it for the removal of steam and acid gases to produce a treated gas containing primarily carbon monoxide, hydrogen and methane; recovering carbon monoxide and hydrogen from the treated gas as a chemical synthesis product gas; mixing the remainder of the treated gas consisting essentially of methane with steam; passing the resultant mixture into a steam reforming furnace where the methane reacts with the steam to produce carbon monoxide and hydrogen; and passing the effluent from the reforming furnace into the gasifier.