Showing papers by "Ford Motor Company published in 1993"

Raman study of CeO2: Second-order scattering, lattice dynamics, and particle-size effects.

Abstract: Polarized Raman-scattering spectra are obtained from oriented single crystals of ${\mathrm{CeO}}_{2}$. Second-order features are assigned to phonon overtones from the X and L points on the Brillouin-zone boundary on the basis of selection rules and by analogy to another fluorite structure compound, ${\mathrm{BaF}}_{2}$, in which the phonon dispersion curves are known. Complete selection rules for second-order scattering from these high-symmetry points are determined. A rigid-ion model is constructed for the phonon dispersion curves by fitting several of these features and the known zone-center optical modes. The ${\mathit{F}}_{2\mathit{g}}$ Raman-active mode at 465 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in ${\mathrm{CeO}}_{2}$ shifts and broadens with decreased particle size [G. W. Graham, W. H. Weber, C. R. Peters, and R. Usmen, J. Catalysis 130, 310 (1991)]. It is shown using the calculated dispersion curves that this particle-size effect cannot be explained with the spatial-correlation model.

Mechanical stability and adhesion of microstructures under capillary forces. I. Basic theory

Abstract: Strong capillary forces are developed in the fabrication process of surface micromachined structures during the wet etch of sacrificial layers. The magnitude of these forces is in some cases sufficient to deform and pin these structures to the substrate resulting in device failure. The deflection, mechanical stability, and adhesion of thin micromechanical structure under capillary forces are examined. These phenomena are divided into two separate stages of mechanical collapse and adhesion to the underlying substrate. The basic theory of collapse is described. Approximate conditions are computed to prevent contact to the substrate. >

Mechanical stability and adhesion of microstructures under capillary forces. II. Experiments

Abstract: For pt.I see ibid., vol.2, p. 33 (1993). Strong capillary forces are developed in the fabrication process of surface micromachined structures during the wet etch of sacrificial layers. The magnitude of these forces is in some cases sufficient to deform and pin these structures to the substrate resulting in device failure. The deflection, mechanical stability, and adhesion of thin micromechanical structure under capillary forces are examined. Microstructure adhesion is considered and experimental data for polycrystalline silicon microstructures are presented. >

Applications of Optimal Control to Advanced Automotive Suspension Design

Abstract: The paper surveys applications of optimal control techniques to the design of active suspensions, starting from simple quarter-car, 1D models, which are followed by their half-car, 2D, and full-car, 3D, counterparts. The emphasis is on Linear-Quadratic (LQ) optimal control and automotive vehicles

Metal-matrix composites in the automotive industry: Opportunities and challenges

Abstract: Metal-matrix composites offer considerable promise to help automotive engineers meet the challenges of current and future demands for recyclable, fuel-efficient, safe, and low-emission vehicles. These materials can be engineered to match the design requirements of automotive power-train or chassis components. Technological and infrastructural barriers tend to limit the implementation of these materials, but it is believed these barriers can be overcome and that metal-matrix composites can be applied in high-volume vehicle production. Reducing these barriers will require much effort by engineers and scientists, managers and planners at automotive manufacturers, and their suppliers. The result will be the gradual introduction of metal-matrix composites in high-volume vehicle production to satisfy customer desires while meeting regulatory requirements and competitive pressures.

Role of kinins and nitric oxide in the effects of angiotensin converting enzyme inhibitors on neointima formation.

Abstract: Marked neointima formation occurs after balloon injury to the intima of rat arteries. Angiotensin II has been implicated as a growth factor in this process, since angiotensin converting enzyme (ACE) inhibitors block neointima formation after injury. However, ACE is an important kininase, and its inhibitors may act in part by a kinin-mediated mechanism. Kinins are also known to stimulate synthesis of endothelium-derived relaxing factor/nitric oxide (EDRF/NO) and prostacyclin, both of which have antigrowth effects. To determine whether the effect of ACE inhibitors on neointima formation is due to blockade of angiotensin II synthesis alone and/or inhibition of kinin inactivation, we followed two approaches. First, we compared the inhibition of neointima formation induced by the AT1-type angiotensin II receptor antagonist losartan with that caused by the ACE inhibitor ramipril. We also studied whether a kinin receptor antagonist, Hoe 140, blocks the effect of two different ACE inhibitors, ramipril and enalapril, on neointima formation. In addition, we studied whether the effect of ramipril is blocked by an NO synthesis inhibitor, N omega-nitro-L-arginine-methyl ester (L-NAME). Although both ramipril and losartan significantly reduced neointima formation, ramipril had a more marked effect (p < 0.05 for ramipril versus losartan). The kinin antagonist Hoe 140 reduced the inhibitory effect of ramipril and enalapril by 73% and 62%, respectively. The remaining effect of the ACE inhibitors was now similar to that of losartan. Inhibition of neointima formation by ramipril was also blocked by the NO synthesis inhibitor L-NAME.(ABSTRACT TRUNCATED AT 250 WORDS)

Space frame construction

Abstract: A space frame for an automotive vehicle included a plurality of hoop shaped structural member (12,14) and a structure (28,38,40) disposed on adjacent portions of the structural members for allowing nesting engagement therebetween to form a substantially flush outer surface (22,36) between the structural members.

Platelet function, thrombin and fibrinolytic activity in patients with heart failure

Abstract: Assays which detect the release of platelet-specific proteins and of peptides during thrombogenesis and are considered markers of activation of platelets and the coagulation system have recently been developed. This study was designed to utilize these haemostasis-related markers to test the hypothesis that a prethrombotic state is related to the presence, aetiology and severity of heart failure. Seventy patients with heart failure were evaluated and data were compared with 36 normal volunteers and 41 patients with coronary artery disease without heart failure (CAD). Thrombogenesis was documented using assays which measure platelet function, thrombin activity and fibrinolysis. Platelet function was measured by determining plasma concentrations of platelet factor 4 (PF4) and beta-thromboglobulin (BTG). Thrombin-antithrombin III complexes (TAT) and fibrinopeptide A (FPA) were determined to evaluate thrombin activity. Fibrinolytic activity was assessed by measuring D-Dimer levels. Patients with heart failure, when compared to normals, had increased plasma levels of BTG (89 +/- 62 IU.ml-1 vs 50 +/- 59 IU.ml-1, P < 0.01), TAT (4.6 +/- 4.3 micrograms.l-1 vs 2.3 +/- 0.64 micrograms.l-1, P < 0.005), and D-Dimer levels (506 +/- 444 IU.ml-1 vs 191 +/- 144 IU.ml-1, P < 0.0001). Patients with heart failure, when compared to the CAD group, had increased plasma levels of D-Dimer (506 +/- 444 ng.ml-1 vs 191 +/- 144 ng.ml-1, P < 0.05). Aetiology of heart failure did not affect these measurements. Patients with severe heart failure, as determined by high plasma norepinephrine concentration or low ejection fraction, were more likely to have activation of platelets and the coagulation system.(ABSTRACT TRUNCATED AT 250 WORDS)

Skip-cycle strategies for four cycle engine

Abstract: Strategies for operating a four cycle engine in skip-cycle manner include providing the engine with a valve control so that each intake and exhaust valve for each cylinder can be individually activated or deactivated essentially instantaneously to provide a skip-cycle pattern that varies as a function of the load. Individual of the valves permits changing the purpose of the stroke off each piston of each deactivated cylinder from compression to exhaust or intake to expansion, as the case may be, to assure firing of all of the engine cylinders within as short a period as one skip cycle to prevent cylinder cooldown, which promotes emissions. Unthrottled operation also is provided by closing the intake and exhaust valves in a particular sequence during skip cycle operation, and controlling the intake valve closure timing during load periods between skip cycle periods to continue unthrottled operation for all load levels. Further individual activation or deactivation of the fuel injectors and spark plugs enhances the skip cycle, unthrottled operation.

Powertrain component with adherent film having a graded composition

Abstract: A powertrain component (10) for use in an internal combustion engine, the powertrain component comprising a coating system including a film (30) selected from the group consisting of amorphous hydrogenated carbon, silicon-doped amorphous hydrogenated carbon, boron-, nitrogen-, boron nitride-, or metal-doped amorphous hydrogenated carbon, and mixtures thereof. The film (30) is formed on the powertrain component (10), and imparts the characteristics of low friction and wear resistance to the component. The powertrain component (10) also includes an interlayer (42) formed between the film and the component. The interlayer (42) accommodates stresses engendered by formation of the film (30), and thereby improves adherence of the film (30) to the substrate (10). To enable engineering of desired surface properties, the film (30), the interlayer (42), or both may be provided with a graded composition.

Observations of climate, albedo, and surface radiation over cleared and undisturbed amazonian forest

Abstract: Measurements from the first comparative study of climate over Amazonian tropical forest and an embedded deforested clearing are presented. Observations comprise a continuous 60-day run of data from mid-October to mid-December 1990, covering the end of the dry season and the beginning of the wet season. Mean hourly observations are calculated for the whole period; and for two 10-day periods, one in the dry season and one at the start of the wet season. Much greater variation in weather variables was observed at the clearing compared with over the forest. While the mean values of temperature and specific humidity deficit differed by less than 1°C and 1 g kg-' respectively, their daily ranges at the clearing were twice those at the forest. Mean daily albedo of the forest was 13.1 per cent, agreeing well with other tropical forest measurements, and of the clearing was 16.3 per cent, somewhat lower than the values currently being used in GCMs. The surface energy balance was investigated and mean available energy calculated for each site. The significant difference in the daily pattern of net radiation between the sites was found to be at least as much due to differences in the longwave radiation balance as to differences in albedo. The diurnal pattern of net radiation therefore changed between dry and wet periods as the higher plant water stress experienced by clearing vegetation altered the daily temperature cycle.

A characterization of hypothalamic-pituitary-adrenal axis function during and after human cardiac arrest.

Abstract: OBJECTIVE This study characterizes hypothalamic-pituitary-adrenal axis function during cardiopulmonary arrest and after return of spontaneous circulation. DESIGN Prospective case series. SETTING A large urban emergency department and intensive care unit over an 8-month period. PATIENTS Two hundred five adult patients presenting in cardiopulmonary arrest to an urban emergency department. Three patients known to be taking corticosteroids were excluded from the study. MEASUREMENTS AND MAIN RESULTS Cortisol concentrations were measured before and after advanced cardiac life support and for five consecutive hours after return of spontaneous circulation. Adrenocorticotropic hormone (ACTH) concentrations were measured before advanced cardiac life support and when the cosyntropin stimulation tests were performed 6 and 24 hrs after the return of spontaneous circulation. The mean initial serum cortisol concentration was 32.0 +/- 33.1 micrograms/dL (882.9 +/- 913.2 nmol/L). Fifty-three percent of patients had cortisol concentrations of 10 micrograms/dL (> 276 nmol/L) and 73% of patients had initial cortisol concentrations of > 20 micrograms/dL (> 552 nmol/L). Mean serum cortisol concentrations increased significantly (p = .0001) from 1 to 6 hrs after return of spontaneous circulation and decreased significantly (p = .03) from 6 to 24 hrs. A serum cortisol concentration of < 30 micrograms/dL (< 828 nmol/L) was associated with a 96% and 100% mortality rate at 6 and 24 hrs, respectively. Mean ACTH concentrations were increased without a significant difference between the initial and 6-hr concentrations. Mean ACTH concentrations decreased between 6 and 24 hrs (p = .06). There were no significant responses to the cosyntropin stimulation at 6 and 24 hrs. CONCLUSIONS Cortisol concentrations after out-of-hospital cardiac arrest are lower than those concentrations reported in other stress states. There is an association between cortisol concentrations and short-term survival after cardiac arrest. Survivors have a significantly greater increase in serum cortisol concentrations than nonsurvivors during the first 24 hrs. Lower than expected cortisol concentrations for the extreme stress of cardiac arrest may have pathologic significance in the hemodynamic instability seen after return of spontaneous circulation. The etiology of the low cortisol concentrations may be primary adrenal dysfunction.

System and method for controlling the transient torque output of a variable displacement internal combustion engine

Abstract: A system for controlling the transient torque output of a multicylinder, variable displacement, spark-ignited, fuel injected automotive internal combustion engine during periods when the effective displacement of the engine is being changed includes a spark timing controller, a throttle controller for positioning an intake air throttle, an engine cylinder operator for deactivating and reactivating at least some of the engine's cylinders, and an engine controller having a processor for selecting the number of cylinders for operation and for operating the spark timing controller, the throttle controller, and the cylinder operator so that during any transition from operation with a first number of activated cylinders to operation with a second number of activated cylinders, the processor will alter the spark advance and control the amount of air entering the engine cylinders so that the torque output of the engine will remain relatively unchanged during the transition.

Combination seat frame and ventilation apparatus

Abstract: A seat frame apparatus for a motor vehicle having a sealed duct capable of directing the flow of air while simultaneously supporting the structural loads imposed upon a conventional seat frame.

Capacitive surface micromachined differential pressure sensor

Abstract: A surface layer and a sacrificial layer are deposited on a substrate. A conductive structural layer bridges over the sacrificial layer and is anchored to the surface layer for creating paired conductive areas. A backside opening is etched in the substrate for defining a flexible diaphragm layer of reduced thickness. The sacrificial layer is removed so that pressures exerted on the backside opening will cause a change in capacitance between the paired conductive areas. Temporary posts support the conductive structural layer as the sacrificial layer is removed.

Controllable transparency panel with solar load reduction

Abstract: A laminated glazing unit has controllable transparency to visible light and a solar load reduction element which preferentially excludes infrared radiation while being substantially transparent to visible light. Electro-active material for controlling the transmission of visible light through the glazing unit is sandwiched between electrodes deposited on facing surfaces of plys or layers of an inextensible polymeric material, such as polyethylene terephthalate. One or both electrodes comprises a solar load reduction ("SLR") element, i.e., a Fabry-Perot interference filter which includes preferably at least one silver metal film sandwiched between zinc oxide films.

Energy management system for hybrid vehicle

Abstract: An energy management system for a hybrid vehicle having wheels drivingly connected to traction motors, which motors are alternatively energized by an internal combustion engine generator or an electrical storage battery. The system comprises an electrical storage battery, a high voltage electrically heated catalyst (300-400 volts) for treating the exhaust gas of the internal combustion engine, a generator driven by the selective operation of the internal combustion engine to energize the traction motors and to sometimes produce electrical energy in excess of that consumed by the traction motors, and a high voltage controller for selectively transferring electrical energy generated by the internal combustion engine generator and the electrical energy produced by the traction motors when driven by the wheels to preferentially the electrically heated catalyst and secondarily to the storage battery. Selection is carried out by an on-board microprocessor as a means for controlling the selection of energy transfer paths to provide transfer in accordance with: (i) the temperature of the electrically heated catalyst, (ii) the temperature of the engine coolant; (iii) the speed of the vehicle; and (iv) the state of charge of the storage battery.

Modelling the chemistry of ozone, halogen compounds, and hydrocarbons in the arctic troposphere during spring

Abstract: The box model MoccaIce has been developed to study the chemistry of the arctic boundary layer. It treats chemical reactions in the gas phase and in the aerosol, as well as exchange between the 2 phases. Photolysis rates vary according to the solar declination during polar sunrise. Apart from the standard tropospheric chemistry of ozone, hydrocarbons, and nitrogen species, the reaction mechanism includes sulfur and the halogens Cl, Br, and I. Modeling an ozone depletion event, we found that iodine species contribute to the chemical destruction of ozone significantly if IO mixing ratios are about 1 pmol/mol. The reactions of BrO with BrO and IO are the main pathways of the ozone destruction cycle. Hydrocarbon concentrations decrease during ozone depletion events due to reaction with halogen atoms. The rate of ozone destruction depends on whether the addition of Br to C 2 H 4 and C 2 H 2 yields inert products or intermediates from which Br can be regenerated. Bromine and HCHO are positively correlated. The model produces HCHO during ozone depletion events, though not as much as reported from field observations. After the destruction of ozone has been competed, the halogen species are converted to halides and subsequently scavenged by aerosol particles. DOI: 10.1034/j.1600-0889.49.issue5.8.x

Multi-stage digital RF translator

Abstract: An apparatus for performing digital signal frequency translation in a digital receiver is disclosed. The apparatus uses a plurality of mixer-filter-decimator stages for performing the digital signal frequency translation. The translation function converts the digital signal to an intermediate frequency (IF), where such translation is distributed among the plurality of mixer-filter-decimator stages to thereby simplify the mixing requirements.

Supersonic exhaust nozzle having reduced noise levels for CO2 cleaning system

Abstract: A CO 2 nozzle receives and expels liquid CO 2 through orifices sized for converting the CO 2 liquid into CO 2 snow. A body, defining an elongated cavity therein, is coupled to the CO 2 nozzle such that the CO 2 snow is ejected into the cavity. An exhaust nozzle is coupled to the body and the cavity therein for directing the pressurized CO 2 snow toward the workpiece. The exhaust nozzle is operated in an overexpanded mode for containing the shockwave within the nozzle for reducing the shear noise therefrom. Pressurized air is injected into the elongated cavity for exhausting the CO 2 snow under pressure.

A dry-release method based on polymer columns for microstructure fabrication

Abstract: A fabrication process that eliminates the adhesion of surface-micromachined suspended mechanical structures to the underlying substrate during a sacrificial-etch release is presented. The method is based on the construction of a periodic array of polymer columns or rubber feet that stiffen the structure during the sacrificial etch. Flat polycrystalline silicon plates measuring 3000*3000*1- mu m suspended 1 mu m above the substrate are easily fabricated by this method. This process has applications in the fabrication of micromachined plates used in devices such as accelerometers and pressure sensors. >

Computer program architecture for onboard vehicle diagnostic system

Abstract: A computer program architecture for a motor vehicle on-board diagnostic system includes a plurality of monitor modules for monitoring vehicle systems or components and issuing a malfunction subroutine call to a diagnostic executive upon detecting a system or component malfunction. The executive includes a plurality of software objects or modules for carrying out malfunction indicator light control and fault code storage strategies. A diagnostic scheduler module implemented as a finite state machine, controls and coordinates the sequence of the test to be run by the monitor modules as well as on-demand self tests. A malfunction indicator light (MIL) control module implements four distinct light control strategies through finite machines for illuminating and extinguishing the light and for storing and erasing fault codes under predetermined conditions.

Climate control system for electric vehicle

Abstract: A climate control system for a vehicle comprising a closed refrigerant system including variable speed compressor means (8), said control system further comprising vehicle operator input means (53) for selecting a desired interior temperature, ambient air sensor means (30) for monitoring the temperature of the ambient air, in-vehicle sensor means (32) for monitoring the temperature of the interior of the vehicle, programmable computer means (50) programmed to determine a set temperature value related to said desired temperature but limited to a value between a fixed predetermined minimum temperature value and a variable maximum temperature value equal to the temperature of the ambient air, said computer means (50) being further programmed to determine an air conditioning value related to the difference between said set temperature value and the temperature of the interior of the vehicle as provided by said in-vehicle sensor means and for controlling the speed of said compressor means (8) as a function of said air conditioning value.