Showing papers by "Ford Motor Company published in 1974"

Measurement of Hydroxyl Concentrations in Air Using a Tunable uv Laser Beam

Abstract: We report the first measurement of hydroxyl (OH) concentrations in air by detecting the resonance fluorescence excited by tunable radiation near 2825.8 \AA{}. On a particular day, the OH concentrations deduced from these measurements ranged from a high of 1.5 \ifmmode\times\else\texttimes\fi{} ${10}^{8}$ OH/${\mathrm{cm}}^{3}$ in the early afternoon to a level below 5 \ifmmode\times\else\texttimes\fi{} ${10}^{6}$ OH/${\mathrm{cm}}^{3}$ at night.

Cyclic deformation and fracture of polymers

Abstract: The cyclic stress-strain behaviour of a wide variety of rigid polymers has been studied Three classes of fatigue response can be defined, each class displaying a characteristic evolutionary pattern in the stress-strain relation as deformation proceeds from the initial fatigue cycle to fatigue-crack propagation Ductile polymers undergo a marked decrease in deformation resistance prior to crack formation; the detailed mechanism by which this “softening” develops can be related to the material microstructure and thermomechanical history Amorphous polymers with a moderate degree of ductility soften slightly; in these materials crazing plays a dominant role in both the cyclic stress-strain response and the structural fatigue resistance Brittle and nearly-brittle polymers are essentially stable in cyclic deformation; the fatigue resistance of these materials is very sensitive to strain amplitude in cyclic deformation

Airborne particulate debris from rubber tires

Abstract: Airborne particulate matter worn from tires has been detected in the atmospheres of two vehicle tunnels and in the open air. The amount is about 20 per cent as great as that from vehicle e...

Station-keeping for a translunar communication station

Abstract: A translunar communication station is to be kept close to a nominal unstable periodic ‘Halo’ orbit, visible at all times from Earth. The analytically computed nominal orbit is not perfect, requiring an average control acceleration of about 10−6g's for tight control. An adjustable quadratic combination of position deviation and control acceleration is minimized to provide an (adjustable) control law with period feedback gains and a periodic bias. The average control acceleration can be reduced to less than 10−8g's with an error settling time of less than 21/2 months. The resulting limiting motion provides, in turn, an improved nominal, permitting the same low control cost with much tighter control, corresponding to settling times of the order of one day.

Carbide refining heat treatments for 52100 bearing steel

Abstract: The life of through-hardened 52100 anti-friction bearing components is improved if the excess carbides, undissolved during austenitization, are small and uniformly dispersed. One kind of carbide-refining heat treatment consists of 1) dissolving all carbides, 2) isothermally transforming the austenite to pearlite or bainite, and 3) austenitizing, quenching and tempering in the usual manner. Each step in this sequence of treatments was investigated, and the behavior of pearlitic and bainitic microstructures during subsequent austenitization was contrasted with the behavior of ferrite/spheroidized-carbide microstructures. It was shown that: 1) The usual hardening treatments given spheroidize-annealed bearing components result in an inhomogeneous microstructure, possibly due to the faster dissolution of carbides near austenite grain boundaries. 2) Austenitization of pearlite or bainite produces very uniform dispersions of ultra-fine carbides on the order of 0.1 µm diameter or less. 3) Specimens with ultra-fine carbides tend to have more retained austenite. 4) The rate of coarsening of ultra-fine carbides at austenitizing temperatures of 840°C and below, is slow enough so that conventional furnace heat treatments are satisfactory for producing this microstructure.

An experimentally validated dynamic model of the spine

Abstract: : Although there has been a large number of mathematical models proposed for the simulation of spinal response to acceleration, few have been validated against experimental data and none appears to reflect the actual conditions of load transmission from one vertebra to the next. This paper provides a brief survey of existing spinal models and presents a discrete parameter model with experimental validation. The transmission of load via the articular facets is a major new feature of the model, based on previously obtained experimental data. Good correlation was obtained between the model results and experimentally measured spinal loads for different impact acceleration levels and spinal configurations.

Mean and fluctuating flow measurements in the hypersonic boundary layer over a cooled wall

Abstract: Measurements of the mean flow, intermittent structure and turbulent fluctuations were made in a cold-wall boundary layer at a stream Mach number of 9·4 and Reynolds number based on momentum thickness of 36 800. For these conditions, the r.m.s. sublayer thickness was 32 times smaller than that of the boundary layer proper, and the interfacial standard deviation of the latter was about three times proportionately smaller than has been found at low speeds. The mean flow data, which extended well into the sublayer, revealed a large increase in static pressure from the layer edge to the wall and a quadratic law relation between the total temperature and velocity. While the transformed velocity profile was in good agreement with the incompressible law of the wake, no indication of a linear variation of velocity in the sublayer was detected.Hot-wire fluctuation data, interpreted with the use of appropriate assumptions concerning the nature of the sound field, indicated that the turbulence is dominated by high-frequency pressure fluctuations whose magnitude at the wall and beyond the layer edge agree with extrapolation of data acquired at supersonic speeds. The static temperature fluctuations agreed with expectations from adiabatic, supersonicdata apparently because they were suppressed by the cooled-wall condition. The fluctuations in the longitudinal velocity component were generally small and differed little from lower Mach number results. The high turbulence Reynolds numbers found generated an inertial-subrange spectral decay, while the longitudinal integral scales were found independent of turbulence mode and about one-fifth the boundary-layer thickness.

Quick-connect tubing coupling

Abstract: A quick-connect tubing coupling comprising a cup-shaped cage externally attached to a first tube with an end portion of the tube concentrically contained within the cage. The inside diameter of the cage is sufficiently greater than the outside diameter of the tube portion contained therein to provide a space therebetween. The cage has a plurality of axially extending cantilevered leaf springs projecting radially inwardly toward the first tube portion, some of the leaf springs being longer than the others. A second tube is outwardly cupped at one end to encapsulate an O-ring, the cupped end portion of the second tube being concentrically received between the cage and the first tube end portion. The cupped end of the second tube provides a shoulder behind which the longer leaf springs can lock with the O-ring in a sealed mode or behind which the shorter leaf springs can lock with the first and second tubes axially displaced to provide a pressure relief vent. Interengageable positioning means on the first and second tubes provide an anti-rotational interlock therebetween.

Method of welding galvanized steel

Abstract: A method of welding galvanized steel with a high energy density beam is disclosed. The high energy density can be created by an electron or laser beam with a power density of at least 4 X 106 watts per square inch. A flux material, such as iron oxide, is disposed adjacent the welding zone, preferably by painting thereon, which is effective to from a compound with the zinc of the galvanized steel upon heating. The compound has a vapor pressure substantially the same or lower than the vapor pressure of the steel substrate so that disruption of the weld puddle is prevented to insure that all of the weld puddle will be available to properly close the weld void.

The purification of bovine cathepsin B1 and its mode of action on bovine collagens.

Abstract: 1. Cathepsin B1 was isolated from bovine spleen by autolysis, (NH4)2SO4 fractionation and chromatography on Amberlite IRC-50. Two isoenzyme forms were purified to homogeneity by chromatography on CM-cellulose and DEAE-Sephadex. 2. A collagenolytic cathepsin was separated from cathepsin B1 during purification. The remaining collagenolytic activity of the purified cathepsin-B1 isoenzymes was no greater than 0.3 unit/unit of cathepsin B1 compared with about 5.0 unit/unit of cathepsin B1 in the autolysed spleen extracts. 3. The cathepsin B1 isoenzymes lowered the viscosity of gelatin at 37°C. Optimum activity was at pH4–5. 4. At 28°C the interchain cross-links in native tropocollagen were cleaved most effectively at pH4–5. Insoluble tendon collagen was digested at pH3.5 and 28°C to yield mainly α-chain components, with the loss of a short N-terminal sequence. 5. Electron-microscope studies of collagen fibrils showed that cathepsin B1 caused longitudinal splitting and dissociation of the protofilaments. The effect was not general but occurred at selected sites. 6. The isoenzymes of cathepsin B1 cleaved the telopeptide region of calf skin tropocollagen between the lysine-derived cross-link and the triple helix. The CB1 peptide fragments obtained from enzyme-degraded α1 chains were hydrolysed at Gly12-Ile13 and Ser14-Val15. The residual α2 CB1 peptides were hydrolysed at Ala8-Asp9 and Asp9-Phe10.

Salt-soluble elastin from lathyritic chicks

Abstract: The isolation of a salt-soluble homogeneous elastin from the aortas of lathyritic chicks by chromatography on DEAE-cellulose and salt precipitation is described. These new techniques, as well as some previously published by other workers, were evaluated with the help of antiserum raised in sheep against insoluble chick elastin. The purified elastin was very basic and behaved in a predictable manner in coacervation studies. The protein migrated in sodium dodecyl sulphate–polyacrylamide gels as a single band moving slightly faster than pyruvate kinase (mol.wt. 57000).

Suspension for truck cab

Abstract: The present disclosure relates to suspension means for supporting the cab of a truck on a truck chassis frame. It is disclosed in the environment of a tilt cab type truck. The suspension includes a pair of front and a pair of rear suspension arms that interconnect the cab and the frame. Front air springs are interposed between the front arms and the frame. The rear arms are connected to the frame by releaseable latch mechanisms and rear air springs are interposed between the latch mechanisms and the cab. An anti-roll stabilizer bar extends transversely between the front arms and functions to prevent tilting of the cab about a longitudinal roll axis.

Piston Ring Lubrication and Cylinder Bore Wear Analyses, Part II—Theory Verification

Abstract: Based on the analytical method presented in the previous paper (Part I), comparisons of predicted wear curves along the major and minor side-thrust sides of the cylinder bore are made with the measured ones obtained from several truck engines for various vehicle mileages. The agreement was found to be good. This indicates the analytical model developed in Part I is relevant and suitable for predicting the severity of piston-ring bore contact for varying engine operating and lubrication conditions. From this, the necessary parameter changes may be found such that the wear rate of the cylinder bore may be reduced. Wear factor data, however, must be available in order to make quantitative predictions of wear. The model ultimately may be useful also in the design optimization of engine components. Since the method is general, it also can be applied to other reciprocating piston devices, such as gas compressor, Rankine cycle engine, or Stirling engine.

Variable reluctance motor pump

Abstract: A motor pump wherein the motor is a variable reluctance motor having a rotor which functions as an impellor to provide pumping action as a result of centrifugal force acting upon a fluid supplied to the motor pump. The motor pump is extremely simple in that it has only one moving part, its rotor, which is formed of a plurality of ferromagnetic elements spaced from one another with flow passages located between the elements. Fluid enters the pump on the radially inner side of the ferromagnetic elements and flows radially through the flow passages to the pump discharge outlet.

Waterproof electrical connector

Abstract: A separable waterproof electrical connector for a plurality of pairs of axially interconnectable cylindrical electrical terminals coupled to the ends of insulated wires, each terminal having an annular external recess in its cylindrical peripheral surface. The connector comprises a pair of elongated, rigid, non-conductive elastomeric, tubular members having generally complementary end portions fitted one into the other. A soft elastomeric sealing sleeve is concentrically interposed between the interengaged end portions to prevent the passage of moisture therebetween. Releasable clamping means on the exterior of the tubular member end portion hold the latter in engagement. Each elastomeric tubular member has an interior partition wall extending laterally of its longitudinal axis in juxtaposition to the interengaged end portions. Each partition wall has a plurality of axially extending apertures therethrough that are equally spaced around the longitudinal axis of the tubular members. The electrical terminals are seated in the apertures. A portion of the wall of each aperture comprises an axially extending cantilevered locking member hinged at one end to the partition wall and having a detent spaced from its hinged end. The detent is adapted to engage the external recess on the terminal seated in a respective aperture to prevent axial displacement of the latter. Each partition wall has an axially extending cavity communicating with the locking members. A displaceable plug means is seated in the partition cavity in abutting relation to the locking member to hold the detents on the latter in the respective terminal recesses. A grommet is seated in the tubular member outwardly of the partition wall through which the insulated wires extend. The grommets are in sealing engagement with the interior walls of the tubular members and the insulated wires in watertight relation.

Ion Exchange in Sodium Borosilicate Glasses

Abstract: The kinetics of K+-Na+ exchange in sodium borosilicate glasses containing 20 mol% Na2O were studied as a function of glass composition and exchange time and temperature. The distribution of K in the glass after exchange in molten KNO3 was determined using an electron microprobe. In those specimens which were not chemically attacked by the molten salt, the K profiles were consistent with Fickean behavior. The calculated interdiffusion coefficients varied with local composition in each specimen. This composition dependence and its variation with temperature could be fitted approximately to a mixed-alkali model using the Nernst-Planck relation for diffusive fluxes. However, some deviation from this behavior, presumably as a result of the generation of microscopic stresses around an exchange site, was observed. The dependence of the apparent activation energy, Ẽ, on the B/Si ratio was analogous to that of the activation energy for ionic conduction in these glasses: Ẽ decreased with increasing fraction of nonbridging oxygen. This result disagrees with the presumed behavior in sodium aluminosilicate glasses.

The nucleation and solidification of Al-Ti alloys

Abstract: A series of hyperperitectic Al-Ti alloys at 0.35, 0.5, 0.7 and 0.8 wt pct Ti has been frozen at rates varying from less than 1°C/s to in excess of 100°C/s. Cooling-curve analyses, metallographic and microprobe examinations, taken altogether, allow identification both of the nucleants and the solidification modes acting in this important alloy system. Two sets of conclusions are drawn, one in general about low concentration peritectic systems like Al-Ti, and the other about particular interactions in Al-Ti. For example, it is revealed that AlxTi compounds exist; Al3Ti, AlxTi and Al are nucleated by TiC; and AlxTi and TiC are both nucleants for aluminum.

A study of grain boundary segregants in thermally embrittled maraging steel

Abstract: Auger electron spectroscopy was employed to directly determine the cause of thermal embrittlement of 250 series maraging steel. A drop in CVN energy with introduction of an embrittling intermediate anneal was directly correlated with a build-up of both Ti and C on the prior austenite grain boundaries. By following grain boundary concentration of Ti as a function of time at a given temperature, the diffusion coefficient for Ti in the maraging steel at 1600°F was determined. Finally, the further drastic drop in CVN energy on aging an embrittled specimen was shown to be due to a segregation of B to the already embrittled prior austenite grain boundaries, causing a further loss of cohesion.

On the cellular regulation of growth and development in skeletal muscle.

Abstract: Summary 1. Fibres of skeletal muscle in different mammalian species vary more in number and in their rates of growth than in their ultimate breadth, and they grow more slowly in cattle and man than in rats and mice. Cells of large mammalian species probably divide comparatively slowly in pre-natal life but do so for longer, and thus they attain greater numbers than do their counterparts in smaller mammals. Such cells include the precursors of muscle, and common mechanisms may therefore limit rates of growth before and after muscles form. If some metabolic processes are slower in mammals destined to be large, corresponding trends in age-related cellular changes which ultimately suppress mitotic activity may cause differences between species in the overall size of muscles and in that of other tissues. This is probably an oversimplification. 2. It is difficult to decide how far the rate of growth and the final diameters of muscle fibres reflect the number of myoblasts which initially fuse into myotubes and the number of myoblasts which are subsequently incorporated into individual fibres. New nuclei are probably added with age along the length of a fibre, but it is uncertain whether they then synthesize ribosomes which produce contractile protein. It seems likely that fibres elongate to different extents by adding myoblasts terminally. 3. There is some evidence that myofibrils grow throughout the depth of a fibre by adding new myofilaments to their surface, but there is none that is convincing to the effect that myofibrils form de novo at a fibre's periphery. Ribosome-like structures distributed in the sarcoplasm between myofibrils have been described, and their numbers decline in comparison with those of the myofibrils during growth. Thus, fibres possibly attain their maximum breadth when the loss of superficial filaments from myofibrils exceeds the capacity of ribosomes to replace them. The evidence is inconclusive as to whether myofitrillar protein is broken down and replaced at rates which vary within a muscle or between muscles differing in physiological properties. Sarcoplasmic proteins appear to be replaced more rapidly than those in myofibrils. It is also speculated that muscle proteins are synthesized and degraded more slowly in species which take longer to develop. 4. Observations, with the microscope suggest that new ribosomes appear in cells which are becoming myoblasts. Whether the ribosomes subsequently break down is not established. The evidence that I-somes occur in muscle is inconclusive, as is that for the existence of messenger RNA and its selective synthesis when muscle is forming in the embryo. 5. A decline in the synthesis of RNA occurs as myotubes appear and contractile protein begins to accumulate. The significance of this phenomenon is not known, and in more mature muscle some RNA also appears to fluctuate in a fashion which is unrelated to rates of controlling protein synthesis. Such RNA may occur at the periphery of fibres or in satellite cells. In some instances it may be formed by cells of the connective tissue and capillaries. There are indications that the growth of muscle does not require the continued transport of new RNA and ribosomes into the body of a fibre. 6. As regards the existence of polyribosomes in muscle and the activity of muscle ribosomes in zlitro, most relevant phenomena can be explained if the ribosomes are aggregated, inter ah, by newly completed protein and if observed variations in activity are some function of the residual amounts of nascent protein which remain on the ribosomes. The morphological appearance of ribosomes in myoblasts is difficult to reconcile with the notion of ribosomes linked by messenger RNA. There is also some rather inconclusive evidence that the sarcoplasm varies in the effectiveness with which it supports protein synthesis by ribosomes. 7. Muscle fibres differ markedly in the number of mitochondria which they exhibit in histological sections and in the rate at which the homogenized fibres catalyse the processes of aerobic respiration which occur in mitochondria. It is uncertain how far such variation is determined by the properties of myoblasts and myotubes, by the nature of subsequent contractile activity and by dilution of the mitochondria as myofibrillar protein accumulates. In part, the tendency of fibres richest in mitochondria to be comparatively small may reflect the diversion of energy sources and oxidizable precursors of protein into energy-generating pathways. However, such fibres perhaps also possess fewer nuclei and fewer functional ribosomes. 8. Within a given animal, variation between fibres in the activity of sarcoplasmic enzymes becomes most pronounced after the myoblast stage. Assuming that these sarcoplasmic proteins are increasing by dissimilar amounts, genes in different fibres are perhaps varying in activity, but this has not been studied. It may be that the intermittent and increasingly forceful contractions of developing fast-phasic fibres simply cause them to accumulate increased amounts of amino acids in the pool from which protein is synthesized, so that a generalized stimulation of protein synthesis follows. Sarcoplasmic protein should then accumulate more than myofibrillar protein relative to starting quantities. This is a consequence of sarcoplasmic protein turning over faster. However, in addition, one must postulate that sarcoplasmic enzymes vary in stability between fibre types. It also remains to assess whether such differences reflect the presence of different molecular forms of each enzyme and whether the latter possess dissimilarities of amino-acid sequence or of molecular configuration. Similar unsolved problems arise regarding the ATPase activity of myosin in developing muscles and its variation between fibres.

Circuit for converting a temperature dependent input signal to a temperature independent output signal

Abstract: A bridge circuit for combination with a variable resistance sensor whose resistance may vary as a function of a sensed variable and also as a function of a parasitic variable such as, for example, temperature. The bridge circuit includes at least one variable resistance which varies as a function of the parasitic parameter and is relatively insensitive to the sensed parameter. The bridge circuit comprises a first leg incorporating the sensor resistor having a tap junction whose voltage varies as a function of the sensed parameter and of the parasitic parameter, a second leg including the parasitic parameter responsive resistance and having a voltage tap whose voltage varies only as a function of the parasitic parameter and a third leg interconnecting the first and second leg voltage taps and having a signal tap whose voltage varies only as a function of the sensed parameter. In a preferred embodiment, a resistance type exhaust gas sensor whose resistance varies as a function of the partial pressure of oxygen in the exhaust system of an internal combustion engine and also as a function of the temperature of the environment of the exhaust system is compensated by the circuit of the present invention to remove temperature dependency effects.

Password operated system for preventing unauthorized or accidental computer memory alteration

Abstract: Manipulation of a digital computer magnetic memory is locked out to prevent unauthorized or accidental erasure. The memory is provided with a unique password. Unless the correct password is present in the computer, or entered into the computer by the operator, the computer will not run and the memory cannot be altered.