Showing papers on "Slab published in 1972"
TL;DR: In this article, it was shown that phase transformations play a major role in driving the lithosphere slab into the mantle at depths greater than 300 km, and also control the stress distribution within the slab.
160 citations
TL;DR: In this article, the determination of the maximum load domain that is safe with respect to shakedown is formulated as a mathematical programming problem by means of a finite element technique for plane stress problems.
129 citations
TL;DR: In this paper, the force on a rectangular current-carrying coil moving above and parallel to a conducting plate of arbitrary thickness is investigated, and expressions for the lift and drag forces on the coil as a function of speed are developed.
Abstract: The force on a rectangular current‐carrying coil moving above and parallel to a conducting plate of arbitrary thickness is investigated. Expressions are developed for the lift and drag forces on the coil as a function of speed. Numerical calculations are made for a very thick plate and for plates with thickness of the order of the skin depth. Thick‐plate results are compared with experimental measurements of lift and drag on a superconducting coil suspended above a rotating aluminum wheel.
107 citations
TL;DR: In this paper, a model containing a descending lithospheric slab was used to predict an extensive P-wave shadow zone covering much of Canada and Europe and this was in close agreement with the pattern of reported magnitudes.
Abstract: Summary
Well documented short period seismic observations from the nuclear explosion Longshot provide an unusual opportunity to study seismic wave propagation in the mantle beneath an island arc. Ray calculations for a model containing a descending lithospheric slab predict an extensive P-wave shadow zone covering much of Canada and Europe and this is in close agreement with the pattern of reported magnitudes. Other features of the short period waveform which occur on some seismograms also seem amenable to explanation in terms of the complications that a slab introduces into seismic wave propagation in the vicinity of an island arc. Many examples are cited, including instances where a slab beneath the observing station also modifies the waveform.
62 citations
TL;DR: In this article, the authors investigate the heating of an infinitely extended slab of finite thickness for various configurations of the laser beam for which exact solutions can be found, for which the case of the slab resting on a substrate is considered by means of a modified image method for planar sources, enabling them to find all solutions by the superpositon of the well-known result for point sources.
Abstract: The mathematical treatment of laser machining involves the solution of the equation of heat conduction under conditions which generally impose the use of either approximate or numerical methods. Therefore, it seemed of interest to investigate the heating of an infinitely extended slab of finite thickness for various configurations of the laser beam for which exact solutions can be found. In particular, solutions are given (i) for beams with a Gaussian profile and for pencil‐shaped beams (intensity a radial step function) decaying exponentially, and for their limits of very fast (surface source) and very slow (radial heat flow only) decay, and (ii) for beams with radially constant intensity (axial heat flow). For the latter, the case of the slab resting on a substrate is considered by means of a modified image method for planar sources, enabling us to find all solutions by the superpositon of the well‐known result for point sources.
58 citations
Patent•
06 Nov 1972
TL;DR: The process of making a nailable, lightweight, fireproof and waterproof construction slab includes: A. COMBINING Portland cement, perlite, glass fiber, cellulose pulp, slaked lime and water to form an aqueous admixture, and B. Forming and CURING the SLAB from SAID ADMIXTURE, including SUBJECTING the FORMED SLAB TO PRESSURIZATION to SQUEEZE WATER thereFROM as mentioned in this paper.
Abstract: The process of making a nailable, lightweight, fireproof and waterproof construction slab includes: A. COMBINING Portland cement, perlite, glass fiber, cellulose pulp, slaked lime and water to form an aqueous admixture, and B. FORMING AND CURING THE SLAB FROM SAID ADMIXTURE, SAID CURING INCLUDING SUBJECTING THE FORMED SLAB TO PRESSURIZATION TO SQUEEZE WATER THEREFROM.
55 citations
53 citations
TL;DR: In this article, the effects of nongray self-absorption by cold boundary layers can then be readily estimated for gas in a channel with simple straight-line boundary layer profiles at the walls and constant temperature in the center.
Abstract: Nongray molecular gas radiation can be formulated in terms of slab band absorptance, which can be calculated from correlations of laboratory-measured values of band absorption. Slab-band absorptance is not only useful for obtaining the emissivity or mean beam length but also for the formulation of the radiant flux in a nonisothermal gas. Effects of nongray self-absorption by cold boundary layers can then be readily estimated. Illustrative results are presented for gas in a channel with simple straight-line boundary layer profiles at the walls and constant temperature in the center.
43 citations
Patent•
[...]
27 Mar 1972
TL;DR: A CONCRETE COMPSOITION as discussed by the authors was developed to provide a MATERIAL of CONSTRUCTION, which can be used to build all kinds of structures, including HOUSES, OFFICE BUILDINGS, and the like, which is capable of being WET MIXED and SUBSEQUENTLY MOLDED into CONVENIENT and USEFUL SHAPES.
Abstract: A CONCRETE COMPSOITION DEVELOPED TO PROVIDE A MATERIAL OF CONSTRUCTION WHICH CAN BE UTILIZED TO BUILD ESSENTIALLY ALL TYPES OF STRUCTURES, INCLUDING HOUSES, OFFICE BUILDINGS, AND THE LIKE, WHICH IS CAPABLE OF BEING WET MIXED AND SUBSEQUENTLY MOLDED INTO CONVENIENT AND USEFUL SHAPES. THE COMPOSITION HAS GREAT STRENGTH, EXCELLENT SHRINK RESISTANCE PROPERTIES, IS SHOCK RESISTANT, AND PROVIDES GOOD INSULATION FOR STRUCTURES, AND IS ADAPTED FOR USE WITH SUITABLE MOLDS TO FORM THE ENTIRE WALL, SLAB AND ROOF STRUCTURE OF A HOUSE OR OTHER BUILDING IN A SINGLE POURING.
39 citations
Patent•
24 Oct 1972
TL;DR: In this paper, precast concrete slabs are joined together to form a walk or patio-like matrix by embedding a plurality of rods in each slab and providing cavities in the bottom faces of each slab.
Abstract: Precast concrete slabs are joined together to form a walk or patio-like matrix by embedding a plurality of rods in each slab and providing cavities in the bottom faces of each slab. Each rod has a hooked end portion which projects beyond opposing end walls of the slab, the hooked end portions and the cavities being positioned such that the hooked end portions of one slab are receivable in the cavities of another slab, whereby the slabs may be interlocked end to end to form a strip of slabs. Similar cavities and rods having hooked ends may be positioned in each slab at right angles to the aforementioned rods and cavities to permit sidewise connection of the slabs along with the end-to-end connection.
35 citations
Patent•
27 Jul 1972
TL;DR: In this paper, an approach for forming a series of spaced parallel grooves in the surface of a newly laid pavement slab characterized by engaging the surface with a molding cylinder having a plurality of circumferential ribs formed thereon is presented.
Abstract: Apparatus for forming a series of spaced parallel grooves in the surface of a newly laid pavement slab characterized by engaging the surface of the pavement slab with a molding cylinder having a plurality of circumferential ribs formed thereon and moving the molding cylinder across the surface of the pavement slab while simultaneously rotating the molding cylinder about its longitudinal axis at a rate slightly greater than a free roll. Means are disclosed for preventing damage to the parallel edges of the pavement slab during the grooving process, and means are disclosed for simultaneously spraying water on the surface of the pavement slab and the surface of the molding cylinder during the grooving process.
TL;DR: Turn-up and turn-down is a phenomenon which occurs in the hot rolling of flat products when the nose of a slab, or the whole slab, curls up or down upon emerging from the rolls and remains deformed as discussed by the authors.
Abstract: Turn-up and turn-down is a phenomenon which occurs in the hot rolling of flat products when the nose of a slab, or the whole slab, curls up or down upon emerging from the rolls and remains deformed...
TL;DR: In this article, the initial state of stress in fallen snow is calculated by considering incremental gravity loading of the accreting snow slab, and it is then postulated that slab avalanche release is initiated by a reduction of shear strength on a critical layer to a value below that of the existing shearing stress.
Abstract: The initial state of stress in fallen snow is calculated by considering incremental gravity loading of the accreting snow slab. It is then postulated that slab avalanche release is initiated by a reduction of shear strength on a critical layer to a value below that of the existing shearing stress. The manner of top tensile failure, side shear failure, and either buckling or shear compression failure at the lower end of the slab is then described. These results provide avalanche dimensions that are lower bounds on those occurring naturally.
Patent•
02 Aug 1972
TL;DR: A self-propelled, automated machine for operating over a form to which concrete is introduced, the main functions of the machine being to level, vibrate and screed the concrete to provide a concrete slab without voids, and especially a slab in which both upper and lower surfaces, as well as opposite side edges and other sectional configurations are finished.
Abstract: A self-propelled, automated machine for operating over a form to which concrete is introduced, the main functions of the machine being to level, vibrate and screed the concrete to provide a concrete slab without voids, and especially a slab in which both upper and lower surfaces, as well as opposite side edges and other sectional configurations are finished.
TL;DR: In this paper, a modified approach based on the orthotropic plate theory for computing the natural frequencies of bridge slabs is presented through a set of empirical relationships between the plate parameters, and the results from the present investigation are compared with those obtained by other methods; good agreements are obtained.
TL;DR: An investigation of stopping-power ratio evaluation methods based on the treatment of the film dosimeter as a nonperturbing cavity demonstrated that a constant value could be used for each material in a two-layer absorber independent of the thickness of each layer.
Abstract: Electron depth-dose distribution measurements were made using the Chalkley-McLaughlin dye film dosimeter in two-layer slab absorbers of polystyrene-copper, polystyrene-tin, and aluminum-gold. A plane-parallel 2.0-MeV electron beam was used. Data were obtained for 12 cases by varying the location of the interface and by reversing the order of the slab components. Reproducibility of the measurements was ±6% (2 σ). An investigation of stopping-power ratio evaluation methods based on the treatment of the film dosimeter as a nonperturbing cavity demonstrated that a constant value could be used for each material in a two-layer absorber independent of the thickness of each layer. The error in absorbed dose determination introduced by the use of a constant value ranged up to 8%. A film placed at the interface between the two components of the slab was used to estimate the dose at the interface surfaces. Corresponding theoretical calculations were made using a multilayer electron transport computer code developed ...
TL;DR: In this paper, the spectral absorption coefficient of the glass was measured from 2000 to 2300 deg F, and two analyses were performed: one for a diffuse platinum-glass boundary and the other for a specular boundary.
Abstract: One-dimensional temperature profiles and heat fluxes within a slab of molten glass were measured experimentally. The glass slab was contained between two parallel platinum-lined ceramic plates. The plate temperatures were kept above 2000 deg F so that radiation heat flux was always equal to or larger than conduction. An optical method of temperature measurement was developed in which a helium–neon laser beam was directed along an isothermal path through the glass. The attenuation of the beam was a strong function of temperature and was used to evaluate the local temperatures within the glass slab. In order to perform a theoretical analysis the spectral absorption coefficient of the glass was measured from 2000 to 2300 deg F. Two analyses were performed: one for a diffuse platinum–glass boundary and the other for a specular boundary. The calculated temperatures agree with the measured values within 5 deg F throughout the slab, and the measured and predicted heat fluxes agree within 10 percent.
TL;DR: The time-dependent heat balance equation has been solved numerically for a material having the measured low-field conductivity of amorphous As30Te48Ge10Si12 as mentioned in this paper.
Abstract: The time-dependent heat balance equation has been solved numerically for a material having the measured low-field conductivity of amorphous As30Te48Ge10Si12. For a 60 μm thick infinite slab, with boundaries held at ambient temperature and a constant electric field applied parallel to the slab faces, the temperature and current distributions remain relatively uniform until a critical field is exceeded. The current then becomes progressively channelled in the region of the central plane and, for a field of 5.9 × 107 V m−1, it increases by two orders of magnitude within 100 psec as the centre temperature rises from 750 to 1000 K. Time-dependent solutions have also been obtained for a cylindrical block geometry, where heat flow is considered simultaneously both parallel and transverse to the axis. For sufficiently large applied potentials a current channel forms with the hottest point initially at the centre of the block. Hot spots, with associated channel constriction, then grow and move out towards the electrodes.
Patent•
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03 Mar 1972
TL;DR: In this article, a concrete slab is used to anchor a mobile home to a fixed block on the ground and the brackets are tightened to draw the frame down to the blocks to rigidly anchor the mobile home in position on the slab.
Abstract: A mobile home anchor which includes a concrete slab poured in the surface of the ground and having a foundation extending downwardly therefrom. The slab has a metallic eye anchored therein and extending above the top surface thereof. The mobile home is positioned on the concrete slab and a plurality of extensible and contractible brackets are hooked to the frame of the mobile home and to the eyes extending upwardly from the concrete. The frame is blocked up by fixed blocks resting on the slab and the brackets are tightened to draw the frame down to the blocks to rigidly anchor the mobile home in its position on the slab.
Patent•
13 Nov 1972
TL;DR: A slab conditioning system including a pair of rotatable leaves for supporting metal slabs and a conditioning tool platform mounted above the leaves and adapted to traverse the slab during the conditioning process is described in this article.
Abstract: A slab conditioning system including a pair of rotatable leaves for supporting metal slabs and a conditioning tool platform mounted above the leaves and adapted to traverse the slab during the conditioning process.
Patent•
02 Nov 1972
TL;DR: A cementitious product slab useful in construction is made by: PREPARING a FLOWABLE AQUEOUS CEMENTITIOUS SLURRY, forming a SELECTED QUANTITY of the SLURR into SLAB shape, SAID FORMING STEP INCLUDING VIBRATING SAID SLURRIER QUANTity to AID SLAB SHAPE FORMATION, PRESSURIZING the FORMED SLAB TO SQUEEZE WATER THEREFROM, and CURING the RESULTANT SLAB as discussed by the authors.
Abstract: A cementitious product slab useful in construction is made by: A. PREPARING A FLOWABLE AQUEOUS CEMENTITIOUS SLURRY, B. FORMING A SELECTED QUANTITY OF THE SLURRY INTO SLAB SHAPE, SAID FORMING STEP INCLUDING VIBRATING SAID SLURRY QUANTITY TO AID SLAB SHAPE FORMATION, C. PRESSURIZING THE FORMED SLAB TO SQUEEZE WATER THEREFROM, AND D. CURING THE RESULTANT SLAB.
TL;DR: In this paper, the authors describe the formation of a theoretical model which aims to describe the behavior of a reinforced concrete slab throughout the whole of its loading range from initial loading to ultimate collapse.
Abstract: Synopsis The paper describes the formation of a theoretical model which aims to describe the behaviour of a reinforced concrete slab throughout the whole of its loading range from initial loading to ultimate collapse. The model is based on the use of anisotropic finite elements, and a successive approximation technique. It synthesizes the section properties ofa slab from fundamental properties of the concrete and reinforcing steel. Moments, deflections and crack patterns are produced. The use of the model is illustrated by the analysis of a slab: the results of this analysis are compared with experimental results.
TL;DR: In this article, the authors presented a method of analysis for the dynamic response of a simply supported beam and slab bridge under the action of a moving vehicle, where the bridge is idealized as an orthotropic plate and, in the analysis, is subdivided into a number of finite strips.
Abstract: This paper presents a method of analysis for the dynamic response of a simply supported beam and slab bridge under the action of a moving vehicle. The bridge is idealized as an orthotropic plate and, in the analysis, is subdivided into a number of finite strips. The vehicle is idealized as a moving sprung mass. Viscous damping is taken into account for both bridge and vehicle.
The results show that there is significant variation of response across transverse sections of the bridge. Furthermore the dynamic magnification is considerably greater than that predicted by a more approximate method in which the bridge is idealized as a simple prismatic beam.
01 Jan 1972
TL;DR: In this article, a refinement of current methods for quantifying the strength of SLAB-COLUMN JUNCTIONS CARRYing UNBALANCED MOMENT and SHEAR in FLAT PLATE CONCRETE STRUCTURES is described.
Abstract: A REFINEMENT OF CURRENT METHODS FOR CALCULATING THE STRENGTH OF SLAB-COLUMN JUNCTIONS CARRYING UNBALANCED MOMENT AND SHEAR IN FLAT PLATE CONCRETE STRUCTURES IS DESCRIBED. THE SLAB SECTIONS FRAMING INTO EACH COLUMN FACE ARE IDEALIZED AS BEAM SECTIONS WHICH CAN DEVELOP THE ULTIMATE BENDING MOMENT, TORQUE, OR SHEAR APPROPRIATE FOR THE GIVEN LOADING CONDITION. THIS PROCEDURE PREDICTS THE STRENGTHS MEASURED IN LABORATORY TESTS, SIMULATING CONNECTIONS AT BOTH INTERIOR AND EXTERIOR COLUMNS. IT IS SHOWN THAT, IN ADDITION TO FLEXURE, TWO MODES OF FAILURE ARE POSSIBLE, MOMENT-TORSION AND SHEAR-TORSION. /ACI/
01 May 1972
TL;DR: In this article, a plus or minus 18% correlation between experimentally and calculated SHEAR-BOND STRESS is found to exist between the two types of failures.
Abstract: SHEAR-BOND MAY BE CLASSED AS A BRITTLE TYPE OF FAILURE AND IS CHARACTERIZED BY THE FORMATION OF AN APPROXIMATE DIAGONAL CRACK, RESULTING IN END-SLIP AND LOSS OF BOND BETWEEN THE STEEL DECK AND CONCRETE. THE ULTIMATE SHEAR-BOND CAPACITY OF STEEL-DECK-REINFORCED SYSTEMS IS A FUNCTION OF THE COMPRESSIVE STRENGTH OF CONCRETE, THE DEPTH AND WIDTH OF SLAB, THE THICKNESS OF STEEL DECK, THE SHEAR SPAN AND 2 CONSTANTS TO BE EVALUATED FROM EXPERIMENTAL TEST DATA. A PLUS OR MINUS 18% CORRELATION BETWEEN EXPERIMENTAL AND CALCULATED SHEAR-BOND STRESSES EXISTED. /AUTHOR/
Patent•
02 Oct 1972TL;DR: In this article, the top face of the reactor shield slab is provided in the portion adjacent to the seal plug opening with a flat bearing rim which supports the annular flange of the plug and is slightly raised with respect to the remainder of the slab.
Abstract: The top face of the reactor shield slab is provided in the portion adjacent to the seal plug opening with a flat bearing rim which supports the annular flange of the plug and is slightly raised with respect to the remainder of the slab. Provision is made between the plug flange and the top slab face for sealing means consisting of flexible O-ring seals, sliding means consisting of friction slideways, lifting means consisting of inflatable seals, ducts being provided in the slab for injecting a barrier of neutral gas under pressure.
TL;DR: In this article, an improved version of the BOUSSM was used to find the stiffness matrix of the SLAB, which was then combined with the FLEXIBILITY MATRIX to obtain the complete stiffness matrix.
Abstract: STRESSES IN RIGID PAVEMENTS WERE OBTAINED BY USING A FOUNDATION MODEL RATHER THAN THE DENSE LIQUID MODEL. THE FOUNDATION WAS TREATED AS AN ELASTIC CONTINUOUS, BUT DIFFERENT BOUNDARY CONDITIONS WERE CONSIDERED FOR THE PAVEMENT SLAB, AND AN IMPROVED COMPUTATION TECHNIQUE WAS USED. IN THIS METHOD, THE SLAB WAS TREATED AS AN ASSEMBLAGE OF PLATE ELEMENTS, WHILE THE FOUNDATION WAS TREATED AS AN IDEALIZED ELASTIC HALF SPACE FOR WHICH THE FLEXIBILITY MATRIX WAS DETERMINED USING BOUSSINESQ'S EQUATION FOR SURFACE DEFLECTION. THE STIFFNESS MATRIX OF THE FOUNDATION WAS OBTAINED BY INVERTING THE FLEXIBILITY MATRIX. IT WAS THEN COMBINED WITH THAT OF THE SLAB TO OBTAIN THE COMPLETE STIFFNESS MATRIX OF THE STRUCTURE. THE STRESSES IN THE PAVEMENT SLAB WERE THEN DETERMINED FOR DIFFERENT LOADS AND DIFFERENT TYPES OF SUBGRADES. THE RESULTS WERE COMPARED WITH THE STRESSES DETERMINED BY CONVENTIONAL METHODS. THE COMPARISON SHOWED THAT THE CONVENTIONAL METHODS GIVE LOWER STRESSES THAT ARE ON THE UNSAFE SIDE. /AUTHOR/