Hollow Objects Research Articles

The Use of Sulphur in Hollow Ancient Gold Objects

Archaeologists interpreted residues inside hollow gold rings found in Roman burials of girls in the Rhineland as a “cement for chasing”. The aim of this study was to analyse this material and to compare it with Mediaeval and modern specimens made from pitch with inorganic filler and organic additives. The cement inside the Roman rings was identified as crystalline sulphur, which has occasionally been reported in the analytical literature as a filler in hollow gold objects from Hellenistic to Merovingian times. As was shown by practical experiments, the consistency of solidified sulphur can easily be adjusted to allow embossing and chasing of filled objects. Therefore, sulphur might act not only as a filler in such items, as was sometimes suggested, but also play a decisive role in the manufacturing of them.

Process for coating hollow objects

Process for coating hollow objects

The Numerical Analysis of Laplace's Equation in Cylindrical and Hollow Cylindrical Objects with Rotational Symmetry. Applying to Guard-Ring Capacitor.

Fundamental formulations are given for the potential distribution of acylindrical and a hollow cylindrical objects with a rotational symmetry.Thisprocedure is performed by solving Laplace's equation in polar coordinates usingthe method of separation of variables.By limiting the inner radius of ahollow cylinder to zero, it can be proved that all the formulations for the hollowcylinder become to those for the cylinder.A few examples of numericalanalysis are quantitatively done for the boundary conditions with constantpotential value on the cylindrical and hollow cylindrical surface.The obtaineddata with respect to convergence of a series sum and resultant potentialdistribution are presented for the different boundary conditions.

Conduite à tenir face aux corps étrangers œsogastriques chez l'enfant

Various methods have been used to remove foreign bodies; hollow foreign bodies deserve special consideration. The main difficulty encountered in such situations is the anatomic obstacle of the lower and upper esophageal sphincters along with a risk of perforation.We describe a unique approach by using an esophageal balloon dilator to anchor a hollow foreign body onto an endoscope, which allows for the successful extraction of such objects with minimal risk.Case series.Shands Jacksonville and University of Florida/Jacksonville, Jacksonville, Florida.Two consecutive patients with hollow foreign bodies in the stomach that required removal.A combined approach by using an endoscope and a 20-mm by 8-cm esophageal balloon dilator to remove hollow foreign bodies from the stomach.Nonsurgical removal of hollow gastric foreign bodies.Both foreign bodies were successfully removed from the stomach and extracted by mouth with this technique. There were no complications after both procedures.The inflated esophageal balloon that anchors a hollow foreign body onto a flexible endoscopic technique is a safe and effective alternative to previously described methods for removal of such foreign bodies in the gastric cavity. This method may be applicable to the removal of other hollow objects within the gastric lumen.

Calculation of the parameters of radiographic quality control of annular welded joints of cylindrical and spherical hollow objects : Udralov, Y.I. Soviet Journal of Nondestructive Testing, Vol. 27, No. 3, pp. 214–219 (Nov. 1991)

Calculation of the parameters of radiographic quality control of annular welded joints of cylindrical and spherical hollow objects : Udralov, Y.I. Soviet Journal of Nondestructive Testing, Vol. 27, No. 3, pp. 214–219 (Nov. 1991)

Production of free standing objects by high velocity oxy-fuel (HVOF) thermal spraying process

The feasibility of manufacturing free-standing thin walled objects by HVOF thermal spraying process is investigated. By this method hollow cylindrical objects have been produced using different metallic materials. Coating materials in the form of powder were sprayed on pre-shaped cores. Some releasing agent was used to separate the free standing body from the pre-shaped cores. These free standing objects were characterised for the mechanical properties. The parameters measured includes hardness, porosity and surface roughness.

Fabrication of Three—Dimensional Objects Using Laser Lithography

AbstractThere is no established technique for the 3‐dimensional (3‐D) pattern formation, and many structures cannot be formed using the conventional CAD/CAM technology. We have constructed a simpler economical system for the 3‐D pattern formation by using an ultraviolet laser and light‐sensitive resins. In this technique, the CAD data designed by a computer are sliced horizontally. Using the sliced data, the laser is moved in a 2‐D direction and the light‐sensitive resin is irradiated. Then solidified thin plates are stacked to form a pattern. Using this technique, such complicated patterns as holes, screws and hollow objects, can be formed by one process. Since it is not necessary to maintain the cutting tools and the cutting scraps, a completely automated process can be achieved.

From visual-motor anticipation to conceptualization: Reaction to solid and hollow objects and knowledge of the function of containment

This research investigates the development of visual-manual coordination during infancy with respect to the spatial property of concavity and the development of the capacity to expect or understand that a hollow object affords specific manual behaviors. Tumblers closed at the top by a plexiglas plate were used: They seemed to be open but resisted introduction of the hand. Infants' behavior towards these deceptive objects was compared with their behavior towards identical objects that looked and felt closed or open. The results show that from the 8th month infants exhibit to the deceptive objects an anticipatory visuomotor behavior and from ninth month they exhibit exploratory behavior that suggests that they are trying to understand the discrepancy between the objects' visual and tactile properties. It can therefore be concluded that a rudimentary conceptualization of containment appears to be elaborated by infants from ninth month.

TL dating: A novel form of differential dating

The basic age equation of thermoluminescence dating contains two types of quantities, namely accumulated dose and dose-rates which, on closer inspection, are dependent on the size of grains used in the dating experiment. This is caused by the attenuation of radiation within the grains and can be made more explicit by introducing functions into the age equation, which quantitatively describe the effect of attenuation. The age then becomes a function of grain size and concentration of radioactive elements. As the specific functions for alpha-, beta- and gamma-radiation contribute to very different degrees to the total annual dose, a potential age determination is offered. In a first approximation it is based only on the grain size attenuation of beta-radiation to which the object was exposed. Such kind of dating requires several grain sizes to be investigated, preferably ranging from 100 to 1000 μm in order to make differences in the archaeodose more easily measurable. The linear relation between archaeodose and attenuation factor of beta-radiation permits the evaluation of the age from the gradient and the environmental dose-rate from the intercept of an appropriate plot. The technique has been tested with quartz grains extracted from well-dated 700–800-years-old bricks. Results obtained agree fairly well with known historical dates and also indicated that this dating procedure avoids several disadvantages of the former subtraction dating technique. As the environmental dose-rate is eliminated,it seems a suitable way to date cores of hollow cast objects.

Dependence of the optical contrast of vesicle walls on lamellarity and curvature

Using photometric phase-contrast microscopy it was possible to discern the number of lammellae in thin walls of artificial phospholipid-vesicles. By comparing the contrast of spheres and elongated tubes with same diameters we could analyse the dependence of the contrast on both principal curvatures. The characteristics of the intensity distribution of the light in the image plane of the phase-contrast microscope is discussed for thin hollow phase objects.

Preparation of hollow spherical articles

A novel method for making hollow articles in spherical and other shapes is outlined. These spheres are prepared by dissolving a film-forming polymer in a sublimable core solvent, shaping the blend while molten, cooling to solidify, and subsequently removing the solid core material as a vapour. The film-forming solid migrates to form a shell having the original core shape and a honeycomb-like porous wall. Inorganic hollow objects can also be made by introducing sinterable solids to the hot solution, subsequently heating to remove the organic portion and further heating to effect sintering. Size, strength, wall thickness, bulk density and surface characteristics can be controlled to suit the end use.

Method of rapidly forming hollow objects from reinforced plastic sheeting : Segal, L. (Allied Chemical Corporation Inc. New York, USA) US Pat 3 919 386 (11 November 1975)

Method of rapidly forming hollow objects from reinforced plastic sheeting : Segal, L. (Allied Chemical Corporation Inc. New York, USA) US Pat 3 919 386 (11 November 1975)

The Formation of Curved Polymer Crystals: Polychlorotrifluoroethylene.

The habits and fine structure of crystals of polychlorotrifluoroethylene (PCTFE) grown from dilute solution were studied as functions of crystallization temperature. The solvent used was a low molecular weight PCTFE oil. The simplest crystals found were monolayered chain folded lamellae formed at 110 °C. These lamellae are planar and possess an unusual texture characterized by the presence of fine channel-like voids in the interior of the crystals. These lamellae do not exhibit well-formed crystal faces but are disc-like in overall shape. At lower crystallization temperatures the crystals take the form of complex arrays of curved lamellae which are aggregated into, among others, watchglass-shaped or hollow spherical objects. The variation of the curvature of the crystals with crystallization temperature is discussed in the light of previous studies of the formation of curved crystals of poly(4-methylpentene-1) and polyoxymethylene.

Extraterrestrial abiogenic organization of organic matter: the hollow spheres of the orgueil meteorite.

Fragments of the Orgueil meteorite were macerated in mineral acids (HNO3-HF-HNO3) to dissolve the mineral matrix and separate the acid-resistant organic residues; a routine procedure in the extraction of pollen and spores from terrestrial sediments. Numerous spherical hollow objects were found, optically resembling the brown amorphous residual organic matrix of the meteorite. Their morphology, size-distribution, and chemical composition, revealed by electron microprobe with reference to carbon and phosphorus, are described, and evaluated in connection with criteria of biogenicity. The intrinsic criteria are satisfactorily met, but the extrinsic requirement of a sedimentary environment is not met. A review of the literature concerning the meteoritic environment suggests an explanation of these spheres based on the environment of their formation. It is proposed that they are organic coatings on olivine microchondrules, magnetite and glass globules, the mineral component of which has been dissolved by the acid maceration. They could have initially resulted from the polymerization of dispersed small organic molecules condensing on the surface of the microchrondrules. The latter were injected from a volcanic ‘nuee ardente’ into the dispersed cold primordial cosmic dust of hydrated silicates and organic molecules, around the meteorite parent-body. This presumably occurred before the cosmic dust accreted as the carbonaceous chondritic outer layer of the parent-body. Upsurging reducing hot gases from the ‘nuee ardente’ would polymerize part of the dispersed organic matter as the insoluble brown amorphous matrix, possibly the ‘sticking’ agent when the cosmic dust accreted. The spiraled form of several of the organic structures described here are suggestive of atmospheric heat microturbulences. Organic membranes and comet-form tails of spherical coatings suggest polymerization in the wake of injected microchondrules. These diverse organic structures would result in our view from the abiogenic thermal organization of organic matter in an extraterrestrial gas-solid system.

Penetration of Electrophoretic Deposits into Cylindrical Tubes

The process of electrophoretic deposition of organic coatings has the inherent advantage of superior penetration of the electrodeposited film into the interior of hollow metal objects. In the work reported here a mathematical treatment of the extent of penetration of electrodeposited film into a tube is developed, based on a model that assumes electrophoretic deposition ceases when either (i) the film is sufficiently thick to block the passage of current or (ii) the supply of polymer particles to the substrate is inadequate. Experimental data relating the length of film penetration to polymer concentration, applied voltage, tube radius, and time are also reported. Good agreement between theory and experiment is obtained.

REMOVAL OF GLASS BEADS AND OTHER HOLLOW OBJECTS FROM THE LUNGS

It is believed that a method of real merit has been developed for the removal of glass beads and similar hollow objects. So far as I know, this method has not been previously described. Recent articles by Chevalier Jackson, Ellen J. Patterson and others do not mention it. REPORT OF CASE J. M., a colored girl, aged 6, while playing, Feb. 6, 1924, suddenly inspired into the trachea a glass bead 13 by 8 mm. This was followed by typical symptoms of dyspnea. I saw her in the afternoon of the same day and advised immediate operation. For some reason my advice was not taken, and the next I heard from her was that she was in the hospital under the care of a confrere, who, it appears, had made an unsuccessful effort at removal. Roentgen-ray examination revealed the intruder's presence in the right bronchus at the level of the

Centrifugal Casting

Abstract The paper describes the process of centrifugal casting of hollow metal objects. The author first takes up the field of centrifugal casting and the history of the development of the art, which he follows by a discussion of the mechanics of the problem and a description of the operation of the casting machine. He then takes up the thermal conditions in the mold and the field of application of hot-mold centrifugal casting, and closes with a discussion of the manufacture of plates by the centrifugal casting process. In appendices to the paper are given a bibliography of the subject, a list of patents, some of the mathematics covering the cases of casting about a vertical and about a horizontal axis, and the forces acting on the liquid metal in the direction of the axis of the mold, a discussion of temperature control in the casting and in the mold, and an analysis of the stresses in the mold.