Matte Finish Research Articles

Characteristic spectra of Munsell colors

The 1257 reflectance spectra of the chips in the Munsell Book of Color—Matte Finish Collection (Munsell Color, Baltimore, Md., 1976) were measured with a rapid acousto-optic spectrophotometer. Measured spectra were sampled from 400 to 700 nm at 5-nm intervals. The correlation matrix of this sample set was formed, and the characteristic vectors of this matrix were computed. It is shown, contradictory to earlier recommendations [ Psychon. Sci.1, 369 ( 1964)], that as many as eight characteristic spectra are needed to achieve good representation for all spectra.

A New Surgical Knife

Original ArticlesA New Surgical Knife Kenneth G. ReidFRCS Kenneth G. Reid Consultant Cardiac Surgeon, Department of Surgery, King Faisal Specialist Hospital and Research Centre, P. O. Box 3354, Riyadh 11211, Saudi Arabia Search for more papers by this author Published Online:1 Jul 1987https://doi.org/10.5144/0256-4947.1987.239SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutABSTRACTABSTRACTA new surgical knife has been designed, developed through prototypes, and clinically tested over four years. It allows the surgeon intraoperatively to vary the position of the cutting blade relative to the long axis of the knife handle. The instrument has been designed primarily to extend the safety and accuracy of conservative mitral valve surgery during open heart operations and to promote new techniques of repair.IntroductionA well-designed product, be it a tractor or a pair of shoes, is something that works: it fulfills the wants, tastes, needs and priorities of those who use it. It is a successful fusion of market requirements, aesthetics and technology.—Louis Van Praag, in The Times, 15 October 1984RATIONALEThe mitral valve lies eight or nine inches from the surgeon’s hand, within the left atrium. The plane of the valve relative to the line of surgical access through a conventional left atriotomy varies with each patient from 45° to 90°. This restricted access imposes limitations on the use of a conventional straight knife when accurate and delicate surgery has to be performed at supravalve, valve and sub valve levels. It became necessary to develop an instrument that allows the angle of incidence of the cutting edge to the plane of the valve to be varied easily and intraoperatively by the surgeon.Four prototypes were tested clinically to achieve optimal length, weight, locking mechanism, materials, surface finish and cost effectiveness.DESCRIPTION OF INSTRUMENTThe knife consists of a cylindrical, machined and milled handle, as seen in Figure 1, with a screw thread at the distal end. An axle carrying a milled steel wheel (Figure 2) which is welded to a Swann-Morton blade holder rests within a short cylindrical head that screws onto the handle with a reversed thread so that pressure on the blade edge tightens it. A steel chisel also rests in the blade-carrying head. The position of the chisel is maintained by means of a pin slotting into a longitudinal groove in the side of the chisel. As the head is tightened on the handle, the chisel edge engages the milled grooves on the axle wheel, thus locking the blade in position. Unscrewing the head allows the chisel to fall back and disengage, and the surgeon can adjust the angle of the blade before relocking it. The blade can, therefore, be placed in any position through 180°, and by virtue of the cylindrical handle, in any plane. The blade has the same flexibility of position as a universal joint without the latter’s disadvantages (Figure 3).Figure 1. Distal screw thread and wheel axle.Download FigureFigure 2. The milled wheel and mounted blade carrier.Download FigureFigure 3. The blade may be placed in any angle through 180°.Download FigureThe knife handle is 8.5 inches long and made of surgical stainless steel which has been oxidized to give a black matt finish. It is fitted with standard surgical blades.CLINICAL APPLICATIONThe knife has been widely used for conservative mitral valve surgery and the design was endorsed at the 2nd International Mitral Valve Workshop in Santander, Spain, in September 1984. It has also been used for the excision of failed valve prostheses, for infundibular resection in obstructive cardiomyopathy and tetralogy of Fallot, and in resecting calcified aortic valves. Its particular merit is that it permits greater precision and safety when surgical access is limited.The knife is currently being tried in other surgical disciplines where the blade action has important advantages over conventional instruments.The instrument is unique and has established an important new principle which can be modified for use in many fields. Previous article Next article FiguresReferencesRelatedDetails Volume 7, Issue 3July 1987 Metrics History Accepted12 November 1986Published online1 July 1987 KeywordsSurgical instrumentsMitral valve - surgeryACKNOWLEDGEMENTThe author would like to thank Miss Lesley Skeates for preparing the illustrations. Manufacturer: Downs Surgical PLC, Mitcham, Surrey, EnglandInformationCopyright © 1987, Annals of Saudi Medicine

Effect of metal surface treatment on ceramic bond strength

This study indicates that the unaltered specimens of both alloys produced the lowest bond values; for the gold-palladium alloy, a short degassing period (manufacturer's recommendation) and a 10-minute degassing period resulted in significantly lower bond strengths than those observed with the aluminum oxide and the steam cleaning treatments; and all treatments of the silver-palladium alloy gave comparable bond strengths to that obtained with the manufacturer's recommendation for surface treatment. Because the simplified methods gave equivalent or higher bond strength values than the manufacturer's recommendations, and because of the time saving, we recommend the following procedures for the porcelain-alloy systems tested: After casting and investment removal, use an abrasive to remove casting irregularities and to modify or correct the surface that will receive porcelain. Create a uniform matte finish on the surface that is to receive porcelain by pressure blasting with 50 micron aluminum oxide particles, or steam clean the surface for 30 seconds, or both. Proceed with opaquing.

Discrepant results obtained with two versions of the Farnsworth Panel D-15 test in patients with acquired blue-yellow defects.

Two commercially available Panel D-15 tests were administered to two patients with acquired blue-yellow defects. The results obtained with each test were different and apparently influenced by the cap construction which is the only difference between the two tests. In one test the surface of the cap is concave and polished while in the other test the cap surface is flat and has a matte or dull finish. The mechanism accounting for the different results is not obvious.

The Gynecology of Childhood and Adolescence

Since The Gynecology of Childhood and Adolescence by John W. Huffman appeared in 1968, it has been the definitive text in the area for pediatricians and gynecologists. In the second edition, Dr Huffman has been joined by two other experts in the field, C. John Dewhurst and Vincent J. Capraro, which should have resulted in an even more comprehensive volume; unfortunately, the new edition does not fulfill such expectations. Although the book is attractively bound and liberally illustrated, the gross photographs and photomicrographs are not reproduced as clearly as in the first edition. Some of this may be the result of switching from a glossy paper to a dull matte finish. The most serious deficiency is that the book is out of date in many areas. The field of endocrinology has expanded rapidly in the past decade with the advent of newer diagnostic tests and more sophisticated analyses. Of the

Clinical Interpretation of Laboratory Tests

The seventh edition differs from the previous editions in several aspects. The new edition has been reduced from 539 pages to 484 pages of text without much loss of information. Also, the paper has been changed to a glare-free matte finish that is much easier on the eyes. The chapter on serology has been completely rewritten with emphasis on the newer concepts of immunity, including a discussion of immunoglobulins. The text is generally clear and informative but is frequently superficial. Several subjects have been neglected, eg, such as parasitology, radioimmunoassay, and chromosome analysis. Also absent are details such as specific handling of specimens, which would be very helpful to clinicians, particularly housestaff. Despite these omissions, the book still manages to convey a large amount of information within a relatively few pages. The medical student will find this a helpful primer in his course in laboratory medicine (clinical pathology). Nursing students

Development of ceramic and ceramic composite devices for maxillofacial applications.

AbstractCeramic and ceramic composite materials and devices were developed for specific maxillofacial applications. These applications included: (1) Replacement of hard tissue voids in low stress areas with a phosphate‐bonded alumina‐foamed ceramic and a calcium aluminate‐bonded alumina foam; (2) development of porous ceramic‐coated metallic devices for stabilization of mandibles with avulsed segments; (3) development of implantable ceramic tooth roots onto which more or less conventional crowns may be mounted.Efforts to date have been rewarding. Using the rhesus monkey for all experimental implant work, incorporation of porous ceramic foam prostheses to eliminate maxillary defects has been accomplished. Also, we have succeeded in stabilizing the mandible where segments of from 3 to 8 mm were removed. Bridging of the gap with new bone occurred within 6 weeks resulting in a total regeneration of the resected area with restoration of normal mandibular function. Finally, implantable tooth roots were developed. Three different surface treatment techniques have been used on a basic high‐density alumina core. The first is a high‐density matt finish which can only permit a fibrous tissue attachment or bony approximation but no ingrowth. The second is a porous alumina coating intended to permit bone ingrowth. The third is a rough surface consisting of particles of alumina sintered to the surface to maximize the bone/ceramic interface shear strength potential. Implantations of both anterior and posterior tooth roots with all three surface configurations have been successful for periods of up to six months.

Salvage of JAMA Covers

To the Editor:— It has seemed a regretful waste of the beautiful color reproductions on covers ofThe Journalwhen the journal is bound and the cover discarded. These covers can be salvaged and made into decorative wall plaques. The technique is relatively simple. Method.— The cover is trimmed to appropriate margins, preserving the legend if needed, and mounted with ordinary white glue on a block of scrap wood, usually one-half inch thick. The cover is then sprayed with either glossy varnish, or with a matte finish varnish for an antique effect. Three to four coats of varnish are sufficient. A false frame is easily constructed by using one of the acrylic polymer preparations available at most artist supply stores. Hyplar Modeling Paste ( Grumbacher) was found most adaptable. The first thin coat of modeling paste is applied with a palette knife around the margin of the cover and allowed to

Symmetrical and Sequential Images

In the paintings, drawings and sculptures I have recently made, I have used both a deliberate and an unplanned selection of images fused with form and color. My concern for a fusion of dichotomies has also extended to multiples of graphic images and pure geometrical of simplified organic colorshapes. I have found two methods of transferring printed images suitable for my purposes. The polymer method which involves: (1) selection of appropriate images from magazine advertisements or illustrations (must be clay base paper); (2) brushing three layers of polymer medium (matte finish) directly on the image to be transferred to canvas or paper, allowing each coat to dry; (3) applying one final film of medium and pressing the cut-out image face down on the painting or drawing surface; (4) allowing the

Improved acetate peel technique

The materials required are a clay block, acetone and thin acetone film (.002 to .003 in. thick) with a matte finish on 1 side. The sample is cut with a saw to produce a flat surface which is then polished with silicon carbide grit, the final polish being with no. 400 size material. The polished surface is etched in dilute (about 10%) HCl for a few seconds, and is then washed and thoroughly dried. The dry sample is placed on the clay block with the flat side up and close to horizontal. Acetone is applied to the etched surface, and the frosted side of the acetone peel is then rolled on from 1 edge. The sample is dry enough to move in about 10 sec. The sample is then placed face down on a flat surface and allowed to dry thoroughly for several hours. The advantages of this method are ease of application, maximum detail in the peel, and minimum shrinkage and curling after the peel is removed.

Metal Spraying in the Radio Industry

IT is today the normal practice to protect all ferrous metal parts used in the manufacture of chassis, decks, cabinets, etc., for commercial radio work, with an applied spraying of non‐ferrous metal. The metals most commonly used are zinc and aluminium, although it is right to say that practically any metal, which can be drawn into a wire, can be sprayed for protection purposes. Zinc is perhaps the most generally used, on account of its relatively low cost. The sprayed metal reacts favourably to cleaning with wire brushes and an attractive matt finish is readily obtained without the trouble attendant on normal polishing. Hand or rotary brushes can be used with flexible shafts for small articles or large areas. The applied coating can be of various thicknesses, dependent upon the type of atmospheric conditions it is expected to encounter, such as industrial pollution, salt‐laden sea air and spray, and tropical or highly humid atmospheres. The thickness is measured by a direct‐reading contact meter and 0.003 to 0.010 in. depth of metal applied is quite adequate protection for 12 to 15 years.

THE PRODUCTION OF SOME WHITE ENAMELS FOR COPPER1

The investigation deals with the development of some white enamels for copper watch dials, thermometer scale plates, and signs. The effect of varying Na2O, PbO, cryolite, SiO2 and B2O3 on the properties of the enamels was studied in twenty enamel compositions. The following conclusions were reached: (1) Correct melting is extremely important in the preparation of copper enamels; (a) Slow air cooling of the frit is preferable to quenching in water. (b) Repeated melting tends to promote opacity and to eliminate dissolved gases. (2) A somewhat reducing atmosphere during firing avoids oxidation of the copper. (3) Slight changes in enamel composition have a decided effect on the resultant properties. (4) Sodium oxide promotes gloss but reduces opacity very decidedly. (5) Lead oxide promotes fusibility without materially reducing opacity, except by dilution. (6) Cryolite is not a desirable flux or opacifier as it tends to develop a matt finish. (7) It is desirable to keep the boric oxide content low and good enamels may be produced without it. (8) By using “white arsenic” as an opacifier tin oxide is unnecessary. (9) The following were the best enamels obtained and these appear to be equal to a number of watch dial enamels examined: C-19 and C-20. 20. (10) A second group of compositions which appear to promote results equal to those in use for thermometer scales, advertising letters, etc., are C-10. 10. C-21, C-22, and C-24. In selecting these compositions, all factors such as opacity, gloss, texture, fit and resistance to attack of copper have been considered.