Brass Ring Research Articles

Catching the brass ring

Eventhough most senior executives in the larger software firms boast engineering, marketing, legal, and business school backgrounds, most engineering organizations aren't led by the software people. We discuss about the factors that govern such selections and what software engineering professionals can do about it. We also discuss about why the software professionals often aren't tapped for top corporate leadership positions and about their role in the business organisations.

A new method to reduce the desorption time of a QCM sensor, using a halogen spot for heating

The quartz crystal microbalance (QCM) can be used as a mass sensor in the gas phase. It is suitable for online monitoring volatile organic compounds in a broad spectrum of every day life situations, i.e. monitoring certain volatile organic compounds (VOCs) at the work place or to control the ripening of cheese. It is desirable to have a short period of time in between measurements. First it safes time for the user on mobile units, secondly the online survey of VOCs is more precise and alarm system can be triggered earlier. This paper explains a new method using two standard halogen spots. In one spot the light bulb is replaced with QCM and the socket is modified to hold the quartz. Both spots are merged with a brass ring in the middle for gas inlet and outlet. Switching on the light bulb during desorption phase, reduces the time of desorption enormously.

The millennium problems: the seven greatest unsolved mathematical puzzles of our time

The definitive lay reader's account of Everests of mathematics--the seven unsolved problems that definethe state of art in contemporary math. In 2000, Clay Foundation of Cambridge, Massachusetts, announced a historic competition: whoever could solve any of seven extraordinarily difficult mathematical problems, and have solution acknowledged as correct by experts, would receive USD1 million in prize money. There was some precedent for doing this: in 1900 David Hilbert, one of greatest mathematicians of his day, proposed twenty-three problems, now known as Hilbert Problems, that set much of agenda for mathematics in twentieth century. The Millennium Problems are likely to acquire similar stature, and their solution (or lack of one) is likely to play a strong role in determining course of mathematics in current century. Keith Devlin, renowned expositor of mathematics, tells here what seven problems are, how they came about, and what they mean for math and science. These problems are brass rings held out to today's mathematicians, glittering and just out of reach. In hands of Keith Devlin, the Math Guy from NPR's Weekend Edition, each Millennium Problem becomes a fascinating window onto deepest and toughest questions in field. For mathematicians, physicists, engineers, and everyone else with an interest in mathematics' cutting edge, The Millennium Problems is definitive account of a subject that will have a very long shelf life.

Bevacizumab Grabs the ‘Brass Ring’ with Positive Results in Metastatic Colorectal Cancer Trial

Bevacizumab Grabs the ‘Brass Ring’ with Positive Results in Metastatic Colorectal Cancer Trial

Reaching for the Brass Ring: The U.S. News & World Report Rankings and Competition

The annual U.S News & World Report ranking of the nation's academic institutions exacerbates their competitiveness. Institutions, trying to influence the rankings, alter their behavior in ways that misserve individual students and higher education as a whole. However, institutions should not use the rankings as an excuse for failing to collaborate in ways that make sense both educationally and financially. The paper suggests how USNWR rankings could encourage such collaborations.

Capacitance bridge measurements of magnetostriction

Magnetostriction effects were investigated for three different materials by using a simple, reproducible, and cost-effective method recently developed in our laboratory. The magnetostriction effects were generated by a large oscillating magnetic field produced by a high current 60 Hz ac welder power supply, capable of reaching saturation levels for the material, and then detected by a change in capacitance between a hollow cylindrical sample and a concentric brass ring. This capacitance change was continuously monitored at a high frequency rate by a standard laboratory capacitance bridge meter. The output voltage of the bridge was fed into a storage cathode-ray oscilloscope and its voltage versus time signals were then analyzed by a computer program. Two ferromagnetic rings, constructed of high-speed steels 4620 and 4340, which have proven applicability for use in magnetoelastic torque sensing, were used as the samples for investigating the magnetostriction effects, while a paramagnetic aluminum ring was used for the control sample. Our study showed that the 4340 ring, which had higher nickel, cobalt, and chromium content than that of the 4620 ring, had the largest magnetostriction effect, and that the aluminum ring displayed no magnetostriction effect, as was expected. We have found this experimental method to be both reproducible and sufficient to rank different ferromagnetic materials by their magnetostriction level, which is a significant consideration in producing effective magnetoelastic torque sensors.

A Crystal‐Chemical Study of Remains found in the Tomb of Giuseppe Tartini (1692–1770)

We describe a crystal‐chemical investigation on extremely altered skeletal material and a greatly altered ring found in the tomb of the musician and composer Giuseppe Tartini. X‐ray powder diffraction and electron probe microanalysis show the presence of brushite and a small amount of hydroxyapatite in the skeletal remains. The brass ring is composed of an inner core part of cuprite (Cu2O) surrounded by parascholzite (CaZn2(PO4)2??2H2O in the outer part. This indicates that Tartini's body underwent chemical attack by a strong acid, probably sulphuric acid, as an intentional technique of mortuary hygiene in the second half of the 18th century.

Brass Rings or Brass Buttons in Engineering Design*

AbstractThe purpose of this paper is to point out two distinct selections for student design projects. The main decision maker is assumed to be the faculty advisor for the projects, although the students would be expected to have input. The brass ring project involves some aspect of cutting edge technology. The brass button project is one that satisfies the typical criteria of a thoroughly designed, fabricated, and documented “component.” Both types of projects have great value for the students although one is obviously more visible outside the academic community. These two philosophical approaches in engineering design projects reflect the distinction between entrepreneurial and traditional engineering education. As we move from the concept of engineers working for large companies to engineers starting companies, this distinction becomes more important. The primary example base is drawn from electrical and mechanical engineering due to our experiences. While two philosophical approaches are indicated, there are ultimately numerous methodologies and end points possible as a result of diversions along the way.

Effects of filler composition and surface treatment on the characteristics of opaque resin composites

The effects of filler composition and surface treatment of titanium dioxide (TiO2) on the shear bond strength to noble metal and mechanical properties of opaque dental resin composites were assessed. A series of fillers for resin composites were prepared with untreated TiO2 or treated silica/alumina-coated TiO2 with silane coupling agent; these fillers were replaced with silanized SiO2 in increasing amounts. Each of various powder compositions were mixed with the liquid and applied to the surface of a silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy and light cured. A light-activated resin-veneering composite material was placed on top with the use of a brass ring mold and light cured. Specimens were stored at 37 °C in water for a period of 24 h. Additionally some specimens were thermocycled at 4 °C and 60 °C in water baths for 1 min each for 5000 cycles before shear mode testing was performed. Light-activated opaque resin composites containing filler with specific filler compositions of 50 wt% of untreated TiO2—50 wt% of silanized SiO2 (untreated TiO250) and 40 wt% of untreated TiO2—60 wt% of silanized SiO2 (untreated TiO240) showed higher shear bond strengths to the Ag-Pd-Cu-Au alloy than any other specific compositions when no thermocycling was involved. Surface treatment of TiO2 filler and TiO250- and TiO240-opaque resin composites prepared thereof showed significantly higher shear bond strengths than untreated TiO250- and TiO240-opaque resin composites when subjected to thermocycling. Surface-treated opaque resin composite had significantly higher compressive and flexural strength than untreated opaque resin composite after immersion in water for 1 month. Scanning electron microscopy of the fractured opaque resin composite surface showed an interface failure between TiO2 and the matrix resin for untreated composite, and cohesive failure within the resin for surface-treated composite. Surface-treated TiO250 and TiO240 may be clinically useful as the filler for light-activated opaque dental resin composites. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 525–530, 2001

Effects of filler composition and surface treatment on the characteristics of opaque resin composites.

The effects of filler composition and surface treatment of titanium dioxide (TiO2) on the shear bond strength to noble metal and mechanical properties of opaque dental resin composites were assessed. A series of fillers for resin composites were prepared with untreated TiO2 or treated silica/alumina-coated TiO2 with silane coupling agent; these fillers were replaced with silanized SiO2 in increasing amounts. Each of various powder compositions were mixed with the liquid and applied to the surface of a silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy and light cured. A light-activated resin-veneering composite material was placed on top with the use of a brass ring mold and light cured. Specimens were stored at 37 degrees C in water for a period of 24 h. Additionally some specimens were thermocycled at 4 degrees C and 60 degrees C in water baths for 1 min each for 5000 cycles before shear mode testing was performed. Light-activated opaque resin composites containing filler with specific filler compositions of 50 wt% of untreated TiO2-50 wt% of silanized SiO2 (untreated TiO2(50)) and 40 wt% of untreated TiO2-60 wt% of silanized SiO2 (untreated TiO2(40)) showed higher shear bond strengths to the Ag-Pd-Cu-Au alloy than any other specific compositions when no thermocycling was involved. Surface treatment of TiO2 filler and TiO2(50)- and TiO2(40)-opaque resin composites prepared thereof showed significantly higher shear bond strengths than untreated TiO2(50)- and TiO2(40)-opaque resin composites when subjected to thermocycling. Surface-treated opaque resin composite had significantly higher compressive and flexural strength than untreated opaque resin composite after immersion in water for 1 month. Scanning electron microscopy of the fractured opaque resin composite surface showed an interface failure between TiO2 and the matrix resin for untreated composite, and cohesive failure within the resin for surface-treated composite. Surface-treated TiO2(50) and TiO2(40) may be clinically useful as the filler for light-activated opaque dental resin composites.

A Shot at the Brass Ring

A Shot at the Brass Ring

Effect of MMA–PMMA resin polymerization initiators on the bond strengths of adhesive primers for noble metal

Objectives: This study was conducted to investigate the effect of MMA–PMMA resin polymerization initiators on the bond strengths of two adhesive metal primers by evaluating the shear bond strengths of resins to silver–palladium–copper–gold (Ag–Pd–Cu–Au) alloy. Methods: Three types of MMA–PMMA resins for which the polymerization initiators were TBB, BPO-amine and CQ-amine, and two adhesive primers, Metal PrimerII and V-Primer, were used. A brass ring placed over the nonprimed or primed casting alloy disk surface was filled with each resin. The half specimens were stored in water at 37°C for 24 h. In addition, another half specimens were then immersed alternately in water baths at 4°C and 60°C for 1 min each for 20 000 thermal cycles before shear mode testing at a crosshead speed of 0.5 mm/min. Results: There were no significant differences ( p>0.05) in bond strength between the three types of resins with or without thermal cycling when Metal PrimerII was used. However, when Ag–Pd–Cu–Au alloy was primed with V-Primer, the bond strength of CQ-amine resin was significantly weaker than that of TBB resin. Metal PrimerII was more effective for enhancing the bond strength and the bond strength was not affected by thermal cycling, in contrast to V-Primer. Significance: The effectiveness of Metal PrimerII to enhance the bond strength is not influenced by polymerization mode of MMA–PMMA resin, in contrast to V-Primer when the resin is bonded to Ag–Pd–Cu–Au alloy.

接着耐久性試験において試料の形態および材質が試験結果に及ぼす影響

The thermocycling test is one of the most important methods for evaluating adhesion durability of metal-bonded resin system. However, researchers have adopted various kinds of thermocyclings pecimens which greatly differ from one another in size, shape, restriction method for adhesive area, etc. These differences in specimens make the comparison of test results difficult and the uniformity of adhesion specimens is to be desired.In this study, adhesion specimens applied the three metal bonding systems were constructed, and the influence of the difference in configuration and material of the specimens were studied based on the results of thermocycling test up to 50, 000 times.The results were as follows:1. The shear bond strength of 5-mm diameter specimens showed higher value than that of 3-mm diameter when the bonding area was restricted by the shape of the handle end.2. The specimen with adhesive area restricted by masking tape showed higher bond strength compared with the specimen whose bonding area was restricted by the shape of the handle end.3. The highest bond strength was obtained in the specimen with a handle made of the same material as the adhered disk.4. Thermocycling stress influenced most severely the specimen with a brass ring handle.

Effect of a resin-modified glass ionomer liner on volumetric polymerization shrinkage of various composites

Objective. The aim of this study was to evaluate the volumetric polymerization shrinkage of a selection of composite resins alone, and in contact with a resin-modified glass ionomer (RMGI) liner. Methods. Volumetric polymerization shrinkage was measured for five different composite resins by means of the Watts and Cash deflecting disk method. Shrinkage measurements were determined for 300 s for each composite alone, and when placed over pre-cured RMGI liner. Each sample was placed within a brass ring fixed to a glass microscope slide. A linear vertical displacement transducer (LVDT) was brought into contact with a flexible glass coverslip placed over the composite sample. On curing, the contraction of the setting composite sample caused distortion of the coverslip, the resulting deflection being recorded via the LVDT by means of data-logging software. All RMGI samples were prepared at 85% relative humidity (RH) and 35°C. In all cases the composite was light-cured at ambient RH and 35°C. Results. Analysis of the data demonstrated statistically significantly less shrinkage for each composite when cured in contact with the set RMGI liner than when cured alone, at p<0.001. Significance. Use of an RMGI liner was found to significantly reduce volumetric polymerization contraction for all the light-curing composite resin restorative materials tested.

Lacustrine sockeye salmon return straight to their natal area from open water using both visual and olfactory cues.

Mechanisms of the amazing ability of salmon to migrate a long distance from open water to natal streams for spawning are still unknown. Lacustrine sockeye salmon (Oncorhynchus nerka) in Lake Toya offers an excellent model system for studying the orientation mechanism in open water, because mature fish return to the natal area with a high degree of accuracy. First we examined the percentage of fish returning to the natal area after they were released 7 km south of the natal area. Forty percent of control male mature fish and 25% of the fish blinded by injection of a mixture of carbon toner and corn oil into the eyeball were captured in the natal area within 5 days. Forty-four percent of fish with brass rings (control) and 31% of fish with NdFe magnetic rings which interfere with the magnetic cue were captured in the natal area within 3 days. These experiments suggested that, although the number of blinded fish captured in the natal area was less than that of the controls, the difference was not statistically significant. In the fish captured in the natal area within 3 or 5 days, fish which found the natal area using their olfactory cue after random swimming for a long time and returned to that area may be included. Hence we tracked fish telemetrically using an ultrasonic tracking system, and found that mature males released at a long distance (3.6 or 6.8 km) from the natal area swam straight to the vicinity of the natal area. Interference of the magnetic cue by the attachment of a magnetic ring did not affect their direct return. Blockage of the visual cue caused them to move randomly. These data suggest that lacustrine sockeye salmon return straight to the vicinity of the natal area using their visual cue and finally reach the exact homing point using their olfactory cue.

Is Al going mainstream as last? a look inside Microsoft Research

For many years, many in the Al and intelligent systems field have yearned to grab the brass ring of the mass market. Longing for broad deployment of AI into mainstream computing, some have even aspired to become the Microsoft of the AI world. However, after AI's 15 minutes of fame in the mid-80s, analysts grew tired of waiting for AI to hit the big time and tucked it into a promising technology niche. Although AI has continued to make significant strides in theory, technology, and even deployed applications, its impact has yet to reach its full potential and profitability.

New American Classics Written for Brass Ring

New American Classics Written for Brass Ring

How an anesthesiologist can use the ethics consultation service.

How an anesthesiologist can use the ethics consultation service.

Effects of adhesive primers on bond strength of self-curing resin to cobalt-chromium alloy

Purpose. This study evaluated the effects of four adhesive primers on the shear bond strength of a self-curing resin to cobalt-chromium alloy. Material and methods. The adhesive primers Acryl Bond (AB), Cesead Opaque Primer (COP), Metal PrimerII (MPII), and MR Bond (MRB) were used. A brass ring placed over the casting alloy disk surface nonprimed or primed with each primer was filled with the self-curing methyl methacrylate–polymethyl methacrylate resin. The specimens were stored in water at 37° C for 24 hours and then alternately immersed in water baths at 4° C and 60° C for 1 minute each for up to 20,000 thermal cycles before shear mode testing at a crosshead speed of 0.5 mm/min. Results. All the primers examined improved the shear bond strength between the resin and cobalt-chromium alloy compared with nonprimed specimens before thermal cycling. However, after 20,000 thermal cycles, the bond strengths of resin to cobalt-chromium alloy primed with COP or MPII primers were significantly greater than those of specimens primed with AB or MRB primers and nonprimed controls. Conclusion. This study indicated that COP and MPII are effective primers to obtain higher bond strength between resin and cobalt-chromium alloy.

Development of a method to measure the period of swelling of calcium phosphate cements

In the field of biomaterials the development of calcium phosphate cements dates back to 1983 [1]. Despite their good biocompatibility these biomaterials have seldom been used in animal and clinical trials. In our experience one of the properties that limits the applicability of calcium phosphate cements in animal and clinical trials is their swelling and superficial disintegration upon premature contact with blood or other body fluids. This property is comparable to the hygroscopic expansion of gypsum investments [2] or the increased solubility and disintegration of dental silicate cements and zinc phosphate cements [3] upon premature contact with water and saliva, respectively. The surgeon must therefore keep the field of operation free of blood or other body fluids during the whole period over which the calcium phosphate cement swells or disintegrates. Therefore, the property of swelling must be brought under control, before a calcium phosphate cement can be offered to clinicians for animal or clinical trials. The purpose of the present study was twofold: (i) to develop a method or methods to measure the period of swelling, and (ii) to observe whether the addition of a nucleator phase to the cement powder and/or that of an accelerator to the cement liquid can help to reduce the period of swelling. An apatitic calcium phosphate cement, developed in a previous study [4], was chosen for the present investigation. It contained alpha-tertiary calcium phosphate (a-TCP) as an active ingredient in its powder, to which particles of precipitated hydroxyapatite (PHA) were added, which functioned as a nucleator for the precipitation of calcium deficient hydroxyapatite (CDHA) formed during the setting reaction. Water was used as cement liquid, in which disodium hydrogen ph0sphate (Na2HPO4) could be dissolved to function as an accelerator of the setting reaction. Optimum milling conditions for the cement powder and an optimum of 0.32 wt% of liquid to powder were used [4]. The cement powders used contained either 2, 4 or 6 wt % PHA and the liquids either 0, 2, 3 or 4 wt % Na2HPO4. The initial (I) and final (F) setting times known to occur in the combinations studied are given in Table I. Adequate amounts of powder and liquid were mixed in a mortar for 1 min. Brass rings with internal diameter 9.3 mm and height 5.0 mm were filled with the cement mass, while resting on a glass plate. They were stored at room temperature in air until soaking was commenced. Soaking was carried out in Ringer's solution at 37 °C. Immediately after soaking observation of any disintegration was done by visual inspection (method 1). After 30min of soaking the thickness of the cement mass was measured with a micrometer (while still held in the brass ring) and the diameter of the cement cylinder was determined (in this case, the cement mass was removed from the brass ring just prior to the