The purpose of this investigation was to develop an expression to represent the torque versus speed behavior of instrument ball bearings between 1000 and 40,000 rpm with various combinations of radial and axial load ranging between 0 and 200 grams. Because of the lack of experimental data for instrument bearings over any range of speeds, loads and sizes, it was necessary to construct a suitable bearing tester and accumulate the required data. The testers used were based on previous work by H.H. Mabie at Sandia Corporation and G.E. Clarke at V.P.I. The driving source was a small air turbine developed by Mabie which performed smoothly and reliably between 0 and 50,000 rpm. The torque measuring system employed strain gages on a very small beam which was used to sense forces on the stationary outer race of the bearing while the inner race was driven at speed. Each test was conducted from 0 to 40,000 rpm. The radial load took on va1ues of 50, 100, and 200 grams. The axial load was 0, 50, 100, and 200 grams. All combinations of these loads were used for each size bearing. The sizes tested were R-2, R-3, R-4. Six bearings of each size were used with all six bearings of each size undergoing the same test program in order to yield statistically reasonable averages. Investigation of analytical methods of predicting the running torque indicated that production tolerances of ball bearings rendered such an approach impractical. This led to the development of an empirical expression to predict the running torque within the same range of sizes, loads, and speeds for which experimental test data was obtained. Such an empirical expression was successfully developed and the reSUlting torque predictions compared with the experimental values of torque. The empirical expression proved capable of predicting the running torques within the envelope of the sample standard deviations for a given bearing size and loading in most cases. During the investigation of supplementary topics, it was determined that frictional heating was insignificant during the conduct of the torque tests which had a duration of approximately two minutes. All tests were at ambient temperature. All tests conducted were with oil lubricant and ribbon retainer ba1l bearings. There was no evidence that the empirical expression for friction torque developed here was valid when extrapolated beyond the limits of size, load, and speed used in its development. / Ph. D.

This thesis is a treatise on optimal assembly methods for double row ball bearings. As with common single row bearings, double row ball bearings, consist of four general components, namely, an inner ring, an outer ring, a complement of balls and a cage or retainer to keep the balls separate. Unlike single row bearings, however, double row ball bearings have two complements of balls in two distinct parallel races. Although this double row configuration is desirable in a number of applications, it makes the bearings more difficult and expensive to assemble. In addition, current manual assembly procedures require a great deal of digital manipulation, leading to concern about carpal tunnel syndrome and other long-term repetitive motion injuries. This thesis attempts to develop an improved assembly process for all types of double row bearings. Although the work is intended to be general, the Torrington 5203 double row ball bearing is adopted as a specific application example. This bearing's assembly difficulties and additional cost are a result of its manual Conrad assembly method and a rubber O-ring and groove used solely for bearing assembly. In the assembly process, the O-ring supports the upper balls temporarily until the two rings can be aligned concentrically, thus snapping the balls into the bearing races. This thesis addresses the replacement of the rubber O-ring and explores opportunities for bearing assembly automation. Design synthesis of a retractable or reusable assembly component to replace the rubber O-ring supporting the upper balls during assembly is presented. A large group of design concepts are developed and evaluated, resulting in a small group of feasible designs. These feasible solutions are then tested, and a design that has the potential immediate implementation in an improved manual assembly process is proposed. In addition, two design concepts are presented as candidates for possible implementation in an automated assembly process. / Master of Science

The effects of using different ball clays on the physical properties of the standard body have been shown. Although variations in all of the physical properties can be attributed to the use of different ball clays, these variations are more pronounced on the compressive strength properties. Since feldspar mainly controls fired shrinkage and fired absorption, and since the same amount of feldspar was used in each body, the effects of using different ball clays on these physical properties were not so pronounced. / Master of Science

Of the studies that have been conducted on the operational characteristics of instrument ball bearings, a great majority have been in accordance with MIL-STD-206. Since tests in compliance with this specification determine bearing quality or rate bearings comparatively, nothing was known of the operational characteristics of the bearings in their final application. A few investigators have developed sensors to study torque characteristics of instrument ball bearings. However, in no case has a report been made of the effect on torque when both radial and axial loads were varied. In seeking to obtain improvements in methods of measuring small torques, a pneumatic sensor was developed for testing R-3 instrument ball bearings under varying radial and axial loads. This sensor was based upon the principle of the flapper-nozzle valve. The flapper valve consisted of two orifices in series, one of constant area, the other of variable area, which was determined by flapper position. Since the pressure between the two orifices was dependent upon flapper position, indirect measurements of torque acting on the flapper were obtained by measuring this pressure. As a result of this study, it was concluded that the pneumatic sensor accurately measured the running torque of R-3 instrument bearings. This statement was based upon good agreement with data from other investigators working under identical conditions. It was also concluded that for a range of 50 to 200 gm. radial loading, no significant effect on torque was observed. For axial loads in the same range, the torque was found to vary in proportion to the equivalent load acting on the bearing. / Master of Science

Although many studies have been made on the operating characteristics of instrument bearings, most were conducted at two rpm or less and with thrust load only. A study by H.H. Mable tested the running torques of radially loaded bearings from 1,000 to 40,000 rpm. The purpose of this investigation was to study the running torques of R-3 size instrument ball bearings at speeds up to 40,000 rpm while under combined radial and axial load. Much of this investigation was devoted to the construction of an accurate torque sensing device. The method employed relied on the amplification of strain gage signals by a strain gage indicator and an x-y plotter. The strain gages were used to detect the strain at the base of a small beam that prevented rotation of the outer race.of a test bearing while the inner race was driven at test speed by an air turbine. The accumulated data was the result or 30 test series, with each series being constituted of a test sample of six ball bearings. From the study, it was consluded that the strain gage method of torque sensing accurately measured the running torque of R-3 size ball bearings at ambient temperatures. It was also concluded that the effect of axial loading or an R-3 ball bearing loaded with 47 grams radially is negligible until the axial: load equals o.r exceeds the radial loading. By comparing lubricants, it was concluded that grease lubricated ball bearings demonstrate running torques approximately twice as great as bearings lubricated with a similar weight of oil. / Master of Science

No / Mechanochemistry enabled the selective synthesis of the recherche´ orange polymorph of Wilkinson’s catalyst [RhCl(PPh3)3]. The mechanochemically prepared Rh-complex catalysed the solvent-free dehydrogenation of Me2NHBH3 in a ball mill. The in situ-generated hydrogen (H2) could be utilised for Rh-catalysed hydrogenation reactions by ball milling. / We thank the RWTH Aachen University for support from the Distinguished Professorship Program funded by the Excellence Initiative of the German federal and state governments, and the EPSRC for funding (EP/L019655/1).

Cette recherche s'appuie sur un corpus de plusieurs milliers d'articles de basket-ball extraits du quotidien "L'Auto", dominant le marché de la presse sportive sur l'ensemble de la période d'étude. La première borne temporelle correspond à la prime apparition du jeu dans les feuilles d'un journal français. L’année 1898 marque alors la naissance médiatique de la balle au panier lorsque plusieurs titres, dont La Vie au Grand Air, décrivent grossièrement quelques-unes de ses caractéristiques. L objet de l étude menée réside dans l analyse de cette définition du basket que la presse formule. Quelle image de cette activité sportive le journal diffuse-t-il ? Le média ne reflète pas exactement le réel, il n est qu un miroir brisé dont seuls quelques bris épars réfléchissent une fraction de la réalité. Il s agit donc de montrer que les représentations du basket que véhicule L Auto ces bris épars peuvent interférer sur l évolution de la pratique, sur la manière de jouer. En formulant leur propre définition du jeu, les journalistes lui donnent une forme. La démonstration de cette hypothèse s articule autour de deux ruptures fondamentales. Le début des années 1920, d abord, est empreint des premières signatures de journalistes spécialisés. Dans les colonnes de L Auto, la forme de la pratique évolue à mesure que ces journalistes mutent en de véritables prédicants, exhibant là leur rôle prépondérant dans le développement du sport. Ensuite, le milieu des années 1930 découvre un basket différent, majuscule, américain, qui renvoie la technique des Français au rang des jeux insignifiants. Les rédacteurs s emparent de cette modalité de jeu éminemment efficace et cérébrale et tendent, une fois encore, à orienter la pratique vers cette manière de jouer. En définitive, cette recherche entend montrer que le basket-ball évolue, sous l influence des journalistes de L Auto, d'une in-définition à une forme reconnue, un sport d’envergure / This research is based on a corpus of several thousand articles of basketball which are excerpted from the newspaper L'Auto, dominating the market for the sports press on the whole study périod. The first time point is the early appearance in the game the leaves of a french newspaper. The year 1898 marks the birth of basketball in the press when several titles, including La Vie au grand air, coarsely describe some of its caracteristics.The purpose of the study is the analysis of the definition of basketball that is formulated by the press. What image of this sport is diffused by newspaper? The media does not accuratly reflect reality, it is broken mirror. Only few scattered shards reflect a fraction of reality.So, this study shows that representations of basketball which are cinveyed by L'Auto - these scattered shads- can intere in evolution of the practice, how to play. In formulating their own definition of the game, journalists give it a sharpe. The demonstration of this hypothésis is based on two fundamental changes. The early 1920s, the first signatures of journalists appear. In L'Auto, the shape of the practice is changing as these journalistsmutate into genuine preachers.Then their role in the developement of sports is shown.Then the mid-1930s discovers a different baskekball, "capital", american, which shows, in contrast, that the French technique is an insignificant game. Consequently, journalists try to guide practice towards this form of game which shows as highly effective and intellectual. Ultimately, this research intends to show that basketball is evolving under the influence journalists of L'Auto, from a lack of definition towards a recognized from, a major sport

No description available.

The object of this study was to determine the current attitudes of Ball State University students toward hazardous waste disposal. A survey questionnaire was used to collect data on political affiliation and ideology, knowledge of the hazardous waste issue. and environmental attitudes. A total of 103 freshmen and 77 seniors returned usable questionnaires for an overall response rate of 49%. Computer analysis of returned questionnaires answering six research questions and forming conclusions. It was determined that there were measurable differences in attitudes between freshmen and senior students. While both groups expressed environmental concern, seniors were more knowledgable of the issues and more thoughtful in their choices. However, several indications were discovered that environmental concern in this survey group will probably not lead to political action.Ball State UniversityMuncie, IN 47306

No description available.