A computer solution for the dynamic load, lubricant film thickness and surface temperatures in spiral bevel gears

A complete analysis of spiral bevel gear sets is presented. The gear profile is described by the movements of the cutting tools. The contact patterns of the rigid body gears are investigated. The tooth dynamic force is studied by combining the effects of variable teeth meshing stiffness, speed, damping, and bearing stiffness. The lubrication performance is also accomplished by including the effects of the lubricant viscosity, ambient temperature, and gear speed. A set of numerical results is also presented

New high fill-factor triangular micro-lens array fabrication method using UV proximity printing

A simple and effective method to fabricate a high fill-factor triangular microlens array using the proximity printing in lithography process is reported. The technology utilizes the UV proximity printing by controlling a printing gap between the mask and substrate. The designed approximate triangle microlens array pattern can be fabricated the high fill-factor triangular microlens array in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produce a certain exposure in photoresist material outside the aperture edges. This method can precisely control the geometric profile of high fill factor triangular microlens array. The experimental results showed that the triangular micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micrometers to 840 micrometers. The gapless triangular microlens array will be used to increases of luminance for backlight module of liquid crystal displays.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Frequency standards requirements of the NASA deep space network to support outer planet missions

Navigation of Mariner spacecraft to Jupiter and beyond will require greater accuracy of positional determination than heretofore obtained if the full experimental capabilities of this type of spacecraft are to be utilized. Advanced navigational techniques which will be available by 1977 include Very Long Baseline Interferometry (VLBI), three-way Doppler tracking (sometimes called quasi-VLBI), and two-way Doppler tracking. It is shown that VLBI and quasi-VLBI methods depend on the same basic concept, and that they impose nearly the same requirements on the stability of frequency standards at the tracking stations. It is also shown how a realistic modelling of spacecraft navigational errors prevents overspecifying the requirements to frequency stability

A computer solution for the dynamic load, lubricant film thickness, and surface temperatures in spiral-bevel gears

A computer method for determining the dynamic load between spiral bevel pinion and gear teeth contact along the path of contact is described. The dynamic load analysis governs both the surface temperature and film thickness. Computer methods for determining the surface temperature, and film thickness are presented along with results obtained for a pair of typical spiral bevel gears

CsCl-type compounds in binary alloys of rare-earth metals with gold and silver

In binary alloys of silver with Sm, Tb, Ho, and Tm, and of gold with Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, and Tm, intermediate phases containing stoichiometric proportions of the two metals were found to crystallize into the CsCl (B2)-type structure. The lattice parameters of these phases are reported and a correlation has been found between these lattice parameters and the trivalent ionic radii of the rare-earth metals

A method of selecting grid size to account for Hertz deformation in finite element analysis of spur gears

A method of selecting grid size for the finite element analysis of gear tooth deflection is presented. The method is based on a finite element study of two cylinders in line contact, where the criterion for establishing element size was that there be agreement with the classical Hertzian solution for deflection. The results are applied to calculate deflection for the gear specimen used in the NASA spur gear test rig. Comparisons are made between the present results and the results of two other methods of calculation. The results have application in design of gear tooth profile modifications to reduce noise and dynamic loads

Units of Evidence for Analyzing Subdisciplinary Difference in Data Practice Studies

Digital libraries (DLs) are adapting to accommodate research data and related services. The complexities of this new content spans the elements of DL development, and there are questions concerning data selection, service development, and how best to align these with local, institutional initiatives for cyberinfrastructure, data-intensive research, and data stewardship. Small science disciplines are of particular relevance due to the prevalence of this mode of research in the academy, and the anticipated magnitude of data production. To support data acquisition into DLs – and subsequent data reuse – there is a need for new knowledge on the range and complexities inherent in practice-data-curation arrangements for small science research. We present a flexible methodological approach crafted to generate data units to analyze these relationships and facilitate crossdisciplinary comparisons.Library Services (LG-06-07-0032-07) and National Science Foundation (OCI-0830976).is peer reviewe

Subtropical middle atmosphere dynamics observed by the Chung Li radar

The Chung Li Radar (24.91 N; 121.24 E) has been operating since 1986. A five beam observational configuration was used on a regular basis to study the various dynamics processes in the atmosphere-lower stratosphere height region. Due to its geographical location, the annual Typhoon and Mei-Yu seasons provide good opportunities to study the various interesting dynamic processes such as instabilities, generation of gravity waves, wave mean field interaction, etc. Three dimensional air motions due to these fronts are presented. Special cases of gravity wave generation, propagation and their effects on the turbulent layers are discussed