Designing Rolling-Element Bearings

Bearing Analysis Tool (BAT) is a computer program for designing rolling-element bearings for cryogenic turbomachines. BAT provides a graphical user interface (GUI) that guides the entry of data to develop mathematical models of bearings. The GUI breaks model data into logical subsets that are entered through logic-driven input screens. The software generates a threedimensional graphical model of a bearing as the data are entered. Most dataentry errors become immediately obvious in the graphical model. BAT provides for storage of all the data on a shaft/bearing system, enabling the creation of a library of proven designs. Data from the library can be transferred to subsequent projects by use of simple cut-and-paste routines. BAT includes a library of temperature- dependent cryogenic bearing-material properties for use in the mathematical models. BAT implements algorithms that (1) enable the user to select combinations of design and/or operating-condition parameters, and then (2) automatically optimize the design by performing trade studies over all of the parameter combinations. This feature enables optimization over a large trade space in a fraction of the time taken when using prior bearingmodel software

Update on Integrated Optical Design Analyzer

Updated information on the Integrated Optical Design Analyzer (IODA) computer program has become available. IODA was described in Software for Multidisciplinary Concurrent Optical Design (MFS-31452), NASA Tech Briefs, Vol. 25, No. 10 (October 2001), page 8a. To recapitulate: IODA facilitates multidisciplinary concurrent engineering of highly precise optical instruments. The architecture of IODA was developed by reviewing design processes and software in an effort to automate design procedures. IODA significantly reduces design iteration cycle time and eliminates many potential sources of error. IODA integrates the modeling efforts of a team of experts in different disciplines (e.g., optics, structural analysis, and heat transfer) working at different locations and provides seamless fusion of data among thermal, structural, and optical models used to design an instrument. IODA is compatible with data files generated by the NASTRAN structural-analysis program and the Code V (Registered Trademark) optical-analysis program, and can be used to couple analyses performed by these two programs. IODA supports multiple-load-case analysis for quickly accomplishing trade studies. IODA can also model the transient response of an instrument under the influence of dynamic loads and disturbances

A Boilerplate Capsule Test Technique for the Orion Parachute Test Program

The test program developing parachutes for the Orion/MPCV includes drop tests of a Parachute Test Vehicle designed to emulate the wake of the Orion capsule. Delivery of this test vehicle to the initial velocity, altitude, and orientation required for the test is a difficult problem involving multiple engineering disciplines. The available delivery of aircraft options imposed constraints on the test vehicle development and concept of operations. This paper describes the development of this test technique. The engineering challenges include the extraction from an aircraft and separation of two aerodynamically unstable vehicles, one of which will be delivered to a specific orientation with reasonably small rates. The desired attitude is achieved by precisely targeting the separation point using on-board monitoring of the motion. The design of the test vehicle is described. The trajectory simulations and other analyses used to develop this technique and predict the behavior of the test article are reviewed in detail. The application of the technique on several successful drop tests is summarized

Balancing Power with Responsibility: How Academic Libraries Balance Web Analytics and Patron Privacy

This paper describes an exploratory study that was conducted to determine how academic libraries use Google Analytics, and how they balance the implementation of Google Analytics with their patrons’ privacy. UNC System Library websites were surveyed to determine whether or not they utilized Google Analytics. The privacy policies of the 13 websites that ran Google Analytics were examined to determine whether their privacy policies contained language disclosing the presence of Google Analytics on the library website. In addition, interviews were conducted with employees from five of the libraries to determine how those libraries employ Google Analytics on their websites and how they balance the employment of Google Analytics with the privacy of their patrons. Four out of the five libraries reported actively using Google Analytics, but only one of those five library websites contained a privacy policy with explicit language pertaining to the website’s use of Google Analytics.Master of Science in Information Scienc

The DEF’s of LIGA: An Update to the ABC’s of LIGA

The article offers information on ABC\u27s of Louisiana Insurance Guaranty Association (LIGA), and discusses its role in interpreting and understanding the law applicable to the LIGA, and discusses its benefits to legal practitioners

INFLUENCE OF PHOSPHATE SOURCE ON VESICULAR-ARBUSCULAR MYCORRHIZAE OF \u3ci\u3eBOUTELOUA GRACILIS\u3c/i\u3e

Non-mycorrhizal and vesicular-arbuscular mycorrhizal Bouteloua gracilis infected with Glomus fasciculatus were grown in defined media containing different phosphate sources and compared with respect to phosphate content and form, biomass, chlorophyll concentration, and root phosphatase activity. The phosphate sources were sodium monobasic phosphate, a mixture of sodium monobasic phosphate and calcium phytate, and calcium phytate. Inositol and inositol plus calcium were added to the sodium phosphate medium as additional treatments. Mycorrhizal infection was highest in roots of plants grown in the presence of phytate (75%). Lower root infection levels were noted in plants from the sodium phosphate (19%) and mixed phosphate (22%) media. No penetration by fungi occurred in plants from the sodium phosphate plus inositol or inositol and calcium media. Dry wts of non-mycorrhizal plants were highest when grown in media containing phytate and sodium phosphate plus inositol and calcium followed in decreasing order by sodium phosphate plus inositol, mixed phosphates, and sodium phosphate. Mycorrhizal infection increased leaf dry wt in plants from the sodium phosphate medium and root dry wt from the phytate medium. Phosphate concentrations in the plants were highest when grown in mixed phosphate medium followed by sodium phosphate and phytate. Mycorrhizal infection always increased significantly leaf phosphate concentrations but increased root phosphate concentrations only in the phytate medium. Phosphates were found predominantly as organicallybound compounds in leaves of mycorrhizal plants whereas in leaves of non-mycorrhizal plants, most of the phosphate was inorganic. Chlorophyll concentrations increased significantly with mycorrhizal infection with no change in a/b ratios. Mycorrhizal plants grown in the phytate medium had substantially higher alkaline phosphatase activity than did non-mycorrhizal plants; acid phosphatase activity was not affected by mycorrhizal condition. These results suggest that form of the phosphate in the root environment influences naycorrhizal establishment and effect of mycorrhizae on plant growth

INFLUENCE OF PHOSPHATE SOURCE ON VESICULAR-ARBUSCULAR MYCORRHIZAE OF \u3ci\u3eBOUTELOUA GRACILIS\u3c/i\u3e

Non-mycorrhizal and vesicular-arbuscular mycorrhizal Bouteloua gracilis infected with Glomus fasciculatus were grown in defined media containing different phosphate sources and compared with respect to phosphate content and form, biomass, chlorophyll concentration, and root phosphatase activity. The phosphate sources were sodium monobasic phosphate, a mixture of sodium monobasic phosphate and calcium phytate, and calcium phytate. Inositol and inositol plus calcium were added to the sodium phosphate medium as additional treatments. Mycorrhizal infection was highest in roots of plants grown in the presence of phytate (75%). Lower root infection levels were noted in plants from the sodium phosphate (19%) and mixed phosphate (22%) media. No penetration by fungi occurred in plants from the sodium phosphate plus inositol or inositol and calcium media. Dry wts of non-mycorrhizal plants were highest when grown in media containing phytate and sodium phosphate plus inositol and calcium followed in decreasing order by sodium phosphate plus inositol, mixed phosphates, and sodium phosphate. Mycorrhizal infection increased leaf dry wt in plants from the sodium phosphate medium and root dry wt from the phytate medium. Phosphate concentrations in the plants were highest when grown in mixed phosphate medium followed by sodium phosphate and phytate. Mycorrhizal infection always increased significantly leaf phosphate concentrations but increased root phosphate concentrations only in the phytate medium. Phosphates were found predominantly as organicallybound compounds in leaves of mycorrhizal plants whereas in leaves of non-mycorrhizal plants, most of the phosphate was inorganic. Chlorophyll concentrations increased significantly with mycorrhizal infection with no change in a/b ratios. Mycorrhizal plants grown in the phytate medium had substantially higher alkaline phosphatase activity than did non-mycorrhizal plants; acid phosphatase activity was not affected by mycorrhizal condition. These results suggest that form of the phosphate in the root environment influences naycorrhizal establishment and effect of mycorrhizae on plant growth

Microparticle image velocimetry approach to flow measurements in isolated contracting lymphatic vessels

We describe the development of an optical flow visualization method for resolving the flow velocity vector field in lymphatic vessels, in vitro. The aim is to develop an experimental protocol for accurately estimating flow parameters, such as flow rate and shear stresses, with high spatial and temporal resolution. Previous studies in situ have relied on lymphocytes as tracers, but their low density resulted in a reduced spatial resolution whereas the assumption that the flow was fully developed in order to determine the flow parameters of interest may not be valid, especially in the vicinity of the valves, where the flow is undoubtedly more complex. To overcome these issues, we have applied the time-resolved micro-Particle Image Velocimetry technique, a well-established method that can provide increased spatial and temporal resolution that this transient flow demands. To that end, we have developed a custom light source, utilizing high-power light-emitting diodes, and associated control and image processing software. This manuscript reports the performance of the system and the results of a series of preliminary experiments performed on vessels isolated from rat mesenteries, demonstrating, for the first time, the successful application of the micro-PIV technique in these vessels