Investigations of lubricant rheology as applied to elastohydrodynamic lubrication

The pressure viscometer was modified to permit the measurement of viscosity at elevated pressures and shear stresses up to 5 x 10 to the 6th power N/sq m (720 psi). This shear stress is within a factor of three of the shear stress occurring in a sliding ehd point contact such as occurs in the ehd simulator. Viscosity data were taken on five lubricant samples, and it was found that viscous heating effects on the viscosity were predominant and not non-Newtonian behavior at the high shear stresses. The development of the infrared temperature measuring technique for the ehd simulator was completed, and temperature data for a set of operating conditions and one lubricant are reported. The numerical analysis of the behavior of nonlinear lubricants in the lubrication of rollers is reported

Evaluation of automated decisionmaking methodologies and development of an integrated robotic system simulation, appendix A

A generic computer simulation for manipulator systems (ROBSIM) was implemented and the specific technologies necessary to increase the role of automation in various missions were developed. The specific items developed were: (1) Capability for definition of a manipulator system consisting of multiple arms, load objects, and an environment; (2) Capability for kinematic analysis, requirements analysis, and response simulation of manipulator motion; (3) Postprocessing options such as graphic replay of simulated motion and manipulator parameter plotting; (4) Investigation and simulation of various control methods including manual force/torque and active compliance control; (5) Evaluation and implementation of three obstacle avoidance methods; (6) Video simulation and edge detection; and (7) Software simulation validation. This appendix is the user's guide and includes examples of program runs and outputs as well as instructions for program use

Evaluation of automated decisionmaking methodologies and development of an integrated robotic system simulation

A generic computer simulation for manipulator systems (ROBSIM) was implemented and the specific technologies necessary to increase the role of automation in various missions were developed. The specific items developed are: (1) capability for definition of a manipulator system consisting of multiple arms, load objects, and an environment; (2) capability for kinematic analysis, requirements analysis, and response simulation of manipulator motion; (3) postprocessing options such as graphic replay of simulated motion and manipulator parameter plotting; (4) investigation and simulation of various control methods including manual force/torque and active compliances control; (5) evaluation and implementation of three obstacle avoidance methods; (6) video simulation and edge detection; and (7) software simulation validation

Evaluation of automated decisionmaking methodologies and development of an integrated robotic system simulation. Appendix A: ROBSIM user's guide

The purpose of the Robotics Simulation Program is to provide a broad range of computer capabilities to assist in the design, verification, simulation, and study of robotics systems. ROBSIM is program in FORTRAN 77 for use on a VAX 11/750 computer under the VMS operating system. This user's guide describes the capabilities of the ROBSIM programs, including the system definition function, the analysis tools function and the postprocessor function. The options a user may encounter with each of these executables are explained in detail and the different program prompts appearing to the user are included. Some useful suggestions concerning the appropriate answers to be given by the user are provided. An example user interactive run in enclosed for each of the main program services, and some of the capabilities are illustrated

Evaluation of automated decision making methodologies and development of an integrated robotic system simulation: Study results

The implementation of a generic computer simulation for manipulator systems (ROBSIM) is described. The program is written in FORTRAN, and allows the user to: (1) Interactively define a manipulator system consisting of multiple arms, load objects, targets, and an environment; (2) Request graphic display or replay of manipulator motion; (3) Investigate and simulate various control methods including manual force/torque and active compliance control; and (4) Perform kinematic analysis, requirements analysis, and response simulation of manipulamotion. Previous reports have described the algorithms and procedures for using ROBSIM. These reports are superseded and additional features which were added are described. They are: (1) The ability to define motion profiles and compute loads on a common base to which manipulator arms are attached; (2) Capability to accept data describing manipulator geometry from a Computer Aided Design data base using the Initial Graphics exchange Specification format; (3) A manipulator control algorithm derived from processing the TV image of known reference points on a target; and (4) A vocabulary of simple high level task commands which can be used to define task scenarios

Thermal Adaptation and Diversity in Tropical Ecosystems: Evidence from Cicadas (Hemiptera, Cicadidae)

The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54′ of longitude and 21°4′ of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors

Association of Leptin Gene Markers with Carcass Traits in Beef Cattle

The objective of this study was to evaluate four genetic markers on the leptin gene for association with carcass traits in three crossbred families. Three half-sib families were developed from crossbred sires. Families 1, 2, and 3 comprised 26, 21, and 66 offspring, respectively (n = 113). The genetic background of the sires, dams, and offspring was 1/3 Angus, 1/3 Hereford, 1/3 Simmental. Carcass traits collected were finished weight, hot carcass weight (HCW), marbling score, Quality Grade, Longissimus muscle area (LMA), rib fat, Yield Grade, and percent kidney, pelvic, and heart fat (KPH). The four markers analyzed were located on the exon 2, exon 3, and promoter region of the leptin gene. There was an association of marbling score with leptin exon 3 (P \u3c 0.05), and ability to grade choice with leptin exon 2 (P \u3c 0.05), exon 3 (P \u3c 0.001), and promoter (P \u3c 0.01) in family 2. Family 2 also displayed allelic effects for ability to grade choice (P \u3c 0.01) with leptin exon 3 and promoter. Family 3 showed an association between leptin exon 2 (P \u3c 0.05) and marbling score. No association was detected (P \u3e 0.05) on family 1

Bostonia. Volume 15

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

An integrated approach for multi-level sample size determination

this paper gives an integrated approach to sampling problems involving a series of increasingly sensitive measurements on correspondingly smaller sample sizes which proceeds logically from level to level with increasing accuracy. The methods and results are consistent with those presently used by the International Atomic Energy Agency (IAEA), serve to elucidate the underlying concepts, and often simplify the calculations