The Conflicting Interests of Airport Owner and Nearby Property Owner

QC 20140910</p

Study of crack-initiation phenomena associated with stress corrosion of aluminum alloys Annual report, 6 Jun. 1967 - 6 Jun. 1968

Electron microscopic, fractographic, and microprobe observations of crack initiation and propagation phenomena associated with stress corrosion of aluminum alloy

Laser transit anemometer measurements on a slender cone in the Langley unitary plan wind tunnel

A laser transit anemometer (LTA) system was used to probe the boundary layer on a slender (5 degree half angle) cone model in the Langley unitary plan wind tunnel. The anemometer system utilized a pair of laser beams with a diameter of 40 micrometers spaced 1230 micrometers apart to measure the transit times of ensembles of seeding particles using a cross-correlation technique. From these measurements, boundary layer profiles around the model were constructed and compared with CFD calculations. The measured boundary layer profiles representing the boundary layer velocity normalized to the edge velocity as a function of height above the model surface were collected with the model at zero angle of attack for four different flow conditions, and were collected in a vertical plane that bisected the model's longitudinal center line at a location 635 mm from the tip of the forebody cone. The results indicate an excellent ability of the LTA system to make velocity measurements deep into the boundary layer. However, because of disturbances in the flow field caused by onboard seeding, premature transition occurred implying that upstream seeding is mandatory if model flow field integrity is to be maintained. A description and results of the flow field surveys are presented

Relative abundance of amphibians in forest canopy gaps of natural origin vs. timber harvest origin

Small-scale canopy gaps created by logging may retain adequate habitat structure to maintain amphibian abundance. We used pitfalls with drift fences to measure relative abundance of amphibians in 44 harvested gaps, 19 natural treefall gaps, and 36 closed-canopy forest plots. Metamorphs had relatively lower capture rates in large harvest gaps for Ambystoma maculatum, Lithobates catesbeianus, L. clamitans, and L. sylvaticus but we did not detect statistically significant (p < 0.1) differences among gap types for Lithobates palustris metamorphs. L. clamitans juveniles and L. sylvaticus juveniles and adults had relatively lower capture rates in large harvest gaps. For juvenile-adult A. maculatum, we caught relatively fewer individuals in all gap types than in closed-canopy areas. Some groups with overall lower capture rates (immature Plethodon cinereus, juvenile L. palustris) had mixed differences among gap types, and Notophthalmus viridescens (efts) and adult P. cinereus showed no differences among gap types. One species, L. clamitans, was captured more often at gap edges than gap centers. These results suggest that harvest gaps, especially small gaps, provided habitat similar to natural gaps for some, but not all, amphibian species or life-stages

Application of laser Doppler velocimeter to chemical vapor laser system

A laser Doppler velocimeter (LDV) system was used to measure iodide vapor flow fields inside two different-sized tubes. Typical velocity profiles across the laser tubes were obtained with an estimated +/-1 percent bias and +/-0.3 to 0.5 percent random uncertainty in the mean values and +/-2.5 percent random uncertainty in the turbulence-intensity values. Centerline velocities and turbulence intensities for various longitudinal locations ranged from 13 to 17.5 m/sec and 6 to 20 percent, respectively. In view of these findings, the effects of turbulence should be considered for flow field modeling. The LDV system provided calibration data for pressure and mass flow systems used routinely to monitor the research laser gas flow velocity

The Research Component of Doctoral Programs in Social Work: A Survey

The doctoral program in social work has traditionally been viewed as encompassing a predominantly research-oriented, knowledge-building emphasis. It is acknowledged that if social workers are to be prepared to competently understand, utilize, participate in, and produce practice-relevant empirical studies, research must constitute an integral component of the educational process at the doctoral level. The rapid increase in doctoral programs, heightened confusion over the function of the Ph.D. and DSW, current trends to reconceptualize the structure of social work education, and the obvious consequences posed by the progressive erosion of master\u27s-level research curricula, this is an area strongly in need of immediate attention. Few attempts have been made to systematically analyze the development and experiences of social work doctoral training and few (if any) studies have been published that focus on the research component of doctoral programs in social work.1 Thus, the purpose of this article is to present the results of an empirically-based research study that investigates the research objectives, research content, and educational objectives of doctoral programs in social work