Coastal Zone Color Scanner studies

Activities over the past year have included cooperative work with a summer faculty fellow using the Coastal Zone Color Scanner (CZCS) imagery to study the effects of gradients in trophic resources on coral reefs in the Caribbean. Other research included characterization of ocean radiances specific to an acid-waste plume. Other activities include involvement in the quality control of imagery produced in the processing of the global CZCS data set, the collection of various other data global sets, and the subsequent data comparison and analysis

Efficient numerical method for computation of thermohydrodynamics of laminar lubricating films

The purpose of this paper is to describe an accurate, yet economical, method for computing temperature effects in laminar lubricating films in two dimensions. The procedure presented here is a sequel to one presented in Leeds in 1986 that was carried out for the one-dimensional case. Because of the marked dependence of lubricant viscosity on temperature, the effect of viscosity variation both across and along a lubricating film can dwarf other deviations from ideal constant-property lubrication. In practice, a thermohydrodynamics program will involve simultaneous solution of the film lubrication problem, together with heat conduction in a solid, complex structure. The extent of computation required makes economy in numerical processing of utmost importance. In pursuit of such economy, we here use techniques similar to those for Gaussian quadrature. We show that, for many purposes, the use of just two properly positioned temperatures (Lobatto points) characterizes well the transverse temperature distribution

Investigation of SSME alternate high pressure fuel turbopump lift-off seal fluid and structural dynamic interaction

The Space Shuttle main engine (SSME) alternate turbopump development program (ATD) high pressure fuel turbopump (HPFTP) design utilizes an innovative lift-off seal (LOS) design that is located in close proximity to the turbine end bearing. Cooling flow exiting the bearing passes through the lift-off seal during steady state operation. The potential for fluid excitation of lift-off seal structural resonances is investigated. No fluid excitation of LOS resonances is predicted. However, if predicted LOS natural frequencies are significantly lowered by the presence of the coolant, pressure oscillations caused by synchronous whirl of the HPFTP rotor may excite a resonance

Damper bearing rotordynamics

High side loads reduce the life of the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP) bearings. High stiffness damper seals were recommended to reduce the loads on the pump and turbine end bearings in the HPOTP. The seals designed for use on the pump end are expected to adequately reduce the bearing loads; the predicted performance of the planned turbine end seal is marginal. An alternative to the suggested turbine end seal design is a damper bearing with radial holes from the pressurized center of the turbopump rotor, feeding a smooth land region between two rough-stator/smooth-rotor annular seals. An analysis was prepared to predict the leakage and rotor dynamic coefficients (stiffness, damping, and added mass) of the damper bearing. Governing equations of the seal analysis modified to model the damper bearing; differences between the upstream conditions of the damper bearing and a typical annular seal; prediction of the damper bearing analysis; and assumptions of the analysis which require further investigation are described

Service evaluation of aluminum-brazed titanium (ABTi)

Long term creep-rupture, flight service and jet engine exhaust tests on aluminum-brazed titanium (ABTi), originally initiated under the DOT/SST follow-on program, were completed. These tests included exposure to natural airline service environments for up to 6 years. The results showed that ABTi has adequate corrosion resistance for long time commercial airplane structural applications. Special precautions are required for those sandwich structures designed for sound attenuation that utilize perforated skins. ABTi was also shown to have usable creep-rupture strength and to be metallurgically stable at temperatures up to 425 C (800 F)

Experimental rotordynamic coefficient results for honeycomb seals

Test results (leakage and rotordynamic coefficients) are presented for seven honeycomb-stator smooth-rotor seals. Tests were carried out with air at rotor speeds up to 16,000 cpm and supply pressures up to 8.2 bars. Test results for the seven seals are compared, and the most stable configuration is identified based on the whirl frequency ratio. Results from tests of a smooth-rotor/smooth-stator seal, a teeth-on-stator labyrinth seal, and the most stable honeycomb seal are compared

Equilibrium properties of the Skylab CMG rotation law

The equilibrium properties of the control moment gyroscopes of the Skylab are discussed. A rotation law is developed to produce gimbal rates which distribute the angular momentum contributions among the control moment gyroscopes to avoid gimbal stop encounters. The implications for gimbal angle management under various angular momentum situations are described. Conditions were obtained for the existence of equilibria and corresponding stability properties

Joanna Brooks, American Lazarus: Religion and the Rise of African and Native American Literatures

One might imagine Joanna Brooks\u27s American Lazarus: Religion and the Rise of African-American and Native American Literatures in the tradition of Jones and Allen\u27s historical record straightening. Her detailed, lucidly presented narrative of contexts, communities, and texts (including that of Jones and Allen) is notable not only for its thorough explication o

PEMANFAATAN ANALISIS DAN PERANCANGAN DATABASE SISTEM SUMBER DAYA MANUSIA UNTUK MENINGKATKAN KINERJA DALAM PEREKRUTAN, PENGGAJIAN DAN PEMBERHENTIAN PADA PT. ESHAM DIMA MANDIRI

PEMANFAATAN ANALISIS DAN PERANCANGAN DATABASE SISTEM SUMBER DAYA MANUSIA UNTUK MENINGKATKAN KINERJA DALAM PEREKRUTAN, PENGGAJIAN DAN PEMBERHENTIAN PADA PT. ESHAM DIMA MANDIRI

OF DIVORCE, CHILDREN AND NATIONAL POLICY

Public Economics,