Liquid-metal heat transfer in a cocurrent- flow, double-pipe heat exchanger is investigated

Analysis of liquid-metal heat transfer in cocurrent-flow, double-pipe heat exchangers shows that heat-transfer coefficients depend upon the operating conditions of the heat exchanger and that use of the customary design equation to predict heat-exchanger performance leads to significant errors

Graded requirement for the zygotic terminal gene, tailless, in the brain and tail region of the Drosophila embryo

We have used hypomorphic and null tailless (tll) alleles to carry out a detailed analysis of the effects of the lack of tll gene activity on anterior and posterior regions of the embryo. The arrangement of tll alleles into a continuous series clarifies the relationship between the anterior and posterior functions of the tll gene and indicates that there is a graded sensitivity of anterior and posterior structures to a decrease in tll gene activity. With the deletion of both anterior and posterior pattern domains in tll null embryos, there is a poleward expansion of the remaining pattern. Using anti-horseradish peroxidase staining, we show that the formation of the embryonic brain requires tll. A phenotypic and genetic study of other pattern mutants places the tll gene within the hierarchy of maternal and zygotic genes required for the formation of the normal body pattern. Analysis of mutants doubly deficient in tll and maternal terminal genes is consistent with the idea that these genes act together in a common pathway to establish the domains at opposite ends of the embryo. We propose that tll establishes anterior and posterior subdomains (acron and tail regions, respectively) within the larger pattern regions affected by the maternal terminal genes

Performance prediction and analysis of the lunar heat flow probes

This report describes the mathematical modeling of the thermal behavior of the heat flow probes and surrounding medium. The computer models developed simulate the thermal performance of the conductivity experiments and will aid in the interpretation of lunar data.Under Subcontract No. 8 of Prime Contract No. NAS 9-6037 with Columbia Universityby D. Nathanson and R. Merriam.Introduction -- Brief review of Heat Flow Experiment -- Description of thermal models -- Evaluation of computer mathematical models -- Predicted performance in the lunar environment -- Conclusions and recommendations -- Appendice

Lunar Ascent and Rendezvous Trajectory Design

The Lunar Lander Ascent Module (LLAM) will leave the lunar surface and actively rendezvous in lunar orbit with the Crew Exploration Vehicle (CEV). For initial LLAM vehicle sizing efforts, a nominal trajectory, along with required delta-V and a few key sensitivities, is very useful. A nominal lunar ascent and rendezvous trajectory is shown, along with rationale and discussion of the trajectory shaping. Also included are ascent delta-V sensitivities to changes in target orbit and design thrust-to-weight of the vehicle. A sample launch window for a particular launch site has been completed and is included. The launch window shows that budgeting enough delta-V for two missed launch opportunities may be reasonable. A comparison between yaw steering and on-orbit plane change maneuvers is included. The comparison shows that for large plane changes, which are potentially necessary for an anytime return from mid-latitude locations, an on-orbit maneuver is much more efficient than ascent yaw steering. For a planned return, small amounts of yaw steering may be necessary during ascent and must be accounted for in the ascent delta-V budget. The delta-V cost of ascent yaw steering is shown, along with sensitivity to launch site latitude. Some discussion of off-nominal scenarios is also included. In particular, in the case of a failed Powered Descent Initiation burn, the requirements for subsequent rendezvous with the Orion vehicle are outlined

Simpson Filled Sinkholes in Eastern Kansas

Six sinkholes involving rocks of Simpson age (Ordovician) were found from examination of logs of wells drilled in eastern Kansas. These sinks contain abnormally thick Simpson sediments, chiefly St. Peter sandstone, which is interpreted as having been deposited as fill in sinkholes developed on an eroded surface of dolomite and limestone of the Arbuckle group. Chert conglomerate and green shale are present in the bottom of the sinks. The shale consists mainly of an illitic clay and quartz, which may be residual weathering products formed in place or washed into the sinks. It is believed that these subsurface features are similar to the Otterville structure in Cooper County, Missouri