Improved calorimeter provides accurate thermal measurements of space batteries

Isothermal continuous flow calorimeter measures the thermal characteristics of space batteries undergoing typical orbital cycling. This is 28 times as sensitive as calorimeters previously used

An engine trade study for a supersonic STOVL fighter-attack aircraft, volume 1

The best main engine for an advanced STOVL aircraft flight demonstrator was studied. The STOVL aircraft uses ejectors powered by engine bypass flow together with vectored core exhaust to achieve vertical thrust capability. Bypass flow and core flow are exhausted through separate nozzles during wingborne flight. Six near term turbofan engines were examined for suitability for this aircraft concept. Fan pressure ratio, thrust split between bypass and core flow, and total thrust level were used to compare engines. One of the six candidate engines was selected for the flight demonstrator configuration. Propulsion related to this aircraft concept was studied. A preliminary candidate for the aircraft reaction control system for hover attitude control was selected. A mathematical model of transfer of bypass thrust from ejectors to aft directed nozzle during the transition to wingborne flight was developed. An equation to predict ejector secondary air flow rate and ram drag is derived. Additional topics discussed include: nozzle area control, ejector to engine inlet reingestion, bypass/core thrust split variation, and gyroscopic behavior during hover

Experimental L-band SST satellite communications/surveillance terminal study. Volume 1 - Study summary

Study of design for experimental L band supersonic transport communications/surveillance termina

Research into fundamental phenomena associated with spacecraft electrochemical devices - calorimetry of nickel-cadmium cells Progress report, 1 Oct. 1966 - 31 Dec. 1966

Cycling, charge efficiency, and transducer studies with nickel-cadmium cell for spacecraft power supply system

Experimental L-band SST satellite communications/surveillance terminal study. Volume 5 - Aircraft terminal definition

Aircraft terminal designs for experimental and operational supersonic transport for L band satellite air traffic contro

Study of aerodynamic technology for single-cruise-engine VSTOL fighter/attack aircraft, phase 1

A conceptual design and analysis on a single engine VSTOL fighter/attack aircraft is completed. The aircraft combines a NASA/deHavilland ejector with vectored thrust and is capable of accomplishing the mission and point performance of type Specification 169, and a flight demonstrator could be built with an existing F101/DFE engine. The aerodynamic, aero/propulsive, and propulsive uncertainties are identified, and a wind tunnel program is proposed to address those uncertainties associated with wing borne flight

Genomics-Based Studies Identify Cis And Trans Acting Post-Transcriptional Regulators

The identity of every organism is stored in its genetic material. Each gene is transcribed into an intermediate RNA molecule, which undergoes complex processing before translation into a functional protein. RNA processing is controlled by RNA binding proteins (RBPs). Each RBP binds to and regulates the processing, stability, and translation of hundreds to thousands of RNA targets, thereby making these proteins essential for organismal development. RBPs bind to their targets by recognizing both the RNA sequence and secondary structure, which is the interaction between complementary RNA sequences within a single molecule. These interactions can be regulated by changing the chemical makeup of RNA nucleotides via covalent modification, thereby altering the secondary structure and RBP-binding of an RNA molecule. Therefore, the interplay between covalent modifications, secondary structure, and RNA-protein interactions regulates the processing and regulation of each RNA transcript. In this dissertation, I have examined these cis and trans acting post-transcriptional regulators to determine their role in RNA processing. To do this, we have applied a next generation sequencing technique to globally identify RNA-protein interactions and RNA secondary structure in the nuclei of Arabidopsis seedlings. This work has revealed a strong anti-correlation between RNA structure and protein binding. We next utilized this same technique to help identify RBPs that regulate root hair cell development. Hair cells are located on the root epidermis and are responsible for the uptake of water and nutrients from the environment. Therefore, increasing hair cell number can increase plant survival. During this work, we identified two RBPs that regulate root hair cell fate, one of which functions in the phosphate starvation response pathway. These findings reveal novel pathways involved in this developmental process. Finally, we examined the role of covalent modifications in RNA processing. By identifying modifications across the nuclear and cytoplasmic transcriptomes, we found broad populations of modifications corresponding to altered stability. These results illustrate the various regulatory roles held by covalent modifications. Together, this work has advanced the field of post-transcriptional regulation using the model plant Arabidopsis thaliana, by identifying fundamental features of RNA processing, and has raised many questions for future studies to address

Early and Late-Time Observations of SN 2008ha: Additional Constraints for the Progenitor and Explosion

We present a new maximum-light optical spectrum of the the extremely low luminosity and exceptionally low energy Type Ia supernova (SN Ia) 2008ha, obtained one week before the earliest published spectrum. Previous observations of SN 2008ha were unable to distinguish between a massive star and white dwarf origin for the SN. The new maximum-light spectrum, obtained one week before the earliest previously published spectrum, unambiguously shows features corresponding to intermediate mass elements, including silicon, sulfur, and carbon. Although strong silicon features are seen in some core-collapse SNe, sulfur features, which are a signature of carbon/oxygen burning, have always been observed to be weak in such events. It is therefore likely that SN 2008ha was the result of a thermonuclear explosion of a carbon-oxygen white dwarf. Carbon features at maximum light show that unburned material is present to significant depths in the SN ejecta, strengthening the case that SN 2008ha was a failed deflagration. We also present late-time imaging and spectroscopy that are consistent with this scenario.Comment: ApJL, accepted. 5 pages, 3 figure