Lessons learned: DC-X

The DC-X was conceived and developed specifically to lay the ground work for significantly lowering the cost of space operations. The system design was based on an initial set of program goals and a finite, limited set of resources. The goal in its simplest terms was to demonstrate vertical landing after rotation of the vehicle from a nose-first to an engines-first altitude. Finite resources actually drove the selection of a robust design to reduce fabrication and preflight testing costs. The result was a system with a large amount of flexibility which allowed expansion of the test goals as the system, and test program, evolved. The use of the vehicle flight computer interfacing with the ground control system for flight crew training was also not an initial concept. However, by defining an architecture for the system control modes which allowed additions and modifications as learning progressed, the 6 DOF codes used for flight controls software development were transported to the operating system to be used in a simulated flight mode. Flight data reduction was also greatly improved as the program progressed, and the data needs and presentation were refined. The software, avionics hardware, and the FOCC system development proceeded ahead of the vehicle, primarily because most of the hardware elements were existing at the outset of the program. The Built-in-Test (BIT) for avionics and propulsion systems were adequate. Particularly the flight readiness system which verified the vehicle health after engine start and before throttle-up for flight

Power distribution unit (Array E)

his specification establishes the requirements for performance, design, test, and qualification of the component identified ast he power distribution unit (PDU) of the central station subsystem (specification AL 210 100) for the Apollo Lunar Surface Experiments Package (ALSEP) Array E.prepared by D. J. Steinmeyer

Rapid single-cell electroporation for labeling organotypic cultures

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Vita.Includes bibliographical references (p. 37-39).Single-cell electroporation is a technique for transfecting individual cells in tissue culture at relatively high efficiencies, however it is both time-consuming and low-throughput and this limits the number of different labeling agents that can be effectively introduced into a region of tissue in reasonable periods of time. A novel system that will rapidly load, clean, and accurately position a glass micropipette electrode into tissue culture for single-cell electroporation is proposed. The system will significantly increase the number of different labeling agents that can be introduced into a single tissue culture per unit time. This in turn, will provide a means for improving the study of neural anatomy at cellular resolutions in both tissue culture and in vivo environments.Supported by grants from the National Institutes of Health and by the MIT Dept. of Electrical Engineering and Computer Scienceby Joseph D. Steinmeyer.S.M

Hydrogen Isotope Permeation In Elastomeric Materials

The permeabilities of elastomeric and polymeric materials to hydrogen isotopes were measured at room temperature. The technique for measuring permeation rates is based on the following constant-volume method: a fixed pressure of gas is applied to one side of the specimen to be studied and the permeability constant is determined from the observed rate of pressure increase in an initially evacuated volume on the other side of the specimen. Permeability constants for hydrogen, deuterium, and tritium were measured for Mylar, Teflon, Kapton, Saran, Buna-N, and latex rubber. Results were compared with literature values for hydrogen and deuterium where available and showed excellent agreement

Coherence as ultrashort pulse train generator

Intense, well-controlled regular light pulse trains start to play a crucial role in many fields of physics. We theoretically demonstrate a very simple and robust technique for generating such periodic ultrashort pulses from a continuous probe wave which propagates in a dispersive thermal gas media

The European Network for Translational Research in Atrial Fibrillation (EUTRAF): objectives and initial results.

Atrial fibrillation (AF) is the most common sustained arrhythmia in the general population. As an age-related arrhythmia AF is becoming a huge socio-economic burden for European healthcare systems. Despite significant progress in our understanding of the pathophysiology of AF, therapeutic strategies for AF have not changed substantially and the major challenges in the management of AF are still unmet. This lack of progress may be related to the multifactorial pathogenesis of atrial remodelling and AF that hampers the identification of causative pathophysiological alterations in individual patients. Also, again new mechanisms have been identified and the relative contribution of these mechanisms still has to be established. In November 2010, the European Union launched the large collaborative project EUTRAF (European Network of Translational Research in Atrial Fibrillation) to address these challenges. The main aims of EUTRAF are to study the main mechanisms of initiation and perpetuation of AF, to identify the molecular alterations underlying atrial remodelling, to develop markers allowing to monitor this processes, and suggest strategies to treat AF based on insights in newly defined disease mechanisms. This article reports on the objectives, the structure, and initial results of this network

Transpiration actuation: the design, fabrication and characterization of biomimetic microactuators driven by the surface tension of water

We have designed, fabricated and characterized large displacement distributed-force polymer actuators driven only by the surface tension of water. The devices were inspired by the hygroscopic spore dispersal mechanism in fern sporangia. Microdevices were fabricated through a single mask process using a commercial photo-patternable silicone polymer to mimic the mechanical characteristics of plant cellulose. An analytical model for predicting the microactuator behavior was developed using the principle of virtual work, and a variety of designs were simulated and compared to the empirical data. Fabricated devices experienced tip deflections of more than 3.5 mm and angular rotations of more than 330° due to the surface tension of water. The devices generated forces per unit length of 5.75 mN m−1 to 67.75 mN m−1. We show initial results indicating that the transient water-driven deflections can be manipulated to generate devices that self-assemble into stable configurations. Our model shows that devices should scale well into the submicron regime. Lastly, the actuation mechanism presented may provide a robust method for embedding geometry-programmable and environment-scavenged force generation into common materials.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49048/2/jmm6_11_018.pd

Organ-targeted high-throughput in vivo biologics screen identifies materials for RNA delivery

Therapies based on biologics involving delivery of proteins, DNA, and RNA are currently among the most promising approaches. However, although large combinatorial libraries of biologics and delivery vehicles can be readily synthesized, there are currently no means to rapidly characterize them in vivo using animal models. Here, we demonstrate high-throughput in vivo screening of biologics and delivery vehicles by automated delivery into target tissues of small vertebrates with developed organs. Individual zebrafish larvae are automatically oriented and immobilized within hydrogel droplets in an array format using a microfluidic system, and delivery vehicles are automatically microinjected to target organs with high repeatability and precision. We screened a library of lipid-like delivery vehicles for their ability to facilitate the expression of protein-encoding RNAs in the central nervous system. We discovered delivery vehicles that are effective in both larval zebrafish and rats. Our results showed that the in vivo zebrafish model can be significantly more predictive of both false positives and false negatives in mammals than in vitro mammalian cell culture assays. Our screening results also suggest certain structure–activity relationships, which can potentially be applied to design novel delivery vehicles.National Institutes of Health (U.S.) (Transformative Research Award R01 NS073127)National Institutes of Health (U.S.) (Director's Innovator Award DP2 OD002989)David & Lucile Packard Foundation (Award in Science and Engineering)Sanofi Aventis (Firm)Foxconn International Holdings Ltd.Hertz Foundation (Fellowship)University Grants Committee (Hong Kong, China) (Early Career Award 125012)National Natural Science Foundation (China) (81201164)ITC (ITS/376/13)Chinese University of Hong Kong (Grant 9610215)Chinese University of Hong Kong (Grant 7200269