2,041 research outputs found

    Viking '75 spacecraft design and test summary. Volume 1: Lander design

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    The Viking Mars program is summarized. The design of the Viking lander spacecraft is described

    Some Activities of MISSE 6 Mission

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    The objective of the Materials International Space Station Experiment (MISSE) is to study the performance of novel materials when subjected to the synergistic effects of the harsh space environment for several months. In this paper, a few laser and optical elements from NASA Langley Research Center (LaRC) that have been flown on MISSE 6 mission will be discussed. These items were characterized and packed inside a ruggedized Passive Experiment Container (PEC) that resembles a suitcase. The PEC was tested for survivability due to launch conditions. Subsequently, the MISSE 6 PEC was transported by the STS-123 mission to International Space Station (ISS) on March 11, 2008. The astronauts successfully attached the PEC to external handrails and opened the PEC for long term exposure to the space environment. The plan is to retrieve the MISSE 6 PEC by STS-128 mission in August 2009

    Lab-on-a-chip Thermoelectric and Solid-phase Immunodetection of Biochemical Analytes and Extracellular Vesicles: Experimental and Computational Analysis

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    Microfluidics is the technology of controlling and manipulating fluids at the microscale. Microfluidic platforms provide precise fluidic control coupled with low sample volume and an increase in the speed of biochemical reactions. Lab-on-a-chip platforms are used for detection and quantification of biochemical analytes, capture, and characterization of various proteins, sensitive analysis of cytokines, and isolation and detection of extracellular vesicles (EVs). This study focuses on the development of microfluidic and solid-phase capture pin platforms for the detection of cytokines, extracellular vesicles, and cell co-culture. The fabrication processes of the devices, experimental workflows, numerical analysis to identify optimal design parameters, and reproducibility studies have been discussed. Layer-by-layer assembly of polyelectrolytes has been developed to functionalize glass and stainless-steel substrates with biotin for the immobilization of streptavidinconjugated antibodies for selective capture of cytokines or EVs. Microstructure characterization techniques (SEM, EDX, and fluorescence microscopy) have been implemented to assess the efficiency of substrate functionalization. A detailed overview of current methods for purification and analysis of EVs is discussed as well. Additionally, the dissertation demonstrates the feasibility of a calorimetric microfluidic immunosensor with an integrated antimony-bismuth (Sb/Bi) thermopile sensor for the detection of cytokines with picomolar sensitivity. The developed platform can be used for the universal detection of both exothermic or endothermic reactions. A three-dimensional numerical model was developed to define the critical design parameters that enhance the sensitivity of the platform. Mathematical analyses identified the optimal combinations of substrate material and dimensions that will maximize the heat transfer to the sensor. Lab-on-a-chip cell co-culture platform with integrated pneumatic valve was designed, numerically characterized, and fabricated. This device enables the reversible separation of two cell culture chambers and serves as a tool for the effective analysis of cell-to-cell communication. Intercellular communication is mediated by extracellular vesicles. A protocol for the functionalization of stainless-steel probe with exosomespecific CD63 antibody was developed. The efficiency of the layer-by-layer deposition of polyelectrolytes and the effectiveness of biotin and streptavidin covalent boding were characterized using fluorescent and scanning electron microscopy

    A lunar base reference mission for the phased implementation of bioregenerative life support system components

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    Previous design efforts of a cost effective and reliable regenerative life support system (RLSS) provided the foundation for the characterization of organisms or 'biological processors' in engineering terms and a methodology was developed for their integration into an engineered ecological LSS in order to minimize the mass flow imbalances between consumers and producers. These techniques for the design and the evaluation of bioregenerative LSS have now been integrated into a lunar base reference mission, emphasizing the phased implementation of components of such a BLSS. In parallel, a designers handbook was compiled from knowledge and experience gained during past design projects to aid in the design and planning of future space missions requiring advanced RLSS technologies. The lunar base reference mission addresses in particular the phased implementation and integration of BLS parts and includes the resulting infrastructure burdens and needs such as mass, power, volume, and structural requirements of the LSS. Also, operational aspects such as manpower requirements and the possible need and application of 'robotics' were addressed

    Aeronautics and space report of the President, 1982 activities

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    Achievements of the space program are summerized in the area of communication, Earth resources, environment, space sciences, transportation, aeronautics, and space energy. Space program activities of the various deprtments and agencies of the Federal Government are discussed in relation to the agencies' goals and policies. Records of U.S. and world spacecraft launchings, successful U.S. launches for 1982, U.S. launched applications and scientific satellites and space probes since 1975, U.S. and Soviet manned spaceflights since 1961, data on U.S. space launch vehicles, and budget summaries are provided. The national space policy and the aeronautical research and technology policy statements are included

    Optothermal Trapping of Fluorescent Nanodiamonds using a Drop-casted Gold Nanoparticle

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    Deterministic optical manipulation of fluorescent nanodiamonds (FNDs) in a fluid environment has emerged as an experimental challenge in multimodal biological imaging. The design and development of nano-optical trapping strategies to serve this purpose is an important task. In this letter, we show how a drop-casted gold nanoparticle (Au np) can facilitate optothermal potential to trap individual entities of FNDs using a low power density illumination (532nm laser, 0.1 mW/μ\mum2^2). We utilize the same trapping excitation source to capture the spectral signatures of single FNDs and track their position. Furthermore, by tracking the dynamics of FND, we measure the trapping stiffness as a function of laser power and surfactant concentration and emphasize their relevance as vital parameters for nano-manipulation. Our trapping configuration combines the thermoplasmonic fields generated by individual gold nanoparticles and the optothermoelectric effect facilitated by surfactants to realize a nano-optical trap down to a single FND 120 nm in size. We envisage that our drop-casting platform can be extrapolated to perform targeted, low-power trapping, manipulation, and multimodal imaging of FNDs inside biological systems such as cells.Comment: 17 pages, 4 figures, 3 tables. Supplementary videos may be found at: https://drive.google.com/drive/folders/1gkW9g5Z7Fhl4i3ZQUOBQYuUYAPrHykzY?usp=sharin

    The Biology Instrument for the Viking Mars Mission

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    Two Viking spacecraft have successfully soft landed on the surface of Mars. Each carries, along with other scientific instruments, one biology laboratory with three different experiments designed to search for evidence of living microorganisms in material sampled from the Martian surface. This 15.5-kg biology instrument which occupies a volume of almost 28.3 dm3 is the first to carry out an in situ search for extraterrestrial life on a planet. The three experiments are called the pyrolytic release, labeled release, and gas exchange. The pyrolytic release experiment has the capability to measure the fixation of carbon dioxide or carbon monoxide into organic matter. The labeled release experiment detects metabolic processes by monitoring the production of volatile carbon compounds from a radioactively labeled nutrient mixture. The gas exchange experiment monitors the gas changes in the head space above a soil sample which is either incubated in a humid environment or supplied with a rich organic nutrient solution. Each experiment can analyze a soil sample as it is received from the surface or, as a control, analyze a soil which has been heated to above 160C. Each instrument has the capability to receive four different soils dug from the Martian surface and perform a number of analysis cycles depending on the particular experiment. This paper describes in detail the design and operation of the three experiments and the supporting subsystems

    Power Approaches for Implantable Medical Devices.

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    Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health). In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources
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