Turbulence characterization of algae and viscous cyanobacterial polycultures in open-channel raceways: Implications in the design of cultivation systems.
Abstract not provided.
Quiroz-Arita, Carlos↗
Engineering topics
Mancinelli, Rocco
Publications and source records attributed to Mancinelli, Rocco.
Water Walls Architecture: Massively Redundant And Highly Reliable Life Support For Long Duration Exploration Missions
The Water Wall concept proposes a system for structural elements that provide,thermal, radiation, water, solids and air treatment functions which are placed at the periphery of inflatable or rigid habitats. It also provides novel and potentially game changing mass reduction and reuse options for radiation protection. The approach would allow water recycling, air treatment, thermal control, and solids residuals treatment and recycling to be removed from the usable habitat volume, and placed in the walls by way of a radiation shielding water wall. It would also provide a mechanism to recover and reuse water treatment (solids) residuals to strengthen the habitat shell and a method of deriving radiation shielding from wastes generated on orbit. Water wall treatment elements would be a much-enlarged version of the commercially available hydration bags. Some water bags may have pervaporation membranes facing outward, which would provide the ability to remove H20, C02 and trace organics from the atmosphere and some would have hydrophobic internal membranes which would provide water, and waste recycling and some power generation.
Water Recycling↗
Testing of Synthetic Biological Membranes for Forward Osmosis Applications
Commercially available forward osmosis membranes have been extensively tested for human space flight wastewater treatment. Despite the improvements achieved in the last decades, there is still a challenge to produce reliable membranes with anti-fouling properties, chemical resistance, and high flux and selectivity. Synthetic biological membranes that mimic the ones present in nature, which underwent millions of years of evolution, represent a potential solution for further development and progress in membrane technology. Biomimetic forward osmosis membranes based on a polymeric support filter and coated with surfactant multilayers have been engineered to investigate how different manufacturing processes impact the performance and structure of the membrane. However, initial results of the first generation prototype membranes tests reveal a high scatter in the data, due to the current testing apparatus set up. The testing apparatus has been upgraded to improve data collection, reduce errors, and to allow higher control of the testing process.
Forward osmosis↗
Life Science Research in Outer Space: New Platform Technologies for Low-Cost, Autonomous Small Satellite Missions
We develop integrated instruments and platforms suitable for economical, frequent space access for autonomous life science experiments and processes in outer space. The technologies represented by three of our recent free-flyer small-satellite missions are the basis of a rapidly growing toolbox of miniaturized biologically/biochemically-oriented instrumentation now enabling a new generation of in-situ space experiments. Autonomous small satellites (~ 1 50 kg) are less expensive to develop and build than fullsize spacecraft and not subject to the comparatively high costs and scheduling challenges of human-tended experimentation on the International Space Station, Space Shuttle, and comparable platforms. A growing number of commercial, government, military, and civilian space launches now carry small secondary science payloads at far lower cost than dedicated missions; the number of opportunities is particularly large for so-called cube-sat and multicube satellites in the 1 10 kg range. The recent explosion in nano-, micro-, and miniature technologies, spanning fields from telecommunications to materials to bio/chemical analysis, enables development of remarkably capable autonomous miniaturized instruments to accomplish remote biological experimentation. High-throughput drug discovery, point-of-care medical diagnostics, and genetic analysis are applications driving rapid progress in autonomous bioanalytical technology. Three of our recent missions exemplify the development of miniaturized analytical payload instrumentation: GeneSat-1 (launched: December 2006), PharmaSat (launched: May 2009), and O/OREOS (organism/organics exposure to orbital stresses; scheduled launch: May 2010). We will highlight the overall architecture and integration of fluidic, optical, sensor, thermal, and electronic technologies and subsystems to support and monitor the growth of microorganisms in culture in these small autonomous space satellites, including real-time tracking of their culture density, gene expression, and metabolic activity while in the space environment. Flight data and results will be presented from GeneSat-1, which tracked gene expression levels of GFP-labeled E. coli and from PharmaSat, which monitored the dose dependency of an antifungal agent against S. cerevisiae. The O/OREOS SESLO instrument, which will study the effects of radiation and microgravity upon the viability and growth characteristics of B. subtilis and the halophile Halorubrum chaoviatoris for periods of 0 - 6 months in space, will be described as well. The ongoing expansion of the small satellite toolbox of biological technologies will be summarized.
Ricco, Antonio J.↗
Effect of shadowing on survival of bacteria under conditions simulating the Martian atmosphere and UV radiation
Spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in Atacama Desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated Martian atmospheric and UV irradiation conditions. All non-spore-forming cells that were prepared in nutrient-depleted, 0.2-μm-filtered desert soil (DSE) microcosms and desiccated for 75 days on aluminum died, whereas cells prepared similarly in 60-μm-filtered desert soil (DS) microcosms survived such conditions. Among the bacterial cells tested, Microbacterium schleiferi and Arthrobacter sp. exhibited elevated resistance to 254-nm UV irradiation (low-pressure Hg lamp), and their survival indices were comparable to those of DS- and DSE-associated Bacillus pumilus spores. Desiccated DSE-associated spores survived exposure to full Martian UV irradiation (200 to 400 nm) for 5 min and were only slightly affected by Martian atmospheric conditions in the absence of UV irradiation. Although prolonged UV irradiation (5 min to 12 h) killed substantial portions of the spores in DSE microcosms (~5- to 6-log reduction with Martian UV irradiation), dramatic survival of spores was apparent in DS-spore microcosms. The survival of soil-associated wild-type spores under Martian conditions could have repercussions for forward contamination of extraterrestrial environments, especially Mars.
Venkateswaran, Kasthuri↗
Mars Geochemical Instrument (MarGI): An instrument for the analysis of the Martian surface and the search for evidence of life
The Mars Geochemical Instrument, MarGI, was developed to provide a comprehensive analysis of the rocks and surface material on Mars. The instrument combines Differential Thermal Analysis (DTA) with miniature Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) to identify minerals, the presence and state of water, and organic compounds. Miniature pyrolysis ovens are used to both, conduct DTA analysis of soil or crushed rocks samples, and pyrolyze the samples at temperatures up to 1000 degrees C for GC-IMS analysis of the released gases. This combination of analytical processes and techniques, which can characterize the mineralogy of the rocks and soil, and identify and quantify volatiles released during pyrolysis, has applications across a wide range of target sites including comets, planets, asteroids, and moons such as Titan and Europa. The MarGI analytical approach evolved from the Cometary Ice and Dust Experiment (CIDEX) selected to fly on the Comet Rendezvous Asteroid Flyby Mission (CRAF).
Kojiro, Daniel R.↗
Carbon-Based Compounds and Exobiology
The Committee for Planetary and Lunar Explorations (COMPLEX) posed questions related to exobiological exploration of Mars and the possibility of a population of carbonaceous materials in cometary nuclei to be addressed by future space missions. The scientific objectives for such missions are translated into a series of measurements and/or observations to be performed by Martian landers. These are: (1) A detailed mineralogical, chemical, and textural assessment of rock diversity at a landing site; (2) Chemical characterization of the materials at a local site; (3) Abundance of Hydrogen at any accessible sites; (4) Identification of specific minerals that would be diagnostic of aqueous processes; (5) Textual examination of lithologies thought to be formed by aqueous activity; (6) Search for minerals that might have been produced as a result of biological processes; (7) Mapping the distribution, in three dimensions, of the oxidant(s) identified on the Martian surface by the Viking mission; (8) Definition of the local chemical environment; (9) Determination of stable-isotopic ratios for the biogenic elements in surface mineral deposits; (10) Quantitative analysis of organic (non-carbonate) carbon; (11) Elemental and isotopic composition of bulk organic material; (12) Search for specific organic compounds that would yield information about synthetic mechanisms, in the case of prebiotic evolution, and about possible bio-markers, in the case of extinct or extant life; (13) and Coring, sampling, and detection of entrained gases and cosmic-ray induced reaction products at the polar ice cap. A discussion of measurements and/or observations required for cometary landers is included as well.
Kerridge, John↗
Science exploration opportunities for manned missions to the Moon, Mars, Phobos, and an asteroid
Scientific exploration opportunities for human missions to the Moon, Phobos, Mars, and an asteroid are addressed. These planetary objects are of prime interest to scientists because they are the accessible, terresterial-like bodies most likely to be the next destinations for human missions beyond Earth orbit. Three categories of science opportunities are defined and discussed: target science, platform science, and cruise science. Target science is the study of the planetary object and its surroundings (including geological, biological, atmospheric, and fields and particle sciences) to determine the object's natural physical characteristics, planetological history, mode of origin, relation to possible extant or extinct like forms, surface environmental properties, resource potential, and suitability for human bases or outposts. Platform science takes advantage of the target body using it as a site for establishing laboratory facilities and observatories; and cruise science consists of studies conducted by the crew during the voyage to and from a target body. Generic and specific science opportunities for each target are summarized along with listings of strawman payloads, desired or required precursor information, priorities for initial scientific objectives, and candidate landing sites. An appendix details the potential use of the Moon for astronomical observatories and specialized observatories, and a bibliography compiles recent work on topics relating to human scientific exploration of the Moon, Phobos, Mars, and asteroids. It is concluded that there are a wide variety of scientific exploration opportunities that can be pursued during human missions to planetary targets but that more detailed studies and precursor unmanned missions should be carried out first.
Nash, Douglas B.↗
Design requirements for a Mars base greenhouse
One potential method of supplying life support to a manned base on Mars utilizes a Controlled Ecological Life Support Systems (CELSS). A major component of the CELSS is a plant growth unit to produce food. This paper describes the results of several experiments conducted to determine whether or not a low atmospheric pressure greenhouse could be used to grow crop plants on the Martian surface. The results of these experiments are described and integrated with other information to produce a set of design requirements and a conceptual design for such a greenhouse.
Schwartzkopf, Steven H.↗