Catalytic surface effects on space thermal protection system during Earth entry of flights STS-2 through STS-5

An on going orbiter experiment catalytic surface effects experiment being conducted on the Space Shuttle is discussed. The catalytic surface effects experiment was peformed on four of the five flights of Columbia. Temperature time histories and distributions along the midfuselage and wing of the orbiter were used to determine the surface catalytic efficiency of the baseline high temperature reusable surface insulation. Correlation parameters are shown that allow the comparison of all flight data with predictions from the design and surface emittance decreased as a result of contaminants during the five flights of the Space Shuttle

Separation Dynamics of Multibody Clusters of Hinged and/or Linked Lifting-Entry Vehicles

A digital simulation has been developed to compute the kinematics of separation of as many as five auxiliary (boost) elements attached around the periphery of a central core (orbital) element in six rigid-body degrees of freedom for the core and three rigid-body degrees of freedom for each attached auxiliary element. Once separated, all vehicles have six degrees of freedom. All vehicles are assumed to be lifting-entry vehicles and calculations include the aerodynamic properties of both auxiliary and core elements, in addition to the aerodynamic interference obtained from wind tunnel tests. Several separation mechanism options, such as rear pivot, linkages, and lateral thrusters are provided

Effect of gaseous and solid simulated jet plumes on a 040A space shuttle launch configuration at Mach numbers from 1.6 to 2.2

An experimental investigation was conducted in a 9- by 7-foot supersonic wind tunnel to determine the effect of plume-induced flow separation and aspiration effects due to operation of both the orbiter and the solid rocket motors on a 0.019-scale model of the launch configuration of the space shuttle vehicle. Longitudinal and lateral-directional stability data were obtained at Mach numbers of 1.6, 2.0, and 2.2 with and without the engines operating. The plumes exiting from the engines were simulated by a cold gas jet supplied by an auxiliary 200 atmosphere air supply system, and by solid body plume simulators. Comparisons of the aerodynamic effects produced by these two simulation procedures are presented. The data indicate that the parameters most significantly affected by the jet plumes are the pitching moment, the elevon control effectiveness, the axial force, and the orbiter wing loads

Phantom membrane microfluidic cross-flow filtration device for the direct optical detection of water pollutants

The diffusion of autonomous sensing platforms capable of a remote large-scale surveillance of environmental water basins is currently limited by the cost and complexity of standard analytical methods. In order to create a new generation of water analysis systems suitable for continuous monitoring of a large number of sites, novel technical solutions for fluid handling and detection are needed. Here we present a microfluidic device hosting a perfluorinated microporous membrane with refractive index similar to that of water, which enables the combination of filtration and label-free sensing of adsorbing substances, mainly pollutants, in environmental water samples. The cross-flow design of the microfluidic device avoids the clogging of the membrane due to particulate, whereas molecules with some hydrophobic moiety contained in the crossing flow are partially retained and their adhesion on the inner surface of the membrane yields an increase of light scattering intensity, which can be easily measured using a simple instrument based on Light Emitting Diode illumination. By cycling sample water and pure water as a reference, we demonstrate the detection of 0.5 \uce\ubcM of a model cationic surfactant and regeneration of the sensing surface. The optical response of the membrane sensor was characterized using a simple theoretical model that enables to quantify the concentration of target molecules from the amplitude and kinetics of the measured binding curves. The device was tested with real water samples containing large amount of environmental particles, without showing clogging of the membrane, and enabling nonspecific quantification of adsorbing substances in a few minutes

The macrobenthic species of the infralittoral to circalittoral transition zone off the northeastern coast of Malta (Central Mediterranean)

The macrobenthic assemblages of the sedimentary bottoms off the northeastern coast of Malta were studied during the summer of 1993. Crab and dredge samples were collected from depths of 21-75tn from an area of approximately 48 km2 off Comino, Mellieha Bay and St. Paul's Bay. Below ctr. 40m the bottorn was predominantly sandy with meadows of Posidonia oceanica, giving way to bare sand it1 the lower infralittoral. Between 45rn and 75r11, the bottom consisted of organogenic gravel with abundunt free-living culcureous rhodophytes, predominantly the corallines Phymatolithon calcareum and Lithothamnion corallioides. Such bot~oms, known as maerl, have not been reported previously from the Maltese Islands. 19 species of macroalgae, I phanerogam, and 108 species of macrofaunu were recorded, the bulk of these from the maerl bottom. An additional 122 species of molluscs occurred as etnpty shells. Maerl bottoms support a high species richness, even if abundance is low. There is evidence to suggest that maerl is the predominant bottom type all along the northeastern coast of the Maltese Islands in the tramition between the lower infralittoral and the circalittoral, which occurs at depths of 45-75m.peer-reviewe

Vertedero de residuos sólidos urbanos: Pedogénesis comparada entre sitios de una plantación de Eucalyptus camaldulensis Dehnh. y de vegetación herbácea naturalizad

The purpose of this work was compared different levels of pedogenetics process between sites with Eucalyptus camaldulensis plantation and naturalized grass. The trial was installed on landfill soil cover in Villa Domínico, Buenos Aires Province, Argentine, CEAMSE, 34°40’S,50’’; 58°18’45’’W; 4m osl. At five age of trees and forteen of the Landfill was realized the following determination: 1- Physical and Chemicals caracterization of own microsite tree and analogical microsite without trees influence. 2- Biomass root system of trees and naturalized herbaceus vegetation; 3- Microrganims qualitative evaluation in trees rhizosphere and 4- Survival trees and its developpmen as too patologycal and physiological damage. The results showing the antropyc evolution soil with ability to support life on differents espression. It was registred the culturals horizon in the cover landfill generated through the time. Exits the advantage about this process in the microsites tree more than the microsites grass.El objetivo de este trabajo fue comparar distintos niveles de procesos pedogenéticos entre sitios con una plantación de Eucalyptus camaldulensis y otros con vegetación herbácea naturalizada. El experimento se ubicó en la cubierta del vertedero de residuos sólidos urbanos de Villa Domínico, Buenos Aires, Argentina, (34 o 40’ 50’’ S; 58º 18’ 45’’W; 4 m snm). A las edades de seis años de la plantación y 14 del vertedero de residuos sólidos urbanos, fueron realizadas las siguientes determinaciones: 1- Caracterización físico química de micrositios análogos con influencia del árbol y del pastizal naturalizado; 2- Biomasa radicular de árboles y tapiz herbáceo naturalizado; 3- Evaluación cualitativa de microorganismos rizosféricos y 4- Desarrollo y estado sanitario de los árboles. Los resultados mostraron capacidad de soporte biológico producido por una marcada evolución pedogenética antrópica. Se registraron horizontes culturales dentro de la cubierta del vertedero de residuos sólidos urbanos a través del tiempo. Existió una ventaja de estos procesos en los micrositios con árboles respecto de los pastizales

Epiparasitic plants specialized on arbuscular mycorrhizal fungi

Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature

Multi-omics approaches explain the growth-promoting effect of the apocarotenoid growth regulator zaxinone in rice

Wang et al. report zaxinone as a global regulator of the transcriptome and metabolome, as well as of hormonal and cellular composition of rice roots. This study shows that zaxinone promotes rice growth by enhancing root sugar uptake and metabolism and modulation of cytokinin content, indicating the potential application of this compound in increasing rice performance

Revealing natural relationships among arbuscular mycorrhizal fungi: culture line BEG47 represents Diversispora epigaea, not Glomus versiforme

Background: Understanding the mechanisms underlying biological phenomena, such as evolutionarily conservative trait inheritance, is predicated on knowledge of the natural relationships among organisms. However, despite their enormous ecological significance, many of the ubiquitous soil inhabiting and plant symbiotic arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are incorrectly classified. Methodology/Principal Findings: Here, we focused on a frequently used model AMF registered as culture BEG47. This fungus is a descendent of the ex-type culture-lineage of Glomus epigaeum, which in 1983 was synonymised with Glomus versiforme. It has since then been used as ‘G. versiforme BEG47’. We show by morphological comparisons, based on type material, collected 1860–61, of G. versiforme and on type material and living ex-type cultures of G. epigaeum, that these two AMF species cannot be conspecific, and by molecular phylogenetics that BEG47 is a member of the genus Diversispora. Conclusions: This study highlights that experimental works published during the last >25 years on an AMF named ‘G. versiforme’ or ‘BEG47’ refer to D. epigaea, a species that is actually evolutionarily separated by hundreds of millions of years from all members of the genera in the Glomerales and thus from most other commonly used AMF ‘laboratory strains’. Detailed redescriptions substantiate the renaming of G. epigaeum (BEG47) as D. epigaea, positioning it systematically in the order Diversisporales, thus enabling an evolutionary understanding of genetical, physiological, and ecological traits, relative to those of other AMF. Diversispora epigaea is widely cultured as a laboratory strain of AMF, whereas G. versiforme appears not to have been cultured nor found in the field since its original description

Maerl grounds : habitats of high biodiversity in European seas

The BIOMAERL programme is a 3-year collaborative programme between laboratories in UK, Spain, France and Malta which began in February 1996. Its main plans are described in the workplan. A full inventory of the biological composition (biodiversity) of maerl bed assemblages in these regions therefore has yet to be completed, but progress is outlined below.peer-reviewe