Deployable and erectable concepts for large spacecraft

Computerized structural sizing techniques were used to determine structural proportions of minimum mass tetrahedral truss platforms designed for low Earth and geosynchronous orbit. Optimum (minimum mass) deployable and erectable, hexagonal shaped spacecraft are sized to satisfy multiple design requirements and constraints. Strut dimensions characterizing minimum mass designs are found to be significantly more slender than those conventionally used for structural applications. Comparison studies show that mass characteristics of deployable and erectable platforms are approximately equal and that the shuttle flights required by deployable trusses become excessive above certain critical stiffness values. Recent investigations of eractable strut assembly are reviewed. Initial erectable structure assembly experiments show that a pair of astronauts can achieve EVA assembly times of 2-5 min/strut and studies indicate that an automated assembler can achieve times of less than 1 min/strut for around the clock operation

Ongoing methane discharge at well site 22/4b (North Sea)and discovery of a spiral vortex bubble plume motion

Highlights • Mega ebullition of biogenic methane from an abandoned offshore gas well, North Sea. • Evidence for midwater bubble plume intrusion, fallback, and short-circuiting of the plume. • Effective trapping of seabed released methane underneath the thermocline. • First observation of a spiral vortex methane plume and marginal turbulences. • Megaplumes appear less efficient in terms of vertical methane transport than previously thought. Abstract First direct evidence for ongoing gas seepage activity on the abandoned well site 22/4b (Northern North Sea, 57°55′ N, 01°38′ E) and discovery of neighboring seepage activity is provided from observations since 2005. A manned submersible dive in 2006 discovered several extraordinary intense seepage sites within a 60 m wide and 20 m deep crater cut into the flat 96 m deep seafloor. Capture and (isotope) chemical analyses of the gas bubbles near the seafloor revealed in situ concentrations of methane between 88 and 90%Vol. with δ13C–CH4 values around −74‰ VPDB, indicating a biogenic origin. Bulk methane concentrations throughout the water column were assessed by 120 Niskin water samples showing up to 400.000 nM CH4 in the crater at depth. In contrast, concentrations above the thermocline were orders of magnitude lower, with a median value of 20 nM. A dye tracer injection into the gas seeps revealed upwelling bubble and water motion with gas plume rise velocities up to ∼1 ms−1 (determined near the seabed). However, the dissolved dye did not pass the thermocline, but returned down to the seabed. Measurements of direct bubble-mediated atmospheric flux revealed low values of 0.7 ± 0.3 kty−1, much less than current state-of-the-art bubble dissolution models would predict for such a strong and upwelling in situ gas bubble flux at shallow water depths (i.e. ∼100 m). Acoustic multibeam water column imaging data indicate a pronounced 200 m lateral intrusion at the thermocline together with high methane concentration at this layer. A partly downward-orientated bubble plume motion is also visible in the acoustic data with potential short-circuiting in accordance to the dye experiment. This observation could partly explain the observed trapping of most of the released gas below the well-established thermocline in the North Sea. Moreover, 3D analyses of the multibeam water column data reveal that the upwelling plume transforms into a spiral expanding vortex while rising through the water column. Such a spiral vortex motion has never been reported before for marine gas seepage and might represent an important process with strong implication on plume dynamics, dissolution behavior, gas escape to the atmosphere, and is considered very important for respective modeling approaches

Reading Skills in a Paperback Classroom

Humanities teachers have been reluctant, with justification, to trust mathematical measurements of literary experience. They know that the learning in which students participate in the classroom cannot be put on a bubble sheet with a number two pencil, but the threat of accountability and standardized testing is forcing them into a defensive position. Those teachers who have enjoyed the satisfactions of working with relevant material in the past few years are now threatened by basics. The good teachers, of course, never stopped teaching the basics but found that relevancy could be used as a motivational tool. The best of the lot always learn how to ride out the waves of educational fadism by adapting the demands of current philosophy to fit what they believed all along

Vanadium

International audienceVanadium (chemical symbol, V) is a d-block transition metal,silver in color, appearing in the first long period of the peri-odic table between titanium and chromium. Vanadium hastwo stable isotopes: 50V and 51V, with atomic abundance of0.25 % and 99.75 %, respectively. Vanadium has several oxidation forms (between 2+ and 5+). In the lithosphere, Voccurs as reducing V(III) form, whereas in oxidizing con- ditions V prevails under V(IV) form. Vanadium(II) is partic- ularly unstable in the environment. Vanadium(III) is more stable than V(II), but it is also gradually oxidized by the air or dissolved oxygen. Vanadium(V) is expected to be the prevailing form in waters exposed to atmospheric oxygen, whereas V(IV) may be present in reducing environments. Depending upon geometry and environment, V ionic radii vary between 36 pm and 79 pm. Vanadium has a high melting point of 1910 42 C and is a mildly incompatible, refractory,lithophile (siderophile in the iron core and chondrites) ele- ment. Vanadium has an electronegativity of 1.63 on the Pau- ling scale and displays a first ionization potential of 6.74 eV. More details can be found in Richards (2006) and Haynes (2015)

Indications of a link between seismotectonics and CH4 release from seeps off Costa Rica

Measurements of CH4 concentrations in the bottom water during two discrete sampling periods in subsequent years above different cold seeps at the Pacific margin off Costa Rica indicate large-scale variations of CH4 release. CH4 is emitted from mud extrusions and a slide scar at 1000–2300 m water depth. Maximum CH4 concentrations were found to be lower above all investigated sites in autumn 2003 than in autumn 2002 although seep sites are up to 300 km apart. Tidal and current changes were observed but found to apply only to individual seep sites. Increased seismic activity connected to the moment magnitude (M W ) 6.4 earthquake offshore Costa Rica in June 2002 could have had an impact on all seep sites and thereby caused an increase in CH4 emission. This is supported by the largest variations of CH4 concentration found above mud extrusions located above faults likely more strongly affected by tectonic movements. Even though our data indicate a relation between seismicity and CH4 seepage, the relation is not proven, and future work is needed to comprehensively test this hypothesis

Свободные аминокислоты и их азотсодержащие метаболиты в гипоталамусе крыс при острой интоксикации динилом и их корреляция с аминокислотным спектром плазмы крови

аминокислотыгипоталамусдинилотравлениеплазм

Glucose-6-phosphate dehydrogenase deficiency with recurrent infections: case report

OBJECTIVE: To report a case of rare neutrophil functional disorder with clinical and laboratory findings similar to those of chronic granulomatous disease. METHODS: Patient with extremely reduced level of glucose-6-phosphate dehydrogenase and recurrent infections that improved after continuous use of cotrimoxazole. The patient presented leukocytes with defective respiratory burst, similar to what occurs in chronic granulomatous disease. COMMENTS: The diagnosis of glucose-6-phosphate dehydrogenase deficiency in neutrophils should be considered in any patient with hemolytic anemia whose level of G6PD is extremely low or in any patient that presents recurrent infections as differential diagnosis of chronic granulomatous disease.OBJETIVO: relatar a ocorrência de uma deficiência funcional de neutrófilos rara, com quadro clínico e laboratorial semelhante ao da doença granulomatosa crônica. MÉTODOS: relato de caso de paciente com deficiência acentuada da glicose-6-fosfato desidrogenase e infecções de repetição. Realizada pesquisa bibliográfica utilizando as bases de dados Medline e Lilacs, abrangendo o período de 1972 a 2000. RESULTADOS: paciente com nível da glicose-6-fosfato desidrogenase extremamente reduzido e quadro de infeções graves com melhora clínica após uso de cotrimoxazol contínuo. Os leucócitos do paciente apresentam defeito no metabolismo oxidativo, similar ao da doença granulomatosa crônica. CONCLUSÕES: o diagnóstico da deficiência da glicose-6-fosfato desidrogenase em neutrófilos deve ser considerado em qualquer paciente com anemia hemolítica não esferocítica congênita no qual o nível da glicose-6-fosfato desidrogenase esteja anormalmente baixo ou apresente infeções de repetição. É diagnóstico diferencial da doença granulomatosa crônica.Univ. Federal de São Paulo Depto. de Pediatria Disc. de Alergia, Imunologia ClínicaUniv. Federal do Rio de Janeiro Fac. de Medicina Depto. de Medicina PreventivaUNICAMP Faculdade de Ciências Médicas Depto. de PediatriaUniv. de São Paulo Fac. de MedicinaUNIFESP-EPM Depto. de PediatriaUSP Instituto de Ciências Biomédicas Depto. de ImunologiaUFRJ Fac. Med. Depto. de Medicina PreventivaUFRJ Fac. de Medicina Depto. de PediatriaUNIFESP, EPM, Depto. de PediatriaSciEL

Feature integration in natural language concepts

Two experiments measured the joint influence of three key sets of semantic features on the frequency with which artifacts (Experiment 1) or plants and creatures (Experiment 2) were categorized in familiar categories. For artifacts, current function outweighed both originally intended function and current appearance. For biological kinds, appearance and behavior, an inner biological function, and appearance and behavior of offspring all had similarly strong effects on categorization. The data were analyzed to determine whether an independent cue model or an interactive model best accounted for how the effects of the three feature sets combined. Feature integration was found to be additive for artifacts but interactive for biological kinds. In keeping with this, membership in contrasting artifact categories tended to be superadditive, indicating overlapping categories, whereas for biological kinds, it was subadditive, indicating conceptual gaps between categories. It is argued that the results underline a key domain difference between artifact and biological concepts