18,410 research outputs found

    USSR Space Life Sciences Digest, issue 32

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    This is the thirty-second issue of NASA's USSR Space Life Sciences Digest. It contains abstracts of 34 journal or conference papers published in Russian and of 4 Soviet monographs. Selected abstracts are illustrated with figures and tables from the original. The abstracts in this issue have been identified as relevant to 18 areas of space biology and medicine. These areas include: adaptation, aviation medicine, biological rhythms, biospherics, cardiovascular and respiratory systems, developmental biology, exobiology, habitability and environmental effects, human performance, hematology, mathematical models, metabolism, microbiology, musculoskeletal system, neurophysiology, operational medicine, and reproductive system

    Study of lead phytoavailability for atmospheric industrial micronic and sub-micronic particles in relation with lead speciation

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    Particles from channelled emissions of a battery recycling facility were size-segregated and investigated to correlate their speciation and morphology with their transfer towards lettuce. Microculture experiments carried out with various calcareous soils spiked with micronic and sub-micronic particles (1650 20 mg Pb kg1) highlighted a greater transfer in soils mixed with the finest particles. According to XRD and Raman spectroscopy results, the two fractions presented differences in the amount of minor lead compounds like carbonates, but their speciation was quite similar, in decreasing order of abundance: PbS, PbSO4, PbSO4$PbO, a-PbO and Pb0. Morphology investigations revealed that PM2.5 (i.e. Particulate Matter 2.5 composed of particles suspended in air with aerodynamic diameters of 2.5 mm or less) contained many Pb nanoballs and nanocrystals which could influence lead availability. The soil– plant transfer of lead was mainly influenced by size and was very well estimated by 0.01 M CaCl2 extractio

    Measuring Liquefied Residual Strength Using Full-Scale Shake Table Cyclic Simple Shear Tests

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    This research consists of full-scale cyclic shake table tests to investigate liquefied residual strength of #2/16 Monterey Sand. A simple shear testing apparatus was mounted to a full-scale one-dimensional shake table to mimic a confined layer of saturated sand subjected to strong ground motions. Testing was performed at the Parson’s Geotechnical and Earthquake Laboratory at California Polytechnic State University, San Luis Obispo. T-bar penetrometer pullout tests were used to measure residual strength of the liquefied soil during cyclic testing. Cone Penetration Testing (CPT) was performed on the soil specimen throughout testing to relate the laboratory specimen to field index test data and to compare CPT results of the #2/16 Monterey sand before and after liquefaction. The generation and dissipation of excess pore pressures during cyclic motion are measured and discussed. The effects of liquefied soil on seismic ground motion are investigated. Measured residual strengths are compared to previous correlations comparing liquefied residual strength ratios and CPT tip resistance

    A low cost mobile mapping system (LCMMS) for field data acquisition: a potential use to validate aerial/satellite building damage assessment

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    Among the major natural disasters that occurred in 2010, the Haiti earthquake was a real turning point concerning the availability, dissemination and licensing of a huge quantity of geospatial data. In a few days several map products based on the analysis of remotely sensed data-sets were delivered to users. This demonstrated the need for reliable methods to validate the increasing variety of open source data and remote sensing-derived products for crisis management, with the aim to correctly spatially reference and interconnect these data with other global digital archives. As far as building damage assessment is concerned, the need for accurate field data to overcome the limitations of both vertical and oblique view satellite and aerial images was evident. To cope with the aforementioned need, a newly developed Low-Cost Mobile Mapping System (LCMMS) was deployed in Port-au-Prince (Haiti) and tested during a five-day survey in FebruaryMarch 2010. The system allows for acquisition of movies and single georeferenced frames by means of a transportable device easily installable (or adaptable) to every type of vehicle. It is composed of four webcams with a total field of view of about 180 degrees and one Global Positioning System (GPS) receiver, with the main aim to rapidly cover large areas for effective usage in emergency situations. The main technical features of the LCMMS, the operational use in the field (and related issues) and a potential approach to be adopted for the validation of satellite/aerial building damage assessments are thoroughly described in the articl

    Particle size and metal distributions in anaerobically digested pig slurry

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    Particle size distribution and trace element patterns were studied in a full-scale anaerobic digestion plant treating pig slurry. Mass balance was established for major (N, P, K, Ca, Fe, Mg and S) and minor (Al, Cu, Mn and Zn) elements. Most of the elements were conserved through the process but part of the P, Ca, Mg and Mn was deposited as crystals lining the digester. In the dry matter of the slurry, Cu and Zn occurred at between 170 and 2600 mg kg1 due to pig diet supplements. Analyses of particle size distributions in raw and digested slurries showed a general shift in distribution towards larger sizes due to degradation of small and easily degradable particles as well as formation of large microbial filaments. Graded sieving of digested slurry showed metals to be mainly present on 3–25 lm particles. Less than 2% Cu and Zn was removed by passage through a 250 lm rotary screen

    An appraisal of nutrient supplies available for tree growth in a pumice soil

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    Chemical analyses have confirmed and explained the results of an earlier pot trial in which the availability of major nutrients in six pumice ash layers of Kaingaroa silty sand was assessed by the growth of radiata pine seedlings. Almost all of the tree-available P is found in the present topsoil: the quantities-of P that occur in two buried soils (Waimihia and Rotoma ashes) are almost entirely in the form of organic P which is apparently very resistant to breakdown due to complexing with allophane. The N in these layers is similarly unavailable. The mineral layers, about 4 ft in thickness (Taupo pumice and lapilli), which lie between the present topsoil and the uppermost buried soil, are very low in total N and P and exchangeable Mg, but relatively high in exchangeable K. Only the lower buried soil contains a reasonable quantity of exchangeable Mg and has a Mg : K ratio in favour of Mg

    Studies on barley starch

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    Elastase-alpha1-proteinase inhibitor complex

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    Extraction and characterization of phosphorus from organic algal biochar

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    Algae has become a major research focus in the past few years. Treatments such as pyrolysis, hydrothermal carbonization, hydrothermal liquefaction, hydrothermal gasification are being used to process algae and yield products such as lipids, lipid-rich hydrochar, biocrude, methane and hydrogen. These treatments also produce biochars as a product of thermal decomposition of organic material under limited supply of oxygen at temperatures less than 700oC. Biochars have potential for use as a soil amendment, both to improve soil quality and to sequester carbon. Algal biochar used in this study was produced by hydrothermal liquefaction of algae at 350oC which was grown at Lawrence Wastewater Treatment Plant using municipal wastewater as the feedstock. This biochar was black in color, very smooth & powdery in texture and tremendously hydrophobic in nature. This study was aimed at extraction and characterization of phosphorus from this organic algal biochar. Since biochars are often used as a mixture with soils and there are no currently established methods for extraction of phosphorus from biochars, various soil P extraction methods were studied and investigated to be used on this biochar. For estimation of total P, acid digestion of biochar with sulphuric acid was attempted, but failed to achieve good digestion. Microwave acid digestion was tried with different combinations of acids, with reverse aqua regia (HCl:HNO3::1:3) working best to digest this algal biochar. Most elements that were analyzed in the biochar, including Ca and P were present in biochar at a higher concentration than in algae. ICP analysis of the digested samples gave a total P content of 7.4±0.58 % by wt. which was 3.2 times the total P in algae (2.3±0.03% by. wt.). Similarly, a high amount of total Ca was also found in the biochar (17.10±1.31% by wt.) as compared to 5.70±0.18% by wt. in algae. Approximately 89% of calcium and 95% of phosphorus initially present in the algae were recovered from the biochar after hydrothermal liquefaction. Because of the high Ca content, it was thought that P in char might be mostly present as calcium phosphates. The Olsen Method was used to estimate bioavailable phosphorus from biochar because it is best suited for calcareous soils. On ICP analysis, a very small fraction (less than 1%) of total P in algal biochar was found to be extractable by the Olsen reagent. However, when shaking time was doubled from 30 minutes to 60 minutes in Olsen method, the amount of soluble P doubled from 287±110 ppm to 581±116 ppm. This meant that the calcium associated P in biochar may slowly release over time. Water extraction was completely ineffective in extracting any P from biochar. These low Olsen and water extraction P results may be because of insufficient contact of biochar with reagents owing to its hydrophobicity. Biochar was difficult to mix well with reagents for estimation of bioavailable P due to its hydrophobic nature. Heating at 105oC overnight to get rid of the volatile organic fractions did not improve mixing. This study provides a preliminary idea of the nature of P in this biochar. Based on the extraction results, it appears that P in this biochar is mostly unavailable to plants. Hydrophobic nature of biochar may hinder its ability to mix well with soil and thus it may need to be treated before being used for soil amendment. There is scope for further research on this biochar including testing it with different extraction methods, performing extractions after washing biochar with an organic solvent, engineering the hydrophobicity of this biochar by altering the production conditions, and studying the actual long-term release of P under real or simulated field conditions
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