Soybean cultivar selection for Bioregenerative Life Support Systems (BLSSs) – Hydroponic cultivation

Four soybean cultivars (‘Atlantic’, ‘Cresir’, ‘Pr91m10’ and ‘Regir’), selected through a theoretical procedure as suitable for cultivation in BLSS, were evaluated in terms of growth and production. Germination percentage and Mean Germination Time (MGT) were measured. Plants were cultivated in a growth chamber equipped with a recirculating hydroponic system (Nutrient Film Technique). Cultivation was performed under controlled environmental conditions (12 h photoperiod, light intensity 350 μmol m⁻² s⁻¹, temperature regime 26/20 °C light/dark, relative humidity 65–75%). Fertigation was performed with a standard Hoagland solution, modified for soybean specific requirements, and EC and pH were kept at 2.0 dS m⁻¹ and 5.5 respectively.     

CO_2激光烧蚀水所形成气蚀空穴机理研究

分析了激光烧蚀液体时形成表面空穴的机理。利用高速相机获得CO2激光烧蚀蒸馏水的流场照片,对空穴的发展过程进行了分析,发现空穴的快速发展期在最初的100μs内,之后在几百μs内保持平衡。用简单模型计算了不同能流密度下,空穴平衡时的形状,并分析了模型的局限性。研究结果对于揭示激光烧蚀水产生推力的机理有重要意义,有利于促进水工质激光推进的发展。     

Wireless Sensor Networks – A potential tool to probe for water on Moon

A Wireless Sensor Network for in situ probing of lunar water/ice is proposed. The mission scenario in single and multi-tier architectures for probing water in a permanently shadowed region of the Moon and different scenarios of exploration are discussed. The ideas presented in the paper are a positive assertion of feasibility for the sensor node hardware, given current levels of technological advancements.     

Development of a gas chromatography compatible Sample Processing System (SPS) for the in-situ analysis of refractory organic matter in martian soil: preliminary results

In the frame of the 2009 Mars Science Laboratory (MSL) mission a new sample preparation system (SPS) compatible with gas chromatography–mass spectrometry (GC–MS) has been developed for the in situ analysis of complex organic molecules in the Martian soil. The goal is to detect, if they exist, some of the key compounds that play an important role in life on Earth including carboxylic acids, amino acids and nucleobases.     

镁基水反应金属燃料的热分解性能

采用热重-差热分析联用(TG-DTA)、差示扫描量热(DSC)、加压热重(PTG)等热分析方法,研究了镁基水反应金属燃料热分解反应的基本特性及其变化规律。研究发现,燃料热分解过程中先后发生AP分解反应、HTPB分解反应,氩气中不发生Mg的氧化反应;添加催化剂、减小AP粒度、增大氧化剂与粘合剂比例、增大细Mg粉含量等,可以降低燃料中AP的分解温度T,减小表观活化能Ea,增大反应速率常数k;减小AP粒度、增大氧化剂与粘合剂比例可以降低燃料中HTPB的分解温度,减小表观活化能Ea,增大反应速率常数k;随着压强增大,AP与HTPB分解失重速率增大、AP失重百分数增大、燃料热分解凝聚相产物质量百分数减少,压强对AP分解影响较大,对HTPB分解影响较小。     

制泥废水及烧结废水的处理与回用

通过对处理制泥废水及烧结废水工艺、设备、措施及综合利用进行了详细的描述,对拟用新措施将污水二次处理预期达到饮用及绿化水标准提出了建设性的设想,采用现代计算机FLASH软件将生产工艺制作成动画演示,强化了工厂管理体系.     

压缩空气瓶内凝结水水位检测方法的探讨

由于压缩空气瓶在使用过程中会出现瓶内残留凝结水的现象,从而影响压缩空气瓶的容积,并产生化学腐蚀,影响气瓶的整体强度和耐压性能及其的寿命。为此,应掌握气瓶内凝结水水位情况,并且提高检测水位准确度。提出了一种利用气体状态方程来计算压缩空气瓶的冷凝水水位新见解,对压缩空气瓶的安全使用具有重要意义。     

Kinetics of gas-Grain Reactions in the Solar Nebula

Thermochemical equilibrium calculations predict gas phase, gas-grain, and solid phase reactions as a function of pressure and temperature in the solar nebula. However, chemical reactions proceed at different rates, which generally decrease exponentially with decreasing temperature. At sufficiently low temperatures (which vary depending on the specific reaction) there may not have been enough time for the predicted equilibrium chemistry to have taken place before the local environment cooled significantly or before the gaseous solar nebula was dispersed. As a consequence, some of the high temperature chemistry established in sufficiently hot regions of the solar nebula may be quenched or frozen in without the production of predicted low temperature phases. Experimental studies and theoretical models of three exemplary low temperature reactions, the formation of troilite (FeS), magnetite (Fe₃O₄), and hydrous silicates, have been done to quantify these ideas. A comparison of the chemical reaction rates with the estimated nebular lifetime of 0.1-10 million years indicates that troilite formation proceeded to completion in the solar nebula. Magnetite formation was much slower and only thin magnetite rims could have formed on metal grains. Hydrous silicate formation is predicted to be even slower, and hydrous silicates in meteorites and interplanetary dust particles probably formed later on the parent bodies of these objects, instead of in the solar nebula. This revised version was published online in June 2006 with corrections to the Cover Date.     

An assessment of semi-analytical models based on the absorption coefficient in retrieving the chlorophyll-a concentration from a reservoir

Monitoring chlorophyll-a (Chl-a) concentrations in inland waters is crucial for water quality management, since Chl-a is a proxy for phytoplankton biomass and, thus, for ecological health of a water environment. Chl-a concentration can be retrieved through the inherent optical properties (IOPs) of a water system, which, in turn, can be remotely sensed obtained. Quasi-analytical algorithm (QAA), originally developed for ocean waters, can also retrieve IOPs for inland waters after re-parameterizations. This study is aimed at assessing the performance of sixteen schemes composed by QAA original and re-parameterized versions followed by models that use absorption coefficients as inputs for estimating Chl-a concentration in Ibitinga reservoir, located at Tietê River cascading system, São Paulo State, Brazil. It was verified that only QAA_V5 based schemes were able to obtain reasonable estimates for image data and that by four models tested presented similar and acceptable results for QAA_V5 outputs. The best model were applied to a Ocean and Land Colour Instrument (OLCI) image. Light absorption in the reservoir showed to be dominated by colored dissolved organic matter (CDOM), and wide spatial and temporal variability of optical and water quality properties was observed.     

Implicit discontinuous Galerkin method on agglomerated high-order grids for 3D simulations

High quality of geometry representation is regarded essential for high-order methods to maintain their high-order accuracy. An agglomerated high-order mesh generating method is inves-tigated in combination with discontinuous Galerkin (DG) method for solving the 3D compressible Euler and Navier-Stokes equations. In this method, a fine linear mesh is first generated by standard commercial mesh generation tools. By taking advantage of an agglomeration method, a quadratic high-order mesh is quickly obtained, which is coarse but provides a high-quality geometry represen-tation, thus very suitable for high-order computations. High-order discretizations are performed on the obtained grids with DG method and the discretized system is treated fully implicitly to obtain steady state solutions. Numerical experiments on several flow problems indicate that the agglomer-ated high-order mesh works well with DG method in dealing with flow problems of curved geome-tries. It is also found that with a fully implicit discretized system and a p-sequencing method, the DG method can achieve convergence state within several time steps which shows significant effi-ciency improvements compared to its explicit counterparts.