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161.
The common thread of energy release suggests that diverse microbial metabolic processes can be compared through thermodynamic analyses. The resulting energy and power requirements can provide quantitative constraints on habitability. Because previous thermodynamic analyses have focused on the minimum amount of energy needed for the growth of a microorganism or community, the focus of this study is to gain a fuller understanding of the microbial response to highly habitable conditions. This communication summarizes the results of a thermodynamic analysis of the energy and power consumed by microorganisms in experiments that were designed to optimize growth. Reports of microbial growth experiments taken from the literature were combined with speciation and standard state calculations to assess the overall Gibbs energy change during the experiments. Results show that similar numbers of cells (10(9) to 10(10) ) were produced in these experiments regardless of the duration of log phase growth (from <2 to >200 hours) or the total Gibbs energy change [from 1.3-29.6 kJ (mol electrons transferred)(1)]. As a result, optimal growth conditions appear to produce between 10(10) and 10(14) cells per watt of power consumed. 相似文献
162.
This paper considers the issue of direct and indirect effects of lightning strikes on aircraft. It is proposed to study electromagnetic fields and interferences that affect aircraft instruments based on the theory of large-scale experiment. 相似文献
163.
S. Z. Sverdlov 《Russian Aeronautics (Iz VUZ)》2017,60(2):163-168
In this paper, it is proposed the flight duration to be assessed by the potential value and the helicopter number. The data on the available power and the relative efficiency for a number of multicopter models are provided. 相似文献
164.
In this paper, the finite element analysis of the stress-strain state for cylindrical structures is discussed. In this case, various fundamental hypotheses can be used in the framework of a model that is of interest for design and optimization. Numerical examples are presented to evaluate the possibilities of this model. 相似文献
165.
The major features of President Obama’s new US space policy are discussed and particular aspects are compared with those of the previous Bush policy. In many cases there are similarities of substance but the tone of the latest policy is more outward looking and inclusive, with a far greater emphasis on cooperation, both internationally and with the private sector. And while some complain that the policy does not sufficiently emphasize US leadership, a statement by President Obama on the day of its release makes clear that this remains a paramount goal. Serious questions remain, however, about implementation of the new policy, particularly where it requires substantial government funding such as human spaceflight and the restructured weather/environmental satellite programs. 相似文献
166.
W.B. Rossow F. Mosher E. Kinsella A. Arking M. Desbois E. Harrison P. Minnis E. Ruprecht G. Sèze E. Smith 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(6):185
The International Satellite Cloud Climatology Project (ISCCP) will provide a uniform global climatology of satellite-measured radiances and derive a climatology of cloud radiative properties from these radiances. For this purpose, a pilot study of cloud analysis algorithms was initiated to define a state-of-the-art algorithm for ISCCP. This study compared the results of applying the nine different algorithms to the same satellite radiance data. The comparison allowed for a sharper understanding of the process of detecting clouds and shows that all algorithms can be improved by better information about clear sky radiance values (essentially equivalent to surface property information) and by better understanding of cloud size distribution variations. The dependence of all methods on cloud size distribution led to selection of an advanced bispectral threshold technique for ISCCP because this method is currently better understood and more developed. Further research on cloud algorithms is clearly suggested by these results. 相似文献
167.
J.-P. Treilhou T.V. Kozelova L.L. Lazutin V.G. Petrov I.Z. Zhulin A. Pedersen R. Pellinen W.K. Riedler G. Marklund 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(4):163-169
Measurements of the electric field in the ionosphere and the equatorial plane during the pre-onset and actives phases of a substorm (March 4, 1979) are compared. Correlations and disagrements between the measurements are considered. The preliminary conclusion is reached that the model of electrojet polarisation proposed by CORONITI and KENNEL (1972) could possibly explain part of our observations. 相似文献
168.
M. Hayosh Z. Nme
ek J. afrnkov G.N. Zastenker 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2005,36(12):2417-2422
The magnetosheath plays a dominant role in the Sun–Earth connection because the magnetosheath field and plasma actually interact with the magnetosphere. The interactions change the magnetospheric magnetic field from its nominal value through a long chain of different processes. The change is usually described by geomagnetic indices and thus it can be expected that these indices would reflect changes in the magnetosheath. The present paper analyzes the relation between geomagnetic activity characterized by changes of the Kp, DST and AE indices and ion flux measured in the night-side magnetosheath. The results suggest a weak dependence of the DST index on the ion flux in the inner magnetosheath that is connected with a magnetopause displacement. On the other hand, fluctuations of the ion flux in the analyzed frequency range do not correlate with any of the indices. 相似文献
169.
X Zhang X B Li S Z Yang S G Li P D Jiang Z H Lin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,32(8):1577-1583
Using the cultured chicken embryonic chondrocytes as a model, the effects of simulated microgravity on the microtubular system of the cellular skeleton, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration and mitochondrial ATP synthase activity with its oligomycin inhibition rate were studied with a clinostat. The microtubular content was measured by a flow cytometer. The decrease of microtubular content showed the impairment of the cellular skeleton system. Observation on the extracellular matrix by the scanning electron microscopy showed that it decreased significantly after rotating, and the fibers in the extracellular matrix were more tiny and disorderly than that of the control group. It can be concluded that the simulated microgravity can affect the secreting and assembly of the extracellular matrix. In contrast to the control, there was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization. Meanwhile a significant drop in the intracellular calcium concentration happened at the beginning of rotation. These results indicate that simulated microgravity can suppress matrix calcification of cultured chondrocytes, and intracellular free calcium may be involved in the regulation of matrix calcification as the second signal transmitter. No significant changes happened in the mitochondrial ATP synthase activity and its oligomycin inhibition rate. Perhaps the energy metabolism wasn't affected by the simulated microgravity. The possible mechanisms about them were discussed. 相似文献
170.
Melanie J Correll Katrina M Coveney Steven V Raines Jack L Mullen Roger P Hangarter John Z Kiss 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,31(10):2203-2210
Phototropism as well as gravitropism plays a role in the oriented growth of roots in flowering plants. In blue or white light, roots exhibit negative phototropism, but red light induces positive phototropism in Arabidopsis roots. Phytochrome A (phyA) and phyB mediate the positive red-light-based photoresponse in roots since single mutants (and the double phyAB mutant) were severely impaired in this response. In blue-light-based negative phototropism, phyA and phyAB (but not phyB) were inhibited in the response relative to the WT. In root gravitropism, phyB and phyAB (but not phyA) were inhibited in the response compared to the WT. The differences observed in tropistic responses were not due to growth limitations since the growth rates among all the mutants tested were not significantly different from that of the WT. Thus, our study shows that the blue-light and red-light systems interact in roots and that phytochrome plays a key role in plant development by integrating multiple environmental stimuli. 相似文献