A gaseous mixture containing 4. Glacial deposits often form at high latitudes near the poles. Explain why glacial deposits have been found in Africa. Read the summary. Babylon was in the heartland of Mesopotamia, the site of the First Agricultural Revolution 1. Based on cuneiform writings on clay tablets, researchers know that farm products included sesame, barley, and dates,.
You can view more similar questions or ask a new question. Questions Science Why do deposits form in the steam vents of irons in parts of the country? So far I have the the Up Country is the north and the Low Country is the south, as well as that the low country mainly the Southern Social Studies Which of the following is an example of specializing in the service sector?
Which of the Economics The table shows the amounts held as the various components of M1 and M2. Calculate the mass of steam in the vessel, the final pressure of the steam and the heat Chem Very hot zinc will react with steam to form zinc oxide and hydrogen. World History Read the summary. Log in. So they asked us, Why do long steam pipes often have one or more relatively large U shaped sections of pipe? Um, I'm assuming I'm not exactly what they're kind of saying here, but I'm assuming they have kind of an s shape.
Well, I guess this is a Z shape or reverse a shape section of pipe. I'm assuming that they mean like that. I'm not just that it, you know, because there's really no point of having a pipe where it just comes back to itself. So I'm assuming that they mean this, Um and so if they mean that, then it's probably it's because, um, you know, with it's a steam pipe.
So again, it's going to assuming that, um, you know, sometimes there's steam and it sometimes there isn't steaming, and it's gonna have quite a bit of change of temperature because, as you know, as the steam goes through, um, it's gonna change the temperature of the pipe wall, and that's gonna want to make it thermally expand.
And so, if you just have a straight pipe wall and you have a kind of fixed at both ends, you should have a straight pipe and it wants to thermally expand. It's going to basically have to compress compress itself. It's going to be under a lot of compression here because it wants to expand. But it can't. And it might actually buckle, um, like, basically was shown in the in the chapter with the railroads Uh, the railroad tracks, Um, so, you know, in in, like with railroad tracks and other things, you can usually put like a small joint in there so you can make a little gap.
So as one section expands the other, you know, they can expand and fill this gap. Um, that's again a lot of reasons you see the, you know, expansion joints, basically also in Woodford. At your two, you have expansion joints because as the wood, um, swells and contracts as it absorbs moisture and and, you know, dries out. Um, you need expansion crack. You know, the expansion joints to allow for that, um, so that you don't get cracking in the wood or buckling in the wood.
So I think these are This is basically the problem is with the pipe, you can't have an expansion joint, right, because you need to have at least to be continuous. So this is essentially an expansion joint, um, in in a steam pipe. And why that is, is that basically allows, you know, this the pipe to bend in these regions instead of actually compressed.
And, you know, these pipes are generally going to be much, much less stiff in bending than they are in to stretch them.
So you know, you're going to have less stress is here, um, in these in these in these corner regions. And if you just had a straight pipe here and it was basically under compression, the other reason I could think of to if you really do have we're talking about you sections like this. Um, that would probably be if there was water condensing in there and you wanted to drain the water off.
The phylogeny of AOA crenarchaea has been the subject of a recent proposal for a third phylum within the Archaea: Crenarchaeota, Euryarchaeota and newly proposed Thaumarchaeota for marine planktonic Crenarchaea and closely related organisms Brochier-Armanet Clones from Hawaii nonsulfur steam deposits branched monophyletically were closely related to AOA. If these Hawaii organisms can be demonstrated by enrichment culture, amo A gene sequences or other methods to be AOA then this represents a new AOA habitat.
The number of published uncultured Crenarchaeota sequences continues to grow exponentially Hershberger et al. Nevertheless, our analysis uncovered many novel archaeal lineages and nonsulfur steam deposits appear to be rich sources of novel thermophilic Archaea.
Microscopic investigation found that enrichment cultures grew Archaea-like cells from the majority of the steam deposit samples Fig. Based on visual identification by microscopy, 10 of the cultures had spherical Archaea-like cells and all except one of the enrichment cultures had rod-shaped Bacteria-like cells Table 5.
Despite the clear evidence of the Archaea-like cells, and the confirmation of Archaea from the clone libraries, we only obtained six pure archaeal isolates from four different sulfur-type vents. All of these isolates were related to cultured and uncultured Sulfolobus or Acidianus , although they appeared to be distantly related to cultured organisms based on the blast identity values Table 6. Both Sulfolobus and Acidianus are able to grow aerobically, oxidizing sulfur or iron. The ability of Acidianus to change its mode of metabolism from aerobic to anaerobic in response to its environment likely explains the recurrent appearance of this organism in cultures isolated from high-temperature steam deposits present in cave and vent steam deposits.
Crenarchaeota were enriched from the nonsulfur vents, but we were unable to isolate organisms in pure culture. The Archaea from in these enrichments always grew with Bacteria on the Gelrite overlays, and we were not able to separate the archaeal isolates from bacterial isolates on the Gelrite.
With the exception of one set of sequences that were closely related to a cultured autotroph high-temperature ammonia oxidizer Candidatus Nitrosocaldus yellowstonii , the Archaea found in the nonsulfur vents were highly divergent from any well-characterized organisms, making physiological inferences uncertain.
The fact that silica and oxygen were the main components in the nonsulfur deposits Fig. Interestingly, ammonia was one of the most abundant nutrients in the steam vent deposits, especially in the nonsulfur vents Table 2 , suggesting that ammonia oxidation may also be important in these habitats. Futher work, including attempts to cultivate ammonia oxidizers, is needed to determine whether these vent deposit Archaea are autotrophic or whether they are obligate symbionts as members of the complex bacterial communities in these steam deposits.
These enrichment cultures may also be a ready source of interesting new hyperthermophilic archaeal viruses Snyder et al. Our culture-based studies showed that organisms clearly survive at the measured steam deposit temperatures.
It is generally difficult to grow novel thermophilic organisms from environmental samples and the likelihood for success was low because we used only a single pH and a single temperature.
In addition, the laboratory culture incubation temperature was much lower than what we measured in the steam vents. In spite of using a single pH and a lower incubation temperature, the enrichment cultures grew well Table 5. Furthermore, the isolated microorganisms made a great deal of sense, given the habitats e. Sulfolobales in sulfur steam deposits; Table 6. The fact that we obtained cultures at a lower temperature supports the idea that a range of temperatures may exist for these organisms, and it is possible that optimum temperature for growth may not coincide with the environmental temperature.
Nevertheless, the steam deposit environments have rich microbial communities that are continually bathed in very hot steam and many of the organisms present likely grow optimally at these temperatures e.
Acidianus relatives. Although the main focus of our study was on the presence and diversity of Archaea in steam vent deposits, we also report the discovery of bacterial 16S rRNA gene sequences from four of the HAVO steam vent deposit communities.
Overall, the Bacteria of these communities appeared to be more diverse than the Archaea and many of the 16S rRNA gene sequences we determined are from organisms that had no cultured representatives Table 4. The nonsulfur caves contained nonphotosynthetic Bacteria Planctomycetes similar to those found in the Red Layer Microbial Observatory Boomer et al. Our studies of the bacterial communities are quite preliminary at this point, but certainly confirm our ability to derive bacterial sequences from these environments, confirming the results of Mayhew et al.
Further study of these unknown steam deposit organisms will provide a better understanding of the bacterial communities in fumarole deposits. The diversity of steam deposits raises the fundamental question of whether the organisms detected in this study arose from the subsurface or by some other means such as aerial movement Bonheyo et al.
The steam vents we studied were similar in many respects to flowing hot springs, with a continual discharge from the subsurface along an aquifer or a silica-lined exit channel. Also, like flowing springs, steam vent water carries both Archaea and Bacteria to the surface, where they can be detected in condensed samples Ellis et al. However, direct evidence for this is presently lacking, leaving this a fertile area for future study. We wish to thank Eyobed Worku and Ann McAfee for their help with the culturing of steam deposit microorganisms.
Schering-Plough Biopharma provided financial support and assistance for this study. Finally, we thank the editor and anonymous reviewers for their helpful comments on the manuscript.
Eos T Am Geophys Un Google Scholar. Google Preview. Appl Environ Microb 75 : — Nat Rev Microbiol 6 : — Springer-Verlag , New York. Geol Soc Am Bull 86 : — Nucleic Acids Res 33 : D — D Environ Microbiol 10 : — Frank DN XplorSeq: a software environment for integrated management and phylogenetic analysis of metagenomic sequence data. BMC Bioinformatics 9 : Environ Chem 3 : — J Microbiol Meth 70 : 1 — Nature : Microbes Environ 23 : — Jones ME Ammonia equilibrium between vapor and liquid aqueous phases at elevated temperatures.
J Phys Chem 67 : — Butterworths , London. Nature : — Nucleic Acids Res 32 : — Appl Environ Microb 73 : — Geomicrobiol J 24 : — Int J Syst Evol Micr 57 : — Curr Opin Microbiol 8 : — Nov: facultatively aerobic, extremely acidophilic thermophilic sulfur-metabolizing Archaebacteria.
Int J Syst Bacteriol 36 : — Geomicrobiol J 23 : — Res Microbiol : — Sinauer , Sunderland, MA. Microbes Environ 19 : 13 — Appl Environ Microb 76 : — Curr Microbiol 53 : — Supplement S2. Principal component analysis.
Supplement S6. Table S1. Comparative summary of environmental DNA extraction methods. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries other than missing material should be directed to the corresponding author for the article. Oxford University Press is a department of the University of Oxford.
It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Abstract. Materials and methods. Supporting Information. Microbial diversity in nonsulfur, sulfur and iron geothermal steam vents. Benson , Courtney A.
Oxford Academic. Richard W. David A. Scott T. Correspondence: Scott T. Revision received:. Cite Cite Courtney A. Select Format Select format. Permissions Icon Permissions.
Abstract Fumaroles, commonly called steam vents, are ubiquitous features of geothermal habitats. Open in new tab Download slide. ND, not determined. Open in new tab.
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