Structure and methanogenic activity of granules from an ASBR treating dilute wastewater at low temperatures

1997 ◽  
Vol 36 (6-7) ◽  
pp. 149-156 ◽  
Author(s):  
Gouranga C. Banik ◽  
Timothy G. Ellis ◽  
Richard R. Dague
Keyword(s):  
Electron Microscopy ◽  
Low Temperatures ◽  
Significant Variation ◽  
Uniform Structure ◽  
Microbial Structure ◽  
Methanogenic Activity ◽  
Transmission Electron ◽  
Dry Milk ◽  
Specific Methanogenic Activity ◽  
Role Activity

The microstructure of ASBR granules treating synthetic substrate consisting of non-fat-dry-milk at temperatures of 5, 15 and 25°C was analyzed by scanning and transmission electron microscopy. The specific methanogenic activity of the granules was tested at 35°C using acetate and mixtures of acetate and propionate as substrates. Results revealed no significant variation in microbial structure for the different temperature conditions. Granules at 15 and 25°C exhibited uniform structure, predominantly Methanothrix-like microorganisms, while granules at 5°C indicated the existence of a layered structure. This reinforces the hypothesis that layering is largely substrate specific, but also suggests that temperature may have a role. Activity tests revealed that even after long periods of operation at psychrophilic temperatures, mesophilic bacteria are active and have the ability to rapidly degrade acetate and mixtures of acetate and propionate.

Ultrastructure of the soil fungus, Geomyces pannorus

1984 ◽  
Vol 42 ◽  
pp. 738-739
Author(s):  
J. A. Traquair ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
Low Temperatures ◽  
Soil Fungus ◽  
Organic Soils ◽  
Anatomical Studies ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Scanning Electron

With the advent of improved dehydration techniques, scanning electron microscopy has become routine in anatomical studies of fungi. Fine structure of hyphae and spore surfaces has been illustrated for many hyphomycetes, and yet, the ultrastructure of the ubiquitous soil fungus, Geomyces pannorus (Link) Sigler & Carmichael has been neglected. This presentation shows that scanning and transmission electron microscopical data must be correlated in resolving septal structure and conidial release in G. pannorus.Although it is reported to be cellulolytic but not keratinolytic, G. pannorus is found on human skin, animals, birds, mushrooms, dung, roots, and frozen meat in addition to various organic soils. In fact, it readily adapts to growth at low temperatures.

Structural Properties of Amorphous Silicon Produced by Electron Irradiation

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yamasaki ◽  
S. Takeda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Distribution Function ◽  
Structural Properties ◽  
Electron Irradiation ◽  
Low Temperatures ◽  
Crystalline Silicon ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Means Of Transmission

AbstractThe structural properties of the amorphous Si (a-Si), which was created from crystalline silicon by 2 MeV electron irradiation at low temperatures about 25 K, are examined in detail by means of transmission electron microscopy and transmission electron diffraction. The peak positions in the radial distribution function (RDF) of the a-Si correspond well to those of a-Si fabricated by other techniques. The electron-irradiation-induced a-Si returns to crystalline Si after annealing at 550°C.

Effects of Dopants on the Nucleation and Growth of NiSi2 on Silicon

1987 ◽  
Vol 94 ◽  
Author(s):  
S. W. Lu ◽  
C. W. Nieh ◽  
J. J. Chu ◽  
L. J. Chen
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Low Temperatures ◽  
Nucleation And Growth ◽  
The Other ◽  
Size Factor ◽  
Atomic Size ◽  
Nickel Thin Films ◽  
Transmission Electron

ABSTRACTThe influences of implantation impurities, including BF2, B, F, As and P on the formation of epitaxial NiSi2 in nickel thin films on ion-implanted silicon have been investigated by transmission electron microscopy.The presence of BF2, B, and F atoms was observed to promote the epitaxial growth of NiSi2 at low temperatures. Little or no effect on the formation of NiSi2 was found in samples implanted with As or P ions.The results indicated that the influences of the implantation impurities are not likely to be electronic in origin. Good correlation, on the other hand, was found between the atomic size factor and resulting stress and NiSi2 epitaxy at low temperatures.

Synthesis of Carbon Nanosphere at Low Temperatures Based on Bamboo Fiber

2019 ◽  
Vol 966 ◽  
pp. 163-168 ◽  
Author(s):  
Yulia Kirana Lahsmin ◽  
Dahlang Tahir ◽  
Bualkar Abdullah ◽  
Sultan Ilyas ◽  
Inayatul Mutmainna
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperatures ◽  
Potassium Hydroxide ◽  
Bamboo Fiber ◽  
X Ray Diffraction ◽  
Activation Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Bamboo Fibers

Carbon Nanosphere (CNs) has been successfully synthesized from bamboo fibers at low temperatures by carbonization and activation. For activation used Potassium Hydroxide (KOH) at temperature 105°C, 155°C, 205°C, 255°C and 305°C. X-Ray Diffraction (XRD) spectra shows hexagonal and amorphous phase and Fourier Transform Infrared (FTIR) spectra shows decrease C-O bond with increasing activation temperature. Transmission Electron Microscopy (TEM) image for activation temperature of 105°C confirmed that sources the formation of Carbon Nanosphere. In this study shows bamboo fiber has a high potential as a carbon nanosphere material.

Crystallization of Al-Gd-La-Ni Metallic Glasses

1999 ◽  
Vol 580 ◽  
Author(s):  
T.K. Croat ◽  
A.K. Gangopadhyay ◽  
K.F. Kelton
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metallic Glasses ◽  
Low Temperatures ◽  
Alloy Composition ◽  
Composition Range ◽  
Scanning Calorimetry ◽  
Crystallization Sequence ◽  
Transmission Electron ◽  
Kinetics Of

AbstractThe crystallization kinetics of Al-Gd-La-Ni metallic glasses to nanostructured phases are analyzed using differential scanning calorimetry and transmission electron microscopy. In a narrow alloy composition range near Al88Gd6La2Ni4, TEM reveals an amorphous phase separation that occurs upon annealing at low temperatures prior to crystallization. Al-enriched regions, typically 40 nm in diameter, bounded by rare-earth rich regions, are visible. Upon crystallization, α-Al forms preferentially at the interface between these phase separated regions. The relevance of this crystallization sequence to previous work in Al-RE-TM glasses and to the evolution of nanoscale microstructures common in the crystallization of other metallic glasses are discussed.

Sonochemical synthesis of large-scale single-crystal PbS nanorods

2003 ◽  
Vol 18 (5) ◽  
pp. 1188-1191 ◽  
Author(s):  
S. M. Zhou ◽  
Y. S. Feng ◽  
L. D. Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Large Scale ◽  
Three Dimensional ◽  
Ultrasound Irradiation ◽  
Building Blocks ◽  
Uniform Structure ◽  
X Ray ◽  
Transmission Electron

Large-scale single-crystal cubic PbS nanorods were successfully achieved by using ultrasound irradiation in certain ethylenediamine tetraacetic acid (EDTA) solutions, particularly in the solution of Pb:EDTA = 1:1. The obtained PbS nanorods were characterized using x-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersed x-ray spectrometry, selected area electronic diffraction, and high-resolution transmission electron microscopy. The results reveal that the PbS nanorods with straight and uniform structure have a diameter of about 70–80 nm and length of about 1000 nm, where the growth mechanism is tentatively discussed. The successful synthesis of these cubic structure semiconductor PbS nanorods may open up new possibilities for using these materials as building blocks to create functional two-dimensional or three-dimensional nanostructured materials.

Microbial structure and activity of UASB granules treating different wastewaters

1994 ◽  
Vol 30 (12) ◽  
pp. 87-96 ◽  
Author(s):  
H. H. P. Fang ◽  
H. K. Chui ◽  
Y. Y. Li
Keyword(s):  
Layered Structure ◽  
Soluble Carbohydrates ◽  
Uniform Structure ◽  
Supporting Evidence ◽  
Structural Element ◽  
Methanogenic Activity ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Uasb Granules ◽  
And Diffusion

The microstructure of three types of UASB granules respectively treating sucrose, glutamate and brewery wastewaters in mesophilic conditions were analyzed by light, scanning electron and transmission electron microscopies, along with the specific methanogenic activity (SMA) of the granules. Results showed that the granule's microstructure was dependent on the nature of the substrate. Those degrading soluble carbohydrates exhibited a layered structure, while those degrading glutamate exhibited a rather uniform structure. Such a difference was explained based on the substrate's rates of acidogenesis and diffusion. A model of the typical layered structure was proposed. In addition, the acetoclastic Methanothrix was found as the key structural element in all the granules, suggesting that it plays an important role in granulation. Three types of syntrophic microcolonies were found to be abundant in granules degrading soluble carbohydrates: two were juxtapositioned syntrophic microcolonies, each was composed of hydrogen-producing acetogens and hydrogen-consuming methanogens, while the third was a cluster-type of syntrophic association between two microcolonies. The SMA data using individual VFA as substrate provided supporting evidence to the observations of the bacterial compositions in the granules.

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