pH and Organic Carbon Dose Rates Control Microbially Driven Bioremediation Efficacy in Alkaline Bauxite Residue

2016 ◽  
Vol 50 (20) ◽  
pp. 11164-11173 ◽  
Author(s):  
Talitha C. Santini ◽  
Laura I. Malcolm ◽  
Gene W. Tyson ◽  
Lesley A. Warren
Keyword(s):  
Organic Carbon ◽  
Bauxite Residue ◽  
Dose Rates

scholarly journals Improvement of aggregate‐associated organic carbon and its stability in bauxite residue by substrate amendment addition

2020 ◽  
Vol 31 (16) ◽  
pp. 2405-2416
Author(s):  
Tao Tian ◽  
Zheng Liu ◽  
Feng Zhu ◽  
William Hartley ◽  
Yuzhen Ye ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Bauxite Residue ◽  
Substrate Amendment

scholarly journals The Effects of Holocene Podzolisation on Radionuclide Distributions and Dose Rates in Sandy Coastal Sediments

2008 ◽  
Vol 31 (-1) ◽  
pp. 53-63 ◽  
Author(s):  
Asger Nielsen ◽  
Andrew Murray
Keyword(s):  
Organic Carbon ◽  
Parent Material ◽  
Luminescence Dating ◽  
Coastal Sediments ◽  
Geochemical Data ◽  
Organic Carbon Content ◽  
Additional Material ◽  
Dose Rates ◽  
Radionuclide Distribution ◽  
Extractable Iron

The Effects of Holocene Podzolisation on Radionuclide Distributions and Dose Rates in Sandy Coastal SedimentsThis study analyses the effect of a specific kind of soil development, podzolisation, on selected radionuclide concentrations and the derived dose rates. 100 samples from four sandy, podzolised regions in Jutland, Denmark, were dated by luminescence dating. Dose rates were determined by gamma spectrometry. Of the 100 samples, 31 were retrieved from three profiles intersecting soil horizons affected by podzolisation. At 35 locations, additional material was collected for supplementary geochemical analyses (soil pH, organic carbon content and extractable iron and aluminium). The geochemical data and grain size data were correlated with radionuclide activity concentrations. These correlations do not indicate any significant relationship between organic carbon or extractable iron/aluminium and radionuclide concentrations; this suggests that the radionuclides are mainly internally bound in primary minerals, unlike the extractable iron, which is generally associated with surface coatings. We conclude that the radionuclide distribution in these young sandy soils has been relatively unaffected by the podzolisation process. Thus it appears that the dose rate at these sites is unlikely to have changed significantly with time as a result of podzolisation, because the parent material is relatively unweathered and the activity is dominated by internally bound radionuclides.

Effects of natural weathering processes on the distribution characteristics of organic carbon and its composition in bauxite residue aggregates

2017 ◽  
Vol 37 (4) ◽  
Author(s):  
朱锋 ZHU Feng ◽  
李萌 LI Meng ◽  
薛生国 XUE Shengguo ◽  
邹奇 ZOU Qi ◽  
吴昊 WU Hao ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Bauxite Residue ◽  
Natural Weathering ◽  
Distribution Characteristics ◽  
Weathering Processes

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Electron Beam Damage of Biomolecules Assessed by Energy Loss Spectroscopy

1978 ◽  
Vol 36 (3) ◽  
pp. 61-69
Author(s):  
M. Isaacson ◽  
M.L. Collins ◽  
M. Listvan
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Structural Integrity ◽  
Analytical Electron Microscopy ◽  
High Dose ◽  
Dose Rates ◽  
Special Cases ◽  
Analytical Electron ◽  
Atom Migration ◽  
Beam Damage

Over the past five years it has become evident that radiation damage provides the fundamental limit to the study of blomolecular structure by electron microscopy. In some special cases structural determinations at very low doses can be achieved through superposition techniques to study periodic (Unwin & Henderson, 1975) and nonperiodic (Saxton & Frank, 1977) specimens. In addition, protection methods such as glucose embedding (Unwin & Henderson, 1975) and maintenance of specimen hydration at low temperatures (Taylor & Glaeser, 1976) have also shown promise. Despite these successes, the basic nature of radiation damage in the electron microscope is far from clear. In general we cannot predict exactly how different structures will behave during electron Irradiation at high dose rates. Moreover, with the rapid rise of analytical electron microscopy over the last few years, nvicroscopists are becoming concerned with questions of compositional as well as structural integrity. It is important to measure changes in elemental composition arising from atom migration in or loss from the specimen as a result of electron bombardment.

Electron-diffraction studies in synthetic polymer materials

1983 ◽  
Vol 41 ◽  
pp. 362-365
Author(s):  
D.T. Grubb
Keyword(s):  
Electron Diffraction ◽  
Synthetic Polymer ◽  
Polymer Materials ◽  
Crystallographic Structure ◽  
High Dose ◽  
Electron Dose ◽  
Dose Rates ◽  
First Case ◽  
Diffraction Patterns ◽  
The Many

Diffraction studies in polymeric and other beam sensitive materials may bring to mind the many experiments where diffracted intensity has been used as a measure of the electron dose required to destroy fine structure in the TEM. But this paper is concerned with a range of cases where the diffraction pattern itself contains the important information.In the first case, electron diffraction from paraffins, degraded polyethylene and polyethylene single crystals, all the samples are highly ordered, and their crystallographic structure is well known. The diffraction patterns fade on irradiation and may also change considerably in a-spacing, increasing the unit cell volume on irradiation. The effect is large and continuous far C94H190 paraffin and for PE, while for shorter chains to C 28H58 the change is less, levelling off at high dose, Fig.l. It is also found that the change in a-spacing increases at higher dose rates and at higher irradiation temperatures.

Deployable Decentralized Biofilm System to Degrade Organic Carbon, Nutrients and Benzene from Wastewater

2009 ◽  
Author(s):  
Dong Chen ◽  
Che-Jen Lin ◽  
R. Gavin Jones ◽  
Sehul Patel ◽  
Rachelle Smith ◽  
...  
Keyword(s):  
Organic Carbon
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