scholarly journals Investigating Community Dynamics and Performance During Microbial Electrochemical Degradation of Whey

2020 ◽  
Vol 7 (4) ◽  
pp. 989-997 ◽  
Author(s):  
Diana Y. Alvarez Esquivel ◽  
Yuting Guo ◽  
Robert K. Brown ◽  
Susann Müller ◽  
Uwe Schröder ◽  
...  
Keyword(s):  
Community Dynamics ◽  
Electrochemical Degradation ◽  
And Performance

scholarly journals Bacterial Community Dynamics in Full-Scale Activated Sludge Bioreactors: Operational and Ecological Factors Driving Community Assembly and Performance

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e42524 ◽  
Author(s):  
Alexis Valentín-Vargas ◽  
Gladys Toro-Labrador ◽  
Arturo A. Massol-Deyá
Keyword(s):  
Bacterial Community ◽  
Activated Sludge ◽  
Community Assembly ◽  
Community Dynamics ◽  
Ecological Factors ◽  
Full Scale ◽  
Bacterial Community Dynamics ◽  
And Performance

scholarly journals The Microbial Ecology of Moderately Thermophilic Mineral Leaching Reactors: The Effect of Solids Loading and Organic Carbon Supplementation on Reactor Performance

2015 ◽  
Vol 1130 ◽  
pp. 427-430
Author(s):  
Jonathan Dean ◽  
Robert P. van Hille ◽  
Susan T.L. Harrison
Keyword(s):  
Organic Carbon ◽  
Community Dynamics ◽  
Operating Conditions ◽  
Microbial Consortia ◽  
Reactor Performance ◽  
Moderately Thermophilic ◽  
Microbial Community Dynamics ◽  
Solids Loading ◽  
Metabolic Role ◽  
And Performance

Tank bioleaching of refractory sulphidic gold ores is well established, with potential to expand application to base metal concentrates. With increasing commercial tank bioleaching operations, understanding their microbial consortia is essential for process robustness. Recently, it has been shown that the consortia implicated in tank mineral bioleaching of gold-containing pyritic ores are dynamic, responding to the leaching environment. Factors driving the microbial dynamics of these consortia are under investigation, with emphasis also placed on determining the metabolic role of the key players in these consortia. Here, the combined influence of solids loading and organic carbon availability on microbial community dynamics and performance has been studied in agitated, aerated slurry bioreactors at 45°C. The control (autotrophic) and experimental (organic carbon added) reactors performed comparably at low solids loadings (4%, 7% and 10%). At 20% solids loadings, higher ferric iron concentrations (31 g/L vs 25g/L) and sulphide oxidation (66% vs 45%) were observed in the experimental reactor over the control. Under operating conditions used, a shift from bacterially-dominated cultures with L.ferriphilum as major species towards increasing archaeal abundance was observed. Archaeal abundance was higher in the organic carbon supplemented reactor at all solids loadings. The increased microbial diversity with organic supplementation appears to contribute to increased community robustness and associated leaching with increasing stress.

scholarly journals Design, Performance Evaluation and Investigation of the Dynamic Mechanisms of Earthworm-Microorganisms interactions for wastewater treatment through Vermifiltration technology

2020 ◽  
Author(s):  
Sudipti Arora ◽  
Sakshi Saraswat ◽  
Rinki Mishra ◽  
Jayana Rajvanshi ◽  
Jasmine Sethi ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Performance Evaluation ◽  
Microbial Community ◽  
Community Dynamics ◽  
Protein Profiling ◽  
Filter Media ◽  
Treatment Performance ◽  
Microbial Community Dynamics ◽  
And Performance ◽  
Media Layer

AbstractThe present study points to the relevance of the earthworms-microorganism’s symbiotic and synergistic interactions that drive the wastewater treatment by identifying the most essential mechanisms underlying the removal of contaminants during vermifiltration technology. Previous studies have showed the presence of earthworms improves treatment performance of vermifilter (VF), but earthworm microbial community dynamics, their structure and functional characteristics in VF were not fully investigated. To investigate the effects of earthworms on the inherent microbial community of the VF, the present study envisages the dynamics of the complex symbiosis of earthworms & microorganisms associated to the treatment mechanisms. In this study, the design, operations and performance evaluation and influent, effluent and filter media layer were investigated for microbial diversity inside the earthworm population, along with the antimicrobial activity, enzymatic activity, and protein profiling assays. The results showed that earthworm gut microbial communities were dominated by Gammaproteobacteria, and the percentages arrived to 59–60% of the microbial species detected, while filter media layer showed presence of Firmicutes and Actinobacteria. The protein profiling of the microbiota associated with the VF showed that earthworms feeding and earthworm–microorganism interaction were responsible for enhanced treatment performance. The finding provides an insight into the complex earthworm microbial dynamics and mechanisms for wastewater treatment in VF. Furthermore, earthworm predation strongly regulated microbial biomass while improving microbial activity, and is deciphered as the possible mechanisms behind the vermifiltration technology.

Preparation and performance of highly active and long-life mesopore Ti/SnO2–Sb electrodes for electrochemical degradation of phenol

2021 ◽  
pp. 161657
Author(s):  
Qiang Bi ◽  
Zekun Zhang ◽  
Yifei Sun ◽  
Sisi Jiang ◽  
Ziyu Wang ◽  
...  
Keyword(s):  
Electrochemical Degradation ◽  
Highly Active ◽  
Long Life ◽  
And Performance

Transmission Scanning Electron Microscopy and Energy Analysis with the Siemens ELMISKOP 101

1972 ◽  
Vol 30 ◽  
pp. 450-451
Author(s):  
H. M. Thieringer
Keyword(s):  
Objective Lens ◽  
Transmission Microscopy ◽  
Image Recording ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
And Performance ◽  
Convergent Beam ◽  
Ray Path ◽  
Beam Diffraction

It has repeatedly been show that with conventional electron microscopes very fine electron probes can be produced, therefore allowing various micro-techniques such as micro recording, X-ray microanalysis and convergent beam diffraction. In this paper the function and performance of an SIEMENS ELMISKOP 101 used as a scanning transmission microscope (STEM) is described. This mode of operation has some advantages over the conventional transmission microscopy (CTEM) especially for the observation of thick specimen, in spite of somewhat longer image recording times.Fig.1 shows schematically the ray path and the additional electronics of an ELMISKOP 101 working as a STEM. With a point-cathode, and using condensor I and the objective lens as a demagnifying system, an electron probe with a half-width ob about 25 Å and a typical current of 5.10-11 amp at 100 kV can be obtained in the back focal plane of the objective lens.

Angular Resolved Electron Spectroscopy with Parallel Recording

1990 ◽  
Vol 48 (2) ◽  
pp. 370-371
Author(s):  
Huang Min ◽  
P.S. Flora ◽  
C.J. Harland ◽  
J.A. Venables
Keyword(s):  
Electron Spectroscopy ◽  
Low Voltage ◽  
Solid Angle ◽  
Detection System ◽  
Voltage Electron ◽  
Cylindrical Mirror ◽  
Inner Radius ◽  
Channel Plate ◽  
And Performance ◽  
Type Detector

A cylindrical mirror analyser (CMA) has been built with a parallel recording detection system. It is being used for angular resolved electron spectroscopy (ARES) within a SEM. The CMA has been optimised for imaging applications; the inner cylinder contains a magnetically focused and scanned, 30kV, SEM electron-optical column. The CMA has a large inner radius (50.8mm) and a large collection solid angle (Ω > 1sterad). An energy resolution (ΔE/E) of 1-2% has been achieved. The design and performance of the combination SEM/CMA instrument has been described previously and the CMA and detector system has been used for low voltage electron spectroscopy. Here we discuss the use of the CMA for ARES and present some preliminary results.The CMA has been designed for an axis-to-ring focus and uses an annular type detector. This detector consists of a channel-plate/YAG/mirror assembly which is optically coupled to either a photomultiplier for spectroscopy or a TV camera for parallel detection.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

Trace nanoanalysis

1994 ◽  
Vol 52 ◽  
pp. 940-941
Author(s):  
D. E. Newbury ◽  
R. D. Leapman
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Detection Efficiency ◽  
Volume Element ◽  
And Performance ◽  
Trace Constituents ◽  
Secondary Ion ◽  
Concentration Levels ◽  
Structure Properties

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).

Relationship of stress and performance among first-year dental students

1986 ◽  
Vol 50 (5) ◽  
pp. 264-267 ◽  
Author(s):  
GH Westerman ◽  
TG Grandy ◽  
JV Lupo ◽  
RE Mitchell
Keyword(s):  
Dental Students ◽  
First Year ◽  
And Performance ◽  
Relationship Of
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