Alteration of Repository Structural Materials Within the First Few Years

1997 ◽  
Vol 506 ◽  
Author(s):  
J. M. West ◽  
M. Cave ◽  
P. Coombs ◽  
A. E. Milodowski ◽  
C. A. Rochelle
Keyword(s):  
Microbial Activity ◽  
Chemical Equilibrium ◽  
Host Rock ◽  
Laboratory Experiments ◽  
Geochemical Modelling ◽  
Aerobic Conditions ◽  
Rock Materials ◽  
Radionuclide Sorption ◽  
Redox Disequilibrium ◽  
Set Up

ABSTRACTA series of batch laboratory experiments were set up to study the gross effects of microbial activity on repository geochemistry, radionuclide sorption and integrity of repository and host rock materials. The experiments were fully monitored for 550 days and some were continued, under apparently aerobic conditions, for 1700 days. Geochemical modelling of the experiments reproduced many of their features, but showed that the contents were not in chemical equilibrium after 1700 days with redox disequilibrium a likely feature. The models could not predict localised reactions such as enhanced pitting of steel which appeared to be microbially mediated.

The Effect of Microbial Activity on the Near and Far Fields of a Swiss Type b Repository

1991 ◽  
Vol 257 ◽  
Author(s):  
J.M. West ◽  
M. Cave ◽  
J.J.W. Higgo ◽  
A.E. Milodowski ◽  
C.A. Rochelle ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Laboratory Experiments ◽  
Steel Corrosion ◽  
Type B ◽  
Anaerobic Conditions ◽  
Long Term Stability ◽  
Black Boxes ◽  
Set Up ◽  
Deep Pits

ABSTRACTA series of batch laboratory experiments (‘black boxes’) were set up to study the gross effects of microbial activity on repository geochemistry, radionuclide sorption and the integrity of repository and host rock materials in a Swiss type B repository. The observed principal chemical exchanges and precipitations were confirmed by modelling and could be interpreted by excluding microbiological effects. However, mineralogical studies showed steel corrosion to be localised in deep pits with microbiology playing a possible role. Talc was precipitated in all of the cells which lowered ambient pH through removal of OH- causing dissolution of CSH compounds. This has implications for the long term stability of cements. Microbiology influenced far-field radiochemistry experiments in which added microbes increased Cs sorption particularly under anaerobic conditions.

Investigation of nitrite pathways in sugar beet extraction

2014 ◽  
pp. 626-635 ◽  
Author(s):  
Florian Emerstorfer ◽  
Christer Bergwall ◽  
Walter Hein ◽  
Mats Bengtsson ◽  
John P. Jensen
Keyword(s):  
Sugar Beet ◽  
Laboratory Experiments ◽  
Ph Value ◽  
Full Scale ◽  
Chemical Effect ◽  
Spectrophotometric Detection ◽  
Sugar Factory ◽  
Chemical Effects ◽  
Set Up ◽  
Nitrate And Nitrite

The investigations presented in this work were carried out in order to further deepen the knowledge about nitrite pathways in the area of sugar beet extraction. The article consists of two parts with different experimental set-up: the first part focuses on laboratory trials in which the fate of nitrate and nitrite was studied in a so-called mini-fermenter. These trials were carried out using juice from the hot part of the cossette mixer of an Agrana sugar factory in Austria. In the experiments, two common sugar factory disinfectants were used in order to study microbial as well as microbial-chemical effects on nitrite formation and degradation caused by bacteria present in the juice. The trials demonstrated that the direct microbial effect (denitrification) on nitrite degradation is more pronounced than the indirect microbial-chemical effect coming from pH value decrease by these bacteria and subsequent nitrite loss. The second part describes the findings from laboratory experiments and full scale factory trials using a mobile laboratory set-up based on insulated stainless steel containers and spectrophotometric detection of nitrite in various factory juices. The trials were made at two Nordzucker factories located in Finland (factory A) and Sweden (factory B). The inhibiting effect of the two common sugar factory disinfectants on nitrite formation was evaluated in laboratory trials, whereas the full scale trials focused on one disinfectant. Other trials to evaluate potential contamination sources of thermophilic nitrite producing bacteria to the extraction system, reactivation of nitrite producing bacteria in raw juice and the effect of a pH gradient on bacterial nitrite activity in cossette mixer juice are also reported.

Effect of selenite additions on microbial activity and dynamics in three soils incubated under aerobic conditions

2007 ◽  
Vol 39 (10) ◽  
pp. 2670-2674 ◽  
Author(s):  
C.S. Haudin ◽  
P. Renault ◽  
E. Leclerc-Cessac ◽  
S. Staunton
Keyword(s):  
Microbial Activity ◽  
Aerobic Conditions

FFT Analysis Using LabView as a Part of Vibration and Preventive Maintenance Class for Senior Level MET students

2005 ◽  
Author(s):  
Aniruddha Mitra ◽  
Sahana Sen
Keyword(s):  
Preventive Maintenance ◽  
Laboratory Experiments ◽  
Vibration Signal ◽  
Engineering Technology ◽  
Technology Program ◽  
Student Activities ◽  
Labview Software ◽  
Vibration Data ◽  
Set Up ◽  
Fft Analysis

An existing senior level elective course on vibration in Mechanical Engineering Technology program at Georgia Southern University has been modified significantly. Two major components have been added to this course. Those are theoretical topics on preventive maintenance and laboratory experiments. As a part of laboratory experiments, Fast Fourier Transform (FFT) was introduced as a possible tool for vibration analysis for the purposes of machine diagnosis. Utilizing the current laboratory set up for the data acquisition systems, LabView software has been used for FFT analysis of signals from various sources. Four different modules were developed and implemented. The modules are as follows: random variation in acceleration of a toy cart due to roughness of the track and pulley, regular uniform wave signal which is generated by the lateral vibration of a cantilever beam at its natural frequency, signal generated by the imported raw data from other sources (e.g. MATLAB) and vibration signal of a shaft mounted on ball bearings in order to detect the defects in the bearing. Each of these modules is illustrated in this paper with suitable examples and suggested student activities and involvements. The results from FFT analysis have been cross checked using other methods and observations. As a follow up, students have been taken to a local industry where significant amount of emphasis is given to preventive maintenance of machineries by vibration data analysis using FFT. Future possible projects include the analysis of vibration data gathered from actual machine shop. This project opens the scope for greater collaborative effort between local industries and classroom activities.

Note on Preliminary Field Trials of a Bacterium to Control the Codling Moth

1953 ◽  
Vol 85 (1) ◽  
pp. 8-8 ◽  
Author(s):  
C. M. Phillips ◽  
Gordon E. Bucher ◽  
June M. Stephens
Keyword(s):  
Bacillus Cereus ◽  
Laboratory Experiments ◽  
Codling Moth ◽  
Field Trials ◽  
Set Up

A bacterium, Bacillus cereus F. and F., which was isolated from diseased larvae of the codling moth, Carpocapsa pomonella (L.), is pathogenic to the codling moth in laboratory experiments (Stephens, 1952).A series of trials was set up at Kentville to test the effectiveness of this bacterium against codling moth larvae in the field. B. cereus spores were propagated according to the method of Reed and McKercher (1948) and shipped to the field as spore suspensions.

Physical Properties of Oil-contaminated Sand Affected by Microbial Activity under Aerobic Conditions

2012 ◽  
Author(s):  
K. Titov ◽  
Y. Ilyin ◽  
P. Konosavsky ◽  
O. Orlova ◽  
O. Rybaltchenko ◽  
...  
Keyword(s):  
Physical Properties ◽  
Microbial Activity ◽  
Aerobic Conditions

scholarly journals Competitive interactions between species of freshwater snails: I. Laboratory: Ia. General methodology

1983 ◽  
Vol 78 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Frederico Simões Barbosa ◽  
Dirceu P. Pereira da Costa ◽  
Francisco Arruda
Keyword(s):  
Laboratory Experiments ◽  
Freshwater Snail ◽  
Current Paper ◽  
Competitive Interactions ◽  
Laboratory Work ◽  
Freshwater Snails ◽  
Technical Advance ◽  
General Methodology ◽  
Different Types ◽  
Set Up

For the development of laboratory experiments on the competitive interacitons between freshwater snail populations, special snail rooms were set up in the main building of the Research Center "Aggeu Magalhães". In the current paper, the first of a series on this subject, the general methodology of the laboratory work is described in detail. Using indoor cement channels in which a uniform seminatural environment was created, interactions of freshwater snail populations can be studied with minimal interference of the usual variables. Controlled indoor environmental techniques, as described in the current paper, may also be utilized in different types of experiments in malacology, and represent a substantial technical advance in malacological work.

Substrate interactions during aerobic biodegradation of methane, ethene, vinyl chloride and 1,2-dichloroethenes

2001 ◽  
Vol 43 (5) ◽  
pp. 333-340 ◽  
Author(s):  
D. L. Freedman ◽  
A. S. Danko ◽  
M. F. Verce
Keyword(s):  
Vinyl Chloride ◽  
Natural Attenuation ◽  
Enrichment Culture ◽  
Active Role ◽  
Aerobic Biodegradation ◽  
Aerobic Conditions ◽  
Lag Period ◽  
Anaerobic Zone ◽  
Set Up ◽  
Cis And Trans

Intrinsic biodegradation of trichloroethene and 1,1,1-trichloroethane in groundwater at a Superfund site in California has been observed. An anaerobic zone exists in the area closest to the source location, yielding the expected complement of reductive dechlorination daughter products, including cis-1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Significant levels of methane and ethene were also generated in the anaerobic zone. The groundwater returns to aerobic conditions downgradient of the source, with methane, ethene, VC, and several other compounds still present. Attenuation of VC in the aerobic zone suggests that it is being biodegraded. In this study microcosms were used to evaluate the role of methane and ethene as primary substrates for aerobic biodegradation of VC. Biodegradation of VC was fastest in the bottles containing ethene, with 40 μmol of VC consumed over a 150 day period, compared to approximately 15–20 μmol with methane or a mixture of methane and ethene. VC did not noticeably inhibit ethene biodegradation but did slow the rate of methane use. Methane inhibited ethene metabolism, which apparently caused a reduction in VC biodegradation when methane was present with ethene. These results suggest that ethene plays an important role during in situ natural attenuation of VC under aerobic conditions. Microcosms were also set up with VC alone. Following a 75 day lag period, VC consumption began and subsequent additions were consumed without a lag, suggesting the presence of organisms capable of using VC as a growth substrate. After providing VC alone for nearly 400 days, aliquots of the enrichment culture were used to evaluate its ability to biodegrade cis- and trans-DCE. Both compounds were readily consumed, although addition of VC as the primary substrate was needed to sustain biodegradation of repeated additions. This result suggests that organisms capable of using VC as a sole substrate may play an active role in aerobic natural attenuation of DCEs.

scholarly journals Volumetric flow rate in simulations of microfluidic devices

2018 ◽  
Vol 180 ◽  
pp. 02046
Author(s):  
KristÍna Kovalčíková ◽  
Martin Slavík ◽  
Katarína Bachratá ◽  
Hynek Bachratý ◽  
Alžbeta Bohiniková
Keyword(s):  
External Force ◽  
Flow Rate ◽  
Laboratory Experiments ◽  
Fluid Velocity ◽  
Volumetric Flow Rate ◽  
Microfluidic Devices ◽  
Fixed Set ◽  
Volumetric Rate ◽  
Simulation Parameter ◽  
Set Up

In this work, we examine the volumetric flow rate of microfluidic devices. The volumetric flow rate is a parameter which is necessary to correctly set up a simulation of a real device and to check the conformity of a simulation and a laboratory experiments [1]. Instead of defining the volumetric rate at the beginning as a simulation parameter, a parameter of external force is set. The proposed hypothesis is that for a fixed set of other parameters (topology, viscosity of the liquid, …) the volumetric flow rate is linearly dependent on external force in typical ranges of fluid velocity used in our simulations. To confirm this linearity hypothesis and to find numerical limits of this approach, we test several values of the external force parameter. The tests are designed for three different topologies of simulation box and for various haematocrits. The topologies of the microfluidic devices are inspired by existing laboratory experiments [3 - 6]. The linear relationship between the external force and the volumetric flow rate is verified in orders of magnitudes similar to the values obtained from laboratory experiments.

Modeling the Thermomechanical Response of Ore Materials During Microwave Processing

1994 ◽  
Vol 347 ◽  
Author(s):  
R. L. Williamson ◽  
J. B. Salsman ◽  
W. K. Tolley
Keyword(s):  
Power Density ◽  
Host Rock ◽  
Mechanical Response ◽  
Numerical Study ◽  
Particle Diameter ◽  
Microwave Energy ◽  
Uniaxial Tensile ◽  
Mineral Particle ◽  
Rock Materials ◽  
Uniaxial Tensile Strength

ABSTRACTA finite element numerical model is used to predict the thermal and mechanical response of mineral-bearing ores irradiated by microwave energy. The model considers a small, spherical, pyrite particle surrounded by a matrix of calcite. Power density data are determined from the dielectric properties of the mineral and host rock materials at typical microwave frequencies and power capabilities. The effects of varying power density and mineral particle diameter are studied. Using power densities within the expected achievable range for pyrite, significant temperature differences are predicted between the mineral particle and host rock. These temperature gradients lead to circumferential tensile stresses in the host rock well in excess of the reported uniaxial tensile strength of common rock materials. It is shown that, for a fixed microwave energy source, both the temperature difference between the mineral and host rock, and the peak tensile stress in the host rock are reduced as the mineral particle size is reduced. Recent experimental efforts to corroborate this numerical study are briefly described.

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